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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e1eaea46 AC |
2 | /* |
3 | * n_gsm.c GSM 0710 tty multiplexor | |
4 | * Copyright (c) 2009/10 Intel Corporation | |
e6b3d55b | 5 | * Copyright (c) 2022/23 Siemens Mobility GmbH |
e1eaea46 | 6 | * |
e1eaea46 AC |
7 | * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE * |
8 | * | |
0af02167 DS |
9 | * Outgoing path: |
10 | * tty -> DLCI fifo -> scheduler -> GSM MUX data queue ---o-> ldisc | |
11 | * control message -> GSM MUX control queue --´ | |
12 | * | |
13 | * Incoming path: | |
14 | * ldisc -> gsm_queue() -o--> tty | |
15 | * `-> gsm_control_response() | |
16 | * | |
e1eaea46 AC |
17 | * TO DO: |
18 | * Mostly done: ioctls for setting modes/timing | |
5f9a31d6 | 19 | * Partly done: hooks so you can pull off frames to non tty devs |
e1eaea46 | 20 | * Restart DLCI 0 when it closes ? |
e1eaea46 AC |
21 | * Improve the tx engine |
22 | * Resolve tx side locking by adding a queue_head and routing | |
23 | * all control traffic via it | |
24 | * General tidy/document | |
25 | * Review the locking/move to refcounts more (mux now moved to an | |
26 | * alloc/free model ready) | |
27 | * Use newest tty open/close port helpers and install hooks | |
28 | * What to do about power functions ? | |
29 | * Termios setting and negotiation | |
30 | * Do we need a 'which mux are you' ioctl to correlate mux and tty sets | |
31 | * | |
32 | */ | |
33 | ||
34 | #include <linux/types.h> | |
35 | #include <linux/major.h> | |
36 | #include <linux/errno.h> | |
37 | #include <linux/signal.h> | |
38 | #include <linux/fcntl.h> | |
174cd4b1 | 39 | #include <linux/sched/signal.h> |
e1eaea46 AC |
40 | #include <linux/interrupt.h> |
41 | #include <linux/tty.h> | |
92f1f0c3 | 42 | #include <linux/bitfield.h> |
e1eaea46 AC |
43 | #include <linux/ctype.h> |
44 | #include <linux/mm.h> | |
2ec7a802 | 45 | #include <linux/math.h> |
2b3174c9 | 46 | #include <linux/nospec.h> |
e1eaea46 AC |
47 | #include <linux/string.h> |
48 | #include <linux/slab.h> | |
49 | #include <linux/poll.h> | |
50 | #include <linux/bitops.h> | |
51 | #include <linux/file.h> | |
52 | #include <linux/uaccess.h> | |
53 | #include <linux/module.h> | |
54 | #include <linux/timer.h> | |
55 | #include <linux/tty_flip.h> | |
56 | #include <linux/tty_driver.h> | |
57 | #include <linux/serial.h> | |
58 | #include <linux/kfifo.h> | |
59 | #include <linux/skbuff.h> | |
bcd5abe2 RG |
60 | #include <net/arp.h> |
61 | #include <linux/ip.h> | |
62 | #include <linux/netdevice.h> | |
63 | #include <linux/etherdevice.h> | |
e1eaea46 | 64 | #include <linux/gsmmux.h> |
5ffa6e34 | 65 | #include "tty.h" |
e1eaea46 AC |
66 | |
67 | static int debug; | |
68 | module_param(debug, int, 0600); | |
69 | ||
c07da737 DS |
70 | /* Module debug bits */ |
71 | #define DBG_DUMP BIT(0) /* Data transmission dump. */ | |
72 | #define DBG_CD_ON BIT(1) /* Always assume CD line on. */ | |
73 | #define DBG_DATA BIT(2) /* Data transmission details. */ | |
74 | #define DBG_ERRORS BIT(3) /* Details for fail conditions. */ | |
75 | #define DBG_TTY BIT(4) /* Transmission statistics for DLCI TTYs. */ | |
c22d054f | 76 | #define DBG_PAYLOAD BIT(5) /* Limits DBG_DUMP to payload frames. */ |
c07da737 | 77 | |
a8d12007 AC |
78 | /* Defaults: these are from the specification */ |
79 | ||
80 | #define T1 10 /* 100mS */ | |
81 | #define T2 34 /* 333mS */ | |
2ec7a802 | 82 | #define T3 10 /* 10s */ |
a8d12007 | 83 | #define N2 3 /* Retry 3 times */ |
2ec7a802 DS |
84 | #define K 2 /* outstanding I frames */ |
85 | ||
86 | #define MAX_T3 255 /* In seconds. */ | |
87 | #define MAX_WINDOW_SIZE 7 /* Limit of K in error recovery mode. */ | |
e1eaea46 AC |
88 | |
89 | /* Use long timers for testing at low speed with debug on */ | |
90 | #ifdef DEBUG_TIMING | |
a8d12007 AC |
91 | #define T1 100 |
92 | #define T2 200 | |
e1eaea46 AC |
93 | #endif |
94 | ||
5f9a31d6 | 95 | /* |
25985edc | 96 | * Semi-arbitrary buffer size limits. 0710 is normally run with 32-64 byte |
5f9a31d6 AC |
97 | * limits so this is plenty |
98 | */ | |
bcd5abe2 RG |
99 | #define MAX_MRU 1500 |
100 | #define MAX_MTU 1500 | |
7a121247 | 101 | #define MIN_MTU (PROT_OVERHEAD + 1) |
535bf600 DS |
102 | /* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */ |
103 | #define PROT_OVERHEAD 7 | |
bcd5abe2 RG |
104 | #define GSM_NET_TX_TIMEOUT (HZ*10) |
105 | ||
b410e35d | 106 | /* |
bcd5abe2 | 107 | * struct gsm_mux_net - network interface |
bcd5abe2 RG |
108 | * |
109 | * Created when net interface is initialized. | |
724ac070 | 110 | */ |
bcd5abe2 RG |
111 | struct gsm_mux_net { |
112 | struct kref ref; | |
113 | struct gsm_dlci *dlci; | |
bcd5abe2 RG |
114 | }; |
115 | ||
e1eaea46 AC |
116 | /* |
117 | * Each block of data we have queued to go out is in the form of | |
25985edc | 118 | * a gsm_msg which holds everything we need in a link layer independent |
e1eaea46 AC |
119 | * format |
120 | */ | |
121 | ||
122 | struct gsm_msg { | |
b4338e1e | 123 | struct list_head list; |
e1eaea46 AC |
124 | u8 addr; /* DLCI address + flags */ |
125 | u8 ctrl; /* Control byte + flags */ | |
126 | unsigned int len; /* Length of data block (can be zero) */ | |
127 | unsigned char *data; /* Points into buffer but not at the start */ | |
2f202d03 | 128 | unsigned char buffer[]; |
e1eaea46 AC |
129 | }; |
130 | ||
72ae8cc1 JS |
131 | enum gsm_dlci_state { |
132 | DLCI_CLOSED, | |
4ca58966 | 133 | DLCI_WAITING_CONFIG, /* Waiting for DLCI configuration from user */ |
92f1f0c3 | 134 | DLCI_CONFIGURE, /* Sending PN (for adaption > 1) */ |
72ae8cc1 JS |
135 | DLCI_OPENING, /* Sending SABM not seen UA */ |
136 | DLCI_OPEN, /* SABM/UA complete */ | |
137 | DLCI_CLOSING, /* Sending DISC not seen UA/DM */ | |
138 | }; | |
139 | ||
e1785996 JS |
140 | enum gsm_dlci_mode { |
141 | DLCI_MODE_ABM, /* Normal Asynchronous Balanced Mode */ | |
142 | DLCI_MODE_ADM, /* Asynchronous Disconnected Mode */ | |
143 | }; | |
144 | ||
e1eaea46 AC |
145 | /* |
146 | * Each active data link has a gsm_dlci structure associated which ties | |
147 | * the link layer to an optional tty (if the tty side is open). To avoid | |
148 | * complexity right now these are only ever freed up when the mux is | |
149 | * shut down. | |
150 | * | |
151 | * At the moment we don't free DLCI objects until the mux is torn down | |
152 | * this avoid object life time issues but might be worth review later. | |
153 | */ | |
154 | ||
155 | struct gsm_dlci { | |
156 | struct gsm_mux *gsm; | |
157 | int addr; | |
72ae8cc1 | 158 | enum gsm_dlci_state state; |
bcd5abe2 | 159 | struct mutex mutex; |
e1eaea46 AC |
160 | |
161 | /* Link layer */ | |
e1785996 | 162 | enum gsm_dlci_mode mode; |
e1eaea46 AC |
163 | spinlock_t lock; /* Protects the internal state */ |
164 | struct timer_list t1; /* Retransmit timer for SABM and UA */ | |
165 | int retries; | |
166 | /* Uplink tty if active */ | |
167 | struct tty_port port; /* The tty bound to this DLCI if there is one */ | |
9361ebfb | 168 | #define TX_SIZE 4096 /* Must be power of 2. */ |
036bca1f | 169 | struct kfifo fifo; /* Queue fifo for the DLCI */ |
e1eaea46 | 170 | int adaption; /* Adaption layer in use */ |
bcd5abe2 | 171 | int prev_adaption; |
e1eaea46 AC |
172 | u32 modem_rx; /* Our incoming virtual modem lines */ |
173 | u32 modem_tx; /* Our outgoing modem lines */ | |
2ec7a802 | 174 | unsigned int mtu; |
5677fcf3 | 175 | bool dead; /* Refuse re-open */ |
2ec7a802 DS |
176 | /* Configuration */ |
177 | u8 prio; /* Priority */ | |
178 | u8 ftype; /* Frame type */ | |
179 | u8 k; /* Window size */ | |
e1eaea46 | 180 | /* Flow control */ |
e9360b9a | 181 | bool throttled; /* Private copy of throttle state */ |
7a9ed9c0 | 182 | bool constipated; /* Throttle status for outgoing */ |
e1eaea46 AC |
183 | /* Packetised I/O */ |
184 | struct sk_buff *skb; /* Frame being sent */ | |
185 | struct sk_buff_head skb_list; /* Queued frames */ | |
186 | /* Data handling callback */ | |
4feb7a4a TL |
187 | void (*data)(struct gsm_dlci *dlci, const u8 *data, int len); |
188 | void (*prev_data)(struct gsm_dlci *dlci, const u8 *data, int len); | |
bcd5abe2 | 189 | struct net_device *net; /* network interface, if created */ |
e1eaea46 AC |
190 | }; |
191 | ||
92f1f0c3 DS |
192 | /* |
193 | * Parameter bits used for parameter negotiation according to 3GPP 27.010 | |
194 | * chapter 5.4.6.3.1. | |
195 | */ | |
196 | ||
197 | struct gsm_dlci_param_bits { | |
198 | u8 d_bits; | |
199 | u8 i_cl_bits; | |
200 | u8 p_bits; | |
201 | u8 t_bits; | |
202 | __le16 n_bits; | |
203 | u8 na_bits; | |
204 | u8 k_bits; | |
205 | }; | |
206 | ||
207 | static_assert(sizeof(struct gsm_dlci_param_bits) == 8); | |
208 | ||
209 | #define PN_D_FIELD_DLCI GENMASK(5, 0) | |
210 | #define PN_I_CL_FIELD_FTYPE GENMASK(3, 0) | |
211 | #define PN_I_CL_FIELD_ADAPTION GENMASK(7, 4) | |
212 | #define PN_P_FIELD_PRIO GENMASK(5, 0) | |
213 | #define PN_T_FIELD_T1 GENMASK(7, 0) | |
214 | #define PN_N_FIELD_N1 GENMASK(15, 0) | |
215 | #define PN_NA_FIELD_N2 GENMASK(7, 0) | |
216 | #define PN_K_FIELD_K GENMASK(2, 0) | |
217 | ||
796492de DS |
218 | /* Total number of supported devices */ |
219 | #define GSM_TTY_MINORS 256 | |
220 | ||
c33eecc7 | 221 | /* DLCI 0, 62/63 are special or reserved see gsmtty_open */ |
e1eaea46 AC |
222 | |
223 | #define NUM_DLCI 64 | |
224 | ||
225 | /* | |
226 | * DLCI 0 is used to pass control blocks out of band of the data | |
227 | * flow (and with a higher link priority). One command can be outstanding | |
228 | * at a time and we use this structure to manage them. They are created | |
229 | * and destroyed by the user context, and updated by the receive paths | |
230 | * and timers | |
231 | */ | |
232 | ||
233 | struct gsm_control { | |
234 | u8 cmd; /* Command we are issuing */ | |
235 | u8 *data; /* Data for the command in case we retransmit */ | |
236 | int len; /* Length of block for retransmission */ | |
237 | int done; /* Done flag */ | |
238 | int error; /* Error if any */ | |
239 | }; | |
240 | ||
19fb0a66 DS |
241 | enum gsm_encoding { |
242 | GSM_BASIC_OPT, | |
243 | GSM_ADV_OPT, | |
244 | }; | |
245 | ||
329aa6e6 JS |
246 | enum gsm_mux_state { |
247 | GSM_SEARCH, | |
248 | GSM_START, | |
249 | GSM_ADDRESS, | |
250 | GSM_CONTROL, | |
251 | GSM_LEN, | |
252 | GSM_DATA, | |
253 | GSM_FCS, | |
254 | GSM_OVERRUN, | |
255 | GSM_LEN0, | |
256 | GSM_LEN1, | |
257 | GSM_SSOF, | |
258 | }; | |
259 | ||
e1eaea46 AC |
260 | /* |
261 | * Each GSM mux we have is represented by this structure. If we are | |
262 | * operating as an ldisc then we use this structure as our ldisc | |
263 | * state. We need to sort out lifetimes and locking with respect | |
264 | * to the gsm mux array. For now we don't free DLCI objects that | |
265 | * have been instantiated until the mux itself is terminated. | |
266 | * | |
267 | * To consider further: tty open versus mux shutdown. | |
268 | */ | |
269 | ||
270 | struct gsm_mux { | |
271 | struct tty_struct *tty; /* The tty our ldisc is bound to */ | |
272 | spinlock_t lock; | |
dfabf7ff | 273 | struct mutex mutex; |
d50f6dca | 274 | unsigned int num; |
6ab8fba7 | 275 | struct kref ref; |
e1eaea46 AC |
276 | |
277 | /* Events on the GSM channel */ | |
278 | wait_queue_head_t event; | |
279 | ||
0af02167 DS |
280 | /* ldisc send work */ |
281 | struct work_struct tx_work; | |
282 | ||
e1eaea46 AC |
283 | /* Bits for GSM mode decoding */ |
284 | ||
285 | /* Framing Layer */ | |
286 | unsigned char *buf; | |
329aa6e6 | 287 | enum gsm_mux_state state; |
e1eaea46 AC |
288 | unsigned int len; |
289 | unsigned int address; | |
290 | unsigned int count; | |
c50704bd | 291 | bool escape; |
19fb0a66 | 292 | enum gsm_encoding encoding; |
e1eaea46 AC |
293 | u8 control; |
294 | u8 fcs; | |
295 | u8 *txframe; /* TX framing buffer */ | |
296 | ||
a579767c | 297 | /* Method for the receiver side */ |
e1eaea46 | 298 | void (*receive)(struct gsm_mux *gsm, u8 ch); |
e1eaea46 AC |
299 | |
300 | /* Link Layer */ | |
301 | unsigned int mru; | |
302 | unsigned int mtu; | |
303 | int initiator; /* Did we initiate connection */ | |
5677fcf3 | 304 | bool dead; /* Has the mux been shut down */ |
e1eaea46 | 305 | struct gsm_dlci *dlci[NUM_DLCI]; |
f4f7d632 | 306 | int old_c_iflag; /* termios c_iflag value before attach */ |
7a9ed9c0 | 307 | bool constipated; /* Asked by remote to shut up */ |
01aecd91 | 308 | bool has_devices; /* Devices were registered */ |
e1eaea46 | 309 | |
acdab4cb | 310 | spinlock_t tx_lock; |
e1eaea46 AC |
311 | unsigned int tx_bytes; /* TX data outstanding */ |
312 | #define TX_THRESH_HI 8192 | |
313 | #define TX_THRESH_LO 2048 | |
0af02167 DS |
314 | struct list_head tx_ctrl_list; /* Pending control packets */ |
315 | struct list_head tx_data_list; /* Pending data packets */ | |
e1eaea46 AC |
316 | |
317 | /* Control messages */ | |
15743ae5 | 318 | struct timer_list kick_timer; /* Kick TX queuing on timeout */ |
e1eaea46 AC |
319 | struct timer_list t2_timer; /* Retransmit timer for commands */ |
320 | int cretries; /* Command retry counter */ | |
321 | struct gsm_control *pending_cmd;/* Our current pending command */ | |
322 | spinlock_t control_lock; /* Protects the pending command */ | |
323 | ||
72206cc7 DS |
324 | /* Keep-alive */ |
325 | struct timer_list ka_timer; /* Keep-alive response timer */ | |
326 | u8 ka_num; /* Keep-alive match pattern */ | |
327 | signed int ka_retries; /* Keep-alive retry counter, -1 if not yet initialized */ | |
328 | ||
e1eaea46 AC |
329 | /* Configuration */ |
330 | int adaption; /* 1 or 2 supported */ | |
331 | u8 ftype; /* UI or UIH */ | |
332 | int t1, t2; /* Timers in 1/100th of a sec */ | |
2ec7a802 | 333 | unsigned int t3; /* Power wake-up timer in seconds. */ |
e1eaea46 | 334 | int n2; /* Retry count */ |
2ec7a802 | 335 | u8 k; /* Window size */ |
4ca58966 | 336 | bool wait_config; /* Wait for configuration by ioctl before DLCI open */ |
72206cc7 | 337 | u32 keep_alive; /* Control channel keep-alive in 10ms */ |
e1eaea46 AC |
338 | |
339 | /* Statistics (not currently exposed) */ | |
340 | unsigned long bad_fcs; | |
341 | unsigned long malformed; | |
342 | unsigned long io_error; | |
a1ce6da0 | 343 | unsigned long open_error; |
e1eaea46 AC |
344 | unsigned long bad_size; |
345 | unsigned long unsupported; | |
346 | }; | |
347 | ||
348 | ||
349 | /* | |
350 | * Mux objects - needed so that we can translate a tty index into the | |
351 | * relevant mux and DLCI. | |
352 | */ | |
353 | ||
354 | #define MAX_MUX 4 /* 256 minors */ | |
355 | static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */ | |
399d44a1 | 356 | static DEFINE_SPINLOCK(gsm_mux_lock); |
e1eaea46 | 357 | |
d50f6dca RG |
358 | static struct tty_driver *gsm_tty_driver; |
359 | ||
e1eaea46 AC |
360 | /* |
361 | * This section of the driver logic implements the GSM encodings | |
362 | * both the basic and the 'advanced'. Reliable transport is not | |
363 | * supported. | |
364 | */ | |
365 | ||
366 | #define CR 0x02 | |
367 | #define EA 0x01 | |
368 | #define PF 0x10 | |
369 | ||
370 | /* I is special: the rest are ..*/ | |
371 | #define RR 0x01 | |
372 | #define UI 0x03 | |
373 | #define RNR 0x05 | |
374 | #define REJ 0x09 | |
375 | #define DM 0x0F | |
376 | #define SABM 0x2F | |
377 | #define DISC 0x43 | |
378 | #define UA 0x63 | |
379 | #define UIH 0xEF | |
380 | ||
381 | /* Channel commands */ | |
382 | #define CMD_NSC 0x09 | |
383 | #define CMD_TEST 0x11 | |
384 | #define CMD_PSC 0x21 | |
385 | #define CMD_RLS 0x29 | |
386 | #define CMD_FCOFF 0x31 | |
387 | #define CMD_PN 0x41 | |
388 | #define CMD_RPN 0x49 | |
389 | #define CMD_FCON 0x51 | |
390 | #define CMD_CLD 0x61 | |
391 | #define CMD_SNC 0x69 | |
392 | #define CMD_MSC 0x71 | |
393 | ||
394 | /* Virtual modem bits */ | |
395 | #define MDM_FC 0x01 | |
396 | #define MDM_RTC 0x02 | |
397 | #define MDM_RTR 0x04 | |
398 | #define MDM_IC 0x20 | |
399 | #define MDM_DV 0x40 | |
400 | ||
401 | #define GSM0_SOF 0xF9 | |
5f9a31d6 | 402 | #define GSM1_SOF 0x7E |
e1eaea46 AC |
403 | #define GSM1_ESCAPE 0x7D |
404 | #define GSM1_ESCAPE_BITS 0x20 | |
405 | #define XON 0x11 | |
406 | #define XOFF 0x13 | |
8838b2af | 407 | #define ISO_IEC_646_MASK 0x7F |
e1eaea46 AC |
408 | |
409 | static const struct tty_port_operations gsm_port_ops; | |
410 | ||
411 | /* | |
412 | * CRC table for GSM 0710 | |
413 | */ | |
414 | ||
415 | static const u8 gsm_fcs8[256] = { | |
416 | 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, | |
417 | 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B, | |
418 | 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, | |
419 | 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, | |
420 | 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, | |
421 | 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43, | |
422 | 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, | |
423 | 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F, | |
424 | 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, | |
425 | 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B, | |
426 | 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, | |
427 | 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, | |
428 | 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, | |
429 | 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33, | |
430 | 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, | |
431 | 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F, | |
432 | 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, | |
433 | 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B, | |
434 | 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, | |
435 | 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, | |
436 | 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, | |
437 | 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3, | |
438 | 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, | |
439 | 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF, | |
440 | 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, | |
441 | 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB, | |
442 | 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, | |
443 | 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, | |
444 | 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, | |
445 | 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3, | |
446 | 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, | |
447 | 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF | |
448 | }; | |
449 | ||
450 | #define INIT_FCS 0xFF | |
451 | #define GOOD_FCS 0xCF | |
452 | ||
92f1f0c3 | 453 | static void gsm_dlci_close(struct gsm_dlci *dlci); |
a579767c | 454 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len); |
c19ffe00 | 455 | static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk); |
0af02167 DS |
456 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, |
457 | u8 ctrl); | |
458 | static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg); | |
4ca58966 | 459 | static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr); |
0af02167 DS |
460 | static void gsmld_write_trigger(struct gsm_mux *gsm); |
461 | static void gsmld_write_task(struct work_struct *work); | |
a579767c | 462 | |
e1eaea46 AC |
463 | /** |
464 | * gsm_fcs_add - update FCS | |
465 | * @fcs: Current FCS | |
466 | * @c: Next data | |
467 | * | |
468 | * Update the FCS to include c. Uses the algorithm in the specification | |
469 | * notes. | |
470 | */ | |
471 | ||
472 | static inline u8 gsm_fcs_add(u8 fcs, u8 c) | |
473 | { | |
474 | return gsm_fcs8[fcs ^ c]; | |
475 | } | |
476 | ||
477 | /** | |
478 | * gsm_fcs_add_block - update FCS for a block | |
479 | * @fcs: Current FCS | |
480 | * @c: buffer of data | |
481 | * @len: length of buffer | |
482 | * | |
483 | * Update the FCS to include c. Uses the algorithm in the specification | |
484 | * notes. | |
485 | */ | |
486 | ||
487 | static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len) | |
488 | { | |
489 | while (len--) | |
490 | fcs = gsm_fcs8[fcs ^ *c++]; | |
491 | return fcs; | |
492 | } | |
493 | ||
494 | /** | |
495 | * gsm_read_ea - read a byte into an EA | |
496 | * @val: variable holding value | |
724ac070 | 497 | * @c: byte going into the EA |
e1eaea46 AC |
498 | * |
499 | * Processes one byte of an EA. Updates the passed variable | |
500 | * and returns 1 if the EA is now completely read | |
501 | */ | |
502 | ||
503 | static int gsm_read_ea(unsigned int *val, u8 c) | |
504 | { | |
505 | /* Add the next 7 bits into the value */ | |
506 | *val <<= 7; | |
507 | *val |= c >> 1; | |
508 | /* Was this the last byte of the EA 1 = yes*/ | |
509 | return c & EA; | |
510 | } | |
511 | ||
bec02248 DS |
512 | /** |
513 | * gsm_read_ea_val - read a value until EA | |
514 | * @val: variable holding value | |
515 | * @data: buffer of data | |
516 | * @dlen: length of data | |
517 | * | |
518 | * Processes an EA value. Updates the passed variable and | |
519 | * returns the processed data length. | |
520 | */ | |
521 | static unsigned int gsm_read_ea_val(unsigned int *val, const u8 *data, int dlen) | |
522 | { | |
523 | unsigned int len = 0; | |
524 | ||
525 | for (; dlen > 0; dlen--) { | |
526 | len++; | |
527 | if (gsm_read_ea(val, *data++)) | |
528 | break; | |
529 | } | |
530 | return len; | |
531 | } | |
532 | ||
e1eaea46 AC |
533 | /** |
534 | * gsm_encode_modem - encode modem data bits | |
535 | * @dlci: DLCI to encode from | |
536 | * | |
537 | * Returns the correct GSM encoded modem status bits (6 bit field) for | |
538 | * the current status of the DLCI and attached tty object | |
539 | */ | |
540 | ||
541 | static u8 gsm_encode_modem(const struct gsm_dlci *dlci) | |
542 | { | |
543 | u8 modembits = 0; | |
544 | /* FC is true flow control not modem bits */ | |
545 | if (dlci->throttled) | |
546 | modembits |= MDM_FC; | |
547 | if (dlci->modem_tx & TIOCM_DTR) | |
548 | modembits |= MDM_RTC; | |
549 | if (dlci->modem_tx & TIOCM_RTS) | |
550 | modembits |= MDM_RTR; | |
551 | if (dlci->modem_tx & TIOCM_RI) | |
552 | modembits |= MDM_IC; | |
737b0ef3 | 553 | if (dlci->modem_tx & TIOCM_CD || dlci->gsm->initiator) |
e1eaea46 | 554 | modembits |= MDM_DV; |
42ec0b93 DS |
555 | /* special mappings for passive side to operate as UE */ |
556 | if (dlci->modem_tx & TIOCM_OUT1) | |
557 | modembits |= MDM_IC; | |
558 | if (dlci->modem_tx & TIOCM_OUT2) | |
559 | modembits |= MDM_DV; | |
e1eaea46 AC |
560 | return modembits; |
561 | } | |
562 | ||
925ea0fa TL |
563 | static void gsm_hex_dump_bytes(const char *fname, const u8 *data, |
564 | unsigned long len) | |
565 | { | |
566 | char *prefix; | |
567 | ||
568 | if (!fname) { | |
569 | print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, data, len, | |
570 | true); | |
571 | return; | |
572 | } | |
573 | ||
e74024b2 | 574 | prefix = kasprintf(GFP_ATOMIC, "%s: ", fname); |
925ea0fa TL |
575 | if (!prefix) |
576 | return; | |
577 | print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len, | |
578 | true); | |
579 | kfree(prefix); | |
580 | } | |
581 | ||
92f1f0c3 DS |
582 | /** |
583 | * gsm_encode_params - encode DLCI parameters | |
584 | * @dlci: DLCI to encode from | |
585 | * @params: buffer to fill with the encoded parameters | |
586 | * | |
587 | * Encodes the parameters according to GSM 07.10 section 5.4.6.3.1 | |
588 | * table 3. | |
589 | */ | |
590 | static int gsm_encode_params(const struct gsm_dlci *dlci, | |
591 | struct gsm_dlci_param_bits *params) | |
592 | { | |
593 | const struct gsm_mux *gsm = dlci->gsm; | |
594 | unsigned int i, cl; | |
595 | ||
596 | switch (dlci->ftype) { | |
597 | case UIH: | |
598 | i = 0; /* UIH */ | |
599 | break; | |
600 | case UI: | |
601 | i = 1; /* UI */ | |
602 | break; | |
603 | default: | |
604 | pr_debug("unsupported frame type %d\n", dlci->ftype); | |
605 | return -EINVAL; | |
606 | } | |
607 | ||
608 | switch (dlci->adaption) { | |
609 | case 1: /* Unstructured */ | |
610 | cl = 0; /* convergence layer type 1 */ | |
611 | break; | |
612 | case 2: /* Unstructured with modem bits. */ | |
613 | cl = 1; /* convergence layer type 2 */ | |
614 | break; | |
615 | default: | |
616 | pr_debug("unsupported adaption %d\n", dlci->adaption); | |
617 | return -EINVAL; | |
618 | } | |
619 | ||
620 | params->d_bits = FIELD_PREP(PN_D_FIELD_DLCI, dlci->addr); | |
621 | /* UIH, convergence layer type 1 */ | |
622 | params->i_cl_bits = FIELD_PREP(PN_I_CL_FIELD_FTYPE, i) | | |
623 | FIELD_PREP(PN_I_CL_FIELD_ADAPTION, cl); | |
624 | params->p_bits = FIELD_PREP(PN_P_FIELD_PRIO, dlci->prio); | |
625 | params->t_bits = FIELD_PREP(PN_T_FIELD_T1, gsm->t1); | |
626 | params->n_bits = cpu_to_le16(FIELD_PREP(PN_N_FIELD_N1, dlci->mtu)); | |
627 | params->na_bits = FIELD_PREP(PN_NA_FIELD_N2, gsm->n2); | |
628 | params->k_bits = FIELD_PREP(PN_K_FIELD_K, dlci->k); | |
629 | ||
630 | return 0; | |
631 | } | |
632 | ||
01aecd91 DS |
633 | /** |
634 | * gsm_register_devices - register all tty devices for a given mux index | |
635 | * | |
636 | * @driver: the tty driver that describes the tty devices | |
637 | * @index: the mux number is used to calculate the minor numbers of the | |
638 | * ttys for this mux and may differ from the position in the | |
639 | * mux array. | |
640 | */ | |
641 | static int gsm_register_devices(struct tty_driver *driver, unsigned int index) | |
642 | { | |
643 | struct device *dev; | |
644 | int i; | |
645 | unsigned int base; | |
646 | ||
647 | if (!driver || index >= MAX_MUX) | |
648 | return -EINVAL; | |
649 | ||
650 | base = index * NUM_DLCI; /* first minor for this index */ | |
651 | for (i = 1; i < NUM_DLCI; i++) { | |
652 | /* Don't register device 0 - this is the control channel | |
653 | * and not a usable tty interface | |
654 | */ | |
655 | dev = tty_register_device(gsm_tty_driver, base + i, NULL); | |
656 | if (IS_ERR(dev)) { | |
c07da737 | 657 | if (debug & DBG_ERRORS) |
01aecd91 DS |
658 | pr_info("%s failed to register device minor %u", |
659 | __func__, base + i); | |
660 | for (i--; i >= 1; i--) | |
661 | tty_unregister_device(gsm_tty_driver, base + i); | |
662 | return PTR_ERR(dev); | |
663 | } | |
664 | } | |
665 | ||
666 | return 0; | |
667 | } | |
668 | ||
669 | /** | |
670 | * gsm_unregister_devices - unregister all tty devices for a given mux index | |
671 | * | |
672 | * @driver: the tty driver that describes the tty devices | |
673 | * @index: the mux number is used to calculate the minor numbers of the | |
674 | * ttys for this mux and may differ from the position in the | |
675 | * mux array. | |
676 | */ | |
677 | static void gsm_unregister_devices(struct tty_driver *driver, | |
678 | unsigned int index) | |
679 | { | |
680 | int i; | |
681 | unsigned int base; | |
682 | ||
683 | if (!driver || index >= MAX_MUX) | |
684 | return; | |
685 | ||
686 | base = index * NUM_DLCI; /* first minor for this index */ | |
687 | for (i = 1; i < NUM_DLCI; i++) { | |
688 | /* Don't unregister device 0 - this is the control | |
689 | * channel and not a usable tty interface | |
690 | */ | |
691 | tty_unregister_device(gsm_tty_driver, base + i); | |
692 | } | |
693 | } | |
694 | ||
e1eaea46 AC |
695 | /** |
696 | * gsm_print_packet - display a frame for debug | |
697 | * @hdr: header to print before decode | |
698 | * @addr: address EA from the frame | |
57435c42 | 699 | * @cr: C/R bit seen as initiator |
e1eaea46 AC |
700 | * @control: control including PF bit |
701 | * @data: following data bytes | |
702 | * @dlen: length of data | |
703 | * | |
704 | * Displays a packet in human readable format for debugging purposes. The | |
705 | * style is based on amateur radio LAP-B dump display. | |
706 | */ | |
707 | ||
708 | static void gsm_print_packet(const char *hdr, int addr, int cr, | |
709 | u8 control, const u8 *data, int dlen) | |
710 | { | |
c07da737 | 711 | if (!(debug & DBG_DUMP)) |
e1eaea46 | 712 | return; |
c22d054f DS |
713 | /* Only show user payload frames if debug & DBG_PAYLOAD */ |
714 | if (!(debug & DBG_PAYLOAD) && addr != 0) | |
715 | if ((control & ~PF) == UI || (control & ~PF) == UIH) | |
716 | return; | |
e1eaea46 | 717 | |
5f9a31d6 | 718 | pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]); |
e1eaea46 AC |
719 | |
720 | switch (control & ~PF) { | |
721 | case SABM: | |
5f9a31d6 | 722 | pr_cont("SABM"); |
e1eaea46 AC |
723 | break; |
724 | case UA: | |
5f9a31d6 | 725 | pr_cont("UA"); |
e1eaea46 AC |
726 | break; |
727 | case DISC: | |
5f9a31d6 | 728 | pr_cont("DISC"); |
e1eaea46 AC |
729 | break; |
730 | case DM: | |
5f9a31d6 | 731 | pr_cont("DM"); |
e1eaea46 AC |
732 | break; |
733 | case UI: | |
5f9a31d6 | 734 | pr_cont("UI"); |
e1eaea46 AC |
735 | break; |
736 | case UIH: | |
5f9a31d6 | 737 | pr_cont("UIH"); |
e1eaea46 AC |
738 | break; |
739 | default: | |
740 | if (!(control & 0x01)) { | |
5f9a31d6 | 741 | pr_cont("I N(S)%d N(R)%d", |
47fdd641 | 742 | (control & 0x0E) >> 1, (control & 0xE0) >> 5); |
e1eaea46 | 743 | } else switch (control & 0x0F) { |
5f9a31d6 AC |
744 | case RR: |
745 | pr_cont("RR(%d)", (control & 0xE0) >> 5); | |
746 | break; | |
747 | case RNR: | |
748 | pr_cont("RNR(%d)", (control & 0xE0) >> 5); | |
749 | break; | |
750 | case REJ: | |
751 | pr_cont("REJ(%d)", (control & 0xE0) >> 5); | |
752 | break; | |
753 | default: | |
754 | pr_cont("[%02X]", control); | |
e1eaea46 AC |
755 | } |
756 | } | |
757 | ||
758 | if (control & PF) | |
5f9a31d6 | 759 | pr_cont("(P)"); |
e1eaea46 | 760 | else |
5f9a31d6 | 761 | pr_cont("(F)"); |
e1eaea46 | 762 | |
925ea0fa | 763 | gsm_hex_dump_bytes(NULL, data, dlen); |
e1eaea46 AC |
764 | } |
765 | ||
766 | ||
767 | /* | |
768 | * Link level transmission side | |
769 | */ | |
770 | ||
771 | /** | |
542a121a | 772 | * gsm_stuff_frame - bytestuff a packet |
724ac070 JS |
773 | * @input: input buffer |
774 | * @output: output buffer | |
e1eaea46 AC |
775 | * @len: length of input |
776 | * | |
777 | * Expand a buffer by bytestuffing it. The worst case size change | |
778 | * is doubling and the caller is responsible for handing out | |
779 | * suitable sized buffers. | |
780 | */ | |
781 | ||
782 | static int gsm_stuff_frame(const u8 *input, u8 *output, int len) | |
783 | { | |
784 | int olen = 0; | |
785 | while (len--) { | |
786 | if (*input == GSM1_SOF || *input == GSM1_ESCAPE | |
8838b2af | 787 | || (*input & ISO_IEC_646_MASK) == XON |
788 | || (*input & ISO_IEC_646_MASK) == XOFF) { | |
e1eaea46 AC |
789 | *output++ = GSM1_ESCAPE; |
790 | *output++ = *input++ ^ GSM1_ESCAPE_BITS; | |
791 | olen++; | |
792 | } else | |
793 | *output++ = *input++; | |
794 | olen++; | |
795 | } | |
796 | return olen; | |
797 | } | |
798 | ||
e1eaea46 AC |
799 | /** |
800 | * gsm_send - send a control frame | |
801 | * @gsm: our GSM mux | |
802 | * @addr: address for control frame | |
57435c42 | 803 | * @cr: command/response bit seen as initiator |
e1eaea46 AC |
804 | * @control: control byte including PF bit |
805 | * | |
0af02167 DS |
806 | * Format up and transmit a control frame. These should be transmitted |
807 | * ahead of data when they are needed. | |
e1eaea46 | 808 | */ |
0af02167 | 809 | static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) |
e1eaea46 | 810 | { |
0af02167 DS |
811 | struct gsm_msg *msg; |
812 | u8 *dp; | |
57435c42 | 813 | int ocr; |
acdab4cb | 814 | unsigned long flags; |
0af02167 DS |
815 | |
816 | msg = gsm_data_alloc(gsm, addr, 0, control); | |
817 | if (!msg) | |
818 | return -ENOMEM; | |
57435c42 | 819 | |
820 | /* toggle C/R coding if not initiator */ | |
821 | ocr = cr ^ (gsm->initiator ? 0 : 1); | |
e1eaea46 | 822 | |
0af02167 DS |
823 | msg->data -= 3; |
824 | dp = msg->data; | |
825 | *dp++ = (addr << 2) | (ocr << 1) | EA; | |
826 | *dp++ = control; | |
827 | ||
19fb0a66 | 828 | if (gsm->encoding == GSM_BASIC_OPT) |
0af02167 DS |
829 | *dp++ = EA; /* Length of data = 0 */ |
830 | ||
831 | *dp = 0xFF - gsm_fcs_add_block(INIT_FCS, msg->data, dp - msg->data); | |
832 | msg->len = (dp - msg->data) + 1; | |
833 | ||
834 | gsm_print_packet("Q->", addr, cr, control, NULL, 0); | |
835 | ||
acdab4cb | 836 | spin_lock_irqsave(&gsm->tx_lock, flags); |
0af02167 DS |
837 | list_add_tail(&msg->list, &gsm->tx_ctrl_list); |
838 | gsm->tx_bytes += msg->len; | |
acdab4cb | 839 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
0af02167 DS |
840 | gsmld_write_trigger(gsm); |
841 | ||
842 | return 0; | |
843 | } | |
844 | ||
845 | /** | |
846 | * gsm_dlci_clear_queues - remove outstanding data for a DLCI | |
847 | * @gsm: mux | |
848 | * @dlci: clear for this DLCI | |
849 | * | |
850 | * Clears the data queues for a given DLCI. | |
851 | */ | |
852 | static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci) | |
853 | { | |
854 | struct gsm_msg *msg, *nmsg; | |
855 | int addr = dlci->addr; | |
856 | unsigned long flags; | |
857 | ||
858 | /* Clear DLCI write fifo first */ | |
859 | spin_lock_irqsave(&dlci->lock, flags); | |
860 | kfifo_reset(&dlci->fifo); | |
861 | spin_unlock_irqrestore(&dlci->lock, flags); | |
862 | ||
863 | /* Clear data packets in MUX write queue */ | |
acdab4cb | 864 | spin_lock_irqsave(&gsm->tx_lock, flags); |
0af02167 DS |
865 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) { |
866 | if (msg->addr != addr) | |
867 | continue; | |
868 | gsm->tx_bytes -= msg->len; | |
869 | list_del(&msg->list); | |
870 | kfree(msg); | |
f999c3b3 | 871 | } |
acdab4cb | 872 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
e1eaea46 AC |
873 | } |
874 | ||
875 | /** | |
876 | * gsm_response - send a control response | |
877 | * @gsm: our GSM mux | |
878 | * @addr: address for control frame | |
879 | * @control: control byte including PF bit | |
880 | * | |
881 | * Format up and transmit a link level response frame. | |
882 | */ | |
883 | ||
884 | static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) | |
885 | { | |
57435c42 | 886 | gsm_send(gsm, addr, 0, control); |
e1eaea46 AC |
887 | } |
888 | ||
889 | /** | |
890 | * gsm_command - send a control command | |
891 | * @gsm: our GSM mux | |
892 | * @addr: address for control frame | |
893 | * @control: control byte including PF bit | |
894 | * | |
895 | * Format up and transmit a link level command frame. | |
896 | */ | |
897 | ||
898 | static inline void gsm_command(struct gsm_mux *gsm, int addr, int control) | |
899 | { | |
900 | gsm_send(gsm, addr, 1, control); | |
901 | } | |
902 | ||
903 | /* Data transmission */ | |
904 | ||
905 | #define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */ | |
906 | ||
907 | /** | |
908 | * gsm_data_alloc - allocate data frame | |
909 | * @gsm: GSM mux | |
910 | * @addr: DLCI address | |
911 | * @len: length excluding header and FCS | |
912 | * @ctrl: control byte | |
913 | * | |
914 | * Allocate a new data buffer for sending frames with data. Space is left | |
915 | * at the front for header bytes but that is treated as an implementation | |
916 | * detail and not for the high level code to use | |
917 | */ | |
918 | ||
919 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, | |
920 | u8 ctrl) | |
921 | { | |
922 | struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN, | |
923 | GFP_ATOMIC); | |
924 | if (m == NULL) | |
925 | return NULL; | |
926 | m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */ | |
927 | m->len = len; | |
928 | m->addr = addr; | |
929 | m->ctrl = ctrl; | |
b4338e1e | 930 | INIT_LIST_HEAD(&m->list); |
e1eaea46 AC |
931 | return m; |
932 | } | |
933 | ||
0af02167 DS |
934 | /** |
935 | * gsm_send_packet - sends a single packet | |
936 | * @gsm: GSM Mux | |
937 | * @msg: packet to send | |
938 | * | |
939 | * The given packet is encoded and sent out. No memory is freed. | |
940 | * The caller must hold the gsm tx lock. | |
941 | */ | |
942 | static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg) | |
943 | { | |
944 | int len, ret; | |
945 | ||
946 | ||
19fb0a66 | 947 | if (gsm->encoding == GSM_BASIC_OPT) { |
0af02167 DS |
948 | gsm->txframe[0] = GSM0_SOF; |
949 | memcpy(gsm->txframe + 1, msg->data, msg->len); | |
950 | gsm->txframe[msg->len + 1] = GSM0_SOF; | |
951 | len = msg->len + 2; | |
952 | } else { | |
953 | gsm->txframe[0] = GSM1_SOF; | |
954 | len = gsm_stuff_frame(msg->data, gsm->txframe + 1, msg->len); | |
955 | gsm->txframe[len + 1] = GSM1_SOF; | |
956 | len += 2; | |
957 | } | |
958 | ||
c07da737 | 959 | if (debug & DBG_DATA) |
0af02167 DS |
960 | gsm_hex_dump_bytes(__func__, gsm->txframe, len); |
961 | gsm_print_packet("-->", msg->addr, gsm->initiator, msg->ctrl, msg->data, | |
962 | msg->len); | |
963 | ||
964 | ret = gsmld_output(gsm, gsm->txframe, len); | |
965 | if (ret <= 0) | |
966 | return ret; | |
967 | /* FIXME: Can eliminate one SOF in many more cases */ | |
968 | gsm->tx_bytes -= msg->len; | |
969 | ||
970 | return 0; | |
971 | } | |
972 | ||
bec02248 DS |
973 | /** |
974 | * gsm_is_flow_ctrl_msg - checks if flow control message | |
975 | * @msg: message to check | |
976 | * | |
977 | * Returns true if the given message is a flow control command of the | |
978 | * control channel. False is returned in any other case. | |
979 | */ | |
980 | static bool gsm_is_flow_ctrl_msg(struct gsm_msg *msg) | |
981 | { | |
982 | unsigned int cmd; | |
983 | ||
984 | if (msg->addr > 0) | |
985 | return false; | |
986 | ||
987 | switch (msg->ctrl & ~PF) { | |
988 | case UI: | |
989 | case UIH: | |
990 | cmd = 0; | |
991 | if (gsm_read_ea_val(&cmd, msg->data + 2, msg->len - 2) < 1) | |
992 | break; | |
993 | switch (cmd & ~PF) { | |
994 | case CMD_FCOFF: | |
995 | case CMD_FCON: | |
996 | return true; | |
997 | } | |
998 | break; | |
999 | } | |
1000 | ||
1001 | return false; | |
1002 | } | |
1003 | ||
e1eaea46 | 1004 | /** |
0af02167 | 1005 | * gsm_data_kick - poke the queue |
e1eaea46 AC |
1006 | * @gsm: GSM Mux |
1007 | * | |
1008 | * The tty device has called us to indicate that room has appeared in | |
0af02167 | 1009 | * the transmit queue. Ram more data into the pipe if we have any. |
c01af4fe | 1010 | * If we have been flow-stopped by a CMD_FCOFF, then we can only |
0af02167 DS |
1011 | * send messages on DLCI0 until CMD_FCON. The caller must hold |
1012 | * the gsm tx lock. | |
e1eaea46 | 1013 | */ |
0af02167 | 1014 | static int gsm_data_kick(struct gsm_mux *gsm) |
e1eaea46 | 1015 | { |
b4338e1e | 1016 | struct gsm_msg *msg, *nmsg; |
0af02167 DS |
1017 | struct gsm_dlci *dlci; |
1018 | int ret; | |
1019 | ||
1020 | clear_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); | |
e1eaea46 | 1021 | |
0af02167 DS |
1022 | /* Serialize control messages and control channel messages first */ |
1023 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_ctrl_list, list) { | |
bec02248 | 1024 | if (gsm->constipated && !gsm_is_flow_ctrl_msg(msg)) |
59ff0680 | 1025 | continue; |
0af02167 DS |
1026 | ret = gsm_send_packet(gsm, msg); |
1027 | switch (ret) { | |
1028 | case -ENOSPC: | |
1029 | return -ENOSPC; | |
1030 | case -ENODEV: | |
1031 | /* ldisc not open */ | |
1032 | gsm->tx_bytes -= msg->len; | |
1033 | list_del(&msg->list); | |
1034 | kfree(msg); | |
c01af4fe | 1035 | continue; |
0af02167 DS |
1036 | default: |
1037 | if (ret >= 0) { | |
1038 | list_del(&msg->list); | |
1039 | kfree(msg); | |
1040 | } | |
e1eaea46 | 1041 | break; |
0af02167 DS |
1042 | } |
1043 | } | |
c01af4fe | 1044 | |
0af02167 DS |
1045 | if (gsm->constipated) |
1046 | return -EAGAIN; | |
01dbb362 | 1047 | |
0af02167 DS |
1048 | /* Serialize other channels */ |
1049 | if (list_empty(&gsm->tx_data_list)) | |
1050 | return 0; | |
1051 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) { | |
1052 | dlci = gsm->dlci[msg->addr]; | |
1053 | /* Send only messages for DLCIs with valid state */ | |
1054 | if (dlci->state != DLCI_OPEN) { | |
1055 | gsm->tx_bytes -= msg->len; | |
1056 | list_del(&msg->list); | |
1057 | kfree(msg); | |
1058 | continue; | |
1059 | } | |
1060 | ret = gsm_send_packet(gsm, msg); | |
1061 | switch (ret) { | |
1062 | case -ENOSPC: | |
1063 | return -ENOSPC; | |
1064 | case -ENODEV: | |
1065 | /* ldisc not open */ | |
1066 | gsm->tx_bytes -= msg->len; | |
1067 | list_del(&msg->list); | |
1068 | kfree(msg); | |
1069 | continue; | |
1070 | default: | |
1071 | if (ret >= 0) { | |
1072 | list_del(&msg->list); | |
1073 | kfree(msg); | |
1074 | } | |
1075 | break; | |
01dbb362 | 1076 | } |
e1eaea46 | 1077 | } |
0af02167 DS |
1078 | |
1079 | return 1; | |
e1eaea46 AC |
1080 | } |
1081 | ||
1082 | /** | |
1083 | * __gsm_data_queue - queue a UI or UIH frame | |
1084 | * @dlci: DLCI sending the data | |
1085 | * @msg: message queued | |
1086 | * | |
1087 | * Add data to the transmit queue and try and get stuff moving | |
1088 | * out of the mux tty if not already doing so. The Caller must hold | |
1089 | * the gsm tx lock. | |
1090 | */ | |
1091 | ||
1092 | static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
1093 | { | |
1094 | struct gsm_mux *gsm = dlci->gsm; | |
1095 | u8 *dp = msg->data; | |
1096 | u8 *fcs = dp + msg->len; | |
1097 | ||
1098 | /* Fill in the header */ | |
19fb0a66 | 1099 | if (gsm->encoding == GSM_BASIC_OPT) { |
e1eaea46 AC |
1100 | if (msg->len < 128) |
1101 | *--dp = (msg->len << 1) | EA; | |
1102 | else { | |
be7a7411 KM |
1103 | *--dp = (msg->len >> 7); /* bits 7 - 15 */ |
1104 | *--dp = (msg->len & 127) << 1; /* bits 0 - 6 */ | |
e1eaea46 AC |
1105 | } |
1106 | } | |
1107 | ||
1108 | *--dp = msg->ctrl; | |
1109 | if (gsm->initiator) | |
87127773 | 1110 | *--dp = (msg->addr << 2) | CR | EA; |
e1eaea46 AC |
1111 | else |
1112 | *--dp = (msg->addr << 2) | EA; | |
1113 | *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp); | |
1114 | /* Ugly protocol layering violation */ | |
1115 | if (msg->ctrl == UI || msg->ctrl == (UI|PF)) | |
1116 | *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len); | |
1117 | *fcs = 0xFF - *fcs; | |
1118 | ||
1119 | gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl, | |
1120 | msg->data, msg->len); | |
1121 | ||
1122 | /* Move the header back and adjust the length, also allow for the FCS | |
1123 | now tacked on the end */ | |
1124 | msg->len += (msg->data - dp) + 1; | |
1125 | msg->data = dp; | |
1126 | ||
1127 | /* Add to the actual output queue */ | |
0af02167 DS |
1128 | switch (msg->ctrl & ~PF) { |
1129 | case UI: | |
1130 | case UIH: | |
1131 | if (msg->addr > 0) { | |
1132 | list_add_tail(&msg->list, &gsm->tx_data_list); | |
1133 | break; | |
1134 | } | |
1135 | fallthrough; | |
1136 | default: | |
1137 | list_add_tail(&msg->list, &gsm->tx_ctrl_list); | |
1138 | break; | |
1139 | } | |
e1eaea46 | 1140 | gsm->tx_bytes += msg->len; |
0af02167 DS |
1141 | |
1142 | gsmld_write_trigger(gsm); | |
15743ae5 | 1143 | mod_timer(&gsm->kick_timer, jiffies + 10 * gsm->t1 * HZ / 100); |
e1eaea46 AC |
1144 | } |
1145 | ||
1146 | /** | |
1147 | * gsm_data_queue - queue a UI or UIH frame | |
1148 | * @dlci: DLCI sending the data | |
1149 | * @msg: message queued | |
1150 | * | |
1151 | * Add data to the transmit queue and try and get stuff moving | |
1152 | * out of the mux tty if not already doing so. Take the | |
1153 | * the gsm tx lock and dlci lock. | |
1154 | */ | |
1155 | ||
1156 | static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
1157 | { | |
acdab4cb FP |
1158 | unsigned long flags; |
1159 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); | |
e1eaea46 | 1160 | __gsm_data_queue(dlci, msg); |
acdab4cb | 1161 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); |
e1eaea46 AC |
1162 | } |
1163 | ||
1164 | /** | |
1165 | * gsm_dlci_data_output - try and push data out of a DLCI | |
1166 | * @gsm: mux | |
1167 | * @dlci: the DLCI to pull data from | |
1168 | * | |
1169 | * Pull data from a DLCI and send it into the transmit queue if there | |
1170 | * is data. Keep to the MRU of the mux. This path handles the usual tty | |
1171 | * interface which is a byte stream with optional modem data. | |
1172 | * | |
acdab4cb | 1173 | * Caller must hold the tx_lock of the mux. |
e1eaea46 AC |
1174 | */ |
1175 | ||
1176 | static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) | |
1177 | { | |
1178 | struct gsm_msg *msg; | |
1179 | u8 *dp; | |
556fc8ac DS |
1180 | int h, len, size; |
1181 | ||
1182 | /* for modem bits without break data */ | |
1183 | h = ((dlci->adaption == 1) ? 0 : 1); | |
1184 | ||
1185 | len = kfifo_len(&dlci->fifo); | |
1186 | if (len == 0) | |
1187 | return 0; | |
1188 | ||
1189 | /* MTU/MRU count only the data bits but watch adaption mode */ | |
2ec7a802 DS |
1190 | if ((len + h) > dlci->mtu) |
1191 | len = dlci->mtu - h; | |
556fc8ac DS |
1192 | |
1193 | size = len + h; | |
1194 | ||
2ec7a802 | 1195 | msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); |
556fc8ac DS |
1196 | if (!msg) |
1197 | return -ENOMEM; | |
1198 | dp = msg->data; | |
1199 | switch (dlci->adaption) { | |
1200 | case 1: /* Unstructured */ | |
1201 | break; | |
1202 | case 2: /* Unstructured with modem bits. | |
1203 | * Always one byte as we never send inline break data | |
1204 | */ | |
1205 | *dp++ = (gsm_encode_modem(dlci) << 1) | EA; | |
1206 | break; | |
1207 | default: | |
1208 | pr_err("%s: unsupported adaption %d\n", __func__, | |
1209 | dlci->adaption); | |
1210 | break; | |
e1eaea46 | 1211 | } |
556fc8ac DS |
1212 | |
1213 | WARN_ON(len != kfifo_out_locked(&dlci->fifo, dp, len, | |
1214 | &dlci->lock)); | |
1215 | ||
1216 | /* Notify upper layer about available send space. */ | |
1217 | tty_port_tty_wakeup(&dlci->port); | |
1218 | ||
1219 | __gsm_data_queue(dlci, msg); | |
e1eaea46 | 1220 | /* Bytes of data we used up */ |
556fc8ac | 1221 | return size; |
e1eaea46 AC |
1222 | } |
1223 | ||
1224 | /** | |
1225 | * gsm_dlci_data_output_framed - try and push data out of a DLCI | |
1226 | * @gsm: mux | |
1227 | * @dlci: the DLCI to pull data from | |
1228 | * | |
1229 | * Pull data from a DLCI and send it into the transmit queue if there | |
1230 | * is data. Keep to the MRU of the mux. This path handles framed data | |
1231 | * queued as skbuffs to the DLCI. | |
1232 | * | |
acdab4cb | 1233 | * Caller must hold the tx_lock of the mux. |
e1eaea46 AC |
1234 | */ |
1235 | ||
1236 | static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, | |
1237 | struct gsm_dlci *dlci) | |
1238 | { | |
1239 | struct gsm_msg *msg; | |
1240 | u8 *dp; | |
1241 | int len, size; | |
1242 | int last = 0, first = 0; | |
1243 | int overhead = 0; | |
1244 | ||
1245 | /* One byte per frame is used for B/F flags */ | |
1246 | if (dlci->adaption == 4) | |
1247 | overhead = 1; | |
1248 | ||
acdab4cb | 1249 | /* dlci->skb is locked by tx_lock */ |
e1eaea46 | 1250 | if (dlci->skb == NULL) { |
88ed2a60 | 1251 | dlci->skb = skb_dequeue_tail(&dlci->skb_list); |
e1eaea46 AC |
1252 | if (dlci->skb == NULL) |
1253 | return 0; | |
1254 | first = 1; | |
1255 | } | |
1256 | len = dlci->skb->len + overhead; | |
1257 | ||
1258 | /* MTU/MRU count only the data bits */ | |
2ec7a802 | 1259 | if (len > dlci->mtu) { |
e1eaea46 AC |
1260 | if (dlci->adaption == 3) { |
1261 | /* Over long frame, bin it */ | |
329e5678 | 1262 | dev_kfree_skb_any(dlci->skb); |
e1eaea46 AC |
1263 | dlci->skb = NULL; |
1264 | return 0; | |
1265 | } | |
2ec7a802 | 1266 | len = dlci->mtu; |
e1eaea46 AC |
1267 | } else |
1268 | last = 1; | |
1269 | ||
1270 | size = len + overhead; | |
2ec7a802 | 1271 | msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); |
88ed2a60 RG |
1272 | if (msg == NULL) { |
1273 | skb_queue_tail(&dlci->skb_list, dlci->skb); | |
1274 | dlci->skb = NULL; | |
e1eaea46 | 1275 | return -ENOMEM; |
88ed2a60 | 1276 | } |
e1eaea46 AC |
1277 | dp = msg->data; |
1278 | ||
1279 | if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ | |
1280 | /* Flag byte to carry the start/end info */ | |
1281 | *dp++ = last << 7 | first << 6 | 1; /* EA */ | |
1282 | len--; | |
1283 | } | |
57f2104f RG |
1284 | memcpy(dp, dlci->skb->data, len); |
1285 | skb_pull(dlci->skb, len); | |
e1eaea46 | 1286 | __gsm_data_queue(dlci, msg); |
bcd5abe2 | 1287 | if (last) { |
329e5678 | 1288 | dev_kfree_skb_any(dlci->skb); |
e1eaea46 | 1289 | dlci->skb = NULL; |
bcd5abe2 | 1290 | } |
e1eaea46 AC |
1291 | return size; |
1292 | } | |
1293 | ||
c19ffe00 DS |
1294 | /** |
1295 | * gsm_dlci_modem_output - try and push modem status out of a DLCI | |
1296 | * @gsm: mux | |
1297 | * @dlci: the DLCI to pull modem status from | |
1298 | * @brk: break signal | |
1299 | * | |
1300 | * Push an empty frame in to the transmit queue to update the modem status | |
1301 | * bits and to transmit an optional break. | |
1302 | * | |
acdab4cb | 1303 | * Caller must hold the tx_lock of the mux. |
c19ffe00 DS |
1304 | */ |
1305 | ||
1306 | static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci, | |
1307 | u8 brk) | |
1308 | { | |
1309 | u8 *dp = NULL; | |
1310 | struct gsm_msg *msg; | |
19317433 | 1311 | int size = 0; |
c19ffe00 DS |
1312 | |
1313 | /* for modem bits without break data */ | |
19317433 DS |
1314 | switch (dlci->adaption) { |
1315 | case 1: /* Unstructured */ | |
1316 | break; | |
1317 | case 2: /* Unstructured with modem bits. */ | |
1318 | size++; | |
c19ffe00 DS |
1319 | if (brk > 0) |
1320 | size++; | |
19317433 DS |
1321 | break; |
1322 | default: | |
c19ffe00 DS |
1323 | pr_err("%s: unsupported adaption %d\n", __func__, |
1324 | dlci->adaption); | |
19317433 | 1325 | return -EINVAL; |
c19ffe00 DS |
1326 | } |
1327 | ||
2ec7a802 | 1328 | msg = gsm_data_alloc(gsm, dlci->addr, size, dlci->ftype); |
c19ffe00 DS |
1329 | if (!msg) { |
1330 | pr_err("%s: gsm_data_alloc error", __func__); | |
1331 | return -ENOMEM; | |
1332 | } | |
1333 | dp = msg->data; | |
1334 | switch (dlci->adaption) { | |
1335 | case 1: /* Unstructured */ | |
1336 | break; | |
1337 | case 2: /* Unstructured with modem bits. */ | |
1338 | if (brk == 0) { | |
1339 | *dp++ = (gsm_encode_modem(dlci) << 1) | EA; | |
1340 | } else { | |
1341 | *dp++ = gsm_encode_modem(dlci) << 1; | |
1342 | *dp++ = (brk << 4) | 2 | EA; /* Length, Break, EA */ | |
1343 | } | |
1344 | break; | |
1345 | default: | |
1346 | /* Handled above */ | |
1347 | break; | |
1348 | } | |
1349 | ||
1350 | __gsm_data_queue(dlci, msg); | |
1351 | return size; | |
1352 | } | |
1353 | ||
e1eaea46 AC |
1354 | /** |
1355 | * gsm_dlci_data_sweep - look for data to send | |
1356 | * @gsm: the GSM mux | |
1357 | * | |
1358 | * Sweep the GSM mux channels in priority order looking for ones with | |
1359 | * data to send. We could do with optimising this scan a bit. We aim | |
1360 | * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit | |
1361 | * TX_THRESH_LO we get called again | |
1362 | * | |
1363 | * FIXME: We should round robin between groups and in theory you can | |
1364 | * renegotiate DLCI priorities with optional stuff. Needs optimising. | |
1365 | */ | |
1366 | ||
c568f708 | 1367 | static int gsm_dlci_data_sweep(struct gsm_mux *gsm) |
e1eaea46 | 1368 | { |
e1eaea46 | 1369 | /* Priority ordering: We should do priority with RR of the groups */ |
0af02167 DS |
1370 | int i, len, ret = 0; |
1371 | bool sent; | |
1372 | struct gsm_dlci *dlci; | |
e1eaea46 | 1373 | |
0af02167 DS |
1374 | while (gsm->tx_bytes < TX_THRESH_HI) { |
1375 | for (sent = false, i = 1; i < NUM_DLCI; i++) { | |
1376 | dlci = gsm->dlci[i]; | |
1377 | /* skip unused or blocked channel */ | |
1378 | if (!dlci || dlci->constipated) | |
1379 | continue; | |
1380 | /* skip channels with invalid state */ | |
1381 | if (dlci->state != DLCI_OPEN) | |
1382 | continue; | |
1383 | /* count the sent data per adaption */ | |
1384 | if (dlci->adaption < 3 && !dlci->net) | |
1385 | len = gsm_dlci_data_output(gsm, dlci); | |
1386 | else | |
1387 | len = gsm_dlci_data_output_framed(gsm, dlci); | |
1388 | /* on error exit */ | |
1389 | if (len < 0) | |
1390 | return ret; | |
1391 | if (len > 0) { | |
1392 | ret++; | |
1393 | sent = true; | |
1394 | /* The lower DLCs can starve the higher DLCs! */ | |
1395 | break; | |
1396 | } | |
1397 | /* try next */ | |
e1eaea46 | 1398 | } |
0af02167 | 1399 | if (!sent) |
e73790a5 | 1400 | break; |
a3be423f | 1401 | } |
c568f708 DS |
1402 | |
1403 | return ret; | |
e1eaea46 AC |
1404 | } |
1405 | ||
1406 | /** | |
1407 | * gsm_dlci_data_kick - transmit if possible | |
1408 | * @dlci: DLCI to kick | |
1409 | * | |
1410 | * Transmit data from this DLCI if the queue is empty. We can't rely on | |
1411 | * a tty wakeup except when we filled the pipe so we need to fire off | |
1412 | * new data ourselves in other cases. | |
1413 | */ | |
1414 | ||
1415 | static void gsm_dlci_data_kick(struct gsm_dlci *dlci) | |
1416 | { | |
acdab4cb | 1417 | unsigned long flags; |
192b6041 | 1418 | int sweep; |
e1eaea46 | 1419 | |
f3c909b4 | 1420 | if (dlci->constipated) |
c01af4fe | 1421 | return; |
c01af4fe | 1422 | |
acdab4cb | 1423 | spin_lock_irqsave(&dlci->gsm->tx_lock, flags); |
e1eaea46 | 1424 | /* If we have nothing running then we need to fire up */ |
192b6041 | 1425 | sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO); |
bcd5abe2 RG |
1426 | if (dlci->gsm->tx_bytes == 0) { |
1427 | if (dlci->net) | |
1428 | gsm_dlci_data_output_framed(dlci->gsm, dlci); | |
1429 | else | |
1430 | gsm_dlci_data_output(dlci->gsm, dlci); | |
192b6041 RG |
1431 | } |
1432 | if (sweep) | |
f3c909b4 | 1433 | gsm_dlci_data_sweep(dlci->gsm); |
acdab4cb | 1434 | spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); |
e1eaea46 AC |
1435 | } |
1436 | ||
1437 | /* | |
1438 | * Control message processing | |
1439 | */ | |
1440 | ||
1441 | ||
de640bc6 DS |
1442 | /** |
1443 | * gsm_control_command - send a command frame to a control | |
1444 | * @gsm: gsm channel | |
1445 | * @cmd: the command to use | |
1446 | * @data: data to follow encoded info | |
1447 | * @dlen: length of data | |
1448 | * | |
1449 | * Encode up and queue a UI/UIH frame containing our command. | |
1450 | */ | |
1451 | static int gsm_control_command(struct gsm_mux *gsm, int cmd, const u8 *data, | |
1452 | int dlen) | |
1453 | { | |
2ec7a802 | 1454 | struct gsm_msg *msg; |
57677126 | 1455 | struct gsm_dlci *dlci = gsm->dlci[0]; |
de640bc6 | 1456 | |
57677126 | 1457 | msg = gsm_data_alloc(gsm, 0, dlen + 2, dlci->ftype); |
de640bc6 DS |
1458 | if (msg == NULL) |
1459 | return -ENOMEM; | |
1460 | ||
1461 | msg->data[0] = (cmd << 1) | CR | EA; /* Set C/R */ | |
1462 | msg->data[1] = (dlen << 1) | EA; | |
1463 | memcpy(msg->data + 2, data, dlen); | |
57677126 | 1464 | gsm_data_queue(dlci, msg); |
de640bc6 DS |
1465 | |
1466 | return 0; | |
1467 | } | |
1468 | ||
e1eaea46 AC |
1469 | /** |
1470 | * gsm_control_reply - send a response frame to a control | |
1471 | * @gsm: gsm channel | |
1472 | * @cmd: the command to use | |
1473 | * @data: data to follow encoded info | |
1474 | * @dlen: length of data | |
1475 | * | |
1476 | * Encode up and queue a UI/UIH frame containing our response. | |
1477 | */ | |
1478 | ||
4feb7a4a | 1479 | static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data, |
e1eaea46 AC |
1480 | int dlen) |
1481 | { | |
1482 | struct gsm_msg *msg; | |
57677126 | 1483 | struct gsm_dlci *dlci = gsm->dlci[0]; |
2ec7a802 | 1484 | |
57677126 | 1485 | msg = gsm_data_alloc(gsm, 0, dlen + 2, dlci->ftype); |
093d8046 KM |
1486 | if (msg == NULL) |
1487 | return; | |
e1eaea46 AC |
1488 | msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ |
1489 | msg->data[1] = (dlen << 1) | EA; | |
1490 | memcpy(msg->data + 2, data, dlen); | |
57677126 | 1491 | gsm_data_queue(dlci, msg); |
e1eaea46 AC |
1492 | } |
1493 | ||
1494 | /** | |
1495 | * gsm_process_modem - process received modem status | |
1496 | * @tty: virtual tty bound to the DLCI | |
1497 | * @dlci: DLCI to affect | |
1498 | * @modem: modem bits (full EA) | |
687f9ad4 | 1499 | * @slen: number of signal octets |
e1eaea46 AC |
1500 | * |
1501 | * Used when a modem control message or line state inline in adaption | |
1502 | * layer 2 is processed. Sort out the local modem state and throttles | |
1503 | */ | |
1504 | ||
1505 | static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, | |
687f9ad4 | 1506 | u32 modem, int slen) |
e1eaea46 AC |
1507 | { |
1508 | int mlines = 0; | |
7263287a | 1509 | u8 brk = 0; |
c01af4fe | 1510 | int fc; |
7263287a | 1511 | |
687f9ad4 | 1512 | /* The modem status command can either contain one octet (V.24 signals) |
1513 | * or two octets (V.24 signals + break signals). This is specified in | |
1514 | * section 5.4.6.3.7 of the 07.10 mux spec. | |
1515 | */ | |
7263287a | 1516 | |
687f9ad4 | 1517 | if (slen == 1) |
7263287a RG |
1518 | modem = modem & 0x7f; |
1519 | else { | |
1520 | brk = modem & 0x7f; | |
1521 | modem = (modem >> 7) & 0x7f; | |
c01af4fe | 1522 | } |
e1eaea46 AC |
1523 | |
1524 | /* Flow control/ready to communicate */ | |
c01af4fe FB |
1525 | fc = (modem & MDM_FC) || !(modem & MDM_RTR); |
1526 | if (fc && !dlci->constipated) { | |
e1eaea46 | 1527 | /* Need to throttle our output on this device */ |
7a9ed9c0 | 1528 | dlci->constipated = true; |
c01af4fe | 1529 | } else if (!fc && dlci->constipated) { |
7a9ed9c0 | 1530 | dlci->constipated = false; |
e1eaea46 AC |
1531 | gsm_dlci_data_kick(dlci); |
1532 | } | |
c01af4fe | 1533 | |
e1eaea46 | 1534 | /* Map modem bits */ |
c01af4fe FB |
1535 | if (modem & MDM_RTC) |
1536 | mlines |= TIOCM_DSR | TIOCM_DTR; | |
e1eaea46 AC |
1537 | if (modem & MDM_RTR) |
1538 | mlines |= TIOCM_RTS | TIOCM_CTS; | |
1539 | if (modem & MDM_IC) | |
1540 | mlines |= TIOCM_RI; | |
1541 | if (modem & MDM_DV) | |
1542 | mlines |= TIOCM_CD; | |
1543 | ||
1544 | /* Carrier drop -> hangup */ | |
1545 | if (tty) { | |
1546 | if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) | |
9db276f8 | 1547 | if (!C_CLOCAL(tty)) |
e1eaea46 | 1548 | tty_hangup(tty); |
e1eaea46 | 1549 | } |
92a19f9c JS |
1550 | if (brk & 0x01) |
1551 | tty_insert_flip_char(&dlci->port, 0, TTY_BREAK); | |
e1eaea46 | 1552 | dlci->modem_rx = mlines; |
684ae4f9 | 1553 | wake_up_interruptible(&dlci->gsm->event); |
e1eaea46 AC |
1554 | } |
1555 | ||
92f1f0c3 DS |
1556 | /** |
1557 | * gsm_process_negotiation - process received parameters | |
1558 | * @gsm: GSM channel | |
1559 | * @addr: DLCI address | |
1560 | * @cr: command/response | |
1561 | * @params: encoded parameters from the parameter negotiation message | |
1562 | * | |
1563 | * Used when the response for our parameter negotiation command was | |
1564 | * received. | |
1565 | */ | |
1566 | static int gsm_process_negotiation(struct gsm_mux *gsm, unsigned int addr, | |
1567 | unsigned int cr, | |
1568 | const struct gsm_dlci_param_bits *params) | |
1569 | { | |
1570 | struct gsm_dlci *dlci = gsm->dlci[addr]; | |
1571 | unsigned int ftype, i, adaption, prio, n1, k; | |
1572 | ||
1573 | i = FIELD_GET(PN_I_CL_FIELD_FTYPE, params->i_cl_bits); | |
1574 | adaption = FIELD_GET(PN_I_CL_FIELD_ADAPTION, params->i_cl_bits) + 1; | |
1575 | prio = FIELD_GET(PN_P_FIELD_PRIO, params->p_bits); | |
1576 | n1 = FIELD_GET(PN_N_FIELD_N1, get_unaligned_le16(¶ms->n_bits)); | |
1577 | k = FIELD_GET(PN_K_FIELD_K, params->k_bits); | |
1578 | ||
1579 | if (n1 < MIN_MTU) { | |
1580 | if (debug & DBG_ERRORS) | |
1581 | pr_info("%s N1 out of range in PN\n", __func__); | |
1582 | return -EINVAL; | |
1583 | } | |
1584 | ||
1585 | switch (i) { | |
1586 | case 0x00: | |
1587 | ftype = UIH; | |
1588 | break; | |
1589 | case 0x01: | |
1590 | ftype = UI; | |
1591 | break; | |
1592 | case 0x02: /* I frames are not supported */ | |
1593 | if (debug & DBG_ERRORS) | |
1594 | pr_info("%s unsupported I frame request in PN\n", | |
1595 | __func__); | |
e74c048a | 1596 | gsm->unsupported++; |
92f1f0c3 DS |
1597 | return -EINVAL; |
1598 | default: | |
1599 | if (debug & DBG_ERRORS) | |
1600 | pr_info("%s i out of range in PN\n", __func__); | |
1601 | return -EINVAL; | |
1602 | } | |
1603 | ||
1604 | if (!cr && gsm->initiator) { | |
1605 | if (adaption != dlci->adaption) { | |
1606 | if (debug & DBG_ERRORS) | |
1607 | pr_info("%s invalid adaption %d in PN\n", | |
1608 | __func__, adaption); | |
1609 | return -EINVAL; | |
1610 | } | |
1611 | if (prio != dlci->prio) { | |
1612 | if (debug & DBG_ERRORS) | |
1613 | pr_info("%s invalid priority %d in PN", | |
1614 | __func__, prio); | |
1615 | return -EINVAL; | |
1616 | } | |
1617 | if (n1 > gsm->mru || n1 > dlci->mtu) { | |
1618 | /* We requested a frame size but the other party wants | |
1619 | * to send larger frames. The standard allows only a | |
1620 | * smaller response value than requested (5.4.6.3.1). | |
1621 | */ | |
1622 | if (debug & DBG_ERRORS) | |
1623 | pr_info("%s invalid N1 %d in PN\n", __func__, | |
1624 | n1); | |
1625 | return -EINVAL; | |
1626 | } | |
1627 | dlci->mtu = n1; | |
1628 | if (ftype != dlci->ftype) { | |
1629 | if (debug & DBG_ERRORS) | |
1630 | pr_info("%s invalid i %d in PN\n", __func__, i); | |
1631 | return -EINVAL; | |
1632 | } | |
1633 | if (ftype != UI && ftype != UIH && k > dlci->k) { | |
1634 | if (debug & DBG_ERRORS) | |
1635 | pr_info("%s invalid k %d in PN\n", __func__, k); | |
1636 | return -EINVAL; | |
1637 | } | |
1638 | dlci->k = k; | |
1639 | } else if (cr && !gsm->initiator) { | |
1640 | /* Only convergence layer type 1 and 2 are supported. */ | |
1641 | if (adaption != 1 && adaption != 2) { | |
1642 | if (debug & DBG_ERRORS) | |
1643 | pr_info("%s invalid adaption %d in PN\n", | |
1644 | __func__, adaption); | |
1645 | return -EINVAL; | |
1646 | } | |
1647 | dlci->adaption = adaption; | |
1648 | if (n1 > gsm->mru) { | |
1649 | /* Propose a smaller value */ | |
1650 | dlci->mtu = gsm->mru; | |
1651 | } else if (n1 > MAX_MTU) { | |
1652 | /* Propose a smaller value */ | |
1653 | dlci->mtu = MAX_MTU; | |
1654 | } else { | |
1655 | dlci->mtu = n1; | |
1656 | } | |
1657 | dlci->prio = prio; | |
1658 | dlci->ftype = ftype; | |
1659 | dlci->k = k; | |
1660 | } else { | |
1661 | return -EINVAL; | |
1662 | } | |
1663 | ||
1664 | return 0; | |
1665 | } | |
1666 | ||
e1eaea46 AC |
1667 | /** |
1668 | * gsm_control_modem - modem status received | |
1669 | * @gsm: GSM channel | |
1670 | * @data: data following command | |
1671 | * @clen: command length | |
1672 | * | |
1673 | * We have received a modem status control message. This is used by | |
1674 | * the GSM mux protocol to pass virtual modem line status and optionally | |
1675 | * to indicate break signals. Unpack it, convert to Linux representation | |
1676 | * and if need be stuff a break message down the tty. | |
1677 | */ | |
1678 | ||
4feb7a4a | 1679 | static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) |
e1eaea46 AC |
1680 | { |
1681 | unsigned int addr = 0; | |
1682 | unsigned int modem = 0; | |
1683 | struct gsm_dlci *dlci; | |
1684 | int len = clen; | |
669609ce | 1685 | int cl = clen; |
4feb7a4a | 1686 | const u8 *dp = data; |
e1eaea46 AC |
1687 | struct tty_struct *tty; |
1688 | ||
669609ce DS |
1689 | len = gsm_read_ea_val(&addr, data, cl); |
1690 | if (len < 1) | |
e1eaea46 AC |
1691 | return; |
1692 | ||
1693 | addr >>= 1; | |
1694 | /* Closed port, or invalid ? */ | |
1695 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1696 | return; | |
1697 | dlci = gsm->dlci[addr]; | |
1698 | ||
669609ce DS |
1699 | /* Must be at least one byte following the EA */ |
1700 | if ((cl - len) < 1) | |
1701 | return; | |
1702 | ||
1703 | dp += len; | |
1704 | cl -= len; | |
1705 | ||
1706 | /* get the modem status */ | |
1707 | len = gsm_read_ea_val(&modem, dp, cl); | |
1708 | if (len < 1) | |
1709 | return; | |
1710 | ||
e1eaea46 | 1711 | tty = tty_port_tty_get(&dlci->port); |
669609ce | 1712 | gsm_process_modem(tty, dlci, modem, cl); |
e1eaea46 AC |
1713 | if (tty) { |
1714 | tty_wakeup(tty); | |
1715 | tty_kref_put(tty); | |
1716 | } | |
1717 | gsm_control_reply(gsm, CMD_MSC, data, clen); | |
1718 | } | |
1719 | ||
92f1f0c3 DS |
1720 | /** |
1721 | * gsm_control_negotiation - parameter negotiation received | |
1722 | * @gsm: GSM channel | |
1723 | * @cr: command/response flag | |
1724 | * @data: data following command | |
1725 | * @dlen: data length | |
1726 | * | |
1727 | * We have received a parameter negotiation message. This is used by | |
1728 | * the GSM mux protocol to configure protocol parameters for a new DLCI. | |
1729 | */ | |
1730 | static void gsm_control_negotiation(struct gsm_mux *gsm, unsigned int cr, | |
1731 | const u8 *data, unsigned int dlen) | |
1732 | { | |
1733 | unsigned int addr; | |
1734 | struct gsm_dlci_param_bits pn_reply; | |
1735 | struct gsm_dlci *dlci; | |
1736 | struct gsm_dlci_param_bits *params; | |
1737 | ||
a1ce6da0 DS |
1738 | if (dlen < sizeof(struct gsm_dlci_param_bits)) { |
1739 | gsm->open_error++; | |
92f1f0c3 | 1740 | return; |
a1ce6da0 | 1741 | } |
92f1f0c3 DS |
1742 | |
1743 | /* Invalid DLCI? */ | |
1744 | params = (struct gsm_dlci_param_bits *)data; | |
1745 | addr = FIELD_GET(PN_D_FIELD_DLCI, params->d_bits); | |
a1ce6da0 DS |
1746 | if (addr == 0 || addr >= NUM_DLCI || !gsm->dlci[addr]) { |
1747 | gsm->open_error++; | |
92f1f0c3 | 1748 | return; |
a1ce6da0 | 1749 | } |
92f1f0c3 DS |
1750 | dlci = gsm->dlci[addr]; |
1751 | ||
1752 | /* Too late for parameter negotiation? */ | |
a1ce6da0 DS |
1753 | if ((!cr && dlci->state == DLCI_OPENING) || dlci->state == DLCI_OPEN) { |
1754 | gsm->open_error++; | |
92f1f0c3 | 1755 | return; |
a1ce6da0 | 1756 | } |
92f1f0c3 DS |
1757 | |
1758 | /* Process the received parameters */ | |
1759 | if (gsm_process_negotiation(gsm, addr, cr, params) != 0) { | |
1760 | /* Negotiation failed. Close the link. */ | |
1761 | if (debug & DBG_ERRORS) | |
1762 | pr_info("%s PN failed\n", __func__); | |
a1ce6da0 | 1763 | gsm->open_error++; |
92f1f0c3 DS |
1764 | gsm_dlci_close(dlci); |
1765 | return; | |
1766 | } | |
1767 | ||
1768 | if (cr) { | |
1769 | /* Reply command with accepted parameters. */ | |
1770 | if (gsm_encode_params(dlci, &pn_reply) == 0) | |
1771 | gsm_control_reply(gsm, CMD_PN, (const u8 *)&pn_reply, | |
1772 | sizeof(pn_reply)); | |
1773 | else if (debug & DBG_ERRORS) | |
1774 | pr_info("%s PN invalid\n", __func__); | |
1775 | } else if (dlci->state == DLCI_CONFIGURE) { | |
1776 | /* Proceed with link setup by sending SABM before UA */ | |
1777 | dlci->state = DLCI_OPENING; | |
1778 | gsm_command(gsm, dlci->addr, SABM|PF); | |
1779 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1780 | } else { | |
1781 | if (debug & DBG_ERRORS) | |
1782 | pr_info("%s PN in invalid state\n", __func__); | |
a1ce6da0 | 1783 | gsm->open_error++; |
92f1f0c3 DS |
1784 | } |
1785 | } | |
1786 | ||
e1eaea46 AC |
1787 | /** |
1788 | * gsm_control_rls - remote line status | |
1789 | * @gsm: GSM channel | |
1790 | * @data: data bytes | |
1791 | * @clen: data length | |
1792 | * | |
1793 | * The modem sends us a two byte message on the control channel whenever | |
1794 | * it wishes to send us an error state from the virtual link. Stuff | |
1795 | * this into the uplink tty if present | |
1796 | */ | |
1797 | ||
4feb7a4a | 1798 | static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen) |
e1eaea46 | 1799 | { |
92a19f9c | 1800 | struct tty_port *port; |
f3c909b4 | 1801 | unsigned int addr = 0; |
e1eaea46 AC |
1802 | u8 bits; |
1803 | int len = clen; | |
4feb7a4a | 1804 | const u8 *dp = data; |
e1eaea46 AC |
1805 | |
1806 | while (gsm_read_ea(&addr, *dp++) == 0) { | |
1807 | len--; | |
1808 | if (len == 0) | |
1809 | return; | |
1810 | } | |
1811 | /* Must be at least one byte following ea */ | |
1812 | len--; | |
1813 | if (len <= 0) | |
1814 | return; | |
1815 | addr >>= 1; | |
1816 | /* Closed port, or invalid ? */ | |
1817 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1818 | return; | |
1819 | /* No error ? */ | |
1820 | bits = *dp; | |
1821 | if ((bits & 1) == 0) | |
1822 | return; | |
e1eaea46 | 1823 | |
92a19f9c JS |
1824 | port = &gsm->dlci[addr]->port; |
1825 | ||
1826 | if (bits & 2) | |
1827 | tty_insert_flip_char(port, 0, TTY_OVERRUN); | |
1828 | if (bits & 4) | |
1829 | tty_insert_flip_char(port, 0, TTY_PARITY); | |
1830 | if (bits & 8) | |
1831 | tty_insert_flip_char(port, 0, TTY_FRAME); | |
1832 | ||
2e124b4a JS |
1833 | tty_flip_buffer_push(port); |
1834 | ||
e1eaea46 AC |
1835 | gsm_control_reply(gsm, CMD_RLS, data, clen); |
1836 | } | |
1837 | ||
1838 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci); | |
1839 | ||
1840 | /** | |
1841 | * gsm_control_message - DLCI 0 control processing | |
1842 | * @gsm: our GSM mux | |
1843 | * @command: the command EA | |
1844 | * @data: data beyond the command/length EAs | |
1845 | * @clen: length | |
1846 | * | |
1847 | * Input processor for control messages from the other end of the link. | |
1848 | * Processes the incoming request and queues a response frame or an | |
1849 | * NSC response if not supported | |
1850 | */ | |
1851 | ||
1852 | static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, | |
4feb7a4a | 1853 | const u8 *data, int clen) |
e1eaea46 AC |
1854 | { |
1855 | u8 buf[1]; | |
5e44708f | 1856 | |
e1eaea46 AC |
1857 | switch (command) { |
1858 | case CMD_CLD: { | |
a8c5b825 | 1859 | struct gsm_dlci *dlci = gsm->dlci[0]; |
e1eaea46 AC |
1860 | /* Modem wishes to close down */ |
1861 | if (dlci) { | |
5677fcf3 JS |
1862 | dlci->dead = true; |
1863 | gsm->dead = true; | |
a8c5b825 | 1864 | gsm_dlci_begin_close(dlci); |
e1eaea46 AC |
1865 | } |
1866 | } | |
1867 | break; | |
1868 | case CMD_TEST: | |
1869 | /* Modem wishes to test, reply with the data */ | |
1870 | gsm_control_reply(gsm, CMD_TEST, data, clen); | |
1871 | break; | |
1872 | case CMD_FCON: | |
e1eaea46 | 1873 | /* Modem can accept data again */ |
7a9ed9c0 | 1874 | gsm->constipated = false; |
c01af4fe | 1875 | gsm_control_reply(gsm, CMD_FCON, NULL, 0); |
e1eaea46 | 1876 | /* Kick the link in case it is idling */ |
0af02167 | 1877 | gsmld_write_trigger(gsm); |
e1eaea46 | 1878 | break; |
c01af4fe FB |
1879 | case CMD_FCOFF: |
1880 | /* Modem wants us to STFU */ | |
7a9ed9c0 | 1881 | gsm->constipated = true; |
c01af4fe FB |
1882 | gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); |
1883 | break; | |
e1eaea46 AC |
1884 | case CMD_MSC: |
1885 | /* Out of band modem line change indicator for a DLCI */ | |
1886 | gsm_control_modem(gsm, data, clen); | |
1887 | break; | |
1888 | case CMD_RLS: | |
1889 | /* Out of band error reception for a DLCI */ | |
1890 | gsm_control_rls(gsm, data, clen); | |
1891 | break; | |
1892 | case CMD_PSC: | |
1893 | /* Modem wishes to enter power saving state */ | |
1894 | gsm_control_reply(gsm, CMD_PSC, NULL, 0); | |
1895 | break; | |
92f1f0c3 DS |
1896 | /* Optional commands */ |
1897 | case CMD_PN: | |
1898 | /* Modem sends a parameter negotiation command */ | |
1899 | gsm_control_negotiation(gsm, 1, data, clen); | |
1900 | break; | |
e1eaea46 | 1901 | /* Optional unsupported commands */ |
25985edc LDM |
1902 | case CMD_RPN: /* Remote port negotiation */ |
1903 | case CMD_SNC: /* Service negotiation command */ | |
e74c048a DS |
1904 | gsm->unsupported++; |
1905 | fallthrough; | |
e1eaea46 AC |
1906 | default: |
1907 | /* Reply to bad commands with an NSC */ | |
1908 | buf[0] = command; | |
1909 | gsm_control_reply(gsm, CMD_NSC, buf, 1); | |
1910 | break; | |
1911 | } | |
1912 | } | |
1913 | ||
1914 | /** | |
1915 | * gsm_control_response - process a response to our control | |
1916 | * @gsm: our GSM mux | |
1917 | * @command: the command (response) EA | |
1918 | * @data: data beyond the command/length EA | |
1919 | * @clen: length | |
1920 | * | |
1921 | * Process a response to an outstanding command. We only allow a single | |
1922 | * control message in flight so this is fairly easy. All the clean up | |
1923 | * is done by the caller, we just update the fields, flag it as done | |
1924 | * and return | |
1925 | */ | |
1926 | ||
1927 | static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, | |
4feb7a4a | 1928 | const u8 *data, int clen) |
e1eaea46 AC |
1929 | { |
1930 | struct gsm_control *ctrl; | |
72206cc7 | 1931 | struct gsm_dlci *dlci; |
e1eaea46 AC |
1932 | unsigned long flags; |
1933 | ||
1934 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1935 | ||
1936 | ctrl = gsm->pending_cmd; | |
72206cc7 | 1937 | dlci = gsm->dlci[0]; |
e1eaea46 | 1938 | command |= 1; |
92f1f0c3 | 1939 | /* Does the reply match our command */ |
e1eaea46 AC |
1940 | if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { |
1941 | /* Our command was replied to, kill the retry timer */ | |
1942 | del_timer(&gsm->t2_timer); | |
1943 | gsm->pending_cmd = NULL; | |
1944 | /* Rejected by the other end */ | |
1945 | if (command == CMD_NSC) | |
1946 | ctrl->error = -EOPNOTSUPP; | |
1947 | ctrl->done = 1; | |
1948 | wake_up(&gsm->event); | |
92f1f0c3 DS |
1949 | /* Or did we receive the PN response to our PN command */ |
1950 | } else if (command == CMD_PN) { | |
1951 | gsm_control_negotiation(gsm, 0, data, clen); | |
72206cc7 DS |
1952 | /* Or did we receive the TEST response to our TEST command */ |
1953 | } else if (command == CMD_TEST && clen == 1 && *data == gsm->ka_num) { | |
1954 | gsm->ka_retries = -1; /* trigger new keep-alive message */ | |
1955 | if (dlci && !dlci->dead) | |
1956 | mod_timer(&gsm->ka_timer, jiffies + gsm->keep_alive * HZ / 100); | |
1957 | } | |
1958 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1959 | } | |
1960 | ||
1961 | /** | |
1962 | * gsm_control_keep_alive - check timeout or start keep-alive | |
1963 | * @t: timer contained in our gsm object | |
1964 | * | |
1965 | * Called off the keep-alive timer expiry signaling that our link | |
1966 | * partner is not responding anymore. Link will be closed. | |
1967 | * This is also called to startup our timer. | |
1968 | */ | |
1969 | ||
1970 | static void gsm_control_keep_alive(struct timer_list *t) | |
1971 | { | |
1972 | struct gsm_mux *gsm = from_timer(gsm, t, ka_timer); | |
1973 | unsigned long flags; | |
1974 | ||
1975 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1976 | if (gsm->ka_num && gsm->ka_retries == 0) { | |
1977 | /* Keep-alive expired -> close the link */ | |
1978 | if (debug & DBG_ERRORS) | |
1979 | pr_debug("%s keep-alive timed out\n", __func__); | |
1980 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1981 | if (gsm->dlci[0]) | |
1982 | gsm_dlci_begin_close(gsm->dlci[0]); | |
1983 | return; | |
1984 | } else if (gsm->keep_alive && gsm->dlci[0] && !gsm->dlci[0]->dead) { | |
1985 | if (gsm->ka_retries > 0) { | |
1986 | /* T2 expired for keep-alive -> resend */ | |
1987 | gsm->ka_retries--; | |
1988 | } else { | |
1989 | /* Start keep-alive timer */ | |
1990 | gsm->ka_num++; | |
1991 | if (!gsm->ka_num) | |
1992 | gsm->ka_num++; | |
1993 | gsm->ka_retries = (signed int)gsm->n2; | |
1994 | } | |
1995 | gsm_control_command(gsm, CMD_TEST, &gsm->ka_num, | |
1996 | sizeof(gsm->ka_num)); | |
1997 | mod_timer(&gsm->ka_timer, | |
1998 | jiffies + gsm->t2 * HZ / 100); | |
e1eaea46 AC |
1999 | } |
2000 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
2001 | } | |
2002 | ||
2003 | /** | |
5f9a31d6 | 2004 | * gsm_control_transmit - send control packet |
e1eaea46 AC |
2005 | * @gsm: gsm mux |
2006 | * @ctrl: frame to send | |
2007 | * | |
2008 | * Send out a pending control command (called under control lock) | |
2009 | */ | |
2010 | ||
2011 | static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) | |
2012 | { | |
de640bc6 | 2013 | gsm_control_command(gsm, ctrl->cmd, ctrl->data, ctrl->len); |
e1eaea46 AC |
2014 | } |
2015 | ||
2016 | /** | |
2017 | * gsm_control_retransmit - retransmit a control frame | |
724ac070 | 2018 | * @t: timer contained in our gsm object |
e1eaea46 AC |
2019 | * |
2020 | * Called off the T2 timer expiry in order to retransmit control frames | |
2021 | * that have been lost in the system somewhere. The control_lock protects | |
2022 | * us from colliding with another sender or a receive completion event. | |
2023 | * In that situation the timer may still occur in a small window but | |
2024 | * gsm->pending_cmd will be NULL and we just let the timer expire. | |
2025 | */ | |
2026 | ||
e99e88a9 | 2027 | static void gsm_control_retransmit(struct timer_list *t) |
e1eaea46 | 2028 | { |
e99e88a9 | 2029 | struct gsm_mux *gsm = from_timer(gsm, t, t2_timer); |
e1eaea46 AC |
2030 | struct gsm_control *ctrl; |
2031 | unsigned long flags; | |
2032 | spin_lock_irqsave(&gsm->control_lock, flags); | |
2033 | ctrl = gsm->pending_cmd; | |
2034 | if (ctrl) { | |
4fae831b | 2035 | if (gsm->cretries == 0 || !gsm->dlci[0] || gsm->dlci[0]->dead) { |
e1eaea46 AC |
2036 | gsm->pending_cmd = NULL; |
2037 | ctrl->error = -ETIMEDOUT; | |
2038 | ctrl->done = 1; | |
2039 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
2040 | wake_up(&gsm->event); | |
2041 | return; | |
2042 | } | |
d0bcdffc | 2043 | gsm->cretries--; |
e1eaea46 AC |
2044 | gsm_control_transmit(gsm, ctrl); |
2045 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); | |
2046 | } | |
2047 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
2048 | } | |
2049 | ||
2050 | /** | |
2051 | * gsm_control_send - send a control frame on DLCI 0 | |
2052 | * @gsm: the GSM channel | |
2053 | * @command: command to send including CR bit | |
2054 | * @data: bytes of data (must be kmalloced) | |
724ac070 | 2055 | * @clen: length of the block to send |
e1eaea46 AC |
2056 | * |
2057 | * Queue and dispatch a control command. Only one command can be | |
2058 | * active at a time. In theory more can be outstanding but the matching | |
2059 | * gets really complicated so for now stick to one outstanding. | |
2060 | */ | |
2061 | ||
2062 | static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, | |
2063 | unsigned int command, u8 *data, int clen) | |
2064 | { | |
2065 | struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), | |
7b7dfe48 | 2066 | GFP_ATOMIC); |
e1eaea46 AC |
2067 | unsigned long flags; |
2068 | if (ctrl == NULL) | |
2069 | return NULL; | |
2070 | retry: | |
2071 | wait_event(gsm->event, gsm->pending_cmd == NULL); | |
2072 | spin_lock_irqsave(&gsm->control_lock, flags); | |
2073 | if (gsm->pending_cmd != NULL) { | |
2074 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
2075 | goto retry; | |
2076 | } | |
2077 | ctrl->cmd = command; | |
2078 | ctrl->data = data; | |
2079 | ctrl->len = clen; | |
2080 | gsm->pending_cmd = ctrl; | |
e9ec2254 TL |
2081 | |
2082 | /* If DLCI0 is in ADM mode skip retries, it won't respond */ | |
2083 | if (gsm->dlci[0]->mode == DLCI_MODE_ADM) | |
d0bcdffc | 2084 | gsm->cretries = 0; |
e9ec2254 TL |
2085 | else |
2086 | gsm->cretries = gsm->n2; | |
2087 | ||
e1eaea46 AC |
2088 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); |
2089 | gsm_control_transmit(gsm, ctrl); | |
2090 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
2091 | return ctrl; | |
2092 | } | |
2093 | ||
2094 | /** | |
2095 | * gsm_control_wait - wait for a control to finish | |
2096 | * @gsm: GSM mux | |
2097 | * @control: control we are waiting on | |
2098 | * | |
2099 | * Waits for the control to complete or time out. Frees any used | |
2100 | * resources and returns 0 for success, or an error if the remote | |
2101 | * rejected or ignored the request. | |
2102 | */ | |
2103 | ||
2104 | static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) | |
2105 | { | |
2106 | int err; | |
2107 | wait_event(gsm->event, control->done == 1); | |
2108 | err = control->error; | |
2109 | kfree(control); | |
2110 | return err; | |
2111 | } | |
2112 | ||
2113 | ||
2114 | /* | |
2115 | * DLCI level handling: Needs krefs | |
2116 | */ | |
2117 | ||
2118 | /* | |
2119 | * State transitions and timers | |
2120 | */ | |
2121 | ||
2122 | /** | |
2123 | * gsm_dlci_close - a DLCI has closed | |
2124 | * @dlci: DLCI that closed | |
2125 | * | |
2126 | * Perform processing when moving a DLCI into closed state. If there | |
2127 | * is an attached tty this is hung up | |
2128 | */ | |
2129 | ||
2130 | static void gsm_dlci_close(struct gsm_dlci *dlci) | |
2131 | { | |
2132 | del_timer(&dlci->t1); | |
c07da737 | 2133 | if (debug & DBG_ERRORS) |
5f9a31d6 | 2134 | pr_debug("DLCI %d goes closed.\n", dlci->addr); |
e1eaea46 | 2135 | dlci->state = DLCI_CLOSED; |
ac77f007 DS |
2136 | /* Prevent us from sending data before the link is up again */ |
2137 | dlci->constipated = true; | |
e1eaea46 | 2138 | if (dlci->addr != 0) { |
aa27a094 | 2139 | tty_port_tty_hangup(&dlci->port, false); |
0af02167 | 2140 | gsm_dlci_clear_queues(dlci->gsm, dlci); |
a2ab75b8 | 2141 | /* Ensure that gsmtty_open() can return. */ |
515be7ba | 2142 | tty_port_set_initialized(&dlci->port, false); |
a2ab75b8 | 2143 | wake_up_interruptible(&dlci->port.open_wait); |
72206cc7 DS |
2144 | } else { |
2145 | del_timer(&dlci->gsm->ka_timer); | |
5677fcf3 | 2146 | dlci->gsm->dead = true; |
72206cc7 | 2147 | } |
e1eaea46 AC |
2148 | /* A DLCI 0 close is a MUX termination so we need to kick that |
2149 | back to userspace somehow */ | |
0af02167 | 2150 | gsm_dlci_data_kick(dlci); |
684ae4f9 | 2151 | wake_up_all(&dlci->gsm->event); |
e1eaea46 AC |
2152 | } |
2153 | ||
2154 | /** | |
2155 | * gsm_dlci_open - a DLCI has opened | |
2156 | * @dlci: DLCI that opened | |
2157 | * | |
2158 | * Perform processing when moving a DLCI into open state. | |
2159 | */ | |
2160 | ||
2161 | static void gsm_dlci_open(struct gsm_dlci *dlci) | |
2162 | { | |
72206cc7 DS |
2163 | struct gsm_mux *gsm = dlci->gsm; |
2164 | ||
e1eaea46 AC |
2165 | /* Note that SABM UA .. SABM UA first UA lost can mean that we go |
2166 | open -> open */ | |
2167 | del_timer(&dlci->t1); | |
2168 | /* This will let a tty open continue */ | |
2169 | dlci->state = DLCI_OPEN; | |
ac77f007 | 2170 | dlci->constipated = false; |
c07da737 | 2171 | if (debug & DBG_ERRORS) |
5f9a31d6 | 2172 | pr_debug("DLCI %d goes open.\n", dlci->addr); |
48473802 | 2173 | /* Send current modem state */ |
72206cc7 | 2174 | if (dlci->addr) { |
c19ffe00 | 2175 | gsm_modem_update(dlci, 0); |
72206cc7 DS |
2176 | } else { |
2177 | /* Start keep-alive control */ | |
2178 | gsm->ka_num = 0; | |
2179 | gsm->ka_retries = -1; | |
2180 | mod_timer(&gsm->ka_timer, | |
2181 | jiffies + gsm->keep_alive * HZ / 100); | |
2182 | } | |
0af02167 | 2183 | gsm_dlci_data_kick(dlci); |
e1eaea46 AC |
2184 | wake_up(&dlci->gsm->event); |
2185 | } | |
2186 | ||
92f1f0c3 DS |
2187 | /** |
2188 | * gsm_dlci_negotiate - start parameter negotiation | |
2189 | * @dlci: DLCI to open | |
2190 | * | |
2191 | * Starts the parameter negotiation for the new DLCI. This needs to be done | |
2192 | * before the DLCI initialized the channel via SABM. | |
2193 | */ | |
2194 | static int gsm_dlci_negotiate(struct gsm_dlci *dlci) | |
2195 | { | |
2196 | struct gsm_mux *gsm = dlci->gsm; | |
2197 | struct gsm_dlci_param_bits params; | |
2198 | int ret; | |
2199 | ||
2200 | ret = gsm_encode_params(dlci, ¶ms); | |
2201 | if (ret != 0) | |
2202 | return ret; | |
2203 | ||
2204 | /* We cannot asynchronous wait for the command response with | |
2205 | * gsm_command() and gsm_control_wait() at this point. | |
2206 | */ | |
2207 | ret = gsm_control_command(gsm, CMD_PN, (const u8 *)¶ms, | |
2208 | sizeof(params)); | |
2209 | ||
2210 | return ret; | |
2211 | } | |
2212 | ||
e1eaea46 AC |
2213 | /** |
2214 | * gsm_dlci_t1 - T1 timer expiry | |
724ac070 | 2215 | * @t: timer contained in the DLCI that opened |
e1eaea46 AC |
2216 | * |
2217 | * The T1 timer handles retransmits of control frames (essentially of | |
2218 | * SABM and DISC). We resend the command until the retry count runs out | |
2219 | * in which case an opening port goes back to closed and a closing port | |
2220 | * is simply put into closed state (any further frames from the other | |
2221 | * end will get a DM response) | |
ea3d8465 TL |
2222 | * |
2223 | * Some control dlci can stay in ADM mode with other dlci working just | |
2224 | * fine. In that case we can just keep the control dlci open after the | |
2225 | * DLCI_OPENING retries time out. | |
e1eaea46 AC |
2226 | */ |
2227 | ||
e99e88a9 | 2228 | static void gsm_dlci_t1(struct timer_list *t) |
e1eaea46 | 2229 | { |
e99e88a9 | 2230 | struct gsm_dlci *dlci = from_timer(dlci, t, t1); |
e1eaea46 AC |
2231 | struct gsm_mux *gsm = dlci->gsm; |
2232 | ||
2233 | switch (dlci->state) { | |
92f1f0c3 DS |
2234 | case DLCI_CONFIGURE: |
2235 | if (dlci->retries && gsm_dlci_negotiate(dlci) == 0) { | |
2236 | dlci->retries--; | |
2237 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
2238 | } else { | |
a1ce6da0 | 2239 | gsm->open_error++; |
92f1f0c3 DS |
2240 | gsm_dlci_begin_close(dlci); /* prevent half open link */ |
2241 | } | |
2242 | break; | |
e1eaea46 | 2243 | case DLCI_OPENING: |
e1eaea46 | 2244 | if (dlci->retries) { |
f30e10ca | 2245 | dlci->retries--; |
e1eaea46 AC |
2246 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); |
2247 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
ea3d8465 | 2248 | } else if (!dlci->addr && gsm->control == (DM | PF)) { |
c07da737 | 2249 | if (debug & DBG_ERRORS) |
ea3d8465 TL |
2250 | pr_info("DLCI %d opening in ADM mode.\n", |
2251 | dlci->addr); | |
e9ec2254 | 2252 | dlci->mode = DLCI_MODE_ADM; |
ea3d8465 TL |
2253 | gsm_dlci_open(dlci); |
2254 | } else { | |
a1ce6da0 | 2255 | gsm->open_error++; |
e3b7468f | 2256 | gsm_dlci_begin_close(dlci); /* prevent half open link */ |
ea3d8465 TL |
2257 | } |
2258 | ||
e1eaea46 AC |
2259 | break; |
2260 | case DLCI_CLOSING: | |
e1eaea46 | 2261 | if (dlci->retries) { |
f30e10ca | 2262 | dlci->retries--; |
e1eaea46 AC |
2263 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); |
2264 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
2265 | } else | |
2266 | gsm_dlci_close(dlci); | |
2267 | break; | |
72ae8cc1 JS |
2268 | default: |
2269 | pr_debug("%s: unhandled state: %d\n", __func__, dlci->state); | |
2270 | break; | |
e1eaea46 AC |
2271 | } |
2272 | } | |
2273 | ||
2274 | /** | |
2275 | * gsm_dlci_begin_open - start channel open procedure | |
2276 | * @dlci: DLCI to open | |
2277 | * | |
2278 | * Commence opening a DLCI from the Linux side. We issue SABM messages | |
ea3d8465 TL |
2279 | * to the modem which should then reply with a UA or ADM, at which point |
2280 | * we will move into open state. Opening is done asynchronously with retry | |
e1eaea46 | 2281 | * running off timers and the responses. |
92f1f0c3 | 2282 | * Parameter negotiation is performed before SABM if required. |
e1eaea46 AC |
2283 | */ |
2284 | ||
2285 | static void gsm_dlci_begin_open(struct gsm_dlci *dlci) | |
2286 | { | |
92f1f0c3 DS |
2287 | struct gsm_mux *gsm = dlci ? dlci->gsm : NULL; |
2288 | bool need_pn = false; | |
2289 | ||
2290 | if (!gsm) | |
e1eaea46 | 2291 | return; |
92f1f0c3 DS |
2292 | |
2293 | if (dlci->addr != 0) { | |
2294 | if (gsm->adaption != 1 || gsm->adaption != dlci->adaption) | |
2295 | need_pn = true; | |
2296 | if (dlci->prio != (roundup(dlci->addr + 1, 8) - 1)) | |
2297 | need_pn = true; | |
2298 | if (gsm->ftype != dlci->ftype) | |
2299 | need_pn = true; | |
2300 | } | |
2301 | ||
2302 | switch (dlci->state) { | |
2303 | case DLCI_CLOSED: | |
4ca58966 | 2304 | case DLCI_WAITING_CONFIG: |
92f1f0c3 DS |
2305 | case DLCI_CLOSING: |
2306 | dlci->retries = gsm->n2; | |
2307 | if (!need_pn) { | |
2308 | dlci->state = DLCI_OPENING; | |
2309 | gsm_command(gsm, dlci->addr, SABM|PF); | |
2310 | } else { | |
2311 | /* Configure DLCI before setup */ | |
2312 | dlci->state = DLCI_CONFIGURE; | |
2313 | if (gsm_dlci_negotiate(dlci) != 0) { | |
2314 | gsm_dlci_close(dlci); | |
2315 | return; | |
2316 | } | |
2317 | } | |
2318 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
2319 | break; | |
2320 | default: | |
2321 | break; | |
2322 | } | |
e1eaea46 AC |
2323 | } |
2324 | ||
ac77f007 DS |
2325 | /** |
2326 | * gsm_dlci_set_opening - change state to opening | |
2327 | * @dlci: DLCI to open | |
2328 | * | |
2329 | * Change internal state to wait for DLCI open from initiator side. | |
2330 | * We set off timers and responses upon reception of an SABM. | |
2331 | */ | |
2332 | static void gsm_dlci_set_opening(struct gsm_dlci *dlci) | |
2333 | { | |
2334 | switch (dlci->state) { | |
2335 | case DLCI_CLOSED: | |
4ca58966 | 2336 | case DLCI_WAITING_CONFIG: |
ac77f007 DS |
2337 | case DLCI_CLOSING: |
2338 | dlci->state = DLCI_OPENING; | |
2339 | break; | |
2340 | default: | |
2341 | break; | |
2342 | } | |
2343 | } | |
2344 | ||
4ca58966 DS |
2345 | /** |
2346 | * gsm_dlci_set_wait_config - wait for channel configuration | |
2347 | * @dlci: DLCI to configure | |
2348 | * | |
2349 | * Wait for a DLCI configuration from the application. | |
2350 | */ | |
2351 | static void gsm_dlci_set_wait_config(struct gsm_dlci *dlci) | |
2352 | { | |
2353 | switch (dlci->state) { | |
2354 | case DLCI_CLOSED: | |
2355 | case DLCI_CLOSING: | |
2356 | dlci->state = DLCI_WAITING_CONFIG; | |
2357 | break; | |
2358 | default: | |
2359 | break; | |
2360 | } | |
2361 | } | |
2362 | ||
e1eaea46 AC |
2363 | /** |
2364 | * gsm_dlci_begin_close - start channel open procedure | |
2365 | * @dlci: DLCI to open | |
2366 | * | |
2367 | * Commence closing a DLCI from the Linux side. We issue DISC messages | |
2368 | * to the modem which should then reply with a UA, at which point we | |
2369 | * will move into closed state. Closing is done asynchronously with retry | |
2370 | * off timers. We may also receive a DM reply from the other end which | |
2371 | * indicates the channel was already closed. | |
2372 | */ | |
2373 | ||
2374 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci) | |
2375 | { | |
2376 | struct gsm_mux *gsm = dlci->gsm; | |
2377 | if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING) | |
2378 | return; | |
2379 | dlci->retries = gsm->n2; | |
2380 | dlci->state = DLCI_CLOSING; | |
2381 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); | |
2382 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
684ae4f9 | 2383 | wake_up_interruptible(&gsm->event); |
e1eaea46 AC |
2384 | } |
2385 | ||
2386 | /** | |
2387 | * gsm_dlci_data - data arrived | |
2388 | * @dlci: channel | |
2389 | * @data: block of bytes received | |
724ac070 | 2390 | * @clen: length of received block |
e1eaea46 AC |
2391 | * |
2392 | * A UI or UIH frame has arrived which contains data for a channel | |
2393 | * other than the control channel. If the relevant virtual tty is | |
2394 | * open we shovel the bits down it, if not we drop them. | |
2395 | */ | |
2396 | ||
4feb7a4a | 2397 | static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) |
e1eaea46 AC |
2398 | { |
2399 | /* krefs .. */ | |
2400 | struct tty_port *port = &dlci->port; | |
2e124b4a | 2401 | struct tty_struct *tty; |
e1eaea46 | 2402 | unsigned int modem = 0; |
669609ce | 2403 | int len; |
e1eaea46 | 2404 | |
c07da737 | 2405 | if (debug & DBG_TTY) |
669609ce | 2406 | pr_debug("%d bytes for tty\n", clen); |
2e124b4a JS |
2407 | switch (dlci->adaption) { |
2408 | /* Unsupported types */ | |
3e913eeb | 2409 | case 4: /* Packetised interruptible data */ |
2e124b4a | 2410 | break; |
3e913eeb | 2411 | case 3: /* Packetised uininterruptible voice/data */ |
2e124b4a | 2412 | break; |
3e913eeb | 2413 | case 2: /* Asynchronous serial with line state in each frame */ |
669609ce DS |
2414 | len = gsm_read_ea_val(&modem, data, clen); |
2415 | if (len < 1) | |
2416 | return; | |
2e124b4a JS |
2417 | tty = tty_port_tty_get(port); |
2418 | if (tty) { | |
669609ce | 2419 | gsm_process_modem(tty, dlci, modem, len); |
1adf6fee | 2420 | tty_wakeup(tty); |
2e124b4a | 2421 | tty_kref_put(tty); |
e1eaea46 | 2422 | } |
669609ce DS |
2423 | /* Skip processed modem data */ |
2424 | data += len; | |
2425 | clen -= len; | |
df561f66 | 2426 | fallthrough; |
3e913eeb | 2427 | case 1: /* Line state will go via DLCI 0 controls only */ |
2e124b4a | 2428 | default: |
669609ce | 2429 | tty_insert_flip_string(port, data, clen); |
2e124b4a | 2430 | tty_flip_buffer_push(port); |
e1eaea46 AC |
2431 | } |
2432 | } | |
2433 | ||
2434 | /** | |
542a121a | 2435 | * gsm_dlci_command - data arrived on control channel |
e1eaea46 AC |
2436 | * @dlci: channel |
2437 | * @data: block of bytes received | |
2438 | * @len: length of received block | |
2439 | * | |
2440 | * A UI or UIH frame has arrived which contains data for DLCI 0 the | |
2441 | * control channel. This should contain a command EA followed by | |
2442 | * control data bytes. The command EA contains a command/response bit | |
2443 | * and we divide up the work accordingly. | |
2444 | */ | |
2445 | ||
4feb7a4a | 2446 | static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len) |
e1eaea46 AC |
2447 | { |
2448 | /* See what command is involved */ | |
2449 | unsigned int command = 0; | |
669609ce DS |
2450 | unsigned int clen = 0; |
2451 | unsigned int dlen; | |
2452 | ||
2453 | /* read the command */ | |
2454 | dlen = gsm_read_ea_val(&command, data, len); | |
2455 | len -= dlen; | |
2456 | data += dlen; | |
2457 | ||
2458 | /* read any control data */ | |
2459 | dlen = gsm_read_ea_val(&clen, data, len); | |
2460 | len -= dlen; | |
2461 | data += dlen; | |
2462 | ||
2463 | /* Malformed command? */ | |
b99f51ba DS |
2464 | if (clen > len) { |
2465 | dlci->gsm->malformed++; | |
669609ce | 2466 | return; |
b99f51ba | 2467 | } |
669609ce DS |
2468 | |
2469 | if (command & 1) | |
2470 | gsm_control_message(dlci->gsm, command, data, clen); | |
2471 | else | |
2472 | gsm_control_response(dlci->gsm, command, data, clen); | |
e1eaea46 AC |
2473 | } |
2474 | ||
c568f708 | 2475 | /** |
15743ae5 FP |
2476 | * gsm_kick_timer - transmit if possible |
2477 | * @t: timer contained in our gsm object | |
c568f708 DS |
2478 | * |
2479 | * Transmit data from DLCIs if the queue is empty. We can't rely on | |
2480 | * a tty wakeup except when we filled the pipe so we need to fire off | |
2481 | * new data ourselves in other cases. | |
2482 | */ | |
15743ae5 | 2483 | static void gsm_kick_timer(struct timer_list *t) |
c568f708 | 2484 | { |
15743ae5 | 2485 | struct gsm_mux *gsm = from_timer(gsm, t, kick_timer); |
acdab4cb | 2486 | unsigned long flags; |
c568f708 DS |
2487 | int sent = 0; |
2488 | ||
acdab4cb | 2489 | spin_lock_irqsave(&gsm->tx_lock, flags); |
c568f708 DS |
2490 | /* If we have nothing running then we need to fire up */ |
2491 | if (gsm->tx_bytes < TX_THRESH_LO) | |
2492 | sent = gsm_dlci_data_sweep(gsm); | |
acdab4cb | 2493 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
c568f708 | 2494 | |
c07da737 | 2495 | if (sent && debug & DBG_DATA) |
c568f708 DS |
2496 | pr_info("%s TX queue stalled\n", __func__); |
2497 | } | |
2498 | ||
4ca58966 DS |
2499 | /** |
2500 | * gsm_dlci_copy_config_values - copy DLCI configuration | |
2501 | * @dlci: source DLCI | |
2502 | * @dc: configuration structure to fill | |
2503 | */ | |
2504 | static void gsm_dlci_copy_config_values(struct gsm_dlci *dlci, struct gsm_dlci_config *dc) | |
2505 | { | |
2506 | memset(dc, 0, sizeof(*dc)); | |
2507 | dc->channel = (u32)dlci->addr; | |
2508 | dc->adaption = (u32)dlci->adaption; | |
2509 | dc->mtu = (u32)dlci->mtu; | |
2510 | dc->priority = (u32)dlci->prio; | |
2511 | if (dlci->ftype == UIH) | |
2512 | dc->i = 1; | |
2513 | else | |
2514 | dc->i = 2; | |
2515 | dc->k = (u32)dlci->k; | |
2516 | } | |
2517 | ||
2518 | /** | |
2519 | * gsm_dlci_config - configure DLCI from configuration | |
2520 | * @dlci: DLCI to configure | |
2521 | * @dc: DLCI configuration | |
2522 | * @open: open DLCI after configuration? | |
2523 | */ | |
2524 | static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, int open) | |
2525 | { | |
2526 | struct gsm_mux *gsm; | |
2527 | bool need_restart = false; | |
2528 | bool need_open = false; | |
2529 | unsigned int i; | |
2530 | ||
2531 | /* | |
2532 | * Check that userspace doesn't put stuff in here to prevent breakages | |
2533 | * in the future. | |
2534 | */ | |
2535 | for (i = 0; i < ARRAY_SIZE(dc->reserved); i++) | |
2536 | if (dc->reserved[i]) | |
2537 | return -EINVAL; | |
2538 | ||
2539 | if (!dlci) | |
2540 | return -EINVAL; | |
2541 | gsm = dlci->gsm; | |
2542 | ||
2543 | /* Stuff we don't support yet - I frame transport */ | |
2544 | if (dc->adaption != 1 && dc->adaption != 2) | |
2545 | return -EOPNOTSUPP; | |
2546 | if (dc->mtu > MAX_MTU || dc->mtu < MIN_MTU || dc->mtu > gsm->mru) | |
2547 | return -EINVAL; | |
2548 | if (dc->priority >= 64) | |
2549 | return -EINVAL; | |
2550 | if (dc->i == 0 || dc->i > 2) /* UIH and UI only */ | |
2551 | return -EINVAL; | |
2552 | if (dc->k > 7) | |
2553 | return -EINVAL; | |
a031c77d DS |
2554 | if (dc->flags & ~GSM_FL_RESTART) /* allow future extensions */ |
2555 | return -EINVAL; | |
4ca58966 DS |
2556 | |
2557 | /* | |
2558 | * See what is needed for reconfiguration | |
2559 | */ | |
2560 | /* Framing fields */ | |
2561 | if (dc->adaption != dlci->adaption) | |
2562 | need_restart = true; | |
2563 | if (dc->mtu != dlci->mtu) | |
2564 | need_restart = true; | |
2565 | if (dc->i != dlci->ftype) | |
2566 | need_restart = true; | |
2567 | /* Requires care */ | |
2568 | if (dc->priority != dlci->prio) | |
2569 | need_restart = true; | |
a031c77d DS |
2570 | if (dc->flags & GSM_FL_RESTART) |
2571 | need_restart = true; | |
4ca58966 DS |
2572 | |
2573 | if ((open && gsm->wait_config) || need_restart) | |
2574 | need_open = true; | |
2575 | if (dlci->state == DLCI_WAITING_CONFIG) { | |
2576 | need_restart = false; | |
2577 | need_open = true; | |
2578 | } | |
2579 | ||
2580 | /* | |
2581 | * Close down what is needed, restart and initiate the new | |
2582 | * configuration. | |
2583 | */ | |
2584 | if (need_restart) { | |
2585 | gsm_dlci_begin_close(dlci); | |
2586 | wait_event_interruptible(gsm->event, dlci->state == DLCI_CLOSED); | |
2587 | if (signal_pending(current)) | |
2588 | return -EINTR; | |
2589 | } | |
2590 | /* | |
2591 | * Setup the new configuration values | |
2592 | */ | |
2593 | dlci->adaption = (int)dc->adaption; | |
2594 | ||
2595 | if (dc->mtu) | |
2596 | dlci->mtu = (unsigned int)dc->mtu; | |
2597 | else | |
2598 | dlci->mtu = gsm->mtu; | |
2599 | ||
2600 | if (dc->priority) | |
2601 | dlci->prio = (u8)dc->priority; | |
2602 | else | |
2603 | dlci->prio = roundup(dlci->addr + 1, 8) - 1; | |
2604 | ||
2605 | if (dc->i == 1) | |
2606 | dlci->ftype = UIH; | |
2607 | else if (dc->i == 2) | |
2608 | dlci->ftype = UI; | |
2609 | ||
2610 | if (dc->k) | |
2611 | dlci->k = (u8)dc->k; | |
2612 | else | |
2613 | dlci->k = gsm->k; | |
2614 | ||
2615 | if (need_open) { | |
2616 | if (gsm->initiator) | |
2617 | gsm_dlci_begin_open(dlci); | |
2618 | else | |
2619 | gsm_dlci_set_opening(dlci); | |
2620 | } | |
2621 | ||
2622 | return 0; | |
2623 | } | |
2624 | ||
e1eaea46 AC |
2625 | /* |
2626 | * Allocate/Free DLCI channels | |
2627 | */ | |
2628 | ||
2629 | /** | |
2630 | * gsm_dlci_alloc - allocate a DLCI | |
2631 | * @gsm: GSM mux | |
2632 | * @addr: address of the DLCI | |
2633 | * | |
2634 | * Allocate and install a new DLCI object into the GSM mux. | |
2635 | * | |
2636 | * FIXME: review locking races | |
2637 | */ | |
2638 | ||
2639 | static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) | |
2640 | { | |
2641 | struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC); | |
2642 | if (dlci == NULL) | |
2643 | return NULL; | |
2644 | spin_lock_init(&dlci->lock); | |
bcd5abe2 | 2645 | mutex_init(&dlci->mutex); |
9361ebfb | 2646 | if (kfifo_alloc(&dlci->fifo, TX_SIZE, GFP_KERNEL) < 0) { |
e1eaea46 AC |
2647 | kfree(dlci); |
2648 | return NULL; | |
2649 | } | |
2650 | ||
2651 | skb_queue_head_init(&dlci->skb_list); | |
e99e88a9 | 2652 | timer_setup(&dlci->t1, gsm_dlci_t1, 0); |
e1eaea46 AC |
2653 | tty_port_init(&dlci->port); |
2654 | dlci->port.ops = &gsm_port_ops; | |
2655 | dlci->gsm = gsm; | |
2656 | dlci->addr = addr; | |
2657 | dlci->adaption = gsm->adaption; | |
2ec7a802 DS |
2658 | dlci->mtu = gsm->mtu; |
2659 | if (addr == 0) | |
2660 | dlci->prio = 0; | |
2661 | else | |
2662 | dlci->prio = roundup(addr + 1, 8) - 1; | |
2663 | dlci->ftype = gsm->ftype; | |
2664 | dlci->k = gsm->k; | |
e1eaea46 | 2665 | dlci->state = DLCI_CLOSED; |
ac77f007 | 2666 | if (addr) { |
e1eaea46 | 2667 | dlci->data = gsm_dlci_data; |
ac77f007 DS |
2668 | /* Prevent us from sending data before the link is up */ |
2669 | dlci->constipated = true; | |
2670 | } else { | |
e1eaea46 | 2671 | dlci->data = gsm_dlci_command; |
ac77f007 | 2672 | } |
e1eaea46 AC |
2673 | gsm->dlci[addr] = dlci; |
2674 | return dlci; | |
2675 | } | |
2676 | ||
2677 | /** | |
6ab8fba7 | 2678 | * gsm_dlci_free - free DLCI |
724ac070 | 2679 | * @port: tty port for DLCI to free |
6ab8fba7 RG |
2680 | * |
2681 | * Free up a DLCI. | |
2682 | * | |
2683 | * Can sleep. | |
2684 | */ | |
9a8e62bc | 2685 | static void gsm_dlci_free(struct tty_port *port) |
6ab8fba7 | 2686 | { |
9a8e62bc | 2687 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); |
6ab8fba7 | 2688 | |
292a089d | 2689 | timer_shutdown_sync(&dlci->t1); |
6ab8fba7 | 2690 | dlci->gsm->dlci[dlci->addr] = NULL; |
036bca1f | 2691 | kfifo_free(&dlci->fifo); |
6ab8fba7 | 2692 | while ((dlci->skb = skb_dequeue(&dlci->skb_list))) |
329e5678 | 2693 | dev_kfree_skb(dlci->skb); |
6ab8fba7 RG |
2694 | kfree(dlci); |
2695 | } | |
2696 | ||
2697 | static inline void dlci_get(struct gsm_dlci *dlci) | |
2698 | { | |
9a8e62bc | 2699 | tty_port_get(&dlci->port); |
6ab8fba7 RG |
2700 | } |
2701 | ||
2702 | static inline void dlci_put(struct gsm_dlci *dlci) | |
2703 | { | |
9a8e62bc | 2704 | tty_port_put(&dlci->port); |
6ab8fba7 RG |
2705 | } |
2706 | ||
4d9b1090 DB |
2707 | static void gsm_destroy_network(struct gsm_dlci *dlci); |
2708 | ||
6ab8fba7 RG |
2709 | /** |
2710 | * gsm_dlci_release - release DLCI | |
e1eaea46 AC |
2711 | * @dlci: DLCI to destroy |
2712 | * | |
6ab8fba7 RG |
2713 | * Release a DLCI. Actual free is deferred until either |
2714 | * mux is closed or tty is closed - whichever is last. | |
e1eaea46 AC |
2715 | * |
2716 | * Can sleep. | |
2717 | */ | |
6ab8fba7 | 2718 | static void gsm_dlci_release(struct gsm_dlci *dlci) |
e1eaea46 AC |
2719 | { |
2720 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); | |
2721 | if (tty) { | |
4d9b1090 DB |
2722 | mutex_lock(&dlci->mutex); |
2723 | gsm_destroy_network(dlci); | |
2724 | mutex_unlock(&dlci->mutex); | |
2725 | ||
96b169f0 | 2726 | /* We cannot use tty_hangup() because in tty_kref_put() the tty |
2727 | * driver assumes that the hangup queue is free and reuses it to | |
2728 | * queue release_one_tty() -> NULL pointer panic in | |
2729 | * process_one_work(). | |
2730 | */ | |
2731 | tty_vhangup(tty); | |
be706572 | 2732 | |
4d9b1090 | 2733 | tty_port_tty_set(&dlci->port, NULL); |
e1eaea46 AC |
2734 | tty_kref_put(tty); |
2735 | } | |
4d9b1090 | 2736 | dlci->state = DLCI_CLOSED; |
6ab8fba7 | 2737 | dlci_put(dlci); |
e1eaea46 AC |
2738 | } |
2739 | ||
e1eaea46 AC |
2740 | /* |
2741 | * LAPBish link layer logic | |
2742 | */ | |
2743 | ||
2744 | /** | |
2745 | * gsm_queue - a GSM frame is ready to process | |
2746 | * @gsm: pointer to our gsm mux | |
2747 | * | |
2748 | * At this point in time a frame has arrived and been demangled from | |
2749 | * the line encoding. All the differences between the encodings have | |
2750 | * been handled below us and the frame is unpacked into the structures. | |
2751 | * The fcs holds the header FCS but any data FCS must be added here. | |
2752 | */ | |
2753 | ||
2754 | static void gsm_queue(struct gsm_mux *gsm) | |
2755 | { | |
2756 | struct gsm_dlci *dlci; | |
2757 | u8 cr; | |
2758 | int address; | |
e1eaea46 | 2759 | |
e1eaea46 AC |
2760 | if (gsm->fcs != GOOD_FCS) { |
2761 | gsm->bad_fcs++; | |
c07da737 | 2762 | if (debug & DBG_DATA) |
5f9a31d6 | 2763 | pr_debug("BAD FCS %02x\n", gsm->fcs); |
e1eaea46 AC |
2764 | return; |
2765 | } | |
2766 | address = gsm->address >> 1; | |
2767 | if (address >= NUM_DLCI) | |
2768 | goto invalid; | |
2769 | ||
2770 | cr = gsm->address & 1; /* C/R bit */ | |
57435c42 | 2771 | cr ^= gsm->initiator ? 0 : 1; /* Flip so 1 always means command */ |
e1eaea46 AC |
2772 | |
2773 | gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); | |
2774 | ||
e1eaea46 AC |
2775 | dlci = gsm->dlci[address]; |
2776 | ||
2777 | switch (gsm->control) { | |
2778 | case SABM|PF: | |
a1ce6da0 DS |
2779 | if (cr == 1) { |
2780 | gsm->open_error++; | |
e1eaea46 | 2781 | goto invalid; |
a1ce6da0 | 2782 | } |
e1eaea46 AC |
2783 | if (dlci == NULL) |
2784 | dlci = gsm_dlci_alloc(gsm, address); | |
a1ce6da0 DS |
2785 | if (dlci == NULL) { |
2786 | gsm->open_error++; | |
e1eaea46 | 2787 | return; |
a1ce6da0 | 2788 | } |
e1eaea46 | 2789 | if (dlci->dead) |
cc0f4212 | 2790 | gsm_response(gsm, address, DM|PF); |
e1eaea46 | 2791 | else { |
cc0f4212 | 2792 | gsm_response(gsm, address, UA|PF); |
e1eaea46 AC |
2793 | gsm_dlci_open(dlci); |
2794 | } | |
2795 | break; | |
2796 | case DISC|PF: | |
cd936621 | 2797 | if (cr == 1) |
e1eaea46 AC |
2798 | goto invalid; |
2799 | if (dlci == NULL || dlci->state == DLCI_CLOSED) { | |
cc0f4212 | 2800 | gsm_response(gsm, address, DM|PF); |
e1eaea46 AC |
2801 | return; |
2802 | } | |
2803 | /* Real close complete */ | |
a8c5b825 DS |
2804 | gsm_response(gsm, address, UA|PF); |
2805 | gsm_dlci_close(dlci); | |
e1eaea46 | 2806 | break; |
e1eaea46 AC |
2807 | case UA|PF: |
2808 | if (cr == 0 || dlci == NULL) | |
2809 | break; | |
2810 | switch (dlci->state) { | |
2811 | case DLCI_CLOSING: | |
2812 | gsm_dlci_close(dlci); | |
2813 | break; | |
2814 | case DLCI_OPENING: | |
2815 | gsm_dlci_open(dlci); | |
2816 | break; | |
72ae8cc1 JS |
2817 | default: |
2818 | pr_debug("%s: unhandled state: %d\n", __func__, | |
2819 | dlci->state); | |
2820 | break; | |
e1eaea46 AC |
2821 | } |
2822 | break; | |
2823 | case DM: /* DM can be valid unsolicited */ | |
2824 | case DM|PF: | |
2825 | if (cr) | |
2826 | goto invalid; | |
2827 | if (dlci == NULL) | |
2828 | return; | |
2829 | gsm_dlci_close(dlci); | |
2830 | break; | |
2831 | case UI: | |
2832 | case UI|PF: | |
2833 | case UIH: | |
2834 | case UIH|PF: | |
e1eaea46 | 2835 | if (dlci == NULL || dlci->state != DLCI_OPEN) { |
18a948c7 | 2836 | gsm_response(gsm, address, DM|PF); |
e1eaea46 AC |
2837 | return; |
2838 | } | |
2839 | dlci->data(dlci, gsm->buf, gsm->len); | |
2840 | break; | |
2841 | default: | |
2842 | goto invalid; | |
2843 | } | |
2844 | return; | |
2845 | invalid: | |
2846 | gsm->malformed++; | |
2847 | return; | |
2848 | } | |
2849 | ||
2850 | ||
2851 | /** | |
2852 | * gsm0_receive - perform processing for non-transparency | |
2853 | * @gsm: gsm data for this ldisc instance | |
2854 | * @c: character | |
2855 | * | |
2856 | * Receive bytes in gsm mode 0 | |
2857 | */ | |
2858 | ||
2859 | static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) | |
2860 | { | |
c2f2f000 AC |
2861 | unsigned int len; |
2862 | ||
e1eaea46 AC |
2863 | switch (gsm->state) { |
2864 | case GSM_SEARCH: /* SOF marker */ | |
2865 | if (c == GSM0_SOF) { | |
2866 | gsm->state = GSM_ADDRESS; | |
2867 | gsm->address = 0; | |
2868 | gsm->len = 0; | |
2869 | gsm->fcs = INIT_FCS; | |
2870 | } | |
c2f2f000 AC |
2871 | break; |
2872 | case GSM_ADDRESS: /* Address EA */ | |
e1eaea46 AC |
2873 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
2874 | if (gsm_read_ea(&gsm->address, c)) | |
2875 | gsm->state = GSM_CONTROL; | |
2876 | break; | |
2877 | case GSM_CONTROL: /* Control Byte */ | |
2878 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2879 | gsm->control = c; | |
c2f2f000 | 2880 | gsm->state = GSM_LEN0; |
e1eaea46 | 2881 | break; |
c2f2f000 | 2882 | case GSM_LEN0: /* Length EA */ |
e1eaea46 AC |
2883 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
2884 | if (gsm_read_ea(&gsm->len, c)) { | |
2885 | if (gsm->len > gsm->mru) { | |
2886 | gsm->bad_size++; | |
2887 | gsm->state = GSM_SEARCH; | |
2888 | break; | |
2889 | } | |
2890 | gsm->count = 0; | |
c2f2f000 AC |
2891 | if (!gsm->len) |
2892 | gsm->state = GSM_FCS; | |
2893 | else | |
2894 | gsm->state = GSM_DATA; | |
2895 | break; | |
e1eaea46 | 2896 | } |
c2f2f000 AC |
2897 | gsm->state = GSM_LEN1; |
2898 | break; | |
2899 | case GSM_LEN1: | |
2900 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2901 | len = c; | |
2902 | gsm->len |= len << 7; | |
2903 | if (gsm->len > gsm->mru) { | |
2904 | gsm->bad_size++; | |
2905 | gsm->state = GSM_SEARCH; | |
2906 | break; | |
e1eaea46 | 2907 | } |
c2f2f000 AC |
2908 | gsm->count = 0; |
2909 | if (!gsm->len) | |
2910 | gsm->state = GSM_FCS; | |
2911 | else | |
2912 | gsm->state = GSM_DATA; | |
e1eaea46 AC |
2913 | break; |
2914 | case GSM_DATA: /* Data */ | |
2915 | gsm->buf[gsm->count++] = c; | |
7a0e4b17 DS |
2916 | if (gsm->count == gsm->len) { |
2917 | /* Calculate final FCS for UI frames over all data */ | |
2918 | if ((gsm->control & ~PF) != UIH) { | |
2919 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, | |
2920 | gsm->count); | |
2921 | } | |
e1eaea46 | 2922 | gsm->state = GSM_FCS; |
7a0e4b17 | 2923 | } |
e1eaea46 AC |
2924 | break; |
2925 | case GSM_FCS: /* FCS follows the packet */ | |
7a0e4b17 | 2926 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
c2f2f000 AC |
2927 | gsm->state = GSM_SSOF; |
2928 | break; | |
2929 | case GSM_SSOF: | |
7a0e4b17 DS |
2930 | gsm->state = GSM_SEARCH; |
2931 | if (c == GSM0_SOF) | |
2932 | gsm_queue(gsm); | |
2933 | else | |
2934 | gsm->bad_size++; | |
e1eaea46 | 2935 | break; |
329aa6e6 JS |
2936 | default: |
2937 | pr_debug("%s: unhandled state: %d\n", __func__, gsm->state); | |
2938 | break; | |
e1eaea46 AC |
2939 | } |
2940 | } | |
2941 | ||
2942 | /** | |
c2f2f000 | 2943 | * gsm1_receive - perform processing for non-transparency |
e1eaea46 AC |
2944 | * @gsm: gsm data for this ldisc instance |
2945 | * @c: character | |
2946 | * | |
2947 | * Receive bytes in mode 1 (Advanced option) | |
2948 | */ | |
2949 | ||
2950 | static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) | |
2951 | { | |
f4f7d632 DS |
2952 | /* handle XON/XOFF */ |
2953 | if ((c & ISO_IEC_646_MASK) == XON) { | |
2954 | gsm->constipated = true; | |
2955 | return; | |
2956 | } else if ((c & ISO_IEC_646_MASK) == XOFF) { | |
2957 | gsm->constipated = false; | |
2958 | /* Kick the link in case it is idling */ | |
0af02167 | 2959 | gsmld_write_trigger(gsm); |
f4f7d632 DS |
2960 | return; |
2961 | } | |
e1eaea46 | 2962 | if (c == GSM1_SOF) { |
7a0e4b17 DS |
2963 | /* EOF is only valid in frame if we have got to the data state */ |
2964 | if (gsm->state == GSM_DATA) { | |
2965 | if (gsm->count < 1) { | |
2966 | /* Missing FSC */ | |
2967 | gsm->malformed++; | |
2968 | gsm->state = GSM_START; | |
2969 | return; | |
2970 | } | |
2971 | /* Remove the FCS from data */ | |
e1eaea46 | 2972 | gsm->count--; |
7a0e4b17 DS |
2973 | if ((gsm->control & ~PF) != UIH) { |
2974 | /* Calculate final FCS for UI frames over all | |
2975 | * data but FCS | |
2976 | */ | |
2977 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, | |
2978 | gsm->count); | |
2979 | } | |
2980 | /* Add the FCS itself to test against GOOD_FCS */ | |
e1eaea46 AC |
2981 | gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); |
2982 | gsm->len = gsm->count; | |
2983 | gsm_queue(gsm); | |
2984 | gsm->state = GSM_START; | |
2985 | return; | |
2986 | } | |
2987 | /* Any partial frame was a runt so go back to start */ | |
2988 | if (gsm->state != GSM_START) { | |
a24b4b2f DS |
2989 | if (gsm->state != GSM_SEARCH) |
2990 | gsm->malformed++; | |
e1eaea46 AC |
2991 | gsm->state = GSM_START; |
2992 | } | |
2993 | /* A SOF in GSM_START means we are still reading idling or | |
2994 | framing bytes */ | |
2995 | return; | |
2996 | } | |
2997 | ||
2998 | if (c == GSM1_ESCAPE) { | |
c50704bd | 2999 | gsm->escape = true; |
e1eaea46 AC |
3000 | return; |
3001 | } | |
3002 | ||
3003 | /* Only an unescaped SOF gets us out of GSM search */ | |
3004 | if (gsm->state == GSM_SEARCH) | |
3005 | return; | |
3006 | ||
3007 | if (gsm->escape) { | |
3008 | c ^= GSM1_ESCAPE_BITS; | |
c50704bd | 3009 | gsm->escape = false; |
e1eaea46 AC |
3010 | } |
3011 | switch (gsm->state) { | |
3012 | case GSM_START: /* First byte after SOF */ | |
3013 | gsm->address = 0; | |
3014 | gsm->state = GSM_ADDRESS; | |
3015 | gsm->fcs = INIT_FCS; | |
df561f66 | 3016 | fallthrough; |
e1eaea46 AC |
3017 | case GSM_ADDRESS: /* Address continuation */ |
3018 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
3019 | if (gsm_read_ea(&gsm->address, c)) | |
3020 | gsm->state = GSM_CONTROL; | |
3021 | break; | |
3022 | case GSM_CONTROL: /* Control Byte */ | |
3023 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
3024 | gsm->control = c; | |
3025 | gsm->count = 0; | |
3026 | gsm->state = GSM_DATA; | |
3027 | break; | |
3028 | case GSM_DATA: /* Data */ | |
5f9a31d6 | 3029 | if (gsm->count > gsm->mru) { /* Allow one for the FCS */ |
e1eaea46 AC |
3030 | gsm->state = GSM_OVERRUN; |
3031 | gsm->bad_size++; | |
3032 | } else | |
3033 | gsm->buf[gsm->count++] = c; | |
3034 | break; | |
3035 | case GSM_OVERRUN: /* Over-long - eg a dropped SOF */ | |
3036 | break; | |
329aa6e6 JS |
3037 | default: |
3038 | pr_debug("%s: unhandled state: %d\n", __func__, gsm->state); | |
3039 | break; | |
e1eaea46 AC |
3040 | } |
3041 | } | |
3042 | ||
3043 | /** | |
3044 | * gsm_error - handle tty error | |
3045 | * @gsm: ldisc data | |
e1eaea46 AC |
3046 | * |
3047 | * Handle an error in the receipt of data for a frame. Currently we just | |
3048 | * go back to hunting for a SOF. | |
3049 | * | |
3050 | * FIXME: better diagnostics ? | |
3051 | */ | |
3052 | ||
ea502201 | 3053 | static void gsm_error(struct gsm_mux *gsm) |
e1eaea46 AC |
3054 | { |
3055 | gsm->state = GSM_SEARCH; | |
3056 | gsm->io_error++; | |
3057 | } | |
3058 | ||
3059 | /** | |
3060 | * gsm_cleanup_mux - generic GSM protocol cleanup | |
3061 | * @gsm: our mux | |
aa371e96 | 3062 | * @disc: disconnect link? |
e1eaea46 AC |
3063 | * |
3064 | * Clean up the bits of the mux which are the same for all framing | |
3065 | * protocols. Remove the mux from the mux table, stop all the timers | |
3066 | * and then shut down each device hanging up the channels as we go. | |
3067 | */ | |
3068 | ||
aa371e96 | 3069 | static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) |
e1eaea46 AC |
3070 | { |
3071 | int i; | |
3c4f8333 | 3072 | struct gsm_dlci *dlci; |
329e5678 | 3073 | struct gsm_msg *txq, *ntxq; |
e1eaea46 | 3074 | |
5677fcf3 | 3075 | gsm->dead = true; |
aa371e96 | 3076 | mutex_lock(&gsm->mutex); |
e1eaea46 | 3077 | |
3c4f8333 | 3078 | dlci = gsm->dlci[0]; |
aa371e96 DS |
3079 | if (dlci) { |
3080 | if (disc && dlci->state != DLCI_CLOSED) { | |
3081 | gsm_dlci_begin_close(dlci); | |
3082 | wait_event(gsm->event, dlci->state == DLCI_CLOSED); | |
e1eaea46 | 3083 | } |
aa371e96 | 3084 | dlci->dead = true; |
e1eaea46 | 3085 | } |
e1eaea46 | 3086 | |
aa371e96 | 3087 | /* Finish outstanding timers, making sure they are done */ |
15743ae5 | 3088 | del_timer_sync(&gsm->kick_timer); |
e1eaea46 | 3089 | del_timer_sync(&gsm->t2_timer); |
72206cc7 | 3090 | del_timer_sync(&gsm->ka_timer); |
71e07791 | 3091 | |
0af02167 DS |
3092 | /* Finish writing to ldisc */ |
3093 | flush_work(&gsm->tx_work); | |
3094 | ||
deefc58b | 3095 | /* Free up any link layer users and finally the control channel */ |
01aecd91 DS |
3096 | if (gsm->has_devices) { |
3097 | gsm_unregister_devices(gsm_tty_driver, gsm->num); | |
3098 | gsm->has_devices = false; | |
3099 | } | |
deefc58b | 3100 | for (i = NUM_DLCI - 1; i >= 0; i--) |
29346e21 | 3101 | if (gsm->dlci[i]) |
6ab8fba7 | 3102 | gsm_dlci_release(gsm->dlci[i]); |
dfabf7ff | 3103 | mutex_unlock(&gsm->mutex); |
e1eaea46 | 3104 | /* Now wipe the queues */ |
17eac652 | 3105 | tty_ldisc_flush(gsm->tty); |
0af02167 DS |
3106 | list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list) |
3107 | kfree(txq); | |
3108 | INIT_LIST_HEAD(&gsm->tx_ctrl_list); | |
3109 | list_for_each_entry_safe(txq, ntxq, &gsm->tx_data_list, list) | |
e1eaea46 | 3110 | kfree(txq); |
0af02167 | 3111 | INIT_LIST_HEAD(&gsm->tx_data_list); |
e1eaea46 | 3112 | } |
e1eaea46 AC |
3113 | |
3114 | /** | |
3115 | * gsm_activate_mux - generic GSM setup | |
3116 | * @gsm: our mux | |
3117 | * | |
3118 | * Set up the bits of the mux which are the same for all framing | |
3119 | * protocols. Add the mux to the mux table so it can be opened and | |
3120 | * finally kick off connecting to DLCI 0 on the modem. | |
3121 | */ | |
3122 | ||
54af5836 | 3123 | static int gsm_activate_mux(struct gsm_mux *gsm) |
e1eaea46 AC |
3124 | { |
3125 | struct gsm_dlci *dlci; | |
01aecd91 | 3126 | int ret; |
e1eaea46 | 3127 | |
73496604 DS |
3128 | dlci = gsm_dlci_alloc(gsm, 0); |
3129 | if (dlci == NULL) | |
3130 | return -ENOMEM; | |
3131 | ||
19fb0a66 | 3132 | if (gsm->encoding == GSM_BASIC_OPT) |
e1eaea46 AC |
3133 | gsm->receive = gsm0_receive; |
3134 | else | |
3135 | gsm->receive = gsm1_receive; | |
e1eaea46 | 3136 | |
01aecd91 DS |
3137 | ret = gsm_register_devices(gsm_tty_driver, gsm->num); |
3138 | if (ret) | |
3139 | return ret; | |
3140 | ||
01aecd91 | 3141 | gsm->has_devices = true; |
5677fcf3 | 3142 | gsm->dead = false; /* Tty opens are now permissible */ |
e1eaea46 AC |
3143 | return 0; |
3144 | } | |
e1eaea46 AC |
3145 | |
3146 | /** | |
3147 | * gsm_free_mux - free up a mux | |
724ac070 | 3148 | * @gsm: mux to free |
e1eaea46 | 3149 | * |
6ab8fba7 | 3150 | * Dispose of allocated resources for a dead mux |
e1eaea46 | 3151 | */ |
54af5836 | 3152 | static void gsm_free_mux(struct gsm_mux *gsm) |
e1eaea46 | 3153 | { |
1ec92e97 DS |
3154 | int i; |
3155 | ||
3156 | for (i = 0; i < MAX_MUX; i++) { | |
3157 | if (gsm == gsm_mux[i]) { | |
3158 | gsm_mux[i] = NULL; | |
3159 | break; | |
3160 | } | |
3161 | } | |
3162 | mutex_destroy(&gsm->mutex); | |
e1eaea46 AC |
3163 | kfree(gsm->txframe); |
3164 | kfree(gsm->buf); | |
3165 | kfree(gsm); | |
3166 | } | |
e1eaea46 | 3167 | |
6ab8fba7 RG |
3168 | /** |
3169 | * gsm_free_muxr - free up a mux | |
724ac070 | 3170 | * @ref: kreference to the mux to free |
6ab8fba7 RG |
3171 | * |
3172 | * Dispose of allocated resources for a dead mux | |
3173 | */ | |
3174 | static void gsm_free_muxr(struct kref *ref) | |
3175 | { | |
3176 | struct gsm_mux *gsm = container_of(ref, struct gsm_mux, ref); | |
3177 | gsm_free_mux(gsm); | |
3178 | } | |
3179 | ||
3180 | static inline void mux_get(struct gsm_mux *gsm) | |
3181 | { | |
1ec92e97 DS |
3182 | unsigned long flags; |
3183 | ||
3184 | spin_lock_irqsave(&gsm_mux_lock, flags); | |
6ab8fba7 | 3185 | kref_get(&gsm->ref); |
1ec92e97 | 3186 | spin_unlock_irqrestore(&gsm_mux_lock, flags); |
6ab8fba7 RG |
3187 | } |
3188 | ||
3189 | static inline void mux_put(struct gsm_mux *gsm) | |
3190 | { | |
1ec92e97 DS |
3191 | unsigned long flags; |
3192 | ||
3193 | spin_lock_irqsave(&gsm_mux_lock, flags); | |
6ab8fba7 | 3194 | kref_put(&gsm->ref, gsm_free_muxr); |
1ec92e97 | 3195 | spin_unlock_irqrestore(&gsm_mux_lock, flags); |
6ab8fba7 RG |
3196 | } |
3197 | ||
43a9e710 MH |
3198 | static inline unsigned int mux_num_to_base(struct gsm_mux *gsm) |
3199 | { | |
3200 | return gsm->num * NUM_DLCI; | |
3201 | } | |
3202 | ||
3203 | static inline unsigned int mux_line_to_num(unsigned int line) | |
3204 | { | |
3205 | return line / NUM_DLCI; | |
3206 | } | |
3207 | ||
e1eaea46 AC |
3208 | /** |
3209 | * gsm_alloc_mux - allocate a mux | |
3210 | * | |
3211 | * Creates a new mux ready for activation. | |
3212 | */ | |
3213 | ||
54af5836 | 3214 | static struct gsm_mux *gsm_alloc_mux(void) |
e1eaea46 | 3215 | { |
1ec92e97 | 3216 | int i; |
e1eaea46 AC |
3217 | struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); |
3218 | if (gsm == NULL) | |
3219 | return NULL; | |
3220 | gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL); | |
3221 | if (gsm->buf == NULL) { | |
3222 | kfree(gsm); | |
3223 | return NULL; | |
3224 | } | |
535bf600 | 3225 | gsm->txframe = kmalloc(2 * (MAX_MTU + PROT_OVERHEAD - 1), GFP_KERNEL); |
e1eaea46 AC |
3226 | if (gsm->txframe == NULL) { |
3227 | kfree(gsm->buf); | |
3228 | kfree(gsm); | |
3229 | return NULL; | |
3230 | } | |
3231 | spin_lock_init(&gsm->lock); | |
dfabf7ff | 3232 | mutex_init(&gsm->mutex); |
6ab8fba7 | 3233 | kref_init(&gsm->ref); |
0af02167 DS |
3234 | INIT_LIST_HEAD(&gsm->tx_ctrl_list); |
3235 | INIT_LIST_HEAD(&gsm->tx_data_list); | |
15743ae5 | 3236 | timer_setup(&gsm->kick_timer, gsm_kick_timer, 0); |
4bb1a53b | 3237 | timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); |
72206cc7 | 3238 | timer_setup(&gsm->ka_timer, gsm_control_keep_alive, 0); |
4bb1a53b TH |
3239 | INIT_WORK(&gsm->tx_work, gsmld_write_task); |
3240 | init_waitqueue_head(&gsm->event); | |
3241 | spin_lock_init(&gsm->control_lock); | |
acdab4cb | 3242 | spin_lock_init(&gsm->tx_lock); |
e1eaea46 AC |
3243 | |
3244 | gsm->t1 = T1; | |
3245 | gsm->t2 = T2; | |
2ec7a802 | 3246 | gsm->t3 = T3; |
e1eaea46 | 3247 | gsm->n2 = N2; |
2ec7a802 | 3248 | gsm->k = K; |
e1eaea46 | 3249 | gsm->ftype = UIH; |
e1eaea46 | 3250 | gsm->adaption = 1; |
19fb0a66 | 3251 | gsm->encoding = GSM_ADV_OPT; |
e1eaea46 AC |
3252 | gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ |
3253 | gsm->mtu = 64; | |
5677fcf3 | 3254 | gsm->dead = true; /* Avoid early tty opens */ |
4ca58966 | 3255 | gsm->wait_config = false; /* Disabled */ |
72206cc7 | 3256 | gsm->keep_alive = 0; /* Disabled */ |
e1eaea46 | 3257 | |
1ec92e97 DS |
3258 | /* Store the instance to the mux array or abort if no space is |
3259 | * available. | |
3260 | */ | |
3261 | spin_lock(&gsm_mux_lock); | |
3262 | for (i = 0; i < MAX_MUX; i++) { | |
3263 | if (!gsm_mux[i]) { | |
3264 | gsm_mux[i] = gsm; | |
3265 | gsm->num = i; | |
3266 | break; | |
3267 | } | |
3268 | } | |
3269 | spin_unlock(&gsm_mux_lock); | |
3270 | if (i == MAX_MUX) { | |
3271 | mutex_destroy(&gsm->mutex); | |
3272 | kfree(gsm->txframe); | |
3273 | kfree(gsm->buf); | |
3274 | kfree(gsm); | |
3275 | return NULL; | |
3276 | } | |
3277 | ||
e1eaea46 AC |
3278 | return gsm; |
3279 | } | |
e1eaea46 | 3280 | |
33841040 TL |
3281 | static void gsm_copy_config_values(struct gsm_mux *gsm, |
3282 | struct gsm_config *c) | |
3283 | { | |
3284 | memset(c, 0, sizeof(*c)); | |
3285 | c->adaption = gsm->adaption; | |
3286 | c->encapsulation = gsm->encoding; | |
3287 | c->initiator = gsm->initiator; | |
3288 | c->t1 = gsm->t1; | |
3289 | c->t2 = gsm->t2; | |
2ec7a802 | 3290 | c->t3 = gsm->t3; |
33841040 TL |
3291 | c->n2 = gsm->n2; |
3292 | if (gsm->ftype == UIH) | |
3293 | c->i = 1; | |
3294 | else | |
3295 | c->i = 2; | |
3296 | pr_debug("Ftype %d i %d\n", gsm->ftype, c->i); | |
3297 | c->mru = gsm->mru; | |
3298 | c->mtu = gsm->mtu; | |
2ec7a802 | 3299 | c->k = gsm->k; |
33841040 TL |
3300 | } |
3301 | ||
3302 | static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) | |
3303 | { | |
3304 | int need_close = 0; | |
3305 | int need_restart = 0; | |
3306 | ||
8629745c DS |
3307 | /* Stuff we don't support yet - UI or I frame transport */ |
3308 | if (c->adaption != 1 && c->adaption != 2) | |
33841040 TL |
3309 | return -EOPNOTSUPP; |
3310 | /* Check the MRU/MTU range looks sane */ | |
7a121247 DS |
3311 | if (c->mru < MIN_MTU || c->mtu < MIN_MTU) |
3312 | return -EINVAL; | |
3313 | if (c->mru > MAX_MRU || c->mtu > MAX_MTU) | |
33841040 | 3314 | return -EINVAL; |
2ec7a802 DS |
3315 | if (c->t3 > MAX_T3) |
3316 | return -EINVAL; | |
d0bcdffc | 3317 | if (c->n2 > 255) |
33841040 TL |
3318 | return -EINVAL; |
3319 | if (c->encapsulation > 1) /* Basic, advanced, no I */ | |
3320 | return -EINVAL; | |
3321 | if (c->initiator > 1) | |
3322 | return -EINVAL; | |
2ec7a802 DS |
3323 | if (c->k > MAX_WINDOW_SIZE) |
3324 | return -EINVAL; | |
33841040 TL |
3325 | if (c->i == 0 || c->i > 2) /* UIH and UI only */ |
3326 | return -EINVAL; | |
3327 | /* | |
3328 | * See what is needed for reconfiguration | |
3329 | */ | |
3330 | ||
3331 | /* Timing fields */ | |
3332 | if (c->t1 != 0 && c->t1 != gsm->t1) | |
3333 | need_restart = 1; | |
3334 | if (c->t2 != 0 && c->t2 != gsm->t2) | |
3335 | need_restart = 1; | |
3336 | if (c->encapsulation != gsm->encoding) | |
3337 | need_restart = 1; | |
3338 | if (c->adaption != gsm->adaption) | |
3339 | need_restart = 1; | |
3340 | /* Requires care */ | |
3341 | if (c->initiator != gsm->initiator) | |
3342 | need_close = 1; | |
3343 | if (c->mru != gsm->mru) | |
3344 | need_restart = 1; | |
3345 | if (c->mtu != gsm->mtu) | |
3346 | need_restart = 1; | |
3347 | ||
3348 | /* | |
3349 | * Close down what is needed, restart and initiate the new | |
aa371e96 DS |
3350 | * configuration. On the first time there is no DLCI[0] |
3351 | * and closing or cleaning up is not necessary. | |
33841040 | 3352 | */ |
aa371e96 DS |
3353 | if (need_close || need_restart) |
3354 | gsm_cleanup_mux(gsm, true); | |
33841040 TL |
3355 | |
3356 | gsm->initiator = c->initiator; | |
3357 | gsm->mru = c->mru; | |
3358 | gsm->mtu = c->mtu; | |
19fb0a66 | 3359 | gsm->encoding = c->encapsulation ? GSM_ADV_OPT : GSM_BASIC_OPT; |
33841040 TL |
3360 | gsm->adaption = c->adaption; |
3361 | gsm->n2 = c->n2; | |
3362 | ||
3363 | if (c->i == 1) | |
3364 | gsm->ftype = UIH; | |
3365 | else if (c->i == 2) | |
3366 | gsm->ftype = UI; | |
3367 | ||
3368 | if (c->t1) | |
3369 | gsm->t1 = c->t1; | |
3370 | if (c->t2) | |
3371 | gsm->t2 = c->t2; | |
2ec7a802 DS |
3372 | if (c->t3) |
3373 | gsm->t3 = c->t3; | |
3374 | if (c->k) | |
3375 | gsm->k = c->k; | |
33841040 TL |
3376 | |
3377 | /* | |
3378 | * FIXME: We need to separate activation/deactivation from adding | |
3379 | * and removing from the mux array | |
3380 | */ | |
edd5f60c | 3381 | if (gsm->dead) { |
e1c90bbb | 3382 | int ret = gsm_activate_mux(gsm); |
edd5f60c DS |
3383 | if (ret) |
3384 | return ret; | |
3385 | if (gsm->initiator) | |
3386 | gsm_dlci_begin_open(gsm->dlci[0]); | |
3387 | } | |
33841040 TL |
3388 | return 0; |
3389 | } | |
3390 | ||
72206cc7 DS |
3391 | static void gsm_copy_config_ext_values(struct gsm_mux *gsm, |
3392 | struct gsm_config_ext *ce) | |
3393 | { | |
3394 | memset(ce, 0, sizeof(*ce)); | |
4ca58966 | 3395 | ce->wait_config = gsm->wait_config ? 1 : 0; |
72206cc7 DS |
3396 | ce->keep_alive = gsm->keep_alive; |
3397 | } | |
3398 | ||
3399 | static int gsm_config_ext(struct gsm_mux *gsm, struct gsm_config_ext *ce) | |
3400 | { | |
e112ec42 | 3401 | bool need_restart = false; |
72206cc7 DS |
3402 | unsigned int i; |
3403 | ||
3404 | /* | |
3405 | * Check that userspace doesn't put stuff in here to prevent breakages | |
3406 | * in the future. | |
3407 | */ | |
3408 | for (i = 0; i < ARRAY_SIZE(ce->reserved); i++) | |
3409 | if (ce->reserved[i]) | |
3410 | return -EINVAL; | |
e112ec42 DS |
3411 | if (ce->flags & ~GSM_FL_RESTART) |
3412 | return -EINVAL; | |
3413 | ||
3414 | /* Requires care */ | |
3415 | if (ce->flags & GSM_FL_RESTART) | |
3416 | need_restart = true; | |
3417 | ||
3418 | /* | |
3419 | * Close down what is needed, restart and initiate the new | |
3420 | * configuration. On the first time there is no DLCI[0] | |
3421 | * and closing or cleaning up is not necessary. | |
3422 | */ | |
3423 | if (need_restart) | |
3424 | gsm_cleanup_mux(gsm, true); | |
72206cc7 | 3425 | |
4ca58966 DS |
3426 | /* |
3427 | * Setup the new configuration values | |
3428 | */ | |
3429 | gsm->wait_config = ce->wait_config ? true : false; | |
72206cc7 | 3430 | gsm->keep_alive = ce->keep_alive; |
4ca58966 | 3431 | |
e112ec42 DS |
3432 | if (gsm->dead) { |
3433 | int ret = gsm_activate_mux(gsm); | |
3434 | if (ret) | |
3435 | return ret; | |
3436 | if (gsm->initiator) | |
3437 | gsm_dlci_begin_open(gsm->dlci[0]); | |
3438 | } | |
3439 | ||
72206cc7 DS |
3440 | return 0; |
3441 | } | |
3442 | ||
e1eaea46 AC |
3443 | /** |
3444 | * gsmld_output - write to link | |
3445 | * @gsm: our mux | |
3446 | * @data: bytes to output | |
3447 | * @len: size | |
3448 | * | |
3449 | * Write a block of data from the GSM mux to the data channel. This | |
3450 | * will eventually be serialized from above but at the moment isn't. | |
3451 | */ | |
3452 | ||
3453 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) | |
3454 | { | |
3455 | if (tty_write_room(gsm->tty) < len) { | |
3456 | set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); | |
3457 | return -ENOSPC; | |
3458 | } | |
c07da737 | 3459 | if (debug & DBG_DATA) |
925ea0fa | 3460 | gsm_hex_dump_bytes(__func__, data, len); |
9136c683 | 3461 | return gsm->tty->ops->write(gsm->tty, data, len); |
e1eaea46 AC |
3462 | } |
3463 | ||
0af02167 DS |
3464 | |
3465 | /** | |
3466 | * gsmld_write_trigger - schedule ldisc write task | |
3467 | * @gsm: our mux | |
3468 | */ | |
3469 | static void gsmld_write_trigger(struct gsm_mux *gsm) | |
3470 | { | |
3471 | if (!gsm || !gsm->dlci[0] || gsm->dlci[0]->dead) | |
3472 | return; | |
3473 | schedule_work(&gsm->tx_work); | |
3474 | } | |
3475 | ||
3476 | ||
3477 | /** | |
3478 | * gsmld_write_task - ldisc write task | |
3479 | * @work: our tx write work | |
3480 | * | |
3481 | * Writes out data to the ldisc if possible. We are doing this here to | |
3482 | * avoid dead-locking. This returns if no space or data is left for output. | |
3483 | */ | |
3484 | static void gsmld_write_task(struct work_struct *work) | |
3485 | { | |
3486 | struct gsm_mux *gsm = container_of(work, struct gsm_mux, tx_work); | |
acdab4cb | 3487 | unsigned long flags; |
0af02167 DS |
3488 | int i, ret; |
3489 | ||
3490 | /* All outstanding control channel and control messages and one data | |
3491 | * frame is sent. | |
3492 | */ | |
3493 | ret = -ENODEV; | |
acdab4cb | 3494 | spin_lock_irqsave(&gsm->tx_lock, flags); |
0af02167 DS |
3495 | if (gsm->tty) |
3496 | ret = gsm_data_kick(gsm); | |
acdab4cb | 3497 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
0af02167 DS |
3498 | |
3499 | if (ret >= 0) | |
3500 | for (i = 0; i < NUM_DLCI; i++) | |
3501 | if (gsm->dlci[i]) | |
3502 | tty_port_tty_wakeup(&gsm->dlci[i]->port); | |
3503 | } | |
3504 | ||
e1eaea46 AC |
3505 | /** |
3506 | * gsmld_attach_gsm - mode set up | |
3507 | * @tty: our tty structure | |
3508 | * @gsm: our mux | |
3509 | * | |
3510 | * Set up the MUX for basic mode and commence connecting to the | |
3511 | * modem. Currently called from the line discipline set up but | |
3512 | * will need moving to an ioctl path. | |
3513 | */ | |
3514 | ||
01aecd91 | 3515 | static void gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) |
e1eaea46 | 3516 | { |
e1eaea46 | 3517 | gsm->tty = tty_kref_get(tty); |
f4f7d632 DS |
3518 | /* Turn off tty XON/XOFF handling to handle it explicitly. */ |
3519 | gsm->old_c_iflag = tty->termios.c_iflag; | |
3520 | tty->termios.c_iflag &= (IXON | IXOFF); | |
e1eaea46 AC |
3521 | } |
3522 | ||
e1eaea46 AC |
3523 | /** |
3524 | * gsmld_detach_gsm - stop doing 0710 mux | |
70f23fd6 | 3525 | * @tty: tty attached to the mux |
e1eaea46 AC |
3526 | * @gsm: mux |
3527 | * | |
3528 | * Shutdown and then clean up the resources used by the line discipline | |
3529 | */ | |
3530 | ||
3531 | static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) | |
3532 | { | |
3533 | WARN_ON(tty != gsm->tty); | |
f4f7d632 DS |
3534 | /* Restore tty XON/XOFF handling. */ |
3535 | gsm->tty->termios.c_iflag = gsm->old_c_iflag; | |
e1eaea46 AC |
3536 | tty_kref_put(gsm->tty); |
3537 | gsm->tty = NULL; | |
3538 | } | |
3539 | ||
a8d9cd23 | 3540 | static void gsmld_receive_buf(struct tty_struct *tty, const u8 *cp, |
892bc209 | 3541 | const u8 *fp, size_t count) |
e1eaea46 AC |
3542 | { |
3543 | struct gsm_mux *gsm = tty->disc_data; | |
82f91fe0 | 3544 | char flags = TTY_NORMAL; |
e1eaea46 | 3545 | |
c07da737 | 3546 | if (debug & DBG_DATA) |
925ea0fa | 3547 | gsm_hex_dump_bytes(__func__, cp, count); |
e1eaea46 | 3548 | |
b93db97e JS |
3549 | for (; count; count--, cp++) { |
3550 | if (fp) | |
3551 | flags = *fp++; | |
e1eaea46 AC |
3552 | switch (flags) { |
3553 | case TTY_NORMAL: | |
f16c6d2e MAH |
3554 | if (gsm->receive) |
3555 | gsm->receive(gsm, *cp); | |
e1eaea46 AC |
3556 | break; |
3557 | case TTY_OVERRUN: | |
3558 | case TTY_BREAK: | |
3559 | case TTY_PARITY: | |
3560 | case TTY_FRAME: | |
ea502201 | 3561 | gsm_error(gsm); |
e1eaea46 AC |
3562 | break; |
3563 | default: | |
c01af4fe | 3564 | WARN_ONCE(1, "%s: unknown flag %d\n", |
429b4749 | 3565 | tty_name(tty), flags); |
e1eaea46 AC |
3566 | break; |
3567 | } | |
3568 | } | |
3569 | /* FASYNC if needed ? */ | |
3570 | /* If clogged call tty_throttle(tty); */ | |
3571 | } | |
3572 | ||
e1eaea46 AC |
3573 | /** |
3574 | * gsmld_flush_buffer - clean input queue | |
3575 | * @tty: terminal device | |
3576 | * | |
3577 | * Flush the input buffer. Called when the line discipline is | |
3578 | * being closed, when the tty layer wants the buffer flushed (eg | |
3579 | * at hangup). | |
3580 | */ | |
3581 | ||
3582 | static void gsmld_flush_buffer(struct tty_struct *tty) | |
3583 | { | |
3584 | } | |
3585 | ||
3586 | /** | |
3587 | * gsmld_close - close the ldisc for this tty | |
3588 | * @tty: device | |
3589 | * | |
3590 | * Called from the terminal layer when this line discipline is | |
3591 | * being shut down, either because of a close or becsuse of a | |
3592 | * discipline change. The function will not be called while other | |
3593 | * ldisc methods are in progress. | |
3594 | */ | |
3595 | ||
3596 | static void gsmld_close(struct tty_struct *tty) | |
3597 | { | |
3598 | struct gsm_mux *gsm = tty->disc_data; | |
3599 | ||
284260f2 DS |
3600 | /* The ldisc locks and closes the port before calling our close. This |
3601 | * means we have no way to do a proper disconnect. We will not bother | |
3602 | * to do one. | |
3603 | */ | |
3604 | gsm_cleanup_mux(gsm, false); | |
3605 | ||
e1eaea46 AC |
3606 | gsmld_detach_gsm(tty, gsm); |
3607 | ||
3608 | gsmld_flush_buffer(tty); | |
3609 | /* Do other clean up here */ | |
6ab8fba7 | 3610 | mux_put(gsm); |
e1eaea46 AC |
3611 | } |
3612 | ||
3613 | /** | |
3614 | * gsmld_open - open an ldisc | |
3615 | * @tty: terminal to open | |
3616 | * | |
3617 | * Called when this line discipline is being attached to the | |
3618 | * terminal device. Can sleep. Called serialized so that no | |
3619 | * other events will occur in parallel. No further open will occur | |
3620 | * until a close. | |
3621 | */ | |
3622 | ||
3623 | static int gsmld_open(struct tty_struct *tty) | |
3624 | { | |
3625 | struct gsm_mux *gsm; | |
3626 | ||
67c37756 TLSC |
3627 | if (!capable(CAP_NET_ADMIN)) |
3628 | return -EPERM; | |
3629 | ||
e1eaea46 AC |
3630 | if (tty->ops->write == NULL) |
3631 | return -EINVAL; | |
3632 | ||
3633 | /* Attach our ldisc data */ | |
3634 | gsm = gsm_alloc_mux(); | |
3635 | if (gsm == NULL) | |
3636 | return -ENOMEM; | |
3637 | ||
3638 | tty->disc_data = gsm; | |
3639 | tty->receive_room = 65536; | |
3640 | ||
3641 | /* Attach the initial passive connection */ | |
01aecd91 DS |
3642 | gsmld_attach_gsm(tty, gsm); |
3643 | ||
4ca58966 DS |
3644 | /* The mux will not be activated yet, we wait for correct |
3645 | * configuration first. | |
3646 | */ | |
3647 | if (gsm->encoding == GSM_BASIC_OPT) | |
3648 | gsm->receive = gsm0_receive; | |
3649 | else | |
3650 | gsm->receive = gsm1_receive; | |
3651 | ||
01aecd91 | 3652 | return 0; |
e1eaea46 AC |
3653 | } |
3654 | ||
3655 | /** | |
3656 | * gsmld_write_wakeup - asynchronous I/O notifier | |
3657 | * @tty: tty device | |
3658 | * | |
3659 | * Required for the ptys, serial driver etc. since processes | |
3660 | * that attach themselves to the master and rely on ASYNC | |
3661 | * IO must be woken up | |
3662 | */ | |
3663 | ||
3664 | static void gsmld_write_wakeup(struct tty_struct *tty) | |
3665 | { | |
3666 | struct gsm_mux *gsm = tty->disc_data; | |
3667 | ||
3668 | /* Queue poll */ | |
0af02167 | 3669 | gsmld_write_trigger(gsm); |
e1eaea46 AC |
3670 | } |
3671 | ||
3672 | /** | |
3673 | * gsmld_read - read function for tty | |
3674 | * @tty: tty device | |
3675 | * @file: file object | |
3676 | * @buf: userspace buffer pointer | |
3677 | * @nr: size of I/O | |
542a121a LJ |
3678 | * @cookie: unused |
3679 | * @offset: unused | |
e1eaea46 AC |
3680 | * |
3681 | * Perform reads for the line discipline. We are guaranteed that the | |
3682 | * line discipline will not be closed under us but we may get multiple | |
3683 | * parallel readers and must handle this ourselves. We may also get | |
3684 | * a hangup. Always called in user context, may sleep. | |
3685 | * | |
3686 | * This code must be sure never to sleep through a hangup. | |
3687 | */ | |
3688 | ||
49b8220c JSS |
3689 | static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, u8 *buf, |
3690 | size_t nr, void **cookie, unsigned long offset) | |
e1eaea46 AC |
3691 | { |
3692 | return -EOPNOTSUPP; | |
3693 | } | |
3694 | ||
3695 | /** | |
3696 | * gsmld_write - write function for tty | |
3697 | * @tty: tty device | |
3698 | * @file: file object | |
3699 | * @buf: userspace buffer pointer | |
3700 | * @nr: size of I/O | |
3701 | * | |
3702 | * Called when the owner of the device wants to send a frame | |
3703 | * itself (or some other control data). The data is transferred | |
3704 | * as-is and must be properly framed and checksummed as appropriate | |
3705 | * by userspace. Frames are either sent whole or not at all as this | |
3706 | * avoids pain user side. | |
3707 | */ | |
3708 | ||
3709 | static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, | |
49b8220c | 3710 | const u8 *buf, size_t nr) |
e1eaea46 | 3711 | { |
32dd59f9 | 3712 | struct gsm_mux *gsm = tty->disc_data; |
acdab4cb | 3713 | unsigned long flags; |
32dd59f9 DS |
3714 | int space; |
3715 | int ret; | |
3716 | ||
3717 | if (!gsm) | |
3718 | return -ENODEV; | |
3719 | ||
3720 | ret = -ENOBUFS; | |
acdab4cb | 3721 | spin_lock_irqsave(&gsm->tx_lock, flags); |
32dd59f9 | 3722 | space = tty_write_room(tty); |
e1eaea46 | 3723 | if (space >= nr) |
32dd59f9 DS |
3724 | ret = tty->ops->write(tty, buf, nr); |
3725 | else | |
3726 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
acdab4cb | 3727 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
32dd59f9 DS |
3728 | |
3729 | return ret; | |
e1eaea46 AC |
3730 | } |
3731 | ||
3732 | /** | |
3733 | * gsmld_poll - poll method for N_GSM0710 | |
3734 | * @tty: terminal device | |
3735 | * @file: file accessing it | |
3736 | * @wait: poll table | |
3737 | * | |
3738 | * Called when the line discipline is asked to poll() for data or | |
3739 | * for special events. This code is not serialized with respect to | |
3740 | * other events save open/close. | |
3741 | * | |
3742 | * This code must be sure never to sleep through a hangup. | |
3743 | * Called without the kernel lock held - fine | |
3744 | */ | |
3745 | ||
afc9a42b | 3746 | static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file, |
e1eaea46 AC |
3747 | poll_table *wait) |
3748 | { | |
afc9a42b | 3749 | __poll_t mask = 0; |
e1eaea46 AC |
3750 | struct gsm_mux *gsm = tty->disc_data; |
3751 | ||
3752 | poll_wait(file, &tty->read_wait, wait); | |
3753 | poll_wait(file, &tty->write_wait, wait); | |
7e5b4322 DS |
3754 | |
3755 | if (gsm->dead) | |
3756 | mask |= EPOLLHUP; | |
e1eaea46 | 3757 | if (tty_hung_up_p(file)) |
a9a08845 | 3758 | mask |= EPOLLHUP; |
7e5b4322 DS |
3759 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
3760 | mask |= EPOLLHUP; | |
e1eaea46 | 3761 | if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) |
a9a08845 | 3762 | mask |= EPOLLOUT | EPOLLWRNORM; |
e1eaea46 AC |
3763 | return mask; |
3764 | } | |
3765 | ||
d78328bc JS |
3766 | static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd, |
3767 | unsigned long arg) | |
e1eaea46 AC |
3768 | { |
3769 | struct gsm_config c; | |
72206cc7 | 3770 | struct gsm_config_ext ce; |
afe3154b | 3771 | struct gsm_dlci_config dc; |
e1eaea46 | 3772 | struct gsm_mux *gsm = tty->disc_data; |
2b3174c9 | 3773 | unsigned int base, addr; |
afe3154b | 3774 | struct gsm_dlci *dlci; |
e1eaea46 AC |
3775 | |
3776 | switch (cmd) { | |
3777 | case GSMIOC_GETCONF: | |
33841040 | 3778 | gsm_copy_config_values(gsm, &c); |
edd05a73 | 3779 | if (copy_to_user((void __user *)arg, &c, sizeof(c))) |
e1eaea46 AC |
3780 | return -EFAULT; |
3781 | return 0; | |
3782 | case GSMIOC_SETCONF: | |
edd05a73 | 3783 | if (copy_from_user(&c, (void __user *)arg, sizeof(c))) |
e1eaea46 | 3784 | return -EFAULT; |
33841040 | 3785 | return gsm_config(gsm, &c); |
a7b121b4 MH |
3786 | case GSMIOC_GETFIRST: |
3787 | base = mux_num_to_base(gsm); | |
3788 | return put_user(base + 1, (__u32 __user *)arg); | |
72206cc7 DS |
3789 | case GSMIOC_GETCONF_EXT: |
3790 | gsm_copy_config_ext_values(gsm, &ce); | |
3791 | if (copy_to_user((void __user *)arg, &ce, sizeof(ce))) | |
3792 | return -EFAULT; | |
3793 | return 0; | |
3794 | case GSMIOC_SETCONF_EXT: | |
3795 | if (copy_from_user(&ce, (void __user *)arg, sizeof(ce))) | |
3796 | return -EFAULT; | |
3797 | return gsm_config_ext(gsm, &ce); | |
afe3154b DS |
3798 | case GSMIOC_GETCONF_DLCI: |
3799 | if (copy_from_user(&dc, (void __user *)arg, sizeof(dc))) | |
3800 | return -EFAULT; | |
3801 | if (dc.channel == 0 || dc.channel >= NUM_DLCI) | |
3802 | return -EINVAL; | |
2b3174c9 IJ |
3803 | addr = array_index_nospec(dc.channel, NUM_DLCI); |
3804 | dlci = gsm->dlci[addr]; | |
afe3154b | 3805 | if (!dlci) { |
2b3174c9 | 3806 | dlci = gsm_dlci_alloc(gsm, addr); |
afe3154b DS |
3807 | if (!dlci) |
3808 | return -ENOMEM; | |
3809 | } | |
3810 | gsm_dlci_copy_config_values(dlci, &dc); | |
3811 | if (copy_to_user((void __user *)arg, &dc, sizeof(dc))) | |
3812 | return -EFAULT; | |
3813 | return 0; | |
3814 | case GSMIOC_SETCONF_DLCI: | |
3815 | if (copy_from_user(&dc, (void __user *)arg, sizeof(dc))) | |
3816 | return -EFAULT; | |
3817 | if (dc.channel == 0 || dc.channel >= NUM_DLCI) | |
3818 | return -EINVAL; | |
2b3174c9 IJ |
3819 | addr = array_index_nospec(dc.channel, NUM_DLCI); |
3820 | dlci = gsm->dlci[addr]; | |
afe3154b | 3821 | if (!dlci) { |
2b3174c9 | 3822 | dlci = gsm_dlci_alloc(gsm, addr); |
afe3154b DS |
3823 | if (!dlci) |
3824 | return -ENOMEM; | |
3825 | } | |
3826 | return gsm_dlci_config(dlci, &dc, 0); | |
e1eaea46 | 3827 | default: |
7c783601 | 3828 | return n_tty_ioctl_helper(tty, cmd, arg); |
e1eaea46 AC |
3829 | } |
3830 | } | |
3831 | ||
bcd5abe2 RG |
3832 | /* |
3833 | * Network interface | |
3834 | * | |
3835 | */ | |
3836 | ||
3837 | static int gsm_mux_net_open(struct net_device *net) | |
3838 | { | |
3839 | pr_debug("%s called\n", __func__); | |
3840 | netif_start_queue(net); | |
3841 | return 0; | |
3842 | } | |
3843 | ||
3844 | static int gsm_mux_net_close(struct net_device *net) | |
3845 | { | |
3846 | netif_stop_queue(net); | |
3847 | return 0; | |
3848 | } | |
3849 | ||
bcd5abe2 RG |
3850 | static void dlci_net_free(struct gsm_dlci *dlci) |
3851 | { | |
3852 | if (!dlci->net) { | |
3853 | WARN_ON(1); | |
3854 | return; | |
3855 | } | |
3856 | dlci->adaption = dlci->prev_adaption; | |
3857 | dlci->data = dlci->prev_data; | |
3858 | free_netdev(dlci->net); | |
3859 | dlci->net = NULL; | |
3860 | } | |
3861 | static void net_free(struct kref *ref) | |
3862 | { | |
3863 | struct gsm_mux_net *mux_net; | |
3864 | struct gsm_dlci *dlci; | |
3865 | ||
3866 | mux_net = container_of(ref, struct gsm_mux_net, ref); | |
3867 | dlci = mux_net->dlci; | |
3868 | ||
3869 | if (dlci->net) { | |
3870 | unregister_netdev(dlci->net); | |
3871 | dlci_net_free(dlci); | |
3872 | } | |
3873 | } | |
3874 | ||
6ab8fba7 RG |
3875 | static inline void muxnet_get(struct gsm_mux_net *mux_net) |
3876 | { | |
3877 | kref_get(&mux_net->ref); | |
3878 | } | |
3879 | ||
3880 | static inline void muxnet_put(struct gsm_mux_net *mux_net) | |
3881 | { | |
3882 | kref_put(&mux_net->ref, net_free); | |
3883 | } | |
3884 | ||
2468b3e4 | 3885 | static netdev_tx_t gsm_mux_net_start_xmit(struct sk_buff *skb, |
bcd5abe2 RG |
3886 | struct net_device *net) |
3887 | { | |
5dbc32a8 | 3888 | struct gsm_mux_net *mux_net = netdev_priv(net); |
bcd5abe2 | 3889 | struct gsm_dlci *dlci = mux_net->dlci; |
6ab8fba7 | 3890 | muxnet_get(mux_net); |
bcd5abe2 RG |
3891 | |
3892 | skb_queue_head(&dlci->skb_list, skb); | |
47baf1ad TK |
3893 | net->stats.tx_packets++; |
3894 | net->stats.tx_bytes += skb->len; | |
bcd5abe2 RG |
3895 | gsm_dlci_data_kick(dlci); |
3896 | /* And tell the kernel when the last transmit started. */ | |
860e9538 | 3897 | netif_trans_update(net); |
6ab8fba7 | 3898 | muxnet_put(mux_net); |
bcd5abe2 RG |
3899 | return NETDEV_TX_OK; |
3900 | } | |
3901 | ||
3902 | /* called when a packet did not ack after watchdogtimeout */ | |
0290bd29 | 3903 | static void gsm_mux_net_tx_timeout(struct net_device *net, unsigned int txqueue) |
bcd5abe2 RG |
3904 | { |
3905 | /* Tell syslog we are hosed. */ | |
3906 | dev_dbg(&net->dev, "Tx timed out.\n"); | |
3907 | ||
3908 | /* Update statistics */ | |
47baf1ad | 3909 | net->stats.tx_errors++; |
bcd5abe2 RG |
3910 | } |
3911 | ||
3912 | static void gsm_mux_rx_netchar(struct gsm_dlci *dlci, | |
4feb7a4a | 3913 | const unsigned char *in_buf, int size) |
bcd5abe2 RG |
3914 | { |
3915 | struct net_device *net = dlci->net; | |
3916 | struct sk_buff *skb; | |
5dbc32a8 | 3917 | struct gsm_mux_net *mux_net = netdev_priv(net); |
6ab8fba7 | 3918 | muxnet_get(mux_net); |
bcd5abe2 RG |
3919 | |
3920 | /* Allocate an sk_buff */ | |
3921 | skb = dev_alloc_skb(size + NET_IP_ALIGN); | |
3922 | if (!skb) { | |
3923 | /* We got no receive buffer. */ | |
47baf1ad | 3924 | net->stats.rx_dropped++; |
6ab8fba7 | 3925 | muxnet_put(mux_net); |
bcd5abe2 RG |
3926 | return; |
3927 | } | |
3928 | skb_reserve(skb, NET_IP_ALIGN); | |
59ae1d12 | 3929 | skb_put_data(skb, in_buf, size); |
bcd5abe2 RG |
3930 | |
3931 | skb->dev = net; | |
75406b3b | 3932 | skb->protocol = htons(ETH_P_IP); |
bcd5abe2 RG |
3933 | |
3934 | /* Ship it off to the kernel */ | |
3935 | netif_rx(skb); | |
3936 | ||
3937 | /* update out statistics */ | |
47baf1ad TK |
3938 | net->stats.rx_packets++; |
3939 | net->stats.rx_bytes += size; | |
6ab8fba7 | 3940 | muxnet_put(mux_net); |
bcd5abe2 RG |
3941 | return; |
3942 | } | |
3943 | ||
bcd5abe2 RG |
3944 | static void gsm_mux_net_init(struct net_device *net) |
3945 | { | |
3946 | static const struct net_device_ops gsm_netdev_ops = { | |
3947 | .ndo_open = gsm_mux_net_open, | |
3948 | .ndo_stop = gsm_mux_net_close, | |
3949 | .ndo_start_xmit = gsm_mux_net_start_xmit, | |
3950 | .ndo_tx_timeout = gsm_mux_net_tx_timeout, | |
bcd5abe2 RG |
3951 | }; |
3952 | ||
3953 | net->netdev_ops = &gsm_netdev_ops; | |
3954 | ||
3955 | /* fill in the other fields */ | |
3956 | net->watchdog_timeo = GSM_NET_TX_TIMEOUT; | |
3957 | net->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; | |
3958 | net->type = ARPHRD_NONE; | |
3959 | net->tx_queue_len = 10; | |
3960 | } | |
3961 | ||
3962 | ||
3963 | /* caller holds the dlci mutex */ | |
3964 | static void gsm_destroy_network(struct gsm_dlci *dlci) | |
3965 | { | |
3966 | struct gsm_mux_net *mux_net; | |
3967 | ||
d8ca4ecf | 3968 | pr_debug("destroy network interface\n"); |
bcd5abe2 RG |
3969 | if (!dlci->net) |
3970 | return; | |
5dbc32a8 | 3971 | mux_net = netdev_priv(dlci->net); |
6ab8fba7 | 3972 | muxnet_put(mux_net); |
bcd5abe2 RG |
3973 | } |
3974 | ||
3975 | ||
3976 | /* caller holds the dlci mutex */ | |
3977 | static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) | |
3978 | { | |
3979 | char *netname; | |
3980 | int retval = 0; | |
3981 | struct net_device *net; | |
3982 | struct gsm_mux_net *mux_net; | |
3983 | ||
3984 | if (!capable(CAP_NET_ADMIN)) | |
3985 | return -EPERM; | |
3986 | ||
3987 | /* Already in a non tty mode */ | |
3988 | if (dlci->adaption > 2) | |
3989 | return -EBUSY; | |
3990 | ||
3991 | if (nc->protocol != htons(ETH_P_IP)) | |
3992 | return -EPROTONOSUPPORT; | |
3993 | ||
3994 | if (nc->adaption != 3 && nc->adaption != 4) | |
3995 | return -EPROTONOSUPPORT; | |
3996 | ||
d8ca4ecf | 3997 | pr_debug("create network interface\n"); |
bcd5abe2 RG |
3998 | |
3999 | netname = "gsm%d"; | |
4000 | if (nc->if_name[0] != '\0') | |
4001 | netname = nc->if_name; | |
c835a677 TG |
4002 | net = alloc_netdev(sizeof(struct gsm_mux_net), netname, |
4003 | NET_NAME_UNKNOWN, gsm_mux_net_init); | |
bcd5abe2 | 4004 | if (!net) { |
d8ca4ecf | 4005 | pr_err("alloc_netdev failed\n"); |
bcd5abe2 RG |
4006 | return -ENOMEM; |
4007 | } | |
2ec7a802 | 4008 | net->mtu = dlci->mtu; |
7a121247 | 4009 | net->min_mtu = MIN_MTU; |
2ec7a802 | 4010 | net->max_mtu = dlci->mtu; |
5dbc32a8 | 4011 | mux_net = netdev_priv(net); |
bcd5abe2 RG |
4012 | mux_net->dlci = dlci; |
4013 | kref_init(&mux_net->ref); | |
4014 | strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */ | |
4015 | ||
4016 | /* reconfigure dlci for network */ | |
4017 | dlci->prev_adaption = dlci->adaption; | |
4018 | dlci->prev_data = dlci->data; | |
4019 | dlci->adaption = nc->adaption; | |
4020 | dlci->data = gsm_mux_rx_netchar; | |
4021 | dlci->net = net; | |
4022 | ||
d8ca4ecf | 4023 | pr_debug("register netdev\n"); |
bcd5abe2 RG |
4024 | retval = register_netdev(net); |
4025 | if (retval) { | |
4026 | pr_err("network register fail %d\n", retval); | |
4027 | dlci_net_free(dlci); | |
4028 | return retval; | |
4029 | } | |
4030 | return net->ifindex; /* return network index */ | |
4031 | } | |
e1eaea46 AC |
4032 | |
4033 | /* Line discipline for real tty */ | |
d3157b2c | 4034 | static struct tty_ldisc_ops tty_ldisc_packet = { |
e1eaea46 | 4035 | .owner = THIS_MODULE, |
fbadf70a | 4036 | .num = N_GSM0710, |
e1eaea46 AC |
4037 | .name = "n_gsm", |
4038 | .open = gsmld_open, | |
4039 | .close = gsmld_close, | |
4040 | .flush_buffer = gsmld_flush_buffer, | |
e1eaea46 AC |
4041 | .read = gsmld_read, |
4042 | .write = gsmld_write, | |
4043 | .ioctl = gsmld_ioctl, | |
4044 | .poll = gsmld_poll, | |
4045 | .receive_buf = gsmld_receive_buf, | |
4046 | .write_wakeup = gsmld_write_wakeup | |
4047 | }; | |
4048 | ||
4049 | /* | |
4050 | * Virtual tty side | |
4051 | */ | |
4052 | ||
c19ffe00 DS |
4053 | /** |
4054 | * gsm_modem_upd_via_data - send modem bits via convergence layer | |
4055 | * @dlci: channel | |
4056 | * @brk: break signal | |
4057 | * | |
4058 | * Send an empty frame to signal mobile state changes and to transmit the | |
4059 | * break signal for adaption 2. | |
4060 | */ | |
4061 | ||
4062 | static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk) | |
e1eaea46 | 4063 | { |
c19ffe00 | 4064 | struct gsm_mux *gsm = dlci->gsm; |
acdab4cb | 4065 | unsigned long flags; |
c19ffe00 DS |
4066 | |
4067 | if (dlci->state != DLCI_OPEN || dlci->adaption != 2) | |
4068 | return; | |
4069 | ||
acdab4cb | 4070 | spin_lock_irqsave(&gsm->tx_lock, flags); |
c19ffe00 | 4071 | gsm_dlci_modem_output(gsm, dlci, brk); |
acdab4cb | 4072 | spin_unlock_irqrestore(&gsm->tx_lock, flags); |
c19ffe00 DS |
4073 | } |
4074 | ||
4075 | /** | |
4076 | * gsm_modem_upd_via_msc - send modem bits via control frame | |
4077 | * @dlci: channel | |
4078 | * @brk: break signal | |
4079 | */ | |
4080 | ||
4081 | static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk) | |
e1eaea46 | 4082 | { |
398867f5 | 4083 | u8 modembits[3]; |
e1eaea46 AC |
4084 | struct gsm_control *ctrl; |
4085 | int len = 2; | |
4086 | ||
19fb0a66 | 4087 | if (dlci->gsm->encoding != GSM_BASIC_OPT) |
c19ffe00 | 4088 | return 0; |
e1eaea46 | 4089 | |
398867f5 | 4090 | modembits[0] = (dlci->addr << 2) | 2 | EA; /* DLCI, Valid, EA */ |
317f86af DS |
4091 | if (!brk) { |
4092 | modembits[1] = (gsm_encode_modem(dlci) << 1) | EA; | |
4093 | } else { | |
4094 | modembits[1] = gsm_encode_modem(dlci) << 1; | |
398867f5 | 4095 | modembits[2] = (brk << 4) | 2 | EA; /* Length, Break, EA */ |
e1eaea46 | 4096 | len++; |
398867f5 DS |
4097 | } |
4098 | ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len); | |
e1eaea46 AC |
4099 | if (ctrl == NULL) |
4100 | return -ENOMEM; | |
4101 | return gsm_control_wait(dlci->gsm, ctrl); | |
4102 | } | |
4103 | ||
c19ffe00 DS |
4104 | /** |
4105 | * gsm_modem_update - send modem status line state | |
4106 | * @dlci: channel | |
4107 | * @brk: break signal | |
4108 | */ | |
4109 | ||
4110 | static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) | |
4111 | { | |
3a75b205 DS |
4112 | if (dlci->gsm->dead) |
4113 | return -EL2HLT; | |
c19ffe00 DS |
4114 | if (dlci->adaption == 2) { |
4115 | /* Send convergence layer type 2 empty data frame. */ | |
4116 | gsm_modem_upd_via_data(dlci, brk); | |
4117 | return 0; | |
19fb0a66 | 4118 | } else if (dlci->gsm->encoding == GSM_BASIC_OPT) { |
c19ffe00 DS |
4119 | /* Send as MSC control message. */ |
4120 | return gsm_modem_upd_via_msc(dlci, brk); | |
4121 | } | |
4122 | ||
4123 | /* Modem status lines are not supported. */ | |
4124 | return -EPROTONOSUPPORT; | |
4125 | } | |
4126 | ||
684ae4f9 DS |
4127 | /** |
4128 | * gsm_wait_modem_change - wait for modem status line change | |
4129 | * @dlci: channel | |
4130 | * @mask: modem status line bits | |
4131 | * | |
4132 | * The function returns if: | |
4133 | * - any given modem status line bit changed | |
4134 | * - the wait event function got interrupted (e.g. by a signal) | |
4135 | * - the underlying DLCI was closed | |
4136 | * - the underlying ldisc device was removed | |
4137 | */ | |
4138 | static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask) | |
4139 | { | |
4140 | struct gsm_mux *gsm = dlci->gsm; | |
4141 | u32 old = dlci->modem_rx; | |
4142 | int ret; | |
4143 | ||
4144 | ret = wait_event_interruptible(gsm->event, gsm->dead || | |
4145 | dlci->state != DLCI_OPEN || | |
4146 | (old ^ dlci->modem_rx) & mask); | |
4147 | if (gsm->dead) | |
4148 | return -ENODEV; | |
4149 | if (dlci->state != DLCI_OPEN) | |
4150 | return -EL2NSYNC; | |
4151 | return ret; | |
4152 | } | |
4153 | ||
b300fb26 | 4154 | static bool gsm_carrier_raised(struct tty_port *port) |
e1eaea46 AC |
4155 | { |
4156 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
b2d89ad9 TL |
4157 | struct gsm_mux *gsm = dlci->gsm; |
4158 | ||
e1eaea46 AC |
4159 | /* Not yet open so no carrier info */ |
4160 | if (dlci->state != DLCI_OPEN) | |
b300fb26 | 4161 | return false; |
c07da737 | 4162 | if (debug & DBG_CD_ON) |
b300fb26 | 4163 | return true; |
b2d89ad9 TL |
4164 | |
4165 | /* | |
4166 | * Basic mode with control channel in ADM mode may not respond | |
4167 | * to CMD_MSC at all and modem_rx is empty. | |
4168 | */ | |
19fb0a66 DS |
4169 | if (gsm->encoding == GSM_BASIC_OPT && |
4170 | gsm->dlci[0]->mode == DLCI_MODE_ADM && !dlci->modem_rx) | |
b300fb26 | 4171 | return true; |
b2d89ad9 | 4172 | |
e1eaea46 AC |
4173 | return dlci->modem_rx & TIOCM_CD; |
4174 | } | |
4175 | ||
5701cb8b | 4176 | static void gsm_dtr_rts(struct tty_port *port, bool active) |
e1eaea46 AC |
4177 | { |
4178 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
4179 | unsigned int modem_tx = dlci->modem_tx; | |
5701cb8b | 4180 | if (active) |
e1eaea46 AC |
4181 | modem_tx |= TIOCM_DTR | TIOCM_RTS; |
4182 | else | |
4183 | modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); | |
4184 | if (modem_tx != dlci->modem_tx) { | |
4185 | dlci->modem_tx = modem_tx; | |
c19ffe00 | 4186 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
4187 | } |
4188 | } | |
4189 | ||
4190 | static const struct tty_port_operations gsm_port_ops = { | |
4191 | .carrier_raised = gsm_carrier_raised, | |
4192 | .dtr_rts = gsm_dtr_rts, | |
9a8e62bc | 4193 | .destruct = gsm_dlci_free, |
e1eaea46 AC |
4194 | }; |
4195 | ||
86176ed9 | 4196 | static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty) |
e1eaea46 AC |
4197 | { |
4198 | struct gsm_mux *gsm; | |
4199 | struct gsm_dlci *dlci; | |
e1eaea46 | 4200 | unsigned int line = tty->index; |
43a9e710 | 4201 | unsigned int mux = mux_line_to_num(line); |
86176ed9 JS |
4202 | bool alloc = false; |
4203 | int ret; | |
e1eaea46 AC |
4204 | |
4205 | line = line & 0x3F; | |
4206 | ||
4207 | if (mux >= MAX_MUX) | |
4208 | return -ENXIO; | |
4209 | /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */ | |
4210 | if (gsm_mux[mux] == NULL) | |
4211 | return -EUNATCH; | |
4212 | if (line == 0 || line > 61) /* 62/63 reserved */ | |
4213 | return -ECHRNG; | |
4214 | gsm = gsm_mux[mux]; | |
4215 | if (gsm->dead) | |
4216 | return -EL2HLT; | |
f3c909b4 AI |
4217 | /* If DLCI 0 is not yet fully open return an error. |
4218 | This is ok from a locking | |
4219 | perspective as we don't have to worry about this | |
4220 | if DLCI0 is lost */ | |
dfabf7ff CB |
4221 | mutex_lock(&gsm->mutex); |
4222 | if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) { | |
4223 | mutex_unlock(&gsm->mutex); | |
7e8ac7b2 | 4224 | return -EL2NSYNC; |
dfabf7ff | 4225 | } |
e1eaea46 | 4226 | dlci = gsm->dlci[line]; |
86176ed9 JS |
4227 | if (dlci == NULL) { |
4228 | alloc = true; | |
e1eaea46 | 4229 | dlci = gsm_dlci_alloc(gsm, line); |
86176ed9 | 4230 | } |
dfabf7ff CB |
4231 | if (dlci == NULL) { |
4232 | mutex_unlock(&gsm->mutex); | |
e1eaea46 | 4233 | return -ENOMEM; |
dfabf7ff | 4234 | } |
86176ed9 JS |
4235 | ret = tty_port_install(&dlci->port, driver, tty); |
4236 | if (ret) { | |
4237 | if (alloc) | |
4238 | dlci_put(dlci); | |
dfabf7ff | 4239 | mutex_unlock(&gsm->mutex); |
86176ed9 JS |
4240 | return ret; |
4241 | } | |
4242 | ||
dfabf7ff CB |
4243 | dlci_get(dlci); |
4244 | dlci_get(gsm->dlci[0]); | |
4245 | mux_get(gsm); | |
e1eaea46 | 4246 | tty->driver_data = dlci; |
dfabf7ff | 4247 | mutex_unlock(&gsm->mutex); |
86176ed9 JS |
4248 | |
4249 | return 0; | |
4250 | } | |
4251 | ||
4252 | static int gsmtty_open(struct tty_struct *tty, struct file *filp) | |
4253 | { | |
4254 | struct gsm_dlci *dlci = tty->driver_data; | |
4255 | struct tty_port *port = &dlci->port; | |
4256 | ||
4257 | port->count++; | |
e1eaea46 AC |
4258 | tty_port_tty_set(port, tty); |
4259 | ||
4260 | dlci->modem_rx = 0; | |
4261 | /* We could in theory open and close before we wait - eg if we get | |
4262 | a DM straight back. This is ok as that will have caused a hangup */ | |
515be7ba | 4263 | tty_port_set_initialized(port, true); |
e1eaea46 | 4264 | /* Start sending off SABM messages */ |
4ca58966 DS |
4265 | if (!dlci->gsm->wait_config) { |
4266 | /* Start sending off SABM messages */ | |
4267 | if (dlci->gsm->initiator) | |
4268 | gsm_dlci_begin_open(dlci); | |
4269 | else | |
4270 | gsm_dlci_set_opening(dlci); | |
4271 | } else { | |
4272 | gsm_dlci_set_wait_config(dlci); | |
4273 | } | |
e1eaea46 AC |
4274 | /* And wait for virtual carrier */ |
4275 | return tty_port_block_til_ready(port, tty, filp); | |
4276 | } | |
4277 | ||
4278 | static void gsmtty_close(struct tty_struct *tty, struct file *filp) | |
4279 | { | |
4280 | struct gsm_dlci *dlci = tty->driver_data; | |
6ab8fba7 | 4281 | |
e1eaea46 AC |
4282 | if (dlci == NULL) |
4283 | return; | |
4d9b1090 DB |
4284 | if (dlci->state == DLCI_CLOSED) |
4285 | return; | |
bcd5abe2 RG |
4286 | mutex_lock(&dlci->mutex); |
4287 | gsm_destroy_network(dlci); | |
4288 | mutex_unlock(&dlci->mutex); | |
e1eaea46 | 4289 | if (tty_port_close_start(&dlci->port, tty, filp) == 0) |
dfabf7ff | 4290 | return; |
e1eaea46 | 4291 | gsm_dlci_begin_close(dlci); |
d41861ca PH |
4292 | if (tty_port_initialized(&dlci->port) && C_HUPCL(tty)) |
4293 | tty_port_lower_dtr_rts(&dlci->port); | |
e1eaea46 AC |
4294 | tty_port_close_end(&dlci->port, tty); |
4295 | tty_port_tty_set(&dlci->port, NULL); | |
dfabf7ff | 4296 | return; |
e1eaea46 AC |
4297 | } |
4298 | ||
4299 | static void gsmtty_hangup(struct tty_struct *tty) | |
4300 | { | |
4301 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
4302 | if (dlci->state == DLCI_CLOSED) |
4303 | return; | |
e1eaea46 AC |
4304 | tty_port_hangup(&dlci->port); |
4305 | gsm_dlci_begin_close(dlci); | |
4306 | } | |
4307 | ||
95713967 | 4308 | static ssize_t gsmtty_write(struct tty_struct *tty, const u8 *buf, size_t len) |
e1eaea46 | 4309 | { |
4d9b1090 | 4310 | int sent; |
e1eaea46 | 4311 | struct gsm_dlci *dlci = tty->driver_data; |
4d9b1090 DB |
4312 | if (dlci->state == DLCI_CLOSED) |
4313 | return -EINVAL; | |
e1eaea46 | 4314 | /* Stuff the bytes into the fifo queue */ |
036bca1f | 4315 | sent = kfifo_in_locked(&dlci->fifo, buf, len, &dlci->lock); |
e1eaea46 AC |
4316 | /* Need to kick the channel */ |
4317 | gsm_dlci_data_kick(dlci); | |
4318 | return sent; | |
4319 | } | |
4320 | ||
03b3b1a2 | 4321 | static unsigned int gsmtty_write_room(struct tty_struct *tty) |
e1eaea46 AC |
4322 | { |
4323 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 | 4324 | if (dlci->state == DLCI_CLOSED) |
6bfbfcfc | 4325 | return 0; |
9361ebfb | 4326 | return kfifo_avail(&dlci->fifo); |
e1eaea46 AC |
4327 | } |
4328 | ||
fff4ef17 | 4329 | static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty) |
e1eaea46 AC |
4330 | { |
4331 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 | 4332 | if (dlci->state == DLCI_CLOSED) |
10eb63e5 | 4333 | return 0; |
036bca1f | 4334 | return kfifo_len(&dlci->fifo); |
e1eaea46 AC |
4335 | } |
4336 | ||
4337 | static void gsmtty_flush_buffer(struct tty_struct *tty) | |
4338 | { | |
4339 | struct gsm_dlci *dlci = tty->driver_data; | |
73029a4d DS |
4340 | unsigned long flags; |
4341 | ||
4d9b1090 DB |
4342 | if (dlci->state == DLCI_CLOSED) |
4343 | return; | |
e1eaea46 AC |
4344 | /* Caution needed: If we implement reliable transport classes |
4345 | then the data being transmitted can't simply be junked once | |
4346 | it has first hit the stack. Until then we can just blow it | |
4347 | away */ | |
73029a4d | 4348 | spin_lock_irqsave(&dlci->lock, flags); |
036bca1f | 4349 | kfifo_reset(&dlci->fifo); |
73029a4d | 4350 | spin_unlock_irqrestore(&dlci->lock, flags); |
e1eaea46 AC |
4351 | /* Need to unhook this DLCI from the transmit queue logic */ |
4352 | } | |
4353 | ||
4354 | static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout) | |
4355 | { | |
4356 | /* The FIFO handles the queue so the kernel will do the right | |
4357 | thing waiting on chars_in_buffer before calling us. No work | |
4358 | to do here */ | |
4359 | } | |
4360 | ||
60b33c13 | 4361 | static int gsmtty_tiocmget(struct tty_struct *tty) |
e1eaea46 AC |
4362 | { |
4363 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
4364 | if (dlci->state == DLCI_CLOSED) |
4365 | return -EINVAL; | |
e1eaea46 AC |
4366 | return dlci->modem_rx; |
4367 | } | |
4368 | ||
20b9d177 | 4369 | static int gsmtty_tiocmset(struct tty_struct *tty, |
e1eaea46 AC |
4370 | unsigned int set, unsigned int clear) |
4371 | { | |
4372 | struct gsm_dlci *dlci = tty->driver_data; | |
4373 | unsigned int modem_tx = dlci->modem_tx; | |
4374 | ||
4d9b1090 DB |
4375 | if (dlci->state == DLCI_CLOSED) |
4376 | return -EINVAL; | |
cf16807b | 4377 | modem_tx &= ~clear; |
e1eaea46 AC |
4378 | modem_tx |= set; |
4379 | ||
4380 | if (modem_tx != dlci->modem_tx) { | |
4381 | dlci->modem_tx = modem_tx; | |
c19ffe00 | 4382 | return gsm_modem_update(dlci, 0); |
e1eaea46 AC |
4383 | } |
4384 | return 0; | |
4385 | } | |
4386 | ||
4387 | ||
6caa76b7 | 4388 | static int gsmtty_ioctl(struct tty_struct *tty, |
e1eaea46 AC |
4389 | unsigned int cmd, unsigned long arg) |
4390 | { | |
bcd5abe2 RG |
4391 | struct gsm_dlci *dlci = tty->driver_data; |
4392 | struct gsm_netconfig nc; | |
4ca58966 | 4393 | struct gsm_dlci_config dc; |
bcd5abe2 RG |
4394 | int index; |
4395 | ||
4d9b1090 DB |
4396 | if (dlci->state == DLCI_CLOSED) |
4397 | return -EINVAL; | |
bcd5abe2 RG |
4398 | switch (cmd) { |
4399 | case GSMIOC_ENABLE_NET: | |
4400 | if (copy_from_user(&nc, (void __user *)arg, sizeof(nc))) | |
4401 | return -EFAULT; | |
4402 | nc.if_name[IFNAMSIZ-1] = '\0'; | |
4403 | /* return net interface index or error code */ | |
4404 | mutex_lock(&dlci->mutex); | |
4405 | index = gsm_create_network(dlci, &nc); | |
4406 | mutex_unlock(&dlci->mutex); | |
4407 | if (copy_to_user((void __user *)arg, &nc, sizeof(nc))) | |
4408 | return -EFAULT; | |
4409 | return index; | |
4410 | case GSMIOC_DISABLE_NET: | |
4411 | if (!capable(CAP_NET_ADMIN)) | |
4412 | return -EPERM; | |
4413 | mutex_lock(&dlci->mutex); | |
4414 | gsm_destroy_network(dlci); | |
4415 | mutex_unlock(&dlci->mutex); | |
4416 | return 0; | |
4ca58966 DS |
4417 | case GSMIOC_GETCONF_DLCI: |
4418 | if (copy_from_user(&dc, (void __user *)arg, sizeof(dc))) | |
4419 | return -EFAULT; | |
4420 | if (dc.channel != dlci->addr) | |
4421 | return -EPERM; | |
4422 | gsm_dlci_copy_config_values(dlci, &dc); | |
4423 | if (copy_to_user((void __user *)arg, &dc, sizeof(dc))) | |
4424 | return -EFAULT; | |
4425 | return 0; | |
4426 | case GSMIOC_SETCONF_DLCI: | |
4427 | if (copy_from_user(&dc, (void __user *)arg, sizeof(dc))) | |
4428 | return -EFAULT; | |
4429 | if (dc.channel >= NUM_DLCI) | |
4430 | return -EINVAL; | |
4431 | if (dc.channel != 0 && dc.channel != dlci->addr) | |
4432 | return -EPERM; | |
4433 | return gsm_dlci_config(dlci, &dc, 1); | |
684ae4f9 DS |
4434 | case TIOCMIWAIT: |
4435 | return gsm_wait_modem_change(dlci, (u32)arg); | |
bcd5abe2 RG |
4436 | default: |
4437 | return -ENOIOCTLCMD; | |
4438 | } | |
e1eaea46 AC |
4439 | } |
4440 | ||
a8c11c15 IJ |
4441 | static void gsmtty_set_termios(struct tty_struct *tty, |
4442 | const struct ktermios *old) | |
e1eaea46 | 4443 | { |
4d9b1090 DB |
4444 | struct gsm_dlci *dlci = tty->driver_data; |
4445 | if (dlci->state == DLCI_CLOSED) | |
4446 | return; | |
e1eaea46 AC |
4447 | /* For the moment its fixed. In actual fact the speed information |
4448 | for the virtual channel can be propogated in both directions by | |
4449 | the RPN control message. This however rapidly gets nasty as we | |
4450 | then have to remap modem signals each way according to whether | |
4451 | our virtual cable is null modem etc .. */ | |
adc8d746 | 4452 | tty_termios_copy_hw(&tty->termios, old); |
e1eaea46 AC |
4453 | } |
4454 | ||
4455 | static void gsmtty_throttle(struct tty_struct *tty) | |
4456 | { | |
4457 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
4458 | if (dlci->state == DLCI_CLOSED) |
4459 | return; | |
9db276f8 | 4460 | if (C_CRTSCTS(tty)) |
c19d9354 | 4461 | dlci->modem_tx &= ~TIOCM_RTS; |
e9360b9a | 4462 | dlci->throttled = true; |
c19d9354 | 4463 | /* Send an MSC with RTS cleared */ |
c19ffe00 | 4464 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
4465 | } |
4466 | ||
4467 | static void gsmtty_unthrottle(struct tty_struct *tty) | |
4468 | { | |
4469 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
4470 | if (dlci->state == DLCI_CLOSED) |
4471 | return; | |
9db276f8 | 4472 | if (C_CRTSCTS(tty)) |
c19d9354 | 4473 | dlci->modem_tx |= TIOCM_RTS; |
e9360b9a | 4474 | dlci->throttled = false; |
c19d9354 | 4475 | /* Send an MSC with RTS set */ |
c19ffe00 | 4476 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
4477 | } |
4478 | ||
4479 | static int gsmtty_break_ctl(struct tty_struct *tty, int state) | |
4480 | { | |
4481 | struct gsm_dlci *dlci = tty->driver_data; | |
4482 | int encode = 0; /* Off */ | |
4d9b1090 DB |
4483 | if (dlci->state == DLCI_CLOSED) |
4484 | return -EINVAL; | |
e1eaea46 AC |
4485 | |
4486 | if (state == -1) /* "On indefinitely" - we can't encode this | |
4487 | properly */ | |
4488 | encode = 0x0F; | |
4489 | else if (state > 0) { | |
4490 | encode = state / 200; /* mS to encoding */ | |
4491 | if (encode > 0x0F) | |
4492 | encode = 0x0F; /* Best effort */ | |
4493 | } | |
c19ffe00 | 4494 | return gsm_modem_update(dlci, encode); |
e1eaea46 AC |
4495 | } |
4496 | ||
8f9cfeed | 4497 | static void gsmtty_cleanup(struct tty_struct *tty) |
dfabf7ff CB |
4498 | { |
4499 | struct gsm_dlci *dlci = tty->driver_data; | |
4500 | struct gsm_mux *gsm = dlci->gsm; | |
4501 | ||
4502 | dlci_put(dlci); | |
4503 | dlci_put(gsm->dlci[0]); | |
4504 | mux_put(gsm); | |
dfabf7ff | 4505 | } |
e1eaea46 AC |
4506 | |
4507 | /* Virtual ttys for the demux */ | |
4508 | static const struct tty_operations gsmtty_ops = { | |
86176ed9 | 4509 | .install = gsmtty_install, |
e1eaea46 AC |
4510 | .open = gsmtty_open, |
4511 | .close = gsmtty_close, | |
4512 | .write = gsmtty_write, | |
4513 | .write_room = gsmtty_write_room, | |
4514 | .chars_in_buffer = gsmtty_chars_in_buffer, | |
4515 | .flush_buffer = gsmtty_flush_buffer, | |
4516 | .ioctl = gsmtty_ioctl, | |
4517 | .throttle = gsmtty_throttle, | |
4518 | .unthrottle = gsmtty_unthrottle, | |
4519 | .set_termios = gsmtty_set_termios, | |
4520 | .hangup = gsmtty_hangup, | |
4521 | .wait_until_sent = gsmtty_wait_until_sent, | |
4522 | .tiocmget = gsmtty_tiocmget, | |
4523 | .tiocmset = gsmtty_tiocmset, | |
4524 | .break_ctl = gsmtty_break_ctl, | |
8f9cfeed | 4525 | .cleanup = gsmtty_cleanup, |
e1eaea46 AC |
4526 | }; |
4527 | ||
4528 | ||
4529 | ||
4530 | static int __init gsm_init(void) | |
4531 | { | |
4532 | /* Fill in our line protocol discipline, and register it */ | |
fbadf70a | 4533 | int status = tty_register_ldisc(&tty_ldisc_packet); |
e1eaea46 | 4534 | if (status != 0) { |
5f9a31d6 AC |
4535 | pr_err("n_gsm: can't register line discipline (err = %d)\n", |
4536 | status); | |
e1eaea46 AC |
4537 | return status; |
4538 | } | |
4539 | ||
796492de | 4540 | gsm_tty_driver = tty_alloc_driver(GSM_TTY_MINORS, TTY_DRIVER_REAL_RAW | |
39b7b42b JS |
4541 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK); |
4542 | if (IS_ERR(gsm_tty_driver)) { | |
5f9a31d6 | 4543 | pr_err("gsm_init: tty allocation failed.\n"); |
39b7b42b | 4544 | status = PTR_ERR(gsm_tty_driver); |
839e0f22 | 4545 | goto err_unreg_ldisc; |
e1eaea46 | 4546 | } |
e1eaea46 AC |
4547 | gsm_tty_driver->driver_name = "gsmtty"; |
4548 | gsm_tty_driver->name = "gsmtty"; | |
4549 | gsm_tty_driver->major = 0; /* Dynamic */ | |
4550 | gsm_tty_driver->minor_start = 0; | |
4551 | gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; | |
4552 | gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; | |
e1eaea46 AC |
4553 | gsm_tty_driver->init_termios = tty_std_termios; |
4554 | /* Fixme */ | |
4555 | gsm_tty_driver->init_termios.c_lflag &= ~ECHO; | |
4556 | tty_set_operations(gsm_tty_driver, &gsmtty_ops); | |
4557 | ||
e1eaea46 | 4558 | if (tty_register_driver(gsm_tty_driver)) { |
5f9a31d6 | 4559 | pr_err("gsm_init: tty registration failed.\n"); |
839e0f22 JS |
4560 | status = -EBUSY; |
4561 | goto err_put_driver; | |
e1eaea46 | 4562 | } |
5f9a31d6 AC |
4563 | pr_debug("gsm_init: loaded as %d,%d.\n", |
4564 | gsm_tty_driver->major, gsm_tty_driver->minor_start); | |
e1eaea46 | 4565 | return 0; |
839e0f22 | 4566 | err_put_driver: |
9f90a4dd | 4567 | tty_driver_kref_put(gsm_tty_driver); |
839e0f22 | 4568 | err_unreg_ldisc: |
f81ee8b8 | 4569 | tty_unregister_ldisc(&tty_ldisc_packet); |
839e0f22 | 4570 | return status; |
e1eaea46 AC |
4571 | } |
4572 | ||
4573 | static void __exit gsm_exit(void) | |
4574 | { | |
357a6a87 | 4575 | tty_unregister_ldisc(&tty_ldisc_packet); |
e1eaea46 | 4576 | tty_unregister_driver(gsm_tty_driver); |
9f90a4dd | 4577 | tty_driver_kref_put(gsm_tty_driver); |
e1eaea46 AC |
4578 | } |
4579 | ||
4580 | module_init(gsm_init); | |
4581 | module_exit(gsm_exit); | |
4582 | ||
4583 | ||
4584 | MODULE_LICENSE("GPL"); | |
4585 | MODULE_ALIAS_LDISC(N_GSM0710); |