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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 | |
5 | * | |
e1eaea46 AC |
6 | * * THIS IS A DEVELOPMENT SNAPSHOT IT IS NOT A FINAL RELEASE * |
7 | * | |
0af02167 DS |
8 | * Outgoing path: |
9 | * tty -> DLCI fifo -> scheduler -> GSM MUX data queue ---o-> ldisc | |
10 | * control message -> GSM MUX control queue --ยด | |
11 | * | |
12 | * Incoming path: | |
13 | * ldisc -> gsm_queue() -o--> tty | |
14 | * `-> gsm_control_response() | |
15 | * | |
e1eaea46 AC |
16 | * TO DO: |
17 | * Mostly done: ioctls for setting modes/timing | |
5f9a31d6 | 18 | * Partly done: hooks so you can pull off frames to non tty devs |
e1eaea46 | 19 | * Restart DLCI 0 when it closes ? |
e1eaea46 AC |
20 | * Improve the tx engine |
21 | * Resolve tx side locking by adding a queue_head and routing | |
22 | * all control traffic via it | |
23 | * General tidy/document | |
24 | * Review the locking/move to refcounts more (mux now moved to an | |
25 | * alloc/free model ready) | |
26 | * Use newest tty open/close port helpers and install hooks | |
27 | * What to do about power functions ? | |
28 | * Termios setting and negotiation | |
29 | * Do we need a 'which mux are you' ioctl to correlate mux and tty sets | |
30 | * | |
31 | */ | |
32 | ||
33 | #include <linux/types.h> | |
34 | #include <linux/major.h> | |
35 | #include <linux/errno.h> | |
36 | #include <linux/signal.h> | |
37 | #include <linux/fcntl.h> | |
174cd4b1 | 38 | #include <linux/sched/signal.h> |
e1eaea46 AC |
39 | #include <linux/interrupt.h> |
40 | #include <linux/tty.h> | |
e1eaea46 AC |
41 | #include <linux/ctype.h> |
42 | #include <linux/mm.h> | |
43 | #include <linux/string.h> | |
44 | #include <linux/slab.h> | |
45 | #include <linux/poll.h> | |
46 | #include <linux/bitops.h> | |
47 | #include <linux/file.h> | |
48 | #include <linux/uaccess.h> | |
49 | #include <linux/module.h> | |
50 | #include <linux/timer.h> | |
51 | #include <linux/tty_flip.h> | |
52 | #include <linux/tty_driver.h> | |
53 | #include <linux/serial.h> | |
54 | #include <linux/kfifo.h> | |
55 | #include <linux/skbuff.h> | |
bcd5abe2 RG |
56 | #include <net/arp.h> |
57 | #include <linux/ip.h> | |
58 | #include <linux/netdevice.h> | |
59 | #include <linux/etherdevice.h> | |
e1eaea46 | 60 | #include <linux/gsmmux.h> |
5ffa6e34 | 61 | #include "tty.h" |
e1eaea46 AC |
62 | |
63 | static int debug; | |
64 | module_param(debug, int, 0600); | |
65 | ||
a8d12007 AC |
66 | /* Defaults: these are from the specification */ |
67 | ||
68 | #define T1 10 /* 100mS */ | |
69 | #define T2 34 /* 333mS */ | |
70 | #define N2 3 /* Retry 3 times */ | |
e1eaea46 AC |
71 | |
72 | /* Use long timers for testing at low speed with debug on */ | |
73 | #ifdef DEBUG_TIMING | |
a8d12007 AC |
74 | #define T1 100 |
75 | #define T2 200 | |
e1eaea46 AC |
76 | #endif |
77 | ||
5f9a31d6 | 78 | /* |
25985edc | 79 | * Semi-arbitrary buffer size limits. 0710 is normally run with 32-64 byte |
5f9a31d6 AC |
80 | * limits so this is plenty |
81 | */ | |
bcd5abe2 RG |
82 | #define MAX_MRU 1500 |
83 | #define MAX_MTU 1500 | |
535bf600 DS |
84 | /* SOF, ADDR, CTRL, LEN1, LEN2, ..., FCS, EOF */ |
85 | #define PROT_OVERHEAD 7 | |
bcd5abe2 RG |
86 | #define GSM_NET_TX_TIMEOUT (HZ*10) |
87 | ||
b410e35d | 88 | /* |
bcd5abe2 | 89 | * struct gsm_mux_net - network interface |
bcd5abe2 RG |
90 | * |
91 | * Created when net interface is initialized. | |
724ac070 | 92 | */ |
bcd5abe2 RG |
93 | struct gsm_mux_net { |
94 | struct kref ref; | |
95 | struct gsm_dlci *dlci; | |
bcd5abe2 RG |
96 | }; |
97 | ||
e1eaea46 AC |
98 | /* |
99 | * Each block of data we have queued to go out is in the form of | |
25985edc | 100 | * a gsm_msg which holds everything we need in a link layer independent |
e1eaea46 AC |
101 | * format |
102 | */ | |
103 | ||
104 | struct gsm_msg { | |
b4338e1e | 105 | struct list_head list; |
e1eaea46 AC |
106 | u8 addr; /* DLCI address + flags */ |
107 | u8 ctrl; /* Control byte + flags */ | |
108 | unsigned int len; /* Length of data block (can be zero) */ | |
109 | unsigned char *data; /* Points into buffer but not at the start */ | |
2f202d03 | 110 | unsigned char buffer[]; |
e1eaea46 AC |
111 | }; |
112 | ||
72ae8cc1 JS |
113 | enum gsm_dlci_state { |
114 | DLCI_CLOSED, | |
115 | DLCI_OPENING, /* Sending SABM not seen UA */ | |
116 | DLCI_OPEN, /* SABM/UA complete */ | |
117 | DLCI_CLOSING, /* Sending DISC not seen UA/DM */ | |
118 | }; | |
119 | ||
e1785996 JS |
120 | enum gsm_dlci_mode { |
121 | DLCI_MODE_ABM, /* Normal Asynchronous Balanced Mode */ | |
122 | DLCI_MODE_ADM, /* Asynchronous Disconnected Mode */ | |
123 | }; | |
124 | ||
e1eaea46 AC |
125 | /* |
126 | * Each active data link has a gsm_dlci structure associated which ties | |
127 | * the link layer to an optional tty (if the tty side is open). To avoid | |
128 | * complexity right now these are only ever freed up when the mux is | |
129 | * shut down. | |
130 | * | |
131 | * At the moment we don't free DLCI objects until the mux is torn down | |
132 | * this avoid object life time issues but might be worth review later. | |
133 | */ | |
134 | ||
135 | struct gsm_dlci { | |
136 | struct gsm_mux *gsm; | |
137 | int addr; | |
72ae8cc1 | 138 | enum gsm_dlci_state state; |
bcd5abe2 | 139 | struct mutex mutex; |
e1eaea46 AC |
140 | |
141 | /* Link layer */ | |
e1785996 | 142 | enum gsm_dlci_mode mode; |
e1eaea46 AC |
143 | spinlock_t lock; /* Protects the internal state */ |
144 | struct timer_list t1; /* Retransmit timer for SABM and UA */ | |
145 | int retries; | |
146 | /* Uplink tty if active */ | |
147 | struct tty_port port; /* The tty bound to this DLCI if there is one */ | |
9361ebfb | 148 | #define TX_SIZE 4096 /* Must be power of 2. */ |
036bca1f | 149 | struct kfifo fifo; /* Queue fifo for the DLCI */ |
e1eaea46 | 150 | int adaption; /* Adaption layer in use */ |
bcd5abe2 | 151 | int prev_adaption; |
e1eaea46 AC |
152 | u32 modem_rx; /* Our incoming virtual modem lines */ |
153 | u32 modem_tx; /* Our outgoing modem lines */ | |
5677fcf3 | 154 | bool dead; /* Refuse re-open */ |
e1eaea46 | 155 | /* Flow control */ |
e9360b9a | 156 | bool throttled; /* Private copy of throttle state */ |
7a9ed9c0 | 157 | bool constipated; /* Throttle status for outgoing */ |
e1eaea46 AC |
158 | /* Packetised I/O */ |
159 | struct sk_buff *skb; /* Frame being sent */ | |
160 | struct sk_buff_head skb_list; /* Queued frames */ | |
161 | /* Data handling callback */ | |
4feb7a4a TL |
162 | void (*data)(struct gsm_dlci *dlci, const u8 *data, int len); |
163 | void (*prev_data)(struct gsm_dlci *dlci, const u8 *data, int len); | |
bcd5abe2 | 164 | struct net_device *net; /* network interface, if created */ |
e1eaea46 AC |
165 | }; |
166 | ||
c33eecc7 | 167 | /* DLCI 0, 62/63 are special or reserved see gsmtty_open */ |
e1eaea46 AC |
168 | |
169 | #define NUM_DLCI 64 | |
170 | ||
171 | /* | |
172 | * DLCI 0 is used to pass control blocks out of band of the data | |
173 | * flow (and with a higher link priority). One command can be outstanding | |
174 | * at a time and we use this structure to manage them. They are created | |
175 | * and destroyed by the user context, and updated by the receive paths | |
176 | * and timers | |
177 | */ | |
178 | ||
179 | struct gsm_control { | |
180 | u8 cmd; /* Command we are issuing */ | |
181 | u8 *data; /* Data for the command in case we retransmit */ | |
182 | int len; /* Length of block for retransmission */ | |
183 | int done; /* Done flag */ | |
184 | int error; /* Error if any */ | |
185 | }; | |
186 | ||
329aa6e6 JS |
187 | enum gsm_mux_state { |
188 | GSM_SEARCH, | |
189 | GSM_START, | |
190 | GSM_ADDRESS, | |
191 | GSM_CONTROL, | |
192 | GSM_LEN, | |
193 | GSM_DATA, | |
194 | GSM_FCS, | |
195 | GSM_OVERRUN, | |
196 | GSM_LEN0, | |
197 | GSM_LEN1, | |
198 | GSM_SSOF, | |
199 | }; | |
200 | ||
e1eaea46 AC |
201 | /* |
202 | * Each GSM mux we have is represented by this structure. If we are | |
203 | * operating as an ldisc then we use this structure as our ldisc | |
204 | * state. We need to sort out lifetimes and locking with respect | |
205 | * to the gsm mux array. For now we don't free DLCI objects that | |
206 | * have been instantiated until the mux itself is terminated. | |
207 | * | |
208 | * To consider further: tty open versus mux shutdown. | |
209 | */ | |
210 | ||
211 | struct gsm_mux { | |
212 | struct tty_struct *tty; /* The tty our ldisc is bound to */ | |
213 | spinlock_t lock; | |
dfabf7ff | 214 | struct mutex mutex; |
d50f6dca | 215 | unsigned int num; |
6ab8fba7 | 216 | struct kref ref; |
e1eaea46 AC |
217 | |
218 | /* Events on the GSM channel */ | |
219 | wait_queue_head_t event; | |
220 | ||
0af02167 DS |
221 | /* ldisc send work */ |
222 | struct work_struct tx_work; | |
223 | ||
e1eaea46 AC |
224 | /* Bits for GSM mode decoding */ |
225 | ||
226 | /* Framing Layer */ | |
227 | unsigned char *buf; | |
329aa6e6 | 228 | enum gsm_mux_state state; |
e1eaea46 AC |
229 | unsigned int len; |
230 | unsigned int address; | |
231 | unsigned int count; | |
c50704bd | 232 | bool escape; |
e1eaea46 AC |
233 | int encoding; |
234 | u8 control; | |
235 | u8 fcs; | |
236 | u8 *txframe; /* TX framing buffer */ | |
237 | ||
a579767c | 238 | /* Method for the receiver side */ |
e1eaea46 | 239 | void (*receive)(struct gsm_mux *gsm, u8 ch); |
e1eaea46 AC |
240 | |
241 | /* Link Layer */ | |
242 | unsigned int mru; | |
243 | unsigned int mtu; | |
244 | int initiator; /* Did we initiate connection */ | |
5677fcf3 | 245 | bool dead; /* Has the mux been shut down */ |
e1eaea46 | 246 | struct gsm_dlci *dlci[NUM_DLCI]; |
f4f7d632 | 247 | int old_c_iflag; /* termios c_iflag value before attach */ |
7a9ed9c0 | 248 | bool constipated; /* Asked by remote to shut up */ |
01aecd91 | 249 | bool has_devices; /* Devices were registered */ |
e1eaea46 | 250 | |
902e02ea | 251 | struct mutex tx_mutex; |
e1eaea46 AC |
252 | unsigned int tx_bytes; /* TX data outstanding */ |
253 | #define TX_THRESH_HI 8192 | |
254 | #define TX_THRESH_LO 2048 | |
0af02167 DS |
255 | struct list_head tx_ctrl_list; /* Pending control packets */ |
256 | struct list_head tx_data_list; /* Pending data packets */ | |
e1eaea46 AC |
257 | |
258 | /* Control messages */ | |
c9ab053e | 259 | struct delayed_work kick_timeout; /* Kick TX queuing on timeout */ |
e1eaea46 AC |
260 | struct timer_list t2_timer; /* Retransmit timer for commands */ |
261 | int cretries; /* Command retry counter */ | |
262 | struct gsm_control *pending_cmd;/* Our current pending command */ | |
263 | spinlock_t control_lock; /* Protects the pending command */ | |
264 | ||
265 | /* Configuration */ | |
266 | int adaption; /* 1 or 2 supported */ | |
267 | u8 ftype; /* UI or UIH */ | |
268 | int t1, t2; /* Timers in 1/100th of a sec */ | |
269 | int n2; /* Retry count */ | |
270 | ||
271 | /* Statistics (not currently exposed) */ | |
272 | unsigned long bad_fcs; | |
273 | unsigned long malformed; | |
274 | unsigned long io_error; | |
275 | unsigned long bad_size; | |
276 | unsigned long unsupported; | |
277 | }; | |
278 | ||
279 | ||
280 | /* | |
281 | * Mux objects - needed so that we can translate a tty index into the | |
282 | * relevant mux and DLCI. | |
283 | */ | |
284 | ||
285 | #define MAX_MUX 4 /* 256 minors */ | |
286 | static struct gsm_mux *gsm_mux[MAX_MUX]; /* GSM muxes */ | |
399d44a1 | 287 | static DEFINE_SPINLOCK(gsm_mux_lock); |
e1eaea46 | 288 | |
d50f6dca RG |
289 | static struct tty_driver *gsm_tty_driver; |
290 | ||
e1eaea46 AC |
291 | /* |
292 | * This section of the driver logic implements the GSM encodings | |
293 | * both the basic and the 'advanced'. Reliable transport is not | |
294 | * supported. | |
295 | */ | |
296 | ||
297 | #define CR 0x02 | |
298 | #define EA 0x01 | |
299 | #define PF 0x10 | |
300 | ||
301 | /* I is special: the rest are ..*/ | |
302 | #define RR 0x01 | |
303 | #define UI 0x03 | |
304 | #define RNR 0x05 | |
305 | #define REJ 0x09 | |
306 | #define DM 0x0F | |
307 | #define SABM 0x2F | |
308 | #define DISC 0x43 | |
309 | #define UA 0x63 | |
310 | #define UIH 0xEF | |
311 | ||
312 | /* Channel commands */ | |
313 | #define CMD_NSC 0x09 | |
314 | #define CMD_TEST 0x11 | |
315 | #define CMD_PSC 0x21 | |
316 | #define CMD_RLS 0x29 | |
317 | #define CMD_FCOFF 0x31 | |
318 | #define CMD_PN 0x41 | |
319 | #define CMD_RPN 0x49 | |
320 | #define CMD_FCON 0x51 | |
321 | #define CMD_CLD 0x61 | |
322 | #define CMD_SNC 0x69 | |
323 | #define CMD_MSC 0x71 | |
324 | ||
325 | /* Virtual modem bits */ | |
326 | #define MDM_FC 0x01 | |
327 | #define MDM_RTC 0x02 | |
328 | #define MDM_RTR 0x04 | |
329 | #define MDM_IC 0x20 | |
330 | #define MDM_DV 0x40 | |
331 | ||
332 | #define GSM0_SOF 0xF9 | |
5f9a31d6 | 333 | #define GSM1_SOF 0x7E |
e1eaea46 AC |
334 | #define GSM1_ESCAPE 0x7D |
335 | #define GSM1_ESCAPE_BITS 0x20 | |
336 | #define XON 0x11 | |
337 | #define XOFF 0x13 | |
8838b2af | 338 | #define ISO_IEC_646_MASK 0x7F |
e1eaea46 AC |
339 | |
340 | static const struct tty_port_operations gsm_port_ops; | |
341 | ||
342 | /* | |
343 | * CRC table for GSM 0710 | |
344 | */ | |
345 | ||
346 | static const u8 gsm_fcs8[256] = { | |
347 | 0x00, 0x91, 0xE3, 0x72, 0x07, 0x96, 0xE4, 0x75, | |
348 | 0x0E, 0x9F, 0xED, 0x7C, 0x09, 0x98, 0xEA, 0x7B, | |
349 | 0x1C, 0x8D, 0xFF, 0x6E, 0x1B, 0x8A, 0xF8, 0x69, | |
350 | 0x12, 0x83, 0xF1, 0x60, 0x15, 0x84, 0xF6, 0x67, | |
351 | 0x38, 0xA9, 0xDB, 0x4A, 0x3F, 0xAE, 0xDC, 0x4D, | |
352 | 0x36, 0xA7, 0xD5, 0x44, 0x31, 0xA0, 0xD2, 0x43, | |
353 | 0x24, 0xB5, 0xC7, 0x56, 0x23, 0xB2, 0xC0, 0x51, | |
354 | 0x2A, 0xBB, 0xC9, 0x58, 0x2D, 0xBC, 0xCE, 0x5F, | |
355 | 0x70, 0xE1, 0x93, 0x02, 0x77, 0xE6, 0x94, 0x05, | |
356 | 0x7E, 0xEF, 0x9D, 0x0C, 0x79, 0xE8, 0x9A, 0x0B, | |
357 | 0x6C, 0xFD, 0x8F, 0x1E, 0x6B, 0xFA, 0x88, 0x19, | |
358 | 0x62, 0xF3, 0x81, 0x10, 0x65, 0xF4, 0x86, 0x17, | |
359 | 0x48, 0xD9, 0xAB, 0x3A, 0x4F, 0xDE, 0xAC, 0x3D, | |
360 | 0x46, 0xD7, 0xA5, 0x34, 0x41, 0xD0, 0xA2, 0x33, | |
361 | 0x54, 0xC5, 0xB7, 0x26, 0x53, 0xC2, 0xB0, 0x21, | |
362 | 0x5A, 0xCB, 0xB9, 0x28, 0x5D, 0xCC, 0xBE, 0x2F, | |
363 | 0xE0, 0x71, 0x03, 0x92, 0xE7, 0x76, 0x04, 0x95, | |
364 | 0xEE, 0x7F, 0x0D, 0x9C, 0xE9, 0x78, 0x0A, 0x9B, | |
365 | 0xFC, 0x6D, 0x1F, 0x8E, 0xFB, 0x6A, 0x18, 0x89, | |
366 | 0xF2, 0x63, 0x11, 0x80, 0xF5, 0x64, 0x16, 0x87, | |
367 | 0xD8, 0x49, 0x3B, 0xAA, 0xDF, 0x4E, 0x3C, 0xAD, | |
368 | 0xD6, 0x47, 0x35, 0xA4, 0xD1, 0x40, 0x32, 0xA3, | |
369 | 0xC4, 0x55, 0x27, 0xB6, 0xC3, 0x52, 0x20, 0xB1, | |
370 | 0xCA, 0x5B, 0x29, 0xB8, 0xCD, 0x5C, 0x2E, 0xBF, | |
371 | 0x90, 0x01, 0x73, 0xE2, 0x97, 0x06, 0x74, 0xE5, | |
372 | 0x9E, 0x0F, 0x7D, 0xEC, 0x99, 0x08, 0x7A, 0xEB, | |
373 | 0x8C, 0x1D, 0x6F, 0xFE, 0x8B, 0x1A, 0x68, 0xF9, | |
374 | 0x82, 0x13, 0x61, 0xF0, 0x85, 0x14, 0x66, 0xF7, | |
375 | 0xA8, 0x39, 0x4B, 0xDA, 0xAF, 0x3E, 0x4C, 0xDD, | |
376 | 0xA6, 0x37, 0x45, 0xD4, 0xA1, 0x30, 0x42, 0xD3, | |
377 | 0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, | |
378 | 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF | |
379 | }; | |
380 | ||
381 | #define INIT_FCS 0xFF | |
382 | #define GOOD_FCS 0xCF | |
383 | ||
a579767c | 384 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len); |
c19ffe00 | 385 | static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk); |
0af02167 DS |
386 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, |
387 | u8 ctrl); | |
388 | static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg); | |
389 | static void gsmld_write_trigger(struct gsm_mux *gsm); | |
390 | static void gsmld_write_task(struct work_struct *work); | |
a579767c | 391 | |
e1eaea46 AC |
392 | /** |
393 | * gsm_fcs_add - update FCS | |
394 | * @fcs: Current FCS | |
395 | * @c: Next data | |
396 | * | |
397 | * Update the FCS to include c. Uses the algorithm in the specification | |
398 | * notes. | |
399 | */ | |
400 | ||
401 | static inline u8 gsm_fcs_add(u8 fcs, u8 c) | |
402 | { | |
403 | return gsm_fcs8[fcs ^ c]; | |
404 | } | |
405 | ||
406 | /** | |
407 | * gsm_fcs_add_block - update FCS for a block | |
408 | * @fcs: Current FCS | |
409 | * @c: buffer of data | |
410 | * @len: length of buffer | |
411 | * | |
412 | * Update the FCS to include c. Uses the algorithm in the specification | |
413 | * notes. | |
414 | */ | |
415 | ||
416 | static inline u8 gsm_fcs_add_block(u8 fcs, u8 *c, int len) | |
417 | { | |
418 | while (len--) | |
419 | fcs = gsm_fcs8[fcs ^ *c++]; | |
420 | return fcs; | |
421 | } | |
422 | ||
423 | /** | |
424 | * gsm_read_ea - read a byte into an EA | |
425 | * @val: variable holding value | |
724ac070 | 426 | * @c: byte going into the EA |
e1eaea46 AC |
427 | * |
428 | * Processes one byte of an EA. Updates the passed variable | |
429 | * and returns 1 if the EA is now completely read | |
430 | */ | |
431 | ||
432 | static int gsm_read_ea(unsigned int *val, u8 c) | |
433 | { | |
434 | /* Add the next 7 bits into the value */ | |
435 | *val <<= 7; | |
436 | *val |= c >> 1; | |
437 | /* Was this the last byte of the EA 1 = yes*/ | |
438 | return c & EA; | |
439 | } | |
440 | ||
bec02248 DS |
441 | /** |
442 | * gsm_read_ea_val - read a value until EA | |
443 | * @val: variable holding value | |
444 | * @data: buffer of data | |
445 | * @dlen: length of data | |
446 | * | |
447 | * Processes an EA value. Updates the passed variable and | |
448 | * returns the processed data length. | |
449 | */ | |
450 | static unsigned int gsm_read_ea_val(unsigned int *val, const u8 *data, int dlen) | |
451 | { | |
452 | unsigned int len = 0; | |
453 | ||
454 | for (; dlen > 0; dlen--) { | |
455 | len++; | |
456 | if (gsm_read_ea(val, *data++)) | |
457 | break; | |
458 | } | |
459 | return len; | |
460 | } | |
461 | ||
e1eaea46 AC |
462 | /** |
463 | * gsm_encode_modem - encode modem data bits | |
464 | * @dlci: DLCI to encode from | |
465 | * | |
466 | * Returns the correct GSM encoded modem status bits (6 bit field) for | |
467 | * the current status of the DLCI and attached tty object | |
468 | */ | |
469 | ||
470 | static u8 gsm_encode_modem(const struct gsm_dlci *dlci) | |
471 | { | |
472 | u8 modembits = 0; | |
473 | /* FC is true flow control not modem bits */ | |
474 | if (dlci->throttled) | |
475 | modembits |= MDM_FC; | |
476 | if (dlci->modem_tx & TIOCM_DTR) | |
477 | modembits |= MDM_RTC; | |
478 | if (dlci->modem_tx & TIOCM_RTS) | |
479 | modembits |= MDM_RTR; | |
480 | if (dlci->modem_tx & TIOCM_RI) | |
481 | modembits |= MDM_IC; | |
737b0ef3 | 482 | if (dlci->modem_tx & TIOCM_CD || dlci->gsm->initiator) |
e1eaea46 AC |
483 | modembits |= MDM_DV; |
484 | return modembits; | |
485 | } | |
486 | ||
925ea0fa TL |
487 | static void gsm_hex_dump_bytes(const char *fname, const u8 *data, |
488 | unsigned long len) | |
489 | { | |
490 | char *prefix; | |
491 | ||
492 | if (!fname) { | |
493 | print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, data, len, | |
494 | true); | |
495 | return; | |
496 | } | |
497 | ||
e74024b2 | 498 | prefix = kasprintf(GFP_ATOMIC, "%s: ", fname); |
925ea0fa TL |
499 | if (!prefix) |
500 | return; | |
501 | print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len, | |
502 | true); | |
503 | kfree(prefix); | |
504 | } | |
505 | ||
01aecd91 DS |
506 | /** |
507 | * gsm_register_devices - register all tty devices for a given mux index | |
508 | * | |
509 | * @driver: the tty driver that describes the tty devices | |
510 | * @index: the mux number is used to calculate the minor numbers of the | |
511 | * ttys for this mux and may differ from the position in the | |
512 | * mux array. | |
513 | */ | |
514 | static int gsm_register_devices(struct tty_driver *driver, unsigned int index) | |
515 | { | |
516 | struct device *dev; | |
517 | int i; | |
518 | unsigned int base; | |
519 | ||
520 | if (!driver || index >= MAX_MUX) | |
521 | return -EINVAL; | |
522 | ||
523 | base = index * NUM_DLCI; /* first minor for this index */ | |
524 | for (i = 1; i < NUM_DLCI; i++) { | |
525 | /* Don't register device 0 - this is the control channel | |
526 | * and not a usable tty interface | |
527 | */ | |
528 | dev = tty_register_device(gsm_tty_driver, base + i, NULL); | |
529 | if (IS_ERR(dev)) { | |
530 | if (debug & 8) | |
531 | pr_info("%s failed to register device minor %u", | |
532 | __func__, base + i); | |
533 | for (i--; i >= 1; i--) | |
534 | tty_unregister_device(gsm_tty_driver, base + i); | |
535 | return PTR_ERR(dev); | |
536 | } | |
537 | } | |
538 | ||
539 | return 0; | |
540 | } | |
541 | ||
542 | /** | |
543 | * gsm_unregister_devices - unregister all tty devices for a given mux index | |
544 | * | |
545 | * @driver: the tty driver that describes the tty devices | |
546 | * @index: the mux number is used to calculate the minor numbers of the | |
547 | * ttys for this mux and may differ from the position in the | |
548 | * mux array. | |
549 | */ | |
550 | static void gsm_unregister_devices(struct tty_driver *driver, | |
551 | unsigned int index) | |
552 | { | |
553 | int i; | |
554 | unsigned int base; | |
555 | ||
556 | if (!driver || index >= MAX_MUX) | |
557 | return; | |
558 | ||
559 | base = index * NUM_DLCI; /* first minor for this index */ | |
560 | for (i = 1; i < NUM_DLCI; i++) { | |
561 | /* Don't unregister device 0 - this is the control | |
562 | * channel and not a usable tty interface | |
563 | */ | |
564 | tty_unregister_device(gsm_tty_driver, base + i); | |
565 | } | |
566 | } | |
567 | ||
e1eaea46 AC |
568 | /** |
569 | * gsm_print_packet - display a frame for debug | |
570 | * @hdr: header to print before decode | |
571 | * @addr: address EA from the frame | |
57435c42 | 572 | * @cr: C/R bit seen as initiator |
e1eaea46 AC |
573 | * @control: control including PF bit |
574 | * @data: following data bytes | |
575 | * @dlen: length of data | |
576 | * | |
577 | * Displays a packet in human readable format for debugging purposes. The | |
578 | * style is based on amateur radio LAP-B dump display. | |
579 | */ | |
580 | ||
581 | static void gsm_print_packet(const char *hdr, int addr, int cr, | |
582 | u8 control, const u8 *data, int dlen) | |
583 | { | |
584 | if (!(debug & 1)) | |
585 | return; | |
586 | ||
5f9a31d6 | 587 | pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]); |
e1eaea46 AC |
588 | |
589 | switch (control & ~PF) { | |
590 | case SABM: | |
5f9a31d6 | 591 | pr_cont("SABM"); |
e1eaea46 AC |
592 | break; |
593 | case UA: | |
5f9a31d6 | 594 | pr_cont("UA"); |
e1eaea46 AC |
595 | break; |
596 | case DISC: | |
5f9a31d6 | 597 | pr_cont("DISC"); |
e1eaea46 AC |
598 | break; |
599 | case DM: | |
5f9a31d6 | 600 | pr_cont("DM"); |
e1eaea46 AC |
601 | break; |
602 | case UI: | |
5f9a31d6 | 603 | pr_cont("UI"); |
e1eaea46 AC |
604 | break; |
605 | case UIH: | |
5f9a31d6 | 606 | pr_cont("UIH"); |
e1eaea46 AC |
607 | break; |
608 | default: | |
609 | if (!(control & 0x01)) { | |
5f9a31d6 | 610 | pr_cont("I N(S)%d N(R)%d", |
47fdd641 | 611 | (control & 0x0E) >> 1, (control & 0xE0) >> 5); |
e1eaea46 | 612 | } else switch (control & 0x0F) { |
5f9a31d6 AC |
613 | case RR: |
614 | pr_cont("RR(%d)", (control & 0xE0) >> 5); | |
615 | break; | |
616 | case RNR: | |
617 | pr_cont("RNR(%d)", (control & 0xE0) >> 5); | |
618 | break; | |
619 | case REJ: | |
620 | pr_cont("REJ(%d)", (control & 0xE0) >> 5); | |
621 | break; | |
622 | default: | |
623 | pr_cont("[%02X]", control); | |
e1eaea46 AC |
624 | } |
625 | } | |
626 | ||
627 | if (control & PF) | |
5f9a31d6 | 628 | pr_cont("(P)"); |
e1eaea46 | 629 | else |
5f9a31d6 | 630 | pr_cont("(F)"); |
e1eaea46 | 631 | |
925ea0fa | 632 | gsm_hex_dump_bytes(NULL, data, dlen); |
e1eaea46 AC |
633 | } |
634 | ||
635 | ||
636 | /* | |
637 | * Link level transmission side | |
638 | */ | |
639 | ||
640 | /** | |
542a121a | 641 | * gsm_stuff_frame - bytestuff a packet |
724ac070 JS |
642 | * @input: input buffer |
643 | * @output: output buffer | |
e1eaea46 AC |
644 | * @len: length of input |
645 | * | |
646 | * Expand a buffer by bytestuffing it. The worst case size change | |
647 | * is doubling and the caller is responsible for handing out | |
648 | * suitable sized buffers. | |
649 | */ | |
650 | ||
651 | static int gsm_stuff_frame(const u8 *input, u8 *output, int len) | |
652 | { | |
653 | int olen = 0; | |
654 | while (len--) { | |
655 | if (*input == GSM1_SOF || *input == GSM1_ESCAPE | |
8838b2af | 656 | || (*input & ISO_IEC_646_MASK) == XON |
657 | || (*input & ISO_IEC_646_MASK) == XOFF) { | |
e1eaea46 AC |
658 | *output++ = GSM1_ESCAPE; |
659 | *output++ = *input++ ^ GSM1_ESCAPE_BITS; | |
660 | olen++; | |
661 | } else | |
662 | *output++ = *input++; | |
663 | olen++; | |
664 | } | |
665 | return olen; | |
666 | } | |
667 | ||
e1eaea46 AC |
668 | /** |
669 | * gsm_send - send a control frame | |
670 | * @gsm: our GSM mux | |
671 | * @addr: address for control frame | |
57435c42 | 672 | * @cr: command/response bit seen as initiator |
e1eaea46 AC |
673 | * @control: control byte including PF bit |
674 | * | |
0af02167 DS |
675 | * Format up and transmit a control frame. These should be transmitted |
676 | * ahead of data when they are needed. | |
e1eaea46 | 677 | */ |
0af02167 | 678 | static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) |
e1eaea46 | 679 | { |
0af02167 DS |
680 | struct gsm_msg *msg; |
681 | u8 *dp; | |
57435c42 | 682 | int ocr; |
0af02167 DS |
683 | |
684 | msg = gsm_data_alloc(gsm, addr, 0, control); | |
685 | if (!msg) | |
686 | return -ENOMEM; | |
57435c42 | 687 | |
688 | /* toggle C/R coding if not initiator */ | |
689 | ocr = cr ^ (gsm->initiator ? 0 : 1); | |
e1eaea46 | 690 | |
0af02167 DS |
691 | msg->data -= 3; |
692 | dp = msg->data; | |
693 | *dp++ = (addr << 2) | (ocr << 1) | EA; | |
694 | *dp++ = control; | |
695 | ||
696 | if (gsm->encoding == 0) | |
697 | *dp++ = EA; /* Length of data = 0 */ | |
698 | ||
699 | *dp = 0xFF - gsm_fcs_add_block(INIT_FCS, msg->data, dp - msg->data); | |
700 | msg->len = (dp - msg->data) + 1; | |
701 | ||
702 | gsm_print_packet("Q->", addr, cr, control, NULL, 0); | |
703 | ||
902e02ea | 704 | mutex_lock(&gsm->tx_mutex); |
0af02167 DS |
705 | list_add_tail(&msg->list, &gsm->tx_ctrl_list); |
706 | gsm->tx_bytes += msg->len; | |
902e02ea | 707 | mutex_unlock(&gsm->tx_mutex); |
0af02167 DS |
708 | gsmld_write_trigger(gsm); |
709 | ||
710 | return 0; | |
711 | } | |
712 | ||
713 | /** | |
714 | * gsm_dlci_clear_queues - remove outstanding data for a DLCI | |
715 | * @gsm: mux | |
716 | * @dlci: clear for this DLCI | |
717 | * | |
718 | * Clears the data queues for a given DLCI. | |
719 | */ | |
720 | static void gsm_dlci_clear_queues(struct gsm_mux *gsm, struct gsm_dlci *dlci) | |
721 | { | |
722 | struct gsm_msg *msg, *nmsg; | |
723 | int addr = dlci->addr; | |
724 | unsigned long flags; | |
725 | ||
726 | /* Clear DLCI write fifo first */ | |
727 | spin_lock_irqsave(&dlci->lock, flags); | |
728 | kfifo_reset(&dlci->fifo); | |
729 | spin_unlock_irqrestore(&dlci->lock, flags); | |
730 | ||
731 | /* Clear data packets in MUX write queue */ | |
902e02ea | 732 | mutex_lock(&gsm->tx_mutex); |
0af02167 DS |
733 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) { |
734 | if (msg->addr != addr) | |
735 | continue; | |
736 | gsm->tx_bytes -= msg->len; | |
737 | list_del(&msg->list); | |
738 | kfree(msg); | |
f999c3b3 | 739 | } |
902e02ea | 740 | mutex_unlock(&gsm->tx_mutex); |
e1eaea46 AC |
741 | } |
742 | ||
743 | /** | |
744 | * gsm_response - send a control response | |
745 | * @gsm: our GSM mux | |
746 | * @addr: address for control frame | |
747 | * @control: control byte including PF bit | |
748 | * | |
749 | * Format up and transmit a link level response frame. | |
750 | */ | |
751 | ||
752 | static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) | |
753 | { | |
57435c42 | 754 | gsm_send(gsm, addr, 0, control); |
e1eaea46 AC |
755 | } |
756 | ||
757 | /** | |
758 | * gsm_command - send a control command | |
759 | * @gsm: our GSM mux | |
760 | * @addr: address for control frame | |
761 | * @control: control byte including PF bit | |
762 | * | |
763 | * Format up and transmit a link level command frame. | |
764 | */ | |
765 | ||
766 | static inline void gsm_command(struct gsm_mux *gsm, int addr, int control) | |
767 | { | |
768 | gsm_send(gsm, addr, 1, control); | |
769 | } | |
770 | ||
771 | /* Data transmission */ | |
772 | ||
773 | #define HDR_LEN 6 /* ADDR CTRL [LEN.2] DATA FCS */ | |
774 | ||
775 | /** | |
776 | * gsm_data_alloc - allocate data frame | |
777 | * @gsm: GSM mux | |
778 | * @addr: DLCI address | |
779 | * @len: length excluding header and FCS | |
780 | * @ctrl: control byte | |
781 | * | |
782 | * Allocate a new data buffer for sending frames with data. Space is left | |
783 | * at the front for header bytes but that is treated as an implementation | |
784 | * detail and not for the high level code to use | |
785 | */ | |
786 | ||
787 | static struct gsm_msg *gsm_data_alloc(struct gsm_mux *gsm, u8 addr, int len, | |
788 | u8 ctrl) | |
789 | { | |
790 | struct gsm_msg *m = kmalloc(sizeof(struct gsm_msg) + len + HDR_LEN, | |
791 | GFP_ATOMIC); | |
792 | if (m == NULL) | |
793 | return NULL; | |
794 | m->data = m->buffer + HDR_LEN - 1; /* Allow for FCS */ | |
795 | m->len = len; | |
796 | m->addr = addr; | |
797 | m->ctrl = ctrl; | |
b4338e1e | 798 | INIT_LIST_HEAD(&m->list); |
e1eaea46 AC |
799 | return m; |
800 | } | |
801 | ||
0af02167 DS |
802 | /** |
803 | * gsm_send_packet - sends a single packet | |
804 | * @gsm: GSM Mux | |
805 | * @msg: packet to send | |
806 | * | |
807 | * The given packet is encoded and sent out. No memory is freed. | |
808 | * The caller must hold the gsm tx lock. | |
809 | */ | |
810 | static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg) | |
811 | { | |
812 | int len, ret; | |
813 | ||
814 | ||
815 | if (gsm->encoding == 0) { | |
816 | gsm->txframe[0] = GSM0_SOF; | |
817 | memcpy(gsm->txframe + 1, msg->data, msg->len); | |
818 | gsm->txframe[msg->len + 1] = GSM0_SOF; | |
819 | len = msg->len + 2; | |
820 | } else { | |
821 | gsm->txframe[0] = GSM1_SOF; | |
822 | len = gsm_stuff_frame(msg->data, gsm->txframe + 1, msg->len); | |
823 | gsm->txframe[len + 1] = GSM1_SOF; | |
824 | len += 2; | |
825 | } | |
826 | ||
827 | if (debug & 4) | |
828 | gsm_hex_dump_bytes(__func__, gsm->txframe, len); | |
829 | gsm_print_packet("-->", msg->addr, gsm->initiator, msg->ctrl, msg->data, | |
830 | msg->len); | |
831 | ||
832 | ret = gsmld_output(gsm, gsm->txframe, len); | |
833 | if (ret <= 0) | |
834 | return ret; | |
835 | /* FIXME: Can eliminate one SOF in many more cases */ | |
836 | gsm->tx_bytes -= msg->len; | |
837 | ||
838 | return 0; | |
839 | } | |
840 | ||
bec02248 DS |
841 | /** |
842 | * gsm_is_flow_ctrl_msg - checks if flow control message | |
843 | * @msg: message to check | |
844 | * | |
845 | * Returns true if the given message is a flow control command of the | |
846 | * control channel. False is returned in any other case. | |
847 | */ | |
848 | static bool gsm_is_flow_ctrl_msg(struct gsm_msg *msg) | |
849 | { | |
850 | unsigned int cmd; | |
851 | ||
852 | if (msg->addr > 0) | |
853 | return false; | |
854 | ||
855 | switch (msg->ctrl & ~PF) { | |
856 | case UI: | |
857 | case UIH: | |
858 | cmd = 0; | |
859 | if (gsm_read_ea_val(&cmd, msg->data + 2, msg->len - 2) < 1) | |
860 | break; | |
861 | switch (cmd & ~PF) { | |
862 | case CMD_FCOFF: | |
863 | case CMD_FCON: | |
864 | return true; | |
865 | } | |
866 | break; | |
867 | } | |
868 | ||
869 | return false; | |
870 | } | |
871 | ||
e1eaea46 | 872 | /** |
0af02167 | 873 | * gsm_data_kick - poke the queue |
e1eaea46 AC |
874 | * @gsm: GSM Mux |
875 | * | |
876 | * The tty device has called us to indicate that room has appeared in | |
0af02167 | 877 | * the transmit queue. Ram more data into the pipe if we have any. |
c01af4fe | 878 | * If we have been flow-stopped by a CMD_FCOFF, then we can only |
0af02167 DS |
879 | * send messages on DLCI0 until CMD_FCON. The caller must hold |
880 | * the gsm tx lock. | |
e1eaea46 | 881 | */ |
0af02167 | 882 | static int gsm_data_kick(struct gsm_mux *gsm) |
e1eaea46 | 883 | { |
b4338e1e | 884 | struct gsm_msg *msg, *nmsg; |
0af02167 DS |
885 | struct gsm_dlci *dlci; |
886 | int ret; | |
887 | ||
888 | clear_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); | |
e1eaea46 | 889 | |
0af02167 DS |
890 | /* Serialize control messages and control channel messages first */ |
891 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_ctrl_list, list) { | |
bec02248 | 892 | if (gsm->constipated && !gsm_is_flow_ctrl_msg(msg)) |
59ff0680 | 893 | continue; |
0af02167 DS |
894 | ret = gsm_send_packet(gsm, msg); |
895 | switch (ret) { | |
896 | case -ENOSPC: | |
897 | return -ENOSPC; | |
898 | case -ENODEV: | |
899 | /* ldisc not open */ | |
900 | gsm->tx_bytes -= msg->len; | |
901 | list_del(&msg->list); | |
902 | kfree(msg); | |
c01af4fe | 903 | continue; |
0af02167 DS |
904 | default: |
905 | if (ret >= 0) { | |
906 | list_del(&msg->list); | |
907 | kfree(msg); | |
908 | } | |
e1eaea46 | 909 | break; |
0af02167 DS |
910 | } |
911 | } | |
c01af4fe | 912 | |
0af02167 DS |
913 | if (gsm->constipated) |
914 | return -EAGAIN; | |
01dbb362 | 915 | |
0af02167 DS |
916 | /* Serialize other channels */ |
917 | if (list_empty(&gsm->tx_data_list)) | |
918 | return 0; | |
919 | list_for_each_entry_safe(msg, nmsg, &gsm->tx_data_list, list) { | |
920 | dlci = gsm->dlci[msg->addr]; | |
921 | /* Send only messages for DLCIs with valid state */ | |
922 | if (dlci->state != DLCI_OPEN) { | |
923 | gsm->tx_bytes -= msg->len; | |
924 | list_del(&msg->list); | |
925 | kfree(msg); | |
926 | continue; | |
927 | } | |
928 | ret = gsm_send_packet(gsm, msg); | |
929 | switch (ret) { | |
930 | case -ENOSPC: | |
931 | return -ENOSPC; | |
932 | case -ENODEV: | |
933 | /* ldisc not open */ | |
934 | gsm->tx_bytes -= msg->len; | |
935 | list_del(&msg->list); | |
936 | kfree(msg); | |
937 | continue; | |
938 | default: | |
939 | if (ret >= 0) { | |
940 | list_del(&msg->list); | |
941 | kfree(msg); | |
942 | } | |
943 | break; | |
01dbb362 | 944 | } |
e1eaea46 | 945 | } |
0af02167 DS |
946 | |
947 | return 1; | |
e1eaea46 AC |
948 | } |
949 | ||
950 | /** | |
951 | * __gsm_data_queue - queue a UI or UIH frame | |
952 | * @dlci: DLCI sending the data | |
953 | * @msg: message queued | |
954 | * | |
955 | * Add data to the transmit queue and try and get stuff moving | |
956 | * out of the mux tty if not already doing so. The Caller must hold | |
957 | * the gsm tx lock. | |
958 | */ | |
959 | ||
960 | static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
961 | { | |
962 | struct gsm_mux *gsm = dlci->gsm; | |
963 | u8 *dp = msg->data; | |
964 | u8 *fcs = dp + msg->len; | |
965 | ||
966 | /* Fill in the header */ | |
967 | if (gsm->encoding == 0) { | |
968 | if (msg->len < 128) | |
969 | *--dp = (msg->len << 1) | EA; | |
970 | else { | |
be7a7411 KM |
971 | *--dp = (msg->len >> 7); /* bits 7 - 15 */ |
972 | *--dp = (msg->len & 127) << 1; /* bits 0 - 6 */ | |
e1eaea46 AC |
973 | } |
974 | } | |
975 | ||
976 | *--dp = msg->ctrl; | |
977 | if (gsm->initiator) | |
87127773 | 978 | *--dp = (msg->addr << 2) | CR | EA; |
e1eaea46 AC |
979 | else |
980 | *--dp = (msg->addr << 2) | EA; | |
981 | *fcs = gsm_fcs_add_block(INIT_FCS, dp , msg->data - dp); | |
982 | /* Ugly protocol layering violation */ | |
983 | if (msg->ctrl == UI || msg->ctrl == (UI|PF)) | |
984 | *fcs = gsm_fcs_add_block(*fcs, msg->data, msg->len); | |
985 | *fcs = 0xFF - *fcs; | |
986 | ||
987 | gsm_print_packet("Q> ", msg->addr, gsm->initiator, msg->ctrl, | |
988 | msg->data, msg->len); | |
989 | ||
990 | /* Move the header back and adjust the length, also allow for the FCS | |
991 | now tacked on the end */ | |
992 | msg->len += (msg->data - dp) + 1; | |
993 | msg->data = dp; | |
994 | ||
995 | /* Add to the actual output queue */ | |
0af02167 DS |
996 | switch (msg->ctrl & ~PF) { |
997 | case UI: | |
998 | case UIH: | |
999 | if (msg->addr > 0) { | |
1000 | list_add_tail(&msg->list, &gsm->tx_data_list); | |
1001 | break; | |
1002 | } | |
1003 | fallthrough; | |
1004 | default: | |
1005 | list_add_tail(&msg->list, &gsm->tx_ctrl_list); | |
1006 | break; | |
1007 | } | |
e1eaea46 | 1008 | gsm->tx_bytes += msg->len; |
0af02167 DS |
1009 | |
1010 | gsmld_write_trigger(gsm); | |
c9ab053e | 1011 | schedule_delayed_work(&gsm->kick_timeout, 10 * gsm->t1 * HZ / 100); |
e1eaea46 AC |
1012 | } |
1013 | ||
1014 | /** | |
1015 | * gsm_data_queue - queue a UI or UIH frame | |
1016 | * @dlci: DLCI sending the data | |
1017 | * @msg: message queued | |
1018 | * | |
1019 | * Add data to the transmit queue and try and get stuff moving | |
1020 | * out of the mux tty if not already doing so. Take the | |
1021 | * the gsm tx lock and dlci lock. | |
1022 | */ | |
1023 | ||
1024 | static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) | |
1025 | { | |
902e02ea | 1026 | mutex_lock(&dlci->gsm->tx_mutex); |
e1eaea46 | 1027 | __gsm_data_queue(dlci, msg); |
902e02ea | 1028 | mutex_unlock(&dlci->gsm->tx_mutex); |
e1eaea46 AC |
1029 | } |
1030 | ||
1031 | /** | |
1032 | * gsm_dlci_data_output - try and push data out of a DLCI | |
1033 | * @gsm: mux | |
1034 | * @dlci: the DLCI to pull data from | |
1035 | * | |
1036 | * Pull data from a DLCI and send it into the transmit queue if there | |
1037 | * is data. Keep to the MRU of the mux. This path handles the usual tty | |
1038 | * interface which is a byte stream with optional modem data. | |
1039 | * | |
902e02ea | 1040 | * Caller must hold the tx_mutex of the mux. |
e1eaea46 AC |
1041 | */ |
1042 | ||
1043 | static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) | |
1044 | { | |
1045 | struct gsm_msg *msg; | |
1046 | u8 *dp; | |
556fc8ac DS |
1047 | int h, len, size; |
1048 | ||
1049 | /* for modem bits without break data */ | |
1050 | h = ((dlci->adaption == 1) ? 0 : 1); | |
1051 | ||
1052 | len = kfifo_len(&dlci->fifo); | |
1053 | if (len == 0) | |
1054 | return 0; | |
1055 | ||
1056 | /* MTU/MRU count only the data bits but watch adaption mode */ | |
1057 | if ((len + h) > gsm->mtu) | |
1058 | len = gsm->mtu - h; | |
1059 | ||
1060 | size = len + h; | |
1061 | ||
1062 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); | |
556fc8ac DS |
1063 | if (!msg) |
1064 | return -ENOMEM; | |
1065 | dp = msg->data; | |
1066 | switch (dlci->adaption) { | |
1067 | case 1: /* Unstructured */ | |
1068 | break; | |
1069 | case 2: /* Unstructured with modem bits. | |
1070 | * Always one byte as we never send inline break data | |
1071 | */ | |
1072 | *dp++ = (gsm_encode_modem(dlci) << 1) | EA; | |
1073 | break; | |
1074 | default: | |
1075 | pr_err("%s: unsupported adaption %d\n", __func__, | |
1076 | dlci->adaption); | |
1077 | break; | |
e1eaea46 | 1078 | } |
556fc8ac DS |
1079 | |
1080 | WARN_ON(len != kfifo_out_locked(&dlci->fifo, dp, len, | |
1081 | &dlci->lock)); | |
1082 | ||
1083 | /* Notify upper layer about available send space. */ | |
1084 | tty_port_tty_wakeup(&dlci->port); | |
1085 | ||
1086 | __gsm_data_queue(dlci, msg); | |
e1eaea46 | 1087 | /* Bytes of data we used up */ |
556fc8ac | 1088 | return size; |
e1eaea46 AC |
1089 | } |
1090 | ||
1091 | /** | |
1092 | * gsm_dlci_data_output_framed - try and push data out of a DLCI | |
1093 | * @gsm: mux | |
1094 | * @dlci: the DLCI to pull data from | |
1095 | * | |
1096 | * Pull data from a DLCI and send it into the transmit queue if there | |
1097 | * is data. Keep to the MRU of the mux. This path handles framed data | |
1098 | * queued as skbuffs to the DLCI. | |
1099 | * | |
902e02ea | 1100 | * Caller must hold the tx_mutex of the mux. |
e1eaea46 AC |
1101 | */ |
1102 | ||
1103 | static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, | |
1104 | struct gsm_dlci *dlci) | |
1105 | { | |
1106 | struct gsm_msg *msg; | |
1107 | u8 *dp; | |
1108 | int len, size; | |
1109 | int last = 0, first = 0; | |
1110 | int overhead = 0; | |
1111 | ||
1112 | /* One byte per frame is used for B/F flags */ | |
1113 | if (dlci->adaption == 4) | |
1114 | overhead = 1; | |
1115 | ||
902e02ea | 1116 | /* dlci->skb is locked by tx_mutex */ |
e1eaea46 | 1117 | if (dlci->skb == NULL) { |
88ed2a60 | 1118 | dlci->skb = skb_dequeue_tail(&dlci->skb_list); |
e1eaea46 AC |
1119 | if (dlci->skb == NULL) |
1120 | return 0; | |
1121 | first = 1; | |
1122 | } | |
1123 | len = dlci->skb->len + overhead; | |
1124 | ||
1125 | /* MTU/MRU count only the data bits */ | |
1126 | if (len > gsm->mtu) { | |
1127 | if (dlci->adaption == 3) { | |
1128 | /* Over long frame, bin it */ | |
329e5678 | 1129 | dev_kfree_skb_any(dlci->skb); |
e1eaea46 AC |
1130 | dlci->skb = NULL; |
1131 | return 0; | |
1132 | } | |
1133 | len = gsm->mtu; | |
1134 | } else | |
1135 | last = 1; | |
1136 | ||
1137 | size = len + overhead; | |
1138 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); | |
88ed2a60 RG |
1139 | if (msg == NULL) { |
1140 | skb_queue_tail(&dlci->skb_list, dlci->skb); | |
1141 | dlci->skb = NULL; | |
e1eaea46 | 1142 | return -ENOMEM; |
88ed2a60 | 1143 | } |
e1eaea46 AC |
1144 | dp = msg->data; |
1145 | ||
1146 | if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ | |
1147 | /* Flag byte to carry the start/end info */ | |
1148 | *dp++ = last << 7 | first << 6 | 1; /* EA */ | |
1149 | len--; | |
1150 | } | |
57f2104f RG |
1151 | memcpy(dp, dlci->skb->data, len); |
1152 | skb_pull(dlci->skb, len); | |
e1eaea46 | 1153 | __gsm_data_queue(dlci, msg); |
bcd5abe2 | 1154 | if (last) { |
329e5678 | 1155 | dev_kfree_skb_any(dlci->skb); |
e1eaea46 | 1156 | dlci->skb = NULL; |
bcd5abe2 | 1157 | } |
e1eaea46 AC |
1158 | return size; |
1159 | } | |
1160 | ||
c19ffe00 DS |
1161 | /** |
1162 | * gsm_dlci_modem_output - try and push modem status out of a DLCI | |
1163 | * @gsm: mux | |
1164 | * @dlci: the DLCI to pull modem status from | |
1165 | * @brk: break signal | |
1166 | * | |
1167 | * Push an empty frame in to the transmit queue to update the modem status | |
1168 | * bits and to transmit an optional break. | |
1169 | * | |
902e02ea | 1170 | * Caller must hold the tx_mutex of the mux. |
c19ffe00 DS |
1171 | */ |
1172 | ||
1173 | static int gsm_dlci_modem_output(struct gsm_mux *gsm, struct gsm_dlci *dlci, | |
1174 | u8 brk) | |
1175 | { | |
1176 | u8 *dp = NULL; | |
1177 | struct gsm_msg *msg; | |
19317433 | 1178 | int size = 0; |
c19ffe00 DS |
1179 | |
1180 | /* for modem bits without break data */ | |
19317433 DS |
1181 | switch (dlci->adaption) { |
1182 | case 1: /* Unstructured */ | |
1183 | break; | |
1184 | case 2: /* Unstructured with modem bits. */ | |
1185 | size++; | |
c19ffe00 DS |
1186 | if (brk > 0) |
1187 | size++; | |
19317433 DS |
1188 | break; |
1189 | default: | |
c19ffe00 DS |
1190 | pr_err("%s: unsupported adaption %d\n", __func__, |
1191 | dlci->adaption); | |
19317433 | 1192 | return -EINVAL; |
c19ffe00 DS |
1193 | } |
1194 | ||
1195 | msg = gsm_data_alloc(gsm, dlci->addr, size, gsm->ftype); | |
1196 | if (!msg) { | |
1197 | pr_err("%s: gsm_data_alloc error", __func__); | |
1198 | return -ENOMEM; | |
1199 | } | |
1200 | dp = msg->data; | |
1201 | switch (dlci->adaption) { | |
1202 | case 1: /* Unstructured */ | |
1203 | break; | |
1204 | case 2: /* Unstructured with modem bits. */ | |
1205 | if (brk == 0) { | |
1206 | *dp++ = (gsm_encode_modem(dlci) << 1) | EA; | |
1207 | } else { | |
1208 | *dp++ = gsm_encode_modem(dlci) << 1; | |
1209 | *dp++ = (brk << 4) | 2 | EA; /* Length, Break, EA */ | |
1210 | } | |
1211 | break; | |
1212 | default: | |
1213 | /* Handled above */ | |
1214 | break; | |
1215 | } | |
1216 | ||
1217 | __gsm_data_queue(dlci, msg); | |
1218 | return size; | |
1219 | } | |
1220 | ||
e1eaea46 AC |
1221 | /** |
1222 | * gsm_dlci_data_sweep - look for data to send | |
1223 | * @gsm: the GSM mux | |
1224 | * | |
1225 | * Sweep the GSM mux channels in priority order looking for ones with | |
1226 | * data to send. We could do with optimising this scan a bit. We aim | |
1227 | * to fill the queue totally or up to TX_THRESH_HI bytes. Once we hit | |
1228 | * TX_THRESH_LO we get called again | |
1229 | * | |
1230 | * FIXME: We should round robin between groups and in theory you can | |
1231 | * renegotiate DLCI priorities with optional stuff. Needs optimising. | |
1232 | */ | |
1233 | ||
c568f708 | 1234 | static int gsm_dlci_data_sweep(struct gsm_mux *gsm) |
e1eaea46 | 1235 | { |
e1eaea46 | 1236 | /* Priority ordering: We should do priority with RR of the groups */ |
0af02167 DS |
1237 | int i, len, ret = 0; |
1238 | bool sent; | |
1239 | struct gsm_dlci *dlci; | |
e1eaea46 | 1240 | |
0af02167 DS |
1241 | while (gsm->tx_bytes < TX_THRESH_HI) { |
1242 | for (sent = false, i = 1; i < NUM_DLCI; i++) { | |
1243 | dlci = gsm->dlci[i]; | |
1244 | /* skip unused or blocked channel */ | |
1245 | if (!dlci || dlci->constipated) | |
1246 | continue; | |
1247 | /* skip channels with invalid state */ | |
1248 | if (dlci->state != DLCI_OPEN) | |
1249 | continue; | |
1250 | /* count the sent data per adaption */ | |
1251 | if (dlci->adaption < 3 && !dlci->net) | |
1252 | len = gsm_dlci_data_output(gsm, dlci); | |
1253 | else | |
1254 | len = gsm_dlci_data_output_framed(gsm, dlci); | |
1255 | /* on error exit */ | |
1256 | if (len < 0) | |
1257 | return ret; | |
1258 | if (len > 0) { | |
1259 | ret++; | |
1260 | sent = true; | |
1261 | /* The lower DLCs can starve the higher DLCs! */ | |
1262 | break; | |
1263 | } | |
1264 | /* try next */ | |
e1eaea46 | 1265 | } |
0af02167 | 1266 | if (!sent) |
e73790a5 | 1267 | break; |
0af02167 | 1268 | }; |
c568f708 DS |
1269 | |
1270 | return ret; | |
e1eaea46 AC |
1271 | } |
1272 | ||
1273 | /** | |
1274 | * gsm_dlci_data_kick - transmit if possible | |
1275 | * @dlci: DLCI to kick | |
1276 | * | |
1277 | * Transmit data from this DLCI if the queue is empty. We can't rely on | |
1278 | * a tty wakeup except when we filled the pipe so we need to fire off | |
1279 | * new data ourselves in other cases. | |
1280 | */ | |
1281 | ||
1282 | static void gsm_dlci_data_kick(struct gsm_dlci *dlci) | |
1283 | { | |
192b6041 | 1284 | int sweep; |
e1eaea46 | 1285 | |
f3c909b4 | 1286 | if (dlci->constipated) |
c01af4fe | 1287 | return; |
c01af4fe | 1288 | |
902e02ea | 1289 | mutex_lock(&dlci->gsm->tx_mutex); |
e1eaea46 | 1290 | /* If we have nothing running then we need to fire up */ |
192b6041 | 1291 | sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO); |
bcd5abe2 RG |
1292 | if (dlci->gsm->tx_bytes == 0) { |
1293 | if (dlci->net) | |
1294 | gsm_dlci_data_output_framed(dlci->gsm, dlci); | |
1295 | else | |
1296 | gsm_dlci_data_output(dlci->gsm, dlci); | |
192b6041 RG |
1297 | } |
1298 | if (sweep) | |
f3c909b4 | 1299 | gsm_dlci_data_sweep(dlci->gsm); |
902e02ea | 1300 | mutex_unlock(&dlci->gsm->tx_mutex); |
e1eaea46 AC |
1301 | } |
1302 | ||
1303 | /* | |
1304 | * Control message processing | |
1305 | */ | |
1306 | ||
1307 | ||
1308 | /** | |
1309 | * gsm_control_reply - send a response frame to a control | |
1310 | * @gsm: gsm channel | |
1311 | * @cmd: the command to use | |
1312 | * @data: data to follow encoded info | |
1313 | * @dlen: length of data | |
1314 | * | |
1315 | * Encode up and queue a UI/UIH frame containing our response. | |
1316 | */ | |
1317 | ||
4feb7a4a | 1318 | static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data, |
e1eaea46 AC |
1319 | int dlen) |
1320 | { | |
1321 | struct gsm_msg *msg; | |
1322 | msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype); | |
093d8046 KM |
1323 | if (msg == NULL) |
1324 | return; | |
e1eaea46 AC |
1325 | msg->data[0] = (cmd & 0xFE) << 1 | EA; /* Clear C/R */ |
1326 | msg->data[1] = (dlen << 1) | EA; | |
1327 | memcpy(msg->data + 2, data, dlen); | |
1328 | gsm_data_queue(gsm->dlci[0], msg); | |
1329 | } | |
1330 | ||
1331 | /** | |
1332 | * gsm_process_modem - process received modem status | |
1333 | * @tty: virtual tty bound to the DLCI | |
1334 | * @dlci: DLCI to affect | |
1335 | * @modem: modem bits (full EA) | |
687f9ad4 | 1336 | * @slen: number of signal octets |
e1eaea46 AC |
1337 | * |
1338 | * Used when a modem control message or line state inline in adaption | |
1339 | * layer 2 is processed. Sort out the local modem state and throttles | |
1340 | */ | |
1341 | ||
1342 | static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, | |
687f9ad4 | 1343 | u32 modem, int slen) |
e1eaea46 AC |
1344 | { |
1345 | int mlines = 0; | |
7263287a | 1346 | u8 brk = 0; |
c01af4fe | 1347 | int fc; |
7263287a | 1348 | |
687f9ad4 | 1349 | /* The modem status command can either contain one octet (V.24 signals) |
1350 | * or two octets (V.24 signals + break signals). This is specified in | |
1351 | * section 5.4.6.3.7 of the 07.10 mux spec. | |
1352 | */ | |
7263287a | 1353 | |
687f9ad4 | 1354 | if (slen == 1) |
7263287a RG |
1355 | modem = modem & 0x7f; |
1356 | else { | |
1357 | brk = modem & 0x7f; | |
1358 | modem = (modem >> 7) & 0x7f; | |
c01af4fe | 1359 | } |
e1eaea46 AC |
1360 | |
1361 | /* Flow control/ready to communicate */ | |
c01af4fe FB |
1362 | fc = (modem & MDM_FC) || !(modem & MDM_RTR); |
1363 | if (fc && !dlci->constipated) { | |
e1eaea46 | 1364 | /* Need to throttle our output on this device */ |
7a9ed9c0 | 1365 | dlci->constipated = true; |
c01af4fe | 1366 | } else if (!fc && dlci->constipated) { |
7a9ed9c0 | 1367 | dlci->constipated = false; |
e1eaea46 AC |
1368 | gsm_dlci_data_kick(dlci); |
1369 | } | |
c01af4fe | 1370 | |
e1eaea46 | 1371 | /* Map modem bits */ |
c01af4fe FB |
1372 | if (modem & MDM_RTC) |
1373 | mlines |= TIOCM_DSR | TIOCM_DTR; | |
e1eaea46 AC |
1374 | if (modem & MDM_RTR) |
1375 | mlines |= TIOCM_RTS | TIOCM_CTS; | |
1376 | if (modem & MDM_IC) | |
1377 | mlines |= TIOCM_RI; | |
1378 | if (modem & MDM_DV) | |
1379 | mlines |= TIOCM_CD; | |
1380 | ||
1381 | /* Carrier drop -> hangup */ | |
1382 | if (tty) { | |
1383 | if ((mlines & TIOCM_CD) == 0 && (dlci->modem_rx & TIOCM_CD)) | |
9db276f8 | 1384 | if (!C_CLOCAL(tty)) |
e1eaea46 | 1385 | tty_hangup(tty); |
e1eaea46 | 1386 | } |
92a19f9c JS |
1387 | if (brk & 0x01) |
1388 | tty_insert_flip_char(&dlci->port, 0, TTY_BREAK); | |
e1eaea46 AC |
1389 | dlci->modem_rx = mlines; |
1390 | } | |
1391 | ||
1392 | /** | |
1393 | * gsm_control_modem - modem status received | |
1394 | * @gsm: GSM channel | |
1395 | * @data: data following command | |
1396 | * @clen: command length | |
1397 | * | |
1398 | * We have received a modem status control message. This is used by | |
1399 | * the GSM mux protocol to pass virtual modem line status and optionally | |
1400 | * to indicate break signals. Unpack it, convert to Linux representation | |
1401 | * and if need be stuff a break message down the tty. | |
1402 | */ | |
1403 | ||
4feb7a4a | 1404 | static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) |
e1eaea46 AC |
1405 | { |
1406 | unsigned int addr = 0; | |
1407 | unsigned int modem = 0; | |
1408 | struct gsm_dlci *dlci; | |
1409 | int len = clen; | |
687f9ad4 | 1410 | int slen; |
4feb7a4a | 1411 | const u8 *dp = data; |
e1eaea46 AC |
1412 | struct tty_struct *tty; |
1413 | ||
1414 | while (gsm_read_ea(&addr, *dp++) == 0) { | |
1415 | len--; | |
1416 | if (len == 0) | |
1417 | return; | |
1418 | } | |
1419 | /* Must be at least one byte following the EA */ | |
1420 | len--; | |
1421 | if (len <= 0) | |
1422 | return; | |
1423 | ||
1424 | addr >>= 1; | |
1425 | /* Closed port, or invalid ? */ | |
1426 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1427 | return; | |
1428 | dlci = gsm->dlci[addr]; | |
1429 | ||
687f9ad4 | 1430 | slen = len; |
e1eaea46 AC |
1431 | while (gsm_read_ea(&modem, *dp++) == 0) { |
1432 | len--; | |
1433 | if (len == 0) | |
1434 | return; | |
1435 | } | |
3ac06b90 | 1436 | len--; |
e1eaea46 | 1437 | tty = tty_port_tty_get(&dlci->port); |
317f86af | 1438 | gsm_process_modem(tty, dlci, modem, slen - len); |
e1eaea46 AC |
1439 | if (tty) { |
1440 | tty_wakeup(tty); | |
1441 | tty_kref_put(tty); | |
1442 | } | |
1443 | gsm_control_reply(gsm, CMD_MSC, data, clen); | |
1444 | } | |
1445 | ||
1446 | /** | |
1447 | * gsm_control_rls - remote line status | |
1448 | * @gsm: GSM channel | |
1449 | * @data: data bytes | |
1450 | * @clen: data length | |
1451 | * | |
1452 | * The modem sends us a two byte message on the control channel whenever | |
1453 | * it wishes to send us an error state from the virtual link. Stuff | |
1454 | * this into the uplink tty if present | |
1455 | */ | |
1456 | ||
4feb7a4a | 1457 | static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen) |
e1eaea46 | 1458 | { |
92a19f9c | 1459 | struct tty_port *port; |
f3c909b4 | 1460 | unsigned int addr = 0; |
e1eaea46 AC |
1461 | u8 bits; |
1462 | int len = clen; | |
4feb7a4a | 1463 | const u8 *dp = data; |
e1eaea46 AC |
1464 | |
1465 | while (gsm_read_ea(&addr, *dp++) == 0) { | |
1466 | len--; | |
1467 | if (len == 0) | |
1468 | return; | |
1469 | } | |
1470 | /* Must be at least one byte following ea */ | |
1471 | len--; | |
1472 | if (len <= 0) | |
1473 | return; | |
1474 | addr >>= 1; | |
1475 | /* Closed port, or invalid ? */ | |
1476 | if (addr == 0 || addr >= NUM_DLCI || gsm->dlci[addr] == NULL) | |
1477 | return; | |
1478 | /* No error ? */ | |
1479 | bits = *dp; | |
1480 | if ((bits & 1) == 0) | |
1481 | return; | |
e1eaea46 | 1482 | |
92a19f9c JS |
1483 | port = &gsm->dlci[addr]->port; |
1484 | ||
1485 | if (bits & 2) | |
1486 | tty_insert_flip_char(port, 0, TTY_OVERRUN); | |
1487 | if (bits & 4) | |
1488 | tty_insert_flip_char(port, 0, TTY_PARITY); | |
1489 | if (bits & 8) | |
1490 | tty_insert_flip_char(port, 0, TTY_FRAME); | |
1491 | ||
2e124b4a JS |
1492 | tty_flip_buffer_push(port); |
1493 | ||
e1eaea46 AC |
1494 | gsm_control_reply(gsm, CMD_RLS, data, clen); |
1495 | } | |
1496 | ||
1497 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci); | |
1498 | ||
1499 | /** | |
1500 | * gsm_control_message - DLCI 0 control processing | |
1501 | * @gsm: our GSM mux | |
1502 | * @command: the command EA | |
1503 | * @data: data beyond the command/length EAs | |
1504 | * @clen: length | |
1505 | * | |
1506 | * Input processor for control messages from the other end of the link. | |
1507 | * Processes the incoming request and queues a response frame or an | |
1508 | * NSC response if not supported | |
1509 | */ | |
1510 | ||
1511 | static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, | |
4feb7a4a | 1512 | const u8 *data, int clen) |
e1eaea46 AC |
1513 | { |
1514 | u8 buf[1]; | |
5e44708f | 1515 | |
e1eaea46 AC |
1516 | switch (command) { |
1517 | case CMD_CLD: { | |
a8c5b825 | 1518 | struct gsm_dlci *dlci = gsm->dlci[0]; |
e1eaea46 AC |
1519 | /* Modem wishes to close down */ |
1520 | if (dlci) { | |
5677fcf3 JS |
1521 | dlci->dead = true; |
1522 | gsm->dead = true; | |
a8c5b825 | 1523 | gsm_dlci_begin_close(dlci); |
e1eaea46 AC |
1524 | } |
1525 | } | |
1526 | break; | |
1527 | case CMD_TEST: | |
1528 | /* Modem wishes to test, reply with the data */ | |
1529 | gsm_control_reply(gsm, CMD_TEST, data, clen); | |
1530 | break; | |
1531 | case CMD_FCON: | |
e1eaea46 | 1532 | /* Modem can accept data again */ |
7a9ed9c0 | 1533 | gsm->constipated = false; |
c01af4fe | 1534 | gsm_control_reply(gsm, CMD_FCON, NULL, 0); |
e1eaea46 | 1535 | /* Kick the link in case it is idling */ |
0af02167 | 1536 | gsmld_write_trigger(gsm); |
e1eaea46 | 1537 | break; |
c01af4fe FB |
1538 | case CMD_FCOFF: |
1539 | /* Modem wants us to STFU */ | |
7a9ed9c0 | 1540 | gsm->constipated = true; |
c01af4fe FB |
1541 | gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); |
1542 | break; | |
e1eaea46 AC |
1543 | case CMD_MSC: |
1544 | /* Out of band modem line change indicator for a DLCI */ | |
1545 | gsm_control_modem(gsm, data, clen); | |
1546 | break; | |
1547 | case CMD_RLS: | |
1548 | /* Out of band error reception for a DLCI */ | |
1549 | gsm_control_rls(gsm, data, clen); | |
1550 | break; | |
1551 | case CMD_PSC: | |
1552 | /* Modem wishes to enter power saving state */ | |
1553 | gsm_control_reply(gsm, CMD_PSC, NULL, 0); | |
1554 | break; | |
1555 | /* Optional unsupported commands */ | |
1556 | case CMD_PN: /* Parameter negotiation */ | |
25985edc LDM |
1557 | case CMD_RPN: /* Remote port negotiation */ |
1558 | case CMD_SNC: /* Service negotiation command */ | |
e1eaea46 AC |
1559 | default: |
1560 | /* Reply to bad commands with an NSC */ | |
1561 | buf[0] = command; | |
1562 | gsm_control_reply(gsm, CMD_NSC, buf, 1); | |
1563 | break; | |
1564 | } | |
1565 | } | |
1566 | ||
1567 | /** | |
1568 | * gsm_control_response - process a response to our control | |
1569 | * @gsm: our GSM mux | |
1570 | * @command: the command (response) EA | |
1571 | * @data: data beyond the command/length EA | |
1572 | * @clen: length | |
1573 | * | |
1574 | * Process a response to an outstanding command. We only allow a single | |
1575 | * control message in flight so this is fairly easy. All the clean up | |
1576 | * is done by the caller, we just update the fields, flag it as done | |
1577 | * and return | |
1578 | */ | |
1579 | ||
1580 | static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, | |
4feb7a4a | 1581 | const u8 *data, int clen) |
e1eaea46 AC |
1582 | { |
1583 | struct gsm_control *ctrl; | |
1584 | unsigned long flags; | |
1585 | ||
1586 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1587 | ||
1588 | ctrl = gsm->pending_cmd; | |
1589 | /* Does the reply match our command */ | |
1590 | command |= 1; | |
1591 | if (ctrl != NULL && (command == ctrl->cmd || command == CMD_NSC)) { | |
1592 | /* Our command was replied to, kill the retry timer */ | |
1593 | del_timer(&gsm->t2_timer); | |
1594 | gsm->pending_cmd = NULL; | |
1595 | /* Rejected by the other end */ | |
1596 | if (command == CMD_NSC) | |
1597 | ctrl->error = -EOPNOTSUPP; | |
1598 | ctrl->done = 1; | |
1599 | wake_up(&gsm->event); | |
1600 | } | |
1601 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1602 | } | |
1603 | ||
1604 | /** | |
5f9a31d6 | 1605 | * gsm_control_transmit - send control packet |
e1eaea46 AC |
1606 | * @gsm: gsm mux |
1607 | * @ctrl: frame to send | |
1608 | * | |
1609 | * Send out a pending control command (called under control lock) | |
1610 | */ | |
1611 | ||
1612 | static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) | |
1613 | { | |
398867f5 | 1614 | struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 2, gsm->ftype); |
e1eaea46 AC |
1615 | if (msg == NULL) |
1616 | return; | |
398867f5 DS |
1617 | msg->data[0] = (ctrl->cmd << 1) | CR | EA; /* command */ |
1618 | msg->data[1] = (ctrl->len << 1) | EA; | |
1619 | memcpy(msg->data + 2, ctrl->data, ctrl->len); | |
e1eaea46 AC |
1620 | gsm_data_queue(gsm->dlci[0], msg); |
1621 | } | |
1622 | ||
1623 | /** | |
1624 | * gsm_control_retransmit - retransmit a control frame | |
724ac070 | 1625 | * @t: timer contained in our gsm object |
e1eaea46 AC |
1626 | * |
1627 | * Called off the T2 timer expiry in order to retransmit control frames | |
1628 | * that have been lost in the system somewhere. The control_lock protects | |
1629 | * us from colliding with another sender or a receive completion event. | |
1630 | * In that situation the timer may still occur in a small window but | |
1631 | * gsm->pending_cmd will be NULL and we just let the timer expire. | |
1632 | */ | |
1633 | ||
e99e88a9 | 1634 | static void gsm_control_retransmit(struct timer_list *t) |
e1eaea46 | 1635 | { |
e99e88a9 | 1636 | struct gsm_mux *gsm = from_timer(gsm, t, t2_timer); |
e1eaea46 AC |
1637 | struct gsm_control *ctrl; |
1638 | unsigned long flags; | |
1639 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1640 | ctrl = gsm->pending_cmd; | |
1641 | if (ctrl) { | |
4fae831b | 1642 | if (gsm->cretries == 0 || !gsm->dlci[0] || gsm->dlci[0]->dead) { |
e1eaea46 AC |
1643 | gsm->pending_cmd = NULL; |
1644 | ctrl->error = -ETIMEDOUT; | |
1645 | ctrl->done = 1; | |
1646 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1647 | wake_up(&gsm->event); | |
1648 | return; | |
1649 | } | |
d0bcdffc | 1650 | gsm->cretries--; |
e1eaea46 AC |
1651 | gsm_control_transmit(gsm, ctrl); |
1652 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); | |
1653 | } | |
1654 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1655 | } | |
1656 | ||
1657 | /** | |
1658 | * gsm_control_send - send a control frame on DLCI 0 | |
1659 | * @gsm: the GSM channel | |
1660 | * @command: command to send including CR bit | |
1661 | * @data: bytes of data (must be kmalloced) | |
724ac070 | 1662 | * @clen: length of the block to send |
e1eaea46 AC |
1663 | * |
1664 | * Queue and dispatch a control command. Only one command can be | |
1665 | * active at a time. In theory more can be outstanding but the matching | |
1666 | * gets really complicated so for now stick to one outstanding. | |
1667 | */ | |
1668 | ||
1669 | static struct gsm_control *gsm_control_send(struct gsm_mux *gsm, | |
1670 | unsigned int command, u8 *data, int clen) | |
1671 | { | |
1672 | struct gsm_control *ctrl = kzalloc(sizeof(struct gsm_control), | |
1673 | GFP_KERNEL); | |
1674 | unsigned long flags; | |
1675 | if (ctrl == NULL) | |
1676 | return NULL; | |
1677 | retry: | |
1678 | wait_event(gsm->event, gsm->pending_cmd == NULL); | |
1679 | spin_lock_irqsave(&gsm->control_lock, flags); | |
1680 | if (gsm->pending_cmd != NULL) { | |
1681 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1682 | goto retry; | |
1683 | } | |
1684 | ctrl->cmd = command; | |
1685 | ctrl->data = data; | |
1686 | ctrl->len = clen; | |
1687 | gsm->pending_cmd = ctrl; | |
e9ec2254 TL |
1688 | |
1689 | /* If DLCI0 is in ADM mode skip retries, it won't respond */ | |
1690 | if (gsm->dlci[0]->mode == DLCI_MODE_ADM) | |
d0bcdffc | 1691 | gsm->cretries = 0; |
e9ec2254 TL |
1692 | else |
1693 | gsm->cretries = gsm->n2; | |
1694 | ||
e1eaea46 AC |
1695 | mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); |
1696 | gsm_control_transmit(gsm, ctrl); | |
1697 | spin_unlock_irqrestore(&gsm->control_lock, flags); | |
1698 | return ctrl; | |
1699 | } | |
1700 | ||
1701 | /** | |
1702 | * gsm_control_wait - wait for a control to finish | |
1703 | * @gsm: GSM mux | |
1704 | * @control: control we are waiting on | |
1705 | * | |
1706 | * Waits for the control to complete or time out. Frees any used | |
1707 | * resources and returns 0 for success, or an error if the remote | |
1708 | * rejected or ignored the request. | |
1709 | */ | |
1710 | ||
1711 | static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control) | |
1712 | { | |
1713 | int err; | |
1714 | wait_event(gsm->event, control->done == 1); | |
1715 | err = control->error; | |
1716 | kfree(control); | |
1717 | return err; | |
1718 | } | |
1719 | ||
1720 | ||
1721 | /* | |
1722 | * DLCI level handling: Needs krefs | |
1723 | */ | |
1724 | ||
1725 | /* | |
1726 | * State transitions and timers | |
1727 | */ | |
1728 | ||
1729 | /** | |
1730 | * gsm_dlci_close - a DLCI has closed | |
1731 | * @dlci: DLCI that closed | |
1732 | * | |
1733 | * Perform processing when moving a DLCI into closed state. If there | |
1734 | * is an attached tty this is hung up | |
1735 | */ | |
1736 | ||
1737 | static void gsm_dlci_close(struct gsm_dlci *dlci) | |
1738 | { | |
1739 | del_timer(&dlci->t1); | |
1740 | if (debug & 8) | |
5f9a31d6 | 1741 | pr_debug("DLCI %d goes closed.\n", dlci->addr); |
e1eaea46 | 1742 | dlci->state = DLCI_CLOSED; |
ac77f007 DS |
1743 | /* Prevent us from sending data before the link is up again */ |
1744 | dlci->constipated = true; | |
e1eaea46 | 1745 | if (dlci->addr != 0) { |
aa27a094 | 1746 | tty_port_tty_hangup(&dlci->port, false); |
0af02167 | 1747 | gsm_dlci_clear_queues(dlci->gsm, dlci); |
a2ab75b8 | 1748 | /* Ensure that gsmtty_open() can return. */ |
1749 | tty_port_set_initialized(&dlci->port, 0); | |
1750 | wake_up_interruptible(&dlci->port.open_wait); | |
e1eaea46 | 1751 | } else |
5677fcf3 | 1752 | dlci->gsm->dead = true; |
e1eaea46 AC |
1753 | /* A DLCI 0 close is a MUX termination so we need to kick that |
1754 | back to userspace somehow */ | |
0af02167 DS |
1755 | gsm_dlci_data_kick(dlci); |
1756 | wake_up(&dlci->gsm->event); | |
e1eaea46 AC |
1757 | } |
1758 | ||
1759 | /** | |
1760 | * gsm_dlci_open - a DLCI has opened | |
1761 | * @dlci: DLCI that opened | |
1762 | * | |
1763 | * Perform processing when moving a DLCI into open state. | |
1764 | */ | |
1765 | ||
1766 | static void gsm_dlci_open(struct gsm_dlci *dlci) | |
1767 | { | |
1768 | /* Note that SABM UA .. SABM UA first UA lost can mean that we go | |
1769 | open -> open */ | |
1770 | del_timer(&dlci->t1); | |
1771 | /* This will let a tty open continue */ | |
1772 | dlci->state = DLCI_OPEN; | |
ac77f007 | 1773 | dlci->constipated = false; |
e1eaea46 | 1774 | if (debug & 8) |
5f9a31d6 | 1775 | pr_debug("DLCI %d goes open.\n", dlci->addr); |
48473802 DS |
1776 | /* Send current modem state */ |
1777 | if (dlci->addr) | |
c19ffe00 | 1778 | gsm_modem_update(dlci, 0); |
0af02167 | 1779 | gsm_dlci_data_kick(dlci); |
e1eaea46 AC |
1780 | wake_up(&dlci->gsm->event); |
1781 | } | |
1782 | ||
1783 | /** | |
1784 | * gsm_dlci_t1 - T1 timer expiry | |
724ac070 | 1785 | * @t: timer contained in the DLCI that opened |
e1eaea46 AC |
1786 | * |
1787 | * The T1 timer handles retransmits of control frames (essentially of | |
1788 | * SABM and DISC). We resend the command until the retry count runs out | |
1789 | * in which case an opening port goes back to closed and a closing port | |
1790 | * is simply put into closed state (any further frames from the other | |
1791 | * end will get a DM response) | |
ea3d8465 TL |
1792 | * |
1793 | * Some control dlci can stay in ADM mode with other dlci working just | |
1794 | * fine. In that case we can just keep the control dlci open after the | |
1795 | * DLCI_OPENING retries time out. | |
e1eaea46 AC |
1796 | */ |
1797 | ||
e99e88a9 | 1798 | static void gsm_dlci_t1(struct timer_list *t) |
e1eaea46 | 1799 | { |
e99e88a9 | 1800 | struct gsm_dlci *dlci = from_timer(dlci, t, t1); |
e1eaea46 AC |
1801 | struct gsm_mux *gsm = dlci->gsm; |
1802 | ||
1803 | switch (dlci->state) { | |
1804 | case DLCI_OPENING: | |
e1eaea46 | 1805 | if (dlci->retries) { |
f30e10ca | 1806 | dlci->retries--; |
e1eaea46 AC |
1807 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); |
1808 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
ea3d8465 TL |
1809 | } else if (!dlci->addr && gsm->control == (DM | PF)) { |
1810 | if (debug & 8) | |
1811 | pr_info("DLCI %d opening in ADM mode.\n", | |
1812 | dlci->addr); | |
e9ec2254 | 1813 | dlci->mode = DLCI_MODE_ADM; |
ea3d8465 TL |
1814 | gsm_dlci_open(dlci); |
1815 | } else { | |
e3b7468f | 1816 | gsm_dlci_begin_close(dlci); /* prevent half open link */ |
ea3d8465 TL |
1817 | } |
1818 | ||
e1eaea46 AC |
1819 | break; |
1820 | case DLCI_CLOSING: | |
e1eaea46 | 1821 | if (dlci->retries) { |
f30e10ca | 1822 | dlci->retries--; |
e1eaea46 AC |
1823 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); |
1824 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1825 | } else | |
1826 | gsm_dlci_close(dlci); | |
1827 | break; | |
72ae8cc1 JS |
1828 | default: |
1829 | pr_debug("%s: unhandled state: %d\n", __func__, dlci->state); | |
1830 | break; | |
e1eaea46 AC |
1831 | } |
1832 | } | |
1833 | ||
1834 | /** | |
1835 | * gsm_dlci_begin_open - start channel open procedure | |
1836 | * @dlci: DLCI to open | |
1837 | * | |
1838 | * Commence opening a DLCI from the Linux side. We issue SABM messages | |
ea3d8465 TL |
1839 | * to the modem which should then reply with a UA or ADM, at which point |
1840 | * we will move into open state. Opening is done asynchronously with retry | |
e1eaea46 AC |
1841 | * running off timers and the responses. |
1842 | */ | |
1843 | ||
1844 | static void gsm_dlci_begin_open(struct gsm_dlci *dlci) | |
1845 | { | |
1846 | struct gsm_mux *gsm = dlci->gsm; | |
1847 | if (dlci->state == DLCI_OPEN || dlci->state == DLCI_OPENING) | |
1848 | return; | |
1849 | dlci->retries = gsm->n2; | |
1850 | dlci->state = DLCI_OPENING; | |
1851 | gsm_command(dlci->gsm, dlci->addr, SABM|PF); | |
1852 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1853 | } | |
1854 | ||
ac77f007 DS |
1855 | /** |
1856 | * gsm_dlci_set_opening - change state to opening | |
1857 | * @dlci: DLCI to open | |
1858 | * | |
1859 | * Change internal state to wait for DLCI open from initiator side. | |
1860 | * We set off timers and responses upon reception of an SABM. | |
1861 | */ | |
1862 | static void gsm_dlci_set_opening(struct gsm_dlci *dlci) | |
1863 | { | |
1864 | switch (dlci->state) { | |
1865 | case DLCI_CLOSED: | |
1866 | case DLCI_CLOSING: | |
1867 | dlci->state = DLCI_OPENING; | |
1868 | break; | |
1869 | default: | |
1870 | break; | |
1871 | } | |
1872 | } | |
1873 | ||
e1eaea46 AC |
1874 | /** |
1875 | * gsm_dlci_begin_close - start channel open procedure | |
1876 | * @dlci: DLCI to open | |
1877 | * | |
1878 | * Commence closing a DLCI from the Linux side. We issue DISC messages | |
1879 | * to the modem which should then reply with a UA, at which point we | |
1880 | * will move into closed state. Closing is done asynchronously with retry | |
1881 | * off timers. We may also receive a DM reply from the other end which | |
1882 | * indicates the channel was already closed. | |
1883 | */ | |
1884 | ||
1885 | static void gsm_dlci_begin_close(struct gsm_dlci *dlci) | |
1886 | { | |
1887 | struct gsm_mux *gsm = dlci->gsm; | |
1888 | if (dlci->state == DLCI_CLOSED || dlci->state == DLCI_CLOSING) | |
1889 | return; | |
1890 | dlci->retries = gsm->n2; | |
1891 | dlci->state = DLCI_CLOSING; | |
1892 | gsm_command(dlci->gsm, dlci->addr, DISC|PF); | |
1893 | mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); | |
1894 | } | |
1895 | ||
1896 | /** | |
1897 | * gsm_dlci_data - data arrived | |
1898 | * @dlci: channel | |
1899 | * @data: block of bytes received | |
724ac070 | 1900 | * @clen: length of received block |
e1eaea46 AC |
1901 | * |
1902 | * A UI or UIH frame has arrived which contains data for a channel | |
1903 | * other than the control channel. If the relevant virtual tty is | |
1904 | * open we shovel the bits down it, if not we drop them. | |
1905 | */ | |
1906 | ||
4feb7a4a | 1907 | static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) |
e1eaea46 AC |
1908 | { |
1909 | /* krefs .. */ | |
1910 | struct tty_port *port = &dlci->port; | |
2e124b4a | 1911 | struct tty_struct *tty; |
e1eaea46 | 1912 | unsigned int modem = 0; |
7263287a | 1913 | int len = clen; |
687f9ad4 | 1914 | int slen = 0; |
e1eaea46 AC |
1915 | |
1916 | if (debug & 16) | |
2e124b4a JS |
1917 | pr_debug("%d bytes for tty\n", len); |
1918 | switch (dlci->adaption) { | |
1919 | /* Unsupported types */ | |
3e913eeb | 1920 | case 4: /* Packetised interruptible data */ |
2e124b4a | 1921 | break; |
3e913eeb | 1922 | case 3: /* Packetised uininterruptible voice/data */ |
2e124b4a | 1923 | break; |
3e913eeb | 1924 | case 2: /* Asynchronous serial with line state in each frame */ |
2e124b4a JS |
1925 | while (gsm_read_ea(&modem, *data++) == 0) { |
1926 | len--; | |
687f9ad4 | 1927 | slen++; |
2e124b4a JS |
1928 | if (len == 0) |
1929 | return; | |
1930 | } | |
fd442e5b | 1931 | len--; |
687f9ad4 | 1932 | slen++; |
2e124b4a JS |
1933 | tty = tty_port_tty_get(port); |
1934 | if (tty) { | |
687f9ad4 | 1935 | gsm_process_modem(tty, dlci, modem, slen); |
1adf6fee | 1936 | tty_wakeup(tty); |
2e124b4a | 1937 | tty_kref_put(tty); |
e1eaea46 | 1938 | } |
df561f66 | 1939 | fallthrough; |
3e913eeb | 1940 | case 1: /* Line state will go via DLCI 0 controls only */ |
2e124b4a JS |
1941 | default: |
1942 | tty_insert_flip_string(port, data, len); | |
1943 | tty_flip_buffer_push(port); | |
e1eaea46 AC |
1944 | } |
1945 | } | |
1946 | ||
1947 | /** | |
542a121a | 1948 | * gsm_dlci_command - data arrived on control channel |
e1eaea46 AC |
1949 | * @dlci: channel |
1950 | * @data: block of bytes received | |
1951 | * @len: length of received block | |
1952 | * | |
1953 | * A UI or UIH frame has arrived which contains data for DLCI 0 the | |
1954 | * control channel. This should contain a command EA followed by | |
1955 | * control data bytes. The command EA contains a command/response bit | |
1956 | * and we divide up the work accordingly. | |
1957 | */ | |
1958 | ||
4feb7a4a | 1959 | static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len) |
e1eaea46 AC |
1960 | { |
1961 | /* See what command is involved */ | |
1962 | unsigned int command = 0; | |
1963 | while (len-- > 0) { | |
1964 | if (gsm_read_ea(&command, *data++) == 1) { | |
1965 | int clen = *data++; | |
1966 | len--; | |
1967 | /* FIXME: this is properly an EA */ | |
1968 | clen >>= 1; | |
1969 | /* Malformed command ? */ | |
1970 | if (clen > len) | |
1971 | return; | |
1972 | if (command & 1) | |
1973 | gsm_control_message(dlci->gsm, command, | |
1974 | data, clen); | |
1975 | else | |
1976 | gsm_control_response(dlci->gsm, command, | |
1977 | data, clen); | |
1978 | return; | |
1979 | } | |
1980 | } | |
1981 | } | |
1982 | ||
c568f708 | 1983 | /** |
c9ab053e FP |
1984 | * gsm_kick_timeout - transmit if possible |
1985 | * @work: work contained in our gsm object | |
c568f708 DS |
1986 | * |
1987 | * Transmit data from DLCIs if the queue is empty. We can't rely on | |
1988 | * a tty wakeup except when we filled the pipe so we need to fire off | |
1989 | * new data ourselves in other cases. | |
1990 | */ | |
c9ab053e | 1991 | static void gsm_kick_timeout(struct work_struct *work) |
c568f708 | 1992 | { |
c9ab053e | 1993 | struct gsm_mux *gsm = container_of(work, struct gsm_mux, kick_timeout.work); |
c568f708 DS |
1994 | int sent = 0; |
1995 | ||
902e02ea | 1996 | mutex_lock(&gsm->tx_mutex); |
c568f708 DS |
1997 | /* If we have nothing running then we need to fire up */ |
1998 | if (gsm->tx_bytes < TX_THRESH_LO) | |
1999 | sent = gsm_dlci_data_sweep(gsm); | |
902e02ea | 2000 | mutex_unlock(&gsm->tx_mutex); |
c568f708 DS |
2001 | |
2002 | if (sent && debug & 4) | |
2003 | pr_info("%s TX queue stalled\n", __func__); | |
2004 | } | |
2005 | ||
e1eaea46 AC |
2006 | /* |
2007 | * Allocate/Free DLCI channels | |
2008 | */ | |
2009 | ||
2010 | /** | |
2011 | * gsm_dlci_alloc - allocate a DLCI | |
2012 | * @gsm: GSM mux | |
2013 | * @addr: address of the DLCI | |
2014 | * | |
2015 | * Allocate and install a new DLCI object into the GSM mux. | |
2016 | * | |
2017 | * FIXME: review locking races | |
2018 | */ | |
2019 | ||
2020 | static struct gsm_dlci *gsm_dlci_alloc(struct gsm_mux *gsm, int addr) | |
2021 | { | |
2022 | struct gsm_dlci *dlci = kzalloc(sizeof(struct gsm_dlci), GFP_ATOMIC); | |
2023 | if (dlci == NULL) | |
2024 | return NULL; | |
2025 | spin_lock_init(&dlci->lock); | |
bcd5abe2 | 2026 | mutex_init(&dlci->mutex); |
9361ebfb | 2027 | if (kfifo_alloc(&dlci->fifo, TX_SIZE, GFP_KERNEL) < 0) { |
e1eaea46 AC |
2028 | kfree(dlci); |
2029 | return NULL; | |
2030 | } | |
2031 | ||
2032 | skb_queue_head_init(&dlci->skb_list); | |
e99e88a9 | 2033 | timer_setup(&dlci->t1, gsm_dlci_t1, 0); |
e1eaea46 AC |
2034 | tty_port_init(&dlci->port); |
2035 | dlci->port.ops = &gsm_port_ops; | |
2036 | dlci->gsm = gsm; | |
2037 | dlci->addr = addr; | |
2038 | dlci->adaption = gsm->adaption; | |
2039 | dlci->state = DLCI_CLOSED; | |
ac77f007 | 2040 | if (addr) { |
e1eaea46 | 2041 | dlci->data = gsm_dlci_data; |
ac77f007 DS |
2042 | /* Prevent us from sending data before the link is up */ |
2043 | dlci->constipated = true; | |
2044 | } else { | |
e1eaea46 | 2045 | dlci->data = gsm_dlci_command; |
ac77f007 | 2046 | } |
e1eaea46 AC |
2047 | gsm->dlci[addr] = dlci; |
2048 | return dlci; | |
2049 | } | |
2050 | ||
2051 | /** | |
6ab8fba7 | 2052 | * gsm_dlci_free - free DLCI |
724ac070 | 2053 | * @port: tty port for DLCI to free |
6ab8fba7 RG |
2054 | * |
2055 | * Free up a DLCI. | |
2056 | * | |
2057 | * Can sleep. | |
2058 | */ | |
9a8e62bc | 2059 | static void gsm_dlci_free(struct tty_port *port) |
6ab8fba7 | 2060 | { |
9a8e62bc | 2061 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); |
6ab8fba7 RG |
2062 | |
2063 | del_timer_sync(&dlci->t1); | |
2064 | dlci->gsm->dlci[dlci->addr] = NULL; | |
036bca1f | 2065 | kfifo_free(&dlci->fifo); |
6ab8fba7 | 2066 | while ((dlci->skb = skb_dequeue(&dlci->skb_list))) |
329e5678 | 2067 | dev_kfree_skb(dlci->skb); |
6ab8fba7 RG |
2068 | kfree(dlci); |
2069 | } | |
2070 | ||
2071 | static inline void dlci_get(struct gsm_dlci *dlci) | |
2072 | { | |
9a8e62bc | 2073 | tty_port_get(&dlci->port); |
6ab8fba7 RG |
2074 | } |
2075 | ||
2076 | static inline void dlci_put(struct gsm_dlci *dlci) | |
2077 | { | |
9a8e62bc | 2078 | tty_port_put(&dlci->port); |
6ab8fba7 RG |
2079 | } |
2080 | ||
4d9b1090 DB |
2081 | static void gsm_destroy_network(struct gsm_dlci *dlci); |
2082 | ||
6ab8fba7 RG |
2083 | /** |
2084 | * gsm_dlci_release - release DLCI | |
e1eaea46 AC |
2085 | * @dlci: DLCI to destroy |
2086 | * | |
6ab8fba7 RG |
2087 | * Release a DLCI. Actual free is deferred until either |
2088 | * mux is closed or tty is closed - whichever is last. | |
e1eaea46 AC |
2089 | * |
2090 | * Can sleep. | |
2091 | */ | |
6ab8fba7 | 2092 | static void gsm_dlci_release(struct gsm_dlci *dlci) |
e1eaea46 AC |
2093 | { |
2094 | struct tty_struct *tty = tty_port_tty_get(&dlci->port); | |
2095 | if (tty) { | |
4d9b1090 DB |
2096 | mutex_lock(&dlci->mutex); |
2097 | gsm_destroy_network(dlci); | |
2098 | mutex_unlock(&dlci->mutex); | |
2099 | ||
96b169f0 | 2100 | /* We cannot use tty_hangup() because in tty_kref_put() the tty |
2101 | * driver assumes that the hangup queue is free and reuses it to | |
2102 | * queue release_one_tty() -> NULL pointer panic in | |
2103 | * process_one_work(). | |
2104 | */ | |
2105 | tty_vhangup(tty); | |
be706572 | 2106 | |
4d9b1090 | 2107 | tty_port_tty_set(&dlci->port, NULL); |
e1eaea46 AC |
2108 | tty_kref_put(tty); |
2109 | } | |
4d9b1090 | 2110 | dlci->state = DLCI_CLOSED; |
6ab8fba7 | 2111 | dlci_put(dlci); |
e1eaea46 AC |
2112 | } |
2113 | ||
e1eaea46 AC |
2114 | /* |
2115 | * LAPBish link layer logic | |
2116 | */ | |
2117 | ||
2118 | /** | |
2119 | * gsm_queue - a GSM frame is ready to process | |
2120 | * @gsm: pointer to our gsm mux | |
2121 | * | |
2122 | * At this point in time a frame has arrived and been demangled from | |
2123 | * the line encoding. All the differences between the encodings have | |
2124 | * been handled below us and the frame is unpacked into the structures. | |
2125 | * The fcs holds the header FCS but any data FCS must be added here. | |
2126 | */ | |
2127 | ||
2128 | static void gsm_queue(struct gsm_mux *gsm) | |
2129 | { | |
2130 | struct gsm_dlci *dlci; | |
2131 | u8 cr; | |
2132 | int address; | |
e1eaea46 | 2133 | |
e1eaea46 AC |
2134 | if (gsm->fcs != GOOD_FCS) { |
2135 | gsm->bad_fcs++; | |
2136 | if (debug & 4) | |
5f9a31d6 | 2137 | pr_debug("BAD FCS %02x\n", gsm->fcs); |
e1eaea46 AC |
2138 | return; |
2139 | } | |
2140 | address = gsm->address >> 1; | |
2141 | if (address >= NUM_DLCI) | |
2142 | goto invalid; | |
2143 | ||
2144 | cr = gsm->address & 1; /* C/R bit */ | |
57435c42 | 2145 | cr ^= gsm->initiator ? 0 : 1; /* Flip so 1 always means command */ |
e1eaea46 AC |
2146 | |
2147 | gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); | |
2148 | ||
e1eaea46 AC |
2149 | dlci = gsm->dlci[address]; |
2150 | ||
2151 | switch (gsm->control) { | |
2152 | case SABM|PF: | |
cd936621 | 2153 | if (cr == 1) |
e1eaea46 AC |
2154 | goto invalid; |
2155 | if (dlci == NULL) | |
2156 | dlci = gsm_dlci_alloc(gsm, address); | |
2157 | if (dlci == NULL) | |
2158 | return; | |
2159 | if (dlci->dead) | |
cc0f4212 | 2160 | gsm_response(gsm, address, DM|PF); |
e1eaea46 | 2161 | else { |
cc0f4212 | 2162 | gsm_response(gsm, address, UA|PF); |
e1eaea46 AC |
2163 | gsm_dlci_open(dlci); |
2164 | } | |
2165 | break; | |
2166 | case DISC|PF: | |
cd936621 | 2167 | if (cr == 1) |
e1eaea46 AC |
2168 | goto invalid; |
2169 | if (dlci == NULL || dlci->state == DLCI_CLOSED) { | |
cc0f4212 | 2170 | gsm_response(gsm, address, DM|PF); |
e1eaea46 AC |
2171 | return; |
2172 | } | |
2173 | /* Real close complete */ | |
a8c5b825 DS |
2174 | gsm_response(gsm, address, UA|PF); |
2175 | gsm_dlci_close(dlci); | |
e1eaea46 | 2176 | break; |
e1eaea46 AC |
2177 | case UA|PF: |
2178 | if (cr == 0 || dlci == NULL) | |
2179 | break; | |
2180 | switch (dlci->state) { | |
2181 | case DLCI_CLOSING: | |
2182 | gsm_dlci_close(dlci); | |
2183 | break; | |
2184 | case DLCI_OPENING: | |
2185 | gsm_dlci_open(dlci); | |
2186 | break; | |
72ae8cc1 JS |
2187 | default: |
2188 | pr_debug("%s: unhandled state: %d\n", __func__, | |
2189 | dlci->state); | |
2190 | break; | |
e1eaea46 AC |
2191 | } |
2192 | break; | |
2193 | case DM: /* DM can be valid unsolicited */ | |
2194 | case DM|PF: | |
2195 | if (cr) | |
2196 | goto invalid; | |
2197 | if (dlci == NULL) | |
2198 | return; | |
2199 | gsm_dlci_close(dlci); | |
2200 | break; | |
2201 | case UI: | |
2202 | case UI|PF: | |
2203 | case UIH: | |
2204 | case UIH|PF: | |
e1eaea46 | 2205 | if (dlci == NULL || dlci->state != DLCI_OPEN) { |
18a948c7 | 2206 | gsm_response(gsm, address, DM|PF); |
e1eaea46 AC |
2207 | return; |
2208 | } | |
2209 | dlci->data(dlci, gsm->buf, gsm->len); | |
2210 | break; | |
2211 | default: | |
2212 | goto invalid; | |
2213 | } | |
2214 | return; | |
2215 | invalid: | |
2216 | gsm->malformed++; | |
2217 | return; | |
2218 | } | |
2219 | ||
2220 | ||
2221 | /** | |
2222 | * gsm0_receive - perform processing for non-transparency | |
2223 | * @gsm: gsm data for this ldisc instance | |
2224 | * @c: character | |
2225 | * | |
2226 | * Receive bytes in gsm mode 0 | |
2227 | */ | |
2228 | ||
2229 | static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) | |
2230 | { | |
c2f2f000 AC |
2231 | unsigned int len; |
2232 | ||
e1eaea46 AC |
2233 | switch (gsm->state) { |
2234 | case GSM_SEARCH: /* SOF marker */ | |
2235 | if (c == GSM0_SOF) { | |
2236 | gsm->state = GSM_ADDRESS; | |
2237 | gsm->address = 0; | |
2238 | gsm->len = 0; | |
2239 | gsm->fcs = INIT_FCS; | |
2240 | } | |
c2f2f000 AC |
2241 | break; |
2242 | case GSM_ADDRESS: /* Address EA */ | |
e1eaea46 AC |
2243 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
2244 | if (gsm_read_ea(&gsm->address, c)) | |
2245 | gsm->state = GSM_CONTROL; | |
2246 | break; | |
2247 | case GSM_CONTROL: /* Control Byte */ | |
2248 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2249 | gsm->control = c; | |
c2f2f000 | 2250 | gsm->state = GSM_LEN0; |
e1eaea46 | 2251 | break; |
c2f2f000 | 2252 | case GSM_LEN0: /* Length EA */ |
e1eaea46 AC |
2253 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
2254 | if (gsm_read_ea(&gsm->len, c)) { | |
2255 | if (gsm->len > gsm->mru) { | |
2256 | gsm->bad_size++; | |
2257 | gsm->state = GSM_SEARCH; | |
2258 | break; | |
2259 | } | |
2260 | gsm->count = 0; | |
c2f2f000 AC |
2261 | if (!gsm->len) |
2262 | gsm->state = GSM_FCS; | |
2263 | else | |
2264 | gsm->state = GSM_DATA; | |
2265 | break; | |
e1eaea46 | 2266 | } |
c2f2f000 AC |
2267 | gsm->state = GSM_LEN1; |
2268 | break; | |
2269 | case GSM_LEN1: | |
2270 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2271 | len = c; | |
2272 | gsm->len |= len << 7; | |
2273 | if (gsm->len > gsm->mru) { | |
2274 | gsm->bad_size++; | |
2275 | gsm->state = GSM_SEARCH; | |
2276 | break; | |
e1eaea46 | 2277 | } |
c2f2f000 AC |
2278 | gsm->count = 0; |
2279 | if (!gsm->len) | |
2280 | gsm->state = GSM_FCS; | |
2281 | else | |
2282 | gsm->state = GSM_DATA; | |
e1eaea46 AC |
2283 | break; |
2284 | case GSM_DATA: /* Data */ | |
2285 | gsm->buf[gsm->count++] = c; | |
7a0e4b17 DS |
2286 | if (gsm->count == gsm->len) { |
2287 | /* Calculate final FCS for UI frames over all data */ | |
2288 | if ((gsm->control & ~PF) != UIH) { | |
2289 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, | |
2290 | gsm->count); | |
2291 | } | |
e1eaea46 | 2292 | gsm->state = GSM_FCS; |
7a0e4b17 | 2293 | } |
e1eaea46 AC |
2294 | break; |
2295 | case GSM_FCS: /* FCS follows the packet */ | |
7a0e4b17 | 2296 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); |
c2f2f000 AC |
2297 | gsm->state = GSM_SSOF; |
2298 | break; | |
2299 | case GSM_SSOF: | |
7a0e4b17 DS |
2300 | gsm->state = GSM_SEARCH; |
2301 | if (c == GSM0_SOF) | |
2302 | gsm_queue(gsm); | |
2303 | else | |
2304 | gsm->bad_size++; | |
e1eaea46 | 2305 | break; |
329aa6e6 JS |
2306 | default: |
2307 | pr_debug("%s: unhandled state: %d\n", __func__, gsm->state); | |
2308 | break; | |
e1eaea46 AC |
2309 | } |
2310 | } | |
2311 | ||
2312 | /** | |
c2f2f000 | 2313 | * gsm1_receive - perform processing for non-transparency |
e1eaea46 AC |
2314 | * @gsm: gsm data for this ldisc instance |
2315 | * @c: character | |
2316 | * | |
2317 | * Receive bytes in mode 1 (Advanced option) | |
2318 | */ | |
2319 | ||
2320 | static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) | |
2321 | { | |
f4f7d632 DS |
2322 | /* handle XON/XOFF */ |
2323 | if ((c & ISO_IEC_646_MASK) == XON) { | |
2324 | gsm->constipated = true; | |
2325 | return; | |
2326 | } else if ((c & ISO_IEC_646_MASK) == XOFF) { | |
2327 | gsm->constipated = false; | |
2328 | /* Kick the link in case it is idling */ | |
0af02167 | 2329 | gsmld_write_trigger(gsm); |
f4f7d632 DS |
2330 | return; |
2331 | } | |
e1eaea46 | 2332 | if (c == GSM1_SOF) { |
7a0e4b17 DS |
2333 | /* EOF is only valid in frame if we have got to the data state */ |
2334 | if (gsm->state == GSM_DATA) { | |
2335 | if (gsm->count < 1) { | |
2336 | /* Missing FSC */ | |
2337 | gsm->malformed++; | |
2338 | gsm->state = GSM_START; | |
2339 | return; | |
2340 | } | |
2341 | /* Remove the FCS from data */ | |
e1eaea46 | 2342 | gsm->count--; |
7a0e4b17 DS |
2343 | if ((gsm->control & ~PF) != UIH) { |
2344 | /* Calculate final FCS for UI frames over all | |
2345 | * data but FCS | |
2346 | */ | |
2347 | gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, | |
2348 | gsm->count); | |
2349 | } | |
2350 | /* Add the FCS itself to test against GOOD_FCS */ | |
e1eaea46 AC |
2351 | gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->buf[gsm->count]); |
2352 | gsm->len = gsm->count; | |
2353 | gsm_queue(gsm); | |
2354 | gsm->state = GSM_START; | |
2355 | return; | |
2356 | } | |
2357 | /* Any partial frame was a runt so go back to start */ | |
2358 | if (gsm->state != GSM_START) { | |
a24b4b2f DS |
2359 | if (gsm->state != GSM_SEARCH) |
2360 | gsm->malformed++; | |
e1eaea46 AC |
2361 | gsm->state = GSM_START; |
2362 | } | |
2363 | /* A SOF in GSM_START means we are still reading idling or | |
2364 | framing bytes */ | |
2365 | return; | |
2366 | } | |
2367 | ||
2368 | if (c == GSM1_ESCAPE) { | |
c50704bd | 2369 | gsm->escape = true; |
e1eaea46 AC |
2370 | return; |
2371 | } | |
2372 | ||
2373 | /* Only an unescaped SOF gets us out of GSM search */ | |
2374 | if (gsm->state == GSM_SEARCH) | |
2375 | return; | |
2376 | ||
2377 | if (gsm->escape) { | |
2378 | c ^= GSM1_ESCAPE_BITS; | |
c50704bd | 2379 | gsm->escape = false; |
e1eaea46 AC |
2380 | } |
2381 | switch (gsm->state) { | |
2382 | case GSM_START: /* First byte after SOF */ | |
2383 | gsm->address = 0; | |
2384 | gsm->state = GSM_ADDRESS; | |
2385 | gsm->fcs = INIT_FCS; | |
df561f66 | 2386 | fallthrough; |
e1eaea46 AC |
2387 | case GSM_ADDRESS: /* Address continuation */ |
2388 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2389 | if (gsm_read_ea(&gsm->address, c)) | |
2390 | gsm->state = GSM_CONTROL; | |
2391 | break; | |
2392 | case GSM_CONTROL: /* Control Byte */ | |
2393 | gsm->fcs = gsm_fcs_add(gsm->fcs, c); | |
2394 | gsm->control = c; | |
2395 | gsm->count = 0; | |
2396 | gsm->state = GSM_DATA; | |
2397 | break; | |
2398 | case GSM_DATA: /* Data */ | |
5f9a31d6 | 2399 | if (gsm->count > gsm->mru) { /* Allow one for the FCS */ |
e1eaea46 AC |
2400 | gsm->state = GSM_OVERRUN; |
2401 | gsm->bad_size++; | |
2402 | } else | |
2403 | gsm->buf[gsm->count++] = c; | |
2404 | break; | |
2405 | case GSM_OVERRUN: /* Over-long - eg a dropped SOF */ | |
2406 | break; | |
329aa6e6 JS |
2407 | default: |
2408 | pr_debug("%s: unhandled state: %d\n", __func__, gsm->state); | |
2409 | break; | |
e1eaea46 AC |
2410 | } |
2411 | } | |
2412 | ||
2413 | /** | |
2414 | * gsm_error - handle tty error | |
2415 | * @gsm: ldisc data | |
e1eaea46 AC |
2416 | * |
2417 | * Handle an error in the receipt of data for a frame. Currently we just | |
2418 | * go back to hunting for a SOF. | |
2419 | * | |
2420 | * FIXME: better diagnostics ? | |
2421 | */ | |
2422 | ||
ea502201 | 2423 | static void gsm_error(struct gsm_mux *gsm) |
e1eaea46 AC |
2424 | { |
2425 | gsm->state = GSM_SEARCH; | |
2426 | gsm->io_error++; | |
2427 | } | |
2428 | ||
2429 | /** | |
2430 | * gsm_cleanup_mux - generic GSM protocol cleanup | |
2431 | * @gsm: our mux | |
aa371e96 | 2432 | * @disc: disconnect link? |
e1eaea46 AC |
2433 | * |
2434 | * Clean up the bits of the mux which are the same for all framing | |
2435 | * protocols. Remove the mux from the mux table, stop all the timers | |
2436 | * and then shut down each device hanging up the channels as we go. | |
2437 | */ | |
2438 | ||
aa371e96 | 2439 | static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc) |
e1eaea46 AC |
2440 | { |
2441 | int i; | |
2442 | struct gsm_dlci *dlci = gsm->dlci[0]; | |
329e5678 | 2443 | struct gsm_msg *txq, *ntxq; |
e1eaea46 | 2444 | |
5677fcf3 | 2445 | gsm->dead = true; |
aa371e96 | 2446 | mutex_lock(&gsm->mutex); |
e1eaea46 | 2447 | |
aa371e96 DS |
2448 | if (dlci) { |
2449 | if (disc && dlci->state != DLCI_CLOSED) { | |
2450 | gsm_dlci_begin_close(dlci); | |
2451 | wait_event(gsm->event, dlci->state == DLCI_CLOSED); | |
e1eaea46 | 2452 | } |
aa371e96 | 2453 | dlci->dead = true; |
e1eaea46 | 2454 | } |
e1eaea46 | 2455 | |
aa371e96 | 2456 | /* Finish outstanding timers, making sure they are done */ |
c9ab053e | 2457 | cancel_delayed_work_sync(&gsm->kick_timeout); |
e1eaea46 | 2458 | del_timer_sync(&gsm->t2_timer); |
71e07791 | 2459 | |
0af02167 DS |
2460 | /* Finish writing to ldisc */ |
2461 | flush_work(&gsm->tx_work); | |
2462 | ||
deefc58b | 2463 | /* Free up any link layer users and finally the control channel */ |
01aecd91 DS |
2464 | if (gsm->has_devices) { |
2465 | gsm_unregister_devices(gsm_tty_driver, gsm->num); | |
2466 | gsm->has_devices = false; | |
2467 | } | |
deefc58b | 2468 | for (i = NUM_DLCI - 1; i >= 0; i--) |
e1eaea46 | 2469 | if (gsm->dlci[i]) |
6ab8fba7 | 2470 | gsm_dlci_release(gsm->dlci[i]); |
dfabf7ff | 2471 | mutex_unlock(&gsm->mutex); |
e1eaea46 | 2472 | /* Now wipe the queues */ |
17eac652 | 2473 | tty_ldisc_flush(gsm->tty); |
0af02167 DS |
2474 | list_for_each_entry_safe(txq, ntxq, &gsm->tx_ctrl_list, list) |
2475 | kfree(txq); | |
2476 | INIT_LIST_HEAD(&gsm->tx_ctrl_list); | |
2477 | list_for_each_entry_safe(txq, ntxq, &gsm->tx_data_list, list) | |
e1eaea46 | 2478 | kfree(txq); |
0af02167 | 2479 | INIT_LIST_HEAD(&gsm->tx_data_list); |
e1eaea46 | 2480 | } |
e1eaea46 AC |
2481 | |
2482 | /** | |
2483 | * gsm_activate_mux - generic GSM setup | |
2484 | * @gsm: our mux | |
2485 | * | |
2486 | * Set up the bits of the mux which are the same for all framing | |
2487 | * protocols. Add the mux to the mux table so it can be opened and | |
2488 | * finally kick off connecting to DLCI 0 on the modem. | |
2489 | */ | |
2490 | ||
54af5836 | 2491 | static int gsm_activate_mux(struct gsm_mux *gsm) |
e1eaea46 AC |
2492 | { |
2493 | struct gsm_dlci *dlci; | |
01aecd91 | 2494 | int ret; |
e1eaea46 | 2495 | |
73496604 DS |
2496 | dlci = gsm_dlci_alloc(gsm, 0); |
2497 | if (dlci == NULL) | |
2498 | return -ENOMEM; | |
2499 | ||
e1eaea46 AC |
2500 | if (gsm->encoding == 0) |
2501 | gsm->receive = gsm0_receive; | |
2502 | else | |
2503 | gsm->receive = gsm1_receive; | |
e1eaea46 | 2504 | |
01aecd91 DS |
2505 | ret = gsm_register_devices(gsm_tty_driver, gsm->num); |
2506 | if (ret) | |
2507 | return ret; | |
2508 | ||
01aecd91 | 2509 | gsm->has_devices = true; |
5677fcf3 | 2510 | gsm->dead = false; /* Tty opens are now permissible */ |
e1eaea46 AC |
2511 | return 0; |
2512 | } | |
e1eaea46 AC |
2513 | |
2514 | /** | |
2515 | * gsm_free_mux - free up a mux | |
724ac070 | 2516 | * @gsm: mux to free |
e1eaea46 | 2517 | * |
6ab8fba7 | 2518 | * Dispose of allocated resources for a dead mux |
e1eaea46 | 2519 | */ |
54af5836 | 2520 | static void gsm_free_mux(struct gsm_mux *gsm) |
e1eaea46 | 2521 | { |
1ec92e97 DS |
2522 | int i; |
2523 | ||
2524 | for (i = 0; i < MAX_MUX; i++) { | |
2525 | if (gsm == gsm_mux[i]) { | |
2526 | gsm_mux[i] = NULL; | |
2527 | break; | |
2528 | } | |
2529 | } | |
902e02ea | 2530 | mutex_destroy(&gsm->tx_mutex); |
1ec92e97 | 2531 | mutex_destroy(&gsm->mutex); |
e1eaea46 AC |
2532 | kfree(gsm->txframe); |
2533 | kfree(gsm->buf); | |
2534 | kfree(gsm); | |
2535 | } | |
e1eaea46 | 2536 | |
6ab8fba7 RG |
2537 | /** |
2538 | * gsm_free_muxr - free up a mux | |
724ac070 | 2539 | * @ref: kreference to the mux to free |
6ab8fba7 RG |
2540 | * |
2541 | * Dispose of allocated resources for a dead mux | |
2542 | */ | |
2543 | static void gsm_free_muxr(struct kref *ref) | |
2544 | { | |
2545 | struct gsm_mux *gsm = container_of(ref, struct gsm_mux, ref); | |
2546 | gsm_free_mux(gsm); | |
2547 | } | |
2548 | ||
2549 | static inline void mux_get(struct gsm_mux *gsm) | |
2550 | { | |
1ec92e97 DS |
2551 | unsigned long flags; |
2552 | ||
2553 | spin_lock_irqsave(&gsm_mux_lock, flags); | |
6ab8fba7 | 2554 | kref_get(&gsm->ref); |
1ec92e97 | 2555 | spin_unlock_irqrestore(&gsm_mux_lock, flags); |
6ab8fba7 RG |
2556 | } |
2557 | ||
2558 | static inline void mux_put(struct gsm_mux *gsm) | |
2559 | { | |
1ec92e97 DS |
2560 | unsigned long flags; |
2561 | ||
2562 | spin_lock_irqsave(&gsm_mux_lock, flags); | |
6ab8fba7 | 2563 | kref_put(&gsm->ref, gsm_free_muxr); |
1ec92e97 | 2564 | spin_unlock_irqrestore(&gsm_mux_lock, flags); |
6ab8fba7 RG |
2565 | } |
2566 | ||
43a9e710 MH |
2567 | static inline unsigned int mux_num_to_base(struct gsm_mux *gsm) |
2568 | { | |
2569 | return gsm->num * NUM_DLCI; | |
2570 | } | |
2571 | ||
2572 | static inline unsigned int mux_line_to_num(unsigned int line) | |
2573 | { | |
2574 | return line / NUM_DLCI; | |
2575 | } | |
2576 | ||
e1eaea46 AC |
2577 | /** |
2578 | * gsm_alloc_mux - allocate a mux | |
2579 | * | |
2580 | * Creates a new mux ready for activation. | |
2581 | */ | |
2582 | ||
54af5836 | 2583 | static struct gsm_mux *gsm_alloc_mux(void) |
e1eaea46 | 2584 | { |
1ec92e97 | 2585 | int i; |
e1eaea46 AC |
2586 | struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL); |
2587 | if (gsm == NULL) | |
2588 | return NULL; | |
2589 | gsm->buf = kmalloc(MAX_MRU + 1, GFP_KERNEL); | |
2590 | if (gsm->buf == NULL) { | |
2591 | kfree(gsm); | |
2592 | return NULL; | |
2593 | } | |
535bf600 | 2594 | gsm->txframe = kmalloc(2 * (MAX_MTU + PROT_OVERHEAD - 1), GFP_KERNEL); |
e1eaea46 AC |
2595 | if (gsm->txframe == NULL) { |
2596 | kfree(gsm->buf); | |
2597 | kfree(gsm); | |
2598 | return NULL; | |
2599 | } | |
2600 | spin_lock_init(&gsm->lock); | |
dfabf7ff | 2601 | mutex_init(&gsm->mutex); |
902e02ea | 2602 | mutex_init(&gsm->tx_mutex); |
6ab8fba7 | 2603 | kref_init(&gsm->ref); |
0af02167 DS |
2604 | INIT_LIST_HEAD(&gsm->tx_ctrl_list); |
2605 | INIT_LIST_HEAD(&gsm->tx_data_list); | |
c9ab053e | 2606 | INIT_DELAYED_WORK(&gsm->kick_timeout, gsm_kick_timeout); |
4bb1a53b TH |
2607 | timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0); |
2608 | INIT_WORK(&gsm->tx_work, gsmld_write_task); | |
2609 | init_waitqueue_head(&gsm->event); | |
2610 | spin_lock_init(&gsm->control_lock); | |
e1eaea46 AC |
2611 | |
2612 | gsm->t1 = T1; | |
2613 | gsm->t2 = T2; | |
2614 | gsm->n2 = N2; | |
2615 | gsm->ftype = UIH; | |
e1eaea46 AC |
2616 | gsm->adaption = 1; |
2617 | gsm->encoding = 1; | |
2618 | gsm->mru = 64; /* Default to encoding 1 so these should be 64 */ | |
2619 | gsm->mtu = 64; | |
5677fcf3 | 2620 | gsm->dead = true; /* Avoid early tty opens */ |
e1eaea46 | 2621 | |
1ec92e97 DS |
2622 | /* Store the instance to the mux array or abort if no space is |
2623 | * available. | |
2624 | */ | |
2625 | spin_lock(&gsm_mux_lock); | |
2626 | for (i = 0; i < MAX_MUX; i++) { | |
2627 | if (!gsm_mux[i]) { | |
2628 | gsm_mux[i] = gsm; | |
2629 | gsm->num = i; | |
2630 | break; | |
2631 | } | |
2632 | } | |
2633 | spin_unlock(&gsm_mux_lock); | |
2634 | if (i == MAX_MUX) { | |
902e02ea | 2635 | mutex_destroy(&gsm->tx_mutex); |
1ec92e97 DS |
2636 | mutex_destroy(&gsm->mutex); |
2637 | kfree(gsm->txframe); | |
2638 | kfree(gsm->buf); | |
2639 | kfree(gsm); | |
2640 | return NULL; | |
2641 | } | |
2642 | ||
e1eaea46 AC |
2643 | return gsm; |
2644 | } | |
e1eaea46 | 2645 | |
33841040 TL |
2646 | static void gsm_copy_config_values(struct gsm_mux *gsm, |
2647 | struct gsm_config *c) | |
2648 | { | |
2649 | memset(c, 0, sizeof(*c)); | |
2650 | c->adaption = gsm->adaption; | |
2651 | c->encapsulation = gsm->encoding; | |
2652 | c->initiator = gsm->initiator; | |
2653 | c->t1 = gsm->t1; | |
2654 | c->t2 = gsm->t2; | |
2655 | c->t3 = 0; /* Not supported */ | |
2656 | c->n2 = gsm->n2; | |
2657 | if (gsm->ftype == UIH) | |
2658 | c->i = 1; | |
2659 | else | |
2660 | c->i = 2; | |
2661 | pr_debug("Ftype %d i %d\n", gsm->ftype, c->i); | |
2662 | c->mru = gsm->mru; | |
2663 | c->mtu = gsm->mtu; | |
2664 | c->k = 0; | |
2665 | } | |
2666 | ||
2667 | static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c) | |
2668 | { | |
edd5f60c | 2669 | int ret = 0; |
33841040 TL |
2670 | int need_close = 0; |
2671 | int need_restart = 0; | |
2672 | ||
2673 | /* Stuff we don't support yet - UI or I frame transport, windowing */ | |
2674 | if ((c->adaption != 1 && c->adaption != 2) || c->k) | |
2675 | return -EOPNOTSUPP; | |
2676 | /* Check the MRU/MTU range looks sane */ | |
2677 | if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) | |
2678 | return -EINVAL; | |
d0bcdffc | 2679 | if (c->n2 > 255) |
33841040 TL |
2680 | return -EINVAL; |
2681 | if (c->encapsulation > 1) /* Basic, advanced, no I */ | |
2682 | return -EINVAL; | |
2683 | if (c->initiator > 1) | |
2684 | return -EINVAL; | |
2685 | if (c->i == 0 || c->i > 2) /* UIH and UI only */ | |
2686 | return -EINVAL; | |
2687 | /* | |
2688 | * See what is needed for reconfiguration | |
2689 | */ | |
2690 | ||
2691 | /* Timing fields */ | |
2692 | if (c->t1 != 0 && c->t1 != gsm->t1) | |
2693 | need_restart = 1; | |
2694 | if (c->t2 != 0 && c->t2 != gsm->t2) | |
2695 | need_restart = 1; | |
2696 | if (c->encapsulation != gsm->encoding) | |
2697 | need_restart = 1; | |
2698 | if (c->adaption != gsm->adaption) | |
2699 | need_restart = 1; | |
2700 | /* Requires care */ | |
2701 | if (c->initiator != gsm->initiator) | |
2702 | need_close = 1; | |
2703 | if (c->mru != gsm->mru) | |
2704 | need_restart = 1; | |
2705 | if (c->mtu != gsm->mtu) | |
2706 | need_restart = 1; | |
2707 | ||
2708 | /* | |
2709 | * Close down what is needed, restart and initiate the new | |
aa371e96 DS |
2710 | * configuration. On the first time there is no DLCI[0] |
2711 | * and closing or cleaning up is not necessary. | |
33841040 | 2712 | */ |
aa371e96 DS |
2713 | if (need_close || need_restart) |
2714 | gsm_cleanup_mux(gsm, true); | |
33841040 TL |
2715 | |
2716 | gsm->initiator = c->initiator; | |
2717 | gsm->mru = c->mru; | |
2718 | gsm->mtu = c->mtu; | |
2719 | gsm->encoding = c->encapsulation; | |
2720 | gsm->adaption = c->adaption; | |
2721 | gsm->n2 = c->n2; | |
2722 | ||
2723 | if (c->i == 1) | |
2724 | gsm->ftype = UIH; | |
2725 | else if (c->i == 2) | |
2726 | gsm->ftype = UI; | |
2727 | ||
2728 | if (c->t1) | |
2729 | gsm->t1 = c->t1; | |
2730 | if (c->t2) | |
2731 | gsm->t2 = c->t2; | |
2732 | ||
2733 | /* | |
2734 | * FIXME: We need to separate activation/deactivation from adding | |
2735 | * and removing from the mux array | |
2736 | */ | |
edd5f60c DS |
2737 | if (gsm->dead) { |
2738 | ret = gsm_activate_mux(gsm); | |
2739 | if (ret) | |
2740 | return ret; | |
2741 | if (gsm->initiator) | |
2742 | gsm_dlci_begin_open(gsm->dlci[0]); | |
2743 | } | |
33841040 TL |
2744 | return 0; |
2745 | } | |
2746 | ||
e1eaea46 AC |
2747 | /** |
2748 | * gsmld_output - write to link | |
2749 | * @gsm: our mux | |
2750 | * @data: bytes to output | |
2751 | * @len: size | |
2752 | * | |
2753 | * Write a block of data from the GSM mux to the data channel. This | |
2754 | * will eventually be serialized from above but at the moment isn't. | |
2755 | */ | |
2756 | ||
2757 | static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) | |
2758 | { | |
2759 | if (tty_write_room(gsm->tty) < len) { | |
2760 | set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags); | |
2761 | return -ENOSPC; | |
2762 | } | |
0a77c4f9 | 2763 | if (debug & 4) |
925ea0fa | 2764 | gsm_hex_dump_bytes(__func__, data, len); |
9136c683 | 2765 | return gsm->tty->ops->write(gsm->tty, data, len); |
e1eaea46 AC |
2766 | } |
2767 | ||
0af02167 DS |
2768 | |
2769 | /** | |
2770 | * gsmld_write_trigger - schedule ldisc write task | |
2771 | * @gsm: our mux | |
2772 | */ | |
2773 | static void gsmld_write_trigger(struct gsm_mux *gsm) | |
2774 | { | |
2775 | if (!gsm || !gsm->dlci[0] || gsm->dlci[0]->dead) | |
2776 | return; | |
2777 | schedule_work(&gsm->tx_work); | |
2778 | } | |
2779 | ||
2780 | ||
2781 | /** | |
2782 | * gsmld_write_task - ldisc write task | |
2783 | * @work: our tx write work | |
2784 | * | |
2785 | * Writes out data to the ldisc if possible. We are doing this here to | |
2786 | * avoid dead-locking. This returns if no space or data is left for output. | |
2787 | */ | |
2788 | static void gsmld_write_task(struct work_struct *work) | |
2789 | { | |
2790 | struct gsm_mux *gsm = container_of(work, struct gsm_mux, tx_work); | |
0af02167 DS |
2791 | int i, ret; |
2792 | ||
2793 | /* All outstanding control channel and control messages and one data | |
2794 | * frame is sent. | |
2795 | */ | |
2796 | ret = -ENODEV; | |
902e02ea | 2797 | mutex_lock(&gsm->tx_mutex); |
0af02167 DS |
2798 | if (gsm->tty) |
2799 | ret = gsm_data_kick(gsm); | |
902e02ea | 2800 | mutex_unlock(&gsm->tx_mutex); |
0af02167 DS |
2801 | |
2802 | if (ret >= 0) | |
2803 | for (i = 0; i < NUM_DLCI; i++) | |
2804 | if (gsm->dlci[i]) | |
2805 | tty_port_tty_wakeup(&gsm->dlci[i]->port); | |
2806 | } | |
2807 | ||
e1eaea46 AC |
2808 | /** |
2809 | * gsmld_attach_gsm - mode set up | |
2810 | * @tty: our tty structure | |
2811 | * @gsm: our mux | |
2812 | * | |
2813 | * Set up the MUX for basic mode and commence connecting to the | |
2814 | * modem. Currently called from the line discipline set up but | |
2815 | * will need moving to an ioctl path. | |
2816 | */ | |
2817 | ||
01aecd91 | 2818 | static void gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) |
e1eaea46 | 2819 | { |
e1eaea46 | 2820 | gsm->tty = tty_kref_get(tty); |
f4f7d632 DS |
2821 | /* Turn off tty XON/XOFF handling to handle it explicitly. */ |
2822 | gsm->old_c_iflag = tty->termios.c_iflag; | |
2823 | tty->termios.c_iflag &= (IXON | IXOFF); | |
e1eaea46 AC |
2824 | } |
2825 | ||
e1eaea46 AC |
2826 | /** |
2827 | * gsmld_detach_gsm - stop doing 0710 mux | |
70f23fd6 | 2828 | * @tty: tty attached to the mux |
e1eaea46 AC |
2829 | * @gsm: mux |
2830 | * | |
2831 | * Shutdown and then clean up the resources used by the line discipline | |
2832 | */ | |
2833 | ||
2834 | static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) | |
2835 | { | |
2836 | WARN_ON(tty != gsm->tty); | |
f4f7d632 DS |
2837 | /* Restore tty XON/XOFF handling. */ |
2838 | gsm->tty->termios.c_iflag = gsm->old_c_iflag; | |
e1eaea46 AC |
2839 | tty_kref_put(gsm->tty); |
2840 | gsm->tty = NULL; | |
2841 | } | |
2842 | ||
55db4c64 | 2843 | static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
0f3dcf3b | 2844 | const char *fp, int count) |
e1eaea46 AC |
2845 | { |
2846 | struct gsm_mux *gsm = tty->disc_data; | |
82f91fe0 | 2847 | char flags = TTY_NORMAL; |
e1eaea46 | 2848 | |
0a77c4f9 | 2849 | if (debug & 4) |
925ea0fa | 2850 | gsm_hex_dump_bytes(__func__, cp, count); |
e1eaea46 | 2851 | |
b93db97e JS |
2852 | for (; count; count--, cp++) { |
2853 | if (fp) | |
2854 | flags = *fp++; | |
e1eaea46 AC |
2855 | switch (flags) { |
2856 | case TTY_NORMAL: | |
f16c6d2e MAH |
2857 | if (gsm->receive) |
2858 | gsm->receive(gsm, *cp); | |
e1eaea46 AC |
2859 | break; |
2860 | case TTY_OVERRUN: | |
2861 | case TTY_BREAK: | |
2862 | case TTY_PARITY: | |
2863 | case TTY_FRAME: | |
ea502201 | 2864 | gsm_error(gsm); |
e1eaea46 AC |
2865 | break; |
2866 | default: | |
c01af4fe | 2867 | WARN_ONCE(1, "%s: unknown flag %d\n", |
429b4749 | 2868 | tty_name(tty), flags); |
e1eaea46 AC |
2869 | break; |
2870 | } | |
2871 | } | |
2872 | /* FASYNC if needed ? */ | |
2873 | /* If clogged call tty_throttle(tty); */ | |
2874 | } | |
2875 | ||
e1eaea46 AC |
2876 | /** |
2877 | * gsmld_flush_buffer - clean input queue | |
2878 | * @tty: terminal device | |
2879 | * | |
2880 | * Flush the input buffer. Called when the line discipline is | |
2881 | * being closed, when the tty layer wants the buffer flushed (eg | |
2882 | * at hangup). | |
2883 | */ | |
2884 | ||
2885 | static void gsmld_flush_buffer(struct tty_struct *tty) | |
2886 | { | |
2887 | } | |
2888 | ||
2889 | /** | |
2890 | * gsmld_close - close the ldisc for this tty | |
2891 | * @tty: device | |
2892 | * | |
2893 | * Called from the terminal layer when this line discipline is | |
2894 | * being shut down, either because of a close or becsuse of a | |
2895 | * discipline change. The function will not be called while other | |
2896 | * ldisc methods are in progress. | |
2897 | */ | |
2898 | ||
2899 | static void gsmld_close(struct tty_struct *tty) | |
2900 | { | |
2901 | struct gsm_mux *gsm = tty->disc_data; | |
2902 | ||
284260f2 DS |
2903 | /* The ldisc locks and closes the port before calling our close. This |
2904 | * means we have no way to do a proper disconnect. We will not bother | |
2905 | * to do one. | |
2906 | */ | |
2907 | gsm_cleanup_mux(gsm, false); | |
2908 | ||
e1eaea46 AC |
2909 | gsmld_detach_gsm(tty, gsm); |
2910 | ||
2911 | gsmld_flush_buffer(tty); | |
2912 | /* Do other clean up here */ | |
6ab8fba7 | 2913 | mux_put(gsm); |
e1eaea46 AC |
2914 | } |
2915 | ||
2916 | /** | |
2917 | * gsmld_open - open an ldisc | |
2918 | * @tty: terminal to open | |
2919 | * | |
2920 | * Called when this line discipline is being attached to the | |
2921 | * terminal device. Can sleep. Called serialized so that no | |
2922 | * other events will occur in parallel. No further open will occur | |
2923 | * until a close. | |
2924 | */ | |
2925 | ||
2926 | static int gsmld_open(struct tty_struct *tty) | |
2927 | { | |
2928 | struct gsm_mux *gsm; | |
2929 | ||
2930 | if (tty->ops->write == NULL) | |
2931 | return -EINVAL; | |
2932 | ||
2933 | /* Attach our ldisc data */ | |
2934 | gsm = gsm_alloc_mux(); | |
2935 | if (gsm == NULL) | |
2936 | return -ENOMEM; | |
2937 | ||
2938 | tty->disc_data = gsm; | |
2939 | tty->receive_room = 65536; | |
2940 | ||
2941 | /* Attach the initial passive connection */ | |
2942 | gsm->encoding = 1; | |
5a640967 | 2943 | |
01aecd91 DS |
2944 | gsmld_attach_gsm(tty, gsm); |
2945 | ||
01aecd91 | 2946 | return 0; |
e1eaea46 AC |
2947 | } |
2948 | ||
2949 | /** | |
2950 | * gsmld_write_wakeup - asynchronous I/O notifier | |
2951 | * @tty: tty device | |
2952 | * | |
2953 | * Required for the ptys, serial driver etc. since processes | |
2954 | * that attach themselves to the master and rely on ASYNC | |
2955 | * IO must be woken up | |
2956 | */ | |
2957 | ||
2958 | static void gsmld_write_wakeup(struct tty_struct *tty) | |
2959 | { | |
2960 | struct gsm_mux *gsm = tty->disc_data; | |
2961 | ||
2962 | /* Queue poll */ | |
0af02167 | 2963 | gsmld_write_trigger(gsm); |
e1eaea46 AC |
2964 | } |
2965 | ||
2966 | /** | |
2967 | * gsmld_read - read function for tty | |
2968 | * @tty: tty device | |
2969 | * @file: file object | |
2970 | * @buf: userspace buffer pointer | |
2971 | * @nr: size of I/O | |
542a121a LJ |
2972 | * @cookie: unused |
2973 | * @offset: unused | |
e1eaea46 AC |
2974 | * |
2975 | * Perform reads for the line discipline. We are guaranteed that the | |
2976 | * line discipline will not be closed under us but we may get multiple | |
2977 | * parallel readers and must handle this ourselves. We may also get | |
2978 | * a hangup. Always called in user context, may sleep. | |
2979 | * | |
2980 | * This code must be sure never to sleep through a hangup. | |
2981 | */ | |
2982 | ||
2983 | static ssize_t gsmld_read(struct tty_struct *tty, struct file *file, | |
3b830a9c LT |
2984 | unsigned char *buf, size_t nr, |
2985 | void **cookie, unsigned long offset) | |
e1eaea46 AC |
2986 | { |
2987 | return -EOPNOTSUPP; | |
2988 | } | |
2989 | ||
2990 | /** | |
2991 | * gsmld_write - write function for tty | |
2992 | * @tty: tty device | |
2993 | * @file: file object | |
2994 | * @buf: userspace buffer pointer | |
2995 | * @nr: size of I/O | |
2996 | * | |
2997 | * Called when the owner of the device wants to send a frame | |
2998 | * itself (or some other control data). The data is transferred | |
2999 | * as-is and must be properly framed and checksummed as appropriate | |
3000 | * by userspace. Frames are either sent whole or not at all as this | |
3001 | * avoids pain user side. | |
3002 | */ | |
3003 | ||
3004 | static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, | |
3005 | const unsigned char *buf, size_t nr) | |
3006 | { | |
32dd59f9 | 3007 | struct gsm_mux *gsm = tty->disc_data; |
32dd59f9 DS |
3008 | int space; |
3009 | int ret; | |
3010 | ||
3011 | if (!gsm) | |
3012 | return -ENODEV; | |
3013 | ||
3014 | ret = -ENOBUFS; | |
902e02ea | 3015 | mutex_lock(&gsm->tx_mutex); |
32dd59f9 | 3016 | space = tty_write_room(tty); |
e1eaea46 | 3017 | if (space >= nr) |
32dd59f9 DS |
3018 | ret = tty->ops->write(tty, buf, nr); |
3019 | else | |
3020 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
902e02ea | 3021 | mutex_unlock(&gsm->tx_mutex); |
32dd59f9 DS |
3022 | |
3023 | return ret; | |
e1eaea46 AC |
3024 | } |
3025 | ||
3026 | /** | |
3027 | * gsmld_poll - poll method for N_GSM0710 | |
3028 | * @tty: terminal device | |
3029 | * @file: file accessing it | |
3030 | * @wait: poll table | |
3031 | * | |
3032 | * Called when the line discipline is asked to poll() for data or | |
3033 | * for special events. This code is not serialized with respect to | |
3034 | * other events save open/close. | |
3035 | * | |
3036 | * This code must be sure never to sleep through a hangup. | |
3037 | * Called without the kernel lock held - fine | |
3038 | */ | |
3039 | ||
afc9a42b | 3040 | static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file, |
e1eaea46 AC |
3041 | poll_table *wait) |
3042 | { | |
afc9a42b | 3043 | __poll_t mask = 0; |
e1eaea46 AC |
3044 | struct gsm_mux *gsm = tty->disc_data; |
3045 | ||
3046 | poll_wait(file, &tty->read_wait, wait); | |
3047 | poll_wait(file, &tty->write_wait, wait); | |
7e5b4322 DS |
3048 | |
3049 | if (gsm->dead) | |
3050 | mask |= EPOLLHUP; | |
e1eaea46 | 3051 | if (tty_hung_up_p(file)) |
a9a08845 | 3052 | mask |= EPOLLHUP; |
7e5b4322 DS |
3053 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
3054 | mask |= EPOLLHUP; | |
e1eaea46 | 3055 | if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) |
a9a08845 | 3056 | mask |= EPOLLOUT | EPOLLWRNORM; |
e1eaea46 AC |
3057 | return mask; |
3058 | } | |
3059 | ||
d78328bc JS |
3060 | static int gsmld_ioctl(struct tty_struct *tty, unsigned int cmd, |
3061 | unsigned long arg) | |
e1eaea46 AC |
3062 | { |
3063 | struct gsm_config c; | |
3064 | struct gsm_mux *gsm = tty->disc_data; | |
a7b121b4 | 3065 | unsigned int base; |
e1eaea46 AC |
3066 | |
3067 | switch (cmd) { | |
3068 | case GSMIOC_GETCONF: | |
33841040 | 3069 | gsm_copy_config_values(gsm, &c); |
edd05a73 | 3070 | if (copy_to_user((void __user *)arg, &c, sizeof(c))) |
e1eaea46 AC |
3071 | return -EFAULT; |
3072 | return 0; | |
3073 | case GSMIOC_SETCONF: | |
edd05a73 | 3074 | if (copy_from_user(&c, (void __user *)arg, sizeof(c))) |
e1eaea46 | 3075 | return -EFAULT; |
33841040 | 3076 | return gsm_config(gsm, &c); |
a7b121b4 MH |
3077 | case GSMIOC_GETFIRST: |
3078 | base = mux_num_to_base(gsm); | |
3079 | return put_user(base + 1, (__u32 __user *)arg); | |
e1eaea46 | 3080 | default: |
7c783601 | 3081 | return n_tty_ioctl_helper(tty, cmd, arg); |
e1eaea46 AC |
3082 | } |
3083 | } | |
3084 | ||
bcd5abe2 RG |
3085 | /* |
3086 | * Network interface | |
3087 | * | |
3088 | */ | |
3089 | ||
3090 | static int gsm_mux_net_open(struct net_device *net) | |
3091 | { | |
3092 | pr_debug("%s called\n", __func__); | |
3093 | netif_start_queue(net); | |
3094 | return 0; | |
3095 | } | |
3096 | ||
3097 | static int gsm_mux_net_close(struct net_device *net) | |
3098 | { | |
3099 | netif_stop_queue(net); | |
3100 | return 0; | |
3101 | } | |
3102 | ||
bcd5abe2 RG |
3103 | static void dlci_net_free(struct gsm_dlci *dlci) |
3104 | { | |
3105 | if (!dlci->net) { | |
3106 | WARN_ON(1); | |
3107 | return; | |
3108 | } | |
3109 | dlci->adaption = dlci->prev_adaption; | |
3110 | dlci->data = dlci->prev_data; | |
3111 | free_netdev(dlci->net); | |
3112 | dlci->net = NULL; | |
3113 | } | |
3114 | static void net_free(struct kref *ref) | |
3115 | { | |
3116 | struct gsm_mux_net *mux_net; | |
3117 | struct gsm_dlci *dlci; | |
3118 | ||
3119 | mux_net = container_of(ref, struct gsm_mux_net, ref); | |
3120 | dlci = mux_net->dlci; | |
3121 | ||
3122 | if (dlci->net) { | |
3123 | unregister_netdev(dlci->net); | |
3124 | dlci_net_free(dlci); | |
3125 | } | |
3126 | } | |
3127 | ||
6ab8fba7 RG |
3128 | static inline void muxnet_get(struct gsm_mux_net *mux_net) |
3129 | { | |
3130 | kref_get(&mux_net->ref); | |
3131 | } | |
3132 | ||
3133 | static inline void muxnet_put(struct gsm_mux_net *mux_net) | |
3134 | { | |
3135 | kref_put(&mux_net->ref, net_free); | |
3136 | } | |
3137 | ||
2468b3e4 | 3138 | static netdev_tx_t gsm_mux_net_start_xmit(struct sk_buff *skb, |
bcd5abe2 RG |
3139 | struct net_device *net) |
3140 | { | |
5dbc32a8 | 3141 | struct gsm_mux_net *mux_net = netdev_priv(net); |
bcd5abe2 | 3142 | struct gsm_dlci *dlci = mux_net->dlci; |
6ab8fba7 | 3143 | muxnet_get(mux_net); |
bcd5abe2 RG |
3144 | |
3145 | skb_queue_head(&dlci->skb_list, skb); | |
47baf1ad TK |
3146 | net->stats.tx_packets++; |
3147 | net->stats.tx_bytes += skb->len; | |
bcd5abe2 RG |
3148 | gsm_dlci_data_kick(dlci); |
3149 | /* And tell the kernel when the last transmit started. */ | |
860e9538 | 3150 | netif_trans_update(net); |
6ab8fba7 | 3151 | muxnet_put(mux_net); |
bcd5abe2 RG |
3152 | return NETDEV_TX_OK; |
3153 | } | |
3154 | ||
3155 | /* called when a packet did not ack after watchdogtimeout */ | |
0290bd29 | 3156 | static void gsm_mux_net_tx_timeout(struct net_device *net, unsigned int txqueue) |
bcd5abe2 RG |
3157 | { |
3158 | /* Tell syslog we are hosed. */ | |
3159 | dev_dbg(&net->dev, "Tx timed out.\n"); | |
3160 | ||
3161 | /* Update statistics */ | |
47baf1ad | 3162 | net->stats.tx_errors++; |
bcd5abe2 RG |
3163 | } |
3164 | ||
3165 | static void gsm_mux_rx_netchar(struct gsm_dlci *dlci, | |
4feb7a4a | 3166 | const unsigned char *in_buf, int size) |
bcd5abe2 RG |
3167 | { |
3168 | struct net_device *net = dlci->net; | |
3169 | struct sk_buff *skb; | |
5dbc32a8 | 3170 | struct gsm_mux_net *mux_net = netdev_priv(net); |
6ab8fba7 | 3171 | muxnet_get(mux_net); |
bcd5abe2 RG |
3172 | |
3173 | /* Allocate an sk_buff */ | |
3174 | skb = dev_alloc_skb(size + NET_IP_ALIGN); | |
3175 | if (!skb) { | |
3176 | /* We got no receive buffer. */ | |
47baf1ad | 3177 | net->stats.rx_dropped++; |
6ab8fba7 | 3178 | muxnet_put(mux_net); |
bcd5abe2 RG |
3179 | return; |
3180 | } | |
3181 | skb_reserve(skb, NET_IP_ALIGN); | |
59ae1d12 | 3182 | skb_put_data(skb, in_buf, size); |
bcd5abe2 RG |
3183 | |
3184 | skb->dev = net; | |
75406b3b | 3185 | skb->protocol = htons(ETH_P_IP); |
bcd5abe2 RG |
3186 | |
3187 | /* Ship it off to the kernel */ | |
3188 | netif_rx(skb); | |
3189 | ||
3190 | /* update out statistics */ | |
47baf1ad TK |
3191 | net->stats.rx_packets++; |
3192 | net->stats.rx_bytes += size; | |
6ab8fba7 | 3193 | muxnet_put(mux_net); |
bcd5abe2 RG |
3194 | return; |
3195 | } | |
3196 | ||
bcd5abe2 RG |
3197 | static void gsm_mux_net_init(struct net_device *net) |
3198 | { | |
3199 | static const struct net_device_ops gsm_netdev_ops = { | |
3200 | .ndo_open = gsm_mux_net_open, | |
3201 | .ndo_stop = gsm_mux_net_close, | |
3202 | .ndo_start_xmit = gsm_mux_net_start_xmit, | |
3203 | .ndo_tx_timeout = gsm_mux_net_tx_timeout, | |
bcd5abe2 RG |
3204 | }; |
3205 | ||
3206 | net->netdev_ops = &gsm_netdev_ops; | |
3207 | ||
3208 | /* fill in the other fields */ | |
3209 | net->watchdog_timeo = GSM_NET_TX_TIMEOUT; | |
3210 | net->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; | |
3211 | net->type = ARPHRD_NONE; | |
3212 | net->tx_queue_len = 10; | |
3213 | } | |
3214 | ||
3215 | ||
3216 | /* caller holds the dlci mutex */ | |
3217 | static void gsm_destroy_network(struct gsm_dlci *dlci) | |
3218 | { | |
3219 | struct gsm_mux_net *mux_net; | |
3220 | ||
d8ca4ecf | 3221 | pr_debug("destroy network interface\n"); |
bcd5abe2 RG |
3222 | if (!dlci->net) |
3223 | return; | |
5dbc32a8 | 3224 | mux_net = netdev_priv(dlci->net); |
6ab8fba7 | 3225 | muxnet_put(mux_net); |
bcd5abe2 RG |
3226 | } |
3227 | ||
3228 | ||
3229 | /* caller holds the dlci mutex */ | |
3230 | static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc) | |
3231 | { | |
3232 | char *netname; | |
3233 | int retval = 0; | |
3234 | struct net_device *net; | |
3235 | struct gsm_mux_net *mux_net; | |
3236 | ||
3237 | if (!capable(CAP_NET_ADMIN)) | |
3238 | return -EPERM; | |
3239 | ||
3240 | /* Already in a non tty mode */ | |
3241 | if (dlci->adaption > 2) | |
3242 | return -EBUSY; | |
3243 | ||
3244 | if (nc->protocol != htons(ETH_P_IP)) | |
3245 | return -EPROTONOSUPPORT; | |
3246 | ||
3247 | if (nc->adaption != 3 && nc->adaption != 4) | |
3248 | return -EPROTONOSUPPORT; | |
3249 | ||
d8ca4ecf | 3250 | pr_debug("create network interface\n"); |
bcd5abe2 RG |
3251 | |
3252 | netname = "gsm%d"; | |
3253 | if (nc->if_name[0] != '\0') | |
3254 | netname = nc->if_name; | |
c835a677 TG |
3255 | net = alloc_netdev(sizeof(struct gsm_mux_net), netname, |
3256 | NET_NAME_UNKNOWN, gsm_mux_net_init); | |
bcd5abe2 | 3257 | if (!net) { |
d8ca4ecf | 3258 | pr_err("alloc_netdev failed\n"); |
bcd5abe2 RG |
3259 | return -ENOMEM; |
3260 | } | |
3261 | net->mtu = dlci->gsm->mtu; | |
9c22b4a3 JW |
3262 | net->min_mtu = 8; |
3263 | net->max_mtu = dlci->gsm->mtu; | |
5dbc32a8 | 3264 | mux_net = netdev_priv(net); |
bcd5abe2 RG |
3265 | mux_net->dlci = dlci; |
3266 | kref_init(&mux_net->ref); | |
3267 | strncpy(nc->if_name, net->name, IFNAMSIZ); /* return net name */ | |
3268 | ||
3269 | /* reconfigure dlci for network */ | |
3270 | dlci->prev_adaption = dlci->adaption; | |
3271 | dlci->prev_data = dlci->data; | |
3272 | dlci->adaption = nc->adaption; | |
3273 | dlci->data = gsm_mux_rx_netchar; | |
3274 | dlci->net = net; | |
3275 | ||
d8ca4ecf | 3276 | pr_debug("register netdev\n"); |
bcd5abe2 RG |
3277 | retval = register_netdev(net); |
3278 | if (retval) { | |
3279 | pr_err("network register fail %d\n", retval); | |
3280 | dlci_net_free(dlci); | |
3281 | return retval; | |
3282 | } | |
3283 | return net->ifindex; /* return network index */ | |
3284 | } | |
e1eaea46 AC |
3285 | |
3286 | /* Line discipline for real tty */ | |
d3157b2c | 3287 | static struct tty_ldisc_ops tty_ldisc_packet = { |
e1eaea46 | 3288 | .owner = THIS_MODULE, |
fbadf70a | 3289 | .num = N_GSM0710, |
e1eaea46 AC |
3290 | .name = "n_gsm", |
3291 | .open = gsmld_open, | |
3292 | .close = gsmld_close, | |
3293 | .flush_buffer = gsmld_flush_buffer, | |
e1eaea46 AC |
3294 | .read = gsmld_read, |
3295 | .write = gsmld_write, | |
3296 | .ioctl = gsmld_ioctl, | |
3297 | .poll = gsmld_poll, | |
3298 | .receive_buf = gsmld_receive_buf, | |
3299 | .write_wakeup = gsmld_write_wakeup | |
3300 | }; | |
3301 | ||
3302 | /* | |
3303 | * Virtual tty side | |
3304 | */ | |
3305 | ||
c19ffe00 DS |
3306 | /** |
3307 | * gsm_modem_upd_via_data - send modem bits via convergence layer | |
3308 | * @dlci: channel | |
3309 | * @brk: break signal | |
3310 | * | |
3311 | * Send an empty frame to signal mobile state changes and to transmit the | |
3312 | * break signal for adaption 2. | |
3313 | */ | |
3314 | ||
3315 | static void gsm_modem_upd_via_data(struct gsm_dlci *dlci, u8 brk) | |
e1eaea46 | 3316 | { |
c19ffe00 | 3317 | struct gsm_mux *gsm = dlci->gsm; |
c19ffe00 DS |
3318 | |
3319 | if (dlci->state != DLCI_OPEN || dlci->adaption != 2) | |
3320 | return; | |
3321 | ||
902e02ea | 3322 | mutex_lock(&gsm->tx_mutex); |
c19ffe00 | 3323 | gsm_dlci_modem_output(gsm, dlci, brk); |
902e02ea | 3324 | mutex_unlock(&gsm->tx_mutex); |
c19ffe00 DS |
3325 | } |
3326 | ||
3327 | /** | |
3328 | * gsm_modem_upd_via_msc - send modem bits via control frame | |
3329 | * @dlci: channel | |
3330 | * @brk: break signal | |
3331 | */ | |
3332 | ||
3333 | static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk) | |
e1eaea46 | 3334 | { |
398867f5 | 3335 | u8 modembits[3]; |
e1eaea46 AC |
3336 | struct gsm_control *ctrl; |
3337 | int len = 2; | |
3338 | ||
c19ffe00 DS |
3339 | if (dlci->gsm->encoding != 0) |
3340 | return 0; | |
e1eaea46 | 3341 | |
398867f5 | 3342 | modembits[0] = (dlci->addr << 2) | 2 | EA; /* DLCI, Valid, EA */ |
317f86af DS |
3343 | if (!brk) { |
3344 | modembits[1] = (gsm_encode_modem(dlci) << 1) | EA; | |
3345 | } else { | |
3346 | modembits[1] = gsm_encode_modem(dlci) << 1; | |
398867f5 | 3347 | modembits[2] = (brk << 4) | 2 | EA; /* Length, Break, EA */ |
e1eaea46 | 3348 | len++; |
398867f5 DS |
3349 | } |
3350 | ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len); | |
e1eaea46 AC |
3351 | if (ctrl == NULL) |
3352 | return -ENOMEM; | |
3353 | return gsm_control_wait(dlci->gsm, ctrl); | |
3354 | } | |
3355 | ||
c19ffe00 DS |
3356 | /** |
3357 | * gsm_modem_update - send modem status line state | |
3358 | * @dlci: channel | |
3359 | * @brk: break signal | |
3360 | */ | |
3361 | ||
3362 | static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk) | |
3363 | { | |
3364 | if (dlci->adaption == 2) { | |
3365 | /* Send convergence layer type 2 empty data frame. */ | |
3366 | gsm_modem_upd_via_data(dlci, brk); | |
3367 | return 0; | |
3368 | } else if (dlci->gsm->encoding == 0) { | |
3369 | /* Send as MSC control message. */ | |
3370 | return gsm_modem_upd_via_msc(dlci, brk); | |
3371 | } | |
3372 | ||
3373 | /* Modem status lines are not supported. */ | |
3374 | return -EPROTONOSUPPORT; | |
3375 | } | |
3376 | ||
e1eaea46 AC |
3377 | static int gsm_carrier_raised(struct tty_port *port) |
3378 | { | |
3379 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
b2d89ad9 TL |
3380 | struct gsm_mux *gsm = dlci->gsm; |
3381 | ||
e1eaea46 AC |
3382 | /* Not yet open so no carrier info */ |
3383 | if (dlci->state != DLCI_OPEN) | |
3384 | return 0; | |
3385 | if (debug & 2) | |
3386 | return 1; | |
b2d89ad9 TL |
3387 | |
3388 | /* | |
3389 | * Basic mode with control channel in ADM mode may not respond | |
3390 | * to CMD_MSC at all and modem_rx is empty. | |
3391 | */ | |
3392 | if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM && | |
3393 | !dlci->modem_rx) | |
3394 | return 1; | |
3395 | ||
e1eaea46 AC |
3396 | return dlci->modem_rx & TIOCM_CD; |
3397 | } | |
3398 | ||
3399 | static void gsm_dtr_rts(struct tty_port *port, int onoff) | |
3400 | { | |
3401 | struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); | |
3402 | unsigned int modem_tx = dlci->modem_tx; | |
3403 | if (onoff) | |
3404 | modem_tx |= TIOCM_DTR | TIOCM_RTS; | |
3405 | else | |
3406 | modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); | |
3407 | if (modem_tx != dlci->modem_tx) { | |
3408 | dlci->modem_tx = modem_tx; | |
c19ffe00 | 3409 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
3410 | } |
3411 | } | |
3412 | ||
3413 | static const struct tty_port_operations gsm_port_ops = { | |
3414 | .carrier_raised = gsm_carrier_raised, | |
3415 | .dtr_rts = gsm_dtr_rts, | |
9a8e62bc | 3416 | .destruct = gsm_dlci_free, |
e1eaea46 AC |
3417 | }; |
3418 | ||
86176ed9 | 3419 | static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty) |
e1eaea46 AC |
3420 | { |
3421 | struct gsm_mux *gsm; | |
3422 | struct gsm_dlci *dlci; | |
e1eaea46 | 3423 | unsigned int line = tty->index; |
43a9e710 | 3424 | unsigned int mux = mux_line_to_num(line); |
86176ed9 JS |
3425 | bool alloc = false; |
3426 | int ret; | |
e1eaea46 AC |
3427 | |
3428 | line = line & 0x3F; | |
3429 | ||
3430 | if (mux >= MAX_MUX) | |
3431 | return -ENXIO; | |
3432 | /* FIXME: we need to lock gsm_mux for lifetimes of ttys eventually */ | |
3433 | if (gsm_mux[mux] == NULL) | |
3434 | return -EUNATCH; | |
3435 | if (line == 0 || line > 61) /* 62/63 reserved */ | |
3436 | return -ECHRNG; | |
3437 | gsm = gsm_mux[mux]; | |
3438 | if (gsm->dead) | |
3439 | return -EL2HLT; | |
f3c909b4 AI |
3440 | /* If DLCI 0 is not yet fully open return an error. |
3441 | This is ok from a locking | |
3442 | perspective as we don't have to worry about this | |
3443 | if DLCI0 is lost */ | |
dfabf7ff CB |
3444 | mutex_lock(&gsm->mutex); |
3445 | if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) { | |
3446 | mutex_unlock(&gsm->mutex); | |
7e8ac7b2 | 3447 | return -EL2NSYNC; |
dfabf7ff | 3448 | } |
e1eaea46 | 3449 | dlci = gsm->dlci[line]; |
86176ed9 JS |
3450 | if (dlci == NULL) { |
3451 | alloc = true; | |
e1eaea46 | 3452 | dlci = gsm_dlci_alloc(gsm, line); |
86176ed9 | 3453 | } |
dfabf7ff CB |
3454 | if (dlci == NULL) { |
3455 | mutex_unlock(&gsm->mutex); | |
e1eaea46 | 3456 | return -ENOMEM; |
dfabf7ff | 3457 | } |
86176ed9 JS |
3458 | ret = tty_port_install(&dlci->port, driver, tty); |
3459 | if (ret) { | |
3460 | if (alloc) | |
3461 | dlci_put(dlci); | |
dfabf7ff | 3462 | mutex_unlock(&gsm->mutex); |
86176ed9 JS |
3463 | return ret; |
3464 | } | |
3465 | ||
dfabf7ff CB |
3466 | dlci_get(dlci); |
3467 | dlci_get(gsm->dlci[0]); | |
3468 | mux_get(gsm); | |
e1eaea46 | 3469 | tty->driver_data = dlci; |
dfabf7ff | 3470 | mutex_unlock(&gsm->mutex); |
86176ed9 JS |
3471 | |
3472 | return 0; | |
3473 | } | |
3474 | ||
3475 | static int gsmtty_open(struct tty_struct *tty, struct file *filp) | |
3476 | { | |
3477 | struct gsm_dlci *dlci = tty->driver_data; | |
3478 | struct tty_port *port = &dlci->port; | |
cbff2b32 | 3479 | struct gsm_mux *gsm = dlci->gsm; |
86176ed9 JS |
3480 | |
3481 | port->count++; | |
e1eaea46 AC |
3482 | tty_port_tty_set(port, tty); |
3483 | ||
3484 | dlci->modem_rx = 0; | |
3485 | /* We could in theory open and close before we wait - eg if we get | |
3486 | a DM straight back. This is ok as that will have caused a hangup */ | |
d41861ca | 3487 | tty_port_set_initialized(port, 1); |
e1eaea46 | 3488 | /* Start sending off SABM messages */ |
cbff2b32 ZZ |
3489 | if (gsm->initiator) |
3490 | gsm_dlci_begin_open(dlci); | |
ac77f007 DS |
3491 | else |
3492 | gsm_dlci_set_opening(dlci); | |
e1eaea46 AC |
3493 | /* And wait for virtual carrier */ |
3494 | return tty_port_block_til_ready(port, tty, filp); | |
3495 | } | |
3496 | ||
3497 | static void gsmtty_close(struct tty_struct *tty, struct file *filp) | |
3498 | { | |
3499 | struct gsm_dlci *dlci = tty->driver_data; | |
6ab8fba7 | 3500 | |
e1eaea46 AC |
3501 | if (dlci == NULL) |
3502 | return; | |
4d9b1090 DB |
3503 | if (dlci->state == DLCI_CLOSED) |
3504 | return; | |
bcd5abe2 RG |
3505 | mutex_lock(&dlci->mutex); |
3506 | gsm_destroy_network(dlci); | |
3507 | mutex_unlock(&dlci->mutex); | |
e1eaea46 | 3508 | if (tty_port_close_start(&dlci->port, tty, filp) == 0) |
dfabf7ff | 3509 | return; |
e1eaea46 | 3510 | gsm_dlci_begin_close(dlci); |
d41861ca PH |
3511 | if (tty_port_initialized(&dlci->port) && C_HUPCL(tty)) |
3512 | tty_port_lower_dtr_rts(&dlci->port); | |
e1eaea46 AC |
3513 | tty_port_close_end(&dlci->port, tty); |
3514 | tty_port_tty_set(&dlci->port, NULL); | |
dfabf7ff | 3515 | return; |
e1eaea46 AC |
3516 | } |
3517 | ||
3518 | static void gsmtty_hangup(struct tty_struct *tty) | |
3519 | { | |
3520 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
3521 | if (dlci->state == DLCI_CLOSED) |
3522 | return; | |
e1eaea46 AC |
3523 | tty_port_hangup(&dlci->port); |
3524 | gsm_dlci_begin_close(dlci); | |
3525 | } | |
3526 | ||
3527 | static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf, | |
3528 | int len) | |
3529 | { | |
4d9b1090 | 3530 | int sent; |
e1eaea46 | 3531 | struct gsm_dlci *dlci = tty->driver_data; |
4d9b1090 DB |
3532 | if (dlci->state == DLCI_CLOSED) |
3533 | return -EINVAL; | |
e1eaea46 | 3534 | /* Stuff the bytes into the fifo queue */ |
036bca1f | 3535 | sent = kfifo_in_locked(&dlci->fifo, buf, len, &dlci->lock); |
e1eaea46 AC |
3536 | /* Need to kick the channel */ |
3537 | gsm_dlci_data_kick(dlci); | |
3538 | return sent; | |
3539 | } | |
3540 | ||
03b3b1a2 | 3541 | static unsigned int gsmtty_write_room(struct tty_struct *tty) |
e1eaea46 AC |
3542 | { |
3543 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 | 3544 | if (dlci->state == DLCI_CLOSED) |
6bfbfcfc | 3545 | return 0; |
9361ebfb | 3546 | return kfifo_avail(&dlci->fifo); |
e1eaea46 AC |
3547 | } |
3548 | ||
fff4ef17 | 3549 | static unsigned int gsmtty_chars_in_buffer(struct tty_struct *tty) |
e1eaea46 AC |
3550 | { |
3551 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 | 3552 | if (dlci->state == DLCI_CLOSED) |
10eb63e5 | 3553 | return 0; |
036bca1f | 3554 | return kfifo_len(&dlci->fifo); |
e1eaea46 AC |
3555 | } |
3556 | ||
3557 | static void gsmtty_flush_buffer(struct tty_struct *tty) | |
3558 | { | |
3559 | struct gsm_dlci *dlci = tty->driver_data; | |
73029a4d DS |
3560 | unsigned long flags; |
3561 | ||
4d9b1090 DB |
3562 | if (dlci->state == DLCI_CLOSED) |
3563 | return; | |
e1eaea46 AC |
3564 | /* Caution needed: If we implement reliable transport classes |
3565 | then the data being transmitted can't simply be junked once | |
3566 | it has first hit the stack. Until then we can just blow it | |
3567 | away */ | |
73029a4d | 3568 | spin_lock_irqsave(&dlci->lock, flags); |
036bca1f | 3569 | kfifo_reset(&dlci->fifo); |
73029a4d | 3570 | spin_unlock_irqrestore(&dlci->lock, flags); |
e1eaea46 AC |
3571 | /* Need to unhook this DLCI from the transmit queue logic */ |
3572 | } | |
3573 | ||
3574 | static void gsmtty_wait_until_sent(struct tty_struct *tty, int timeout) | |
3575 | { | |
3576 | /* The FIFO handles the queue so the kernel will do the right | |
3577 | thing waiting on chars_in_buffer before calling us. No work | |
3578 | to do here */ | |
3579 | } | |
3580 | ||
60b33c13 | 3581 | static int gsmtty_tiocmget(struct tty_struct *tty) |
e1eaea46 AC |
3582 | { |
3583 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
3584 | if (dlci->state == DLCI_CLOSED) |
3585 | return -EINVAL; | |
e1eaea46 AC |
3586 | return dlci->modem_rx; |
3587 | } | |
3588 | ||
20b9d177 | 3589 | static int gsmtty_tiocmset(struct tty_struct *tty, |
e1eaea46 AC |
3590 | unsigned int set, unsigned int clear) |
3591 | { | |
3592 | struct gsm_dlci *dlci = tty->driver_data; | |
3593 | unsigned int modem_tx = dlci->modem_tx; | |
3594 | ||
4d9b1090 DB |
3595 | if (dlci->state == DLCI_CLOSED) |
3596 | return -EINVAL; | |
cf16807b | 3597 | modem_tx &= ~clear; |
e1eaea46 AC |
3598 | modem_tx |= set; |
3599 | ||
3600 | if (modem_tx != dlci->modem_tx) { | |
3601 | dlci->modem_tx = modem_tx; | |
c19ffe00 | 3602 | return gsm_modem_update(dlci, 0); |
e1eaea46 AC |
3603 | } |
3604 | return 0; | |
3605 | } | |
3606 | ||
3607 | ||
6caa76b7 | 3608 | static int gsmtty_ioctl(struct tty_struct *tty, |
e1eaea46 AC |
3609 | unsigned int cmd, unsigned long arg) |
3610 | { | |
bcd5abe2 RG |
3611 | struct gsm_dlci *dlci = tty->driver_data; |
3612 | struct gsm_netconfig nc; | |
3613 | int index; | |
3614 | ||
4d9b1090 DB |
3615 | if (dlci->state == DLCI_CLOSED) |
3616 | return -EINVAL; | |
bcd5abe2 RG |
3617 | switch (cmd) { |
3618 | case GSMIOC_ENABLE_NET: | |
3619 | if (copy_from_user(&nc, (void __user *)arg, sizeof(nc))) | |
3620 | return -EFAULT; | |
3621 | nc.if_name[IFNAMSIZ-1] = '\0'; | |
3622 | /* return net interface index or error code */ | |
3623 | mutex_lock(&dlci->mutex); | |
3624 | index = gsm_create_network(dlci, &nc); | |
3625 | mutex_unlock(&dlci->mutex); | |
3626 | if (copy_to_user((void __user *)arg, &nc, sizeof(nc))) | |
3627 | return -EFAULT; | |
3628 | return index; | |
3629 | case GSMIOC_DISABLE_NET: | |
3630 | if (!capable(CAP_NET_ADMIN)) | |
3631 | return -EPERM; | |
3632 | mutex_lock(&dlci->mutex); | |
3633 | gsm_destroy_network(dlci); | |
3634 | mutex_unlock(&dlci->mutex); | |
3635 | return 0; | |
3636 | default: | |
3637 | return -ENOIOCTLCMD; | |
3638 | } | |
e1eaea46 AC |
3639 | } |
3640 | ||
3641 | static void gsmtty_set_termios(struct tty_struct *tty, struct ktermios *old) | |
3642 | { | |
4d9b1090 DB |
3643 | struct gsm_dlci *dlci = tty->driver_data; |
3644 | if (dlci->state == DLCI_CLOSED) | |
3645 | return; | |
e1eaea46 AC |
3646 | /* For the moment its fixed. In actual fact the speed information |
3647 | for the virtual channel can be propogated in both directions by | |
3648 | the RPN control message. This however rapidly gets nasty as we | |
3649 | then have to remap modem signals each way according to whether | |
3650 | our virtual cable is null modem etc .. */ | |
adc8d746 | 3651 | tty_termios_copy_hw(&tty->termios, old); |
e1eaea46 AC |
3652 | } |
3653 | ||
3654 | static void gsmtty_throttle(struct tty_struct *tty) | |
3655 | { | |
3656 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
3657 | if (dlci->state == DLCI_CLOSED) |
3658 | return; | |
9db276f8 | 3659 | if (C_CRTSCTS(tty)) |
c19d9354 | 3660 | dlci->modem_tx &= ~TIOCM_RTS; |
e9360b9a | 3661 | dlci->throttled = true; |
c19d9354 | 3662 | /* Send an MSC with RTS cleared */ |
c19ffe00 | 3663 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
3664 | } |
3665 | ||
3666 | static void gsmtty_unthrottle(struct tty_struct *tty) | |
3667 | { | |
3668 | struct gsm_dlci *dlci = tty->driver_data; | |
4d9b1090 DB |
3669 | if (dlci->state == DLCI_CLOSED) |
3670 | return; | |
9db276f8 | 3671 | if (C_CRTSCTS(tty)) |
c19d9354 | 3672 | dlci->modem_tx |= TIOCM_RTS; |
e9360b9a | 3673 | dlci->throttled = false; |
c19d9354 | 3674 | /* Send an MSC with RTS set */ |
c19ffe00 | 3675 | gsm_modem_update(dlci, 0); |
e1eaea46 AC |
3676 | } |
3677 | ||
3678 | static int gsmtty_break_ctl(struct tty_struct *tty, int state) | |
3679 | { | |
3680 | struct gsm_dlci *dlci = tty->driver_data; | |
3681 | int encode = 0; /* Off */ | |
4d9b1090 DB |
3682 | if (dlci->state == DLCI_CLOSED) |
3683 | return -EINVAL; | |
e1eaea46 AC |
3684 | |
3685 | if (state == -1) /* "On indefinitely" - we can't encode this | |
3686 | properly */ | |
3687 | encode = 0x0F; | |
3688 | else if (state > 0) { | |
3689 | encode = state / 200; /* mS to encoding */ | |
3690 | if (encode > 0x0F) | |
3691 | encode = 0x0F; /* Best effort */ | |
3692 | } | |
c19ffe00 | 3693 | return gsm_modem_update(dlci, encode); |
e1eaea46 AC |
3694 | } |
3695 | ||
8f9cfeed | 3696 | static void gsmtty_cleanup(struct tty_struct *tty) |
dfabf7ff CB |
3697 | { |
3698 | struct gsm_dlci *dlci = tty->driver_data; | |
3699 | struct gsm_mux *gsm = dlci->gsm; | |
3700 | ||
3701 | dlci_put(dlci); | |
3702 | dlci_put(gsm->dlci[0]); | |
3703 | mux_put(gsm); | |
dfabf7ff | 3704 | } |
e1eaea46 AC |
3705 | |
3706 | /* Virtual ttys for the demux */ | |
3707 | static const struct tty_operations gsmtty_ops = { | |
86176ed9 | 3708 | .install = gsmtty_install, |
e1eaea46 AC |
3709 | .open = gsmtty_open, |
3710 | .close = gsmtty_close, | |
3711 | .write = gsmtty_write, | |
3712 | .write_room = gsmtty_write_room, | |
3713 | .chars_in_buffer = gsmtty_chars_in_buffer, | |
3714 | .flush_buffer = gsmtty_flush_buffer, | |
3715 | .ioctl = gsmtty_ioctl, | |
3716 | .throttle = gsmtty_throttle, | |
3717 | .unthrottle = gsmtty_unthrottle, | |
3718 | .set_termios = gsmtty_set_termios, | |
3719 | .hangup = gsmtty_hangup, | |
3720 | .wait_until_sent = gsmtty_wait_until_sent, | |
3721 | .tiocmget = gsmtty_tiocmget, | |
3722 | .tiocmset = gsmtty_tiocmset, | |
3723 | .break_ctl = gsmtty_break_ctl, | |
8f9cfeed | 3724 | .cleanup = gsmtty_cleanup, |
e1eaea46 AC |
3725 | }; |
3726 | ||
3727 | ||
3728 | ||
3729 | static int __init gsm_init(void) | |
3730 | { | |
3731 | /* Fill in our line protocol discipline, and register it */ | |
fbadf70a | 3732 | int status = tty_register_ldisc(&tty_ldisc_packet); |
e1eaea46 | 3733 | if (status != 0) { |
5f9a31d6 AC |
3734 | pr_err("n_gsm: can't register line discipline (err = %d)\n", |
3735 | status); | |
e1eaea46 AC |
3736 | return status; |
3737 | } | |
3738 | ||
39b7b42b JS |
3739 | gsm_tty_driver = tty_alloc_driver(256, TTY_DRIVER_REAL_RAW | |
3740 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK); | |
3741 | if (IS_ERR(gsm_tty_driver)) { | |
5f9a31d6 | 3742 | pr_err("gsm_init: tty allocation failed.\n"); |
39b7b42b | 3743 | status = PTR_ERR(gsm_tty_driver); |
839e0f22 | 3744 | goto err_unreg_ldisc; |
e1eaea46 | 3745 | } |
e1eaea46 AC |
3746 | gsm_tty_driver->driver_name = "gsmtty"; |
3747 | gsm_tty_driver->name = "gsmtty"; | |
3748 | gsm_tty_driver->major = 0; /* Dynamic */ | |
3749 | gsm_tty_driver->minor_start = 0; | |
3750 | gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; | |
3751 | gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; | |
e1eaea46 AC |
3752 | gsm_tty_driver->init_termios = tty_std_termios; |
3753 | /* Fixme */ | |
3754 | gsm_tty_driver->init_termios.c_lflag &= ~ECHO; | |
3755 | tty_set_operations(gsm_tty_driver, &gsmtty_ops); | |
3756 | ||
e1eaea46 | 3757 | if (tty_register_driver(gsm_tty_driver)) { |
5f9a31d6 | 3758 | pr_err("gsm_init: tty registration failed.\n"); |
839e0f22 JS |
3759 | status = -EBUSY; |
3760 | goto err_put_driver; | |
e1eaea46 | 3761 | } |
5f9a31d6 AC |
3762 | pr_debug("gsm_init: loaded as %d,%d.\n", |
3763 | gsm_tty_driver->major, gsm_tty_driver->minor_start); | |
e1eaea46 | 3764 | return 0; |
839e0f22 | 3765 | err_put_driver: |
9f90a4dd | 3766 | tty_driver_kref_put(gsm_tty_driver); |
839e0f22 | 3767 | err_unreg_ldisc: |
f81ee8b8 | 3768 | tty_unregister_ldisc(&tty_ldisc_packet); |
839e0f22 | 3769 | return status; |
e1eaea46 AC |
3770 | } |
3771 | ||
3772 | static void __exit gsm_exit(void) | |
3773 | { | |
357a6a87 | 3774 | tty_unregister_ldisc(&tty_ldisc_packet); |
e1eaea46 | 3775 | tty_unregister_driver(gsm_tty_driver); |
9f90a4dd | 3776 | tty_driver_kref_put(gsm_tty_driver); |
e1eaea46 AC |
3777 | } |
3778 | ||
3779 | module_init(gsm_init); | |
3780 | module_exit(gsm_exit); | |
3781 | ||
3782 | ||
3783 | MODULE_LICENSE("GPL"); | |
3784 | MODULE_ALIAS_LDISC(N_GSM0710); |