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41597408 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
1da177e4 | 3 | * |
815f62bf RB |
4 | * Copyright (C) Hans Alblas PE1AYX <hans@esrac.ele.tue.nl> |
5 | * Copyright (C) 2004, 05 Ralf Baechle DL5RB <ralf@linux-mips.org> | |
5793f4be | 6 | * Copyright (C) 2004, 05 Thomas Osterried DL9SAU <thomas@x-berg.in-berlin.de> |
1da177e4 | 7 | */ |
1da177e4 | 8 | #include <linux/module.h> |
1da177e4 | 9 | #include <linux/bitops.h> |
7c0f6ba6 | 10 | #include <linux/uaccess.h> |
5793f4be | 11 | #include <linux/crc16.h> |
1da177e4 LT |
12 | #include <linux/string.h> |
13 | #include <linux/mm.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/in.h> | |
16 | #include <linux/inet.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
1da177e4 LT |
18 | #include <linux/tty.h> |
19 | #include <linux/errno.h> | |
20 | #include <linux/netdevice.h> | |
21 | #include <linux/major.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/rtnetlink.h> | |
24 | #include <linux/etherdevice.h> | |
25 | #include <linux/skbuff.h> | |
26 | #include <linux/if_arp.h> | |
cd8749b4 | 27 | #include <linux/jiffies.h> |
4b4de398 | 28 | #include <linux/refcount.h> |
1da177e4 LT |
29 | |
30 | #include <net/ax25.h> | |
31 | ||
815f62bf RB |
32 | #define AX_MTU 236 |
33 | ||
34 | /* SLIP/KISS protocol characters. */ | |
35 | #define END 0300 /* indicates end of frame */ | |
36 | #define ESC 0333 /* indicates byte stuffing */ | |
37 | #define ESC_END 0334 /* ESC ESC_END means END 'data' */ | |
38 | #define ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */ | |
39 | ||
40 | struct mkiss { | |
41 | struct tty_struct *tty; /* ptr to TTY structure */ | |
42 | struct net_device *dev; /* easy for intr handling */ | |
43 | ||
44 | /* These are pointers to the malloc()ed frame buffers. */ | |
45 | spinlock_t buflock;/* lock for rbuf and xbuf */ | |
46 | unsigned char *rbuff; /* receiver buffer */ | |
47 | int rcount; /* received chars counter */ | |
48 | unsigned char *xbuff; /* transmitter buffer */ | |
49 | unsigned char *xhead; /* pointer to next byte to XMIT */ | |
50 | int xleft; /* bytes left in XMIT queue */ | |
51 | ||
815f62bf RB |
52 | /* Detailed SLIP statistics. */ |
53 | int mtu; /* Our mtu (to spot changes!) */ | |
54 | int buffsize; /* Max buffers sizes */ | |
55 | ||
56 | unsigned long flags; /* Flag values/ mode etc */ | |
57 | /* long req'd: used by set_bit --RR */ | |
58 | #define AXF_INUSE 0 /* Channel in use */ | |
59 | #define AXF_ESCAPE 1 /* ESC received */ | |
60 | #define AXF_ERROR 2 /* Parity, etc. error */ | |
61 | #define AXF_KEEPTEST 3 /* Keepalive test flag */ | |
62 | #define AXF_OUTWAIT 4 /* is outpacket was flag */ | |
63 | ||
64 | int mode; | |
65 | int crcmode; /* MW: for FlexNet, SMACK etc. */ | |
5793f4be RB |
66 | int crcauto; /* CRC auto mode */ |
67 | ||
68 | #define CRC_MODE_NONE 0 | |
69 | #define CRC_MODE_FLEX 1 | |
70 | #define CRC_MODE_SMACK 2 | |
71 | #define CRC_MODE_FLEX_TEST 3 | |
72 | #define CRC_MODE_SMACK_TEST 4 | |
815f62bf | 73 | |
4b4de398 | 74 | refcount_t refcnt; |
c2c79a32 | 75 | struct completion dead; |
815f62bf | 76 | }; |
1da177e4 LT |
77 | |
78 | /*---------------------------------------------------------------------------*/ | |
79 | ||
815f62bf RB |
80 | static const unsigned short crc_flex_table[] = { |
81 | 0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38, | |
82 | 0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770, | |
83 | 0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9, | |
84 | 0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1, | |
85 | 0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a, | |
86 | 0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672, | |
87 | 0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb, | |
88 | 0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3, | |
89 | 0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c, | |
90 | 0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574, | |
91 | 0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd, | |
92 | 0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5, | |
93 | 0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e, | |
94 | 0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476, | |
95 | 0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf, | |
96 | 0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7, | |
97 | 0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30, | |
98 | 0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378, | |
99 | 0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1, | |
100 | 0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9, | |
101 | 0xaa8d, 0xbb04, 0x899f, 0x9816, 0xeca9, 0xfd20, 0xcfbb, 0xde32, | |
102 | 0x26c5, 0x374c, 0x05d7, 0x145e, 0x60e1, 0x7168, 0x43f3, 0x527a, | |
103 | 0xba0c, 0xab85, 0x991e, 0x8897, 0xfc28, 0xeda1, 0xdf3a, 0xceb3, | |
104 | 0x3644, 0x27cd, 0x1556, 0x04df, 0x7060, 0x61e9, 0x5372, 0x42fb, | |
105 | 0xc98b, 0xd802, 0xea99, 0xfb10, 0x8faf, 0x9e26, 0xacbd, 0xbd34, | |
106 | 0x45c3, 0x544a, 0x66d1, 0x7758, 0x03e7, 0x126e, 0x20f5, 0x317c, | |
107 | 0xd90a, 0xc883, 0xfa18, 0xeb91, 0x9f2e, 0x8ea7, 0xbc3c, 0xadb5, | |
108 | 0x5542, 0x44cb, 0x7650, 0x67d9, 0x1366, 0x02ef, 0x3074, 0x21fd, | |
109 | 0xe889, 0xf900, 0xcb9b, 0xda12, 0xaead, 0xbf24, 0x8dbf, 0x9c36, | |
110 | 0x64c1, 0x7548, 0x47d3, 0x565a, 0x22e5, 0x336c, 0x01f7, 0x107e, | |
111 | 0xf808, 0xe981, 0xdb1a, 0xca93, 0xbe2c, 0xafa5, 0x9d3e, 0x8cb7, | |
112 | 0x7440, 0x65c9, 0x5752, 0x46db, 0x3264, 0x23ed, 0x1176, 0x00ff | |
1da177e4 LT |
113 | }; |
114 | ||
1da177e4 LT |
115 | static unsigned short calc_crc_flex(unsigned char *cp, int size) |
116 | { | |
815f62bf | 117 | unsigned short crc = 0xffff; |
1da177e4 | 118 | |
815f62bf RB |
119 | while (size--) |
120 | crc = (crc << 8) ^ crc_flex_table[((crc >> 8) ^ *cp++) & 0xff]; | |
1da177e4 | 121 | |
815f62bf RB |
122 | return crc; |
123 | } | |
1da177e4 LT |
124 | |
125 | static int check_crc_flex(unsigned char *cp, int size) | |
126 | { | |
815f62bf | 127 | unsigned short crc = 0xffff; |
1da177e4 | 128 | |
815f62bf RB |
129 | if (size < 3) |
130 | return -1; | |
1da177e4 | 131 | |
815f62bf RB |
132 | while (size--) |
133 | crc = (crc << 8) ^ crc_flex_table[((crc >> 8) ^ *cp++) & 0xff]; | |
1da177e4 | 134 | |
815f62bf RB |
135 | if ((crc & 0xffff) != 0x7070) |
136 | return -1; | |
1da177e4 | 137 | |
815f62bf | 138 | return 0; |
1da177e4 LT |
139 | } |
140 | ||
5793f4be RB |
141 | static int check_crc_16(unsigned char *cp, int size) |
142 | { | |
143 | unsigned short crc = 0x0000; | |
144 | ||
145 | if (size < 3) | |
146 | return -1; | |
147 | ||
148 | crc = crc16(0, cp, size); | |
149 | ||
150 | if (crc != 0x0000) | |
151 | return -1; | |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
815f62bf RB |
156 | /* |
157 | * Standard encapsulation | |
158 | */ | |
1da177e4 | 159 | |
815f62bf | 160 | static int kiss_esc(unsigned char *s, unsigned char *d, int len) |
1da177e4 | 161 | { |
815f62bf RB |
162 | unsigned char *ptr = d; |
163 | unsigned char c; | |
1da177e4 | 164 | |
815f62bf RB |
165 | /* |
166 | * Send an initial END character to flush out any data that may have | |
167 | * accumulated in the receiver due to line noise. | |
168 | */ | |
1da177e4 | 169 | |
815f62bf | 170 | *ptr++ = END; |
1da177e4 | 171 | |
815f62bf RB |
172 | while (len-- > 0) { |
173 | switch (c = *s++) { | |
174 | case END: | |
175 | *ptr++ = ESC; | |
176 | *ptr++ = ESC_END; | |
1da177e4 | 177 | break; |
815f62bf RB |
178 | case ESC: |
179 | *ptr++ = ESC; | |
180 | *ptr++ = ESC_ESC; | |
181 | break; | |
182 | default: | |
183 | *ptr++ = c; | |
184 | break; | |
185 | } | |
1da177e4 LT |
186 | } |
187 | ||
815f62bf RB |
188 | *ptr++ = END; |
189 | ||
190 | return ptr - d; | |
191 | } | |
192 | ||
193 | /* | |
194 | * MW: | |
195 | * OK its ugly, but tell me a better solution without copying the | |
196 | * packet to a temporary buffer :-) | |
197 | */ | |
198 | static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc, | |
199 | int len) | |
200 | { | |
201 | unsigned char *ptr = d; | |
202 | unsigned char c=0; | |
203 | ||
204 | *ptr++ = END; | |
205 | while (len > 0) { | |
206 | if (len > 2) | |
207 | c = *s++; | |
208 | else if (len > 1) | |
209 | c = crc >> 8; | |
6f5d2959 | 210 | else |
815f62bf RB |
211 | c = crc & 0xff; |
212 | ||
213 | len--; | |
1da177e4 | 214 | |
815f62bf RB |
215 | switch (c) { |
216 | case END: | |
217 | *ptr++ = ESC; | |
218 | *ptr++ = ESC_END; | |
219 | break; | |
220 | case ESC: | |
221 | *ptr++ = ESC; | |
222 | *ptr++ = ESC_ESC; | |
223 | break; | |
224 | default: | |
225 | *ptr++ = c; | |
226 | break; | |
227 | } | |
1da177e4 | 228 | } |
815f62bf RB |
229 | *ptr++ = END; |
230 | ||
231 | return ptr - d; | |
232 | } | |
233 | ||
234 | /* Send one completely decapsulated AX.25 packet to the AX.25 layer. */ | |
235 | static void ax_bump(struct mkiss *ax) | |
236 | { | |
237 | struct sk_buff *skb; | |
238 | int count; | |
239 | ||
240 | spin_lock_bh(&ax->buflock); | |
241 | if (ax->rbuff[0] > 0x0f) { | |
5793f4be RB |
242 | if (ax->rbuff[0] & 0x80) { |
243 | if (check_crc_16(ax->rbuff, ax->rcount) < 0) { | |
ddbe9a68 | 244 | ax->dev->stats.rx_errors++; |
5793f4be RB |
245 | spin_unlock_bh(&ax->buflock); |
246 | ||
247 | return; | |
248 | } | |
249 | if (ax->crcmode != CRC_MODE_SMACK && ax->crcauto) { | |
250 | printk(KERN_INFO | |
7b1401cf | 251 | "mkiss: %s: Switching to crc-smack\n", |
5793f4be RB |
252 | ax->dev->name); |
253 | ax->crcmode = CRC_MODE_SMACK; | |
254 | } | |
255 | ax->rcount -= 2; | |
256 | *ax->rbuff &= ~0x80; | |
257 | } else if (ax->rbuff[0] & 0x20) { | |
815f62bf | 258 | if (check_crc_flex(ax->rbuff, ax->rcount) < 0) { |
ddbe9a68 | 259 | ax->dev->stats.rx_errors++; |
5793f4be | 260 | spin_unlock_bh(&ax->buflock); |
815f62bf RB |
261 | return; |
262 | } | |
5793f4be RB |
263 | if (ax->crcmode != CRC_MODE_FLEX && ax->crcauto) { |
264 | printk(KERN_INFO | |
7b1401cf | 265 | "mkiss: %s: Switching to crc-flexnet\n", |
5793f4be RB |
266 | ax->dev->name); |
267 | ax->crcmode = CRC_MODE_FLEX; | |
268 | } | |
815f62bf | 269 | ax->rcount -= 2; |
5793f4be RB |
270 | |
271 | /* | |
272 | * dl9sau bugfix: the trailling two bytes flexnet crc | |
273 | * will not be passed to the kernel. thus we have to | |
274 | * correct the kissparm signature, because it indicates | |
275 | * a crc but there's none | |
815f62bf | 276 | */ |
5793f4be | 277 | *ax->rbuff &= ~0x20; |
1da177e4 | 278 | } |
815f62bf | 279 | } |
815f62bf RB |
280 | |
281 | count = ax->rcount; | |
282 | ||
283 | if ((skb = dev_alloc_skb(count)) == NULL) { | |
284 | printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n", | |
285 | ax->dev->name); | |
ddbe9a68 | 286 | ax->dev->stats.rx_dropped++; |
9f30c768 | 287 | spin_unlock_bh(&ax->buflock); |
815f62bf | 288 | return; |
1da177e4 LT |
289 | } |
290 | ||
59ae1d12 | 291 | skb_put_data(skb, ax->rbuff, count); |
815f62bf RB |
292 | skb->protocol = ax25_type_trans(skb, ax->dev); |
293 | netif_rx(skb); | |
ddbe9a68 SH |
294 | ax->dev->stats.rx_packets++; |
295 | ax->dev->stats.rx_bytes += count; | |
9f30c768 | 296 | spin_unlock_bh(&ax->buflock); |
1da177e4 LT |
297 | } |
298 | ||
815f62bf | 299 | static void kiss_unesc(struct mkiss *ax, unsigned char s) |
1da177e4 | 300 | { |
815f62bf RB |
301 | switch (s) { |
302 | case END: | |
303 | /* drop keeptest bit = VSV */ | |
304 | if (test_bit(AXF_KEEPTEST, &ax->flags)) | |
305 | clear_bit(AXF_KEEPTEST, &ax->flags); | |
306 | ||
307 | if (!test_and_clear_bit(AXF_ERROR, &ax->flags) && (ax->rcount > 2)) | |
308 | ax_bump(ax); | |
309 | ||
310 | clear_bit(AXF_ESCAPE, &ax->flags); | |
311 | ax->rcount = 0; | |
312 | return; | |
313 | ||
314 | case ESC: | |
315 | set_bit(AXF_ESCAPE, &ax->flags); | |
316 | return; | |
317 | case ESC_ESC: | |
318 | if (test_and_clear_bit(AXF_ESCAPE, &ax->flags)) | |
319 | s = ESC; | |
320 | break; | |
321 | case ESC_END: | |
322 | if (test_and_clear_bit(AXF_ESCAPE, &ax->flags)) | |
323 | s = END; | |
324 | break; | |
325 | } | |
326 | ||
327 | spin_lock_bh(&ax->buflock); | |
328 | if (!test_bit(AXF_ERROR, &ax->flags)) { | |
329 | if (ax->rcount < ax->buffsize) { | |
330 | ax->rbuff[ax->rcount++] = s; | |
331 | spin_unlock_bh(&ax->buflock); | |
332 | return; | |
333 | } | |
334 | ||
ddbe9a68 | 335 | ax->dev->stats.rx_over_errors++; |
815f62bf RB |
336 | set_bit(AXF_ERROR, &ax->flags); |
337 | } | |
338 | spin_unlock_bh(&ax->buflock); | |
339 | } | |
340 | ||
341 | static int ax_set_mac_address(struct net_device *dev, void *addr) | |
342 | { | |
343 | struct sockaddr_ax25 *sa = addr; | |
344 | ||
932ff279 | 345 | netif_tx_lock_bh(dev); |
e308a5d8 | 346 | netif_addr_lock(dev); |
815f62bf | 347 | memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN); |
e308a5d8 | 348 | netif_addr_unlock(dev); |
932ff279 | 349 | netif_tx_unlock_bh(dev); |
815f62bf RB |
350 | |
351 | return 0; | |
1da177e4 LT |
352 | } |
353 | ||
815f62bf RB |
354 | /*---------------------------------------------------------------------------*/ |
355 | ||
356 | static void ax_changedmtu(struct mkiss *ax) | |
1da177e4 LT |
357 | { |
358 | struct net_device *dev = ax->dev; | |
359 | unsigned char *xbuff, *rbuff, *oxbuff, *orbuff; | |
360 | int len; | |
361 | ||
362 | len = dev->mtu * 2; | |
363 | ||
364 | /* | |
365 | * allow for arrival of larger UDP packets, even if we say not to | |
366 | * also fixes a bug in which SunOS sends 512-byte packets even with | |
367 | * an MSS of 128 | |
368 | */ | |
369 | if (len < 576 * 2) | |
370 | len = 576 * 2; | |
371 | ||
372 | xbuff = kmalloc(len + 4, GFP_ATOMIC); | |
373 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
374 | ||
375 | if (xbuff == NULL || rbuff == NULL) { | |
815f62bf RB |
376 | printk(KERN_ERR "mkiss: %s: unable to grow ax25 buffers, " |
377 | "MTU change cancelled.\n", | |
1da177e4 LT |
378 | ax->dev->name); |
379 | dev->mtu = ax->mtu; | |
b4558ea9 JJ |
380 | kfree(xbuff); |
381 | kfree(rbuff); | |
1da177e4 LT |
382 | return; |
383 | } | |
384 | ||
385 | spin_lock_bh(&ax->buflock); | |
386 | ||
387 | oxbuff = ax->xbuff; | |
388 | ax->xbuff = xbuff; | |
389 | orbuff = ax->rbuff; | |
390 | ax->rbuff = rbuff; | |
391 | ||
392 | if (ax->xleft) { | |
393 | if (ax->xleft <= len) { | |
394 | memcpy(ax->xbuff, ax->xhead, ax->xleft); | |
395 | } else { | |
396 | ax->xleft = 0; | |
ddbe9a68 | 397 | dev->stats.tx_dropped++; |
1da177e4 LT |
398 | } |
399 | } | |
400 | ||
401 | ax->xhead = ax->xbuff; | |
402 | ||
403 | if (ax->rcount) { | |
404 | if (ax->rcount <= len) { | |
405 | memcpy(ax->rbuff, orbuff, ax->rcount); | |
406 | } else { | |
407 | ax->rcount = 0; | |
ddbe9a68 | 408 | dev->stats.rx_over_errors++; |
1da177e4 LT |
409 | set_bit(AXF_ERROR, &ax->flags); |
410 | } | |
411 | } | |
412 | ||
413 | ax->mtu = dev->mtu + 73; | |
414 | ax->buffsize = len; | |
415 | ||
416 | spin_unlock_bh(&ax->buflock); | |
417 | ||
815f62bf RB |
418 | kfree(oxbuff); |
419 | kfree(orbuff); | |
1da177e4 LT |
420 | } |
421 | ||
422 | /* Encapsulate one AX.25 packet and stuff into a TTY queue. */ | |
815f62bf | 423 | static void ax_encaps(struct net_device *dev, unsigned char *icp, int len) |
1da177e4 | 424 | { |
815f62bf | 425 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 LT |
426 | unsigned char *p; |
427 | int actual, count; | |
428 | ||
429 | if (ax->mtu != ax->dev->mtu + 73) /* Someone has been ifconfigging */ | |
430 | ax_changedmtu(ax); | |
431 | ||
432 | if (len > ax->mtu) { /* Sigh, shouldn't occur BUT ... */ | |
1da177e4 | 433 | printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name); |
ddbe9a68 | 434 | dev->stats.tx_dropped++; |
815f62bf | 435 | netif_start_queue(dev); |
1da177e4 LT |
436 | return; |
437 | } | |
438 | ||
439 | p = icp; | |
440 | ||
441 | spin_lock_bh(&ax->buflock); | |
5793f4be RB |
442 | if ((*p & 0x0f) != 0) { |
443 | /* Configuration Command (kissparms(1). | |
444 | * Protocol spec says: never append CRC. | |
445 | * This fixes a very old bug in the linux | |
446 | * kiss driver. -- dl9sau */ | |
447 | switch (*p & 0xff) { | |
448 | case 0x85: | |
449 | /* command from userspace especially for us, | |
450 | * not for delivery to the tnc */ | |
451 | if (len > 1) { | |
452 | int cmd = (p[1] & 0xff); | |
453 | switch(cmd) { | |
454 | case 3: | |
455 | ax->crcmode = CRC_MODE_SMACK; | |
456 | break; | |
457 | case 2: | |
458 | ax->crcmode = CRC_MODE_FLEX; | |
459 | break; | |
460 | case 1: | |
461 | ax->crcmode = CRC_MODE_NONE; | |
462 | break; | |
463 | case 0: | |
464 | default: | |
465 | ax->crcmode = CRC_MODE_SMACK_TEST; | |
466 | cmd = 0; | |
467 | } | |
468 | ax->crcauto = (cmd ? 0 : 1); | |
45c1fd61 CIK |
469 | printk(KERN_INFO "mkiss: %s: crc mode set to %d\n", |
470 | ax->dev->name, cmd); | |
5793f4be RB |
471 | } |
472 | spin_unlock_bh(&ax->buflock); | |
473 | netif_start_queue(dev); | |
1da177e4 | 474 | |
5793f4be RB |
475 | return; |
476 | default: | |
c2fd03a0 | 477 | count = kiss_esc(p, ax->xbuff, len); |
5793f4be RB |
478 | } |
479 | } else { | |
480 | unsigned short crc; | |
481 | switch (ax->crcmode) { | |
482 | case CRC_MODE_SMACK_TEST: | |
483 | ax->crcmode = CRC_MODE_FLEX_TEST; | |
484 | printk(KERN_INFO "mkiss: %s: Trying crc-smack\n", ax->dev->name); | |
df561f66 | 485 | fallthrough; |
5793f4be RB |
486 | case CRC_MODE_SMACK: |
487 | *p |= 0x80; | |
488 | crc = swab16(crc16(0, p, len)); | |
c2fd03a0 | 489 | count = kiss_esc_crc(p, ax->xbuff, crc, len+2); |
5793f4be RB |
490 | break; |
491 | case CRC_MODE_FLEX_TEST: | |
492 | ax->crcmode = CRC_MODE_NONE; | |
493 | printk(KERN_INFO "mkiss: %s: Trying crc-flexnet\n", ax->dev->name); | |
df561f66 | 494 | fallthrough; |
5793f4be RB |
495 | case CRC_MODE_FLEX: |
496 | *p |= 0x20; | |
497 | crc = calc_crc_flex(p, len); | |
c2fd03a0 | 498 | count = kiss_esc_crc(p, ax->xbuff, crc, len+2); |
5793f4be RB |
499 | break; |
500 | ||
501 | default: | |
c2fd03a0 | 502 | count = kiss_esc(p, ax->xbuff, len); |
5793f4be RB |
503 | } |
504 | } | |
c1854ebc | 505 | spin_unlock_bh(&ax->buflock); |
1da177e4 | 506 | |
815f62bf | 507 | set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); |
f34d7a5b | 508 | actual = ax->tty->ops->write(ax->tty, ax->xbuff, count); |
ddbe9a68 SH |
509 | dev->stats.tx_packets++; |
510 | dev->stats.tx_bytes += actual; | |
815f62bf | 511 | |
860e9538 | 512 | netif_trans_update(ax->dev); |
1da177e4 LT |
513 | ax->xleft = count - actual; |
514 | ax->xhead = ax->xbuff + actual; | |
1da177e4 LT |
515 | } |
516 | ||
1da177e4 | 517 | /* Encapsulate an AX.25 packet and kick it into a TTY queue. */ |
36e4d64a | 518 | static netdev_tx_t ax_xmit(struct sk_buff *skb, struct net_device *dev) |
1da177e4 | 519 | { |
815f62bf | 520 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 | 521 | |
1d5da757 EB |
522 | if (skb->protocol == htons(ETH_P_IP)) |
523 | return ax25_ip_xmit(skb); | |
524 | ||
1da177e4 LT |
525 | if (!netif_running(dev)) { |
526 | printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name); | |
5b548140 | 527 | return NETDEV_TX_BUSY; |
1da177e4 LT |
528 | } |
529 | ||
530 | if (netif_queue_stopped(dev)) { | |
531 | /* | |
532 | * May be we must check transmitter timeout here ? | |
533 | * 14 Oct 1994 Dmitry Gorodchanin. | |
534 | */ | |
4d0e9657 | 535 | if (time_before(jiffies, dev_trans_start(dev) + 20 * HZ)) { |
1da177e4 | 536 | /* 20 sec timeout not reached */ |
5b548140 | 537 | return NETDEV_TX_BUSY; |
1da177e4 LT |
538 | } |
539 | ||
540 | printk(KERN_ERR "mkiss: %s: transmit timed out, %s?\n", dev->name, | |
5608784f | 541 | (tty_chars_in_buffer(ax->tty) || ax->xleft) ? |
1da177e4 LT |
542 | "bad line quality" : "driver error"); |
543 | ||
544 | ax->xleft = 0; | |
815f62bf RB |
545 | clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); |
546 | netif_start_queue(dev); | |
1da177e4 LT |
547 | } |
548 | ||
549 | /* We were not busy, so we are now... :-) */ | |
feb27d15 DC |
550 | netif_stop_queue(dev); |
551 | ax_encaps(dev, skb->data, skb->len); | |
552 | kfree_skb(skb); | |
1da177e4 | 553 | |
6ed10654 | 554 | return NETDEV_TX_OK; |
1da177e4 LT |
555 | } |
556 | ||
815f62bf RB |
557 | static int ax_open_dev(struct net_device *dev) |
558 | { | |
559 | struct mkiss *ax = netdev_priv(dev); | |
560 | ||
561 | if (ax->tty == NULL) | |
562 | return -ENODEV; | |
563 | ||
564 | return 0; | |
565 | } | |
566 | ||
1da177e4 LT |
567 | /* Open the low-level part of the AX25 channel. Easy! */ |
568 | static int ax_open(struct net_device *dev) | |
569 | { | |
815f62bf | 570 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 LT |
571 | unsigned long len; |
572 | ||
573 | if (ax->tty == NULL) | |
574 | return -ENODEV; | |
575 | ||
576 | /* | |
577 | * Allocate the frame buffers: | |
578 | * | |
579 | * rbuff Receive buffer. | |
580 | * xbuff Transmit buffer. | |
581 | */ | |
582 | len = dev->mtu * 2; | |
583 | ||
584 | /* | |
585 | * allow for arrival of larger UDP packets, even if we say not to | |
586 | * also fixes a bug in which SunOS sends 512-byte packets even with | |
587 | * an MSS of 128 | |
588 | */ | |
589 | if (len < 576 * 2) | |
590 | len = 576 * 2; | |
591 | ||
592 | if ((ax->rbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) | |
593 | goto norbuff; | |
594 | ||
595 | if ((ax->xbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) | |
596 | goto noxbuff; | |
597 | ||
598 | ax->mtu = dev->mtu + 73; | |
599 | ax->buffsize = len; | |
600 | ax->rcount = 0; | |
601 | ax->xleft = 0; | |
602 | ||
603 | ax->flags &= (1 << AXF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
604 | ||
605 | spin_lock_init(&ax->buflock); | |
606 | ||
1da177e4 LT |
607 | return 0; |
608 | ||
609 | noxbuff: | |
610 | kfree(ax->rbuff); | |
611 | ||
612 | norbuff: | |
613 | return -ENOMEM; | |
614 | } | |
615 | ||
616 | ||
617 | /* Close the low-level part of the AX25 channel. Easy! */ | |
618 | static int ax_close(struct net_device *dev) | |
619 | { | |
815f62bf | 620 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 | 621 | |
815f62bf RB |
622 | if (ax->tty) |
623 | clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); | |
1da177e4 LT |
624 | |
625 | netif_stop_queue(dev); | |
626 | ||
627 | return 0; | |
628 | } | |
629 | ||
6095e081 SH |
630 | static const struct net_device_ops ax_netdev_ops = { |
631 | .ndo_open = ax_open_dev, | |
632 | .ndo_stop = ax_close, | |
633 | .ndo_start_xmit = ax_xmit, | |
634 | .ndo_set_mac_address = ax_set_mac_address, | |
635 | }; | |
636 | ||
815f62bf RB |
637 | static void ax_setup(struct net_device *dev) |
638 | { | |
815f62bf RB |
639 | /* Finish setting up the DEVICE info. */ |
640 | dev->mtu = AX_MTU; | |
7ba1b689 RB |
641 | dev->hard_header_len = AX25_MAX_HEADER_LEN; |
642 | dev->addr_len = AX25_ADDR_LEN; | |
815f62bf RB |
643 | dev->type = ARPHRD_AX25; |
644 | dev->tx_queue_len = 10; | |
56fc7e71 | 645 | dev->header_ops = &ax25_header_ops; |
6095e081 | 646 | dev->netdev_ops = &ax_netdev_ops; |
3b04ddde | 647 | |
815f62bf | 648 | |
15b1c0e8 RB |
649 | memcpy(dev->broadcast, &ax25_bcast, AX25_ADDR_LEN); |
650 | memcpy(dev->dev_addr, &ax25_defaddr, AX25_ADDR_LEN); | |
815f62bf RB |
651 | |
652 | dev->flags = IFF_BROADCAST | IFF_MULTICAST; | |
1da177e4 LT |
653 | } |
654 | ||
655 | /* | |
815f62bf RB |
656 | * We have a potential race on dereferencing tty->disc_data, because the tty |
657 | * layer provides no locking at all - thus one cpu could be running | |
658 | * sixpack_receive_buf while another calls sixpack_close, which zeroes | |
659 | * tty->disc_data and frees the memory that sixpack_receive_buf is using. The | |
660 | * best way to fix this is to use a rwlock in the tty struct, but for now we | |
661 | * use a single global rwlock for all ttys in ppp line discipline. | |
1da177e4 | 662 | */ |
d5919586 | 663 | static DEFINE_RWLOCK(disc_data_lock); |
815f62bf RB |
664 | |
665 | static struct mkiss *mkiss_get(struct tty_struct *tty) | |
1da177e4 | 666 | { |
815f62bf | 667 | struct mkiss *ax; |
1da177e4 | 668 | |
815f62bf RB |
669 | read_lock(&disc_data_lock); |
670 | ax = tty->disc_data; | |
671 | if (ax) | |
4b4de398 | 672 | refcount_inc(&ax->refcnt); |
815f62bf | 673 | read_unlock(&disc_data_lock); |
1da177e4 | 674 | |
815f62bf RB |
675 | return ax; |
676 | } | |
1da177e4 | 677 | |
815f62bf RB |
678 | static void mkiss_put(struct mkiss *ax) |
679 | { | |
4b4de398 | 680 | if (refcount_dec_and_test(&ax->refcnt)) |
c2c79a32 | 681 | complete(&ax->dead); |
1da177e4 LT |
682 | } |
683 | ||
5793f4be RB |
684 | static int crc_force = 0; /* Can be overridden with insmod */ |
685 | ||
815f62bf | 686 | static int mkiss_open(struct tty_struct *tty) |
1da177e4 | 687 | { |
815f62bf RB |
688 | struct net_device *dev; |
689 | struct mkiss *ax; | |
1da177e4 LT |
690 | int err; |
691 | ||
815f62bf RB |
692 | if (!capable(CAP_NET_ADMIN)) |
693 | return -EPERM; | |
f34d7a5b AC |
694 | if (tty->ops->write == NULL) |
695 | return -EOPNOTSUPP; | |
1da177e4 | 696 | |
c835a677 TG |
697 | dev = alloc_netdev(sizeof(struct mkiss), "ax%d", NET_NAME_UNKNOWN, |
698 | ax_setup); | |
815f62bf RB |
699 | if (!dev) { |
700 | err = -ENOMEM; | |
701 | goto out; | |
702 | } | |
703 | ||
704 | ax = netdev_priv(dev); | |
705 | ax->dev = dev; | |
706 | ||
707 | spin_lock_init(&ax->buflock); | |
4b4de398 | 708 | refcount_set(&ax->refcnt, 1); |
c2c79a32 | 709 | init_completion(&ax->dead); |
1da177e4 LT |
710 | |
711 | ax->tty = tty; | |
712 | tty->disc_data = ax; | |
33f0f88f | 713 | tty->receive_room = 65535; |
1da177e4 | 714 | |
f34d7a5b | 715 | tty_driver_flush_buffer(tty); |
1da177e4 LT |
716 | |
717 | /* Restore default settings */ | |
815f62bf | 718 | dev->type = ARPHRD_AX25; |
1da177e4 LT |
719 | |
720 | /* Perform the low-level AX25 initialization. */ | |
9d332d92 FE |
721 | err = ax_open(ax->dev); |
722 | if (err) | |
815f62bf | 723 | goto out_free_netdev; |
1da177e4 | 724 | |
9d332d92 FE |
725 | err = register_netdev(dev); |
726 | if (err) | |
815f62bf | 727 | goto out_free_buffers; |
1da177e4 | 728 | |
5793f4be RB |
729 | /* after register_netdev() - because else printk smashes the kernel */ |
730 | switch (crc_force) { | |
731 | case 3: | |
732 | ax->crcmode = CRC_MODE_SMACK; | |
733 | printk(KERN_INFO "mkiss: %s: crc mode smack forced.\n", | |
734 | ax->dev->name); | |
735 | break; | |
736 | case 2: | |
737 | ax->crcmode = CRC_MODE_FLEX; | |
738 | printk(KERN_INFO "mkiss: %s: crc mode flexnet forced.\n", | |
739 | ax->dev->name); | |
740 | break; | |
741 | case 1: | |
742 | ax->crcmode = CRC_MODE_NONE; | |
743 | printk(KERN_INFO "mkiss: %s: crc mode disabled.\n", | |
744 | ax->dev->name); | |
745 | break; | |
746 | case 0: | |
5793f4be RB |
747 | default: |
748 | crc_force = 0; | |
749 | printk(KERN_INFO "mkiss: %s: crc mode is auto.\n", | |
750 | ax->dev->name); | |
751 | ax->crcmode = CRC_MODE_SMACK_TEST; | |
752 | } | |
753 | ax->crcauto = (crc_force ? 0 : 1); | |
754 | ||
815f62bf | 755 | netif_start_queue(dev); |
1da177e4 | 756 | |
815f62bf RB |
757 | /* Done. We have linked the TTY line to a channel. */ |
758 | return 0; | |
1da177e4 | 759 | |
815f62bf RB |
760 | out_free_buffers: |
761 | kfree(ax->rbuff); | |
762 | kfree(ax->xbuff); | |
1da177e4 | 763 | |
815f62bf RB |
764 | out_free_netdev: |
765 | free_netdev(dev); | |
1da177e4 | 766 | |
815f62bf RB |
767 | out: |
768 | return err; | |
1da177e4 LT |
769 | } |
770 | ||
815f62bf | 771 | static void mkiss_close(struct tty_struct *tty) |
1da177e4 | 772 | { |
815f62bf | 773 | struct mkiss *ax; |
1da177e4 | 774 | |
5c9934b6 | 775 | write_lock_irq(&disc_data_lock); |
815f62bf RB |
776 | ax = tty->disc_data; |
777 | tty->disc_data = NULL; | |
5c9934b6 | 778 | write_unlock_irq(&disc_data_lock); |
1da177e4 | 779 | |
79ea13ce | 780 | if (!ax) |
815f62bf | 781 | return; |
1da177e4 LT |
782 | |
783 | /* | |
815f62bf RB |
784 | * We have now ensured that nobody can start using ap from now on, but |
785 | * we have to wait for all existing users to finish. | |
1da177e4 | 786 | */ |
4b4de398 | 787 | if (!refcount_dec_and_test(&ax->refcnt)) |
c2c79a32 | 788 | wait_for_completion(&ax->dead); |
fde55c45 A |
789 | /* |
790 | * Halt the transmit queue so that a new transmit cannot scribble | |
791 | * on our buffers | |
792 | */ | |
793 | netif_stop_queue(ax->dev); | |
1da177e4 | 794 | |
815f62bf RB |
795 | /* Free all AX25 frame buffers. */ |
796 | kfree(ax->rbuff); | |
797 | kfree(ax->xbuff); | |
1da177e4 | 798 | |
815f62bf | 799 | ax->tty = NULL; |
d79f16c0 DM |
800 | |
801 | unregister_netdev(ax->dev); | |
1da177e4 LT |
802 | } |
803 | ||
815f62bf RB |
804 | /* Perform I/O control on an active ax25 channel. */ |
805 | static int mkiss_ioctl(struct tty_struct *tty, struct file *file, | |
806 | unsigned int cmd, unsigned long arg) | |
1da177e4 | 807 | { |
815f62bf | 808 | struct mkiss *ax = mkiss_get(tty); |
f40e0638 | 809 | struct net_device *dev; |
815f62bf | 810 | unsigned int tmp, err; |
1da177e4 | 811 | |
815f62bf RB |
812 | /* First make sure we're connected. */ |
813 | if (ax == NULL) | |
814 | return -ENXIO; | |
f40e0638 | 815 | dev = ax->dev; |
1da177e4 | 816 | |
815f62bf RB |
817 | switch (cmd) { |
818 | case SIOCGIFNAME: | |
819 | err = copy_to_user((void __user *) arg, ax->dev->name, | |
820 | strlen(ax->dev->name) + 1) ? -EFAULT : 0; | |
821 | break; | |
822 | ||
823 | case SIOCGIFENCAP: | |
824 | err = put_user(4, (int __user *) arg); | |
825 | break; | |
826 | ||
827 | case SIOCSIFENCAP: | |
828 | if (get_user(tmp, (int __user *) arg)) { | |
829 | err = -EFAULT; | |
830 | break; | |
1da177e4 | 831 | } |
1da177e4 | 832 | |
815f62bf RB |
833 | ax->mode = tmp; |
834 | dev->addr_len = AX25_ADDR_LEN; | |
835 | dev->hard_header_len = AX25_KISS_HEADER_LEN + | |
836 | AX25_MAX_HEADER_LEN + 3; | |
837 | dev->type = ARPHRD_AX25; | |
1da177e4 | 838 | |
815f62bf RB |
839 | err = 0; |
840 | break; | |
1da177e4 | 841 | |
815f62bf RB |
842 | case SIOCSIFHWADDR: { |
843 | char addr[AX25_ADDR_LEN]; | |
1da177e4 | 844 | |
815f62bf RB |
845 | if (copy_from_user(&addr, |
846 | (void __user *) arg, AX25_ADDR_LEN)) { | |
847 | err = -EFAULT; | |
1da177e4 | 848 | break; |
1da177e4 LT |
849 | } |
850 | ||
932ff279 | 851 | netif_tx_lock_bh(dev); |
815f62bf | 852 | memcpy(dev->dev_addr, addr, AX25_ADDR_LEN); |
932ff279 | 853 | netif_tx_unlock_bh(dev); |
815f62bf RB |
854 | |
855 | err = 0; | |
856 | break; | |
857 | } | |
858 | default: | |
859 | err = -ENOIOCTLCMD; | |
1da177e4 | 860 | } |
1da177e4 | 861 | |
815f62bf | 862 | mkiss_put(ax); |
1da177e4 | 863 | |
815f62bf | 864 | return err; |
1da177e4 LT |
865 | } |
866 | ||
815f62bf RB |
867 | /* |
868 | * Handle the 'receiver data ready' interrupt. | |
869 | * This function is called by the 'tty_io' module in the kernel when | |
870 | * a block of data has been received, which can now be decapsulated | |
871 | * and sent on to the AX.25 layer for further processing. | |
872 | */ | |
55db4c64 LT |
873 | static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
874 | char *fp, int count) | |
1da177e4 | 875 | { |
815f62bf | 876 | struct mkiss *ax = mkiss_get(tty); |
1da177e4 | 877 | |
815f62bf | 878 | if (!ax) |
55db4c64 | 879 | return; |
1da177e4 | 880 | |
815f62bf RB |
881 | /* |
882 | * Argh! mtu change time! - costs us the packet part received | |
883 | * at the change | |
884 | */ | |
885 | if (ax->mtu != ax->dev->mtu + 73) | |
886 | ax_changedmtu(ax); | |
1da177e4 | 887 | |
815f62bf | 888 | /* Read the characters out of the buffer */ |
55db4c64 | 889 | while (count--) { |
815f62bf RB |
890 | if (fp != NULL && *fp++) { |
891 | if (!test_and_set_bit(AXF_ERROR, &ax->flags)) | |
ddbe9a68 | 892 | ax->dev->stats.rx_errors++; |
815f62bf RB |
893 | cp++; |
894 | continue; | |
895 | } | |
1da177e4 | 896 | |
815f62bf | 897 | kiss_unesc(ax, *cp++); |
1da177e4 | 898 | } |
815f62bf RB |
899 | |
900 | mkiss_put(ax); | |
39c2e60f | 901 | tty_unthrottle(tty); |
1da177e4 LT |
902 | } |
903 | ||
815f62bf RB |
904 | /* |
905 | * Called by the driver when there's room for more data. If we have | |
906 | * more packets to send, we send them here. | |
907 | */ | |
908 | static void mkiss_write_wakeup(struct tty_struct *tty) | |
1da177e4 | 909 | { |
815f62bf RB |
910 | struct mkiss *ax = mkiss_get(tty); |
911 | int actual; | |
1da177e4 | 912 | |
815f62bf RB |
913 | if (!ax) |
914 | return; | |
1da177e4 | 915 | |
815f62bf RB |
916 | if (ax->xleft <= 0) { |
917 | /* Now serial buffer is almost free & we can start | |
918 | * transmission of another packet | |
919 | */ | |
920 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
1da177e4 | 921 | |
815f62bf RB |
922 | netif_wake_queue(ax->dev); |
923 | goto out; | |
924 | } | |
1da177e4 | 925 | |
f34d7a5b | 926 | actual = tty->ops->write(tty, ax->xhead, ax->xleft); |
815f62bf RB |
927 | ax->xleft -= actual; |
928 | ax->xhead += actual; | |
1da177e4 | 929 | |
815f62bf RB |
930 | out: |
931 | mkiss_put(ax); | |
1da177e4 LT |
932 | } |
933 | ||
a352def2 | 934 | static struct tty_ldisc_ops ax_ldisc = { |
74cfe03f | 935 | .owner = THIS_MODULE, |
815f62bf RB |
936 | .magic = TTY_LDISC_MAGIC, |
937 | .name = "mkiss", | |
938 | .open = mkiss_open, | |
939 | .close = mkiss_close, | |
940 | .ioctl = mkiss_ioctl, | |
941 | .receive_buf = mkiss_receive_buf, | |
815f62bf RB |
942 | .write_wakeup = mkiss_write_wakeup |
943 | }; | |
1da177e4 | 944 | |
afa8c78b | 945 | static const char banner[] __initconst = KERN_INFO \ |
815f62bf | 946 | "mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n"; |
afa8c78b | 947 | static const char msg_regfail[] __initconst = KERN_ERR \ |
815f62bf | 948 | "mkiss: can't register line discipline (err = %d)\n"; |
1da177e4 LT |
949 | |
950 | static int __init mkiss_init_driver(void) | |
951 | { | |
952 | int status; | |
953 | ||
954 | printk(banner); | |
955 | ||
eb33ae24 HE |
956 | status = tty_register_ldisc(N_AX25, &ax_ldisc); |
957 | if (status != 0) | |
958 | printk(msg_regfail, status); | |
1da177e4 | 959 | |
1da177e4 LT |
960 | return status; |
961 | } | |
962 | ||
afa8c78b | 963 | static const char msg_unregfail[] = KERN_ERR \ |
815f62bf RB |
964 | "mkiss: can't unregister line discipline (err = %d)\n"; |
965 | ||
1da177e4 LT |
966 | static void __exit mkiss_exit_driver(void) |
967 | { | |
815f62bf | 968 | int ret; |
1da177e4 | 969 | |
815f62bf RB |
970 | if ((ret = tty_unregister_ldisc(N_AX25))) |
971 | printk(msg_unregfail, ret); | |
1da177e4 LT |
972 | } |
973 | ||
815f62bf | 974 | MODULE_AUTHOR("Ralf Baechle DL5RB <ralf@linux-mips.org>"); |
1da177e4 | 975 | MODULE_DESCRIPTION("KISS driver for AX.25 over TTYs"); |
8d3b33f6 | 976 | module_param(crc_force, int, 0); |
5793f4be | 977 | MODULE_PARM_DESC(crc_force, "crc [0 = auto | 1 = none | 2 = flexnet | 3 = smack]"); |
1da177e4 LT |
978 | MODULE_LICENSE("GPL"); |
979 | MODULE_ALIAS_LDISC(N_AX25); | |
815f62bf | 980 | |
1da177e4 LT |
981 | module_init(mkiss_init_driver); |
982 | module_exit(mkiss_exit_driver); |