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Commit | Line | Data |
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1da177e4 | 1 | /* |
815f62bf RB |
2 | * This program is free software; you can distribute it and/or modify it |
3 | * under the terms of the GNU General Public License (Version 2) as | |
4 | * published by the Free Software Foundation. | |
1da177e4 | 5 | * |
815f62bf RB |
6 | * This program is distributed in the hope it will be useful, but WITHOUT |
7 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
8 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
9 | * for more details. | |
1da177e4 | 10 | * |
815f62bf RB |
11 | * You should have received a copy of the GNU General Public License along |
12 | * with this program; if not, write to the Free Software Foundation, Inc., | |
13 | * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. | |
1da177e4 | 14 | * |
815f62bf RB |
15 | * Copyright (C) Hans Alblas PE1AYX <hans@esrac.ele.tue.nl> |
16 | * Copyright (C) 2004, 05 Ralf Baechle DL5RB <ralf@linux-mips.org> | |
1da177e4 LT |
17 | */ |
18 | ||
19 | #include <linux/config.h> | |
20 | #include <linux/module.h> | |
21 | #include <asm/system.h> | |
22 | #include <linux/bitops.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <linux/string.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/in.h> | |
28 | #include <linux/inet.h> | |
29 | #include <linux/tty.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/netdevice.h> | |
32 | #include <linux/major.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/rtnetlink.h> | |
35 | #include <linux/etherdevice.h> | |
36 | #include <linux/skbuff.h> | |
37 | #include <linux/if_arp.h> | |
cd8749b4 | 38 | #include <linux/jiffies.h> |
1da177e4 LT |
39 | |
40 | #include <net/ax25.h> | |
41 | ||
1da177e4 LT |
42 | #ifdef CONFIG_INET |
43 | #include <linux/ip.h> | |
44 | #include <linux/tcp.h> | |
45 | #endif | |
46 | ||
815f62bf RB |
47 | #define AX_MTU 236 |
48 | ||
49 | /* SLIP/KISS protocol characters. */ | |
50 | #define END 0300 /* indicates end of frame */ | |
51 | #define ESC 0333 /* indicates byte stuffing */ | |
52 | #define ESC_END 0334 /* ESC ESC_END means END 'data' */ | |
53 | #define ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */ | |
54 | ||
55 | struct mkiss { | |
56 | struct tty_struct *tty; /* ptr to TTY structure */ | |
57 | struct net_device *dev; /* easy for intr handling */ | |
58 | ||
59 | /* These are pointers to the malloc()ed frame buffers. */ | |
60 | spinlock_t buflock;/* lock for rbuf and xbuf */ | |
61 | unsigned char *rbuff; /* receiver buffer */ | |
62 | int rcount; /* received chars counter */ | |
63 | unsigned char *xbuff; /* transmitter buffer */ | |
64 | unsigned char *xhead; /* pointer to next byte to XMIT */ | |
65 | int xleft; /* bytes left in XMIT queue */ | |
66 | ||
67 | struct net_device_stats stats; | |
68 | ||
69 | /* Detailed SLIP statistics. */ | |
70 | int mtu; /* Our mtu (to spot changes!) */ | |
71 | int buffsize; /* Max buffers sizes */ | |
72 | ||
73 | unsigned long flags; /* Flag values/ mode etc */ | |
74 | /* long req'd: used by set_bit --RR */ | |
75 | #define AXF_INUSE 0 /* Channel in use */ | |
76 | #define AXF_ESCAPE 1 /* ESC received */ | |
77 | #define AXF_ERROR 2 /* Parity, etc. error */ | |
78 | #define AXF_KEEPTEST 3 /* Keepalive test flag */ | |
79 | #define AXF_OUTWAIT 4 /* is outpacket was flag */ | |
80 | ||
81 | int mode; | |
82 | int crcmode; /* MW: for FlexNet, SMACK etc. */ | |
83 | #define CRC_MODE_NONE 0 | |
84 | #define CRC_MODE_FLEX 1 | |
85 | #define CRC_MODE_SMACK 2 | |
86 | ||
87 | atomic_t refcnt; | |
88 | struct semaphore dead_sem; | |
89 | }; | |
1da177e4 LT |
90 | |
91 | /*---------------------------------------------------------------------------*/ | |
92 | ||
815f62bf RB |
93 | static const unsigned short crc_flex_table[] = { |
94 | 0x0f87, 0x1e0e, 0x2c95, 0x3d1c, 0x49a3, 0x582a, 0x6ab1, 0x7b38, | |
95 | 0x83cf, 0x9246, 0xa0dd, 0xb154, 0xc5eb, 0xd462, 0xe6f9, 0xf770, | |
96 | 0x1f06, 0x0e8f, 0x3c14, 0x2d9d, 0x5922, 0x48ab, 0x7a30, 0x6bb9, | |
97 | 0x934e, 0x82c7, 0xb05c, 0xa1d5, 0xd56a, 0xc4e3, 0xf678, 0xe7f1, | |
98 | 0x2e85, 0x3f0c, 0x0d97, 0x1c1e, 0x68a1, 0x7928, 0x4bb3, 0x5a3a, | |
99 | 0xa2cd, 0xb344, 0x81df, 0x9056, 0xe4e9, 0xf560, 0xc7fb, 0xd672, | |
100 | 0x3e04, 0x2f8d, 0x1d16, 0x0c9f, 0x7820, 0x69a9, 0x5b32, 0x4abb, | |
101 | 0xb24c, 0xa3c5, 0x915e, 0x80d7, 0xf468, 0xe5e1, 0xd77a, 0xc6f3, | |
102 | 0x4d83, 0x5c0a, 0x6e91, 0x7f18, 0x0ba7, 0x1a2e, 0x28b5, 0x393c, | |
103 | 0xc1cb, 0xd042, 0xe2d9, 0xf350, 0x87ef, 0x9666, 0xa4fd, 0xb574, | |
104 | 0x5d02, 0x4c8b, 0x7e10, 0x6f99, 0x1b26, 0x0aaf, 0x3834, 0x29bd, | |
105 | 0xd14a, 0xc0c3, 0xf258, 0xe3d1, 0x976e, 0x86e7, 0xb47c, 0xa5f5, | |
106 | 0x6c81, 0x7d08, 0x4f93, 0x5e1a, 0x2aa5, 0x3b2c, 0x09b7, 0x183e, | |
107 | 0xe0c9, 0xf140, 0xc3db, 0xd252, 0xa6ed, 0xb764, 0x85ff, 0x9476, | |
108 | 0x7c00, 0x6d89, 0x5f12, 0x4e9b, 0x3a24, 0x2bad, 0x1936, 0x08bf, | |
109 | 0xf048, 0xe1c1, 0xd35a, 0xc2d3, 0xb66c, 0xa7e5, 0x957e, 0x84f7, | |
110 | 0x8b8f, 0x9a06, 0xa89d, 0xb914, 0xcdab, 0xdc22, 0xeeb9, 0xff30, | |
111 | 0x07c7, 0x164e, 0x24d5, 0x355c, 0x41e3, 0x506a, 0x62f1, 0x7378, | |
112 | 0x9b0e, 0x8a87, 0xb81c, 0xa995, 0xdd2a, 0xcca3, 0xfe38, 0xefb1, | |
113 | 0x1746, 0x06cf, 0x3454, 0x25dd, 0x5162, 0x40eb, 0x7270, 0x63f9, | |
114 | 0xaa8d, 0xbb04, 0x899f, 0x9816, 0xeca9, 0xfd20, 0xcfbb, 0xde32, | |
115 | 0x26c5, 0x374c, 0x05d7, 0x145e, 0x60e1, 0x7168, 0x43f3, 0x527a, | |
116 | 0xba0c, 0xab85, 0x991e, 0x8897, 0xfc28, 0xeda1, 0xdf3a, 0xceb3, | |
117 | 0x3644, 0x27cd, 0x1556, 0x04df, 0x7060, 0x61e9, 0x5372, 0x42fb, | |
118 | 0xc98b, 0xd802, 0xea99, 0xfb10, 0x8faf, 0x9e26, 0xacbd, 0xbd34, | |
119 | 0x45c3, 0x544a, 0x66d1, 0x7758, 0x03e7, 0x126e, 0x20f5, 0x317c, | |
120 | 0xd90a, 0xc883, 0xfa18, 0xeb91, 0x9f2e, 0x8ea7, 0xbc3c, 0xadb5, | |
121 | 0x5542, 0x44cb, 0x7650, 0x67d9, 0x1366, 0x02ef, 0x3074, 0x21fd, | |
122 | 0xe889, 0xf900, 0xcb9b, 0xda12, 0xaead, 0xbf24, 0x8dbf, 0x9c36, | |
123 | 0x64c1, 0x7548, 0x47d3, 0x565a, 0x22e5, 0x336c, 0x01f7, 0x107e, | |
124 | 0xf808, 0xe981, 0xdb1a, 0xca93, 0xbe2c, 0xafa5, 0x9d3e, 0x8cb7, | |
125 | 0x7440, 0x65c9, 0x5752, 0x46db, 0x3264, 0x23ed, 0x1176, 0x00ff | |
1da177e4 LT |
126 | }; |
127 | ||
1da177e4 LT |
128 | static unsigned short calc_crc_flex(unsigned char *cp, int size) |
129 | { | |
815f62bf | 130 | unsigned short crc = 0xffff; |
1da177e4 | 131 | |
815f62bf RB |
132 | while (size--) |
133 | crc = (crc << 8) ^ crc_flex_table[((crc >> 8) ^ *cp++) & 0xff]; | |
1da177e4 | 134 | |
815f62bf RB |
135 | return crc; |
136 | } | |
1da177e4 LT |
137 | |
138 | static int check_crc_flex(unsigned char *cp, int size) | |
139 | { | |
815f62bf | 140 | unsigned short crc = 0xffff; |
1da177e4 | 141 | |
815f62bf RB |
142 | if (size < 3) |
143 | return -1; | |
1da177e4 | 144 | |
815f62bf RB |
145 | while (size--) |
146 | crc = (crc << 8) ^ crc_flex_table[((crc >> 8) ^ *cp++) & 0xff]; | |
1da177e4 | 147 | |
815f62bf RB |
148 | if ((crc & 0xffff) != 0x7070) |
149 | return -1; | |
1da177e4 | 150 | |
815f62bf | 151 | return 0; |
1da177e4 LT |
152 | } |
153 | ||
815f62bf RB |
154 | /* |
155 | * Standard encapsulation | |
156 | */ | |
1da177e4 | 157 | |
815f62bf | 158 | static int kiss_esc(unsigned char *s, unsigned char *d, int len) |
1da177e4 | 159 | { |
815f62bf RB |
160 | unsigned char *ptr = d; |
161 | unsigned char c; | |
1da177e4 | 162 | |
815f62bf RB |
163 | /* |
164 | * Send an initial END character to flush out any data that may have | |
165 | * accumulated in the receiver due to line noise. | |
166 | */ | |
1da177e4 | 167 | |
815f62bf | 168 | *ptr++ = END; |
1da177e4 | 169 | |
815f62bf RB |
170 | while (len-- > 0) { |
171 | switch (c = *s++) { | |
172 | case END: | |
173 | *ptr++ = ESC; | |
174 | *ptr++ = ESC_END; | |
1da177e4 | 175 | break; |
815f62bf RB |
176 | case ESC: |
177 | *ptr++ = ESC; | |
178 | *ptr++ = ESC_ESC; | |
179 | break; | |
180 | default: | |
181 | *ptr++ = c; | |
182 | break; | |
183 | } | |
1da177e4 LT |
184 | } |
185 | ||
815f62bf RB |
186 | *ptr++ = END; |
187 | ||
188 | return ptr - d; | |
189 | } | |
190 | ||
191 | /* | |
192 | * MW: | |
193 | * OK its ugly, but tell me a better solution without copying the | |
194 | * packet to a temporary buffer :-) | |
195 | */ | |
196 | static int kiss_esc_crc(unsigned char *s, unsigned char *d, unsigned short crc, | |
197 | int len) | |
198 | { | |
199 | unsigned char *ptr = d; | |
200 | unsigned char c=0; | |
201 | ||
202 | *ptr++ = END; | |
203 | while (len > 0) { | |
204 | if (len > 2) | |
205 | c = *s++; | |
206 | else if (len > 1) | |
207 | c = crc >> 8; | |
208 | else if (len > 0) | |
209 | c = crc & 0xff; | |
210 | ||
211 | len--; | |
1da177e4 | 212 | |
815f62bf RB |
213 | switch (c) { |
214 | case END: | |
215 | *ptr++ = ESC; | |
216 | *ptr++ = ESC_END; | |
217 | break; | |
218 | case ESC: | |
219 | *ptr++ = ESC; | |
220 | *ptr++ = ESC_ESC; | |
221 | break; | |
222 | default: | |
223 | *ptr++ = c; | |
224 | break; | |
225 | } | |
1da177e4 | 226 | } |
815f62bf RB |
227 | *ptr++ = END; |
228 | ||
229 | return ptr - d; | |
230 | } | |
231 | ||
232 | /* Send one completely decapsulated AX.25 packet to the AX.25 layer. */ | |
233 | static void ax_bump(struct mkiss *ax) | |
234 | { | |
235 | struct sk_buff *skb; | |
236 | int count; | |
237 | ||
238 | spin_lock_bh(&ax->buflock); | |
239 | if (ax->rbuff[0] > 0x0f) { | |
240 | if (ax->rbuff[0] & 0x20) { | |
241 | ax->crcmode = CRC_MODE_FLEX; | |
242 | if (check_crc_flex(ax->rbuff, ax->rcount) < 0) { | |
243 | ax->stats.rx_errors++; | |
244 | return; | |
245 | } | |
246 | ax->rcount -= 2; | |
247 | /* dl9sau bugfix: the trailling two bytes flexnet crc | |
248 | * will not be passed to the kernel. thus we have | |
249 | * to correct the kissparm signature, because it | |
250 | * indicates a crc but there's none | |
251 | */ | |
252 | *ax->rbuff &= ~0x20; | |
1da177e4 | 253 | } |
815f62bf RB |
254 | } |
255 | spin_unlock_bh(&ax->buflock); | |
256 | ||
257 | count = ax->rcount; | |
258 | ||
259 | if ((skb = dev_alloc_skb(count)) == NULL) { | |
260 | printk(KERN_ERR "mkiss: %s: memory squeeze, dropping packet.\n", | |
261 | ax->dev->name); | |
262 | ax->stats.rx_dropped++; | |
263 | return; | |
1da177e4 LT |
264 | } |
265 | ||
815f62bf RB |
266 | spin_lock_bh(&ax->buflock); |
267 | memcpy(skb_put(skb,count), ax->rbuff, count); | |
268 | spin_unlock_bh(&ax->buflock); | |
269 | skb->protocol = ax25_type_trans(skb, ax->dev); | |
270 | netif_rx(skb); | |
271 | ax->dev->last_rx = jiffies; | |
272 | ax->stats.rx_packets++; | |
273 | ax->stats.rx_bytes += count; | |
1da177e4 LT |
274 | } |
275 | ||
815f62bf | 276 | static void kiss_unesc(struct mkiss *ax, unsigned char s) |
1da177e4 | 277 | { |
815f62bf RB |
278 | switch (s) { |
279 | case END: | |
280 | /* drop keeptest bit = VSV */ | |
281 | if (test_bit(AXF_KEEPTEST, &ax->flags)) | |
282 | clear_bit(AXF_KEEPTEST, &ax->flags); | |
283 | ||
284 | if (!test_and_clear_bit(AXF_ERROR, &ax->flags) && (ax->rcount > 2)) | |
285 | ax_bump(ax); | |
286 | ||
287 | clear_bit(AXF_ESCAPE, &ax->flags); | |
288 | ax->rcount = 0; | |
289 | return; | |
290 | ||
291 | case ESC: | |
292 | set_bit(AXF_ESCAPE, &ax->flags); | |
293 | return; | |
294 | case ESC_ESC: | |
295 | if (test_and_clear_bit(AXF_ESCAPE, &ax->flags)) | |
296 | s = ESC; | |
297 | break; | |
298 | case ESC_END: | |
299 | if (test_and_clear_bit(AXF_ESCAPE, &ax->flags)) | |
300 | s = END; | |
301 | break; | |
302 | } | |
303 | ||
304 | spin_lock_bh(&ax->buflock); | |
305 | if (!test_bit(AXF_ERROR, &ax->flags)) { | |
306 | if (ax->rcount < ax->buffsize) { | |
307 | ax->rbuff[ax->rcount++] = s; | |
308 | spin_unlock_bh(&ax->buflock); | |
309 | return; | |
310 | } | |
311 | ||
312 | ax->stats.rx_over_errors++; | |
313 | set_bit(AXF_ERROR, &ax->flags); | |
314 | } | |
315 | spin_unlock_bh(&ax->buflock); | |
316 | } | |
317 | ||
318 | static int ax_set_mac_address(struct net_device *dev, void *addr) | |
319 | { | |
320 | struct sockaddr_ax25 *sa = addr; | |
321 | ||
322 | spin_lock_irq(&dev->xmit_lock); | |
323 | memcpy(dev->dev_addr, &sa->sax25_call, AX25_ADDR_LEN); | |
324 | spin_unlock_irq(&dev->xmit_lock); | |
325 | ||
326 | return 0; | |
1da177e4 LT |
327 | } |
328 | ||
815f62bf RB |
329 | /*---------------------------------------------------------------------------*/ |
330 | ||
331 | static void ax_changedmtu(struct mkiss *ax) | |
1da177e4 LT |
332 | { |
333 | struct net_device *dev = ax->dev; | |
334 | unsigned char *xbuff, *rbuff, *oxbuff, *orbuff; | |
335 | int len; | |
336 | ||
337 | len = dev->mtu * 2; | |
338 | ||
339 | /* | |
340 | * allow for arrival of larger UDP packets, even if we say not to | |
341 | * also fixes a bug in which SunOS sends 512-byte packets even with | |
342 | * an MSS of 128 | |
343 | */ | |
344 | if (len < 576 * 2) | |
345 | len = 576 * 2; | |
346 | ||
347 | xbuff = kmalloc(len + 4, GFP_ATOMIC); | |
348 | rbuff = kmalloc(len + 4, GFP_ATOMIC); | |
349 | ||
350 | if (xbuff == NULL || rbuff == NULL) { | |
815f62bf RB |
351 | printk(KERN_ERR "mkiss: %s: unable to grow ax25 buffers, " |
352 | "MTU change cancelled.\n", | |
1da177e4 LT |
353 | ax->dev->name); |
354 | dev->mtu = ax->mtu; | |
355 | if (xbuff != NULL) | |
356 | kfree(xbuff); | |
357 | if (rbuff != NULL) | |
358 | kfree(rbuff); | |
359 | return; | |
360 | } | |
361 | ||
362 | spin_lock_bh(&ax->buflock); | |
363 | ||
364 | oxbuff = ax->xbuff; | |
365 | ax->xbuff = xbuff; | |
366 | orbuff = ax->rbuff; | |
367 | ax->rbuff = rbuff; | |
368 | ||
369 | if (ax->xleft) { | |
370 | if (ax->xleft <= len) { | |
371 | memcpy(ax->xbuff, ax->xhead, ax->xleft); | |
372 | } else { | |
373 | ax->xleft = 0; | |
815f62bf | 374 | ax->stats.tx_dropped++; |
1da177e4 LT |
375 | } |
376 | } | |
377 | ||
378 | ax->xhead = ax->xbuff; | |
379 | ||
380 | if (ax->rcount) { | |
381 | if (ax->rcount <= len) { | |
382 | memcpy(ax->rbuff, orbuff, ax->rcount); | |
383 | } else { | |
384 | ax->rcount = 0; | |
815f62bf | 385 | ax->stats.rx_over_errors++; |
1da177e4 LT |
386 | set_bit(AXF_ERROR, &ax->flags); |
387 | } | |
388 | } | |
389 | ||
390 | ax->mtu = dev->mtu + 73; | |
391 | ax->buffsize = len; | |
392 | ||
393 | spin_unlock_bh(&ax->buflock); | |
394 | ||
815f62bf RB |
395 | kfree(oxbuff); |
396 | kfree(orbuff); | |
1da177e4 LT |
397 | } |
398 | ||
399 | /* Encapsulate one AX.25 packet and stuff into a TTY queue. */ | |
815f62bf | 400 | static void ax_encaps(struct net_device *dev, unsigned char *icp, int len) |
1da177e4 | 401 | { |
815f62bf | 402 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 LT |
403 | unsigned char *p; |
404 | int actual, count; | |
405 | ||
406 | if (ax->mtu != ax->dev->mtu + 73) /* Someone has been ifconfigging */ | |
407 | ax_changedmtu(ax); | |
408 | ||
409 | if (len > ax->mtu) { /* Sigh, shouldn't occur BUT ... */ | |
410 | len = ax->mtu; | |
411 | printk(KERN_ERR "mkiss: %s: truncating oversized transmit packet!\n", ax->dev->name); | |
815f62bf RB |
412 | ax->stats.tx_dropped++; |
413 | netif_start_queue(dev); | |
1da177e4 LT |
414 | return; |
415 | } | |
416 | ||
417 | p = icp; | |
418 | ||
419 | spin_lock_bh(&ax->buflock); | |
420 | switch (ax->crcmode) { | |
421 | unsigned short crc; | |
422 | ||
423 | case CRC_MODE_FLEX: | |
424 | *p |= 0x20; | |
425 | crc = calc_crc_flex(p, len); | |
426 | count = kiss_esc_crc(p, (unsigned char *)ax->xbuff, crc, len+2); | |
427 | break; | |
428 | ||
429 | default: | |
430 | count = kiss_esc(p, (unsigned char *)ax->xbuff, len); | |
431 | break; | |
432 | } | |
433 | ||
815f62bf | 434 | set_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); |
1da177e4 | 435 | actual = ax->tty->driver->write(ax->tty, ax->xbuff, count); |
815f62bf RB |
436 | ax->stats.tx_packets++; |
437 | ax->stats.tx_bytes += actual; | |
438 | ||
1da177e4 LT |
439 | ax->dev->trans_start = jiffies; |
440 | ax->xleft = count - actual; | |
441 | ax->xhead = ax->xbuff + actual; | |
442 | ||
443 | spin_unlock_bh(&ax->buflock); | |
444 | } | |
445 | ||
1da177e4 LT |
446 | /* Encapsulate an AX.25 packet and kick it into a TTY queue. */ |
447 | static int ax_xmit(struct sk_buff *skb, struct net_device *dev) | |
448 | { | |
815f62bf | 449 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 LT |
450 | |
451 | if (!netif_running(dev)) { | |
452 | printk(KERN_ERR "mkiss: %s: xmit call when iface is down\n", dev->name); | |
453 | return 1; | |
454 | } | |
455 | ||
456 | if (netif_queue_stopped(dev)) { | |
457 | /* | |
458 | * May be we must check transmitter timeout here ? | |
459 | * 14 Oct 1994 Dmitry Gorodchanin. | |
460 | */ | |
cd8749b4 | 461 | if (time_before(jiffies, dev->trans_start + 20 * HZ)) { |
1da177e4 LT |
462 | /* 20 sec timeout not reached */ |
463 | return 1; | |
464 | } | |
465 | ||
466 | printk(KERN_ERR "mkiss: %s: transmit timed out, %s?\n", dev->name, | |
467 | (ax->tty->driver->chars_in_buffer(ax->tty) || ax->xleft) ? | |
468 | "bad line quality" : "driver error"); | |
469 | ||
470 | ax->xleft = 0; | |
815f62bf RB |
471 | clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); |
472 | netif_start_queue(dev); | |
1da177e4 LT |
473 | } |
474 | ||
475 | /* We were not busy, so we are now... :-) */ | |
476 | if (skb != NULL) { | |
815f62bf RB |
477 | netif_stop_queue(dev); |
478 | ax_encaps(dev, skb->data, skb->len); | |
1da177e4 LT |
479 | kfree_skb(skb); |
480 | } | |
481 | ||
482 | return 0; | |
483 | } | |
484 | ||
815f62bf RB |
485 | static int ax_open_dev(struct net_device *dev) |
486 | { | |
487 | struct mkiss *ax = netdev_priv(dev); | |
488 | ||
489 | if (ax->tty == NULL) | |
490 | return -ENODEV; | |
491 | ||
492 | return 0; | |
493 | } | |
494 | ||
1da177e4 LT |
495 | #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) |
496 | ||
497 | /* Return the frame type ID */ | |
498 | static int ax_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, | |
499 | void *daddr, void *saddr, unsigned len) | |
500 | { | |
501 | #ifdef CONFIG_INET | |
502 | if (type != htons(ETH_P_AX25)) | |
6f74998e | 503 | return ax25_hard_header(skb, dev, type, daddr, saddr, len); |
1da177e4 LT |
504 | #endif |
505 | return 0; | |
506 | } | |
507 | ||
508 | ||
509 | static int ax_rebuild_header(struct sk_buff *skb) | |
510 | { | |
511 | #ifdef CONFIG_INET | |
512 | return ax25_rebuild_header(skb); | |
513 | #else | |
514 | return 0; | |
515 | #endif | |
516 | } | |
517 | ||
518 | #endif /* CONFIG_{AX25,AX25_MODULE} */ | |
519 | ||
520 | /* Open the low-level part of the AX25 channel. Easy! */ | |
521 | static int ax_open(struct net_device *dev) | |
522 | { | |
815f62bf | 523 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 LT |
524 | unsigned long len; |
525 | ||
526 | if (ax->tty == NULL) | |
527 | return -ENODEV; | |
528 | ||
529 | /* | |
530 | * Allocate the frame buffers: | |
531 | * | |
532 | * rbuff Receive buffer. | |
533 | * xbuff Transmit buffer. | |
534 | */ | |
535 | len = dev->mtu * 2; | |
536 | ||
537 | /* | |
538 | * allow for arrival of larger UDP packets, even if we say not to | |
539 | * also fixes a bug in which SunOS sends 512-byte packets even with | |
540 | * an MSS of 128 | |
541 | */ | |
542 | if (len < 576 * 2) | |
543 | len = 576 * 2; | |
544 | ||
545 | if ((ax->rbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) | |
546 | goto norbuff; | |
547 | ||
548 | if ((ax->xbuff = kmalloc(len + 4, GFP_KERNEL)) == NULL) | |
549 | goto noxbuff; | |
550 | ||
551 | ax->mtu = dev->mtu + 73; | |
552 | ax->buffsize = len; | |
553 | ax->rcount = 0; | |
554 | ax->xleft = 0; | |
555 | ||
556 | ax->flags &= (1 << AXF_INUSE); /* Clear ESCAPE & ERROR flags */ | |
557 | ||
558 | spin_lock_init(&ax->buflock); | |
559 | ||
1da177e4 LT |
560 | return 0; |
561 | ||
562 | noxbuff: | |
563 | kfree(ax->rbuff); | |
564 | ||
565 | norbuff: | |
566 | return -ENOMEM; | |
567 | } | |
568 | ||
569 | ||
570 | /* Close the low-level part of the AX25 channel. Easy! */ | |
571 | static int ax_close(struct net_device *dev) | |
572 | { | |
815f62bf | 573 | struct mkiss *ax = netdev_priv(dev); |
1da177e4 | 574 | |
815f62bf RB |
575 | if (ax->tty) |
576 | clear_bit(TTY_DO_WRITE_WAKEUP, &ax->tty->flags); | |
1da177e4 LT |
577 | |
578 | netif_stop_queue(dev); | |
579 | ||
580 | return 0; | |
581 | } | |
582 | ||
815f62bf | 583 | static struct net_device_stats *ax_get_stats(struct net_device *dev) |
1da177e4 | 584 | { |
815f62bf RB |
585 | struct mkiss *ax = netdev_priv(dev); |
586 | ||
587 | return &ax->stats; | |
588 | } | |
589 | ||
590 | static void ax_setup(struct net_device *dev) | |
591 | { | |
592 | static char ax25_bcast[AX25_ADDR_LEN] = | |
593 | {'Q'<<1,'S'<<1,'T'<<1,' '<<1,' '<<1,' '<<1,'0'<<1}; | |
594 | static char ax25_test[AX25_ADDR_LEN] = | |
595 | {'L'<<1,'I'<<1,'N'<<1,'U'<<1,'X'<<1,' '<<1,'1'<<1}; | |
596 | ||
597 | /* Finish setting up the DEVICE info. */ | |
598 | dev->mtu = AX_MTU; | |
599 | dev->hard_start_xmit = ax_xmit; | |
600 | dev->open = ax_open_dev; | |
601 | dev->stop = ax_close; | |
602 | dev->get_stats = ax_get_stats; | |
603 | dev->set_mac_address = ax_set_mac_address; | |
604 | dev->hard_header_len = 0; | |
605 | dev->addr_len = 0; | |
606 | dev->type = ARPHRD_AX25; | |
607 | dev->tx_queue_len = 10; | |
608 | dev->hard_header = ax_header; | |
609 | dev->rebuild_header = ax_rebuild_header; | |
610 | ||
611 | memcpy(dev->broadcast, ax25_bcast, AX25_ADDR_LEN); | |
612 | memcpy(dev->dev_addr, ax25_test, AX25_ADDR_LEN); | |
613 | ||
614 | dev->flags = IFF_BROADCAST | IFF_MULTICAST; | |
1da177e4 LT |
615 | } |
616 | ||
617 | /* | |
815f62bf RB |
618 | * We have a potential race on dereferencing tty->disc_data, because the tty |
619 | * layer provides no locking at all - thus one cpu could be running | |
620 | * sixpack_receive_buf while another calls sixpack_close, which zeroes | |
621 | * tty->disc_data and frees the memory that sixpack_receive_buf is using. The | |
622 | * best way to fix this is to use a rwlock in the tty struct, but for now we | |
623 | * use a single global rwlock for all ttys in ppp line discipline. | |
1da177e4 | 624 | */ |
815f62bf RB |
625 | static rwlock_t disc_data_lock = RW_LOCK_UNLOCKED; |
626 | ||
627 | static struct mkiss *mkiss_get(struct tty_struct *tty) | |
1da177e4 | 628 | { |
815f62bf | 629 | struct mkiss *ax; |
1da177e4 | 630 | |
815f62bf RB |
631 | read_lock(&disc_data_lock); |
632 | ax = tty->disc_data; | |
633 | if (ax) | |
634 | atomic_inc(&ax->refcnt); | |
635 | read_unlock(&disc_data_lock); | |
1da177e4 | 636 | |
815f62bf RB |
637 | return ax; |
638 | } | |
1da177e4 | 639 | |
815f62bf RB |
640 | static void mkiss_put(struct mkiss *ax) |
641 | { | |
642 | if (atomic_dec_and_test(&ax->refcnt)) | |
643 | up(&ax->dead_sem); | |
1da177e4 LT |
644 | } |
645 | ||
815f62bf | 646 | static int mkiss_open(struct tty_struct *tty) |
1da177e4 | 647 | { |
815f62bf RB |
648 | struct net_device *dev; |
649 | struct mkiss *ax; | |
1da177e4 LT |
650 | int err; |
651 | ||
815f62bf RB |
652 | if (!capable(CAP_NET_ADMIN)) |
653 | return -EPERM; | |
1da177e4 | 654 | |
815f62bf RB |
655 | dev = alloc_netdev(sizeof(struct mkiss), "ax%d", ax_setup); |
656 | if (!dev) { | |
657 | err = -ENOMEM; | |
658 | goto out; | |
659 | } | |
660 | ||
661 | ax = netdev_priv(dev); | |
662 | ax->dev = dev; | |
663 | ||
664 | spin_lock_init(&ax->buflock); | |
665 | atomic_set(&ax->refcnt, 1); | |
666 | init_MUTEX_LOCKED(&ax->dead_sem); | |
1da177e4 LT |
667 | |
668 | ax->tty = tty; | |
669 | tty->disc_data = ax; | |
670 | ||
671 | if (tty->driver->flush_buffer) | |
672 | tty->driver->flush_buffer(tty); | |
673 | ||
674 | /* Restore default settings */ | |
815f62bf | 675 | dev->type = ARPHRD_AX25; |
1da177e4 LT |
676 | |
677 | /* Perform the low-level AX25 initialization. */ | |
815f62bf RB |
678 | if ((err = ax_open(ax->dev))) { |
679 | goto out_free_netdev; | |
680 | } | |
1da177e4 | 681 | |
815f62bf RB |
682 | if (register_netdev(dev)) |
683 | goto out_free_buffers; | |
1da177e4 | 684 | |
815f62bf | 685 | netif_start_queue(dev); |
1da177e4 | 686 | |
815f62bf RB |
687 | /* Done. We have linked the TTY line to a channel. */ |
688 | return 0; | |
1da177e4 | 689 | |
815f62bf RB |
690 | out_free_buffers: |
691 | kfree(ax->rbuff); | |
692 | kfree(ax->xbuff); | |
1da177e4 | 693 | |
815f62bf RB |
694 | out_free_netdev: |
695 | free_netdev(dev); | |
1da177e4 | 696 | |
815f62bf RB |
697 | out: |
698 | return err; | |
1da177e4 LT |
699 | } |
700 | ||
815f62bf | 701 | static void mkiss_close(struct tty_struct *tty) |
1da177e4 | 702 | { |
815f62bf | 703 | struct mkiss *ax; |
1da177e4 | 704 | |
815f62bf RB |
705 | write_lock(&disc_data_lock); |
706 | ax = tty->disc_data; | |
707 | tty->disc_data = NULL; | |
708 | write_unlock(&disc_data_lock); | |
1da177e4 | 709 | |
815f62bf RB |
710 | if (ax == 0) |
711 | return; | |
1da177e4 LT |
712 | |
713 | /* | |
815f62bf RB |
714 | * We have now ensured that nobody can start using ap from now on, but |
715 | * we have to wait for all existing users to finish. | |
1da177e4 | 716 | */ |
815f62bf RB |
717 | if (!atomic_dec_and_test(&ax->refcnt)) |
718 | down(&ax->dead_sem); | |
1da177e4 | 719 | |
815f62bf | 720 | unregister_netdev(ax->dev); |
1da177e4 | 721 | |
815f62bf RB |
722 | /* Free all AX25 frame buffers. */ |
723 | kfree(ax->rbuff); | |
724 | kfree(ax->xbuff); | |
1da177e4 | 725 | |
815f62bf | 726 | ax->tty = NULL; |
1da177e4 LT |
727 | } |
728 | ||
815f62bf RB |
729 | /* Perform I/O control on an active ax25 channel. */ |
730 | static int mkiss_ioctl(struct tty_struct *tty, struct file *file, | |
731 | unsigned int cmd, unsigned long arg) | |
1da177e4 | 732 | { |
815f62bf RB |
733 | struct mkiss *ax = mkiss_get(tty); |
734 | struct net_device *dev = ax->dev; | |
735 | unsigned int tmp, err; | |
1da177e4 | 736 | |
815f62bf RB |
737 | /* First make sure we're connected. */ |
738 | if (ax == NULL) | |
739 | return -ENXIO; | |
1da177e4 | 740 | |
815f62bf RB |
741 | switch (cmd) { |
742 | case SIOCGIFNAME: | |
743 | err = copy_to_user((void __user *) arg, ax->dev->name, | |
744 | strlen(ax->dev->name) + 1) ? -EFAULT : 0; | |
745 | break; | |
746 | ||
747 | case SIOCGIFENCAP: | |
748 | err = put_user(4, (int __user *) arg); | |
749 | break; | |
750 | ||
751 | case SIOCSIFENCAP: | |
752 | if (get_user(tmp, (int __user *) arg)) { | |
753 | err = -EFAULT; | |
754 | break; | |
1da177e4 | 755 | } |
1da177e4 | 756 | |
815f62bf RB |
757 | ax->mode = tmp; |
758 | dev->addr_len = AX25_ADDR_LEN; | |
759 | dev->hard_header_len = AX25_KISS_HEADER_LEN + | |
760 | AX25_MAX_HEADER_LEN + 3; | |
761 | dev->type = ARPHRD_AX25; | |
1da177e4 | 762 | |
815f62bf RB |
763 | err = 0; |
764 | break; | |
1da177e4 | 765 | |
815f62bf RB |
766 | case SIOCSIFHWADDR: { |
767 | char addr[AX25_ADDR_LEN]; | |
1da177e4 | 768 | |
815f62bf RB |
769 | if (copy_from_user(&addr, |
770 | (void __user *) arg, AX25_ADDR_LEN)) { | |
771 | err = -EFAULT; | |
1da177e4 | 772 | break; |
1da177e4 LT |
773 | } |
774 | ||
815f62bf RB |
775 | spin_lock_irq(&dev->xmit_lock); |
776 | memcpy(dev->dev_addr, addr, AX25_ADDR_LEN); | |
777 | spin_unlock_irq(&dev->xmit_lock); | |
778 | ||
779 | err = 0; | |
780 | break; | |
781 | } | |
782 | default: | |
783 | err = -ENOIOCTLCMD; | |
1da177e4 | 784 | } |
1da177e4 | 785 | |
815f62bf | 786 | mkiss_put(ax); |
1da177e4 | 787 | |
815f62bf | 788 | return err; |
1da177e4 LT |
789 | } |
790 | ||
815f62bf RB |
791 | /* |
792 | * Handle the 'receiver data ready' interrupt. | |
793 | * This function is called by the 'tty_io' module in the kernel when | |
794 | * a block of data has been received, which can now be decapsulated | |
795 | * and sent on to the AX.25 layer for further processing. | |
796 | */ | |
797 | static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp, | |
798 | char *fp, int count) | |
1da177e4 | 799 | { |
815f62bf | 800 | struct mkiss *ax = mkiss_get(tty); |
1da177e4 | 801 | |
815f62bf RB |
802 | if (!ax) |
803 | return; | |
1da177e4 | 804 | |
815f62bf RB |
805 | /* |
806 | * Argh! mtu change time! - costs us the packet part received | |
807 | * at the change | |
808 | */ | |
809 | if (ax->mtu != ax->dev->mtu + 73) | |
810 | ax_changedmtu(ax); | |
1da177e4 | 811 | |
815f62bf RB |
812 | /* Read the characters out of the buffer */ |
813 | while (count--) { | |
814 | if (fp != NULL && *fp++) { | |
815 | if (!test_and_set_bit(AXF_ERROR, &ax->flags)) | |
816 | ax->stats.rx_errors++; | |
817 | cp++; | |
818 | continue; | |
819 | } | |
1da177e4 | 820 | |
815f62bf | 821 | kiss_unesc(ax, *cp++); |
1da177e4 | 822 | } |
815f62bf RB |
823 | |
824 | mkiss_put(ax); | |
825 | if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) | |
826 | && tty->driver->unthrottle) | |
827 | tty->driver->unthrottle(tty); | |
1da177e4 LT |
828 | } |
829 | ||
815f62bf | 830 | static int mkiss_receive_room(struct tty_struct *tty) |
1da177e4 | 831 | { |
815f62bf | 832 | return 65536; /* We can handle an infinite amount of data. :-) */ |
1da177e4 LT |
833 | } |
834 | ||
815f62bf RB |
835 | /* |
836 | * Called by the driver when there's room for more data. If we have | |
837 | * more packets to send, we send them here. | |
838 | */ | |
839 | static void mkiss_write_wakeup(struct tty_struct *tty) | |
1da177e4 | 840 | { |
815f62bf RB |
841 | struct mkiss *ax = mkiss_get(tty); |
842 | int actual; | |
1da177e4 | 843 | |
815f62bf RB |
844 | if (!ax) |
845 | return; | |
1da177e4 | 846 | |
815f62bf RB |
847 | if (ax->xleft <= 0) { |
848 | /* Now serial buffer is almost free & we can start | |
849 | * transmission of another packet | |
850 | */ | |
851 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
1da177e4 | 852 | |
815f62bf RB |
853 | netif_wake_queue(ax->dev); |
854 | goto out; | |
855 | } | |
1da177e4 | 856 | |
815f62bf RB |
857 | actual = tty->driver->write(tty, ax->xhead, ax->xleft); |
858 | ax->xleft -= actual; | |
859 | ax->xhead += actual; | |
1da177e4 | 860 | |
815f62bf RB |
861 | out: |
862 | mkiss_put(ax); | |
1da177e4 LT |
863 | } |
864 | ||
815f62bf RB |
865 | static struct tty_ldisc ax_ldisc = { |
866 | .magic = TTY_LDISC_MAGIC, | |
867 | .name = "mkiss", | |
868 | .open = mkiss_open, | |
869 | .close = mkiss_close, | |
870 | .ioctl = mkiss_ioctl, | |
871 | .receive_buf = mkiss_receive_buf, | |
872 | .receive_room = mkiss_receive_room, | |
873 | .write_wakeup = mkiss_write_wakeup | |
874 | }; | |
1da177e4 | 875 | |
815f62bf RB |
876 | static char banner[] __initdata = KERN_INFO \ |
877 | "mkiss: AX.25 Multikiss, Hans Albas PE1AYX\n"; | |
878 | static char msg_regfail[] __initdata = KERN_ERR \ | |
879 | "mkiss: can't register line discipline (err = %d)\n"; | |
1da177e4 LT |
880 | |
881 | static int __init mkiss_init_driver(void) | |
882 | { | |
883 | int status; | |
884 | ||
885 | printk(banner); | |
886 | ||
815f62bf RB |
887 | if ((status = tty_register_ldisc(N_AX25, &ax_ldisc)) != 0) |
888 | printk(msg_regfail); | |
1da177e4 | 889 | |
1da177e4 LT |
890 | return status; |
891 | } | |
892 | ||
815f62bf RB |
893 | static const char msg_unregfail[] __exitdata = KERN_ERR \ |
894 | "mkiss: can't unregister line discipline (err = %d)\n"; | |
895 | ||
1da177e4 LT |
896 | static void __exit mkiss_exit_driver(void) |
897 | { | |
815f62bf | 898 | int ret; |
1da177e4 | 899 | |
815f62bf RB |
900 | if ((ret = tty_unregister_ldisc(N_AX25))) |
901 | printk(msg_unregfail, ret); | |
1da177e4 LT |
902 | } |
903 | ||
815f62bf | 904 | MODULE_AUTHOR("Ralf Baechle DL5RB <ralf@linux-mips.org>"); |
1da177e4 | 905 | MODULE_DESCRIPTION("KISS driver for AX.25 over TTYs"); |
1da177e4 LT |
906 | MODULE_LICENSE("GPL"); |
907 | MODULE_ALIAS_LDISC(N_AX25); | |
815f62bf | 908 | |
1da177e4 LT |
909 | module_init(mkiss_init_driver); |
910 | module_exit(mkiss_exit_driver); |