rose_subr.c 12 KB

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  1. /*
  2. * This program is free software; you can redistribute it and/or modify
  3. * it under the terms of the GNU General Public License as published by
  4. * the Free Software Foundation; either version 2 of the License, or
  5. * (at your option) any later version.
  6. *
  7. * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
  8. */
  9. #include <linux/errno.h>
  10. #include <linux/types.h>
  11. #include <linux/socket.h>
  12. #include <linux/in.h>
  13. #include <linux/kernel.h>
  14. #include <linux/timer.h>
  15. #include <linux/string.h>
  16. #include <linux/sockios.h>
  17. #include <linux/net.h>
  18. #include <net/ax25.h>
  19. #include <linux/inet.h>
  20. #include <linux/netdevice.h>
  21. #include <linux/skbuff.h>
  22. #include <net/sock.h>
  23. #include <net/tcp_states.h>
  24. #include <asm/system.h>
  25. #include <linux/fcntl.h>
  26. #include <linux/mm.h>
  27. #include <linux/interrupt.h>
  28. #include <net/rose.h>
  29. static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose);
  30. /*
  31. * This routine purges all of the queues of frames.
  32. */
  33. void rose_clear_queues(struct sock *sk)
  34. {
  35. skb_queue_purge(&sk->sk_write_queue);
  36. skb_queue_purge(&rose_sk(sk)->ack_queue);
  37. }
  38. /*
  39. * This routine purges the input queue of those frames that have been
  40. * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
  41. * SDL diagram.
  42. */
  43. void rose_frames_acked(struct sock *sk, unsigned short nr)
  44. {
  45. struct sk_buff *skb;
  46. struct rose_sock *rose = rose_sk(sk);
  47. /*
  48. * Remove all the ack-ed frames from the ack queue.
  49. */
  50. if (rose->va != nr) {
  51. while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) {
  52. skb = skb_dequeue(&rose->ack_queue);
  53. kfree_skb(skb);
  54. rose->va = (rose->va + 1) % ROSE_MODULUS;
  55. }
  56. }
  57. }
  58. void rose_requeue_frames(struct sock *sk)
  59. {
  60. struct sk_buff *skb, *skb_prev = NULL;
  61. /*
  62. * Requeue all the un-ack-ed frames on the output queue to be picked
  63. * up by rose_kick. This arrangement handles the possibility of an
  64. * empty output queue.
  65. */
  66. while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) {
  67. if (skb_prev == NULL)
  68. skb_queue_head(&sk->sk_write_queue, skb);
  69. else
  70. skb_append(skb_prev, skb, &sk->sk_write_queue);
  71. skb_prev = skb;
  72. }
  73. }
  74. /*
  75. * Validate that the value of nr is between va and vs. Return true or
  76. * false for testing.
  77. */
  78. int rose_validate_nr(struct sock *sk, unsigned short nr)
  79. {
  80. struct rose_sock *rose = rose_sk(sk);
  81. unsigned short vc = rose->va;
  82. while (vc != rose->vs) {
  83. if (nr == vc) return 1;
  84. vc = (vc + 1) % ROSE_MODULUS;
  85. }
  86. return nr == rose->vs;
  87. }
  88. /*
  89. * This routine is called when the packet layer internally generates a
  90. * control frame.
  91. */
  92. void rose_write_internal(struct sock *sk, int frametype)
  93. {
  94. struct rose_sock *rose = rose_sk(sk);
  95. struct sk_buff *skb;
  96. unsigned char *dptr;
  97. unsigned char lci1, lci2;
  98. char buffer[100];
  99. int len, faclen = 0;
  100. len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1;
  101. switch (frametype) {
  102. case ROSE_CALL_REQUEST:
  103. len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN;
  104. faclen = rose_create_facilities(buffer, rose);
  105. len += faclen;
  106. break;
  107. case ROSE_CALL_ACCEPTED:
  108. case ROSE_CLEAR_REQUEST:
  109. case ROSE_RESET_REQUEST:
  110. len += 2;
  111. break;
  112. }
  113. if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
  114. return;
  115. /*
  116. * Space for AX.25 header and PID.
  117. */
  118. skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1);
  119. dptr = skb_put(skb, skb_tailroom(skb));
  120. lci1 = (rose->lci >> 8) & 0x0F;
  121. lci2 = (rose->lci >> 0) & 0xFF;
  122. switch (frametype) {
  123. case ROSE_CALL_REQUEST:
  124. *dptr++ = ROSE_GFI | lci1;
  125. *dptr++ = lci2;
  126. *dptr++ = frametype;
  127. *dptr++ = 0xAA;
  128. memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN);
  129. dptr += ROSE_ADDR_LEN;
  130. memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN);
  131. dptr += ROSE_ADDR_LEN;
  132. memcpy(dptr, buffer, faclen);
  133. dptr += faclen;
  134. break;
  135. case ROSE_CALL_ACCEPTED:
  136. *dptr++ = ROSE_GFI | lci1;
  137. *dptr++ = lci2;
  138. *dptr++ = frametype;
  139. *dptr++ = 0x00; /* Address length */
  140. *dptr++ = 0; /* Facilities length */
  141. break;
  142. case ROSE_CLEAR_REQUEST:
  143. *dptr++ = ROSE_GFI | lci1;
  144. *dptr++ = lci2;
  145. *dptr++ = frametype;
  146. *dptr++ = rose->cause;
  147. *dptr++ = rose->diagnostic;
  148. break;
  149. case ROSE_RESET_REQUEST:
  150. *dptr++ = ROSE_GFI | lci1;
  151. *dptr++ = lci2;
  152. *dptr++ = frametype;
  153. *dptr++ = ROSE_DTE_ORIGINATED;
  154. *dptr++ = 0;
  155. break;
  156. case ROSE_RR:
  157. case ROSE_RNR:
  158. *dptr++ = ROSE_GFI | lci1;
  159. *dptr++ = lci2;
  160. *dptr = frametype;
  161. *dptr++ |= (rose->vr << 5) & 0xE0;
  162. break;
  163. case ROSE_CLEAR_CONFIRMATION:
  164. case ROSE_RESET_CONFIRMATION:
  165. *dptr++ = ROSE_GFI | lci1;
  166. *dptr++ = lci2;
  167. *dptr++ = frametype;
  168. break;
  169. default:
  170. printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype);
  171. kfree_skb(skb);
  172. return;
  173. }
  174. rose_transmit_link(skb, rose->neighbour);
  175. }
  176. int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m)
  177. {
  178. unsigned char *frame;
  179. frame = skb->data;
  180. *ns = *nr = *q = *d = *m = 0;
  181. switch (frame[2]) {
  182. case ROSE_CALL_REQUEST:
  183. case ROSE_CALL_ACCEPTED:
  184. case ROSE_CLEAR_REQUEST:
  185. case ROSE_CLEAR_CONFIRMATION:
  186. case ROSE_RESET_REQUEST:
  187. case ROSE_RESET_CONFIRMATION:
  188. return frame[2];
  189. default:
  190. break;
  191. }
  192. if ((frame[2] & 0x1F) == ROSE_RR ||
  193. (frame[2] & 0x1F) == ROSE_RNR) {
  194. *nr = (frame[2] >> 5) & 0x07;
  195. return frame[2] & 0x1F;
  196. }
  197. if ((frame[2] & 0x01) == ROSE_DATA) {
  198. *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT;
  199. *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT;
  200. *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT;
  201. *nr = (frame[2] >> 5) & 0x07;
  202. *ns = (frame[2] >> 1) & 0x07;
  203. return ROSE_DATA;
  204. }
  205. return ROSE_ILLEGAL;
  206. }
  207. static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len)
  208. {
  209. unsigned char *pt;
  210. unsigned char l, lg, n = 0;
  211. int fac_national_digis_received = 0;
  212. do {
  213. switch (*p & 0xC0) {
  214. case 0x00:
  215. p += 2;
  216. n += 2;
  217. len -= 2;
  218. break;
  219. case 0x40:
  220. if (*p == FAC_NATIONAL_RAND)
  221. facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF);
  222. p += 3;
  223. n += 3;
  224. len -= 3;
  225. break;
  226. case 0x80:
  227. p += 4;
  228. n += 4;
  229. len -= 4;
  230. break;
  231. case 0xC0:
  232. l = p[1];
  233. if (*p == FAC_NATIONAL_DEST_DIGI) {
  234. if (!fac_national_digis_received) {
  235. memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN);
  236. facilities->source_ndigis = 1;
  237. }
  238. }
  239. else if (*p == FAC_NATIONAL_SRC_DIGI) {
  240. if (!fac_national_digis_received) {
  241. memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN);
  242. facilities->dest_ndigis = 1;
  243. }
  244. }
  245. else if (*p == FAC_NATIONAL_FAIL_CALL) {
  246. memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN);
  247. }
  248. else if (*p == FAC_NATIONAL_FAIL_ADD) {
  249. memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN);
  250. }
  251. else if (*p == FAC_NATIONAL_DIGIS) {
  252. fac_national_digis_received = 1;
  253. facilities->source_ndigis = 0;
  254. facilities->dest_ndigis = 0;
  255. for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) {
  256. if (pt[6] & AX25_HBIT)
  257. memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN);
  258. else
  259. memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN);
  260. }
  261. }
  262. p += l + 2;
  263. n += l + 2;
  264. len -= l + 2;
  265. break;
  266. }
  267. } while (*p != 0x00 && len > 0);
  268. return n;
  269. }
  270. static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len)
  271. {
  272. unsigned char l, n = 0;
  273. char callsign[11];
  274. do {
  275. switch (*p & 0xC0) {
  276. case 0x00:
  277. p += 2;
  278. n += 2;
  279. len -= 2;
  280. break;
  281. case 0x40:
  282. p += 3;
  283. n += 3;
  284. len -= 3;
  285. break;
  286. case 0x80:
  287. p += 4;
  288. n += 4;
  289. len -= 4;
  290. break;
  291. case 0xC0:
  292. l = p[1];
  293. if (*p == FAC_CCITT_DEST_NSAP) {
  294. memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN);
  295. memcpy(callsign, p + 12, l - 10);
  296. callsign[l - 10] = '\0';
  297. asc2ax(&facilities->source_call, callsign);
  298. }
  299. if (*p == FAC_CCITT_SRC_NSAP) {
  300. memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN);
  301. memcpy(callsign, p + 12, l - 10);
  302. callsign[l - 10] = '\0';
  303. asc2ax(&facilities->dest_call, callsign);
  304. }
  305. p += l + 2;
  306. n += l + 2;
  307. len -= l + 2;
  308. break;
  309. }
  310. } while (*p != 0x00 && len > 0);
  311. return n;
  312. }
  313. int rose_parse_facilities(unsigned char *p,
  314. struct rose_facilities_struct *facilities)
  315. {
  316. int facilities_len, len;
  317. facilities_len = *p++;
  318. if (facilities_len == 0)
  319. return 0;
  320. while (facilities_len > 0) {
  321. if (*p == 0x00) {
  322. facilities_len--;
  323. p++;
  324. switch (*p) {
  325. case FAC_NATIONAL: /* National */
  326. len = rose_parse_national(p + 1, facilities, facilities_len - 1);
  327. facilities_len -= len + 1;
  328. p += len + 1;
  329. break;
  330. case FAC_CCITT: /* CCITT */
  331. len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1);
  332. facilities_len -= len + 1;
  333. p += len + 1;
  334. break;
  335. default:
  336. printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p);
  337. facilities_len--;
  338. p++;
  339. break;
  340. }
  341. } else
  342. break; /* Error in facilities format */
  343. }
  344. return 1;
  345. }
  346. static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose)
  347. {
  348. unsigned char *p = buffer + 1;
  349. char *callsign;
  350. char buf[11];
  351. int len, nb;
  352. /* National Facilities */
  353. if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) {
  354. *p++ = 0x00;
  355. *p++ = FAC_NATIONAL;
  356. if (rose->rand != 0) {
  357. *p++ = FAC_NATIONAL_RAND;
  358. *p++ = (rose->rand >> 8) & 0xFF;
  359. *p++ = (rose->rand >> 0) & 0xFF;
  360. }
  361. /* Sent before older facilities */
  362. if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) {
  363. int maxdigi = 0;
  364. *p++ = FAC_NATIONAL_DIGIS;
  365. *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis);
  366. for (nb = 0 ; nb < rose->source_ndigis ; nb++) {
  367. if (++maxdigi >= ROSE_MAX_DIGIS)
  368. break;
  369. memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN);
  370. p[6] |= AX25_HBIT;
  371. p += AX25_ADDR_LEN;
  372. }
  373. for (nb = 0 ; nb < rose->dest_ndigis ; nb++) {
  374. if (++maxdigi >= ROSE_MAX_DIGIS)
  375. break;
  376. memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN);
  377. p[6] &= ~AX25_HBIT;
  378. p += AX25_ADDR_LEN;
  379. }
  380. }
  381. /* For compatibility */
  382. if (rose->source_ndigis > 0) {
  383. *p++ = FAC_NATIONAL_SRC_DIGI;
  384. *p++ = AX25_ADDR_LEN;
  385. memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN);
  386. p += AX25_ADDR_LEN;
  387. }
  388. /* For compatibility */
  389. if (rose->dest_ndigis > 0) {
  390. *p++ = FAC_NATIONAL_DEST_DIGI;
  391. *p++ = AX25_ADDR_LEN;
  392. memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN);
  393. p += AX25_ADDR_LEN;
  394. }
  395. }
  396. *p++ = 0x00;
  397. *p++ = FAC_CCITT;
  398. *p++ = FAC_CCITT_DEST_NSAP;
  399. callsign = ax2asc(buf, &rose->dest_call);
  400. *p++ = strlen(callsign) + 10;
  401. *p++ = (strlen(callsign) + 9) * 2; /* ??? */
  402. *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
  403. *p++ = ROSE_ADDR_LEN * 2;
  404. memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN);
  405. p += ROSE_ADDR_LEN;
  406. memcpy(p, callsign, strlen(callsign));
  407. p += strlen(callsign);
  408. *p++ = FAC_CCITT_SRC_NSAP;
  409. callsign = ax2asc(buf, &rose->source_call);
  410. *p++ = strlen(callsign) + 10;
  411. *p++ = (strlen(callsign) + 9) * 2; /* ??? */
  412. *p++ = 0x47; *p++ = 0x00; *p++ = 0x11;
  413. *p++ = ROSE_ADDR_LEN * 2;
  414. memcpy(p, &rose->source_addr, ROSE_ADDR_LEN);
  415. p += ROSE_ADDR_LEN;
  416. memcpy(p, callsign, strlen(callsign));
  417. p += strlen(callsign);
  418. len = p - buffer;
  419. buffer[0] = len - 1;
  420. return len;
  421. }
  422. void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic)
  423. {
  424. struct rose_sock *rose = rose_sk(sk);
  425. rose_stop_timer(sk);
  426. rose_stop_idletimer(sk);
  427. rose_clear_queues(sk);
  428. rose->lci = 0;
  429. rose->state = ROSE_STATE_0;
  430. if (cause != -1)
  431. rose->cause = cause;
  432. if (diagnostic != -1)
  433. rose->diagnostic = diagnostic;
  434. sk->sk_state = TCP_CLOSE;
  435. sk->sk_err = reason;
  436. sk->sk_shutdown |= SEND_SHUTDOWN;
  437. if (!sock_flag(sk, SOCK_DEAD)) {
  438. sk->sk_state_change(sk);
  439. sock_set_flag(sk, SOCK_DEAD);
  440. }
  441. }