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/net/tipc/link.c

https://bitbucket.org/abioy/linux
C | 3367 lines | 2505 code | 462 blank | 400 comment | 474 complexity | e55de7b97d9f6de89ad4ce7530236b7b MD5 | raw file
Possible License(s): CC-BY-SA-3.0, GPL-2.0, LGPL-2.0, AGPL-1.0

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  1. /*
  2. * net/tipc/link.c: TIPC link code
  3. *
  4. * Copyright (c) 1996-2007, Ericsson AB
  5. * Copyright (c) 2004-2007, Wind River Systems
  6. * All rights reserved.
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions are met:
  10. *
  11. * 1. Redistributions of source code must retain the above copyright
  12. * notice, this list of conditions and the following disclaimer.
  13. * 2. Redistributions in binary form must reproduce the above copyright
  14. * notice, this list of conditions and the following disclaimer in the
  15. * documentation and/or other materials provided with the distribution.
  16. * 3. Neither the names of the copyright holders nor the names of its
  17. * contributors may be used to endorse or promote products derived from
  18. * this software without specific prior written permission.
  19. *
  20. * Alternatively, this software may be distributed under the terms of the
  21. * GNU General Public License ("GPL") version 2 as published by the Free
  22. * Software Foundation.
  23. *
  24. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27. * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28. * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34. * POSSIBILITY OF SUCH DAMAGE.
  35. */
  36. #include "core.h"
  37. #include "dbg.h"
  38. #include "link.h"
  39. #include "net.h"
  40. #include "node.h"
  41. #include "port.h"
  42. #include "addr.h"
  43. #include "node_subscr.h"
  44. #include "name_distr.h"
  45. #include "bearer.h"
  46. #include "name_table.h"
  47. #include "discover.h"
  48. #include "config.h"
  49. #include "bcast.h"
  50. /*
  51. * Out-of-range value for link session numbers
  52. */
  53. #define INVALID_SESSION 0x10000
  54. /*
  55. * Limit for deferred reception queue:
  56. */
  57. #define DEF_QUEUE_LIMIT 256u
  58. /*
  59. * Link state events:
  60. */
  61. #define STARTING_EVT 856384768 /* link processing trigger */
  62. #define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
  63. #define TIMEOUT_EVT 560817u /* link timer expired */
  64. /*
  65. * The following two 'message types' is really just implementation
  66. * data conveniently stored in the message header.
  67. * They must not be considered part of the protocol
  68. */
  69. #define OPEN_MSG 0
  70. #define CLOSED_MSG 1
  71. /*
  72. * State value stored in 'exp_msg_count'
  73. */
  74. #define START_CHANGEOVER 100000u
  75. /**
  76. * struct link_name - deconstructed link name
  77. * @addr_local: network address of node at this end
  78. * @if_local: name of interface at this end
  79. * @addr_peer: network address of node at far end
  80. * @if_peer: name of interface at far end
  81. */
  82. struct link_name {
  83. u32 addr_local;
  84. char if_local[TIPC_MAX_IF_NAME];
  85. u32 addr_peer;
  86. char if_peer[TIPC_MAX_IF_NAME];
  87. };
  88. #if 0
  89. /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
  90. /**
  91. * struct link_event - link up/down event notification
  92. */
  93. struct link_event {
  94. u32 addr;
  95. int up;
  96. void (*fcn)(u32, char *, int);
  97. char name[TIPC_MAX_LINK_NAME];
  98. };
  99. #endif
  100. static void link_handle_out_of_seq_msg(struct link *l_ptr,
  101. struct sk_buff *buf);
  102. static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
  103. static int link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
  104. static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
  105. static int link_send_sections_long(struct port *sender,
  106. struct iovec const *msg_sect,
  107. u32 num_sect, u32 destnode);
  108. static void link_check_defragm_bufs(struct link *l_ptr);
  109. static void link_state_event(struct link *l_ptr, u32 event);
  110. static void link_reset_statistics(struct link *l_ptr);
  111. static void link_print(struct link *l_ptr, struct print_buf *buf,
  112. const char *str);
  113. /*
  114. * Debugging code used by link routines only
  115. *
  116. * When debugging link problems on a system that has multiple links,
  117. * the standard TIPC debugging routines may not be useful since they
  118. * allow the output from multiple links to be intermixed. For this reason
  119. * routines of the form "dbg_link_XXX()" have been created that will capture
  120. * debug info into a link's personal print buffer, which can then be dumped
  121. * into the TIPC system log (TIPC_LOG) upon request.
  122. *
  123. * To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
  124. * of the print buffer used by each link. If LINK_LOG_BUF_SIZE is set to 0,
  125. * the dbg_link_XXX() routines simply send their output to the standard
  126. * debug print buffer (DBG_OUTPUT), if it has been defined; this can be useful
  127. * when there is only a single link in the system being debugged.
  128. *
  129. * Notes:
  130. * - When enabled, LINK_LOG_BUF_SIZE should be set to at least TIPC_PB_MIN_SIZE
  131. * - "l_ptr" must be valid when using dbg_link_XXX() macros
  132. */
  133. #define LINK_LOG_BUF_SIZE 0
  134. #define dbg_link(fmt, arg...) \
  135. do { \
  136. if (LINK_LOG_BUF_SIZE) \
  137. tipc_printf(&l_ptr->print_buf, fmt, ## arg); \
  138. } while (0)
  139. #define dbg_link_msg(msg, txt) \
  140. do { \
  141. if (LINK_LOG_BUF_SIZE) \
  142. tipc_msg_dbg(&l_ptr->print_buf, msg, txt); \
  143. } while (0)
  144. #define dbg_link_state(txt) \
  145. do { \
  146. if (LINK_LOG_BUF_SIZE) \
  147. link_print(l_ptr, &l_ptr->print_buf, txt); \
  148. } while (0)
  149. #define dbg_link_dump() do { \
  150. if (LINK_LOG_BUF_SIZE) { \
  151. tipc_printf(LOG, "\n\nDumping link <%s>:\n", l_ptr->name); \
  152. tipc_printbuf_move(LOG, &l_ptr->print_buf); \
  153. } \
  154. } while (0)
  155. static void dbg_print_link(struct link *l_ptr, const char *str)
  156. {
  157. if (DBG_OUTPUT != TIPC_NULL)
  158. link_print(l_ptr, DBG_OUTPUT, str);
  159. }
  160. static void dbg_print_buf_chain(struct sk_buff *root_buf)
  161. {
  162. if (DBG_OUTPUT != TIPC_NULL) {
  163. struct sk_buff *buf = root_buf;
  164. while (buf) {
  165. msg_dbg(buf_msg(buf), "In chain: ");
  166. buf = buf->next;
  167. }
  168. }
  169. }
  170. /*
  171. * Simple link routines
  172. */
  173. static unsigned int align(unsigned int i)
  174. {
  175. return (i + 3) & ~3u;
  176. }
  177. static int link_working_working(struct link *l_ptr)
  178. {
  179. return (l_ptr->state == WORKING_WORKING);
  180. }
  181. static int link_working_unknown(struct link *l_ptr)
  182. {
  183. return (l_ptr->state == WORKING_UNKNOWN);
  184. }
  185. static int link_reset_unknown(struct link *l_ptr)
  186. {
  187. return (l_ptr->state == RESET_UNKNOWN);
  188. }
  189. static int link_reset_reset(struct link *l_ptr)
  190. {
  191. return (l_ptr->state == RESET_RESET);
  192. }
  193. static int link_blocked(struct link *l_ptr)
  194. {
  195. return (l_ptr->exp_msg_count || l_ptr->blocked);
  196. }
  197. static int link_congested(struct link *l_ptr)
  198. {
  199. return (l_ptr->out_queue_size >= l_ptr->queue_limit[0]);
  200. }
  201. static u32 link_max_pkt(struct link *l_ptr)
  202. {
  203. return l_ptr->max_pkt;
  204. }
  205. static void link_init_max_pkt(struct link *l_ptr)
  206. {
  207. u32 max_pkt;
  208. max_pkt = (l_ptr->b_ptr->publ.mtu & ~3);
  209. if (max_pkt > MAX_MSG_SIZE)
  210. max_pkt = MAX_MSG_SIZE;
  211. l_ptr->max_pkt_target = max_pkt;
  212. if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
  213. l_ptr->max_pkt = l_ptr->max_pkt_target;
  214. else
  215. l_ptr->max_pkt = MAX_PKT_DEFAULT;
  216. l_ptr->max_pkt_probes = 0;
  217. }
  218. static u32 link_next_sent(struct link *l_ptr)
  219. {
  220. if (l_ptr->next_out)
  221. return msg_seqno(buf_msg(l_ptr->next_out));
  222. return mod(l_ptr->next_out_no);
  223. }
  224. static u32 link_last_sent(struct link *l_ptr)
  225. {
  226. return mod(link_next_sent(l_ptr) - 1);
  227. }
  228. /*
  229. * Simple non-static link routines (i.e. referenced outside this file)
  230. */
  231. int tipc_link_is_up(struct link *l_ptr)
  232. {
  233. if (!l_ptr)
  234. return 0;
  235. return (link_working_working(l_ptr) || link_working_unknown(l_ptr));
  236. }
  237. int tipc_link_is_active(struct link *l_ptr)
  238. {
  239. return ((l_ptr->owner->active_links[0] == l_ptr) ||
  240. (l_ptr->owner->active_links[1] == l_ptr));
  241. }
  242. /**
  243. * link_name_validate - validate & (optionally) deconstruct link name
  244. * @name - ptr to link name string
  245. * @name_parts - ptr to area for link name components (or NULL if not needed)
  246. *
  247. * Returns 1 if link name is valid, otherwise 0.
  248. */
  249. static int link_name_validate(const char *name, struct link_name *name_parts)
  250. {
  251. char name_copy[TIPC_MAX_LINK_NAME];
  252. char *addr_local;
  253. char *if_local;
  254. char *addr_peer;
  255. char *if_peer;
  256. char dummy;
  257. u32 z_local, c_local, n_local;
  258. u32 z_peer, c_peer, n_peer;
  259. u32 if_local_len;
  260. u32 if_peer_len;
  261. /* copy link name & ensure length is OK */
  262. name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
  263. /* need above in case non-Posix strncpy() doesn't pad with nulls */
  264. strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
  265. if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
  266. return 0;
  267. /* ensure all component parts of link name are present */
  268. addr_local = name_copy;
  269. if ((if_local = strchr(addr_local, ':')) == NULL)
  270. return 0;
  271. *(if_local++) = 0;
  272. if ((addr_peer = strchr(if_local, '-')) == NULL)
  273. return 0;
  274. *(addr_peer++) = 0;
  275. if_local_len = addr_peer - if_local;
  276. if ((if_peer = strchr(addr_peer, ':')) == NULL)
  277. return 0;
  278. *(if_peer++) = 0;
  279. if_peer_len = strlen(if_peer) + 1;
  280. /* validate component parts of link name */
  281. if ((sscanf(addr_local, "%u.%u.%u%c",
  282. &z_local, &c_local, &n_local, &dummy) != 3) ||
  283. (sscanf(addr_peer, "%u.%u.%u%c",
  284. &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
  285. (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
  286. (z_peer > 255) || (c_peer > 4095) || (n_peer > 4095) ||
  287. (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
  288. (if_peer_len <= 1) || (if_peer_len > TIPC_MAX_IF_NAME) ||
  289. (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
  290. (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
  291. return 0;
  292. /* return link name components, if necessary */
  293. if (name_parts) {
  294. name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
  295. strcpy(name_parts->if_local, if_local);
  296. name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
  297. strcpy(name_parts->if_peer, if_peer);
  298. }
  299. return 1;
  300. }
  301. /**
  302. * link_timeout - handle expiration of link timer
  303. * @l_ptr: pointer to link
  304. *
  305. * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
  306. * with tipc_link_delete(). (There is no risk that the node will be deleted by
  307. * another thread because tipc_link_delete() always cancels the link timer before
  308. * tipc_node_delete() is called.)
  309. */
  310. static void link_timeout(struct link *l_ptr)
  311. {
  312. tipc_node_lock(l_ptr->owner);
  313. /* update counters used in statistical profiling of send traffic */
  314. l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
  315. l_ptr->stats.queue_sz_counts++;
  316. if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
  317. l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
  318. if (l_ptr->first_out) {
  319. struct tipc_msg *msg = buf_msg(l_ptr->first_out);
  320. u32 length = msg_size(msg);
  321. if ((msg_user(msg) == MSG_FRAGMENTER) &&
  322. (msg_type(msg) == FIRST_FRAGMENT)) {
  323. length = msg_size(msg_get_wrapped(msg));
  324. }
  325. if (length) {
  326. l_ptr->stats.msg_lengths_total += length;
  327. l_ptr->stats.msg_length_counts++;
  328. if (length <= 64)
  329. l_ptr->stats.msg_length_profile[0]++;
  330. else if (length <= 256)
  331. l_ptr->stats.msg_length_profile[1]++;
  332. else if (length <= 1024)
  333. l_ptr->stats.msg_length_profile[2]++;
  334. else if (length <= 4096)
  335. l_ptr->stats.msg_length_profile[3]++;
  336. else if (length <= 16384)
  337. l_ptr->stats.msg_length_profile[4]++;
  338. else if (length <= 32768)
  339. l_ptr->stats.msg_length_profile[5]++;
  340. else
  341. l_ptr->stats.msg_length_profile[6]++;
  342. }
  343. }
  344. /* do all other link processing performed on a periodic basis */
  345. link_check_defragm_bufs(l_ptr);
  346. link_state_event(l_ptr, TIMEOUT_EVT);
  347. if (l_ptr->next_out)
  348. tipc_link_push_queue(l_ptr);
  349. tipc_node_unlock(l_ptr->owner);
  350. }
  351. static void link_set_timer(struct link *l_ptr, u32 time)
  352. {
  353. k_start_timer(&l_ptr->timer, time);
  354. }
  355. /**
  356. * tipc_link_create - create a new link
  357. * @b_ptr: pointer to associated bearer
  358. * @peer: network address of node at other end of link
  359. * @media_addr: media address to use when sending messages over link
  360. *
  361. * Returns pointer to link.
  362. */
  363. struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
  364. const struct tipc_media_addr *media_addr)
  365. {
  366. struct link *l_ptr;
  367. struct tipc_msg *msg;
  368. char *if_name;
  369. l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
  370. if (!l_ptr) {
  371. warn("Link creation failed, no memory\n");
  372. return NULL;
  373. }
  374. if (LINK_LOG_BUF_SIZE) {
  375. char *pb = kmalloc(LINK_LOG_BUF_SIZE, GFP_ATOMIC);
  376. if (!pb) {
  377. kfree(l_ptr);
  378. warn("Link creation failed, no memory for print buffer\n");
  379. return NULL;
  380. }
  381. tipc_printbuf_init(&l_ptr->print_buf, pb, LINK_LOG_BUF_SIZE);
  382. }
  383. l_ptr->addr = peer;
  384. if_name = strchr(b_ptr->publ.name, ':') + 1;
  385. sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
  386. tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
  387. tipc_node(tipc_own_addr),
  388. if_name,
  389. tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
  390. /* note: peer i/f is appended to link name by reset/activate */
  391. memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
  392. l_ptr->checkpoint = 1;
  393. l_ptr->b_ptr = b_ptr;
  394. link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
  395. l_ptr->state = RESET_UNKNOWN;
  396. l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
  397. msg = l_ptr->pmsg;
  398. msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
  399. msg_set_size(msg, sizeof(l_ptr->proto_msg));
  400. msg_set_session(msg, (tipc_random & 0xffff));
  401. msg_set_bearer_id(msg, b_ptr->identity);
  402. strcpy((char *)msg_data(msg), if_name);
  403. l_ptr->priority = b_ptr->priority;
  404. tipc_link_set_queue_limits(l_ptr, b_ptr->media->window);
  405. link_init_max_pkt(l_ptr);
  406. l_ptr->next_out_no = 1;
  407. INIT_LIST_HEAD(&l_ptr->waiting_ports);
  408. link_reset_statistics(l_ptr);
  409. l_ptr->owner = tipc_node_attach_link(l_ptr);
  410. if (!l_ptr->owner) {
  411. if (LINK_LOG_BUF_SIZE)
  412. kfree(l_ptr->print_buf.buf);
  413. kfree(l_ptr);
  414. return NULL;
  415. }
  416. k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
  417. list_add_tail(&l_ptr->link_list, &b_ptr->links);
  418. tipc_k_signal((Handler)tipc_link_start, (unsigned long)l_ptr);
  419. dbg("tipc_link_create(): tolerance = %u,cont intv = %u, abort_limit = %u\n",
  420. l_ptr->tolerance, l_ptr->continuity_interval, l_ptr->abort_limit);
  421. return l_ptr;
  422. }
  423. /**
  424. * tipc_link_delete - delete a link
  425. * @l_ptr: pointer to link
  426. *
  427. * Note: 'tipc_net_lock' is write_locked, bearer is locked.
  428. * This routine must not grab the node lock until after link timer cancellation
  429. * to avoid a potential deadlock situation.
  430. */
  431. void tipc_link_delete(struct link *l_ptr)
  432. {
  433. if (!l_ptr) {
  434. err("Attempt to delete non-existent link\n");
  435. return;
  436. }
  437. dbg("tipc_link_delete()\n");
  438. k_cancel_timer(&l_ptr->timer);
  439. tipc_node_lock(l_ptr->owner);
  440. tipc_link_reset(l_ptr);
  441. tipc_node_detach_link(l_ptr->owner, l_ptr);
  442. tipc_link_stop(l_ptr);
  443. list_del_init(&l_ptr->link_list);
  444. if (LINK_LOG_BUF_SIZE)
  445. kfree(l_ptr->print_buf.buf);
  446. tipc_node_unlock(l_ptr->owner);
  447. k_term_timer(&l_ptr->timer);
  448. kfree(l_ptr);
  449. }
  450. void tipc_link_start(struct link *l_ptr)
  451. {
  452. dbg("tipc_link_start %x\n", l_ptr);
  453. link_state_event(l_ptr, STARTING_EVT);
  454. }
  455. /**
  456. * link_schedule_port - schedule port for deferred sending
  457. * @l_ptr: pointer to link
  458. * @origport: reference to sending port
  459. * @sz: amount of data to be sent
  460. *
  461. * Schedules port for renewed sending of messages after link congestion
  462. * has abated.
  463. */
  464. static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
  465. {
  466. struct port *p_ptr;
  467. spin_lock_bh(&tipc_port_list_lock);
  468. p_ptr = tipc_port_lock(origport);
  469. if (p_ptr) {
  470. if (!p_ptr->wakeup)
  471. goto exit;
  472. if (!list_empty(&p_ptr->wait_list))
  473. goto exit;
  474. p_ptr->congested_link = l_ptr;
  475. p_ptr->publ.congested = 1;
  476. p_ptr->waiting_pkts = 1 + ((sz - 1) / link_max_pkt(l_ptr));
  477. list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
  478. l_ptr->stats.link_congs++;
  479. exit:
  480. tipc_port_unlock(p_ptr);
  481. }
  482. spin_unlock_bh(&tipc_port_list_lock);
  483. return -ELINKCONG;
  484. }
  485. void tipc_link_wakeup_ports(struct link *l_ptr, int all)
  486. {
  487. struct port *p_ptr;
  488. struct port *temp_p_ptr;
  489. int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
  490. if (all)
  491. win = 100000;
  492. if (win <= 0)
  493. return;
  494. if (!spin_trylock_bh(&tipc_port_list_lock))
  495. return;
  496. if (link_congested(l_ptr))
  497. goto exit;
  498. list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
  499. wait_list) {
  500. if (win <= 0)
  501. break;
  502. list_del_init(&p_ptr->wait_list);
  503. p_ptr->congested_link = NULL;
  504. spin_lock_bh(p_ptr->publ.lock);
  505. p_ptr->publ.congested = 0;
  506. p_ptr->wakeup(&p_ptr->publ);
  507. win -= p_ptr->waiting_pkts;
  508. spin_unlock_bh(p_ptr->publ.lock);
  509. }
  510. exit:
  511. spin_unlock_bh(&tipc_port_list_lock);
  512. }
  513. /**
  514. * link_release_outqueue - purge link's outbound message queue
  515. * @l_ptr: pointer to link
  516. */
  517. static void link_release_outqueue(struct link *l_ptr)
  518. {
  519. struct sk_buff *buf = l_ptr->first_out;
  520. struct sk_buff *next;
  521. while (buf) {
  522. next = buf->next;
  523. buf_discard(buf);
  524. buf = next;
  525. }
  526. l_ptr->first_out = NULL;
  527. l_ptr->out_queue_size = 0;
  528. }
  529. /**
  530. * tipc_link_reset_fragments - purge link's inbound message fragments queue
  531. * @l_ptr: pointer to link
  532. */
  533. void tipc_link_reset_fragments(struct link *l_ptr)
  534. {
  535. struct sk_buff *buf = l_ptr->defragm_buf;
  536. struct sk_buff *next;
  537. while (buf) {
  538. next = buf->next;
  539. buf_discard(buf);
  540. buf = next;
  541. }
  542. l_ptr->defragm_buf = NULL;
  543. }
  544. /**
  545. * tipc_link_stop - purge all inbound and outbound messages associated with link
  546. * @l_ptr: pointer to link
  547. */
  548. void tipc_link_stop(struct link *l_ptr)
  549. {
  550. struct sk_buff *buf;
  551. struct sk_buff *next;
  552. buf = l_ptr->oldest_deferred_in;
  553. while (buf) {
  554. next = buf->next;
  555. buf_discard(buf);
  556. buf = next;
  557. }
  558. buf = l_ptr->first_out;
  559. while (buf) {
  560. next = buf->next;
  561. buf_discard(buf);
  562. buf = next;
  563. }
  564. tipc_link_reset_fragments(l_ptr);
  565. buf_discard(l_ptr->proto_msg_queue);
  566. l_ptr->proto_msg_queue = NULL;
  567. }
  568. #if 0
  569. /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
  570. static void link_recv_event(struct link_event *ev)
  571. {
  572. ev->fcn(ev->addr, ev->name, ev->up);
  573. kfree(ev);
  574. }
  575. static void link_send_event(void (*fcn)(u32 a, char *n, int up),
  576. struct link *l_ptr, int up)
  577. {
  578. struct link_event *ev;
  579. ev = kmalloc(sizeof(*ev), GFP_ATOMIC);
  580. if (!ev) {
  581. warn("Link event allocation failure\n");
  582. return;
  583. }
  584. ev->addr = l_ptr->addr;
  585. ev->up = up;
  586. ev->fcn = fcn;
  587. memcpy(ev->name, l_ptr->name, TIPC_MAX_LINK_NAME);
  588. tipc_k_signal((Handler)link_recv_event, (unsigned long)ev);
  589. }
  590. #else
  591. #define link_send_event(fcn, l_ptr, up) do { } while (0)
  592. #endif
  593. void tipc_link_reset(struct link *l_ptr)
  594. {
  595. struct sk_buff *buf;
  596. u32 prev_state = l_ptr->state;
  597. u32 checkpoint = l_ptr->next_in_no;
  598. int was_active_link = tipc_link_is_active(l_ptr);
  599. msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
  600. /* Link is down, accept any session */
  601. l_ptr->peer_session = INVALID_SESSION;
  602. /* Prepare for max packet size negotiation */
  603. link_init_max_pkt(l_ptr);
  604. l_ptr->state = RESET_UNKNOWN;
  605. dbg_link_state("Resetting Link\n");
  606. if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
  607. return;
  608. tipc_node_link_down(l_ptr->owner, l_ptr);
  609. tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
  610. #if 0
  611. tipc_printf(TIPC_CONS, "\nReset link <%s>\n", l_ptr->name);
  612. dbg_link_dump();
  613. #endif
  614. if (was_active_link && tipc_node_has_active_links(l_ptr->owner) &&
  615. l_ptr->owner->permit_changeover) {
  616. l_ptr->reset_checkpoint = checkpoint;
  617. l_ptr->exp_msg_count = START_CHANGEOVER;
  618. }
  619. /* Clean up all queues: */
  620. link_release_outqueue(l_ptr);
  621. buf_discard(l_ptr->proto_msg_queue);
  622. l_ptr->proto_msg_queue = NULL;
  623. buf = l_ptr->oldest_deferred_in;
  624. while (buf) {
  625. struct sk_buff *next = buf->next;
  626. buf_discard(buf);
  627. buf = next;
  628. }
  629. if (!list_empty(&l_ptr->waiting_ports))
  630. tipc_link_wakeup_ports(l_ptr, 1);
  631. l_ptr->retransm_queue_head = 0;
  632. l_ptr->retransm_queue_size = 0;
  633. l_ptr->last_out = NULL;
  634. l_ptr->first_out = NULL;
  635. l_ptr->next_out = NULL;
  636. l_ptr->unacked_window = 0;
  637. l_ptr->checkpoint = 1;
  638. l_ptr->next_out_no = 1;
  639. l_ptr->deferred_inqueue_sz = 0;
  640. l_ptr->oldest_deferred_in = NULL;
  641. l_ptr->newest_deferred_in = NULL;
  642. l_ptr->fsm_msg_cnt = 0;
  643. l_ptr->stale_count = 0;
  644. link_reset_statistics(l_ptr);
  645. link_send_event(tipc_cfg_link_event, l_ptr, 0);
  646. if (!in_own_cluster(l_ptr->addr))
  647. link_send_event(tipc_disc_link_event, l_ptr, 0);
  648. }
  649. static void link_activate(struct link *l_ptr)
  650. {
  651. l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
  652. tipc_node_link_up(l_ptr->owner, l_ptr);
  653. tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
  654. link_send_event(tipc_cfg_link_event, l_ptr, 1);
  655. if (!in_own_cluster(l_ptr->addr))
  656. link_send_event(tipc_disc_link_event, l_ptr, 1);
  657. }
  658. /**
  659. * link_state_event - link finite state machine
  660. * @l_ptr: pointer to link
  661. * @event: state machine event to process
  662. */
  663. static void link_state_event(struct link *l_ptr, unsigned event)
  664. {
  665. struct link *other;
  666. u32 cont_intv = l_ptr->continuity_interval;
  667. if (!l_ptr->started && (event != STARTING_EVT))
  668. return; /* Not yet. */
  669. if (link_blocked(l_ptr)) {
  670. if (event == TIMEOUT_EVT) {
  671. link_set_timer(l_ptr, cont_intv);
  672. }
  673. return; /* Changeover going on */
  674. }
  675. dbg_link("STATE_EV: <%s> ", l_ptr->name);
  676. switch (l_ptr->state) {
  677. case WORKING_WORKING:
  678. dbg_link("WW/");
  679. switch (event) {
  680. case TRAFFIC_MSG_EVT:
  681. dbg_link("TRF-");
  682. /* fall through */
  683. case ACTIVATE_MSG:
  684. dbg_link("ACT\n");
  685. break;
  686. case TIMEOUT_EVT:
  687. dbg_link("TIM ");
  688. if (l_ptr->next_in_no != l_ptr->checkpoint) {
  689. l_ptr->checkpoint = l_ptr->next_in_no;
  690. if (tipc_bclink_acks_missing(l_ptr->owner)) {
  691. tipc_link_send_proto_msg(l_ptr, STATE_MSG,
  692. 0, 0, 0, 0, 0);
  693. l_ptr->fsm_msg_cnt++;
  694. } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
  695. tipc_link_send_proto_msg(l_ptr, STATE_MSG,
  696. 1, 0, 0, 0, 0);
  697. l_ptr->fsm_msg_cnt++;
  698. }
  699. link_set_timer(l_ptr, cont_intv);
  700. break;
  701. }
  702. dbg_link(" -> WU\n");
  703. l_ptr->state = WORKING_UNKNOWN;
  704. l_ptr->fsm_msg_cnt = 0;
  705. tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
  706. l_ptr->fsm_msg_cnt++;
  707. link_set_timer(l_ptr, cont_intv / 4);
  708. break;
  709. case RESET_MSG:
  710. dbg_link("RES -> RR\n");
  711. info("Resetting link <%s>, requested by peer\n",
  712. l_ptr->name);
  713. tipc_link_reset(l_ptr);
  714. l_ptr->state = RESET_RESET;
  715. l_ptr->fsm_msg_cnt = 0;
  716. tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
  717. l_ptr->fsm_msg_cnt++;
  718. link_set_timer(l_ptr, cont_intv);
  719. break;
  720. default:
  721. err("Unknown link event %u in WW state\n", event);
  722. }
  723. break;
  724. case WORKING_UNKNOWN:
  725. dbg_link("WU/");
  726. switch (event) {
  727. case TRAFFIC_MSG_EVT:
  728. dbg_link("TRF-");
  729. case ACTIVATE_MSG:
  730. dbg_link("ACT -> WW\n");
  731. l_ptr->state = WORKING_WORKING;
  732. l_ptr->fsm_msg_cnt = 0;
  733. link_set_timer(l_ptr, cont_intv);
  734. break;
  735. case RESET_MSG:
  736. dbg_link("RES -> RR\n");
  737. info("Resetting link <%s>, requested by peer "
  738. "while probing\n", l_ptr->name);
  739. tipc_link_reset(l_ptr);
  740. l_ptr->state = RESET_RESET;
  741. l_ptr->fsm_msg_cnt = 0;
  742. tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
  743. l_ptr->fsm_msg_cnt++;
  744. link_set_timer(l_ptr, cont_intv);
  745. break;
  746. case TIMEOUT_EVT:
  747. dbg_link("TIM ");
  748. if (l_ptr->next_in_no != l_ptr->checkpoint) {
  749. dbg_link("-> WW \n");
  750. l_ptr->state = WORKING_WORKING;
  751. l_ptr->fsm_msg_cnt = 0;
  752. l_ptr->checkpoint = l_ptr->next_in_no;
  753. if (tipc_bclink_acks_missing(l_ptr->owner)) {
  754. tipc_link_send_proto_msg(l_ptr, STATE_MSG,
  755. 0, 0, 0, 0, 0);
  756. l_ptr->fsm_msg_cnt++;
  757. }
  758. link_set_timer(l_ptr, cont_intv);
  759. } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
  760. dbg_link("Probing %u/%u,timer = %u ms)\n",
  761. l_ptr->fsm_msg_cnt, l_ptr->abort_limit,
  762. cont_intv / 4);
  763. tipc_link_send_proto_msg(l_ptr, STATE_MSG,
  764. 1, 0, 0, 0, 0);
  765. l_ptr->fsm_msg_cnt++;
  766. link_set_timer(l_ptr, cont_intv / 4);
  767. } else { /* Link has failed */
  768. dbg_link("-> RU (%u probes unanswered)\n",
  769. l_ptr->fsm_msg_cnt);
  770. warn("Resetting link <%s>, peer not responding\n",
  771. l_ptr->name);
  772. tipc_link_reset(l_ptr);
  773. l_ptr->state = RESET_UNKNOWN;
  774. l_ptr->fsm_msg_cnt = 0;
  775. tipc_link_send_proto_msg(l_ptr, RESET_MSG,
  776. 0, 0, 0, 0, 0);
  777. l_ptr->fsm_msg_cnt++;
  778. link_set_timer(l_ptr, cont_intv);
  779. }
  780. break;
  781. default:
  782. err("Unknown link event %u in WU state\n", event);
  783. }
  784. break;
  785. case RESET_UNKNOWN:
  786. dbg_link("RU/");
  787. switch (event) {
  788. case TRAFFIC_MSG_EVT:
  789. dbg_link("TRF-\n");
  790. break;
  791. case ACTIVATE_MSG:
  792. other = l_ptr->owner->active_links[0];
  793. if (other && link_working_unknown(other)) {
  794. dbg_link("ACT\n");
  795. break;
  796. }
  797. dbg_link("ACT -> WW\n");
  798. l_ptr->state = WORKING_WORKING;
  799. l_ptr->fsm_msg_cnt = 0;
  800. link_activate(l_ptr);
  801. tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
  802. l_ptr->fsm_msg_cnt++;
  803. link_set_timer(l_ptr, cont_intv);
  804. break;
  805. case RESET_MSG:
  806. dbg_link("RES \n");
  807. dbg_link(" -> RR\n");
  808. l_ptr->state = RESET_RESET;
  809. l_ptr->fsm_msg_cnt = 0;
  810. tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
  811. l_ptr->fsm_msg_cnt++;
  812. link_set_timer(l_ptr, cont_intv);
  813. break;
  814. case STARTING_EVT:
  815. dbg_link("START-");
  816. l_ptr->started = 1;
  817. /* fall through */
  818. case TIMEOUT_EVT:
  819. dbg_link("TIM \n");
  820. tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
  821. l_ptr->fsm_msg_cnt++;
  822. link_set_timer(l_ptr, cont_intv);
  823. break;
  824. default:
  825. err("Unknown link event %u in RU state\n", event);
  826. }
  827. break;
  828. case RESET_RESET:
  829. dbg_link("RR/ ");
  830. switch (event) {
  831. case TRAFFIC_MSG_EVT:
  832. dbg_link("TRF-");
  833. /* fall through */
  834. case ACTIVATE_MSG:
  835. other = l_ptr->owner->active_links[0];
  836. if (other && link_working_unknown(other)) {
  837. dbg_link("ACT\n");
  838. break;
  839. }
  840. dbg_link("ACT -> WW\n");
  841. l_ptr->state = WORKING_WORKING;
  842. l_ptr->fsm_msg_cnt = 0;
  843. link_activate(l_ptr);
  844. tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
  845. l_ptr->fsm_msg_cnt++;
  846. link_set_timer(l_ptr, cont_intv);
  847. break;
  848. case RESET_MSG:
  849. dbg_link("RES\n");
  850. break;
  851. case TIMEOUT_EVT:
  852. dbg_link("TIM\n");
  853. tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
  854. l_ptr->fsm_msg_cnt++;
  855. link_set_timer(l_ptr, cont_intv);
  856. dbg_link("fsm_msg_cnt %u\n", l_ptr->fsm_msg_cnt);
  857. break;
  858. default:
  859. err("Unknown link event %u in RR state\n", event);
  860. }
  861. break;
  862. default:
  863. err("Unknown link state %u/%u\n", l_ptr->state, event);
  864. }
  865. }
  866. /*
  867. * link_bundle_buf(): Append contents of a buffer to
  868. * the tail of an existing one.
  869. */
  870. static int link_bundle_buf(struct link *l_ptr,
  871. struct sk_buff *bundler,
  872. struct sk_buff *buf)
  873. {
  874. struct tipc_msg *bundler_msg = buf_msg(bundler);
  875. struct tipc_msg *msg = buf_msg(buf);
  876. u32 size = msg_size(msg);
  877. u32 bundle_size = msg_size(bundler_msg);
  878. u32 to_pos = align(bundle_size);
  879. u32 pad = to_pos - bundle_size;
  880. if (msg_user(bundler_msg) != MSG_BUNDLER)
  881. return 0;
  882. if (msg_type(bundler_msg) != OPEN_MSG)
  883. return 0;
  884. if (skb_tailroom(bundler) < (pad + size))
  885. return 0;
  886. if (link_max_pkt(l_ptr) < (to_pos + size))
  887. return 0;
  888. skb_put(bundler, pad + size);
  889. skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
  890. msg_set_size(bundler_msg, to_pos + size);
  891. msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
  892. dbg("Packed msg # %u(%u octets) into pos %u in buf(#%u)\n",
  893. msg_msgcnt(bundler_msg), size, to_pos, msg_seqno(bundler_msg));
  894. msg_dbg(msg, "PACKD:");
  895. buf_discard(buf);
  896. l_ptr->stats.sent_bundled++;
  897. return 1;
  898. }
  899. static void link_add_to_outqueue(struct link *l_ptr,
  900. struct sk_buff *buf,
  901. struct tipc_msg *msg)
  902. {
  903. u32 ack = mod(l_ptr->next_in_no - 1);
  904. u32 seqno = mod(l_ptr->next_out_no++);
  905. msg_set_word(msg, 2, ((ack << 16) | seqno));
  906. msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
  907. buf->next = NULL;
  908. if (l_ptr->first_out) {
  909. l_ptr->last_out->next = buf;
  910. l_ptr->last_out = buf;
  911. } else
  912. l_ptr->first_out = l_ptr->last_out = buf;
  913. l_ptr->out_queue_size++;
  914. }
  915. /*
  916. * tipc_link_send_buf() is the 'full path' for messages, called from
  917. * inside TIPC when the 'fast path' in tipc_send_buf
  918. * has failed, and from link_send()
  919. */
  920. int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
  921. {
  922. struct tipc_msg *msg = buf_msg(buf);
  923. u32 size = msg_size(msg);
  924. u32 dsz = msg_data_sz(msg);
  925. u32 queue_size = l_ptr->out_queue_size;
  926. u32 imp = msg_tot_importance(msg);
  927. u32 queue_limit = l_ptr->queue_limit[imp];
  928. u32 max_packet = link_max_pkt(l_ptr);
  929. msg_set_prevnode(msg, tipc_own_addr); /* If routed message */
  930. /* Match msg importance against queue limits: */
  931. if (unlikely(queue_size >= queue_limit)) {
  932. if (imp <= TIPC_CRITICAL_IMPORTANCE) {
  933. return link_schedule_port(l_ptr, msg_origport(msg),
  934. size);
  935. }
  936. msg_dbg(msg, "TIPC: Congestion, throwing away\n");
  937. buf_discard(buf);
  938. if (imp > CONN_MANAGER) {
  939. warn("Resetting link <%s>, send queue full", l_ptr->name);
  940. tipc_link_reset(l_ptr);
  941. }
  942. return dsz;
  943. }
  944. /* Fragmentation needed ? */
  945. if (size > max_packet)
  946. return tipc_link_send_long_buf(l_ptr, buf);
  947. /* Packet can be queued or sent: */
  948. if (queue_size > l_ptr->stats.max_queue_sz)
  949. l_ptr->stats.max_queue_sz = queue_size;
  950. if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
  951. !link_congested(l_ptr))) {
  952. link_add_to_outqueue(l_ptr, buf, msg);
  953. if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
  954. l_ptr->unacked_window = 0;
  955. } else {
  956. tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
  957. l_ptr->stats.bearer_congs++;
  958. l_ptr->next_out = buf;
  959. }
  960. return dsz;
  961. }
  962. /* Congestion: can message be bundled ?: */
  963. if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
  964. (msg_user(msg) != MSG_FRAGMENTER)) {
  965. /* Try adding message to an existing bundle */
  966. if (l_ptr->next_out &&
  967. link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
  968. tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
  969. return dsz;
  970. }
  971. /* Try creating a new bundle */
  972. if (size <= max_packet * 2 / 3) {
  973. struct sk_buff *bundler = buf_acquire(max_packet);
  974. struct tipc_msg bundler_hdr;
  975. if (bundler) {
  976. msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
  977. INT_H_SIZE, l_ptr->addr);
  978. skb_copy_to_linear_data(bundler, &bundler_hdr,
  979. INT_H_SIZE);
  980. skb_trim(bundler, INT_H_SIZE);
  981. link_bundle_buf(l_ptr, bundler, buf);
  982. buf = bundler;
  983. msg = buf_msg(buf);
  984. l_ptr->stats.sent_bundles++;
  985. }
  986. }
  987. }
  988. if (!l_ptr->next_out)
  989. l_ptr->next_out = buf;
  990. link_add_to_outqueue(l_ptr, buf, msg);
  991. tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
  992. return dsz;
  993. }
  994. /*
  995. * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
  996. * not been selected yet, and the the owner node is not locked
  997. * Called by TIPC internal users, e.g. the name distributor
  998. */
  999. int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
  1000. {
  1001. struct link *l_ptr;
  1002. struct tipc_node *n_ptr;
  1003. int res = -ELINKCONG;
  1004. read_lock_bh(&tipc_net_lock);
  1005. n_ptr = tipc_node_select(dest, selector);
  1006. if (n_ptr) {
  1007. tipc_node_lock(n_ptr);
  1008. l_ptr = n_ptr->active_links[selector & 1];
  1009. if (l_ptr) {
  1010. dbg("tipc_link_send: found link %x for dest %x\n", l_ptr, dest);
  1011. res = tipc_link_send_buf(l_ptr, buf);
  1012. } else {
  1013. dbg("Attempt to send msg to unreachable node:\n");
  1014. msg_dbg(buf_msg(buf),">>>");
  1015. buf_discard(buf);
  1016. }
  1017. tipc_node_unlock(n_ptr);
  1018. } else {
  1019. dbg("Attempt to send msg to unknown node:\n");
  1020. msg_dbg(buf_msg(buf),">>>");
  1021. buf_discard(buf);
  1022. }
  1023. read_unlock_bh(&tipc_net_lock);
  1024. return res;
  1025. }
  1026. /*
  1027. * link_send_buf_fast: Entry for data messages where the
  1028. * destination link is known and the header is complete,
  1029. * inclusive total message length. Very time critical.
  1030. * Link is locked. Returns user data length.
  1031. */
  1032. static int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
  1033. u32 *used_max_pkt)
  1034. {
  1035. struct tipc_msg *msg = buf_msg(buf);
  1036. int res = msg_data_sz(msg);
  1037. if (likely(!link_congested(l_ptr))) {
  1038. if (likely(msg_size(msg) <= link_max_pkt(l_ptr))) {
  1039. if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
  1040. link_add_to_outqueue(l_ptr, buf, msg);
  1041. if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
  1042. &l_ptr->media_addr))) {
  1043. l_ptr->unacked_window = 0;
  1044. msg_dbg(msg,"SENT_FAST:");
  1045. return res;
  1046. }
  1047. dbg("failed sent fast...\n");
  1048. tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
  1049. l_ptr->stats.bearer_congs++;
  1050. l_ptr->next_out = buf;
  1051. return res;
  1052. }
  1053. }
  1054. else
  1055. *used_max_pkt = link_max_pkt(l_ptr);
  1056. }
  1057. return tipc_link_send_buf(l_ptr, buf); /* All other cases */
  1058. }
  1059. /*
  1060. * tipc_send_buf_fast: Entry for data messages where the
  1061. * destination node is known and the header is complete,
  1062. * inclusive total message length.
  1063. * Returns user data length.
  1064. */
  1065. int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
  1066. {
  1067. struct link *l_ptr;
  1068. struct tipc_node *n_ptr;
  1069. int res;
  1070. u32 selector = msg_origport(buf_msg(buf)) & 1;
  1071. u32 dummy;
  1072. if (destnode == tipc_own_addr)
  1073. return tipc_port_recv_msg(buf);
  1074. read_lock_bh(&tipc_net_lock);
  1075. n_ptr = tipc_node_select(destnode, selector);
  1076. if (likely(n_ptr)) {
  1077. tipc_node_lock(n_ptr);
  1078. l_ptr = n_ptr->active_links[selector];
  1079. dbg("send_fast: buf %x selected %x, destnode = %x\n",
  1080. buf, l_ptr, destnode);
  1081. if (likely(l_ptr)) {
  1082. res = link_send_buf_fast(l_ptr, buf, &dummy);
  1083. tipc_node_unlock(n_ptr);
  1084. read_unlock_bh(&tipc_net_lock);
  1085. return res;
  1086. }
  1087. tipc_node_unlock(n_ptr);
  1088. }
  1089. read_unlock_bh(&tipc_net_lock);
  1090. res = msg_data_sz(buf_msg(buf));
  1091. tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
  1092. return res;
  1093. }
  1094. /*
  1095. * tipc_link_send_sections_fast: Entry for messages where the
  1096. * destination processor is known and the header is complete,
  1097. * except for total message length.
  1098. * Returns user data length or errno.
  1099. */
  1100. int tipc_link_send_sections_fast(struct port *sender,
  1101. struct iovec const *msg_sect,
  1102. const u32 num_sect,
  1103. u32 destaddr)
  1104. {
  1105. struct tipc_msg *hdr = &sender->publ.phdr;
  1106. struct link *l_ptr;
  1107. struct sk_buff *buf;
  1108. struct tipc_node *node;
  1109. int res;
  1110. u32 selector = msg_origport(hdr) & 1;
  1111. again:
  1112. /*
  1113. * Try building message using port's max_pkt hint.
  1114. * (Must not hold any locks while building message.)
  1115. */
  1116. res = msg_build(hdr, msg_sect, num_sect, sender->publ.max_pkt,
  1117. !sender->user_port, &buf);
  1118. read_lock_bh(&tipc_net_lock);
  1119. node = tipc_node_select(destaddr, selector);
  1120. if (likely(node)) {
  1121. tipc_node_lock(node);
  1122. l_ptr = node->active_links[selector];
  1123. if (likely(l_ptr)) {
  1124. if (likely(buf)) {
  1125. res = link_send_buf_fast(l_ptr, buf,
  1126. &sender->publ.max_pkt);
  1127. if (unlikely(res < 0))
  1128. buf_discard(buf);
  1129. exit:
  1130. tipc_node_unlock(node);
  1131. read_unlock_bh(&tipc_net_lock);
  1132. return res;
  1133. }
  1134. /* Exit if build request was invalid */
  1135. if (unlikely(res < 0))
  1136. goto exit;
  1137. /* Exit if link (or bearer) is congested */
  1138. if (link_congested(l_ptr) ||
  1139. !list_empty(&l_ptr->b_ptr->cong_links)) {
  1140. res = link_schedule_port(l_ptr,
  1141. sender->publ.ref, res);
  1142. goto exit;
  1143. }
  1144. /*
  1145. * Message size exceeds max_pkt hint; update hint,
  1146. * then re-try fast path or fragment the message
  1147. */
  1148. sender->publ.max_pkt = link_max_pkt(l_ptr);
  1149. tipc_node_unlock(node);
  1150. read_unlock_bh(&tipc_net_lock);
  1151. if ((msg_hdr_sz(hdr) + res) <= sender->publ.max_pkt)
  1152. goto again;
  1153. return link_send_sections_long(sender, msg_sect,
  1154. num_sect, destaddr);
  1155. }
  1156. tipc_node_unlock(node);
  1157. }
  1158. read_unlock_bh(&tipc_net_lock);
  1159. /* Couldn't find a link to the destination node */
  1160. if (buf)
  1161. return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
  1162. if (res >= 0)
  1163. return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
  1164. TIPC_ERR_NO_NODE);
  1165. return res;
  1166. }
  1167. /*
  1168. * link_send_sections_long(): Entry for long messages where the
  1169. * destination node is known and the header is complete,
  1170. * inclusive total message length.
  1171. * Link and bearer congestion status have been checked to be ok,
  1172. * and are ignored if they change.
  1173. *
  1174. * Note that fragments do not use the full link MTU so that they won't have
  1175. * to undergo refragmentation if link changeover causes them to be sent
  1176. * over another link with an additional tunnel header added as prefix.
  1177. * (Refragmentation will still occur if the other link has a smaller MTU.)
  1178. *
  1179. * Returns user data length or errno.
  1180. */
  1181. static int link_send_sections_long(struct port *sender,
  1182. struct iovec const *msg_sect,
  1183. u32 num_sect,
  1184. u32 destaddr)
  1185. {
  1186. struct link *l_ptr;
  1187. struct tipc_node *node;
  1188. struct tipc_msg *hdr = &sender->publ.phdr;
  1189. u32 dsz = msg_data_sz(hdr);
  1190. u32 max_pkt,fragm_sz,rest;
  1191. struct tipc_msg fragm_hdr;
  1192. struct sk_buff *buf,*buf_chain,*prev;
  1193. u32 fragm_crs,fragm_rest,hsz,sect_rest;
  1194. const unchar *sect_crs;
  1195. int curr_sect;
  1196. u32 fragm_no;
  1197. again:
  1198. fragm_no = 1;
  1199. max_pkt = sender->publ.max_pkt - INT_H_SIZE;
  1200. /* leave room for tunnel header in case of link changeover */
  1201. fragm_sz = max_pkt - INT_H_SIZE;
  1202. /* leave room for fragmentation header in each fragment */
  1203. rest = dsz;
  1204. fragm_crs = 0;
  1205. fragm_rest = 0;
  1206. sect_rest = 0;
  1207. sect_crs = NULL;
  1208. curr_sect = -1;
  1209. /* Prepare reusable fragment header: */
  1210. msg_dbg(hdr, ">FRAGMENTING>");
  1211. msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
  1212. INT_H_SIZE, msg_destnode(hdr));
  1213. msg_set_link_selector(&fragm_hdr, sender->publ.ref);
  1214. msg_set_size(&fragm_hdr, max_pkt);
  1215. msg_set_fragm_no(&fragm_hdr, 1);
  1216. /* Prepare header of first fragment: */
  1217. buf_chain = buf = buf_acquire(max_pkt);
  1218. if (!buf)
  1219. return -ENOMEM;
  1220. buf->next = NULL;
  1221. skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
  1222. hsz = msg_hdr_sz(hdr);
  1223. skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
  1224. msg_dbg(buf_msg(buf), ">BUILD>");
  1225. /* Chop up message: */
  1226. fragm_crs = INT_H_SIZE + hsz;
  1227. fragm_rest = fragm_sz - hsz;
  1228. do { /* For all sections */
  1229. u32 sz;
  1230. if (!sect_rest) {
  1231. sect_rest = msg_sect[++curr_sect].iov_len;
  1232. sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
  1233. }
  1234. if (sect_rest < fragm_rest)
  1235. sz = sect_rest;
  1236. else
  1237. sz = fragm_rest;
  1238. if (likely(!sender->user_port)) {
  1239. if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
  1240. error:
  1241. for (; buf_chain; buf_chain = buf) {
  1242. buf = buf_chain->next;
  1243. buf_discard(buf_chain);
  1244. }
  1245. return -EFAULT;
  1246. }
  1247. } else
  1248. skb_copy_to_linear_data_offset(buf, fragm_crs,
  1249. sect_crs, sz);
  1250. sect_crs += sz;
  1251. sect_rest -= sz;
  1252. fragm_crs += sz;
  1253. fragm_rest -= sz;
  1254. rest -= sz;
  1255. if (!fragm_rest && rest) {
  1256. /* Initiate new fragment: */
  1257. if (rest <= fragm_sz) {
  1258. fragm_sz = rest;
  1259. msg_set_type(&fragm_hdr,LAST_FRAGMENT);
  1260. } else {
  1261. msg_set_type(&fragm_hdr, FRAGMENT);
  1262. }
  1263. msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
  1264. msg_set_fragm_no(&fragm_hdr, ++fragm_no);
  1265. prev = buf;
  1266. buf = buf_acquire(fragm_sz + INT_H_SIZE);
  1267. if (!buf)
  1268. goto error;
  1269. buf->next = NULL;
  1270. prev->next = buf;
  1271. skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
  1272. fragm_crs = INT_H_SIZE;
  1273. fragm_rest = fragm_sz;
  1274. msg_dbg(buf_msg(buf)," >BUILD>");
  1275. }
  1276. }
  1277. while (rest > 0);
  1278. /*
  1279. * Now we have a buffer chain. Select a link and check
  1280. * that packet size is still OK
  1281. */
  1282. node = tipc_node_select(destaddr, sender->publ.ref & 1);
  1283. if (likely(node)) {
  1284. tipc_node_lock(node);
  1285. l_ptr = node->active_links[sender->publ.ref & 1];
  1286. if (!l_ptr) {
  1287. tipc_node_unlock(node);
  1288. goto reject;
  1289. }
  1290. if (link_max_pkt(l_ptr) < max_pkt) {
  1291. sender->publ.max_pkt = link_max_pkt(l_ptr);
  1292. tipc_node_unlock(node);
  1293. for (; buf_chain; buf_chain = buf) {
  1294. buf = buf_chain->next;
  1295. buf_discard(buf_chain);
  1296. }
  1297. goto again;
  1298. }
  1299. } else {
  1300. reject:
  1301. for (; buf_chain; buf_chain = buf) {
  1302. buf = buf_chain->next;
  1303. buf_discard(buf_chain);
  1304. }
  1305. return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
  1306. TIPC_ERR_NO_NODE);
  1307. }
  1308. /* Append whole chain to send queue: */
  1309. buf = buf_chain;
  1310. l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
  1311. if (!l_ptr->next_out)
  1312. l_ptr->next_out = buf_chain;
  1313. l_ptr->stats.sent_fragmented++;
  1314. while (buf) {
  1315. struct sk_buff *next = buf->next;
  1316. struct tipc_msg *msg = buf_msg(buf);
  1317. l_ptr->stats.sent_fragments++;
  1318. msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
  1319. link_add_to_outqueue(l_ptr, buf, msg);
  1320. msg_dbg(msg, ">ADD>");
  1321. buf = next;
  1322. }
  1323. /* Send it, if possible: */
  1324. tipc_link_push_queue(l_ptr);
  1325. tipc_node_unlock(node);
  1326. return dsz;
  1327. }
  1328. /*
  1329. * tipc_link_push_packet: Push one unsent packet to the media
  1330. */
  1331. u32 tipc_link_push_packet(struct link *l_ptr)
  1332. {
  1333. struct sk_buff *buf = l_ptr->first_out;
  1334. u32 r_q_size = l_ptr->retransm_queue_size;
  1335. u32 r_q_head = l_ptr->retransm_queue_head;
  1336. /* Step to position where retransmission failed, if any, */
  1337. /* consider that buffers may have been released in meantime */
  1338. if (r_q_size && buf) {
  1339. u32 last = lesser(mod(r_q_head + r_q_size),
  1340. link_last_sent(l_ptr));
  1341. u32 first = msg_seqno(buf_msg(buf));
  1342. while (buf && less(first, r_q_head)) {
  1343. first = mod(first + 1);
  1344. buf = buf->next;
  1345. }
  1346. l_ptr->retransm_queue_head = r_q_head = first;
  1347. l_ptr->retransm_queue_size = r_q_size = mod(last - first);
  1348. }
  1349. /* Continue retransmission now, if there is anything: */
  1350. if (r_q_size && buf && !skb_cloned(buf)) {
  1351. msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
  1352. msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
  1353. if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
  1354. msg_dbg(buf_msg(buf), ">DEF-RETR>");
  1355. l_ptr->retransm_queue_head = mod(++r_q_head);
  1356. l_ptr->retransm_queue_size = --r_q_size;
  1357. l_ptr->stats.retransmitted++;
  1358. return 0;
  1359. } else {
  1360. l_ptr->stats.bearer_congs++;
  1361. msg_dbg(buf_msg(buf), "|>DEF-RETR>");
  1362. return PUSH_FAILED;
  1363. }
  1364. }
  1365. /* Send deferred protocol message, if any: */
  1366. buf = l_ptr->proto_msg_queue;
  1367. if (buf) {
  1368. msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
  1369. msg_set_bcast_ack(buf_msg(buf),l_ptr->owner->bclink.last_in);
  1370. if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
  1371. msg_dbg(buf_msg(buf), ">DEF-PROT>");
  1372. l_ptr->unacked_window = 0;
  1373. buf_discard(buf);
  1374. l_ptr->proto_msg_queue = NULL;
  1375. return 0;
  1376. } else {
  1377. msg_dbg(buf_msg(buf), "|>DEF-PROT>");
  1378. l_ptr->stats.bearer_congs++;
  1379. return PUSH_FAILED;
  1380. }
  1381. }
  1382. /* Send one deferred data message, if send window not full: */
  1383. buf = l_ptr->next_out;
  1384. if (buf) {
  1385. struct tipc_msg *msg = buf_msg(buf);
  1386. u32 next = msg_seqno(msg);
  1387. u32 first = msg_seqno(buf_msg(l_ptr->first_out));
  1388. if (mod(next - first) < l_ptr->queue_limit[0]) {
  1389. msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
  1390. msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
  1391. if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
  1392. if (msg_user(msg) == MSG_BUNDLER)
  1393. msg_set_type(msg, CLOSED_MSG);
  1394. msg_dbg(msg, ">PUSH-DATA>");
  1395. l_ptr->next_out = buf->next;
  1396. return 0;
  1397. } else {
  1398. msg_dbg(msg, "|PUSH-DATA|");
  1399. l_ptr->stats.bearer_congs++;
  1400. return PUSH_FAILED;
  1401. }
  1402. }
  1403. }
  1404. return PUSH_FINISHED;
  1405. }
  1406. /*
  1407. * push_queue(): push out the unsent messages of a link where
  1408. * congestion has abated. Node is locked
  1409. */
  1410. void tipc_link_push_queue(struct link *l_ptr)
  1411. {
  1412. u32 res;
  1413. if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
  1414. return;
  1415. do {
  1416. res = tipc_link_push_packet(l_ptr);
  1417. } while (!res);
  1418. if (res == PUSH_FAILED)
  1419. tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
  1420. }
  1421. static void link_reset_all(unsigned long addr)
  1422. {
  1423. struct tipc_node *n_ptr;
  1424. char addr_string[16];
  1425. u32 i;
  1426. read_lock_bh(&tipc_net_lock);
  1427. n_ptr = tipc_node_find((u32)addr);
  1428. if (!n_ptr) {
  1429. read_unlock_bh(&tipc_net_lock);
  1430. return; /* node no longer exists */
  1431. }
  1432. tipc_node_lock(n_ptr);
  1433. warn("Resetting all links to %s\n",
  1434. addr_string_fill(addr_string, n_ptr->addr));
  1435. for (i = 0; i < MAX_BEARERS; i++) {
  1436. if (n_ptr->links[i]) {
  1437. link_print(n_ptr->links[i], TIPC_OUTPUT,
  1438. "Resetting link\n");
  1439. tipc_link_reset(n_ptr->links[i]);
  1440. }
  1441. }
  1442. tipc_node_unlock(n_ptr);
  1443. read_unlock_bh(&tipc_net_lock);
  1444. }
  1445. static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
  1446. {
  1447. struct tipc_msg *msg = buf_msg(buf);
  1448. warn("Retransmission failure on link <%s>\n", l_ptr->name);
  1449. tipc_msg_dbg(TIPC_OUTPUT, msg, ">RETR-FAIL>");
  1450. if (l_ptr->addr) {
  1451. /* Handle failure on standard link */
  1452. link_print(l_ptr, TIPC_OUTPUT, "Resetting link\n");
  1453. tipc_link_reset(l_ptr);
  1454. } else {
  1455. /* Handle failure on broadcast link */
  1456. struct tipc_node *n_ptr;
  1457. char addr_string[16];
  1458. tipc_printf(TIPC_OUTPUT, "Msg seq number: %u, ", msg_seqno(msg));
  1459. tipc_printf(TIPC_OUTPUT, "Outstanding acks: %lu\n",
  1460. (unsigned long) TIPC_SKB_CB(buf)->handle);
  1461. n_ptr = l_ptr->owner->next;
  1462. tipc_node_lock(n_ptr);
  1463. addr_string_fill(addr_string, n_ptr->addr);
  1464. tipc_printf(TIPC_OUTPUT, "Multicast link info for %s\n", addr_string);
  1465. tipc_printf(TIPC_OUTPUT, "Supported: %d, ", n_ptr->bclink.supported);
  1466. tipc_printf(TIPC_OUTPUT, "Acked: %u\n", n_ptr->bclink.acked);
  1467. tipc_printf(TIPC_OUTPUT, "Last in: %u, ", n_ptr->bclink.last_in);
  1468. tipc_printf(TIPC_OUTPUT, "Gap after: %u, ", n_ptr->bclink.gap_after);
  1469. tipc_printf(TIPC_OUTPUT, "Gap to: %u\n", n_ptr->bclink.gap_to);
  1470. tipc_printf(TIPC_OUTPUT, "Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
  1471. tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
  1472. tipc_node_unlock(n_ptr);
  1473. l_ptr->stale_count = 0;
  1474. }
  1475. }
  1476. void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
  1477. u32 retransmits)
  1478. {
  1479. struct tipc_msg *msg;
  1480. if (!buf)
  1481. return;
  1482. msg = buf_msg(buf);
  1483. dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
  1484. if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
  1485. if (!skb_cloned(buf)) {
  1486. msg_dbg(msg, ">NO_RETR->BCONG>");
  1487. dbg_print_link(l_ptr, " ");
  1488. l_ptr->retransm_queue_head = msg_seqno(msg);
  1489. l_ptr->retransm_queue_size = retransmits;
  1490. return;
  1491. } else {
  1492. /* Don't retransmit if driver already has the buffer */
  1493. }
  1494. } else {
  1495. /* Detect repeated retransmit failures on uncongested bearer */
  1496. if (l_ptr->last_retransmitted == msg_seqno(msg)) {
  1497. if (++l_ptr->stale_count > 100) {
  1498. link_retransmit_failure(l_ptr, buf);
  1499. return;
  1500. }
  1501. } else {
  1502. l_ptr->last_retransmitted = msg_seqno(msg);
  1503. l_ptr->stale_count = 1;
  1504. }
  1505. }
  1506. while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
  1507. msg = buf_msg(buf);
  1508. msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
  1509. msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
  1510. if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
  1511. msg_dbg(buf_msg(buf), ">RETR>");
  1512. buf = buf->next;
  1513. retransmits--;
  1514. l_ptr->stats.retransmitted++;
  1515. } else {
  1516. tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
  1517. l_ptr->stats.bearer_congs++;
  1518. l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
  1519. l_ptr->retransm_queue_size = retransmits;
  1520. return;
  1521. }
  1522. }
  1523. l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
  1524. }
  1525. /**
  1526. * link_insert_deferred_queue - insert deferred messages back into receive chain
  1527. */
  1528. static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr,
  1529. struct sk_buff *buf)
  1530. {
  1531. u32 seq_no;
  1532. if (l_ptr->oldest_deferred_in == NULL)
  1533. return buf;
  1534. seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
  1535. if (seq_no == mod(l_ptr->next_in_no)) {
  1536. l_ptr->newest_deferred_in->next = buf;
  1537. buf = l_ptr->oldest_deferred_in;
  1538. l_ptr->oldest_deferred_in = NULL;
  1539. l_ptr->deferred_inqueue_sz = 0;
  1540. }
  1541. return buf;
  1542. }
  1543. /**
  1544. * link_recv_buf_validate - validate basic format of received message
  1545. *
  1546. * This routine ensures a TIPC message has an acceptable header, and at least
  1547. * as much data as the header indicates it should. The routine also ensures
  1548. * that the entire message header is stored in the main fragment of the message
  1549. * buffer, to simplify future access to message header fields.
  1550. *
  1551. * Note: Having extra info present in the message header or data areas is OK.
  1552. * TIPC will ignore the excess, under the assumption that it is optional info
  1553. * introduced by a later release of the protocol.
  1554. */
  1555. static int link_recv_buf_validate(struct sk_buff *buf)
  1556. {
  1557. static u32 min_data_hdr_size[8] = {
  1558. SHORT_H_SIZE, MCAST_H_SIZE, LONG_H_SIZE, DIR_MSG_H_SIZE,
  1559. MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
  1560. };
  1561. struct tipc_msg *msg;
  1562. u32 tipc_hdr[2];
  1563. u32 size;
  1564. u32 hdr_size;
  1565. u32 min_hdr_size;
  1566. if (unlikely(buf->len < MIN_H_SIZE))
  1567. return 0;
  1568. msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
  1569. if (msg == NULL)
  1570. return 0;
  1571. if (unlikely(msg_version(msg) != TIPC_VERSION))
  1572. return 0;
  1573. size = msg_size(msg);
  1574. hdr_size = msg_hdr_sz(msg);
  1575. min_hdr_size = msg_isdata(msg) ?
  1576. min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
  1577. if (unlikely((hdr_size < min_hdr_size) ||
  1578. (size < hdr_size) ||
  1579. (buf->len < size) ||
  1580. (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
  1581. return 0;
  1582. return pskb_may_pull(buf, hdr_size);
  1583. }
  1584. void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
  1585. {
  1586. read_lock_bh(&tipc_net_lock);
  1587. while (head) {
  1588. struct bearer *b_ptr = (struct bearer *)tb_ptr;
  1589. struct tipc_node *n_ptr;
  1590. struct link *l_ptr;
  1591. struct sk_buff *crs;
  1592. struct sk_buff *buf = head;
  1593. struct tipc_msg *msg;
  1594. u32 seq_no;
  1595. u32 ackd;
  1596. u32 released = 0;
  1597. int type;
  1598. head = head->next;
  1599. /* Ensure message is well-formed */
  1600. if (unlikely(!link_recv_buf_validate(buf)))
  1601. goto cont;
  1602. /* Ensure message data is a single contiguous unit */
  1603. if (unlikely(buf_linearize(buf))) {
  1604. goto cont;
  1605. }
  1606. /* Handle arrival of a non-unicast link message */
  1607. msg = buf_msg(buf);
  1608. if (unlikely(msg_non_seq(msg))) {
  1609. if (msg_user(msg) == LINK_CONFIG)
  1610. tipc_disc_recv_msg(buf, b_ptr);
  1611. else
  1612. tipc_bclink_recv_pkt(buf);
  1613. continue;
  1614. }
  1615. if (unlikely(!msg_short(msg) &&
  1616. (msg_destnode(msg) != tipc_own_addr)))
  1617. goto cont;
  1618. /* Discard non-routeable messages destined for another node */
  1619. if (unlikely(!msg_isdata(msg) &&
  1620. (msg_destnode(msg) != tipc_own_addr))) {
  1621. if ((msg_user(msg) != CONN_MANAGER) &&
  1622. (msg_user(msg) != MSG_FRAGMENTER))
  1623. goto cont;
  1624. }
  1625. /* Locate unicast link endpoint that should handle message */
  1626. n_ptr = tipc_node_find(msg_prevnode(msg));
  1627. if (unlikely(!n_ptr))
  1628. g

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