net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2006, Ericsson AB
   5  * Copyright (c) 2004-2006, 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
  37 #include "core.h"
  38 #include "dbg.h"
  39 #include "link.h"
  40 #include "net.h"
  41 #include "node.h"
  42 #include "port.h"
  43 #include "addr.h"
  44 #include "node_subscr.h"
  45 #include "name_distr.h"
  46 #include "bearer.h"
  47 #include "name_table.h"
  48 #include "discover.h"
  49 #include "config.h"
  50 #include "bcast.h"
  51
  52
  53 /*
  54  * Limit for deferred reception queue:
  55  */
  56
  57 #define DEF_QUEUE_LIMIT 256u
  58
  59 /*
  60  * Link state events:
  61  */
  62
  63 #define  STARTING_EVT    856384768      /* link processing trigger */
  64 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  65 #define  TIMEOUT_EVT     560817u        /* link timer expired */
  66
  67 /*
  68  * The following two 'message types' is really just implementation
  69  * data conveniently stored in the message header.
  70  * They must not be considered part of the protocol
  71  */
  72 #define OPEN_MSG   0
  73 #define CLOSED_MSG 1
  74
  75 /*
  76  * State value stored in 'exp_msg_count'
  77  */
  78
  79 #define START_CHANGEOVER 100000u
  80
  81 /**
  82  * struct link_name - deconstructed link name
  83  * @addr_local: network address of node at this end
  84  * @if_local: name of interface at this end
  85  * @addr_peer: network address of node at far end
  86  * @if_peer: name of interface at far end
  87  */
  88
  89 struct link_name {
  90         u32 addr_local;
  91         char if_local[TIPC_MAX_IF_NAME];
  92         u32 addr_peer;
  93         char if_peer[TIPC_MAX_IF_NAME];
  94 };
  95
  96 #if 0
  97
  98 /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
  99
 100 /**
 101  * struct link_event - link up/down event notification
 102  */
 103
 104 struct link_event {
 105         u32 addr;
 106         int up;
 107         void (*fcn)(u32, char *, int);
 108         char name[TIPC_MAX_LINK_NAME];
 109 };
 110
 111 #endif
 112
 113 static void link_handle_out_of_seq_msg(struct link *l_ptr,
 114                                        struct sk_buff *buf);
 115 static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
 116 static int  link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
 117 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
 118 static int  link_send_sections_long(struct port *sender,
 119                                     struct iovec const *msg_sect,
 120                                     u32 num_sect, u32 destnode);
 121 static void link_check_defragm_bufs(struct link *l_ptr);
 122 static void link_state_event(struct link *l_ptr, u32 event);
 123 static void link_reset_statistics(struct link *l_ptr);
 124 static void link_print(struct link *l_ptr, struct print_buf *buf,
 125                        const char *str);
 126
 127 /*
 128  * Debugging code used by link routines only
 129  *
 130  * When debugging link problems on a system that has multiple links,
 131  * the standard TIPC debugging routines may not be useful since they
 132  * allow the output from multiple links to be intermixed.  For this reason
 133  * routines of the form "dbg_link_XXX()" have been created that will capture
 134  * debug info into a link's personal print buffer, which can then be dumped
 135  * into the TIPC system log (LOG) upon request.
 136  *
 137  * To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
 138  * of the print buffer used by each link.  If LINK_LOG_BUF_SIZE is set to 0,
 139  * the dbg_link_XXX() routines simply send their output to the standard
 140  * debug print buffer (DBG_OUTPUT), if it has been defined; this can be useful
 141  * when there is only a single link in the system being debugged.
 142  *
 143  * Notes:
 144  * - When enabled, LINK_LOG_BUF_SIZE should be set to at least 1000 (bytes)
 145  * - "l_ptr" must be valid when using dbg_link_XXX() macros
 146  */
 147
 148 #define LINK_LOG_BUF_SIZE 0
 149
 150 #define dbg_link(fmt, arg...)  do {if (LINK_LOG_BUF_SIZE) tipc_printf(&l_ptr->print_buf, fmt, ## arg); } while(0)
 151 #define dbg_link_msg(msg, txt) do {if (LINK_LOG_BUF_SIZE) tipc_msg_print(&l_ptr->print_buf, msg, txt); } while(0)
 152 #define dbg_link_state(txt) do {if (LINK_LOG_BUF_SIZE) link_print(l_ptr, &l_ptr->print_buf, txt); } while(0)
 153 #define dbg_link_dump() do { \
 154         if (LINK_LOG_BUF_SIZE) { \
 155                 tipc_printf(LOG, "\n\nDumping link <%s>:\n", l_ptr->name); \
 156                 tipc_printbuf_move(LOG, &l_ptr->print_buf); \
 157         } \
 158 } while (0)
 159
 160 static void dbg_print_link(struct link *l_ptr, const char *str)
 161 {
 162         if (DBG_OUTPUT)
 163                 link_print(l_ptr, DBG_OUTPUT, str);
 164 }
 165
 166 static void dbg_print_buf_chain(struct sk_buff *root_buf)
 167 {
 168         if (DBG_OUTPUT) {
 169                 struct sk_buff *buf = root_buf;
 170
 171                 while (buf) {
 172                         msg_dbg(buf_msg(buf), "In chain: ");
 173                         buf = buf->next;
 174                 }
 175         }
 176 }
 177
 178 /*
 179  *  Simple link routines
 180  */
 181
 182 static unsigned int align(unsigned int i)
 183 {
 184         return (i + 3) & ~3u;
 185 }
 186
 187 static int link_working_working(struct link *l_ptr)
 188 {
 189         return (l_ptr->state == WORKING_WORKING);
 190 }
 191
 192 static int link_working_unknown(struct link *l_ptr)
 193 {
 194         return (l_ptr->state == WORKING_UNKNOWN);
 195 }
 196
 197 static int link_reset_unknown(struct link *l_ptr)
 198 {
 199         return (l_ptr->state == RESET_UNKNOWN);
 200 }
 201
 202 static int link_reset_reset(struct link *l_ptr)
 203 {
 204         return (l_ptr->state == RESET_RESET);
 205 }
 206
 207 static int link_blocked(struct link *l_ptr)
 208 {
 209         return (l_ptr->exp_msg_count || l_ptr->blocked);
 210 }
 211
 212 static int link_congested(struct link *l_ptr)
 213 {
 214         return (l_ptr->out_queue_size >= l_ptr->queue_limit[0]);
 215 }
 216
 217 static u32 link_max_pkt(struct link *l_ptr)
 218 {
 219         return l_ptr->max_pkt;
 220 }
 221
 222 static void link_init_max_pkt(struct link *l_ptr)
 223 {
 224         u32 max_pkt;
 225
 226         max_pkt = (l_ptr->b_ptr->publ.mtu & ~3);
 227         if (max_pkt > MAX_MSG_SIZE)
 228                 max_pkt = MAX_MSG_SIZE;
 229
 230         l_ptr->max_pkt_target = max_pkt;
 231         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 232                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 233         else
 234                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 235
 236         l_ptr->max_pkt_probes = 0;
 237 }
 238
 239 static u32 link_next_sent(struct link *l_ptr)
 240 {
 241         if (l_ptr->next_out)
 242                 return msg_seqno(buf_msg(l_ptr->next_out));
 243         return mod(l_ptr->next_out_no);
 244 }
 245
 246 static u32 link_last_sent(struct link *l_ptr)
 247 {
 248         return mod(link_next_sent(l_ptr) - 1);
 249 }
 250
 251 /*
 252  *  Simple non-static link routines (i.e. referenced outside this file)
 253  */
 254
 255 int tipc_link_is_up(struct link *l_ptr)
 256 {
 257         if (!l_ptr)
 258                 return 0;
 259         return (link_working_working(l_ptr) || link_working_unknown(l_ptr));
 260 }
 261
 262 int tipc_link_is_active(struct link *l_ptr)
 263 {
 264         return ((l_ptr->owner->active_links[0] == l_ptr) ||
 265                 (l_ptr->owner->active_links[1] == l_ptr));
 266 }
 267
 268 /**
 269  * link_name_validate - validate & (optionally) deconstruct link name
 270  * @name - ptr to link name string
 271  * @name_parts - ptr to area for link name components (or NULL if not needed)
 272  *
 273  * Returns 1 if link name is valid, otherwise 0.
 274  */
 275
 276 static int link_name_validate(const char *name, struct link_name *name_parts)
 277 {
 278         char name_copy[TIPC_MAX_LINK_NAME];
 279         char *addr_local;
 280         char *if_local;
 281         char *addr_peer;
 282         char *if_peer;
 283         char dummy;
 284         u32 z_local, c_local, n_local;
 285         u32 z_peer, c_peer, n_peer;
 286         u32 if_local_len;
 287         u32 if_peer_len;
 288
 289         /* copy link name & ensure length is OK */
 290
 291         name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
 292         /* need above in case non-Posix strncpy() doesn't pad with nulls */
 293         strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
 294         if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
 295                 return 0;
 296
 297         /* ensure all component parts of link name are present */
 298
 299         addr_local = name_copy;
 300         if ((if_local = strchr(addr_local, ':')) == NULL)
 301                 return 0;
 302         *(if_local++) = 0;
 303         if ((addr_peer = strchr(if_local, '-')) == NULL)
 304                 return 0;
 305         *(addr_peer++) = 0;
 306         if_local_len = addr_peer - if_local;
 307         if ((if_peer = strchr(addr_peer, ':')) == NULL)
 308                 return 0;
 309         *(if_peer++) = 0;
 310         if_peer_len = strlen(if_peer) + 1;
 311
 312         /* validate component parts of link name */
 313
 314         if ((sscanf(addr_local, "%u.%u.%u%c",
 315                     &z_local, &c_local, &n_local, &dummy) != 3) ||
 316             (sscanf(addr_peer, "%u.%u.%u%c",
 317                     &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
 318             (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
 319             (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
 320             (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
 321             (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) ||
 322             (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
 323             (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
 324                 return 0;
 325
 326         /* return link name components, if necessary */
 327
 328         if (name_parts) {
 329                 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
 330                 strcpy(name_parts->if_local, if_local);
 331                 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
 332                 strcpy(name_parts->if_peer, if_peer);
 333         }
 334         return 1;
 335 }
 336
 337 /**
 338  * link_timeout - handle expiration of link timer
 339  * @l_ptr: pointer to link
 340  *
 341  * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
 342  * with tipc_link_delete().  (There is no risk that the node will be deleted by
 343  * another thread because tipc_link_delete() always cancels the link timer before
 344  * tipc_node_delete() is called.)
 345  */
 346
 347 static void link_timeout(struct link *l_ptr)
 348 {
 349         tipc_node_lock(l_ptr->owner);
 350
 351         /* update counters used in statistical profiling of send traffic */
 352
 353         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 354         l_ptr->stats.queue_sz_counts++;
 355
 356         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 357                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 358
 359         if (l_ptr->first_out) {
 360                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 361                 u32 length = msg_size(msg);
 362
 363                 if ((msg_user(msg) == MSG_FRAGMENTER)
 364                     && (msg_type(msg) == FIRST_FRAGMENT)) {
 365                         length = msg_size(msg_get_wrapped(msg));
 366                 }
 367                 if (length) {
 368                         l_ptr->stats.msg_lengths_total += length;
 369                         l_ptr->stats.msg_length_counts++;
 370                         if (length <= 64)
 371                                 l_ptr->stats.msg_length_profile[0]++;
 372                         else if (length <= 256)
 373                                 l_ptr->stats.msg_length_profile[1]++;
 374                         else if (length <= 1024)
 375                                 l_ptr->stats.msg_length_profile[2]++;
 376                         else if (length <= 4096)
 377                                 l_ptr->stats.msg_length_profile[3]++;
 378                         else if (length <= 16384)
 379                                 l_ptr->stats.msg_length_profile[4]++;
 380                         else if (length <= 32768)
 381                                 l_ptr->stats.msg_length_profile[5]++;
 382                         else
 383                                 l_ptr->stats.msg_length_profile[6]++;
 384                 }
 385         }
 386
 387         /* do all other link processing performed on a periodic basis */
 388
 389         link_check_defragm_bufs(l_ptr);
 390
 391         link_state_event(l_ptr, TIMEOUT_EVT);
 392
 393         if (l_ptr->next_out)
 394                 tipc_link_push_queue(l_ptr);
 395
 396         tipc_node_unlock(l_ptr->owner);
 397 }
 398
 399 static void link_set_timer(struct link *l_ptr, u32 time)
 400 {
 401         k_start_timer(&l_ptr->timer, time);
 402 }
 403
 404 /**
 405  * tipc_link_create - create a new link
 406  * @b_ptr: pointer to associated bearer
 407  * @peer: network address of node at other end of link
 408  * @media_addr: media address to use when sending messages over link
 409  *
 410  * Returns pointer to link.
 411  */
 412
 413 struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
 414                               const struct tipc_media_addr *media_addr)
 415 {
 416         struct link *l_ptr;
 417         struct tipc_msg *msg;
 418         char *if_name;
 419
 420         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 421         if (!l_ptr) {
 422                 warn("Link creation failed, no memory\n");
 423                 return NULL;
 424         }
 425
 426         l_ptr->addr = peer;
 427         if_name = strchr(b_ptr->publ.name, ':') + 1;
 428         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
 429                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 430                 tipc_node(tipc_own_addr),
 431                 if_name,
 432                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 433                 /* note: peer i/f is appended to link name by reset/activate */
 434         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 435         k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
 436         list_add_tail(&l_ptr->link_list, &b_ptr->links);
 437         l_ptr->checkpoint = 1;
 438         l_ptr->b_ptr = b_ptr;
 439         link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
 440         l_ptr->state = RESET_UNKNOWN;
 441
 442         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 443         msg = l_ptr->pmsg;
 444         msg_init(msg, LINK_PROTOCOL, RESET_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
 445         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 446         msg_set_session(msg, tipc_random);
 447         msg_set_bearer_id(msg, b_ptr->identity);
 448         strcpy((char *)msg_data(msg), if_name);
 449
 450         l_ptr->priority = b_ptr->priority;
 451         tipc_link_set_queue_limits(l_ptr, b_ptr->media->window);
 452
 453         link_init_max_pkt(l_ptr);
 454
 455         l_ptr->next_out_no = 1;
 456         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 457
 458         link_reset_statistics(l_ptr);
 459
 460         l_ptr->owner = tipc_node_attach_link(l_ptr);
 461         if (!l_ptr->owner) {
 462                 kfree(l_ptr);
 463                 return NULL;
 464         }
 465
 466         if (LINK_LOG_BUF_SIZE) {
 467                 char *pb = kmalloc(LINK_LOG_BUF_SIZE, GFP_ATOMIC);
 468
 469                 if (!pb) {
 470                         kfree(l_ptr);
 471                         warn("Link creation failed, no memory for print buffer\n");
 472                         return NULL;
 473                 }
 474                 tipc_printbuf_init(&l_ptr->print_buf, pb, LINK_LOG_BUF_SIZE);
 475         }
 476
 477         tipc_k_signal((Handler)tipc_link_start, (unsigned long)l_ptr);
 478
 479         dbg("tipc_link_create(): tolerance = %u,cont intv = %u, abort_limit = %u\n",
 480             l_ptr->tolerance, l_ptr->continuity_interval, l_ptr->abort_limit);
 481
 482         return l_ptr;
 483 }
 484
 485 /**
 486  * tipc_link_delete - delete a link
 487  * @l_ptr: pointer to link
 488  *
 489  * Note: 'tipc_net_lock' is write_locked, bearer is locked.
 490  * This routine must not grab the node lock until after link timer cancellation
 491  * to avoid a potential deadlock situation.
 492  */
 493
 494 void tipc_link_delete(struct link *l_ptr)
 495 {
 496         if (!l_ptr) {
 497                 err("Attempt to delete non-existent link\n");
 498                 return;
 499         }
 500
 501         dbg("tipc_link_delete()\n");
 502
 503         k_cancel_timer(&l_ptr->timer);
 504
 505         tipc_node_lock(l_ptr->owner);
 506         tipc_link_reset(l_ptr);
 507         tipc_node_detach_link(l_ptr->owner, l_ptr);
 508         tipc_link_stop(l_ptr);
 509         list_del_init(&l_ptr->link_list);
 510         if (LINK_LOG_BUF_SIZE)
 511                 kfree(l_ptr->print_buf.buf);
 512         tipc_node_unlock(l_ptr->owner);
 513         k_term_timer(&l_ptr->timer);
 514         kfree(l_ptr);
 515 }
 516
 517 void tipc_link_start(struct link *l_ptr)
 518 {
 519         dbg("tipc_link_start %x\n", l_ptr);
 520         link_state_event(l_ptr, STARTING_EVT);
 521 }
 522
 523 /**
 524  * link_schedule_port - schedule port for deferred sending
 525  * @l_ptr: pointer to link
 526  * @origport: reference to sending port
 527  * @sz: amount of data to be sent
 528  *
 529  * Schedules port for renewed sending of messages after link congestion
 530  * has abated.
 531  */
 532
 533 static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
 534 {
 535         struct port *p_ptr;
 536
 537         spin_lock_bh(&tipc_port_list_lock);
 538         p_ptr = tipc_port_lock(origport);
 539         if (p_ptr) {
 540                 if (!p_ptr->wakeup)
 541                         goto exit;
 542                 if (!list_empty(&p_ptr->wait_list))
 543                         goto exit;
 544                 p_ptr->congested_link = l_ptr;
 545                 p_ptr->publ.congested = 1;
 546                 p_ptr->waiting_pkts = 1 + ((sz - 1) / link_max_pkt(l_ptr));
 547                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 548                 l_ptr->stats.link_congs++;
 549 exit:
 550                 tipc_port_unlock(p_ptr);
 551         }
 552         spin_unlock_bh(&tipc_port_list_lock);
 553         return -ELINKCONG;
 554 }
 555
 556 void tipc_link_wakeup_ports(struct link *l_ptr, int all)
 557 {
 558         struct port *p_ptr;
 559         struct port *temp_p_ptr;
 560         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 561
 562         if (all)
 563                 win = 100000;
 564         if (win <= 0)
 565                 return;
 566         if (!spin_trylock_bh(&tipc_port_list_lock))
 567                 return;
 568         if (link_congested(l_ptr))
 569                 goto exit;
 570         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 571                                  wait_list) {
 572                 if (win <= 0)
 573                         break;
 574                 list_del_init(&p_ptr->wait_list);
 575                 p_ptr->congested_link = NULL;
 576                 spin_lock_bh(p_ptr->publ.lock);
 577                 p_ptr->publ.congested = 0;
 578                 p_ptr->wakeup(&p_ptr->publ);
 579                 win -= p_ptr->waiting_pkts;
 580                 spin_unlock_bh(p_ptr->publ.lock);
 581         }
 582
 583 exit:
 584         spin_unlock_bh(&tipc_port_list_lock);
 585 }
 586
 587 /**
 588  * link_release_outqueue - purge link's outbound message queue
 589  * @l_ptr: pointer to link
 590  */
 591
 592 static void link_release_outqueue(struct link *l_ptr)
 593 {
 594         struct sk_buff *buf = l_ptr->first_out;
 595         struct sk_buff *next;
 596
 597         while (buf) {
 598                 next = buf->next;
 599                 buf_discard(buf);
 600                 buf = next;
 601         }
 602         l_ptr->first_out = NULL;
 603         l_ptr->out_queue_size = 0;
 604 }
 605
 606 /**
 607  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 608  * @l_ptr: pointer to link
 609  */
 610
 611 void tipc_link_reset_fragments(struct link *l_ptr)
 612 {
 613         struct sk_buff *buf = l_ptr->defragm_buf;
 614         struct sk_buff *next;
 615
 616         while (buf) {
 617                 next = buf->next;
 618                 buf_discard(buf);
 619                 buf = next;
 620         }
 621         l_ptr->defragm_buf = NULL;
 622 }
 623
 624 /**
 625  * tipc_link_stop - purge all inbound and outbound messages associated with link
 626  * @l_ptr: pointer to link
 627  */
 628
 629 void tipc_link_stop(struct link *l_ptr)
 630 {
 631         struct sk_buff *buf;
 632         struct sk_buff *next;
 633
 634         buf = l_ptr->oldest_deferred_in;
 635         while (buf) {
 636                 next = buf->next;
 637                 buf_discard(buf);
 638                 buf = next;
 639         }
 640
 641         buf = l_ptr->first_out;
 642         while (buf) {
 643                 next = buf->next;
 644                 buf_discard(buf);
 645                 buf = next;
 646         }
 647
 648         tipc_link_reset_fragments(l_ptr);
 649
 650         buf_discard(l_ptr->proto_msg_queue);
 651         l_ptr->proto_msg_queue = NULL;
 652 }
 653
 654 #if 0
 655
 656 /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
 657
 658 static void link_recv_event(struct link_event *ev)
 659 {
 660         ev->fcn(ev->addr, ev->name, ev->up);
 661         kfree(ev);
 662 }
 663
 664 static void link_send_event(void (*fcn)(u32 a, char *n, int up),
 665                             struct link *l_ptr, int up)
 666 {
 667         struct link_event *ev;
 668
 669         ev = kmalloc(sizeof(*ev), GFP_ATOMIC);
 670         if (!ev) {
 671                 warn("Link event allocation failure\n");
 672                 return;
 673         }
 674         ev->addr = l_ptr->addr;
 675         ev->up = up;
 676         ev->fcn = fcn;
 677         memcpy(ev->name, l_ptr->name, TIPC_MAX_LINK_NAME);
 678         tipc_k_signal((Handler)link_recv_event, (unsigned long)ev);
 679 }
 680
 681 #else
 682
 683 #define link_send_event(fcn, l_ptr, up) do { } while (0)
 684
 685 #endif
 686
 687 void tipc_link_reset(struct link *l_ptr)
 688 {
 689         struct sk_buff *buf;
 690         u32 prev_state = l_ptr->state;
 691         u32 checkpoint = l_ptr->next_in_no;
 692         int was_active_link = tipc_link_is_active(l_ptr);
 693
 694         msg_set_session(l_ptr->pmsg, msg_session(l_ptr->pmsg) + 1);
 695
 696         /* Link is down, accept any session: */
 697         l_ptr->peer_session = 0;
 698
 699         /* Prepare for max packet size negotiation */
 700         link_init_max_pkt(l_ptr);
 701
 702         l_ptr->state = RESET_UNKNOWN;
 703         dbg_link_state("Resetting Link\n");
 704
 705         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 706                 return;
 707
 708         tipc_node_link_down(l_ptr->owner, l_ptr);
 709         tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
 710 #if 0
 711         tipc_printf(TIPC_CONS, "\nReset link <%s>\n", l_ptr->name);
 712         dbg_link_dump();
 713 #endif
 714         if (was_active_link && tipc_node_has_active_links(l_ptr->owner) &&
 715             l_ptr->owner->permit_changeover) {
 716                 l_ptr->reset_checkpoint = checkpoint;
 717                 l_ptr->exp_msg_count = START_CHANGEOVER;
 718         }
 719
 720         /* Clean up all queues: */
 721
 722         link_release_outqueue(l_ptr);
 723         buf_discard(l_ptr->proto_msg_queue);
 724         l_ptr->proto_msg_queue = NULL;
 725         buf = l_ptr->oldest_deferred_in;
 726         while (buf) {
 727                 struct sk_buff *next = buf->next;
 728                 buf_discard(buf);
 729                 buf = next;
 730         }
 731         if (!list_empty(&l_ptr->waiting_ports))
 732                 tipc_link_wakeup_ports(l_ptr, 1);
 733
 734         l_ptr->retransm_queue_head = 0;
 735         l_ptr->retransm_queue_size = 0;
 736         l_ptr->last_out = NULL;
 737         l_ptr->first_out = NULL;
 738         l_ptr->next_out = NULL;
 739         l_ptr->unacked_window = 0;
 740         l_ptr->checkpoint = 1;
 741         l_ptr->next_out_no = 1;
 742         l_ptr->deferred_inqueue_sz = 0;
 743         l_ptr->oldest_deferred_in = NULL;
 744         l_ptr->newest_deferred_in = NULL;
 745         l_ptr->fsm_msg_cnt = 0;
 746         l_ptr->stale_count = 0;
 747         link_reset_statistics(l_ptr);
 748
 749         link_send_event(tipc_cfg_link_event, l_ptr, 0);
 750         if (!in_own_cluster(l_ptr->addr))
 751                 link_send_event(tipc_disc_link_event, l_ptr, 0);
 752 }
 753
 754
 755 static void link_activate(struct link *l_ptr)
 756 {
 757         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 758         tipc_node_link_up(l_ptr->owner, l_ptr);
 759         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 760         link_send_event(tipc_cfg_link_event, l_ptr, 1);
 761         if (!in_own_cluster(l_ptr->addr))
 762                 link_send_event(tipc_disc_link_event, l_ptr, 1);
 763 }
 764
 765 /**
 766  * link_state_event - link finite state machine
 767  * @l_ptr: pointer to link
 768  * @event: state machine event to process
 769  */
 770
 771 static void link_state_event(struct link *l_ptr, unsigned event)
 772 {
 773         struct link *other;
 774         u32 cont_intv = l_ptr->continuity_interval;
 775
 776         if (!l_ptr->started && (event != STARTING_EVT))
 777                 return;         /* Not yet. */
 778
 779         if (link_blocked(l_ptr)) {
 780                 if (event == TIMEOUT_EVT) {
 781                         link_set_timer(l_ptr, cont_intv);
 782                 }
 783                 return;   /* Changeover going on */
 784         }
 785         dbg_link("STATE_EV: <%s> ", l_ptr->name);
 786
 787         switch (l_ptr->state) {
 788         case WORKING_WORKING:
 789                 dbg_link("WW/");
 790                 switch (event) {
 791                 case TRAFFIC_MSG_EVT:
 792                         dbg_link("TRF-");
 793                         /* fall through */
 794                 case ACTIVATE_MSG:
 795                         dbg_link("ACT\n");
 796                         break;
 797                 case TIMEOUT_EVT:
 798                         dbg_link("TIM ");
 799                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 800                                 l_ptr->checkpoint = l_ptr->next_in_no;
 801                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 802                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 803                                                                  0, 0, 0, 0, 0);
 804                                         l_ptr->fsm_msg_cnt++;
 805                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 806                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 807                                                                  1, 0, 0, 0, 0);
 808                                         l_ptr->fsm_msg_cnt++;
 809                                 }
 810                                 link_set_timer(l_ptr, cont_intv);
 811                                 break;
 812                         }
 813                         dbg_link(" -> WU\n");
 814                         l_ptr->state = WORKING_UNKNOWN;
 815                         l_ptr->fsm_msg_cnt = 0;
 816                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 817                         l_ptr->fsm_msg_cnt++;
 818                         link_set_timer(l_ptr, cont_intv / 4);
 819                         break;
 820                 case RESET_MSG:
 821                         dbg_link("RES -> RR\n");
 822                         info("Resetting link <%s>, requested by peer\n",
 823                              l_ptr->name);
 824                         tipc_link_reset(l_ptr);
 825                         l_ptr->state = RESET_RESET;
 826                         l_ptr->fsm_msg_cnt = 0;
 827                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 828                         l_ptr->fsm_msg_cnt++;
 829                         link_set_timer(l_ptr, cont_intv);
 830                         break;
 831                 default:
 832                         err("Unknown link event %u in WW state\n", event);
 833                 }
 834                 break;
 835         case WORKING_UNKNOWN:
 836                 dbg_link("WU/");
 837                 switch (event) {
 838                 case TRAFFIC_MSG_EVT:
 839                         dbg_link("TRF-");
 840                 case ACTIVATE_MSG:
 841                         dbg_link("ACT -> WW\n");
 842                         l_ptr->state = WORKING_WORKING;
 843                         l_ptr->fsm_msg_cnt = 0;
 844                         link_set_timer(l_ptr, cont_intv);
 845                         break;
 846                 case RESET_MSG:
 847                         dbg_link("RES -> RR\n");
 848                         info("Resetting link <%s>, requested by peer "
 849                              "while probing\n", l_ptr->name);
 850                         tipc_link_reset(l_ptr);
 851                         l_ptr->state = RESET_RESET;
 852                         l_ptr->fsm_msg_cnt = 0;
 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                         break;
 857                 case TIMEOUT_EVT:
 858                         dbg_link("TIM ");
 859                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 860                                 dbg_link("-> WW \n");
 861                                 l_ptr->state = WORKING_WORKING;
 862                                 l_ptr->fsm_msg_cnt = 0;
 863                                 l_ptr->checkpoint = l_ptr->next_in_no;
 864                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 865                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 866                                                                  0, 0, 0, 0, 0);
 867                                         l_ptr->fsm_msg_cnt++;
 868                                 }
 869                                 link_set_timer(l_ptr, cont_intv);
 870                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 871                                 dbg_link("Probing %u/%u,timer = %u ms)\n",
 872                                          l_ptr->fsm_msg_cnt, l_ptr->abort_limit,
 873                                          cont_intv / 4);
 874                                 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 875                                                          1, 0, 0, 0, 0);
 876                                 l_ptr->fsm_msg_cnt++;
 877                                 link_set_timer(l_ptr, cont_intv / 4);
 878                         } else {        /* Link has failed */
 879                                 dbg_link("-> RU (%u probes unanswered)\n",
 880                                          l_ptr->fsm_msg_cnt);
 881                                 warn("Resetting link <%s>, peer not responding\n",
 882                                      l_ptr->name);
 883                                 tipc_link_reset(l_ptr);
 884                                 l_ptr->state = RESET_UNKNOWN;
 885                                 l_ptr->fsm_msg_cnt = 0;
 886                                 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
 887                                                          0, 0, 0, 0, 0);
 888                                 l_ptr->fsm_msg_cnt++;
 889                                 link_set_timer(l_ptr, cont_intv);
 890                         }
 891                         break;
 892                 default:
 893                         err("Unknown link event %u in WU state\n", event);
 894                 }
 895                 break;
 896         case RESET_UNKNOWN:
 897                 dbg_link("RU/");
 898                 switch (event) {
 899                 case TRAFFIC_MSG_EVT:
 900                         dbg_link("TRF-\n");
 901                         break;
 902                 case ACTIVATE_MSG:
 903                         other = l_ptr->owner->active_links[0];
 904                         if (other && link_working_unknown(other)) {
 905                                 dbg_link("ACT\n");
 906                                 break;
 907                         }
 908                         dbg_link("ACT -> WW\n");
 909                         l_ptr->state = WORKING_WORKING;
 910                         l_ptr->fsm_msg_cnt = 0;
 911                         link_activate(l_ptr);
 912                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 913                         l_ptr->fsm_msg_cnt++;
 914                         link_set_timer(l_ptr, cont_intv);
 915                         break;
 916                 case RESET_MSG:
 917                         dbg_link("RES \n");
 918                         dbg_link(" -> RR\n");
 919                         l_ptr->state = RESET_RESET;
 920                         l_ptr->fsm_msg_cnt = 0;
 921                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
 922                         l_ptr->fsm_msg_cnt++;
 923                         link_set_timer(l_ptr, cont_intv);
 924                         break;
 925                 case STARTING_EVT:
 926                         dbg_link("START-");
 927                         l_ptr->started = 1;
 928                         /* fall through */
 929                 case TIMEOUT_EVT:
 930                         dbg_link("TIM \n");
 931                         tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 932                         l_ptr->fsm_msg_cnt++;
 933                         link_set_timer(l_ptr, cont_intv);
 934                         break;
 935                 default:
 936                         err("Unknown link event %u in RU state\n", event);
 937                 }
 938                 break;
 939         case RESET_RESET:
 940                 dbg_link("RR/ ");
 941                 switch (event) {
 942                 case TRAFFIC_MSG_EVT:
 943                         dbg_link("TRF-");
 944                         /* fall through */
 945                 case ACTIVATE_MSG:
 946                         other = l_ptr->owner->active_links[0];
 947                         if (other && link_working_unknown(other)) {
 948                                 dbg_link("ACT\n");
 949                                 break;
 950                         }
 951                         dbg_link("ACT -> WW\n");
 952                         l_ptr->state = WORKING_WORKING;
 953                         l_ptr->fsm_msg_cnt = 0;
 954                         link_activate(l_ptr);
 955                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 956                         l_ptr->fsm_msg_cnt++;
 957                         link_set_timer(l_ptr, cont_intv);
 958                         break;
 959                 case RESET_MSG:
 960                         dbg_link("RES\n");
 961                         break;
 962                 case TIMEOUT_EVT:
 963                         dbg_link("TIM\n");
 964                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 965                         l_ptr->fsm_msg_cnt++;
 966                         link_set_timer(l_ptr, cont_intv);
 967                         dbg_link("fsm_msg_cnt %u\n", l_ptr->fsm_msg_cnt);
 968                         break;
 969                 default:
 970                         err("Unknown link event %u in RR state\n", event);
 971                 }
 972                 break;
 973         default:
 974                 err("Unknown link state %u/%u\n", l_ptr->state, event);
 975         }
 976 }
 977
 978 /*
 979  * link_bundle_buf(): Append contents of a buffer to
 980  * the tail of an existing one.
 981  */
 982
 983 static int link_bundle_buf(struct link *l_ptr,
 984                            struct sk_buff *bundler,
 985                            struct sk_buff *buf)
 986 {
 987         struct tipc_msg *bundler_msg = buf_msg(bundler);
 988         struct tipc_msg *msg = buf_msg(buf);
 989         u32 size = msg_size(msg);
 990         u32 bundle_size = msg_size(bundler_msg);
 991         u32 to_pos = align(bundle_size);
 992         u32 pad = to_pos - bundle_size;
 993
 994         if (msg_user(bundler_msg) != MSG_BUNDLER)
 995                 return 0;
 996         if (msg_type(bundler_msg) != OPEN_MSG)
 997                 return 0;
 998         if (skb_tailroom(bundler) < (pad + size))
 999                 return 0;
1000         if (link_max_pkt(l_ptr) < (to_pos + size))
1001                 return 0;
1002
1003         skb_put(bundler, pad + size);
1004         memcpy(bundler->data + to_pos, buf->data, size);
1005         msg_set_size(bundler_msg, to_pos + size);
1006         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
1007         dbg("Packed msg # %u(%u octets) into pos %u in buf(#%u)\n",
1008             msg_msgcnt(bundler_msg), size, to_pos, msg_seqno(bundler_msg));
1009         msg_dbg(msg, "PACKD:");
1010         buf_discard(buf);
1011         l_ptr->stats.sent_bundled++;
1012         return 1;
1013 }
1014
1015 static void link_add_to_outqueue(struct link *l_ptr,
1016                                  struct sk_buff *buf,
1017                                  struct tipc_msg *msg)
1018 {
1019         u32 ack = mod(l_ptr->next_in_no - 1);
1020         u32 seqno = mod(l_ptr->next_out_no++);
1021
1022         msg_set_word(msg, 2, ((ack << 16) | seqno));
1023         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1024         buf->next = NULL;
1025         if (l_ptr->first_out) {
1026                 l_ptr->last_out->next = buf;
1027                 l_ptr->last_out = buf;
1028         } else
1029                 l_ptr->first_out = l_ptr->last_out = buf;
1030         l_ptr->out_queue_size++;
1031 }
1032
1033 /*
1034  * tipc_link_send_buf() is the 'full path' for messages, called from
1035  * inside TIPC when the 'fast path' in tipc_send_buf
1036  * has failed, and from link_send()
1037  */
1038
1039 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
1040 {
1041         struct tipc_msg *msg = buf_msg(buf);
1042         u32 size = msg_size(msg);
1043         u32 dsz = msg_data_sz(msg);
1044         u32 queue_size = l_ptr->out_queue_size;
1045         u32 imp = msg_tot_importance(msg);
1046         u32 queue_limit = l_ptr->queue_limit[imp];
1047         u32 max_packet = link_max_pkt(l_ptr);
1048
1049         msg_set_prevnode(msg, tipc_own_addr);   /* If routed message */
1050
1051         /* Match msg importance against queue limits: */
1052
1053         if (unlikely(queue_size >= queue_limit)) {
1054                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
1055                         return link_schedule_port(l_ptr, msg_origport(msg),
1056                                                   size);
1057                 }
1058                 msg_dbg(msg, "TIPC: Congestion, throwing away\n");
1059                 buf_discard(buf);
1060                 if (imp > CONN_MANAGER) {
1061                         warn("Resetting link <%s>, send queue full", l_ptr->name);
1062                         tipc_link_reset(l_ptr);
1063                 }
1064                 return dsz;
1065         }
1066
1067         /* Fragmentation needed ? */
1068
1069         if (size > max_packet)
1070                 return tipc_link_send_long_buf(l_ptr, buf);
1071
1072         /* Packet can be queued or sent: */
1073
1074         if (queue_size > l_ptr->stats.max_queue_sz)
1075                 l_ptr->stats.max_queue_sz = queue_size;
1076
1077         if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
1078                    !link_congested(l_ptr))) {
1079                 link_add_to_outqueue(l_ptr, buf, msg);
1080
1081                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
1082                         l_ptr->unacked_window = 0;
1083                 } else {
1084                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1085                         l_ptr->stats.bearer_congs++;
1086                         l_ptr->next_out = buf;
1087                 }
1088                 return dsz;
1089         }
1090         /* Congestion: can message be bundled ?: */
1091
1092         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
1093             (msg_user(msg) != MSG_FRAGMENTER)) {
1094
1095                 /* Try adding message to an existing bundle */
1096
1097                 if (l_ptr->next_out &&
1098                     link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
1099                         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
1100                         return dsz;
1101                 }
1102
1103                 /* Try creating a new bundle */
1104
1105                 if (size <= max_packet * 2 / 3) {
1106                         struct sk_buff *bundler = buf_acquire(max_packet);
1107                         struct tipc_msg bundler_hdr;
1108
1109                         if (bundler) {
1110                                 msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
1111                                          TIPC_OK, INT_H_SIZE, l_ptr->addr);
1112                                 memcpy(bundler->data, (unchar *)&bundler_hdr,
1113                                        INT_H_SIZE);
1114                                 skb_trim(bundler, INT_H_SIZE);
1115                                 link_bundle_buf(l_ptr, bundler, buf);
1116                                 buf = bundler;
1117                                 msg = buf_msg(buf);
1118                                 l_ptr->stats.sent_bundles++;
1119                         }
1120                 }
1121         }
1122         if (!l_ptr->next_out)
1123                 l_ptr->next_out = buf;
1124         link_add_to_outqueue(l_ptr, buf, msg);
1125         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
1126         return dsz;
1127 }
1128
1129 /*
1130  * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
1131  * not been selected yet, and the the owner node is not locked
1132  * Called by TIPC internal users, e.g. the name distributor
1133  */
1134
1135 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
1136 {
1137         struct link *l_ptr;
1138         struct node *n_ptr;
1139         int res = -ELINKCONG;
1140
1141         read_lock_bh(&tipc_net_lock);
1142         n_ptr = tipc_node_select(dest, selector);
1143         if (n_ptr) {
1144                 tipc_node_lock(n_ptr);
1145                 l_ptr = n_ptr->active_links[selector & 1];
1146                 if (l_ptr) {
1147                         dbg("tipc_link_send: found link %x for dest %x\n", l_ptr, dest);
1148                         res = tipc_link_send_buf(l_ptr, buf);
1149                 } else {
1150                         dbg("Attempt to send msg to unreachable node:\n");
1151                         msg_dbg(buf_msg(buf),">>>");
1152                         buf_discard(buf);
1153                 }
1154                 tipc_node_unlock(n_ptr);
1155         } else {
1156                 dbg("Attempt to send msg to unknown node:\n");
1157                 msg_dbg(buf_msg(buf),">>>");
1158                 buf_discard(buf);
1159         }
1160         read_unlock_bh(&tipc_net_lock);
1161         return res;
1162 }
1163
1164 /*
1165  * link_send_buf_fast: Entry for data messages where the
1166  * destination link is known and the header is complete,
1167  * inclusive total message length. Very time critical.
1168  * Link is locked. Returns user data length.
1169  */
1170
1171 static int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
1172                               u32 *used_max_pkt)
1173 {
1174         struct tipc_msg *msg = buf_msg(buf);
1175         int res = msg_data_sz(msg);
1176
1177         if (likely(!link_congested(l_ptr))) {
1178                 if (likely(msg_size(msg) <= link_max_pkt(l_ptr))) {
1179                         if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
1180                                 link_add_to_outqueue(l_ptr, buf, msg);
1181                                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
1182                                                             &l_ptr->media_addr))) {
1183                                         l_ptr->unacked_window = 0;
1184                                         msg_dbg(msg,"SENT_FAST:");
1185                                         return res;
1186                                 }
1187                                 dbg("failed sent fast...\n");
1188                                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1189                                 l_ptr->stats.bearer_congs++;
1190                                 l_ptr->next_out = buf;
1191                                 return res;
1192                         }
1193                 }
1194                 else
1195                         *used_max_pkt = link_max_pkt(l_ptr);
1196         }
1197         return tipc_link_send_buf(l_ptr, buf);  /* All other cases */
1198 }
1199
1200 /*
1201  * tipc_send_buf_fast: Entry for data messages where the
1202  * destination node is known and the header is complete,
1203  * inclusive total message length.
1204  * Returns user data length.
1205  */
1206 int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
1207 {
1208         struct link *l_ptr;
1209         struct node *n_ptr;
1210         int res;
1211         u32 selector = msg_origport(buf_msg(buf)) & 1;
1212         u32 dummy;
1213
1214         if (destnode == tipc_own_addr)
1215                 return tipc_port_recv_msg(buf);
1216
1217         read_lock_bh(&tipc_net_lock);
1218         n_ptr = tipc_node_select(destnode, selector);
1219         if (likely(n_ptr)) {
1220                 tipc_node_lock(n_ptr);
1221                 l_ptr = n_ptr->active_links[selector];
1222                 dbg("send_fast: buf %x selected %x, destnode = %x\n",
1223                     buf, l_ptr, destnode);
1224                 if (likely(l_ptr)) {
1225                         res = link_send_buf_fast(l_ptr, buf, &dummy);
1226                         tipc_node_unlock(n_ptr);
1227                         read_unlock_bh(&tipc_net_lock);
1228                         return res;
1229                 }
1230                 tipc_node_unlock(n_ptr);
1231         }
1232         read_unlock_bh(&tipc_net_lock);
1233         res = msg_data_sz(buf_msg(buf));
1234         tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1235         return res;
1236 }
1237
1238
1239 /*
1240  * tipc_link_send_sections_fast: Entry for messages where the
1241  * destination processor is known and the header is complete,
1242  * except for total message length.
1243  * Returns user data length or errno.
1244  */
1245 int tipc_link_send_sections_fast(struct port *sender,
1246                                  struct iovec const *msg_sect,
1247                                  const u32 num_sect,
1248                                  u32 destaddr)
1249 {
1250         struct tipc_msg *hdr = &sender->publ.phdr;
1251         struct link *l_ptr;
1252         struct sk_buff *buf;
1253         struct node *node;
1254         int res;
1255         u32 selector = msg_origport(hdr) & 1;
1256
1257 again:
1258         /*
1259          * Try building message using port's max_pkt hint.
1260          * (Must not hold any locks while building message.)
1261          */
1262
1263         res = msg_build(hdr, msg_sect, num_sect, sender->max_pkt,
1264                         !sender->user_port, &buf);
1265
1266         read_lock_bh(&tipc_net_lock);
1267         node = tipc_node_select(destaddr, selector);
1268         if (likely(node)) {
1269                 tipc_node_lock(node);
1270                 l_ptr = node->active_links[selector];
1271                 if (likely(l_ptr)) {
1272                         if (likely(buf)) {
1273                                 res = link_send_buf_fast(l_ptr, buf,
1274                                                          &sender->max_pkt);
1275                                 if (unlikely(res < 0))
1276                                         buf_discard(buf);
1277 exit:
1278                                 tipc_node_unlock(node);
1279                                 read_unlock_bh(&tipc_net_lock);
1280                                 return res;
1281                         }
1282
1283                         /* Exit if build request was invalid */
1284
1285                         if (unlikely(res < 0))
1286                                 goto exit;
1287
1288                         /* Exit if link (or bearer) is congested */
1289
1290                         if (link_congested(l_ptr) ||
1291                             !list_empty(&l_ptr->b_ptr->cong_links)) {
1292                                 res = link_schedule_port(l_ptr,
1293                                                          sender->publ.ref, res);
1294                                 goto exit;
1295                         }
1296
1297                         /*
1298                          * Message size exceeds max_pkt hint; update hint,
1299                          * then re-try fast path or fragment the message
1300                          */
1301
1302                         sender->max_pkt = link_max_pkt(l_ptr);
1303                         tipc_node_unlock(node);
1304                         read_unlock_bh(&tipc_net_lock);
1305
1306
1307                         if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1308                                 goto again;
1309
1310                         return link_send_sections_long(sender, msg_sect,
1311                                                        num_sect, destaddr);
1312                 }
1313                 tipc_node_unlock(node);
1314         }
1315         read_unlock_bh(&tipc_net_lock);
1316
1317         /* Couldn't find a link to the destination node */
1318
1319         if (buf)
1320                 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1321         if (res >= 0)
1322                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1323                                                  TIPC_ERR_NO_NODE);
1324         return res;
1325 }
1326
1327 /*
1328  * link_send_sections_long(): Entry for long messages where the
1329  * destination node is known and the header is complete,
1330  * inclusive total message length.
1331  * Link and bearer congestion status have been checked to be ok,
1332  * and are ignored if they change.
1333  *
1334  * Note that fragments do not use the full link MTU so that they won't have
1335  * to undergo refragmentation if link changeover causes them to be sent
1336  * over another link with an additional tunnel header added as prefix.
1337  * (Refragmentation will still occur if the other link has a smaller MTU.)
1338  *
1339  * Returns user data length or errno.
1340  */
1341 static int link_send_sections_long(struct port *sender,
1342                                    struct iovec const *msg_sect,
1343                                    u32 num_sect,
1344                                    u32 destaddr)
1345 {
1346         struct link *l_ptr;
1347         struct node *node;
1348         struct tipc_msg *hdr = &sender->publ.phdr;
1349         u32 dsz = msg_data_sz(hdr);
1350         u32 max_pkt,fragm_sz,rest;
1351         struct tipc_msg fragm_hdr;
1352         struct sk_buff *buf,*buf_chain,*prev;
1353         u32 fragm_crs,fragm_rest,hsz,sect_rest;
1354         const unchar *sect_crs;
1355         int curr_sect;
1356         u32 fragm_no;
1357
1358 again:
1359         fragm_no = 1;
1360         max_pkt = sender->max_pkt - INT_H_SIZE;
1361                 /* leave room for tunnel header in case of link changeover */
1362         fragm_sz = max_pkt - INT_H_SIZE;
1363                 /* leave room for fragmentation header in each fragment */
1364         rest = dsz;
1365         fragm_crs = 0;
1366         fragm_rest = 0;
1367         sect_rest = 0;
1368         sect_crs = NULL;
1369         curr_sect = -1;
1370
1371         /* Prepare reusable fragment header: */
1372
1373         msg_dbg(hdr, ">FRAGMENTING>");
1374         msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1375                  TIPC_OK, INT_H_SIZE, msg_destnode(hdr));
1376         msg_set_link_selector(&fragm_hdr, sender->publ.ref);
1377         msg_set_size(&fragm_hdr, max_pkt);
1378         msg_set_fragm_no(&fragm_hdr, 1);
1379
1380         /* Prepare header of first fragment: */
1381
1382         buf_chain = buf = buf_acquire(max_pkt);
1383         if (!buf)
1384                 return -ENOMEM;
1385         buf->next = NULL;
1386         memcpy(buf->data, (unchar *)&fragm_hdr, INT_H_SIZE);
1387         hsz = msg_hdr_sz(hdr);
1388         memcpy(buf->data + INT_H_SIZE, (unchar *)hdr, hsz);
1389         msg_dbg(buf_msg(buf), ">BUILD>");
1390
1391         /* Chop up message: */
1392
1393         fragm_crs = INT_H_SIZE + hsz;
1394         fragm_rest = fragm_sz - hsz;
1395
1396         do {            /* For all sections */
1397                 u32 sz;
1398
1399                 if (!sect_rest) {
1400                         sect_rest = msg_sect[++curr_sect].iov_len;
1401                         sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1402                 }
1403
1404                 if (sect_rest < fragm_rest)
1405                         sz = sect_rest;
1406                 else
1407                         sz = fragm_rest;
1408
1409                 if (likely(!sender->user_port)) {
1410                         if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1411 error:
1412                                 for (; buf_chain; buf_chain = buf) {
1413                                         buf = buf_chain->next;
1414                                         buf_discard(buf_chain);
1415                                 }
1416                                 return -EFAULT;
1417                         }
1418                 } else
1419                         memcpy(buf->data + fragm_crs, sect_crs, sz);
1420
1421                 sect_crs += sz;
1422                 sect_rest -= sz;
1423                 fragm_crs += sz;
1424                 fragm_rest -= sz;
1425                 rest -= sz;
1426
1427                 if (!fragm_rest && rest) {
1428
1429                         /* Initiate new fragment: */
1430                         if (rest <= fragm_sz) {
1431                                 fragm_sz = rest;
1432                                 msg_set_type(&fragm_hdr,LAST_FRAGMENT);
1433                         } else {
1434                                 msg_set_type(&fragm_hdr, FRAGMENT);
1435                         }
1436                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1437                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1438                         prev = buf;
1439                         buf = buf_acquire(fragm_sz + INT_H_SIZE);
1440                         if (!buf)
1441                                 goto error;
1442
1443                         buf->next = NULL;
1444                         prev->next = buf;
1445                         memcpy(buf->data, (unchar *)&fragm_hdr, INT_H_SIZE);
1446                         fragm_crs = INT_H_SIZE;
1447                         fragm_rest = fragm_sz;
1448                         msg_dbg(buf_msg(buf),"  >BUILD>");
1449                 }
1450         }
1451         while (rest > 0);
1452
1453         /*
1454          * Now we have a buffer chain. Select a link and check
1455          * that packet size is still OK
1456          */
1457         node = tipc_node_select(destaddr, sender->publ.ref & 1);
1458         if (likely(node)) {
1459                 tipc_node_lock(node);
1460                 l_ptr = node->active_links[sender->publ.ref & 1];
1461                 if (!l_ptr) {
1462                         tipc_node_unlock(node);
1463                         goto reject;
1464                 }
1465                 if (link_max_pkt(l_ptr) < max_pkt) {
1466                         sender->max_pkt = link_max_pkt(l_ptr);
1467                         tipc_node_unlock(node);
1468                         for (; buf_chain; buf_chain = buf) {
1469                                 buf = buf_chain->next;
1470                                 buf_discard(buf_chain);
1471                         }
1472                         goto again;
1473                 }
1474         } else {
1475 reject:
1476                 for (; buf_chain; buf_chain = buf) {
1477                         buf = buf_chain->next;
1478                         buf_discard(buf_chain);
1479                 }
1480                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1481                                                  TIPC_ERR_NO_NODE);
1482         }
1483
1484         /* Append whole chain to send queue: */
1485
1486         buf = buf_chain;
1487         l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
1488         if (!l_ptr->next_out)
1489                 l_ptr->next_out = buf_chain;
1490         l_ptr->stats.sent_fragmented++;
1491         while (buf) {
1492                 struct sk_buff *next = buf->next;
1493                 struct tipc_msg *msg = buf_msg(buf);
1494
1495                 l_ptr->stats.sent_fragments++;
1496                 msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
1497                 link_add_to_outqueue(l_ptr, buf, msg);
1498                 msg_dbg(msg, ">ADD>");
1499                 buf = next;
1500         }
1501
1502         /* Send it, if possible: */
1503
1504         tipc_link_push_queue(l_ptr);
1505         tipc_node_unlock(node);
1506         return dsz;
1507 }
1508
1509 /*
1510  * tipc_link_push_packet: Push one unsent packet to the media
1511  */
1512 u32 tipc_link_push_packet(struct link *l_ptr)
1513 {
1514         struct sk_buff *buf = l_ptr->first_out;
1515         u32 r_q_size = l_ptr->retransm_queue_size;
1516         u32 r_q_head = l_ptr->retransm_queue_head;
1517
1518         /* Step to position where retransmission failed, if any,    */
1519         /* consider that buffers may have been released in meantime */
1520
1521         if (r_q_size && buf) {
1522                 u32 last = lesser(mod(r_q_head + r_q_size),
1523                                   link_last_sent(l_ptr));
1524                 u32 first = msg_seqno(buf_msg(buf));
1525
1526                 while (buf && less(first, r_q_head)) {
1527                         first = mod(first + 1);
1528                         buf = buf->next;
1529                 }
1530                 l_ptr->retransm_queue_head = r_q_head = first;
1531                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1532         }
1533
1534         /* Continue retransmission now, if there is anything: */
1535
1536         if (r_q_size && buf && !skb_cloned(buf)) {
1537                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1538                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1539                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1540                         msg_dbg(buf_msg(buf), ">DEF-RETR>");
1541                         l_ptr->retransm_queue_head = mod(++r_q_head);
1542                         l_ptr->retransm_queue_size = --r_q_size;
1543                         l_ptr->stats.retransmitted++;
1544                         return TIPC_OK;
1545                 } else {
1546                         l_ptr->stats.bearer_congs++;
1547                         msg_dbg(buf_msg(buf), "|>DEF-RETR>");
1548                         return PUSH_FAILED;
1549                 }
1550         }
1551
1552         /* Send deferred protocol message, if any: */
1553
1554         buf = l_ptr->proto_msg_queue;
1555         if (buf) {
1556                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1557                 msg_set_bcast_ack(buf_msg(buf),l_ptr->owner->bclink.last_in);
1558                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1559                         msg_dbg(buf_msg(buf), ">DEF-PROT>");
1560                         l_ptr->unacked_window = 0;
1561                         buf_discard(buf);
1562                         l_ptr->proto_msg_queue = NULL;
1563                         return TIPC_OK;
1564                 } else {
1565                         msg_dbg(buf_msg(buf), "|>DEF-PROT>");
1566                         l_ptr->stats.bearer_congs++;
1567                         return PUSH_FAILED;
1568                 }
1569         }
1570
1571         /* Send one deferred data message, if send window not full: */
1572
1573         buf = l_ptr->next_out;
1574         if (buf) {
1575                 struct tipc_msg *msg = buf_msg(buf);
1576                 u32 next = msg_seqno(msg);
1577                 u32 first = msg_seqno(buf_msg(l_ptr->first_out));
1578
1579                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1580                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1581                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1582                         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1583                                 if (msg_user(msg) == MSG_BUNDLER)
1584                                         msg_set_type(msg, CLOSED_MSG);
1585                                 msg_dbg(msg, ">PUSH-DATA>");
1586                                 l_ptr->next_out = buf->next;
1587                                 return TIPC_OK;
1588                         } else {
1589                                 msg_dbg(msg, "|PUSH-DATA|");
1590                                 l_ptr->stats.bearer_congs++;
1591                                 return PUSH_FAILED;
1592                         }
1593                 }
1594         }
1595         return PUSH_FINISHED;
1596 }
1597
1598 /*
1599  * push_queue(): push out the unsent messages of a link where
1600  *               congestion has abated. Node is locked
1601  */
1602 void tipc_link_push_queue(struct link *l_ptr)
1603 {
1604         u32 res;
1605
1606         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1607                 return;
1608
1609         do {
1610                 res = tipc_link_push_packet(l_ptr);
1611         }
1612         while (res == TIPC_OK);
1613         if (res == PUSH_FAILED)
1614                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1615 }
1616
1617 static void link_reset_all(unsigned long addr)
1618 {
1619         struct node *n_ptr;
1620         char addr_string[16];
1621         u32 i;
1622
1623         read_lock_bh(&tipc_net_lock);
1624         n_ptr = tipc_node_find((u32)addr);
1625         if (!n_ptr) {
1626                 read_unlock_bh(&tipc_net_lock);
1627                 return; /* node no longer exists */
1628         }
1629
1630         tipc_node_lock(n_ptr);
1631
1632         warn("Resetting all links to %s\n",
1633              addr_string_fill(addr_string, n_ptr->addr));
1634
1635         for (i = 0; i < MAX_BEARERS; i++) {
1636                 if (n_ptr->links[i]) {
1637                         link_print(n_ptr->links[i], TIPC_OUTPUT,
1638                                    "Resetting link\n");
1639                         tipc_link_reset(n_ptr->links[i]);
1640                 }
1641         }
1642
1643         tipc_node_unlock(n_ptr);
1644         read_unlock_bh(&tipc_net_lock);
1645 }
1646
1647 static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
1648 {
1649         struct tipc_msg *msg = buf_msg(buf);
1650
1651         warn("Retransmission failure on link <%s>\n", l_ptr->name);
1652         tipc_msg_print(TIPC_OUTPUT, msg, ">RETR-FAIL>");
1653
1654         if (l_ptr->addr) {
1655
1656                 /* Handle failure on standard link */
1657
1658                 link_print(l_ptr, TIPC_OUTPUT, "Resetting link\n");
1659                 tipc_link_reset(l_ptr);
1660
1661         } else {
1662
1663                 /* Handle failure on broadcast link */
1664
1665                 struct node *n_ptr;
1666                 char addr_string[16];
1667
1668                 tipc_printf(TIPC_OUTPUT, "Msg seq number: %u,  ", msg_seqno(msg));
1669                 tipc_printf(TIPC_OUTPUT, "Outstanding acks: %u\n", (u32)TIPC_SKB_CB(buf)->handle);
1670
1671                 n_ptr = l_ptr->owner->next;
1672                 tipc_node_lock(n_ptr);
1673
1674                 addr_string_fill(addr_string, n_ptr->addr);
1675                 tipc_printf(TIPC_OUTPUT, "Multicast link info for %s\n", addr_string);
1676                 tipc_printf(TIPC_OUTPUT, "Supported: %d,  ", n_ptr->bclink.supported);
1677                 tipc_printf(TIPC_OUTPUT, "Acked: %u\n", n_ptr->bclink.acked);
1678                 tipc_printf(TIPC_OUTPUT, "Last in: %u,  ", n_ptr->bclink.last_in);
1679                 tipc_printf(TIPC_OUTPUT, "Gap after: %u,  ", n_ptr->bclink.gap_after);
1680                 tipc_printf(TIPC_OUTPUT, "Gap to: %u\n", n_ptr->bclink.gap_to);
1681                 tipc_printf(TIPC_OUTPUT, "Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
1682
1683                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1684
1685                 tipc_node_unlock(n_ptr);
1686
1687                 l_ptr->stale_count = 0;
1688         }
1689 }
1690
1691 void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
1692                           u32 retransmits)
1693 {
1694         struct tipc_msg *msg;
1695
1696         if (!buf)
1697                 return;
1698
1699         msg = buf_msg(buf);
1700
1701         dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
1702
1703         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1704                 if (!skb_cloned(buf)) {
1705                         msg_dbg(msg, ">NO_RETR->BCONG>");
1706                         dbg_print_link(l_ptr, "   ");
1707                         l_ptr->retransm_queue_head = msg_seqno(msg);
1708                         l_ptr->retransm_queue_size = retransmits;
1709                         return;
1710                 } else {
1711                         /* Don't retransmit if driver already has the buffer */
1712                 }
1713         } else {
1714                 /* Detect repeated retransmit failures on uncongested bearer */
1715
1716                 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1717                         if (++l_ptr->stale_count > 100) {
1718                                 link_retransmit_failure(l_ptr, buf);
1719                                 return;
1720                         }
1721                 } else {
1722                         l_ptr->last_retransmitted = msg_seqno(msg);
1723                         l_ptr->stale_count = 1;
1724                 }
1725         }
1726
1727         while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
1728                 msg = buf_msg(buf);
1729                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1730                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1731                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1732                         msg_dbg(buf_msg(buf), ">RETR>");
1733                         buf = buf->next;
1734                         retransmits--;
1735                         l_ptr->stats.retransmitted++;
1736                 } else {
1737                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1738                         l_ptr->stats.bearer_congs++;
1739                         l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
1740                         l_ptr->retransm_queue_size = retransmits;
1741                         return;
1742                 }
1743         }
1744
1745         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1746 }
1747
1748 /*
1749  * link_recv_non_seq: Receive packets which are outside
1750  *                    the link sequence flow
1751  */
1752
1753 static void link_recv_non_seq(struct sk_buff *buf)
1754 {
1755         struct tipc_msg *msg = buf_msg(buf);
1756
1757         if (msg_user(msg) ==  LINK_CONFIG)
1758                 tipc_disc_recv_msg(buf);
1759         else
1760                 tipc_bclink_recv_pkt(buf);
1761 }
1762
1763 /**
1764  * link_insert_deferred_queue - insert deferred messages back into receive chain
1765  */
1766
1767 static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr,
1768                                                   struct sk_buff *buf)
1769 {
1770         u32 seq_no;
1771
1772         if (l_ptr->oldest_deferred_in == NULL)
1773                 return buf;
1774
1775         seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1776         if (seq_no == mod(l_ptr->next_in_no)) {
1777                 l_ptr->newest_deferred_in->next = buf;
1778                 buf = l_ptr->oldest_deferred_in;
1779                 l_ptr->oldest_deferred_in = NULL;
1780                 l_ptr->deferred_inqueue_sz = 0;
1781         }
1782         return buf;
1783 }
1784
1785 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
1786 {
1787         read_lock_bh(&tipc_net_lock);
1788         while (head) {
1789                 struct bearer *b_ptr;
1790                 struct node *n_ptr;
1791                 struct link *l_ptr;
1792                 struct sk_buff *crs;
1793                 struct sk_buff *buf = head;
1794                 struct tipc_msg *msg = buf_msg(buf);
1795                 u32 seq_no = msg_seqno(msg);
1796                 u32 ackd = msg_ack(msg);
1797                 u32 released = 0;
1798                 int type;
1799
1800                 b_ptr = (struct bearer *)tb_ptr;
1801                 TIPC_SKB_CB(buf)->handle = b_ptr;
1802
1803                 head = head->next;
1804                 if (unlikely(msg_version(msg) != TIPC_VERSION))
1805                         goto cont;
1806 #if 0
1807                 if (msg_user(msg) != LINK_PROTOCOL)
1808 #endif
1809                         msg_dbg(msg,"<REC<");
1810
1811                 if (unlikely(msg_non_seq(msg))) {
1812                         link_recv_non_seq(buf);
1813                         continue;
1814                 }
1815
1816                 if (unlikely(!msg_short(msg) &&
1817                              (msg_destnode(msg) != tipc_own_addr)))
1818                         goto cont;
1819
1820                 n_ptr = tipc_node_find(msg_prevnode(msg));
1821                 if (unlikely(!n_ptr))
1822                         goto cont;
1823
1824                 tipc_node_lock(n_ptr);
1825                 l_ptr = n_ptr->links[b_ptr->identity];
1826                 if (unlikely(!l_ptr)) {
1827                         tipc_node_unlock(n_ptr);
1828                         goto cont;
1829                 }
1830                 /*
1831                  * Release acked messages
1832                  */
1833                 if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
1834                         if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
1835                                 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1836                 }
1837
1838                 crs = l_ptr->first_out;
1839                 while ((crs != l_ptr->next_out) &&
1840                        less_eq(msg_seqno(buf_msg(crs)), ackd)) {
1841                         struct sk_buff *next = crs->next;
1842
1843                         buf_discard(crs);
1844                         crs = next;
1845                         released++;
1846                 }
1847                 if (released) {
1848                         l_ptr->first_out = crs;
1849                         l_ptr->out_queue_size -= released;
1850                 }
1851                 if (unlikely(l_ptr->next_out))
1852                         tipc_link_push_queue(l_ptr);
1853                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1854                         tipc_link_wakeup_ports(l_ptr, 0);
1855                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1856                         l_ptr->stats.sent_acks++;
1857                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1858                 }
1859
1860 protocol_check:
1861                 if (likely(link_working_working(l_ptr))) {
1862                         if (likely(seq_no == mod(l_ptr->next_in_no))) {
1863                                 l_ptr->next_in_no++;
1864                                 if (unlikely(l_ptr->oldest_deferred_in))
1865                                         head = link_insert_deferred_queue(l_ptr,
1866                                                                           head);
1867                                 if (likely(msg_is_dest(msg, tipc_own_addr))) {
1868 deliver:
1869                                         if (likely(msg_isdata(msg))) {
1870                                                 tipc_node_unlock(n_ptr);
1871                                                 tipc_port_recv_msg(buf);
1872                                                 continue;
1873                                         }
1874                                         switch (msg_user(msg)) {
1875                                         case MSG_BUNDLER:
1876                                                 l_ptr->stats.recv_bundles++;
1877                                                 l_ptr->stats.recv_bundled +=
1878                                                         msg_msgcnt(msg);
1879                                                 tipc_node_unlock(n_ptr);
1880                                                 tipc_link_recv_bundle(buf);
1881                                                 continue;
1882                                         case ROUTE_DISTRIBUTOR:
1883                                                 tipc_node_unlock(n_ptr);
1884                                                 tipc_cltr_recv_routing_table(buf);
1885                                                 continue;
1886                                         case NAME_DISTRIBUTOR:
1887                                                 tipc_node_unlock(n_ptr);
1888                                                 tipc_named_recv(buf);
1889                                                 continue;
1890                                         case CONN_MANAGER:
1891                                                 tipc_node_unlock(n_ptr);
1892                                                 tipc_port_recv_proto_msg(buf);
1893                                                 continue;
1894                                         case MSG_FRAGMENTER:
1895                                                 l_ptr->stats.recv_fragments++;
1896                                                 if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
1897                                                                             &buf, &msg)) {
1898                                                         l_ptr->stats.recv_fragmented++;
1899                                                         goto deliver;
1900                                                 }
1901                                                 break;
1902                                         case CHANGEOVER_PROTOCOL:
1903                                                 type = msg_type(msg);
1904                                                 if (link_recv_changeover_msg(&l_ptr, &buf)) {
1905                                                         msg = buf_msg(buf);
1906                                                         seq_no = msg_seqno(msg);
1907                                                         TIPC_SKB_CB(buf)->handle
1908                                                                 = b_ptr;
1909                                                         if (type == ORIGINAL_MSG)
1910                                                                 goto deliver;
1911                                                         goto protocol_check;
1912                                                 }
1913                                                 break;
1914                                         }
1915                                 }
1916                                 tipc_node_unlock(n_ptr);
1917                                 tipc_net_route_msg(buf);
1918                                 continue;
1919                         }
1920                         link_handle_out_of_seq_msg(l_ptr, buf);
1921                         head = link_insert_deferred_queue(l_ptr, head);
1922                         tipc_node_unlock(n_ptr);
1923                         continue;
1924                 }
1925
1926                 if (msg_user(msg) == LINK_PROTOCOL) {
1927                         link_recv_proto_msg(l_ptr, buf);
1928                         head = link_insert_deferred_queue(l_ptr, head);
1929                         tipc_node_unlock(n_ptr);
1930                         continue;
1931                 }
1932                 msg_dbg(msg,"NSEQ<REC<");
1933                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1934
1935                 if (link_working_working(l_ptr)) {
1936                         /* Re-insert in front of queue */
1937                         msg_dbg(msg,"RECV-REINS:");
1938                         buf->next = head;
1939                         head = buf;
1940                         tipc_node_unlock(n_ptr);
1941                         continue;
1942                 }
1943                 tipc_node_unlock(n_ptr);
1944 cont:
1945                 buf_discard(buf);
1946         }
1947         read_unlock_bh(&tipc_net_lock);
1948 }
1949
1950 /*
1951  * link_defer_buf(): Sort a received out-of-sequence packet
1952  *                   into the deferred reception queue.
1953  * Returns the increase of the queue length,i.e. 0 or 1
1954  */
1955
1956 u32 tipc_link_defer_pkt(struct sk_buff **head,
1957                         struct sk_buff **tail,
1958                         struct sk_buff *buf)
1959 {
1960         struct sk_buff *prev = NULL;
1961         struct sk_buff *crs = *head;
1962         u32 seq_no = msg_seqno(buf_msg(buf));
1963
1964         buf->next = NULL;
1965
1966         /* Empty queue ? */
1967         if (*head == NULL) {
1968                 *head = *tail = buf;
1969                 return 1;
1970         }
1971
1972         /* Last ? */
1973         if (less(msg_seqno(buf_msg(*tail)), seq_no)) {
1974                 (*tail)->next = buf;
1975                 *tail = buf;
1976                 return 1;
1977         }
1978
1979         /* Scan through queue and sort it in */
1980         do {
1981                 struct tipc_msg *msg = buf_msg(crs);
1982
1983                 if (less(seq_no, msg_seqno(msg))) {
1984                         buf->next = crs;
1985                         if (prev)
1986                                 prev->next = buf;
1987                         else
1988                                 *head = buf;
1989                         return 1;
1990                 }
1991                 if (seq_no == msg_seqno(msg)) {
1992                         break;
1993                 }
1994                 prev = crs;
1995                 crs = crs->next;
1996         }
1997         while (crs);
1998
1999         /* Message is a duplicate of an existing message */
2000
2001         buf_discard(buf);
2002         return 0;
2003 }
2004
2005 /**
2006  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
2007  */
2008
2009 static void link_handle_out_of_seq_msg(struct link *l_ptr,
2010                                        struct sk_buff *buf)
2011 {
2012         u32 seq_no = msg_seqno(buf_msg(buf));
2013
2014         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
2015                 link_recv_proto_msg(l_ptr, buf);
2016                 return;
2017         }
2018
2019         dbg("rx OOS msg: seq_no %u, expecting %u (%u)\n",
2020             seq_no, mod(l_ptr->next_in_no), l_ptr->next_in_no);
2021
2022         /* Record OOS packet arrival (force mismatch on next timeout) */
2023
2024         l_ptr->checkpoint--;
2025
2026         /*
2027          * Discard packet if a duplicate; otherwise add it to deferred queue
2028          * and notify peer of gap as per protocol specification
2029          */
2030
2031         if (less(seq_no, mod(l_ptr->next_in_no))) {
2032                 l_ptr->stats.duplicates++;
2033                 buf_discard(buf);
2034                 return;
2035         }
2036
2037         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
2038                                 &l_ptr->newest_deferred_in, buf)) {
2039                 l_ptr->deferred_inqueue_sz++;
2040                 l_ptr->stats.deferred_recv++;
2041                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
2042                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
2043         } else
2044                 l_ptr->stats.duplicates++;
2045 }
2046
2047 /*
2048  * Send protocol message to the other endpoint.
2049  */
2050 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int probe_msg,
2051                               u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
2052 {
2053         struct sk_buff *buf = NULL;
2054         struct tipc_msg *msg = l_ptr->pmsg;
2055         u32 msg_size = sizeof(l_ptr->proto_msg);
2056
2057         if (link_blocked(l_ptr))
2058                 return;
2059         msg_set_type(msg, msg_typ);
2060         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
2061         msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
2062         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
2063
2064         if (msg_typ == STATE_MSG) {
2065                 u32 next_sent = mod(l_ptr->next_out_no);
2066
2067                 if (!tipc_link_is_up(l_ptr))
2068                         return;
2069                 if (l_ptr->next_out)
2070                         next_sent = msg_seqno(buf_msg(l_ptr->next_out));
2071                 msg_set_next_sent(msg, next_sent);
2072                 if (l_ptr->oldest_deferred_in) {
2073                         u32 rec = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
2074                         gap = mod(rec - mod(l_ptr->next_in_no));
2075                 }
2076                 msg_set_seq_gap(msg, gap);
2077                 if (gap)
2078                         l_ptr->stats.sent_nacks++;
2079                 msg_set_link_tolerance(msg, tolerance);
2080                 msg_set_linkprio(msg, priority);
2081                 msg_set_max_pkt(msg, ack_mtu);
2082                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
2083                 msg_set_probe(msg, probe_msg != 0);
2084                 if (probe_msg) {
2085                         u32 mtu = l_ptr->max_pkt;
2086
2087                         if ((mtu < l_ptr->max_pkt_target) &&
2088                             link_working_working(l_ptr) &&
2089                             l_ptr->fsm_msg_cnt) {
2090                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
2091                                 if (l_ptr->max_pkt_probes == 10) {
2092                                         l_ptr->max_pkt_target = (msg_size - 4);
2093                                         l_ptr->max_pkt_probes = 0;
2094                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
2095                                 }
2096                                 l_ptr->max_pkt_probes++;
2097                         }
2098
2099                         l_ptr->stats.sent_probes++;
2100                 }
2101                 l_ptr->stats.sent_states++;
2102         } else {                /* RESET_MSG or ACTIVATE_MSG */
2103                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
2104                 msg_set_seq_gap(msg, 0);
2105                 msg_set_next_sent(msg, 1);
2106                 msg_set_link_tolerance(msg, l_ptr->tolerance);
2107                 msg_set_linkprio(msg, l_ptr->priority);
2108                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
2109         }
2110
2111         if (tipc_node_has_redundant_links(l_ptr->owner)) {
2112                 msg_set_redundant_link(msg);
2113         } else {
2114                 msg_clear_redundant_link(msg);
2115         }
2116         msg_set_linkprio(msg, l_ptr->priority);
2117
2118         /* Ensure sequence number will not fit : */
2119
2120         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
2121
2122         /* Congestion? */
2123
2124         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
2125                 if (!l_ptr->proto_msg_queue) {
2126                         l_ptr->proto_msg_queue =
2127                                 buf_acquire(sizeof(l_ptr->proto_msg));
2128                 }
2129                 buf = l_ptr->proto_msg_queue;
2130                 if (!buf)
2131                         return;
2132                 memcpy(buf->data, (unchar *)msg, sizeof(l_ptr->proto_msg));
2133                 return;
2134         }
2135         msg_set_timestamp(msg, jiffies_to_msecs(jiffies));
2136
2137         /* Message can be sent */
2138
2139         msg_dbg(msg, ">>");
2140
2141         buf = buf_acquire(msg_size);
2142         if (!buf)
2143                 return;
2144
2145         memcpy(buf->data, (unchar *)msg, sizeof(l_ptr->proto_msg));
2146         msg_set_size(buf_msg(buf), msg_size);
2147
2148         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
2149                 l_ptr->unacked_window = 0;
2150                 buf_discard(buf);
2151                 return;
2152         }
2153
2154         /* New congestion */
2155         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
2156         l_ptr->proto_msg_queue = buf;
2157         l_ptr->stats.bearer_congs++;
2158 }
2159
2160 /*
2161  * Receive protocol message :
2162  * Note that network plane id propagates through the network, and may
2163  * change at any time. The node with lowest address rules
2164  */
2165
2166 static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
2167 {
2168         u32 rec_gap = 0;
2169         u32 max_pkt_info;
2170         u32 max_pkt_ack;
2171         u32 msg_tol;
2172         struct tipc_msg *msg = buf_msg(buf);
2173
2174         dbg("AT(%u):", jiffies_to_msecs(jiffies));
2175         msg_dbg(msg, "<<");
2176         if (link_blocked(l_ptr))
2177                 goto exit;
2178
2179         /* record unnumbered packet arrival (force mismatch on next timeout) */
2180
2181         l_ptr->checkpoint--;
2182
2183         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2184                 if (tipc_own_addr > msg_prevnode(msg))
2185                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2186
2187         l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2188
2189         switch (msg_type(msg)) {
2190
2191         case RESET_MSG:
2192                 if (!link_working_unknown(l_ptr) && l_ptr->peer_session) {
2193                         if (msg_session(msg) == l_ptr->peer_session) {
2194                                 dbg("Duplicate RESET: %u<->%u\n",
2195                                     msg_session(msg), l_ptr->peer_session);
2196                                 break; /* duplicate: ignore */
2197                         }
2198                 }
2199                 /* fall thru' */
2200         case ACTIVATE_MSG:
2201                 /* Update link settings according other endpoint's values */
2202
2203                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2204
2205                 if ((msg_tol = msg_link_tolerance(msg)) &&
2206                     (msg_tol > l_ptr->tolerance))
2207                         link_set_supervision_props(l_ptr, msg_tol);
2208
2209                 if (msg_linkprio(msg) > l_ptr->priority)
2210                         l_ptr->priority = msg_linkprio(msg);
2211
2212                 max_pkt_info = msg_max_pkt(msg);
2213                 if (max_pkt_info) {
2214                         if (max_pkt_info < l_ptr->max_pkt_target)
2215                                 l_ptr->max_pkt_target = max_pkt_info;
2216                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2217                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
2218                 } else {
2219                         l_ptr->max_pkt = l_ptr->max_pkt_target;
2220                 }
2221                 l_ptr->owner->bclink.supported = (max_pkt_info != 0);
2222
2223                 link_state_event(l_ptr, msg_type(msg));
2224
2225                 l_ptr->peer_session = msg_session(msg);
2226                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
2227
2228                 /* Synchronize broadcast sequence numbers */
2229                 if (!tipc_node_has_redundant_links(l_ptr->owner)) {
2230                         l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
2231                 }
2232                 break;
2233         case STATE_MSG:
2234
2235                 if ((msg_tol = msg_link_tolerance(msg)))
2236                         link_set_supervision_props(l_ptr, msg_tol);
2237
2238                 if (msg_linkprio(msg) &&
2239                     (msg_linkprio(msg) != l_ptr->priority)) {
2240                         warn("Resetting link <%s>, priority change %u->%u\n",
2241                              l_ptr->name, l_ptr->priority, msg_linkprio(msg));
2242                         l_ptr->priority = msg_linkprio(msg);
2243                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
2244                         break;
2245                 }
2246                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2247                 l_ptr->stats.recv_states++;
2248                 if (link_reset_unknown(l_ptr))
2249                         break;
2250
2251                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2252                         rec_gap = mod(msg_next_sent(msg) -
2253                                       mod(l_ptr->next_in_no));
2254                 }
2255
2256                 max_pkt_ack = msg_max_pkt(msg);
2257                 if (max_pkt_ack > l_ptr->max_pkt) {
2258                         dbg("Link <%s> updated MTU %u -> %u\n",
2259                             l_ptr->name, l_ptr->max_pkt, max_pkt_ack);
2260                         l_ptr->max_pkt = max_pkt_ack;
2261                         l_ptr->max_pkt_probes = 0;
2262                 }
2263
2264                 max_pkt_ack = 0;
2265                 if (msg_probe(msg)) {
2266                         l_ptr->stats.recv_probes++;
2267                         if (msg_size(msg) > sizeof(l_ptr->proto_msg)) {
2268                                 max_pkt_ack = msg_size(msg);
2269                         }
2270                 }
2271
2272                 /* Protocol message before retransmits, reduce loss risk */
2273
2274                 tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
2275
2276                 if (rec_gap || (msg_probe(msg))) {
2277                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2278                                                  0, rec_gap, 0, 0, max_pkt_ack);
2279                 }
2280                 if (msg_seq_gap(msg)) {
2281                         msg_dbg(msg, "With Gap:");
2282                         l_ptr->stats.recv_nacks++;
2283                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
2284                                              msg_seq_gap(msg));
2285                 }
2286                 break;
2287         default:
2288                 msg_dbg(buf_msg(buf), "<DISCARDING UNKNOWN<");
2289         }
2290 exit:
2291         buf_discard(buf);
2292 }
2293
2294
2295 /*
2296  * tipc_link_tunnel(): Send one message via a link belonging to
2297  * another bearer. Owner node is locked.
2298  */
2299 void tipc_link_tunnel(struct link *l_ptr,
2300                       struct tipc_msg *tunnel_hdr,
2301                       struct tipc_msg  *msg,
2302                       u32 selector)
2303 {
2304         struct link *tunnel;
2305         struct sk_buff *buf;
2306         u32 length = msg_size(msg);
2307
2308         tunnel = l_ptr->owner->active_links[selector & 1];
2309         if (!tipc_link_is_up(tunnel)) {
2310                 warn("Link changeover error, "
2311                      "tunnel link no longer available\n");
2312                 return;
2313         }
2314         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2315         buf = buf_acquire(length + INT_H_SIZE);
2316         if (!buf) {
2317                 warn("Link changeover error, "
2318                      "unable to send tunnel msg\n");
2319                 return;
2320         }
2321         memcpy(buf->data, (unchar *)tunnel_hdr, INT_H_SIZE);
2322         memcpy(buf->data + INT_H_SIZE, (unchar *)msg, length);
2323         dbg("%c->%c:", l_ptr->b_ptr->net_plane, tunnel->b_ptr->net_plane);
2324         msg_dbg(buf_msg(buf), ">SEND>");
2325         tipc_link_send_buf(tunnel, buf);
2326 }
2327
2328
2329
2330 /*
2331  * changeover(): Send whole message queue via the remaining link
2332  *               Owner node is locked.
2333  */
2334
2335 void tipc_link_changeover(struct link *l_ptr)
2336 {
2337         u32 msgcount = l_ptr->out_queue_size;
2338         struct sk_buff *crs = l_ptr->first_out;
2339         struct link *tunnel = l_ptr->owner->active_links[0];
2340         struct tipc_msg tunnel_hdr;
2341         int split_bundles;
2342
2343         if (!tunnel)
2344                 return;
2345
2346         if (!l_ptr->owner->permit_changeover) {
2347                 warn("Link changeover error, "
2348                      "peer did not permit changeover\n");
2349                 return;
2350         }
2351
2352         msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2353                  ORIGINAL_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
2354         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2355         msg_set_msgcnt(&tunnel_hdr, msgcount);
2356         dbg("Link changeover requires %u tunnel messages\n", msgcount);
2357
2358         if (!l_ptr->first_out) {
2359                 struct sk_buff *buf;
2360
2361                 buf = buf_acquire(INT_H_SIZE);
2362                 if (buf) {
2363                         memcpy(buf->data, (unchar *)&tunnel_hdr, INT_H_SIZE);
2364                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2365                         dbg("%c->%c:", l_ptr->b_ptr->net_plane,
2366                             tunnel->b_ptr->net_plane);
2367                         msg_dbg(&tunnel_hdr, "EMPTY>SEND>");
2368                         tipc_link_send_buf(tunnel, buf);
2369                 } else {
2370                         warn("Link changeover error, "
2371                              "unable to send changeover msg\n");
2372                 }
2373                 return;
2374         }
2375
2376         split_bundles = (l_ptr->owner->active_links[0] !=
2377                          l_ptr->owner->active_links[1]);
2378
2379         while (crs) {
2380                 struct tipc_msg *msg = buf_msg(crs);
2381
2382                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2383                         u32 msgcount = msg_msgcnt(msg);
2384                         struct tipc_msg *m = msg_get_wrapped(msg);
2385                         unchar* pos = (unchar*)m;
2386
2387                         while (msgcount--) {
2388                                 msg_set_seqno(m,msg_seqno(msg));
2389                                 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2390                                                  msg_link_selector(m));
2391                                 pos += align(msg_size(m));
2392                                 m = (struct tipc_msg *)pos;
2393                         }
2394                 } else {
2395                         tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2396                                          msg_link_selector(msg));
2397                 }
2398                 crs = crs->next;
2399         }
2400 }
2401
2402 void tipc_link_send_duplicate(struct link *l_ptr, struct link *tunnel)
2403 {
2404         struct sk_buff *iter;
2405         struct tipc_msg tunnel_hdr;
2406
2407         msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2408                  DUPLICATE_MSG, TIPC_OK, INT_H_SIZE, l_ptr->addr);
2409         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2410         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2411         iter = l_ptr->first_out;
2412         while (iter) {
2413                 struct sk_buff *outbuf;
2414                 struct tipc_msg *msg = buf_msg(iter);
2415                 u32 length = msg_size(msg);
2416
2417                 if (msg_user(msg) == MSG_BUNDLER)
2418                         msg_set_type(msg, CLOSED_MSG);
2419                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2420                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2421                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2422                 outbuf = buf_acquire(length + INT_H_SIZE);
2423                 if (outbuf == NULL) {
2424                         warn("Link changeover error, "
2425                              "unable to send duplicate msg\n");
2426                         return;
2427                 }
2428                 memcpy(outbuf->data, (unchar *)&tunnel_hdr, INT_H_SIZE);
2429                 memcpy(outbuf->data + INT_H_SIZE, iter->data, length);
2430                 dbg("%c->%c:", l_ptr->b_ptr->net_plane,
2431                     tunnel->b_ptr->net_plane);
2432                 msg_dbg(buf_msg(outbuf), ">SEND>");
2433                 tipc_link_send_buf(tunnel, outbuf);
2434                 if (!tipc_link_is_up(l_ptr))
2435                         return;
2436                 iter = iter->next;
2437         }
2438 }
2439
2440
2441
2442 /**
2443  * buf_extract - extracts embedded TIPC message from another message
2444  * @skb: encapsulating message buffer
2445  * @from_pos: offset to extract from
2446  *
2447  * Returns a new message buffer containing an embedded message.  The
2448  * encapsulating message itself is left unchanged.
2449  */
2450
2451 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2452 {
2453         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2454         u32 size = msg_size(msg);
2455         struct sk_buff *eb;
2456
2457         eb = buf_acquire(size);
2458         if (eb)
2459                 memcpy(eb->data, (unchar *)msg, size);
2460         return eb;
2461 }
2462
2463 /*
2464  *  link_recv_changeover_msg(): Receive tunneled packet sent
2465  *  via other link. Node is locked. Return extracted buffer.
2466  */
2467
2468 static int link_recv_changeover_msg(struct link **l_ptr,
2469                                     struct sk_buff **buf)
2470 {
2471         struct sk_buff *tunnel_buf = *buf;
2472         struct link *dest_link;
2473         struct tipc_msg *msg;
2474         struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2475         u32 msg_typ = msg_type(tunnel_msg);
2476         u32 msg_count = msg_msgcnt(tunnel_msg);
2477
2478         dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2479         if (!dest_link) {
2480                 msg_dbg(tunnel_msg, "NOLINK/<REC<");
2481                 goto exit;
2482         }
2483         if (dest_link == *l_ptr) {
2484                 err("Unexpected changeover message on link <%s>\n",
2485                     (*l_ptr)->name);
2486                 goto exit;
2487         }
2488         dbg("%c<-%c:", dest_link->b_ptr->net_plane,
2489             (*l_ptr)->b_ptr->net_plane);
2490         *l_ptr = dest_link;
2491         msg = msg_get_wrapped(tunnel_msg);
2492
2493         if (msg_typ == DUPLICATE_MSG) {
2494                 if (less(msg_seqno(msg), mod(dest_link->next_in_no))) {
2495                         msg_dbg(tunnel_msg, "DROP/<REC<");
2496                         goto exit;
2497                 }
2498                 *buf = buf_extract(tunnel_buf,INT_H_SIZE);
2499                 if (*buf == NULL) {
2500                         warn("Link changeover error, duplicate msg dropped\n");
2501                         goto exit;
2502                 }
2503                 msg_dbg(tunnel_msg, "TNL<REC<");
2504                 buf_discard(tunnel_buf);
2505                 return 1;
2506         }
2507
2508         /* First original message ?: */
2509
2510         if (tipc_link_is_up(dest_link)) {
2511                 msg_dbg(tunnel_msg, "UP/FIRST/<REC<");
2512                 info("Resetting link <%s>, changeover initiated by peer\n",
2513                      dest_link->name);
2514                 tipc_link_reset(dest_link);
2515                 dest_link->exp_msg_count = msg_count;
2516                 dbg("Expecting %u tunnelled messages\n", msg_count);
2517                 if (!msg_count)
2518                         goto exit;
2519         } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2520                 msg_dbg(tunnel_msg, "BLK/FIRST/<REC<");
2521                 dest_link->exp_msg_count = msg_count;
2522                 dbg("Expecting %u tunnelled messages\n", msg_count);
2523                 if (!msg_count)
2524                         goto exit;
2525         }
2526
2527         /* Receive original message */
2528
2529         if (dest_link->exp_msg_count == 0) {
2530                 warn("Link switchover error, "
2531                      "got too many tunnelled messages\n");
2532                 msg_dbg(tunnel_msg, "OVERDUE/DROP/<REC<");
2533                 dbg_print_link(dest_link, "LINK:");
2534                 goto exit;
2535         }
2536         dest_link->exp_msg_count--;
2537         if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2538                 msg_dbg(tunnel_msg, "DROP/DUPL/<REC<");
2539                 goto exit;
2540         } else {
2541                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2542                 if (*buf != NULL) {
2543                         msg_dbg(tunnel_msg, "TNL<REC<");
2544                         buf_discard(tunnel_buf);
2545                         return 1;
2546                 } else {
2547                         warn("Link changeover error, original msg dropped\n");
2548                 }
2549         }
2550 exit:
2551         *buf = NULL;
2552         buf_discard(tunnel_buf);
2553         return 0;
2554 }
2555
2556 /*
2557  *  Bundler functionality:
2558  */
2559 void tipc_link_recv_bundle(struct sk_buff *buf)
2560 {
2561         u32 msgcount = msg_msgcnt(buf_msg(buf));
2562         u32 pos = INT_H_SIZE;
2563         struct sk_buff *obuf;
2564
2565         msg_dbg(buf_msg(buf), "<BNDL<: ");
2566         while (msgcount--) {
2567                 obuf = buf_extract(buf, pos);
2568                 if (obuf == NULL) {
2569                         warn("Link unable to unbundle message(s)\n");
2570                         break;
2571                 };
2572                 pos += align(msg_size(buf_msg(obuf)));
2573                 msg_dbg(buf_msg(obuf), "     /");
2574                 tipc_net_route_msg(obuf);
2575         }
2576         buf_discard(buf);
2577 }
2578
2579 /*
2580  *  Fragmentation/defragmentation:
2581  */
2582
2583
2584 /*
2585  * tipc_link_send_long_buf: Entry for buffers needing fragmentation.
2586  * The buffer is complete, inclusive total message length.
2587  * Returns user data length.
2588  */
2589 int tipc_link_send_long_buf(struct link *l_ptr, struct sk_buff *buf)
2590 {
2591         struct tipc_msg *inmsg = buf_msg(buf);
2592         struct tipc_msg fragm_hdr;
2593         u32 insize = msg_size(inmsg);
2594         u32 dsz = msg_data_sz(inmsg);
2595         unchar *crs = buf->data;
2596         u32 rest = insize;
2597         u32 pack_sz = link_max_pkt(l_ptr);
2598         u32 fragm_sz = pack_sz - INT_H_SIZE;
2599         u32 fragm_no = 1;
2600         u32 destaddr = msg_destnode(inmsg);
2601
2602         if (msg_short(inmsg))
2603                 destaddr = l_ptr->addr;
2604
2605         if (msg_routed(inmsg))
2606                 msg_set_prevnode(inmsg, tipc_own_addr);
2607
2608         /* Prepare reusable fragment header: */
2609
2610         msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2611                  TIPC_OK, INT_H_SIZE, destaddr);
2612         msg_set_link_selector(&fragm_hdr, msg_link_selector(inmsg));
2613         msg_set_long_msgno(&fragm_hdr, mod(l_ptr->long_msg_seq_no++));
2614         msg_set_fragm_no(&fragm_hdr, fragm_no);
2615         l_ptr->stats.sent_fragmented++;
2616
2617         /* Chop up message: */
2618
2619         while (rest > 0) {
2620                 struct sk_buff *fragm;
2621
2622                 if (rest <= fragm_sz) {
2623                         fragm_sz = rest;
2624                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2625                 }
2626                 fragm = buf_acquire(fragm_sz + INT_H_SIZE);
2627                 if (fragm == NULL) {
2628                         warn("Link unable to fragment message\n");
2629                         dsz = -ENOMEM;
2630                         goto exit;
2631                 }
2632                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2633                 memcpy(fragm->data, (unchar *)&fragm_hdr, INT_H_SIZE);
2634                 memcpy(fragm->data + INT_H_SIZE, crs, fragm_sz);
2635
2636                 /*  Send queued messages first, if any: */
2637
2638                 l_ptr->stats.sent_fragments++;
2639                 tipc_link_send_buf(l_ptr, fragm);
2640                 if (!tipc_link_is_up(l_ptr))
2641                         return dsz;
2642                 msg_set_fragm_no(&fragm_hdr, ++fragm_no);
2643                 rest -= fragm_sz;
2644                 crs += fragm_sz;
2645                 msg_set_type(&fragm_hdr, FRAGMENT);
2646         }
2647 exit:
2648         buf_discard(buf);
2649         return dsz;
2650 }
2651
2652 /*
2653  * A pending message being re-assembled must store certain values
2654  * to handle subsequent fragments correctly. The following functions
2655  * help storing these values in unused, available fields in the
2656  * pending message. This makes dynamic memory allocation unecessary.
2657  */
2658
2659 static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
2660 {
2661         msg_set_seqno(buf_msg(buf), seqno);
2662 }
2663
2664 static u32 get_fragm_size(struct sk_buff *buf)
2665 {
2666         return msg_ack(buf_msg(buf));
2667 }
2668
2669 static void set_fragm_size(struct sk_buff *buf, u32 sz)
2670 {
2671         msg_set_ack(buf_msg(buf), sz);
2672 }
2673
2674 static u32 get_expected_frags(struct sk_buff *buf)
2675 {
2676         return msg_bcast_ack(buf_msg(buf));
2677 }
2678
2679 static void set_expected_frags(struct sk_buff *buf, u32 exp)
2680 {
2681         msg_set_bcast_ack(buf_msg(buf), exp);
2682 }
2683
2684 static u32 get_timer_cnt(struct sk_buff *buf)
2685 {
2686         return msg_reroute_cnt(buf_msg(buf));
2687 }
2688
2689 static void incr_timer_cnt(struct sk_buff *buf)
2690 {
2691         msg_incr_reroute_cnt(buf_msg(buf));
2692 }
2693
2694 /*
2695  * tipc_link_recv_fragment(): Called with node lock on. Returns
2696  * the reassembled buffer if message is complete.
2697  */
2698 int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
2699                             struct tipc_msg **m)
2700 {
2701         struct sk_buff *prev = NULL;
2702         struct sk_buff *fbuf = *fb;
2703         struct tipc_msg *fragm = buf_msg(fbuf);
2704         struct sk_buff *pbuf = *pending;
2705         u32 long_msg_seq_no = msg_long_msgno(fragm);
2706
2707         *fb = NULL;
2708         msg_dbg(fragm,"FRG<REC<");
2709
2710         /* Is there an incomplete message waiting for this fragment? */
2711
2712         while (pbuf && ((msg_seqno(buf_msg(pbuf)) != long_msg_seq_no)
2713                         || (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2714                 prev = pbuf;
2715                 pbuf = pbuf->next;
2716         }
2717
2718         if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2719                 struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2720                 u32 msg_sz = msg_size(imsg);
2721                 u32 fragm_sz = msg_data_sz(fragm);
2722                 u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2723                 u32 max =  TIPC_MAX_USER_MSG_SIZE + LONG_H_SIZE;
2724                 if (msg_type(imsg) == TIPC_MCAST_MSG)
2725                         max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2726                 if (msg_size(imsg) > max) {
2727                         msg_dbg(fragm,"<REC<Oversized: ");
2728                         buf_discard(fbuf);
2729                         return 0;
2730                 }
2731                 pbuf = buf_acquire(msg_size(imsg));
2732                 if (pbuf != NULL) {
2733                         pbuf->next = *pending;
2734                         *pending = pbuf;
2735                         memcpy(pbuf->data, (unchar *)imsg, msg_data_sz(fragm));
2736
2737                         /*  Prepare buffer for subsequent fragments. */
2738
2739                         set_long_msg_seqno(pbuf, long_msg_seq_no);
2740                         set_fragm_size(pbuf,fragm_sz);
2741                         set_expected_frags(pbuf,exp_fragm_cnt - 1);
2742                 } else {
2743                         warn("Link unable to reassemble fragmented message\n");
2744                 }
2745                 buf_discard(fbuf);
2746                 return 0;
2747         } else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
2748                 u32 dsz = msg_data_sz(fragm);
2749                 u32 fsz = get_fragm_size(pbuf);
2750                 u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
2751                 u32 exp_frags = get_expected_frags(pbuf) - 1;
2752                 memcpy(pbuf->data + crs, msg_data(fragm), dsz);
2753                 buf_discard(fbuf);
2754
2755                 /* Is message complete? */
2756
2757                 if (exp_frags == 0) {
2758                         if (prev)
2759                                 prev->next = pbuf->next;
2760                         else
2761                                 *pending = pbuf->next;
2762                         msg_reset_reroute_cnt(buf_msg(pbuf));
2763                         *fb = pbuf;
2764                         *m = buf_msg(pbuf);
2765                         return 1;
2766                 }
2767                 set_expected_frags(pbuf,exp_frags);
2768                 return 0;
2769         }
2770         dbg(" Discarding orphan fragment %x\n",fbuf);
2771         msg_dbg(fragm,"ORPHAN:");
2772         dbg("Pending long buffers:\n");
2773         dbg_print_buf_chain(*pending);
2774         buf_discard(fbuf);
2775         return 0;
2776 }
2777
2778 /**
2779  * link_check_defragm_bufs - flush stale incoming message fragments
2780  * @l_ptr: pointer to link
2781  */
2782
2783 static void link_check_defragm_bufs(struct link *l_ptr)
2784 {
2785         struct sk_buff *prev = NULL;
2786         struct sk_buff *next = NULL;
2787         struct sk_buff *buf = l_ptr->defragm_buf;
2788
2789         if (!buf)
2790                 return;
2791         if (!link_working_working(l_ptr))
2792                 return;
2793         while (buf) {
2794                 u32 cnt = get_timer_cnt(buf);
2795
2796                 next = buf->next;
2797                 if (cnt < 4) {
2798                         incr_timer_cnt(buf);
2799                         prev = buf;
2800                 } else {
2801                         dbg(" Discarding incomplete long buffer\n");
2802                         msg_dbg(buf_msg(buf), "LONG:");
2803                         dbg_print_link(l_ptr, "curr:");
2804                         dbg("Pending long buffers:\n");
2805                         dbg_print_buf_chain(l_ptr->defragm_buf);
2806                         if (prev)
2807                                 prev->next = buf->next;
2808                         else
2809                                 l_ptr->defragm_buf = buf->next;
2810                         buf_discard(buf);
2811                 }
2812                 buf = next;
2813         }
2814 }
2815
2816
2817
2818 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
2819 {
2820         l_ptr->tolerance = tolerance;
2821         l_ptr->continuity_interval =
2822                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2823         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2824 }
2825
2826
2827 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window)
2828 {
2829         /* Data messages from this node, inclusive FIRST_FRAGM */
2830         l_ptr->queue_limit[DATA_LOW] = window;
2831         l_ptr->queue_limit[DATA_MEDIUM] = (window / 3) * 4;
2832         l_ptr->queue_limit[DATA_HIGH] = (window / 3) * 5;
2833         l_ptr->queue_limit[DATA_CRITICAL] = (window / 3) * 6;
2834         /* Transiting data messages,inclusive FIRST_FRAGM */
2835         l_ptr->queue_limit[DATA_LOW + 4] = 300;
2836         l_ptr->queue_limit[DATA_MEDIUM + 4] = 600;
2837         l_ptr->queue_limit[DATA_HIGH + 4] = 900;
2838         l_ptr->queue_limit[DATA_CRITICAL + 4] = 1200;
2839         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2840         l_ptr->queue_limit[ROUTE_DISTRIBUTOR] = 1200;
2841         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2842         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2843         /* FRAGMENT and LAST_FRAGMENT packets */
2844         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2845 }
2846
2847 /**
2848  * link_find_link - locate link by name
2849  * @name - ptr to link name string
2850  * @node - ptr to area to be filled with ptr to associated node
2851  *
2852  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2853  * this also prevents link deletion.
2854  *
2855  * Returns pointer to link (or 0 if invalid link name).
2856  */
2857
2858 static struct link *link_find_link(const char *name, struct node **node)
2859 {
2860         struct link_name link_name_parts;
2861         struct bearer *b_ptr;
2862         struct link *l_ptr;
2863
2864         if (!link_name_validate(name, &link_name_parts))
2865                 return NULL;
2866
2867         b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2868         if (!b_ptr)
2869                 return NULL;
2870
2871         *node = tipc_node_find(link_name_parts.addr_peer);
2872         if (!*node)
2873                 return NULL;
2874
2875         l_ptr = (*node)->links[b_ptr->identity];
2876         if (!l_ptr || strcmp(l_ptr->name, name))
2877                 return NULL;
2878
2879         return l_ptr;
2880 }
2881
2882 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2883                                      u16 cmd)
2884 {
2885         struct tipc_link_config *args;
2886         u32 new_value;
2887         struct link *l_ptr;
2888         struct node *node;
2889         int res;
2890
2891         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2892                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2893
2894         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2895         new_value = ntohl(args->value);
2896
2897         if (!strcmp(args->name, tipc_bclink_name)) {
2898                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2899                     (tipc_bclink_set_queue_limits(new_value) == 0))
2900                         return tipc_cfg_reply_none();
2901                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2902                                                    " (cannot change setting on broadcast link)");
2903         }
2904
2905         read_lock_bh(&tipc_net_lock);
2906         l_ptr = link_find_link(args->name, &node);
2907         if (!l_ptr) {
2908                 read_unlock_bh(&tipc_net_lock);
2909                 return tipc_cfg_reply_error_string("link not found");
2910         }
2911
2912         tipc_node_lock(node);
2913         res = -EINVAL;
2914         switch (cmd) {
2915         case TIPC_CMD_SET_LINK_TOL:
2916                 if ((new_value >= TIPC_MIN_LINK_TOL) &&
2917                     (new_value <= TIPC_MAX_LINK_TOL)) {
2918                         link_set_supervision_props(l_ptr, new_value);
2919                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2920                                                  0, 0, new_value, 0, 0);
2921                         res = TIPC_OK;
2922                 }
2923                 break;
2924         case TIPC_CMD_SET_LINK_PRI:
2925                 if ((new_value >= TIPC_MIN_LINK_PRI) &&
2926                     (new_value <= TIPC_MAX_LINK_PRI)) {
2927                         l_ptr->priority = new_value;
2928                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2929                                                  0, 0, 0, new_value, 0);
2930                         res = TIPC_OK;
2931                 }
2932                 break;
2933         case TIPC_CMD_SET_LINK_WINDOW:
2934                 if ((new_value >= TIPC_MIN_LINK_WIN) &&
2935                     (new_value <= TIPC_MAX_LINK_WIN)) {
2936                         tipc_link_set_queue_limits(l_ptr, new_value);
2937                         res = TIPC_OK;
2938                 }
2939                 break;
2940         }
2941         tipc_node_unlock(node);
2942
2943         read_unlock_bh(&tipc_net_lock);
2944         if (res)
2945                 return tipc_cfg_reply_error_string("cannot change link setting");
2946
2947         return tipc_cfg_reply_none();
2948 }
2949
2950 /**
2951  * link_reset_statistics - reset link statistics
2952  * @l_ptr: pointer to link
2953  */
2954
2955 static void link_reset_statistics(struct link *l_ptr)
2956 {
2957         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2958         l_ptr->stats.sent_info = l_ptr->next_out_no;
2959         l_ptr->stats.recv_info = l_ptr->next_in_no;
2960 }
2961
2962 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2963 {
2964         char *link_name;
2965         struct link *l_ptr;
2966         struct node *node;
2967
2968         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2969                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2970
2971         link_name = (char *)TLV_DATA(req_tlv_area);
2972         if (!strcmp(link_name, tipc_bclink_name)) {
2973                 if (tipc_bclink_reset_stats())
2974                         return tipc_cfg_reply_error_string("link not found");
2975                 return tipc_cfg_reply_none();
2976         }
2977
2978         read_lock_bh(&tipc_net_lock);
2979         l_ptr = link_find_link(link_name, &node);
2980         if (!l_ptr) {
2981                 read_unlock_bh(&tipc_net_lock);
2982                 return tipc_cfg_reply_error_string("link not found");
2983         }
2984
2985         tipc_node_lock(node);
2986         link_reset_statistics(l_ptr);
2987         tipc_node_unlock(node);
2988         read_unlock_bh(&tipc_net_lock);
2989         return tipc_cfg_reply_none();
2990 }
2991
2992 /**
2993  * percent - convert count to a percentage of total (rounding up or down)
2994  */
2995
2996 static u32 percent(u32 count, u32 total)
2997 {
2998         return (count * 100 + (total / 2)) / total;
2999 }
3000
3001 /**
3002  * tipc_link_stats - print link statistics
3003  * @name: link name
3004  * @buf: print buffer area
3005  * @buf_size: size of print buffer area
3006  *
3007  * Returns length of print buffer data string (or 0 if error)
3008  */
3009
3010 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
3011 {
3012         struct print_buf pb;
3013         struct link *l_ptr;
3014         struct node *node;
3015         char *status;
3016         u32 profile_total = 0;
3017
3018         if (!strcmp(name, tipc_bclink_name))
3019                 return tipc_bclink_stats(buf, buf_size);
3020
3021         tipc_printbuf_init(&pb, buf, buf_size);
3022
3023         read_lock_bh(&tipc_net_lock);
3024         l_ptr = link_find_link(name, &node);
3025         if (!l_ptr) {
3026                 read_unlock_bh(&tipc_net_lock);
3027                 return 0;
3028         }
3029         tipc_node_lock(node);
3030
3031         if (tipc_link_is_active(l_ptr))
3032                 status = "ACTIVE";
3033         else if (tipc_link_is_up(l_ptr))
3034                 status = "STANDBY";
3035         else
3036                 status = "DEFUNCT";
3037         tipc_printf(&pb, "Link <%s>\n"
3038                          "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
3039                          "  Window:%u packets\n",
3040                     l_ptr->name, status, link_max_pkt(l_ptr),
3041                     l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
3042         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
3043                     l_ptr->next_in_no - l_ptr->stats.recv_info,
3044                     l_ptr->stats.recv_fragments,
3045                     l_ptr->stats.recv_fragmented,
3046                     l_ptr->stats.recv_bundles,
3047                     l_ptr->stats.recv_bundled);
3048         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
3049                     l_ptr->next_out_no - l_ptr->stats.sent_info,
3050                     l_ptr->stats.sent_fragments,
3051                     l_ptr->stats.sent_fragmented,
3052                     l_ptr->stats.sent_bundles,
3053                     l_ptr->stats.sent_bundled);
3054         profile_total = l_ptr->stats.msg_length_counts;
3055         if (!profile_total)
3056                 profile_total = 1;
3057         tipc_printf(&pb, "  TX profile sample:%u packets  average:%u octets\n"
3058                          "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
3059                          "-16354:%u%% -32768:%u%% -66000:%u%%\n",
3060                     l_ptr->stats.msg_length_counts,
3061                     l_ptr->stats.msg_lengths_total / profile_total,
3062                     percent(l_ptr->stats.msg_length_profile[0], profile_total),
3063                     percent(l_ptr->stats.msg_length_profile[1], profile_total),
3064                     percent(l_ptr->stats.msg_length_profile[2], profile_total),
3065                     percent(l_ptr->stats.msg_length_profile[3], profile_total),
3066                     percent(l_ptr->stats.msg_length_profile[4], profile_total),
3067                     percent(l_ptr->stats.msg_length_profile[5], profile_total),
3068                     percent(l_ptr->stats.msg_length_profile[6], profile_total));
3069         tipc_printf(&pb, "  RX states:%u probes:%u naks:%u defs:%u dups:%u\n",
3070                     l_ptr->stats.recv_states,
3071                     l_ptr->stats.recv_probes,
3072                     l_ptr->stats.recv_nacks,
3073                     l_ptr->stats.deferred_recv,
3074                     l_ptr->stats.duplicates);
3075         tipc_printf(&pb, "  TX states:%u probes:%u naks:%u acks:%u dups:%u\n",
3076                     l_ptr->stats.sent_states,
3077                     l_ptr->stats.sent_probes,
3078                     l_ptr->stats.sent_nacks,
3079                     l_ptr->stats.sent_acks,
3080                     l_ptr->stats.retransmitted);
3081         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
3082                     l_ptr->stats.bearer_congs,
3083                     l_ptr->stats.link_congs,
3084                     l_ptr->stats.max_queue_sz,
3085                     l_ptr->stats.queue_sz_counts
3086                     ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
3087                     : 0);
3088
3089         tipc_node_unlock(node);
3090         read_unlock_bh(&tipc_net_lock);
3091         return tipc_printbuf_validate(&pb);
3092 }
3093
3094 #define MAX_LINK_STATS_INFO 2000
3095
3096 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
3097 {
3098         struct sk_buff *buf;
3099         struct tlv_desc *rep_tlv;
3100         int str_len;
3101
3102         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
3103                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
3104
3105         buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
3106         if (!buf)
3107                 return NULL;
3108
3109         rep_tlv = (struct tlv_desc *)buf->data;
3110
3111         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
3112                                   (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
3113         if (!str_len) {
3114                 buf_discard(buf);
3115                 return tipc_cfg_reply_error_string("link not found");
3116         }
3117
3118         skb_put(buf, TLV_SPACE(str_len));
3119         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
3120
3121         return buf;
3122 }
3123
3124 #if 0
3125 int link_control(const char *name, u32 op, u32 val)
3126 {
3127         int res = -EINVAL;
3128         struct link *l_ptr;
3129         u32 bearer_id;
3130         struct node * node;
3131         u32 a;
3132
3133         a = link_name2addr(name, &bearer_id);
3134         read_lock_bh(&tipc_net_lock);
3135         node = tipc_node_find(a);
3136         if (node) {
3137                 tipc_node_lock(node);
3138                 l_ptr = node->links[bearer_id];
3139                 if (l_ptr) {
3140                         if (op == TIPC_REMOVE_LINK) {
3141                                 struct bearer *b_ptr = l_ptr->b_ptr;
3142                                 spin_lock_bh(&b_ptr->publ.lock);
3143                                 tipc_link_delete(l_ptr);
3144                                 spin_unlock_bh(&b_ptr->publ.lock);
3145                         }
3146                         if (op == TIPC_CMD_BLOCK_LINK) {
3147                                 tipc_link_reset(l_ptr);
3148                                 l_ptr->blocked = 1;
3149                         }
3150                         if (op == TIPC_CMD_UNBLOCK_LINK) {
3151                                 l_ptr->blocked = 0;
3152                         }
3153                         res = TIPC_OK;
3154                 }
3155                 tipc_node_unlock(node);
3156         }
3157         read_unlock_bh(&tipc_net_lock);
3158         return res;
3159 }
3160 #endif
3161
3162 /**
3163  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
3164  * @dest: network address of destination node
3165  * @selector: used to select from set of active links
3166  *
3167  * If no active link can be found, uses default maximum packet size.
3168  */
3169
3170 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
3171 {
3172         struct node *n_ptr;
3173         struct link *l_ptr;
3174         u32 res = MAX_PKT_DEFAULT;
3175
3176         if (dest == tipc_own_addr)
3177                 return MAX_MSG_SIZE;
3178
3179         read_lock_bh(&tipc_net_lock);
3180         n_ptr = tipc_node_select(dest, selector);
3181         if (n_ptr) {
3182                 tipc_node_lock(n_ptr);
3183                 l_ptr = n_ptr->active_links[selector & 1];
3184                 if (l_ptr)
3185                         res = link_max_pkt(l_ptr);
3186                 tipc_node_unlock(n_ptr);
3187         }
3188         read_unlock_bh(&tipc_net_lock);
3189         return res;
3190 }
3191
3192 #if 0
3193 static void link_dump_rec_queue(struct link *l_ptr)
3194 {
3195         struct sk_buff *crs;
3196
3197         if (!l_ptr->oldest_deferred_in) {
3198                 info("Reception queue empty\n");
3199                 return;
3200         }
3201         info("Contents of Reception queue:\n");
3202         crs = l_ptr->oldest_deferred_in;
3203         while (crs) {
3204                 if (crs->data == (void *)0x0000a3a3) {
3205                         info("buffer %x invalid\n", crs);
3206                         return;
3207                 }
3208                 msg_dbg(buf_msg(crs), "In rec queue: \n");
3209                 crs = crs->next;
3210         }
3211 }
3212 #endif
3213
3214 static void link_dump_send_queue(struct link *l_ptr)
3215 {
3216         if (l_ptr->next_out) {
3217                 info("\nContents of unsent queue:\n");
3218                 dbg_print_buf_chain(l_ptr->next_out);
3219         }
3220         info("\nContents of send queue:\n");
3221         if (l_ptr->first_out) {
3222                 dbg_print_buf_chain(l_ptr->first_out);
3223         }
3224         info("Empty send queue\n");
3225 }
3226
3227 static void link_print(struct link *l_ptr, struct print_buf *buf,
3228                        const char *str)
3229 {
3230         tipc_printf(buf, str);
3231         if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
3232                 return;
3233         tipc_printf(buf, "Link %x<%s>:",
3234                     l_ptr->addr, l_ptr->b_ptr->publ.name);
3235         tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
3236         tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
3237         tipc_printf(buf, "SQUE");
3238         if (l_ptr->first_out) {
3239                 tipc_printf(buf, "[%u..", msg_seqno(buf_msg(l_ptr->first_out)));
3240                 if (l_ptr->next_out)
3241                         tipc_printf(buf, "%u..",
3242                                     msg_seqno(buf_msg(l_ptr->next_out)));
3243                 tipc_printf(buf, "%u]",
3244                             msg_seqno(buf_msg
3245                                       (l_ptr->last_out)), l_ptr->out_queue_size);
3246                 if ((mod(msg_seqno(buf_msg(l_ptr->last_out)) -
3247                          msg_seqno(buf_msg(l_ptr->first_out)))
3248                      != (l_ptr->out_queue_size - 1))
3249                     || (l_ptr->last_out->next != 0)) {
3250                         tipc_printf(buf, "\nSend queue inconsistency\n");
3251                         tipc_printf(buf, "first_out= %x ", l_ptr->first_out);
3252                         tipc_printf(buf, "next_out= %x ", l_ptr->next_out);
3253                         tipc_printf(buf, "last_out= %x ", l_ptr->last_out);
3254                         link_dump_send_queue(l_ptr);
3255                 }
3256         } else
3257                 tipc_printf(buf, "[]");
3258         tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
3259         if (l_ptr->oldest_deferred_in) {
3260                 u32 o = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
3261                 u32 n = msg_seqno(buf_msg(l_ptr->newest_deferred_in));
3262                 tipc_printf(buf, ":RQUE[%u..%u]", o, n);
3263                 if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
3264                         tipc_printf(buf, ":RQSIZ(%u)",
3265                                     l_ptr->deferred_inqueue_sz);
3266                 }
3267         }
3268         if (link_working_unknown(l_ptr))
3269                 tipc_printf(buf, ":WU");
3270         if (link_reset_reset(l_ptr))
3271                 tipc_printf(buf, ":RR");
3272         if (link_reset_unknown(l_ptr))
3273                 tipc_printf(buf, ":RU");
3274         if (link_working_working(l_ptr))
3275                 tipc_printf(buf, ":WW");
3276         tipc_printf(buf, "\n");
3277 }
3278