ldp/ldp_session.c

   1
   2 /*
   3  *  Copyright (C) James R. Leu 2000
   4  *  jleu@mindspring.com
   5  *
   6  *  This software is covered under the LGPL, for more
   7  *  info check out http://www.gnu.org/copyleft/lgpl.html
   8  */
   9
  10 #include <stdlib.h>
  11 #include "ldp_struct.h"
  12 #include "ldp_outlabel.h"
  13 #include "ldp_session.h"
  14 #include "ldp_entity.h"
  15 #include "ldp_inlabel.h"
  16 #include "ldp_outlabel.h"
  17 #include "ldp_addr.h"
  18 #include "ldp_attr.h"
  19 #include "ldp_adj.h"
  20 #include "ldp_mesg.h"
  21 #include "ldp_buf.h"
  22 #include "ldp_inet_addr.h"
  23 #include "ldp_global.h"
  24 #include "ldp_state_machine.h"
  25 #include "ldp_label_rel_with.h"
  26 #include "ldp_label_request.h"
  27 #include "ldp_label_mapping.h"
  28
  29 #include "mpls_refcnt.h"
  30 #include "mpls_assert.h"
  31 #include "mpls_mm_impl.h"
  32 #include "mpls_timer_impl.h"
  33 #include "mpls_socket_impl.h"
  34 #include "mpls_trace_impl.h"
  35 #include "mpls_ifmgr_impl.h"
  36 #include "mpls_policy_impl.h"
  37 #include "mpls_lock_impl.h"
  38
  39 static uint32_t _ldp_session_next_index = 1;
  40
  41 mpls_return_enum ldp_session_attempt_setup(ldp_global *g, ldp_session *s);
  42 mpls_return_enum ldp_session_backoff_stop(ldp_global * g, ldp_session * s);
  43
  44 static void ldp_session_backoff_callback(mpls_timer_handle timer, void *extra,
  45   mpls_cfg_handle handle)
  46 {
  47   ldp_session *s = (ldp_session *)extra;
  48   ldp_global *g = (ldp_global*)handle;
  49
  50   LDP_ENTER(g->user_data, "ldp_session_backoff");
  51
  52   LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_TIMER,
  53     "Session Backoff Timer fired: session(%s)\n", s->session_name);
  54
  55   mpls_lock_get(g->global_lock);
  56
  57   s->backoff_timer = 0;
  58
  59   if (s->oper_role == LDP_ACTIVE) {
  60     if (ldp_session_attempt_setup(g, s) != MPLS_SUCCESS) {
  61       s->backoff += g->backoff_step;
  62       s->backoff_timer = timer;
  63       mpls_timer_start(g->timer_handle, timer, MPLS_TIMER_ONESHOT);
  64
  65       LDP_EXIT(g->user_data, "ldp_session_backoff-error");
  66
  67       goto ldp_session_backoff_end;
  68     }
  69   } else if (s->oper_role == LDP_PASSIVE) {
  70     /* this is a passive session that never received an init, kill it
  71      * session current on the global list and the timer holds a refcnt.
  72      * shutdown takes this session off of the global list, so when the
  73      * timer refcnt is released the session will be deleted */
  74     ldp_session_shutdown(g, s, MPLS_BOOL_TRUE);
  75   } else {
  76     MPLS_ASSERT(0);
  77   }
  78
  79   mpls_timer_stop(g->timer_handle, timer);
  80   mpls_timer_delete(g->timer_handle, timer);
  81   MPLS_REFCNT_RELEASE(s, ldp_session_delete);
  82
  83 ldp_session_backoff_end:
  84
  85   mpls_lock_release(g->global_lock);
  86
  87   LDP_EXIT(g->user_data, "ldp_session_backoff");
  88 }
  89
  90 ldp_session *ldp_session_create()
  91 {
  92   ldp_session *s = (ldp_session *) mpls_malloc(sizeof(ldp_session));
  93
  94   if (s) {
  95     memset(s, 0, sizeof(ldp_session));
  96     MPLS_REFCNT_INIT(s, 0);
  97     MPLS_LIST_ELEM_INIT(s, _global);
  98     MPLS_LIST_INIT(&s->outlabel_root, ldp_outlabel);
  99     MPLS_LIST_INIT(&s->attr_root, ldp_attr);
 100     MPLS_LIST_INIT(&s->adj_root, ldp_adj);
 101     mpls_link_list_init(&s->inlabel_root);
 102     mpls_link_list_init(&s->addr_root);
 103
 104     s->on_global = MPLS_BOOL_FALSE;
 105     s->tx_buffer = ldp_buf_create(MPLS_PDUMAXLEN);
 106     s->tx_message = ldp_mesg_create();
 107     s->index = _ldp_session_get_next_index();
 108     s->oper_role = LDP_NONE;
 109   }
 110   return s;
 111 }
 112
 113 mpls_return_enum ldp_session_attempt_setup(ldp_global *g, ldp_session *s) {
 114   mpls_socket_handle socket = mpls_socket_create_tcp(g->socket_handle);
 115   mpls_return_enum retval;
 116
 117   LDP_ENTER(g->user_data, "ldp_session_attempt_setup");
 118
 119   if (mpls_socket_handle_verify(g->socket_handle, socket) == MPLS_BOOL_FALSE) {
 120     return MPLS_FAILURE;
 121   }
 122   if (mpls_socket_options(g->socket_handle, socket, MPLS_SOCKOP_NONBLOCK) ==
 123     MPLS_FAILURE) {
 124     goto ldp_session_attempt_setup_error;
 125   }
 126
 127   retval = mpls_socket_tcp_connect(g->socket_handle, socket, &s->remote_dest);
 128
 129   switch (retval) {
 130     case MPLS_NON_BLOCKING:
 131       {
 132         LDP_TRACE_OUT(g->user_data,
 133           "ldp_session_attempt_setup: MPLS_NON_BLOCKING\n");
 134         mpls_socket_writelist_add(g->socket_handle, socket, (void *)s,
 135           MPLS_SOCKET_TCP_CONNECT);
 136         break;
 137       }
 138     case MPLS_SUCCESS:
 139       {
 140         LDP_TRACE_OUT(g->user_data,
 141           "ldp_session_attempt_setup: MPLS_SUCCESS\n");
 142         if (ldp_state_machine(g, s, NULL, NULL, LDP_EVENT_CONNECT, NULL,
 143             NULL) == MPLS_FAILURE) {
 144           goto ldp_session_attempt_setup_error;
 145         }
 146         break;
 147       }
 148     default:
 149       {
 150         LDP_TRACE_OUT(g->user_data,
 151           "ldp_session_attempt_setup: MPLS_FAILURE\n");
 152         goto ldp_session_attempt_setup_error;
 153       }
 154       break;
 155   }
 156
 157   s->socket = socket;
 158   LDP_EXIT(g->user_data, "ldp_session_attempt_setup");
 159   return MPLS_SUCCESS;
 160
 161 ldp_session_attempt_setup_error:
 162
 163   mpls_socket_close(g->socket_handle, socket);
 164   LDP_EXIT(g->user_data, "ldp_session_attempt_setup");
 165   return MPLS_FAILURE;
 166 }
 167
 168 mpls_return_enum ldp_session_create_active(ldp_global * g, ldp_adj * a)
 169 {
 170   mpls_return_enum retval = MPLS_FAILURE;
 171   mpls_inet_addr *addr = NULL;
 172   ldp_session *s = NULL;
 173   ldp_adj* ap;
 174
 175   MPLS_ASSERT(g && a && (!a->session));
 176
 177   LDP_ENTER(g->user_data, "ldp_session_create_active");
 178
 179   ap = MPLS_LIST_HEAD(&g->adj);
 180   while (ap) {
 181     if ((!mpls_inet_addr_compare(&ap->remote_lsr_address,
 182       &a->remote_lsr_address)) &&
 183       ap->remote_label_space == a->remote_label_space &&
 184       a->index != ap->index && ap->session) {
 185       ldp_adj_add_session(a, ap->session);
 186       retval = MPLS_SUCCESS;
 187       goto ldp_session_create_active;
 188     }
 189     ap = MPLS_LIST_NEXT(&g->adj, ap, _global);
 190   }
 191
 192   if ((s = ldp_session_create())) {
 193     if (a->remote_transport_address.type != MPLS_FAMILY_NONE) {
 194       addr = &a->remote_transport_address;
 195     } else {
 196       addr = &a->remote_source_address;
 197     }
 198
 199     _ldp_global_add_session(g, s);
 200     ldp_adj_add_session(a, s);
 201     s->state = LDP_STATE_NON_EXIST;
 202
 203     memcpy(&s->remote_dest.addr, addr, sizeof(mpls_inet_addr));
 204     s->remote_dest.port = s->cfg_peer_tcp_port;
 205
 206     LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_DEBUG,
 207       "ldp_session_create_active: (%d) changed to NON_EXIST\n", s->index);
 208
 209     if (ldp_session_attempt_setup(g, s) != MPLS_SUCCESS) {
 210       /* go into backoff */
 211       ldp_session_backoff_start(g, s);
 212     }
 213     retval = MPLS_SUCCESS;
 214   }
 215
 216 ldp_session_create_active:
 217
 218   LDP_EXIT(g->user_data, "ldp_session_create_active");
 219   return retval;
 220 }
 221
 222 ldp_session *ldp_session_create_passive(ldp_global * g,
 223   mpls_socket_handle socket, mpls_dest * from)
 224 {
 225   ldp_session *s = NULL;
 226
 227   MPLS_ASSERT(g);
 228
 229   LDP_ENTER(g->user_data, "ldp_session_create_passive");
 230
 231   if ((s = ldp_session_create())) {
 232     s->socket = socket;
 233     s->state = LDP_STATE_NON_EXIST;
 234
 235     if (mpls_socket_options(g->socket_handle, socket, MPLS_SOCKOP_NONBLOCK) ==
 236       MPLS_SUCCESS) {
 237       LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_DEBUG,
 238         "ldp_session_create_passive: (%d) changed to NON_EXIST\n", s->index);
 239       _ldp_global_add_session(g, s);
 240     } else {
 241       ldp_session_delete(s);
 242       s = NULL;
 243     }
 244   }
 245
 246   LDP_EXIT(g->user_data, "ldp_session_create_passive (%p)", s);
 247
 248   return s;
 249 }
 250
 251 void ldp_session_delete(ldp_session * s)
 252 {
 253   fprintf(stderr,"session delete\n");
 254   MPLS_REFCNT_ASSERT(s, 0);
 255   mpls_free(s);
 256 }
 257
 258 mpls_return_enum ldp_session_startup(ldp_global * g, ldp_session * s)
 259 {
 260   mpls_return_enum retval = MPLS_FAILURE;
 261   ldp_addr *addr;
 262
 263   void (*callback) (mpls_timer_handle timer, void *extra, mpls_cfg_handle g);
 264
 265   MPLS_ASSERT(s && g && (s->oper_role != LDP_NONE));
 266
 267   LDP_ENTER(g->user_data, "ldp_session_startup");
 268
 269   /* when we make it to operational, get rid of any backoff timers */
 270   ldp_session_backoff_stop(g, s);
 271   s->state = LDP_STATE_OPERATIONAL;
 272   s->oper_up = time(NULL);
 273
 274   LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_DEBUG,
 275     "ldp_session_startup: (%d) changed to OPERATIONAL\n", s->index);
 276
 277   /*
 278    * if configured to distribute addr messages walk the if table
 279    * and send an addr message for each
 280    */
 281   if (g->send_address_messages) {
 282     addr = MPLS_LIST_HEAD(&g->addr);
 283     while (addr) {
 284       /* only locally attached addrs will have a valid iff */
 285       if (addr->iff) {
 286         if (ldp_addr_send(g, s, &addr->address) != MPLS_SUCCESS)
 287           goto ldp_session_startup_end;
 288       }
 289       addr = MPLS_LIST_NEXT(&g->addr, addr, _global);
 290     }
 291   }
 292
 293   /* depending on the mode, grab a pointer to the correct callback */
 294   switch (s->oper_distribution_mode) {
 295     case LDP_DISTRIBUTION_ONDEMAND:
 296       callback = ldp_label_request_initial_callback;
 297       break;
 298     case LDP_DISTRIBUTION_UNSOLICITED:
 299       callback = ldp_label_mapping_initial_callback;
 300       break;
 301     default:
 302       MPLS_ASSERT(0);
 303   }
 304
 305   /*
 306    * create a timer which will go about "chunking" the initial
 307    * set of requests or mappings
 308    */
 309   MPLS_REFCNT_HOLD(s);
 310   s->initial_distribution_timer = mpls_timer_create(g->timer_handle,
 311     MPLS_UNIT_SEC, LDP_REQUEST_CHUNK, (void *)s, g, callback);
 312
 313   if (mpls_timer_handle_verify(g->timer_handle,
 314       s->initial_distribution_timer) == MPLS_BOOL_FALSE) {
 315     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 316
 317     LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_DEBUG,
 318       "ldp_session_startup: initial distrib error(%d)\n", s->index);
 319
 320     /* timer error, we might as well shutdown the session, it's usless */
 321     s->shutdown_notif = LDP_NOTIF_INTERNAL_ERROR;
 322     s->shutdown_fatal = MPLS_BOOL_TRUE;
 323     retval = MPLS_FAILURE;
 324   } else {
 325     mpls_timer_start(g->timer_handle, s->initial_distribution_timer,
 326       MPLS_TIMER_ONESHOT);
 327     retval = MPLS_SUCCESS;
 328   }
 329
 330 ldp_session_startup_end:
 331
 332   LDP_EXIT(g->user_data, "ldp_session_startup");
 333
 334   return retval;
 335 }
 336
 337 void ldp_session_shutdown(ldp_global * g, ldp_session * s, mpls_bool complete)
 338 {
 339   ldp_addr *a = NULL;
 340   ldp_attr *attr = NULL;
 341   ldp_attr *temp_attr = NULL;
 342   ldp_adj* ap;
 343
 344   MPLS_ASSERT(s);
 345
 346   LDP_ENTER(g->user_data, "ldp_session_shutdown");
 347
 348   /*
 349    * hold a refcount so this session doesn't disappear on us
 350    * while cleaning up
 351    */
 352   MPLS_REFCNT_HOLD(s);
 353
 354   s->state = LDP_STATE_NONE;
 355   LDP_TRACE_LOG(g->user_data, MPLS_TRACE_STATE_ALL, LDP_TRACE_FLAG_DEBUG,
 356     "ldp_session_shutdown: (%d) changed to NONE\n", s->index);
 357
 358   /*
 359    * kill the timers for the session
 360    */
 361   if (mpls_timer_handle_verify(g->timer_handle, s->keepalive_recv_timer) ==
 362     MPLS_BOOL_TRUE) {
 363     mpls_timer_stop(g->timer_handle, s->keepalive_recv_timer);
 364     mpls_timer_delete(g->timer_handle, s->keepalive_recv_timer);
 365     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 366     s->keepalive_recv_timer = (mpls_timer_handle) 0;
 367   }
 368   if (mpls_timer_handle_verify(g->timer_handle, s->keepalive_send_timer) ==
 369     MPLS_BOOL_TRUE) {
 370     mpls_timer_stop(g->timer_handle, s->keepalive_send_timer);
 371     mpls_timer_delete(g->timer_handle, s->keepalive_send_timer);
 372     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 373     s->keepalive_send_timer = (mpls_timer_handle) 0;
 374   }
 375   if (mpls_timer_handle_verify(g->timer_handle,s->initial_distribution_timer) ==
 376     MPLS_BOOL_TRUE) {
 377     mpls_timer_stop(g->timer_handle, s->initial_distribution_timer);
 378     mpls_timer_delete(g->timer_handle, s->initial_distribution_timer);
 379     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 380     s->initial_distribution_timer = (mpls_timer_handle) 0;
 381   }
 382
 383   /*
 384    * get rid of the socket
 385    */
 386   if (mpls_socket_handle_verify(g->socket_handle, s->socket) ==
 387     MPLS_BOOL_TRUE) {
 388     mpls_socket_readlist_del(g->socket_handle, s->socket);
 389     mpls_socket_close(g->socket_handle, s->socket);
 390   }
 391
 392   /*
 393    * get rid of out cached keepalive
 394    */
 395   if (s->keepalive != NULL) {
 396     ldp_mesg_delete(s->keepalive);
 397     s->keepalive = NULL;
 398   }
 399
 400   ldp_session_backoff_stop(g,s);
 401
 402   attr = MPLS_LIST_HEAD(&g->attr);
 403   while (attr != NULL) {
 404     if (attr->session && attr->session->index == s->index) {
 405       temp_attr = attr;
 406       MPLS_REFCNT_HOLD(temp_attr);
 407       /*
 408        * ldp_attr_remove_complete removed everythig associated with the attr.
 409        * in and out labels, and cross connects as well
 410        */
 411       ldp_attr_remove_complete(g, attr, complete);
 412     } else {
 413       temp_attr = NULL;
 414     }
 415     attr = MPLS_LIST_NEXT(&g->attr, attr, _global);
 416     if (temp_attr)
 417       MPLS_REFCNT_RELEASE(temp_attr, ldp_attr_delete);
 418   }
 419
 420   /*
 421    * clean up the addrs we created
 422    */
 423   while ((a = (ldp_addr*)mpls_link_list_head_data(&s->addr_root))) {
 424     ldp_session_del_addr(g, s, a);
 425   }
 426
 427   /*
 428    * if we have an adj AND we are shuting down for a protocol reason, start a
 429    * backoff timer, so we can try again in the near future
 430    */
 431   if ((complete == MPLS_BOOL_TRUE) || (s->oper_role != LDP_ACTIVE)) {
 432     while ((ap = MPLS_LIST_HEAD(&s->adj_root))) {
 433       ldp_adj_del_session(ap, s);
 434     }
 435
 436     if (s->on_global == MPLS_BOOL_TRUE) {
 437       _ldp_global_del_session(g, s);
 438     }
 439   } else {
 440     if (s->oper_role == LDP_ACTIVE) {
 441       ldp_session_backoff_start(g, s);
 442     }
 443   }
 444
 445   /*
 446    * it is safe to release this refcnt now, if it is the last one, the
 447    * session will be deleted (this will be the last one in the case of
 448    * 'complete' == MPLS_BOOL_TRUE
 449    */
 450   MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 451
 452   LDP_EXIT(g->user_data, "ldp_session_shutdown");
 453 }
 454
 455 mpls_return_enum ldp_session_maintain_timer(ldp_global * g, ldp_session * s,
 456   int flag)
 457 {
 458   mpls_return_enum result = MPLS_FAILURE;
 459
 460   LDP_ENTER(g->user_data, "ldp_session_maintain_timer");
 461
 462   /*
 463    * all session keepalive maintainance comes through here (SEND and RECV)
 464    */
 465   if (flag == LDP_KEEPALIVE_RECV) {
 466     mpls_timer_stop(g->timer_handle, s->keepalive_recv_timer);
 467     result = mpls_timer_start(g->timer_handle, s->keepalive_recv_timer,
 468       MPLS_TIMER_ONESHOT);
 469   } else {
 470     mpls_timer_stop(g->timer_handle, s->keepalive_send_timer);
 471     result = mpls_timer_start(g->timer_handle, s->keepalive_send_timer,
 472       MPLS_TIMER_REOCCURRING);
 473   }
 474
 475   LDP_EXIT(g->user_data, "ldp_session_maintain_timer");
 476
 477   return result;
 478 }
 479
 480 void ldp_session_add_outlabel(ldp_session * s, ldp_outlabel * o)
 481 {
 482   MPLS_ASSERT(s && o);
 483   MPLS_REFCNT_HOLD(o);
 484   MPLS_LIST_ADD_HEAD(&s->outlabel_root, o, _session, ldp_outlabel);
 485   _ldp_outlabel_add_session(o, s);
 486 }
 487
 488 void ldp_session_del_outlabel(ldp_session * s, ldp_outlabel * o)
 489 {
 490   MPLS_ASSERT(s && o);
 491   MPLS_LIST_REMOVE(&s->outlabel_root, o, _session);
 492   _ldp_outlabel_del_session(o);
 493   MPLS_REFCNT_RELEASE(o, ldp_outlabel_delete);
 494 }
 495
 496 mpls_return_enum ldp_session_add_inlabel(ldp_session * s, ldp_inlabel * i)
 497 {
 498   MPLS_ASSERT(s && i);
 499   MPLS_REFCNT_HOLD(i);
 500   if (mpls_link_list_add_tail(&s->inlabel_root, i) == MPLS_SUCCESS) {
 501     if (_ldp_inlabel_add_session(i, s) == MPLS_SUCCESS) {
 502       return MPLS_SUCCESS;
 503     }
 504     mpls_link_list_remove_data(&s->inlabel_root, i);
 505   }
 506   MPLS_REFCNT_RELEASE(i, ldp_inlabel_delete);
 507   return MPLS_FAILURE;
 508 }
 509
 510 void ldp_session_del_inlabel(ldp_session * s, ldp_inlabel * i)
 511 {
 512   MPLS_ASSERT(s && i);
 513   mpls_link_list_remove_data(&s->inlabel_root, i);
 514   _ldp_inlabel_del_session(i, s);
 515   MPLS_REFCNT_RELEASE(i, ldp_inlabel_delete)
 516 }
 517
 518 void _ldp_session_add_attr(ldp_session * s, ldp_attr * a)
 519 {
 520   MPLS_ASSERT(s && a);
 521   MPLS_REFCNT_HOLD(a);
 522   MPLS_LIST_ADD_HEAD(&s->attr_root, a, _session, ldp_attr);
 523 }
 524
 525 void _ldp_session_del_attr(ldp_session * s, ldp_attr * a)
 526 {
 527   MPLS_ASSERT(s && a);
 528   MPLS_LIST_REMOVE(&s->attr_root, a, _session);
 529   MPLS_REFCNT_RELEASE(a, ldp_attr_delete);
 530 }
 531
 532 mpls_return_enum ldp_session_add_addr(ldp_global *g, ldp_session * s,
 533   ldp_addr * a)
 534 {
 535   struct mpls_link_list_node *lln;
 536   struct mpls_link_list_node *llnp;
 537   ldp_addr *data;
 538
 539   MPLS_ASSERT(s && a);
 540
 541   MPLS_REFCNT_HOLD(a);
 542   lln = mpls_link_list_node_create(a);
 543   if (lln) {
 544     if (_ldp_addr_add_session(a, s) == MPLS_SUCCESS) {
 545       MPLS_LINK_LIST_LOOP(&s->addr_root, data, llnp) {
 546         if (data->index > a->index) {
 547           mpls_link_list_add_node_before(&s->addr_root, llnp, lln);
 548           return MPLS_SUCCESS;
 549         }
 550       }
 551
 552       mpls_link_list_add_node_tail(&s->addr_root, lln);
 553       return MPLS_SUCCESS;
 554     }
 555     mpls_link_list_node_delete(lln);
 556   }
 557   MPLS_REFCNT_RELEASE2(g, a, ldp_addr_delete);
 558   return MPLS_FAILURE;
 559 }
 560
 561 void ldp_session_del_addr(ldp_global *g, ldp_session * s, ldp_addr * a) {
 562   MPLS_ASSERT(s && a);
 563   mpls_link_list_remove_data(&s->addr_root, a);
 564   _ldp_addr_del_session(a, s);
 565   MPLS_REFCNT_RELEASE2(g, a, ldp_addr_delete);
 566 }
 567
 568 void _ldp_session_add_adj(ldp_session * s, ldp_adj * a)
 569 {
 570   ldp_adj *ap = NULL;
 571   struct in_addr lsr_address;
 572
 573   MPLS_ASSERT(s && a);
 574   MPLS_REFCNT_HOLD(a);
 575
 576   s->cfg_remote_in_ttl_less_domain = a->entity->remote_in_ttl_less_domain;
 577   s->cfg_distribution_mode = a->entity->label_distribution_mode;
 578   s->cfg_loop_detection_mode = a->entity->loop_detection_mode;
 579   s->cfg_label_request_count = a->entity->label_request_count;
 580   s->cfg_label_request_timer = a->entity->label_request_timer;
 581   s->cfg_label_space = ldp_entity_label_space(a->entity);
 582   s->cfg_path_vector_limit = a->entity->path_vector_limit;
 583   s->cfg_hop_count_limit = a->entity->hop_count_limit;
 584   s->cfg_peer_tcp_port = a->entity->remote_tcp_port;
 585   s->cfg_keepalive = a->entity->keepalive_timer;
 586   s->cfg_max_pdu = a->entity->max_pdu;
 587
 588   lsr_address.s_addr = htonl(a->remote_lsr_address.u.ipv4);
 589   sprintf(s->session_name, "%s:%d", inet_ntoa(lsr_address),
 590     a->remote_label_space);
 591   s->oper_role = a->role;
 592
 593   ap = MPLS_LIST_HEAD(&s->adj_root);
 594   while (ap) {
 595     if (ap->index > a->index) {
 596       MPLS_LIST_INSERT_BEFORE(&s->adj_root, ap, a, _session);
 597       return;
 598     }
 599     ap = MPLS_LIST_NEXT(&s->adj_root, ap, _session);
 600   }
 601   MPLS_LIST_ADD_TAIL(&s->adj_root, a, _session, ldp_adj);
 602 }
 603
 604 void _ldp_session_del_adj(ldp_session * s, ldp_adj * a)
 605 {
 606   MPLS_ASSERT(s && a);
 607   MPLS_LIST_REMOVE(&s->adj_root, a, _session);
 608   MPLS_REFCNT_RELEASE(a, ldp_adj_delete);
 609 }
 610
 611 uint32_t _ldp_session_get_next_index()
 612 {
 613   uint32_t retval = _ldp_session_next_index;
 614
 615   _ldp_session_next_index++;
 616   if (retval > _ldp_session_next_index) {
 617     _ldp_session_next_index = 1;
 618   }
 619   return retval;
 620 }
 621
 622 mpls_return_enum ldp_session_find_raddr_index(ldp_session * s, uint32_t index,
 623   ldp_addr ** addr)
 624 {
 625   struct mpls_link_list_node *lln;
 626   ldp_addr *a = NULL;
 627
 628   if (s && index > 0) {
 629     /* because we sort our inserts by index, this lets us know
 630        if we've "walked" past the end of the list */
 631
 632     if (mpls_link_list_isempty(&s->addr_root)) {
 633       *addr = NULL;
 634       return MPLS_END_OF_LIST;
 635     }
 636
 637     if ((a = (ldp_addr*)mpls_link_list_tail_data(&s->addr_root))) {
 638       if (a->index < index) {
 639         *addr = NULL;
 640         return MPLS_END_OF_LIST;
 641       }
 642     }
 643
 644     MPLS_LINK_LIST_LOOP(&s->addr_root, a, lln) {
 645       if (a->index == index) {
 646         *addr = a;
 647         return MPLS_SUCCESS;
 648       }
 649     }
 650   }
 651   *addr = NULL;
 652   return MPLS_FAILURE;
 653 }
 654
 655 mpls_return_enum ldp_session_backoff_stop(ldp_global * g, ldp_session * s)
 656 {
 657
 658   LDP_ENTER(g->user_data, "ldp_session_backoff_stop");
 659
 660   s->backoff = 0;
 661   if (mpls_timer_handle_verify(g->timer_handle, s->backoff_timer) ==
 662     MPLS_BOOL_TRUE) {
 663
 664     mpls_timer_stop(g->timer_handle, s->backoff_timer);
 665     mpls_timer_delete(g->timer_handle, s->backoff_timer);
 666     s->backoff_timer = (mpls_timer_handle) 0;
 667     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 668   }
 669
 670   LDP_EXIT(g->user_data, "ldp_session_backoff_stop");
 671
 672   return MPLS_SUCCESS;
 673 }
 674
 675 mpls_return_enum ldp_session_backoff_start(ldp_global * g, ldp_session * s)
 676 {
 677   mpls_bool valid;
 678
 679   MPLS_ASSERT(s);
 680
 681   LDP_ENTER(g->user_data, "ldp_session_backoff_start");
 682
 683   valid = mpls_timer_handle_verify(g->timer_handle,s->backoff_timer);
 684
 685   MPLS_ASSERT(valid == MPLS_BOOL_FALSE);
 686
 687   s->backoff += g->backoff_step;
 688
 689 #if 0 /* if the above assert shouldn't be made this code should be executed */
 690   {
 691     /* this should never happen, but if so */
 692     mpls_timer_stop(g->timer_handle, s->backoff_timer);
 693     mpls_timer_delete(g->timer_handle, s->backoff_timer);
 694     s->backoff_timer = (mpls_timer_handle) 0;
 695     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 696   }
 697
 698   if (!s) {              /* if we deleted session due to the above RELEASE */
 699     LDP_EXIT(g->user_data, "ldp_session_backoff_start-error");
 700     return MPLS_FAILURE;
 701   }
 702 #endif
 703
 704   MPLS_REFCNT_HOLD(s);
 705   s->backoff_timer = mpls_timer_create(g->timer_handle, MPLS_UNIT_SEC,
 706     s->backoff, (void *)s, g, ldp_session_backoff_callback);
 707   if (mpls_timer_handle_verify(g->timer_handle, s->backoff_timer) ==
 708     MPLS_BOOL_FALSE) {
 709
 710     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 711     LDP_EXIT(g->user_data, "ldp_session_backoff_start-error");
 712     return MPLS_FAILURE;
 713   }
 714
 715   if (mpls_timer_start(g->timer_handle, s->backoff_timer,
 716     MPLS_TIMER_ONESHOT) != MPLS_SUCCESS) {
 717
 718     mpls_timer_delete(g->timer_handle, s->backoff_timer);
 719     MPLS_REFCNT_RELEASE(s, ldp_session_delete);
 720     LDP_EXIT(g->user_data, "ldp_session_backoff_start-error");
 721     return MPLS_FAILURE;
 722   }
 723
 724   LDP_EXIT(g->user_data, "ldp_session_backoff_start");
 725
 726   return MPLS_SUCCESS;
 727 }
 728
 729 ldp_session *ldp_session_for_nexthop(ldp_nexthop *nh)
 730 {
 731   MPLS_ASSERT(nh);
 732
 733   if (nh->info.type & MPLS_NH_IP) {
 734     MPLS_ASSERT(mpls_link_list_count(&nh->addr->session_root) < 2);
 735     ldp_session *s = mpls_link_list_head_data(&nh->addr->session_root);
 736     if (s) {
 737       return s;
 738     }
 739   }
 740   if (nh->info.type & MPLS_NH_IF) {
 741     ldp_session *s = NULL;
 742     if (nh->iff && (s = mpls_link_list_head_data(&nh->iff->session_root))) {
 743       return s;
 744     }
 745   }
 746   if (nh->info.type & MPLS_NH_OUTSEGMENT) {
 747     MPLS_ASSERT(0);
 748   }
 749   return NULL;
 750 }