src/connectivity.c

   1 /**
   2  * collectd - src/connectivity.c
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  20  * DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors:
  23  *   Red Hat NFVPE
  24  *     Andrew Bays <abays at redhat.com>
  25  *     Aneesh Puttur <aputtur at redhat.com>
  26  **/
  27
  28 #include "collectd.h"
  29
  30 #include "common.h"
  31 #include "plugin.h"
  32 #include "utils_complain.h"
  33 #include "utils_ignorelist.h"
  34
  35 #include <asm/types.h>
  36 #include <errno.h>
  37 #include <net/if.h>
  38 #include <netinet/in.h>
  39 #include <pthread.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <sys/socket.h>
  43 #include <unistd.h>
  44
  45 #include <libmnl/libmnl.h>
  46 #include <linux/netlink.h>
  47 #include <linux/rtnetlink.h>
  48
  49 #include <yajl/yajl_common.h>
  50 #include <yajl/yajl_gen.h>
  51 #if HAVE_YAJL_YAJL_VERSION_H
  52 #include <yajl/yajl_version.h>
  53 #endif
  54 #if defined(YAJL_MAJOR) && (YAJL_MAJOR > 1)
  55 #define HAVE_YAJL_V2 1
  56 #endif
  57
  58 #define MYPROTO NETLINK_ROUTE
  59
  60 #define LINK_STATE_DOWN 0
  61 #define LINK_STATE_UP 1
  62 #define LINK_STATE_UNKNOWN 2
  63
  64 #define CONNECTIVITY_DOMAIN_FIELD "domain"
  65 #define CONNECTIVITY_DOMAIN_VALUE "stateChange"
  66 #define CONNECTIVITY_EVENT_ID_FIELD "eventId"
  67 #define CONNECTIVITY_EVENT_NAME_FIELD "eventName"
  68 #define CONNECTIVITY_EVENT_NAME_DOWN_VALUE "down"
  69 #define CONNECTIVITY_EVENT_NAME_UP_VALUE "up"
  70 #define CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD "lastEpochMicrosec"
  71 #define CONNECTIVITY_PRIORITY_FIELD "priority"
  72 #define CONNECTIVITY_PRIORITY_VALUE "high"
  73 #define CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD "reportingEntityName"
  74 #define CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE "collectd connectivity plugin"
  75 #define CONNECTIVITY_SEQUENCE_FIELD "sequence"
  76 #define CONNECTIVITY_SEQUENCE_VALUE "0"
  77 #define CONNECTIVITY_SOURCE_NAME_FIELD "sourceName"
  78 #define CONNECTIVITY_START_EPOCH_MICROSEC_FIELD "startEpochMicrosec"
  79 #define CONNECTIVITY_VERSION_FIELD "version"
  80 #define CONNECTIVITY_VERSION_VALUE "1.0"
  81
  82 #define CONNECTIVITY_NEW_STATE_FIELD "newState"
  83 #define CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE "outOfService"
  84 #define CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE "inService"
  85 #define CONNECTIVITY_OLD_STATE_FIELD "oldState"
  86 #define CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE "outOfService"
  87 #define CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE "inService"
  88 #define CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD "stateChangeFields"
  89 #define CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD                         \
  90   "stateChangeFieldsVersion"
  91 #define CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE "1.0"
  92 #define CONNECTIVITY_STATE_INTERFACE_FIELD "stateInterface"
  93
  94 /*
  95  * Private data types
  96  */
  97
  98 struct interface_list_s {
  99   char *interface;
 100
 101   uint32_t status;
 102   uint32_t prev_status;
 103   uint32_t sent;
 104   cdtime_t timestamp;
 105
 106   struct interface_list_s *next;
 107 };
 108 typedef struct interface_list_s interface_list_t;
 109
 110 /*
 111  * Private variables
 112  */
 113
 114 static ignorelist_t *ignorelist = NULL;
 115
 116 static interface_list_t *interface_list_head = NULL;
 117 static int monitor_all_interfaces = 1;
 118
 119 static int connectivity_netlink_thread_loop = 0;
 120 static int connectivity_netlink_thread_error = 0;
 121 static pthread_t connectivity_netlink_thread_id;
 122 static int connectivity_dequeue_thread_loop = 0;
 123 static pthread_t connectivity_dequeue_thread_id;
 124 static pthread_mutex_t connectivity_threads_lock = PTHREAD_MUTEX_INITIALIZER;
 125 static pthread_mutex_t connectivity_data_lock = PTHREAD_MUTEX_INITIALIZER;
 126 static pthread_cond_t connectivity_cond = PTHREAD_COND_INITIALIZER;
 127 static int nl_sock = -1;
 128 static int event_id = 0;
 129 static int statuses_to_send = 0;
 130
 131 static const char *config_keys[] = {"Interface", "IgnoreSelected"};
 132 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
 133
 134 /*
 135  * Private functions
 136  */
 137
 138 static int gen_message_payload(int state, int old_state, const char *interface,
 139                                cdtime_t timestamp, char **buf) {
 140   const unsigned char *buf2;
 141   yajl_gen g;
 142   char json_str[DATA_MAX_NAME_LEN];
 143
 144 #if !defined(HAVE_YAJL_V2)
 145   yajl_gen_config conf = {0};
 146 #endif
 147
 148 #if HAVE_YAJL_V2
 149   size_t len;
 150   g = yajl_gen_alloc(NULL);
 151   yajl_gen_config(g, yajl_gen_beautify, 0);
 152 #else
 153   unsigned int len;
 154   g = yajl_gen_alloc(&conf, NULL);
 155 #endif
 156
 157   yajl_gen_clear(g);
 158
 159   // *** BEGIN common event header ***
 160
 161   if (yajl_gen_map_open(g) != yajl_gen_status_ok)
 162     goto err;
 163
 164   // domain
 165   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_DOMAIN_FIELD,
 166                       strlen(CONNECTIVITY_DOMAIN_FIELD)) != yajl_gen_status_ok)
 167     goto err;
 168
 169   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_DOMAIN_VALUE,
 170                       strlen(CONNECTIVITY_DOMAIN_VALUE)) != yajl_gen_status_ok)
 171     goto err;
 172
 173   // eventId
 174   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_EVENT_ID_FIELD,
 175                       strlen(CONNECTIVITY_EVENT_ID_FIELD)) !=
 176       yajl_gen_status_ok)
 177     goto err;
 178
 179   event_id = event_id + 1;
 180   if (snprintf(json_str, sizeof(json_str), "%d", event_id) < 0) {
 181     goto err;
 182   }
 183
 184   if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
 185     goto err;
 186   }
 187
 188   // eventName
 189   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_EVENT_NAME_FIELD,
 190                       strlen(CONNECTIVITY_EVENT_NAME_FIELD)) !=
 191       yajl_gen_status_ok)
 192     goto err;
 193
 194   if (snprintf(json_str, sizeof(json_str), "interface %s %s", interface,
 195                (state == 0 ? CONNECTIVITY_EVENT_NAME_DOWN_VALUE
 196                            : CONNECTIVITY_EVENT_NAME_UP_VALUE)) < 0) {
 197     goto err;
 198   }
 199
 200   if (yajl_gen_string(g, (u_char *)json_str, strlen(json_str)) !=
 201       yajl_gen_status_ok) {
 202     goto err;
 203   }
 204
 205   // lastEpochMicrosec
 206   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD,
 207                       strlen(CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD)) !=
 208       yajl_gen_status_ok)
 209     goto err;
 210
 211   if (snprintf(json_str, sizeof(json_str), "%lu", CDTIME_T_TO_US(cdtime())) <
 212       0) {
 213     goto err;
 214   }
 215
 216   if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
 217     goto err;
 218   }
 219
 220   // priority
 221   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_PRIORITY_FIELD,
 222                       strlen(CONNECTIVITY_PRIORITY_FIELD)) !=
 223       yajl_gen_status_ok)
 224     goto err;
 225
 226   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_PRIORITY_VALUE,
 227                       strlen(CONNECTIVITY_PRIORITY_VALUE)) !=
 228       yajl_gen_status_ok)
 229     goto err;
 230
 231   // reportingEntityName
 232   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD,
 233                       strlen(CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD)) !=
 234       yajl_gen_status_ok)
 235     goto err;
 236
 237   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE,
 238                       strlen(CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE)) !=
 239       yajl_gen_status_ok)
 240     goto err;
 241
 242   // sequence
 243   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_SEQUENCE_FIELD,
 244                       strlen(CONNECTIVITY_SEQUENCE_FIELD)) !=
 245       yajl_gen_status_ok)
 246     goto err;
 247
 248   if (yajl_gen_number(g, CONNECTIVITY_SEQUENCE_VALUE,
 249                       strlen(CONNECTIVITY_SEQUENCE_VALUE)) !=
 250       yajl_gen_status_ok)
 251     goto err;
 252
 253   // sourceName
 254   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_SOURCE_NAME_FIELD,
 255                       strlen(CONNECTIVITY_SOURCE_NAME_FIELD)) !=
 256       yajl_gen_status_ok)
 257     goto err;
 258
 259   if (yajl_gen_string(g, (u_char *)interface, strlen(interface)) !=
 260       yajl_gen_status_ok)
 261     goto err;
 262
 263   // startEpochMicrosec
 264   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_START_EPOCH_MICROSEC_FIELD,
 265                       strlen(CONNECTIVITY_START_EPOCH_MICROSEC_FIELD)) !=
 266       yajl_gen_status_ok)
 267     goto err;
 268
 269   if (snprintf(json_str, sizeof(json_str), "%lu", timestamp) < 0) {
 270     goto err;
 271   }
 272
 273   if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
 274     goto err;
 275   }
 276
 277   // version
 278   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_VERSION_FIELD,
 279                       strlen(CONNECTIVITY_VERSION_FIELD)) != yajl_gen_status_ok)
 280     goto err;
 281
 282   if (yajl_gen_number(g, CONNECTIVITY_VERSION_VALUE,
 283                       strlen(CONNECTIVITY_VERSION_VALUE)) != yajl_gen_status_ok)
 284     goto err;
 285
 286   // *** END common event header ***
 287
 288   // *** BEGIN state change fields ***
 289
 290   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD,
 291                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD)) !=
 292       yajl_gen_status_ok)
 293     goto err;
 294
 295   if (yajl_gen_map_open(g) != yajl_gen_status_ok)
 296     goto err;
 297
 298   // newState
 299   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_NEW_STATE_FIELD,
 300                       strlen(CONNECTIVITY_NEW_STATE_FIELD)) !=
 301       yajl_gen_status_ok)
 302     goto err;
 303
 304   int new_state_len =
 305       (state == 0 ? strlen(CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE)
 306                   : strlen(CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE));
 307
 308   if (yajl_gen_string(
 309           g, (u_char *)(state == 0 ? CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE
 310                                    : CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE),
 311           new_state_len) != yajl_gen_status_ok)
 312     goto err;
 313
 314   // oldState
 315   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_OLD_STATE_FIELD,
 316                       strlen(CONNECTIVITY_OLD_STATE_FIELD)) !=
 317       yajl_gen_status_ok)
 318     goto err;
 319
 320   int old_state_len =
 321       (old_state == 0 ? strlen(CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE)
 322                       : strlen(CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE));
 323
 324   if (yajl_gen_string(
 325           g, (u_char *)(old_state == 0 ? CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE
 326                                        : CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE),
 327           old_state_len) != yajl_gen_status_ok)
 328     goto err;
 329
 330   // stateChangeFieldsVersion
 331   if (yajl_gen_string(g,
 332                       (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD,
 333                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD)) !=
 334       yajl_gen_status_ok)
 335     goto err;
 336
 337   if (yajl_gen_number(g, CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE,
 338                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE)) !=
 339       yajl_gen_status_ok)
 340     goto err;
 341
 342   // stateInterface
 343   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_INTERFACE_FIELD,
 344                       strlen(CONNECTIVITY_STATE_INTERFACE_FIELD)) !=
 345       yajl_gen_status_ok)
 346     goto err;
 347
 348   if (yajl_gen_string(g, (u_char *)interface, strlen(interface)) !=
 349       yajl_gen_status_ok)
 350     goto err;
 351
 352   // close state change and header fields
 353   if (yajl_gen_map_close(g) != yajl_gen_status_ok ||
 354       yajl_gen_map_close(g) != yajl_gen_status_ok)
 355     goto err;
 356
 357   // *** END state change fields ***
 358
 359   if (yajl_gen_get_buf(g, &buf2, &len) != yajl_gen_status_ok)
 360     goto err;
 361
 362   *buf = strdup((char *)buf2);
 363
 364   if (*buf == NULL) {
 365     ERROR("connectivity plugin: strdup failed during gen_message_payload: %s",
 366           STRERRNO);
 367     goto err;
 368   }
 369
 370   yajl_gen_free(g);
 371
 372   return 0;
 373
 374 err:
 375   yajl_gen_free(g);
 376   ERROR("connectivity plugin: gen_message_payload failed to generate JSON");
 377   return -1;
 378 }
 379
 380 static interface_list_t *add_interface(const char *interface, int status,
 381                                        int prev_status) {
 382   interface_list_t *il = calloc(1, sizeof(*il));
 383
 384   if (il == NULL) {
 385     ERROR("connectivity plugin: calloc failed during add_interface: %s",
 386           STRERRNO);
 387     return NULL;
 388   }
 389
 390   char *interface2 = strdup(interface);
 391   if (interface2 == NULL) {
 392     sfree(il);
 393     ERROR("connectivity plugin: strdup failed during add_interface: %s",
 394           STRERRNO);
 395     return NULL;
 396   }
 397
 398   il->interface = interface2;
 399   il->status = status;
 400   il->prev_status = prev_status;
 401   il->timestamp = CDTIME_T_TO_US(cdtime());
 402   il->sent = 0;
 403   il->next = interface_list_head;
 404   interface_list_head = il;
 405
 406   DEBUG("connectivity plugin: added interface %s", interface2);
 407
 408   return il;
 409 }
 410
 411 static int connectivity_link_state(struct nlmsghdr *msg) {
 412   pthread_mutex_lock(&connectivity_data_lock);
 413
 414   struct nlattr *attr;
 415   struct ifinfomsg *ifi = mnl_nlmsg_get_payload(msg);
 416
 417   /* Scan attribute list for device name. */
 418   mnl_attr_for_each(attr, msg, sizeof(*ifi)) {
 419     if (mnl_attr_get_type(attr) != IFLA_IFNAME)
 420       continue;
 421
 422     if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
 423       ERROR("connectivity plugin: connectivity_link_state: IFLA_IFNAME "
 424             "mnl_attr_validate "
 425             "failed.");
 426       pthread_mutex_unlock(&connectivity_data_lock);
 427       return MNL_CB_ERROR;
 428     }
 429
 430     const char *dev = mnl_attr_get_str(attr);
 431
 432     // Check the list of interfaces we should monitor, if we've chosen
 433     // a subset.  If we don't care about this one, abort.
 434     if (ignorelist_match(ignorelist, dev) != 0) {
 435       DEBUG("connectivity plugin: Ignoring link state change for unmonitored "
 436             "interface: %s",
 437             dev);
 438       break;
 439     }
 440
 441     interface_list_t *il = NULL;
 442
 443     for (il = interface_list_head; il != NULL; il = il->next)
 444       if (strcmp(dev, il->interface) == 0)
 445         break;
 446
 447     if (il == NULL) {
 448       // We haven't encountered this interface yet, so add it to the linked list
 449       il = add_interface(dev, LINK_STATE_UNKNOWN, LINK_STATE_UNKNOWN);
 450
 451       if (il == NULL) {
 452         ERROR("connectivity plugin: unable to add interface %s during "
 453               "connectivity_link_state",
 454               dev);
 455         return MNL_CB_ERROR;
 456       }
 457     }
 458
 459     uint32_t prev_status;
 460
 461     prev_status = il->status;
 462     il->status =
 463         ((ifi->ifi_flags & IFF_RUNNING) ? LINK_STATE_UP : LINK_STATE_DOWN);
 464     il->timestamp = CDTIME_T_TO_US(cdtime());
 465
 466     // If the new status is different than the previous status,
 467     // store the previous status and set sent to zero, and set the
 468     // global flag to indicate there are statuses to dispatch
 469     if (il->status != prev_status) {
 470       il->prev_status = prev_status;
 471       il->sent = 0;
 472       statuses_to_send = 1;
 473     }
 474
 475     DEBUG("connectivity plugin (%llu): Interface %s status is now %s",
 476           il->timestamp, dev, ((ifi->ifi_flags & IFF_RUNNING) ? "UP" : "DOWN"));
 477
 478     // no need to loop again, we found the interface name attr
 479     // (otherwise the first if-statement in the loop would
 480     // have moved us on with 'continue')
 481     break;
 482   }
 483
 484   pthread_mutex_unlock(&connectivity_data_lock);
 485
 486   return 0;
 487 }
 488
 489 static int msg_handler(struct nlmsghdr *msg) {
 490   switch (msg->nlmsg_type) {
 491   case RTM_NEWADDR:
 492   case RTM_DELADDR:
 493   case RTM_NEWROUTE:
 494   case RTM_DELROUTE:
 495   case RTM_DELLINK:
 496     // Not of interest in current version
 497     break;
 498   case RTM_NEWLINK:
 499     connectivity_link_state(msg);
 500     break;
 501   default:
 502     ERROR("connectivity plugin: msg_handler: Unknown netlink nlmsg_type %d",
 503           msg->nlmsg_type);
 504     break;
 505   }
 506   return 0;
 507 }
 508
 509 static int read_event(int nl, int (*msg_handler)(struct nlmsghdr *)) {
 510   int ret = 0;
 511   int recv_flags = MSG_DONTWAIT;
 512
 513   if (nl == -1)
 514     return ret;
 515
 516   while (42) {
 517     pthread_mutex_lock(&connectivity_threads_lock);
 518
 519     if (connectivity_netlink_thread_loop <= 0) {
 520       pthread_mutex_unlock(&connectivity_threads_lock);
 521       return ret;
 522     }
 523
 524     pthread_mutex_unlock(&connectivity_threads_lock);
 525
 526     char buf[4096];
 527     int status = recv(nl, buf, sizeof(buf), recv_flags);
 528
 529     if (status < 0) {
 530
 531       // If there were no more messages to drain from the socket,
 532       // then signal the dequeue thread and allow it to dispatch
 533       // any saved interface status changes.  Then continue, but
 534       // block and wait for new messages
 535       if (errno == EWOULDBLOCK || errno == EAGAIN) {
 536         pthread_cond_signal(&connectivity_cond);
 537
 538         recv_flags = 0;
 539         continue;
 540       }
 541
 542       if (errno == EINTR) {
 543         // Interrupt, so just continue and try again
 544         continue;
 545       }
 546
 547       /* Anything else is an error */
 548       ERROR("connectivity plugin: read_event: Error recv: %d", status);
 549       return status;
 550     }
 551
 552     // Message received successfully, so we'll stop blocking on the
 553     // receive call for now (until we get a "would block" error, which
 554     // will be handled above)
 555     recv_flags = MSG_DONTWAIT;
 556
 557     if (status == 0) {
 558       DEBUG("connectivity plugin: read_event: EOF");
 559     }
 560
 561     /* We need to handle more than one message per 'recvmsg' */
 562     for (struct nlmsghdr *h = (struct nlmsghdr *)buf;
 563          NLMSG_OK(h, (unsigned int)status); h = NLMSG_NEXT(h, status)) {
 564       /* Finish reading */
 565       if (h->nlmsg_type == NLMSG_DONE)
 566         return ret;
 567
 568       /* Message is some kind of error */
 569       if (h->nlmsg_type == NLMSG_ERROR) {
 570         ERROR("connectivity plugin: read_event: Message is an error");
 571         return -1; // Error
 572       }
 573
 574       /* Call message handler */
 575       if (msg_handler) {
 576         ret = (*msg_handler)(h);
 577         if (ret < 0) {
 578           ERROR("connectivity plugin: read_event: Message handler error %d",
 579                 ret);
 580           return ret;
 581         }
 582       } else {
 583         ERROR("connectivity plugin: read_event: Error NULL message handler");
 584         return -1;
 585       }
 586     }
 587   }
 588
 589   return ret;
 590 }
 591
 592 static void connectivity_dispatch_notification(const char *interface,
 593                                                const char *type, gauge_t value,
 594                                                gauge_t old_value,
 595                                                cdtime_t timestamp) {
 596
 597   notification_t n = {(value == LINK_STATE_UP ? NOTIF_OKAY : NOTIF_FAILURE),
 598                       cdtime(),
 599                       "",
 600                       "",
 601                       "connectivity",
 602                       "",
 603                       "",
 604                       "",
 605                       NULL};
 606
 607   sstrncpy(n.host, hostname_g, sizeof(n.host));
 608   sstrncpy(n.plugin_instance, interface, sizeof(n.plugin_instance));
 609   sstrncpy(n.type, "gauge", sizeof(n.type));
 610   sstrncpy(n.type_instance, "interface_status", sizeof(n.type_instance));
 611
 612   char *buf = NULL;
 613
 614   gen_message_payload(value, old_value, interface, timestamp, &buf);
 615
 616   notification_meta_t *m = calloc(1, sizeof(*m));
 617
 618   if (m == NULL) {
 619     sfree(buf);
 620     ERROR("connectivity plugin: unable to allocate metadata: %s", STRERRNO);
 621     return;
 622   }
 623
 624   sstrncpy(m->name, "ves", sizeof(m->name));
 625   m->nm_value.nm_string = sstrdup(buf);
 626   m->type = NM_TYPE_STRING;
 627   n.meta = m;
 628
 629   DEBUG("connectivity plugin: notification message: %s",
 630         n.meta->nm_value.nm_string);
 631
 632   DEBUG("connectivity plugin: dispatching state %d for interface %s",
 633         (int)value, interface);
 634
 635   plugin_dispatch_notification(&n);
 636   plugin_notification_meta_free(n.meta);
 637
 638   // strdup'd in gen_message_payload
 639   if (buf != NULL)
 640     sfree(buf);
 641 }
 642
 643 // NOTE: Caller MUST hold connectivity_data_lock when calling this function
 644 static void send_interface_status() {
 645   for (interface_list_t *il = interface_list_head; il != NULL;
 646        il = il->next) /* {{{ */
 647   {
 648     uint32_t status = il->status;
 649     uint32_t prev_status = il->prev_status;
 650     uint32_t sent = il->sent;
 651
 652     if (status != prev_status && sent == 0) {
 653       connectivity_dispatch_notification(il->interface, "gauge", status,
 654                                          prev_status, il->timestamp);
 655       il->sent = 1;
 656     }
 657   } /* }}} for (il = interface_list_head; il != NULL; il = il->next) */
 658
 659   statuses_to_send = 0;
 660 }
 661
 662 static void read_interface_status() /* {{{ */
 663 {
 664   pthread_mutex_lock(&connectivity_data_lock);
 665
 666   // If we don't have any interface statuses to dispatch,
 667   // then we wait until signalled
 668   if (!statuses_to_send)
 669     pthread_cond_wait(&connectivity_cond, &connectivity_data_lock);
 670
 671   send_interface_status();
 672
 673   pthread_mutex_unlock(&connectivity_data_lock);
 674 } /* }}} int *read_interface_status */
 675
 676 static void *connectivity_netlink_thread(void *arg) /* {{{ */
 677 {
 678   pthread_mutex_lock(&connectivity_threads_lock);
 679
 680   while (connectivity_netlink_thread_loop > 0) {
 681     pthread_mutex_unlock(&connectivity_threads_lock);
 682
 683     int status = read_event(nl_sock, msg_handler);
 684
 685     pthread_mutex_lock(&connectivity_threads_lock);
 686
 687     if (status < 0) {
 688       connectivity_netlink_thread_error = 1;
 689       break;
 690     }
 691   } /* while (connectivity_netlink_thread_loop > 0) */
 692
 693   pthread_mutex_unlock(&connectivity_threads_lock);
 694
 695   return (void *)0;
 696 } /* }}} void *connectivity_netlink_thread */
 697
 698 static void *connectivity_dequeue_thread(void *arg) /* {{{ */
 699 {
 700   pthread_mutex_lock(&connectivity_threads_lock);
 701
 702   while (connectivity_dequeue_thread_loop > 0) {
 703     pthread_mutex_unlock(&connectivity_threads_lock);
 704
 705     read_interface_status();
 706
 707     pthread_mutex_lock(&connectivity_threads_lock);
 708   } /* while (connectivity_dequeue_thread_loop > 0) */
 709
 710   pthread_mutex_unlock(&connectivity_threads_lock);
 711
 712   return ((void *)0);
 713 } /* }}} void *connectivity_dequeue_thread */
 714
 715 static int nl_connect() {
 716   struct sockaddr_nl sa_nl = {
 717       .nl_family = AF_NETLINK, .nl_groups = RTMGRP_LINK, .nl_pid = getpid(),
 718   };
 719
 720   nl_sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 721   if (nl_sock == -1) {
 722     ERROR("connectivity plugin: socket open failed: %s", STRERRNO);
 723     return -1;
 724   }
 725
 726   int rc = bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl));
 727   if (rc == -1) {
 728     ERROR("connectivity plugin: socket bind failed: %s", STRERRNO);
 729     close(nl_sock);
 730     return -1;
 731   }
 732
 733   return 0;
 734 }
 735
 736 static int start_netlink_thread(void) /* {{{ */
 737 {
 738   pthread_mutex_lock(&connectivity_threads_lock);
 739
 740   if (connectivity_netlink_thread_loop != 0) {
 741     pthread_mutex_unlock(&connectivity_threads_lock);
 742     return 0;
 743   }
 744
 745   connectivity_netlink_thread_loop = 1;
 746   connectivity_netlink_thread_error = 0;
 747
 748   int status;
 749
 750   if (nl_sock == -1) {
 751     status = nl_connect();
 752
 753     if (status != 0) {
 754       pthread_mutex_unlock(&connectivity_threads_lock);
 755       return status;
 756     }
 757   }
 758
 759   status = plugin_thread_create(&connectivity_netlink_thread_id,
 760                                 /* attr = */ NULL, connectivity_netlink_thread,
 761                                 /* arg = */ (void *)0, "connectivity");
 762   if (status != 0) {
 763     connectivity_netlink_thread_loop = 0;
 764     ERROR("connectivity plugin: Starting thread failed.");
 765     pthread_mutex_unlock(&connectivity_threads_lock);
 766
 767     int status2 = close(nl_sock);
 768
 769     if (status2 != 0) {
 770       ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
 771             status2, STRERRNO);
 772     } else
 773       nl_sock = -1;
 774
 775     return -1;
 776   }
 777
 778   pthread_mutex_unlock(&connectivity_threads_lock);
 779
 780   return status;
 781 }
 782
 783 static int start_dequeue_thread(void) /* {{{ */
 784 {
 785   pthread_mutex_lock(&connectivity_threads_lock);
 786
 787   if (connectivity_dequeue_thread_loop != 0) {
 788     pthread_mutex_unlock(&connectivity_threads_lock);
 789     return 0;
 790   }
 791
 792   connectivity_dequeue_thread_loop = 1;
 793
 794   int status =
 795       plugin_thread_create(&connectivity_dequeue_thread_id,
 796                            /* attr = */ NULL, connectivity_dequeue_thread,
 797                            /* arg = */ (void *)0, "connectivity");
 798   if (status != 0) {
 799     connectivity_dequeue_thread_loop = 0;
 800     ERROR("connectivity plugin: Starting dequeue thread failed.");
 801     pthread_mutex_unlock(&connectivity_threads_lock);
 802     return -1;
 803   }
 804
 805   pthread_mutex_unlock(&connectivity_threads_lock);
 806
 807   return status;
 808 } /* }}} int start_dequeue_thread */
 809
 810 static int start_threads(void) /* {{{ */
 811 {
 812   int status = start_netlink_thread();
 813   int status2 = start_dequeue_thread();
 814
 815   if (status != 0)
 816     return status;
 817   else
 818     return status2;
 819 } /* }}} int start_threads */
 820
 821 static int stop_netlink_thread(int shutdown) /* {{{ */
 822 {
 823   int socket_status;
 824
 825   if (nl_sock != -1) {
 826     socket_status = close(nl_sock);
 827     if (socket_status != 0) {
 828       ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
 829             socket_status, STRERRNO);
 830     } else
 831       nl_sock = -1;
 832   } else
 833     socket_status = 0;
 834
 835   pthread_mutex_lock(&connectivity_threads_lock);
 836
 837   if (connectivity_netlink_thread_loop == 0) {
 838     pthread_mutex_unlock(&connectivity_threads_lock);
 839     // Thread has already been terminated, nothing more to attempt
 840     return socket_status;
 841   }
 842
 843   // Set thread termination status
 844   connectivity_netlink_thread_loop = 0;
 845   pthread_mutex_unlock(&connectivity_threads_lock);
 846
 847   // Let threads waiting on access to the interface list know to move
 848   // on such that they'll see the thread's termination status
 849   pthread_cond_broadcast(&connectivity_cond);
 850
 851   int thread_status;
 852
 853   if (shutdown == 1) {
 854     // Since the thread is blocking, calling pthread_join
 855     // doesn't actually succeed in stopping it.  It will stick around
 856     // until a NETLINK message is received on the socket (at which
 857     // it will realize that "connectivity_netlink_thread_loop" is 0 and will
 858     // break out of the read loop and be allowed to die).  This is
 859     // fine when the process isn't supposed to be exiting, but in
 860     // the case of a process shutdown, we don't want to have an
 861     // idle thread hanging around.  Calling pthread_cancel here in
 862     // the case of a shutdown is just assures that the thread is
 863     // gone and that the process has been fully terminated.
 864
 865     DEBUG("connectivity plugin: Canceling netlink thread for process shutdown");
 866
 867     thread_status = pthread_cancel(connectivity_netlink_thread_id);
 868
 869     if (thread_status != 0 && thread_status != ESRCH) {
 870       ERROR("connectivity plugin: Unable to cancel netlink thread: %d",
 871             thread_status);
 872       thread_status = -1;
 873     } else
 874       thread_status = 0;
 875   } else {
 876     thread_status =
 877         pthread_join(connectivity_netlink_thread_id, /* return = */ NULL);
 878     if (thread_status != 0 && thread_status != ESRCH) {
 879       ERROR("connectivity plugin: Stopping netlink thread failed: %d",
 880             thread_status);
 881       thread_status = -1;
 882     } else
 883       thread_status = 0;
 884   }
 885
 886   pthread_mutex_lock(&connectivity_threads_lock);
 887   memset(&connectivity_netlink_thread_id, 0,
 888          sizeof(connectivity_netlink_thread_id));
 889   connectivity_netlink_thread_error = 0;
 890   pthread_mutex_unlock(&connectivity_threads_lock);
 891
 892   DEBUG("connectivity plugin: Finished requesting stop of netlink thread");
 893
 894   if (socket_status != 0)
 895     return socket_status;
 896   else
 897     return thread_status;
 898 }
 899
 900 static int stop_dequeue_thread(int shutdown) /* {{{ */
 901 {
 902   pthread_mutex_lock(&connectivity_threads_lock);
 903
 904   if (connectivity_dequeue_thread_loop == 0) {
 905     pthread_mutex_unlock(&connectivity_threads_lock);
 906     return -1;
 907   }
 908
 909   // Set thread termination status
 910   connectivity_dequeue_thread_loop = 0;
 911   pthread_mutex_unlock(&connectivity_threads_lock);
 912
 913   // Let threads waiting on access to the interface list know to move
 914   // on such that they'll see the threads termination status
 915   pthread_cond_broadcast(&connectivity_cond);
 916
 917   int status;
 918
 919   if (shutdown == 1) {
 920     // Calling pthread_cancel here in
 921     // the case of a shutdown just assures that the thread is
 922     // gone and that the process has been fully terminated.
 923
 924     DEBUG("connectivity plugin: Canceling dequeue thread for process shutdown");
 925
 926     status = pthread_cancel(connectivity_dequeue_thread_id);
 927
 928     if (status != 0 && status != ESRCH) {
 929       ERROR("connectivity plugin: Unable to cancel dequeue thread: %d", status);
 930       status = -1;
 931     } else
 932       status = 0;
 933   } else {
 934     status = pthread_join(connectivity_dequeue_thread_id, /* return = */ NULL);
 935     if (status != 0 && status != ESRCH) {
 936       ERROR("connectivity plugin: Stopping dequeue thread failed.");
 937       status = -1;
 938     } else
 939       status = 0;
 940   }
 941
 942   pthread_mutex_lock(&connectivity_threads_lock);
 943   memset(&connectivity_dequeue_thread_id, 0,
 944          sizeof(connectivity_dequeue_thread_id));
 945   pthread_mutex_unlock(&connectivity_threads_lock);
 946
 947   DEBUG("connectivity plugin: Finished requesting stop of dequeue thread");
 948
 949   return status;
 950 } /* }}} int stop_dequeue_thread */
 951
 952 static int stop_threads(int shutdown) /* {{{ */
 953 {
 954   int status = stop_netlink_thread(shutdown);
 955   int status2 = stop_dequeue_thread(shutdown);
 956
 957   if (status != 0)
 958     return status;
 959   else
 960     return status2;
 961 } /* }}} int stop_threads */
 962
 963 static int connectivity_init(void) /* {{{ */
 964 {
 965   if (monitor_all_interfaces) {
 966     NOTICE("connectivity plugin: No interfaces have been selected, so all will "
 967            "be monitored");
 968   }
 969
 970   return start_threads();
 971 } /* }}} int connectivity_init */
 972
 973 static int connectivity_config(const char *key, const char *value) /* {{{ */
 974 {
 975   if (ignorelist == NULL) {
 976     ignorelist = ignorelist_create(/* invert = */ 1);
 977
 978     if (ignorelist == NULL)
 979       return -1;
 980   }
 981
 982   if (strcasecmp(key, "Interface") == 0) {
 983     ignorelist_add(ignorelist, value);
 984     monitor_all_interfaces = 0;
 985   } else if (strcasecmp(key, "IgnoreSelected") == 0) {
 986     int invert = 1;
 987     if (IS_TRUE(value))
 988       invert = 0;
 989     ignorelist_set_invert(ignorelist, invert);
 990   } else {
 991     return -1;
 992   }
 993
 994   return 0;
 995 } /* }}} int connectivity_config */
 996
 997 static int connectivity_read(void) /* {{{ */
 998 {
 999   pthread_mutex_lock(&connectivity_threads_lock);
1000
1001   if (connectivity_netlink_thread_error != 0) {
1002
1003     pthread_mutex_unlock(&connectivity_threads_lock);
1004
1005     ERROR("connectivity plugin: The netlink thread had a problem. Restarting "
1006           "it.");
1007
1008     stop_netlink_thread(0);
1009
1010     for (interface_list_t *il = interface_list_head; il != NULL;
1011          il = il->next) {
1012       il->status = LINK_STATE_UNKNOWN;
1013       il->prev_status = LINK_STATE_UNKNOWN;
1014       il->sent = 0;
1015     }
1016
1017     start_netlink_thread();
1018
1019     return -1;
1020   } /* if (connectivity_netlink_thread_error != 0) */
1021
1022   pthread_mutex_unlock(&connectivity_threads_lock);
1023
1024   return 0;
1025 } /* }}} int connectivity_read */
1026
1027 static int connectivity_shutdown(void) /* {{{ */
1028 {
1029   DEBUG("connectivity plugin: Shutting down thread.");
1030
1031   int status = stop_threads(1);
1032
1033   interface_list_t *il = interface_list_head;
1034   while (il != NULL) {
1035     interface_list_t *il_next;
1036
1037     il_next = il->next;
1038
1039     sfree(il->interface);
1040     sfree(il);
1041
1042     il = il_next;
1043   }
1044
1045   ignorelist_free(ignorelist);
1046
1047   return status;
1048 } /* }}} int connectivity_shutdown */
1049
1050 void module_register(void) {
1051   plugin_register_config("connectivity", connectivity_config, config_keys,
1052                          config_keys_num);
1053   plugin_register_init("connectivity", connectivity_init);
1054   plugin_register_read("connectivity", connectivity_read);
1055   plugin_register_shutdown("connectivity", connectivity_shutdown);
1056 } /* void module_register */