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 "plugin.h"
  31 #include "utils/common/common.h"
  32 #include "utils/ignorelist/ignorelist.h"
  33 #include "utils_complain.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), "%" PRIu64,
 212                CDTIME_T_TO_US(cdtime())) < 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), "%" PRIu64,
 270                CDTIME_T_TO_US(timestamp)) < 0) {
 271     goto err;
 272   }
 273
 274   if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
 275     goto err;
 276   }
 277
 278   // version
 279   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_VERSION_FIELD,
 280                       strlen(CONNECTIVITY_VERSION_FIELD)) != yajl_gen_status_ok)
 281     goto err;
 282
 283   if (yajl_gen_number(g, CONNECTIVITY_VERSION_VALUE,
 284                       strlen(CONNECTIVITY_VERSION_VALUE)) != yajl_gen_status_ok)
 285     goto err;
 286
 287   // *** END common event header ***
 288
 289   // *** BEGIN state change fields ***
 290
 291   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD,
 292                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD)) !=
 293       yajl_gen_status_ok)
 294     goto err;
 295
 296   if (yajl_gen_map_open(g) != yajl_gen_status_ok)
 297     goto err;
 298
 299   // newState
 300   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_NEW_STATE_FIELD,
 301                       strlen(CONNECTIVITY_NEW_STATE_FIELD)) !=
 302       yajl_gen_status_ok)
 303     goto err;
 304
 305   int new_state_len =
 306       (state == 0 ? strlen(CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE)
 307                   : strlen(CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE));
 308
 309   if (yajl_gen_string(g,
 310                       (u_char *)(state == 0
 311                                      ? CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE
 312                                      : CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE),
 313                       new_state_len) != yajl_gen_status_ok)
 314     goto err;
 315
 316   // oldState
 317   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_OLD_STATE_FIELD,
 318                       strlen(CONNECTIVITY_OLD_STATE_FIELD)) !=
 319       yajl_gen_status_ok)
 320     goto err;
 321
 322   int old_state_len =
 323       (old_state == 0 ? strlen(CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE)
 324                       : strlen(CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE));
 325
 326   if (yajl_gen_string(g,
 327                       (u_char *)(old_state == 0
 328                                      ? CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE
 329                                      : CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE),
 330                       old_state_len) != yajl_gen_status_ok)
 331     goto err;
 332
 333   // stateChangeFieldsVersion
 334   if (yajl_gen_string(g,
 335                       (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD,
 336                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD)) !=
 337       yajl_gen_status_ok)
 338     goto err;
 339
 340   if (yajl_gen_number(g, CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE,
 341                       strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE)) !=
 342       yajl_gen_status_ok)
 343     goto err;
 344
 345   // stateInterface
 346   if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_INTERFACE_FIELD,
 347                       strlen(CONNECTIVITY_STATE_INTERFACE_FIELD)) !=
 348       yajl_gen_status_ok)
 349     goto err;
 350
 351   if (yajl_gen_string(g, (u_char *)interface, strlen(interface)) !=
 352       yajl_gen_status_ok)
 353     goto err;
 354
 355   // close state change and header fields
 356   if (yajl_gen_map_close(g) != yajl_gen_status_ok ||
 357       yajl_gen_map_close(g) != yajl_gen_status_ok)
 358     goto err;
 359
 360   // *** END state change fields ***
 361
 362   if (yajl_gen_get_buf(g, &buf2, &len) != yajl_gen_status_ok)
 363     goto err;
 364
 365   *buf = strdup((char *)buf2);
 366
 367   if (*buf == NULL) {
 368     ERROR("connectivity plugin: strdup failed during gen_message_payload: %s",
 369           STRERRNO);
 370     goto err;
 371   }
 372
 373   yajl_gen_free(g);
 374
 375   return 0;
 376
 377 err:
 378   yajl_gen_free(g);
 379   ERROR("connectivity plugin: gen_message_payload failed to generate JSON");
 380   return -1;
 381 }
 382
 383 static interface_list_t *add_interface(const char *interface, int status,
 384                                        int prev_status) {
 385   interface_list_t *il = calloc(1, sizeof(*il));
 386
 387   if (il == NULL) {
 388     ERROR("connectivity plugin: calloc failed during add_interface: %s",
 389           STRERRNO);
 390     return NULL;
 391   }
 392
 393   char *interface2 = strdup(interface);
 394   if (interface2 == NULL) {
 395     sfree(il);
 396     ERROR("connectivity plugin: strdup failed during add_interface: %s",
 397           STRERRNO);
 398     return NULL;
 399   }
 400
 401   il->interface = interface2;
 402   il->status = status;
 403   il->prev_status = prev_status;
 404   il->timestamp = cdtime();
 405   il->sent = 0;
 406   il->next = interface_list_head;
 407   interface_list_head = il;
 408
 409   DEBUG("connectivity plugin: added interface %s", interface2);
 410
 411   return il;
 412 }
 413
 414 static int connectivity_link_state(struct nlmsghdr *msg) {
 415   pthread_mutex_lock(&connectivity_data_lock);
 416
 417   struct nlattr *attr;
 418   struct ifinfomsg *ifi = mnl_nlmsg_get_payload(msg);
 419
 420   /* Scan attribute list for device name. */
 421   mnl_attr_for_each(attr, msg, sizeof(*ifi)) {
 422     if (mnl_attr_get_type(attr) != IFLA_IFNAME)
 423       continue;
 424
 425     if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) {
 426       ERROR("connectivity plugin: connectivity_link_state: IFLA_IFNAME "
 427             "mnl_attr_validate "
 428             "failed.");
 429       pthread_mutex_unlock(&connectivity_data_lock);
 430       return MNL_CB_ERROR;
 431     }
 432
 433     const char *dev = mnl_attr_get_str(attr);
 434
 435     // Check the list of interfaces we should monitor, if we've chosen
 436     // a subset.  If we don't care about this one, abort.
 437     if (ignorelist_match(ignorelist, dev) != 0) {
 438       DEBUG("connectivity plugin: Ignoring link state change for unmonitored "
 439             "interface: %s",
 440             dev);
 441       break;
 442     }
 443
 444     interface_list_t *il = NULL;
 445
 446     for (il = interface_list_head; il != NULL; il = il->next)
 447       if (strcmp(dev, il->interface) == 0)
 448         break;
 449
 450     if (il == NULL) {
 451       // We haven't encountered this interface yet, so add it to the linked list
 452       il = add_interface(dev, LINK_STATE_UNKNOWN, LINK_STATE_UNKNOWN);
 453
 454       if (il == NULL) {
 455         ERROR("connectivity plugin: unable to add interface %s during "
 456               "connectivity_link_state",
 457               dev);
 458         return MNL_CB_ERROR;
 459       }
 460     }
 461
 462     uint32_t prev_status = il->status;
 463     il->status =
 464         ((ifi->ifi_flags & IFF_RUNNING) ? LINK_STATE_UP : LINK_STATE_DOWN);
 465     il->timestamp = cdtime();
 466
 467     // If the new status is different than the previous status,
 468     // store the previous status and set sent to zero, and set the
 469     // global flag to indicate there are statuses to dispatch
 470     if (il->status != prev_status) {
 471       il->prev_status = prev_status;
 472       il->sent = 0;
 473       statuses_to_send = 1;
 474     }
 475
 476     DEBUG("connectivity plugin (%llu): Interface %s status is now %s",
 477           (unsigned long long)il->timestamp, dev,
 478           ((ifi->ifi_flags & IFF_RUNNING) ? "UP" : "DOWN"));
 479
 480     // no need to loop again, we found the interface name attr
 481     // (otherwise the first if-statement in the loop would
 482     // have moved us on with 'continue')
 483     break;
 484   }
 485
 486   pthread_mutex_unlock(&connectivity_data_lock);
 487
 488   return 0;
 489 }
 490
 491 static int msg_handler(struct nlmsghdr *msg) {
 492   // We are only interested in RTM_NEWLINK messages
 493   if (msg->nlmsg_type != RTM_NEWLINK) {
 494     return 0;
 495   }
 496   return connectivity_link_state(msg);
 497 }
 498
 499 static int read_event(int (*msg_handler)(struct nlmsghdr *)) {
 500   int ret = 0;
 501   int recv_flags = MSG_DONTWAIT;
 502
 503   if (nl_sock == -1 || msg_handler == NULL)
 504     return EINVAL;
 505
 506   while (42) {
 507     pthread_mutex_lock(&connectivity_threads_lock);
 508
 509     if (connectivity_netlink_thread_loop <= 0) {
 510       pthread_mutex_unlock(&connectivity_threads_lock);
 511       return ret;
 512     }
 513
 514     pthread_mutex_unlock(&connectivity_threads_lock);
 515
 516     char buf[4096];
 517     int status = recv(nl_sock, buf, sizeof(buf), recv_flags);
 518
 519     if (status < 0) {
 520
 521       // If there were no more messages to drain from the socket,
 522       // then signal the dequeue thread and allow it to dispatch
 523       // any saved interface status changes.  Then continue, but
 524       // block and wait for new messages
 525       if (errno == EWOULDBLOCK || errno == EAGAIN) {
 526         pthread_cond_signal(&connectivity_cond);
 527
 528         recv_flags = 0;
 529         continue;
 530       }
 531
 532       if (errno == EINTR) {
 533         // Interrupt, so just continue and try again
 534         continue;
 535       }
 536
 537       if (errno == EINTR)
 538       {
 539         // Interrupt, so just return
 540         return 0;
 541       }
 542
 543       /* Anything else is an error */
 544       ERROR("connectivity plugin: read_event: Error recv: %d", status);
 545       return status;
 546     }
 547
 548     // Message received successfully, so we'll stop blocking on the
 549     // receive call for now (until we get a "would block" error, which
 550     // will be handled above)
 551     recv_flags = MSG_DONTWAIT;
 552
 553     if (status == 0) {
 554       DEBUG("connectivity plugin: read_event: EOF");
 555     }
 556
 557     /* We need to handle more than one message per 'recvmsg' */
 558     for (struct nlmsghdr *h = (struct nlmsghdr *)buf;
 559          NLMSG_OK(h, (unsigned int)status); h = NLMSG_NEXT(h, status)) {
 560       /* Finish reading */
 561       if (h->nlmsg_type == NLMSG_DONE)
 562         return ret;
 563
 564       /* Message is some kind of error */
 565       if (h->nlmsg_type == NLMSG_ERROR) {
 566         struct nlmsgerr *l_err = (struct nlmsgerr *)NLMSG_DATA(h);
 567         ERROR("connectivity plugin: read_event: Message is an error: %d",
 568               l_err->error);
 569         return -1; // Error
 570       }
 571
 572       /* Call message handler */
 573       if (msg_handler) {
 574         ret = (*msg_handler)(h);
 575         if (ret < 0) {
 576           ERROR("connectivity plugin: read_event: Message handler error %d",
 577                 ret);
 578           return ret;
 579         }
 580       } else {
 581         ERROR("connectivity plugin: read_event: Error NULL message handler");
 582         return -1;
 583       }
 584     }
 585   }
 586
 587   return ret;
 588 }
 589
 590 static void connectivity_dispatch_notification(const char *interface,
 591                                                gauge_t value, gauge_t old_value,
 592                                                cdtime_t timestamp) {
 593
 594   notification_t n = {
 595       .severity = (value == LINK_STATE_UP ? NOTIF_OKAY : NOTIF_FAILURE),
 596       .time = cdtime(),
 597       .plugin = "connectivity",
 598       .type = "gauge",
 599       .type_instance = "interface_status",
 600   };
 601
 602   sstrncpy(n.host, hostname_g, sizeof(n.host));
 603   sstrncpy(n.plugin_instance, interface, sizeof(n.plugin_instance));
 604
 605   char *buf = NULL;
 606
 607   gen_message_payload(value, old_value, interface, timestamp, &buf);
 608
 609   int status = plugin_notification_meta_add_string(&n, "ves", buf);
 610
 611   if (status < 0) {
 612     sfree(buf);
 613     ERROR("connectivity plugin: unable to set notification VES metadata: %s",
 614           STRERRNO);
 615     return;
 616   }
 617
 618   DEBUG("connectivity plugin: notification VES metadata: %s",
 619         n.meta->nm_value.nm_string);
 620
 621   DEBUG("connectivity plugin: dispatching state %d for interface %s",
 622         (int)value, interface);
 623
 624   plugin_dispatch_notification(&n);
 625   plugin_notification_meta_free(n.meta);
 626
 627   // strdup'd in gen_message_payload
 628   if (buf != NULL)
 629     sfree(buf);
 630 }
 631
 632 // NOTE: Caller MUST hold connectivity_data_lock when calling this function
 633 static void send_interface_status() {
 634   for (interface_list_t *il = interface_list_head; il != NULL;
 635        il = il->next) /* {{{ */
 636   {
 637     uint32_t status = il->status;
 638     uint32_t prev_status = il->prev_status;
 639     uint32_t sent = il->sent;
 640
 641     if (status != prev_status && sent == 0) {
 642       connectivity_dispatch_notification(il->interface, status, prev_status,
 643                                          il->timestamp);
 644       il->sent = 1;
 645     }
 646   } /* }}} for (il = interface_list_head; il != NULL; il = il->next) */
 647
 648   statuses_to_send = 0;
 649 }
 650
 651 static void read_interface_status() /* {{{ */
 652 {
 653   pthread_mutex_lock(&connectivity_data_lock);
 654
 655   // If we don't have any interface statuses to dispatch,
 656   // then we wait until signalled
 657   if (!statuses_to_send)
 658     pthread_cond_wait(&connectivity_cond, &connectivity_data_lock);
 659
 660   send_interface_status();
 661
 662   pthread_mutex_unlock(&connectivity_data_lock);
 663 } /* }}} int *read_interface_status */
 664
 665 static void *connectivity_netlink_thread(void *arg) /* {{{ */
 666 {
 667   pthread_mutex_lock(&connectivity_threads_lock);
 668
 669   while (connectivity_netlink_thread_loop > 0) {
 670     pthread_mutex_unlock(&connectivity_threads_lock);
 671
 672     int status = read_event(msg_handler);
 673
 674     pthread_mutex_lock(&connectivity_threads_lock);
 675
 676     if (status < 0) {
 677       connectivity_netlink_thread_error = 1;
 678       break;
 679     }
 680   } /* while (connectivity_netlink_thread_loop > 0) */
 681
 682   pthread_mutex_unlock(&connectivity_threads_lock);
 683
 684   return (void *)0;
 685 } /* }}} void *connectivity_netlink_thread */
 686
 687 static void *connectivity_dequeue_thread(void *arg) /* {{{ */
 688 {
 689   pthread_mutex_lock(&connectivity_threads_lock);
 690
 691   while (connectivity_dequeue_thread_loop > 0) {
 692     pthread_mutex_unlock(&connectivity_threads_lock);
 693
 694     read_interface_status();
 695
 696     pthread_mutex_lock(&connectivity_threads_lock);
 697   } /* while (connectivity_dequeue_thread_loop > 0) */
 698
 699   pthread_mutex_unlock(&connectivity_threads_lock);
 700
 701   return ((void *)0);
 702 } /* }}} void *connectivity_dequeue_thread */
 703
 704 static int nl_connect() {
 705   struct sockaddr_nl sa_nl = {
 706       .nl_family = AF_NETLINK,
 707       .nl_groups = RTMGRP_LINK,
 708       .nl_pid = getpid(),
 709   };
 710
 711   nl_sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 712   if (nl_sock == -1) {
 713     ERROR("connectivity plugin: socket open failed: %s", STRERRNO);
 714     return -1;
 715   }
 716
 717   int rc = bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl));
 718   if (rc == -1) {
 719     ERROR("connectivity plugin: socket bind failed: %s", STRERRNO);
 720     close(nl_sock);
 721     nl_sock = -1;
 722     return -1;
 723   }
 724
 725   return 0;
 726 }
 727
 728 static int start_netlink_thread(void) /* {{{ */
 729 {
 730   pthread_mutex_lock(&connectivity_threads_lock);
 731
 732   if (connectivity_netlink_thread_loop != 0) {
 733     pthread_mutex_unlock(&connectivity_threads_lock);
 734     return 0;
 735   }
 736
 737   connectivity_netlink_thread_loop = 1;
 738   connectivity_netlink_thread_error = 0;
 739
 740   int status;
 741
 742   if (nl_sock == -1) {
 743     status = nl_connect();
 744
 745     if (status != 0) {
 746       pthread_mutex_unlock(&connectivity_threads_lock);
 747       return status;
 748     }
 749   }
 750
 751   status = plugin_thread_create(&connectivity_netlink_thread_id,
 752                                 /* attr = */ NULL, connectivity_netlink_thread,
 753                                 /* arg = */ (void *)0, "connectivity");
 754   if (status != 0) {
 755     connectivity_netlink_thread_loop = 0;
 756     ERROR("connectivity plugin: Starting thread failed.");
 757     pthread_mutex_unlock(&connectivity_threads_lock);
 758
 759     int status2 = close(nl_sock);
 760
 761     if (status2 != 0) {
 762       ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
 763             status2, STRERRNO);
 764     }
 765
 766     nl_sock = -1;
 767
 768     return -1;
 769   }
 770
 771   pthread_mutex_unlock(&connectivity_threads_lock);
 772
 773   return status;
 774 }
 775
 776 static int start_dequeue_thread(void) /* {{{ */
 777 {
 778   pthread_mutex_lock(&connectivity_threads_lock);
 779
 780   if (connectivity_dequeue_thread_loop != 0) {
 781     pthread_mutex_unlock(&connectivity_threads_lock);
 782     return 0;
 783   }
 784
 785   connectivity_dequeue_thread_loop = 1;
 786
 787   int status =
 788       plugin_thread_create(&connectivity_dequeue_thread_id,
 789                            /* attr = */ NULL, connectivity_dequeue_thread,
 790                            /* arg = */ (void *)0, "connectivity");
 791   if (status != 0) {
 792     connectivity_dequeue_thread_loop = 0;
 793     ERROR("connectivity plugin: Starting dequeue thread failed.");
 794     pthread_mutex_unlock(&connectivity_threads_lock);
 795     return -1;
 796   }
 797
 798   pthread_mutex_unlock(&connectivity_threads_lock);
 799
 800   return status;
 801 } /* }}} int start_dequeue_thread */
 802
 803 static int start_threads(void) /* {{{ */
 804 {
 805   int status = start_netlink_thread();
 806   int status2 = start_dequeue_thread();
 807
 808   if (status != 0)
 809     return status;
 810   else
 811     return status2;
 812 } /* }}} int start_threads */
 813
 814 static int stop_netlink_thread(int shutdown) /* {{{ */
 815 {
 816   int socket_status;
 817
 818   if (nl_sock != -1) {
 819     socket_status = close(nl_sock);
 820     if (socket_status != 0) {
 821       ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
 822             socket_status, STRERRNO);
 823     }
 824
 825     nl_sock = -1;
 826   } else
 827     socket_status = 0;
 828
 829   pthread_mutex_lock(&connectivity_threads_lock);
 830
 831   if (connectivity_netlink_thread_loop == 0) {
 832     pthread_mutex_unlock(&connectivity_threads_lock);
 833     // Thread has already been terminated, nothing more to attempt
 834     return socket_status;
 835   }
 836
 837   // Set thread termination status
 838   connectivity_netlink_thread_loop = 0;
 839   pthread_mutex_unlock(&connectivity_threads_lock);
 840
 841   // Let threads waiting on access to the interface list know to move
 842   // on such that they'll see the thread's termination status
 843   pthread_cond_broadcast(&connectivity_cond);
 844
 845   int thread_status;
 846
 847   if (shutdown == 1) {
 848     // Since the thread is blocking, calling pthread_join
 849     // doesn't actually succeed in stopping it.  It will stick around
 850     // until a NETLINK message is received on the socket (at which
 851     // it will realize that "connectivity_netlink_thread_loop" is 0 and will
 852     // break out of the read loop and be allowed to die).  This is
 853     // fine when the process isn't supposed to be exiting, but in
 854     // the case of a process shutdown, we don't want to have an
 855     // idle thread hanging around.  Calling pthread_cancel here in
 856     // the case of a shutdown is just assures that the thread is
 857     // gone and that the process has been fully terminated.
 858
 859     DEBUG("connectivity plugin: Canceling netlink thread for process shutdown");
 860
 861     thread_status = pthread_cancel(connectivity_netlink_thread_id);
 862
 863     if (thread_status != 0 && thread_status != ESRCH) {
 864       ERROR("connectivity plugin: Unable to cancel netlink thread: %d",
 865             thread_status);
 866       thread_status = -1;
 867     } else
 868       thread_status = 0;
 869   } else {
 870     thread_status =
 871         pthread_join(connectivity_netlink_thread_id, /* return = */ NULL);
 872     if (thread_status != 0 && thread_status != ESRCH) {
 873       ERROR("connectivity plugin: Stopping netlink thread failed: %d",
 874             thread_status);
 875       thread_status = -1;
 876     } else
 877       thread_status = 0;
 878   }
 879
 880   pthread_mutex_lock(&connectivity_threads_lock);
 881   memset(&connectivity_netlink_thread_id, 0,
 882          sizeof(connectivity_netlink_thread_id));
 883   connectivity_netlink_thread_error = 0;
 884   pthread_mutex_unlock(&connectivity_threads_lock);
 885
 886   DEBUG("connectivity plugin: Finished requesting stop of netlink thread");
 887
 888   if (socket_status != 0)
 889     return socket_status;
 890   else
 891     return thread_status;
 892 }
 893
 894 static int stop_dequeue_thread() /* {{{ */
 895 {
 896   pthread_mutex_lock(&connectivity_threads_lock);
 897
 898   if (connectivity_dequeue_thread_loop == 0) {
 899     pthread_mutex_unlock(&connectivity_threads_lock);
 900     return -1;
 901   }
 902
 903   // Set thread termination status
 904   connectivity_dequeue_thread_loop = 0;
 905   pthread_mutex_unlock(&connectivity_threads_lock);
 906
 907   // Let threads waiting on access to the interface list know to move
 908   // on such that they'll see the threads termination status
 909   pthread_cond_broadcast(&connectivity_cond);
 910
 911   // Calling pthread_cancel here just assures that the thread is
 912   // gone and that the process has been fully terminated.
 913
 914   DEBUG("connectivity plugin: Canceling dequeue thread for process shutdown");
 915
 916   int status = pthread_cancel(connectivity_dequeue_thread_id);
 917
 918   if (status != 0 && status != ESRCH) {
 919     ERROR("connectivity plugin: Unable to cancel dequeue thread: %d", status);
 920     status = -1;
 921   } else
 922     status = 0;
 923
 924   pthread_mutex_lock(&connectivity_threads_lock);
 925   memset(&connectivity_dequeue_thread_id, 0,
 926          sizeof(connectivity_dequeue_thread_id));
 927   pthread_mutex_unlock(&connectivity_threads_lock);
 928
 929   DEBUG("connectivity plugin: Finished requesting stop of dequeue thread");
 930
 931   return status;
 932 } /* }}} int stop_dequeue_thread */
 933
 934 static int stop_threads() /* {{{ */
 935 {
 936   int status = stop_netlink_thread(1);
 937   int status2 = stop_dequeue_thread();
 938
 939   if (status != 0)
 940     return status;
 941   else
 942     return status2;
 943 } /* }}} int stop_threads */
 944
 945 static int connectivity_init(void) /* {{{ */
 946 {
 947   if (monitor_all_interfaces) {
 948     NOTICE("connectivity plugin: No interfaces have been selected, so all will "
 949            "be monitored");
 950   }
 951
 952   return start_threads();
 953 } /* }}} int connectivity_init */
 954
 955 static int connectivity_config(const char *key, const char *value) /* {{{ */
 956 {
 957   if (ignorelist == NULL) {
 958     ignorelist = ignorelist_create(/* invert = */ 1);
 959
 960     if (ignorelist == NULL)
 961       return -1;
 962   }
 963
 964   if (strcasecmp(key, "Interface") == 0) {
 965     ignorelist_add(ignorelist, value);
 966     monitor_all_interfaces = 0;
 967   } else if (strcasecmp(key, "IgnoreSelected") == 0) {
 968     int invert = 1;
 969     if (IS_TRUE(value))
 970       invert = 0;
 971     ignorelist_set_invert(ignorelist, invert);
 972   } else {
 973     return -1;
 974   }
 975
 976   return 0;
 977 } /* }}} int connectivity_config */
 978
 979 static int connectivity_read(void) /* {{{ */
 980 {
 981   pthread_mutex_lock(&connectivity_threads_lock);
 982
 983   if (connectivity_netlink_thread_error != 0) {
 984
 985     pthread_mutex_unlock(&connectivity_threads_lock);
 986
 987     ERROR("connectivity plugin: The netlink thread had a problem. Restarting "
 988           "it.");
 989
 990     stop_netlink_thread(0);
 991
 992     for (interface_list_t *il = interface_list_head; il != NULL;
 993          il = il->next) {
 994       il->status = LINK_STATE_UNKNOWN;
 995       il->prev_status = LINK_STATE_UNKNOWN;
 996       il->sent = 0;
 997     }
 998
 999     start_netlink_thread();
1000
1001     return -1;
1002   } /* if (connectivity_netlink_thread_error != 0) */
1003
1004   pthread_mutex_unlock(&connectivity_threads_lock);
1005
1006   return 0;
1007 } /* }}} int connectivity_read */
1008
1009 static int connectivity_shutdown(void) /* {{{ */
1010 {
1011   DEBUG("connectivity plugin: Shutting down thread.");
1012
1013   int status = stop_threads();
1014
1015   interface_list_t *il = interface_list_head;
1016   while (il != NULL) {
1017     interface_list_t *il_next;
1018
1019     il_next = il->next;
1020
1021     sfree(il->interface);
1022     sfree(il);
1023
1024     il = il_next;
1025   }
1026
1027   ignorelist_free(ignorelist);
1028
1029   return status;
1030 } /* }}} int connectivity_shutdown */
1031
1032 void module_register(void) {
1033   plugin_register_config("connectivity", connectivity_config, config_keys,
1034                          config_keys_num);
1035   plugin_register_init("connectivity", connectivity_init);
1036   plugin_register_read("connectivity", connectivity_read);
1037   plugin_register_shutdown("connectivity", connectivity_shutdown);
1038 } /* void module_register */