Merge pull request #3329 from efuss/fix-3311
[collectd.git] / src / connectivity.c
index 5a27fe1..45b65aa 100644 (file)
@@ -27,8 +27,9 @@
 
 #include "collectd.h"
 
-#include "common.h"
 #include "plugin.h"
+#include "utils/common/common.h"
+#include "utils/ignorelist/ignorelist.h"
 #include "utils_complain.h"
 
 #include <asm/types.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
 
+#include <yajl/yajl_common.h>
+#include <yajl/yajl_gen.h>
+#if HAVE_YAJL_YAJL_VERSION_H
+#include <yajl/yajl_version.h>
+#endif
+#if defined(YAJL_MAJOR) && (YAJL_MAJOR > 1)
+#define HAVE_YAJL_V2 1
+#endif
+
 #define MYPROTO NETLINK_ROUTE
 
+#define LINK_STATE_DOWN 0
+#define LINK_STATE_UP 1
+#define LINK_STATE_UNKNOWN 2
+
+#define CONNECTIVITY_DOMAIN_FIELD "domain"
+#define CONNECTIVITY_DOMAIN_VALUE "stateChange"
+#define CONNECTIVITY_EVENT_ID_FIELD "eventId"
+#define CONNECTIVITY_EVENT_NAME_FIELD "eventName"
+#define CONNECTIVITY_EVENT_NAME_DOWN_VALUE "down"
+#define CONNECTIVITY_EVENT_NAME_UP_VALUE "up"
+#define CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD "lastEpochMicrosec"
+#define CONNECTIVITY_PRIORITY_FIELD "priority"
+#define CONNECTIVITY_PRIORITY_VALUE "high"
+#define CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD "reportingEntityName"
+#define CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE "collectd connectivity plugin"
+#define CONNECTIVITY_SEQUENCE_FIELD "sequence"
+#define CONNECTIVITY_SEQUENCE_VALUE "0"
+#define CONNECTIVITY_SOURCE_NAME_FIELD "sourceName"
+#define CONNECTIVITY_START_EPOCH_MICROSEC_FIELD "startEpochMicrosec"
+#define CONNECTIVITY_VERSION_FIELD "version"
+#define CONNECTIVITY_VERSION_VALUE "1.0"
+
+#define CONNECTIVITY_NEW_STATE_FIELD "newState"
+#define CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE "outOfService"
+#define CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE "inService"
+#define CONNECTIVITY_OLD_STATE_FIELD "oldState"
+#define CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE "outOfService"
+#define CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE "inService"
+#define CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD "stateChangeFields"
+#define CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD                         \
+  "stateChangeFieldsVersion"
+#define CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE "1.0"
+#define CONNECTIVITY_STATE_INTERFACE_FIELD "stateInterface"
+
 /*
  * Private data types
  */
-struct interfacelist_s {
+
+struct interface_list_s {
   char *interface;
 
   uint32_t status;
   uint32_t prev_status;
   uint32_t sent;
-  uint32_t sec;
-  uint32_t usec;
+  cdtime_t timestamp;
 
-  struct interfacelist_s *next;
+  struct interface_list_s *next;
 };
-typedef struct interfacelist_s interfacelist_t;
+typedef struct interface_list_s interface_list_t;
 
 /*
  * Private variables
  */
-static interfacelist_t *interfacelist_head = NULL;
 
-static int connectivity_thread_loop = 0;
-static int connectivity_thread_error = 0;
-static pthread_t connectivity_thread_id;
-static pthread_mutex_t connectivity_lock = PTHREAD_MUTEX_INITIALIZER;
+static ignorelist_t *ignorelist = NULL;
+
+static interface_list_t *interface_list_head = NULL;
+static int monitor_all_interfaces = 1;
+
+static int connectivity_netlink_thread_loop = 0;
+static int connectivity_netlink_thread_error = 0;
+static pthread_t connectivity_netlink_thread_id;
+static int connectivity_dequeue_thread_loop = 0;
+static pthread_t connectivity_dequeue_thread_id;
+static pthread_mutex_t connectivity_threads_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t connectivity_data_lock = PTHREAD_MUTEX_INITIALIZER;
 static pthread_cond_t connectivity_cond = PTHREAD_COND_INITIALIZER;
-static struct mnl_socket *sock;
+static int nl_sock = -1;
+static int event_id = 0;
+static int statuses_to_send = 0;
 
-static const char *config_keys[] = {"Interface"};
+static const char *config_keys[] = {"Interface", "IgnoreSelected"};
 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
 
 /*
  * Private functions
  */
 
-static int connectivity_link_state(struct nlmsghdr *msg) {
-  int retval = 0;
-  struct ifinfomsg *ifi = mnl_nlmsg_get_payload(msg);
-  struct nlattr *attr;
-  const char *dev = NULL;
+static int gen_message_payload(int state, int old_state, const char *interface,
+                               cdtime_t timestamp, char **buf) {
+  const unsigned char *buf2;
+  yajl_gen g;
+  char json_str[DATA_MAX_NAME_LEN];
+
+#if !defined(HAVE_YAJL_V2)
+  yajl_gen_config conf = {0};
+#endif
+
+#if HAVE_YAJL_V2
+  size_t len;
+  g = yajl_gen_alloc(NULL);
+  yajl_gen_config(g, yajl_gen_beautify, 0);
+#else
+  unsigned int len;
+  g = yajl_gen_alloc(&conf, NULL);
+#endif
+
+  yajl_gen_clear(g);
+
+  // *** BEGIN common event header ***
+
+  if (yajl_gen_map_open(g) != yajl_gen_status_ok)
+    goto err;
+
+  // domain
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_DOMAIN_FIELD,
+                      strlen(CONNECTIVITY_DOMAIN_FIELD)) != yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_DOMAIN_VALUE,
+                      strlen(CONNECTIVITY_DOMAIN_VALUE)) != yajl_gen_status_ok)
+    goto err;
+
+  // eventId
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_EVENT_ID_FIELD,
+                      strlen(CONNECTIVITY_EVENT_ID_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  event_id = event_id + 1;
+  if (snprintf(json_str, sizeof(json_str), "%d", event_id) < 0) {
+    goto err;
+  }
+
+  if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
+    goto err;
+  }
+
+  // eventName
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_EVENT_NAME_FIELD,
+                      strlen(CONNECTIVITY_EVENT_NAME_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (snprintf(json_str, sizeof(json_str), "interface %s %s", interface,
+               (state == 0 ? CONNECTIVITY_EVENT_NAME_DOWN_VALUE
+                           : CONNECTIVITY_EVENT_NAME_UP_VALUE)) < 0) {
+    goto err;
+  }
+
+  if (yajl_gen_string(g, (u_char *)json_str, strlen(json_str)) !=
+      yajl_gen_status_ok) {
+    goto err;
+  }
+
+  // lastEpochMicrosec
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD,
+                      strlen(CONNECTIVITY_LAST_EPOCH_MICROSEC_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (snprintf(json_str, sizeof(json_str), "%" PRIu64,
+               CDTIME_T_TO_US(cdtime())) < 0) {
+    goto err;
+  }
+
+  if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
+    goto err;
+  }
+
+  // priority
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_PRIORITY_FIELD,
+                      strlen(CONNECTIVITY_PRIORITY_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_PRIORITY_VALUE,
+                      strlen(CONNECTIVITY_PRIORITY_VALUE)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // reportingEntityName
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD,
+                      strlen(CONNECTIVITY_REPORTING_ENTITY_NAME_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE,
+                      strlen(CONNECTIVITY_REPORTING_ENTITY_NAME_VALUE)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // sequence
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_SEQUENCE_FIELD,
+                      strlen(CONNECTIVITY_SEQUENCE_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_number(g, CONNECTIVITY_SEQUENCE_VALUE,
+                      strlen(CONNECTIVITY_SEQUENCE_VALUE)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // sourceName
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_SOURCE_NAME_FIELD,
+                      strlen(CONNECTIVITY_SOURCE_NAME_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_string(g, (u_char *)interface, strlen(interface)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // startEpochMicrosec
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_START_EPOCH_MICROSEC_FIELD,
+                      strlen(CONNECTIVITY_START_EPOCH_MICROSEC_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (snprintf(json_str, sizeof(json_str), "%" PRIu64,
+               CDTIME_T_TO_US(timestamp)) < 0) {
+    goto err;
+  }
+
+  if (yajl_gen_number(g, json_str, strlen(json_str)) != yajl_gen_status_ok) {
+    goto err;
+  }
+
+  // version
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_VERSION_FIELD,
+                      strlen(CONNECTIVITY_VERSION_FIELD)) != yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_number(g, CONNECTIVITY_VERSION_VALUE,
+                      strlen(CONNECTIVITY_VERSION_VALUE)) != yajl_gen_status_ok)
+    goto err;
+
+  // *** END common event header ***
+
+  // *** BEGIN state change fields ***
+
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD,
+                      strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_map_open(g) != yajl_gen_status_ok)
+    goto err;
+
+  // newState
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_NEW_STATE_FIELD,
+                      strlen(CONNECTIVITY_NEW_STATE_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  int new_state_len =
+      (state == 0 ? strlen(CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE)
+                  : strlen(CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE));
+
+  if (yajl_gen_string(g,
+                      (u_char *)(state == 0
+                                     ? CONNECTIVITY_NEW_STATE_FIELD_DOWN_VALUE
+                                     : CONNECTIVITY_NEW_STATE_FIELD_UP_VALUE),
+                      new_state_len) != yajl_gen_status_ok)
+    goto err;
+
+  // oldState
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_OLD_STATE_FIELD,
+                      strlen(CONNECTIVITY_OLD_STATE_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  int old_state_len =
+      (old_state == 0 ? strlen(CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE)
+                      : strlen(CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE));
+
+  if (yajl_gen_string(g,
+                      (u_char *)(old_state == 0
+                                     ? CONNECTIVITY_OLD_STATE_FIELD_DOWN_VALUE
+                                     : CONNECTIVITY_OLD_STATE_FIELD_UP_VALUE),
+                      old_state_len) != yajl_gen_status_ok)
+    goto err;
+
+  // stateChangeFieldsVersion
+  if (yajl_gen_string(g,
+                      (u_char *)CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD,
+                      strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_number(g, CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE,
+                      strlen(CONNECTIVITY_STATE_CHANGE_FIELDS_VERSION_VALUE)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // stateInterface
+  if (yajl_gen_string(g, (u_char *)CONNECTIVITY_STATE_INTERFACE_FIELD,
+                      strlen(CONNECTIVITY_STATE_INTERFACE_FIELD)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  if (yajl_gen_string(g, (u_char *)interface, strlen(interface)) !=
+      yajl_gen_status_ok)
+    goto err;
+
+  // close state change and header fields
+  if (yajl_gen_map_close(g) != yajl_gen_status_ok ||
+      yajl_gen_map_close(g) != yajl_gen_status_ok)
+    goto err;
+
+  // *** END state change fields ***
+
+  if (yajl_gen_get_buf(g, &buf2, &len) != yajl_gen_status_ok)
+    goto err;
+
+  *buf = strdup((char *)buf2);
+
+  if (*buf == NULL) {
+    ERROR("connectivity plugin: strdup failed during gen_message_payload: %s",
+          STRERRNO);
+    goto err;
+  }
+
+  yajl_gen_free(g);
+
+  return 0;
+
+err:
+  yajl_gen_free(g);
+  ERROR("connectivity plugin: gen_message_payload failed to generate JSON");
+  return -1;
+}
+
+static interface_list_t *add_interface(const char *interface, int status,
+                                       int prev_status) {
+  interface_list_t *il = calloc(1, sizeof(*il));
+
+  if (il == NULL) {
+    ERROR("connectivity plugin: calloc failed during add_interface: %s",
+          STRERRNO);
+    return NULL;
+  }
+
+  char *interface2 = strdup(interface);
+  if (interface2 == NULL) {
+    sfree(il);
+    ERROR("connectivity plugin: strdup failed during add_interface: %s",
+          STRERRNO);
+    return NULL;
+  }
+
+  il->interface = interface2;
+  il->status = status;
+  il->prev_status = prev_status;
+  il->timestamp = cdtime();
+  il->sent = 0;
+  il->next = interface_list_head;
+  interface_list_head = il;
 
-  pthread_mutex_lock(&connectivity_lock);
+  DEBUG("connectivity plugin: added interface %s", interface2);
 
-  interfacelist_t *il;
+  return il;
+}
+
+static int connectivity_link_state(struct nlmsghdr *msg) {
+  pthread_mutex_lock(&connectivity_data_lock);
+
+  struct nlattr *attr;
+  struct ifinfomsg *ifi = mnl_nlmsg_get_payload(msg);
 
   /* Scan attribute list for device name. */
   mnl_attr_for_each(attr, msg, sizeof(*ifi)) {
@@ -101,233 +426,423 @@ static int connectivity_link_state(struct nlmsghdr *msg) {
       ERROR("connectivity plugin: connectivity_link_state: IFLA_IFNAME "
             "mnl_attr_validate "
             "failed.");
-      pthread_mutex_unlock(&connectivity_lock);
+      pthread_mutex_unlock(&connectivity_data_lock);
       return MNL_CB_ERROR;
     }
 
-    dev = mnl_attr_get_str(attr);
+    const char *dev = mnl_attr_get_str(attr);
 
-    for (il = interfacelist_head; il != NULL; il = il->next)
+    // Check the list of interfaces we should monitor, if we've chosen
+    // a subset.  If we don't care about this one, abort.
+    if (ignorelist_match(ignorelist, dev) != 0) {
+      DEBUG("connectivity plugin: Ignoring link state change for unmonitored "
+            "interface: %s",
+            dev);
+      break;
+    }
+
+    interface_list_t *il = NULL;
+
+    for (il = interface_list_head; il != NULL; il = il->next)
       if (strcmp(dev, il->interface) == 0)
         break;
 
     if (il == NULL) {
-      INFO("connectivity plugin: Ignoring link state change for unmonitored "
-           "interface: %s",
-           dev);
-    } else {
-      uint32_t prev_status;
-      struct timeval tv;
-
-      gettimeofday(&tv, NULL);
-
-      unsigned long long millisecondsSinceEpoch =
-          (unsigned long long)(tv.tv_sec) * 1000 +
-          (unsigned long long)(tv.tv_usec) / 1000;
-
-      INFO("connectivity plugin (%llu): Interface %s status is now %s",
-           millisecondsSinceEpoch, dev,
-           ((ifi->ifi_flags & IFF_RUNNING) ? "UP" : "DOWN"));
-      prev_status = il->status;
-      il->status = ((ifi->ifi_flags & IFF_RUNNING) ? 1 : 0);
-      il->sec = tv.tv_sec;
-      il->usec = tv.tv_usec;
-      // If the new status is different than the previous status,
-      // store the previous status and set sent to zero
-      if (il->status != prev_status) {
-        il->prev_status = prev_status;
-        il->sent = 0;
+      // We haven't encountered this interface yet, so add it to the linked list
+      il = add_interface(dev, LINK_STATE_UNKNOWN, LINK_STATE_UNKNOWN);
+
+      if (il == NULL) {
+        ERROR("connectivity plugin: unable to add interface %s during "
+              "connectivity_link_state",
+              dev);
+        return MNL_CB_ERROR;
       }
     }
 
-    // no need to loop again, we found the interface name
+    uint32_t prev_status = il->status;
+    il->status =
+        ((ifi->ifi_flags & IFF_RUNNING) ? LINK_STATE_UP : LINK_STATE_DOWN);
+    il->timestamp = cdtime();
+
+    // If the new status is different than the previous status,
+    // store the previous status and set sent to zero, and set the
+    // global flag to indicate there are statuses to dispatch
+    if (il->status != prev_status) {
+      il->prev_status = prev_status;
+      il->sent = 0;
+      statuses_to_send = 1;
+    }
+
+    DEBUG("connectivity plugin (%llu): Interface %s status is now %s",
+          (unsigned long long)il->timestamp, dev,
+          ((ifi->ifi_flags & IFF_RUNNING) ? "UP" : "DOWN"));
+
+    // no need to loop again, we found the interface name attr
     // (otherwise the first if-statement in the loop would
     // have moved us on with 'continue')
     break;
   }
 
-  pthread_mutex_unlock(&connectivity_lock);
+  pthread_mutex_unlock(&connectivity_data_lock);
 
-  return retval;
+  return 0;
 }
 
 static int msg_handler(struct nlmsghdr *msg) {
-  switch (msg->nlmsg_type) {
-  case RTM_NEWADDR:
-    break;
-  case RTM_DELADDR:
-    break;
-  case RTM_NEWROUTE:
-    break;
-  case RTM_DELROUTE:
-    break;
-  case RTM_NEWLINK:
-    connectivity_link_state(msg);
-    break;
-  case RTM_DELLINK:
-    break;
-  default:
-    ERROR("connectivity plugin: msg_handler: Unknown netlink nlmsg_type %d\n",
-          msg->nlmsg_type);
-    break;
+  // We are only interested in RTM_NEWLINK messages
+  if (msg->nlmsg_type != RTM_NEWLINK) {
+    return 0;
   }
-  return 0;
+  return connectivity_link_state(msg);
 }
 
-static int read_event(struct mnl_socket *nl,
-                      int (*msg_handler)(struct nlmsghdr *)) {
-  int status;
+static int read_event(int (*msg_handler)(struct nlmsghdr *)) {
   int ret = 0;
-  char buf[4096];
-  struct nlmsghdr *h;
+  int recv_flags = MSG_DONTWAIT;
 
-  if (nl == NULL)
-    return ret;
+  if (nl_sock == -1 || msg_handler == NULL)
+    return EINVAL;
 
-  status = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+  while (42) {
+    pthread_mutex_lock(&connectivity_threads_lock);
 
-  if (status < 0) {
-    /* Socket non-blocking so bail out once we have read everything */
-    if (errno == EWOULDBLOCK || errno == EAGAIN)
+    if (connectivity_netlink_thread_loop <= 0) {
+      pthread_mutex_unlock(&connectivity_threads_lock);
       return ret;
+    }
 
-    /* Anything else is an error */
-    ERROR("connectivity plugin: read_event: Error mnl_socket_recvfrom: %d\n",
-          status);
-    return status;
-  }
+    pthread_mutex_unlock(&connectivity_threads_lock);
 
-  if (status == 0) {
-    DEBUG("connectivity plugin: read_event: EOF\n");
-  }
+    char buf[4096];
+    int status = recv(nl_sock, buf, sizeof(buf), recv_flags);
 
-  /* We need to handle more than one message per 'recvmsg' */
-  for (h = (struct nlmsghdr *)buf; NLMSG_OK(h, (unsigned int)status);
-       h = NLMSG_NEXT(h, status)) {
-    /* Finish reading */
-    if (h->nlmsg_type == NLMSG_DONE)
-      return ret;
+    if (status < 0) {
+
+      // If there were no more messages to drain from the socket,
+      // then signal the dequeue thread and allow it to dispatch
+      // any saved interface status changes.  Then continue, but
+      // block and wait for new messages
+      if (errno == EWOULDBLOCK || errno == EAGAIN) {
+        pthread_cond_signal(&connectivity_cond);
+
+        recv_flags = 0;
+        continue;
+      }
+
+      if (errno == EINTR) {
+        // Interrupt, so just continue and try again
+        continue;
+      }
+
+      /* Anything else is an error */
+      ERROR("connectivity plugin: read_event: Error recv: %d", status);
+      return status;
+    }
 
-    /* Message is some kind of error */
-    if (h->nlmsg_type == NLMSG_ERROR) {
-      ERROR("connectivity plugin: read_event: Message is an error - decode "
-            "TBD\n");
-      return -1; // Error
+    // Message received successfully, so we'll stop blocking on the
+    // receive call for now (until we get a "would block" error, which
+    // will be handled above)
+    recv_flags = MSG_DONTWAIT;
+
+    if (status == 0) {
+      DEBUG("connectivity plugin: read_event: EOF");
     }
 
-    /* Call message handler */
-    if (msg_handler) {
-      ret = (*msg_handler)(h);
-      if (ret < 0) {
-        ERROR("connectivity plugin: read_event: Message handler error %d\n",
-              ret);
+    /* We need to handle more than one message per 'recvmsg' */
+    for (struct nlmsghdr *h = (struct nlmsghdr *)buf;
+         NLMSG_OK(h, (unsigned int)status); h = NLMSG_NEXT(h, status)) {
+      /* Finish reading */
+      if (h->nlmsg_type == NLMSG_DONE)
         return ret;
+
+      /* Message is some kind of error */
+      if (h->nlmsg_type == NLMSG_ERROR) {
+        struct nlmsgerr *l_err = (struct nlmsgerr *)NLMSG_DATA(h);
+        ERROR("connectivity plugin: read_event: Message is an error: %d",
+              l_err->error);
+        return -1; // Error
+      }
+
+      /* Call message handler */
+      if (msg_handler) {
+        ret = (*msg_handler)(h);
+        if (ret < 0) {
+          ERROR("connectivity plugin: read_event: Message handler error %d",
+                ret);
+          return ret;
+        }
+      } else {
+        ERROR("connectivity plugin: read_event: Error NULL message handler");
+        return -1;
       }
-    } else {
-      ERROR("connectivity plugin: read_event: Error NULL message handler\n");
-      return -1;
     }
   }
 
   return ret;
 }
 
-static void *connectivity_thread(void *arg) /* {{{ */
+static void connectivity_dispatch_notification(const char *interface,
+                                               gauge_t value, gauge_t old_value,
+                                               cdtime_t timestamp) {
+
+  notification_t n = {
+      .severity = (value == LINK_STATE_UP ? NOTIF_OKAY : NOTIF_FAILURE),
+      .time = cdtime(),
+      .plugin = "connectivity",
+      .type = "gauge",
+      .type_instance = "interface_status",
+  };
+
+  sstrncpy(n.host, hostname_g, sizeof(n.host));
+  sstrncpy(n.plugin_instance, interface, sizeof(n.plugin_instance));
+
+  char *buf = NULL;
+
+  gen_message_payload(value, old_value, interface, timestamp, &buf);
+
+  int status = plugin_notification_meta_add_string(&n, "ves", buf);
+
+  if (status < 0) {
+    sfree(buf);
+    ERROR("connectivity plugin: unable to set notification VES metadata: %s",
+          STRERRNO);
+    return;
+  }
+
+  DEBUG("connectivity plugin: notification VES metadata: %s",
+        n.meta->nm_value.nm_string);
+
+  DEBUG("connectivity plugin: dispatching state %d for interface %s",
+        (int)value, interface);
+
+  plugin_dispatch_notification(&n);
+  plugin_notification_meta_free(n.meta);
+
+  // strdup'd in gen_message_payload
+  if (buf != NULL)
+    sfree(buf);
+}
+
+// NOTE: Caller MUST hold connectivity_data_lock when calling this function
+static void send_interface_status() {
+  for (interface_list_t *il = interface_list_head; il != NULL;
+       il = il->next) /* {{{ */
+  {
+    uint32_t status = il->status;
+    uint32_t prev_status = il->prev_status;
+    uint32_t sent = il->sent;
+
+    if (status != prev_status && sent == 0) {
+      connectivity_dispatch_notification(il->interface, status, prev_status,
+                                         il->timestamp);
+      il->sent = 1;
+    }
+  } /* }}} for (il = interface_list_head; il != NULL; il = il->next) */
+
+  statuses_to_send = 0;
+}
+
+static void read_interface_status() /* {{{ */
 {
-  pthread_mutex_lock(&connectivity_lock);
+  pthread_mutex_lock(&connectivity_data_lock);
 
-  while (connectivity_thread_loop > 0) {
-    int status;
+  // If we don't have any interface statuses to dispatch,
+  // then we wait until signalled
+  if (!statuses_to_send)
+    pthread_cond_wait(&connectivity_cond, &connectivity_data_lock);
 
-    pthread_mutex_unlock(&connectivity_lock);
+  send_interface_status();
 
-    status = read_event(sock, msg_handler);
+  pthread_mutex_unlock(&connectivity_data_lock);
+} /* }}} int *read_interface_status */
+
+static void *connectivity_netlink_thread(void *arg) /* {{{ */
+{
+  pthread_mutex_lock(&connectivity_threads_lock);
 
-    pthread_mutex_lock(&connectivity_lock);
+  while (connectivity_netlink_thread_loop > 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+
+    int status = read_event(msg_handler);
+
+    pthread_mutex_lock(&connectivity_threads_lock);
 
     if (status < 0) {
-      connectivity_thread_error = 1;
+      connectivity_netlink_thread_error = 1;
       break;
     }
+  } /* while (connectivity_netlink_thread_loop > 0) */
 
-    if (connectivity_thread_loop <= 0)
-      break;
-  } /* while (connectivity_thread_loop > 0) */
+  pthread_mutex_unlock(&connectivity_threads_lock);
+
+  return (void *)0;
+} /* }}} void *connectivity_netlink_thread */
+
+static void *connectivity_dequeue_thread(void *arg) /* {{{ */
+{
+  pthread_mutex_lock(&connectivity_threads_lock);
+
+  while (connectivity_dequeue_thread_loop > 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+
+    read_interface_status();
+
+    pthread_mutex_lock(&connectivity_threads_lock);
+  } /* while (connectivity_dequeue_thread_loop > 0) */
 
-  pthread_mutex_unlock(&connectivity_lock);
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
   return ((void *)0);
-} /* }}} void *connectivity_thread */
+} /* }}} void *connectivity_dequeue_thread */
+
+static int nl_connect() {
+  struct sockaddr_nl sa_nl = {
+      .nl_family = AF_NETLINK,
+      .nl_groups = RTMGRP_LINK,
+      .nl_pid = getpid(),
+  };
+
+  nl_sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+  if (nl_sock == -1) {
+    ERROR("connectivity plugin: socket open failed: %s", STRERRNO);
+    return -1;
+  }
 
-static int start_thread(void) /* {{{ */
-{
-  int status;
+  int rc = bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl));
+  if (rc == -1) {
+    ERROR("connectivity plugin: socket bind failed: %s", STRERRNO);
+    close(nl_sock);
+    nl_sock = -1;
+    return -1;
+  }
 
-  pthread_mutex_lock(&connectivity_lock);
+  return 0;
+}
 
-  if (connectivity_thread_loop != 0) {
-    pthread_mutex_unlock(&connectivity_lock);
-    return (0);
+static int start_netlink_thread(void) /* {{{ */
+{
+  pthread_mutex_lock(&connectivity_threads_lock);
+
+  if (connectivity_netlink_thread_loop != 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+    return 0;
   }
 
-  connectivity_thread_loop = 1;
-  connectivity_thread_error = 0;
+  connectivity_netlink_thread_loop = 1;
+  connectivity_netlink_thread_error = 0;
 
-  if (sock == NULL) {
-    sock = mnl_socket_open(NETLINK_ROUTE);
-    if (sock == NULL) {
-      ERROR(
-          "connectivity plugin: connectivity_thread: mnl_socket_open failed.");
-      pthread_mutex_unlock(&connectivity_lock);
-      return (-1);
-    }
+  int status;
 
-    if (mnl_socket_bind(sock, RTMGRP_LINK, MNL_SOCKET_AUTOPID) < 0) {
-      ERROR(
-          "connectivity plugin: connectivity_thread: mnl_socket_bind failed.");
-      pthread_mutex_unlock(&connectivity_lock);
-      return (1);
+  if (nl_sock == -1) {
+    status = nl_connect();
+
+    if (status != 0) {
+      pthread_mutex_unlock(&connectivity_threads_lock);
+      return status;
     }
   }
 
-  status = plugin_thread_create(&connectivity_thread_id, /* attr = */ NULL,
-                                connectivity_thread,
+  status = plugin_thread_create(&connectivity_netlink_thread_id,
+                                /* attr = */ NULL, connectivity_netlink_thread,
                                 /* arg = */ (void *)0, "connectivity");
   if (status != 0) {
-    connectivity_thread_loop = 0;
+    connectivity_netlink_thread_loop = 0;
     ERROR("connectivity plugin: Starting thread failed.");
-    pthread_mutex_unlock(&connectivity_lock);
-    mnl_socket_close(sock);
-    return (-1);
+    pthread_mutex_unlock(&connectivity_threads_lock);
+
+    int status2 = close(nl_sock);
+
+    if (status2 != 0) {
+      ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
+            status2, STRERRNO);
+    }
+
+    nl_sock = -1;
+
+    return -1;
   }
 
-  pthread_mutex_unlock(&connectivity_lock);
-  return (0);
-} /* }}} int start_thread */
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
-static int stop_thread(int shutdown) /* {{{ */
+  return status;
+}
+
+static int start_dequeue_thread(void) /* {{{ */
 {
-  int status;
+  pthread_mutex_lock(&connectivity_threads_lock);
+
+  if (connectivity_dequeue_thread_loop != 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+    return 0;
+  }
+
+  connectivity_dequeue_thread_loop = 1;
+
+  int status =
+      plugin_thread_create(&connectivity_dequeue_thread_id,
+                           /* attr = */ NULL, connectivity_dequeue_thread,
+                           /* arg = */ (void *)0, "connectivity");
+  if (status != 0) {
+    connectivity_dequeue_thread_loop = 0;
+    ERROR("connectivity plugin: Starting dequeue thread failed.");
+    pthread_mutex_unlock(&connectivity_threads_lock);
+    return -1;
+  }
 
-  if (sock != NULL)
-    mnl_socket_close(sock);
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
-  pthread_mutex_lock(&connectivity_lock);
+  return status;
+} /* }}} int start_dequeue_thread */
 
-  if (connectivity_thread_loop == 0) {
-    pthread_mutex_unlock(&connectivity_lock);
-    return (-1);
+static int start_threads(void) /* {{{ */
+{
+  int status = start_netlink_thread();
+  int status2 = start_dequeue_thread();
+
+  if (status != 0)
+    return status;
+  else
+    return status2;
+} /* }}} int start_threads */
+
+static int stop_netlink_thread(int shutdown) /* {{{ */
+{
+  int socket_status;
+
+  if (nl_sock != -1) {
+    socket_status = close(nl_sock);
+    if (socket_status != 0) {
+      ERROR("connectivity plugin: failed to close socket %d: %d (%s)", nl_sock,
+            socket_status, STRERRNO);
+    }
+
+    nl_sock = -1;
+  } else
+    socket_status = 0;
+
+  pthread_mutex_lock(&connectivity_threads_lock);
+
+  if (connectivity_netlink_thread_loop == 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+    // Thread has already been terminated, nothing more to attempt
+    return socket_status;
   }
 
-  connectivity_thread_loop = 0;
+  // Set thread termination status
+  connectivity_netlink_thread_loop = 0;
+  pthread_mutex_unlock(&connectivity_threads_lock);
+
+  // Let threads waiting on access to the interface list know to move
+  // on such that they'll see the thread's termination status
   pthread_cond_broadcast(&connectivity_cond);
-  pthread_mutex_unlock(&connectivity_lock);
+
+  int thread_status;
 
   if (shutdown == 1) {
     // Since the thread is blocking, calling pthread_join
     // doesn't actually succeed in stopping it.  It will stick around
     // until a NETLINK message is received on the socket (at which
-    // it will realize that "connectivity_thread_loop" is 0 and will
+    // it will realize that "connectivity_netlink_thread_loop" is 0 and will
     // break out of the read loop and be allowed to die).  This is
     // fine when the process isn't supposed to be exiting, but in
     // the case of a process shutdown, we don't want to have an
@@ -335,177 +850,165 @@ static int stop_thread(int shutdown) /* {{{ */
     // the case of a shutdown is just assures that the thread is
     // gone and that the process has been fully terminated.
 
-    INFO("connectivity plugin: Canceling thread for process shutdown");
+    DEBUG("connectivity plugin: Canceling netlink thread for process shutdown");
 
-    status = pthread_cancel(connectivity_thread_id);
+    thread_status = pthread_cancel(connectivity_netlink_thread_id);
 
-    if (status != 0) {
-      ERROR("connectivity plugin: Unable to cancel thread: %d", status);
-      status = -1;
-    }
+    if (thread_status != 0 && thread_status != ESRCH) {
+      ERROR("connectivity plugin: Unable to cancel netlink thread: %d",
+            thread_status);
+      thread_status = -1;
+    } else
+      thread_status = 0;
   } else {
-    status = pthread_join(connectivity_thread_id, /* return = */ NULL);
-    if (status != 0) {
-      ERROR("connectivity plugin: Stopping thread failed.");
-      status = -1;
-    }
+    thread_status =
+        pthread_join(connectivity_netlink_thread_id, /* return = */ NULL);
+    if (thread_status != 0 && thread_status != ESRCH) {
+      ERROR("connectivity plugin: Stopping netlink thread failed: %d",
+            thread_status);
+      thread_status = -1;
+    } else
+      thread_status = 0;
   }
 
-  pthread_mutex_lock(&connectivity_lock);
-  memset(&connectivity_thread_id, 0, sizeof(connectivity_thread_id));
-  connectivity_thread_error = 0;
-  pthread_mutex_unlock(&connectivity_lock);
+  pthread_mutex_lock(&connectivity_threads_lock);
+  memset(&connectivity_netlink_thread_id, 0,
+         sizeof(connectivity_netlink_thread_id));
+  connectivity_netlink_thread_error = 0;
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
-  INFO("connectivity plugin: Finished requesting stop of thread");
+  DEBUG("connectivity plugin: Finished requesting stop of netlink thread");
 
-  return (status);
-} /* }}} int stop_thread */
+  if (socket_status != 0)
+    return socket_status;
+  else
+    return thread_status;
+}
 
-static int connectivity_init(void) /* {{{ */
+static int stop_dequeue_thread() /* {{{ */
 {
-  if (interfacelist_head == NULL) {
-    NOTICE("connectivity plugin: No interfaces have been configured.");
-    return (-1);
+  pthread_mutex_lock(&connectivity_threads_lock);
+
+  if (connectivity_dequeue_thread_loop == 0) {
+    pthread_mutex_unlock(&connectivity_threads_lock);
+    return -1;
   }
 
-  return (start_thread());
-} /* }}} int connectivity_init */
+  // Set thread termination status
+  connectivity_dequeue_thread_loop = 0;
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
-static int connectivity_config(const char *key, const char *value) /* {{{ */
-{
-  if (strcasecmp(key, "Interface") == 0) {
-    interfacelist_t *il;
-    char *interface;
+  // Let threads waiting on access to the interface list know to move
+  // on such that they'll see the threads termination status
+  pthread_cond_broadcast(&connectivity_cond);
 
-    il = malloc(sizeof(*il));
-    if (il == NULL) {
-      char errbuf[1024];
-      ERROR("connectivity plugin: malloc failed during connectivity_config: %s",
-            sstrerror(errno, errbuf, sizeof(errbuf)));
-      return (1);
-    }
+  // Calling pthread_cancel here just assures that the thread is
+  // gone and that the process has been fully terminated.
 
-    interface = strdup(value);
-    if (interface == NULL) {
-      char errbuf[1024];
-      sfree(il);
-      ERROR("connectivity plugin: strdup failed connectivity_config: %s",
-            sstrerror(errno, errbuf, sizeof(errbuf)));
-      return (1);
-    }
+  DEBUG("connectivity plugin: Canceling dequeue thread for process shutdown");
 
-    il->interface = interface;
-    il->status = 2; // "unknown"
-    il->prev_status = 2;
-    il->sent = 0;
-    il->next = interfacelist_head;
-    interfacelist_head = il;
+  int status = pthread_cancel(connectivity_dequeue_thread_id);
 
-  } else {
-    return (-1);
-  }
+  if (status != 0 && status != ESRCH) {
+    ERROR("connectivity plugin: Unable to cancel dequeue thread: %d", status);
+    status = -1;
+  } else
+    status = 0;
 
-  return (0);
-} /* }}} int connectivity_config */
+  pthread_mutex_lock(&connectivity_threads_lock);
+  memset(&connectivity_dequeue_thread_id, 0,
+         sizeof(connectivity_dequeue_thread_id));
+  pthread_mutex_unlock(&connectivity_threads_lock);
 
-static void submit(const char *interface, const char *type, /* {{{ */
-                   gauge_t value, uint32_t sec, uint32_t usec) {
-  value_list_t vl = VALUE_LIST_INIT;
-  char hostname[1024];
-  vl.values = &(value_t){.gauge = value};
-  vl.values_len = 1;
-  sstrncpy(vl.plugin, "connectivity", sizeof(vl.plugin));
-  sstrncpy(vl.type_instance, interface, sizeof(vl.type_instance));
-  sstrncpy(vl.type, type, sizeof(vl.type));
-
-  // Create metadata to store JSON key-values
-  meta_data_t *meta = meta_data_create();
-
-  vl.meta = meta;
-  // For latency measurement
-  struct timeval tv;
-  gettimeofday(&tv, NULL);
-  gethostname(hostname, sizeof(hostname));
-  char strSec[11];
-  char struSec[11];
-  snprintf(strSec, sizeof strSec, "%" PRIu32, sec);
-  snprintf(struSec, sizeof struSec, "%" PRIu32, usec);
-  if (value == 1) {
-    meta_data_add_string(meta, "condition", "interface_up");
-    meta_data_add_string(meta, "entity", interface);
-    meta_data_add_string(meta, "source", hostname);
-    meta_data_add_string(meta, "sec", strSec);
-    meta_data_add_string(meta, "usec", struSec);
-    meta_data_add_string(meta, "dest", "interface_down");
-  } else {
-    meta_data_add_string(meta, "condition", "interface_down");
-    meta_data_add_string(meta, "entity", interface);
-    meta_data_add_string(meta, "source", hostname);
-    meta_data_add_string(meta, "sec", strSec);
-    meta_data_add_string(meta, "usec", struSec);
-    meta_data_add_string(meta, "dest", "interface_up");
+  DEBUG("connectivity plugin: Finished requesting stop of dequeue thread");
+
+  return status;
+} /* }}} int stop_dequeue_thread */
+
+static int stop_threads() /* {{{ */
+{
+  int status = stop_netlink_thread(1);
+  int status2 = stop_dequeue_thread();
+
+  if (status != 0)
+    return status;
+  else
+    return status2;
+} /* }}} int stop_threads */
+
+static int connectivity_init(void) /* {{{ */
+{
+  if (monitor_all_interfaces) {
+    NOTICE("connectivity plugin: No interfaces have been selected, so all will "
+           "be monitored");
   }
 
-  plugin_dispatch_values(&vl);
-} /* }}} void interface_submit */
+  return start_threads();
+} /* }}} int connectivity_init */
 
-static int connectivity_read(void) /* {{{ */
+static int connectivity_config(const char *key, const char *value) /* {{{ */
 {
-  if (connectivity_thread_error != 0) {
-    ERROR("connectivity plugin: The interface thread had a problem. Restarting "
-          "it.");
+  if (ignorelist == NULL) {
+    ignorelist = ignorelist_create(/* invert = */ 1);
 
-    stop_thread(0);
+    if (ignorelist == NULL)
+      return -1;
+  }
 
-    for (interfacelist_t *il = interfacelist_head; il != NULL; il = il->next) {
-      il->status = 2; // signifies "unknown"
-      il->prev_status = 2;
-      il->sent = 0;
-    }
+  if (strcasecmp(key, "Interface") == 0) {
+    ignorelist_add(ignorelist, value);
+    monitor_all_interfaces = 0;
+  } else if (strcasecmp(key, "IgnoreSelected") == 0) {
+    int invert = 1;
+    if (IS_TRUE(value))
+      invert = 0;
+    ignorelist_set_invert(ignorelist, invert);
+  } else {
+    return -1;
+  }
 
-    start_thread();
+  return 0;
+} /* }}} int connectivity_config */
 
-    return (-1);
-  } /* if (connectivity_thread_error != 0) */
+static int connectivity_read(void) /* {{{ */
+{
+  pthread_mutex_lock(&connectivity_threads_lock);
 
-  for (interfacelist_t *il = interfacelist_head; il != NULL;
-       il = il->next) /* {{{ */
-  {
-    uint32_t status;
-    uint32_t prev_status;
-    uint32_t sent;
+  if (connectivity_netlink_thread_error != 0) {
 
-    /* Locking here works, because the structure of the linked list is only
-     * changed during configure and shutdown. */
-    pthread_mutex_lock(&connectivity_lock);
+    pthread_mutex_unlock(&connectivity_threads_lock);
 
-    status = il->status;
-    prev_status = il->prev_status;
-    sent = il->sent;
+    ERROR("connectivity plugin: The netlink thread had a problem. Restarting "
+          "it.");
 
-    if (status != prev_status && sent == 0) {
-      submit(il->interface, "gauge", status, il->sec, il->usec);
+    stop_netlink_thread(0);
 
-      il->sent = 1;
+    for (interface_list_t *il = interface_list_head; il != NULL;
+         il = il->next) {
+      il->status = LINK_STATE_UNKNOWN;
+      il->prev_status = LINK_STATE_UNKNOWN;
+      il->sent = 0;
     }
 
-    pthread_mutex_unlock(&connectivity_lock);
-  } /* }}} for (il = interfacelist_head; il != NULL; il = il->next) */
+    start_netlink_thread();
+
+    return -1;
+  } /* if (connectivity_netlink_thread_error != 0) */
 
-  return (0);
+  pthread_mutex_unlock(&connectivity_threads_lock);
+
+  return 0;
 } /* }}} int connectivity_read */
 
 static int connectivity_shutdown(void) /* {{{ */
 {
-  interfacelist_t *il;
+  DEBUG("connectivity plugin: Shutting down thread.");
 
-  INFO("connectivity plugin: Shutting down thread.");
-  if (stop_thread(1) < 0)
-    return (-1);
+  int status = stop_threads();
 
-  il = interfacelist_head;
+  interface_list_t *il = interface_list_head;
   while (il != NULL) {
-    interfacelist_t *il_next;
+    interface_list_t *il_next;
 
     il_next = il->next;
 
@@ -515,7 +1018,9 @@ static int connectivity_shutdown(void) /* {{{ */
     il = il_next;
   }
 
-  return (0);
+  ignorelist_free(ignorelist);
+
+  return status;
 } /* }}} int connectivity_shutdown */
 
 void module_register(void) {