src/core/or/orconn_event.c

   1 /* Copyright (c) 2007-2021, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * \file orconn_event.c
   6  * \brief Publish state change messages for OR connections
   7  *
   8  * Implements a basic publish-subscribe framework for messages about
   9  * the state of OR connections.  The publisher calls the subscriber
  10  * callback functions synchronously.
  11  *
  12  * Although the synchronous calls might not simplify the call graph,
  13  * this approach improves data isolation because the publisher doesn't
  14  * need knowledge about the internals of subscribing subsystems.  It
  15  * also avoids race conditions that might occur in asynchronous
  16  * frameworks.
  17  **/
  18
  19 #include "core/or/or.h"
  20 #include "lib/pubsub/pubsub.h"
  21 #include "lib/subsys/subsys.h"
  22
  23 #define ORCONN_EVENT_PRIVATE
  24 #include "core/or/orconn_event.h"
  25 #include "core/or/or_sys.h"
  26
  27 DECLARE_PUBLISH(orconn_state);
  28 DECLARE_PUBLISH(orconn_status);
  29
  30 static void
  31 orconn_event_free(msg_aux_data_t u)
  32 {
  33   tor_free_(u.ptr);
  34 }
  35
  36 static char *
  37 orconn_state_fmt(msg_aux_data_t u)
  38 {
  39   orconn_state_msg_t *msg = (orconn_state_msg_t *)u.ptr;
  40   char *s = NULL;
  41
  42   tor_asprintf(&s, "<gid=%"PRIu64" chan=%"PRIu64" proxy_type=%d state=%d>",
  43                msg->gid, msg->chan, msg->proxy_type, msg->state);
  44   return s;
  45 }
  46
  47 static char *
  48 orconn_status_fmt(msg_aux_data_t u)
  49 {
  50   orconn_status_msg_t *msg = (orconn_status_msg_t *)u.ptr;
  51   char *s = NULL;
  52
  53   tor_asprintf(&s, "<gid=%"PRIu64" status=%d reason=%d>",
  54                msg->gid, msg->status, msg->reason);
  55   return s;
  56 }
  57
  58 static dispatch_typefns_t orconn_state_fns = {
  59   .free_fn = orconn_event_free,
  60   .fmt_fn = orconn_state_fmt,
  61 };
  62
  63 static dispatch_typefns_t orconn_status_fns = {
  64   .free_fn = orconn_event_free,
  65   .fmt_fn = orconn_status_fmt,
  66 };
  67
  68 int
  69 orconn_add_pubsub(struct pubsub_connector_t *connector)
  70 {
  71   if (DISPATCH_REGISTER_TYPE(connector, orconn_state, &orconn_state_fns))
  72     return -1;
  73   if (DISPATCH_REGISTER_TYPE(connector, orconn_status, &orconn_status_fns))
  74     return -1;
  75   if (DISPATCH_ADD_PUB(connector, orconn, orconn_state) != 0)
  76     return -1;
  77   if (DISPATCH_ADD_PUB(connector, orconn, orconn_status) != 0)
  78     return -1;
  79   return 0;
  80 }
  81
  82 void
  83 orconn_state_publish(orconn_state_msg_t *msg)
  84 {
  85   PUBLISH(orconn_state, msg);
  86 }
  87
  88 void
  89 orconn_status_publish(orconn_status_msg_t *msg)
  90 {
  91   PUBLISH(orconn_status, msg);
  92 }