Rework origin circuit tracking to use pubsub

Part of ticket 29976.

4 files changed, 108 insertions, 83 deletions

diff --git a/src/core/or/circuitbuild.c b/src/core/or/circuitbuild.c
index 3a4e729429..ff809c01cf 100644
--- a/src/core/or/circuitbuild.c
+++ b/src/core/or/circuitbuild.c
@@ -522,14 +522,13 @@ origin_circuit_get_guard_state(origin_circuit_t *circ)
 static void
 circuit_chan_publish(const origin_circuit_t *circ, const channel_t *chan)
 {
-  ocirc_event_msg_t msg;
+  ocirc_chan_msg_t *msg = tor_malloc(sizeof(*msg));
 
-  msg.type = OCIRC_MSGTYPE_CHAN;
-  msg.u.chan.gid = circ->global_identifier;
-  msg.u.chan.chan = chan->global_identifier;
-  msg.u.chan.onehop = circ->build_state->onehop_tunnel;
+  msg->gid = circ->global_identifier;
+  msg->chan = chan->global_identifier;
+  msg->onehop = circ->build_state->onehop_tunnel;
 
-  ocirc_event_publish(&msg);
+  ocirc_chan_publish(msg);
 }
 
 /** Start establishing the first hop of our circuit. Figure out what
diff --git a/src/core/or/circuitlist.c b/src/core/or/circuitlist.c
index 72952a8a52..55f04a77b9 100644
--- a/src/core/or/circuitlist.c
+++ b/src/core/or/circuitlist.c
@@ -496,17 +496,16 @@ int
 circuit_event_status(origin_circuit_t *circ, circuit_status_event_t tp,
                      int reason_code)
 {
-  ocirc_event_msg_t msg;
+  ocirc_cevent_msg_t *msg = tor_malloc(sizeof(*msg));
 
   tor_assert(circ);
 
-  msg.type = OCIRC_MSGTYPE_CEVENT;
-  msg.u.cevent.gid = circ->global_identifier;
-  msg.u.cevent.evtype = tp;
-  msg.u.cevent.reason = reason_code;
-  msg.u.cevent.onehop = circ->build_state->onehop_tunnel;
+  msg->gid = circ->global_identifier;
+  msg->evtype = tp;
+  msg->reason = reason_code;
+  msg->onehop = circ->build_state->onehop_tunnel;
 
-  ocirc_event_publish(&msg);
+  ocirc_cevent_publish(msg);
   return control_event_circuit_status(circ, tp, reason_code);
 }
 
@@ -514,26 +513,25 @@ circuit_event_status(origin_circuit_t *circ, circuit_status_event_t tp,
  * Helper function to publish a state change message
  *
  * circuit_set_state() calls this to notify subscribers about a change
- * of the state of an origin circuit.
+ * of the state of an origin circuit.  @a circ must be an origin
+ * circuit.
  **/
 static void
 circuit_state_publish(const circuit_t *circ)
 {
-  ocirc_event_msg_t msg;
+  ocirc_state_msg_t *msg = tor_malloc(sizeof(*msg));
   const origin_circuit_t *ocirc;
 
-  if (!CIRCUIT_IS_ORIGIN(circ))
-    return;
+  tor_assert(CIRCUIT_IS_ORIGIN(circ));
   ocirc = CONST_TO_ORIGIN_CIRCUIT(circ);
   /* Only inbound OR circuits can be in this state, not origin circuits. */
   tor_assert(circ->state != CIRCUIT_STATE_ONIONSKIN_PENDING);
 
-  msg.type = OCIRC_MSGTYPE_STATE;
-  msg.u.state.gid = ocirc->global_identifier;
-  msg.u.state.state = circ->state;
-  msg.u.state.onehop = ocirc->build_state->onehop_tunnel;
+  msg->gid = ocirc->global_identifier;
+  msg->state = circ->state;
+  msg->onehop = ocirc->build_state->onehop_tunnel;
 
-  ocirc_event_publish(&msg);
+  ocirc_state_publish(msg);
 }
 
 /** Change the state of <b>circ</b> to <b>state</b>, adding it to or removing
@@ -565,7 +563,8 @@ circuit_set_state(circuit_t *circ, uint8_t state)
   if (state == CIRCUIT_STATE_GUARD_WAIT || state == CIRCUIT_STATE_OPEN)
     tor_assert(!circ->n_chan_create_cell);
   circ->state = state;
-  circuit_state_publish(circ);
+  if (CIRCUIT_IS_ORIGIN(circ))
+    circuit_state_publish(circ);
 }
 
 /** Append to <b>out</b> all circuits in state CHAN_WAIT waiting for
diff --git a/src/core/or/ocirc_event.c b/src/core/or/ocirc_event.c
index 4a6fc748c9..3cb9147134 100644
--- a/src/core/or/ocirc_event.c
+++ b/src/core/or/ocirc_event.c
@@ -26,59 +26,103 @@
 #include "core/or/origin_circuit_st.h"
 #include "lib/subsys/subsys.h"
 
-/** List of subscribers */
-static smartlist_t *ocirc_event_rcvrs;
+DECLARE_PUBLISH(ocirc_state);
+DECLARE_PUBLISH(ocirc_chan);
+DECLARE_PUBLISH(ocirc_cevent);
+
+static void
+ocirc_event_free(msg_aux_data_t u)
+{
+  tor_free_(u.ptr);
+}
+
+static char *
+ocirc_state_fmt(msg_aux_data_t u)
+{
+  ocirc_state_msg_t *msg = (ocirc_state_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" state=%d onehop=%d>",
+               msg->gid, msg->state, msg->onehop);
+  return s;
+}
+
+static char *
+ocirc_chan_fmt(msg_aux_data_t u)
+{
+  ocirc_chan_msg_t *msg = (ocirc_chan_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" chan=%"PRIu64" onehop=%d>",
+               msg->gid, msg->chan, msg->onehop);
+  return s;
+}
+
+static char *
+ocirc_cevent_fmt(msg_aux_data_t u)
+{
+  ocirc_cevent_msg_t *msg = (ocirc_cevent_msg_t *)u.ptr;
+  char *s = NULL;
+
+  tor_asprintf(&s, "<gid=%"PRIu32" evtype=%d reason=%d onehop=%d>",
+               msg->gid, msg->evtype, msg->reason, msg->onehop);
+  return s;
+}
+
+static dispatch_typefns_t ocirc_state_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_state_fmt,
+};
+
+static dispatch_typefns_t ocirc_chan_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_chan_fmt,
+};
+
+static dispatch_typefns_t ocirc_cevent_fns = {
+  .free_fn = ocirc_event_free,
+  .fmt_fn = ocirc_cevent_fmt,
+};
 
-/** Initialize subscriber list */
 static int
-ocirc_event_init(void)
+ocirc_add_pubsub(struct pubsub_connector_t *connector)
 {
-  ocirc_event_rcvrs = smartlist_new();
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_state, &ocirc_state_fns))
+    return -1;
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_chan, &ocirc_chan_fns))
+    return -1;
+  if (DISPATCH_REGISTER_TYPE(connector, ocirc_cevent, &ocirc_cevent_fns))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_state))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_chan))
+    return -1;
+  if (DISPATCH_ADD_PUB(connector, ocirc, ocirc_cevent))
+    return -1;
   return 0;
 }
 
-/** Free subscriber list */
-static void
-ocirc_event_fini(void)
+void
+ocirc_state_publish(ocirc_state_msg_t *msg)
 {
-  smartlist_free(ocirc_event_rcvrs);
+  PUBLISH(ocirc_state, msg);
 }
 
-/**
- * Subscribe to messages about origin circuit events
- *
- * Register a callback function to receive messages about origin
- * circuits.  The publisher calls this function synchronously.
- **/
 void
-ocirc_event_subscribe(ocirc_event_rcvr_t fn)
+ocirc_chan_publish(ocirc_chan_msg_t *msg)
 {
-  tor_assert(fn);
-  /* Don't duplicate subscriptions. */
-  if (smartlist_contains(ocirc_event_rcvrs, fn))
-    return;
-
-  smartlist_add(ocirc_event_rcvrs, fn);
+  PUBLISH(ocirc_chan, msg);
 }
 
-/**
- * Publish a message about OR connection events
- *
- * This calls the subscriber receiver function synchronously.
- **/
 void
-ocirc_event_publish(const ocirc_event_msg_t *msg)
+ocirc_cevent_publish(ocirc_cevent_msg_t *msg)
 {
-  SMARTLIST_FOREACH_BEGIN(ocirc_event_rcvrs, ocirc_event_rcvr_t, fn) {
-    tor_assert(fn);
-    (*fn)(msg);
-  } SMARTLIST_FOREACH_END(fn);
+  PUBLISH(ocirc_cevent, msg);
 }
 
 const subsys_fns_t sys_ocirc_event = {
   .name = "ocirc_event",
   .supported = true,
   .level = -32,
-  .initialize = ocirc_event_init,
-  .shutdown = ocirc_event_fini,
+  .add_pubsub = ocirc_add_pubsub,
 };
diff --git a/src/core/or/ocirc_event.h b/src/core/or/ocirc_event.h
index 0b125c2898..ad6d69ffbe 100644
--- a/src/core/or/ocirc_event.h
+++ b/src/core/or/ocirc_event.h
@@ -12,6 +12,7 @@
 #include <stdbool.h>
 
 #include "lib/cc/torint.h"
+#include "lib/pubsub/pubsub.h"
 
 /** Used to indicate the type of a circuit event passed to the controller.
  * The various types are defined in control-spec.txt */
@@ -30,6 +31,8 @@ typedef struct ocirc_state_msg_t {
   bool onehop;        /**< one-hop circuit? */
 } ocirc_state_msg_t;
 
+DECLARE_MESSAGE(ocirc_state, ocirc_state, ocirc_state_msg_t *);
+
 /**
  * Message when a channel gets associated to a circuit.
  *
@@ -44,6 +47,8 @@ typedef struct ocirc_chan_msg_t {
   bool onehop;                  /**< one-hop circuit? */
 } ocirc_chan_msg_t;
 
+DECLARE_MESSAGE(ocirc_chan, ocirc_chan, ocirc_chan_msg_t *);
+
 /**
  * Message for origin circuit status event
  *
@@ -56,34 +61,12 @@ typedef struct ocirc_cevent_msg_t {
   bool onehop;                  /**< one-hop circuit? */
 } ocirc_cevent_msg_t;
 
-/** Discriminant values for origin circuit event message */
-typedef enum ocirc_msgtype_t {
-  OCIRC_MSGTYPE_STATE,
-  OCIRC_MSGTYPE_CHAN,
-  OCIRC_MSGTYPE_CEVENT,
-} ocirc_msgtype_t;
-
-/** Discriminated union for the actual message */
-typedef struct ocirc_event_msg_t {
-  int type;
-  union {
-    ocirc_state_msg_t state;
-    ocirc_chan_msg_t chan;
-    ocirc_cevent_msg_t cevent;
-  } u;
-} ocirc_event_msg_t;
-
-/**
- * Receiver function pointer for origin circuit subscribers
- *
- * This function gets called synchronously by the publisher.
- **/
-typedef void (*ocirc_event_rcvr_t)(const ocirc_event_msg_t *);
-
-void ocirc_event_subscribe(ocirc_event_rcvr_t fn);
+DECLARE_MESSAGE(ocirc_cevent, ocirc_cevent, ocirc_cevent_msg_t *);
 
 #ifdef OCIRC_EVENT_PRIVATE
-void ocirc_event_publish(const ocirc_event_msg_t *msg);
+void ocirc_state_publish(ocirc_state_msg_t *msg);
+void ocirc_chan_publish(ocirc_chan_msg_t *msg);
+void ocirc_cevent_publish(ocirc_cevent_msg_t *msg);
 #endif
 
 #endif  /* defined(TOR_OCIRC_EVENT_STATE_H) */