make control interface stream IDs monotonically increasing to prevent possible races

svn:r3715

src/or/connection.c

@@ -110,6 +110,7 @@ static int connection_bucket_read_limit(connection_t *conn);
  * Initialize conn's timestamps to now.
  */
 connection_t *connection_new(int type) {
+  static uint32_t n_connections_allocated = 0;
   connection_t *conn;
   time_t now = time(NULL);
 
@@ -117,6 +118,7 @@ connection_t *connection_new(int type) {
   conn->magic = CONNECTION_MAGIC;
   conn->s = -1; /* give it a default of 'not used' */
   conn->poll_index = -1; /* also default to 'not used' */
+  conn->global_identifier = n_connections_allocated++;
 
   conn->type = type;
   if (!connection_is_listener(conn)) { /* listeners never use their buf */

src/or/control.c

@@ -769,7 +769,7 @@ control_event_stream_status(connection_t *conn, stream_status_event_t tp)
   len = strlen(buf);
   msg = tor_malloc(5+len+1);
   msg[0] = (uint8_t) tp;
-  set_uint32(msg+1, htonl(conn->s)); /* ???? Is this a security problem? */
+  set_uint32(msg+1, htonl(conn->global_identifier));
   strlcpy(msg+5, buf, len+1);
 
   send_control_event(EVENT_STREAM_STATUS, (uint16_t)(5+len+1), msg);

src/or/or.h

@@ -598,6 +598,10 @@ struct connection_t {
   socks_request_t *socks_request; /**< SOCKS structure describing request (AP
                                    * only.) */
 
+  /** Quasi-global identifier for this connection; used for control.c */
+  /* XXXX NM This can get re-used after 2**32 circuits. */
+  uint32_t global_identifier;
+
   /* Used only by control connections */
   uint32_t event_mask;
 };
@@ -874,7 +878,7 @@ struct circuit_t {
   struct circuit_t *rend_splice;
 
   /** Quasi-global identifier for this circuit; used for control.c */
-  /* XXXX009 NM This can get re-used after 2**32 circuits. */
+  /* XXXX NM This can get re-used after 2**32 circuits. */
   uint32_t global_identifier;
 
   struct circuit_t *next; /**< Next circuit in linked list. */