r6922@Kushana: nickm | 2006-07-26 16:32:24 -0400

 Rename some fields, compress a bitfield, and document some structs and fields


svn:r6919

7 files changed, 123 insertions, 96 deletions

diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 90929d0051..a74ed97a4b 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -420,12 +420,12 @@ circuit_free_cpath_node(crypt_path_t *victim)
  * of information about circuit <b>circ</b>.
  */
 static void
-circuit_dump_details(int severity, circuit_t *circ, int poll_index,
+circuit_dump_details(int severity, circuit_t *circ, int conn_array_index,
                      const char *type, int this_circid, int other_circid)
 {
   log(severity, LD_CIRC, "Conn %d has %s circuit: circID %d (other side %d), "
       "state %d (%s), born %d:",
-      poll_index, type, this_circid, other_circid, circ->state,
+      conn_array_index, type, this_circid, other_circid, circ->state,
       circuit_state_to_string(circ->state), (int)circ->timestamp_created);
   if (CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */
     circuit_log_path(severity, LD_CIRC, TO_ORIGIN_CIRCUIT(circ));
@@ -451,26 +451,26 @@ circuit_dump_by_conn(connection_t *conn, int severity)
 
     if (! CIRCUIT_IS_ORIGIN(circ) && TO_OR_CIRCUIT(circ)->p_conn &&
         TO_CONN(TO_OR_CIRCUIT(circ)->p_conn) == conn)
-      circuit_dump_details(severity, circ, conn->poll_index, "App-ward",
+      circuit_dump_details(severity, circ, conn->conn_array_index, "App-ward",
                            p_circ_id, n_circ_id);
     if (CIRCUIT_IS_ORIGIN(circ)) {
       for (tmpconn=TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
            tmpconn=tmpconn->next_stream) {
         if (TO_CONN(tmpconn) == conn) {
-          circuit_dump_details(severity, circ, conn->poll_index, "App-ward",
-                               p_circ_id, n_circ_id);
+          circuit_dump_details(severity, circ, conn->conn_array_index,
+                               "App-ward", p_circ_id, n_circ_id);
         }
       }
     }
     if (circ->n_conn && TO_CONN(circ->n_conn) == conn)
-      circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward",
+      circuit_dump_details(severity, circ, conn->conn_array_index, "Exit-ward",
                            n_circ_id, p_circ_id);
     if (! CIRCUIT_IS_ORIGIN(circ)) {
       for (tmpconn=TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
            tmpconn=tmpconn->next_stream) {
         if (TO_CONN(tmpconn) == conn) {
-          circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward",
-                               n_circ_id, p_circ_id);
+          circuit_dump_details(severity, circ, conn->conn_array_index,
+                               "Exit-ward", n_circ_id, p_circ_id);
         }
       }
     }
@@ -480,7 +480,7 @@ circuit_dump_by_conn(connection_t *conn, int severity)
         conn->type == CONN_TYPE_OR &&
         !memcmp(TO_OR_CONN(conn)->identity_digest, circ->n_conn_id_digest,
                 DIGEST_LEN)) {
-      circuit_dump_details(severity, circ, conn->poll_index,
+      circuit_dump_details(severity, circ, conn->conn_array_index,
                            (circ->state == CIRCUIT_STATE_OPEN &&
                             !CIRCUIT_IS_ORIGIN(circ)) ?
                              "Endpoint" : "Pending",
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 2d5188c874..ba819de4d3 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -982,13 +982,13 @@ circuit_get_open_circ_or_launch(edge_connection_t *conn,
     if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) {
       if (conn->chosen_exit_name) {
         routerinfo_t *r;
-        int opt = conn->chosen_exit_optional;
+        int opt = conn->_base.chosen_exit_optional;
         if (!(r = router_get_by_nickname(conn->chosen_exit_name, 1))) {
           log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
                  "Requested exit point '%s' is not known. %s.",
                  conn->chosen_exit_name, opt ? "Trying others" : "Closing");
           if (opt) {
-            conn->chosen_exit_optional = 0;
+            conn->_base.chosen_exit_optional = 0;
             tor_free(conn->chosen_exit_name);
             return 0;
           }
@@ -1173,13 +1173,13 @@ connection_ap_handshake_attach_circuit(edge_connection_t *conn)
 
     if (conn->chosen_exit_name) {
       routerinfo_t *router = router_get_by_nickname(conn->chosen_exit_name, 1);
-      int opt = conn->chosen_exit_optional;
+      int opt = conn->_base.chosen_exit_optional;
       if (!router) {
         log_fn(opt ? LOG_INFO : LOG_WARN, LD_APP,
                "Requested exit point '%s' is not known. %s.",
                conn->chosen_exit_name, opt ? "Trying others" : "Closing");
         if (opt) {
-          conn->chosen_exit_optional = 0;
+          conn->_base.chosen_exit_optional = 0;
           tor_free(conn->chosen_exit_name);
           return 0;
         }
@@ -1190,7 +1190,7 @@ connection_ap_handshake_attach_circuit(edge_connection_t *conn)
                "Requested exit point '%s' would refuse request. %s.",
                conn->chosen_exit_name, opt ? "Trying others" : "Closing");
         if (opt) {
-          conn->chosen_exit_optional = 0;
+          conn->_base.chosen_exit_optional = 0;
           tor_free(conn->chosen_exit_name);
           return 0;
         }
diff --git a/src/or/connection.c b/src/or/connection.c
index 48ceb2623d..ecf838830e 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -145,7 +145,7 @@ conn_state_to_string(int type, int state)
 /** Allocate space for a new connection_t. This function just initializes
  * conn; you must call connection_add() to link it into the main array.
  *
- * Set conn-\>type to <b>type</b>. Set conn-\>s and conn-\>poll_index to
+ * Set conn-\>type to <b>type</b>. Set conn-\>s and conn-\>conn_array_index to
  * -1 to signify they are not yet assigned.
  *
  * If conn is not a listener type, allocate buffers for it. If it's
@@ -191,7 +191,7 @@ connection_new(int type)
   conn = tor_malloc_zero(length);
   conn->magic = magic;
   conn->s = -1; /* give it a default of 'not used' */
-  conn->poll_index = -1; /* also default to 'not used' */
+  conn->conn_array_index = -1; /* also default to 'not used' */
   conn->global_identifier = n_connections_allocated++;
 
   conn->type = type;
@@ -2182,7 +2182,7 @@ assert_connection_ok(connection_t *conn, time_t now)
   if (conn->hold_open_until_flushed)
     tor_assert(conn->marked_for_close);
 
-  /* XXX check: wants_to_read, wants_to_write, s, poll_index,
+  /* XXX check: wants_to_read, wants_to_write, s, conn_array_index,
    * marked_for_close. */
 
   /* buffers */
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 127783dbeb..7839a91de2 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -1139,7 +1139,7 @@ connection_ap_handshake_rewrite_and_attach(edge_connection_t *conn,
              routers with this nickname */
           conn->chosen_exit_name =
             tor_strdup(hex_str(r->cache_info.identity_digest, DIGEST_LEN));
-          conn->chosen_exit_optional = 1;
+          conn->_base.chosen_exit_optional = 1;
         }
       }
 
diff --git a/src/or/main.c b/src/or/main.c
index 6d0ab93c7c..4ef3260e8b 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -50,13 +50,12 @@ static time_t time_to_fetch_directory = 0;
 /** When do we next download a running-routers summary? */
 static time_t time_to_fetch_running_routers = 0;
 
-/** Array of all open connections; each element corresponds to the element of
- * poll_array in the same position.  The first nfds elements are valid. */
+/** Array of all open connections.  The first n_conns elements are valid. */
 static connection_t *connection_array[MAXCONNECTIONS+1] =
         { NULL };
 static smartlist_t *closeable_connection_lst = NULL;
 
-static int nfds=0; /**< Number of connections currently active. */
+static int n_conns=0; /**< Number of connections currently active. */
 
 /** We set this to 1 when we've opened a circuit, so we can print a log
  * entry to inform the user that Tor is working. */
@@ -121,8 +120,7 @@ static char* nt_strerror(uint32_t errnum);
 /****************************************************************************
 *
 * This section contains accessors and other methods on the connection_array
-* and poll_array variables (which are global within this file and unavailable
-* outside it).
+* variables (which are global within this file and unavailable outside it).
 *
 ****************************************************************************/
 
@@ -136,15 +134,15 @@ connection_add(connection_t *conn)
   tor_assert(conn);
   tor_assert(conn->s >= 0);
 
-  if (nfds >= get_options()->_ConnLimit-1) {
+  if (n_conns >= get_options()->_ConnLimit-1) {
     log_warn(LD_NET,"Failing because we have %d connections already. Please "
-             "raise your ulimit -n.", nfds);
+             "raise your ulimit -n.", n_conns);
     return -1;
   }
 
-  tor_assert(conn->poll_index == -1); /* can only connection_add once */
-  conn->poll_index = nfds;
-  connection_array[nfds] = conn;
+  tor_assert(conn->conn_array_index == -1); /* can only connection_add once */
+  conn->conn_array_index = n_conns;
+  connection_array[n_conns] = conn;
 
   conn->read_event = tor_malloc_zero(sizeof(struct event));
   conn->write_event = tor_malloc_zero(sizeof(struct event));
@@ -153,10 +151,10 @@ connection_add(connection_t *conn)
   event_set(conn->write_event, conn->s, EV_WRITE|EV_PERSIST,
             conn_write_callback, conn);
 
-  nfds++;
+  n_conns++;
 
-  log_debug(LD_NET,"new conn type %s, socket %d, nfds %d.",
-            conn_type_to_string(conn->type), conn->s, nfds);
+  log_debug(LD_NET,"new conn type %s, socket %d, n_conns %d.",
+            conn_type_to_string(conn->type), conn->s, n_conns);
 
   return 0;
 }
@@ -171,24 +169,24 @@ connection_remove(connection_t *conn)
   int current_index;
 
   tor_assert(conn);
-  tor_assert(nfds>0);
+  tor_assert(n_conns>0);
 
-  log_debug(LD_NET,"removing socket %d (type %s), nfds now %d",
-            conn->s, conn_type_to_string(conn->type), nfds-1);
+  log_debug(LD_NET,"removing socket %d (type %s), n_conns now %d",
+            conn->s, conn_type_to_string(conn->type), n_conns-1);
 
-  tor_assert(conn->poll_index >= 0);
-  current_index = conn->poll_index;
-  if (current_index == nfds-1) { /* this is the end */
-    nfds--;
+  tor_assert(conn->conn_array_index >= 0);
+  current_index = conn->conn_array_index;
+  if (current_index == n_conns-1) { /* this is the end */
+    n_conns--;
     return 0;
   }
 
   connection_unregister(conn);
 
   /* replace this one with the one at the end */
-  nfds--;
-  connection_array[current_index] = connection_array[nfds];
-  connection_array[current_index]->poll_index = current_index;
+  n_conns--;
+  connection_array[current_index] = connection_array[n_conns];
+  connection_array[current_index]->conn_array_index = current_index;
 
   return 0;
 }
@@ -243,7 +241,7 @@ int
 connection_in_array(connection_t *conn)
 {
   int i;
-  for (i=0; i<nfds; ++i) {
+  for (i=0; i<n_conns; ++i) {
     if (conn==connection_array[i])
       return 1;
   }
@@ -258,7 +256,7 @@ void
 get_connection_array(connection_t ***array, int *n)
 {
   *array = connection_array;
-  *n = nfds;
+  *n = n_conns;
 }
 
 /** Set the event mask on <b>conn</b> to <b>events</b>.  (The event
@@ -382,10 +380,10 @@ close_closeable_connections(void)
   int i;
   for (i = 0; i < smartlist_len(closeable_connection_lst); ) {
     connection_t *conn = smartlist_get(closeable_connection_lst, i);
-    if (conn->poll_index < 0) {
+    if (conn->conn_array_index < 0) {
       connection_unlink(conn, 0); /* blow it away right now */
     } else {
-      if (!conn_close_if_marked(conn->poll_index))
+      if (!conn_close_if_marked(conn->conn_array_index))
         ++i;
     }
   }
@@ -893,11 +891,11 @@ run_scheduled_events(time_t now)
     circuit_build_needed_circs(now);
 
   /** 5. We do housekeeping for each connection... */
-  for (i=0;i<nfds;i++) {
+  for (i=0;i<n_conns;i++) {
     run_connection_housekeeping(i, now);
   }
   if (time_to_shrink_buffers < now) {
-    for (i=0;i<nfds;i++) {
+    for (i=0;i<n_conns;i++) {
       connection_t *conn = connection_array[i];
       if (conn->outbuf)
         buf_shrink(conn->outbuf);
@@ -1306,7 +1304,7 @@ dumpmemusage(int severity)
   log(severity, LD_GENERAL,
       "In buffers: "U64_FORMAT" used/"U64_FORMAT" allocated (%d conns).",
       U64_PRINTF_ARG(buf_total_used), U64_PRINTF_ARG(buf_total_alloc),
-      nfds);
+      n_conns);
   log(severity, LD_GENERAL, "In rephist: "U64_FORMAT" used by %d Tors.",
       U64_PRINTF_ARG(rephist_total_alloc), rephist_total_num);
   dump_routerlist_mem_usage(severity);
@@ -1324,7 +1322,7 @@ dumpstats(int severity)
 
   log(severity, LD_GENERAL, "Dumping stats:");
 
-  for (i=0;i<nfds;i++) {
+  for (i=0;i<n_conns;i++) {
     conn = connection_array[i];
     log(severity, LD_GENERAL,
         "Conn %d (socket %d) type %d (%s), state %d (%s), created %d secs ago",
diff --git a/src/or/or.h b/src/or/or.h
index 8624214e9f..5eaa3e4b88 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -600,8 +600,9 @@ typedef struct socks_request_t socks_request_t;
  * conn->outbuf.  Connections differ primarily in the functions called
  * to fill and drain these buffers.
  */
-struct connection_t {
-  uint32_t magic; /**< For memory debugging: must equal CONNECTION_MAGIC. */
+typedef struct connection_t {
+  uint32_t magic; /**< For memory debugging: must equal one of
+                   * *_CONNECTION_MAGIC. */
 
   uint8_t type; /**< What kind of connection is this? */
   uint8_t state; /**< Current state of this connection. */
@@ -622,9 +623,12 @@ struct connection_t {
   unsigned int control_events_are_extended:1;
   /** Used for OR conns that shouldn't get any new circs attached to them. */
   unsigned int or_is_obsolete:1;
+  /** For AP connections only. If 1, and we fail to reach the chosen exit,
+   * stop requiring it. */
+  unsigned int chosen_exit_optional:1;
 
   int s; /**< Our socket; -1 if this connection is closed. */
-  int poll_index; /* XXXX rename. */
+  int conn_array_index; /**< Index into the global connection array. */
   struct event *read_event; /**< Libevent event structure. */
   struct event *write_event; /**< Libevent event structure. */
   buf_t *inbuf; /**< Buffer holding data read over this connection. */
@@ -657,12 +661,10 @@ struct connection_t {
   /** 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;
+} connection_t;
 
-};
-
-typedef struct connection_t connection_t;
-
-/** DOCDOC */
+/** Subtype of connection_t for an "OR connection" -- that is, one that speaks
+ * cells over TLS. */
 typedef struct or_connection_t {
   connection_t _base;
 
@@ -670,7 +672,7 @@ typedef struct or_connection_t {
                                      * the other side's signing key. */
   char *nickname; /**< Nickname of OR on other side (if any). */
 
-  tor_tls_t *tls; /**< TLS connection state (OR only.) */
+  tor_tls_t *tls; /**< TLS connection state */
 
   /* bandwidth* and receiver_bucket only used by ORs in OPEN state: */
   int bandwidthrate; /**< Bytes/s added to the bucket. (OPEN ORs only.) */
@@ -687,21 +689,21 @@ typedef struct or_connection_t {
                                            * identity digest as this one. */
   uint16_t next_circ_id; /**< Which circ_id do we try to use next on
                           * this connection?  This is always in the
-                          * range 0..1<<15-1. (OR only.)*/
+                          * range 0..1<<15-1. */
 } or_connection_t;
 
+/** Subtype of connection_t for an "edge connection" -- that is, a socks (ap)
+ * connection, or an exit. */
 typedef struct edge_connection_t {
   connection_t _base;
 
-  uint16_t stream_id;
   struct edge_connection_t *next_stream; /**< Points to the next stream at this
-                                          * edge, if any (Edge only). */
+                                          * edge, if any */
   struct crypt_path_t *cpath_layer; /**< A pointer to which node in the circ
-                                     * this conn exits at. (Edge only.) */
-  int package_window; /**< How many more relay cells can i send into the
-                       * circuit? (Edge only.) */
-  int deliver_window; /**< How many more relay cells can end at me? (Edge
-                       * only.) */
+                                     * this conn exits at. */
+  int package_window; /**< How many more relay cells can I send into the
+                       * circuit? */
+  int deliver_window; /**< How many more relay cells can end at me? */
 
   /** Number of times we've reassigned this application connection to
    * a new circuit. We keep track because the timeout is longer if we've
@@ -710,32 +712,34 @@ typedef struct edge_connection_t {
 
   /** Nickname of planned exit node -- used with .exit support. */
   char *chosen_exit_name;
-  /** If 1, and we fail to reach the chosen exit, stop requiring it. */
-  unsigned int chosen_exit_optional:1;
 
-/* Used only by AP connections */
   socks_request_t *socks_request; /**< SOCKS structure describing request (AP
                                    * only.) */
-
   struct circuit_t *on_circuit; /**< The circuit (if any) that this edge
                                  * connection is using. */
 
   uint32_t address_ttl; /**< TTL for address-to-addr mapping on exit
                          * connection.  Exit connections only. */
 
-/* Used only by DIR and AP connections: */
+  uint16_t stream_id; /**< The stream ID used for this edge connection on its
+                       * circuit */
+
   char rend_query[REND_SERVICE_ID_LEN+1]; /**< What rendezvous service are we
-                                           * querying for? (DIR/AP only) */
+                                           * querying for? (AP only) */
 } edge_connection_t;
 
+/** Subtype of connection_t for an "directory connection" -- that is, an HTTP
+ * connection to retrieve or serve directory material. */
 typedef struct dir_connection_t {
   connection_t _base;
 
-/* Used only by Dir connections */
   char *requested_resource; /**< Which 'resource' did we ask the directory
                              * for? */
   unsigned int dirconn_direct:1; /**< Is this dirconn direct, or via Tor? */
-/* Used only for server sides of some dir connections. */
+
+  /* Used only for server sides of some dir connections, to implement
+   * "spooling" of directory material to the outbuf.  Otherwise, we'd have
+   * to append everything to the outbuf in one enormous chunk. */
   enum {
     DIR_SPOOL_NONE=0, DIR_SPOOL_SERVER_BY_DIGEST, DIR_SPOOL_SERVER_BY_FP,
     DIR_SPOOL_CACHED_DIR, DIR_SPOOL_NETWORKSTATUS
@@ -745,19 +749,19 @@ typedef struct dir_connection_t {
   off_t cached_dir_offset;
   tor_zlib_state_t *zlib_state;
 
-/* Used only by DIR and AP connections: */
   char rend_query[REND_SERVICE_ID_LEN+1]; /**< What rendezvous service are we
-                                           * querying for? (DIR/AP only) */
+                                           * querying for? */
 
   char identity_digest[DIGEST_LEN]; /**< Hash of the public RSA key for
                                      * the directory server's signing key. */
 } dir_connection_t;
 
+/** Subtype of connection_t for an connection to a controller. */
 typedef struct control_connection_t {
   connection_t _base;
 
-  /* Used only by control connections */
-  uint32_t event_mask;
+  uint32_t event_mask; /**< Bitfield: which events does this controller
+                        * care about? */
   uint32_t incoming_cmd_len;
   uint32_t incoming_cmd_cur_len;
   char *incoming_cmd;
@@ -765,13 +769,23 @@ typedef struct control_connection_t {
   uint16_t incoming_cmd_type;
 } control_connection_t;
 
+/** Cast a connection_t subtype pointer to a connection_t **/
 #define TO_CONN(c) &(((c)->_base))
+/** Helper macro: Given a pointer to to._base, of type from*, return &to. */
 #define DOWNCAST(from, to, ptr) \
   (to*) (((from*)(ptr)) - STRUCT_OFFSET(to, _base))
 
+/** Convert a connection_t* to an or_connection_t*; assert if the cast is
+ * invalid. */
 or_connection_t *TO_OR_CONN(connection_t *);
+/** Convert a connection_t* to a dir_connection_t*; assert if the cast is
+ * invalid. */
 dir_connection_t *TO_DIR_CONN(connection_t *);
+/** Convert a connection_t* to an edge_connection_t*; assert if the cast is
+ * invalid. */
 edge_connection_t *TO_EDGE_CONN(connection_t *);
+/** Convert a connection_t* to an control_connection_t*; assert if the cast is
+ * invalid. */
 control_connection_t *TO_CONTROL_CONN(connection_t *);
 
 extern INLINE or_connection_t *TO_OR_CONN(connection_t *c)
@@ -1115,13 +1129,14 @@ typedef uint16_t circid_t;
  * OR connections multiplex many circuits at once, and stay standing even
  * when there are no circuits running over them.
  *
- * A circuit_t structure fills two roles.  First, a circuit_t links two
- * connections together: either an edge connection and an OR connection,
- * or two OR connections.  (When joined to an OR connection, a circuit_t
- * affects only cells sent to a particular circID on that connection.  When
- * joined to an edge connection, a circuit_t affects all data.)
-
- * Second, a circuit_t holds the cipher keys and state for sending data
+ * A circuit_t structure cann fill one of two roles.  First, a or_circuit_t
+ * links two connections together: either an edge connection and an OR
+ * connection, or two OR connections.  (When joined to an OR connection, a
+ * circuit_t affects only cells sent to a particular circID on that
+ * connection.  When joined to an edge connection, a circuit_t affects all
+ * data.)
+
+ * Second, an origin_circuit_t holds the cipher keys and state for sending data
  * along a given circuit.  At the OP, it has a sequence of ciphers, each
  * of which is shared with a single OR along the circuit.  Separate
  * ciphers are used for data going "forward" (away from the OP) and
@@ -1178,6 +1193,8 @@ typedef struct circuit_t {
   struct circuit_t *next; /**< Next circuit in linked list. */
 } circuit_t;
 
+/** An origin_circuit_t holds data necessary to build and use a circuit.
+ */
 typedef struct origin_circuit_t {
   circuit_t _base;
 
@@ -1219,6 +1236,8 @@ typedef struct origin_circuit_t {
 
 } origin_circuit_t;
 
+/** An or_circuit_t holds information needed to implement a circuit at an
+ * OR. */
 typedef struct or_circuit_t {
   circuit_t _base;
 
@@ -1258,23 +1277,30 @@ typedef struct or_circuit_t {
 #endif
 
   /** A hash of location-hidden service's PK if purpose is INTRO_POINT, or a
-   * rendezvous cookie if purpose is REND_POINT_WAITING or
-   * C_ESTABLISH_REND. Filled with zeroes otherwise.
+   * rendezvous cookie if purpose is REND_POINT_WAITING. Filled with zeroes
+   * otherwise.
    */
   char rend_token[REND_TOKEN_LEN];
 
   char handshake_digest[DIGEST_LEN]; /**< Stores KH for intermediate hops. */
 } or_circuit_t;
 
+/** Convert a circuit subtype to a circuit_t.*/
 #define TO_CIRCUIT(x)  (&((x)->_base))
-or_circuit_t *TO_OR_CIRCUIT(circuit_t *x);
+
+/** Convert a circuit_t* to a pointer to the enclosing or_circuit_t.  Asserts
+ * if the cast is impossible. */
+or_circuit_t *TO_OR_CIRCUIT(circuit_t *);
+/** Convert a circuit_t* to a pointer to the enclosing origin_circuit_t.
+ * Asserts if the cast is impossible. */
+origin_circuit_t *TO_ORIGIN_CIRCUIT(circuit_t *);
+
 extern INLINE or_circuit_t *TO_OR_CIRCUIT(circuit_t *x)
 {
   tor_assert(x->magic == OR_CIRCUIT_MAGIC);
   //return (or_circuit_t*) (((char*)x) - STRUCT_OFFSET(or_circuit_t, _base));
   return DOWNCAST(circuit_t, or_circuit_t, x);
 }
-origin_circuit_t *TO_ORIGIN_CIRCUIT(circuit_t *x);
 extern INLINE origin_circuit_t *TO_ORIGIN_CIRCUIT(circuit_t *x)
 {
   tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
diff --git a/src/or/relay.c b/src/or/relay.c
index 094697361f..f7eee2917b 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -717,8 +717,9 @@ connection_edge_process_end_not_open(
         /* rewrite it to an IP if we learned one. */
         addressmap_rewrite(conn->socks_request->address,
                            sizeof(conn->socks_request->address));
-        if (conn->chosen_exit_optional) { /* stop wanting a specific exit */
-          conn->chosen_exit_optional = 0;
+        if (conn->_base.chosen_exit_optional) {
+          /* stop wanting a specific exit */
+          conn->_base.chosen_exit_optional = 0;
           tor_free(conn->chosen_exit_name);
         }
         if (connection_ap_detach_retriable(conn, circ) >= 0)
@@ -726,7 +727,7 @@ connection_edge_process_end_not_open(
         /* else, conn will get closed below */
         break;
       case END_STREAM_REASON_CONNECTREFUSED:
-        if (!conn->chosen_exit_optional)
+        if (!conn->_base.chosen_exit_optional)
           break; /* break means it'll close, below */
         /* Else fall through: expire this circuit, clear the
          * chosen_exit_name field, and try again. */
@@ -740,8 +741,9 @@ connection_edge_process_end_not_open(
           tor_assert(circ->_base.timestamp_dirty);
           circ->_base.timestamp_dirty -= get_options()->MaxCircuitDirtiness;
 
-          if (conn->chosen_exit_optional) { /* stop wanting a specific exit */
-            conn->chosen_exit_optional = 0;
+          if (conn->_base.chosen_exit_optional) {
+            /* stop wanting a specific exit */
+            conn->_base.chosen_exit_optional = 0;
             tor_free(conn->chosen_exit_name);
           }
           if (connection_ap_detach_retriable(conn, circ) >= 0)
@@ -764,8 +766,9 @@ connection_edge_process_end_not_open(
           exitrouter->exit_policy =
             router_parse_addr_policy_from_string("reject *:*", -1);
         }
-        if (conn->chosen_exit_optional) { /* stop wanting a specific exit */
-          conn->chosen_exit_optional = 0;
+        if (conn->_base.chosen_exit_optional) {
+          /* stop wanting a specific exit */
+          conn->_base.chosen_exit_optional = 0;
           tor_free(conn->chosen_exit_name);
         }
         if (connection_ap_detach_retriable(conn, circ) >= 0)