r15653@tombo: nickm | 2007-12-23 14:15:12 -0500

 Refactor circuit_launch* functions to take a bitfield of flags rather than 4 separate nonconsecutive flags arguments.  Also, note a possible but in circuit_find_to_cannibalize, which seems to be ignoring its purpose argument.


svn:r12948

8 files changed, 99 insertions, 79 deletions

diff --git a/doc/TODO b/doc/TODO
index 9f7746cb24..2d9c2432cf 100644
--- a/doc/TODO
+++ b/doc/TODO
@@ -75,7 +75,7 @@ Things we'd like to do in 0.2.0.x:
     info and it's old enough, delete it. same with cached-routers*.
   - document the "3/4 and 7/8" business in the clients fetching consensus
     documents timeline. then document the bridge user download timeline.
-  - refactor circuit_launch_by_foo so all those flags at the end are
+  o refactor circuit_launch_by_foo so all those flags at the end are
     actually a flags argument.
   - config option __ControllerLimit that hangs up if there are a limit
     of controller connections already.
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 6ca23b9d51..851d7ff430 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -283,19 +283,23 @@ again:
 }
 
 /** Create and return a new origin circuit. Initialize its purpose and
- * build-state based on our arguments. */
+ * build-state based on our arguments.  The <b>flags</b> argument is a
+ * bitfield of CIRCLAUNCH_* flags. */
 origin_circuit_t *
-origin_circuit_init(uint8_t purpose, int onehop_tunnel,
-                    int need_uptime, int need_capacity, int internal)
+origin_circuit_init(uint8_t purpose, int flags)
 {
   /* sets circ->p_circ_id and circ->p_conn */
   origin_circuit_t *circ = origin_circuit_new();
   circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OR_WAIT);
   circ->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));
-  circ->build_state->onehop_tunnel = onehop_tunnel;
-  circ->build_state->need_uptime = need_uptime;
-  circ->build_state->need_capacity = need_capacity;
-  circ->build_state->is_internal = internal;
+  circ->build_state->onehop_tunnel =
+    ((flags & CIRCLAUNCH_ONEHOP_TUNNEL) ? 1 : 0);
+  circ->build_state->need_uptime =
+    ((flags & CIRCLAUNCH_NEED_UPTIME) ? 1 : 0);
+  circ->build_state->need_capacity =
+    ((flags & CIRCLAUNCH_NEED_CAPACITY) ? 1 : 0);
+  circ->build_state->is_internal =
+    ((flags & CIRCLAUNCH_IS_INTERNAL) ? 1 : 0);
   circ->_base.purpose = purpose;
   return circ;
 }
@@ -308,15 +312,12 @@ origin_circuit_init(uint8_t purpose, int onehop_tunnel,
  * it's not open already.
  */
 origin_circuit_t *
-circuit_establish_circuit(uint8_t purpose, int onehop_tunnel,
-                          extend_info_t *exit,
-                          int need_uptime, int need_capacity, int internal)
+circuit_establish_circuit(uint8_t purpose, extend_info_t *exit, int flags)
 {
   origin_circuit_t *circ;
   int err_reason = 0;
 
-  circ = origin_circuit_init(purpose, onehop_tunnel,
-                             need_uptime, need_capacity, internal);
+  circ = origin_circuit_init(purpose, flags);
 
   if (onion_pick_cpath_exit(circ, exit) < 0 ||
       onion_populate_cpath(circ) < 0) {
diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 375156b4e3..8eb442df84 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -791,19 +791,24 @@ circuit_get_intro_point(const char *digest)
 }
 
 /** Return a circuit that is open, is CIRCUIT_PURPOSE_C_GENERAL,
- * has a timestamp_dirty value of 0, is uptime/capacity/internal
- * if required, and if info is defined, does not already use info
+ * has a timestamp_dirty value of 0, has flags matching the CIRCLAUNCH_*
+ * flags in <b>flags</b>, and if info is defined, does not already use info
  * as any of its hops; or NULL if no circuit fits this description.
  *
- * If ! need_uptime, prefer returning non-uptime circuits.
+ * If !CIRCLAUNCH_NEED_UPTIME, prefer returning non-uptime circuits.
  */
 origin_circuit_t *
 circuit_find_to_cannibalize(uint8_t purpose, extend_info_t *info,
-                            int need_uptime,
-                            int need_capacity, int internal)
+                            int flags)
 {
+  /*XXXX020 arma: The purpose argument is ignored.  Can that possibly be
+   * right? */
+
   circuit_t *_circ;
   origin_circuit_t *best=NULL;
+  int need_uptime = flags & CIRCLAUNCH_NEED_UPTIME;
+  int need_capacity = flags & CIRCLAUNCH_NEED_CAPACITY;
+  int internal = flags & CIRCLAUNCH_IS_INTERNAL;
 
   log_debug(LD_CIRC,
             "Hunting for a circ to cannibalize: purpose %d, uptime %d, "
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 5bad9e65fe..fb752e0d2e 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -371,6 +371,7 @@ circuit_predict_and_launch_new(void)
   int hidserv_needs_uptime=0, hidserv_needs_capacity=1;
   int port_needs_uptime=0, port_needs_capacity=1;
   time_t now = time(NULL);
+  int flags = 0;
 
   /* First, count how many of each type of circuit we have already. */
   for (circ=global_circuitlist;circ;circ = circ->next) {
@@ -402,22 +403,26 @@ circuit_predict_and_launch_new(void)
    * and no circuit is currently available that can handle it. */
   if (!circuit_all_predicted_ports_handled(now, &port_needs_uptime,
                                            &port_needs_capacity)) {
+    if (port_needs_uptime)
+      flags |= CIRCLAUNCH_NEED_UPTIME;
+    if (port_needs_capacity)
+      flags |= CIRCLAUNCH_NEED_CAPACITY;
     log_info(LD_CIRC,
              "Have %d clean circs (%d internal), need another exit circ.",
              num, num_internal);
-    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, 0, NULL,
-                             port_needs_uptime, port_needs_capacity, 0);
+    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
     return;
   }
 
   /* Third, see if we need any more hidden service (server) circuits. */
   if (num_rend_services() && num_uptime_internal < 3) {
+    flags = (CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_NEED_UPTIME |
+             CIRCLAUNCH_IS_INTERNAL);
     log_info(LD_CIRC,
              "Have %d clean circs (%d internal), need another internal "
              "circ for my hidden service.",
              num, num_internal);
-    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, 0, NULL,
-                             1, 1, 1);
+    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
     return;
   }
 
@@ -426,12 +431,16 @@ circuit_predict_and_launch_new(void)
                                       &hidserv_needs_capacity) &&
       ((num_uptime_internal<2 && hidserv_needs_uptime) ||
         num_internal<2)) {
+    if (hidserv_needs_uptime)
+      flags |= CIRCLAUNCH_NEED_UPTIME;
+    if (hidserv_needs_capacity)
+      flags |= CIRCLAUNCH_NEED_CAPACITY;
+    flags |= CIRCLAUNCH_IS_INTERNAL;
     log_info(LD_CIRC,
              "Have %d clean circs (%d uptime-internal, %d internal), need"
              " another hidserv circ.",
              num, num_uptime_internal, num_internal);
-    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, 0, NULL,
-                             hidserv_needs_uptime, hidserv_needs_capacity, 1);
+    circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, flags);
     return;
   }
 }
@@ -469,7 +478,7 @@ circuit_build_needed_circs(time_t now)
         circ &&
         circ->timestamp_created + TESTING_CIRCUIT_INTERVAL < now) {
       log_fn(LOG_INFO,"Creating a new testing circuit.");
-      circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, 0, NULL, 0, 0, 0);
+      circuit_launch_by_router(CIRCUIT_PURPOSE_C_GENERAL, NULL, 0);
     }
 #endif
   }
@@ -798,34 +807,33 @@ static int did_circs_fail_last_period = 0;
 /** Launch a new circuit; see circuit_launch_by_extend_info() for
  * details on arguments. */
 origin_circuit_t *
-circuit_launch_by_router(uint8_t purpose, int onehop_tunnel,
-                         routerinfo_t *exit, int need_uptime,
-                         int need_capacity, int internal)
+circuit_launch_by_router(uint8_t purpose,
+                         routerinfo_t *exit, int flags)
 {
   origin_circuit_t *circ;
   extend_info_t *info = NULL;
   if (exit)
     info = extend_info_from_router(exit);
-  circ = circuit_launch_by_extend_info(
-    purpose, onehop_tunnel, info, need_uptime, need_capacity, internal);
+  circ = circuit_launch_by_extend_info(purpose, info, flags);
   if (info)
     extend_info_free(info);
   return circ;
 }
 
 /** Launch a new circuit with purpose <b>purpose</b> and exit node
- * <b>extend_info</b> (or NULL to select a random exit node).
- * If <b>need_uptime</b> is true,
- * choose among routers with high uptime.  If <b>need_capacity</b> is true,
- * choose among routers with high bandwidth.  If <b>internal</b> is true, the
- * last hop need not be an exit node. Return the newly allocated circuit on
- * success, or NULL on failure. */
+ * <b>extend_info</b> (or NULL to select a random exit node).  If flags
+ * contains CIRCLAUNCH_NEED_UPTIME, choose among routers with high uptime.  If
+ * CIRCLAUNCH_NEED_CAPACITY is set, choose among routers with high bandwidth.
+ * If CIRCLAUNCH_IS_INTERNAL is true, the last hop need not be an exit node.
+ * If CIRCLAUNCH_ONEHOP_TUNNEL is set, the circuit will have only one hop.
+ * Return the newly allocated circuit on success, or NULL on failure. */
 origin_circuit_t *
-circuit_launch_by_extend_info(uint8_t purpose, int onehop_tunnel,
-                              extend_info_t *extend_info, int need_uptime,
-                              int need_capacity, int internal)
+circuit_launch_by_extend_info(uint8_t purpose,
+                              extend_info_t *extend_info,
+                              int flags)
 {
   origin_circuit_t *circ;
+  int onehop_tunnel = flags & CIRCLAUNCH_ONEHOP_TUNNEL;
 
   if (!onehop_tunnel && !router_have_minimum_dir_info()) {
     log_debug(LD_CIRC,"Haven't fetched enough directory info yet; canceling "
@@ -838,8 +846,7 @@ circuit_launch_by_extend_info(uint8_t purpose, int onehop_tunnel,
     /* see if there are appropriate circs available to cannibalize. */
     /* XXX020 if we're planning to add a hop, perhaps we want to look for
      * internal circs rather than exit circs? -RD */
-    circ = circuit_find_to_cannibalize(purpose, extend_info,
-                                       need_uptime, need_capacity, internal);
+    circ = circuit_find_to_cannibalize(purpose, extend_info, flags);
     if (circ) {
       log_info(LD_CIRC,"Cannibalizing circ '%s' for purpose %d",
                build_state_get_exit_nickname(circ->build_state), purpose);
@@ -881,16 +888,14 @@ circuit_launch_by_extend_info(uint8_t purpose, int onehop_tunnel,
 
   /* try a circ. if it fails, circuit_mark_for_close will increment
    * n_circuit_failures */
-  return circuit_establish_circuit(purpose, onehop_tunnel, extend_info,
-                                   need_uptime, need_capacity, internal);
+  return circuit_establish_circuit(purpose, extend_info, flags);
 }
 
 /** Launch a new circuit; see circuit_launch_by_extend_info() for
  * details on arguments. */
 origin_circuit_t *
-circuit_launch_by_nickname(uint8_t purpose, int onehop_tunnel,
-                           const char *exit_nickname,
-                           int need_uptime, int need_capacity, int internal)
+circuit_launch_by_nickname(uint8_t purpose,
+                           const char *exit_nickname, int flags)
 {
   routerinfo_t *router = NULL;
 
@@ -902,8 +907,7 @@ circuit_launch_by_nickname(uint8_t purpose, int onehop_tunnel,
       return NULL;
     }
   }
-  return circuit_launch_by_router(purpose, onehop_tunnel, router,
-                                  need_uptime, need_capacity, internal);
+  return circuit_launch_by_router(purpose, router, flags);
 }
 
 /** Record another failure at opening a general circuit. When we have
@@ -1085,9 +1089,15 @@ circuit_get_open_circ_or_launch(edge_connection_t *conn,
     else
       new_circ_purpose = desired_circuit_purpose;
 
-    circ = circuit_launch_by_extend_info(
-              new_circ_purpose, want_onehop, extend_info,
-              need_uptime, 1, need_internal);
+    {
+      int flags = CIRCLAUNCH_NEED_CAPACITY;
+      if (want_onehop) flags |= CIRCLAUNCH_ONEHOP_TUNNEL;
+      if (need_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
+      if (need_internal) flags |= CIRCLAUNCH_IS_INTERNAL;
+      circ = circuit_launch_by_extend_info(new_circ_purpose, extend_info,
+                                           flags);
+    }
+
     if (extend_info)
       extend_info_free(extend_info);
 
diff --git a/src/or/control.c b/src/or/control.c
index 64712cff96..c91890cf6c 100644
--- a/src/or/control.c
+++ b/src/or/control.c
@@ -2019,7 +2019,7 @@ handle_control_extendcircuit(control_connection_t *conn, uint32_t len,
 
   if (zero_circ) {
     /* start a new circuit */
-    circ = origin_circuit_init(intended_purpose, 0, 0, 0, 0);
+    circ = origin_circuit_init(intended_purpose, 0);
   }
 
   /* now circ refers to something that is ready to be extended */
diff --git a/src/or/or.h b/src/or/or.h
index 5e2610994e..1e817144a0 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2473,13 +2473,10 @@ char *circuit_list_path_for_controller(origin_circuit_t *circ);
 void circuit_log_path(int severity, unsigned int domain,
                       origin_circuit_t *circ);
 void circuit_rep_hist_note_result(origin_circuit_t *circ);
-origin_circuit_t *origin_circuit_init(uint8_t purpose, int onehop_tunnel,
-                                      int need_uptime,
-                                      int need_capacity, int internal);
+origin_circuit_t *origin_circuit_init(uint8_t purpose, int flags);
 origin_circuit_t *circuit_establish_circuit(uint8_t purpose,
-                                     int onehop_tunnel, extend_info_t *exit,
-                                     int need_uptime, int need_capacity,
-                                     int internal);
+                                            extend_info_t *exit,
+                                            int flags);
 int circuit_handle_first_hop(origin_circuit_t *circ);
 void circuit_n_conn_done(or_connection_t *or_conn, int status);
 int inform_testing_reachability(void);
@@ -2556,9 +2553,7 @@ origin_circuit_t *circuit_get_next_by_pk_and_purpose(origin_circuit_t *start,
 or_circuit_t *circuit_get_rendezvous(const char *cookie);
 or_circuit_t *circuit_get_intro_point(const char *digest);
 origin_circuit_t *circuit_find_to_cannibalize(uint8_t purpose,
-                                       extend_info_t *info,
-                                       int need_uptime,
-                                       int need_capacity, int internal);
+                                              extend_info_t *info, int flags);
 void circuit_mark_all_unused_circs(void);
 void circuit_expire_all_dirty_circs(void);
 void _circuit_mark_for_close(circuit_t *circ, int reason,
@@ -2590,21 +2585,24 @@ int circuit_enough_testing_circs(void);
 
 void circuit_has_opened(origin_circuit_t *circ);
 void circuit_build_failed(origin_circuit_t *circ);
+
+/** Flag to set when a circuit should have only a single hop. */
+#define CIRCLAUNCH_ONEHOP_TUNNEL  (1<<0)
+/** Flag to set when a circuit needs to be built of high-uptime nodes */
+#define CIRCLAUNCH_NEED_UPTIME    (1<<1)
+/** Flag to set when a circuit needs to be build of high-capcity nodes */
+#define CIRCLAUNCH_NEED_CAPACITY  (1<<2)
+/** Flag to set when the last hop of a circuit doesn't need to be an
+ * exit node. */
+#define CIRCLAUNCH_IS_INTERNAL    (1<<3)
 origin_circuit_t *circuit_launch_by_nickname(uint8_t purpose,
-                                      int onehop_tunnel,
-                                      const char *exit_nickname,
-                                      int need_uptime, int need_capacity,
-                                      int is_internal);
+                                             const char *exit_nickname,
+                                             int flags);
 origin_circuit_t *circuit_launch_by_extend_info(uint8_t purpose,
-                                         int onehop_tunnel,
-                                         extend_info_t *info,
-                                         int need_uptime, int need_capacity,
-                                         int is_internal);
+                                                extend_info_t *info,
+                                                int flags);
 origin_circuit_t *circuit_launch_by_router(uint8_t purpose,
-                                    int onehop_tunnel,
-                                    routerinfo_t *exit,
-                                    int need_uptime, int need_capacity,
-                                    int is_internal);
+                                           routerinfo_t *exit, int flags);
 void circuit_reset_failure_count(int timeout);
 int connection_ap_handshake_attach_chosen_circuit(edge_connection_t *conn,
                                                   origin_circuit_t *circ,
diff --git a/src/or/rendservice.c b/src/or/rendservice.c
index e80d5e947e..60bced974d 100644
--- a/src/or/rendservice.c
+++ b/src/or/rendservice.c
@@ -647,9 +647,10 @@ rend_service_introduce(origin_circuit_t *circuit, const char *request,
   /* Launch a circuit to alice's chosen rendezvous point.
    */
   for (i=0;i<MAX_REND_FAILURES;i++) {
+    int flags = CIRCLAUNCH_NEED_CAPACITY | CIRCLAUNCH_IS_INTERNAL;
+    if (circ_needs_uptime) flags |= CIRCLAUNCH_NEED_UPTIME;
     launched = circuit_launch_by_extend_info(
-          CIRCUIT_PURPOSE_S_CONNECT_REND, 0, extend_info,
-          circ_needs_uptime, 1, 1);
+                        CIRCUIT_PURPOSE_S_CONNECT_REND, extend_info, flags);
 
     if (launched)
       break;
@@ -728,8 +729,10 @@ rend_service_relaunch_rendezvous(origin_circuit_t *oldcirc)
   log_info(LD_REND,"Reattempting rendezvous circuit to '%s'",
            oldstate->chosen_exit->nickname);
 
-  newcirc = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_CONNECT_REND, 0,
-                               oldstate->chosen_exit, 0, 1, 1);
+  newcirc = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_CONNECT_REND,
+                            oldstate->chosen_exit,
+                            CIRCLAUNCH_NEED_CAPACITY|CIRCLAUNCH_IS_INTERNAL);
+
   if (!newcirc) {
     log_warn(LD_REND,"Couldn't relaunch rendezvous circuit to '%s'.",
              oldstate->chosen_exit->nickname);
@@ -769,7 +772,9 @@ rend_service_launch_establish_intro(rend_service_t *service,
 
   ++service->n_intro_circuits_launched;
   launched = circuit_launch_by_extend_info(CIRCUIT_PURPOSE_S_ESTABLISH_INTRO,
-                                           0, intro->extend_info, 1, 0, 1);
+                             intro->extend_info,
+                             CIRCLAUNCH_NEED_UPTIME|CIRCLAUNCH_IS_INTERNAL);
+
   if (!launched) {
     log_info(LD_REND,
              "Can't launch circuit to establish introduction at %s.",
diff --git a/src/or/router.c b/src/or/router.c
index 510b0b773c..cdceac44ad 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -699,7 +699,8 @@ consider_testing_reachability(int test_or, int test_dir)
     log_info(LD_CIRC, "Testing %s of my ORPort: %s:%d.",
              !orport_reachable ? "reachability" : "bandwidth",
              me->address, me->or_port);
-    circuit_launch_by_router(CIRCUIT_PURPOSE_TESTING, 0, me, 0, 1, 1);
+    circuit_launch_by_router(CIRCUIT_PURPOSE_TESTING, me,
+                             CIRCLAUNCH_NEED_CAPACITY|CIRCLAUNCH_IS_INTERNAL);
     control_event_server_status(LOG_NOTICE,
                                 "CHECKING_REACHABILITY ORADDRESS=%s:%d",
                                 me->address, me->or_port);