Merge branch 'bug12844'

Conflicts:
	src/or/circuituse.c
	src/test/include.am
	src/test/test_entrynodes.c

7 files changed, 117 insertions, 7 deletions

diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index fa5a2f5242..57056b2a66 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1737,6 +1737,83 @@ choose_good_exit_server_general(int need_uptime, int need_capacity)
   return NULL;
 }
 
+#if defined(ENABLE_TOR2WEB_MODE) || defined(TOR_UNIT_TESTS)
+/* The config option Tor2webRendezvousPoints has been set and we need
+ * to pick an RP out of that set. Make sure that the RP we choose is
+ * alive, and return it. Return NULL if no usable RP could be found in
+ * Tor2webRendezvousPoints. */
+STATIC const node_t *
+pick_tor2web_rendezvous_node(router_crn_flags_t flags,
+                             const or_options_t *options)
+{
+  const node_t *rp_node = NULL;
+  const int allow_invalid = (flags & CRN_ALLOW_INVALID) != 0;
+  const int need_desc = (flags & CRN_NEED_DESC) != 0;
+
+  smartlist_t *whitelisted_live_rps = smartlist_new();
+  smartlist_t *all_live_nodes = smartlist_new();
+
+  tor_assert(options->Tor2webRendezvousPoints);
+
+  /* Add all running nodes to all_live_nodes */
+  router_add_running_nodes_to_smartlist(all_live_nodes,
+                                        allow_invalid,
+                                        0, 0, 0,
+                                        need_desc);
+
+  /* Filter all_live_nodes to only add live *and* whitelisted RPs to
+   * the list whitelisted_live_rps. */
+  SMARTLIST_FOREACH_BEGIN(all_live_nodes, node_t *, live_node) {
+    if (routerset_contains_node(options->Tor2webRendezvousPoints, live_node)) {
+      smartlist_add(whitelisted_live_rps, live_node);
+    }
+  } SMARTLIST_FOREACH_END(live_node);
+
+  /* Honor ExcludeNodes */
+  if (options->ExcludeNodes) {
+    routerset_subtract_nodes(whitelisted_live_rps, options->ExcludeNodes);
+  }
+
+  /* Now pick randomly amongst the whitelisted RPs. No need to waste time
+     doing bandwidth load balancing, for most use cases
+     'whitelisted_live_rps' contains a single OR anyway. */
+  rp_node = smartlist_choose(whitelisted_live_rps);
+
+  if (!rp_node) {
+    log_warn(LD_REND, "Could not find a Rendezvous Point that suits "
+             "the purposes of Tor2webRendezvousPoints. Choosing random one.");
+  }
+
+  smartlist_free(whitelisted_live_rps);
+  smartlist_free(all_live_nodes);
+
+  return rp_node;
+}
+#endif
+
+/* Pick a Rendezvous Point for our HS circuits according to <b>flags</b>. */
+static const node_t *
+pick_rendezvous_node(router_crn_flags_t flags)
+{
+  const or_options_t *options = get_options();
+
+  if (options->AllowInvalid_ & ALLOW_INVALID_RENDEZVOUS)
+    flags |= CRN_ALLOW_INVALID;
+
+#ifdef ENABLE_TOR2WEB_MODE
+  /* The user wants us to pick specific RPs. */
+  if (options->Tor2webRendezvousPoints) {
+    const node_t *tor2web_rp = pick_tor2web_rendezvous_node(flags, options);
+    if (tor2web_rp) {
+      return tor2web_rp;
+    }
+    /* Else, if no tor2web RP was found, fall back to choosing a random node */
+  }
+#endif
+
+  return router_choose_random_node(NULL, options->ExcludeNodes, flags);
+}
+
 /** Return a pointer to a suitable router to be the exit node for the
  * circuit of purpose <b>purpose</b> that we're about to build (or NULL
  * if no router is suitable).
@@ -1767,9 +1844,13 @@ choose_good_exit_server(uint8_t purpose,
       else
         return choose_good_exit_server_general(need_uptime,need_capacity);
     case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
-      if (options->AllowInvalid_ & ALLOW_INVALID_RENDEZVOUS)
-        flags |= CRN_ALLOW_INVALID;
-      return router_choose_random_node(NULL, options->ExcludeNodes, flags);
+      {
+        /* Pick a new RP */
+        const node_t *rendezvous_node = pick_rendezvous_node(flags);
+        log_info(LD_REND, "Picked new RP: %s",
+                 safe_str_client(node_describe(rendezvous_node)));
+        return rendezvous_node;
+      }
   }
   log_warn(LD_BUG,"Unhandled purpose %d", purpose);
   tor_fragile_assert();
diff --git a/src/or/circuitbuild.h b/src/or/circuitbuild.h
index c72016d530..ddf86416fc 100644
--- a/src/or/circuitbuild.h
+++ b/src/or/circuitbuild.h
@@ -61,6 +61,9 @@ const node_t *choose_good_entry_server(uint8_t purpose,
 
 #ifdef CIRCUITBUILD_PRIVATE
 STATIC circid_t get_unique_circ_id_by_chan(channel_t *chan);
+STATIC const node_t *pick_tor2web_rendezvous_node(router_crn_flags_t flags,
+                                                  const or_options_t *options);
+
 #endif
 
 #endif
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 612b536bad..c463b0a40f 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -1677,6 +1677,7 @@ circuit_launch_by_extend_info(uint8_t purpose,
   origin_circuit_t *circ;
   int onehop_tunnel = (flags & CIRCLAUNCH_ONEHOP_TUNNEL) != 0;
   int have_path = have_enough_path_info(! (flags & CIRCLAUNCH_IS_INTERNAL) );
+  int need_specific_rp = 0;
 
   if (!onehop_tunnel && (!router_have_minimum_dir_info() || !have_path)) {
     log_debug(LD_CIRC,"Haven't %s yet; canceling "
@@ -1687,8 +1688,17 @@ circuit_launch_by_extend_info(uint8_t purpose,
     return NULL;
   }
 
+  /* If Tor2webRendezvousPoints is enabled and we are dealing with an
+     RP circuit, we want a specific RP node so we shouldn't canibalize
+     an already existing circuit. */
+  if (get_options()->Tor2webRendezvousPoints &&
+      purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND) {
+    need_specific_rp = 1;
+  }
+
   if ((extend_info || purpose != CIRCUIT_PURPOSE_C_GENERAL) &&
-      purpose != CIRCUIT_PURPOSE_TESTING && !onehop_tunnel) {
+      purpose != CIRCUIT_PURPOSE_TESTING &&
+      !onehop_tunnel && !need_specific_rp) {
     /* see if there are appropriate circs available to cannibalize. */
     /* XXX if we're planning to add a hop, perhaps we want to look for
      * internal circs rather than exit circs? -RD */
diff --git a/src/or/config.c b/src/or/config.c
index de0baa40d9..ad4fd45846 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -80,6 +80,7 @@ static config_abbrev_t option_abbrevs_[] = {
   PLURAL(AuthDirRejectCC),
   PLURAL(EntryNode),
   PLURAL(ExcludeNode),
+  PLURAL(Tor2webRendezvousPoint),
   PLURAL(FirewallPort),
   PLURAL(LongLivedPort),
   PLURAL(HiddenServiceNode),
@@ -404,6 +405,7 @@ static config_var_t option_vars_[] = {
   V(TestSocks,                   BOOL,     "0"),
   V(TokenBucketRefillInterval,   MSEC_INTERVAL, "100 msec"),
   V(Tor2webMode,                 BOOL,     "0"),
+  V(Tor2webRendezvousPoints,      ROUTERSET, NULL),
   V(TLSECGroup,                  STRING,   NULL),
   V(TrackHostExits,              CSV,      NULL),
   V(TrackHostExitsExpire,        INTERVAL, "30 minutes"),
@@ -1262,7 +1264,8 @@ options_need_geoip_info(const or_options_t *options, const char **reason_out)
     routerset_needs_geoip(options->EntryNodes) ||
     routerset_needs_geoip(options->ExitNodes) ||
     routerset_needs_geoip(options->ExcludeExitNodes) ||
-    routerset_needs_geoip(options->ExcludeNodes);
+    routerset_needs_geoip(options->ExcludeNodes) ||
+    routerset_needs_geoip(options->Tor2webRendezvousPoints);
 
   if (routerset_usage && reason_out) {
     *reason_out = "We've been configured to use (or avoid) nodes in certain "
@@ -1395,7 +1398,7 @@ options_act(const or_options_t *old_options)
     log_err(LD_CONFIG, "This copy of Tor was not compiled to run in "
             "'tor2web mode'. It cannot be run with the Tor2webMode torrc "
             "option enabled. To enable Tor2webMode recompile with the "
-            "--enable-tor2webmode option.");
+            "--enable-tor2web-mode option.");
     return -1;
   }
 #endif
@@ -1651,6 +1654,8 @@ options_act(const or_options_t *old_options)
                          options->ExcludeExitNodes) ||
         !routerset_equal(old_options->EntryNodes, options->EntryNodes) ||
         !routerset_equal(old_options->ExitNodes, options->ExitNodes) ||
+        !routerset_equal(old_options->Tor2webRendezvousPoints,
+                         options->Tor2webRendezvousPoints) ||
         options->StrictNodes != old_options->StrictNodes) {
       log_info(LD_CIRC,
                "Changed to using entry guards or bridges, or changed "
@@ -3057,6 +3062,10 @@ options_validate(or_options_t *old_options, or_options_t *options,
     options->UseEntryGuards = 0;
   }
 
+  if (options->Tor2webRendezvousPoints && !options->Tor2webMode) {
+    REJECT("Tor2webRendezvousPoints cannot be set without Tor2webMode.");
+  }
+
   if (!(options->UseEntryGuards) &&
       (options->RendConfigLines != NULL)) {
     log_warn(LD_CONFIG,
diff --git a/src/or/or.h b/src/or/or.h
index 5d70798d8e..560f5ff5b7 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3567,6 +3567,9 @@ typedef struct {
    * circuits.) */
   int Tor2webMode;
 
+  /** A routerset that should be used when picking RPs for HS circuits. */
+  routerset_t *Tor2webRendezvousPoints;
+
   /** Close hidden service client circuits immediately when they reach
    * the normal circuit-build timeout, even if they have already sent
    * an INTRODUCE1 cell on its way to the service. */
diff --git a/src/or/routerlist.c b/src/or/routerlist.c
index fe92ac0050..64c43c298b 100644
--- a/src/or/routerlist.c
+++ b/src/or/routerlist.c
@@ -1775,7 +1775,7 @@ routerlist_add_node_and_family(smartlist_t *sl, const routerinfo_t *router)
 /** Add every suitable node from our nodelist to <b>sl</b>, so that
  * we can pick a node for a circuit.
  */
-static void
+void
 router_add_running_nodes_to_smartlist(smartlist_t *sl, int allow_invalid,
                                       int need_uptime, int need_capacity,
                                       int need_guard, int need_desc)
diff --git a/src/or/routerlist.h b/src/or/routerlist.h
index f106ca2316..78c3fbb880 100644
--- a/src/or/routerlist.h
+++ b/src/or/routerlist.h
@@ -58,6 +58,10 @@ const routerstatus_t *router_pick_fallback_dirserver(dirinfo_type_t type,
 int router_get_my_share_of_directory_requests(double *v3_share_out);
 void router_reset_status_download_failures(void);
 int routers_have_same_or_addrs(const routerinfo_t *r1, const routerinfo_t *r2);
+void router_add_running_nodes_to_smartlist(smartlist_t *sl, int allow_invalid,
+                                           int need_uptime, int need_capacity,
+                                           int need_guard, int need_desc);
+
 const routerinfo_t *routerlist_find_my_routerinfo(void);
 uint32_t router_get_advertised_bandwidth(const routerinfo_t *router);
 uint32_t router_get_advertised_bandwidth_capped(const routerinfo_t *router);