Add new circuit purposes for hsdir activity.

This lets us control their path len and usage.

5 files changed, 113 insertions, 21 deletions

diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 707654adf2..680b32953f 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -1662,11 +1662,14 @@ route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei)
   if (circuit_should_use_vanguards(purpose)) {
     /* Clients want an extra hop for rends to avoid linkability.
      * Services want it for intro points to avoid publishing their
-     * layer3 guards.
+     * layer3 guards. They want it for hsdir posts to use
+     * their full layer3 guard set for those connections.
      * Ex: C - G - L2 - L3 - R
+     *     S - G - L2 - L3 - HSDIR
      *     S - G - L2 - L3 - I
      */
     if (purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND ||
+        purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
         purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)
       return routelen+1;
 
@@ -1683,9 +1686,11 @@ route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei)
      * Same goes for intro points. Note that the route len
      * includes the intro point or hsdir, hence the +2.
      * Ex: C - G - L2 - L3 - M - I
+     *     C - G - L2 - L3 - M - HSDIR
      *     S - G - L2 - L3 - M - R
      */
     if (purpose == CIRCUIT_PURPOSE_S_CONNECT_REND ||
+        purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
         purpose == CIRCUIT_PURPOSE_C_INTRODUCING)
       return routelen+2;
   }
@@ -1706,6 +1711,8 @@ route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei)
     /* These three purposes connect to a router that someone else
      * might have chosen, so add an extra hop to protect anonymity. */
   case CIRCUIT_PURPOSE_C_GENERAL:
+  case CIRCUIT_PURPOSE_C_HSDIR_GET:
+  case CIRCUIT_PURPOSE_S_HSDIR_POST:
     /* connecting to hidden service directory */
   case CIRCUIT_PURPOSE_C_INTRODUCING:
     /* client connecting to introduction point */
@@ -2271,6 +2278,8 @@ choose_good_exit_server(uint8_t purpose,
     flags |= CRN_RENDEZVOUS_V3;
 
   switch (purpose) {
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
     case CIRCUIT_PURPOSE_C_GENERAL:
       if (is_internal) /* pick it like a middle hop */
         return router_choose_random_node(NULL, options->ExcludeNodes, flags);
@@ -2315,6 +2324,8 @@ warn_if_last_router_excluded(origin_circuit_t *circ,
                (int)purpose,
                circuit_purpose_to_string(purpose));
       return;
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
     case CIRCUIT_PURPOSE_C_GENERAL:
       if (circ->build_state->is_internal)
         return;
diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 028fdbfc2f..03e1a71074 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -689,6 +689,10 @@ circuit_purpose_to_controller_string(uint8_t purpose)
 
     case CIRCUIT_PURPOSE_C_GENERAL:
       return "GENERAL";
+
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
+      return "HS_CLIENT_HSDIR";
+
     case CIRCUIT_PURPOSE_C_INTRODUCING:
     case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
     case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
@@ -700,6 +704,9 @@ circuit_purpose_to_controller_string(uint8_t purpose)
     case CIRCUIT_PURPOSE_C_REND_JOINED:
       return "HS_CLIENT_REND";
 
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
+      return "HS_SERVICE_HSDIR";
+
     case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
     case CIRCUIT_PURPOSE_S_INTRO:
       return "HS_SERVICE_INTRO";
@@ -753,6 +760,7 @@ circuit_purpose_to_controller_hs_state_string(uint8_t purpose)
     case CIRCUIT_PURPOSE_REND_ESTABLISHED:
       return "OR_HS_R_JOINED";
 
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
     case CIRCUIT_PURPOSE_C_INTRODUCING:
       return "HSCI_CONNECTING";
     case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
@@ -769,6 +777,7 @@ circuit_purpose_to_controller_hs_state_string(uint8_t purpose)
     case CIRCUIT_PURPOSE_C_REND_JOINED:
       return "HSCR_JOINED";
 
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
     case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
       return "HSSI_CONNECTING";
     case CIRCUIT_PURPOSE_S_INTRO:
@@ -813,6 +822,9 @@ circuit_purpose_to_string(uint8_t purpose)
       return "Hidden service client: Pending rendezvous point (ack received)";
     case CIRCUIT_PURPOSE_C_REND_JOINED:
       return "Hidden service client: Active rendezvous point";
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
+      return "Hidden service client: Fetching HS descriptor";
+
     case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
       return "Measuring circuit timeout";
 
@@ -824,6 +836,8 @@ circuit_purpose_to_string(uint8_t purpose)
       return "Hidden service: Connecting to rendezvous point";
     case CIRCUIT_PURPOSE_S_REND_JOINED:
       return "Hidden service: Active rendezvous point";
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
+      return "Hidden service: Uploading HS descriptor";
 
     case CIRCUIT_PURPOSE_TESTING:
       return "Testing circuit";
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index e7be8fa22a..96eb43162d 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -156,7 +156,9 @@ circuit_is_acceptable(const origin_circuit_t *origin_circ,
   if (need_internal != build_state->is_internal)
     return 0;
 
-  if (purpose == CIRCUIT_PURPOSE_C_GENERAL) {
+  if (purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+      purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+      purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) {
     tor_addr_t addr;
     const int family = tor_addr_parse(&addr, conn->socks_request->address);
     if (!exitnode && !build_state->onehop_tunnel) {
@@ -238,6 +240,8 @@ circuit_is_better(const origin_circuit_t *oa, const origin_circuit_t *ob,
     return 1; /* oa is better. It's not relaxed. */
 
   switch (purpose) {
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
     case CIRCUIT_PURPOSE_C_GENERAL:
       /* if it's used but less dirty it's best;
        * else if it's more recently created it's best
@@ -323,6 +327,8 @@ circuit_get_best(const entry_connection_t *conn,
   tor_assert(conn);
 
   tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+             purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+             purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
              purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT ||
              purpose == CIRCUIT_PURPOSE_C_REND_JOINED);
 
@@ -1458,6 +1464,8 @@ circuit_expire_old_circuits_clientside(void)
     } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) {
       if (timercmp(&circ->timestamp_began, &cutoff, OP_LT)) {
         if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+                circ->purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+                circ->purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
                 circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT ||
                 circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
                 circ->purpose == CIRCUIT_PURPOSE_TESTING ||
@@ -1650,6 +1658,8 @@ circuit_has_opened(origin_circuit_t *circ)
       hs_client_circuit_has_opened(circ);
       break;
     case CIRCUIT_PURPOSE_C_GENERAL:
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
       /* Tell any AP connections that have been waiting for a new
        * circuit that one is ready. */
       circuit_try_attaching_streams(circ);
@@ -1786,6 +1796,8 @@ circuit_build_failed(origin_circuit_t *circ)
   }
 
   switch (circ->base_.purpose) {
+    case CIRCUIT_PURPOSE_C_HSDIR_GET:
+    case CIRCUIT_PURPOSE_S_HSDIR_POST:
     case CIRCUIT_PURPOSE_C_GENERAL:
       /* If we never built the circuit, note it as a failure. */
       circuit_increment_failure_count();
@@ -1877,14 +1889,14 @@ int
 circuit_purpose_is_hidden_service(uint8_t purpose)
 {
    /* Client-side purpose */
-   if (purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
-       purpose <= CIRCUIT_PURPOSE_C_REND_JOINED) {
+   if (purpose >= CIRCUIT_PURPOSE_C_HS_MIN_ &&
+       purpose <= CIRCUIT_PURPOSE_C_HS_MAX_) {
      return 1;
    }
 
    /* Service-side purpose */
-   if (purpose >= CIRCUIT_PURPOSE_S_ESTABLISH_INTRO &&
-       purpose <= CIRCUIT_PURPOSE_S_REND_JOINED) {
+   if (purpose >= CIRCUIT_PURPOSE_S_HS_MIN_ &&
+       purpose <= CIRCUIT_PURPOSE_S_HS_MAX_) {
      return 1;
    }
 
@@ -2009,6 +2021,8 @@ circuit_launch_by_extend_info(uint8_t purpose,
         case CIRCUIT_PURPOSE_C_INTRODUCING:
         case CIRCUIT_PURPOSE_S_CONNECT_REND:
         case CIRCUIT_PURPOSE_C_GENERAL:
+        case CIRCUIT_PURPOSE_S_HSDIR_POST:
+        case CIRCUIT_PURPOSE_C_HSDIR_GET:
         case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
           /* need to add a new hop */
           tor_assert(extend_info);
@@ -2273,7 +2287,9 @@ circuit_get_open_circ_or_launch(entry_connection_t *conn,
     /* If we have specified a particular exit node for our
      * connection, then be sure to open a circuit to that exit node.
      */
-    if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) {
+    if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+        desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
+        desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET) {
       if (conn->chosen_exit_name) {
         const node_t *r;
         int opt = conn->chosen_exit_optional;
@@ -2381,7 +2397,9 @@ circuit_get_open_circ_or_launch(entry_connection_t *conn,
 
     /* Now trigger things that need to happen when we launch circuits */
 
-    if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL) {
+    if (desired_circuit_purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+        desired_circuit_purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+        desired_circuit_purpose == CIRCUIT_PURPOSE_S_HSDIR_POST) {
       /* We just caused a circuit to get built because of this stream.
        * If this stream has caused a _lot_ of circuits to be built, that's
        * a bad sign: we should tell the user. */
@@ -2510,6 +2528,8 @@ link_apconn_to_circ(entry_connection_t *apconn, origin_circuit_t *circ,
   /* See if we can use optimistic data on this circuit */
   if (optimistic_data_enabled() &&
       (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+       circ->base_.purpose == CIRCUIT_PURPOSE_C_HSDIR_GET ||
+       circ->base_.purpose == CIRCUIT_PURPOSE_S_HSDIR_POST ||
        circ->base_.purpose == CIRCUIT_PURPOSE_C_REND_JOINED))
     apconn->may_use_optimistic_data = 1;
   else
@@ -2630,6 +2650,39 @@ connection_ap_handshake_attach_chosen_circuit(entry_connection_t *conn,
   return 1;
 }
 
+/**
+ * Return an appropriate circuit purpose for non-rend streams.
+ * We don't handle rends here because a rend stream triggers two
+ * circuit builds with different purposes, so it is handled elsewhere.
+ *
+ * This function just figures out what type of hsdir activity this is,
+ * and tells us. Everything else is general.
+ */
+static int
+connection_ap_get_nonrend_circ_purpose(const entry_connection_t *conn)
+{
+  const connection_t *base_conn = ENTRY_TO_CONN(conn);
+  tor_assert_nonfatal(!connection_edge_is_rendezvous_stream(
+                      ENTRY_TO_EDGE_CONN(conn)));
+
+  if (base_conn->linked_conn &&
+      base_conn->linked_conn->type == CONN_TYPE_DIR) {
+    /* Set a custom purpose for hsdir activity */
+    if (base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2 ||
+       base_conn->linked_conn->purpose == DIR_PURPOSE_UPLOAD_HSDESC) {
+      return CIRCUIT_PURPOSE_S_HSDIR_POST;
+    } else if (base_conn->linked_conn->purpose
+                 == DIR_PURPOSE_FETCH_RENDDESC_V2 ||
+               base_conn->linked_conn->purpose
+                 == DIR_PURPOSE_FETCH_HSDESC) {
+      return CIRCUIT_PURPOSE_C_HSDIR_GET;
+    }
+  }
+
+  /* All other purposes are general for now */
+  return CIRCUIT_PURPOSE_C_GENERAL;
+}
+
 /** Try to find a safe live circuit for stream <b>conn</b>.  If we find one,
  * attach the stream, send appropriate cells, and return 1.  Otherwise,
  * try to launch new circuit(s) for the stream.  If we can launch
@@ -2728,9 +2781,12 @@ connection_ap_handshake_attach_circuit(entry_connection_t *conn)
     }
 
     /* Find the circuit that we should use, if there is one. Otherwise
-     * launch it. */
-    retval = circuit_get_open_circ_or_launch(
-        conn, CIRCUIT_PURPOSE_C_GENERAL, &circ);
+     * launch it
+     */
+    retval = circuit_get_open_circ_or_launch(conn,
+            connection_ap_get_nonrend_circ_purpose(conn),
+            &circ);
+
     if (retval < 1) {
       /* We were either told "-1" (complete failure) or 0 (circuit in
        * progress); we can't attach this stream yet. */
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 0c4352ea13..4021ca9e0c 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -2592,6 +2592,8 @@ connection_ap_supports_optimistic_data(const entry_connection_t *conn)
   if (edge_conn->on_circuit == NULL ||
       edge_conn->on_circuit->state != CIRCUIT_STATE_OPEN ||
       (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
+       edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_HSDIR_GET &&
+       edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_S_HSDIR_POST &&
        edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_REND_JOINED))
     return 0;
 
diff --git a/src/or/or.h b/src/or/or.h
index 54e9786c75..b878ef8fd4 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -506,6 +506,7 @@ typedef enum {
  */
 /** Client-side circuit purpose: Normal circuit, with cpath. */
 #define CIRCUIT_PURPOSE_C_GENERAL 5
+#define CIRCUIT_PURPOSE_C_HS_MIN_ 6
 /** Client-side circuit purpose: at the client, connecting to intro point. */
 #define CIRCUIT_PURPOSE_C_INTRODUCING 6
 /** Client-side circuit purpose: at the client, sent INTRODUCE1 to intro point,
@@ -523,28 +524,36 @@ typedef enum {
 #define CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED 11
 /** Client-side circuit purpose: at the client, rendezvous established. */
 #define CIRCUIT_PURPOSE_C_REND_JOINED 12
+/** This circuit is used for getting hsdirs */
+#define CIRCUIT_PURPOSE_C_HSDIR_GET 13
+#define CIRCUIT_PURPOSE_C_HS_MAX_ 13
 /** This circuit is used for build time measurement only */
-#define CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT 13
-#define CIRCUIT_PURPOSE_C_MAX_ 13
+#define CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT 14
+#define CIRCUIT_PURPOSE_C_MAX_ 14
+
+#define CIRCUIT_PURPOSE_S_HS_MIN_ 15
 /** Hidden-service-side circuit purpose: at the service, waiting for
  * introductions. */
-#define CIRCUIT_PURPOSE_S_ESTABLISH_INTRO 14
+#define CIRCUIT_PURPOSE_S_ESTABLISH_INTRO 15
 /** Hidden-service-side circuit purpose: at the service, successfully
  * established intro. */
-#define CIRCUIT_PURPOSE_S_INTRO 15
+#define CIRCUIT_PURPOSE_S_INTRO 16
 /** Hidden-service-side circuit purpose: at the service, connecting to rend
  * point. */
-#define CIRCUIT_PURPOSE_S_CONNECT_REND 16
+#define CIRCUIT_PURPOSE_S_CONNECT_REND 17
 /** Hidden-service-side circuit purpose: at the service, rendezvous
  * established. */
-#define CIRCUIT_PURPOSE_S_REND_JOINED 17
+#define CIRCUIT_PURPOSE_S_REND_JOINED 18
+/** This circuit is used for uploading hsdirs */
+#define CIRCUIT_PURPOSE_S_HSDIR_POST 19
+#define CIRCUIT_PURPOSE_S_HS_MAX_ 19
 /** A testing circuit; not meant to be used for actual traffic. */
-#define CIRCUIT_PURPOSE_TESTING 18
+#define CIRCUIT_PURPOSE_TESTING 20
 /** A controller made this circuit and Tor should not use it. */
-#define CIRCUIT_PURPOSE_CONTROLLER 19
+#define CIRCUIT_PURPOSE_CONTROLLER 21
 /** This circuit is used for path bias probing only */
-#define CIRCUIT_PURPOSE_PATH_BIAS_TESTING 20
-#define CIRCUIT_PURPOSE_MAX_ 20
+#define CIRCUIT_PURPOSE_PATH_BIAS_TESTING 22
+#define CIRCUIT_PURPOSE_MAX_ 22
 /** A catch-all for unrecognized purposes. Currently we don't expect
  * to make or see any circuits with this purpose. */
 #define CIRCUIT_PURPOSE_UNKNOWN 255