dos: Pass transport name on new client connection

For a bridge configured with a pluggable transport, the transport name is
used, with the IP address, for the GeoIP client cache entry.

However, the DoS subsystem was not aware of it and always passing NULL when
doing a lookup into the GeoIP cache.

This resulted in bridges with a PT are never able to apply DoS defenses for
newly created connections.

Fixes #33491

Signed-off-by: David Goulet <dgoulet@torproject.org>

changes/ticket33491

@@ -0,0 +1,6 @@
+  o Major bugfixes (DoS defenses, bridges, pluggable transport):
+    - DoS subsystem was not given the transport name of the client connection
+      when tor is a bridge and thus failing to find the GeoIP cache entry for
+      that client address. This resulted in failing to apply DoS defenses on
+      bridges with a pluggable transport. Fixes bug 33491; bugfix on
+      0.3.3.2-alpha.

src/core/or/channel.c

@@ -1871,7 +1871,7 @@ channel_do_open_actions(channel_t *chan)
         tor_free(transport_name);
         /* Notify the DoS subsystem of a new client. */
         if (tlschan && tlschan->conn) {
-          dos_new_client_conn(tlschan->conn);
+          dos_new_client_conn(tlschan->conn, transport_name);
         }
       }
       /* Otherwise the underlying transport can't tell us this, so skip it */

src/core/or/dos.c

@@ -671,7 +671,7 @@ dos_log_heartbeat(void)
 /* Called when a new client connection has been established on the given
  * address. */
 void
-dos_new_client_conn(or_connection_t *or_conn)
+dos_new_client_conn(or_connection_t *or_conn, const char *transport_name)
 {
   clientmap_entry_t *entry;
 
@@ -692,7 +692,7 @@ dos_new_client_conn(or_connection_t *or_conn)
   }
 
   /* We are only interested in client connection from the geoip cache. */
-  entry = geoip_lookup_client(&or_conn->real_addr, NULL,
+  entry = geoip_lookup_client(&or_conn->real_addr, transport_name,
                               GEOIP_CLIENT_CONNECT);
   if (BUG(entry == NULL)) {
     /* Should never happen because we note down the address in the geoip

src/core/or/dos.h

@@ -53,7 +53,8 @@ int dos_enabled(void);
 void dos_log_heartbeat(void);
 void dos_geoip_entry_about_to_free(const struct clientmap_entry_t *geoip_ent);
 
-void dos_new_client_conn(or_connection_t *or_conn);
+void dos_new_client_conn(or_connection_t *or_conn,
+                         const char *transport_name);
 void dos_close_client_conn(const or_connection_t *or_conn);
 
 int dos_should_refuse_single_hop_client(void);

src/test/test_dos.c

@@ -79,7 +79,7 @@ test_dos_conn_creation(void *arg)
   { /* Register many conns from this client but not enough to get it blocked */
     unsigned int i;
     for (i = 0; i < max_concurrent_conns; i++) {
-      dos_new_client_conn(&or_conn);
+      dos_new_client_conn(&or_conn, NULL);
     }
   }
 
@@ -88,7 +88,7 @@ test_dos_conn_creation(void *arg)
             dos_conn_addr_get_defense_type(addr));
 
   /* Register another conn and check that new conns are not allowed anymore */
-  dos_new_client_conn(&or_conn);
+  dos_new_client_conn(&or_conn, NULL);
   tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ,
             dos_conn_addr_get_defense_type(addr));
 
@@ -98,7 +98,7 @@ test_dos_conn_creation(void *arg)
             dos_conn_addr_get_defense_type(addr));
 
   /* Register another conn and see that defense measures get reactivated */
-  dos_new_client_conn(&or_conn);
+  dos_new_client_conn(&or_conn, NULL);
   tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ,
             dos_conn_addr_get_defense_type(addr));
 
@@ -153,7 +153,7 @@ test_dos_circuit_creation(void *arg)
    * circuit counting subsystem */
   geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now);
   for (i = 0; i < min_conc_conns_for_cc ; i++) {
-    dos_new_client_conn(&or_conn);
+    dos_new_client_conn(&or_conn, NULL);
   }
 
   /* Register new circuits for this client and conn, but not enough to get
@@ -217,7 +217,7 @@ test_dos_bucket_refill(void *arg)
 
   /* Register this client */
   geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now);
-  dos_new_client_conn(&or_conn);
+  dos_new_client_conn(&or_conn, NULL);
 
   /* Fetch this client from the geoip cache and get its DoS structs */
   clientmap_entry_t *entry = geoip_lookup_client(addr, NULL,
@@ -460,11 +460,11 @@ test_known_relay(void *arg)
   geoip_note_client_seen(GEOIP_CLIENT_CONNECT, &or_conn.real_addr, NULL, 0);
   /* Suppose we have 5 connections in rapid succession, the counter should
    * always be 0 because we should ignore this. */
-  dos_new_client_conn(&or_conn);
-  dos_new_client_conn(&or_conn);
-  dos_new_client_conn(&or_conn);
-  dos_new_client_conn(&or_conn);
-  dos_new_client_conn(&or_conn);
+  dos_new_client_conn(&or_conn, NULL);
+  dos_new_client_conn(&or_conn, NULL);
+  dos_new_client_conn(&or_conn, NULL);
+  dos_new_client_conn(&or_conn, NULL);
+  dos_new_client_conn(&or_conn, NULL);
   entry = geoip_lookup_client(&or_conn.real_addr, NULL, GEOIP_CLIENT_CONNECT);
   tt_assert(entry);
   /* We should have a count of 0. */
@@ -474,8 +474,8 @@ test_known_relay(void *arg)
    * connection and see if we do get it. */
   tor_addr_parse(&or_conn.real_addr, "42.42.42.43");
   geoip_note_client_seen(GEOIP_CLIENT_CONNECT, &or_conn.real_addr, NULL, 0);
-  dos_new_client_conn(&or_conn);
-  dos_new_client_conn(&or_conn);
+  dos_new_client_conn(&or_conn, NULL);
+  dos_new_client_conn(&or_conn, NULL);
   entry = geoip_lookup_client(&or_conn.real_addr, NULL, GEOIP_CLIENT_CONNECT);
   tt_assert(entry);
   /* We should have a count of 2. */