Add proxy headers as early as possible.

This patch moves the logic that adds the proxy headers to an earlier
point in the exit connection lifetime, which ensures that the
application data cannot be written to the outbuf before the proxy header
is added.

See: https://bugs.torproject.org/4700

diff --git a/src/core/or/connection_edge.c b/src/core/or/connection_edge.c
index 0eff007e36c7f63dc7e5cbd0968b4eb4dfc51871..ab2acaa39c75c7b908b377e34932ab780f9a918f 100644 (file)
--- a/src/core/or/connection_edge.c
+++ b/src/core/or/connection_edge.c
@@ -600,8 +600,7 @@ connected_cell_format_payload(uint8_t *payload_out,
 /* This is an onion service client connection: Export the client circuit ID
  * according to the HAProxy proxy protocol. */
 STATIC void
-export_hs_client_circuit_id(const edge_connection_t *edge_conn,
-                            connection_t *conn,
+export_hs_client_circuit_id(edge_connection_t *edge_conn,
                             hs_circuit_id_protocol_t protocol)
 {
   /* We only support HAProxy right now. */
@@ -633,7 +632,7 @@ export_hs_client_circuit_id(const edge_connection_t *edge_conn,
                gid >> 16, gid & 0x0000ffff,
                dst_ipv6, src_port, dst_port);
 
-  connection_buf_add(buf, strlen(buf), conn);
+  connection_buf_add(buf, strlen(buf), TO_CONN(edge_conn));
 
   tor_free(buf);
 }
@@ -659,14 +658,6 @@ connection_edge_finished_connecting(edge_connection_t *edge_conn)
 
   conn->state = EXIT_CONN_STATE_OPEN;
 
-  /* If it's an onion service connection, we might want to include the proxy
-   * protocol header: */
-  if (edge_conn->hs_ident) {
-    hs_circuit_id_protocol_t circuit_id_protocol =
-      hs_service_exports_circuit_id(&edge_conn->hs_ident->identity_pk);
-    export_hs_client_circuit_id(edge_conn, conn, circuit_id_protocol);
-  }
-
   connection_watch_events(conn, READ_EVENT); /* stop writing, keep reading */
   if (connection_get_outbuf_len(conn)) /* in case there are any queued relay
                                         * cells */
@@ -3452,6 +3443,14 @@ handle_hs_exit_conn(circuit_t *circ, edge_connection_t *conn)
 
   hs_inc_rdv_stream_counter(origin_circ);
 
+  /* If it's an onion service connection, we might want to include the proxy
+   * protocol header: */
+  if (conn->hs_ident) {
+    hs_circuit_id_protocol_t circuit_id_protocol =
+      hs_service_exports_circuit_id(&conn->hs_ident->identity_pk);
+    export_hs_client_circuit_id(conn, circuit_id_protocol);
+  }
+
   /* Connect tor to the hidden service destination. */
   connection_exit_connect(conn);
 

diff --git a/src/core/or/connection_edge.h b/src/core/or/connection_edge.h
index c5ad3128a264462227fb48d63c40f722bfec6d81..5b694428ded77de32220cf81c12884595e7d2174 100644 (file)
--- a/src/core/or/connection_edge.h
+++ b/src/core/or/connection_edge.h
@@ -246,8 +246,7 @@ STATIC void connection_ap_handshake_rewrite(entry_connection_t *conn,
 
 STATIC int connection_ap_process_http_connect(entry_connection_t *conn);
 STATIC void
-export_hs_client_circuit_id(const edge_connection_t *edge_conn,
-                            connection_t *conn,
+export_hs_client_circuit_id(edge_connection_t *edge_conn,
                             hs_circuit_id_protocol_t protocol);
 
 #endif /* defined(CONNECTION_EDGE_PRIVATE) */

diff --git a/src/test/test_hs_service.c b/src/test/test_hs_service.c
index 955bcc8aff8916e80b75b4705f6c57b23e7e4077..dace2b63d8d33bb02d4b1a135cb907d1a14fb7bf 100644 (file)
--- a/src/test/test_hs_service.c
+++ b/src/test/test_hs_service.c
@@ -2047,8 +2047,7 @@ test_export_client_circuit_id(void *arg)
   or_circ->global_identifier = 666;
 
   /* Export circuit ID */
-  export_hs_client_circuit_id(edge_conn, conn,
-                              service->config.circuit_id_protocol);
+  export_hs_client_circuit_id(edge_conn, service->config.circuit_id_protocol);
 
   /* Check contents */
   cp1 = buf_get_contents(conn->outbuf, &sz);
@@ -2059,8 +2058,7 @@ test_export_client_circuit_id(void *arg)
   or_circ->global_identifier = 22;
 
   /* check changes */
-  export_hs_client_circuit_id(edge_conn, conn,
-                              service->config.circuit_id_protocol);
+  export_hs_client_circuit_id(edge_conn, service->config.circuit_id_protocol);
   cp2 = buf_get_contents(conn->outbuf, &sz);
   tt_str_op(cp1, OP_NE, cp2);
   tor_free(cp1);
@@ -2068,8 +2066,7 @@ test_export_client_circuit_id(void *arg)
   /* Check that GID with UINT32_MAX works. */
   or_circ->global_identifier = UINT32_MAX;
 
-  export_hs_client_circuit_id(edge_conn, conn,
-                              service->config.circuit_id_protocol);
+  export_hs_client_circuit_id(edge_conn, service->config.circuit_id_protocol);
   cp1 = buf_get_contents(conn->outbuf, &sz);
   tt_str_op(cp1, OP_EQ,
             "PROXY TCP6 fc00:dead:beef:4dad::ffff:ffff ::1 65535 42\r\n");
@@ -2078,8 +2075,7 @@ test_export_client_circuit_id(void *arg)
   /* Check that GID with UINT16_MAX works. */
   or_circ->global_identifier = UINT16_MAX;
 
-  export_hs_client_circuit_id(edge_conn, conn,
-                              service->config.circuit_id_protocol);
+  export_hs_client_circuit_id(edge_conn, service->config.circuit_id_protocol);
   cp1 = buf_get_contents(conn->outbuf, &sz);
   tt_str_op(cp1, OP_EQ,
             "PROXY TCP6 fc00:dead:beef:4dad::0:ffff ::1 65535 42\r\n");
@@ -2088,8 +2084,7 @@ test_export_client_circuit_id(void *arg)
   /* Check that GID with UINT16_MAX + 7 works. */
   or_circ->global_identifier = UINT16_MAX + 7;
 
-  export_hs_client_circuit_id(edge_conn, conn,
-                              service->config.circuit_id_protocol);
+  export_hs_client_circuit_id(edge_conn, service->config.circuit_id_protocol);
   cp1 = buf_get_contents(conn->outbuf, &sz);
   tt_str_op(cp1, OP_EQ, "PROXY TCP6 fc00:dead:beef:4dad::1:6 ::1 6 42\r\n");