r16285@catbus: nickm | 2007-10-30 17:43:25 -0400

Implement (but do not enable) link connection version negotiation


svn:r12286

doc/TODO

@@ -43,7 +43,7 @@ Things we'd like to do in 0.2.0.x:
       - 105 only
         - Need to get a finished proposal 105
         o "Pick a version" function
-        - Have a 'waiting_for_version' state.
+        o Have a 'waiting_for_version' state.
         o Store version in or_connection_t.
         o Generate netinfo cells
         o Accept netinfo cells
@@ -52,7 +52,7 @@ Things we'd like to do in 0.2.0.x:
           o Set it when we get a match for a routerinfo we have.
           - Don't extend a circuit over a noncanonical connection with
             mismatched address.
-        - Version negotiation: send a version cell and enter
+        o Version negotiation: send a version cell and enter
           waiting-for-version; when version cell arrives, pick version
           and send netinfo and be "open".
         o On netinfo, warn if there's skew from a server.

src/common/tortls.c

@@ -888,3 +888,10 @@ _check_no_tls_errors(const char *fname, int line)
   tls_log_errors(LOG_WARN, NULL);
 }
 
+/**DOCDOC */
+int
+tor_tls_used_v1_handshake(tor_tls_t *tls)
+{
+  (void)tls;
+  return 1;
+}

src/common/tortls.h

@@ -64,6 +64,8 @@ size_t tor_tls_get_forced_write_size(tor_tls_t *tls);
 void tor_tls_get_n_raw_bytes(tor_tls_t *tls,
                              size_t *n_read, size_t *n_written);
 
+int tor_tls_used_v1_handshake(tor_tls_t *tls);
+
 /* Log and abort if there are unhandled TLS errors in OpenSSL's error stack.
  */
 #define check_no_tls_errors() _check_no_tls_errors(__FILE__,__LINE__)

src/or/command.c

@@ -395,7 +395,8 @@ command_process_versions_cell(cell_t *cell, or_connection_t *conn)
   uint16_t versionslen;
   int highest_supported_version = 0;
   const char *cp, *end;
-  if (conn->link_proto != 0) {
+  if (conn->link_proto != 0 ||
+      conn->_base.state != OR_CONN_STATE_WAITING_FOR_VERSIONS) {
     log_fn(LOG_PROTOCOL_WARN, LD_OR,
            "Received a VERSIONS cell on a connection with its version "
            "already set to %d; dropping", (int) conn->link_proto);
@@ -412,13 +413,18 @@ command_process_versions_cell(cell_t *cell, or_connection_t *conn)
         highest_supported_version = v;
     }
   }
-  if (!versionslen) {
+  if (!highest_supported_version) {
     log_fn(LOG_PROTOCOL_WARN, LD_OR,
            "Couldn't find a version in common; defaulting to v1.");
     /*XXXX020 or just break the connection?*/
     conn->link_proto = 1;
     return;
   }
+  conn->link_proto = highest_supported_version;
+  conn->_base.state = OR_CONN_STATE_OPEN;
+
+  if (highest_supported_version >= 2)
+    connection_or_send_netinfo(conn);
 }
 
 /** Process a 'netinfo' cell. DOCDOC say more. */
@@ -433,9 +439,9 @@ command_process_netinfo_cell(cell_t *cell, or_connection_t *conn)
   uint8_t n_other_addrs;
   time_t now = time(NULL);
 
-  /*XXXX020 reject duplicat netinfos. */
+  /*XXXX020 reject duplicate netinfos. */
 
-  if (conn->link_proto < 2) {
+  if (conn->link_proto < 2 || conn->_base.state != OR_CONN_STATE_OPEN) {
     log_fn(LOG_PROTOCOL_WARN, LD_OR,
            "Received a NETINFO cell on %s connection; dropping.",
            conn->link_proto == 0 ? "non-versioned" : "a v1");

src/or/connection_or.c

@@ -16,6 +16,7 @@ const char connection_or_c_id[] =
 
 static int connection_tls_finish_handshake(or_connection_t *conn);
 static int connection_or_process_cells_from_inbuf(or_connection_t *conn);
+static int connection_or_send_versions(or_connection_t *conn);
 
 /**************************************************************/
 
@@ -732,8 +733,25 @@ connection_tls_finish_handshake(or_connection_t *conn)
   }
 
   directory_set_dirty();
+
+  if (tor_tls_used_v1_handshake(conn->tls)) {
+    conn->link_proto = 1;
+    return connection_or_set_state_open(conn);
+  } else {
+    /*XXXX020 actually, we'll need to send some kind of authentication. */
+    conn->_base.state = OR_CONN_STATE_WAITING_FOR_VERSIONS;
+    return connection_or_send_versions(conn);
+  }
+}
+
+/**DOCDOC*/
+int
+connection_or_set_state_open(or_connection_t *conn)
+{
+  int started_here = connection_or_nonopen_was_started_here(conn);
   conn->_base.state = OR_CONN_STATE_OPEN;
   control_event_or_conn_status(conn, OR_CONN_EVENT_CONNECTED, 0);
+
   if (started_here) {
     rep_hist_note_connect_succeeded(conn->identity_digest, time(NULL));
     if (entry_guard_register_connect_status(conn->identity_digest, 1,
@@ -746,7 +764,6 @@ connection_tls_finish_handshake(or_connection_t *conn)
   connection_watch_events(TO_CONN(conn), EV_READ);
   circuit_n_conn_done(conn, 1); /* send the pending creates, if any. */
 
-  conn->link_proto = 1; /* Version negotiation not yet enabled.XXX020 */
   return 0;
 }
 
@@ -850,10 +867,12 @@ connection_or_send_versions(or_connection_t *conn)
   }
 
   connection_or_write_cell_to_buf(&cell, conn);
+
+  return 0;
 }
 
 /** DOCDOC */
-static int
+int
 connection_or_send_netinfo(or_connection_t *conn)
 {
   cell_t cell;
@@ -881,7 +900,5 @@ connection_or_send_netinfo(or_connection_t *conn)
 
   connection_or_write_cell_to_buf(&cell, conn);
 
-  /*XXXX020 remove these once we send netinfo and versions cells. */
+  return 0;
-  (void) connection_or_send_netinfo;
-  (void) connection_or_send_versions;
 }

src/or/or.h

@@ -236,9 +236,12 @@ typedef enum {
 #define OR_CONN_STATE_PROXY_READING 3
 /** State for a connection to an OR: SSL is handshaking, not done yet. */
 #define OR_CONN_STATE_HANDSHAKING 4
+/** State for a connection to an OR: We sent a VERSIONS cell and want one back
+ */
+#define OR_CONN_STATE_WAITING_FOR_VERSIONS 5
 /** State for a connection to an OR: Ready to send/receive cells. */
-#define OR_CONN_STATE_OPEN 5
+#define OR_CONN_STATE_OPEN 6
-#define _OR_CONN_STATE_MAX 5
+#define _OR_CONN_STATE_MAX 6
 
 #define _EXIT_CONN_STATE_MIN 1
 /** State for an exit connection: waiting for response from dns farm. */
@@ -2717,10 +2720,12 @@ or_connection_t *connection_or_connect(uint32_t addr, uint16_t port,
 int connection_tls_start_handshake(or_connection_t *conn, int receiving);
 int connection_tls_continue_handshake(or_connection_t *conn);
 
+int connection_or_set_state_open(or_connection_t *conn);
 void connection_or_write_cell_to_buf(const cell_t *cell,
                                      or_connection_t *conn);
 int connection_or_send_destroy(uint16_t circ_id, or_connection_t *conn,
                                int reason);
+int connection_or_send_netinfo(or_connection_t *conn);
 
 void cell_pack(packed_cell_t *dest, const cell_t *src);