Implement RedirectExit.

svn:r2550

doc/TODO

@@ -28,9 +28,9 @@ R       - figure out enclaves, e.g. so we know what to recommend that people
           do, and so running a tor server on your website is helpful.
           - Do enclaves for same IP only.
           - Resolve first, then if IP is an OR, connect to next guy.
-N       - let tor servers use proxies for port 80 exits
-          - Use generic port redirector for IP/bits:Port->IP:Port .
-          - Make use of them when we're doing exit connections.
+        o let tor servers use proxies for port 80 exits
+          o Use generic port redirector for IP/bits:Port->IP:Port .
+          o Make use of them when we're doing exit connections.
         X We should set things in options to NULL, not rely on memset(...0)
           being equivalent.
           o We should check for memset(0) setting things to NULL with autoconf,
@@ -59,6 +59,8 @@ R       - learn from ben about his openssl-reinitialization-trick to
         D nt services on win32.
 
       0.0.9 and beyond:
+        - Should redirects change conn->addr/port or not? Either HTTP
+          proxying or exit redirection is doing the wrong thing.
         - fix sprintf's to snprintf's?
         . Make intro points and rendezvous points accept $KEYID in addition
           to nicknames.

src/or/config.c

@@ -38,6 +38,7 @@ static int parse_dir_server_line(const char *line);
 static int parse_redirect_line(or_options_t *options,
                                struct config_line_t *line);
 
+
 /** Helper: Read a list of configuration options from the command line. */
 static struct config_line_t *
 config_get_commandlines(int argc, char **argv)
@@ -483,9 +484,10 @@ free_options(or_options_t *options)
   config_free_lines(options->NodeFamilies);
   config_free_lines(options->RedirectExit);
   if (options->RedirectExitList) {
-    SMARTLIST_FOREACH(options->RedirectExitList,exit_redirect_t *, p, tor_free(p));
+    SMARTLIST_FOREACH(options->RedirectExitList,
+                      exit_redirect_t *, p, tor_free(p));
     smartlist_free(options->RedirectExitList);
-    options->RedirectExitList = NULL;
+    options->RedirectExitList = NULL;                      
   }
   if (options->FirewallPorts) {
     SMARTLIST_FOREACH(options->FirewallPorts, char *, cp, tor_free(cp));

src/or/connection_edge.c

@@ -599,7 +599,7 @@ int connection_ap_make_bridge(char *address, uint16_t port) {
   conn->socks_request->command = SOCKS_COMMAND_CONNECT;
 
   conn->address = tor_strdup("(local bridge)");
-  conn->addr = ntohs(0);
+  conn->addr = 0;
   conn->port = 0;
 
   if(connection_add(conn) < 0) { /* no space, forget it */
@@ -882,6 +882,8 @@ int connection_exit_begin_resolve(cell_t *cell, circuit_t *circ) {
  */
 void connection_exit_connect(connection_t *conn) {
   unsigned char connected_payload[4];
+  uint32_t addr;
+  uint16_t port;
 
   if (!connection_edge_is_rendezvous_stream(conn) &&
       router_compare_to_my_exit_policy(conn) == ADDR_POLICY_REJECTED) {
@@ -892,8 +894,24 @@ void connection_exit_connect(connection_t *conn) {
     return;
   }
 
+  addr = conn->addr;
+  port = conn->port;
+  SMARTLIST_FOREACH(options.RedirectExitList, exit_redirect_t *, r,
+    {
+      if ((addr&r->mask)==(r->addr&r->mask) &&
+          (r->port_min <= port) && (port <= r->port_max)) {
+        struct in_addr in;
+        addr = r->addr_dest;
+        port = r->port_dest;
+        in.s_addr = htonl(addr);
+        log_fn(LOG_DEBUG, "Redirecting connection from %s:%d to %s:%d",
+               conn->address, conn->port, inet_ntoa(in), port);
+        break;
+      }
+    });
+
   log_fn(LOG_DEBUG,"about to try connecting");
-  switch(connection_connect(conn, conn->address, conn->addr, conn->port)) {
+  switch(connection_connect(conn, conn->address, addr, port)) {
     case -1:
       connection_edge_end(conn, END_STREAM_REASON_CONNECTFAILED, conn->cpath_layer);
       circuit_detach_stream(circuit_get_by_conn(conn), conn);
@@ -922,6 +940,7 @@ void connection_exit_connect(connection_t *conn) {
     connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED,
                                  NULL, 0, conn->cpath_layer);
   } else { /* normal stream */
+    /* This must be the original address, not the redirected address. */
     *(uint32_t*)connected_payload = htonl(conn->addr);
     connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED,
                                  connected_payload, 4, conn->cpath_layer);