"(Socks|Control|etc)Port auto" now tells Tor to open an arbitrary port

This is the major part of the implementation for trac issue 3076.

1 files changed, 32 insertions, 13 deletions

diff --git a/src/or/connection.c b/src/or/connection.c
index eaae791efc..47e5423e0b 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -37,7 +37,7 @@
 #include "routerparse.h"
 
 static connection_t *connection_create_listener(
-                               struct sockaddr *listensockaddr,
+                               const struct sockaddr *listensockaddr,
                                socklen_t listensocklen, int type,
                                char* address);
 static void connection_init(time_t now, connection_t *conn, int type,
@@ -759,7 +759,7 @@ connection_expire_held_open(void)
  * The listenaddr struct has to be freed by the caller.
  */
 static struct sockaddr_in *
-create_inet_sockaddr(const char *listenaddress, uint16_t listenport,
+create_inet_sockaddr(const char *listenaddress, int listenport,
                      char **readable_address, socklen_t *socklen_out) {
   struct sockaddr_in *listenaddr = NULL;
   uint32_t addr;
@@ -771,8 +771,10 @@ create_inet_sockaddr(const char *listenaddress, uint16_t listenport,
              "Error parsing/resolving ListenAddress %s", listenaddress);
     goto err;
   }
-  if (usePort==0)
-    usePort = listenport;
+  if (usePort==0) {
+    if (listenport != CFG_AUTO_PORT)
+      usePort = listenport;
+  }
 
   listenaddr = tor_malloc_zero(sizeof(struct sockaddr_in));
   listenaddr->sin_addr.s_addr = htonl(addr);
@@ -858,12 +860,13 @@ warn_too_many_conns(void)
  * to the conn.
  */
 static connection_t *
-connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
+connection_create_listener(const struct sockaddr *listensockaddr,
+                           socklen_t socklen,
                            int type, char* address)
 {
   connection_t *conn;
   int s; /* the socket we're going to make */
-  uint16_t usePort = 0;
+  uint16_t usePort = 0, gotPort = 0;
   int start_reading = 0;
 
   if (get_n_open_sockets() >= get_options()->_ConnLimit-1) {
@@ -872,6 +875,7 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
   }
 
   if (listensockaddr->sa_family == AF_INET) {
+    tor_addr_t addr;
     int is_tcp = (type != CONN_TYPE_AP_DNS_LISTENER);
 #ifndef MS_WINDOWS
     int one=1;
@@ -879,11 +883,10 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
     if (is_tcp)
       start_reading = 1;
 
-    usePort = ntohs( (uint16_t)
-                     ((struct sockaddr_in *)listensockaddr)->sin_port);
+    tor_addr_from_sockaddr(&addr, listensockaddr, &usePort);
 
     log_notice(LD_NET, "Opening %s on %s:%d",
-               conn_type_to_string(type), address, usePort);
+               conn_type_to_string(type), fmt_addr(&addr), usePort);
 
     s = tor_open_socket(PF_INET,
                         is_tcp ? SOCK_STREAM : SOCK_DGRAM,
@@ -921,6 +924,21 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
         goto err;
       }
     }
+
+    if (usePort != 0) {
+      gotPort = usePort;
+    } else {
+      tor_addr_t addr2;
+      struct sockaddr_storage ss;
+      socklen_t ss_len=sizeof(ss);
+      if (getsockname(s, (struct sockaddr*)&ss, &ss_len)<0) {
+        log_warn(LD_NET, "getsockname() couldn't learn address for %s: %s",
+                 conn_type_to_string(type),
+                 tor_socket_strerror(tor_socket_errno(s)));
+        gotPort = 0;
+      }
+      tor_addr_from_sockaddr(&addr2, (struct sockaddr*)&ss, &gotPort);
+    }
 #ifdef HAVE_SYS_UN_H
   } else if (listensockaddr->sa_family == AF_UNIX) {
     start_reading = 1;
@@ -968,7 +986,7 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
   conn->socket_family = listensockaddr->sa_family;
   conn->s = s;
   conn->address = tor_strdup(address);
-  conn->port = usePort;
+  conn->port = gotPort;
 
   if (connection_add(conn) < 0) { /* no space, forget it */
     log_warn(LD_NET,"connection_add for listener failed. Giving up.");
@@ -976,8 +994,9 @@ connection_create_listener(struct sockaddr *listensockaddr, socklen_t socklen,
     goto err;
   }
 
-  log_debug(LD_NET,"%s listening on port %u.",
-            conn_type_to_string(type), usePort);
+  log_fn(usePort==gotPort ? LOG_DEBUG : LOG_NOTICE, LD_NET,
+         "%s listening on port %u.",
+         conn_type_to_string(type), gotPort);
 
   conn->state = LISTENER_STATE_READY;
   if (start_reading) {
@@ -1804,7 +1823,7 @@ retry_listeners(int type, config_line_t *cfg,
           case AF_INET:
             listensockaddr = (struct sockaddr *)
                              create_inet_sockaddr(cfg_line->value,
-                                                  (uint16_t) port_option,
+                                                  port_option,
                                                   &address, &listensocklen);
             break;
           case AF_UNIX: