Separate "SOCKS_COMMAND_CONNECT_DIR" into two flags in

edge_connection_t: want_onehop if it must attach to a circuit with
only one hop (e.g. for the current tunnelled connections that use
begin_dir), and use_begindir if we mean to use a BEGIN_DIR relay
command to establish the stream rather than the normal BEGIN. Now
we can make anonymized begin_dir connections for (e.g.) more secure
hidden service posting and fetching.


svn:r12244

7 files changed, 66 insertions, 53 deletions

diff --git a/ChangeLog b/ChangeLog
index 062c55d92..fb19a3acd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,13 @@
 Changes in version 0.2.0.10-alpha - 2007-1?-??
+  o Major features:
+    - Separate "SOCKS_COMMAND_CONNECT_DIR" into two flags in
+      edge_connection_t: want_onehop if it must attach to a circuit with
+      only one hop (e.g. for the current tunnelled connections that use
+      begin_dir), and use_begindir if we mean to use a BEGIN_DIR relay
+      command to establish the stream rather than the normal BEGIN. Now
+      we can make anonymized begin_dir connections for (e.g.) more secure
+      hidden service posting and fetching.
+
   o Major bugfixes:
     - Stop servers from crashing if they set a Family option (or
       maybe in other situations too). Bugfix on 0.2.0.9-alpha; reported
diff --git a/doc/spec/socks-extensions.txt b/doc/spec/socks-extensions.txt
index 8097c6645..49c9660b1 100644
--- a/doc/spec/socks-extensions.txt
+++ b/doc/spec/socks-extensions.txt
@@ -60,6 +60,8 @@ Tor's extensions to the SOCKS protocol
   directory port of the Tor server specified by address:port (the port
   specified should be the ORPort of the server). It uses a one-hop tunnel
   and a "BEGIN_DIR" relay cell to accomplish this secure connection.
+  Th F2 command value was removed in Tor 0.2.0.10-alpha in favor of a
+  new use_begindir flag in edge_connection_t.
 
 4. HTTP-resistance
 
diff --git a/src/or/buffers.c b/src/or/buffers.c
index a225962b1..d98233059 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -1197,7 +1197,6 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req,
         return 0; /* not yet */
       req->command = (unsigned char) *(buf->cur+1);
       if (req->command != SOCKS_COMMAND_CONNECT &&
-          req->command != SOCKS_COMMAND_CONNECT_DIR &&
           req->command != SOCKS_COMMAND_RESOLVE &&
           req->command != SOCKS_COMMAND_RESOLVE_PTR) {
         /* not a connect or resolve or a resolve_ptr? we don't support it. */
@@ -1292,7 +1291,6 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req,
 
       req->command = (unsigned char) *(buf->cur+1);
       if (req->command != SOCKS_COMMAND_CONNECT &&
-          req->command != SOCKS_COMMAND_CONNECT_DIR &&
           req->command != SOCKS_COMMAND_RESOLVE) {
         /* not a connect or resolve? we don't support it. (No resolve_ptr with
          * socks4.) */
diff --git a/src/or/circuituse.c b/src/or/circuituse.c
index 1021cc1e4..ca1f4d333 100644
--- a/src/or/circuituse.c
+++ b/src/or/circuituse.c
@@ -87,7 +87,7 @@ circuit_is_acceptable(circuit_t *circ, edge_connection_t *conn,
                  * or is a rendezvous circuit. */
     }
     if (build_state->onehop_tunnel) {
-      if (conn->socks_request->command != SOCKS_COMMAND_CONNECT_DIR) {
+      if (!conn->want_onehop) {
         log_debug(LD_CIRC,"Skipping one-hop circuit.");
         return 0;
       }
@@ -100,7 +100,7 @@ circuit_is_acceptable(circuit_t *circ, edge_connection_t *conn,
           return 0; /* this is a circuit to somewhere else */
       }
     } else {
-      if (conn->socks_request->command == SOCKS_COMMAND_CONNECT_DIR) {
+      if (conn->want_onehop) {
         /* don't use three-hop circuits -- that could hurt our anonymity. */
         return 0;
       }
@@ -835,6 +835,8 @@ circuit_launch_by_extend_info(uint8_t purpose, int onehop_tunnel,
   if ((extend_info || purpose != CIRCUIT_PURPOSE_C_GENERAL) &&
       purpose != CIRCUIT_PURPOSE_TESTING && !onehop_tunnel) {
     /* see if there are appropriate circs available to cannibalize. */
+    /* XXX020 if we're planning to add a hop, perhaps we want to look for
+     * internal circs rather than exit circs? -RD */
     circ = circuit_find_to_cannibalize(purpose, extend_info,
                                        need_uptime, need_capacity, internal);
     if (circ) {
@@ -948,11 +950,12 @@ circuit_get_open_circ_or_launch(edge_connection_t *conn,
   tor_assert(circp);
   tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
   check_exit_policy =
-      (conn->socks_request->command == SOCKS_COMMAND_CONNECT) &&
+      conn->socks_request->command == SOCKS_COMMAND_CONNECT &&
+      !conn->use_begindir &&
       !connection_edge_is_rendezvous_stream(conn);
-  want_onehop = conn->socks_request->command == SOCKS_COMMAND_CONNECT_DIR;
+  want_onehop = conn->want_onehop;
 
-  need_uptime = (conn->socks_request->command == SOCKS_COMMAND_CONNECT) &&
+  need_uptime = !conn->want_onehop && !conn->use_begindir &&
                 smartlist_string_num_isin(options->LongLivedPorts,
                                           conn->socks_request->port);
   need_internal = desired_circuit_purpose != CIRCUIT_PURPOSE_C_GENERAL;
@@ -1005,6 +1008,8 @@ circuit_get_open_circ_or_launch(edge_connection_t *conn,
   /* is one already on the way? */
   circ = circuit_get_best(conn, 0, desired_circuit_purpose,
                           need_uptime, need_internal);
+  if (circ)
+    log_debug(LD_CIRC, "one on the way!");
   if (!circ) {
     extend_info_t *extend_info=NULL;
     uint8_t new_circ_purpose;
@@ -1221,17 +1226,14 @@ connection_ap_handshake_attach_chosen_circuit(edge_connection_t *conn,
 
   link_apconn_to_circ(conn, circ, cpath);
   tor_assert(conn->socks_request);
-  switch (conn->socks_request->command) {
-    case SOCKS_COMMAND_CONNECT:
+  if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
+    if (!conn->use_begindir)
       consider_recording_trackhost(conn, circ);
-      /* fall through */
-    case SOCKS_COMMAND_CONNECT_DIR:
-      if (connection_ap_handshake_send_begin(conn) < 0)
-        return -1;
-      break;
-    default:
-      if (connection_ap_handshake_send_resolve(conn) < 0)
-        return -1;
+    if (connection_ap_handshake_send_begin(conn) < 0)
+      return -1;
+  } else {
+    if (connection_ap_handshake_send_resolve(conn) < 0)
+      return -1;
   }
 
   return 1;
@@ -1254,7 +1256,7 @@ connection_ap_handshake_attach_circuit(edge_connection_t *conn)
   tor_assert(conn);
   tor_assert(conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
   tor_assert(conn->socks_request);
-  want_onehop = conn->socks_request->command == SOCKS_COMMAND_CONNECT_DIR;
+  want_onehop = conn->want_onehop;
 
   conn_age = time(NULL) - conn->_base.timestamp_created;
 
@@ -1307,7 +1309,7 @@ connection_ap_handshake_attach_circuit(edge_connection_t *conn)
     log_debug(LD_APP|LD_CIRC,
               "Attaching apconn to circ %d (stream %d sec old).",
               circ->_base.n_circ_id, conn_age);
-    /* here, print the circ's path. so people can figure out which circs are
+    /* print the circ's path, so people can figure out which circs are
      * sucking. */
     circuit_log_path(LOG_INFO,LD_APP|LD_CIRC,circ);
 
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index da78784d8..ba0d2a85a 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -1379,7 +1379,7 @@ connection_ap_handshake_rewrite_and_attach(edge_connection_t *conn,
         return -1;
       }
 
-      if (!conn->chosen_exit_name && !circ) {
+      if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
         /* see if we can find a suitable enclave exit */
         routerinfo_t *r =
           router_find_exact_exit_enclave(socks->address, socks->port);
@@ -1395,11 +1395,12 @@ connection_ap_handshake_rewrite_and_attach(edge_connection_t *conn,
         }
       }
 
-      /* help predict this next time */
-      rep_hist_note_used_port(socks->port, time(NULL));
+      if (!conn->use_begindir) {
+        /* help predict this next time */
+        rep_hist_note_used_port(socks->port, time(NULL));
+      }
     } else if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
       rep_hist_note_used_resolve(time(NULL)); /* help predict this next time */
-    } else if (socks->command == SOCKS_COMMAND_CONNECT_DIR) {
       ; /* nothing */
     } else {
       tor_fragile_assert();
@@ -1840,8 +1841,8 @@ connection_ap_handshake_send_begin(edge_connection_t *ap_conn)
   log_debug(LD_APP,
             "Sending relay cell to begin stream %d.", ap_conn->stream_id);
 
-  begin_type = ap_conn->socks_request->command == SOCKS_COMMAND_CONNECT ?
-                 RELAY_COMMAND_BEGIN : RELAY_COMMAND_BEGIN_DIR;
+  begin_type = ap_conn->use_begindir ?
+                 RELAY_COMMAND_BEGIN_DIR : RELAY_COMMAND_BEGIN;
   if (begin_type == RELAY_COMMAND_BEGIN) {
     tor_assert(circ->build_state->onehop_tunnel == 0);
   }
@@ -1955,7 +1956,7 @@ connection_ap_handshake_send_resolve(edge_connection_t *ap_conn)
  */
 edge_connection_t *
 connection_ap_make_link(char *address, uint16_t port,
-                        const char *digest, int command)
+                        const char *digest, int use_begindir, int want_onehop)
 {
   edge_connection_t *conn;
 
@@ -1973,8 +1974,10 @@ connection_ap_make_link(char *address, uint16_t port,
   strlcpy(conn->socks_request->address, address,
           sizeof(conn->socks_request->address));
   conn->socks_request->port = port;
-  conn->socks_request->command = command;
-  if (command == SOCKS_COMMAND_CONNECT_DIR) {
+  conn->socks_request->command = SOCKS_COMMAND_CONNECT;
+  conn->want_onehop = want_onehop;
+  conn->use_begindir = use_begindir;
+  if (use_begindir) {
     conn->chosen_exit_name = tor_malloc(HEX_DIGEST_LEN+2);
     conn->chosen_exit_name[0] = '$';
     base16_encode(conn->chosen_exit_name+1,HEX_DIGEST_LEN+1,
@@ -2622,7 +2625,8 @@ connection_ap_can_use_exit(edge_connection_t *conn, routerinfo_t *exit)
     }
   }
 
-  if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
+  if (conn->socks_request->command == SOCKS_COMMAND_CONNECT &&
+      !conn->use_begindir) {
     struct in_addr in;
     uint32_t addr = 0;
     addr_policy_result_t r;
diff --git a/src/or/directory.c b/src/or/directory.c
index fb27d71be..131b0e710 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -609,17 +609,17 @@ directory_initiate_command(const char *address, uint32_t addr,
 {
   dir_connection_t *conn;
   or_options_t *options = get_options();
-  int want_to_tunnel = options->TunnelDirConns && supports_begindir &&
-                       !anonymized_connection && or_port &&
-                       fascist_firewall_allows_address_or(addr, or_port);
+  int use_begindir = options->TunnelDirConns && supports_begindir && or_port &&
+                     (anonymized_connection ||
+                      fascist_firewall_allows_address_or(addr, or_port));
 
   tor_assert(address);
   tor_assert(addr);
   tor_assert(or_port || dir_port);
   tor_assert(digest);
 
-  log_debug(LD_DIR, "anonymized %d, want_to_tunnel %d.",
-            anonymized_connection, want_to_tunnel);
+  log_debug(LD_DIR, "anonymized %d, use_begindir %d.",
+            anonymized_connection, use_begindir);
 
   log_debug(LD_DIR, "Initiating %s", dir_conn_purpose_to_string(dir_purpose));
 
@@ -627,7 +627,7 @@ directory_initiate_command(const char *address, uint32_t addr,
 
   /* set up conn so it's got all the data we need to remember */
   conn->_base.addr = addr;
-  conn->_base.port = want_to_tunnel ? or_port : dir_port;
+  conn->_base.port = use_begindir ? or_port : dir_port;
   conn->_base.address = tor_strdup(address);
   memcpy(conn->identity_digest, digest, DIGEST_LEN);
 
@@ -637,11 +637,12 @@ directory_initiate_command(const char *address, uint32_t addr,
   /* give it an initial state */
   conn->_base.state = DIR_CONN_STATE_CONNECTING;
 
-  if (!anonymized_connection && !want_to_tunnel) {
-    /* then we want to connect directly */
+  /* decide whether we can learn our IP address from this conn */
+  conn->dirconn_direct = !anonymized_connection;
+
+  if (!anonymized_connection && !use_begindir) {
+    /* then we want to connect to dirport directly */
 
-    /* XXX020 we should set dirconn_direct to 1 even if want_to_tunnel -RD */
-    conn->dirconn_direct = 1;
     if (options->HttpProxy) {
       addr = options->HttpProxyAddr;
       dir_port = options->HttpProxyPort;
@@ -665,19 +666,15 @@ directory_initiate_command(const char *address, uint32_t addr,
         /* writable indicates finish, readable indicates broken link,
            error indicates broken link in windowsland. */
     }
-  } else { /* we want to connect via tor */
+  } else { /* we want to connect via a tor connection */
     edge_connection_t *linked_conn;
     /* make an AP connection
      * populate it and add it at the right state
      * hook up both sides
      */
-    conn->dirconn_direct = 0;
     linked_conn =
       connection_ap_make_link(conn->_base.address, conn->_base.port,
-                              digest,
-                              anonymized_connection ?
-                                SOCKS_COMMAND_CONNECT :
-                                SOCKS_COMMAND_CONNECT_DIR);
+                              digest, use_begindir, conn->dirconn_direct);
     if (!linked_conn) {
       log_warn(LD_NET,"Making tunnel to dirserver failed.");
       connection_mark_for_close(TO_CONN(conn));
diff --git a/src/or/or.h b/src/or/or.h
index 344745d8e..e151a678c 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -910,6 +910,12 @@ typedef struct edge_connection_t {
   /** True iff this connection is for a dns request only. */
   unsigned int is_dns_request : 1;
 
+  /** True iff this stream wants a one-hop circuit (e.g. for begin_dir). */
+  int want_onehop:1;
+  /** True iff this stream should use a begin_dir connection (either via
+   * onehop or via a whole circuit). */
+  int use_begindir:1;
+
   /** If this is a DNSPort connection, this field holds the pending DNS
    * request that we're going to try to answer.  */
   struct evdns_server_request *dns_server_request;
@@ -2212,13 +2218,7 @@ static INLINE void or_state_mark_dirty(or_state_t *state, time_t when)
 /** Please turn this IP address into an FQDN, privately. */
 #define SOCKS_COMMAND_RESOLVE_PTR   0xF1
 
-/** Please open an encrypted direct TCP connection to the directory port
- * of the Tor server specified by address:port. (In this case address:port
- * specifies the ORPort of the server.) */
-#define SOCKS_COMMAND_CONNECT_DIR   0xF2
-
-#define SOCKS_COMMAND_IS_CONNECT(c) ((c)==SOCKS_COMMAND_CONNECT || \
-                                     (c)==SOCKS_COMMAND_CONNECT_DIR)
+#define SOCKS_COMMAND_IS_CONNECT(c) ((c)==SOCKS_COMMAND_CONNECT)
 #define SOCKS_COMMAND_IS_RESOLVE(c) ((c)==SOCKS_COMMAND_RESOLVE || \
                                      (c)==SOCKS_COMMAND_RESOLVE_PTR)
 
@@ -2583,7 +2583,8 @@ int connection_ap_handshake_send_begin(edge_connection_t *ap_conn);
 int connection_ap_handshake_send_resolve(edge_connection_t *ap_conn);
 
 edge_connection_t  *connection_ap_make_link(char *address, uint16_t port,
-                                            const char *digest, int command);
+                                            const char *digest,
+                                            int use_begindir, int want_onehop);
 void connection_ap_handshake_socks_reply(edge_connection_t *conn, char *reply,
                                          size_t replylen,
                                          int endreason);