Commit message: TROVE-2017-004: Fix assertion failure in relay_send_end_cell_from_edge_

This fixes an assertion failure in relay_send_end_cell_from_edge_() when an
origin circuit and a cpath_layer = NULL were passed.

A service rendezvous circuit could do such a thing when a malformed BEGIN cell
is received but shouldn't in the first place because the service needs to send
an END cell on the circuit for which it can not do without a cpath_layer.

Fixes #22493

Reported-by: Roger Dingledine <arma@torproject.org>
Signed-off-by: David Goulet <dgoulet@torproject.org>
CVE: CVE-2017-0375
CWE: CWE-617
Vulnerability description: The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relay_send_end_cell_from_edge_ function via a malformed BEGIN cell.

Project: tor
File: connection_edge.c

MOCK_IMPL(void,
connection_mark_unattached_ap_,(entry_connection_t *conn, int endreason,
                                int line, const char *file))
{
  connection_t *base_conn = ENTRY_TO_CONN(conn);
  edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
  tor_assert(base_conn->type == CONN_TYPE_AP);
  ENTRY_TO_EDGE_CONN(conn)->edge_has_sent_end = 1; /* no circ yet */

  /* If this is a rendezvous stream and it is failing without ever
   * being attached to a circuit, assume that an attempt to connect to
   * the destination hidden service has just ended.
   *
   * XXXX This condition doesn't limit to only streams failing
   * without ever being attached.  That sloppiness should be harmless,
   * but we should fix it someday anyway. */
  if ((edge_conn->on_circuit != NULL || edge_conn->edge_has_sent_end) &&
      connection_edge_is_rendezvous_stream(edge_conn)) {
    rend_client_note_connection_attempt_ended(edge_conn->rend_data);
  }

  if (base_conn->marked_for_close) {
    /* This call will warn as appropriate. */
    connection_mark_for_close_(base_conn, line, file);
    return;
  }

  if (!conn->socks_request->has_finished) {
    if (endreason & END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED)
      log_warn(LD_BUG,
               "stream (marked at %s:%d) sending two socks replies?",
               file, line);

    if (SOCKS_COMMAND_IS_CONNECT(conn->socks_request->command))
      connection_ap_handshake_socks_reply(conn, NULL, 0, endreason);
    else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command))
      connection_ap_handshake_socks_resolved(conn,
                                             RESOLVED_TYPE_ERROR_TRANSIENT,
                                             0, NULL, -1, -1);
    else /* unknown or no handshake at all. send no response. */
      conn->socks_request->has_finished = 1;
  }

  connection_mark_and_flush_(base_conn, line, file);

  ENTRY_TO_EDGE_CONN(conn)->end_reason = endreason;
}

Project: tor
File: connection_edge.c

MOCK_IMPL(void,
connection_ap_handshake_socks_resolved,(entry_connection_t *conn,
                                       int answer_type,
                                       size_t answer_len,
                                       const uint8_t *answer,
                                       int ttl,
                                       time_t expires))
{
  char buf[384];
  size_t replylen;

  if (ttl >= 0) {
    if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
      tor_addr_t a;
      tor_addr_from_ipv4n(&a, get_uint32(answer));
      if (! tor_addr_is_null(&a)) {
        client_dns_set_addressmap(conn,
                                  conn->socks_request->address, &a,
                                  conn->chosen_exit_name, ttl);
      }
    } else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
      tor_addr_t a;
      tor_addr_from_ipv6_bytes(&a, (char*)answer);
      if (! tor_addr_is_null(&a)) {
        client_dns_set_addressmap(conn,
                                  conn->socks_request->address, &a,
                                  conn->chosen_exit_name, ttl);
      }
    } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
      char *cp = tor_strndup((char*)answer, answer_len);
      client_dns_set_reverse_addressmap(conn,
                                        conn->socks_request->address,
                                        cp,
                                        conn->chosen_exit_name, ttl);
      tor_free(cp);
    }
  }

  if (ENTRY_TO_EDGE_CONN(conn)->is_dns_request) {
    if (conn->dns_server_request) {
      /* We had a request on our DNS port: answer it. */
      dnsserv_resolved(conn, answer_type, answer_len, (char*)answer, ttl);
      conn->socks_request->has_finished = 1;
      return;
    } else {
      /* This must be a request from the controller. Since answers to those
       * requests are not cached, they do not generate an ADDRMAP event on
       * their own. */
      tell_controller_about_resolved_result(conn, answer_type, answer_len,
                                            (char*)answer, ttl, expires);
      conn->socks_request->has_finished = 1;
      return;
    }
    /* We shouldn't need to free conn here; it gets marked by the caller. */
  }

  if (conn->socks_request->socks_version == 4) {
    buf[0] = 0x00; /* version */
    if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
      buf[1] = SOCKS4_GRANTED;
      set_uint16(buf+2, 0);
      memcpy(buf+4, answer, 4); /* address */
      replylen = SOCKS4_NETWORK_LEN;
    } else { /* "error" */
      buf[1] = SOCKS4_REJECT;
      memset(buf+2, 0, 6);
      replylen = SOCKS4_NETWORK_LEN;
    }
  } else if (conn->socks_request->socks_version == 5) {
    /* SOCKS5 */
    buf[0] = 0x05; /* version */
    if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
      buf[1] = SOCKS5_SUCCEEDED;
      buf[2] = 0; /* reserved */
      buf[3] = 0x01; /* IPv4 address type */
      memcpy(buf+4, answer, 4); /* address */
      set_uint16(buf+8, 0); /* port == 0. */
      replylen = 10;
    } else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
      buf[1] = SOCKS5_SUCCEEDED;
      buf[2] = 0; /* reserved */
      buf[3] = 0x04; /* IPv6 address type */
      memcpy(buf+4, answer, 16); /* address */
      set_uint16(buf+20, 0); /* port == 0. */
      replylen = 22;
    } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
      buf[1] = SOCKS5_SUCCEEDED;
      buf[2] = 0; /* reserved */
      buf[3] = 0x03; /* Domainname address type */
      buf[4] = (char)answer_len;
      memcpy(buf+5, answer, answer_len); /* address */
      set_uint16(buf+5+answer_len, 0); /* port == 0. */
      replylen = 5+answer_len+2;
    } else {
      buf[1] = SOCKS5_HOST_UNREACHABLE;
      memset(buf+2, 0, 8);
      replylen = 10;
    }
  } else {
    /* no socks version info; don't send anything back */
    return;
  }
  connection_ap_handshake_socks_reply(conn, buf, replylen,
          (answer_type == RESOLVED_TYPE_IPV4 ||
           answer_type == RESOLVED_TYPE_IPV6 ||
           answer_type == RESOLVED_TYPE_HOSTNAME) ?
                                      0 : END_STREAM_REASON_RESOLVEFAILED);
}

Project: tor

circuit_clear_isolation(origin_circuit_t *circ)
{
  if (circ->isolation_any_streams_attached) {
    log_warn(LD_BUG, "Tried to clear the isolation status of a dirty circuit");
    return;
  }
  if (TO_CIRCUIT(circ)->state != CIRCUIT_STATE_OPEN) {
    log_warn(LD_BUG, "Tried to clear the isolation status of a non-open "
             "circuit");
    return;
  }

  circ->isolation_values_set = 0;
  circ->isolation_flags_mixed = 0;
  circ->associated_isolated_stream_global_id = 0;
  circ->client_proto_type = 0;
  circ->client_proto_socksver = 0;
  circ->dest_port = 0;
  tor_addr_make_unspec(&circ->client_addr);
  tor_free(circ->dest_address);
  circ->session_group = -1;
  circ->nym_epoch = 0;
  if (circ->socks_username) {
    memwipe(circ->socks_username, 0x11, circ->socks_username_len);
    tor_free(circ->socks_username);
  }
  if (circ->socks_password) {
    memwipe(circ->socks_password, 0x05, circ->socks_password_len);
    tor_free(circ->socks_password);
  }
  circ->socks_username_len = circ->socks_password_len = 0;
}

Project: tor
File: connection_edge.c

circuit_discard_optional_exit_enclaves(extend_info_t *info)
{
  entry_connection_t *entry_conn;
  const node_t *r1, *r2;

  smartlist_t *conns = get_connection_array();
  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
    if (conn->marked_for_close ||
        conn->type != CONN_TYPE_AP ||
        conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
      continue;
    entry_conn = TO_ENTRY_CONN(conn);
    if (!entry_conn->chosen_exit_optional &&
        !entry_conn->chosen_exit_retries)
      continue;
    r1 = node_get_by_nickname(entry_conn->chosen_exit_name, 0);
    r2 = node_get_by_id(info->identity_digest);
    if (!r1 || !r2 || r1 != r2)
      continue;
    tor_assert(entry_conn->socks_request);
    if (entry_conn->chosen_exit_optional) {
      log_info(LD_APP, "Giving up on enclave exit '%s' for destination %s.",
               safe_str_client(entry_conn->chosen_exit_name),
               escaped_safe_str_client(entry_conn->socks_request->address));
      entry_conn->chosen_exit_optional = 0;
      tor_free(entry_conn->chosen_exit_name); /* clears it */
      /* if this port is dangerous, warn or reject it now that we don't
       * think it'll be using an enclave. */
      consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
    }
    if (entry_conn->chosen_exit_retries) {
      if (--entry_conn->chosen_exit_retries == 0) { /* give up! */
        clear_trackexithost_mappings(entry_conn->chosen_exit_name);
        tor_free(entry_conn->chosen_exit_name); /* clears it */
        /* if this port is dangerous, warn or reject it now that we don't
         * think it'll be using an enclave. */
        consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
      }
    }
  } SMARTLIST_FOREACH_END(conn);
}

Project: tor
File: connection_edge.c

compute_retry_timeout(entry_connection_t *conn)
{
  int timeout = get_options()->CircuitStreamTimeout;
  if (timeout) /* if our config options override the default, use them */
    return timeout;
  if (conn->num_socks_retries < 2) /* try 0 and try 1 */
    return 10;
  return 15;
}

Project: tor
File: connection_edge.c

connected_cell_format_payload(uint8_t *payload_out,
                              const tor_addr_t *addr,
                              uint32_t ttl)
{
  const sa_family_t family = tor_addr_family(addr);
  int connected_payload_len;

  /* should be needless */
  memset(payload_out, 0, MAX_CONNECTED_CELL_PAYLOAD_LEN);

  if (family == AF_INET) {
    set_uint32(payload_out, tor_addr_to_ipv4n(addr));
    connected_payload_len = 4;
  } else if (family == AF_INET6) {
    set_uint32(payload_out, 0);
    set_uint8(payload_out + 4, 6);
    memcpy(payload_out + 5, tor_addr_to_in6_addr8(addr), 16);
    connected_payload_len = 21;
  } else {
    return -1;
  }

  set_uint32(payload_out + connected_payload_len, htonl(dns_clip_ttl(ttl)));
  connected_payload_len += 4;

  tor_assert(connected_payload_len <= MAX_CONNECTED_CELL_PAYLOAD_LEN);

  return connected_payload_len;
}

Project: tor
File: connection_edge.c

connection_ap_about_to_close(entry_connection_t *entry_conn)
{
  circuit_t *circ;
  edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
  connection_t *conn = ENTRY_TO_CONN(entry_conn);

  connection_edge_about_to_close(edge_conn);

  if (entry_conn->socks_request->has_finished == 0) {
    /* since conn gets removed right after this function finishes,
     * there's no point trying to send back a reply at this point. */
    log_warn(LD_BUG,"Closing stream (marked at %s:%d) without sending"
             " back a socks reply.",
             conn->marked_for_close_file, conn->marked_for_close);
  }
  if (!edge_conn->end_reason) {
    log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
             " set end_reason.",
             conn->marked_for_close_file, conn->marked_for_close);
  }
  if (entry_conn->dns_server_request) {
    log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
             " replied to DNS request.",
             conn->marked_for_close_file, conn->marked_for_close);
    dnsserv_reject_request(entry_conn);
  }

  if (TO_CONN(edge_conn)->state == AP_CONN_STATE_CIRCUIT_WAIT) {
    smartlist_remove(pending_entry_connections, entry_conn);
  }

#if 1
  /* Check to make sure that this isn't in pending_entry_connections if it
   * didn't actually belong there. */
  if (TO_CONN(edge_conn)->type == CONN_TYPE_AP) {
    connection_ap_warn_and_unmark_if_pending_circ(entry_conn,
                                                  "about_to_close");
  }
#endif

  control_event_stream_bandwidth(edge_conn);
  control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
                              edge_conn->end_reason);
  circ = circuit_get_by_edge_conn(edge_conn);
  if (circ)
    circuit_detach_stream(circ, edge_conn);
}

Project: tor

connection_ap_can_use_exit(const entry_connection_t *conn,
                           const node_t *exit_node)
{
  const or_options_t *options = get_options();

  tor_assert(conn);
  tor_assert(conn->socks_request);
  tor_assert(exit_node);

  /* If a particular exit node has been requested for the new connection,
   * make sure the exit node of the existing circuit matches exactly.
   */
  if (conn->chosen_exit_name) {
    const node_t *chosen_exit =
      node_get_by_nickname(conn->chosen_exit_name, 1);
    if (!chosen_exit || tor_memneq(chosen_exit->identity,
                               exit_node->identity, DIGEST_LEN)) {
      /* doesn't match */
      return 0;
    }
  }

  if (conn->use_begindir) {
    /* Internal directory fetches do not count as exiting. */
    return 1;
  }

  if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
    tor_addr_t addr, *addrp = NULL;
    addr_policy_result_t r;
    if (0 == tor_addr_parse(&addr, conn->socks_request->address)) {
      addrp = &addr;
    } else if (!conn->entry_cfg.ipv4_traffic && conn->entry_cfg.ipv6_traffic) {
      tor_addr_make_null(&addr, AF_INET6);
      addrp = &addr;
    } else if (conn->entry_cfg.ipv4_traffic && !conn->entry_cfg.ipv6_traffic) {
      tor_addr_make_null(&addr, AF_INET);
      addrp = &addr;
    }
    r = compare_tor_addr_to_node_policy(addrp, conn->socks_request->port,
                                        exit_node);
    if (r == ADDR_POLICY_REJECTED)
      return 0; /* We know the address, and the exit policy rejects it. */
    if (r == ADDR_POLICY_PROBABLY_REJECTED && !conn->chosen_exit_name)
      return 0; /* We don't know the addr, but the exit policy rejects most
                 * addresses with this port. Since the user didn't ask for
                 * this node, err on the side of caution. */
  } else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
    /* Don't send DNS requests to non-exit servers by default. */
    if (!conn->chosen_exit_name && node_exit_policy_rejects_all(exit_node))
      return 0;
  }
  if (routerset_contains_node(options->ExcludeExitNodesUnion_, exit_node)) {
    /* Not a suitable exit. Refuse it. */
    return 0;
  }

  return 1;
}

Project: tor
File: connection_edge.c

connection_ap_detach_retriable(entry_connection_t *conn,
                               origin_circuit_t *circ,
                               int reason)
{
  control_event_stream_status(conn, STREAM_EVENT_FAILED_RETRIABLE, reason);
  ENTRY_TO_CONN(conn)->timestamp_lastread = time(NULL);

  /* Roll back path bias use state so that we probe the circuit
   * if nothing else succeeds on it */
  pathbias_mark_use_rollback(circ);

  if (conn->pending_optimistic_data) {
    buf_set_to_copy(&conn->sending_optimistic_data,
                    conn->pending_optimistic_data);
  }

  if (!get_options()->LeaveStreamsUnattached || conn->use_begindir) {
    /* If we're attaching streams ourself, or if this connection is
     * a tunneled directory connection, then just attach it. */
    ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;
    circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
    connection_ap_mark_as_pending_circuit(conn);
  } else {
    CONNECTION_AP_EXPECT_NONPENDING(conn);
    ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
    circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
  }
  return 0;
}

Project: tor
File: connection_edge.c

connection_ap_expire_beginning(void)
{
  edge_connection_t *conn;
  entry_connection_t *entry_conn;
  circuit_t *circ;
  time_t now = time(NULL);
  const or_options_t *options = get_options();
  int severity;
  int cutoff;
  int seconds_idle, seconds_since_born;
  smartlist_t *conns = get_connection_array();

  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
    if (base_conn->type != CONN_TYPE_AP || base_conn->marked_for_close)
      continue;
    entry_conn = TO_ENTRY_CONN(base_conn);
    conn = ENTRY_TO_EDGE_CONN(entry_conn);
    /* if it's an internal linked connection, don't yell its status. */
    severity = (tor_addr_is_null(&base_conn->addr) && !base_conn->port)
      ? LOG_INFO : LOG_NOTICE;
    seconds_idle = (int)( now - base_conn->timestamp_lastread );
    seconds_since_born = (int)( now - base_conn->timestamp_created );

    if (base_conn->state == AP_CONN_STATE_OPEN)
      continue;

    /* We already consider SocksTimeout in
     * connection_ap_handshake_attach_circuit(), but we need to consider
     * it here too because controllers that put streams in controller_wait
     * state never ask Tor to attach the circuit. */
    if (AP_CONN_STATE_IS_UNATTACHED(base_conn->state)) {
      if (seconds_since_born >= options->SocksTimeout) {
        log_fn(severity, LD_APP,
            "Tried for %d seconds to get a connection to %s:%d. "
            "Giving up. (%s)",
            seconds_since_born,
            safe_str_client(entry_conn->socks_request->address),
            entry_conn->socks_request->port,
            conn_state_to_string(CONN_TYPE_AP, base_conn->state));
        connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
      }
      continue;
    }

    /* We're in state connect_wait or resolve_wait now -- waiting for a
     * reply to our relay cell. See if we want to retry/give up. */

    cutoff = compute_retry_timeout(entry_conn);
    if (seconds_idle < cutoff)
      continue;
    circ = circuit_get_by_edge_conn(conn);
    if (!circ) { /* it's vanished? */
      log_info(LD_APP,"Conn is waiting (address %s), but lost its circ.",
               safe_str_client(entry_conn->socks_request->address));
      connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
      continue;
    }
    if (circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
      if (seconds_idle >= options->SocksTimeout) {
        log_fn(severity, LD_REND,
               "Rend stream is %d seconds late. Giving up on address"
               " '%s.onion'.",
               seconds_idle,
               safe_str_client(entry_conn->socks_request->address));
        /* Roll back path bias use state so that we probe the circuit
         * if nothing else succeeds on it */
        pathbias_mark_use_rollback(TO_ORIGIN_CIRCUIT(circ));

        connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
        connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
      }
      continue;
    }
    if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
        circ->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT &&
        circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
      log_warn(LD_BUG, "circuit->purpose == CIRCUIT_PURPOSE_C_GENERAL failed. "
               "The purpose on the circuit was %s; it was in state %s, "
               "path_state %s.",
               circuit_purpose_to_string(circ->purpose),
               circuit_state_to_string(circ->state),
               CIRCUIT_IS_ORIGIN(circ) ?
                pathbias_state_to_string(TO_ORIGIN_CIRCUIT(circ)->path_state) :
                "none");
    }
    log_fn(cutoff < 15 ? LOG_INFO : severity, LD_APP,
           "We tried for %d seconds to connect to '%s' using exit %s."
           " Retrying on a new circuit.",
           seconds_idle,
           safe_str_client(entry_conn->socks_request->address),
           conn->cpath_layer ?
             extend_info_describe(conn->cpath_layer->extend_info):
             "*unnamed*");
    /* send an end down the circuit */
    connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
    /* un-mark it as ending, since we're going to reuse it */
    conn->edge_has_sent_end = 0;
    conn->end_reason = 0;
    /* make us not try this circuit again, but allow
     * current streams on it to survive if they can */
    mark_circuit_unusable_for_new_conns(TO_ORIGIN_CIRCUIT(circ));

    /* give our stream another 'cutoff' seconds to try */
    conn->base_.timestamp_lastread += cutoff;
    if (entry_conn->num_socks_retries < 250) /* avoid overflow */
      entry_conn->num_socks_retries++;
    /* move it back into 'pending' state, and try to attach. */
    if (connection_ap_detach_retriable(entry_conn, TO_ORIGIN_CIRCUIT(circ),
                                       END_STREAM_REASON_TIMEOUT)<0) {
      if (!base_conn->marked_for_close)
        connection_mark_unattached_ap(entry_conn,
                                      END_STREAM_REASON_CANT_ATTACH);
    }
  } SMARTLIST_FOREACH_END(base_conn);
}

Project: tor
File: connection_edge.c

connection_ap_fail_onehop(const char *failed_digest,
                          cpath_build_state_t *build_state)
{
  entry_connection_t *entry_conn;
  char digest[DIGEST_LEN];
  smartlist_t *conns = get_connection_array();
  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
    if (conn->marked_for_close ||
        conn->type != CONN_TYPE_AP ||
        conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
      continue;
    entry_conn = TO_ENTRY_CONN(conn);
    if (!entry_conn->want_onehop)
      continue;
    if (hexdigest_to_digest(entry_conn->chosen_exit_name, digest) < 0 ||
        tor_memneq(digest, failed_digest, DIGEST_LEN))
      continue;
    if (tor_digest_is_zero(digest)) {
      /* we don't know the digest; have to compare addr:port */
      tor_addr_t addr;
      if (!build_state || !build_state->chosen_exit ||
          !entry_conn->socks_request) {
        continue;
      }
      if (tor_addr_parse(&addr, entry_conn->socks_request->address)<0 ||
          !tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
          build_state->chosen_exit->port != entry_conn->socks_request->port)
        continue;
    }
    log_info(LD_APP, "Closing one-hop stream to '%s/%s' because the OR conn "
                     "just failed.", entry_conn->chosen_exit_name,
                     entry_conn->socks_request->address);
    connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
  } SMARTLIST_FOREACH_END(conn);
}

Project: tor
File: connection_edge.c

connection_ap_get_begincell_flags(entry_connection_t *ap_conn)
{
  edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
  const node_t *exitnode = NULL;
  const crypt_path_t *cpath_layer = edge_conn->cpath_layer;
  uint32_t flags = 0;

  /* No flags for begindir */
  if (ap_conn->use_begindir)
    return 0;

  /* No flags for hidden services. */
  if (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL)
    return 0;

  /* If only IPv4 is supported, no flags */
  if (ap_conn->entry_cfg.ipv4_traffic && !ap_conn->entry_cfg.ipv6_traffic)
    return 0;

  if (! cpath_layer ||
      ! cpath_layer->extend_info)
    return 0;

  if (!ap_conn->entry_cfg.ipv4_traffic)
    flags |= BEGIN_FLAG_IPV4_NOT_OK;

  exitnode = node_get_by_id(cpath_layer->extend_info->identity_digest);

  if (ap_conn->entry_cfg.ipv6_traffic && exitnode) {
    tor_addr_t a;
    tor_addr_make_null(&a, AF_INET6);
    if (compare_tor_addr_to_node_policy(&a, ap_conn->socks_request->port,
                                        exitnode)
        != ADDR_POLICY_REJECTED) {
      /* Only say "IPv6 OK" if the exit node supports IPv6. Otherwise there's
       * no point. */
      flags |= BEGIN_FLAG_IPV6_OK;
    }
  }

  if (flags == BEGIN_FLAG_IPV6_OK) {
    /* When IPv4 and IPv6 are both allowed, consider whether to say we
     * prefer IPv6.  Otherwise there's no point in declaring a preference */
    if (ap_conn->entry_cfg.prefer_ipv6)
      flags |= BEGIN_FLAG_IPV6_PREFERRED;
  }

  if (flags == BEGIN_FLAG_IPV4_NOT_OK) {
    log_warn(LD_EDGE, "I'm about to ask a node for a connection that I "
             "am telling it to fulfil with neither IPv4 nor IPv6. That's "
             "not going to work. Did you perhaps ask for an IPv6 address "
             "on an IPv4Only port, or vice versa?");
  }

  return flags;
}

Project: tor
File: connection_edge.c

connection_ap_get_original_destination(entry_connection_t *conn,
                                       socks_request_t *req)
{
#ifdef TRANS_NETFILTER
  return destination_from_socket(conn, req);
#elif defined(TRANS_PF)
  const or_options_t *options = get_options();

  if (options->TransProxyType_parsed == TPT_PF_DIVERT)
    return destination_from_socket(conn, req);

  if (options->TransProxyType_parsed == TPT_DEFAULT ||
      options->TransProxyType_parsed == TPT_IPFW)
    return destination_from_pf(conn, req);

  (void)conn;
  (void)req;
  log_warn(LD_BUG, "Proxy destination determination mechanism %s unknown.",
           options->TransProxyType);
  return -1;
#else
  (void)conn;
  (void)req;
  log_warn(LD_BUG, "Called connection_ap_get_original_destination, but no "
           "transparent proxy method was configured.");
  return -1;
#endif
}

Project: tor
File: connection_edge.c

connection_ap_handshake_rewrite(entry_connection_t *conn,
                                rewrite_result_t *out)
{
  socks_request_t *socks = conn->socks_request;
  const or_options_t *options = get_options();
  tor_addr_t addr_tmp;

  /* Initialize all the fields of 'out' to reasonable defaults */
  out->automap = 0;
  out->exit_source = ADDRMAPSRC_NONE;
  out->map_expires = TIME_MAX;
  out->end_reason = 0;
  out->should_close = 0;
  out->orig_address[0] = 0;

  /* We convert all incoming addresses to lowercase. */
  tor_strlower(socks->address);
  /* Remember the original address. */
  strlcpy(out->orig_address, socks->address, sizeof(out->orig_address));
  log_debug(LD_APP,"Client asked for %s:%d",
            safe_str_client(socks->address),
            socks->port);

  /* Check for whether this is a .exit address.  By default, those are
   * disallowed when they're coming straight from the client, but you're
   * allowed to have them in MapAddress commands and so forth. */
  if (!strcmpend(socks->address, ".exit") && !options->AllowDotExit) {
    log_warn(LD_APP, "The  \".exit\" notation is disabled in Tor due to "
             "security risks. Set AllowDotExit in your torrc to enable "
             "it (at your own risk).");
    control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                escaped(socks->address));
    out->end_reason = END_STREAM_REASON_TORPROTOCOL;
    out->should_close = 1;
    return;
  }

  /* Remember the original address so we can tell the user about what
   * they actually said, not just what it turned into. */
  /* XXX yes, this is the same as out->orig_address above. One is
   * in the output, and one is in the connection. */
  if (! conn->original_dest_address) {
    /* Is the 'if' necessary here? XXXX */
    conn->original_dest_address = tor_strdup(conn->socks_request->address);
  }

  /* First, apply MapAddress and MAPADDRESS mappings. We need to do
   * these only for non-reverse lookups, since they don't exist for those.
   * We also need to do this before we consider automapping, since we might
   * e.g. resolve irc.oftc.net into irconionaddress.onion, at which point
   * we'd need to automap it. */
  if (socks->command != SOCKS_COMMAND_RESOLVE_PTR) {
    const unsigned rewrite_flags = AMR_FLAG_USE_MAPADDRESS;
    if (addressmap_rewrite(socks->address, sizeof(socks->address),
                       rewrite_flags, &out->map_expires, &out->exit_source)) {
      control_event_stream_status(conn, STREAM_EVENT_REMAP,
                                  REMAP_STREAM_SOURCE_CACHE);
    }
  }

  /* Now see if we need to create or return an existing Hostname->IP
   * automapping.  Automapping happens when we're asked to resolve a
   * hostname, and AutomapHostsOnResolve is set, and the hostname has a
   * suffix listed in AutomapHostsSuffixes.  It's a handy feature
   * that lets you have Tor assign e.g. IPv6 addresses for .onion
   * names, and return them safely from DNSPort.
   */
  if (socks->command == SOCKS_COMMAND_RESOLVE &&
      tor_addr_parse(&addr_tmp, socks->address)<0 &&
      options->AutomapHostsOnResolve) {
    /* Check the suffix... */
    out->automap = addressmap_address_should_automap(socks->address, options);
    if (out->automap) {
      /* If we get here, then we should apply an automapping for this. */
      const char *new_addr;
      /* We return an IPv4 address by default, or an IPv6 address if we
       * are allowed to do so. */
      int addr_type = RESOLVED_TYPE_IPV4;
      if (conn->socks_request->socks_version != 4) {
        if (!conn->entry_cfg.ipv4_traffic ||
            (conn->entry_cfg.ipv6_traffic && conn->entry_cfg.prefer_ipv6) ||
            conn->entry_cfg.prefer_ipv6_virtaddr)
          addr_type = RESOLVED_TYPE_IPV6;
      }
      /* Okay, register the target address as automapped, and find the new
       * address we're supposed to give as a resolve answer.  (Return a cached
       * value if we've looked up this address before.
       */
      new_addr = addressmap_register_virtual_address(
                                    addr_type, tor_strdup(socks->address));
      if (! new_addr) {
        log_warn(LD_APP, "Unable to automap address %s",
                 escaped_safe_str(socks->address));
        out->end_reason = END_STREAM_REASON_INTERNAL;
        out->should_close = 1;
        return;
      }
      log_info(LD_APP, "Automapping %s to %s",
               escaped_safe_str_client(socks->address),
               safe_str_client(new_addr));
      strlcpy(socks->address, new_addr, sizeof(socks->address));
    }
  }

  /* Now handle reverse lookups, if they're in the cache.  This doesn't
   * happen too often, since client-side DNS caching is off by default,
   * and very deprecated. */
  if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
    unsigned rewrite_flags = 0;
    if (conn->entry_cfg.use_cached_ipv4_answers)
      rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
    if (conn->entry_cfg.use_cached_ipv6_answers)
      rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;

    if (addressmap_rewrite_reverse(socks->address, sizeof(socks->address),
                                   rewrite_flags, &out->map_expires)) {
      char *result = tor_strdup(socks->address);
      /* remember _what_ is supposed to have been resolved. */
      tor_snprintf(socks->address, sizeof(socks->address), "REVERSE[%s]",
                   out->orig_address);
      connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_HOSTNAME,
                                             strlen(result), (uint8_t*)result,
                                             -1,
                                             out->map_expires);
      tor_free(result);
      out->end_reason = END_STREAM_REASON_DONE |
                        END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
      out->should_close = 1;
      return;
    }

    /* Hang on, did we find an answer saying that this is a reverse lookup for
     * an internal address?  If so, we should reject it if we're configured to
     * do so. */
    if (options->ClientDNSRejectInternalAddresses) {
      /* Don't let clients try to do a reverse lookup on 10.0.0.1. */
      tor_addr_t addr;
      int ok;
      ok = tor_addr_parse_PTR_name(
                               &addr, socks->address, AF_UNSPEC, 1);
      if (ok == 1 && tor_addr_is_internal(&addr, 0)) {
        connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_ERROR,
                                               0, NULL, -1, TIME_MAX);
        out->end_reason = END_STREAM_REASON_SOCKSPROTOCOL |
                          END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
        out->should_close = 1;
        return;
      }
    }
  }

  /* If we didn't automap it before, then this is still the address that
   * came straight from the user, mapped according to any
   * MapAddress/MAPADDRESS commands.  Now apply other mappings,
   * including previously registered Automap entries (IP back to
   * hostname), TrackHostExits entries, and client-side DNS cache
   * entries (if they're turned on).
   */
  if (socks->command != SOCKS_COMMAND_RESOLVE_PTR &&
      !out->automap) {
    unsigned rewrite_flags = AMR_FLAG_USE_AUTOMAP | AMR_FLAG_USE_TRACKEXIT;
    addressmap_entry_source_t exit_source2;
    if (conn->entry_cfg.use_cached_ipv4_answers)
      rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
    if (conn->entry_cfg.use_cached_ipv6_answers)
      rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;
    if (addressmap_rewrite(socks->address, sizeof(socks->address),
                        rewrite_flags, &out->map_expires, &exit_source2)) {
      control_event_stream_status(conn, STREAM_EVENT_REMAP,
                                  REMAP_STREAM_SOURCE_CACHE);
    }
    if (out->exit_source == ADDRMAPSRC_NONE) {
      /* If it wasn't a .exit before, maybe it turned into a .exit. Remember
       * the original source of a .exit. */
      out->exit_source = exit_source2;
    }
  }

  /* Check to see whether we're about to use an address in the virtual
   * range without actually having gotten it from an Automap. */
  if (!out->automap && address_is_in_virtual_range(socks->address)) {
    /* This address was probably handed out by
     * client_dns_get_unmapped_address, but the mapping was discarded for some
     * reason.  Or the user typed in a virtual address range manually.  We
     * *don't* want to send the address through Tor; that's likely to fail,
     * and may leak information.
     */
    log_warn(LD_APP,"Missing mapping for virtual address '%s'. Refusing.",
             safe_str_client(socks->address));
    out->end_reason = END_STREAM_REASON_INTERNAL;
    out->should_close = 1;
    return;
  }
}

Project: tor
File: connection_edge.c

connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
                                           origin_circuit_t *circ,
                                           crypt_path_t *cpath)
{
  socks_request_t *socks = conn->socks_request;
  const or_options_t *options = get_options();
  connection_t *base_conn = ENTRY_TO_CONN(conn);
  time_t now = time(NULL);
  rewrite_result_t rr;

  /* First we'll do the rewrite part.  Let's see if we get a reasonable
   * answer.
   */
  memset(&rr, 0, sizeof(rr));
  connection_ap_handshake_rewrite(conn,&rr);

  if (rr.should_close) {
    /* connection_ap_handshake_rewrite told us to close the connection:
     * either because it sent back an answer, or because it sent back an
     * error */
    connection_mark_unattached_ap(conn, rr.end_reason);
    if (END_STREAM_REASON_DONE == (rr.end_reason & END_STREAM_REASON_MASK))
      return 0;
    else
      return -1;
  }

  const time_t map_expires = rr.map_expires;
  const int automap = rr.automap;
  const addressmap_entry_source_t exit_source = rr.exit_source;

  /* Now, we parse the address to see if it's an .onion or .exit or
   * other special address.
   */
  const hostname_type_t addresstype = parse_extended_hostname(socks->address);

  /* Now see whether the hostname is bogus.  This could happen because of an
   * onion hostname whose format we don't recognize. */
  if (addresstype == BAD_HOSTNAME) {
    control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                escaped(socks->address));
    connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
    return -1;
  }

  /* If this is a .exit hostname, strip off the .name.exit part, and
   * see whether we're willing to connect there, and and otherwise handle the
   * .exit address.
   *
   * We'll set chosen_exit_name and/or close the connection as appropriate.
   */
  if (addresstype == EXIT_HOSTNAME) {
    /* If StrictNodes is not set, then .exit overrides ExcludeNodes but
     * not ExcludeExitNodes. */
    routerset_t *excludeset = options->StrictNodes ?
      options->ExcludeExitNodesUnion_ : options->ExcludeExitNodes;
    const node_t *node = NULL;

    /* If this .exit was added by an AUTOMAP, then it came straight from
     * a user.  Make sure that options->AllowDotExit permits that! */
    if (exit_source == ADDRMAPSRC_AUTOMAP && !options->AllowDotExit) {
      /* Whoops; this one is stale.  It must have gotten added earlier,
       * when AllowDotExit was on. */
      log_warn(LD_APP,"Stale automapped address for '%s.exit', with "
               "AllowDotExit disabled. Refusing.",
               safe_str_client(socks->address));
      control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                  escaped(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }

    /* Double-check to make sure there are no .exits coming from
     * impossible/weird sources. */
    if (exit_source == ADDRMAPSRC_DNS ||
        (exit_source == ADDRMAPSRC_NONE && !options->AllowDotExit)) {
      /* It shouldn't be possible to get a .exit address from any of these
       * sources. */
      log_warn(LD_BUG,"Address '%s.exit', with impossible source for the "
               ".exit part. Refusing.",
               safe_str_client(socks->address));
      control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                  escaped(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }

    tor_assert(!automap);

    /* Now, find the character before the .(name) part.
     * (The ".exit" part got stripped off by "parse_extended_hostname").
     *
     * We're going to put the exit name into conn->chosen_exit_name, and
     * look up a node correspondingly. */
    char *s = strrchr(socks->address,'.');
    if (s) {
      /* The address was of the form "(stuff).(name).exit */
      if (s[1] != '\0') {
        /* Looks like a real .exit one. */
        conn->chosen_exit_name = tor_strdup(s+1);
        node = node_get_by_nickname(conn->chosen_exit_name, 1);

        if (exit_source == ADDRMAPSRC_TRACKEXIT) {
          /* We 5 tries before it expires the addressmap */
          conn->chosen_exit_retries = TRACKHOSTEXITS_RETRIES;
        }
        *s = 0;
      } else {
        /* Oops, the address was (stuff)..exit.  That's not okay. */
        log_warn(LD_APP,"Malformed exit address '%s.exit'. Refusing.",
                 safe_str_client(socks->address));
        control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                    escaped(socks->address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
        return -1;
      }
    } else {
      /* It looks like they just asked for "foo.exit".  That's a special
       * form that means (foo's address).foo.exit. */

      conn->chosen_exit_name = tor_strdup(socks->address);
      node = node_get_by_nickname(conn->chosen_exit_name, 1);
      if (node) {
        *socks->address = 0;
        node_get_address_string(node, socks->address, sizeof(socks->address));
      }
    }

    /* Now make sure that the chosen exit exists... */
    if (!node) {
      log_warn(LD_APP,
               "Unrecognized relay in exit address '%s.exit'. Refusing.",
               safe_str_client(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }
    /* ...and make sure that it isn't excluded. */
    if (routerset_contains_node(excludeset, node)) {
      log_warn(LD_APP,
               "Excluded relay in exit address '%s.exit'. Refusing.",
               safe_str_client(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }
    /* XXXX-1090 Should we also allow foo.bar.exit if ExitNodes is set and
       Bar is not listed in it?  I say yes, but our revised manpage branch
       implies no. */
  }

  /* Now, we handle everything that isn't a .onion address. */
  if (addresstype != ONION_HOSTNAME) {
    /* Not a hidden-service request.  It's either a hostname or an IP,
     * possibly with a .exit that we stripped off.  We're going to check
     * if we're allowed to connect/resolve there, and then launch the
     * appropriate request. */

    /* Check for funny characters in the address. */
    if (address_is_invalid_destination(socks->address, 1)) {
      control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                  escaped(socks->address));
      log_warn(LD_APP,
               "Destination '%s' seems to be an invalid hostname. Failing.",
               safe_str_client(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }

#ifdef ENABLE_TOR2WEB_MODE
    /* If we're running in Tor2webMode, we don't allow anything BUT .onion
     * addresses. */
    if (options->Tor2webMode) {
      log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname "
               "or IP address %s because tor2web mode is enabled.",
               safe_str_client(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
      return -1;
    }
#endif

    /* socks->address is a non-onion hostname or IP address.
     * If we can't do any non-onion requests, refuse the connection.
     * If we have a hostname but can't do DNS, refuse the connection.
     * If we have an IP address, but we can't use that address family,
     * refuse the connection.
     *
     * If we can do DNS requests, and we can use at least one address family,
     * then we have to resolve the address first. Then we'll know if it
     * resolves to a usable address family. */

    /* First, check if all non-onion traffic is disabled */
    if (!conn->entry_cfg.dns_request && !conn->entry_cfg.ipv4_traffic
        && !conn->entry_cfg.ipv6_traffic) {
        log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname "
                 "or IP address %s because Port has OnionTrafficOnly set (or "
                 "NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic).",
                 safe_str_client(socks->address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
        return -1;
    }

    /* Then check if we have a hostname or IP address, and whether DNS or
     * the IP address family are permitted.  Reject if not. */
    tor_addr_t dummy_addr;
    int socks_family = tor_addr_parse(&dummy_addr, socks->address);
    /* family will be -1 for a non-onion hostname that's not an IP */
    if (socks_family == -1) {
      if (!conn->entry_cfg.dns_request) {
        log_warn(LD_APP, "Refusing to connect to hostname %s "
                 "because Port has NoDNSRequest set.",
                 safe_str_client(socks->address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
        return -1;
      }
    } else if (socks_family == AF_INET) {
      if (!conn->entry_cfg.ipv4_traffic) {
        log_warn(LD_APP, "Refusing to connect to IPv4 address %s because "
                 "Port has NoIPv4Traffic set.",
                 safe_str_client(socks->address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
        return -1;
      }
    } else if (socks_family == AF_INET6) {
      if (!conn->entry_cfg.ipv6_traffic) {
        log_warn(LD_APP, "Refusing to connect to IPv6 address %s because "
                 "Port has NoIPv6Traffic set.",
                 safe_str_client(socks->address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
        return -1;
      }
    } else {
      tor_assert_nonfatal_unreached_once();
    }

    /* See if this is a hostname lookup that we can answer immediately.
     * (For example, an attempt to look up the IP address for an IP address.)
     */
    if (socks->command == SOCKS_COMMAND_RESOLVE) {
      tor_addr_t answer;
      /* Reply to resolves immediately if we can. */
      if (tor_addr_parse(&answer, socks->address) >= 0) {/* is it an IP? */
        /* remember _what_ is supposed to have been resolved. */
        strlcpy(socks->address, rr.orig_address, sizeof(socks->address));
        connection_ap_handshake_socks_resolved_addr(conn, &answer, -1,
                                                    map_expires);
        connection_mark_unattached_ap(conn,
                                END_STREAM_REASON_DONE |
                                END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
        return 0;
      }
      tor_assert(!automap);
      rep_hist_note_used_resolve(now); /* help predict this next time */
    } else if (socks->command == SOCKS_COMMAND_CONNECT) {
      /* Now see if this is a connect request that we can reject immediately */

      tor_assert(!automap);
      /* Don't allow connections to port 0. */
      if (socks->port == 0) {
        log_notice(LD_APP,"Application asked to connect to port 0. Refusing.");
        connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
        return -1;
      }
      /* You can't make connections to internal addresses, by default.
       * Exceptions are begindir requests (where the address is meaningless),
       * or cases where you've hand-configured a particular exit, thereby
       * making the local address meaningful. */
      if (options->ClientRejectInternalAddresses &&
          !conn->use_begindir && !conn->chosen_exit_name && !circ) {
        /* If we reach this point then we don't want to allow internal
         * addresses.  Check if we got one. */
        tor_addr_t addr;
        if (tor_addr_hostname_is_local(socks->address) ||
            (tor_addr_parse(&addr, socks->address) >= 0 &&
             tor_addr_is_internal(&addr, 0))) {
          /* If this is an explicit private address with no chosen exit node,
           * then we really don't want to try to connect to it.  That's
           * probably an error. */
          if (conn->is_transparent_ap) {
#define WARN_INTRVL_LOOP 300
            static ratelim_t loop_warn_limit = RATELIM_INIT(WARN_INTRVL_LOOP);
            char *m;
            if ((m = rate_limit_log(&loop_warn_limit, approx_time()))) {
              log_warn(LD_NET,
                       "Rejecting request for anonymous connection to private "
                       "address %s on a TransPort or NATDPort.  Possible loop "
                       "in your NAT rules?%s", safe_str_client(socks->address),
                       m);
              tor_free(m);
            }
          } else {
#define WARN_INTRVL_PRIV 300
            static ratelim_t priv_warn_limit = RATELIM_INIT(WARN_INTRVL_PRIV);
            char *m;
            if ((m = rate_limit_log(&priv_warn_limit, approx_time()))) {
              log_warn(LD_NET,
                       "Rejecting SOCKS request for anonymous connection to "
                       "private address %s.%s",
                       safe_str_client(socks->address),m);
              tor_free(m);
            }
          }
          connection_mark_unattached_ap(conn, END_STREAM_REASON_PRIVATE_ADDR);
          return -1;
        }
      } /* end "if we should check for internal addresses" */

      /* Okay.  We're still doing a CONNECT, and it wasn't a private
       * address.  Here we do special handling for literal IP addresses,
       * to see if we should reject this preemptively, and to set up
       * fields in conn->entry_cfg to tell the exit what AF we want. */
      {
        tor_addr_t addr;
        /* XXX Duplicate call to tor_addr_parse. */
        if (tor_addr_parse(&addr, socks->address) >= 0) {
          /* If we reach this point, it's an IPv4 or an IPv6 address. */
          sa_family_t family = tor_addr_family(&addr);

          if ((family == AF_INET && ! conn->entry_cfg.ipv4_traffic) ||
              (family == AF_INET6 && ! conn->entry_cfg.ipv6_traffic)) {
            /* You can't do an IPv4 address on a v6-only socks listener,
             * or vice versa. */
            log_warn(LD_NET, "Rejecting SOCKS request for an IP address "
                     "family that this listener does not support.");
            connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
            return -1;
          } else if (family == AF_INET6 && socks->socks_version == 4) {
            /* You can't make a socks4 request to an IPv6 address. Socks4
             * doesn't support that. */
            log_warn(LD_NET, "Rejecting SOCKS4 request for an IPv6 address.");
            connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
            return -1;
          } else if (socks->socks_version == 4 &&
                     !conn->entry_cfg.ipv4_traffic) {
            /* You can't do any kind of Socks4 request when IPv4 is forbidden.
             *
             * XXX raise this check outside the enclosing block? */
            log_warn(LD_NET, "Rejecting SOCKS4 request on a listener with "
                     "no IPv4 traffic supported.");
            connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
            return -1;
          } else if (family == AF_INET6) {
            /* Tell the exit: we won't accept any ipv4 connection to an IPv6
             * address. */
            conn->entry_cfg.ipv4_traffic = 0;
          } else if (family == AF_INET) {
            /* Tell the exit: we won't accept any ipv6 connection to an IPv4
             * address. */
            conn->entry_cfg.ipv6_traffic = 0;
          }
        }
      }

      /* we never allow IPv6 answers on socks4. (TODO: Is this smart?) */
      if (socks->socks_version == 4)
        conn->entry_cfg.ipv6_traffic = 0;

      /* Still handling CONNECT. Now, check for exit enclaves.  (Which we
       * don't do on BEGINDIR, or when there is a chosen exit.)
       *
       * TODO: Should we remove this?  Exit enclaves are nutty and don't
       * work very well
       */
      if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
        /* see if we can find a suitable enclave exit */
        const node_t *r =
          router_find_exact_exit_enclave(socks->address, socks->port);
        if (r) {
          log_info(LD_APP,
                   "Redirecting address %s to exit at enclave router %s",
                   safe_str_client(socks->address), node_describe(r));
          /* use the hex digest, not nickname, in case there are two
             routers with this nickname */
          conn->chosen_exit_name =
            tor_strdup(hex_str(r->identity, DIGEST_LEN));
          conn->chosen_exit_optional = 1;
        }
      }

      /* Still handling CONNECT: warn or reject if it's using a dangerous
       * port. */
      if (!conn->use_begindir && !conn->chosen_exit_name && !circ)
        if (consider_plaintext_ports(conn, socks->port) < 0)
          return -1;

      /* Remember the port so that we will predict that more requests
         there will happen in the future. */
      if (!conn->use_begindir) {
        /* help predict this next time */
        rep_hist_note_used_port(now, socks->port);
      }
    } else if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
      rep_hist_note_used_resolve(now); /* help predict this next time */
      /* no extra processing needed */
    } else {
      /* We should only be doing CONNECT, RESOLVE, or RESOLVE_PTR! */
      tor_fragile_assert();
    }

    /* Okay. At this point we've set chosen_exit_name if needed, rewritten the
     * address, and decided not to reject it for any number of reasons. Now
     * mark the connection as waiting for a circuit, and try to attach it!
     */
    base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;

    /* If we were given a circuit to attach to, try to attach. Otherwise,
     * try to find a good one and attach to that. */
    int rv;
    if (circ) {
      rv = connection_ap_handshake_attach_chosen_circuit(conn, circ, cpath);
    } else {
      /* We'll try to attach it at the next event loop, or whenever
       * we call connection_ap_attach_pending() */
      connection_ap_mark_as_pending_circuit(conn);
      rv = 0;
    }

    /* If the above function returned 0 then we're waiting for a circuit.
     * if it returned 1, we're attached.  Both are okay.  But if it returned
     * -1, there was an error, so make sure the connection is marked, and
     * return -1. */
    if (rv < 0) {
      if (!base_conn->marked_for_close)
        connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
      return -1;
    }

    return 0;
  } else {
    /* If we get here, it's a request for a .onion address! */
    tor_assert(!automap);

    /* If .onion address requests are disabled, refuse the request */
    if (!conn->entry_cfg.onion_traffic) {
      log_warn(LD_APP, "Onion address %s requested from a port with .onion "
                       "disabled", safe_str_client(socks->address));
      connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
      return -1;
    }

    /* Check whether it's RESOLVE or RESOLVE_PTR.  We don't handle those
     * for hidden service addresses. */
    if (SOCKS_COMMAND_IS_RESOLVE(socks->command)) {
      /* if it's a resolve request, fail it right now, rather than
       * building all the circuits and then realizing it won't work. */
      log_warn(LD_APP,
               "Resolve requests to hidden services not allowed. Failing.");
      connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,
                                             0,NULL,-1,TIME_MAX);
      connection_mark_unattached_ap(conn,
                                END_STREAM_REASON_SOCKSPROTOCOL |
                                END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
      return -1;
    }

    /* If we were passed a circuit, then we need to fail.  .onion addresses
     * only work when we launch our own circuits for now. */
    if (circ) {
      log_warn(LD_CONTROL, "Attachstream to a circuit is not "
               "supported for .onion addresses currently. Failing.");
      connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
      return -1;
    }

    /* Look up if we have client authorization configured for this hidden
     * service.  If we do, associate it with the rend_data. */
    rend_service_authorization_t *client_auth =
      rend_client_lookup_service_authorization(socks->address);

    const uint8_t *cookie = NULL;
    rend_auth_type_t auth_type = REND_NO_AUTH;
    if (client_auth) {
      log_info(LD_REND, "Using previously configured client authorization "
               "for hidden service request.");
      auth_type = client_auth->auth_type;
      cookie = client_auth->descriptor_cookie;
    }

    /* Fill in the rend_data field so we can start doing a connection to
     * a hidden service. */
    rend_data_t *rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data =
      rend_data_client_create(socks->address, NULL, (char *) cookie,
                              auth_type);
    if (rend_data == NULL) {
      return -1;
    }
    const char *onion_address = rend_data_get_address(rend_data);
    log_info(LD_REND,"Got a hidden service request for ID '%s'",
             safe_str_client(onion_address));

    /* Lookup the given onion address. If invalid, stop right now.
     * Otherwise, we might have it in the cache or not. */
    unsigned int refetch_desc = 0;
    rend_cache_entry_t *entry = NULL;
    const int rend_cache_lookup_result =
      rend_cache_lookup_entry(onion_address, -1, &entry);
    if (rend_cache_lookup_result < 0) {
      switch (-rend_cache_lookup_result) {
      case EINVAL:
        /* We should already have rejected this address! */
        log_warn(LD_BUG,"Invalid service name '%s'",
                 safe_str_client(onion_address));
        connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
        return -1;
      case ENOENT:
        /* We didn't have this; we should look it up. */
        refetch_desc = 1;
        break;
      default:
        log_warn(LD_BUG, "Unknown cache lookup error %d",
            rend_cache_lookup_result);
        return -1;
      }
    }

    /* Help predict that we'll want to do hidden service circuits in the
     * future. We're not sure if it will need a stable circuit yet, but
     * we know we'll need *something*. */
    rep_hist_note_used_internal(now, 0, 1);

    /* Now we have a descriptor but is it usable or not? If not, refetch.
     * Also, a fetch could have been requested if the onion address was not
     * found in the cache previously. */
    if (refetch_desc || !rend_client_any_intro_points_usable(entry)) {
      connection_ap_mark_as_non_pending_circuit(conn);
      base_conn->state = AP_CONN_STATE_RENDDESC_WAIT;
      log_info(LD_REND, "Unknown descriptor %s. Fetching.",
               safe_str_client(onion_address));
      rend_client_refetch_v2_renddesc(rend_data);
      return 0;
    }

    /* We have the descriptor!  So launch a connection to the HS. */
    base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
    log_info(LD_REND, "Descriptor is here. Great.");

    /* We'll try to attach it at the next event loop, or whenever
     * we call connection_ap_attach_pending() */
    connection_ap_mark_as_pending_circuit(conn);
    return 0;
  }

  return 0; /* unreached but keeps the compiler happy */
}

Project: tor
File: connection_edge.c

connection_ap_handshake_send_begin(entry_connection_t *ap_conn)
{
  char payload[CELL_PAYLOAD_SIZE];
  int payload_len;
  int begin_type;
  const or_options_t *options = get_options();
  origin_circuit_t *circ;
  edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
  connection_t *base_conn = TO_CONN(edge_conn);
  tor_assert(edge_conn->on_circuit);
  circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);

  tor_assert(base_conn->type == CONN_TYPE_AP);
  tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
  tor_assert(ap_conn->socks_request);
  tor_assert(SOCKS_COMMAND_IS_CONNECT(ap_conn->socks_request->command));

  edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
  if (edge_conn->stream_id==0) {
    /* XXXX+ Instead of closing this stream, we should make it get
     * retried on another circuit. */
    connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);

    /* Mark this circuit "unusable for new streams". */
    mark_circuit_unusable_for_new_conns(circ);
    return -1;
  }

  /* Set up begin cell flags. */
  edge_conn->begincell_flags = connection_ap_get_begincell_flags(ap_conn);

  tor_snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:%d",
               (circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL) ?
                 ap_conn->socks_request->address : "",
               ap_conn->socks_request->port);
  payload_len = (int)strlen(payload)+1;
  if (payload_len <= RELAY_PAYLOAD_SIZE - 4 && edge_conn->begincell_flags) {
    set_uint32(payload + payload_len, htonl(edge_conn->begincell_flags));
    payload_len += 4;
  }

  log_info(LD_APP,
           "Sending relay cell %d on circ %u to begin stream %d.",
           (int)ap_conn->use_begindir,
           (unsigned)circ->base_.n_circ_id,
           edge_conn->stream_id);

  begin_type = ap_conn->use_begindir ?
                 RELAY_COMMAND_BEGIN_DIR : RELAY_COMMAND_BEGIN;

  /* Check that circuits are anonymised, based on their type. */
  if (begin_type == RELAY_COMMAND_BEGIN) {
    /* This connection is a standard OR connection.
     * Make sure its path length is anonymous, or that we're in a
     * non-anonymous mode. */
    assert_circ_anonymity_ok(circ, options);
  } else if (begin_type == RELAY_COMMAND_BEGIN_DIR) {
    /* This connection is a begindir directory connection.
     * Look at the linked directory connection to access the directory purpose.
     * If a BEGINDIR connection is ever not linked, that's a bug. */
    if (BUG(!base_conn->linked)) {
      return -1;
    }
    connection_t *linked_dir_conn_base = base_conn->linked_conn;
    /* If the linked connection has been unlinked by other code, we can't send
     * a begin cell on it. */
    if (!linked_dir_conn_base) {
      return -1;
    }
    /* Sensitive directory connections must have an anonymous path length.
     * Otherwise, directory connections are typically one-hop.
     * This matches the earlier check for directory connection path anonymity
     * in directory_initiate_command_rend(). */
    if (purpose_needs_anonymity(linked_dir_conn_base->purpose,
                    TO_DIR_CONN(linked_dir_conn_base)->router_purpose,
                    TO_DIR_CONN(linked_dir_conn_base)->requested_resource)) {
      assert_circ_anonymity_ok(circ, options);
    }
  } else {
    /* This code was written for the two connection types BEGIN and BEGIN_DIR
     */
    tor_assert_unreached();
  }

  if (connection_edge_send_command(edge_conn, begin_type,
                  begin_type == RELAY_COMMAND_BEGIN ? payload : NULL,
                  begin_type == RELAY_COMMAND_BEGIN ? payload_len : 0) < 0)
    return -1; /* circuit is closed, don't continue */

  edge_conn->package_window = STREAMWINDOW_START;
  edge_conn->deliver_window = STREAMWINDOW_START;
  base_conn->state = AP_CONN_STATE_CONNECT_WAIT;
  log_info(LD_APP,"Address/port sent, ap socket "TOR_SOCKET_T_FORMAT
           ", n_circ_id %u",
           base_conn->s, (unsigned)circ->base_.n_circ_id);
  control_event_stream_status(ap_conn, STREAM_EVENT_SENT_CONNECT, 0);

  /* If there's queued-up data, send it now */
  if ((connection_get_inbuf_len(base_conn) ||
       ap_conn->sending_optimistic_data) &&
      connection_ap_supports_optimistic_data(ap_conn)) {
    log_info(LD_APP, "Sending up to %ld + %ld bytes of queued-up data",
             (long)connection_get_inbuf_len(base_conn),
             ap_conn->sending_optimistic_data ?
             (long)buf_datalen(ap_conn->sending_optimistic_data) : 0);
    if (connection_edge_package_raw_inbuf(edge_conn, 1, NULL) < 0) {
      connection_mark_for_close(base_conn);
    }
  }

  return 0;
}

Project: tor
File: connection_edge.c

connection_ap_handshake_send_resolve(entry_connection_t *ap_conn)
{
  int payload_len, command;
  const char *string_addr;
  char inaddr_buf[REVERSE_LOOKUP_NAME_BUF_LEN];
  origin_circuit_t *circ;
  edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
  connection_t *base_conn = TO_CONN(edge_conn);
  tor_assert(edge_conn->on_circuit);
  circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);

  tor_assert(base_conn->type == CONN_TYPE_AP);
  tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
  tor_assert(ap_conn->socks_request);
  tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL);

  command = ap_conn->socks_request->command;
  tor_assert(SOCKS_COMMAND_IS_RESOLVE(command));

  edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
  if (edge_conn->stream_id==0) {
    /* XXXX+ Instead of closing this stream, we should make it get
     * retried on another circuit. */
    connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);

    /* Mark this circuit "unusable for new streams". */
    mark_circuit_unusable_for_new_conns(circ);
    return -1;
  }

  if (command == SOCKS_COMMAND_RESOLVE) {
    string_addr = ap_conn->socks_request->address;
    payload_len = (int)strlen(string_addr)+1;
  } else {
    /* command == SOCKS_COMMAND_RESOLVE_PTR */
    const char *a = ap_conn->socks_request->address;
    tor_addr_t addr;
    int r;

    /* We're doing a reverse lookup.  The input could be an IP address, or
     * could be an .in-addr.arpa or .ip6.arpa address */
    r = tor_addr_parse_PTR_name(&addr, a, AF_UNSPEC, 1);
    if (r <= 0) {
      log_warn(LD_APP, "Rejecting ill-formed reverse lookup of %s",
               safe_str_client(a));
      connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
      return -1;
    }

    r = tor_addr_to_PTR_name(inaddr_buf, sizeof(inaddr_buf), &addr);
    if (r < 0) {
      log_warn(LD_BUG, "Couldn't generate reverse lookup hostname of %s",
               safe_str_client(a));
      connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
      return -1;
    }

    string_addr = inaddr_buf;
    payload_len = (int)strlen(inaddr_buf)+1;
    tor_assert(payload_len <= (int)sizeof(inaddr_buf));
  }

  log_debug(LD_APP,
            "Sending relay cell to begin stream %d.", edge_conn->stream_id);

  if (connection_edge_send_command(edge_conn,
                           RELAY_COMMAND_RESOLVE,
                           string_addr, payload_len) < 0)
    return -1; /* circuit is closed, don't continue */

  if (!base_conn->address) {
    /* This might be unnecessary. XXXX */
    base_conn->address = tor_addr_to_str_dup(&base_conn->addr);
  }
  base_conn->state = AP_CONN_STATE_RESOLVE_WAIT;
  log_info(LD_APP,"Address sent for resolve, ap socket "TOR_SOCKET_T_FORMAT
           ", n_circ_id %u",
           base_conn->s, (unsigned)circ->base_.n_circ_id);
  control_event_stream_status(ap_conn, STREAM_EVENT_SENT_RESOLVE, 0);
  return 0;
}

Project: tor

connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
                                    size_t replylen, int endreason)
{
  char buf[256];
  socks5_reply_status_t status =
    stream_end_reason_to_socks5_response(endreason);

  tor_assert(conn->socks_request); /* make sure it's an AP stream */

  if (!SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
    control_event_stream_status(conn, status==SOCKS5_SUCCEEDED ?
                                STREAM_EVENT_SUCCEEDED : STREAM_EVENT_FAILED,
                                endreason);
  }

  /* Flag this stream's circuit as having completed a stream successfully
   * (for path bias) */
  if (status == SOCKS5_SUCCEEDED ||
      endreason == END_STREAM_REASON_RESOLVEFAILED ||
      endreason == END_STREAM_REASON_CONNECTREFUSED ||
      endreason == END_STREAM_REASON_CONNRESET ||
      endreason == END_STREAM_REASON_NOROUTE ||
      endreason == END_STREAM_REASON_RESOURCELIMIT) {
    if (!conn->edge_.on_circuit ||
       !CIRCUIT_IS_ORIGIN(conn->edge_.on_circuit)) {
      if (endreason != END_STREAM_REASON_RESOLVEFAILED) {
        log_info(LD_BUG,
                 "No origin circuit for successful SOCKS stream "U64_FORMAT
                 ". Reason: %d",
                 U64_PRINTF_ARG(ENTRY_TO_CONN(conn)->global_identifier),
                 endreason);
      }
      /*
       * Else DNS remaps and failed hidden service lookups can send us
       * here with END_STREAM_REASON_RESOLVEFAILED; ignore it
       *
       * Perhaps we could make the test more precise; we can tell hidden
       * services by conn->edge_.renddata != NULL; anything analogous for
       * the DNS remap case?
       */
    } else {
      pathbias_mark_use_success(TO_ORIGIN_CIRCUIT(conn->edge_.on_circuit));
    }
  }

  if (conn->socks_request->has_finished) {
    log_warn(LD_BUG, "(Harmless.) duplicate calls to "
             "connection_ap_handshake_socks_reply.");
    return;
  }
  if (replylen) { /* we already have a reply in mind */
    connection_write_to_buf(reply, replylen, ENTRY_TO_CONN(conn));
    conn->socks_request->has_finished = 1;
    return;
  }
  if (conn->socks_request->socks_version == 4) {
    memset(buf,0,SOCKS4_NETWORK_LEN);
    buf[1] = (status==SOCKS5_SUCCEEDED ? SOCKS4_GRANTED : SOCKS4_REJECT);
    /* leave version, destport, destip zero */
    connection_write_to_buf(buf, SOCKS4_NETWORK_LEN, ENTRY_TO_CONN(conn));
  } else if (conn->socks_request->socks_version == 5) {
    size_t buf_len;
    memset(buf,0,sizeof(buf));
    if (tor_addr_family(&conn->edge_.base_.addr) == AF_INET) {
      buf[0] = 5; /* version 5 */
      buf[1] = (char)status;
      buf[2] = 0;
      buf[3] = 1; /* ipv4 addr */
      /* 4 bytes for the header, 2 bytes for the port, 4 for the address. */
      buf_len = 10;
    } else { /* AF_INET6. */
      buf[0] = 5; /* version 5 */
      buf[1] = (char)status;
      buf[2] = 0;
      buf[3] = 4; /* ipv6 addr */
      /* 4 bytes for the header, 2 bytes for the port, 16 for the address. */
      buf_len = 22;
    }
    connection_write_to_buf(buf,buf_len,ENTRY_TO_CONN(conn));
  }
  /* If socks_version isn't 4 or 5, don't send anything.
   * This can happen in the case of AP bridges. */
  conn->socks_request->has_finished = 1;
  return;
}

Project: tor
File: connection_edge.c

connection_ap_make_link(connection_t *partner,
                        char *address, uint16_t port,
                        const char *digest,
                        int session_group, int isolation_flags,
                        int use_begindir, int want_onehop)
{
  entry_connection_t *conn;
  connection_t *base_conn;

  log_info(LD_APP,"Making internal %s tunnel to %s:%d ...",
           want_onehop ? "direct" : "anonymized",
           safe_str_client(address), port);

  conn = entry_connection_new(CONN_TYPE_AP, tor_addr_family(&partner->addr));
  base_conn = ENTRY_TO_CONN(conn);
  base_conn->linked = 1; /* so that we can add it safely below. */

  /* populate conn->socks_request */

  /* leave version at zero, so the socks_reply is empty */
  conn->socks_request->socks_version = 0;
  conn->socks_request->has_finished = 0; /* waiting for 'connected' */
  strlcpy(conn->socks_request->address, address,
          sizeof(conn->socks_request->address));
  conn->socks_request->port = port;
  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] = '$';
    tor_assert(digest);
    base16_encode(conn->chosen_exit_name+1,HEX_DIGEST_LEN+1,
                  digest, DIGEST_LEN);
  }

  /* Populate isolation fields. */
  conn->socks_request->listener_type = CONN_TYPE_DIR_LISTENER;
  conn->original_dest_address = tor_strdup(address);
  conn->entry_cfg.session_group = session_group;
  conn->entry_cfg.isolation_flags = isolation_flags;

  base_conn->address = tor_strdup("(Tor_internal)");
  tor_addr_make_unspec(&base_conn->addr);
  base_conn->port = 0;

  connection_link_connections(partner, base_conn);

  if (connection_add(base_conn) < 0) { /* no space, forget it */
    connection_free(base_conn);
    return NULL;
  }

  base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;

  control_event_stream_status(conn, STREAM_EVENT_NEW, 0);

  /* attaching to a dirty circuit is fine */
  connection_ap_mark_as_pending_circuit(conn);
  log_info(LD_APP,"... application connection created and linked.");
  return conn;
}

Project: tor
File: connection_edge.c

connection_ap_mark_as_non_pending_circuit(entry_connection_t *entry_conn)
{
  if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
    return;
  UNMARK();
  smartlist_remove(pending_entry_connections, entry_conn);
}

Project: tor
File: connection_edge.c

connection_ap_mark_as_pending_circuit_(entry_connection_t *entry_conn,
                                       const char *fname, int lineno)
{
  connection_t *conn = ENTRY_TO_CONN(entry_conn);
  tor_assert(conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
  tor_assert(conn->magic == ENTRY_CONNECTION_MAGIC);
  if (conn->marked_for_close)
    return;

  if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
    pending_entry_connections = smartlist_new();

  if (PREDICT_UNLIKELY(smartlist_contains(pending_entry_connections,
                                          entry_conn))) {
    log_warn(LD_BUG, "What?? pending_entry_connections already contains %p! "
             "(Called from %s:%d.)",
             entry_conn, fname, lineno);
#ifdef DEBUGGING_17659
    const char *f2 = entry_conn->marked_pending_circ_file;
    log_warn(LD_BUG, "(Previously called from %s:%d.)\n",
             f2 ? f2 : "<NULL>",
             entry_conn->marked_pending_circ_line);
#endif
    log_backtrace(LOG_WARN, LD_BUG, "To debug, this may help");
    return;
  }

#ifdef DEBUGGING_17659
  entry_conn->marked_pending_circ_line = (uint16_t) lineno;
  entry_conn->marked_pending_circ_file = fname;
#endif

  untried_pending_connections = 1;
  smartlist_add(pending_entry_connections, entry_conn);

  /* Work-around for bug 19969: we handle pending_entry_connections at
   * the end of run_main_loop_once(), but in many cases that function will
   * take a very long time, if ever, to finish its call to event_base_loop().
   *
   * So the fix is to tell it right now that it ought to finish its loop at
   * its next available opportunity.
   */
  tell_event_loop_to_finish();
}

Project: tor
File: connection_edge.c

connection_ap_process_natd(entry_connection_t *conn)
{
  char tmp_buf[36], *tbuf, *daddr;
  size_t tlen = 30;
  int err, port_ok;
  socks_request_t *socks;

  tor_assert(conn);
  tor_assert(ENTRY_TO_CONN(conn)->state == AP_CONN_STATE_NATD_WAIT);
  tor_assert(conn->socks_request);
  socks = conn->socks_request;

  log_debug(LD_APP,"entered.");

  /* look for LF-terminated "[DEST ip_addr port]"
   * where ip_addr is a dotted-quad and port is in string form */
  err = connection_fetch_from_buf_line(ENTRY_TO_CONN(conn), tmp_buf, &tlen);
  if (err == 0)
    return 0;
  if (err < 0) {
    log_warn(LD_APP,"NATD handshake failed (DEST too long). Closing");
    connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
    return -1;
  }

  if (strcmpstart(tmp_buf, "[DEST ")) {
    log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
             "said: %s",
             escaped(tmp_buf));
    connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
    return -1;
  }

  daddr = tbuf = &tmp_buf[0] + 6; /* after end of "[DEST " */
  if (!(tbuf = strchr(tbuf, ' '))) {
    log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
             "said: %s",
             escaped(tmp_buf));
    connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
    return -1;
  }
  *tbuf++ = '\0';

  /* pretend that a socks handshake completed so we don't try to
   * send a socks reply down a natd conn */
  strlcpy(socks->address, daddr, sizeof(socks->address));
  socks->port = (uint16_t)
    tor_parse_long(tbuf, 10, 1, 65535, &port_ok, &daddr);
  if (!port_ok) {
    log_warn(LD_APP,"NATD handshake failed; port %s is ill-formed or out "
             "of range.", escaped(tbuf));
    connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
    return -1;
  }

  socks->command = SOCKS_COMMAND_CONNECT;
  socks->has_finished = 1;

  control_event_stream_status(conn, STREAM_EVENT_NEW, 0);

  ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;

  return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
}

Project: tor
File: connection_edge.c

connection_ap_process_transparent(entry_connection_t *conn)
{
  socks_request_t *socks;

  tor_assert(conn);
  tor_assert(conn->socks_request);
  socks = conn->socks_request;

  /* pretend that a socks handshake completed so we don't try to
   * send a socks reply down a transparent conn */
  socks->command = SOCKS_COMMAND_CONNECT;
  socks->has_finished = 1;

  log_debug(LD_APP,"entered.");

  if (connection_ap_get_original_destination(conn, socks) < 0) {
    log_warn(LD_APP,"Fetching original destination failed. Closing.");
    connection_mark_unattached_ap(conn,
                               END_STREAM_REASON_CANT_FETCH_ORIG_DEST);
    return -1;
  }
  /* we have the original destination */

  control_event_stream_status(conn, STREAM_EVENT_NEW, 0);

  return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
}

Project: tor
File: connection_edge.c

connection_ap_rescan_and_attach_pending(void)
{
  entry_connection_t *entry_conn;
  smartlist_t *conns = get_connection_array();

  if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
    pending_entry_connections = smartlist_new();

  SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
    if (conn->marked_for_close ||
        conn->type != CONN_TYPE_AP ||
        conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
      continue;

    entry_conn = TO_ENTRY_CONN(conn);
    tor_assert(entry_conn);
    if (! smartlist_contains(pending_entry_connections, entry_conn)) {
      log_warn(LD_BUG, "Found a connection %p that was supposed to be "
               "in pending_entry_connections, but wasn't. No worries; "
               "adding it.",
               pending_entry_connections);
      untried_pending_connections = 1;
      connection_ap_mark_as_pending_circuit(entry_conn);
    }

  } SMARTLIST_FOREACH_END(conn);

  connection_ap_attach_pending(1);
}

Project: tor
File: connection_edge.c

connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn,
                                            origin_circuit_t *circ,
                                            crypt_path_t *cpath)
{
  const or_options_t *options = get_options();

  if (options->LeaveStreamsUnattached) {
    CONNECTION_AP_EXPECT_NONPENDING(conn);
    ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
    return 0;
  }
  return connection_ap_handshake_rewrite_and_attach(conn, circ, cpath);
}

Project: tor
File: connection_edge.c

connection_ap_supports_optimistic_data(const entry_connection_t *conn)
{
  const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
  /* We can only send optimistic data if we're connected to an open
     general circuit. */
  if (edge_conn->on_circuit == NULL ||
      edge_conn->on_circuit->state != CIRCUIT_STATE_OPEN ||
      (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
       edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_REND_JOINED))
    return 0;

  return conn->may_use_optimistic_data;
}

Project: tor
File: connection_edge.c

connection_ap_warn_and_unmark_if_pending_circ(entry_connection_t *entry_conn,
                                              const char *where)
{
  if (pending_entry_connections &&
      smartlist_contains(pending_entry_connections, entry_conn)) {
    log_warn(LD_BUG, "What was %p doing in pending_entry_connections in %s?",
             entry_conn, where);
    connection_ap_mark_as_non_pending_circuit(entry_conn);
  }
}

Project: tor
File: connection_edge.c

connection_edge_about_to_close(edge_connection_t *edge_conn)
{
  if (!edge_conn->edge_has_sent_end) {
    connection_t *conn = TO_CONN(edge_conn);
    log_warn(LD_BUG, "(Harmless.) Edge connection (marked at %s:%d) "
             "hasn't sent end yet?",
             conn->marked_for_close_file, conn->marked_for_close);
    tor_fragile_assert();
  }
}

Project: tor

connection_edge_compatible_with_circuit(const entry_connection_t *conn,
                                        const origin_circuit_t *circ)
{
  const uint8_t iso = conn->entry_cfg.isolation_flags;
  const socks_request_t *sr = conn->socks_request;

  /* If circ has never been used for an isolated connection, we can
   * totally use it for this one. */
  if (!circ->isolation_values_set)
    return 1;

  /* If circ has been used for connections having more than one value
   * for some field f, it will have the corresponding bit set in
   * isolation_flags_mixed.  If isolation_flags_mixed has any bits
   * in common with iso, then conn must be isolated from at least
   * one stream that has been attached to circ. */
  if ((iso & circ->isolation_flags_mixed) != 0) {
    /* For at least one field where conn is isolated, the circuit
     * already has mixed streams. */
    return 0;
  }

  if (! conn->original_dest_address) {
    log_warn(LD_BUG, "Reached connection_edge_compatible_with_circuit without "
             "having set conn->original_dest_address");
    ((entry_connection_t*)conn)->original_dest_address =
      tor_strdup(conn->socks_request->address);
  }

  if ((iso & ISO_STREAM) &&
      (circ->associated_isolated_stream_global_id !=
       ENTRY_TO_CONN(conn)->global_identifier))
    return 0;

  if ((iso & ISO_DESTPORT) && conn->socks_request->port != circ->dest_port)
    return 0;
  if ((iso & ISO_DESTADDR) &&
      strcasecmp(conn->original_dest_address, circ->dest_address))
    return 0;
  if ((iso & ISO_SOCKSAUTH) &&
      (! memeq_opt(sr->username, sr->usernamelen,
                   circ->socks_username, circ->socks_username_len) ||
       ! memeq_opt(sr->password, sr->passwordlen,
                   circ->socks_password, circ->socks_password_len)))
    return 0;
  if ((iso & ISO_CLIENTPROTO) &&
      (conn->socks_request->listener_type != circ->client_proto_type ||
       conn->socks_request->socks_version != circ->client_proto_socksver))
    return 0;
  if ((iso & ISO_CLIENTADDR) &&
      !tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
    return 0;
  if ((iso & ISO_SESSIONGRP) &&
      conn->entry_cfg.session_group != circ->session_group)
    return 0;
  if ((iso & ISO_NYM_EPOCH) && conn->nym_epoch != circ->nym_epoch)
    return 0;

  return 1;
}

Project: tor
File: connection_edge.c

connection_edge_destroy(circid_t circ_id, edge_connection_t *conn)
{
  if (!conn->base_.marked_for_close) {
    log_info(LD_EDGE, "CircID %u: At an edge. Marking connection for close.",
             (unsigned) circ_id);
    if (conn->base_.type == CONN_TYPE_AP) {
      entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
      connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_DESTROY);
      control_event_stream_bandwidth(conn);
      control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
                                  END_STREAM_REASON_DESTROY);
      conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
    } else {
      /* closing the circuit, nothing to send an END to */
      conn->edge_has_sent_end = 1;
      conn->end_reason = END_STREAM_REASON_DESTROY;
      conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
      connection_mark_and_flush(TO_CONN(conn));
    }
  }
  conn->cpath_layer = NULL;
  conn->on_circuit = NULL;
  return 0;
}

Project: tor
File: connection_edge.c

connection_edge_end_errno(edge_connection_t *conn)
{
  uint8_t reason;
  tor_assert(conn);
  reason = errno_to_stream_end_reason(tor_socket_errno(conn->base_.s));
  return connection_edge_end(conn, reason);
}

Project: tor
File: connection_edge.c

connection_edge_finished_connecting(edge_connection_t *edge_conn)
{
  connection_t *conn;

  tor_assert(edge_conn);
  tor_assert(edge_conn->base_.type == CONN_TYPE_EXIT);
  conn = TO_CONN(edge_conn);
  tor_assert(conn->state == EXIT_CONN_STATE_CONNECTING);

  log_info(LD_EXIT,"Exit connection to %s:%u (%s) established.",
           escaped_safe_str(conn->address), conn->port,
           safe_str(fmt_and_decorate_addr(&conn->addr)));

  rep_hist_note_exit_stream_opened(conn->port);

  conn->state = EXIT_CONN_STATE_OPEN;
  connection_watch_events(conn, READ_EVENT); /* stop writing, keep reading */
  if (connection_get_outbuf_len(conn)) /* in case there are any queued relay
                                        * cells */
    connection_start_writing(conn);
  /* deliver a 'connected' relay cell back through the circuit. */
  if (connection_edge_is_rendezvous_stream(edge_conn)) {
    if (connection_edge_send_command(edge_conn,
                                     RELAY_COMMAND_CONNECTED, NULL, 0) < 0)
      return 0; /* circuit is closed, don't continue */
  } else {
    uint8_t connected_payload[MAX_CONNECTED_CELL_PAYLOAD_LEN];
    int connected_payload_len =
      connected_cell_format_payload(connected_payload, &conn->addr,
                                    edge_conn->address_ttl);
    if (connected_payload_len < 0)
      return -1;

    if (connection_edge_send_command(edge_conn,
                        RELAY_COMMAND_CONNECTED,
                        (char*)connected_payload, connected_payload_len) < 0)
      return 0; /* circuit is closed, don't continue */
  }
  tor_assert(edge_conn->package_window > 0);
  /* in case the server has written anything */
  return connection_edge_process_inbuf(edge_conn, 1);
}

Project: tor
File: connection_edge.c

connection_edge_finished_flushing(edge_connection_t *conn)
{
  tor_assert(conn);

  switch (conn->base_.state) {
    case AP_CONN_STATE_OPEN:
    case EXIT_CONN_STATE_OPEN:
      connection_edge_consider_sending_sendme(conn);
      return 0;
    case AP_CONN_STATE_SOCKS_WAIT:
    case AP_CONN_STATE_NATD_WAIT:
    case AP_CONN_STATE_RENDDESC_WAIT:
    case AP_CONN_STATE_CIRCUIT_WAIT:
    case AP_CONN_STATE_CONNECT_WAIT:
    case AP_CONN_STATE_CONTROLLER_WAIT:
    case AP_CONN_STATE_RESOLVE_WAIT:
      return 0;
    default:
      log_warn(LD_BUG, "Called in unexpected state %d.",conn->base_.state);
      tor_fragile_assert();
      return -1;
  }
  return 0;
}

Project: tor
File: connection_edge.c

connection_edge_flushed_some(edge_connection_t *conn)
{
  switch (conn->base_.state) {
    case AP_CONN_STATE_OPEN:
    case EXIT_CONN_STATE_OPEN:
      connection_edge_consider_sending_sendme(conn);
      break;
  }
  return 0;
}

Project: tor

connection_edge_free_all(void)
{
  untried_pending_connections = 0;
  smartlist_free(pending_entry_connections);
  pending_entry_connections = NULL;
}

Project: tor

connection_edge_is_rendezvous_stream(const edge_connection_t *conn)
{
  tor_assert(conn);
  if (conn->rend_data)
    return 1;
  return 0;
}

Project: tor
File: connection_edge.c

connection_edge_reached_eof(edge_connection_t *conn)
{
  if (connection_get_inbuf_len(TO_CONN(conn)) &&
      connection_state_is_open(TO_CONN(conn))) {
    /* it still has stuff to process. don't let it die yet. */
    return 0;
  }
  log_info(LD_EDGE,"conn (fd "TOR_SOCKET_T_FORMAT") reached eof. Closing.",
           conn->base_.s);
  if (!conn->base_.marked_for_close) {
    /* only mark it if not already marked. it's possible to
     * get the 'end' right around when the client hangs up on us. */
    connection_edge_end(conn, END_STREAM_REASON_DONE);
    if (conn->base_.type == CONN_TYPE_AP) {
      /* eof, so don't send a socks reply back */
      if (EDGE_TO_ENTRY_CONN(conn)->socks_request)
        EDGE_TO_ENTRY_CONN(conn)->socks_request->has_finished = 1;
    }
    connection_mark_for_close(TO_CONN(conn));
  }
  return 0;
}

Project: tor

connection_edge_update_circuit_isolation(const entry_connection_t *conn,
                                         origin_circuit_t *circ,
                                         int dry_run)
{
  const socks_request_t *sr = conn->socks_request;
  if (! conn->original_dest_address) {
    log_warn(LD_BUG, "Reached connection_update_circuit_isolation without "
             "having set conn->original_dest_address");
    ((entry_connection_t*)conn)->original_dest_address =
      tor_strdup(conn->socks_request->address);
  }

  if (!circ->isolation_values_set) {
    if (dry_run)
      return -1;
    circ->associated_isolated_stream_global_id =
      ENTRY_TO_CONN(conn)->global_identifier;
    circ->dest_port = conn->socks_request->port;
    circ->dest_address = tor_strdup(conn->original_dest_address);
    circ->client_proto_type = conn->socks_request->listener_type;
    circ->client_proto_socksver = conn->socks_request->socks_version;
    tor_addr_copy(&circ->client_addr, &ENTRY_TO_CONN(conn)->addr);
    circ->session_group = conn->entry_cfg.session_group;
    circ->nym_epoch = conn->nym_epoch;
    circ->socks_username = sr->username ?
      tor_memdup(sr->username, sr->usernamelen) : NULL;
    circ->socks_password = sr->password ?
      tor_memdup(sr->password, sr->passwordlen) : NULL;
    circ->socks_username_len = sr->usernamelen;
    circ->socks_password_len = sr->passwordlen;

    circ->isolation_values_set = 1;
    return 0;
  } else {
    uint8_t mixed = 0;
    if (conn->socks_request->port != circ->dest_port)
      mixed |= ISO_DESTPORT;
    if (strcasecmp(conn->original_dest_address, circ->dest_address))
      mixed |= ISO_DESTADDR;
    if (!memeq_opt(sr->username, sr->usernamelen,
                   circ->socks_username, circ->socks_username_len) ||
        !memeq_opt(sr->password, sr->passwordlen,
                   circ->socks_password, circ->socks_password_len))
      mixed |= ISO_SOCKSAUTH;
    if ((conn->socks_request->listener_type != circ->client_proto_type ||
         conn->socks_request->socks_version != circ->client_proto_socksver))
      mixed |= ISO_CLIENTPROTO;
    if (!tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
      mixed |= ISO_CLIENTADDR;
    if (conn->entry_cfg.session_group != circ->session_group)
      mixed |= ISO_SESSIONGRP;
    if (conn->nym_epoch != circ->nym_epoch)
      mixed |= ISO_NYM_EPOCH;

    if (dry_run)
      return mixed;

    if ((mixed & conn->entry_cfg.isolation_flags) != 0) {
      log_warn(LD_BUG, "Updating a circuit with seemingly incompatible "
               "isolation flags.");
    }
    circ->isolation_flags_mixed |= mixed;
    return 0;
  }
}

Project: tor
File: connection_edge.c

connection_exit_about_to_close(edge_connection_t *edge_conn)
{
  circuit_t *circ;
  connection_t *conn = TO_CONN(edge_conn);

  connection_edge_about_to_close(edge_conn);

  circ = circuit_get_by_edge_conn(edge_conn);
  if (circ)
    circuit_detach_stream(circ, edge_conn);
  if (conn->state == EXIT_CONN_STATE_RESOLVING) {
    connection_dns_remove(edge_conn);
  }
}

Project: tor
File: connection_edge.c

connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ)
{
  edge_connection_t *dummy_conn;
  relay_header_t rh;

  assert_circuit_ok(TO_CIRCUIT(circ));
  relay_header_unpack(&rh, cell->payload);
  if (rh.length > RELAY_PAYLOAD_SIZE)
    return -1;

  /* This 'dummy_conn' only exists to remember the stream ID
   * associated with the resolve request; and to make the
   * implementation of dns.c more uniform.  (We really only need to
   * remember the circuit, the stream ID, and the hostname to be
   * resolved; but if we didn't store them in a connection like this,
   * the housekeeping in dns.c would get way more complicated.)
   */
  dummy_conn = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
  dummy_conn->stream_id = rh.stream_id;
  dummy_conn->base_.address = tor_strndup(
                                       (char*)cell->payload+RELAY_HEADER_SIZE,
                                       rh.length);
  dummy_conn->base_.port = 0;
  dummy_conn->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
  dummy_conn->base_.purpose = EXIT_PURPOSE_RESOLVE;

  dummy_conn->on_circuit = TO_CIRCUIT(circ);

  /* send it off to the gethostbyname farm */
  switch (dns_resolve(dummy_conn)) {
    case -1: /* Impossible to resolve; a resolved cell was sent. */
      /* Connection freed; don't touch it. */
      return 0;
    case 1: /* The result was cached; a resolved cell was sent. */
      if (!dummy_conn->base_.marked_for_close)
        connection_free(TO_CONN(dummy_conn));
      return 0;
    case 0: /* resolve added to pending list */
      assert_circuit_ok(TO_CIRCUIT(circ));
      break;
  }
  return 0;
}