mirror of
https://gitlab.torproject.org/tpo/core/tor.git
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f2153f9716
Regardless of the setting of ExtendAllowPrivateAddresses.
This fixes a bug with pluggable transports that ignore the
(potentially private) address in their bridge line.
Fixes bug 18517; bugfix on 23b088907f in tor-0.2.8.1-alpha.
2446 lines
83 KiB
C
2446 lines
83 KiB
C
/* Copyright (c) 2001 Matej Pfajfar.
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* Copyright (c) 2001-2004, Roger Dingledine.
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* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
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* Copyright (c) 2007-2016, The Tor Project, Inc. */
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/* See LICENSE for licensing information */
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/**
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* \file circuitbuild.c
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*
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* \brief Implements the details of building circuits (by chosing paths,
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* constructing/sending create/extend cells, and so on).
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**/
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#define CIRCUITBUILD_PRIVATE
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#include "or.h"
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#include "channel.h"
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#include "circpathbias.h"
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#define CIRCUITBUILD_PRIVATE
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#include "circuitbuild.h"
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#include "circuitlist.h"
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#include "circuitstats.h"
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#include "circuituse.h"
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#include "command.h"
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#include "config.h"
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#include "confparse.h"
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#include "connection.h"
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#include "connection_edge.h"
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#include "connection_or.h"
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#include "control.h"
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#include "directory.h"
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#include "entrynodes.h"
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#include "main.h"
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#include "microdesc.h"
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#include "networkstatus.h"
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#include "nodelist.h"
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#include "onion.h"
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#include "onion_tap.h"
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#include "onion_fast.h"
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#include "policies.h"
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#include "transports.h"
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#include "relay.h"
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#include "rephist.h"
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#include "router.h"
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#include "routerlist.h"
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#include "routerparse.h"
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#include "routerset.h"
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#include "crypto.h"
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#ifndef MIN
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#define MIN(a,b) ((a)<(b)?(a):(b))
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#endif
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static channel_t * channel_connect_for_circuit(const tor_addr_t *addr,
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uint16_t port,
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const char *id_digest);
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static int circuit_deliver_create_cell(circuit_t *circ,
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const create_cell_t *create_cell,
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int relayed);
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static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit);
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static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath);
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static int onion_extend_cpath(origin_circuit_t *circ);
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static int count_acceptable_nodes(smartlist_t *routers);
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static int onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice);
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static int circuits_can_use_ntor(void);
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/** This function tries to get a channel to the specified endpoint,
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* and then calls command_setup_channel() to give it the right
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* callbacks.
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*/
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static channel_t *
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channel_connect_for_circuit(const tor_addr_t *addr, uint16_t port,
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const char *id_digest)
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{
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channel_t *chan;
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chan = channel_connect(addr, port, id_digest);
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if (chan) command_setup_channel(chan);
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return chan;
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}
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/** Search for a value for circ_id that we can use on <b>chan</b> for an
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* outbound circuit, until we get a circ_id that is not in use by any other
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* circuit on that conn.
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*
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* Return it, or 0 if can't get a unique circ_id.
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*/
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STATIC circid_t
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get_unique_circ_id_by_chan(channel_t *chan)
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{
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/* This number is chosen somewhat arbitrarily; see comment below for more
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* info. When the space is 80% full, it gives a one-in-a-million failure
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* chance; when the space is 90% full, it gives a one-in-850 chance; and when
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* the space is 95% full, it gives a one-in-26 failure chance. That seems
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* okay, though you could make a case IMO for anything between N=32 and
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* N=256. */
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#define MAX_CIRCID_ATTEMPTS 64
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int in_use;
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unsigned n_with_circ = 0, n_pending_destroy = 0, n_weird_pending_destroy = 0;
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circid_t test_circ_id;
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circid_t attempts=0;
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circid_t high_bit, max_range, mask;
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int64_t pending_destroy_time_total = 0;
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int64_t pending_destroy_time_max = 0;
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tor_assert(chan);
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if (chan->circ_id_type == CIRC_ID_TYPE_NEITHER) {
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log_warn(LD_BUG,
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"Trying to pick a circuit ID for a connection from "
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"a client with no identity.");
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return 0;
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}
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max_range = (chan->wide_circ_ids) ? (1u<<31) : (1u<<15);
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mask = max_range - 1;
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high_bit = (chan->circ_id_type == CIRC_ID_TYPE_HIGHER) ? max_range : 0;
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do {
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if (++attempts > MAX_CIRCID_ATTEMPTS) {
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/* Make sure we don't loop forever because all circuit IDs are used.
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*
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* Once, we would try until we had tried every possible circuit ID. But
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* that's quite expensive. Instead, we try MAX_CIRCID_ATTEMPTS random
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* circuit IDs, and then give up.
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*
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* This potentially causes us to give up early if our circuit ID space
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* is nearly full. If we have N circuit IDs in use, then we will reject
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* a new circuit with probability (N / max_range) ^ MAX_CIRCID_ATTEMPTS.
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* This means that in practice, a few percent of our circuit ID capacity
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* will go unused.
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*
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* The alternative here, though, is to do a linear search over the
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* whole circuit ID space every time we extend a circuit, which is
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* not so great either.
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*/
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int64_t queued_destroys;
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char *m = rate_limit_log(&chan->last_warned_circ_ids_exhausted,
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approx_time());
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if (m == NULL)
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return 0; /* This message has been rate-limited away. */
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if (n_pending_destroy)
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pending_destroy_time_total /= n_pending_destroy;
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log_warn(LD_CIRC,"No unused circIDs found on channel %s wide "
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"circID support, with %u inbound and %u outbound circuits. "
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"Found %u circuit IDs in use by circuits, and %u with "
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"pending destroy cells. (%u of those were marked bogusly.) "
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"The ones with pending destroy cells "
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"have been marked unusable for an average of %ld seconds "
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"and a maximum of %ld seconds. This channel is %ld seconds "
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"old. Failing a circuit.%s",
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chan->wide_circ_ids ? "with" : "without",
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chan->num_p_circuits, chan->num_n_circuits,
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n_with_circ, n_pending_destroy, n_weird_pending_destroy,
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(long)pending_destroy_time_total,
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(long)pending_destroy_time_max,
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(long)(approx_time() - chan->timestamp_created),
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m);
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tor_free(m);
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if (!chan->cmux) {
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/* This warning should be impossible. */
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log_warn(LD_BUG, " This channel somehow has no cmux on it!");
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return 0;
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}
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/* analysis so far on 12184 suggests that we're running out of circuit
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IDs because it looks like we have too many pending destroy
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cells. Let's see how many we really have pending.
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*/
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queued_destroys = circuitmux_count_queued_destroy_cells(chan,
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chan->cmux);
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log_warn(LD_CIRC, " Circuitmux on this channel has %u circuits, "
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"of which %u are active. It says it has "I64_FORMAT
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" destroy cells queued.",
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circuitmux_num_circuits(chan->cmux),
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circuitmux_num_active_circuits(chan->cmux),
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I64_PRINTF_ARG(queued_destroys));
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/* Change this into "if (1)" in order to get more information about
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* possible failure modes here. You'll need to know how to use gdb with
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* Tor: this will make Tor exit with an assertion failure if the cmux is
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* corrupt. */
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if (0)
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circuitmux_assert_okay(chan->cmux);
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channel_dump_statistics(chan, LOG_WARN);
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return 0;
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}
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do {
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crypto_rand((char*) &test_circ_id, sizeof(test_circ_id));
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test_circ_id &= mask;
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} while (test_circ_id == 0);
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test_circ_id |= high_bit;
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in_use = circuit_id_in_use_on_channel(test_circ_id, chan);
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if (in_use == 1)
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++n_with_circ;
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else if (in_use == 2) {
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time_t since_when;
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++n_pending_destroy;
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since_when =
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circuit_id_when_marked_unusable_on_channel(test_circ_id, chan);
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if (since_when) {
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time_t waiting = approx_time() - since_when;
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pending_destroy_time_total += waiting;
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if (waiting > pending_destroy_time_max)
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pending_destroy_time_max = waiting;
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} else {
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++n_weird_pending_destroy;
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}
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}
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} while (in_use);
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return test_circ_id;
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}
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/** If <b>verbose</b> is false, allocate and return a comma-separated list of
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* the currently built elements of <b>circ</b>. If <b>verbose</b> is true, also
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* list information about link status in a more verbose format using spaces.
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* If <b>verbose_names</b> is false, give nicknames for Named routers and hex
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* digests for others; if <b>verbose_names</b> is true, use $DIGEST=Name style
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* names.
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*/
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static char *
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circuit_list_path_impl(origin_circuit_t *circ, int verbose, int verbose_names)
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{
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crypt_path_t *hop;
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smartlist_t *elements;
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const char *states[] = {"closed", "waiting for keys", "open"};
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char *s;
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elements = smartlist_new();
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if (verbose) {
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const char *nickname = build_state_get_exit_nickname(circ->build_state);
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smartlist_add_asprintf(elements, "%s%s circ (length %d%s%s):",
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circ->build_state->is_internal ? "internal" : "exit",
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circ->build_state->need_uptime ? " (high-uptime)" : "",
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circ->build_state->desired_path_len,
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circ->base_.state == CIRCUIT_STATE_OPEN ? "" : ", last hop ",
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circ->base_.state == CIRCUIT_STATE_OPEN ? "" :
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(nickname?nickname:"*unnamed*"));
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}
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hop = circ->cpath;
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do {
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char *elt;
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const char *id;
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const node_t *node;
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if (!hop)
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break;
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if (!verbose && hop->state != CPATH_STATE_OPEN)
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break;
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if (!hop->extend_info)
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break;
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id = hop->extend_info->identity_digest;
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if (verbose_names) {
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elt = tor_malloc(MAX_VERBOSE_NICKNAME_LEN+1);
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if ((node = node_get_by_id(id))) {
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node_get_verbose_nickname(node, elt);
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} else if (is_legal_nickname(hop->extend_info->nickname)) {
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elt[0] = '$';
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base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
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elt[HEX_DIGEST_LEN+1]= '~';
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strlcpy(elt+HEX_DIGEST_LEN+2,
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hop->extend_info->nickname, MAX_NICKNAME_LEN+1);
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} else {
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elt[0] = '$';
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base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
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}
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} else { /* ! verbose_names */
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node = node_get_by_id(id);
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if (node && node_is_named(node)) {
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elt = tor_strdup(node_get_nickname(node));
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} else {
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elt = tor_malloc(HEX_DIGEST_LEN+2);
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elt[0] = '$';
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base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN);
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}
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}
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tor_assert(elt);
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if (verbose) {
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tor_assert(hop->state <= 2);
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smartlist_add_asprintf(elements,"%s(%s)",elt,states[hop->state]);
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tor_free(elt);
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} else {
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smartlist_add(elements, elt);
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}
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hop = hop->next;
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} while (hop != circ->cpath);
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s = smartlist_join_strings(elements, verbose?" ":",", 0, NULL);
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SMARTLIST_FOREACH(elements, char*, cp, tor_free(cp));
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smartlist_free(elements);
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return s;
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}
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/** If <b>verbose</b> is false, allocate and return a comma-separated
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* list of the currently built elements of <b>circ</b>. If
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* <b>verbose</b> is true, also list information about link status in
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* a more verbose format using spaces.
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*/
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char *
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circuit_list_path(origin_circuit_t *circ, int verbose)
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{
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return circuit_list_path_impl(circ, verbose, 0);
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}
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/** Allocate and return a comma-separated list of the currently built elements
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* of <b>circ</b>, giving each as a verbose nickname.
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*/
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char *
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circuit_list_path_for_controller(origin_circuit_t *circ)
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{
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return circuit_list_path_impl(circ, 0, 1);
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}
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/** Log, at severity <b>severity</b>, the nicknames of each router in
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* <b>circ</b>'s cpath. Also log the length of the cpath, and the intended
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* exit point.
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*/
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void
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circuit_log_path(int severity, unsigned int domain, origin_circuit_t *circ)
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{
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char *s = circuit_list_path(circ,1);
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tor_log(severity,domain,"%s",s);
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tor_free(s);
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}
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/** Tell the rep(utation)hist(ory) module about the status of the links
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* in <b>circ</b>. Hops that have become OPEN are marked as successfully
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* extended; the _first_ hop that isn't open (if any) is marked as
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* unable to extend.
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*/
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/* XXXX Someday we should learn from OR circuits too. */
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void
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circuit_rep_hist_note_result(origin_circuit_t *circ)
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{
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crypt_path_t *hop;
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const char *prev_digest = NULL;
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hop = circ->cpath;
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if (!hop) /* circuit hasn't started building yet. */
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return;
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if (server_mode(get_options())) {
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const routerinfo_t *me = router_get_my_routerinfo();
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if (!me)
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return;
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prev_digest = me->cache_info.identity_digest;
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}
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do {
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const node_t *node = node_get_by_id(hop->extend_info->identity_digest);
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if (node) { /* Why do we check this? We know the identity. -NM XXXX */
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if (prev_digest) {
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if (hop->state == CPATH_STATE_OPEN)
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rep_hist_note_extend_succeeded(prev_digest, node->identity);
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else {
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rep_hist_note_extend_failed(prev_digest, node->identity);
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break;
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}
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}
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prev_digest = node->identity;
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} else {
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prev_digest = NULL;
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}
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hop=hop->next;
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} while (hop!=circ->cpath);
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}
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/** Return 1 iff at least one node in circ's cpath supports ntor. */
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static int
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circuit_cpath_supports_ntor(const origin_circuit_t *circ)
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{
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crypt_path_t *head, *cpath;
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cpath = head = circ->cpath;
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do {
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if (cpath->extend_info &&
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!tor_mem_is_zero(
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(const char*)cpath->extend_info->curve25519_onion_key.public_key,
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CURVE25519_PUBKEY_LEN))
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return 1;
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cpath = cpath->next;
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} while (cpath != head);
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return 0;
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}
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/** Pick all the entries in our cpath. Stop and return 0 when we're
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* happy, or return -1 if an error occurs. */
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static int
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onion_populate_cpath(origin_circuit_t *circ)
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{
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int n_tries = 0;
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const int using_ntor = circuits_can_use_ntor();
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#define MAX_POPULATE_ATTEMPTS 32
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while (1) {
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int r = onion_extend_cpath(circ);
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if (r < 0) {
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log_info(LD_CIRC,"Generating cpath hop failed.");
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return -1;
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}
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if (r == 1) {
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/* This circuit doesn't need/shouldn't be forced to have an ntor hop */
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if (circ->build_state->desired_path_len <= 1 || ! using_ntor)
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return 0;
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/* This circuit has an ntor hop. great! */
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if (circuit_cpath_supports_ntor(circ))
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return 0;
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/* No node in the circuit supports ntor. Have we already tried too many
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* times? */
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if (++n_tries >= MAX_POPULATE_ATTEMPTS)
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break;
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/* Clear the path and retry */
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circuit_clear_cpath(circ);
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}
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}
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log_warn(LD_CIRC, "I tried for %d times, but I couldn't build a %d-hop "
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"circuit with at least one node that supports ntor.",
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MAX_POPULATE_ATTEMPTS,
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circ->build_state->desired_path_len);
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return -1;
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}
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/** Create and return a new origin circuit. Initialize its purpose and
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* build-state based on our arguments. The <b>flags</b> argument is a
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* bitfield of CIRCLAUNCH_* flags. */
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origin_circuit_t *
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origin_circuit_init(uint8_t purpose, int flags)
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{
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/* sets circ->p_circ_id and circ->p_chan */
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origin_circuit_t *circ = origin_circuit_new();
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circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_CHAN_WAIT);
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circ->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));
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circ->build_state->onehop_tunnel =
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((flags & CIRCLAUNCH_ONEHOP_TUNNEL) ? 1 : 0);
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circ->build_state->need_uptime =
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((flags & CIRCLAUNCH_NEED_UPTIME) ? 1 : 0);
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circ->build_state->need_capacity =
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((flags & CIRCLAUNCH_NEED_CAPACITY) ? 1 : 0);
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circ->build_state->is_internal =
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((flags & CIRCLAUNCH_IS_INTERNAL) ? 1 : 0);
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circ->base_.purpose = purpose;
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return circ;
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}
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/** Build a new circuit for <b>purpose</b>. If <b>exit</b>
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* is defined, then use that as your exit router, else choose a suitable
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* exit node.
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*
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* Also launch a connection to the first OR in the chosen path, if
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* it's not open already.
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*/
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origin_circuit_t *
|
|
circuit_establish_circuit(uint8_t purpose, extend_info_t *exit, int flags)
|
|
{
|
|
origin_circuit_t *circ;
|
|
int err_reason = 0;
|
|
|
|
circ = origin_circuit_init(purpose, flags);
|
|
|
|
if (onion_pick_cpath_exit(circ, exit) < 0 ||
|
|
onion_populate_cpath(circ) < 0) {
|
|
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOPATH);
|
|
return NULL;
|
|
}
|
|
|
|
control_event_circuit_status(circ, CIRC_EVENT_LAUNCHED, 0);
|
|
|
|
if ((err_reason = circuit_handle_first_hop(circ)) < 0) {
|
|
circuit_mark_for_close(TO_CIRCUIT(circ), -err_reason);
|
|
return NULL;
|
|
}
|
|
return circ;
|
|
}
|
|
|
|
/** Start establishing the first hop of our circuit. Figure out what
|
|
* OR we should connect to, and if necessary start the connection to
|
|
* it. If we're already connected, then send the 'create' cell.
|
|
* Return 0 for ok, -reason if circ should be marked-for-close. */
|
|
int
|
|
circuit_handle_first_hop(origin_circuit_t *circ)
|
|
{
|
|
crypt_path_t *firsthop;
|
|
channel_t *n_chan;
|
|
int err_reason = 0;
|
|
const char *msg = NULL;
|
|
int should_launch = 0;
|
|
const or_options_t *options = get_options();
|
|
|
|
firsthop = onion_next_hop_in_cpath(circ->cpath);
|
|
tor_assert(firsthop);
|
|
tor_assert(firsthop->extend_info);
|
|
|
|
/* Some bridges are on private addresses. Others pass a dummy private
|
|
* address to the pluggable transport, which ignores it.
|
|
* Deny the connection if:
|
|
* - the address is internal, and
|
|
* - we're not connecting to a configured bridge, and
|
|
* - we're not configured to allow extends to private addresses. */
|
|
if (tor_addr_is_internal(&firsthop->extend_info->addr, 0) &&
|
|
!extend_info_is_a_configured_bridge(firsthop->extend_info) &&
|
|
!options->ExtendAllowPrivateAddresses) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Client asked me to connect directly to a private address");
|
|
return -END_CIRC_REASON_TORPROTOCOL;
|
|
}
|
|
|
|
/* now see if we're already connected to the first OR in 'route' */
|
|
log_debug(LD_CIRC,"Looking for firsthop '%s'",
|
|
fmt_addrport(&firsthop->extend_info->addr,
|
|
firsthop->extend_info->port));
|
|
|
|
n_chan = channel_get_for_extend(firsthop->extend_info->identity_digest,
|
|
&firsthop->extend_info->addr,
|
|
&msg,
|
|
&should_launch);
|
|
|
|
if (!n_chan) {
|
|
/* not currently connected in a useful way. */
|
|
log_info(LD_CIRC, "Next router is %s: %s",
|
|
safe_str_client(extend_info_describe(firsthop->extend_info)),
|
|
msg?msg:"???");
|
|
circ->base_.n_hop = extend_info_dup(firsthop->extend_info);
|
|
|
|
if (should_launch) {
|
|
if (circ->build_state->onehop_tunnel)
|
|
control_event_bootstrap(BOOTSTRAP_STATUS_CONN_DIR, 0);
|
|
n_chan = channel_connect_for_circuit(
|
|
&firsthop->extend_info->addr,
|
|
firsthop->extend_info->port,
|
|
firsthop->extend_info->identity_digest);
|
|
if (!n_chan) { /* connect failed, forget the whole thing */
|
|
log_info(LD_CIRC,"connect to firsthop failed. Closing.");
|
|
return -END_CIRC_REASON_CONNECTFAILED;
|
|
}
|
|
}
|
|
|
|
log_debug(LD_CIRC,"connecting in progress (or finished). Good.");
|
|
/* return success. The onion/circuit/etc will be taken care of
|
|
* automatically (may already have been) whenever n_chan reaches
|
|
* OR_CONN_STATE_OPEN.
|
|
*/
|
|
return 0;
|
|
} else { /* it's already open. use it. */
|
|
tor_assert(!circ->base_.n_hop);
|
|
circ->base_.n_chan = n_chan;
|
|
log_debug(LD_CIRC,"Conn open. Delivering first onion skin.");
|
|
if ((err_reason = circuit_send_next_onion_skin(circ)) < 0) {
|
|
log_info(LD_CIRC,"circuit_send_next_onion_skin failed.");
|
|
circ->base_.n_chan = NULL;
|
|
return err_reason;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/** Find any circuits that are waiting on <b>or_conn</b> to become
|
|
* open and get them to send their create cells forward.
|
|
*
|
|
* Status is 1 if connect succeeded, or 0 if connect failed.
|
|
*
|
|
* Close_origin_circuits is 1 if we should close all the origin circuits
|
|
* through this channel, or 0 otherwise. (This happens when we want to retry
|
|
* an older guard.)
|
|
*/
|
|
void
|
|
circuit_n_chan_done(channel_t *chan, int status, int close_origin_circuits)
|
|
{
|
|
smartlist_t *pending_circs;
|
|
int err_reason = 0;
|
|
|
|
tor_assert(chan);
|
|
|
|
log_debug(LD_CIRC,"chan to %s/%s, status=%d",
|
|
chan->nickname ? chan->nickname : "NULL",
|
|
channel_get_canonical_remote_descr(chan), status);
|
|
|
|
pending_circs = smartlist_new();
|
|
circuit_get_all_pending_on_channel(pending_circs, chan);
|
|
|
|
SMARTLIST_FOREACH_BEGIN(pending_circs, circuit_t *, circ)
|
|
{
|
|
/* These checks are redundant wrt get_all_pending_on_or_conn, but I'm
|
|
* leaving them in in case it's possible for the status of a circuit to
|
|
* change as we're going down the list. */
|
|
if (circ->marked_for_close || circ->n_chan || !circ->n_hop ||
|
|
circ->state != CIRCUIT_STATE_CHAN_WAIT)
|
|
continue;
|
|
|
|
if (tor_digest_is_zero(circ->n_hop->identity_digest)) {
|
|
/* Look at addr/port. This is an unkeyed connection. */
|
|
if (!channel_matches_extend_info(chan, circ->n_hop))
|
|
continue;
|
|
} else {
|
|
/* We expected a key. See if it's the right one. */
|
|
if (tor_memneq(chan->identity_digest,
|
|
circ->n_hop->identity_digest, DIGEST_LEN))
|
|
continue;
|
|
}
|
|
if (!status) { /* chan failed; close circ */
|
|
log_info(LD_CIRC,"Channel failed; closing circ.");
|
|
circuit_mark_for_close(circ, END_CIRC_REASON_CHANNEL_CLOSED);
|
|
continue;
|
|
}
|
|
if (close_origin_circuits && CIRCUIT_IS_ORIGIN(circ)) {
|
|
log_info(LD_CIRC,"Channel deprecated for origin circs; closing circ.");
|
|
circuit_mark_for_close(circ, END_CIRC_REASON_CHANNEL_CLOSED);
|
|
continue;
|
|
}
|
|
log_debug(LD_CIRC, "Found circ, sending create cell.");
|
|
/* circuit_deliver_create_cell will set n_circ_id and add us to
|
|
* chan_circuid_circuit_map, so we don't need to call
|
|
* set_circid_chan here. */
|
|
circ->n_chan = chan;
|
|
extend_info_free(circ->n_hop);
|
|
circ->n_hop = NULL;
|
|
|
|
if (CIRCUIT_IS_ORIGIN(circ)) {
|
|
if ((err_reason =
|
|
circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ))) < 0) {
|
|
log_info(LD_CIRC,
|
|
"send_next_onion_skin failed; circuit marked for closing.");
|
|
circuit_mark_for_close(circ, -err_reason);
|
|
continue;
|
|
/* XXX could this be bad, eg if next_onion_skin failed because conn
|
|
* died? */
|
|
}
|
|
} else {
|
|
/* pull the create cell out of circ->n_chan_create_cell, and send it */
|
|
tor_assert(circ->n_chan_create_cell);
|
|
if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell, 1)<0) {
|
|
circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
|
|
continue;
|
|
}
|
|
tor_free(circ->n_chan_create_cell);
|
|
circuit_set_state(circ, CIRCUIT_STATE_OPEN);
|
|
}
|
|
}
|
|
SMARTLIST_FOREACH_END(circ);
|
|
|
|
smartlist_free(pending_circs);
|
|
}
|
|
|
|
/** Find a new circid that isn't currently in use on the circ->n_chan
|
|
* for the outgoing
|
|
* circuit <b>circ</b>, and deliver the cell <b>create_cell</b> to this
|
|
* circuit. If <b>relayed</b> is true, this is a create cell somebody
|
|
* gave us via an EXTEND cell, so we shouldn't worry if we don't understand
|
|
* it. Return -1 if we failed to find a suitable circid, else return 0.
|
|
*/
|
|
static int
|
|
circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell,
|
|
int relayed)
|
|
{
|
|
cell_t cell;
|
|
circid_t id;
|
|
int r;
|
|
|
|
tor_assert(circ);
|
|
tor_assert(circ->n_chan);
|
|
tor_assert(create_cell);
|
|
tor_assert(create_cell->cell_type == CELL_CREATE ||
|
|
create_cell->cell_type == CELL_CREATE_FAST ||
|
|
create_cell->cell_type == CELL_CREATE2);
|
|
|
|
id = get_unique_circ_id_by_chan(circ->n_chan);
|
|
if (!id) {
|
|
static ratelim_t circid_warning_limit = RATELIM_INIT(9600);
|
|
log_fn_ratelim(&circid_warning_limit, LOG_WARN, LD_CIRC,
|
|
"failed to get unique circID.");
|
|
goto error;
|
|
}
|
|
|
|
memset(&cell, 0, sizeof(cell_t));
|
|
r = relayed ? create_cell_format_relayed(&cell, create_cell)
|
|
: create_cell_format(&cell, create_cell);
|
|
if (r < 0) {
|
|
log_warn(LD_CIRC,"Couldn't format create cell");
|
|
goto error;
|
|
}
|
|
log_debug(LD_CIRC,"Chosen circID %u.", (unsigned)id);
|
|
circuit_set_n_circid_chan(circ, id, circ->n_chan);
|
|
cell.circ_id = circ->n_circ_id;
|
|
|
|
append_cell_to_circuit_queue(circ, circ->n_chan, &cell,
|
|
CELL_DIRECTION_OUT, 0);
|
|
|
|
if (CIRCUIT_IS_ORIGIN(circ)) {
|
|
/* Update began timestamp for circuits starting their first hop */
|
|
if (TO_ORIGIN_CIRCUIT(circ)->cpath->state == CPATH_STATE_CLOSED) {
|
|
if (!CHANNEL_IS_OPEN(circ->n_chan)) {
|
|
log_warn(LD_CIRC,
|
|
"Got first hop for a circuit without an opened channel. "
|
|
"State: %s.", channel_state_to_string(circ->n_chan->state));
|
|
tor_fragile_assert();
|
|
}
|
|
|
|
tor_gettimeofday(&circ->timestamp_began);
|
|
}
|
|
|
|
/* mark it so it gets better rate limiting treatment. */
|
|
channel_timestamp_client(circ->n_chan);
|
|
}
|
|
|
|
return 0;
|
|
error:
|
|
circ->n_chan = NULL;
|
|
return -1;
|
|
}
|
|
|
|
/** We've decided to start our reachability testing. If all
|
|
* is set, log this to the user. Return 1 if we did, or 0 if
|
|
* we chose not to log anything. */
|
|
int
|
|
inform_testing_reachability(void)
|
|
{
|
|
char dirbuf[128];
|
|
char *address;
|
|
const routerinfo_t *me = router_get_my_routerinfo();
|
|
if (!me)
|
|
return 0;
|
|
address = tor_dup_ip(me->addr);
|
|
control_event_server_status(LOG_NOTICE,
|
|
"CHECKING_REACHABILITY ORADDRESS=%s:%d",
|
|
address, me->or_port);
|
|
if (me->dir_port) {
|
|
tor_snprintf(dirbuf, sizeof(dirbuf), " and DirPort %s:%d",
|
|
address, me->dir_port);
|
|
control_event_server_status(LOG_NOTICE,
|
|
"CHECKING_REACHABILITY DIRADDRESS=%s:%d",
|
|
address, me->dir_port);
|
|
}
|
|
log_notice(LD_OR, "Now checking whether ORPort %s:%d%s %s reachable... "
|
|
"(this may take up to %d minutes -- look for log "
|
|
"messages indicating success)",
|
|
address, me->or_port,
|
|
me->dir_port ? dirbuf : "",
|
|
me->dir_port ? "are" : "is",
|
|
TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT/60);
|
|
|
|
tor_free(address);
|
|
return 1;
|
|
}
|
|
|
|
/** Return true iff we should send a create_fast cell to start building a given
|
|
* circuit */
|
|
static inline int
|
|
should_use_create_fast_for_circuit(origin_circuit_t *circ)
|
|
{
|
|
const or_options_t *options = get_options();
|
|
tor_assert(circ->cpath);
|
|
tor_assert(circ->cpath->extend_info);
|
|
|
|
if (!circ->cpath->extend_info->onion_key)
|
|
return 1; /* our hand is forced: only a create_fast will work. */
|
|
if (public_server_mode(options)) {
|
|
/* We're a server, and we know an onion key. We can choose.
|
|
* Prefer to blend our circuit into the other circuits we are
|
|
* creating on behalf of others. */
|
|
return 0;
|
|
}
|
|
if (options->FastFirstHopPK == -1) {
|
|
/* option is "auto", so look at the consensus. */
|
|
return networkstatus_get_param(NULL, "usecreatefast", 1, 0, 1);
|
|
}
|
|
|
|
return options->FastFirstHopPK;
|
|
}
|
|
|
|
/** Return true if <b>circ</b> is the type of circuit we want to count
|
|
* timeouts from. In particular, we want it to have not completed yet
|
|
* (already completing indicates we cannibalized it), and we want it to
|
|
* have exactly three hops.
|
|
*/
|
|
int
|
|
circuit_timeout_want_to_count_circ(origin_circuit_t *circ)
|
|
{
|
|
return !circ->has_opened
|
|
&& circ->build_state->desired_path_len == DEFAULT_ROUTE_LEN;
|
|
}
|
|
|
|
/** Return true if the ntor handshake is enabled in the configuration, or if
|
|
* it's been set to "auto" in the configuration and it's enabled in the
|
|
* consensus. */
|
|
static int
|
|
circuits_can_use_ntor(void)
|
|
{
|
|
const or_options_t *options = get_options();
|
|
if (options->UseNTorHandshake != -1)
|
|
return options->UseNTorHandshake;
|
|
return networkstatus_get_param(NULL, "UseNTorHandshake", 0, 0, 1);
|
|
}
|
|
|
|
/** Decide whether to use a TAP or ntor handshake for connecting to <b>ei</b>
|
|
* directly, and set *<b>cell_type_out</b> and *<b>handshake_type_out</b>
|
|
* accordingly. */
|
|
static void
|
|
circuit_pick_create_handshake(uint8_t *cell_type_out,
|
|
uint16_t *handshake_type_out,
|
|
const extend_info_t *ei)
|
|
{
|
|
if (!tor_mem_is_zero((const char*)ei->curve25519_onion_key.public_key,
|
|
CURVE25519_PUBKEY_LEN) &&
|
|
circuits_can_use_ntor()) {
|
|
*cell_type_out = CELL_CREATE2;
|
|
*handshake_type_out = ONION_HANDSHAKE_TYPE_NTOR;
|
|
return;
|
|
}
|
|
|
|
*cell_type_out = CELL_CREATE;
|
|
*handshake_type_out = ONION_HANDSHAKE_TYPE_TAP;
|
|
}
|
|
|
|
/** Decide whether to use a TAP or ntor handshake for connecting to <b>ei</b>
|
|
* directly, and set *<b>handshake_type_out</b> accordingly. Decide whether,
|
|
* in extending through <b>node</b> to do so, we should use an EXTEND2 or an
|
|
* EXTEND cell to do so, and set *<b>cell_type_out</b> and
|
|
* *<b>create_cell_type_out</b> accordingly. */
|
|
static void
|
|
circuit_pick_extend_handshake(uint8_t *cell_type_out,
|
|
uint8_t *create_cell_type_out,
|
|
uint16_t *handshake_type_out,
|
|
const node_t *node_prev,
|
|
const extend_info_t *ei)
|
|
{
|
|
uint8_t t;
|
|
circuit_pick_create_handshake(&t, handshake_type_out, ei);
|
|
/* XXXX024 The check for whether the node has a curve25519 key is a bad
|
|
* proxy for whether it can do extend2 cells; once a version that
|
|
* handles extend2 cells is out, remove it. */
|
|
if (node_prev &&
|
|
*handshake_type_out != ONION_HANDSHAKE_TYPE_TAP &&
|
|
(node_has_curve25519_onion_key(node_prev) ||
|
|
(node_prev->rs && node_prev->rs->version_supports_extend2_cells))) {
|
|
*cell_type_out = RELAY_COMMAND_EXTEND2;
|
|
*create_cell_type_out = CELL_CREATE2;
|
|
} else {
|
|
*cell_type_out = RELAY_COMMAND_EXTEND;
|
|
*create_cell_type_out = CELL_CREATE;
|
|
}
|
|
}
|
|
|
|
/** This is the backbone function for building circuits.
|
|
*
|
|
* If circ's first hop is closed, then we need to build a create
|
|
* cell and send it forward.
|
|
*
|
|
* Otherwise, we need to build a relay extend cell and send it
|
|
* forward.
|
|
*
|
|
* Return -reason if we want to tear down circ, else return 0.
|
|
*/
|
|
int
|
|
circuit_send_next_onion_skin(origin_circuit_t *circ)
|
|
{
|
|
crypt_path_t *hop;
|
|
const node_t *node;
|
|
|
|
tor_assert(circ);
|
|
|
|
if (circ->cpath->state == CPATH_STATE_CLOSED) {
|
|
/* This is the first hop. */
|
|
create_cell_t cc;
|
|
int fast;
|
|
int len;
|
|
log_debug(LD_CIRC,"First skin; sending create cell.");
|
|
memset(&cc, 0, sizeof(cc));
|
|
if (circ->build_state->onehop_tunnel)
|
|
control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE, 0);
|
|
else
|
|
control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE, 0);
|
|
|
|
node = node_get_by_id(circ->base_.n_chan->identity_digest);
|
|
fast = should_use_create_fast_for_circuit(circ);
|
|
if (!fast) {
|
|
/* We are an OR and we know the right onion key: we should
|
|
* send a create cell.
|
|
*/
|
|
circuit_pick_create_handshake(&cc.cell_type, &cc.handshake_type,
|
|
circ->cpath->extend_info);
|
|
note_request("cell: create", 1);
|
|
} else {
|
|
/* We are not an OR, and we're building the first hop of a circuit to a
|
|
* new OR: we can be speedy and use CREATE_FAST to save an RSA operation
|
|
* and a DH operation. */
|
|
cc.cell_type = CELL_CREATE_FAST;
|
|
cc.handshake_type = ONION_HANDSHAKE_TYPE_FAST;
|
|
note_request("cell: create fast", 1);
|
|
}
|
|
|
|
len = onion_skin_create(cc.handshake_type,
|
|
circ->cpath->extend_info,
|
|
&circ->cpath->handshake_state,
|
|
cc.onionskin);
|
|
if (len < 0) {
|
|
log_warn(LD_CIRC,"onion_skin_create (first hop) failed.");
|
|
return - END_CIRC_REASON_INTERNAL;
|
|
}
|
|
cc.handshake_len = len;
|
|
|
|
if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0)
|
|
return - END_CIRC_REASON_RESOURCELIMIT;
|
|
|
|
circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
|
|
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING);
|
|
log_info(LD_CIRC,"First hop: finished sending %s cell to '%s'",
|
|
fast ? "CREATE_FAST" : "CREATE",
|
|
node ? node_describe(node) : "<unnamed>");
|
|
} else {
|
|
extend_cell_t ec;
|
|
int len;
|
|
tor_assert(circ->cpath->state == CPATH_STATE_OPEN);
|
|
tor_assert(circ->base_.state == CIRCUIT_STATE_BUILDING);
|
|
log_debug(LD_CIRC,"starting to send subsequent skin.");
|
|
hop = onion_next_hop_in_cpath(circ->cpath);
|
|
memset(&ec, 0, sizeof(ec));
|
|
if (!hop) {
|
|
/* done building the circuit. whew. */
|
|
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
|
|
if (circuit_timeout_want_to_count_circ(circ)) {
|
|
struct timeval end;
|
|
long timediff;
|
|
tor_gettimeofday(&end);
|
|
timediff = tv_mdiff(&circ->base_.timestamp_began, &end);
|
|
|
|
/*
|
|
* If the circuit build time is much greater than we would have cut
|
|
* it off at, we probably had a suspend event along this codepath,
|
|
* and we should discard the value.
|
|
*/
|
|
if (timediff < 0 ||
|
|
timediff > 2*get_circuit_build_close_time_ms()+1000) {
|
|
log_notice(LD_CIRC, "Strange value for circuit build time: %ldmsec. "
|
|
"Assuming clock jump. Purpose %d (%s)", timediff,
|
|
circ->base_.purpose,
|
|
circuit_purpose_to_string(circ->base_.purpose));
|
|
} else if (!circuit_build_times_disabled()) {
|
|
/* Only count circuit times if the network is live */
|
|
if (circuit_build_times_network_check_live(
|
|
get_circuit_build_times())) {
|
|
circuit_build_times_add_time(get_circuit_build_times_mutable(),
|
|
(build_time_t)timediff);
|
|
circuit_build_times_set_timeout(get_circuit_build_times_mutable());
|
|
}
|
|
|
|
if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
|
|
circuit_build_times_network_circ_success(
|
|
get_circuit_build_times_mutable());
|
|
}
|
|
}
|
|
}
|
|
log_info(LD_CIRC,"circuit built!");
|
|
circuit_reset_failure_count(0);
|
|
|
|
if (circ->build_state->onehop_tunnel || circ->has_opened) {
|
|
control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS, 0);
|
|
}
|
|
|
|
pathbias_count_build_success(circ);
|
|
circuit_rep_hist_note_result(circ);
|
|
circuit_has_opened(circ); /* do other actions as necessary */
|
|
|
|
if (!have_completed_a_circuit() && !circ->build_state->onehop_tunnel) {
|
|
const or_options_t *options = get_options();
|
|
note_that_we_completed_a_circuit();
|
|
/* FFFF Log a count of known routers here */
|
|
log_notice(LD_GENERAL,
|
|
"Tor has successfully opened a circuit. "
|
|
"Looks like client functionality is working.");
|
|
if (control_event_bootstrap(BOOTSTRAP_STATUS_DONE, 0) == 0) {
|
|
log_notice(LD_GENERAL,
|
|
"Tor has successfully opened a circuit. "
|
|
"Looks like client functionality is working.");
|
|
}
|
|
control_event_client_status(LOG_NOTICE, "CIRCUIT_ESTABLISHED");
|
|
clear_broken_connection_map(1);
|
|
if (server_mode(options) && !check_whether_orport_reachable()) {
|
|
inform_testing_reachability();
|
|
consider_testing_reachability(1, 1);
|
|
}
|
|
}
|
|
|
|
/* We're done with measurement circuits here. Just close them */
|
|
if (circ->base_.purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) {
|
|
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
if (tor_addr_family(&hop->extend_info->addr) != AF_INET) {
|
|
log_warn(LD_BUG, "Trying to extend to a non-IPv4 address.");
|
|
return - END_CIRC_REASON_INTERNAL;
|
|
}
|
|
|
|
{
|
|
const node_t *prev_node;
|
|
prev_node = node_get_by_id(hop->prev->extend_info->identity_digest);
|
|
circuit_pick_extend_handshake(&ec.cell_type,
|
|
&ec.create_cell.cell_type,
|
|
&ec.create_cell.handshake_type,
|
|
prev_node,
|
|
hop->extend_info);
|
|
}
|
|
|
|
tor_addr_copy(&ec.orport_ipv4.addr, &hop->extend_info->addr);
|
|
ec.orport_ipv4.port = hop->extend_info->port;
|
|
tor_addr_make_unspec(&ec.orport_ipv6.addr);
|
|
memcpy(ec.node_id, hop->extend_info->identity_digest, DIGEST_LEN);
|
|
|
|
len = onion_skin_create(ec.create_cell.handshake_type,
|
|
hop->extend_info,
|
|
&hop->handshake_state,
|
|
ec.create_cell.onionskin);
|
|
if (len < 0) {
|
|
log_warn(LD_CIRC,"onion_skin_create failed.");
|
|
return - END_CIRC_REASON_INTERNAL;
|
|
}
|
|
ec.create_cell.handshake_len = len;
|
|
|
|
log_info(LD_CIRC,"Sending extend relay cell.");
|
|
note_request("cell: extend", 1);
|
|
{
|
|
uint8_t command = 0;
|
|
uint16_t payload_len=0;
|
|
uint8_t payload[RELAY_PAYLOAD_SIZE];
|
|
if (extend_cell_format(&command, &payload_len, payload, &ec)<0) {
|
|
log_warn(LD_CIRC,"Couldn't format extend cell");
|
|
return -END_CIRC_REASON_INTERNAL;
|
|
}
|
|
|
|
/* send it to hop->prev, because it will transfer
|
|
* it to a create cell and then send to hop */
|
|
if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
|
|
command,
|
|
(char*)payload, payload_len,
|
|
hop->prev) < 0)
|
|
return 0; /* circuit is closed */
|
|
}
|
|
hop->state = CPATH_STATE_AWAITING_KEYS;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/** Our clock just jumped by <b>seconds_elapsed</b>. Assume
|
|
* something has also gone wrong with our network: notify the user,
|
|
* and abandon all not-yet-used circuits. */
|
|
void
|
|
circuit_note_clock_jumped(int seconds_elapsed)
|
|
{
|
|
int severity = server_mode(get_options()) ? LOG_WARN : LOG_NOTICE;
|
|
tor_log(severity, LD_GENERAL, "Your system clock just jumped %d seconds %s; "
|
|
"assuming established circuits no longer work.",
|
|
seconds_elapsed >=0 ? seconds_elapsed : -seconds_elapsed,
|
|
seconds_elapsed >=0 ? "forward" : "backward");
|
|
control_event_general_status(LOG_WARN, "CLOCK_JUMPED TIME=%d",
|
|
seconds_elapsed);
|
|
/* so we log when it works again */
|
|
note_that_we_maybe_cant_complete_circuits();
|
|
control_event_client_status(severity, "CIRCUIT_NOT_ESTABLISHED REASON=%s",
|
|
"CLOCK_JUMPED");
|
|
circuit_mark_all_unused_circs();
|
|
circuit_mark_all_dirty_circs_as_unusable();
|
|
if (seconds_elapsed < 0) {
|
|
/* Restart all the timers in case we jumped a long way into the past. */
|
|
reset_all_main_loop_timers();
|
|
}
|
|
}
|
|
|
|
/** Take the 'extend' <b>cell</b>, pull out addr/port plus the onion
|
|
* skin and identity digest for the next hop. If we're already connected,
|
|
* pass the onion skin to the next hop using a create cell; otherwise
|
|
* launch a new OR connection, and <b>circ</b> will notice when the
|
|
* connection succeeds or fails.
|
|
*
|
|
* Return -1 if we want to warn and tear down the circuit, else return 0.
|
|
*/
|
|
int
|
|
circuit_extend(cell_t *cell, circuit_t *circ)
|
|
{
|
|
channel_t *n_chan;
|
|
relay_header_t rh;
|
|
extend_cell_t ec;
|
|
const char *msg = NULL;
|
|
int should_launch = 0;
|
|
|
|
if (circ->n_chan) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"n_chan already set. Bug/attack. Closing.");
|
|
return -1;
|
|
}
|
|
if (circ->n_hop) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"conn to next hop already launched. Bug/attack. Closing.");
|
|
return -1;
|
|
}
|
|
|
|
if (!server_mode(get_options())) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Got an extend cell, but running as a client. Closing.");
|
|
return -1;
|
|
}
|
|
|
|
relay_header_unpack(&rh, cell->payload);
|
|
|
|
if (extend_cell_parse(&ec, rh.command,
|
|
cell->payload+RELAY_HEADER_SIZE,
|
|
rh.length) < 0) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Can't parse extend cell. Closing circuit.");
|
|
return -1;
|
|
}
|
|
|
|
if (!ec.orport_ipv4.port || tor_addr_is_null(&ec.orport_ipv4.addr)) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Client asked me to extend to zero destination port or addr.");
|
|
return -1;
|
|
}
|
|
|
|
if (tor_addr_is_internal(&ec.orport_ipv4.addr, 0) &&
|
|
!get_options()->ExtendAllowPrivateAddresses) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Client asked me to extend to a private address");
|
|
return -1;
|
|
}
|
|
|
|
/* Check if they asked us for 0000..0000. We support using
|
|
* an empty fingerprint for the first hop (e.g. for a bridge relay),
|
|
* but we don't want to let people send us extend cells for empty
|
|
* fingerprints -- a) because it opens the user up to a mitm attack,
|
|
* and b) because it lets an attacker force the relay to hold open a
|
|
* new TLS connection for each extend request. */
|
|
if (tor_digest_is_zero((const char*)ec.node_id)) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Client asked me to extend without specifying an id_digest.");
|
|
return -1;
|
|
}
|
|
|
|
/* Next, check if we're being asked to connect to the hop that the
|
|
* extend cell came from. There isn't any reason for that, and it can
|
|
* assist circular-path attacks. */
|
|
if (tor_memeq(ec.node_id,
|
|
TO_OR_CIRCUIT(circ)->p_chan->identity_digest,
|
|
DIGEST_LEN)) {
|
|
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
|
|
"Client asked me to extend back to the previous hop.");
|
|
return -1;
|
|
}
|
|
|
|
n_chan = channel_get_for_extend((const char*)ec.node_id,
|
|
&ec.orport_ipv4.addr,
|
|
&msg,
|
|
&should_launch);
|
|
|
|
if (!n_chan) {
|
|
log_debug(LD_CIRC|LD_OR,"Next router (%s): %s",
|
|
fmt_addrport(&ec.orport_ipv4.addr,ec.orport_ipv4.port),
|
|
msg?msg:"????");
|
|
|
|
circ->n_hop = extend_info_new(NULL /*nickname*/,
|
|
(const char*)ec.node_id,
|
|
NULL /*onion_key*/,
|
|
NULL /*curve25519_key*/,
|
|
&ec.orport_ipv4.addr,
|
|
ec.orport_ipv4.port);
|
|
|
|
circ->n_chan_create_cell = tor_memdup(&ec.create_cell,
|
|
sizeof(ec.create_cell));
|
|
|
|
circuit_set_state(circ, CIRCUIT_STATE_CHAN_WAIT);
|
|
|
|
if (should_launch) {
|
|
/* we should try to open a connection */
|
|
n_chan = channel_connect_for_circuit(&ec.orport_ipv4.addr,
|
|
ec.orport_ipv4.port,
|
|
(const char*)ec.node_id);
|
|
if (!n_chan) {
|
|
log_info(LD_CIRC,"Launching n_chan failed. Closing circuit.");
|
|
circuit_mark_for_close(circ, END_CIRC_REASON_CONNECTFAILED);
|
|
return 0;
|
|
}
|
|
log_debug(LD_CIRC,"connecting in progress (or finished). Good.");
|
|
}
|
|
/* return success. The onion/circuit/etc will be taken care of
|
|
* automatically (may already have been) whenever n_chan reaches
|
|
* OR_CONN_STATE_OPEN.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
tor_assert(!circ->n_hop); /* Connection is already established. */
|
|
circ->n_chan = n_chan;
|
|
log_debug(LD_CIRC,
|
|
"n_chan is %s",
|
|
channel_get_canonical_remote_descr(n_chan));
|
|
|
|
if (circuit_deliver_create_cell(circ, &ec.create_cell, 1) < 0)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in
|
|
* key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are
|
|
* used as follows:
|
|
* - 20 to initialize f_digest
|
|
* - 20 to initialize b_digest
|
|
* - 16 to key f_crypto
|
|
* - 16 to key b_crypto
|
|
*
|
|
* (If 'reverse' is true, then f_XX and b_XX are swapped.)
|
|
*/
|
|
int
|
|
circuit_init_cpath_crypto(crypt_path_t *cpath, const char *key_data,
|
|
int reverse)
|
|
{
|
|
crypto_digest_t *tmp_digest;
|
|
crypto_cipher_t *tmp_crypto;
|
|
|
|
tor_assert(cpath);
|
|
tor_assert(key_data);
|
|
tor_assert(!(cpath->f_crypto || cpath->b_crypto ||
|
|
cpath->f_digest || cpath->b_digest));
|
|
|
|
cpath->f_digest = crypto_digest_new();
|
|
crypto_digest_add_bytes(cpath->f_digest, key_data, DIGEST_LEN);
|
|
cpath->b_digest = crypto_digest_new();
|
|
crypto_digest_add_bytes(cpath->b_digest, key_data+DIGEST_LEN, DIGEST_LEN);
|
|
|
|
if (!(cpath->f_crypto =
|
|
crypto_cipher_new(key_data+(2*DIGEST_LEN)))) {
|
|
log_warn(LD_BUG,"Forward cipher initialization failed.");
|
|
return -1;
|
|
}
|
|
if (!(cpath->b_crypto =
|
|
crypto_cipher_new(key_data+(2*DIGEST_LEN)+CIPHER_KEY_LEN))) {
|
|
log_warn(LD_BUG,"Backward cipher initialization failed.");
|
|
return -1;
|
|
}
|
|
|
|
if (reverse) {
|
|
tmp_digest = cpath->f_digest;
|
|
cpath->f_digest = cpath->b_digest;
|
|
cpath->b_digest = tmp_digest;
|
|
tmp_crypto = cpath->f_crypto;
|
|
cpath->f_crypto = cpath->b_crypto;
|
|
cpath->b_crypto = tmp_crypto;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** A "created" cell <b>reply</b> came back to us on circuit <b>circ</b>.
|
|
* (The body of <b>reply</b> varies depending on what sort of handshake
|
|
* this is.)
|
|
*
|
|
* Calculate the appropriate keys and digests, make sure KH is
|
|
* correct, and initialize this hop of the cpath.
|
|
*
|
|
* Return - reason if we want to mark circ for close, else return 0.
|
|
*/
|
|
int
|
|
circuit_finish_handshake(origin_circuit_t *circ,
|
|
const created_cell_t *reply)
|
|
{
|
|
char keys[CPATH_KEY_MATERIAL_LEN];
|
|
crypt_path_t *hop;
|
|
int rv;
|
|
|
|
if ((rv = pathbias_count_build_attempt(circ)) < 0) {
|
|
log_warn(LD_CIRC, "pathbias_count_build_attempt failed: %d", rv);
|
|
return rv;
|
|
}
|
|
|
|
if (circ->cpath->state == CPATH_STATE_AWAITING_KEYS) {
|
|
hop = circ->cpath;
|
|
} else {
|
|
hop = onion_next_hop_in_cpath(circ->cpath);
|
|
if (!hop) { /* got an extended when we're all done? */
|
|
log_warn(LD_PROTOCOL,"got extended when circ already built? Closing.");
|
|
return - END_CIRC_REASON_TORPROTOCOL;
|
|
}
|
|
}
|
|
tor_assert(hop->state == CPATH_STATE_AWAITING_KEYS);
|
|
|
|
{
|
|
const char *msg = NULL;
|
|
if (onion_skin_client_handshake(hop->handshake_state.tag,
|
|
&hop->handshake_state,
|
|
reply->reply, reply->handshake_len,
|
|
(uint8_t*)keys, sizeof(keys),
|
|
(uint8_t*)hop->rend_circ_nonce,
|
|
&msg) < 0) {
|
|
if (msg)
|
|
log_warn(LD_CIRC,"onion_skin_client_handshake failed: %s", msg);
|
|
return -END_CIRC_REASON_TORPROTOCOL;
|
|
}
|
|
}
|
|
|
|
onion_handshake_state_release(&hop->handshake_state);
|
|
|
|
if (circuit_init_cpath_crypto(hop, keys, 0)<0) {
|
|
return -END_CIRC_REASON_TORPROTOCOL;
|
|
}
|
|
|
|
hop->state = CPATH_STATE_OPEN;
|
|
log_info(LD_CIRC,"Finished building circuit hop:");
|
|
circuit_log_path(LOG_INFO,LD_CIRC,circ);
|
|
control_event_circuit_status(circ, CIRC_EVENT_EXTENDED, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** We received a relay truncated cell on circ.
|
|
*
|
|
* Since we don't send truncates currently, getting a truncated
|
|
* means that a connection broke or an extend failed. For now,
|
|
* just give up: force circ to close, and return 0.
|
|
*/
|
|
int
|
|
circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer, int reason)
|
|
{
|
|
// crypt_path_t *victim;
|
|
// connection_t *stream;
|
|
|
|
tor_assert(circ);
|
|
tor_assert(layer);
|
|
|
|
/* XXX Since we don't send truncates currently, getting a truncated
|
|
* means that a connection broke or an extend failed. For now,
|
|
* just give up.
|
|
*/
|
|
circuit_mark_for_close(TO_CIRCUIT(circ),
|
|
END_CIRC_REASON_FLAG_REMOTE|reason);
|
|
return 0;
|
|
|
|
#if 0
|
|
while (layer->next != circ->cpath) {
|
|
/* we need to clear out layer->next */
|
|
victim = layer->next;
|
|
log_debug(LD_CIRC, "Killing a layer of the cpath.");
|
|
|
|
for (stream = circ->p_streams; stream; stream=stream->next_stream) {
|
|
if (stream->cpath_layer == victim) {
|
|
log_info(LD_APP, "Marking stream %d for close because of truncate.",
|
|
stream->stream_id);
|
|
/* no need to send 'end' relay cells,
|
|
* because the other side's already dead
|
|
*/
|
|
connection_mark_unattached_ap(stream, END_STREAM_REASON_DESTROY);
|
|
}
|
|
}
|
|
|
|
layer->next = victim->next;
|
|
circuit_free_cpath_node(victim);
|
|
}
|
|
|
|
log_info(LD_CIRC, "finished");
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/** Given a response payload and keys, initialize, then send a created
|
|
* cell back.
|
|
*/
|
|
int
|
|
onionskin_answer(or_circuit_t *circ,
|
|
const created_cell_t *created_cell,
|
|
const char *keys,
|
|
const uint8_t *rend_circ_nonce)
|
|
{
|
|
cell_t cell;
|
|
crypt_path_t *tmp_cpath;
|
|
|
|
if (created_cell_format(&cell, created_cell) < 0) {
|
|
log_warn(LD_BUG,"couldn't format created cell (type=%d, len=%d)",
|
|
(int)created_cell->cell_type, (int)created_cell->handshake_len);
|
|
return -1;
|
|
}
|
|
cell.circ_id = circ->p_circ_id;
|
|
|
|
tmp_cpath = tor_malloc_zero(sizeof(crypt_path_t));
|
|
tmp_cpath->magic = CRYPT_PATH_MAGIC;
|
|
|
|
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN);
|
|
|
|
log_debug(LD_CIRC,"init digest forward 0x%.8x, backward 0x%.8x.",
|
|
(unsigned int)get_uint32(keys),
|
|
(unsigned int)get_uint32(keys+20));
|
|
if (circuit_init_cpath_crypto(tmp_cpath, keys, 0)<0) {
|
|
log_warn(LD_BUG,"Circuit initialization failed");
|
|
tor_free(tmp_cpath);
|
|
return -1;
|
|
}
|
|
circ->n_digest = tmp_cpath->f_digest;
|
|
circ->n_crypto = tmp_cpath->f_crypto;
|
|
circ->p_digest = tmp_cpath->b_digest;
|
|
circ->p_crypto = tmp_cpath->b_crypto;
|
|
tmp_cpath->magic = 0;
|
|
tor_free(tmp_cpath);
|
|
|
|
memcpy(circ->rend_circ_nonce, rend_circ_nonce, DIGEST_LEN);
|
|
|
|
circ->is_first_hop = (created_cell->cell_type == CELL_CREATED_FAST);
|
|
|
|
append_cell_to_circuit_queue(TO_CIRCUIT(circ),
|
|
circ->p_chan, &cell, CELL_DIRECTION_IN, 0);
|
|
log_debug(LD_CIRC,"Finished sending '%s' cell.",
|
|
circ->is_first_hop ? "created_fast" : "created");
|
|
|
|
/* Ignore the local bit when ExtendAllowPrivateAddresses is set:
|
|
* it violates the assumption that private addresses are local.
|
|
* Also, many test networks run on local addresses, and
|
|
* TestingTorNetwork sets ExtendAllowPrivateAddresses. */
|
|
if ((!channel_is_local(circ->p_chan)
|
|
|| get_options()->ExtendAllowPrivateAddresses)
|
|
&& !channel_is_outgoing(circ->p_chan)) {
|
|
/* record that we could process create cells from a non-local conn
|
|
* that we didn't initiate; presumably this means that create cells
|
|
* can reach us too. */
|
|
router_orport_found_reachable();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** Choose a length for a circuit of purpose <b>purpose</b>: three + the
|
|
* number of endpoints that would give something away about our destination.
|
|
*
|
|
* If the routerlist <b>nodes</b> doesn't have enough routers
|
|
* to handle the desired path length, return -1.
|
|
*/
|
|
static int
|
|
new_route_len(uint8_t purpose, extend_info_t *exit, smartlist_t *nodes)
|
|
{
|
|
int num_acceptable_routers;
|
|
int routelen;
|
|
|
|
tor_assert(nodes);
|
|
|
|
routelen = DEFAULT_ROUTE_LEN;
|
|
if (exit &&
|
|
purpose != CIRCUIT_PURPOSE_TESTING &&
|
|
purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)
|
|
routelen++;
|
|
|
|
num_acceptable_routers = count_acceptable_nodes(nodes);
|
|
|
|
log_debug(LD_CIRC,"Chosen route length %d (%d/%d routers suitable).",
|
|
routelen, num_acceptable_routers, smartlist_len(nodes));
|
|
|
|
if (num_acceptable_routers < routelen) {
|
|
log_info(LD_CIRC,
|
|
"Not enough acceptable routers (%d/%d). Discarding this circuit.",
|
|
num_acceptable_routers, routelen);
|
|
return -1;
|
|
}
|
|
|
|
return routelen;
|
|
}
|
|
|
|
/** Return a newly allocated list of uint16_t * for each predicted port not
|
|
* handled by a current circuit. */
|
|
static smartlist_t *
|
|
circuit_get_unhandled_ports(time_t now)
|
|
{
|
|
smartlist_t *dest = rep_hist_get_predicted_ports(now);
|
|
circuit_remove_handled_ports(dest);
|
|
return dest;
|
|
}
|
|
|
|
/** Return 1 if we already have circuits present or on the way for
|
|
* all anticipated ports. Return 0 if we should make more.
|
|
*
|
|
* If we're returning 0, set need_uptime and need_capacity to
|
|
* indicate any requirements that the unhandled ports have.
|
|
*/
|
|
int
|
|
circuit_all_predicted_ports_handled(time_t now, int *need_uptime,
|
|
int *need_capacity)
|
|
{
|
|
int i, enough;
|
|
uint16_t *port;
|
|
smartlist_t *sl = circuit_get_unhandled_ports(now);
|
|
smartlist_t *LongLivedServices = get_options()->LongLivedPorts;
|
|
tor_assert(need_uptime);
|
|
tor_assert(need_capacity);
|
|
// Always predict need_capacity
|
|
*need_capacity = 1;
|
|
enough = (smartlist_len(sl) == 0);
|
|
for (i = 0; i < smartlist_len(sl); ++i) {
|
|
port = smartlist_get(sl, i);
|
|
if (smartlist_contains_int_as_string(LongLivedServices, *port))
|
|
*need_uptime = 1;
|
|
tor_free(port);
|
|
}
|
|
smartlist_free(sl);
|
|
return enough;
|
|
}
|
|
|
|
/** Return 1 if <b>node</b> can handle one or more of the ports in
|
|
* <b>needed_ports</b>, else return 0.
|
|
*/
|
|
static int
|
|
node_handles_some_port(const node_t *node, smartlist_t *needed_ports)
|
|
{ /* XXXX MOVE */
|
|
int i;
|
|
uint16_t port;
|
|
|
|
for (i = 0; i < smartlist_len(needed_ports); ++i) {
|
|
addr_policy_result_t r;
|
|
/* alignment issues aren't a worry for this dereference, since
|
|
needed_ports is explicitly a smartlist of uint16_t's */
|
|
port = *(uint16_t *)smartlist_get(needed_ports, i);
|
|
tor_assert(port);
|
|
if (node)
|
|
r = compare_tor_addr_to_node_policy(NULL, port, node);
|
|
else
|
|
continue;
|
|
if (r != ADDR_POLICY_REJECTED && r != ADDR_POLICY_PROBABLY_REJECTED)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/** Return true iff <b>conn</b> needs another general circuit to be
|
|
* built. */
|
|
static int
|
|
ap_stream_wants_exit_attention(connection_t *conn)
|
|
{
|
|
entry_connection_t *entry;
|
|
if (conn->type != CONN_TYPE_AP)
|
|
return 0;
|
|
entry = TO_ENTRY_CONN(conn);
|
|
|
|
if (conn->state == AP_CONN_STATE_CIRCUIT_WAIT &&
|
|
!conn->marked_for_close &&
|
|
!(entry->want_onehop) && /* ignore one-hop streams */
|
|
!(entry->use_begindir) && /* ignore targeted dir fetches */
|
|
!(entry->chosen_exit_name) && /* ignore defined streams */
|
|
!connection_edge_is_rendezvous_stream(TO_EDGE_CONN(conn)) &&
|
|
!circuit_stream_is_being_handled(TO_ENTRY_CONN(conn), 0,
|
|
MIN_CIRCUITS_HANDLING_STREAM))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/** Return a pointer to a suitable router to be the exit node for the
|
|
* general-purpose circuit we're about to build.
|
|
*
|
|
* Look through the connection array, and choose a router that maximizes
|
|
* the number of pending streams that can exit from this router.
|
|
*
|
|
* Return NULL if we can't find any suitable routers.
|
|
*/
|
|
static const node_t *
|
|
choose_good_exit_server_general(int need_uptime, int need_capacity)
|
|
{
|
|
int *n_supported;
|
|
int n_pending_connections = 0;
|
|
smartlist_t *connections;
|
|
int best_support = -1;
|
|
int n_best_support=0;
|
|
const or_options_t *options = get_options();
|
|
const smartlist_t *the_nodes;
|
|
const node_t *node=NULL;
|
|
|
|
connections = get_connection_array();
|
|
|
|
/* Count how many connections are waiting for a circuit to be built.
|
|
* We use this for log messages now, but in the future we may depend on it.
|
|
*/
|
|
SMARTLIST_FOREACH(connections, connection_t *, conn,
|
|
{
|
|
if (ap_stream_wants_exit_attention(conn))
|
|
++n_pending_connections;
|
|
});
|
|
// log_fn(LOG_DEBUG, "Choosing exit node; %d connections are pending",
|
|
// n_pending_connections);
|
|
/* Now we count, for each of the routers in the directory, how many
|
|
* of the pending connections could possibly exit from that
|
|
* router (n_supported[i]). (We can't be sure about cases where we
|
|
* don't know the IP address of the pending connection.)
|
|
*
|
|
* -1 means "Don't use this router at all."
|
|
*/
|
|
the_nodes = nodelist_get_list();
|
|
n_supported = tor_calloc(smartlist_len(the_nodes), sizeof(int));
|
|
SMARTLIST_FOREACH_BEGIN(the_nodes, const node_t *, node) {
|
|
const int i = node_sl_idx;
|
|
if (router_digest_is_me(node->identity)) {
|
|
n_supported[i] = -1;
|
|
// log_fn(LOG_DEBUG,"Skipping node %s -- it's me.", router->nickname);
|
|
/* XXX there's probably a reverse predecessor attack here, but
|
|
* it's slow. should we take this out? -RD
|
|
*/
|
|
continue;
|
|
}
|
|
if (!node_has_descriptor(node)) {
|
|
n_supported[i] = -1;
|
|
continue;
|
|
}
|
|
if (!node->is_running || node->is_bad_exit) {
|
|
n_supported[i] = -1;
|
|
continue; /* skip routers that are known to be down or bad exits */
|
|
}
|
|
if (node_get_purpose(node) != ROUTER_PURPOSE_GENERAL) {
|
|
/* never pick a non-general node as a random exit. */
|
|
n_supported[i] = -1;
|
|
continue;
|
|
}
|
|
if (routerset_contains_node(options->ExcludeExitNodesUnion_, node)) {
|
|
n_supported[i] = -1;
|
|
continue; /* user asked us not to use it, no matter what */
|
|
}
|
|
if (options->ExitNodes &&
|
|
!routerset_contains_node(options->ExitNodes, node)) {
|
|
n_supported[i] = -1;
|
|
continue; /* not one of our chosen exit nodes */
|
|
}
|
|
|
|
if (node_is_unreliable(node, need_uptime, need_capacity, 0)) {
|
|
n_supported[i] = -1;
|
|
continue; /* skip routers that are not suitable. Don't worry if
|
|
* this makes us reject all the possible routers: if so,
|
|
* we'll retry later in this function with need_update and
|
|
* need_capacity set to 0. */
|
|
}
|
|
if (!(node->is_valid || options->AllowInvalid_ & ALLOW_INVALID_EXIT)) {
|
|
/* if it's invalid and we don't want it */
|
|
n_supported[i] = -1;
|
|
// log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- invalid router.",
|
|
// router->nickname, i);
|
|
continue; /* skip invalid routers */
|
|
}
|
|
if (options->ExcludeSingleHopRelays &&
|
|
node_allows_single_hop_exits(node)) {
|
|
n_supported[i] = -1;
|
|
continue;
|
|
}
|
|
if (node_exit_policy_rejects_all(node)) {
|
|
n_supported[i] = -1;
|
|
// log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- it rejects all.",
|
|
// router->nickname, i);
|
|
continue; /* skip routers that reject all */
|
|
}
|
|
n_supported[i] = 0;
|
|
/* iterate over connections */
|
|
SMARTLIST_FOREACH_BEGIN(connections, connection_t *, conn) {
|
|
if (!ap_stream_wants_exit_attention(conn))
|
|
continue; /* Skip everything but APs in CIRCUIT_WAIT */
|
|
if (connection_ap_can_use_exit(TO_ENTRY_CONN(conn), node)) {
|
|
++n_supported[i];
|
|
// log_fn(LOG_DEBUG,"%s is supported. n_supported[%d] now %d.",
|
|
// router->nickname, i, n_supported[i]);
|
|
} else {
|
|
// log_fn(LOG_DEBUG,"%s (index %d) would reject this stream.",
|
|
// router->nickname, i);
|
|
}
|
|
} SMARTLIST_FOREACH_END(conn);
|
|
if (n_pending_connections > 0 && n_supported[i] == 0) {
|
|
/* Leave best_support at -1 if that's where it is, so we can
|
|
* distinguish it later. */
|
|
continue;
|
|
}
|
|
if (n_supported[i] > best_support) {
|
|
/* If this router is better than previous ones, remember its index
|
|
* and goodness, and start counting how many routers are this good. */
|
|
best_support = n_supported[i]; n_best_support=1;
|
|
// log_fn(LOG_DEBUG,"%s is new best supported option so far.",
|
|
// router->nickname);
|
|
} else if (n_supported[i] == best_support) {
|
|
/* If this router is _as good_ as the best one, just increment the
|
|
* count of equally good routers.*/
|
|
++n_best_support;
|
|
}
|
|
} SMARTLIST_FOREACH_END(node);
|
|
log_info(LD_CIRC,
|
|
"Found %d servers that might support %d/%d pending connections.",
|
|
n_best_support, best_support >= 0 ? best_support : 0,
|
|
n_pending_connections);
|
|
|
|
/* If any routers definitely support any pending connections, choose one
|
|
* at random. */
|
|
if (best_support > 0) {
|
|
smartlist_t *supporting = smartlist_new();
|
|
|
|
SMARTLIST_FOREACH(the_nodes, const node_t *, node, {
|
|
if (n_supported[node_sl_idx] == best_support)
|
|
smartlist_add(supporting, (void*)node);
|
|
});
|
|
|
|
node = node_sl_choose_by_bandwidth(supporting, WEIGHT_FOR_EXIT);
|
|
smartlist_free(supporting);
|
|
} else {
|
|
/* Either there are no pending connections, or no routers even seem to
|
|
* possibly support any of them. Choose a router at random that satisfies
|
|
* at least one predicted exit port. */
|
|
|
|
int attempt;
|
|
smartlist_t *needed_ports, *supporting;
|
|
|
|
if (best_support == -1) {
|
|
if (need_uptime || need_capacity) {
|
|
log_info(LD_CIRC,
|
|
"We couldn't find any live%s%s routers; falling back "
|
|
"to list of all routers.",
|
|
need_capacity?", fast":"",
|
|
need_uptime?", stable":"");
|
|
tor_free(n_supported);
|
|
return choose_good_exit_server_general(0, 0);
|
|
}
|
|
log_notice(LD_CIRC, "All routers are down or won't exit%s -- "
|
|
"choosing a doomed exit at random.",
|
|
options->ExcludeExitNodesUnion_ ? " or are Excluded" : "");
|
|
}
|
|
supporting = smartlist_new();
|
|
needed_ports = circuit_get_unhandled_ports(time(NULL));
|
|
for (attempt = 0; attempt < 2; attempt++) {
|
|
/* try once to pick only from routers that satisfy a needed port,
|
|
* then if there are none, pick from any that support exiting. */
|
|
SMARTLIST_FOREACH_BEGIN(the_nodes, const node_t *, node) {
|
|
if (n_supported[node_sl_idx] != -1 &&
|
|
(attempt || node_handles_some_port(node, needed_ports))) {
|
|
// log_fn(LOG_DEBUG,"Try %d: '%s' is a possibility.",
|
|
// try, router->nickname);
|
|
smartlist_add(supporting, (void*)node);
|
|
}
|
|
} SMARTLIST_FOREACH_END(node);
|
|
|
|
node = node_sl_choose_by_bandwidth(supporting, WEIGHT_FOR_EXIT);
|
|
if (node)
|
|
break;
|
|
smartlist_clear(supporting);
|
|
/* If we reach this point, we can't actually support any unhandled
|
|
* predicted ports, so clear all the remaining ones. */
|
|
if (smartlist_len(needed_ports))
|
|
rep_hist_remove_predicted_ports(needed_ports);
|
|
}
|
|
SMARTLIST_FOREACH(needed_ports, uint16_t *, cp, tor_free(cp));
|
|
smartlist_free(needed_ports);
|
|
smartlist_free(supporting);
|
|
}
|
|
|
|
tor_free(n_supported);
|
|
if (node) {
|
|
log_info(LD_CIRC, "Chose exit server '%s'", node_describe(node));
|
|
return node;
|
|
}
|
|
if (options->ExitNodes) {
|
|
log_warn(LD_CIRC,
|
|
"No specified %sexit routers seem to be running: "
|
|
"can't choose an exit.",
|
|
options->ExcludeExitNodesUnion_ ? "non-excluded " : "");
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#if defined(ENABLE_TOR2WEB_MODE) || defined(TOR_UNIT_TESTS)
|
|
/* The config option Tor2webRendezvousPoints has been set and we need
|
|
* to pick an RP out of that set. Make sure that the RP we choose is
|
|
* alive, and return it. Return NULL if no usable RP could be found in
|
|
* Tor2webRendezvousPoints. */
|
|
STATIC const node_t *
|
|
pick_tor2web_rendezvous_node(router_crn_flags_t flags,
|
|
const or_options_t *options)
|
|
{
|
|
const node_t *rp_node = NULL;
|
|
const int allow_invalid = (flags & CRN_ALLOW_INVALID) != 0;
|
|
const int need_desc = (flags & CRN_NEED_DESC) != 0;
|
|
|
|
smartlist_t *whitelisted_live_rps = smartlist_new();
|
|
smartlist_t *all_live_nodes = smartlist_new();
|
|
|
|
tor_assert(options->Tor2webRendezvousPoints);
|
|
|
|
/* Add all running nodes to all_live_nodes */
|
|
router_add_running_nodes_to_smartlist(all_live_nodes,
|
|
allow_invalid,
|
|
0, 0, 0,
|
|
need_desc, 0);
|
|
|
|
/* Filter all_live_nodes to only add live *and* whitelisted RPs to
|
|
* the list whitelisted_live_rps. */
|
|
SMARTLIST_FOREACH_BEGIN(all_live_nodes, node_t *, live_node) {
|
|
if (routerset_contains_node(options->Tor2webRendezvousPoints, live_node)) {
|
|
smartlist_add(whitelisted_live_rps, live_node);
|
|
}
|
|
} SMARTLIST_FOREACH_END(live_node);
|
|
|
|
/* Honor ExcludeNodes */
|
|
if (options->ExcludeNodes) {
|
|
routerset_subtract_nodes(whitelisted_live_rps, options->ExcludeNodes);
|
|
}
|
|
|
|
/* Now pick randomly amongst the whitelisted RPs. No need to waste time
|
|
doing bandwidth load balancing, for most use cases
|
|
'whitelisted_live_rps' contains a single OR anyway. */
|
|
rp_node = smartlist_choose(whitelisted_live_rps);
|
|
|
|
if (!rp_node) {
|
|
log_warn(LD_REND, "Could not find a Rendezvous Point that suits "
|
|
"the purposes of Tor2webRendezvousPoints. Choosing random one.");
|
|
}
|
|
|
|
smartlist_free(whitelisted_live_rps);
|
|
smartlist_free(all_live_nodes);
|
|
|
|
return rp_node;
|
|
}
|
|
#endif
|
|
|
|
/* Pick a Rendezvous Point for our HS circuits according to <b>flags</b>. */
|
|
static const node_t *
|
|
pick_rendezvous_node(router_crn_flags_t flags)
|
|
{
|
|
const or_options_t *options = get_options();
|
|
|
|
if (options->AllowInvalid_ & ALLOW_INVALID_RENDEZVOUS)
|
|
flags |= CRN_ALLOW_INVALID;
|
|
|
|
#ifdef ENABLE_TOR2WEB_MODE
|
|
/* The user wants us to pick specific RPs. */
|
|
if (options->Tor2webRendezvousPoints) {
|
|
const node_t *tor2web_rp = pick_tor2web_rendezvous_node(flags, options);
|
|
if (tor2web_rp) {
|
|
return tor2web_rp;
|
|
}
|
|
/* Else, if no tor2web RP was found, fall back to choosing a random node */
|
|
}
|
|
#endif
|
|
|
|
return router_choose_random_node(NULL, options->ExcludeNodes, flags);
|
|
}
|
|
|
|
/** Return a pointer to a suitable router to be the exit node for the
|
|
* circuit of purpose <b>purpose</b> that we're about to build (or NULL
|
|
* if no router is suitable).
|
|
*
|
|
* For general-purpose circuits, pass it off to
|
|
* choose_good_exit_server_general()
|
|
*
|
|
* For client-side rendezvous circuits, choose a random node, weighted
|
|
* toward the preferences in 'options'.
|
|
*/
|
|
static const node_t *
|
|
choose_good_exit_server(uint8_t purpose,
|
|
int need_uptime, int need_capacity, int is_internal)
|
|
{
|
|
const or_options_t *options = get_options();
|
|
router_crn_flags_t flags = CRN_NEED_DESC;
|
|
if (need_uptime)
|
|
flags |= CRN_NEED_UPTIME;
|
|
if (need_capacity)
|
|
flags |= CRN_NEED_CAPACITY;
|
|
|
|
switch (purpose) {
|
|
case CIRCUIT_PURPOSE_C_GENERAL:
|
|
if (options->AllowInvalid_ & ALLOW_INVALID_MIDDLE)
|
|
flags |= CRN_ALLOW_INVALID;
|
|
if (is_internal) /* pick it like a middle hop */
|
|
return router_choose_random_node(NULL, options->ExcludeNodes, flags);
|
|
else
|
|
return choose_good_exit_server_general(need_uptime,need_capacity);
|
|
case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
|
|
{
|
|
/* Pick a new RP */
|
|
const node_t *rendezvous_node = pick_rendezvous_node(flags);
|
|
log_info(LD_REND, "Picked new RP: %s",
|
|
safe_str_client(node_describe(rendezvous_node)));
|
|
return rendezvous_node;
|
|
}
|
|
}
|
|
log_warn(LD_BUG,"Unhandled purpose %d", purpose);
|
|
tor_fragile_assert();
|
|
return NULL;
|
|
}
|
|
|
|
/** Log a warning if the user specified an exit for the circuit that
|
|
* has been excluded from use by ExcludeNodes or ExcludeExitNodes. */
|
|
static void
|
|
warn_if_last_router_excluded(origin_circuit_t *circ, const extend_info_t *exit)
|
|
{
|
|
const or_options_t *options = get_options();
|
|
routerset_t *rs = options->ExcludeNodes;
|
|
const char *description;
|
|
uint8_t purpose = circ->base_.purpose;
|
|
|
|
if (circ->build_state->onehop_tunnel)
|
|
return;
|
|
|
|
switch (purpose)
|
|
{
|
|
default:
|
|
case CIRCUIT_PURPOSE_OR:
|
|
case CIRCUIT_PURPOSE_INTRO_POINT:
|
|
case CIRCUIT_PURPOSE_REND_POINT_WAITING:
|
|
case CIRCUIT_PURPOSE_REND_ESTABLISHED:
|
|
log_warn(LD_BUG, "Called on non-origin circuit (purpose %d, %s)",
|
|
(int)purpose,
|
|
circuit_purpose_to_string(purpose));
|
|
return;
|
|
case CIRCUIT_PURPOSE_C_GENERAL:
|
|
if (circ->build_state->is_internal)
|
|
return;
|
|
description = "requested exit node";
|
|
rs = options->ExcludeExitNodesUnion_;
|
|
break;
|
|
case CIRCUIT_PURPOSE_C_INTRODUCING:
|
|
case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
|
|
case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
|
|
case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
|
|
case CIRCUIT_PURPOSE_S_CONNECT_REND:
|
|
case CIRCUIT_PURPOSE_S_REND_JOINED:
|
|
case CIRCUIT_PURPOSE_TESTING:
|
|
return;
|
|
case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
|
|
case CIRCUIT_PURPOSE_C_REND_READY:
|
|
case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
|
|
case CIRCUIT_PURPOSE_C_REND_JOINED:
|
|
description = "chosen rendezvous point";
|
|
break;
|
|
case CIRCUIT_PURPOSE_CONTROLLER:
|
|
rs = options->ExcludeExitNodesUnion_;
|
|
description = "controller-selected circuit target";
|
|
break;
|
|
}
|
|
|
|
if (routerset_contains_extendinfo(rs, exit)) {
|
|
/* We should never get here if StrictNodes is set to 1. */
|
|
if (options->StrictNodes) {
|
|
log_warn(LD_BUG, "Using %s '%s' which is listed in ExcludeNodes%s, "
|
|
"even though StrictNodes is set. Please report. "
|
|
"(Circuit purpose: %s)",
|
|
description, extend_info_describe(exit),
|
|
rs==options->ExcludeNodes?"":" or ExcludeExitNodes",
|
|
circuit_purpose_to_string(purpose));
|
|
} else {
|
|
log_warn(LD_CIRC, "Using %s '%s' which is listed in "
|
|
"ExcludeNodes%s, because no better options were available. To "
|
|
"prevent this (and possibly break your Tor functionality), "
|
|
"set the StrictNodes configuration option. "
|
|
"(Circuit purpose: %s)",
|
|
description, extend_info_describe(exit),
|
|
rs==options->ExcludeNodes?"":" or ExcludeExitNodes",
|
|
circuit_purpose_to_string(purpose));
|
|
}
|
|
circuit_log_path(LOG_WARN, LD_CIRC, circ);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/** Decide a suitable length for circ's cpath, and pick an exit
|
|
* router (or use <b>exit</b> if provided). Store these in the
|
|
* cpath. Return 0 if ok, -1 if circuit should be closed. */
|
|
static int
|
|
onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit)
|
|
{
|
|
cpath_build_state_t *state = circ->build_state;
|
|
|
|
if (state->onehop_tunnel) {
|
|
log_debug(LD_CIRC, "Launching a one-hop circuit for dir tunnel.");
|
|
state->desired_path_len = 1;
|
|
} else {
|
|
int r = new_route_len(circ->base_.purpose, exit, nodelist_get_list());
|
|
if (r < 1) /* must be at least 1 */
|
|
return -1;
|
|
state->desired_path_len = r;
|
|
}
|
|
|
|
if (exit) { /* the circuit-builder pre-requested one */
|
|
warn_if_last_router_excluded(circ, exit);
|
|
log_info(LD_CIRC,"Using requested exit node '%s'",
|
|
extend_info_describe(exit));
|
|
exit = extend_info_dup(exit);
|
|
} else { /* we have to decide one */
|
|
const node_t *node =
|
|
choose_good_exit_server(circ->base_.purpose, state->need_uptime,
|
|
state->need_capacity, state->is_internal);
|
|
if (!node) {
|
|
log_warn(LD_CIRC,"Failed to choose an exit server");
|
|
return -1;
|
|
}
|
|
exit = extend_info_from_node(node, 0);
|
|
tor_assert(exit);
|
|
}
|
|
state->chosen_exit = exit;
|
|
return 0;
|
|
}
|
|
|
|
/** Give <b>circ</b> a new exit destination to <b>exit</b>, and add a
|
|
* hop to the cpath reflecting this. Don't send the next extend cell --
|
|
* the caller will do this if it wants to.
|
|
*/
|
|
int
|
|
circuit_append_new_exit(origin_circuit_t *circ, extend_info_t *exit)
|
|
{
|
|
cpath_build_state_t *state;
|
|
tor_assert(exit);
|
|
tor_assert(circ);
|
|
|
|
state = circ->build_state;
|
|
tor_assert(state);
|
|
extend_info_free(state->chosen_exit);
|
|
state->chosen_exit = extend_info_dup(exit);
|
|
|
|
++circ->build_state->desired_path_len;
|
|
onion_append_hop(&circ->cpath, exit);
|
|
return 0;
|
|
}
|
|
|
|
/** Take an open <b>circ</b>, and add a new hop at the end, based on
|
|
* <b>info</b>. Set its state back to CIRCUIT_STATE_BUILDING, and then
|
|
* send the next extend cell to begin connecting to that hop.
|
|
*/
|
|
int
|
|
circuit_extend_to_new_exit(origin_circuit_t *circ, extend_info_t *exit)
|
|
{
|
|
int err_reason = 0;
|
|
warn_if_last_router_excluded(circ, exit);
|
|
|
|
tor_gettimeofday(&circ->base_.timestamp_began);
|
|
|
|
circuit_append_new_exit(circ, exit);
|
|
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING);
|
|
if ((err_reason = circuit_send_next_onion_skin(circ))<0) {
|
|
log_warn(LD_CIRC, "Couldn't extend circuit to new point %s.",
|
|
extend_info_describe(exit));
|
|
circuit_mark_for_close(TO_CIRCUIT(circ), -err_reason);
|
|
return -1;
|
|
}
|
|
|
|
// XXX: Should cannibalized circuits be dirty or not? Not easy to say..
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** Return the number of routers in <b>routers</b> that are currently up
|
|
* and available for building circuits through.
|
|
*/
|
|
static int
|
|
count_acceptable_nodes(smartlist_t *nodes)
|
|
{
|
|
int num=0;
|
|
|
|
SMARTLIST_FOREACH_BEGIN(nodes, const node_t *, node) {
|
|
// log_debug(LD_CIRC,
|
|
// "Contemplating whether router %d (%s) is a new option.",
|
|
// i, r->nickname);
|
|
if (! node->is_running)
|
|
// log_debug(LD_CIRC,"Nope, the directory says %d is not running.",i);
|
|
continue;
|
|
if (! node->is_valid)
|
|
// log_debug(LD_CIRC,"Nope, the directory says %d is not valid.",i);
|
|
continue;
|
|
if (! node_has_descriptor(node))
|
|
continue;
|
|
/* XXX This clause makes us count incorrectly: if AllowInvalidRouters
|
|
* allows this node in some places, then we're getting an inaccurate
|
|
* count. For now, be conservative and don't count it. But later we
|
|
* should try to be smarter. */
|
|
++num;
|
|
} SMARTLIST_FOREACH_END(node);
|
|
|
|
// log_debug(LD_CIRC,"I like %d. num_acceptable_routers now %d.",i, num);
|
|
|
|
return num;
|
|
}
|
|
|
|
/** Add <b>new_hop</b> to the end of the doubly-linked-list <b>head_ptr</b>.
|
|
* This function is used to extend cpath by another hop.
|
|
*/
|
|
void
|
|
onion_append_to_cpath(crypt_path_t **head_ptr, crypt_path_t *new_hop)
|
|
{
|
|
if (*head_ptr) {
|
|
new_hop->next = (*head_ptr);
|
|
new_hop->prev = (*head_ptr)->prev;
|
|
(*head_ptr)->prev->next = new_hop;
|
|
(*head_ptr)->prev = new_hop;
|
|
} else {
|
|
*head_ptr = new_hop;
|
|
new_hop->prev = new_hop->next = new_hop;
|
|
}
|
|
}
|
|
|
|
/** A helper function used by onion_extend_cpath(). Use <b>purpose</b>
|
|
* and <b>state</b> and the cpath <b>head</b> (currently populated only
|
|
* to length <b>cur_len</b> to decide a suitable middle hop for a
|
|
* circuit. In particular, make sure we don't pick the exit node or its
|
|
* family, and make sure we don't duplicate any previous nodes or their
|
|
* families. */
|
|
static const node_t *
|
|
choose_good_middle_server(uint8_t purpose,
|
|
cpath_build_state_t *state,
|
|
crypt_path_t *head,
|
|
int cur_len)
|
|
{
|
|
int i;
|
|
const node_t *r, *choice;
|
|
crypt_path_t *cpath;
|
|
smartlist_t *excluded;
|
|
const or_options_t *options = get_options();
|
|
router_crn_flags_t flags = CRN_NEED_DESC;
|
|
tor_assert(CIRCUIT_PURPOSE_MIN_ <= purpose &&
|
|
purpose <= CIRCUIT_PURPOSE_MAX_);
|
|
|
|
log_debug(LD_CIRC, "Contemplating intermediate hop %d: random choice.",
|
|
cur_len);
|
|
excluded = smartlist_new();
|
|
if ((r = build_state_get_exit_node(state))) {
|
|
nodelist_add_node_and_family(excluded, r);
|
|
}
|
|
for (i = 0, cpath = head; i < cur_len; ++i, cpath=cpath->next) {
|
|
if ((r = node_get_by_id(cpath->extend_info->identity_digest))) {
|
|
nodelist_add_node_and_family(excluded, r);
|
|
}
|
|
}
|
|
|
|
if (state->need_uptime)
|
|
flags |= CRN_NEED_UPTIME;
|
|
if (state->need_capacity)
|
|
flags |= CRN_NEED_CAPACITY;
|
|
if (options->AllowInvalid_ & ALLOW_INVALID_MIDDLE)
|
|
flags |= CRN_ALLOW_INVALID;
|
|
choice = router_choose_random_node(excluded, options->ExcludeNodes, flags);
|
|
smartlist_free(excluded);
|
|
return choice;
|
|
}
|
|
|
|
/** Pick a good entry server for the circuit to be built according to
|
|
* <b>state</b>. Don't reuse a chosen exit (if any), don't use this
|
|
* router (if we're an OR), and respect firewall settings; if we're
|
|
* configured to use entry guards, return one.
|
|
*
|
|
* If <b>state</b> is NULL, we're choosing a router to serve as an entry
|
|
* guard, not for any particular circuit.
|
|
*/
|
|
/* XXXX024 I'd like to have this be static again, but entrynodes.c needs it. */
|
|
const node_t *
|
|
choose_good_entry_server(uint8_t purpose, cpath_build_state_t *state)
|
|
{
|
|
const node_t *choice;
|
|
smartlist_t *excluded;
|
|
const or_options_t *options = get_options();
|
|
/* If possible, choose an entry server with a preferred address,
|
|
* otherwise, choose one with an allowed address */
|
|
router_crn_flags_t flags = CRN_NEED_GUARD|CRN_NEED_DESC|CRN_PREF_ADDR;
|
|
const node_t *node;
|
|
|
|
if (state && options->UseEntryGuards &&
|
|
(purpose != CIRCUIT_PURPOSE_TESTING || options->BridgeRelay)) {
|
|
/* This request is for an entry server to use for a regular circuit,
|
|
* and we use entry guard nodes. Just return one of the guard nodes. */
|
|
return choose_random_entry(state);
|
|
}
|
|
|
|
excluded = smartlist_new();
|
|
|
|
if (state && (node = build_state_get_exit_node(state))) {
|
|
/* Exclude the exit node from the state, if we have one. Also exclude its
|
|
* family. */
|
|
nodelist_add_node_and_family(excluded, node);
|
|
}
|
|
/* and exclude current entry guards and their families,
|
|
* unless we're in a test network, and excluding guards
|
|
* would exclude all nodes (i.e. we're in an incredibly small tor network,
|
|
* or we're using TestingAuthVoteGuard *).
|
|
* This is an incomplete fix, but is no worse than the previous behaviour,
|
|
* and only applies to minimal, testing tor networks
|
|
* (so it's no less secure) */
|
|
/*XXXX025 use the using_as_guard flag to accomplish this.*/
|
|
if (options->UseEntryGuards
|
|
&& (!options->TestingTorNetwork ||
|
|
smartlist_len(nodelist_get_list()) > smartlist_len(get_entry_guards())
|
|
)) {
|
|
SMARTLIST_FOREACH(get_entry_guards(), const entry_guard_t *, entry,
|
|
{
|
|
if ((node = node_get_by_id(entry->identity))) {
|
|
nodelist_add_node_and_family(excluded, node);
|
|
}
|
|
});
|
|
}
|
|
|
|
if (state) {
|
|
if (state->need_uptime)
|
|
flags |= CRN_NEED_UPTIME;
|
|
if (state->need_capacity)
|
|
flags |= CRN_NEED_CAPACITY;
|
|
}
|
|
if (options->AllowInvalid_ & ALLOW_INVALID_ENTRY)
|
|
flags |= CRN_ALLOW_INVALID;
|
|
|
|
choice = router_choose_random_node(excluded, options->ExcludeNodes, flags);
|
|
smartlist_free(excluded);
|
|
return choice;
|
|
}
|
|
|
|
/** Return the first non-open hop in cpath, or return NULL if all
|
|
* hops are open. */
|
|
static crypt_path_t *
|
|
onion_next_hop_in_cpath(crypt_path_t *cpath)
|
|
{
|
|
crypt_path_t *hop = cpath;
|
|
do {
|
|
if (hop->state != CPATH_STATE_OPEN)
|
|
return hop;
|
|
hop = hop->next;
|
|
} while (hop != cpath);
|
|
return NULL;
|
|
}
|
|
|
|
/** Choose a suitable next hop in the cpath <b>head_ptr</b>,
|
|
* based on <b>state</b>. Append the hop info to head_ptr.
|
|
*
|
|
* Return 1 if the path is complete, 0 if we successfully added a hop,
|
|
* and -1 on error.
|
|
*/
|
|
static int
|
|
onion_extend_cpath(origin_circuit_t *circ)
|
|
{
|
|
uint8_t purpose = circ->base_.purpose;
|
|
cpath_build_state_t *state = circ->build_state;
|
|
int cur_len = circuit_get_cpath_len(circ);
|
|
extend_info_t *info = NULL;
|
|
|
|
if (cur_len >= state->desired_path_len) {
|
|
log_debug(LD_CIRC, "Path is complete: %d steps long",
|
|
state->desired_path_len);
|
|
return 1;
|
|
}
|
|
|
|
log_debug(LD_CIRC, "Path is %d long; we want %d", cur_len,
|
|
state->desired_path_len);
|
|
|
|
if (cur_len == state->desired_path_len - 1) { /* Picking last node */
|
|
info = extend_info_dup(state->chosen_exit);
|
|
} else if (cur_len == 0) { /* picking first node */
|
|
const node_t *r = choose_good_entry_server(purpose, state);
|
|
if (r) {
|
|
/* If we're a client, use the preferred address rather than the
|
|
primary address, for potentially connecting to an IPv6 OR
|
|
port. Servers always want the primary (IPv4) address. */
|
|
int client = (server_mode(get_options()) == 0);
|
|
info = extend_info_from_node(r, client);
|
|
/* Clients can fail to find an allowed address */
|
|
tor_assert(info || client);
|
|
}
|
|
} else {
|
|
const node_t *r =
|
|
choose_good_middle_server(purpose, state, circ->cpath, cur_len);
|
|
if (r) {
|
|
info = extend_info_from_node(r, 0);
|
|
tor_assert(info);
|
|
}
|
|
}
|
|
|
|
if (!info) {
|
|
log_warn(LD_CIRC,"Failed to find node for hop %d of our path. Discarding "
|
|
"this circuit.", cur_len);
|
|
return -1;
|
|
}
|
|
|
|
log_debug(LD_CIRC,"Chose router %s for hop %d (exit is %s)",
|
|
extend_info_describe(info),
|
|
cur_len+1, build_state_get_exit_nickname(state));
|
|
|
|
onion_append_hop(&circ->cpath, info);
|
|
extend_info_free(info);
|
|
return 0;
|
|
}
|
|
|
|
/** Create a new hop, annotate it with information about its
|
|
* corresponding router <b>choice</b>, and append it to the
|
|
* end of the cpath <b>head_ptr</b>. */
|
|
static int
|
|
onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice)
|
|
{
|
|
crypt_path_t *hop = tor_malloc_zero(sizeof(crypt_path_t));
|
|
|
|
/* link hop into the cpath, at the end. */
|
|
onion_append_to_cpath(head_ptr, hop);
|
|
|
|
hop->magic = CRYPT_PATH_MAGIC;
|
|
hop->state = CPATH_STATE_CLOSED;
|
|
|
|
hop->extend_info = extend_info_dup(choice);
|
|
|
|
hop->package_window = circuit_initial_package_window();
|
|
hop->deliver_window = CIRCWINDOW_START;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/** Allocate a new extend_info object based on the various arguments. */
|
|
extend_info_t *
|
|
extend_info_new(const char *nickname, const char *digest,
|
|
crypto_pk_t *onion_key,
|
|
const curve25519_public_key_t *curve25519_key,
|
|
const tor_addr_t *addr, uint16_t port)
|
|
{
|
|
extend_info_t *info = tor_malloc_zero(sizeof(extend_info_t));
|
|
memcpy(info->identity_digest, digest, DIGEST_LEN);
|
|
if (nickname)
|
|
strlcpy(info->nickname, nickname, sizeof(info->nickname));
|
|
if (onion_key)
|
|
info->onion_key = crypto_pk_dup_key(onion_key);
|
|
if (curve25519_key)
|
|
memcpy(&info->curve25519_onion_key, curve25519_key,
|
|
sizeof(curve25519_public_key_t));
|
|
tor_addr_copy(&info->addr, addr);
|
|
info->port = port;
|
|
return info;
|
|
}
|
|
|
|
/** Allocate and return a new extend_info that can be used to build a
|
|
* circuit to or through the node <b>node</b>. Use the primary address
|
|
* of the node (i.e. its IPv4 address) unless
|
|
* <b>for_direct_connect</b> is true, in which case the preferred
|
|
* address is used instead. May return NULL if there is not enough
|
|
* info about <b>node</b> to extend to it--for example, if there is no
|
|
* routerinfo_t or microdesc_t, or if for_direct_connect is true and none of
|
|
* the node's addresses are allowed by tor's firewall and IP version config.
|
|
**/
|
|
extend_info_t *
|
|
extend_info_from_node(const node_t *node, int for_direct_connect)
|
|
{
|
|
tor_addr_port_t ap;
|
|
int valid_addr = 0;
|
|
|
|
if (node->ri == NULL && (node->rs == NULL || node->md == NULL))
|
|
return NULL;
|
|
|
|
/* Choose a preferred address first, but fall back to an allowed address.
|
|
* choose_address returns 1 on success, but get_prim_orport returns 0. */
|
|
if (for_direct_connect)
|
|
valid_addr = fascist_firewall_choose_address_node(node,
|
|
FIREWALL_OR_CONNECTION,
|
|
0, &ap);
|
|
else
|
|
valid_addr = !node_get_prim_orport(node, &ap);
|
|
|
|
if (valid_addr)
|
|
log_debug(LD_CIRC, "using %s for %s",
|
|
fmt_addrport(&ap.addr, ap.port),
|
|
node->ri ? node->ri->nickname : node->rs->nickname);
|
|
else
|
|
log_warn(LD_CIRC, "Could not choose valid address for %s",
|
|
node->ri ? node->ri->nickname : node->rs->nickname);
|
|
|
|
if (valid_addr && node->ri)
|
|
return extend_info_new(node->ri->nickname,
|
|
node->identity,
|
|
node->ri->onion_pkey,
|
|
node->ri->onion_curve25519_pkey,
|
|
&ap.addr,
|
|
ap.port);
|
|
else if (valid_addr && node->rs && node->md)
|
|
return extend_info_new(node->rs->nickname,
|
|
node->identity,
|
|
node->md->onion_pkey,
|
|
node->md->onion_curve25519_pkey,
|
|
&ap.addr,
|
|
ap.port);
|
|
else
|
|
return NULL;
|
|
}
|
|
|
|
/** Release storage held by an extend_info_t struct. */
|
|
void
|
|
extend_info_free(extend_info_t *info)
|
|
{
|
|
if (!info)
|
|
return;
|
|
crypto_pk_free(info->onion_key);
|
|
tor_free(info);
|
|
}
|
|
|
|
/** Allocate and return a new extend_info_t with the same contents as
|
|
* <b>info</b>. */
|
|
extend_info_t *
|
|
extend_info_dup(extend_info_t *info)
|
|
{
|
|
extend_info_t *newinfo;
|
|
tor_assert(info);
|
|
newinfo = tor_malloc(sizeof(extend_info_t));
|
|
memcpy(newinfo, info, sizeof(extend_info_t));
|
|
if (info->onion_key)
|
|
newinfo->onion_key = crypto_pk_dup_key(info->onion_key);
|
|
else
|
|
newinfo->onion_key = NULL;
|
|
return newinfo;
|
|
}
|
|
|
|
/** Return the routerinfo_t for the chosen exit router in <b>state</b>.
|
|
* If there is no chosen exit, or if we don't know the routerinfo_t for
|
|
* the chosen exit, return NULL.
|
|
*/
|
|
const node_t *
|
|
build_state_get_exit_node(cpath_build_state_t *state)
|
|
{
|
|
if (!state || !state->chosen_exit)
|
|
return NULL;
|
|
return node_get_by_id(state->chosen_exit->identity_digest);
|
|
}
|
|
|
|
/** Return the nickname for the chosen exit router in <b>state</b>. If
|
|
* there is no chosen exit, or if we don't know the routerinfo_t for the
|
|
* chosen exit, return NULL.
|
|
*/
|
|
const char *
|
|
build_state_get_exit_nickname(cpath_build_state_t *state)
|
|
{
|
|
if (!state || !state->chosen_exit)
|
|
return NULL;
|
|
return state->chosen_exit->nickname;
|
|
}
|
|
|
|
/** Return true iff the given address can be used to extend to. */
|
|
int
|
|
extend_info_addr_is_allowed(const tor_addr_t *addr)
|
|
{
|
|
tor_assert(addr);
|
|
|
|
/* Check if we have a private address and if we can extend to it. */
|
|
if ((tor_addr_is_internal(addr, 0) || tor_addr_is_multicast(addr)) &&
|
|
!get_options()->ExtendAllowPrivateAddresses) {
|
|
goto disallow;
|
|
}
|
|
/* Allowed! */
|
|
return 1;
|
|
disallow:
|
|
return 0;
|
|
}
|
|
|