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circuitlist.c
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circuitlist.c
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/* Copyright 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2018, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file circuitlist.c
*
* \brief Manage global structures that list and index circuits, and
* look up circuits within them.
*
* One of the most frequent operations in Tor occurs every time that
* a relay cell arrives on a channel. When that happens, we need to
* find which circuit it is associated with, based on the channel and the
* circuit ID in the relay cell.
*
* To handle that, we maintain a global list of circuits, and a hashtable
* mapping [channel,circID] pairs to circuits. Circuits are added to and
* removed from this mapping using circuit_set_p_circid_chan() and
* circuit_set_n_circid_chan(). To look up a circuit from this map, most
* callers should use circuit_get_by_circid_channel(), though
* circuit_get_by_circid_channel_even_if_marked() is appropriate under some
* circumstances.
*
* We also need to allow for the possibility that we have blocked use of a
* circuit ID (because we are waiting to send a DESTROY cell), but the
* circuit is not there any more. For that case, we allow placeholder
* entries in the table, using channel_mark_circid_unusable().
*
* To efficiently handle a channel that has just opened, we also maintain a
* list of the circuits waiting for channels, so we can attach them as
* needed without iterating through the whole list of circuits, using
* circuit_get_all_pending_on_channel().
*
* In this module, we also handle the list of circuits that have been
* marked for close elsewhere, and close them as needed. (We use this
* "mark now, close later" pattern here and elsewhere to avoid
* unpredictable recursion if we closed every circuit immediately upon
* realizing it needed to close.) See circuit_mark_for_close() for the
* mark function, and circuit_close_all_marked() for the close function.
*
* For hidden services, we need to be able to look up introduction point
* circuits and rendezvous circuits by cookie, key, etc. These are
* currently handled with linear searches in
* circuit_get_ready_rend_circuit_by_rend_data(),
* circuit_get_next_by_pk_and_purpose(), and with hash lookups in
* circuit_get_rendezvous() and circuit_get_intro_point().
*
* This module is also the entry point for our out-of-memory handler
* logic, which was originally circuit-focused.
**/
#define CIRCUITLIST_PRIVATE
#include "lib/cc/torint.h" /* TOR_PRIuSZ */
#include "core/or/or.h"
#include "core/or/channel.h"
#include "core/or/channeltls.h"
#include "feature/client/circpathbias.h"
#include "core/or/circuitbuild.h"
#include "core/or/circuitlist.h"
#include "core/or/circuituse.h"
#include "core/or/circuitstats.h"
#include "core/or/circuitpadding.h"
#include "core/mainloop/connection.h"
#include "app/config/config.h"
#include "core/or/connection_edge.h"
#include "core/or/connection_or.h"
#include "feature/control/control.h"
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/crypt_ops/crypto_util.h"
#include "lib/crypt_ops/crypto_dh.h"
#include "feature/dircommon/directory.h"
#include "feature/client/entrynodes.h"
#include "core/mainloop/mainloop.h"
#include "feature/hs/hs_circuit.h"
#include "feature/hs/hs_circuitmap.h"
#include "feature/hs/hs_ident.h"
#include "feature/nodelist/networkstatus.h"
#include "feature/nodelist/nodelist.h"
#include "feature/relay/onion_queue.h"
#include "core/crypto/onion_crypto.h"
#include "core/crypto/onion_fast.h"
#include "core/or/policies.h"
#include "core/or/relay.h"
#include "core/crypto/relay_crypto.h"
#include "feature/rend/rendclient.h"
#include "feature/rend/rendcommon.h"
#include "feature/stats/predict_ports.h"
#include "feature/stats/rephist.h"
#include "feature/nodelist/routerlist.h"
#include "feature/nodelist/routerset.h"
#include "core/or/channelpadding.h"
#include "lib/compress/compress.h"
#include "lib/compress/compress_lzma.h"
#include "lib/compress/compress_zlib.h"
#include "lib/compress/compress_zstd.h"
#include "lib/container/buffers.h"
#include "ht.h"
#include "core/or/cpath_build_state_st.h"
#include "core/or/crypt_path_reference_st.h"
#include "feature/dircommon/dir_connection_st.h"
#include "core/or/edge_connection_st.h"
#include "core/or/half_edge_st.h"
#include "core/or/extend_info_st.h"
#include "core/or/or_circuit_st.h"
#include "core/or/origin_circuit_st.h"
/********* START VARIABLES **********/
/** A global list of all circuits at this hop. */
static smartlist_t *global_circuitlist = NULL;
/** A global list of all origin circuits. Every element of this is also
* an element of global_circuitlist. */
static smartlist_t *global_origin_circuit_list = NULL;
/** A list of all the circuits in CIRCUIT_STATE_CHAN_WAIT. */
static smartlist_t *circuits_pending_chans = NULL;
/** List of all the (origin) circuits whose state is
* CIRCUIT_STATE_GUARD_WAIT. */
static smartlist_t *circuits_pending_other_guards = NULL;
/** A list of all the circuits that have been marked with
* circuit_mark_for_close and which are waiting for circuit_about_to_free. */
static smartlist_t *circuits_pending_close = NULL;
static void circuit_free_cpath_node(crypt_path_t *victim);
static void cpath_ref_decref(crypt_path_reference_t *cpath_ref);
static void circuit_about_to_free_atexit(circuit_t *circ);
static void circuit_about_to_free(circuit_t *circ);
/**
* A cached value of the current state of the origin circuit list. Has the
* value 1 if we saw any opened circuits recently (since the last call to
* circuit_any_opened_circuits(), which gets called around once a second by
* circuit_expire_building). 0 otherwise.
*/
static int any_opened_circs_cached_val = 0;
/********* END VARIABLES ************/
or_circuit_t *
TO_OR_CIRCUIT(circuit_t *x)
{
tor_assert(x->magic == OR_CIRCUIT_MAGIC);
return DOWNCAST(or_circuit_t, x);
}
const or_circuit_t *
CONST_TO_OR_CIRCUIT(const circuit_t *x)
{
tor_assert(x->magic == OR_CIRCUIT_MAGIC);
return DOWNCAST(or_circuit_t, x);
}
origin_circuit_t *
TO_ORIGIN_CIRCUIT(circuit_t *x)
{
tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
return DOWNCAST(origin_circuit_t, x);
}
const origin_circuit_t *
CONST_TO_ORIGIN_CIRCUIT(const circuit_t *x)
{
tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
return DOWNCAST(origin_circuit_t, x);
}
/** A map from channel and circuit ID to circuit. (Lookup performance is
* very important here, since we need to do it every time a cell arrives.) */
typedef struct chan_circid_circuit_map_t {
HT_ENTRY(chan_circid_circuit_map_t) node;
channel_t *chan;
circid_t circ_id;
circuit_t *circuit;
/* For debugging 12184: when was this placeholder item added? */
time_t made_placeholder_at;
} chan_circid_circuit_map_t;
/** Helper for hash tables: compare the channel and circuit ID for a and
* b, and return less than, equal to, or greater than zero appropriately.
*/
static inline int
chan_circid_entries_eq_(chan_circid_circuit_map_t *a,
chan_circid_circuit_map_t *b)
{
return a->chan == b->chan && a->circ_id == b->circ_id;
}
/** Helper: return a hash based on circuit ID and the pointer value of
* chan in <b>a</b>. */
static inline unsigned int
chan_circid_entry_hash_(chan_circid_circuit_map_t *a)
{
/* Try to squeze the siphash input into 8 bytes to save any extra siphash
* rounds. This hash function is in the critical path. */
uintptr_t chan = (uintptr_t) (void*) a->chan;
uint32_t array[2];
array[0] = a->circ_id;
/* The low bits of the channel pointer are uninteresting, since the channel
* is a pretty big structure. */
array[1] = (uint32_t) (chan >> 6);
return (unsigned) siphash24g(array, sizeof(array));
}
/** Map from [chan,circid] to circuit. */
static HT_HEAD(chan_circid_map, chan_circid_circuit_map_t)
chan_circid_map = HT_INITIALIZER();
HT_PROTOTYPE(chan_circid_map, chan_circid_circuit_map_t, node,
chan_circid_entry_hash_, chan_circid_entries_eq_)
HT_GENERATE2(chan_circid_map, chan_circid_circuit_map_t, node,
chan_circid_entry_hash_, chan_circid_entries_eq_, 0.6,
tor_reallocarray_, tor_free_)
/** The most recently returned entry from circuit_get_by_circid_chan;
* used to improve performance when many cells arrive in a row from the
* same circuit.
*/
static chan_circid_circuit_map_t *_last_circid_chan_ent = NULL;
/** Implementation helper for circuit_set_{p,n}_circid_channel: A circuit ID
* and/or channel for circ has just changed from <b>old_chan, old_id</b>
* to <b>chan, id</b>. Adjust the chan,circid map as appropriate, removing
* the old entry (if any) and adding a new one. */
static void
circuit_set_circid_chan_helper(circuit_t *circ, int direction,
circid_t id,
channel_t *chan)
{
chan_circid_circuit_map_t search;
chan_circid_circuit_map_t *found;
channel_t *old_chan, **chan_ptr;
circid_t old_id, *circid_ptr;
int make_active, attached = 0;
if (direction == CELL_DIRECTION_OUT) {
chan_ptr = &circ->n_chan;
circid_ptr = &circ->n_circ_id;
make_active = circ->n_chan_cells.n > 0;
} else {
or_circuit_t *c = TO_OR_CIRCUIT(circ);
chan_ptr = &c->p_chan;
circid_ptr = &c->p_circ_id;
make_active = c->p_chan_cells.n > 0;
}
old_chan = *chan_ptr;
old_id = *circid_ptr;
if (id == old_id && chan == old_chan)
return;
if (_last_circid_chan_ent &&
((old_id == _last_circid_chan_ent->circ_id &&
old_chan == _last_circid_chan_ent->chan) ||
(id == _last_circid_chan_ent->circ_id &&
chan == _last_circid_chan_ent->chan))) {
_last_circid_chan_ent = NULL;
}
if (old_chan) {
/*
* If we're changing channels or ID and had an old channel and a non
* zero old ID and weren't marked for close (i.e., we should have been
* attached), detach the circuit. ID changes require this because
* circuitmux hashes on (channel_id, circuit_id).
*/
if (old_id != 0 && (old_chan != chan || old_id != id) &&
!(circ->marked_for_close)) {
tor_assert(old_chan->cmux);
circuitmux_detach_circuit(old_chan->cmux, circ);
}
/* we may need to remove it from the conn-circid map */
search.circ_id = old_id;
search.chan = old_chan;
found = HT_REMOVE(chan_circid_map, &chan_circid_map, &search);
if (found) {
tor_free(found);
if (direction == CELL_DIRECTION_OUT) {
/* One fewer circuits use old_chan as n_chan */
--(old_chan->num_n_circuits);
} else {
/* One fewer circuits use old_chan as p_chan */
--(old_chan->num_p_circuits);
}
}
}
/* Change the values only after we have possibly made the circuit inactive
* on the previous chan. */
*chan_ptr = chan;
*circid_ptr = id;
if (chan == NULL)
return;
/* now add the new one to the conn-circid map */
search.circ_id = id;
search.chan = chan;
found = HT_FIND(chan_circid_map, &chan_circid_map, &search);
if (found) {
found->circuit = circ;
found->made_placeholder_at = 0;
} else {
found = tor_malloc_zero(sizeof(chan_circid_circuit_map_t));
found->circ_id = id;
found->chan = chan;
found->circuit = circ;
HT_INSERT(chan_circid_map, &chan_circid_map, found);
}
/*
* Attach to the circuitmux if we're changing channels or IDs and
* have a new channel and ID to use and the circuit is not marked for
* close.
*/
if (chan && id != 0 && (old_chan != chan || old_id != id) &&
!(circ->marked_for_close)) {
tor_assert(chan->cmux);
circuitmux_attach_circuit(chan->cmux, circ, direction);
attached = 1;
}
/*
* This is a no-op if we have no cells, but if we do it marks us active to
* the circuitmux
*/
if (make_active && attached)
update_circuit_on_cmux(circ, direction);
/* Adjust circuit counts on new channel */
if (direction == CELL_DIRECTION_OUT) {
++chan->num_n_circuits;
} else {
++chan->num_p_circuits;
}
}
/** Mark that circuit id <b>id</b> shouldn't be used on channel <b>chan</b>,
* even if there is no circuit on the channel. We use this to keep the
* circuit id from getting re-used while we have queued but not yet sent
* a destroy cell. */
void
channel_mark_circid_unusable(channel_t *chan, circid_t id)
{
chan_circid_circuit_map_t search;
chan_circid_circuit_map_t *ent;
/* See if there's an entry there. That wouldn't be good. */
memset(&search, 0, sizeof(search));
search.chan = chan;
search.circ_id = id;
ent = HT_FIND(chan_circid_map, &chan_circid_map, &search);
if (ent && ent->circuit) {
/* we have a problem. */
log_warn(LD_BUG, "Tried to mark %u unusable on %p, but there was already "
"a circuit there.", (unsigned)id, chan);
} else if (ent) {
/* It's already marked. */
if (!ent->made_placeholder_at)
ent->made_placeholder_at = approx_time();
} else {
ent = tor_malloc_zero(sizeof(chan_circid_circuit_map_t));
ent->chan = chan;
ent->circ_id = id;
/* leave circuit at NULL. */
ent->made_placeholder_at = approx_time();
HT_INSERT(chan_circid_map, &chan_circid_map, ent);
}
}
/** Mark that a circuit id <b>id</b> can be used again on <b>chan</b>.
* We use this to re-enable the circuit ID after we've sent a destroy cell.
*/
void
channel_mark_circid_usable(channel_t *chan, circid_t id)
{
chan_circid_circuit_map_t search;
chan_circid_circuit_map_t *ent;
/* See if there's an entry there. That wouldn't be good. */
memset(&search, 0, sizeof(search));
search.chan = chan;
search.circ_id = id;
ent = HT_REMOVE(chan_circid_map, &chan_circid_map, &search);
if (ent && ent->circuit) {
log_warn(LD_BUG, "Tried to mark %u usable on %p, but there was already "
"a circuit there.", (unsigned)id, chan);
return;
}
if (_last_circid_chan_ent == ent)
_last_circid_chan_ent = NULL;
tor_free(ent);
}
/** Called to indicate that a DESTROY is pending on <b>chan</b> with
* circuit ID <b>id</b>, but hasn't been sent yet. */
void
channel_note_destroy_pending(channel_t *chan, circid_t id)
{
circuit_t *circ = circuit_get_by_circid_channel_even_if_marked(id,chan);
if (circ) {
if (circ->n_chan == chan && circ->n_circ_id == id) {
circ->n_delete_pending = 1;
} else {
or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
if (orcirc->p_chan == chan && orcirc->p_circ_id == id) {
circ->p_delete_pending = 1;
}
}
return;
}
channel_mark_circid_unusable(chan, id);
}
/** Called to indicate that a DESTROY is no longer pending on <b>chan</b> with
* circuit ID <b>id</b> -- typically, because it has been sent. */
MOCK_IMPL(void,
channel_note_destroy_not_pending,(channel_t *chan, circid_t id))
{
circuit_t *circ = circuit_get_by_circid_channel_even_if_marked(id,chan);
if (circ) {
if (circ->n_chan == chan && circ->n_circ_id == id) {
circ->n_delete_pending = 0;
} else {
or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
if (orcirc->p_chan == chan && orcirc->p_circ_id == id) {
circ->p_delete_pending = 0;
}
}
/* XXXX this shouldn't happen; log a bug here. */
return;
}
channel_mark_circid_usable(chan, id);
}
/** Set the p_conn field of a circuit <b>circ</b>, along
* with the corresponding circuit ID, and add the circuit as appropriate
* to the (chan,id)-\>circuit map. */
void
circuit_set_p_circid_chan(or_circuit_t *or_circ, circid_t id,
channel_t *chan)
{
circuit_t *circ = TO_CIRCUIT(or_circ);
channel_t *old_chan = or_circ->p_chan;
circid_t old_id = or_circ->p_circ_id;
circuit_set_circid_chan_helper(circ, CELL_DIRECTION_IN, id, chan);
if (chan) {
chan->timestamp_last_had_circuits = approx_time();
}
if (circ->p_delete_pending && old_chan) {
channel_mark_circid_unusable(old_chan, old_id);
circ->p_delete_pending = 0;
}
}
/** Set the n_conn field of a circuit <b>circ</b>, along
* with the corresponding circuit ID, and add the circuit as appropriate
* to the (chan,id)-\>circuit map. */
void
circuit_set_n_circid_chan(circuit_t *circ, circid_t id,
channel_t *chan)
{
channel_t *old_chan = circ->n_chan;
circid_t old_id = circ->n_circ_id;
circuit_set_circid_chan_helper(circ, CELL_DIRECTION_OUT, id, chan);
if (chan) {
chan->timestamp_last_had_circuits = approx_time();
}
if (circ->n_delete_pending && old_chan) {
channel_mark_circid_unusable(old_chan, old_id);
circ->n_delete_pending = 0;
}
}
/** Change the state of <b>circ</b> to <b>state</b>, adding it to or removing
* it from lists as appropriate. */
void
circuit_set_state(circuit_t *circ, uint8_t state)
{
tor_assert(circ);
if (state == circ->state)
return;
if (PREDICT_UNLIKELY(!circuits_pending_chans))
circuits_pending_chans = smartlist_new();
if (PREDICT_UNLIKELY(!circuits_pending_other_guards))
circuits_pending_other_guards = smartlist_new();
if (circ->state == CIRCUIT_STATE_CHAN_WAIT) {
/* remove from waiting-circuit list. */
smartlist_remove(circuits_pending_chans, circ);
}
if (state == CIRCUIT_STATE_CHAN_WAIT) {
/* add to waiting-circuit list. */
smartlist_add(circuits_pending_chans, circ);
}
if (circ->state == CIRCUIT_STATE_GUARD_WAIT) {
smartlist_remove(circuits_pending_other_guards, circ);
}
if (state == CIRCUIT_STATE_GUARD_WAIT) {
smartlist_add(circuits_pending_other_guards, circ);
}
if (state == CIRCUIT_STATE_GUARD_WAIT || state == CIRCUIT_STATE_OPEN)
tor_assert(!circ->n_chan_create_cell);
circ->state = state;
}
/** Append to <b>out</b> all circuits in state CHAN_WAIT waiting for
* the given connection. */
void
circuit_get_all_pending_on_channel(smartlist_t *out, channel_t *chan)
{
tor_assert(out);
tor_assert(chan);
if (!circuits_pending_chans)
return;
SMARTLIST_FOREACH_BEGIN(circuits_pending_chans, circuit_t *, circ) {
if (circ->marked_for_close)
continue;
if (!circ->n_hop)
continue;
tor_assert(circ->state == CIRCUIT_STATE_CHAN_WAIT);
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;
}
smartlist_add(out, circ);
} SMARTLIST_FOREACH_END(circ);
}
/** Return the number of circuits in state CHAN_WAIT, waiting for the given
* channel. */
int
circuit_count_pending_on_channel(channel_t *chan)
{
int cnt;
smartlist_t *sl = smartlist_new();
tor_assert(chan);
circuit_get_all_pending_on_channel(sl, chan);
cnt = smartlist_len(sl);
smartlist_free(sl);
log_debug(LD_CIRC,"or_conn to %s, %d pending circs",
channel_get_canonical_remote_descr(chan),
cnt);
return cnt;
}
/** Remove <b>origin_circ</b> from the global list of origin circuits.
* Called when we are freeing a circuit.
*/
static void
circuit_remove_from_origin_circuit_list(origin_circuit_t *origin_circ)
{
int origin_idx = origin_circ->global_origin_circuit_list_idx;
if (origin_idx < 0)
return;
origin_circuit_t *c2;
tor_assert(origin_idx <= smartlist_len(global_origin_circuit_list));
c2 = smartlist_get(global_origin_circuit_list, origin_idx);
tor_assert(origin_circ == c2);
smartlist_del(global_origin_circuit_list, origin_idx);
if (origin_idx < smartlist_len(global_origin_circuit_list)) {
origin_circuit_t *replacement =
smartlist_get(global_origin_circuit_list, origin_idx);
replacement->global_origin_circuit_list_idx = origin_idx;
}
origin_circ->global_origin_circuit_list_idx = -1;
}
/** Add <b>origin_circ</b> to the global list of origin circuits. Called
* when creating the circuit. */
static void
circuit_add_to_origin_circuit_list(origin_circuit_t *origin_circ)
{
tor_assert(origin_circ->global_origin_circuit_list_idx == -1);
smartlist_t *lst = circuit_get_global_origin_circuit_list();
smartlist_add(lst, origin_circ);
origin_circ->global_origin_circuit_list_idx = smartlist_len(lst) - 1;
}
/** Detach from the global circuit list, and deallocate, all
* circuits that have been marked for close.
*/
void
circuit_close_all_marked(void)
{
if (circuits_pending_close == NULL)
return;
smartlist_t *lst = circuit_get_global_list();
SMARTLIST_FOREACH_BEGIN(circuits_pending_close, circuit_t *, circ) {
tor_assert(circ->marked_for_close);
/* Remove it from the circuit list. */
int idx = circ->global_circuitlist_idx;
smartlist_del(lst, idx);
if (idx < smartlist_len(lst)) {
circuit_t *replacement = smartlist_get(lst, idx);
replacement->global_circuitlist_idx = idx;
}
circ->global_circuitlist_idx = -1;
/* Remove it from the origin circuit list, if appropriate. */
if (CIRCUIT_IS_ORIGIN(circ)) {
circuit_remove_from_origin_circuit_list(TO_ORIGIN_CIRCUIT(circ));
}
circuit_about_to_free(circ);
circuit_free(circ);
} SMARTLIST_FOREACH_END(circ);
smartlist_clear(circuits_pending_close);
}
/** Return a pointer to the global list of circuits. */
MOCK_IMPL(smartlist_t *,
circuit_get_global_list,(void))
{
if (NULL == global_circuitlist)
global_circuitlist = smartlist_new();
return global_circuitlist;
}
/** Return a pointer to the global list of origin circuits. */
smartlist_t *
circuit_get_global_origin_circuit_list(void)
{
if (NULL == global_origin_circuit_list)
global_origin_circuit_list = smartlist_new();
return global_origin_circuit_list;
}
/**
* Return true if we have any opened general-purpose 3 hop
* origin circuits.
*
* The result from this function is cached for use by
* circuit_any_opened_circuits_cached().
*/
int
circuit_any_opened_circuits(void)
{
SMARTLIST_FOREACH_BEGIN(circuit_get_global_origin_circuit_list(),
const origin_circuit_t *, next_circ) {
if (!TO_CIRCUIT(next_circ)->marked_for_close &&
next_circ->has_opened &&
TO_CIRCUIT(next_circ)->state == CIRCUIT_STATE_OPEN &&
TO_CIRCUIT(next_circ)->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT &&
next_circ->build_state &&
next_circ->build_state->desired_path_len == DEFAULT_ROUTE_LEN) {
circuit_cache_opened_circuit_state(1);
return 1;
}
} SMARTLIST_FOREACH_END(next_circ);
circuit_cache_opened_circuit_state(0);
return 0;
}
/**
* Cache the "any circuits opened" state, as specified in param
* circuits_are_opened. This is a helper function to update
* the circuit opened status whenever we happen to look at the
* circuit list.
*/
void
circuit_cache_opened_circuit_state(int circuits_are_opened)
{
any_opened_circs_cached_val = circuits_are_opened;
}
/**
* Return true if there were any opened circuits since the last call to
* circuit_any_opened_circuits(), or since circuit_expire_building() last
* ran (it runs roughly once per second).
*/
int
circuit_any_opened_circuits_cached(void)
{
return any_opened_circs_cached_val;
}
/** Function to make circ-\>state human-readable */
const char *
circuit_state_to_string(int state)
{
static char buf[64];
switch (state) {
case CIRCUIT_STATE_BUILDING: return "doing handshakes";
case CIRCUIT_STATE_ONIONSKIN_PENDING: return "processing the onion";
case CIRCUIT_STATE_CHAN_WAIT: return "connecting to server";
case CIRCUIT_STATE_GUARD_WAIT: return "waiting to see how other "
"guards perform";
case CIRCUIT_STATE_OPEN: return "open";
default:
log_warn(LD_BUG, "Unknown circuit state %d", state);
tor_snprintf(buf, sizeof(buf), "unknown state [%d]", state);
return buf;
}
}
/** Map a circuit purpose to a string suitable to be displayed to a
* controller. */
const char *
circuit_purpose_to_controller_string(uint8_t purpose)
{
static char buf[32];
switch (purpose) {
case CIRCUIT_PURPOSE_OR:
case CIRCUIT_PURPOSE_INTRO_POINT:
case CIRCUIT_PURPOSE_REND_POINT_WAITING:
case CIRCUIT_PURPOSE_REND_ESTABLISHED:
return "SERVER"; /* A controller should never see these, actually. */
case CIRCUIT_PURPOSE_C_GENERAL:
return "GENERAL";
case CIRCUIT_PURPOSE_C_HSDIR_GET:
return "HS_CLIENT_HSDIR";
case CIRCUIT_PURPOSE_C_INTRODUCING:
case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
return "HS_CLIENT_INTRO";
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:
return "HS_CLIENT_REND";
case CIRCUIT_PURPOSE_S_HSDIR_POST:
return "HS_SERVICE_HSDIR";
case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
case CIRCUIT_PURPOSE_S_INTRO:
return "HS_SERVICE_INTRO";
case CIRCUIT_PURPOSE_S_CONNECT_REND:
case CIRCUIT_PURPOSE_S_REND_JOINED:
return "HS_SERVICE_REND";
case CIRCUIT_PURPOSE_TESTING:
return "TESTING";
case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
return "MEASURE_TIMEOUT";
case CIRCUIT_PURPOSE_CONTROLLER:
return "CONTROLLER";
case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
return "PATH_BIAS_TESTING";
case CIRCUIT_PURPOSE_HS_VANGUARDS:
return "HS_VANGUARDS";
default:
tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
return buf;
}
}
/** Return a string specifying the state of the hidden-service circuit
* purpose <b>purpose</b>, or NULL if <b>purpose</b> is not a
* hidden-service-related circuit purpose. */
const char *
circuit_purpose_to_controller_hs_state_string(uint8_t purpose)
{
switch (purpose)
{
default:
log_fn(LOG_WARN, LD_BUG,
"Unrecognized circuit purpose: %d",
(int)purpose);
tor_fragile_assert();
/* fall through */
case CIRCUIT_PURPOSE_OR:
case CIRCUIT_PURPOSE_C_GENERAL:
case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
case CIRCUIT_PURPOSE_TESTING:
case CIRCUIT_PURPOSE_CONTROLLER:
case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
case CIRCUIT_PURPOSE_HS_VANGUARDS:
return NULL;
case CIRCUIT_PURPOSE_INTRO_POINT:
return "OR_HSSI_ESTABLISHED";
case CIRCUIT_PURPOSE_REND_POINT_WAITING:
return "OR_HSCR_ESTABLISHED";
case CIRCUIT_PURPOSE_REND_ESTABLISHED:
return "OR_HS_R_JOINED";
case CIRCUIT_PURPOSE_C_HSDIR_GET:
case CIRCUIT_PURPOSE_C_INTRODUCING:
return "HSCI_CONNECTING";
case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
return "HSCI_INTRO_SENT";
case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
return "HSCI_DONE";
case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
return "HSCR_CONNECTING";
case CIRCUIT_PURPOSE_C_REND_READY:
return "HSCR_ESTABLISHED_IDLE";
case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
return "HSCR_ESTABLISHED_WAITING";
case CIRCUIT_PURPOSE_C_REND_JOINED:
return "HSCR_JOINED";
case CIRCUIT_PURPOSE_S_HSDIR_POST:
case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
return "HSSI_CONNECTING";
case CIRCUIT_PURPOSE_S_INTRO:
return "HSSI_ESTABLISHED";
case CIRCUIT_PURPOSE_S_CONNECT_REND:
return "HSSR_CONNECTING";
case CIRCUIT_PURPOSE_S_REND_JOINED:
return "HSSR_JOINED";
}
}
/** Return a human-readable string for the circuit purpose <b>purpose</b>. */
const char *
circuit_purpose_to_string(uint8_t purpose)
{
static char buf[32];
switch (purpose)
{
case CIRCUIT_PURPOSE_OR:
return "Circuit at relay";
case CIRCUIT_PURPOSE_INTRO_POINT:
return "Acting as intro point";
case CIRCUIT_PURPOSE_REND_POINT_WAITING:
return "Acting as rendezvous (pending)";
case CIRCUIT_PURPOSE_REND_ESTABLISHED:
return "Acting as rendezvous (established)";
case CIRCUIT_PURPOSE_C_GENERAL:
return "General-purpose client";
case CIRCUIT_PURPOSE_C_INTRODUCING:
return "Hidden service client: Connecting to intro point";
case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT:
return "Hidden service client: Waiting for ack from intro point";
case CIRCUIT_PURPOSE_C_INTRODUCE_ACKED:
return "Hidden service client: Received ack from intro point";
case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
return "Hidden service client: Establishing rendezvous point";
case CIRCUIT_PURPOSE_C_REND_READY:
return "Hidden service client: Pending rendezvous point";
case CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED:
return "Hidden service client: Pending rendezvous point (ack received)";
case CIRCUIT_PURPOSE_C_REND_JOINED:
return "Hidden service client: Active rendezvous point";
case CIRCUIT_PURPOSE_C_HSDIR_GET:
return "Hidden service client: Fetching HS descriptor";
case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
return "Measuring circuit timeout";
case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
return "Hidden service: Establishing introduction point";
case CIRCUIT_PURPOSE_S_INTRO:
return "Hidden service: Introduction point";
case CIRCUIT_PURPOSE_S_CONNECT_REND:
return "Hidden service: Connecting to rendezvous point";
case CIRCUIT_PURPOSE_S_REND_JOINED:
return "Hidden service: Active rendezvous point";
case CIRCUIT_PURPOSE_S_HSDIR_POST:
return "Hidden service: Uploading HS descriptor";
case CIRCUIT_PURPOSE_TESTING:
return "Testing circuit";
case CIRCUIT_PURPOSE_CONTROLLER:
return "Circuit made by controller";
case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
return "Path-bias testing circuit";
case CIRCUIT_PURPOSE_HS_VANGUARDS:
return "Hidden service: Pre-built vanguard circuit";
default:
tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
return buf;
}
}
/** Pick a reasonable package_window to start out for our circuits.
* Originally this was hard-coded at 1000, but now the consensus votes
* on the answer. See proposal 168. */
int32_t
circuit_initial_package_window(void)
{
int32_t num = networkstatus_get_param(NULL, "circwindow", CIRCWINDOW_START,
CIRCWINDOW_START_MIN,
CIRCWINDOW_START_MAX);
/* If the consensus tells us a negative number, we'd assert. */
if (num < 0)
num = CIRCWINDOW_START;
return num;
}
/** Initialize the common elements in a circuit_t, and add it to the global
* list. */
static void
init_circuit_base(circuit_t *circ)
{
tor_gettimeofday(&circ->timestamp_created);
// Gets reset when we send CREATE_FAST.
// circuit_expire_building() expects these to be equal
// until the orconn is built.
circ->timestamp_began = circ->timestamp_created;
circ->package_window = circuit_initial_package_window();
circ->deliver_window = CIRCWINDOW_START;
cell_queue_init(&circ->n_chan_cells);
smartlist_add(circuit_get_global_list(), circ);
circ->global_circuitlist_idx = smartlist_len(circuit_get_global_list()) - 1;
}
/** If we haven't yet decided on a good timeout value for circuit
* building, we close idle circuits aggressively so we can get more
* data points. These are the default, min, and max consensus values */
#define DFLT_IDLE_TIMEOUT_WHILE_LEARNING (3*60)
#define MIN_IDLE_TIMEOUT_WHILE_LEARNING (10)
#define MAX_IDLE_TIMEOUT_WHILE_LEARNING (1000*60)
/** Allocate space for a new circuit, initializing with <b>p_circ_id</b>
* and <b>p_conn</b>. Add it to the global circuit list.
*/
origin_circuit_t *
origin_circuit_new(void)
{
origin_circuit_t *circ;
/* never zero, since a global ID of 0 is treated specially by the
* controller */
static uint32_t n_circuits_allocated = 1;
circ = tor_malloc_zero(sizeof(origin_circuit_t));
circ->base_.magic = ORIGIN_CIRCUIT_MAGIC;
circ->next_stream_id = crypto_rand_int(1<<16);
circ->global_identifier = n_circuits_allocated++;
circ->remaining_relay_early_cells = MAX_RELAY_EARLY_CELLS_PER_CIRCUIT;
circ->remaining_relay_early_cells -= crypto_rand_int(2);
init_circuit_base(TO_CIRCUIT(circ));
/* Add to origin-list. */
circ->global_origin_circuit_list_idx = -1;
circuit_add_to_origin_circuit_list(circ);
circuit_build_times_update_last_circ(get_circuit_build_times_mutable());
if (! circuit_build_times_disabled(get_options()) &&
circuit_build_times_needs_circuits(get_circuit_build_times())) {
/* Circuits should be shorter lived if we need more of them
* for learning a good build timeout */
circ->circuit_idle_timeout =
networkstatus_get_param(NULL, "cbtlearntimeout",
DFLT_IDLE_TIMEOUT_WHILE_LEARNING,
MIN_IDLE_TIMEOUT_WHILE_LEARNING,
MAX_IDLE_TIMEOUT_WHILE_LEARNING);
} else {
// This should always be larger than the current port prediction time
// remaining, or else we'll end up with the case where a circuit times out
// and another one is built, effectively doubling the timeout window.
//
// We also randomize it by up to 5% more (ie 5% of 0 to 3600 seconds,
// depending on how much circuit prediction time is remaining) so that
// we don't close a bunch of unused circuits all at the same time.
int prediction_time_remaining =
predicted_ports_prediction_time_remaining(time(NULL));
circ->circuit_idle_timeout = prediction_time_remaining+1+
crypto_rand_int(1+prediction_time_remaining/20);
if (circ->circuit_idle_timeout <= 0) {
log_warn(LD_BUG,
"Circuit chose a negative idle timeout of %d based on "
"%d seconds of predictive building remaining.",