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tor/src/or/circuitlist.c
Nick Mathewson 1068e50aec Discard circuit paths on which nobody supports ntor 
Right now this accounts for about 1% of circuits over all, but if you
pick a guard that's running 0.2.3, it will be about 6% of the circuits
running through that guard.

Making sure that every circuit has at least one ntor link means that
we're getting plausibly good forward secrecy on every circuit.

This implements ticket 9777,
2014-02-07 10:45:34 -05:00

1785 lines
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/* Copyright 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file circuitlist.c
* \brief Manage the global circuit list.
**/
#include "or.h"
#include "channel.h"
#include "circuitbuild.h"
#include "circuitlist.h"
#include "circuituse.h"
#include "circuitstats.h"
#include "connection.h"
#include "config.h"
#include "connection_edge.h"
#include "connection_or.h"
#include "control.h"
#include "networkstatus.h"
#include "nodelist.h"
#include "onion.h"
#include "onion_fast.h"
#include "policies.h"
#include "relay.h"
#include "rendclient.h"
#include "rendcommon.h"
#include "rephist.h"
#include "routerlist.h"
#include "routerset.h"
#include "ht.h"
/********* START VARIABLES **********/
/** A global list of all circuits at this hop. */
circuit_t *global_circuitlist=NULL;
/** A list of all the circuits in CIRCUIT_STATE_CHAN_WAIT. */
static smartlist_t *circuits_pending_chans = NULL;
static void circuit_free(circuit_t *circ);
static void circuit_free_cpath(crypt_path_t *cpath);
static void circuit_free_cpath_node(crypt_path_t *victim);
static void cpath_ref_decref(crypt_path_reference_t *cpath_ref);
/********* END VARIABLES ************/
/** 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;
} 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)
{
return ((unsigned)a->circ_id) ^ (unsigned)(uintptr_t)(a->chan);
}
/** 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_GENERATE(chan_circid_map, chan_circid_circuit_map_t, node,
chan_circid_entry_hash_, chan_circid_entries_eq_, 0.6,
malloc, realloc, 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.
*/
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;
} 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;
}
}
/** 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 *circ, circid_t id,
channel_t *chan)
{
circuit_set_circid_chan_helper(TO_CIRCUIT(circ), CELL_DIRECTION_IN,
id, chan);
if (chan)
tor_assert(bool_eq(circ->p_chan_cells.n, circ->next_active_on_p_chan));
}
/** 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)
{
circuit_set_circid_chan_helper(circ, CELL_DIRECTION_OUT, id, chan);
if (chan)
tor_assert(bool_eq(circ->n_chan_cells.n, circ->next_active_on_n_chan));
}
/** 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 (!circuits_pending_chans)
circuits_pending_chans = 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 (state == CIRCUIT_STATE_OPEN)
tor_assert(!circ->n_chan_create_cell);
circ->state = state;
}
/** Add <b>circ</b> to the global list of circuits. This is called only from
* within circuit_new.
*/
static void
circuit_add(circuit_t *circ)
{
if (!global_circuitlist) { /* first one */
global_circuitlist = circ;
circ->next = NULL;
} else {
circ->next = global_circuitlist;
global_circuitlist = circ;
}
}
/** 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 at %s, %d pending circs",
chan->nickname ? chan->nickname : "NULL",
channel_get_canonical_remote_descr(chan),
cnt);
return cnt;
}
/** Detach from the global circuit list, and deallocate, all
* circuits that have been marked for close.
*/
void
circuit_close_all_marked(void)
{
circuit_t *tmp,*m;
while (global_circuitlist && global_circuitlist->marked_for_close) {
tmp = global_circuitlist->next;
circuit_free(global_circuitlist);
global_circuitlist = tmp;
}
tmp = global_circuitlist;
while (tmp && tmp->next) {
if (tmp->next->marked_for_close) {
m = tmp->next->next;
circuit_free(tmp->next);
tmp->next = m;
/* Need to check new tmp->next; don't advance tmp. */
} else {
/* Advance tmp. */
tmp = tmp->next;
}
}
}
/** Return the head of the global linked list of circuits. */
circuit_t *
circuit_get_global_list_(void)
{
return global_circuitlist;
}
/** 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_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_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_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";
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:
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_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_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 rendevous (pending)";
case CIRCUIT_PURPOSE_REND_ESTABLISHED:
return "Acting as rendevous (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_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_TESTING:
return "Testing circuit";
case CIRCUIT_PURPOSE_CONTROLLER:
return "Circuit made by controller";
case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
return "Path-bias testing 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;
circuit_add(circ);
}
/** 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));
circ_times.last_circ_at = approx_time();
return circ;
}
/** Allocate a new or_circuit_t, connected to <b>p_conn</b> as
* <b>p_circ_id</b>. If <b>p_conn</b> is NULL, the circuit is unattached. */
or_circuit_t *
or_circuit_new(circid_t p_circ_id, channel_t *p_chan)
{
/* CircIDs */
or_circuit_t *circ;
circ = tor_malloc_zero(sizeof(or_circuit_t));
circ->base_.magic = OR_CIRCUIT_MAGIC;
if (p_chan)
circuit_set_p_circid_chan(circ, p_circ_id, p_chan);
circ->remaining_relay_early_cells = MAX_RELAY_EARLY_CELLS_PER_CIRCUIT;
init_circuit_base(TO_CIRCUIT(circ));
return circ;
}
/** Deallocate space associated with circ.
*/
static void
circuit_free(circuit_t *circ)
{
void *mem;
size_t memlen;
if (!circ)
return;
if (CIRCUIT_IS_ORIGIN(circ)) {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
mem = ocirc;
memlen = sizeof(origin_circuit_t);
tor_assert(circ->magic == ORIGIN_CIRCUIT_MAGIC);
if (ocirc->build_state) {
extend_info_free(ocirc->build_state->chosen_exit);
circuit_free_cpath_node(ocirc->build_state->pending_final_cpath);
cpath_ref_decref(ocirc->build_state->service_pending_final_cpath_ref);
}
tor_free(ocirc->build_state);
circuit_free_cpath(ocirc->cpath);
crypto_pk_free(ocirc->intro_key);
rend_data_free(ocirc->rend_data);
tor_free(ocirc->dest_address);
if (ocirc->socks_username) {
memwipe(ocirc->socks_username, 0x12, ocirc->socks_username_len);
tor_free(ocirc->socks_username);
}
if (ocirc->socks_password) {
memwipe(ocirc->socks_password, 0x06, ocirc->socks_password_len);
tor_free(ocirc->socks_password);
}
addr_policy_list_free(ocirc->prepend_policy);
} else {
or_circuit_t *ocirc = TO_OR_CIRCUIT(circ);
/* Remember cell statistics for this circuit before deallocating. */
if (get_options()->CellStatistics)
rep_hist_buffer_stats_add_circ(circ, time(NULL));
mem = ocirc;
memlen = sizeof(or_circuit_t);
tor_assert(circ->magic == OR_CIRCUIT_MAGIC);
crypto_cipher_free(ocirc->p_crypto);
crypto_digest_free(ocirc->p_digest);
crypto_cipher_free(ocirc->n_crypto);
crypto_digest_free(ocirc->n_digest);
if (ocirc->rend_splice) {
or_circuit_t *other = ocirc->rend_splice;
tor_assert(other->base_.magic == OR_CIRCUIT_MAGIC);
other->rend_splice = NULL;
}
/* remove from map. */
circuit_set_p_circid_chan(ocirc, 0, NULL);
/* Clear cell queue _after_ removing it from the map. Otherwise our
* "active" checks will be violated. */
cell_queue_clear(&ocirc->p_chan_cells);
}
extend_info_free(circ->n_hop);
tor_free(circ->n_chan_create_cell);
/* Remove from map. */
circuit_set_n_circid_chan(circ, 0, NULL);
/* Clear cell queue _after_ removing it from the map. Otherwise our
* "active" checks will be violated. */
cell_queue_clear(&circ->n_chan_cells);
memwipe(mem, 0xAA, memlen); /* poison memory */
tor_free(mem);
}
/** Deallocate space associated with the linked list <b>cpath</b>. */
static void
circuit_free_cpath(crypt_path_t *cpath)
{
crypt_path_t *victim, *head=cpath;
if (!cpath)
return;
/* it's a circular list, so we have to notice when we've
* gone through it once. */
while (cpath->next && cpath->next != head) {
victim = cpath;
cpath = victim->next;
circuit_free_cpath_node(victim);
}
circuit_free_cpath_node(cpath);
}
/** Remove all the items in the cpath on <b>circ</b>.*/
void
circuit_clear_cpath(origin_circuit_t *circ)
{
circuit_free_cpath(circ->cpath);
circ->cpath = NULL;
}
/** Release all storage held by circuits. */
void
circuit_free_all(void)
{
circuit_t *next;
while (global_circuitlist) {
next = global_circuitlist->next;
if (! CIRCUIT_IS_ORIGIN(global_circuitlist)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(global_circuitlist);
while (or_circ->resolving_streams) {
edge_connection_t *next_conn;
next_conn = or_circ->resolving_streams->next_stream;
connection_free(TO_CONN(or_circ->resolving_streams));
or_circ->resolving_streams = next_conn;
}
}
circuit_free(global_circuitlist);
global_circuitlist = next;
}
smartlist_free(circuits_pending_chans);
circuits_pending_chans = NULL;
HT_CLEAR(chan_circid_map, &chan_circid_map);
}
/** Deallocate space associated with the cpath node <b>victim</b>. */
static void
circuit_free_cpath_node(crypt_path_t *victim)
{
if (!victim)
return;
crypto_cipher_free(victim->f_crypto);
crypto_cipher_free(victim->b_crypto);
crypto_digest_free(victim->f_digest);
crypto_digest_free(victim->b_digest);
onion_handshake_state_release(&victim->handshake_state);
crypto_dh_free(victim->rend_dh_handshake_state);
extend_info_free(victim->extend_info);
memwipe(victim, 0xBB, sizeof(crypt_path_t)); /* poison memory */
tor_free(victim);
}
/** Release a crypt_path_reference_t*, which may be NULL. */
static void
cpath_ref_decref(crypt_path_reference_t *cpath_ref)
{
if (cpath_ref != NULL) {
if (--(cpath_ref->refcount) == 0) {
circuit_free_cpath_node(cpath_ref->cpath);
tor_free(cpath_ref);
}
}
}
/** A helper function for circuit_dump_by_conn() below. Log a bunch
* of information about circuit <b>circ</b>.
*/
static void
circuit_dump_conn_details(int severity,
circuit_t *circ,
int conn_array_index,
const char *type,
circid_t this_circid,
circid_t other_circid)
{
tor_log(severity, LD_CIRC, "Conn %d has %s circuit: circID %u "
"(other side %u), state %d (%s), born %ld:",
conn_array_index, type, (unsigned)this_circid, (unsigned)other_circid,
circ->state, circuit_state_to_string(circ->state),
(long)circ->timestamp_began.tv_sec);
if (CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */
circuit_log_path(severity, LD_CIRC, TO_ORIGIN_CIRCUIT(circ));
}
}
/** Log, at severity <b>severity</b>, information about each circuit
* that is connected to <b>conn</b>.
*/
void
circuit_dump_by_conn(connection_t *conn, int severity)
{
circuit_t *circ;
edge_connection_t *tmpconn;
for (circ = global_circuitlist; circ; circ = circ->next) {
circid_t n_circ_id = circ->n_circ_id, p_circ_id = 0;
if (circ->marked_for_close) {
continue;
}
if (!CIRCUIT_IS_ORIGIN(circ)) {
p_circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
}
if (CIRCUIT_IS_ORIGIN(circ)) {
for (tmpconn=TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
tmpconn=tmpconn->next_stream) {
if (TO_CONN(tmpconn) == conn) {
circuit_dump_conn_details(severity, circ, conn->conn_array_index,
"App-ward", p_circ_id, n_circ_id);
}
}
}
if (! CIRCUIT_IS_ORIGIN(circ)) {
for (tmpconn=TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
tmpconn=tmpconn->next_stream) {
if (TO_CONN(tmpconn) == conn) {
circuit_dump_conn_details(severity, circ, conn->conn_array_index,
"Exit-ward", n_circ_id, p_circ_id);
}
}
}
}
}
/** A helper function for circuit_dump_by_chan() below. Log a bunch
* of information about circuit <b>circ</b>.
*/
static void
circuit_dump_chan_details(int severity,
circuit_t *circ,
channel_t *chan,
const char *type,
circid_t this_circid,
circid_t other_circid)
{
tor_log(severity, LD_CIRC, "Conn %p has %s circuit: circID %u "
"(other side %u), state %d (%s), born %ld:",
chan, type, (unsigned)this_circid, (unsigned)other_circid, circ->state,
circuit_state_to_string(circ->state),
(long)circ->timestamp_began.tv_sec);
if (CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */
circuit_log_path(severity, LD_CIRC, TO_ORIGIN_CIRCUIT(circ));
}
}
/** Log, at severity <b>severity</b>, information about each circuit
* that is connected to <b>chan</b>.
*/
void
circuit_dump_by_chan(channel_t *chan, int severity)
{
circuit_t *circ;
tor_assert(chan);
for (circ = global_circuitlist; circ; circ = circ->next) {
circid_t n_circ_id = circ->n_circ_id, p_circ_id = 0;
if (circ->marked_for_close) {
continue;
}
if (!CIRCUIT_IS_ORIGIN(circ)) {
p_circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
}
if (! CIRCUIT_IS_ORIGIN(circ) && TO_OR_CIRCUIT(circ)->p_chan &&
TO_OR_CIRCUIT(circ)->p_chan == chan) {
circuit_dump_chan_details(severity, circ, chan, "App-ward",
p_circ_id, n_circ_id);
}
if (circ->n_chan && circ->n_chan == chan) {
circuit_dump_chan_details(severity, circ, chan, "Exit-ward",
n_circ_id, p_circ_id);
}
if (!circ->n_chan && circ->n_hop &&
channel_matches_extend_info(chan, circ->n_hop) &&
tor_memeq(chan->identity_digest,
circ->n_hop->identity_digest, DIGEST_LEN)) {
circuit_dump_chan_details(severity, circ, chan,
(circ->state == CIRCUIT_STATE_OPEN &&
!CIRCUIT_IS_ORIGIN(circ)) ?
"Endpoint" : "Pending",
n_circ_id, p_circ_id);
}
}
}
/** Return the circuit whose global ID is <b>id</b>, or NULL if no
* such circuit exists. */
origin_circuit_t *
circuit_get_by_global_id(uint32_t id)
{
circuit_t *circ;
for (circ=global_circuitlist;circ;circ = circ->next) {
if (CIRCUIT_IS_ORIGIN(circ) &&
TO_ORIGIN_CIRCUIT(circ)->global_identifier == id) {
if (circ->marked_for_close)
return NULL;
else
return TO_ORIGIN_CIRCUIT(circ);
}
}
return NULL;
}
/** Return a circ such that:
* - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
* - circ is attached to <b>chan</b>, either as p_chan or n_chan.
* Return NULL if no such circuit exists.
*/
static INLINE circuit_t *
circuit_get_by_circid_channel_impl(circid_t circ_id, channel_t *chan)
{
chan_circid_circuit_map_t search;
chan_circid_circuit_map_t *found;
if (_last_circid_chan_ent &&
circ_id == _last_circid_chan_ent->circ_id &&
chan == _last_circid_chan_ent->chan) {
found = _last_circid_chan_ent;
} else {
search.circ_id = circ_id;
search.chan = chan;
found = HT_FIND(chan_circid_map, &chan_circid_map, &search);
_last_circid_chan_ent = found;
}
if (found && found->circuit) {
log_debug(LD_CIRC,
"circuit_get_by_circid_channel_impl() returning circuit %p for"
" circ_id %u, channel ID " U64_FORMAT " (%p)",
found->circuit, (unsigned)circ_id,
U64_PRINTF_ARG(chan->global_identifier), chan);
return found->circuit;
}
log_debug(LD_CIRC,
"circuit_get_by_circid_channel_impl() found nothing for"
" circ_id %u, channel ID " U64_FORMAT " (%p)",
(unsigned)circ_id,
U64_PRINTF_ARG(chan->global_identifier), chan);
return NULL;
/* The rest of this checks for bugs. Disabled by default. */
/* We comment it out because coverity complains otherwise.
{
circuit_t *circ;
for (circ=global_circuitlist;circ;circ = circ->next) {
if (! CIRCUIT_IS_ORIGIN(circ)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
if (or_circ->p_chan == chan && or_circ->p_circ_id == circ_id) {
log_warn(LD_BUG,
"circuit matches p_chan, but not in hash table (Bug!)");
return circ;
}
}
if (circ->n_chan == chan && circ->n_circ_id == circ_id) {
log_warn(LD_BUG,
"circuit matches n_chan, but not in hash table (Bug!)");
return circ;
}
}
return NULL;
} */
}
/** Return a circ such that:
* - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
* - circ is attached to <b>chan</b>, either as p_chan or n_chan.
* - circ is not marked for close.
* Return NULL if no such circuit exists.
*/
circuit_t *
circuit_get_by_circid_channel(circid_t circ_id, channel_t *chan)
{
circuit_t *circ = circuit_get_by_circid_channel_impl(circ_id, chan);
if (!circ || circ->marked_for_close)
return NULL;
else
return circ;
}
/** Return a circ such that:
* - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and
* - circ is attached to <b>chan</b>, either as p_chan or n_chan.
* Return NULL if no such circuit exists.
*/
circuit_t *
circuit_get_by_circid_channel_even_if_marked(circid_t circ_id,
channel_t *chan)
{
return circuit_get_by_circid_channel_impl(circ_id, chan);
}
/** Return true iff the circuit ID <b>circ_id</b> is currently used by a
* circuit, marked or not, on <b>chan</b>. */
int
circuit_id_in_use_on_channel(circid_t circ_id, channel_t *chan)
{
return circuit_get_by_circid_channel_impl(circ_id, chan) != NULL;
}
/** Return the circuit that a given edge connection is using. */
circuit_t *
circuit_get_by_edge_conn(edge_connection_t *conn)
{
circuit_t *circ;
circ = conn->on_circuit;
tor_assert(!circ ||
(CIRCUIT_IS_ORIGIN(circ) ? circ->magic == ORIGIN_CIRCUIT_MAGIC
: circ->magic == OR_CIRCUIT_MAGIC));
return circ;
}
/** For each circuit that has <b>chan</b> as n_chan or p_chan, unlink the
* circuit from the chan,circid map, and mark it for close if it hasn't
* been marked already.
*/
void
circuit_unlink_all_from_channel(channel_t *chan, int reason)
{
circuit_t *circ;
channel_unlink_all_circuits(chan);
for (circ = global_circuitlist; circ; circ = circ->next) {
int mark = 0;
if (circ->n_chan == chan) {
circuit_set_n_circid_chan(circ, 0, NULL);
mark = 1;
/* If we didn't request this closure, pass the remote
* bit to mark_for_close. */
if (chan->reason_for_closing != CHANNEL_CLOSE_REQUESTED)
reason |= END_CIRC_REASON_FLAG_REMOTE;
}
if (! CIRCUIT_IS_ORIGIN(circ)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
if (or_circ->p_chan == chan) {
circuit_set_p_circid_chan(or_circ, 0, NULL);
mark = 1;
}
}
if (mark && !circ->marked_for_close)
circuit_mark_for_close(circ, reason);
}
}
/** Return a circ such that
* - circ-\>rend_data-\>onion_address is equal to
* <b>rend_data</b>-\>onion_address,
* - circ-\>rend_data-\>rend_cookie is equal to
* <b>rend_data</b>-\>rend_cookie, and
* - circ-\>purpose is equal to CIRCUIT_PURPOSE_C_REND_READY.
*
* Return NULL if no such circuit exists.
*/
origin_circuit_t *
circuit_get_ready_rend_circ_by_rend_data(const rend_data_t *rend_data)
{
circuit_t *circ;
for (circ = global_circuitlist; circ; circ = circ->next) {
if (!circ->marked_for_close &&
circ->purpose == CIRCUIT_PURPOSE_C_REND_READY) {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
if (ocirc->rend_data &&
!rend_cmp_service_ids(rend_data->onion_address,
ocirc->rend_data->onion_address) &&
tor_memeq(ocirc->rend_data->rend_cookie,
rend_data->rend_cookie,
REND_COOKIE_LEN))
return ocirc;
}
}
return NULL;
}
/** Return the first circuit originating here in global_circuitlist after
* <b>start</b> whose purpose is <b>purpose</b>, and where
* <b>digest</b> (if set) matches the rend_pk_digest field. Return NULL if no
* circuit is found. If <b>start</b> is NULL, begin at the start of the list.
*/
origin_circuit_t *
circuit_get_next_by_pk_and_purpose(origin_circuit_t *start,
const char *digest, uint8_t purpose)
{
circuit_t *circ;
tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(purpose));
if (start == NULL)
circ = global_circuitlist;
else
circ = TO_CIRCUIT(start)->next;
for ( ; circ; circ = circ->next) {
if (circ->marked_for_close)
continue;
if (circ->purpose != purpose)
continue;
if (!digest)
return TO_ORIGIN_CIRCUIT(circ);
else if (TO_ORIGIN_CIRCUIT(circ)->rend_data &&
tor_memeq(TO_ORIGIN_CIRCUIT(circ)->rend_data->rend_pk_digest,
digest, DIGEST_LEN))
return TO_ORIGIN_CIRCUIT(circ);
}
return NULL;
}
/** Return the first OR circuit in the global list whose purpose is
* <b>purpose</b>, and whose rend_token is the <b>len</b>-byte
* <b>token</b>. */
static or_circuit_t *
circuit_get_by_rend_token_and_purpose(uint8_t purpose, const char *token,
size_t len)
{
circuit_t *circ;
for (circ = global_circuitlist; circ; circ = circ->next) {
if (! circ->marked_for_close &&
circ->purpose == purpose &&
tor_memeq(TO_OR_CIRCUIT(circ)->rend_token, token, len))
return TO_OR_CIRCUIT(circ);
}
return NULL;
}
/** Return the circuit waiting for a rendezvous with the provided cookie.
* Return NULL if no such circuit is found.
*/
or_circuit_t *
circuit_get_rendezvous(const char *cookie)
{
return circuit_get_by_rend_token_and_purpose(
CIRCUIT_PURPOSE_REND_POINT_WAITING,
cookie, REND_COOKIE_LEN);
}
/** Return the circuit waiting for intro cells of the given digest.
* Return NULL if no such circuit is found.
*/
or_circuit_t *
circuit_get_intro_point(const char *digest)
{
return circuit_get_by_rend_token_and_purpose(
CIRCUIT_PURPOSE_INTRO_POINT, digest,
DIGEST_LEN);
}
/** Return a circuit that is open, is CIRCUIT_PURPOSE_C_GENERAL,
* has a timestamp_dirty value of 0, has flags matching the CIRCLAUNCH_*
* flags in <b>flags</b>, and if info is defined, does not already use info
* as any of its hops; or NULL if no circuit fits this description.
*
* The <b>purpose</b> argument (currently ignored) refers to the purpose of
* the circuit we want to create, not the purpose of the circuit we want to
* cannibalize.
*
* If !CIRCLAUNCH_NEED_UPTIME, prefer returning non-uptime circuits.
*/
origin_circuit_t *
circuit_find_to_cannibalize(uint8_t purpose, extend_info_t *info,
int flags)
{
circuit_t *circ_;
origin_circuit_t *best=NULL;
int need_uptime = (flags & CIRCLAUNCH_NEED_UPTIME) != 0;
int need_capacity = (flags & CIRCLAUNCH_NEED_CAPACITY) != 0;
int internal = (flags & CIRCLAUNCH_IS_INTERNAL) != 0;
const or_options_t *options = get_options();
/* Make sure we're not trying to create a onehop circ by
* cannibalization. */
tor_assert(!(flags & CIRCLAUNCH_ONEHOP_TUNNEL));
log_debug(LD_CIRC,
"Hunting for a circ to cannibalize: purpose %d, uptime %d, "
"capacity %d, internal %d",
purpose, need_uptime, need_capacity, internal);
for (circ_=global_circuitlist; circ_; circ_ = circ_->next) {
if (CIRCUIT_IS_ORIGIN(circ_) &&
circ_->state == CIRCUIT_STATE_OPEN &&
!circ_->marked_for_close &&
circ_->purpose == CIRCUIT_PURPOSE_C_GENERAL &&
!circ_->timestamp_dirty) {
origin_circuit_t *circ = TO_ORIGIN_CIRCUIT(circ_);
if ((!need_uptime || circ->build_state->need_uptime) &&
(!need_capacity || circ->build_state->need_capacity) &&
(internal == circ->build_state->is_internal) &&
!circ->unusable_for_new_conns &&
circ->remaining_relay_early_cells &&
circ->build_state->desired_path_len == DEFAULT_ROUTE_LEN &&
!circ->build_state->onehop_tunnel &&
!circ->isolation_values_set) {
if (info) {
/* need to make sure we don't duplicate hops */
crypt_path_t *hop = circ->cpath;
const node_t *ri1 = node_get_by_id(info->identity_digest);
do {
const node_t *ri2;
if (tor_memeq(hop->extend_info->identity_digest,
info->identity_digest, DIGEST_LEN))
goto next;
if (ri1 &&
(ri2 = node_get_by_id(hop->extend_info->identity_digest))
&& nodes_in_same_family(ri1, ri2))
goto next;
hop=hop->next;
} while (hop!=circ->cpath);
}
if (options->ExcludeNodes) {
/* Make sure no existing nodes in the circuit are excluded for
* general use. (This may be possible if StrictNodes is 0, and we
* thought we needed to use an otherwise excluded node for, say, a
* directory operation.) */
crypt_path_t *hop = circ->cpath;
do {
if (routerset_contains_extendinfo(options->ExcludeNodes,
hop->extend_info))
goto next;
hop = hop->next;
} while (hop != circ->cpath);
}
if (!best || (best->build_state->need_uptime && !need_uptime))
best = circ;
next: ;
}
}
}
return best;
}
/** Return the number of hops in circuit's path. */
int
circuit_get_cpath_len(origin_circuit_t *circ)
{
int n = 0;
if (circ && circ->cpath) {
crypt_path_t *cpath, *cpath_next = NULL;
for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
cpath_next = cpath->next;
++n;
}
}
return n;
}
/** Return the <b>hopnum</b>th hop in <b>circ</b>->cpath, or NULL if there
* aren't that many hops in the list. */
crypt_path_t *
circuit_get_cpath_hop(origin_circuit_t *circ, int hopnum)
{
if (circ && circ->cpath && hopnum > 0) {
crypt_path_t *cpath, *cpath_next = NULL;
for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) {
cpath_next = cpath->next;
if (--hopnum <= 0)
return cpath;
}
}
return NULL;
}
/** Go through the circuitlist; mark-for-close each circuit that starts
* at us but has not yet been used. */
void
circuit_mark_all_unused_circs(void)
{
circuit_t *circ;
for (circ=global_circuitlist; circ; circ = circ->next) {
if (CIRCUIT_IS_ORIGIN(circ) &&
!circ->marked_for_close &&
!circ->timestamp_dirty)
circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
}
}
/** Go through the circuitlist; for each circuit that starts at us
* and is dirty, frob its timestamp_dirty so we won't use it for any
* new streams.
*
* This is useful for letting the user change pseudonyms, so new
* streams will not be linkable to old streams.
*/
void
circuit_mark_all_dirty_circs_as_unusable(void)
{
circuit_t *circ;
for (circ=global_circuitlist; circ; circ = circ->next) {
if (CIRCUIT_IS_ORIGIN(circ) &&
!circ->marked_for_close &&
circ->timestamp_dirty) {
mark_circuit_unusable_for_new_conns(TO_ORIGIN_CIRCUIT(circ));
}
}
}
/** Mark <b>circ</b> to be closed next time we call
* circuit_close_all_marked(). Do any cleanup needed:
* - If state is onionskin_pending, remove circ from the onion_pending
* list.
* - If circ isn't open yet: call circuit_build_failed() if we're
* the origin, and in either case call circuit_rep_hist_note_result()
* to note stats.
* - If purpose is C_INTRODUCE_ACK_WAIT, report the intro point
* failure we just had to the hidden service client module.
* - If purpose is C_INTRODUCING and <b>reason</b> isn't TIMEOUT,
* report to the hidden service client module that the intro point
* we just tried may be unreachable.
* - Send appropriate destroys and edge_destroys for conns and
* streams attached to circ.
* - If circ->rend_splice is set (we are the midpoint of a joined
* rendezvous stream), then mark the other circuit to close as well.
*/
void
circuit_mark_for_close_(circuit_t *circ, int reason, int line,
const char *file)
{
int orig_reason = reason; /* Passed to the controller */
assert_circuit_ok(circ);
tor_assert(line);
tor_assert(file);
if (circ->marked_for_close) {
log_warn(LD_BUG,
"Duplicate call to circuit_mark_for_close at %s:%d"
" (first at %s:%d)", file, line,
circ->marked_for_close_file, circ->marked_for_close);
return;
}
if (reason == END_CIRC_AT_ORIGIN) {
if (!CIRCUIT_IS_ORIGIN(circ)) {
log_warn(LD_BUG, "Specified 'at-origin' non-reason for ending circuit, "
"but circuit was not at origin. (called %s:%d, purpose=%d)",
file, line, circ->purpose);
}
reason = END_CIRC_REASON_NONE;
}
if (CIRCUIT_IS_ORIGIN(circ)) {
if (pathbias_check_close(TO_ORIGIN_CIRCUIT(circ), reason) == -1) {
/* Don't close it yet, we need to test it first */
return;
}
/* We don't send reasons when closing circuits at the origin. */
reason = END_CIRC_REASON_NONE;
}
if (reason & END_CIRC_REASON_FLAG_REMOTE)
reason &= ~END_CIRC_REASON_FLAG_REMOTE;
if (reason < END_CIRC_REASON_MIN_ || reason > END_CIRC_REASON_MAX_) {
if (!(orig_reason & END_CIRC_REASON_FLAG_REMOTE))
log_warn(LD_BUG, "Reason %d out of range at %s:%d", reason, file, line);
reason = END_CIRC_REASON_NONE;
}
if (circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) {
onion_pending_remove(TO_OR_CIRCUIT(circ));
}
/* If the circuit ever became OPEN, we sent it to the reputation history
* module then. If it isn't OPEN, we send it there now to remember which
* links worked and which didn't.
*/
if (circ->state != CIRCUIT_STATE_OPEN) {
if (CIRCUIT_IS_ORIGIN(circ)) {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
circuit_build_failed(ocirc); /* take actions if necessary */
circuit_rep_hist_note_result(ocirc);
}
}
if (circ->state == CIRCUIT_STATE_CHAN_WAIT) {
if (circuits_pending_chans)
smartlist_remove(circuits_pending_chans, circ);
}
if (CIRCUIT_IS_ORIGIN(circ)) {
control_event_circuit_status(TO_ORIGIN_CIRCUIT(circ),
(circ->state == CIRCUIT_STATE_OPEN)?CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED,
orig_reason);
}
if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
int timed_out = (reason == END_CIRC_REASON_TIMEOUT);
tor_assert(circ->state == CIRCUIT_STATE_OPEN);
tor_assert(ocirc->build_state->chosen_exit);
tor_assert(ocirc->rend_data);
/* treat this like getting a nack from it */
log_info(LD_REND, "Failed intro circ %s to %s (awaiting ack). %s",
safe_str_client(ocirc->rend_data->onion_address),
safe_str_client(build_state_get_exit_nickname(ocirc->build_state)),
timed_out ? "Recording timeout." : "Removing from descriptor.");
rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
ocirc->rend_data,
timed_out ?
INTRO_POINT_FAILURE_TIMEOUT :
INTRO_POINT_FAILURE_GENERIC);
} else if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
reason != END_CIRC_REASON_TIMEOUT) {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
if (ocirc->build_state->chosen_exit && ocirc->rend_data) {
log_info(LD_REND, "Failed intro circ %s to %s "
"(building circuit to intro point). "
"Marking intro point as possibly unreachable.",
safe_str_client(ocirc->rend_data->onion_address),
safe_str_client(build_state_get_exit_nickname(ocirc->build_state)));
rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
ocirc->rend_data,
INTRO_POINT_FAILURE_UNREACHABLE);
}
}
if (circ->n_chan) {
circuit_clear_cell_queue(circ, circ->n_chan);
/* Only send destroy if the channel isn't closing anyway */
if (!(circ->n_chan->state == CHANNEL_STATE_CLOSING ||
circ->n_chan->state == CHANNEL_STATE_CLOSED ||
circ->n_chan->state == CHANNEL_STATE_ERROR)) {
channel_send_destroy(circ->n_circ_id, circ->n_chan, reason);
}
circuitmux_detach_circuit(circ->n_chan->cmux, circ);
}
if (! CIRCUIT_IS_ORIGIN(circ)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
edge_connection_t *conn;
for (conn=or_circ->n_streams; conn; conn=conn->next_stream)
connection_edge_destroy(or_circ->p_circ_id, conn);
or_circ->n_streams = NULL;
while (or_circ->resolving_streams) {
conn = or_circ->resolving_streams;
or_circ->resolving_streams = conn->next_stream;
if (!conn->base_.marked_for_close) {
/* The client will see a DESTROY, and infer that the connections
* are closing because the circuit is getting torn down. No need
* to send an end cell. */
conn->edge_has_sent_end = 1;
conn->end_reason = END_STREAM_REASON_DESTROY;
conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
connection_mark_for_close(TO_CONN(conn));
}
conn->on_circuit = NULL;
}
if (or_circ->p_chan) {
circuit_clear_cell_queue(circ, or_circ->p_chan);
/* Only send destroy if the channel isn't closing anyway */
if (!(or_circ->p_chan->state == CHANNEL_STATE_CLOSING ||
or_circ->p_chan->state == CHANNEL_STATE_CLOSED ||
or_circ->p_chan->state == CHANNEL_STATE_ERROR)) {
channel_send_destroy(or_circ->p_circ_id, or_circ->p_chan, reason);
}
circuitmux_detach_circuit(or_circ->p_chan->cmux, circ);
}
} else {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
edge_connection_t *conn;
for (conn=ocirc->p_streams; conn; conn=conn->next_stream)
connection_edge_destroy(circ->n_circ_id, conn);
ocirc->p_streams = NULL;
}
circ->marked_for_close = line;
circ->marked_for_close_file = file;
if (!CIRCUIT_IS_ORIGIN(circ)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
if (or_circ->rend_splice) {
if (!or_circ->rend_splice->base_.marked_for_close) {
/* do this after marking this circuit, to avoid infinite recursion. */
circuit_mark_for_close(TO_CIRCUIT(or_circ->rend_splice), reason);
}
or_circ->rend_splice = NULL;
}
}
}
/** Given a marked circuit <b>circ</b>, aggressively free its cell queues to
* recover memory. */
static void
marked_circuit_free_cells(circuit_t *circ)
{
if (!circ->marked_for_close) {
log_warn(LD_BUG, "Called on non-marked circuit");
return;
}
cell_queue_clear(&circ->n_chan_cells);
if (! CIRCUIT_IS_ORIGIN(circ))
cell_queue_clear(& TO_OR_CIRCUIT(circ)->p_chan_cells);
}
/** Return the number of cells used by the circuit <b>c</b>'s cell queues. */
static size_t
n_cells_in_circ_queues(const circuit_t *c)
{
size_t n = c->n_chan_cells.n;
if (! CIRCUIT_IS_ORIGIN(c)) {
circuit_t *cc = (circuit_t *) c;
n += TO_OR_CIRCUIT(cc)->p_chan_cells.n;
}
return n;
}
/**
* Return the age of the oldest cell queued on <b>c</b>, in milliseconds.
* Return 0 if there are no cells queued on c. Requires that <b>now</b> be
* the current time in milliseconds since the epoch, truncated.
*
* This function will return incorrect results if the oldest cell queued on
* the circuit is older than 2**32 msec (about 49 days) old.
*/
static uint32_t
circuit_max_queued_cell_age(const circuit_t *c, uint32_t now)
{
uint32_t age = 0;
if (c->n_chan_cells.head)
age = now - c->n_chan_cells.head->inserted_time;
if (! CIRCUIT_IS_ORIGIN(c)) {
const or_circuit_t *orcirc = TO_OR_CIRCUIT((circuit_t*)c);
if (orcirc->p_chan_cells.head) {
uint32_t age2 = now - orcirc->p_chan_cells.head->inserted_time;
if (age2 > age)
return age2;
}
}
return age;
}
/** Temporary variable for circuits_compare_by_oldest_queued_cell_ This is a
* kludge to work around the fact that qsort doesn't provide a way for
* comparison functions to take an extra argument. */
static uint32_t circcomp_now_tmp;
/** Helper to sort a list of circuit_t by age of oldest cell, in descending
* order. Requires that circcomp_now_tmp is set correctly. */
static int
circuits_compare_by_oldest_queued_cell_(const void **a_, const void **b_)
{
const circuit_t *a = *a_;
const circuit_t *b = *b_;
uint32_t age_a = circuit_max_queued_cell_age(a, circcomp_now_tmp);
uint32_t age_b = circuit_max_queued_cell_age(b, circcomp_now_tmp);
if (age_a < age_b)
return 1;
else if (age_a == age_b)
return 0;
else
return -1;
}
#define FRACTION_OF_CELLS_TO_RETAIN_ON_OOM 0.90
/** We're out of memory for cells, having allocated <b>current_allocation</b>
* bytes' worth. Kill the 'worst' circuits until we're under
* FRACTION_OF_CIRCS_TO_RETAIN_ON_OOM of our maximum usage. */
void
circuits_handle_oom(size_t current_allocation)
{
/* Let's hope there's enough slack space for this allocation here... */
smartlist_t *circlist = smartlist_new();
circuit_t *circ;
size_t n_cells_removed=0, n_cells_to_remove;
int n_circuits_killed=0;
struct timeval now;
log_notice(LD_GENERAL, "We're low on memory. Killing circuits with "
"over-long queues. (This behavior is controlled by "
"MaxMemInCellQueues.)");
{
size_t mem_target = (size_t)(get_options()->MaxMemInCellQueues *
FRACTION_OF_CELLS_TO_RETAIN_ON_OOM);
size_t mem_to_recover;
if (current_allocation <= mem_target)
return;
mem_to_recover = current_allocation - mem_target;
n_cells_to_remove = CEIL_DIV(mem_to_recover, packed_cell_mem_cost());
}
/* This algorithm itself assumes that you've got enough memory slack
* to actually run it. */
for (circ = global_circuitlist; circ; circ = circ->next)
smartlist_add(circlist, circ);
/* Set circcomp_now_tmp so that the sort can work. */
tor_gettimeofday_cached(&now);
circcomp_now_tmp = (uint32_t)tv_to_msec(&now);
/* This is O(n log n); there are faster algorithms we could use instead.
* Let's hope this doesn't happen enough to be in the critical path. */
smartlist_sort(circlist, circuits_compare_by_oldest_queued_cell_);
/* Okay, now the worst circuits are at the front of the list. Let's mark
* them, and reclaim their storage aggressively. */
SMARTLIST_FOREACH_BEGIN(circlist, circuit_t *, circ) {
size_t n = n_cells_in_circ_queues(circ);
if (! circ->marked_for_close) {
circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
}
marked_circuit_free_cells(circ);
++n_circuits_killed;
n_cells_removed += n;
if (n_cells_removed >= n_cells_to_remove)
break;
} SMARTLIST_FOREACH_END(circ);
clean_cell_pool(); /* In case this helps. */
log_notice(LD_GENERAL, "Removed "U64_FORMAT" bytes by killing %d circuits.",
U64_PRINTF_ARG(n_cells_removed * packed_cell_mem_cost()),
n_circuits_killed);
smartlist_free(circlist);
}
/** Verify that cpath layer <b>cp</b> has all of its invariants
* correct. Trigger an assert if anything is invalid.
*/
void
assert_cpath_layer_ok(const crypt_path_t *cp)
{
// tor_assert(cp->addr); /* these are zero for rendezvous extra-hops */
// tor_assert(cp->port);
tor_assert(cp);
tor_assert(cp->magic == CRYPT_PATH_MAGIC);
switch (cp->state)
{
case CPATH_STATE_OPEN:
tor_assert(cp->f_crypto);
tor_assert(cp->b_crypto);
/* fall through */
case CPATH_STATE_CLOSED:
/*XXXX Assert that there's no handshake_state either. */
tor_assert(!cp->rend_dh_handshake_state);
break;
case CPATH_STATE_AWAITING_KEYS:
/* tor_assert(cp->dh_handshake_state); */
break;
default:
log_fn(LOG_ERR, LD_BUG, "Unexpected state %d", cp->state);
tor_assert(0);
}
tor_assert(cp->package_window >= 0);
tor_assert(cp->deliver_window >= 0);
}
/** Verify that cpath <b>cp</b> has all of its invariants
* correct. Trigger an assert if anything is invalid.
*/
static void
assert_cpath_ok(const crypt_path_t *cp)
{
const crypt_path_t *start = cp;
do {
assert_cpath_layer_ok(cp);
/* layers must be in sequence of: "open* awaiting? closed*" */
if (cp != start) {
if (cp->state == CPATH_STATE_AWAITING_KEYS) {
tor_assert(cp->prev->state == CPATH_STATE_OPEN);
} else if (cp->state == CPATH_STATE_OPEN) {
tor_assert(cp->prev->state == CPATH_STATE_OPEN);
}
}
cp = cp->next;
tor_assert(cp);
} while (cp != start);
}
/** Verify that circuit <b>c</b> has all of its invariants
* correct. Trigger an assert if anything is invalid.
*/
void
assert_circuit_ok(const circuit_t *c)
{
edge_connection_t *conn;
const or_circuit_t *or_circ = NULL;
const origin_circuit_t *origin_circ = NULL;
tor_assert(c);
tor_assert(c->magic == ORIGIN_CIRCUIT_MAGIC || c->magic == OR_CIRCUIT_MAGIC);
tor_assert(c->purpose >= CIRCUIT_PURPOSE_MIN_ &&
c->purpose <= CIRCUIT_PURPOSE_MAX_);
{
/* Having a separate variable for this pleases GCC 4.2 in ways I hope I
* never understand. -NM. */
circuit_t *nonconst_circ = (circuit_t*) c;
if (CIRCUIT_IS_ORIGIN(c))
origin_circ = TO_ORIGIN_CIRCUIT(nonconst_circ);
else
or_circ = TO_OR_CIRCUIT(nonconst_circ);
}
if (c->n_chan) {
tor_assert(!c->n_hop);
if (c->n_circ_id) {
/* We use the _impl variant here to make sure we don't fail on marked
* circuits, which would not be returned by the regular function. */
circuit_t *c2 = circuit_get_by_circid_channel_impl(c->n_circ_id,
c->n_chan);
tor_assert(c == c2);
}
}
if (or_circ && or_circ->p_chan) {
if (or_circ->p_circ_id) {
/* ibid */
circuit_t *c2 = circuit_get_by_circid_channel_impl(or_circ->p_circ_id,
or_circ->p_chan);
tor_assert(c == c2);
}
}
if (or_circ)
for (conn = or_circ->n_streams; conn; conn = conn->next_stream)
tor_assert(conn->base_.type == CONN_TYPE_EXIT);
tor_assert(c->deliver_window >= 0);
tor_assert(c->package_window >= 0);
if (c->state == CIRCUIT_STATE_OPEN) {
tor_assert(!c->n_chan_create_cell);
if (or_circ) {
tor_assert(or_circ->n_crypto);
tor_assert(or_circ->p_crypto);
tor_assert(or_circ->n_digest);
tor_assert(or_circ->p_digest);
}
}
if (c->state == CIRCUIT_STATE_CHAN_WAIT && !c->marked_for_close) {
tor_assert(circuits_pending_chans &&
smartlist_contains(circuits_pending_chans, c));
} else {
tor_assert(!circuits_pending_chans ||
!smartlist_contains(circuits_pending_chans, c));
}
if (origin_circ && origin_circ->cpath) {
assert_cpath_ok(origin_circ->cpath);
}
if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) {
tor_assert(or_circ);
if (!c->marked_for_close) {
tor_assert(or_circ->rend_splice);
tor_assert(or_circ->rend_splice->rend_splice == or_circ);
}
tor_assert(or_circ->rend_splice != or_circ);
} else {
tor_assert(!or_circ || !or_circ->rend_splice);
}
}
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