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Diffstat (limited to 'src/or/entrynodes.c')
-rw-r--r-- | src/or/entrynodes.c | 2561 |
1 files changed, 0 insertions, 2561 deletions
diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c deleted file mode 100644 index 265b6dcda1..0000000000 --- a/src/or/entrynodes.c +++ /dev/null @@ -1,2561 +0,0 @@ -/* Copyright (c) 2001 Matej Pfajfar. - * Copyright (c) 2001-2004, Roger Dingledine. - * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2016, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file entrynodes.c - * \brief Code to manage our fixed first nodes for various functions. - * - * Entry nodes can be guards (for general use) or bridges (for censorship - * circumvention). - **/ - -#define ENTRYNODES_PRIVATE - -#include "or.h" -#include "circpathbias.h" -#include "circuitbuild.h" -#include "circuitstats.h" -#include "config.h" -#include "confparse.h" -#include "connection.h" -#include "connection_or.h" -#include "control.h" -#include "directory.h" -#include "entrynodes.h" -#include "main.h" -#include "microdesc.h" -#include "networkstatus.h" -#include "nodelist.h" -#include "policies.h" -#include "router.h" -#include "routerlist.h" -#include "routerparse.h" -#include "routerset.h" -#include "transports.h" -#include "statefile.h" - -/** Information about a configured bridge. Currently this just matches the - * ones in the torrc file, but one day we may be able to learn about new - * bridges on our own, and remember them in the state file. */ -typedef struct { - /** Address of the bridge. */ - tor_addr_t addr; - /** TLS port for the bridge. */ - uint16_t port; - /** Boolean: We are re-parsing our bridge list, and we are going to remove - * this one if we don't find it in the list of configured bridges. */ - unsigned marked_for_removal : 1; - /** Expected identity digest, or all zero bytes if we don't know what the - * digest should be. */ - char identity[DIGEST_LEN]; - - /** Name of pluggable transport protocol taken from its config line. */ - char *transport_name; - - /** When should we next try to fetch a descriptor for this bridge? */ - download_status_t fetch_status; - - /** A smartlist of k=v values to be passed to the SOCKS proxy, if - transports are used for this bridge. */ - smartlist_t *socks_args; -} bridge_info_t; - -/** A list of our chosen entry guards. */ -static smartlist_t *entry_guards = NULL; -/** A value of 1 means that the entry_guards list has changed - * and those changes need to be flushed to disk. */ -static int entry_guards_dirty = 0; - -static void bridge_free(bridge_info_t *bridge); -static const node_t *choose_random_entry_impl(cpath_build_state_t *state, - int for_directory, - dirinfo_type_t dirtype, - int *n_options_out); -static int num_bridges_usable(void); - -/* Default number of entry guards in the case where the NumEntryGuards - * consensus parameter is not set */ -#define DEFAULT_N_GUARDS 1 -/* Minimum and maximum number of entry guards (in case the NumEntryGuards - * consensus parameter is set). */ -#define MIN_N_GUARDS 1 -#define MAX_N_GUARDS 10 - -/** Return the list of entry guards, creating it if necessary. */ -const smartlist_t * -get_entry_guards(void) -{ - if (! entry_guards) - entry_guards = smartlist_new(); - return entry_guards; -} - -/** Check whether the entry guard <b>e</b> is usable, given the directory - * authorities' opinion about the router (stored in <b>ri</b>) and the user's - * configuration (in <b>options</b>). Set <b>e</b>->bad_since - * accordingly. Return true iff the entry guard's status changes. - * - * If it's not usable, set *<b>reason</b> to a static string explaining why. - */ -static int -entry_guard_set_status(entry_guard_t *e, const node_t *node, - time_t now, const or_options_t *options, - const char **reason) -{ - char buf[HEX_DIGEST_LEN+1]; - int changed = 0; - - *reason = NULL; - - /* Do we want to mark this guard as bad? */ - if (!node) - *reason = "unlisted"; - else if (!node->is_running) - *reason = "down"; - else if (options->UseBridges && (!node->ri || - node->ri->purpose != ROUTER_PURPOSE_BRIDGE)) - *reason = "not a bridge"; - else if (options->UseBridges && !node_is_a_configured_bridge(node)) - *reason = "not a configured bridge"; - else if (!options->UseBridges && !node->is_possible_guard && - !routerset_contains_node(options->EntryNodes,node)) - *reason = "not recommended as a guard"; - else if (routerset_contains_node(options->ExcludeNodes, node)) - *reason = "excluded"; - /* We only care about OR connection connectivity for entry guards. */ - else if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, 0)) - *reason = "unreachable by config"; - else if (e->path_bias_disabled) - *reason = "path-biased"; - - if (*reason && ! e->bad_since) { - /* Router is newly bad. */ - base16_encode(buf, sizeof(buf), e->identity, DIGEST_LEN); - log_info(LD_CIRC, "Entry guard %s (%s) is %s: marking as unusable.", - e->nickname, buf, *reason); - - e->bad_since = now; - control_event_guard(e->nickname, e->identity, "BAD"); - changed = 1; - } else if (!*reason && e->bad_since) { - /* There's nothing wrong with the router any more. */ - base16_encode(buf, sizeof(buf), e->identity, DIGEST_LEN); - log_info(LD_CIRC, "Entry guard %s (%s) is no longer unusable: " - "marking as ok.", e->nickname, buf); - - e->bad_since = 0; - control_event_guard(e->nickname, e->identity, "GOOD"); - changed = 1; - } - - if (node) { - int is_dir = node_is_dir(node); - if (options->UseBridges && node_is_a_configured_bridge(node)) - is_dir = 1; - if (e->is_dir_cache != is_dir) { - e->is_dir_cache = is_dir; - changed = 1; - } - } - - return changed; -} - -/** Return true iff enough time has passed since we last tried to connect - * to the unreachable guard <b>e</b> that we're willing to try again. */ -STATIC int -entry_is_time_to_retry(const entry_guard_t *e, time_t now) -{ - struct guard_retry_period_s { - time_t period_duration; - time_t interval_during_period; - }; - - struct guard_retry_period_s periods[] = { - { 6*60*60, 60*60 }, /* For first 6 hrs., retry hourly; */ - { 3*24*60*60, 4*60*60 }, /* Then retry every 4 hrs. until the - 3-day mark; */ - { 7*24*60*60, 18*60*60 }, /* After 3 days, retry every 18 hours until - 1 week mark. */ - { TIME_MAX, 36*60*60 } /* After 1 week, retry every 36 hours. */ - }; - - time_t ith_deadline_for_retry; - time_t unreachable_for; - unsigned i; - - if (e->last_attempted < e->unreachable_since) - return 1; - - unreachable_for = now - e->unreachable_since; - - for (i = 0; i < ARRAY_LENGTH(periods); i++) { - if (unreachable_for <= periods[i].period_duration) { - ith_deadline_for_retry = e->last_attempted + - periods[i].interval_during_period; - - return (now > ith_deadline_for_retry); - } - } - return 0; -} - -/** Return the node corresponding to <b>e</b>, if <b>e</b> is - * working well enough that we are willing to use it as an entry - * right now. (Else return NULL.) In particular, it must be - * - Listed as either up or never yet contacted; - * - Present in the routerlist; - * - Listed as 'stable' or 'fast' by the current dirserver consensus, - * if demanded by <b>need_uptime</b> or <b>need_capacity</b> - * (unless it's a configured EntryNode); - * - Allowed by our current ReachableORAddresses config option; and - * - Currently thought to be reachable by us (unless <b>assume_reachable</b> - * is true). - * - * If the answer is no, set *<b>msg</b> to an explanation of why. - * - * If need_descriptor is true, only return the node if we currently have - * a descriptor (routerinfo or microdesc) for it. - */ -STATIC const node_t * -entry_is_live(const entry_guard_t *e, entry_is_live_flags_t flags, - const char **msg) -{ - const node_t *node; - const or_options_t *options = get_options(); - int need_uptime = (flags & ENTRY_NEED_UPTIME) != 0; - int need_capacity = (flags & ENTRY_NEED_CAPACITY) != 0; - const int assume_reachable = (flags & ENTRY_ASSUME_REACHABLE) != 0; - const int need_descriptor = (flags & ENTRY_NEED_DESCRIPTOR) != 0; - - tor_assert(msg); - - if (e->path_bias_disabled) { - *msg = "path-biased"; - return NULL; - } - if (e->bad_since) { - *msg = "bad"; - return NULL; - } - /* no good if it's unreachable, unless assume_unreachable or can_retry. */ - if (!assume_reachable && !e->can_retry && - e->unreachable_since && !entry_is_time_to_retry(e, time(NULL))) { - *msg = "unreachable"; - return NULL; - } - node = node_get_by_id(e->identity); - if (!node) { - *msg = "no node info"; - return NULL; - } - if (need_descriptor && !node_has_descriptor(node)) { - *msg = "no descriptor"; - return NULL; - } - if (get_options()->UseBridges) { - if (node_get_purpose(node) != ROUTER_PURPOSE_BRIDGE) { - *msg = "not a bridge"; - return NULL; - } - if (!node_is_a_configured_bridge(node)) { - *msg = "not a configured bridge"; - return NULL; - } - } else { /* !get_options()->UseBridges */ - if (node_get_purpose(node) != ROUTER_PURPOSE_GENERAL) { - *msg = "not general-purpose"; - return NULL; - } - } - if (routerset_contains_node(options->EntryNodes, node)) { - /* they asked for it, they get it */ - need_uptime = need_capacity = 0; - } - if (node_is_unreliable(node, need_uptime, need_capacity, 0)) { - *msg = "not fast/stable"; - return NULL; - } - if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, 0)) { - *msg = "unreachable by config"; - return NULL; - } - return node; -} - -/** Return the number of entry guards that we think are usable. */ -int -num_live_entry_guards(int for_directory) -{ - int n = 0; - const char *msg; - /* Set the entry node attributes we are interested in. */ - entry_is_live_flags_t entry_flags = ENTRY_NEED_CAPACITY; - if (!for_directory) { - entry_flags |= ENTRY_NEED_DESCRIPTOR; - } - - if (! entry_guards) - return 0; - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, entry) { - if (for_directory && !entry->is_dir_cache) - continue; - if (entry_is_live(entry, entry_flags, &msg)) - ++n; - } SMARTLIST_FOREACH_END(entry); - return n; -} - -/** If <b>digest</b> matches the identity of any node in the - * entry_guards list, return that node. Else return NULL. */ -entry_guard_t * -entry_guard_get_by_id_digest(const char *digest) -{ - SMARTLIST_FOREACH(entry_guards, entry_guard_t *, entry, - if (tor_memeq(digest, entry->identity, DIGEST_LEN)) - return entry; - ); - return NULL; -} - -/** Dump a description of our list of entry guards to the log at level - * <b>severity</b>. */ -static void -log_entry_guards(int severity) -{ - smartlist_t *elements = smartlist_new(); - char *s; - - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) - { - const char *msg = NULL; - if (entry_is_live(e, ENTRY_NEED_CAPACITY, &msg)) - smartlist_add_asprintf(elements, "%s [%s] (up %s)", - e->nickname, - hex_str(e->identity, DIGEST_LEN), - e->made_contact ? "made-contact" : "never-contacted"); - else - smartlist_add_asprintf(elements, "%s [%s] (%s, %s)", - e->nickname, - hex_str(e->identity, DIGEST_LEN), - msg, - e->made_contact ? "made-contact" : "never-contacted"); - } - SMARTLIST_FOREACH_END(e); - - s = smartlist_join_strings(elements, ",", 0, NULL); - SMARTLIST_FOREACH(elements, char*, cp, tor_free(cp)); - smartlist_free(elements); - log_fn(severity,LD_CIRC,"%s",s); - tor_free(s); -} - -/** Called when one or more guards that we would previously have used for some - * purpose are no longer in use because a higher-priority guard has become - * usable again. */ -static void -control_event_guard_deferred(void) -{ - /* XXXX We don't actually have a good way to figure out _how many_ entries - * are live for some purpose. We need an entry_is_even_slightly_live() - * function for this to work right. NumEntryGuards isn't reliable: if we - * need guards with weird properties, we can have more than that number - * live. - **/ -#if 0 - int n = 0; - const char *msg; - const or_options_t *options = get_options(); - if (!entry_guards) - return; - SMARTLIST_FOREACH(entry_guards, entry_guard_t *, entry, - { - if (entry_is_live(entry, 0, 1, 0, &msg)) { - if (n++ == options->NumEntryGuards) { - control_event_guard(entry->nickname, entry->identity, "DEFERRED"); - return; - } - } - }); -#endif -} - -/** Largest amount that we'll backdate chosen_on_date */ -#define CHOSEN_ON_DATE_SLOP (30*86400) - -/** Add a new (preferably stable and fast) router to our - * entry_guards list. Return a pointer to the router if we succeed, - * or NULL if we can't find any more suitable entries. - * - * If <b>chosen</b> is defined, use that one, and if it's not - * already in our entry_guards list, put it at the *beginning*. - * Else, put the one we pick at the end of the list. */ -STATIC const node_t * -add_an_entry_guard(const node_t *chosen, int reset_status, int prepend, - int for_discovery, int for_directory) -{ - const node_t *node; - entry_guard_t *entry; - - if (chosen) { - node = chosen; - entry = entry_guard_get_by_id_digest(node->identity); - if (entry) { - if (reset_status) { - entry->bad_since = 0; - entry->can_retry = 1; - } - entry->is_dir_cache = node_is_dir(node); - if (get_options()->UseBridges && node_is_a_configured_bridge(node)) - entry->is_dir_cache = 1; - - return NULL; - } - } else if (!for_directory) { - node = choose_good_entry_server(CIRCUIT_PURPOSE_C_GENERAL, NULL); - if (!node) - return NULL; - } else { - const routerstatus_t *rs; - rs = router_pick_directory_server(MICRODESC_DIRINFO|V3_DIRINFO, - PDS_FOR_GUARD); - if (!rs) - return NULL; - node = node_get_by_id(rs->identity_digest); - if (!node) - return NULL; - } - if (node->using_as_guard) - return NULL; - if (entry_guard_get_by_id_digest(node->identity) != NULL) { - log_info(LD_CIRC, "I was about to add a duplicate entry guard."); - /* This can happen if we choose a guard, then the node goes away, then - * comes back. */ - ((node_t*) node)->using_as_guard = 1; - return NULL; - } - entry = tor_malloc_zero(sizeof(entry_guard_t)); - log_info(LD_CIRC, "Chose %s as new entry guard.", - node_describe(node)); - strlcpy(entry->nickname, node_get_nickname(node), sizeof(entry->nickname)); - memcpy(entry->identity, node->identity, DIGEST_LEN); - entry->is_dir_cache = node_is_dir(node); - if (get_options()->UseBridges && node_is_a_configured_bridge(node)) - entry->is_dir_cache = 1; - - /* Choose expiry time smudged over the past month. The goal here - * is to a) spread out when Tor clients rotate their guards, so they - * don't all select them on the same day, and b) avoid leaving a - * precise timestamp in the state file about when we first picked - * this guard. For details, see the Jan 2010 or-dev thread. */ - time_t now = time(NULL); - entry->chosen_on_date = crypto_rand_time_range(now - 3600*24*30, now); - entry->chosen_by_version = tor_strdup(VERSION); - - /* Are we picking this guard because all of our current guards are - * down so we need another one (for_discovery is 1), or because we - * decided we need more variety in our guard list (for_discovery is 0)? - * - * Currently we hack this behavior into place by setting "made_contact" - * for guards of the latter variety, so we'll be willing to use any of - * them right off the bat. - */ - if (!for_discovery) - entry->made_contact = 1; - - ((node_t*)node)->using_as_guard = 1; - if (prepend) - smartlist_insert(entry_guards, 0, entry); - else - smartlist_add(entry_guards, entry); - control_event_guard(entry->nickname, entry->identity, "NEW"); - control_event_guard_deferred(); - log_entry_guards(LOG_INFO); - return node; -} - -/** Choose how many entry guards or directory guards we'll use. If - * <b>for_directory</b> is true, we return how many directory guards to - * use; else we return how many entry guards to use. */ -STATIC int -decide_num_guards(const or_options_t *options, int for_directory) -{ - if (for_directory) { - int answer; - if (options->NumDirectoryGuards != 0) - return options->NumDirectoryGuards; - answer = networkstatus_get_param(NULL, "NumDirectoryGuards", 0, 0, 10); - if (answer) /* non-zero means use the consensus value */ - return answer; - } - - if (options->NumEntryGuards) - return options->NumEntryGuards; - - /* Use the value from the consensus, or 3 if no guidance. */ - return networkstatus_get_param(NULL, "NumEntryGuards", DEFAULT_N_GUARDS, - MIN_N_GUARDS, MAX_N_GUARDS); -} - -/** If the use of entry guards is configured, choose more entry guards - * until we have enough in the list. */ -static void -pick_entry_guards(const or_options_t *options, int for_directory) -{ - int changed = 0; - const int num_needed = decide_num_guards(options, for_directory); - - tor_assert(entry_guards); - - while (num_live_entry_guards(for_directory) < num_needed) { - if (!add_an_entry_guard(NULL, 0, 0, 0, for_directory)) - break; - changed = 1; - } - if (changed) - entry_guards_changed(); -} - -/** How long (in seconds) do we allow an entry guard to be nonfunctional, - * unlisted, excluded, or otherwise nonusable before we give up on it? */ -#define ENTRY_GUARD_REMOVE_AFTER (30*24*60*60) - -/** Release all storage held by <b>e</b>. */ -static void -entry_guard_free(entry_guard_t *e) -{ - if (!e) - return; - tor_free(e->chosen_by_version); - tor_free(e); -} - -/** - * Return the minimum lifetime of working entry guard, in seconds, - * as given in the consensus networkstatus. (Plus CHOSEN_ON_DATE_SLOP, - * so that we can do the chosen_on_date randomization while achieving the - * desired minimum lifetime.) - */ -static int32_t -guards_get_lifetime(void) -{ - const or_options_t *options = get_options(); -#define DFLT_GUARD_LIFETIME (86400 * 60) /* Two months. */ -#define MIN_GUARD_LIFETIME (86400 * 30) /* One months. */ -#define MAX_GUARD_LIFETIME (86400 * 1826) /* Five years. */ - - if (options->GuardLifetime >= 1) { - return CLAMP(MIN_GUARD_LIFETIME, - options->GuardLifetime, - MAX_GUARD_LIFETIME) + CHOSEN_ON_DATE_SLOP; - } - - return networkstatus_get_param(NULL, "GuardLifetime", - DFLT_GUARD_LIFETIME, - MIN_GUARD_LIFETIME, - MAX_GUARD_LIFETIME) + CHOSEN_ON_DATE_SLOP; -} - -/** Remove any entry guard which was selected by an unknown version of Tor, - * or which was selected by a version of Tor that's known to select - * entry guards badly, or which was selected more 2 months ago. */ -/* XXXX The "obsolete guards" and "chosen long ago guards" things should - * probably be different functions. */ -static int -remove_obsolete_entry_guards(time_t now) -{ - int changed = 0, i; - int32_t guard_lifetime = guards_get_lifetime(); - - for (i = 0; i < smartlist_len(entry_guards); ++i) { - entry_guard_t *entry = smartlist_get(entry_guards, i); - const char *ver = entry->chosen_by_version; - const char *msg = NULL; - tor_version_t v; - int version_is_bad = 0, date_is_bad = 0; - if (!ver) { - msg = "does not say what version of Tor it was selected by"; - version_is_bad = 1; - } else if (tor_version_parse(ver, &v)) { - msg = "does not seem to be from any recognized version of Tor"; - version_is_bad = 1; - } - if (!version_is_bad && entry->chosen_on_date + guard_lifetime < now) { - /* It's been too long since the date listed in our state file. */ - msg = "was selected several months ago"; - date_is_bad = 1; - } - - if (version_is_bad || date_is_bad) { /* we need to drop it */ - char dbuf[HEX_DIGEST_LEN+1]; - tor_assert(msg); - base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN); - log_fn(version_is_bad ? LOG_NOTICE : LOG_INFO, LD_CIRC, - "Entry guard '%s' (%s) %s. (Version=%s.) Replacing it.", - entry->nickname, dbuf, msg, ver?escaped(ver):"none"); - control_event_guard(entry->nickname, entry->identity, "DROPPED"); - entry_guard_free(entry); - smartlist_del_keeporder(entry_guards, i--); - log_entry_guards(LOG_INFO); - changed = 1; - } - } - - return changed ? 1 : 0; -} - -/** Remove all entry guards that have been down or unlisted for so - * long that we don't think they'll come up again. Return 1 if we - * removed any, or 0 if we did nothing. */ -static int -remove_dead_entry_guards(time_t now) -{ - char dbuf[HEX_DIGEST_LEN+1]; - char tbuf[ISO_TIME_LEN+1]; - int i; - int changed = 0; - - for (i = 0; i < smartlist_len(entry_guards); ) { - entry_guard_t *entry = smartlist_get(entry_guards, i); - if (entry->bad_since && - ! entry->path_bias_disabled && - entry->bad_since + ENTRY_GUARD_REMOVE_AFTER < now) { - - base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN); - format_local_iso_time(tbuf, entry->bad_since); - log_info(LD_CIRC, "Entry guard '%s' (%s) has been down or unlisted " - "since %s local time; removing.", - entry->nickname, dbuf, tbuf); - control_event_guard(entry->nickname, entry->identity, "DROPPED"); - entry_guard_free(entry); - smartlist_del_keeporder(entry_guards, i); - log_entry_guards(LOG_INFO); - changed = 1; - } else - ++i; - } - return changed ? 1 : 0; -} - -/** Remove all currently listed entry guards. So new ones will be chosen. */ -void -remove_all_entry_guards(void) -{ - char dbuf[HEX_DIGEST_LEN+1]; - - while (smartlist_len(entry_guards)) { - entry_guard_t *entry = smartlist_get(entry_guards, 0); - base16_encode(dbuf, sizeof(dbuf), entry->identity, DIGEST_LEN); - log_info(LD_CIRC, "Entry guard '%s' (%s) has been dropped.", - entry->nickname, dbuf); - control_event_guard(entry->nickname, entry->identity, "DROPPED"); - entry_guard_free(entry); - smartlist_del(entry_guards, 0); - } - log_entry_guards(LOG_INFO); - entry_guards_changed(); -} - -/** A new directory or router-status has arrived; update the down/listed - * status of the entry guards. - * - * An entry is 'down' if the directory lists it as nonrunning. - * An entry is 'unlisted' if the directory doesn't include it. - * - * Don't call this on startup; only on a fresh download. Otherwise we'll - * think that things are unlisted. - */ -void -entry_guards_compute_status(const or_options_t *options, time_t now) -{ - int changed = 0; - digestmap_t *reasons; - - if (! entry_guards) - return; - - if (options->EntryNodes) /* reshuffle the entry guard list if needed */ - entry_nodes_should_be_added(); - - reasons = digestmap_new(); - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, entry) - { - const node_t *r = node_get_by_id(entry->identity); - const char *reason = NULL; - if (entry_guard_set_status(entry, r, now, options, &reason)) - changed = 1; - - if (entry->bad_since) - tor_assert(reason); - if (reason) - digestmap_set(reasons, entry->identity, (char*)reason); - } - SMARTLIST_FOREACH_END(entry); - - if (remove_dead_entry_guards(now)) - changed = 1; - if (remove_obsolete_entry_guards(now)) - changed = 1; - - if (changed) { - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, entry) { - const char *reason = digestmap_get(reasons, entry->identity); - const char *live_msg = ""; - const node_t *r = entry_is_live(entry, ENTRY_NEED_CAPACITY, &live_msg); - log_info(LD_CIRC, "Summary: Entry %s [%s] is %s, %s%s%s, and %s%s.", - entry->nickname, - hex_str(entry->identity, DIGEST_LEN), - entry->unreachable_since ? "unreachable" : "reachable", - entry->bad_since ? "unusable" : "usable", - reason ? ", ": "", - reason ? reason : "", - r ? "live" : "not live / ", - r ? "" : live_msg); - } SMARTLIST_FOREACH_END(entry); - log_info(LD_CIRC, " (%d/%d entry guards are usable/new)", - num_live_entry_guards(0), smartlist_len(entry_guards)); - log_entry_guards(LOG_INFO); - entry_guards_changed(); - } - - digestmap_free(reasons, NULL); -} - -/** Called when a connection to an OR with the identity digest <b>digest</b> - * is established (<b>succeeded</b>==1) or has failed (<b>succeeded</b>==0). - * If the OR is an entry, change that entry's up/down status. - * Return 0 normally, or -1 if we want to tear down the new connection. - * - * If <b>mark_relay_status</b>, also call router_set_status() on this - * relay. - */ -/* XXX We could change succeeded and mark_relay_status into 'int flags'. - * Too many boolean arguments is a recipe for confusion. - */ -int -entry_guard_register_connect_status(const char *digest, int succeeded, - int mark_relay_status, time_t now) -{ - int changed = 0; - int refuse_conn = 0; - int first_contact = 0; - entry_guard_t *entry = NULL; - int idx = -1; - char buf[HEX_DIGEST_LEN+1]; - - if (! entry_guards) - return 0; - - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - tor_assert(e); - if (tor_memeq(e->identity, digest, DIGEST_LEN)) { - entry = e; - idx = e_sl_idx; - break; - } - } SMARTLIST_FOREACH_END(e); - - if (!entry) - return 0; - - base16_encode(buf, sizeof(buf), entry->identity, DIGEST_LEN); - - if (succeeded) { - if (entry->unreachable_since) { - log_info(LD_CIRC, "Entry guard '%s' (%s) is now reachable again. Good.", - entry->nickname, buf); - entry->can_retry = 0; - entry->unreachable_since = 0; - entry->last_attempted = now; - control_event_guard(entry->nickname, entry->identity, "UP"); - changed = 1; - } - if (!entry->made_contact) { - entry->made_contact = 1; - first_contact = changed = 1; - } - } else { /* ! succeeded */ - if (!entry->made_contact) { - /* We've never connected to this one. */ - log_info(LD_CIRC, - "Connection to never-contacted entry guard '%s' (%s) failed. " - "Removing from the list. %d/%d entry guards usable/new.", - entry->nickname, buf, - num_live_entry_guards(0)-1, smartlist_len(entry_guards)-1); - control_event_guard(entry->nickname, entry->identity, "DROPPED"); - entry_guard_free(entry); - smartlist_del_keeporder(entry_guards, idx); - log_entry_guards(LOG_INFO); - changed = 1; - } else if (!entry->unreachable_since) { - log_info(LD_CIRC, "Unable to connect to entry guard '%s' (%s). " - "Marking as unreachable.", entry->nickname, buf); - entry->unreachable_since = entry->last_attempted = now; - control_event_guard(entry->nickname, entry->identity, "DOWN"); - changed = 1; - entry->can_retry = 0; /* We gave it an early chance; no good. */ - } else { - char tbuf[ISO_TIME_LEN+1]; - format_iso_time(tbuf, entry->unreachable_since); - log_debug(LD_CIRC, "Failed to connect to unreachable entry guard " - "'%s' (%s). It has been unreachable since %s.", - entry->nickname, buf, tbuf); - entry->last_attempted = now; - entry->can_retry = 0; /* We gave it an early chance; no good. */ - } - } - - /* if the caller asked us to, also update the is_running flags for this - * relay */ - if (mark_relay_status) - router_set_status(digest, succeeded); - - if (first_contact) { - /* We've just added a new long-term entry guard. Perhaps the network just - * came back? We should give our earlier entries another try too, - * and close this connection so we don't use it before we've given - * the others a shot. */ - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - if (e == entry) - break; - if (e->made_contact) { - const char *msg; - const node_t *r = entry_is_live(e, - ENTRY_NEED_CAPACITY | ENTRY_ASSUME_REACHABLE, - &msg); - if (r && e->unreachable_since) { - refuse_conn = 1; - e->can_retry = 1; - } - } - } SMARTLIST_FOREACH_END(e); - if (refuse_conn) { - log_info(LD_CIRC, - "Connected to new entry guard '%s' (%s). Marking earlier " - "entry guards up. %d/%d entry guards usable/new.", - entry->nickname, buf, - num_live_entry_guards(0), smartlist_len(entry_guards)); - log_entry_guards(LOG_INFO); - changed = 1; - } - } - - if (changed) - entry_guards_changed(); - return refuse_conn ? -1 : 0; -} - -/** When we try to choose an entry guard, should we parse and add - * config's EntryNodes first? */ -static int should_add_entry_nodes = 0; - -/** Called when the value of EntryNodes changes in our configuration. */ -void -entry_nodes_should_be_added(void) -{ - log_info(LD_CIRC, "EntryNodes config option set. Putting configured " - "relays at the front of the entry guard list."); - should_add_entry_nodes = 1; -} - -/** Update the using_as_guard fields of all the nodes. We do this after we - * remove entry guards from the list: This is the only function that clears - * the using_as_guard field. */ -static void -update_node_guard_status(void) -{ - smartlist_t *nodes = nodelist_get_list(); - SMARTLIST_FOREACH(nodes, node_t *, node, node->using_as_guard = 0); - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, entry) { - node_t *node = node_get_mutable_by_id(entry->identity); - if (node) - node->using_as_guard = 1; - } SMARTLIST_FOREACH_END(entry); -} - -/** Adjust the entry guards list so that it only contains entries from - * EntryNodes, adding new entries from EntryNodes to the list as needed. */ -STATIC void -entry_guards_set_from_config(const or_options_t *options) -{ - smartlist_t *entry_nodes, *worse_entry_nodes, *entry_fps; - smartlist_t *old_entry_guards_on_list, *old_entry_guards_not_on_list; - const int numentryguards = decide_num_guards(options, 0); - tor_assert(entry_guards); - - should_add_entry_nodes = 0; - - if (!options->EntryNodes) { - /* It's possible that a controller set EntryNodes, thus making - * should_add_entry_nodes set, then cleared it again, all before the - * call to choose_random_entry() that triggered us. If so, just return. - */ - return; - } - - { - char *string = routerset_to_string(options->EntryNodes); - log_info(LD_CIRC,"Adding configured EntryNodes '%s'.", string); - tor_free(string); - } - - entry_nodes = smartlist_new(); - worse_entry_nodes = smartlist_new(); - entry_fps = smartlist_new(); - old_entry_guards_on_list = smartlist_new(); - old_entry_guards_not_on_list = smartlist_new(); - - /* Split entry guards into those on the list and those not. */ - - routerset_get_all_nodes(entry_nodes, options->EntryNodes, - options->ExcludeNodes, 0); - SMARTLIST_FOREACH(entry_nodes, const node_t *,node, - smartlist_add(entry_fps, (void*)node->identity)); - - SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e, { - if (smartlist_contains_digest(entry_fps, e->identity)) - smartlist_add(old_entry_guards_on_list, e); - else - smartlist_add(old_entry_guards_not_on_list, e); - }); - - /* Remove all currently configured guard nodes, excluded nodes, unreachable - * nodes, or non-Guard nodes from entry_nodes. */ - SMARTLIST_FOREACH_BEGIN(entry_nodes, const node_t *, node) { - if (entry_guard_get_by_id_digest(node->identity)) { - SMARTLIST_DEL_CURRENT(entry_nodes, node); - continue; - } else if (routerset_contains_node(options->ExcludeNodes, node)) { - SMARTLIST_DEL_CURRENT(entry_nodes, node); - continue; - } else if (!fascist_firewall_allows_node(node, FIREWALL_OR_CONNECTION, - 0)) { - SMARTLIST_DEL_CURRENT(entry_nodes, node); - continue; - } else if (! node->is_possible_guard) { - smartlist_add(worse_entry_nodes, (node_t*)node); - SMARTLIST_DEL_CURRENT(entry_nodes, node); - } - } SMARTLIST_FOREACH_END(node); - - /* Now build the new entry_guards list. */ - smartlist_clear(entry_guards); - /* First, the previously configured guards that are in EntryNodes. */ - smartlist_add_all(entry_guards, old_entry_guards_on_list); - /* Next, scramble the rest of EntryNodes, putting the guards first. */ - smartlist_shuffle(entry_nodes); - smartlist_shuffle(worse_entry_nodes); - smartlist_add_all(entry_nodes, worse_entry_nodes); - - /* Next, the rest of EntryNodes */ - SMARTLIST_FOREACH_BEGIN(entry_nodes, const node_t *, node) { - add_an_entry_guard(node, 0, 0, 1, 0); - if (smartlist_len(entry_guards) > numentryguards * 10) - break; - } SMARTLIST_FOREACH_END(node); - log_notice(LD_GENERAL, "%d entries in guards", smartlist_len(entry_guards)); - /* Finally, free the remaining previously configured guards that are not in - * EntryNodes. */ - SMARTLIST_FOREACH(old_entry_guards_not_on_list, entry_guard_t *, e, - entry_guard_free(e)); - - update_node_guard_status(); - - smartlist_free(entry_nodes); - smartlist_free(worse_entry_nodes); - smartlist_free(entry_fps); - smartlist_free(old_entry_guards_on_list); - smartlist_free(old_entry_guards_not_on_list); - entry_guards_changed(); -} - -/** Return 0 if we're fine adding arbitrary routers out of the - * directory to our entry guard list, or return 1 if we have a - * list already and we must stick to it. - */ -int -entry_list_is_constrained(const or_options_t *options) -{ - if (options->EntryNodes) - return 1; - if (options->UseBridges) - return 1; - return 0; -} - -/** Pick a live (up and listed) entry guard from entry_guards. If - * <b>state</b> is non-NULL, this is for a specific circuit -- - * make sure not to pick this circuit's exit or any node in the - * exit's family. If <b>state</b> is NULL, we're looking for a random - * guard (likely a bridge). If <b>dirinfo</b> is not NO_DIRINFO (zero), - * then only select from nodes that know how to answer directory questions - * of that type. */ -const node_t * -choose_random_entry(cpath_build_state_t *state) -{ - return choose_random_entry_impl(state, 0, NO_DIRINFO, NULL); -} - -/** Pick a live (up and listed) directory guard from entry_guards for - * downloading information of type <b>type</b>. */ -const node_t * -choose_random_dirguard(dirinfo_type_t type) -{ - return choose_random_entry_impl(NULL, 1, type, NULL); -} - -/** Filter <b>all_entry_guards</b> for usable entry guards and put them - * in <b>live_entry_guards</b>. We filter based on whether the node is - * currently alive, and on whether it satisfies the restrictions - * imposed by the other arguments of this function. - * - * We don't place more guards than NumEntryGuards in <b>live_entry_guards</b>. - * - * If <b>chosen_exit</b> is set, it contains the exit node of this - * circuit. Make sure to not use it or its family as an entry guard. - * - * If <b>need_uptime</b> is set, we are looking for a stable entry guard. - * if <b>need_capacity</b> is set, we are looking for a fast entry guard. - * - * The rest of the arguments are the same as in choose_random_entry_impl(). - * - * Return 1 if we should choose a guard right away. Return 0 if we - * should try to add more nodes to our list before deciding on a - * guard. - */ -STATIC int -populate_live_entry_guards(smartlist_t *live_entry_guards, - const smartlist_t *all_entry_guards, - const node_t *chosen_exit, - dirinfo_type_t dirinfo_type, - int for_directory, - int need_uptime, int need_capacity) -{ - const or_options_t *options = get_options(); - const node_t *node = NULL; - const int num_needed = decide_num_guards(options, for_directory); - smartlist_t *exit_family = smartlist_new(); - int retval = 0; - entry_is_live_flags_t entry_flags = 0; - - (void) dirinfo_type; - - { /* Set the flags we want our entry node to have */ - if (need_uptime) { - entry_flags |= ENTRY_NEED_UPTIME; - } - if (need_capacity) { - entry_flags |= ENTRY_NEED_CAPACITY; - } - if (!for_directory) { - entry_flags |= ENTRY_NEED_DESCRIPTOR; - } - } - - tor_assert(all_entry_guards); - - if (chosen_exit) { - nodelist_add_node_and_family(exit_family, chosen_exit); - } - - SMARTLIST_FOREACH_BEGIN(all_entry_guards, const entry_guard_t *, entry) { - const char *msg; - node = entry_is_live(entry, entry_flags, &msg); - if (!node) - continue; /* down, no point */ - if (for_directory) { - if (!entry->is_dir_cache) - continue; /* We need a directory and didn't get one. */ - } - if (node == chosen_exit) - continue; /* don't pick the same node for entry and exit */ - if (smartlist_contains(exit_family, node)) - continue; /* avoid relays that are family members of our exit */ - smartlist_add(live_entry_guards, (void*)node); - if (!entry->made_contact) { - /* Always start with the first not-yet-contacted entry - * guard. Otherwise we might add several new ones, pick - * the second new one, and now we've expanded our entry - * guard list without needing to. */ - retval = 1; - goto done; - } - if (smartlist_len(live_entry_guards) >= num_needed) { - retval = 1; - goto done; /* We picked enough entry guards. Done! */ - } - } SMARTLIST_FOREACH_END(entry); - - done: - smartlist_free(exit_family); - - return retval; -} - -/** Pick a node to be used as the entry guard of a circuit. - * - * If <b>state</b> is set, it contains the information we know about - * the upcoming circuit. - * - * If <b>for_directory</b> is set, we are looking for a directory guard. - * - * <b>dirinfo_type</b> contains the kind of directory information we - * are looking for in our node, or NO_DIRINFO (zero) if we are not - * looking for any particular directory information (when set to - * NO_DIRINFO, the <b>dirinfo_type</b> filter is ignored). - * - * If <b>n_options_out</b> is set, we set it to the number of - * candidate guard nodes we had before picking a specific guard node. - * - * On success, return the node that should be used as the entry guard - * of the circuit. Return NULL if no such node could be found. - * - * Helper for choose_random{entry,dirguard}. -*/ -static const node_t * -choose_random_entry_impl(cpath_build_state_t *state, int for_directory, - dirinfo_type_t dirinfo_type, int *n_options_out) -{ - const or_options_t *options = get_options(); - smartlist_t *live_entry_guards = smartlist_new(); - const node_t *chosen_exit = - state?build_state_get_exit_node(state) : NULL; - const node_t *node = NULL; - int need_uptime = state ? state->need_uptime : 0; - int need_capacity = state ? state->need_capacity : 0; - int preferred_min = 0; - const int num_needed = decide_num_guards(options, for_directory); - int retval = 0; - - if (n_options_out) - *n_options_out = 0; - - if (!entry_guards) - entry_guards = smartlist_new(); - - if (should_add_entry_nodes) - entry_guards_set_from_config(options); - - if (!entry_list_is_constrained(options) && - smartlist_len(entry_guards) < num_needed) - pick_entry_guards(options, for_directory); - - retry: - smartlist_clear(live_entry_guards); - - /* Populate the list of live entry guards so that we pick one of - them. */ - retval = populate_live_entry_guards(live_entry_guards, - entry_guards, - chosen_exit, - dirinfo_type, - for_directory, - need_uptime, need_capacity); - - if (retval == 1) { /* We should choose a guard right now. */ - goto choose_and_finish; - } - - if (entry_list_is_constrained(options)) { - /* If we prefer the entry nodes we've got, and we have at least - * one choice, that's great. Use it. */ - preferred_min = 1; - } else { - /* Try to have at least 2 choices available. This way we don't - * get stuck with a single live-but-crummy entry and just keep - * using it. - * (We might get 2 live-but-crummy entry guards, but so be it.) */ - preferred_min = 2; - } - - if (smartlist_len(live_entry_guards) < preferred_min) { - if (!entry_list_is_constrained(options)) { - /* still no? try adding a new entry then */ - /* XXX if guard doesn't imply fast and stable, then we need - * to tell add_an_entry_guard below what we want, or it might - * be a long time til we get it. -RD */ - node = add_an_entry_guard(NULL, 0, 0, 1, for_directory); - if (node) { - entry_guards_changed(); - /* XXX we start over here in case the new node we added shares - * a family with our exit node. There's a chance that we'll just - * load up on entry guards here, if the network we're using is - * one big family. Perhaps we should teach add_an_entry_guard() - * to understand nodes-to-avoid-if-possible? -RD */ - goto retry; - } - } - if (!node && need_uptime) { - need_uptime = 0; /* try without that requirement */ - goto retry; - } - if (!node && need_capacity) { - /* still no? last attempt, try without requiring capacity */ - need_capacity = 0; - goto retry; - } - - /* live_entry_guards may be empty below. Oh well, we tried. */ - } - - choose_and_finish: - if (entry_list_is_constrained(options)) { - /* We need to weight by bandwidth, because our bridges or entryguards - * were not already selected proportional to their bandwidth. */ - node = node_sl_choose_by_bandwidth(live_entry_guards, WEIGHT_FOR_GUARD); - } else { - /* We choose uniformly at random here, because choose_good_entry_server() - * already weights its choices by bandwidth, so we don't want to - * *double*-weight our guard selection. */ - node = smartlist_choose(live_entry_guards); - } - if (n_options_out) - *n_options_out = smartlist_len(live_entry_guards); - smartlist_free(live_entry_guards); - return node; -} - -/** Parse <b>state</b> and learn about the entry guards it describes. - * If <b>set</b> is true, and there are no errors, replace the global - * entry_list with what we find. - * On success, return 0. On failure, alloc into *<b>msg</b> a string - * describing the error, and return -1. - */ -int -entry_guards_parse_state(or_state_t *state, int set, char **msg) -{ - entry_guard_t *node = NULL; - smartlist_t *new_entry_guards = smartlist_new(); - config_line_t *line; - time_t now = time(NULL); - const char *state_version = state->TorVersion; - digestmap_t *added_by = digestmap_new(); - - *msg = NULL; - for (line = state->EntryGuards; line; line = line->next) { - if (!strcasecmp(line->key, "EntryGuard")) { - smartlist_t *args = smartlist_new(); - node = tor_malloc_zero(sizeof(entry_guard_t)); - /* all entry guards on disk have been contacted */ - node->made_contact = 1; - smartlist_add(new_entry_guards, node); - smartlist_split_string(args, line->value, " ", - SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0); - if (smartlist_len(args)<2) { - *msg = tor_strdup("Unable to parse entry nodes: " - "Too few arguments to EntryGuard"); - } else if (!is_legal_nickname(smartlist_get(args,0))) { - *msg = tor_strdup("Unable to parse entry nodes: " - "Bad nickname for EntryGuard"); - } else { - strlcpy(node->nickname, smartlist_get(args,0), MAX_NICKNAME_LEN+1); - if (base16_decode(node->identity, DIGEST_LEN, smartlist_get(args,1), - strlen(smartlist_get(args,1))) != DIGEST_LEN) { - *msg = tor_strdup("Unable to parse entry nodes: " - "Bad hex digest for EntryGuard"); - } - } - if (smartlist_len(args) >= 3) { - const char *is_cache = smartlist_get(args, 2); - if (!strcasecmp(is_cache, "DirCache")) { - node->is_dir_cache = 1; - } else if (!strcasecmp(is_cache, "NoDirCache")) { - node->is_dir_cache = 0; - } else { - log_warn(LD_CONFIG, "Bogus third argument to EntryGuard line: %s", - escaped(is_cache)); - } - } - SMARTLIST_FOREACH(args, char*, cp, tor_free(cp)); - smartlist_free(args); - if (*msg) - break; - } else if (!strcasecmp(line->key, "EntryGuardDownSince") || - !strcasecmp(line->key, "EntryGuardUnlistedSince")) { - time_t when; - time_t last_try = 0; - if (!node) { - *msg = tor_strdup("Unable to parse entry nodes: " - "EntryGuardDownSince/UnlistedSince without EntryGuard"); - break; - } - if (parse_iso_time_(line->value, &when, 0)<0) { - *msg = tor_strdup("Unable to parse entry nodes: " - "Bad time in EntryGuardDownSince/UnlistedSince"); - break; - } - if (when > now) { - /* It's a bad idea to believe info in the future: you can wind - * up with timeouts that aren't allowed to happen for years. */ - continue; - } - if (strlen(line->value) >= ISO_TIME_LEN+ISO_TIME_LEN+1) { - /* ignore failure */ - (void) parse_iso_time(line->value+ISO_TIME_LEN+1, &last_try); - } - if (!strcasecmp(line->key, "EntryGuardDownSince")) { - node->unreachable_since = when; - node->last_attempted = last_try; - } else { - node->bad_since = when; - } - } else if (!strcasecmp(line->key, "EntryGuardAddedBy")) { - char d[DIGEST_LEN]; - /* format is digest version date */ - if (strlen(line->value) < HEX_DIGEST_LEN+1+1+1+ISO_TIME_LEN) { - log_warn(LD_BUG, "EntryGuardAddedBy line is not long enough."); - continue; - } - if (base16_decode(d, sizeof(d), - line->value, HEX_DIGEST_LEN) != sizeof(d) || - line->value[HEX_DIGEST_LEN] != ' ') { - log_warn(LD_BUG, "EntryGuardAddedBy line %s does not begin with " - "hex digest", escaped(line->value)); - continue; - } - digestmap_set(added_by, d, tor_strdup(line->value+HEX_DIGEST_LEN+1)); - } else if (!strcasecmp(line->key, "EntryGuardPathUseBias")) { - const or_options_t *options = get_options(); - double use_cnt, success_cnt; - - if (!node) { - *msg = tor_strdup("Unable to parse entry nodes: " - "EntryGuardPathUseBias without EntryGuard"); - break; - } - - if (tor_sscanf(line->value, "%lf %lf", - &use_cnt, &success_cnt) != 2) { - log_info(LD_GENERAL, "Malformed path use bias line for node %s", - node->nickname); - continue; - } - - if (use_cnt < success_cnt) { - int severity = LOG_INFO; - /* If this state file was written by a Tor that would have - * already fixed it, then the overcounting bug is still there.. */ - if (tor_version_as_new_as(state_version, "0.2.4.13-alpha")) { - severity = LOG_NOTICE; - } - log_fn(severity, LD_BUG, - "State file contains unexpectedly high usage success " - "counts %lf/%lf for Guard %s ($%s)", - success_cnt, use_cnt, - node->nickname, hex_str(node->identity, DIGEST_LEN)); - success_cnt = use_cnt; - } - - node->use_attempts = use_cnt; - node->use_successes = success_cnt; - - log_info(LD_GENERAL, "Read %f/%f path use bias for node %s", - node->use_successes, node->use_attempts, node->nickname); - - /* Note: We rely on the < comparison here to allow us to set a 0 - * rate and disable the feature entirely. If refactoring, don't - * change to <= */ - if (pathbias_get_use_success_count(node)/node->use_attempts - < pathbias_get_extreme_use_rate(options) && - pathbias_get_dropguards(options)) { - node->path_bias_disabled = 1; - log_info(LD_GENERAL, - "Path use bias is too high (%f/%f); disabling node %s", - node->circ_successes, node->circ_attempts, node->nickname); - } - } else if (!strcasecmp(line->key, "EntryGuardPathBias")) { - const or_options_t *options = get_options(); - double hop_cnt, success_cnt, timeouts, collapsed, successful_closed, - unusable; - - if (!node) { - *msg = tor_strdup("Unable to parse entry nodes: " - "EntryGuardPathBias without EntryGuard"); - break; - } - - /* First try 3 params, then 2. */ - /* In the long run: circuit_success ~= successful_circuit_close + - * collapsed_circuits + - * unusable_circuits */ - if (tor_sscanf(line->value, "%lf %lf %lf %lf %lf %lf", - &hop_cnt, &success_cnt, &successful_closed, - &collapsed, &unusable, &timeouts) != 6) { - int old_success, old_hops; - if (tor_sscanf(line->value, "%u %u", &old_success, &old_hops) != 2) { - continue; - } - log_info(LD_GENERAL, "Reading old-style EntryGuardPathBias %s", - escaped(line->value)); - - success_cnt = old_success; - successful_closed = old_success; - hop_cnt = old_hops; - timeouts = 0; - collapsed = 0; - unusable = 0; - } - - if (hop_cnt < success_cnt) { - int severity = LOG_INFO; - /* If this state file was written by a Tor that would have - * already fixed it, then the overcounting bug is still there.. */ - if (tor_version_as_new_as(state_version, "0.2.4.13-alpha")) { - severity = LOG_NOTICE; - } - log_fn(severity, LD_BUG, - "State file contains unexpectedly high success counts " - "%lf/%lf for Guard %s ($%s)", - success_cnt, hop_cnt, - node->nickname, hex_str(node->identity, DIGEST_LEN)); - success_cnt = hop_cnt; - } - - node->circ_attempts = hop_cnt; - node->circ_successes = success_cnt; - - node->successful_circuits_closed = successful_closed; - node->timeouts = timeouts; - node->collapsed_circuits = collapsed; - node->unusable_circuits = unusable; - - log_info(LD_GENERAL, "Read %f/%f path bias for node %s", - node->circ_successes, node->circ_attempts, node->nickname); - /* Note: We rely on the < comparison here to allow us to set a 0 - * rate and disable the feature entirely. If refactoring, don't - * change to <= */ - if (pathbias_get_close_success_count(node)/node->circ_attempts - < pathbias_get_extreme_rate(options) && - pathbias_get_dropguards(options)) { - node->path_bias_disabled = 1; - log_info(LD_GENERAL, - "Path bias is too high (%f/%f); disabling node %s", - node->circ_successes, node->circ_attempts, node->nickname); - } - - } else { - log_warn(LD_BUG, "Unexpected key %s", line->key); - } - } - - SMARTLIST_FOREACH_BEGIN(new_entry_guards, entry_guard_t *, e) { - char *sp; - char *val = digestmap_get(added_by, e->identity); - if (val && (sp = strchr(val, ' '))) { - time_t when; - *sp++ = '\0'; - if (parse_iso_time(sp, &when)<0) { - log_warn(LD_BUG, "Can't read time %s in EntryGuardAddedBy", sp); - } else { - e->chosen_by_version = tor_strdup(val); - e->chosen_on_date = when; - } - } else { - if (state_version) { - e->chosen_on_date = crypto_rand_time_range(now - 3600*24*30, now); - e->chosen_by_version = tor_strdup(state_version); - } - } - if (e->path_bias_disabled && !e->bad_since) - e->bad_since = time(NULL); - } - SMARTLIST_FOREACH_END(e); - - if (*msg || !set) { - SMARTLIST_FOREACH(new_entry_guards, entry_guard_t *, e, - entry_guard_free(e)); - smartlist_free(new_entry_guards); - } else { /* !err && set */ - if (entry_guards) { - SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e, - entry_guard_free(e)); - smartlist_free(entry_guards); - } - entry_guards = new_entry_guards; - entry_guards_dirty = 0; - /* XXX hand new_entry_guards to this func, and move it up a - * few lines, so we don't have to re-dirty it */ - if (remove_obsolete_entry_guards(now)) - entry_guards_dirty = 1; - - update_node_guard_status(); - } - digestmap_free(added_by, tor_free_); - return *msg ? -1 : 0; -} - -/** How long will we let a change in our guard nodes stay un-saved - * when we are trying to avoid disk writes? */ -#define SLOW_GUARD_STATE_FLUSH_TIME 600 -/** How long will we let a change in our guard nodes stay un-saved - * when we are not trying to avoid disk writes? */ -#define FAST_GUARD_STATE_FLUSH_TIME 30 - -/** Our list of entry guards has changed, or some element of one - * of our entry guards has changed. Write the changes to disk within - * the next few minutes. - */ -void -entry_guards_changed(void) -{ - time_t when; - entry_guards_dirty = 1; - - if (get_options()->AvoidDiskWrites) - when = time(NULL) + SLOW_GUARD_STATE_FLUSH_TIME; - else - when = time(NULL) + FAST_GUARD_STATE_FLUSH_TIME; - - /* or_state_save() will call entry_guards_update_state(). */ - or_state_mark_dirty(get_or_state(), when); -} - -/** If the entry guard info has not changed, do nothing and return. - * Otherwise, free the EntryGuards piece of <b>state</b> and create - * a new one out of the global entry_guards list, and then mark - * <b>state</b> dirty so it will get saved to disk. - */ -void -entry_guards_update_state(or_state_t *state) -{ - config_line_t **next, *line; - if (! entry_guards_dirty) - return; - - config_free_lines(state->EntryGuards); - next = &state->EntryGuards; - *next = NULL; - if (!entry_guards) - entry_guards = smartlist_new(); - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - char dbuf[HEX_DIGEST_LEN+1]; - if (!e->made_contact) - continue; /* don't write this one to disk */ - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuard"); - base16_encode(dbuf, sizeof(dbuf), e->identity, DIGEST_LEN); - tor_asprintf(&line->value, "%s %s %sDirCache", e->nickname, dbuf, - e->is_dir_cache ? "" : "No"); - next = &(line->next); - if (e->unreachable_since) { - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuardDownSince"); - line->value = tor_malloc(ISO_TIME_LEN+1+ISO_TIME_LEN+1); - format_iso_time(line->value, e->unreachable_since); - if (e->last_attempted) { - line->value[ISO_TIME_LEN] = ' '; - format_iso_time(line->value+ISO_TIME_LEN+1, e->last_attempted); - } - next = &(line->next); - } - if (e->bad_since) { - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuardUnlistedSince"); - line->value = tor_malloc(ISO_TIME_LEN+1); - format_iso_time(line->value, e->bad_since); - next = &(line->next); - } - if (e->chosen_on_date && e->chosen_by_version && - !strchr(e->chosen_by_version, ' ')) { - char d[HEX_DIGEST_LEN+1]; - char t[ISO_TIME_LEN+1]; - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuardAddedBy"); - base16_encode(d, sizeof(d), e->identity, DIGEST_LEN); - format_iso_time(t, e->chosen_on_date); - tor_asprintf(&line->value, "%s %s %s", - d, e->chosen_by_version, t); - next = &(line->next); - } - if (e->circ_attempts > 0) { - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuardPathBias"); - /* In the long run: circuit_success ~= successful_circuit_close + - * collapsed_circuits + - * unusable_circuits */ - tor_asprintf(&line->value, "%f %f %f %f %f %f", - e->circ_attempts, e->circ_successes, - pathbias_get_close_success_count(e), - e->collapsed_circuits, - e->unusable_circuits, e->timeouts); - next = &(line->next); - } - if (e->use_attempts > 0) { - *next = line = tor_malloc_zero(sizeof(config_line_t)); - line->key = tor_strdup("EntryGuardPathUseBias"); - - tor_asprintf(&line->value, "%f %f", - e->use_attempts, - pathbias_get_use_success_count(e)); - next = &(line->next); - } - - } SMARTLIST_FOREACH_END(e); - if (!get_options()->AvoidDiskWrites) - or_state_mark_dirty(get_or_state(), 0); - entry_guards_dirty = 0; -} - -/** If <b>question</b> is the string "entry-guards", then dump - * to *<b>answer</b> a newly allocated string describing all of - * the nodes in the global entry_guards list. See control-spec.txt - * for details. - * For backward compatibility, we also handle the string "helper-nodes". - * */ -int -getinfo_helper_entry_guards(control_connection_t *conn, - const char *question, char **answer, - const char **errmsg) -{ - (void) conn; - (void) errmsg; - - if (!strcmp(question,"entry-guards") || - !strcmp(question,"helper-nodes")) { - smartlist_t *sl = smartlist_new(); - char tbuf[ISO_TIME_LEN+1]; - char nbuf[MAX_VERBOSE_NICKNAME_LEN+1]; - if (!entry_guards) - entry_guards = smartlist_new(); - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - const char *status = NULL; - time_t when = 0; - const node_t *node; - - if (!e->made_contact) { - status = "never-connected"; - } else if (e->bad_since) { - when = e->bad_since; - status = "unusable"; - } else if (e->unreachable_since) { - when = e->unreachable_since; - status = "down"; - } else { - status = "up"; - } - - node = node_get_by_id(e->identity); - if (node) { - node_get_verbose_nickname(node, nbuf); - } else { - nbuf[0] = '$'; - base16_encode(nbuf+1, sizeof(nbuf)-1, e->identity, DIGEST_LEN); - /* e->nickname field is not very reliable if we don't know about - * this router any longer; don't include it. */ - } - - if (when) { - format_iso_time(tbuf, when); - smartlist_add_asprintf(sl, "%s %s %s\n", nbuf, status, tbuf); - } else { - smartlist_add_asprintf(sl, "%s %s\n", nbuf, status); - } - } SMARTLIST_FOREACH_END(e); - *answer = smartlist_join_strings(sl, "", 0, NULL); - SMARTLIST_FOREACH(sl, char *, c, tor_free(c)); - smartlist_free(sl); - } - return 0; -} - -/** Return 0 if we should apply guardfraction information found in the - * consensus. A specific consensus can be specified with the - * <b>ns</b> argument, if NULL the most recent one will be picked.*/ -int -should_apply_guardfraction(const networkstatus_t *ns) -{ - /* We need to check the corresponding torrc option and the consensus - * parameter if we need to. */ - const or_options_t *options = get_options(); - - /* If UseGuardFraction is 'auto' then check the same-named consensus - * parameter. If the consensus parameter is not present, default to - * "off". */ - if (options->UseGuardFraction == -1) { - return networkstatus_get_param(ns, "UseGuardFraction", - 0, /* default to "off" */ - 0, 1); - } - - return options->UseGuardFraction; -} - -/* Given the original bandwidth of a guard and its guardfraction, - * calculate how much bandwidth the guard should have as a guard and - * as a non-guard. - * - * Quoting from proposal236: - * - * Let Wpf denote the weight from the 'bandwidth-weights' line a - * client would apply to N for position p if it had the guard - * flag, Wpn the weight if it did not have the guard flag, and B the - * measured bandwidth of N in the consensus. Then instead of choosing - * N for position p proportionally to Wpf*B or Wpn*B, clients should - * choose N proportionally to F*Wpf*B + (1-F)*Wpn*B. - * - * This function fills the <b>guardfraction_bw</b> structure. It sets - * <b>guard_bw</b> to F*B and <b>non_guard_bw</b> to (1-F)*B. - */ -void -guard_get_guardfraction_bandwidth(guardfraction_bandwidth_t *guardfraction_bw, - int orig_bandwidth, - uint32_t guardfraction_percentage) -{ - double guardfraction_fraction; - - /* Turn the percentage into a fraction. */ - tor_assert(guardfraction_percentage <= 100); - guardfraction_fraction = guardfraction_percentage / 100.0; - - long guard_bw = tor_lround(guardfraction_fraction * orig_bandwidth); - tor_assert(guard_bw <= INT_MAX); - - guardfraction_bw->guard_bw = (int) guard_bw; - - guardfraction_bw->non_guard_bw = orig_bandwidth - (int) guard_bw; -} - -/** A list of configured bridges. Whenever we actually get a descriptor - * for one, we add it as an entry guard. Note that the order of bridges - * in this list does not necessarily correspond to the order of bridges - * in the torrc. */ -static smartlist_t *bridge_list = NULL; - -/** Mark every entry of the bridge list to be removed on our next call to - * sweep_bridge_list unless it has first been un-marked. */ -void -mark_bridge_list(void) -{ - if (!bridge_list) - bridge_list = smartlist_new(); - SMARTLIST_FOREACH(bridge_list, bridge_info_t *, b, - b->marked_for_removal = 1); -} - -/** Remove every entry of the bridge list that was marked with - * mark_bridge_list if it has not subsequently been un-marked. */ -void -sweep_bridge_list(void) -{ - if (!bridge_list) - bridge_list = smartlist_new(); - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, b) { - if (b->marked_for_removal) { - SMARTLIST_DEL_CURRENT(bridge_list, b); - bridge_free(b); - } - } SMARTLIST_FOREACH_END(b); -} - -/** Initialize the bridge list to empty, creating it if needed. */ -static void -clear_bridge_list(void) -{ - if (!bridge_list) - bridge_list = smartlist_new(); - SMARTLIST_FOREACH(bridge_list, bridge_info_t *, b, bridge_free(b)); - smartlist_clear(bridge_list); -} - -/** Free the bridge <b>bridge</b>. */ -static void -bridge_free(bridge_info_t *bridge) -{ - if (!bridge) - return; - - tor_free(bridge->transport_name); - if (bridge->socks_args) { - SMARTLIST_FOREACH(bridge->socks_args, char*, s, tor_free(s)); - smartlist_free(bridge->socks_args); - } - - tor_free(bridge); -} - -/** If we have a bridge configured whose digest matches <b>digest</b>, or a - * bridge with no known digest whose address matches any of the - * tor_addr_port_t's in <b>orports</b>, return that bridge. Else return - * NULL. */ -static bridge_info_t * -get_configured_bridge_by_orports_digest(const char *digest, - const smartlist_t *orports) -{ - if (!bridge_list) - return NULL; - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, bridge) - { - if (tor_digest_is_zero(bridge->identity)) { - SMARTLIST_FOREACH_BEGIN(orports, tor_addr_port_t *, ap) - { - if (tor_addr_compare(&bridge->addr, &ap->addr, CMP_EXACT) == 0 && - bridge->port == ap->port) - return bridge; - } - SMARTLIST_FOREACH_END(ap); - } - if (digest && tor_memeq(bridge->identity, digest, DIGEST_LEN)) - return bridge; - } - SMARTLIST_FOREACH_END(bridge); - return NULL; -} - -/** If we have a bridge configured whose digest matches <b>digest</b>, or a - * bridge with no known digest whose address matches <b>addr</b>:<b>port</b>, - * return that bridge. Else return NULL. If <b>digest</b> is NULL, check for - * address/port matches only. */ -static bridge_info_t * -get_configured_bridge_by_addr_port_digest(const tor_addr_t *addr, - uint16_t port, - const char *digest) -{ - if (!bridge_list) - return NULL; - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, bridge) - { - if ((tor_digest_is_zero(bridge->identity) || digest == NULL) && - !tor_addr_compare(&bridge->addr, addr, CMP_EXACT) && - bridge->port == port) - return bridge; - if (digest && tor_memeq(bridge->identity, digest, DIGEST_LEN)) - return bridge; - } - SMARTLIST_FOREACH_END(bridge); - return NULL; -} - -/** If we have a bridge configured whose digest matches <b>digest</b>, or a - * bridge with no known digest whose address matches <b>addr</b>:<b>port</b>, - * return 1. Else return 0. If <b>digest</b> is NULL, check for - * address/port matches only. */ -int -addr_is_a_configured_bridge(const tor_addr_t *addr, - uint16_t port, - const char *digest) -{ - tor_assert(addr); - return get_configured_bridge_by_addr_port_digest(addr, port, digest) ? 1 : 0; -} - -/** If we have a bridge configured whose digest matches - * <b>ei->identity_digest</b>, or a bridge with no known digest whose address - * matches <b>ei->addr</b>:<b>ei->port</b>, return 1. Else return 0. - * If <b>ei->onion_key</b> is NULL, check for address/port matches only. */ -int -extend_info_is_a_configured_bridge(const extend_info_t *ei) -{ - const char *digest = ei->onion_key ? ei->identity_digest : NULL; - return addr_is_a_configured_bridge(&ei->addr, ei->port, digest); -} - -/** Wrapper around get_configured_bridge_by_addr_port_digest() to look - * it up via router descriptor <b>ri</b>. */ -static bridge_info_t * -get_configured_bridge_by_routerinfo(const routerinfo_t *ri) -{ - bridge_info_t *bi = NULL; - smartlist_t *orports = router_get_all_orports(ri); - bi = get_configured_bridge_by_orports_digest(ri->cache_info.identity_digest, - orports); - SMARTLIST_FOREACH(orports, tor_addr_port_t *, p, tor_free(p)); - smartlist_free(orports); - return bi; -} - -/** Return 1 if <b>ri</b> is one of our known bridges, else 0. */ -int -routerinfo_is_a_configured_bridge(const routerinfo_t *ri) -{ - return get_configured_bridge_by_routerinfo(ri) ? 1 : 0; -} - -/** Return 1 if <b>node</b> is one of our configured bridges, else 0. */ -int -node_is_a_configured_bridge(const node_t *node) -{ - int retval = 0; - smartlist_t *orports = node_get_all_orports(node); - retval = get_configured_bridge_by_orports_digest(node->identity, - orports) != NULL; - SMARTLIST_FOREACH(orports, tor_addr_port_t *, p, tor_free(p)); - smartlist_free(orports); - return retval; -} - -/** We made a connection to a router at <b>addr</b>:<b>port</b> - * without knowing its digest. Its digest turned out to be <b>digest</b>. - * If it was a bridge, and we still don't know its digest, record it. - */ -void -learned_router_identity(const tor_addr_t *addr, uint16_t port, - const char *digest) -{ - bridge_info_t *bridge = - get_configured_bridge_by_addr_port_digest(addr, port, digest); - if (bridge && tor_digest_is_zero(bridge->identity)) { - char *transport_info = NULL; - const char *transport_name = - find_transport_name_by_bridge_addrport(addr, port); - if (transport_name) - tor_asprintf(&transport_info, " (with transport '%s')", transport_name); - - memcpy(bridge->identity, digest, DIGEST_LEN); - log_notice(LD_DIR, "Learned fingerprint %s for bridge %s%s.", - hex_str(digest, DIGEST_LEN), fmt_addrport(addr, port), - transport_info ? transport_info : ""); - tor_free(transport_info); - } -} - -/** Return true if <b>bridge</b> has the same identity digest as - * <b>digest</b>. If <b>digest</b> is NULL, it matches - * bridges with unspecified identity digests. */ -static int -bridge_has_digest(const bridge_info_t *bridge, const char *digest) -{ - if (digest) - return tor_memeq(digest, bridge->identity, DIGEST_LEN); - else - return tor_digest_is_zero(bridge->identity); -} - -/** We are about to add a new bridge at <b>addr</b>:<b>port</b>, with optional - * <b>digest</b> and <b>transport_name</b>. Mark for removal any previously - * existing bridge with the same address and port, and warn the user as - * appropriate. - */ -static void -bridge_resolve_conflicts(const tor_addr_t *addr, uint16_t port, - const char *digest, const char *transport_name) -{ - /* Iterate the already-registered bridge list: - - If you find a bridge with the same adress and port, mark it for - removal. It doesn't make sense to have two active bridges with - the same IP:PORT. If the bridge in question has a different - digest or transport than <b>digest</b>/<b>transport_name</b>, - it's probably a misconfiguration and we should warn the user. - */ - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, bridge) { - if (bridge->marked_for_removal) - continue; - - if (tor_addr_eq(&bridge->addr, addr) && (bridge->port == port)) { - - bridge->marked_for_removal = 1; - - if (!bridge_has_digest(bridge, digest) || - strcmp_opt(bridge->transport_name, transport_name)) { - /* warn the user */ - char *bridge_description_new, *bridge_description_old; - tor_asprintf(&bridge_description_new, "%s:%s:%s", - fmt_addrport(addr, port), - digest ? hex_str(digest, DIGEST_LEN) : "", - transport_name ? transport_name : ""); - tor_asprintf(&bridge_description_old, "%s:%s:%s", - fmt_addrport(&bridge->addr, bridge->port), - tor_digest_is_zero(bridge->identity) ? - "" : hex_str(bridge->identity,DIGEST_LEN), - bridge->transport_name ? bridge->transport_name : ""); - - log_warn(LD_GENERAL,"Tried to add bridge '%s', but we found a conflict" - " with the already registered bridge '%s'. We will discard" - " the old bridge and keep '%s'. If this is not what you" - " wanted, please change your configuration file accordingly.", - bridge_description_new, bridge_description_old, - bridge_description_new); - - tor_free(bridge_description_new); - tor_free(bridge_description_old); - } - } - } SMARTLIST_FOREACH_END(bridge); -} - -/** Return True if we have a bridge that uses a transport with name - * <b>transport_name</b>. */ -MOCK_IMPL(int, -transport_is_needed, (const char *transport_name)) -{ - if (!bridge_list) - return 0; - - SMARTLIST_FOREACH_BEGIN(bridge_list, const bridge_info_t *, bridge) { - if (bridge->transport_name && - !strcmp(bridge->transport_name, transport_name)) - return 1; - } SMARTLIST_FOREACH_END(bridge); - - return 0; -} - -/** Register the bridge information in <b>bridge_line</b> to the - * bridge subsystem. Steals reference of <b>bridge_line</b>. */ -void -bridge_add_from_config(bridge_line_t *bridge_line) -{ - bridge_info_t *b; - - { /* Log the bridge we are about to register: */ - log_debug(LD_GENERAL, "Registering bridge at %s (transport: %s) (%s)", - fmt_addrport(&bridge_line->addr, bridge_line->port), - bridge_line->transport_name ? - bridge_line->transport_name : "no transport", - tor_digest_is_zero(bridge_line->digest) ? - "no key listed" : hex_str(bridge_line->digest, DIGEST_LEN)); - - if (bridge_line->socks_args) { /* print socks arguments */ - int i = 0; - - tor_assert(smartlist_len(bridge_line->socks_args) > 0); - - log_debug(LD_GENERAL, "Bridge uses %d SOCKS arguments:", - smartlist_len(bridge_line->socks_args)); - SMARTLIST_FOREACH(bridge_line->socks_args, const char *, arg, - log_debug(LD_CONFIG, "%d: %s", ++i, arg)); - } - } - - bridge_resolve_conflicts(&bridge_line->addr, - bridge_line->port, - bridge_line->digest, - bridge_line->transport_name); - - b = tor_malloc_zero(sizeof(bridge_info_t)); - tor_addr_copy(&b->addr, &bridge_line->addr); - b->port = bridge_line->port; - memcpy(b->identity, bridge_line->digest, DIGEST_LEN); - if (bridge_line->transport_name) - b->transport_name = bridge_line->transport_name; - b->fetch_status.schedule = DL_SCHED_BRIDGE; - b->fetch_status.backoff = DL_SCHED_RANDOM_EXPONENTIAL; - b->socks_args = bridge_line->socks_args; - if (!bridge_list) - bridge_list = smartlist_new(); - - tor_free(bridge_line); /* Deallocate bridge_line now. */ - - smartlist_add(bridge_list, b); -} - -/** Return true iff <b>routerset</b> contains the bridge <b>bridge</b>. */ -static int -routerset_contains_bridge(const routerset_t *routerset, - const bridge_info_t *bridge) -{ - int result; - extend_info_t *extinfo; - tor_assert(bridge); - if (!routerset) - return 0; - - extinfo = extend_info_new( - NULL, bridge->identity, NULL, NULL, &bridge->addr, bridge->port); - result = routerset_contains_extendinfo(routerset, extinfo); - extend_info_free(extinfo); - return result; -} - -/** If <b>digest</b> is one of our known bridges, return it. */ -static bridge_info_t * -find_bridge_by_digest(const char *digest) -{ - SMARTLIST_FOREACH(bridge_list, bridge_info_t *, bridge, - { - if (tor_memeq(bridge->identity, digest, DIGEST_LEN)) - return bridge; - }); - return NULL; -} - -/** Given the <b>addr</b> and <b>port</b> of a bridge, if that bridge - * supports a pluggable transport, return its name. Otherwise, return - * NULL. */ -const char * -find_transport_name_by_bridge_addrport(const tor_addr_t *addr, uint16_t port) -{ - if (!bridge_list) - return NULL; - - SMARTLIST_FOREACH_BEGIN(bridge_list, const bridge_info_t *, bridge) { - if (tor_addr_eq(&bridge->addr, addr) && - (bridge->port == port)) - return bridge->transport_name; - } SMARTLIST_FOREACH_END(bridge); - - return NULL; -} - -/** If <b>addr</b> and <b>port</b> match the address and port of a - * bridge of ours that uses pluggable transports, place its transport - * in <b>transport</b>. - * - * Return 0 on success (found a transport, or found a bridge with no - * transport, or found no bridge); return -1 if we should be using a - * transport, but the transport could not be found. - */ -int -get_transport_by_bridge_addrport(const tor_addr_t *addr, uint16_t port, - const transport_t **transport) -{ - *transport = NULL; - if (!bridge_list) - return 0; - - SMARTLIST_FOREACH_BEGIN(bridge_list, const bridge_info_t *, bridge) { - if (tor_addr_eq(&bridge->addr, addr) && - (bridge->port == port)) { /* bridge matched */ - if (bridge->transport_name) { /* it also uses pluggable transports */ - *transport = transport_get_by_name(bridge->transport_name); - if (*transport == NULL) { /* it uses pluggable transports, but - the transport could not be found! */ - return -1; - } - return 0; - } else { /* bridge matched, but it doesn't use transports. */ - break; - } - } - } SMARTLIST_FOREACH_END(bridge); - - *transport = NULL; - return 0; -} - -/** Return a smartlist containing all the SOCKS arguments that we - * should pass to the SOCKS proxy. */ -const smartlist_t * -get_socks_args_by_bridge_addrport(const tor_addr_t *addr, uint16_t port) -{ - bridge_info_t *bridge = get_configured_bridge_by_addr_port_digest(addr, - port, - NULL); - return bridge ? bridge->socks_args : NULL; -} - -/** We need to ask <b>bridge</b> for its server descriptor. */ -static void -launch_direct_bridge_descriptor_fetch(bridge_info_t *bridge) -{ - const or_options_t *options = get_options(); - - if (connection_get_by_type_addr_port_purpose( - CONN_TYPE_DIR, &bridge->addr, bridge->port, - DIR_PURPOSE_FETCH_SERVERDESC)) - return; /* it's already on the way */ - - if (routerset_contains_bridge(options->ExcludeNodes, bridge)) { - download_status_mark_impossible(&bridge->fetch_status); - log_warn(LD_APP, "Not using bridge at %s: it is in ExcludeNodes.", - safe_str_client(fmt_and_decorate_addr(&bridge->addr))); - return; - } - - /* Until we get a descriptor for the bridge, we only know one address for - * it. */ - if (!fascist_firewall_allows_address_addr(&bridge->addr, bridge->port, - FIREWALL_OR_CONNECTION, 0, 0)) { - log_notice(LD_CONFIG, "Tried to fetch a descriptor directly from a " - "bridge, but that bridge is not reachable through our " - "firewall."); - return; - } - - directory_initiate_command(&bridge->addr, bridge->port, - NULL, 0, /*no dirport*/ - bridge->identity, - DIR_PURPOSE_FETCH_SERVERDESC, - ROUTER_PURPOSE_BRIDGE, - DIRIND_ONEHOP, "authority.z", NULL, 0, 0); -} - -/** Fetching the bridge descriptor from the bridge authority returned a - * "not found". Fall back to trying a direct fetch. */ -void -retry_bridge_descriptor_fetch_directly(const char *digest) -{ - bridge_info_t *bridge = find_bridge_by_digest(digest); - if (!bridge) - return; /* not found? oh well. */ - - launch_direct_bridge_descriptor_fetch(bridge); -} - -/** For each bridge in our list for which we don't currently have a - * descriptor, fetch a new copy of its descriptor -- either directly - * from the bridge or via a bridge authority. */ -void -fetch_bridge_descriptors(const or_options_t *options, time_t now) -{ - int num_bridge_auths = get_n_authorities(BRIDGE_DIRINFO); - int ask_bridge_directly; - int can_use_bridge_authority; - - if (!bridge_list) - return; - - /* If we still have unconfigured managed proxies, don't go and - connect to a bridge. */ - if (pt_proxies_configuration_pending()) - return; - - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, bridge) - { - if (!download_status_is_ready(&bridge->fetch_status, now, - IMPOSSIBLE_TO_DOWNLOAD)) - continue; /* don't bother, no need to retry yet */ - if (routerset_contains_bridge(options->ExcludeNodes, bridge)) { - download_status_mark_impossible(&bridge->fetch_status); - log_warn(LD_APP, "Not using bridge at %s: it is in ExcludeNodes.", - safe_str_client(fmt_and_decorate_addr(&bridge->addr))); - continue; - } - - /* schedule another fetch as if this one will fail, in case it does */ - download_status_failed(&bridge->fetch_status, 0); - - can_use_bridge_authority = !tor_digest_is_zero(bridge->identity) && - num_bridge_auths; - ask_bridge_directly = !can_use_bridge_authority || - !options->UpdateBridgesFromAuthority; - log_debug(LD_DIR, "ask_bridge_directly=%d (%d, %d, %d)", - ask_bridge_directly, tor_digest_is_zero(bridge->identity), - !options->UpdateBridgesFromAuthority, !num_bridge_auths); - - if (ask_bridge_directly && - !fascist_firewall_allows_address_addr(&bridge->addr, bridge->port, - FIREWALL_OR_CONNECTION, 0, - 0)) { - log_notice(LD_DIR, "Bridge at '%s' isn't reachable by our " - "firewall policy. %s.", - fmt_addrport(&bridge->addr, bridge->port), - can_use_bridge_authority ? - "Asking bridge authority instead" : "Skipping"); - if (can_use_bridge_authority) - ask_bridge_directly = 0; - else - continue; - } - - if (ask_bridge_directly) { - /* we need to ask the bridge itself for its descriptor. */ - launch_direct_bridge_descriptor_fetch(bridge); - } else { - /* We have a digest and we want to ask an authority. We could - * combine all the requests into one, but that may give more - * hints to the bridge authority than we want to give. */ - char resource[10 + HEX_DIGEST_LEN]; - memcpy(resource, "fp/", 3); - base16_encode(resource+3, HEX_DIGEST_LEN+1, - bridge->identity, DIGEST_LEN); - memcpy(resource+3+HEX_DIGEST_LEN, ".z", 3); - log_info(LD_DIR, "Fetching bridge info '%s' from bridge authority.", - resource); - directory_get_from_dirserver(DIR_PURPOSE_FETCH_SERVERDESC, - ROUTER_PURPOSE_BRIDGE, resource, 0, DL_WANT_AUTHORITY); - } - } - SMARTLIST_FOREACH_END(bridge); -} - -/** If our <b>bridge</b> is configured to be a different address than - * the bridge gives in <b>node</b>, rewrite the routerinfo - * we received to use the address we meant to use. Now we handle - * multihomed bridges better. - */ -static void -rewrite_node_address_for_bridge(const bridge_info_t *bridge, node_t *node) -{ - /* XXXX move this function. */ - /* XXXX overridden addresses should really live in the node_t, so that the - * routerinfo_t and the microdesc_t can be immutable. But we can only - * do that safely if we know that no function that connects to an OR - * does so through an address from any source other than node_get_addr(). - */ - tor_addr_t addr; - const or_options_t *options = get_options(); - - if (node->ri) { - routerinfo_t *ri = node->ri; - tor_addr_from_ipv4h(&addr, ri->addr); - - if ((!tor_addr_compare(&bridge->addr, &addr, CMP_EXACT) && - bridge->port == ri->or_port) || - (!tor_addr_compare(&bridge->addr, &ri->ipv6_addr, CMP_EXACT) && - bridge->port == ri->ipv6_orport)) { - /* they match, so no need to do anything */ - } else { - if (tor_addr_family(&bridge->addr) == AF_INET) { - ri->addr = tor_addr_to_ipv4h(&bridge->addr); - ri->or_port = bridge->port; - log_info(LD_DIR, - "Adjusted bridge routerinfo for '%s' to match configured " - "address %s:%d.", - ri->nickname, fmt_addr32(ri->addr), ri->or_port); - } else if (tor_addr_family(&bridge->addr) == AF_INET6) { - tor_addr_copy(&ri->ipv6_addr, &bridge->addr); - ri->ipv6_orport = bridge->port; - log_info(LD_DIR, - "Adjusted bridge routerinfo for '%s' to match configured " - "address %s.", - ri->nickname, fmt_addrport(&ri->ipv6_addr, ri->ipv6_orport)); - } else { - log_err(LD_BUG, "Address family not supported: %d.", - tor_addr_family(&bridge->addr)); - return; - } - } - - if (options->ClientPreferIPv6ORPort == -1) { - /* Mark which address to use based on which bridge_t we got. */ - node->ipv6_preferred = (tor_addr_family(&bridge->addr) == AF_INET6 && - !tor_addr_is_null(&node->ri->ipv6_addr)); - } else { - /* Mark which address to use based on user preference */ - node->ipv6_preferred = (fascist_firewall_prefer_ipv6_orport(options) && - !tor_addr_is_null(&node->ri->ipv6_addr)); - } - - /* XXXipv6 we lack support for falling back to another address for - the same relay, warn the user */ - if (!tor_addr_is_null(&ri->ipv6_addr)) { - tor_addr_port_t ap; - node_get_pref_orport(node, &ap); - log_notice(LD_CONFIG, - "Bridge '%s' has both an IPv4 and an IPv6 address. " - "Will prefer using its %s address (%s) based on %s.", - ri->nickname, - node->ipv6_preferred ? "IPv6" : "IPv4", - fmt_addrport(&ap.addr, ap.port), - options->ClientPreferIPv6ORPort == -1 ? - "the configured Bridge address" : - "ClientPreferIPv6ORPort"); - } - } - if (node->rs) { - routerstatus_t *rs = node->rs; - tor_addr_from_ipv4h(&addr, rs->addr); - - if (!tor_addr_compare(&bridge->addr, &addr, CMP_EXACT) && - bridge->port == rs->or_port) { - /* they match, so no need to do anything */ - } else { - rs->addr = tor_addr_to_ipv4h(&bridge->addr); - rs->or_port = bridge->port; - log_info(LD_DIR, - "Adjusted bridge routerstatus for '%s' to match " - "configured address %s.", - rs->nickname, fmt_addrport(&bridge->addr, rs->or_port)); - } - } -} - -/** We just learned a descriptor for a bridge. See if that - * digest is in our entry guard list, and add it if not. */ -void -learned_bridge_descriptor(routerinfo_t *ri, int from_cache) -{ - tor_assert(ri); - tor_assert(ri->purpose == ROUTER_PURPOSE_BRIDGE); - if (get_options()->UseBridges) { - int first = num_bridges_usable() <= 1; - bridge_info_t *bridge = get_configured_bridge_by_routerinfo(ri); - time_t now = time(NULL); - router_set_status(ri->cache_info.identity_digest, 1); - - if (bridge) { /* if we actually want to use this one */ - node_t *node; - /* it's here; schedule its re-fetch for a long time from now. */ - if (!from_cache) - download_status_reset(&bridge->fetch_status); - - node = node_get_mutable_by_id(ri->cache_info.identity_digest); - tor_assert(node); - rewrite_node_address_for_bridge(bridge, node); - if (tor_digest_is_zero(bridge->identity)) { - memcpy(bridge->identity,ri->cache_info.identity_digest, DIGEST_LEN); - log_notice(LD_DIR, "Learned identity %s for bridge at %s:%d", - hex_str(bridge->identity, DIGEST_LEN), - fmt_and_decorate_addr(&bridge->addr), - (int) bridge->port); - } - add_an_entry_guard(node, 1, 1, 0, 0); - - log_notice(LD_DIR, "new bridge descriptor '%s' (%s): %s", ri->nickname, - from_cache ? "cached" : "fresh", router_describe(ri)); - /* set entry->made_contact so if it goes down we don't drop it from - * our entry node list */ - entry_guard_register_connect_status(ri->cache_info.identity_digest, - 1, 0, now); - if (first) { - routerlist_retry_directory_downloads(now); - } - } - } -} - -/** Return the number of bridges that have descriptors that - * are marked with purpose 'bridge' and are running. - * - * We use this function to decide if we're ready to start building - * circuits through our bridges, or if we need to wait until the - * directory "server/authority" requests finish. */ -int -any_bridge_descriptors_known(void) -{ - tor_assert(get_options()->UseBridges); - return choose_random_entry(NULL) != NULL; -} - -/** Return the number of bridges that have descriptors that are marked with - * purpose 'bridge' and are running. - */ -static int -num_bridges_usable(void) -{ - int n_options = 0; - tor_assert(get_options()->UseBridges); - (void) choose_random_entry_impl(NULL, 0, 0, &n_options); - return n_options; -} - -/** Return a smartlist containing all bridge identity digests */ -MOCK_IMPL(smartlist_t *, -list_bridge_identities, (void)) -{ - smartlist_t *result = NULL; - char *digest_tmp; - - if (get_options()->UseBridges && bridge_list) { - result = smartlist_new(); - - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, b) { - digest_tmp = tor_malloc(DIGEST_LEN); - memcpy(digest_tmp, b->identity, DIGEST_LEN); - smartlist_add(result, digest_tmp); - } SMARTLIST_FOREACH_END(b); - } - - return result; -} - -/** Get the download status for a bridge descriptor given its identity */ -MOCK_IMPL(download_status_t *, -get_bridge_dl_status_by_id, (const char *digest)) -{ - download_status_t *dl = NULL; - - if (digest && get_options()->UseBridges && bridge_list) { - SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, b) { - if (tor_memeq(digest, b->identity, DIGEST_LEN)) { - dl = &(b->fetch_status); - break; - } - } SMARTLIST_FOREACH_END(b); - } - - return dl; -} - -/** Return 1 if we have at least one descriptor for an entry guard - * (bridge or member of EntryNodes) and all descriptors we know are - * down. Else return 0. If <b>act</b> is 1, then mark the down guards - * up; else just observe and report. */ -static int -entries_retry_helper(const or_options_t *options, int act) -{ - const node_t *node; - int any_known = 0; - int any_running = 0; - int need_bridges = options->UseBridges != 0; - if (!entry_guards) - entry_guards = smartlist_new(); - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - node = node_get_by_id(e->identity); - if (node && node_has_descriptor(node) && - node_is_bridge(node) == need_bridges && - (!need_bridges || (!e->bad_since && - node_is_a_configured_bridge(node)))) { - any_known = 1; - if (node->is_running) - any_running = 1; /* some entry is both known and running */ - else if (act) { - /* Mark all current connections to this OR as unhealthy, since - * otherwise there could be one that started 30 seconds - * ago, and in 30 seconds it will time out, causing us to mark - * the node down and undermine the retry attempt. We mark even - * the established conns, since if the network just came back - * we'll want to attach circuits to fresh conns. */ - connection_or_set_bad_connections(node->identity, 1); - - /* mark this entry node for retry */ - router_set_status(node->identity, 1); - e->can_retry = 1; - e->bad_since = 0; - } - } - } SMARTLIST_FOREACH_END(e); - log_debug(LD_DIR, "%d: any_known %d, any_running %d", - act, any_known, any_running); - return any_known && !any_running; -} - -/** Do we know any descriptors for our bridges / entrynodes, and are - * all the ones we have descriptors for down? */ -int -entries_known_but_down(const or_options_t *options) -{ - tor_assert(entry_list_is_constrained(options)); - return entries_retry_helper(options, 0); -} - -/** Mark all down known bridges / entrynodes up. */ -void -entries_retry_all(const or_options_t *options) -{ - tor_assert(entry_list_is_constrained(options)); - entries_retry_helper(options, 1); -} - -/** Return true if at least one of our bridges runs a Tor version that can - * provide microdescriptors to us. If not, we'll fall back to asking for - * full descriptors. */ -int -any_bridge_supports_microdescriptors(void) -{ - const node_t *node; - if (!get_options()->UseBridges || !entry_guards) - return 0; - SMARTLIST_FOREACH_BEGIN(entry_guards, entry_guard_t *, e) { - node = node_get_by_id(e->identity); - if (node && node->is_running && - node_is_bridge(node) && node_is_a_configured_bridge(node)) { - /* This is one of our current bridges, and we know enough about - * it to know that it will be able to answer our questions. */ - return 1; - } - } SMARTLIST_FOREACH_END(e); - return 0; -} - -/** Release all storage held by the list of entry guards and related - * memory structs. */ -void -entry_guards_free_all(void) -{ - if (entry_guards) { - SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e, - entry_guard_free(e)); - smartlist_free(entry_guards); - entry_guards = NULL; - } - clear_bridge_list(); - smartlist_free(bridge_list); - bridge_list = NULL; - circuit_build_times_free_timeouts(get_circuit_build_times_mutable()); -} - |