/* Copyright 2001-2003 Roger Dingledine, Matej Pfajfar. */ /* See LICENSE for licensing information */ /* $Id$ */ #include "or.h" /** * \file routerlist.c * * \brief Code to * maintain and access the global list of routerinfos for known * servers. **/ /****************************************************************************/ extern or_options_t options; /**< command-line and config-file options */ /* ********************************************************************** */ /* static function prototypes */ static routerinfo_t *router_pick_directory_server_impl(void); static int router_resolve_routerlist(routerlist_t *dir); /****************************************************************************/ /**** * Functions to manage and access our list of known routers. (Note: * dirservers maintain a separate, independent list of known router * descriptors.) *****/ /** Global list of all of the routers that we, as an OR or OP, know about. */ static routerlist_t *routerlist = NULL; extern int has_fetched_directory; /**< from main.c */ /** Try to find a running dirserver. If there are no running dirservers * in our routerlist, reload the routerlist and try again. */ routerinfo_t *router_pick_directory_server(void) { routerinfo_t *choice; choice = router_pick_directory_server_impl(); if(!choice) { log_fn(LOG_WARN,"No dirservers known. Reloading and trying again."); has_fetched_directory=0; /* reset it */ routerlist_clear_trusted_directories(); if(options.RouterFile) { if(router_load_routerlist_from_file(options.RouterFile, 1) < 0) return NULL; } else { if(config_assign_default_dirservers() < 0) return NULL; } /* give it another try */ choice = router_pick_directory_server_impl(); } return choice; } /** Pick a random running router that's a trusted dirserver from our * routerlist. */ static routerinfo_t *router_pick_directory_server_impl(void) { int i; routerinfo_t *router; smartlist_t *sl; if(!routerlist) return NULL; /* Find all the running dirservers we know about. */ sl = smartlist_create(); for(i=0;i< smartlist_len(routerlist->routers); i++) { router = smartlist_get(routerlist->routers, i); if(router->is_running && router->is_trusted_dir) { tor_assert(router->dir_port > 0); smartlist_add(sl, router); } } router = smartlist_choose(sl); smartlist_free(sl); if(router) return router; log_fn(LOG_INFO,"No dirservers are reachable. Trying them all again."); /* No running dir servers found? go through and mark them all as up, * so we cycle through the list again. */ sl = smartlist_create(); for(i=0; i < smartlist_len(routerlist->routers); i++) { router = smartlist_get(routerlist->routers, i); if(router->is_trusted_dir) { tor_assert(router->dir_port > 0); router->is_running = 1; router->status_set_at = time(NULL); smartlist_add(sl, router); } } router = smartlist_choose(sl); smartlist_free(sl); if(!router) log_fn(LOG_WARN,"No dirservers in directory! Returning NULL."); return router; } /** Return 0 if \exists an authoritative dirserver that's currently * thought to be running, else return 1. */ int all_directory_servers_down(void) { int i; routerinfo_t *router; if(!routerlist) return 1; /* if no dirservers, I guess they're all down */ for(i=0;i< smartlist_len(routerlist->routers); i++) { router = smartlist_get(routerlist->routers, i); if(router->is_running && router->is_trusted_dir) { tor_assert(router->dir_port > 0); return 0; } } return 1; } /** Given a comma-and-whitespace separated list of nicknames, see which * nicknames in list name routers in our routerlist that are * currently running. Add the routerinfos for those routers to sl. */ void add_nickname_list_to_smartlist(smartlist_t *sl, const char *list) { const char *start,*end; char nick[MAX_NICKNAME_LEN+1]; routerinfo_t *router; tor_assert(sl); tor_assert(list); while(isspace((int)*list) || *list==',') list++; start = list; while(*start) { end=start; while(*end && !isspace((int)*end) && *end != ',') end++; memcpy(nick,start,end-start); nick[end-start] = 0; /* null terminate it */ router = router_get_by_nickname(nick); if (router) { if (router->is_running) smartlist_add(sl,router); else log_fn(LOG_WARN,"Nickname list includes '%s' which is known but down.",nick); } else log_fn(has_fetched_directory ? LOG_WARN : LOG_INFO, "Nickname list includes '%s' which isn't a known router.",nick); while(isspace((int)*end) || *end==',') end++; start = end; } } /** Add every router from our routerlist that is currently running to * sl. */ void router_add_running_routers_to_smartlist(smartlist_t *sl) { routerinfo_t *router; int i; if(!routerlist) return; for(i=0;irouters);i++) { router = smartlist_get(routerlist->routers, i); if(router->is_running && (!clique_mode() || connection_get_by_identity_digest(router->identity_digest, CONN_TYPE_OR))) smartlist_add(sl, router); } } /** Return a random running router from the routerlist. If any node * named in preferred is available, pick one of those. Never pick a * node named in excluded, or whose routerinfo is in * excludedsmartlist, even if they are the only nodes available. */ routerinfo_t *router_choose_random_node(char *preferred, char *excluded, smartlist_t *excludedsmartlist) { smartlist_t *sl, *excludednodes; routerinfo_t *choice; excludednodes = smartlist_create(); add_nickname_list_to_smartlist(excludednodes,excluded); /* try the nodes in RendNodes first */ sl = smartlist_create(); add_nickname_list_to_smartlist(sl,preferred); smartlist_subtract(sl,excludednodes); if(excludedsmartlist) smartlist_subtract(sl,excludedsmartlist); choice = smartlist_choose(sl); smartlist_free(sl); if(!choice) { sl = smartlist_create(); router_add_running_routers_to_smartlist(sl); smartlist_subtract(sl,excludednodes); if(excludedsmartlist) smartlist_subtract(sl,excludedsmartlist); choice = smartlist_choose(sl); smartlist_free(sl); } smartlist_free(excludednodes); if(!choice) log_fn(LOG_WARN,"No available nodes when trying to choose node. Failing."); return choice; } /** Return the router in our routerlist whose address is addr and * whose OR port is port. Return NULL if no such router is known. */ routerinfo_t *router_get_by_addr_port(uint32_t addr, uint16_t port) { int i; routerinfo_t *router; tor_assert(routerlist); for(i=0;irouters);i++) { router = smartlist_get(routerlist->routers, i); if ((router->addr == addr) && (router->or_port == port)) return router; } return NULL; } /** Return true iff the digest of router's identity key, * encoded in hexadecimal, matches hexdigest (which is * optionally prefixed with a single dollar sign). Return false if * hexdigest is malformed, or it doesn't match. */ static INLINE int router_hex_digest_matches(routerinfo_t *router, const char *hexdigest) { char digest[DIGEST_LEN]; tor_assert(hexdigest); if (hexdigest[0] == '$') ++hexdigest; if (strlen(hexdigest) != HEX_DIGEST_LEN || base16_decode(digest, DIGEST_LEN, hexdigest, HEX_DIGEST_LEN)<0) return 0; else return (!memcmp(digest, router->identity_digest, DIGEST_LEN)); } /* Return true if router's nickname matches nickname * (case-insensitive), or if router's identity key digest * matches a hexadecimal value stored in nickname. Return * false otherwise.*/ int router_nickname_matches(routerinfo_t *router, const char *nickname) { if (nickname[0]!='$' && !strcasecmp(router->nickname, nickname)) return 1; else return router_hex_digest_matches(router, nickname); } /** Return the router in our routerlist whose (case-insensitive) * nickname or (case-sensitive) hexadecimal key digest is * nickname. Return NULL if no such router is known. */ routerinfo_t *router_get_by_nickname(const char *nickname) { int i, maybedigest; routerinfo_t *router; char digest[DIGEST_LEN]; tor_assert(nickname); if (!routerlist) return NULL; if (nickname[0] == '$') return router_get_by_hexdigest(nickname); maybedigest = (strlen(nickname) == HEX_DIGEST_LEN) && (base16_decode(digest,DIGEST_LEN,nickname,HEX_DIGEST_LEN) == 0); for(i=0;irouters);i++) { router = smartlist_get(routerlist->routers, i); if (0 == strcasecmp(router->nickname, nickname) || (maybedigest && 0 == memcmp(digest, router->identity_digest, DIGEST_LEN))) return router; } return NULL; } /** Return the router in our routerlist whose hexadecimal key digest * is hexdigest. Return NULL if no such router is known. */ routerinfo_t *router_get_by_hexdigest(const char *hexdigest) { char digest[DIGEST_LEN]; tor_assert(hexdigest); if (!routerlist) return NULL; if (hexdigest[0]=='$') ++hexdigest; if (strlen(hexdigest) != HEX_DIGEST_LEN || base16_decode(digest,DIGEST_LEN,hexdigest,HEX_DIGEST_LEN) < 0) return NULL; return router_get_by_digest(digest); } /** Return the router in our routerlist whose 20-byte key digest * is hexdigest. Return NULL if no such router is known. */ routerinfo_t *router_get_by_digest(const char *digest) { int i; routerinfo_t *router; tor_assert(digest); for(i=0;irouters);i++) { router = smartlist_get(routerlist->routers, i); if (0 == memcmp(router->identity_digest, digest, DIGEST_LEN)) return router; } return NULL; } /** Set *prouterlist to the current list of all known routers. */ void router_get_routerlist(routerlist_t **prouterlist) { *prouterlist = routerlist; } /** Free all storage held by router. */ void routerinfo_free(routerinfo_t *router) { if (!router) return; tor_free(router->address); tor_free(router->nickname); tor_free(router->platform); if (router->onion_pkey) crypto_free_pk_env(router->onion_pkey); if (router->identity_pkey) crypto_free_pk_env(router->identity_pkey); exit_policy_free(router->exit_policy); free(router); } /** Allocate a fresh copy of router */ routerinfo_t *routerinfo_copy(const routerinfo_t *router) { routerinfo_t *r; struct exit_policy_t **e, *tmp; r = tor_malloc(sizeof(routerinfo_t)); memcpy(r, router, sizeof(routerinfo_t)); r->address = tor_strdup(r->address); r->nickname = tor_strdup(r->nickname); r->platform = tor_strdup(r->platform); if (r->onion_pkey) r->onion_pkey = crypto_pk_dup_key(r->onion_pkey); if (r->identity_pkey) r->identity_pkey = crypto_pk_dup_key(r->identity_pkey); e = &r->exit_policy; while (*e) { tmp = tor_malloc(sizeof(struct exit_policy_t)); memcpy(tmp,*e,sizeof(struct exit_policy_t)); *e = tmp; (*e)->string = tor_strdup((*e)->string); e = & ((*e)->next); } return r; } /** Free all storage held by a routerlist rl */ void routerlist_free(routerlist_t *rl) { SMARTLIST_FOREACH(rl->routers, routerinfo_t *, r, routerinfo_free(r)); smartlist_free(rl->routers); tor_free(rl->software_versions); tor_free(rl); } /** Mark the router with ID digest as non-running in our routerlist. */ void router_mark_as_down(const char *digest) { routerinfo_t *router; tor_assert(digest); router = router_get_by_digest(digest); if(!router) /* we don't seem to know about him in the first place */ return; log_fn(LOG_DEBUG,"Marking %s as down.",router->nickname); router->is_running = 0; router->status_set_at = time(NULL); } /** Add router to the routerlist, if we don't already have it. Replace * older entries (if any) with the same name. Note: Callers should not hold * their pointers to router after invoking this function; router * will either be inserted into the routerlist or freed. Returns 0 if the * router was added; -1 if it was not. */ int router_add_to_routerlist(routerinfo_t *router) { int i; routerinfo_t *r; /* If we have a router with this name, and the identity key is the same, * choose the newer one. If the identity key has changed, drop the router. */ for (i = 0; i < smartlist_len(routerlist->routers); ++i) { r = smartlist_get(routerlist->routers, i); /* XXXX008 should just compare digests instead. */ if (!strcasecmp(router->nickname, r->nickname)) { if (!crypto_pk_cmp_keys(router->identity_pkey, r->identity_pkey)) { if (router->published_on > r->published_on) { log_fn(LOG_DEBUG, "Replacing entry for router '%s'", router->nickname); /* Remember whether we trust this router as a dirserver. */ if (r->is_trusted_dir) router->is_trusted_dir = 1; /* If the address hasn't changed; no need to re-resolve. */ if (!strcasecmp(r->address, router->address)) router->addr = r->addr; routerinfo_free(r); smartlist_set(routerlist->routers, i, router); return 0; } else { log_fn(LOG_DEBUG, "Skipping old entry for router '%s'", router->nickname); /* If we now trust 'router', then we trust the one in the routerlist * too. */ if (router->is_trusted_dir) r->is_trusted_dir = 1; /* Update the is_running status to whatever we were told. */ r->is_running = router->is_running; routerinfo_free(router); return -1; } } else { /* XXXX008 It's okay to have two keys for a nickname as soon as * all the 007 clients are dead. */ log_fn(LOG_WARN, "Identity key mismatch for router '%s'", router->nickname); routerinfo_free(router); return -1; } } } /* We haven't seen a router with this name before. Add it to the end of * the list. */ smartlist_add(routerlist->routers, router); return 0; } /** Remove any routers from the routerlist that are more than ROUTER_MAX_AGE * seconds old. * * (This function is just like dirserv_remove_old_servers. One day we should * merge them.) */ void routerlist_remove_old_routers(void) { int i; time_t cutoff; routerinfo_t *router; if (!routerlist) return; cutoff = time(NULL) - ROUTER_MAX_AGE; for (i = 0; i < smartlist_len(routerlist->routers); ++i) { router = smartlist_get(routerlist->routers, i); if (router->published_on < cutoff && !router->dir_port) { /* Too old. Remove it. But never remove dirservers! */ log_fn(LOG_INFO,"Forgetting obsolete routerinfo for node %s.", router->nickname); routerinfo_free(router); smartlist_del(routerlist->routers, i--); } } } /* * Code to parse router descriptors and directories. */ /** Update the current router list with the one stored in * routerfile. If trusted is true, then we'll use * directory servers from the file. */ int router_load_routerlist_from_file(char *routerfile, int trusted) { char *string; string = read_file_to_str(routerfile); if(!string) { log_fn(LOG_WARN,"Failed to load routerfile %s.",routerfile); return -1; } if(router_load_routerlist_from_string(string, trusted) < 0) { log_fn(LOG_WARN,"The routerfile itself was corrupt."); free(string); return -1; } /* dump_onion_keys(LOG_NOTICE); */ free(string); return 0; } /** Mark all directories in the routerlist as nontrusted. */ void routerlist_clear_trusted_directories(void) { if (!routerlist) return; SMARTLIST_FOREACH(routerlist->routers, routerinfo_t *, r, r->is_trusted_dir = 0); } /** Helper function: read routerinfo elements from s, and throw out the * ones that don't parse and resolve. Add all remaining elements to the * routerlist. If trusted is true, then we'll use * directory servers from the string */ int router_load_routerlist_from_string(const char *s, int trusted) { routerlist_t *new_list=NULL; if (router_parse_list_from_string(&s, &new_list, NULL)) { log(LOG_WARN, "Error parsing router file"); return -1; } if (trusted) { SMARTLIST_FOREACH(new_list->routers, routerinfo_t *, r, if (r->dir_port) r->is_trusted_dir = 1); } if (routerlist) { SMARTLIST_FOREACH(new_list->routers, routerinfo_t *, r, router_add_to_routerlist(r)); smartlist_clear(new_list->routers); routerlist_free(new_list); } else { routerlist = new_list; } if (router_resolve_routerlist(routerlist)) { log(LOG_WARN, "Error resolving routerlist"); return -1; } /* dump_onion_keys(LOG_NOTICE); */ return 0; } /** Add to the current routerlist each router stored in the * signed directory s. If pkey is provided, check the signature against * pkey; else check against the pkey of the signing directory server. */ int router_load_routerlist_from_directory(const char *s, crypto_pk_env_t *pkey) { routerlist_t *new_list = NULL; check_software_version_against_directory(s, options.IgnoreVersion); if (router_parse_routerlist_from_directory(s, &new_list, pkey)) { log_fn(LOG_WARN, "Couldn't parse directory."); return -1; } if (routerlist) { SMARTLIST_FOREACH(new_list->routers, routerinfo_t *, r, router_add_to_routerlist(r)); smartlist_clear(new_list->routers); routerlist->published_on = new_list->published_on; tor_free(routerlist->software_versions); routerlist->software_versions = new_list->software_versions; new_list->software_versions = NULL; routerlist_free(new_list); } else { routerlist = new_list; } if (router_resolve_routerlist(routerlist)) { log_fn(LOG_WARN, "Error resolving routerlist"); return -1; } if (options.AuthoritativeDir) { /* Learn about the descriptors in the directory. */ dirserv_load_from_directory_string(s); } else { /* Remember the directory. */ dirserv_set_cached_directory(s, routerlist->published_on); } return 0; } /** Helper function: resolve the hostname for router. */ static int router_resolve(routerinfo_t *router) { if (tor_lookup_hostname(router->address, &router->addr) != 0 || !router->addr) { log_fn(LOG_WARN,"Could not get address for router %s (%s).", router->address, router->nickname); return -1; } router->addr = ntohl(router->addr); /* get it back into host order */ return 0; } /** Helper function: resolve every router in rl, and ensure that our own * routerinfo is at the front. */ static int router_resolve_routerlist(routerlist_t *rl) { int i, remove; routerinfo_t *r; if (!rl) rl = routerlist; i = 0; if ((r = router_get_my_routerinfo())) { smartlist_insert(rl->routers, 0, routerinfo_copy(r)); ++i; } for ( ; i < smartlist_len(rl->routers); ++i) { remove = 0; r = smartlist_get(rl->routers,i); if (router_is_me(r)) { remove = 1; } else if (r->addr) { /* already resolved. */ } else if (router_resolve(r)) { log_fn(LOG_WARN, "Couldn't resolve router %s; not using", r->address); remove = 1; } if (remove) { routerinfo_free(r); smartlist_del_keeporder(rl->routers, i--); } } return 0; } /** Decide whether a given addr:port is definitely accepted, definitely * rejected, or neither by a given exit policy. If addr is 0, we * don't know the IP of the target address. * * Returns -1 for "rejected", 0 for "accepted", 1 for "maybe" (since IP is * unknown). */ int router_compare_addr_to_exit_policy(uint32_t addr, uint16_t port, struct exit_policy_t *policy) { int maybe_reject = 0; int maybe_accept = 0; int match = 0; int maybe = 0; struct in_addr in; struct exit_policy_t *tmpe; for(tmpe=policy; tmpe; tmpe=tmpe->next) { // log_fn(LOG_DEBUG,"Considering exit policy %s", tmpe->string); maybe = 0; if (!addr) { /* Address is unknown. */ if (port >= tmpe->prt_min && port <= tmpe->prt_max) { /* The port definitely matches. */ if (tmpe->msk == 0) { match = 1; } else { maybe = 1; } } else if (!port) { /* The port maybe matches. */ maybe = 1; } } else { /* Address is known */ if ((addr & tmpe->msk) == (tmpe->addr & tmpe->msk)) { if (port >= tmpe->prt_min && port <= tmpe->prt_max) { /* Exact match for the policy */ match = 1; } else if (!port) { maybe = 1; } } } if (maybe) { if (tmpe->policy_type == EXIT_POLICY_REJECT) maybe_reject = 1; else maybe_accept = 1; } if (match) { in.s_addr = htonl(addr); log_fn(LOG_DEBUG,"Address %s:%d matches exit policy '%s'", inet_ntoa(in), port, tmpe->string); if(tmpe->policy_type == EXIT_POLICY_ACCEPT) { /* If we already hit a clause that might trigger a 'reject', than we * can't be sure of this certain 'accept'.*/ return maybe_reject ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_ACCEPTED; } else { return maybe_accept ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_REJECTED; } } } /* accept all by default. */ return maybe_reject ? ADDR_POLICY_UNKNOWN : ADDR_POLICY_ACCEPTED; } /** Return 1 if all running routers will reject addr:port, return 0 if * any might accept it. */ int router_exit_policy_all_routers_reject(uint32_t addr, uint16_t port) { int i; routerinfo_t *router; for (i=0;irouters);i++) { router = smartlist_get(routerlist->routers, i); if (router->is_running && router_compare_addr_to_exit_policy( addr, port, router->exit_policy) != ADDR_POLICY_REJECTED) return 0; /* this one could be ok. good enough. */ } return 1; /* all will reject. */ } /** Return true iff router does not permit exit streams. */ int router_exit_policy_rejects_all(routerinfo_t *router) { return router_compare_addr_to_exit_policy(0, 0, router->exit_policy) == ADDR_POLICY_REJECTED; } /* Release all space held in rr. */ void running_routers_free(running_routers_t *rr) { tor_assert(rr); if (rr->running_routers) { SMARTLIST_FOREACH(rr->running_routers, char *, s, tor_free(s)); smartlist_free(rr->running_routers); } tor_free(rr); } /* Update the running/not-running status of every router in list, based * on the contents of rr. */ void routerlist_update_from_runningrouters(routerlist_t *list, running_routers_t *rr) { int n_routers, i; routerinfo_t *router; if (!list) return; if (list->published_on >= rr->published_on) return; if (list->running_routers_updated_on >= rr->published_on) return; n_routers = smartlist_len(list->routers); for (i=0; irouters, i); router_update_status_from_smartlist(router, rr->published_on, rr->running_routers); } list->running_routers_updated_on = rr->published_on; } /** Update the is_running and is_verified fields of the router router, * based in its status in the list of strings stored in running_list. * All entries in running_list follow one of these formats: *
  1. nickname -- router is running and verified. *
  2. !nickname -- router is not-running and verified. *
  3. $hexdigest -- router is running and unverified. *
  4. !$hexdigest -- router is not-running and unverified. *
*/ void router_update_status_from_smartlist(routerinfo_t *router, time_t list_time, smartlist_t *running_list) { int n_names, i, running, approved; const char *name; running = approved = 0; n_names = smartlist_len(running_list); for (i=0; istatus_set_at < list_time) { router->status_set_at = list_time; router->is_running = 1; } router->is_verified = (name[1] != '$'); return; } } else { /* *name == '!' */ if (router_nickname_matches(router, name)) { if (router->status_set_at < list_time) { router->status_set_at = list_time; router->is_running = 0; } router->is_verified = (name[1] != '$'); return; } } } } /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */