/* Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file policies.c * \brief Code to parse and use address policies and exit policies. * * We have two key kinds of address policy: full and compressed. A full * policy is an array of accept/reject patterns, to be applied in order. * A short policy is simply a list of ports. This module handles both * kinds, including generic functions to apply them to addresses, and * also including code to manage the global policies that we apply to * incoming and outgoing connections. **/ #define POLICIES_PRIVATE #include "or.h" #include "bridges.h" #include "config.h" #include "dirserv.h" #include "microdesc.h" #include "networkstatus.h" #include "nodelist.h" #include "policies.h" #include "router.h" #include "routerparse.h" #include "geoip.h" #include "ht.h" /** Policy that addresses for incoming SOCKS connections must match. */ static smartlist_t *socks_policy = NULL; /** Policy that addresses for incoming directory connections must match. */ static smartlist_t *dir_policy = NULL; /** Policy that addresses for incoming router descriptors must match in order * to be published by us. */ static smartlist_t *authdir_reject_policy = NULL; /** Policy that addresses for incoming router descriptors must match in order * to be marked as valid in our networkstatus. */ static smartlist_t *authdir_invalid_policy = NULL; /** Policy that addresses for incoming router descriptors must not * match in order to not be marked as BadExit. */ static smartlist_t *authdir_badexit_policy = NULL; /** Parsed addr_policy_t describing which addresses we believe we can start * circuits at. */ static smartlist_t *reachable_or_addr_policy = NULL; /** Parsed addr_policy_t describing which addresses we believe we can connect * to directories at. */ static smartlist_t *reachable_dir_addr_policy = NULL; /** Element of an exit policy summary */ typedef struct policy_summary_item_t { uint16_t prt_min; /**< Lowest port number to accept/reject. */ uint16_t prt_max; /**< Highest port number to accept/reject. */ uint64_t reject_count; /**< Number of IP-Addresses that are rejected to this port range. */ unsigned int accepted:1; /** Has this port already been accepted */ } policy_summary_item_t; /** Private networks. This list is used in two places, once to expand the * "private" keyword when parsing our own exit policy, secondly to ignore * just such networks when building exit policy summaries. It is important * that all authorities agree on that list when creating summaries, so don't * just change this without a proper migration plan and a proposal and stuff. */ static const char *private_nets[] = { "0.0.0.0/8", "169.254.0.0/16", "127.0.0.0/8", "192.168.0.0/16", "10.0.0.0/8", "172.16.0.0/12", "[::]/8", "[fc00::]/7", "[fe80::]/10", "[fec0::]/10", "[ff00::]/8", "[::]/127", NULL }; static int policies_parse_exit_policy_internal( config_line_t *cfg, smartlist_t **dest, int ipv6_exit, int rejectprivate, const smartlist_t *configured_addresses, int reject_interface_addresses, int reject_configured_port_addresses, int add_default_policy, int add_reduced_policy); /** Replace all "private" entries in *policy with their expanded * equivalents. */ void policy_expand_private(smartlist_t **policy) { uint16_t port_min, port_max; int i; smartlist_t *tmp; if (!*policy) /*XXXX disallow NULL policies? */ return; tmp = smartlist_new(); SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, p) { if (! p->is_private) { smartlist_add(tmp, p); continue; } for (i = 0; private_nets[i]; ++i) { addr_policy_t newpolicy; memcpy(&newpolicy, p, sizeof(addr_policy_t)); newpolicy.is_private = 0; newpolicy.is_canonical = 0; if (tor_addr_parse_mask_ports(private_nets[i], 0, &newpolicy.addr, &newpolicy.maskbits, &port_min, &port_max)<0) { tor_assert_unreached(); } smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy)); } addr_policy_free(p); } SMARTLIST_FOREACH_END(p); smartlist_free(*policy); *policy = tmp; } /** Expand each of the AF_UNSPEC elements in *policy (which indicate * protocol-neutral wildcards) into a pair of wildcard elements: one IPv4- * specific and one IPv6-specific. */ void policy_expand_unspec(smartlist_t **policy) { smartlist_t *tmp; if (!*policy) return; tmp = smartlist_new(); SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, p) { sa_family_t family = tor_addr_family(&p->addr); if (family == AF_INET6 || family == AF_INET || p->is_private) { smartlist_add(tmp, p); } else if (family == AF_UNSPEC) { addr_policy_t newpolicy_ipv4; addr_policy_t newpolicy_ipv6; memcpy(&newpolicy_ipv4, p, sizeof(addr_policy_t)); memcpy(&newpolicy_ipv6, p, sizeof(addr_policy_t)); newpolicy_ipv4.is_canonical = 0; newpolicy_ipv6.is_canonical = 0; if (p->maskbits != 0) { log_warn(LD_BUG, "AF_UNSPEC policy with maskbits==%d", p->maskbits); newpolicy_ipv4.maskbits = 0; newpolicy_ipv6.maskbits = 0; } tor_addr_from_ipv4h(&newpolicy_ipv4.addr, 0); tor_addr_from_ipv6_bytes(&newpolicy_ipv6.addr, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"); smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv4)); smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv6)); addr_policy_free(p); } else { log_warn(LD_BUG, "Funny-looking address policy with family %d", family); smartlist_add(tmp, p); } } SMARTLIST_FOREACH_END(p); smartlist_free(*policy); *policy = tmp; } /** * Given a linked list of config lines containing "accept[6]" and "reject[6]" * tokens, parse them and append the result to dest. Return -1 * if any tokens are malformed (and don't append any), else return 0. * * If assume_action is nonnegative, then insert its action * (ADDR_POLICY_ACCEPT or ADDR_POLICY_REJECT) for items that specify no * action. */ static int parse_addr_policy(config_line_t *cfg, smartlist_t **dest, int assume_action) { smartlist_t *result; smartlist_t *entries; addr_policy_t *item; int malformed_list; int r = 0; if (!cfg) return 0; result = smartlist_new(); entries = smartlist_new(); for (; cfg; cfg = cfg->next) { smartlist_split_string(entries, cfg->value, ",", SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0); SMARTLIST_FOREACH_BEGIN(entries, const char *, ent) { log_debug(LD_CONFIG,"Adding new entry '%s'",ent); malformed_list = 0; item = router_parse_addr_policy_item_from_string(ent, assume_action, &malformed_list); if (item) { smartlist_add(result, item); } else if (malformed_list) { /* the error is so severe the entire list should be discarded */ log_warn(LD_CONFIG, "Malformed policy '%s'. Discarding entire policy " "list.", ent); r = -1; } else { /* the error is minor: don't add the item, but keep processing the * rest of the policies in the list */ log_debug(LD_CONFIG, "Ignored policy '%s' due to non-fatal error. " "The remainder of the policy list will be used.", ent); } } SMARTLIST_FOREACH_END(ent); SMARTLIST_FOREACH(entries, char *, ent, tor_free(ent)); smartlist_clear(entries); } smartlist_free(entries); if (r == -1) { addr_policy_list_free(result); } else { policy_expand_private(&result); policy_expand_unspec(&result); if (*dest) { smartlist_add_all(*dest, result); smartlist_free(result); } else { *dest = result; } } return r; } /** Helper: parse the Reachable(Dir|OR)?Addresses fields into * reachable_(or|dir)_addr_policy. The options should already have * been validated by validate_addr_policies. */ static int parse_reachable_addresses(void) { const or_options_t *options = get_options(); int ret = 0; if (options->ReachableDirAddresses && options->ReachableORAddresses && options->ReachableAddresses) { log_warn(LD_CONFIG, "Both ReachableDirAddresses and ReachableORAddresses are set. " "ReachableAddresses setting will be ignored."); } addr_policy_list_free(reachable_or_addr_policy); reachable_or_addr_policy = NULL; if (!options->ReachableORAddresses && options->ReachableAddresses) log_info(LD_CONFIG, "Using ReachableAddresses as ReachableORAddresses."); if (parse_addr_policy(options->ReachableORAddresses ? options->ReachableORAddresses : options->ReachableAddresses, &reachable_or_addr_policy, ADDR_POLICY_ACCEPT)) { log_warn(LD_CONFIG, "Error parsing Reachable%sAddresses entry; ignoring.", options->ReachableORAddresses ? "OR" : ""); ret = -1; } addr_policy_list_free(reachable_dir_addr_policy); reachable_dir_addr_policy = NULL; if (!options->ReachableDirAddresses && options->ReachableAddresses) log_info(LD_CONFIG, "Using ReachableAddresses as ReachableDirAddresses"); if (parse_addr_policy(options->ReachableDirAddresses ? options->ReachableDirAddresses : options->ReachableAddresses, &reachable_dir_addr_policy, ADDR_POLICY_ACCEPT)) { if (options->ReachableDirAddresses) log_warn(LD_CONFIG, "Error parsing ReachableDirAddresses entry; ignoring."); ret = -1; } /* We ignore ReachableAddresses for relays */ if (!server_mode(options)) { if (policy_is_reject_star(reachable_or_addr_policy, AF_UNSPEC, 0) || policy_is_reject_star(reachable_dir_addr_policy, AF_UNSPEC,0)) { log_warn(LD_CONFIG, "Tor cannot connect to the Internet if " "ReachableAddresses, ReachableORAddresses, or " "ReachableDirAddresses reject all addresses. Please accept " "some addresses in these options."); } else if (options->ClientUseIPv4 == 1 && (policy_is_reject_star(reachable_or_addr_policy, AF_INET, 0) || policy_is_reject_star(reachable_dir_addr_policy, AF_INET, 0))) { log_warn(LD_CONFIG, "You have set ClientUseIPv4 1, but " "ReachableAddresses, ReachableORAddresses, or " "ReachableDirAddresses reject all IPv4 addresses. " "Tor will not connect using IPv4."); } else if (fascist_firewall_use_ipv6(options) && (policy_is_reject_star(reachable_or_addr_policy, AF_INET6, 0) || policy_is_reject_star(reachable_dir_addr_policy, AF_INET6, 0))) { log_warn(LD_CONFIG, "You have configured tor to use or prefer IPv6 " "(or UseBridges 1), but " "ReachableAddresses, ReachableORAddresses, or " "ReachableDirAddresses reject all IPv6 addresses. " "Tor will not connect using IPv6."); } } return ret; } /* Return true iff ClientUseIPv4 0 or ClientUseIPv6 0 might block any OR or Dir * address:port combination. */ static int firewall_is_fascist_impl(void) { const or_options_t *options = get_options(); /* Assume every non-bridge relay has an IPv4 address. * Clients which use bridges may only know the IPv6 address of their * bridge, but they will connect regardless of the ClientUseIPv6 setting. */ return options->ClientUseIPv4 == 0; } /** Return true iff the firewall options, including ClientUseIPv4 0 and * ClientUseIPv6 0, might block any OR address:port combination. * Address preferences may still change which address is selected even if * this function returns false. */ int firewall_is_fascist_or(void) { return (reachable_or_addr_policy != NULL || firewall_is_fascist_impl()); } /** Return true iff the firewall options, including ClientUseIPv4 0 and * ClientUseIPv6 0, might block any Dir address:port combination. * Address preferences may still change which address is selected even if * this function returns false. */ int firewall_is_fascist_dir(void) { return (reachable_dir_addr_policy != NULL || firewall_is_fascist_impl()); } /** Return true iff policy (possibly NULL) will allow a * connection to addr:port. */ static int addr_policy_permits_tor_addr(const tor_addr_t *addr, uint16_t port, smartlist_t *policy) { addr_policy_result_t p; p = compare_tor_addr_to_addr_policy(addr, port, policy); switch (p) { case ADDR_POLICY_PROBABLY_ACCEPTED: case ADDR_POLICY_ACCEPTED: return 1; case ADDR_POLICY_PROBABLY_REJECTED: case ADDR_POLICY_REJECTED: return 0; default: log_warn(LD_BUG, "Unexpected result: %d", (int)p); return 0; } } /** Return true iff policy (possibly NULL) will allow a connection to * addr:port. addr is an IPv4 address given in host * order. */ /* XXXX deprecate when possible. */ static int addr_policy_permits_address(uint32_t addr, uint16_t port, smartlist_t *policy) { tor_addr_t a; tor_addr_from_ipv4h(&a, addr); return addr_policy_permits_tor_addr(&a, port, policy); } /** Return true iff we think our firewall will let us make a connection to * addr:port. * * If we are configured as a server, ignore any address family preference and * just use IPv4. * Otherwise: * - return false for all IPv4 addresses: * - if ClientUseIPv4 is 0, or * if pref_only and pref_ipv6 are both true; * - return false for all IPv6 addresses: * - if fascist_firewall_use_ipv6() is 0, or * - if pref_only is true and pref_ipv6 is false. * * Return false if addr is NULL or tor_addr_is_null(), or if port is 0. */ STATIC int fascist_firewall_allows_address(const tor_addr_t *addr, uint16_t port, smartlist_t *firewall_policy, int pref_only, int pref_ipv6) { const or_options_t *options = get_options(); const int client_mode = !server_mode(options); if (!addr || tor_addr_is_null(addr) || !port) { return 0; } /* Clients stop using IPv4 if it's disabled. In most cases, clients also * stop using IPv4 if it's not preferred. * Servers must have IPv4 enabled and preferred. */ if (tor_addr_family(addr) == AF_INET && client_mode && (!options->ClientUseIPv4 || (pref_only && pref_ipv6))) { return 0; } /* Clients and Servers won't use IPv6 unless it's enabled (and in most * cases, IPv6 must also be preferred before it will be used). */ if (tor_addr_family(addr) == AF_INET6 && (!fascist_firewall_use_ipv6(options) || (pref_only && !pref_ipv6))) { return 0; } return addr_policy_permits_tor_addr(addr, port, firewall_policy); } /** Is this client configured to use IPv6? * Returns true if the client might use IPv6 for some of its connections * (including dual-stack and IPv6-only clients), and false if it will never * use IPv6 for any connections. * Use node_ipv6_or/dir_preferred() when checking a specific node and OR/Dir * port: it supports bridge client per-node IPv6 preferences. */ int fascist_firewall_use_ipv6(const or_options_t *options) { /* Clients use IPv6 if it's set, or they use bridges, or they don't use * IPv4, or they prefer it. * ClientPreferIPv6DirPort is deprecated, but check it anyway. */ return (options->ClientUseIPv6 == 1 || options->ClientUseIPv4 == 0 || options->ClientPreferIPv6ORPort == 1 || options->ClientPreferIPv6DirPort == 1 || options->UseBridges == 1); } /** Do we prefer to connect to IPv6, ignoring ClientPreferIPv6ORPort and * ClientPreferIPv6DirPort? * If we're unsure, return -1, otherwise, return 1 for IPv6 and 0 for IPv4. */ static int fascist_firewall_prefer_ipv6_impl(const or_options_t *options) { /* Cheap implementation of config options ClientUseIPv4 & ClientUseIPv6 -- If we're a server or IPv6 is disabled, use IPv4. If IPv4 is disabled, use IPv6. */ if (server_mode(options) || !fascist_firewall_use_ipv6(options)) { return 0; } if (!options->ClientUseIPv4) { return 1; } return -1; } /** Do we prefer to connect to IPv6 ORPorts? * Use node_ipv6_or_preferred() whenever possible: it supports bridge client * per-node IPv6 preferences. */ int fascist_firewall_prefer_ipv6_orport(const or_options_t *options) { int pref_ipv6 = fascist_firewall_prefer_ipv6_impl(options); if (pref_ipv6 >= 0) { return pref_ipv6; } /* We can use both IPv4 and IPv6 - which do we prefer? */ if (options->ClientPreferIPv6ORPort == 1) { return 1; } return 0; } /** Do we prefer to connect to IPv6 DirPorts? * * (node_ipv6_dir_preferred() doesn't support bridge client per-node IPv6 * preferences. There's no reason to use it instead of this function.) */ int fascist_firewall_prefer_ipv6_dirport(const or_options_t *options) { int pref_ipv6 = fascist_firewall_prefer_ipv6_impl(options); if (pref_ipv6 >= 0) { return pref_ipv6; } /* We can use both IPv4 and IPv6 - which do we prefer? */ if (options->ClientPreferIPv6DirPort == 1) { return 1; } return 0; } /** Return true iff we think our firewall will let us make a connection to * addr:port. Uses ReachableORAddresses or ReachableDirAddresses based on * fw_connection. * If pref_only is true, return true if addr is in the client's preferred * address family, which is IPv6 if pref_ipv6 is true, and IPv4 otherwise. * If pref_only is false, ignore pref_ipv6, and return true if addr is allowed. */ int fascist_firewall_allows_address_addr(const tor_addr_t *addr, uint16_t port, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { if (fw_connection == FIREWALL_OR_CONNECTION) { return fascist_firewall_allows_address(addr, port, reachable_or_addr_policy, pref_only, pref_ipv6); } else if (fw_connection == FIREWALL_DIR_CONNECTION) { return fascist_firewall_allows_address(addr, port, reachable_dir_addr_policy, pref_only, pref_ipv6); } else { log_warn(LD_BUG, "Bad firewall_connection_t value %d.", fw_connection); return 0; } } /** Return true iff we think our firewall will let us make a connection to * addr:port (ap). Uses ReachableORAddresses or ReachableDirAddresses based on * fw_connection. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr(). */ static int fascist_firewall_allows_address_ap(const tor_addr_port_t *ap, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { tor_assert(ap); return fascist_firewall_allows_address_addr(&ap->addr, ap->port, fw_connection, pref_only, pref_ipv6); } /* Return true iff we think our firewall will let us make a connection to * ipv4h_or_addr:ipv4_or_port. ipv4h_or_addr is interpreted in host order. * Uses ReachableORAddresses or ReachableDirAddresses based on * fw_connection. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr(). */ static int fascist_firewall_allows_address_ipv4h(uint32_t ipv4h_or_addr, uint16_t ipv4_or_port, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { tor_addr_t ipv4_or_addr; tor_addr_from_ipv4h(&ipv4_or_addr, ipv4h_or_addr); return fascist_firewall_allows_address_addr(&ipv4_or_addr, ipv4_or_port, fw_connection, pref_only, pref_ipv6); } /** Return true iff we think our firewall will let us make a connection to * ipv4h_addr/ipv6_addr. Uses ipv4_orport/ipv6_orport/ReachableORAddresses or * ipv4_dirport/ipv6_dirport/ReachableDirAddresses based on IPv4/IPv6 and * fw_connection. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr(). */ static int fascist_firewall_allows_base(uint32_t ipv4h_addr, uint16_t ipv4_orport, uint16_t ipv4_dirport, const tor_addr_t *ipv6_addr, uint16_t ipv6_orport, uint16_t ipv6_dirport, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { if (fascist_firewall_allows_address_ipv4h(ipv4h_addr, (fw_connection == FIREWALL_OR_CONNECTION ? ipv4_orport : ipv4_dirport), fw_connection, pref_only, pref_ipv6)) { return 1; } if (fascist_firewall_allows_address_addr(ipv6_addr, (fw_connection == FIREWALL_OR_CONNECTION ? ipv6_orport : ipv6_dirport), fw_connection, pref_only, pref_ipv6)) { return 1; } return 0; } /** Like fascist_firewall_allows_base(), but takes ri. */ static int fascist_firewall_allows_ri_impl(const routerinfo_t *ri, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { if (!ri) { return 0; } /* Assume IPv4 and IPv6 DirPorts are the same */ return fascist_firewall_allows_base(ri->addr, ri->or_port, ri->dir_port, &ri->ipv6_addr, ri->ipv6_orport, ri->dir_port, fw_connection, pref_only, pref_ipv6); } /** Like fascist_firewall_allows_rs, but takes pref_ipv6. */ static int fascist_firewall_allows_rs_impl(const routerstatus_t *rs, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { if (!rs) { return 0; } /* Assume IPv4 and IPv6 DirPorts are the same */ return fascist_firewall_allows_base(rs->addr, rs->or_port, rs->dir_port, &rs->ipv6_addr, rs->ipv6_orport, rs->dir_port, fw_connection, pref_only, pref_ipv6); } /** Like fascist_firewall_allows_base(), but takes rs. * When rs is a fake_status from a dir_server_t, it can have a reachable * address, even when the corresponding node does not. * nodes can be missing addresses when there's no consensus (IPv4 and IPv6), * or when there is a microdescriptor consensus, but no microdescriptors * (microdescriptors have IPv6, the microdesc consensus does not). */ int fascist_firewall_allows_rs(const routerstatus_t *rs, firewall_connection_t fw_connection, int pref_only) { if (!rs) { return 0; } /* We don't have access to the node-specific IPv6 preference, so use the * generic IPv6 preference instead. */ const or_options_t *options = get_options(); int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION ? fascist_firewall_prefer_ipv6_orport(options) : fascist_firewall_prefer_ipv6_dirport(options)); return fascist_firewall_allows_rs_impl(rs, fw_connection, pref_only, pref_ipv6); } /** Return true iff we think our firewall will let us make a connection to * ipv6_addr:ipv6_orport based on ReachableORAddresses. * If fw_connection is FIREWALL_DIR_CONNECTION, returns 0. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr(). */ static int fascist_firewall_allows_md_impl(const microdesc_t *md, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { if (!md) { return 0; } /* Can't check dirport, it doesn't have one */ if (fw_connection == FIREWALL_DIR_CONNECTION) { return 0; } /* Also can't check IPv4, doesn't have that either */ return fascist_firewall_allows_address_addr(&md->ipv6_addr, md->ipv6_orport, fw_connection, pref_only, pref_ipv6); } /** Like fascist_firewall_allows_base(), but takes node, and looks up pref_ipv6 * from node_ipv6_or/dir_preferred(). */ int fascist_firewall_allows_node(const node_t *node, firewall_connection_t fw_connection, int pref_only) { if (!node) { return 0; } node_assert_ok(node); const int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION ? node_ipv6_or_preferred(node) : node_ipv6_dir_preferred(node)); /* Sometimes, the rs is missing the IPv6 address info, and we need to go * all the way to the md */ if (node->ri && fascist_firewall_allows_ri_impl(node->ri, fw_connection, pref_only, pref_ipv6)) { return 1; } else if (node->rs && fascist_firewall_allows_rs_impl(node->rs, fw_connection, pref_only, pref_ipv6)) { return 1; } else if (node->md && fascist_firewall_allows_md_impl(node->md, fw_connection, pref_only, pref_ipv6)) { return 1; } else { /* If we know nothing, assume it's unreachable, we'll never get an address * to connect to. */ return 0; } } /** Like fascist_firewall_allows_rs(), but takes ds. */ int fascist_firewall_allows_dir_server(const dir_server_t *ds, firewall_connection_t fw_connection, int pref_only) { if (!ds) { return 0; } /* A dir_server_t always has a fake_status. As long as it has the same * addresses/ports in both fake_status and dir_server_t, this works fine. * (See #17867.) * fascist_firewall_allows_rs only checks the addresses in fake_status. */ return fascist_firewall_allows_rs(&ds->fake_status, fw_connection, pref_only); } /** If a and b are both valid and allowed by fw_connection, * choose one based on want_a and return it. * Otherwise, return whichever is allowed. * Otherwise, return NULL. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr(). */ static const tor_addr_port_t * fascist_firewall_choose_address_impl(const tor_addr_port_t *a, const tor_addr_port_t *b, int want_a, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { const tor_addr_port_t *use_a = NULL; const tor_addr_port_t *use_b = NULL; if (fascist_firewall_allows_address_ap(a, fw_connection, pref_only, pref_ipv6)) { use_a = a; } if (fascist_firewall_allows_address_ap(b, fw_connection, pref_only, pref_ipv6)) { use_b = b; } /* If both are allowed */ if (use_a && use_b) { /* Choose a if we want it */ return (want_a ? use_a : use_b); } else { /* Choose a if we have it */ return (use_a ? use_a : use_b); } } /** If a and b are both valid and preferred by fw_connection, * choose one based on want_a and return it. * Otherwise, return whichever is preferred. * If neither are preferred, and pref_only is false: * - If a and b are both allowed by fw_connection, * choose one based on want_a and return it. * - Otherwise, return whichever is preferred. * Otherwise, return NULL. */ STATIC const tor_addr_port_t * fascist_firewall_choose_address(const tor_addr_port_t *a, const tor_addr_port_t *b, int want_a, firewall_connection_t fw_connection, int pref_only, int pref_ipv6) { const tor_addr_port_t *pref = fascist_firewall_choose_address_impl( a, b, want_a, fw_connection, 1, pref_ipv6); if (pref_only || pref) { /* If there is a preferred address, use it. If we can only use preferred * addresses, and neither address is preferred, pref will be NULL, and we * want to return NULL, so return it. */ return pref; } else { /* If there's no preferred address, and we can return addresses that are * not preferred, use an address that's allowed */ return fascist_firewall_choose_address_impl(a, b, want_a, fw_connection, 0, pref_ipv6); } } /** Copy an address and port into ap that we think our firewall will * let us connect to. Uses ipv4_addr/ipv6_addr and * ipv4_orport/ipv6_orport/ReachableORAddresses or * ipv4_dirport/ipv6_dirport/ReachableDirAddresses based on IPv4/IPv6 and * fw_connection. * If pref_only, only choose preferred addresses. In either case, choose * a preferred address before an address that's not preferred. * If both addresses could be chosen (they are both preferred or both allowed) * choose IPv6 if pref_ipv6 is true, otherwise choose IPv4. */ static void fascist_firewall_choose_address_base(const tor_addr_t *ipv4_addr, uint16_t ipv4_orport, uint16_t ipv4_dirport, const tor_addr_t *ipv6_addr, uint16_t ipv6_orport, uint16_t ipv6_dirport, firewall_connection_t fw_connection, int pref_only, int pref_ipv6, tor_addr_port_t* ap) { const tor_addr_port_t *result = NULL; const int want_ipv4 = !pref_ipv6; tor_assert(ipv6_addr); tor_assert(ap); tor_addr_make_null(&ap->addr, AF_UNSPEC); ap->port = 0; tor_addr_port_t ipv4_ap; tor_addr_copy(&ipv4_ap.addr, ipv4_addr); ipv4_ap.port = (fw_connection == FIREWALL_OR_CONNECTION ? ipv4_orport : ipv4_dirport); tor_addr_port_t ipv6_ap; tor_addr_copy(&ipv6_ap.addr, ipv6_addr); ipv6_ap.port = (fw_connection == FIREWALL_OR_CONNECTION ? ipv6_orport : ipv6_dirport); result = fascist_firewall_choose_address(&ipv4_ap, &ipv6_ap, want_ipv4, fw_connection, pref_only, pref_ipv6); if (result) { tor_addr_copy(&ap->addr, &result->addr); ap->port = result->port; } } /** Like fascist_firewall_choose_address_base(), but takes a host-order IPv4 * address as the first parameter. */ static void fascist_firewall_choose_address_ipv4h(uint32_t ipv4h_addr, uint16_t ipv4_orport, uint16_t ipv4_dirport, const tor_addr_t *ipv6_addr, uint16_t ipv6_orport, uint16_t ipv6_dirport, firewall_connection_t fw_connection, int pref_only, int pref_ipv6, tor_addr_port_t* ap) { tor_addr_t ipv4_addr; tor_addr_from_ipv4h(&ipv4_addr, ipv4h_addr); tor_assert(ap); tor_addr_make_null(&ap->addr, AF_UNSPEC); ap->port = 0; fascist_firewall_choose_address_base(&ipv4_addr, ipv4_orport, ipv4_dirport, ipv6_addr, ipv6_orport, ipv6_dirport, fw_connection, pref_only, pref_ipv6, ap); } /* Some microdescriptor consensus methods have no IPv6 addresses in rs: they * are in the microdescriptors. For these consensus methods, we can't rely on * the node's IPv6 address until its microdescriptor is available (when using * microdescs). * But for bridges, rewrite_node_address_for_bridge() updates node->ri with * the configured address, so we can trust bridge addresses. * (Bridges could gain an IPv6 address if their microdescriptor arrives, but * this will never be their preferred address: that is in the config.) * Returns true if the node needs a microdescriptor for its IPv6 address, and * false if the addresses in the node are already up-to-date. */ static int node_awaiting_ipv6(const or_options_t* options, const node_t *node) { tor_assert(node); /* There's no point waiting for an IPv6 address if we'd never use it */ if (!fascist_firewall_use_ipv6(options)) { return 0; } /* If the node has an IPv6 address, we're not waiting */ if (node_has_ipv6_addr(node)) { return 0; } /* If the current consensus method and flavour has IPv6 addresses, we're not * waiting */ if (networkstatus_consensus_has_ipv6(options)) { return 0; } /* Bridge clients never use the address from a bridge's md, so there's no * need to wait for it. */ if (node_is_a_configured_bridge(node)) { return 0; } /* We are waiting if we_use_microdescriptors_for_circuits() and we have no * md. */ return (!node->md && we_use_microdescriptors_for_circuits(options)); } /** Like fascist_firewall_choose_address_base(), but takes rs. * Consults the corresponding node, then falls back to rs if node is NULL. * This should only happen when there's no valid consensus, and rs doesn't * correspond to a bridge client's bridge. */ void fascist_firewall_choose_address_rs(const routerstatus_t *rs, firewall_connection_t fw_connection, int pref_only, tor_addr_port_t* ap) { tor_assert(ap); tor_addr_make_null(&ap->addr, AF_UNSPEC); ap->port = 0; if (!rs) { return; } const or_options_t *options = get_options(); const node_t *node = node_get_by_id(rs->identity_digest); if (node && !node_awaiting_ipv6(options, node)) { fascist_firewall_choose_address_node(node, fw_connection, pref_only, ap); } else { /* There's no node-specific IPv6 preference, so use the generic IPv6 * preference instead. */ int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION ? fascist_firewall_prefer_ipv6_orport(options) : fascist_firewall_prefer_ipv6_dirport(options)); /* Assume IPv4 and IPv6 DirPorts are the same. * Assume the IPv6 OR and Dir addresses are the same. */ fascist_firewall_choose_address_ipv4h(rs->addr, rs->or_port, rs->dir_port, &rs->ipv6_addr, rs->ipv6_orport, rs->dir_port, fw_connection, pref_only, pref_ipv6, ap); } } /** Like fascist_firewall_choose_address_base(), but takes node, and * looks up the node's IPv6 preference rather than taking an argument * for pref_ipv6. */ void fascist_firewall_choose_address_node(const node_t *node, firewall_connection_t fw_connection, int pref_only, tor_addr_port_t *ap) { tor_assert(ap); tor_addr_make_null(&ap->addr, AF_UNSPEC); ap->port = 0; if (!node) { return; } node_assert_ok(node); /* Calling fascist_firewall_choose_address_node() when the node is missing * IPv6 information breaks IPv6-only clients. * If the node is a hard-coded fallback directory or authority, call * fascist_firewall_choose_address_rs() on the fake (hard-coded) routerstatus * for the node. * If it is not hard-coded, check that the node has a microdescriptor, full * descriptor (routerinfo), or is one of our configured bridges before * calling this function. */ if (BUG(node_awaiting_ipv6(get_options(), node))) { return; } const int pref_ipv6_node = (fw_connection == FIREWALL_OR_CONNECTION ? node_ipv6_or_preferred(node) : node_ipv6_dir_preferred(node)); tor_addr_port_t ipv4_or_ap; node_get_prim_orport(node, &ipv4_or_ap); tor_addr_port_t ipv4_dir_ap; node_get_prim_dirport(node, &ipv4_dir_ap); tor_addr_port_t ipv6_or_ap; node_get_pref_ipv6_orport(node, &ipv6_or_ap); tor_addr_port_t ipv6_dir_ap; node_get_pref_ipv6_dirport(node, &ipv6_dir_ap); /* Assume the IPv6 OR and Dir addresses are the same. */ fascist_firewall_choose_address_base(&ipv4_or_ap.addr, ipv4_or_ap.port, ipv4_dir_ap.port, &ipv6_or_ap.addr, ipv6_or_ap.port, ipv6_dir_ap.port, fw_connection, pref_only, pref_ipv6_node, ap); } /** Like fascist_firewall_choose_address_rs(), but takes ds. */ void fascist_firewall_choose_address_dir_server(const dir_server_t *ds, firewall_connection_t fw_connection, int pref_only, tor_addr_port_t *ap) { tor_assert(ap); tor_addr_make_null(&ap->addr, AF_UNSPEC); ap->port = 0; if (!ds) { return; } /* A dir_server_t always has a fake_status. As long as it has the same * addresses/ports in both fake_status and dir_server_t, this works fine. * (See #17867.) * This function relies on fascist_firewall_choose_address_rs looking up the * node if it can, because that will get the latest info for the relay. */ fascist_firewall_choose_address_rs(&ds->fake_status, fw_connection, pref_only, ap); } /** Return 1 if addr is permitted to connect to our dir port, * based on dir_policy. Else return 0. */ int dir_policy_permits_address(const tor_addr_t *addr) { return addr_policy_permits_tor_addr(addr, 1, dir_policy); } /** Return 1 if addr is permitted to connect to our socks port, * based on socks_policy. Else return 0. */ int socks_policy_permits_address(const tor_addr_t *addr) { return addr_policy_permits_tor_addr(addr, 1, socks_policy); } /** Return true iff the address addr is in a country listed in the * case-insensitive list of country codes cc_list. */ static int addr_is_in_cc_list(uint32_t addr, const smartlist_t *cc_list) { country_t country; const char *name; tor_addr_t tar; if (!cc_list) return 0; /* XXXXipv6 */ tor_addr_from_ipv4h(&tar, addr); country = geoip_get_country_by_addr(&tar); name = geoip_get_country_name(country); return smartlist_contains_string_case(cc_list, name); } /** Return 1 if addr:port is permitted to publish to our * directory, based on authdir_reject_policy. Else return 0. */ int authdir_policy_permits_address(uint32_t addr, uint16_t port) { if (! addr_policy_permits_address(addr, port, authdir_reject_policy)) return 0; return !addr_is_in_cc_list(addr, get_options()->AuthDirRejectCCs); } /** Return 1 if addr:port is considered valid in our * directory, based on authdir_invalid_policy. Else return 0. */ int authdir_policy_valid_address(uint32_t addr, uint16_t port) { if (! addr_policy_permits_address(addr, port, authdir_invalid_policy)) return 0; return !addr_is_in_cc_list(addr, get_options()->AuthDirInvalidCCs); } /** Return 1 if addr:port should be marked as a bad exit, * based on authdir_badexit_policy. Else return 0. */ int authdir_policy_badexit_address(uint32_t addr, uint16_t port) { if (! addr_policy_permits_address(addr, port, authdir_badexit_policy)) return 1; return addr_is_in_cc_list(addr, get_options()->AuthDirBadExitCCs); } #define REJECT(arg) \ STMT_BEGIN *msg = tor_strdup(arg); goto err; STMT_END /** Config helper: If there's any problem with the policy configuration * options in options, return -1 and set msg to a newly * allocated description of the error. Else return 0. */ int validate_addr_policies(const or_options_t *options, char **msg) { /* XXXX Maybe merge this into parse_policies_from_options, to make sure * that the two can't go out of sync. */ smartlist_t *addr_policy=NULL; *msg = NULL; if (policies_parse_exit_policy_from_options(options,0,NULL,&addr_policy)) { REJECT("Error in ExitPolicy entry."); } static int warned_about_exitrelay = 0; const int exitrelay_setting_is_auto = options->ExitRelay == -1; const int policy_accepts_something = ! (policy_is_reject_star(addr_policy, AF_INET, 1) && policy_is_reject_star(addr_policy, AF_INET6, 1)); if (server_mode(options) && ! warned_about_exitrelay && exitrelay_setting_is_auto && policy_accepts_something) { /* Policy accepts something */ warned_about_exitrelay = 1; log_warn(LD_CONFIG, "Tor is running as an exit relay%s. If you did not want this " "behavior, please set the ExitRelay option to 0. If you do " "want to run an exit Relay, please set the ExitRelay option " "to 1 to disable this warning, and for forward compatibility.", options->ExitPolicy == NULL ? " with the default exit policy" : ""); if (options->ExitPolicy == NULL && options->ReducedExitPolicy == 0) { log_warn(LD_CONFIG, "In a future version of Tor, ExitRelay 0 may become the " "default when no ExitPolicy is given."); } } /* The rest of these calls *append* to addr_policy. So don't actually * use the results for anything other than checking if they parse! */ if (parse_addr_policy(options->DirPolicy, &addr_policy, -1)) REJECT("Error in DirPolicy entry."); if (parse_addr_policy(options->SocksPolicy, &addr_policy, -1)) REJECT("Error in SocksPolicy entry."); if (parse_addr_policy(options->AuthDirReject, &addr_policy, ADDR_POLICY_REJECT)) REJECT("Error in AuthDirReject entry."); if (parse_addr_policy(options->AuthDirInvalid, &addr_policy, ADDR_POLICY_REJECT)) REJECT("Error in AuthDirInvalid entry."); if (parse_addr_policy(options->AuthDirBadExit, &addr_policy, ADDR_POLICY_REJECT)) REJECT("Error in AuthDirBadExit entry."); if (parse_addr_policy(options->ReachableAddresses, &addr_policy, ADDR_POLICY_ACCEPT)) REJECT("Error in ReachableAddresses entry."); if (parse_addr_policy(options->ReachableORAddresses, &addr_policy, ADDR_POLICY_ACCEPT)) REJECT("Error in ReachableORAddresses entry."); if (parse_addr_policy(options->ReachableDirAddresses, &addr_policy, ADDR_POLICY_ACCEPT)) REJECT("Error in ReachableDirAddresses entry."); err: addr_policy_list_free(addr_policy); return *msg ? -1 : 0; #undef REJECT } /** Parse string in the same way that the exit policy * is parsed, and put the processed version in *policy. * Ignore port specifiers. */ static int load_policy_from_option(config_line_t *config, const char *option_name, smartlist_t **policy, int assume_action) { int r; int killed_any_ports = 0; addr_policy_list_free(*policy); *policy = NULL; r = parse_addr_policy(config, policy, assume_action); if (r < 0) { return -1; } if (*policy) { SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, n) { /* ports aren't used in these. */ if (n->prt_min > 1 || n->prt_max != 65535) { addr_policy_t newp, *c; memcpy(&newp, n, sizeof(newp)); newp.prt_min = 1; newp.prt_max = 65535; newp.is_canonical = 0; c = addr_policy_get_canonical_entry(&newp); SMARTLIST_REPLACE_CURRENT(*policy, n, c); addr_policy_free(n); killed_any_ports = 1; } } SMARTLIST_FOREACH_END(n); } if (killed_any_ports) { log_warn(LD_CONFIG, "Ignoring ports in %s option.", option_name); } return 0; } /** Set all policies based on options, which should have been validated * first by validate_addr_policies. */ int policies_parse_from_options(const or_options_t *options) { int ret = 0; if (load_policy_from_option(options->SocksPolicy, "SocksPolicy", &socks_policy, -1) < 0) ret = -1; if (load_policy_from_option(options->DirPolicy, "DirPolicy", &dir_policy, -1) < 0) ret = -1; if (load_policy_from_option(options->AuthDirReject, "AuthDirReject", &authdir_reject_policy, ADDR_POLICY_REJECT) < 0) ret = -1; if (load_policy_from_option(options->AuthDirInvalid, "AuthDirInvalid", &authdir_invalid_policy, ADDR_POLICY_REJECT) < 0) ret = -1; if (load_policy_from_option(options->AuthDirBadExit, "AuthDirBadExit", &authdir_badexit_policy, ADDR_POLICY_REJECT) < 0) ret = -1; if (parse_reachable_addresses() < 0) ret = -1; return ret; } /** Compare two provided address policy items, and renturn -1, 0, or 1 * if the first is less than, equal to, or greater than the second. */ static int single_addr_policy_eq(const addr_policy_t *a, const addr_policy_t *b) { int r; #define CMP_FIELD(field) do { \ if (a->field != b->field) { \ return 0; \ } \ } while (0) CMP_FIELD(policy_type); CMP_FIELD(is_private); /* refcnt and is_canonical are irrelevant to equality, * they are hash table implementation details */ if ((r=tor_addr_compare(&a->addr, &b->addr, CMP_EXACT))) return 0; CMP_FIELD(maskbits); CMP_FIELD(prt_min); CMP_FIELD(prt_max); #undef CMP_FIELD return 1; } /** As single_addr_policy_eq, but compare every element of two policies. */ int addr_policies_eq(const smartlist_t *a, const smartlist_t *b) { int i; int len_a = a ? smartlist_len(a) : 0; int len_b = b ? smartlist_len(b) : 0; if (len_a != len_b) return 0; for (i = 0; i < len_a; ++i) { if (! single_addr_policy_eq(smartlist_get(a, i), smartlist_get(b, i))) return 0; } return 1; } /** Node in hashtable used to store address policy entries. */ typedef struct policy_map_ent_t { HT_ENTRY(policy_map_ent_t) node; addr_policy_t *policy; } policy_map_ent_t; /* DOCDOC policy_root */ static HT_HEAD(policy_map, policy_map_ent_t) policy_root = HT_INITIALIZER(); /** Return true iff a and b are equal. */ static inline int policy_eq(policy_map_ent_t *a, policy_map_ent_t *b) { return single_addr_policy_eq(a->policy, b->policy); } /** Return a hashcode for ent */ static unsigned int policy_hash(const policy_map_ent_t *ent) { const addr_policy_t *a = ent->policy; addr_policy_t aa; memset(&aa, 0, sizeof(aa)); aa.prt_min = a->prt_min; aa.prt_max = a->prt_max; aa.maskbits = a->maskbits; aa.policy_type = a->policy_type; aa.is_private = a->is_private; if (a->is_private) { aa.is_private = 1; } else { tor_addr_copy_tight(&aa.addr, &a->addr); } return (unsigned) siphash24g(&aa, sizeof(aa)); } HT_PROTOTYPE(policy_map, policy_map_ent_t, node, policy_hash, policy_eq) HT_GENERATE2(policy_map, policy_map_ent_t, node, policy_hash, policy_eq, 0.6, tor_reallocarray_, tor_free_) /** Given a pointer to an addr_policy_t, return a copy of the pointer to the * "canonical" copy of that addr_policy_t; the canonical copy is a single * reference-counted object. */ addr_policy_t * addr_policy_get_canonical_entry(addr_policy_t *e) { policy_map_ent_t search, *found; if (e->is_canonical) return e; search.policy = e; found = HT_FIND(policy_map, &policy_root, &search); if (!found) { found = tor_malloc_zero(sizeof(policy_map_ent_t)); found->policy = tor_memdup(e, sizeof(addr_policy_t)); found->policy->is_canonical = 1; found->policy->refcnt = 0; HT_INSERT(policy_map, &policy_root, found); } tor_assert(single_addr_policy_eq(found->policy, e)); ++found->policy->refcnt; return found->policy; } /** Helper for compare_tor_addr_to_addr_policy. Implements the case where * addr and port are both known. */ static addr_policy_result_t compare_known_tor_addr_to_addr_policy(const tor_addr_t *addr, uint16_t port, const smartlist_t *policy) { /* We know the address and port, and we know the policy, so we can just * compute an exact match. */ SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) { if (tmpe->addr.family == AF_UNSPEC) { log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only " "matches other AF_UNSPEC addresses."); } /* Address is known */ if (!tor_addr_compare_masked(addr, &tmpe->addr, tmpe->maskbits, CMP_EXACT)) { if (port >= tmpe->prt_min && port <= tmpe->prt_max) { /* Exact match for the policy */ return tmpe->policy_type == ADDR_POLICY_ACCEPT ? ADDR_POLICY_ACCEPTED : ADDR_POLICY_REJECTED; } } } SMARTLIST_FOREACH_END(tmpe); /* accept all by default. */ return ADDR_POLICY_ACCEPTED; } /** Helper for compare_tor_addr_to_addr_policy. Implements the case where * addr is known but port is not. */ static addr_policy_result_t compare_known_tor_addr_to_addr_policy_noport(const tor_addr_t *addr, const smartlist_t *policy) { /* We look to see if there's a definite match. If so, we return that match's value, unless there's an intervening possible match that says something different. */ int maybe_accept = 0, maybe_reject = 0; SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) { if (tmpe->addr.family == AF_UNSPEC) { log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only " "matches other AF_UNSPEC addresses."); } if (!tor_addr_compare_masked(addr, &tmpe->addr, tmpe->maskbits, CMP_EXACT)) { if (tmpe->prt_min <= 1 && tmpe->prt_max >= 65535) { /* Definitely matches, since it covers all ports. */ if (tmpe->policy_type == ADDR_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_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED; } else { return maybe_accept ? ADDR_POLICY_PROBABLY_REJECTED : ADDR_POLICY_REJECTED; } } else { /* Might match. */ if (tmpe->policy_type == ADDR_POLICY_REJECT) maybe_reject = 1; else maybe_accept = 1; } } } SMARTLIST_FOREACH_END(tmpe); /* accept all by default. */ return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED; } /** Helper for compare_tor_addr_to_addr_policy. Implements the case where * port is known but address is not. */ static addr_policy_result_t compare_unknown_tor_addr_to_addr_policy(uint16_t port, const smartlist_t *policy) { /* We look to see if there's a definite match. If so, we return that match's value, unless there's an intervening possible match that says something different. */ int maybe_accept = 0, maybe_reject = 0; SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) { if (tmpe->addr.family == AF_UNSPEC) { log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only " "matches other AF_UNSPEC addresses."); } if (tmpe->prt_min <= port && port <= tmpe->prt_max) { if (tmpe->maskbits == 0) { /* Definitely matches, since it covers all addresses. */ if (tmpe->policy_type == ADDR_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_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED; } else { return maybe_accept ? ADDR_POLICY_PROBABLY_REJECTED : ADDR_POLICY_REJECTED; } } else { /* Might match. */ if (tmpe->policy_type == ADDR_POLICY_REJECT) maybe_reject = 1; else maybe_accept = 1; } } } SMARTLIST_FOREACH_END(tmpe); /* accept all by default. */ return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED; } /** Decide whether a given addr:port is definitely accepted, * definitely rejected, probably accepted, or probably rejected by a * given policy. If addr is 0, we don't know the IP of the * target address. If port is 0, we don't know the port of the * target address. (At least one of addr and port must be * provided. If you want to know whether a policy would definitely reject * an unknown address:port, use policy_is_reject_star().) * * We could do better by assuming that some ranges never match typical * addresses (127.0.0.1, and so on). But we'll try this for now. */ MOCK_IMPL(addr_policy_result_t, compare_tor_addr_to_addr_policy,(const tor_addr_t *addr, uint16_t port, const smartlist_t *policy)) { if (!policy) { /* no policy? accept all. */ return ADDR_POLICY_ACCEPTED; } else if (addr == NULL || tor_addr_is_null(addr)) { if (port == 0) { log_info(LD_BUG, "Rejecting null address with 0 port (family %d)", addr ? tor_addr_family(addr) : -1); return ADDR_POLICY_REJECTED; } return compare_unknown_tor_addr_to_addr_policy(port, policy); } else if (port == 0) { return compare_known_tor_addr_to_addr_policy_noport(addr, policy); } else { return compare_known_tor_addr_to_addr_policy(addr, port, policy); } } /** Return true iff the address policy a covers every case that * would be covered by b, so that a,b is redundant. */ static int addr_policy_covers(addr_policy_t *a, addr_policy_t *b) { if (tor_addr_family(&a->addr) != tor_addr_family(&b->addr)) { /* You can't cover a different family. */ return 0; } /* We can ignore accept/reject, since "accept *:80, reject *:80" reduces * to "accept *:80". */ if (a->maskbits > b->maskbits) { /* a has more fixed bits than b; it can't possibly cover b. */ return 0; } if (tor_addr_compare_masked(&a->addr, &b->addr, a->maskbits, CMP_EXACT)) { /* There's a fixed bit in a that's set differently in b. */ return 0; } return (a->prt_min <= b->prt_min && a->prt_max >= b->prt_max); } /** Return true iff the address policies a and b intersect, * that is, there exists an address/port that is covered by a that * is also covered by b. */ static int addr_policy_intersects(addr_policy_t *a, addr_policy_t *b) { maskbits_t minbits; /* All the bits we care about are those that are set in both * netmasks. If they are equal in a and b's networkaddresses * then the networks intersect. If there is a difference, * then they do not. */ if (a->maskbits < b->maskbits) minbits = a->maskbits; else minbits = b->maskbits; if (tor_addr_compare_masked(&a->addr, &b->addr, minbits, CMP_EXACT)) return 0; if (a->prt_max < b->prt_min || b->prt_max < a->prt_min) return 0; return 1; } /** Add the exit policy described by more to policy. */ STATIC void append_exit_policy_string(smartlist_t **policy, const char *more) { config_line_t tmp; tmp.key = NULL; tmp.value = (char*) more; tmp.next = NULL; if (parse_addr_policy(&tmp, policy, -1)<0) { log_warn(LD_BUG, "Unable to parse internally generated policy %s",more); } } /** Add "reject addr:*" to dest, creating the list as needed. */ void addr_policy_append_reject_addr(smartlist_t **dest, const tor_addr_t *addr) { tor_assert(dest); tor_assert(addr); addr_policy_t p, *add; memset(&p, 0, sizeof(p)); p.policy_type = ADDR_POLICY_REJECT; p.maskbits = tor_addr_family(addr) == AF_INET6 ? 128 : 32; tor_addr_copy(&p.addr, addr); p.prt_min = 1; p.prt_max = 65535; add = addr_policy_get_canonical_entry(&p); if (!*dest) *dest = smartlist_new(); smartlist_add(*dest, add); log_debug(LD_CONFIG, "Adding a reject ExitPolicy 'reject %s:*'", fmt_addr(addr)); } /* Is addr public for the purposes of rejection? */ static int tor_addr_is_public_for_reject(const tor_addr_t *addr) { return (!tor_addr_is_null(addr) && !tor_addr_is_internal(addr, 0) && !tor_addr_is_multicast(addr)); } /* Add "reject addr:*" to dest, creating the list as needed. * Filter the address, only adding an IPv4 reject rule if ipv4_rules * is true, and similarly for ipv6_rules. Check each address returns true for * tor_addr_is_public_for_reject before adding it. */ static void addr_policy_append_reject_addr_filter(smartlist_t **dest, const tor_addr_t *addr, int ipv4_rules, int ipv6_rules) { tor_assert(dest); tor_assert(addr); /* Only reject IP addresses which are public */ if (tor_addr_is_public_for_reject(addr)) { /* Reject IPv4 addresses and IPv6 addresses based on the filters */ int is_ipv4 = tor_addr_is_v4(addr); if ((is_ipv4 && ipv4_rules) || (!is_ipv4 && ipv6_rules)) { addr_policy_append_reject_addr(dest, addr); } } } /** Add "reject addr:*" to dest, for each addr in addrs, creating the * list as needed. */ void addr_policy_append_reject_addr_list(smartlist_t **dest, const smartlist_t *addrs) { tor_assert(dest); tor_assert(addrs); SMARTLIST_FOREACH_BEGIN(addrs, tor_addr_t *, addr) { addr_policy_append_reject_addr(dest, addr); } SMARTLIST_FOREACH_END(addr); } /** Add "reject addr:*" to dest, for each addr in addrs, creating the * list as needed. Filter using */ static void addr_policy_append_reject_addr_list_filter(smartlist_t **dest, const smartlist_t *addrs, int ipv4_rules, int ipv6_rules) { tor_assert(dest); tor_assert(addrs); SMARTLIST_FOREACH_BEGIN(addrs, tor_addr_t *, addr) { addr_policy_append_reject_addr_filter(dest, addr, ipv4_rules, ipv6_rules); } SMARTLIST_FOREACH_END(addr); } /** Detect and excise "dead code" from the policy *dest. */ static void exit_policy_remove_redundancies(smartlist_t *dest) { addr_policy_t *ap, *tmp; int i, j; /* Step one: kill every ipv4 thing after *4:*, every IPv6 thing after *6:* */ { int kill_v4=0, kill_v6=0; for (i = 0; i < smartlist_len(dest); ++i) { sa_family_t family; ap = smartlist_get(dest, i); family = tor_addr_family(&ap->addr); if ((family == AF_INET && kill_v4) || (family == AF_INET6 && kill_v6)) { smartlist_del_keeporder(dest, i--); addr_policy_free(ap); continue; } if (ap->maskbits == 0 && ap->prt_min <= 1 && ap->prt_max >= 65535) { /* This is a catch-all line -- later lines are unreachable. */ if (family == AF_INET) { kill_v4 = 1; } else if (family == AF_INET6) { kill_v6 = 1; } } } } /* Step two: for every entry, see if there's a redundant entry * later on, and remove it. */ for (i = 0; i < smartlist_len(dest)-1; ++i) { ap = smartlist_get(dest, i); for (j = i+1; j < smartlist_len(dest); ++j) { tmp = smartlist_get(dest, j); tor_assert(j > i); if (addr_policy_covers(ap, tmp)) { char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN]; policy_write_item(p1, sizeof(p1), tmp, 0); policy_write_item(p2, sizeof(p2), ap, 0); log_debug(LD_CONFIG, "Removing exit policy %s (%d). It is made " "redundant by %s (%d).", p1, j, p2, i); smartlist_del_keeporder(dest, j--); addr_policy_free(tmp); } } } /* Step three: for every entry A, see if there's an entry B making this one * redundant later on. This is the case if A and B are of the same type * (accept/reject), A is a subset of B, and there is no other entry of * different type in between those two that intersects with A. * * Anybody want to double-check the logic here? XXX */ for (i = 0; i < smartlist_len(dest)-1; ++i) { ap = smartlist_get(dest, i); for (j = i+1; j < smartlist_len(dest); ++j) { // tor_assert(j > i); // j starts out at i+1; j only increases; i only // // decreases. tmp = smartlist_get(dest, j); if (ap->policy_type != tmp->policy_type) { if (addr_policy_intersects(ap, tmp)) break; } else { /* policy_types are equal. */ if (addr_policy_covers(tmp, ap)) { char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN]; policy_write_item(p1, sizeof(p1), ap, 0); policy_write_item(p2, sizeof(p2), tmp, 0); log_debug(LD_CONFIG, "Removing exit policy %s. It is already " "covered by %s.", p1, p2); smartlist_del_keeporder(dest, i--); addr_policy_free(ap); break; } } } } } /** Reject private helper for policies_parse_exit_policy_internal: rejects * publicly routable addresses on this exit relay. * * Add reject entries to the linked list *dest: *