diff options
Diffstat (limited to 'src/or/policies.c')
| -rw-r--r-- | src/or/policies.c | 1323 |
1 files changed, 1233 insertions, 90 deletions
diff --git a/src/or/policies.c b/src/or/policies.c index 8a91509a77..50fec3a773 100644 --- a/src/or/policies.c +++ b/src/or/policies.c @@ -1,6 +1,6 @@ /* Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2013, The Tor Project, Inc. */ + * Copyright (c) 2007-2016, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -8,9 +8,12 @@ * \brief Code to parse and use address policies and exit policies. **/ +#define POLICIES_PRIVATE + #include "or.h" #include "config.h" #include "dirserv.h" +#include "networkstatus.h" #include "nodelist.h" #include "policies.h" #include "router.h" @@ -29,9 +32,6 @@ static smartlist_t *authdir_reject_policy = NULL; * to be marked as valid in our networkstatus. */ static smartlist_t *authdir_invalid_policy = NULL; /** Policy that addresses for incoming router descriptors must <b>not</b> - * match in order to not be marked as BadDirectory. */ -static smartlist_t *authdir_baddir_policy = NULL; -/** Policy that addresses for incoming router descriptors must <b>not</b> * match in order to not be marked as BadExit. */ static smartlist_t *authdir_badexit_policy = NULL; @@ -65,6 +65,16 @@ static const char *private_nets[] = { 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); + /** Replace all "private" entries in *<b>policy</b> with their expanded * equivalents. */ void @@ -148,7 +158,7 @@ policy_expand_unspec(smartlist_t **policy) } /** - * Given a linked list of config lines containing "allow" and "deny" + * Given a linked list of config lines containing "accept[6]" and "reject[6]" * tokens, parse them and append the result to <b>dest</b>. Return -1 * if any tokens are malformed (and don't append any), else return 0. * @@ -163,6 +173,7 @@ parse_addr_policy(config_line_t *cfg, smartlist_t **dest, smartlist_t *result; smartlist_t *entries; addr_policy_t *item; + int malformed_list; int r = 0; if (!cfg) @@ -175,12 +186,22 @@ parse_addr_policy(config_line_t *cfg, smartlist_t **dest, SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0); SMARTLIST_FOREACH_BEGIN(entries, const char *, ent) { log_debug(LD_CONFIG,"Adding new entry '%s'",ent); - item = router_parse_addr_policy_item_from_string(ent, assume_action); + malformed_list = 0; + item = router_parse_addr_policy_item_from_string(ent, assume_action, + &malformed_list); if (item) { smartlist_add(result, item); - } else { - log_warn(LD_CONFIG,"Malformed policy '%s'.", ent); + } 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)); @@ -250,16 +271,76 @@ parse_reachable_addresses(void) "Error parsing ReachableDirAddresses entry; ignoring."); ret = -1; } + + /* We ignore ReachableAddresses for relays */ + if (!server_mode(options)) { + if ((reachable_or_addr_policy + && policy_is_reject_star(reachable_or_addr_policy, AF_UNSPEC)) + || (reachable_dir_addr_policy + && policy_is_reject_star(reachable_dir_addr_policy, AF_UNSPEC))) { + 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 + && ((reachable_or_addr_policy + && policy_is_reject_star(reachable_or_addr_policy, AF_INET)) + || (reachable_dir_addr_policy + && policy_is_reject_star(reachable_dir_addr_policy, AF_INET)))) { + 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) + && ((reachable_or_addr_policy + && policy_is_reject_star(reachable_or_addr_policy, AF_INET6)) + || (reachable_dir_addr_policy + && policy_is_reject_star(reachable_dir_addr_policy, AF_INET6)))) { + log_warn(LD_CONFIG, "You have configured tor to use IPv6 " + "(ClientUseIPv6 1 or UseBridges 1), but " + "ReachableAddresses, ReachableORAddresses, or " + "ReachableDirAddresses reject all IPv6 addresses. " + "Tor will not connect using IPv6."); + } + } + return ret; } -/** Return true iff the firewall options might block any address:port - * combination. +/* 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. */ + return (options->ClientUseIPv4 == 0 + || (!fascist_firewall_use_ipv6(options) + && options->UseBridges == 1)); +} + +/** 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; + 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 <b>policy</b> (possibly NULL) will allow a @@ -297,49 +378,618 @@ addr_policy_permits_address(uint32_t addr, uint16_t port, return addr_policy_permits_tor_addr(&a, port, policy); } -/** Return true iff we think our firewall will let us make an OR connection to - * addr:port. */ -int -fascist_firewall_allows_address_or(const tor_addr_t *addr, uint16_t port) +/** 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, - reachable_or_addr_policy); + firewall_policy); } -/** Return true iff we think our firewall will let us make an OR connection to - * <b>ri</b>. */ +/** Is this client configured to use IPv6? + * 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_allows_or(const routerinfo_t *ri) +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 */ + return (options->ClientUseIPv6 == 1 || options->UseBridges == 1 + || options->ClientUseIPv4 == 0); +} + +/** 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) { - /* XXXX proposal 118 */ - tor_addr_t addr; - tor_addr_from_ipv4h(&addr, ri->addr); - return fascist_firewall_allows_address_or(&addr, ri->or_port); + /* + 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; } -/** Return true iff we think our firewall will let us make an OR connection to - * <b>node</b>. */ +/** 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_allows_node(const node_t *node) +fascist_firewall_prefer_ipv6_orport(const or_options_t *options) { - if (node->ri) { - return fascist_firewall_allows_or(node->ri); - } else if (node->rs) { - tor_addr_t addr; - tor_addr_from_ipv4h(&addr, node->rs->addr); - return fascist_firewall_allows_address_or(&addr, node->rs->or_port); + 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 + * <b>fw_connection</b>. + * 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 <b>fw_connection</b> 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 <b>ap</b> 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 + * <b>fw_connection</b>. + * 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. + * If neither address is chosen, return 0, else return 1. */ +static int +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_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; return 1; + } else { + return 0; } } -/** Return true iff we think our firewall will let us make a directory - * connection to addr:port. */ +/** Like fascist_firewall_choose_address_base(), but takes a host-order IPv4 + * address as the first parameter. */ +static int +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); + return fascist_firewall_choose_address_base(&ipv4_addr, ipv4_orport, + ipv4_dirport, ipv6_addr, + ipv6_orport, ipv6_dirport, + fw_connection, pref_only, + pref_ipv6, ap); +} + +/** Like fascist_firewall_choose_address_base(), but takes <b>rs</b>. + * 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. + */ int -fascist_firewall_allows_address_dir(const tor_addr_t *addr, uint16_t port) +fascist_firewall_choose_address_rs(const routerstatus_t *rs, + firewall_connection_t fw_connection, + int pref_only, tor_addr_port_t* ap) { - return addr_policy_permits_tor_addr(addr, port, - reachable_dir_addr_policy); + if (!rs) { + return 0; + } + + tor_assert(ap); + + const node_t *node = node_get_by_id(rs->identity_digest); + + if (node) { + return 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. */ + 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)); + + /* Assume IPv4 and IPv6 DirPorts are the same. + * Assume the IPv6 OR and Dir addresses are the same. */ + return 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 <b>node</b>, and + * looks up the node's IPv6 preference rather than taking an argument + * for pref_ipv6. */ +int +fascist_firewall_choose_address_node(const node_t *node, + firewall_connection_t fw_connection, + int pref_only, tor_addr_port_t *ap) +{ + if (!node) { + return 0; + } + + node_assert_ok(node); + + 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. */ + return 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 <b>ds</b>. */ +int +fascist_firewall_choose_address_dir_server(const dir_server_t *ds, + firewall_connection_t fw_connection, + int pref_only, + tor_addr_port_t *ap) +{ + 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.) + * 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. */ + return fascist_firewall_choose_address_rs(&ds->fake_status, fw_connection, + pref_only, ap); } /** Return 1 if <b>addr</b> is permitted to connect to our dir port, @@ -400,17 +1050,6 @@ authdir_policy_valid_address(uint32_t addr, uint16_t port) return !addr_is_in_cc_list(addr, get_options()->AuthDirInvalidCCs); } -/** Return 1 if <b>addr</b>:<b>port</b> should be marked as a bad dir, - * based on <b>authdir_baddir_policy</b>. Else return 0. - */ -int -authdir_policy_baddir_address(uint32_t addr, uint16_t port) -{ - if (! addr_policy_permits_address(addr, port, authdir_baddir_policy)) - return 1; - return addr_is_in_cc_list(addr, get_options()->AuthDirBadDirCCs); -} - /** Return 1 if <b>addr</b>:<b>port</b> should be marked as a bad exit, * based on <b>authdir_badexit_policy</b>. Else return 0. */ @@ -437,11 +1076,36 @@ validate_addr_policies(const or_options_t *options, char **msg) smartlist_t *addr_policy=NULL; *msg = NULL; - if (policies_parse_exit_policy(options->ExitPolicy, &addr_policy, - options->IPv6Exit, - options->ExitPolicyRejectPrivate, 0, - !options->BridgeRelay)) + 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) && + policy_is_reject_star(addr_policy, AF_INET6)); + + 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) { + 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! */ @@ -455,9 +1119,6 @@ validate_addr_policies(const or_options_t *options, char **msg) if (parse_addr_policy(options->AuthDirInvalid, &addr_policy, ADDR_POLICY_REJECT)) REJECT("Error in AuthDirInvalid entry."); - if (parse_addr_policy(options->AuthDirBadDir, &addr_policy, - ADDR_POLICY_REJECT)) - REJECT("Error in AuthDirBadDir entry."); if (parse_addr_policy(options->AuthDirBadExit, &addr_policy, ADDR_POLICY_REJECT)) REJECT("Error in AuthDirBadExit entry."); @@ -535,9 +1196,6 @@ policies_parse_from_options(const or_options_t *options) if (load_policy_from_option(options->AuthDirInvalid, "AuthDirInvalid", &authdir_invalid_policy, ADDR_POLICY_REJECT) < 0) ret = -1; - if (load_policy_from_option(options->AuthDirBadDir, "AuthDirBadDir", - &authdir_baddir_policy, ADDR_POLICY_REJECT) < 0) - ret = -1; if (load_policy_from_option(options->AuthDirBadExit, "AuthDirBadExit", &authdir_badexit_policy, ADDR_POLICY_REJECT) < 0) ret = -1; @@ -556,6 +1214,8 @@ cmp_single_addr_policy(addr_policy_t *a, addr_policy_t *b) return r; if ((r=((int)a->is_private - (int)b->is_private))) return r; + /* 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 r; if ((r=((int)a->maskbits - (int)b->maskbits))) @@ -598,7 +1258,7 @@ typedef struct policy_map_ent_t { static HT_HEAD(policy_map, policy_map_ent_t) policy_root = HT_INITIALIZER(); /** Return true iff a and b are equal. */ -static INLINE int +static inline int policy_eq(policy_map_ent_t *a, policy_map_ent_t *b) { return cmp_single_addr_policy(a->policy, b->policy) == 0; @@ -629,8 +1289,8 @@ policy_hash(const policy_map_ent_t *ent) HT_PROTOTYPE(policy_map, policy_map_ent_t, node, policy_hash, policy_eq) -HT_GENERATE(policy_map, policy_map_ent_t, node, policy_hash, - policy_eq, 0.6, malloc, realloc, free) +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 @@ -666,6 +1326,10 @@ compare_known_tor_addr_to_addr_policy(const tor_addr_t *addr, uint16_t port, /* 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)) { @@ -693,6 +1357,10 @@ compare_known_tor_addr_to_addr_policy_noport(const tor_addr_t *addr, 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) { @@ -732,6 +1400,10 @@ compare_unknown_tor_addr_to_addr_policy(uint16_t port, 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. */ @@ -769,9 +1441,9 @@ compare_unknown_tor_addr_to_addr_policy(uint16_t port, * 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. */ -addr_policy_result_t -compare_tor_addr_to_addr_policy(const tor_addr_t *addr, uint16_t port, - const smartlist_t *policy) +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. */ @@ -837,7 +1509,7 @@ addr_policy_intersects(addr_policy_t *a, addr_policy_t *b) /** Add the exit policy described by <b>more</b> to <b>policy</b>. */ -static void +STATIC void append_exit_policy_string(smartlist_t **policy, const char *more) { config_line_t tmp; @@ -854,6 +1526,9 @@ append_exit_policy_string(smartlist_t **policy, const char *more) 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; @@ -866,6 +1541,71 @@ addr_policy_append_reject_addr(smartlist_t **dest, const tor_addr_t *addr) 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 <b>addr</b>:*" to <b>dest</b>, 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 <b>dest</b>, 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 <b>dest</b>, 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 *<b>dest</b>. */ @@ -952,41 +1692,197 @@ exit_policy_remove_redundancies(smartlist_t *dest) } } +/** Reject private helper for policies_parse_exit_policy_internal: rejects + * publicly routable addresses on this exit relay. + * + * Add reject entries to the linked list *<b>dest</b>: + * <ul> + * <li>if configured_addresses is non-NULL, add entries that reject each + * tor_addr_t in the list as a destination. + * <li>if reject_interface_addresses is true, add entries that reject each + * public IPv4 and IPv6 address of each interface on this machine. + * <li>if reject_configured_port_addresses is true, add entries that reject + * each IPv4 and IPv6 address configured for a port. + * </ul> + * + * IPv6 entries are only added if ipv6_exit is true. (All IPv6 addresses are + * already blocked by policies_parse_exit_policy_internal if ipv6_exit is + * false.) + * + * The list in <b>dest</b> is created as needed. + */ +void +policies_parse_exit_policy_reject_private( + smartlist_t **dest, + int ipv6_exit, + const smartlist_t *configured_addresses, + int reject_interface_addresses, + int reject_configured_port_addresses) +{ + tor_assert(dest); + + /* Reject configured addresses, if they are from public netblocks. */ + if (configured_addresses) { + addr_policy_append_reject_addr_list_filter(dest, configured_addresses, + 1, ipv6_exit); + } + + /* Reject configured port addresses, if they are from public netblocks. */ + if (reject_configured_port_addresses) { + const smartlist_t *port_addrs = get_configured_ports(); + + SMARTLIST_FOREACH_BEGIN(port_addrs, port_cfg_t *, port) { + + /* Only reject port IP addresses, not port unix sockets */ + if (!port->is_unix_addr) { + addr_policy_append_reject_addr_filter(dest, &port->addr, 1, ipv6_exit); + } + } SMARTLIST_FOREACH_END(port); + } + + /* Reject local addresses from public netblocks on any interface. */ + if (reject_interface_addresses) { + smartlist_t *public_addresses = NULL; + + /* Reject public IPv4 addresses on any interface */ + public_addresses = get_interface_address6_list(LOG_INFO, AF_INET, 0); + addr_policy_append_reject_addr_list_filter(dest, public_addresses, 1, 0); + free_interface_address6_list(public_addresses); + + /* Don't look for IPv6 addresses if we're configured as IPv4-only */ + if (ipv6_exit) { + /* Reject public IPv6 addresses on any interface */ + public_addresses = get_interface_address6_list(LOG_INFO, AF_INET6, 0); + addr_policy_append_reject_addr_list_filter(dest, public_addresses, 0, 1); + free_interface_address6_list(public_addresses); + } + } + + /* If addresses were added multiple times, remove all but one of them. */ + if (*dest) { + exit_policy_remove_redundancies(*dest); + } +} + +/** + * Iterate through <b>policy</b> looking for redundant entries. Log a + * warning message with the first redundant entry, if any is found. + */ +static void +policies_log_first_redundant_entry(const smartlist_t *policy) +{ + int found_final_effective_entry = 0; + int first_redundant_entry = 0; + tor_assert(policy); + SMARTLIST_FOREACH_BEGIN(policy, const addr_policy_t *, p) { + sa_family_t family; + int found_ipv4_wildcard = 0, found_ipv6_wildcard = 0; + const int i = p_sl_idx; + + /* Look for accept/reject *[4|6|]:* entires */ + if (p->prt_min <= 1 && p->prt_max == 65535 && p->maskbits == 0) { + family = tor_addr_family(&p->addr); + /* accept/reject *:* may have already been expanded into + * accept/reject *4:*,accept/reject *6:* + * But handle both forms. + */ + if (family == AF_INET || family == AF_UNSPEC) { + found_ipv4_wildcard = 1; + } + if (family == AF_INET6 || family == AF_UNSPEC) { + found_ipv6_wildcard = 1; + } + } + + /* We also find accept *4:*,reject *6:* ; and + * accept *4:*,<other policies>,accept *6:* ; and similar. + * That's ok, because they make any subsequent entries redundant. */ + if (found_ipv4_wildcard && found_ipv6_wildcard) { + found_final_effective_entry = 1; + /* if we're not on the final entry in the list */ + if (i < smartlist_len(policy) - 1) { + first_redundant_entry = i + 1; + } + break; + } + } SMARTLIST_FOREACH_END(p); + + /* Work out if there are redundant trailing entries in the policy list */ + if (found_final_effective_entry && first_redundant_entry > 0) { + const addr_policy_t *p; + /* Longest possible policy is + * "accept6 ffff:ffff:..255/128:10000-65535", + * which contains a max-length IPv6 address, plus 24 characters. */ + char line[TOR_ADDR_BUF_LEN + 32]; + + tor_assert(first_redundant_entry < smartlist_len(policy)); + p = smartlist_get(policy, first_redundant_entry); + /* since we've already parsed the policy into an addr_policy_t struct, + * we might not log exactly what the user typed in */ + policy_write_item(line, TOR_ADDR_BUF_LEN + 32, p, 0); + log_warn(LD_DIR, "Exit policy '%s' and all following policies are " + "redundant, as it follows accept/reject *:* rules for both " + "IPv4 and IPv6. They will be removed from the exit policy. (Use " + "accept/reject *:* as the last entry in any exit policy.)", + line); + } +} + #define DEFAULT_EXIT_POLICY \ "reject *:25,reject *:119,reject *:135-139,reject *:445," \ "reject *:563,reject *:1214,reject *:4661-4666," \ "reject *:6346-6429,reject *:6699,reject *:6881-6999,accept *:*" -/** Parse the exit policy <b>cfg</b> into the linked list *<b>dest</b>. If - * cfg doesn't end in an absolute accept or reject and if +/** Parse the exit policy <b>cfg</b> into the linked list *<b>dest</b>. + * + * If <b>ipv6_exit</b> is false, prepend "reject *6:*" to the policy. + * + * If <b>rejectprivate</b> is true: + * - prepend "reject private:*" to the policy. + * - prepend entries that reject publicly routable addresses on this exit + * relay by calling policies_parse_exit_policy_reject_private + * + * If cfg doesn't end in an absolute accept or reject and if * <b>add_default_policy</b> is true, add the default exit - * policy afterwards. If <b>rejectprivate</b> is true, prepend - * "reject private:*" to the policy. Return -1 if we can't parse cfg, - * else return 0. + * policy afterwards. + * + * Return -1 if we can't parse cfg, else return 0. * * This function is used to parse the exit policy from our torrc. For * the functions used to parse the exit policy from a router descriptor, * see router_add_exit_policy. */ -int -policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, - int ipv6_exit, - int rejectprivate, uint32_t local_address, - int add_default_policy) +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) { if (!ipv6_exit) { append_exit_policy_string(dest, "reject *6:*"); } if (rejectprivate) { + /* Reject IPv4 and IPv6 reserved private netblocks */ append_exit_policy_string(dest, "reject private:*"); - if (local_address) { - char buf[POLICY_BUF_LEN]; - tor_snprintf(buf, sizeof(buf), "reject %s:*", fmt_addr32(local_address)); - append_exit_policy_string(dest, buf); - } + /* Reject IPv4 and IPv6 publicly routable addresses on this exit relay */ + policies_parse_exit_policy_reject_private( + dest, ipv6_exit, + configured_addresses, + reject_interface_addresses, + reject_configured_port_addresses); } if (parse_addr_policy(cfg, dest, -1)) return -1; + + /* Before we add the default policy and final rejects, check to see if + * there are any lines after accept *:* or reject *:*. These lines have no + * effect, and are most likely an error. */ + policies_log_first_redundant_entry(*dest); + if (add_default_policy) { append_exit_policy_string(dest, DEFAULT_EXIT_POLICY); } else { @@ -998,6 +1894,157 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, return 0; } +/** Parse exit policy in <b>cfg</b> into <b>dest</b> smartlist. + * + * Prepend an entry that rejects all IPv6 destinations unless + * <b>EXIT_POLICY_IPV6_ENABLED</b> bit is set in <b>options</b> bitmask. + * + * If <b>EXIT_POLICY_REJECT_PRIVATE</b> bit is set in <b>options</b>: + * - prepend an entry that rejects all destinations in all netblocks + * reserved for private use. + * - prepend entries that reject publicly routable addresses on this exit + * relay by calling policies_parse_exit_policy_internal + * + * If <b>EXIT_POLICY_ADD_DEFAULT</b> bit is set in <b>options</b>, append + * default exit policy entries to <b>result</b> smartlist. + */ +int +policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, + exit_policy_parser_cfg_t options, + const smartlist_t *configured_addresses) +{ + int ipv6_enabled = (options & EXIT_POLICY_IPV6_ENABLED) ? 1 : 0; + int reject_private = (options & EXIT_POLICY_REJECT_PRIVATE) ? 1 : 0; + int add_default = (options & EXIT_POLICY_ADD_DEFAULT) ? 1 : 0; + + return policies_parse_exit_policy_internal(cfg,dest,ipv6_enabled, + reject_private, + configured_addresses, + reject_private, + reject_private, + add_default); +} + +/** Helper function that adds a copy of addr to a smartlist as long as it is + * non-NULL and not tor_addr_is_null(). + * + * The caller is responsible for freeing all the tor_addr_t* in the smartlist. + */ +static void +policies_copy_addr_to_smartlist(smartlist_t *addr_list, const tor_addr_t *addr) +{ + if (addr && !tor_addr_is_null(addr)) { + tor_addr_t *addr_copy = tor_malloc(sizeof(tor_addr_t)); + tor_addr_copy(addr_copy, addr); + smartlist_add(addr_list, addr_copy); + } +} + +/** Helper function that adds ipv4h_addr to a smartlist as a tor_addr_t *, + * as long as it is not tor_addr_is_null(), by converting it to a tor_addr_t + * and passing it to policies_add_addr_to_smartlist. + * + * The caller is responsible for freeing all the tor_addr_t* in the smartlist. + */ +static void +policies_copy_ipv4h_to_smartlist(smartlist_t *addr_list, uint32_t ipv4h_addr) +{ + if (ipv4h_addr) { + tor_addr_t ipv4_tor_addr; + tor_addr_from_ipv4h(&ipv4_tor_addr, ipv4h_addr); + policies_copy_addr_to_smartlist(addr_list, &ipv4_tor_addr); + } +} + +/** Helper function that adds copies of + * or_options->OutboundBindAddressIPv[4|6]_ to a smartlist as tor_addr_t *, as + * long as or_options is non-NULL, and the addresses are not + * tor_addr_is_null(), by passing them to policies_add_addr_to_smartlist. + * + * The caller is responsible for freeing all the tor_addr_t* in the smartlist. + */ +static void +policies_copy_outbound_addresses_to_smartlist(smartlist_t *addr_list, + const or_options_t *or_options) +{ + if (or_options) { + policies_copy_addr_to_smartlist(addr_list, + &or_options->OutboundBindAddressIPv4_); + policies_copy_addr_to_smartlist(addr_list, + &or_options->OutboundBindAddressIPv6_); + } +} + +/** Parse <b>ExitPolicy</b> member of <b>or_options</b> into <b>result</b> + * smartlist. + * If <b>or_options->IPv6Exit</b> is false, prepend an entry that + * rejects all IPv6 destinations. + * + * If <b>or_options->ExitPolicyRejectPrivate</b> is true: + * - prepend an entry that rejects all destinations in all netblocks reserved + * for private use. + * - if local_address is non-zero, treat it as a host-order IPv4 address, and + * add it to the list of configured addresses. + * - if ipv6_local_address is non-NULL, and not the null tor_addr_t, add it + * to the list of configured addresses. + * - if or_options->OutboundBindAddressIPv4_ is not the null tor_addr_t, add + * it to the list of configured addresses. + * - if or_options->OutboundBindAddressIPv6_ is not the null tor_addr_t, add + * it to the list of configured addresses. + * + * If <b>or_options->BridgeRelay</b> is false, append entries of default + * Tor exit policy into <b>result</b> smartlist. + * + * If or_options->ExitRelay is false, then make our exit policy into + * "reject *:*" regardless. + */ +int +policies_parse_exit_policy_from_options(const or_options_t *or_options, + uint32_t local_address, + const tor_addr_t *ipv6_local_address, + smartlist_t **result) +{ + exit_policy_parser_cfg_t parser_cfg = 0; + smartlist_t *configured_addresses = NULL; + int rv = 0; + + /* Short-circuit for non-exit relays */ + if (or_options->ExitRelay == 0) { + append_exit_policy_string(result, "reject *4:*"); + append_exit_policy_string(result, "reject *6:*"); + return 0; + } + + configured_addresses = smartlist_new(); + + /* Configure the parser */ + if (or_options->IPv6Exit) { + parser_cfg |= EXIT_POLICY_IPV6_ENABLED; + } + + if (or_options->ExitPolicyRejectPrivate) { + parser_cfg |= EXIT_POLICY_REJECT_PRIVATE; + } + + if (!or_options->BridgeRelay) { + parser_cfg |= EXIT_POLICY_ADD_DEFAULT; + } + + /* Copy the configured addresses into the tor_addr_t* list */ + policies_copy_ipv4h_to_smartlist(configured_addresses, local_address); + policies_copy_addr_to_smartlist(configured_addresses, ipv6_local_address); + policies_copy_outbound_addresses_to_smartlist(configured_addresses, + or_options); + + rv = policies_parse_exit_policy(or_options->ExitPolicy, result, parser_cfg, + configured_addresses); + + SMARTLIST_FOREACH(configured_addresses, tor_addr_t *, a, tor_free(a)); + smartlist_free(configured_addresses); + + return rv; +} + /** Add "reject *:*" to the end of the policy in *<b>dest</b>, allocating * *<b>dest</b> as needed. */ void @@ -1103,7 +2150,7 @@ policy_is_reject_star(const smartlist_t *policy, sa_family_t family) /** Write a single address policy to the buf_len byte buffer at buf. Return * the number of characters written, or -1 on failure. */ int -policy_write_item(char *buf, size_t buflen, addr_policy_t *policy, +policy_write_item(char *buf, size_t buflen, const addr_policy_t *policy, int format_for_desc) { size_t written = 0; @@ -1139,9 +2186,9 @@ policy_write_item(char *buf, size_t buflen, addr_policy_t *policy, if (result < 0) return -1; written += strlen(buf); - /* If the maskbits is 32 we don't need to give it. If the mask is 0, - * we already wrote "*". */ - if (policy->maskbits < 32 && policy->maskbits > 0) { + /* If the maskbits is 32 (IPv4) or 128 (IPv6) we don't need to give it. If + the mask is 0, we already wrote "*". */ + if (policy->maskbits < (is_ip6?128:32) && policy->maskbits > 0) { if (tor_snprintf(buf+written, buflen-written, "/%d", policy->maskbits)<0) return -1; written += strlen(buf+written); @@ -1334,9 +2381,9 @@ policy_summary_add_item(smartlist_t *summary, addr_policy_t *p) * The summary will either be an "accept" plus a comma-separated list of port * ranges or a "reject" plus port-ranges, depending on which is shorter. * - * If no exits are allowed at all then NULL is returned, if no ports - * are blocked instead of "reject " we return "accept 1-65535" (this - * is an exception to the shorter-representation-wins rule). + * If no exits are allowed at all then "reject 1-65535" is returned. If no + * ports are blocked instead of "reject " we return "accept 1-65535". (These + * are an exception to the shorter-representation-wins rule). */ char * policy_summarize(smartlist_t *policy, sa_family_t family) @@ -1621,7 +2668,7 @@ compare_tor_addr_to_short_policy(const tor_addr_t *addr, uint16_t port, * allows exit enclaving. Trying it anyway would open up a cool attack * where the node refuses due to exitpolicy, the client reacts in * surprise by rewriting the node's exitpolicy to reject *:*, and then - * a bad guy targets users by causing them to attempt such connections + * an adversary targets users by causing them to attempt such connections * to 98% of the exits. * * Once microdescriptors can handle addresses in special cases (e.g. if @@ -1682,6 +2729,53 @@ compare_tor_addr_to_node_policy(const tor_addr_t *addr, uint16_t port, } } +/** + * Given <b>policy_list</b>, a list of addr_policy_t, produce a string + * representation of the list. + * If <b>include_ipv4</b> is true, include IPv4 entries. + * If <b>include_ipv6</b> is true, include IPv6 entries. + */ +char * +policy_dump_to_string(const smartlist_t *policy_list, + int include_ipv4, + int include_ipv6) +{ + smartlist_t *policy_string_list; + char *policy_string = NULL; + + policy_string_list = smartlist_new(); + + SMARTLIST_FOREACH_BEGIN(policy_list, addr_policy_t *, tmpe) { + char *pbuf; + int bytes_written_to_pbuf; + if ((tor_addr_family(&tmpe->addr) == AF_INET6) && (!include_ipv6)) { + continue; /* Don't include IPv6 parts of address policy */ + } + if ((tor_addr_family(&tmpe->addr) == AF_INET) && (!include_ipv4)) { + continue; /* Don't include IPv4 parts of address policy */ + } + + pbuf = tor_malloc(POLICY_BUF_LEN); + bytes_written_to_pbuf = policy_write_item(pbuf,POLICY_BUF_LEN, tmpe, 1); + + if (bytes_written_to_pbuf < 0) { + log_warn(LD_BUG, "policy_dump_to_string ran out of room!"); + tor_free(pbuf); + goto done; + } + + smartlist_add(policy_string_list,pbuf); + } SMARTLIST_FOREACH_END(tmpe); + + policy_string = smartlist_join_strings(policy_string_list, "\n", 0, NULL); + + done: + SMARTLIST_FOREACH(policy_string_list, char *, str, tor_free(str)); + smartlist_free(policy_string_list); + + return policy_string; +} + /** Implementation for GETINFO control command: knows the answer for questions * about "exit-policy/..." */ int @@ -1693,6 +2787,57 @@ getinfo_helper_policies(control_connection_t *conn, (void) errmsg; if (!strcmp(question, "exit-policy/default")) { *answer = tor_strdup(DEFAULT_EXIT_POLICY); + } else if (!strcmp(question, "exit-policy/reject-private/default")) { + smartlist_t *private_policy_strings; + const char **priv = private_nets; + + private_policy_strings = smartlist_new(); + + while (*priv != NULL) { + /* IPv6 addresses are in "[]" and contain ":", + * IPv4 addresses are not in "[]" and contain "." */ + smartlist_add_asprintf(private_policy_strings, "reject %s:*", *priv); + priv++; + } + + *answer = smartlist_join_strings(private_policy_strings, + ",", 0, NULL); + + SMARTLIST_FOREACH(private_policy_strings, char *, str, tor_free(str)); + smartlist_free(private_policy_strings); + } else if (!strcmp(question, "exit-policy/reject-private/relay")) { + const or_options_t *options = get_options(); + const routerinfo_t *me = router_get_my_routerinfo(); + + if (!me) { + *errmsg = "router_get_my_routerinfo returned NULL"; + return -1; + } + + if (!options->ExitPolicyRejectPrivate) { + *answer = tor_strdup(""); + return 0; + } + + smartlist_t *private_policy_list = smartlist_new(); + smartlist_t *configured_addresses = smartlist_new(); + + /* Copy the configured addresses into the tor_addr_t* list */ + policies_copy_ipv4h_to_smartlist(configured_addresses, me->addr); + policies_copy_addr_to_smartlist(configured_addresses, &me->ipv6_addr); + policies_copy_outbound_addresses_to_smartlist(configured_addresses, + options); + + policies_parse_exit_policy_reject_private( + &private_policy_list, + options->IPv6Exit, + configured_addresses, + 1, 1); + *answer = policy_dump_to_string(private_policy_list, 1, 1); + + addr_policy_list_free(private_policy_list); + SMARTLIST_FOREACH(configured_addresses, tor_addr_t *, a, tor_free(a)); + smartlist_free(configured_addresses); } else if (!strcmpstart(question, "exit-policy/")) { const routerinfo_t *me = router_get_my_routerinfo(); @@ -1766,8 +2911,6 @@ policies_free_all(void) authdir_reject_policy = NULL; addr_policy_list_free(authdir_invalid_policy); authdir_invalid_policy = NULL; - addr_policy_list_free(authdir_baddir_policy); - authdir_baddir_policy = NULL; addr_policy_list_free(authdir_badexit_policy); authdir_badexit_policy = NULL; |