diff options
Diffstat (limited to 'src/or/policies.c')
| -rw-r--r-- | src/or/policies.c | 218 |
1 files changed, 193 insertions, 25 deletions
diff --git a/src/or/policies.c b/src/or/policies.c index 560b8cb4c3..b247e6a64d 100644 --- a/src/or/policies.c +++ b/src/or/policies.c @@ -67,6 +67,8 @@ static int policies_parse_exit_policy_internal(config_line_t *cfg, int ipv6_exit, int rejectprivate, uint32_t local_address, + tor_addr_t *ipv6_local_address, + int reject_interface_addresses, int add_default_policy); /** Replace all "private" entries in *<b>policy</b> with their expanded @@ -152,7 +154,7 @@ 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. * @@ -167,6 +169,7 @@ 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) @@ -179,12 +182,22 @@ 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)); @@ -430,7 +443,7 @@ validate_addr_policies(const or_options_t *options, char **msg) smartlist_t *addr_policy=NULL; *msg = NULL; - if (policies_parse_exit_policy_from_options(options,0,&addr_policy)) { + if (policies_parse_exit_policy_from_options(options,0,NULL,0,&addr_policy)) { REJECT("Error in ExitPolicy entry."); } @@ -568,6 +581,8 @@ 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))) @@ -969,12 +984,24 @@ exit_policy_remove_redundancies(smartlist_t *dest) "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 true, prepend "reject *6:*" to the policy. + * + * If <b>rejectprivate</b> is true: + * - prepend "reject private:*" to the policy. + * - if local_address is non-zero, treat it as a host-order IPv4 address, + * and prepend an entry that rejects it as a destination. + * - if ipv6_local_address is non-NULL, prepend an entry that rejects it as + * a destination. + * - if reject_interface_addresses is true, prepend entries that reject each + * public IPv4 and IPv6 address of each interface on this machine. + * + * 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, @@ -985,21 +1012,142 @@ policies_parse_exit_policy_internal(config_line_t *cfg, smartlist_t **dest, int ipv6_exit, int rejectprivate, uint32_t local_address, + tor_addr_t *ipv6_local_address, + int reject_interface_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:*"); + /* Reject our local IPv4 address */ 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); + log_info(LD_CONFIG, "Adding a reject ExitPolicy '%s' for our published " + "IPv4 address", buf); + } + /* Reject our local IPv6 address */ + if (ipv6_exit && ipv6_local_address != NULL) { + if (tor_addr_is_v4(ipv6_local_address)) { + log_warn(LD_CONFIG, "IPv4 address '%s' provided as our IPv6 local " + "address", fmt_addr(ipv6_local_address)); + } else { + char buf6[POLICY_BUF_LEN]; + tor_snprintf(buf6, sizeof(buf6), "reject [%s]:*", + fmt_addr(ipv6_local_address)); + append_exit_policy_string(dest, buf6); + log_info(LD_CONFIG, "Adding a reject ExitPolicy '%s' for our " + "published IPv6 address", buf6); + } + } + /* Reject local addresses from public netblocks on any interface, + * but don't reject our published addresses twice */ + if (reject_interface_addresses) { + smartlist_t *public_addresses = NULL; + char bufif[POLICY_BUF_LEN]; + + /* Reject public IPv4 addresses on any interface, + * but don't reject our published IPv4 address twice */ + public_addresses = get_interface_address6_list(LOG_INFO, AF_INET, 0); + SMARTLIST_FOREACH_BEGIN(public_addresses, tor_addr_t *, a) { + if (!tor_addr_eq_ipv4h(a, local_address)) { + tor_snprintf(bufif, sizeof(bufif), "reject %s:*", + fmt_addr(a)); + append_exit_policy_string(dest, bufif); + log_info(LD_CONFIG, "Adding a reject ExitPolicy '%s' for a local " + "interface's public IPv4 address", bufif); + } + } SMARTLIST_FOREACH_END(a); + free_interface_address6_list(public_addresses); + + if (ipv6_exit) { + /* Reject public IPv6 addresses on any interface, + * but don't reject our published IPv6 address (if any) twice */ + public_addresses = get_interface_address6_list(LOG_INFO, AF_INET6, 0); + SMARTLIST_FOREACH_BEGIN(public_addresses, tor_addr_t *, a) { + /* if we don't have an IPv6 local address, we won't have rejected + * it above. This could happen if a future release does IPv6 + * autodiscovery, and we are waiting to discover our external IPv6 + * address */ + if (ipv6_local_address == NULL + || !tor_addr_eq(ipv6_local_address, a)) { + tor_snprintf(bufif, sizeof(bufif), "reject6 [%s]:*", + fmt_addr(a)); + append_exit_policy_string(dest, bufif); + log_info(LD_CONFIG, "Adding a reject ExitPolicy '%s' for a local " + "interface's public IPv6 address", bufif); + } + } SMARTLIST_FOREACH_END(a); + free_interface_address6_list(public_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. */ + int found_final_effective_entry = 0; + int first_redundant_entry = 0; + for (int i = 0; i < smartlist_len(*dest); ++i) { + sa_family_t family; + addr_policy_t *p; + int found_ipv4_wildcard = 0, found_ipv6_wildcard = 0; + + p = smartlist_get(*dest, i); + + /* 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(*dest) - 1) { + first_redundant_entry = i + 1; + } + break; + } + } + /* Work out if there are redundant trailing entries in the policy list */ + if (found_final_effective_entry && first_redundant_entry > 0) { + 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(*dest)); + p = smartlist_get(*dest, 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); + } + if (add_default_policy) { append_exit_policy_string(dest, DEFAULT_EXIT_POLICY); } else { @@ -1013,20 +1161,28 @@ policies_parse_exit_policy_internal(config_line_t *cfg, smartlist_t **dest, /** Parse exit policy in <b>cfg</b> into <b>dest</b> smartlist. * - * Add entry that rejects all IPv6 destinations unless + * 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>, - * do add entry that rejects all destinations in private subnetwork - * Tor is running in. + * 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. + * - if local_address is non-zero, treat it as a host-order IPv4 address, + * and prepend an entry that rejects it as a destination. + * - if ipv6_local_address is non-NULL, prepend an entry that rejects it as + * a destination. + * - if reject_interface_addresses is true, prepend entries that reject each + * public IPv4 and IPv6 address of each interface on this machine. * - * Respectively, if <b>EXIT_POLICY_ADD_DEFAULT</b> bit is set, add + * 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, - uint32_t local_address) + uint32_t local_address, + tor_addr_t *ipv6_local_address, + int reject_interface_addresses) { int ipv6_enabled = (options & EXIT_POLICY_IPV6_ENABLED) ? 1 : 0; int reject_private = (options & EXIT_POLICY_REJECT_PRIVATE) ? 1 : 0; @@ -1035,19 +1191,27 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, return policies_parse_exit_policy_internal(cfg,dest,ipv6_enabled, reject_private, local_address, + ipv6_local_address, + reject_interface_addresses, add_default); } /** Parse <b>ExitPolicy</b> member of <b>or_options</b> into <b>result</b> * smartlist. - * If <b>or_options->IPv6Exit</b> is false, add an entry that + * If <b>or_options->IPv6Exit</b> is false, prepend an entry that * rejects all IPv6 destinations. * - * If <b>or_options->ExitPolicyRejectPrivate</b> is true, add entry that - * rejects all destinations in the private subnetwork of machine Tor - * instance is running in. + * 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 + * prepend an entry that rejects it as a destination. + * - if ipv6_local_address is non-NULL, prepend an entry that rejects it as a + * destination. + * - if reject_interface_addresses is true, prepend entries that reject each + * public IPv4 and IPv6 address of each interface on this machine. * - * If <b>or_options->BridgeRelay</b> is false, add entries of default + * 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 @@ -1056,6 +1220,8 @@ policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest, int policies_parse_exit_policy_from_options(const or_options_t *or_options, uint32_t local_address, + tor_addr_t *ipv6_local_address, + int reject_interface_addresses, smartlist_t **result) { exit_policy_parser_cfg_t parser_cfg = 0; @@ -1079,7 +1245,9 @@ policies_parse_exit_policy_from_options(const or_options_t *or_options, } return policies_parse_exit_policy(or_options->ExitPolicy,result, - parser_cfg,local_address); + parser_cfg,local_address, + ipv6_local_address, + reject_interface_addresses); } /** Add "reject *:*" to the end of the policy in *<b>dest</b>, allocating @@ -1223,9 +1391,9 @@ 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); |