policies.c 109 KB

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  1. /* Copyright (c) 2001-2004, Roger Dingledine.
  2. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
  3. * Copyright (c) 2007-2017, The Tor Project, Inc. */
  4. /* See LICENSE for licensing information */
  5. /**
  6. * \file policies.c
  7. * \brief Code to parse and use address policies and exit policies.
  8. *
  9. * We have two key kinds of address policy: full and compressed. A full
  10. * policy is an array of accept/reject patterns, to be applied in order.
  11. * A short policy is simply a list of ports. This module handles both
  12. * kinds, including generic functions to apply them to addresses, and
  13. * also including code to manage the global policies that we apply to
  14. * incoming and outgoing connections.
  15. **/
  16. #define POLICIES_PRIVATE
  17. #include "or.h"
  18. #include "bridges.h"
  19. #include "config.h"
  20. #include "dirserv.h"
  21. #include "microdesc.h"
  22. #include "networkstatus.h"
  23. #include "nodelist.h"
  24. #include "policies.h"
  25. #include "router.h"
  26. #include "routerparse.h"
  27. #include "geoip.h"
  28. #include "ht.h"
  29. /** Policy that addresses for incoming SOCKS connections must match. */
  30. static smartlist_t *socks_policy = NULL;
  31. /** Policy that addresses for incoming directory connections must match. */
  32. static smartlist_t *dir_policy = NULL;
  33. /** Policy that addresses for incoming router descriptors must match in order
  34. * to be published by us. */
  35. static smartlist_t *authdir_reject_policy = NULL;
  36. /** Policy that addresses for incoming router descriptors must match in order
  37. * to be marked as valid in our networkstatus. */
  38. static smartlist_t *authdir_invalid_policy = NULL;
  39. /** Policy that addresses for incoming router descriptors must <b>not</b>
  40. * match in order to not be marked as BadExit. */
  41. static smartlist_t *authdir_badexit_policy = NULL;
  42. /** Parsed addr_policy_t describing which addresses we believe we can start
  43. * circuits at. */
  44. static smartlist_t *reachable_or_addr_policy = NULL;
  45. /** Parsed addr_policy_t describing which addresses we believe we can connect
  46. * to directories at. */
  47. static smartlist_t *reachable_dir_addr_policy = NULL;
  48. /** Element of an exit policy summary */
  49. typedef struct policy_summary_item_t {
  50. uint16_t prt_min; /**< Lowest port number to accept/reject. */
  51. uint16_t prt_max; /**< Highest port number to accept/reject. */
  52. uint64_t reject_count; /**< Number of IP-Addresses that are rejected to
  53. this port range. */
  54. unsigned int accepted:1; /** Has this port already been accepted */
  55. } policy_summary_item_t;
  56. /** Private networks. This list is used in two places, once to expand the
  57. * "private" keyword when parsing our own exit policy, secondly to ignore
  58. * just such networks when building exit policy summaries. It is important
  59. * that all authorities agree on that list when creating summaries, so don't
  60. * just change this without a proper migration plan and a proposal and stuff.
  61. */
  62. static const char *private_nets[] = {
  63. "0.0.0.0/8", "169.254.0.0/16",
  64. "127.0.0.0/8", "192.168.0.0/16", "10.0.0.0/8", "172.16.0.0/12",
  65. "[::]/8",
  66. "[fc00::]/7", "[fe80::]/10", "[fec0::]/10", "[ff00::]/8", "[::]/127",
  67. NULL
  68. };
  69. static int policies_parse_exit_policy_internal(
  70. config_line_t *cfg,
  71. smartlist_t **dest,
  72. int ipv6_exit,
  73. int rejectprivate,
  74. const smartlist_t *configured_addresses,
  75. int reject_interface_addresses,
  76. int reject_configured_port_addresses,
  77. int add_default_policy,
  78. int add_reduced_policy);
  79. /** Replace all "private" entries in *<b>policy</b> with their expanded
  80. * equivalents. */
  81. void
  82. policy_expand_private(smartlist_t **policy)
  83. {
  84. uint16_t port_min, port_max;
  85. int i;
  86. smartlist_t *tmp;
  87. if (!*policy) /*XXXX disallow NULL policies? */
  88. return;
  89. tmp = smartlist_new();
  90. SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, p) {
  91. if (! p->is_private) {
  92. smartlist_add(tmp, p);
  93. continue;
  94. }
  95. for (i = 0; private_nets[i]; ++i) {
  96. addr_policy_t newpolicy;
  97. memcpy(&newpolicy, p, sizeof(addr_policy_t));
  98. newpolicy.is_private = 0;
  99. newpolicy.is_canonical = 0;
  100. if (tor_addr_parse_mask_ports(private_nets[i], 0,
  101. &newpolicy.addr,
  102. &newpolicy.maskbits, &port_min, &port_max)<0) {
  103. tor_assert_unreached();
  104. }
  105. smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy));
  106. }
  107. addr_policy_free(p);
  108. } SMARTLIST_FOREACH_END(p);
  109. smartlist_free(*policy);
  110. *policy = tmp;
  111. }
  112. /** Expand each of the AF_UNSPEC elements in *<b>policy</b> (which indicate
  113. * protocol-neutral wildcards) into a pair of wildcard elements: one IPv4-
  114. * specific and one IPv6-specific. */
  115. void
  116. policy_expand_unspec(smartlist_t **policy)
  117. {
  118. smartlist_t *tmp;
  119. if (!*policy)
  120. return;
  121. tmp = smartlist_new();
  122. SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, p) {
  123. sa_family_t family = tor_addr_family(&p->addr);
  124. if (family == AF_INET6 || family == AF_INET || p->is_private) {
  125. smartlist_add(tmp, p);
  126. } else if (family == AF_UNSPEC) {
  127. addr_policy_t newpolicy_ipv4;
  128. addr_policy_t newpolicy_ipv6;
  129. memcpy(&newpolicy_ipv4, p, sizeof(addr_policy_t));
  130. memcpy(&newpolicy_ipv6, p, sizeof(addr_policy_t));
  131. newpolicy_ipv4.is_canonical = 0;
  132. newpolicy_ipv6.is_canonical = 0;
  133. if (p->maskbits != 0) {
  134. log_warn(LD_BUG, "AF_UNSPEC policy with maskbits==%d", p->maskbits);
  135. newpolicy_ipv4.maskbits = 0;
  136. newpolicy_ipv6.maskbits = 0;
  137. }
  138. tor_addr_from_ipv4h(&newpolicy_ipv4.addr, 0);
  139. tor_addr_from_ipv6_bytes(&newpolicy_ipv6.addr,
  140. "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
  141. smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv4));
  142. smartlist_add(tmp, addr_policy_get_canonical_entry(&newpolicy_ipv6));
  143. addr_policy_free(p);
  144. } else {
  145. log_warn(LD_BUG, "Funny-looking address policy with family %d", family);
  146. smartlist_add(tmp, p);
  147. }
  148. } SMARTLIST_FOREACH_END(p);
  149. smartlist_free(*policy);
  150. *policy = tmp;
  151. }
  152. /**
  153. * Given a linked list of config lines containing "accept[6]" and "reject[6]"
  154. * tokens, parse them and append the result to <b>dest</b>. Return -1
  155. * if any tokens are malformed (and don't append any), else return 0.
  156. *
  157. * If <b>assume_action</b> is nonnegative, then insert its action
  158. * (ADDR_POLICY_ACCEPT or ADDR_POLICY_REJECT) for items that specify no
  159. * action.
  160. */
  161. static int
  162. parse_addr_policy(config_line_t *cfg, smartlist_t **dest,
  163. int assume_action)
  164. {
  165. smartlist_t *result;
  166. smartlist_t *entries;
  167. addr_policy_t *item;
  168. int malformed_list;
  169. int r = 0;
  170. if (!cfg)
  171. return 0;
  172. result = smartlist_new();
  173. entries = smartlist_new();
  174. for (; cfg; cfg = cfg->next) {
  175. smartlist_split_string(entries, cfg->value, ",",
  176. SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
  177. SMARTLIST_FOREACH_BEGIN(entries, const char *, ent) {
  178. log_debug(LD_CONFIG,"Adding new entry '%s'",ent);
  179. malformed_list = 0;
  180. item = router_parse_addr_policy_item_from_string(ent, assume_action,
  181. &malformed_list);
  182. if (item) {
  183. smartlist_add(result, item);
  184. } else if (malformed_list) {
  185. /* the error is so severe the entire list should be discarded */
  186. log_warn(LD_CONFIG, "Malformed policy '%s'. Discarding entire policy "
  187. "list.", ent);
  188. r = -1;
  189. } else {
  190. /* the error is minor: don't add the item, but keep processing the
  191. * rest of the policies in the list */
  192. log_debug(LD_CONFIG, "Ignored policy '%s' due to non-fatal error. "
  193. "The remainder of the policy list will be used.",
  194. ent);
  195. }
  196. } SMARTLIST_FOREACH_END(ent);
  197. SMARTLIST_FOREACH(entries, char *, ent, tor_free(ent));
  198. smartlist_clear(entries);
  199. }
  200. smartlist_free(entries);
  201. if (r == -1) {
  202. addr_policy_list_free(result);
  203. } else {
  204. policy_expand_private(&result);
  205. policy_expand_unspec(&result);
  206. if (*dest) {
  207. smartlist_add_all(*dest, result);
  208. smartlist_free(result);
  209. } else {
  210. *dest = result;
  211. }
  212. }
  213. return r;
  214. }
  215. /** Helper: parse the Reachable(Dir|OR)?Addresses fields into
  216. * reachable_(or|dir)_addr_policy. The options should already have
  217. * been validated by validate_addr_policies.
  218. */
  219. static int
  220. parse_reachable_addresses(void)
  221. {
  222. const or_options_t *options = get_options();
  223. int ret = 0;
  224. if (options->ReachableDirAddresses &&
  225. options->ReachableORAddresses &&
  226. options->ReachableAddresses) {
  227. log_warn(LD_CONFIG,
  228. "Both ReachableDirAddresses and ReachableORAddresses are set. "
  229. "ReachableAddresses setting will be ignored.");
  230. }
  231. addr_policy_list_free(reachable_or_addr_policy);
  232. reachable_or_addr_policy = NULL;
  233. if (!options->ReachableORAddresses && options->ReachableAddresses)
  234. log_info(LD_CONFIG,
  235. "Using ReachableAddresses as ReachableORAddresses.");
  236. if (parse_addr_policy(options->ReachableORAddresses ?
  237. options->ReachableORAddresses :
  238. options->ReachableAddresses,
  239. &reachable_or_addr_policy, ADDR_POLICY_ACCEPT)) {
  240. log_warn(LD_CONFIG,
  241. "Error parsing Reachable%sAddresses entry; ignoring.",
  242. options->ReachableORAddresses ? "OR" : "");
  243. ret = -1;
  244. }
  245. addr_policy_list_free(reachable_dir_addr_policy);
  246. reachable_dir_addr_policy = NULL;
  247. if (!options->ReachableDirAddresses && options->ReachableAddresses)
  248. log_info(LD_CONFIG,
  249. "Using ReachableAddresses as ReachableDirAddresses");
  250. if (parse_addr_policy(options->ReachableDirAddresses ?
  251. options->ReachableDirAddresses :
  252. options->ReachableAddresses,
  253. &reachable_dir_addr_policy, ADDR_POLICY_ACCEPT)) {
  254. if (options->ReachableDirAddresses)
  255. log_warn(LD_CONFIG,
  256. "Error parsing ReachableDirAddresses entry; ignoring.");
  257. ret = -1;
  258. }
  259. /* We ignore ReachableAddresses for relays */
  260. if (!server_mode(options)) {
  261. if (policy_is_reject_star(reachable_or_addr_policy, AF_UNSPEC, 0)
  262. || policy_is_reject_star(reachable_dir_addr_policy, AF_UNSPEC,0)) {
  263. log_warn(LD_CONFIG, "Tor cannot connect to the Internet if "
  264. "ReachableAddresses, ReachableORAddresses, or "
  265. "ReachableDirAddresses reject all addresses. Please accept "
  266. "some addresses in these options.");
  267. } else if (options->ClientUseIPv4 == 1
  268. && (policy_is_reject_star(reachable_or_addr_policy, AF_INET, 0)
  269. || policy_is_reject_star(reachable_dir_addr_policy, AF_INET, 0))) {
  270. log_warn(LD_CONFIG, "You have set ClientUseIPv4 1, but "
  271. "ReachableAddresses, ReachableORAddresses, or "
  272. "ReachableDirAddresses reject all IPv4 addresses. "
  273. "Tor will not connect using IPv4.");
  274. } else if (fascist_firewall_use_ipv6(options)
  275. && (policy_is_reject_star(reachable_or_addr_policy, AF_INET6, 0)
  276. || policy_is_reject_star(reachable_dir_addr_policy, AF_INET6, 0))) {
  277. log_warn(LD_CONFIG, "You have configured tor to use or prefer IPv6 "
  278. "(or UseBridges 1), but "
  279. "ReachableAddresses, ReachableORAddresses, or "
  280. "ReachableDirAddresses reject all IPv6 addresses. "
  281. "Tor will not connect using IPv6.");
  282. }
  283. }
  284. return ret;
  285. }
  286. /* Return true iff ClientUseIPv4 0 or ClientUseIPv6 0 might block any OR or Dir
  287. * address:port combination. */
  288. static int
  289. firewall_is_fascist_impl(void)
  290. {
  291. const or_options_t *options = get_options();
  292. /* Assume every non-bridge relay has an IPv4 address.
  293. * Clients which use bridges may only know the IPv6 address of their
  294. * bridge, but they will connect regardless of the ClientUseIPv6 setting. */
  295. return options->ClientUseIPv4 == 0;
  296. }
  297. /** Return true iff the firewall options, including ClientUseIPv4 0 and
  298. * ClientUseIPv6 0, might block any OR address:port combination.
  299. * Address preferences may still change which address is selected even if
  300. * this function returns false.
  301. */
  302. int
  303. firewall_is_fascist_or(void)
  304. {
  305. return (reachable_or_addr_policy != NULL || firewall_is_fascist_impl());
  306. }
  307. /** Return true iff the firewall options, including ClientUseIPv4 0 and
  308. * ClientUseIPv6 0, might block any Dir address:port combination.
  309. * Address preferences may still change which address is selected even if
  310. * this function returns false.
  311. */
  312. int
  313. firewall_is_fascist_dir(void)
  314. {
  315. return (reachable_dir_addr_policy != NULL || firewall_is_fascist_impl());
  316. }
  317. /** Return true iff <b>policy</b> (possibly NULL) will allow a
  318. * connection to <b>addr</b>:<b>port</b>.
  319. */
  320. static int
  321. addr_policy_permits_tor_addr(const tor_addr_t *addr, uint16_t port,
  322. smartlist_t *policy)
  323. {
  324. addr_policy_result_t p;
  325. p = compare_tor_addr_to_addr_policy(addr, port, policy);
  326. switch (p) {
  327. case ADDR_POLICY_PROBABLY_ACCEPTED:
  328. case ADDR_POLICY_ACCEPTED:
  329. return 1;
  330. case ADDR_POLICY_PROBABLY_REJECTED:
  331. case ADDR_POLICY_REJECTED:
  332. return 0;
  333. default:
  334. log_warn(LD_BUG, "Unexpected result: %d", (int)p);
  335. return 0;
  336. }
  337. }
  338. /** Return true iff <b> policy</b> (possibly NULL) will allow a connection to
  339. * <b>addr</b>:<b>port</b>. <b>addr</b> is an IPv4 address given in host
  340. * order. */
  341. /* XXXX deprecate when possible. */
  342. static int
  343. addr_policy_permits_address(uint32_t addr, uint16_t port,
  344. smartlist_t *policy)
  345. {
  346. tor_addr_t a;
  347. tor_addr_from_ipv4h(&a, addr);
  348. return addr_policy_permits_tor_addr(&a, port, policy);
  349. }
  350. /** Return true iff we think our firewall will let us make a connection to
  351. * addr:port.
  352. *
  353. * If we are configured as a server, ignore any address family preference and
  354. * just use IPv4.
  355. * Otherwise:
  356. * - return false for all IPv4 addresses:
  357. * - if ClientUseIPv4 is 0, or
  358. * if pref_only and pref_ipv6 are both true;
  359. * - return false for all IPv6 addresses:
  360. * - if fascist_firewall_use_ipv6() is 0, or
  361. * - if pref_only is true and pref_ipv6 is false.
  362. *
  363. * Return false if addr is NULL or tor_addr_is_null(), or if port is 0. */
  364. STATIC int
  365. fascist_firewall_allows_address(const tor_addr_t *addr,
  366. uint16_t port,
  367. smartlist_t *firewall_policy,
  368. int pref_only, int pref_ipv6)
  369. {
  370. const or_options_t *options = get_options();
  371. const int client_mode = !server_mode(options);
  372. if (!addr || tor_addr_is_null(addr) || !port) {
  373. return 0;
  374. }
  375. /* Clients stop using IPv4 if it's disabled. In most cases, clients also
  376. * stop using IPv4 if it's not preferred.
  377. * Servers must have IPv4 enabled and preferred. */
  378. if (tor_addr_family(addr) == AF_INET && client_mode &&
  379. (!options->ClientUseIPv4 || (pref_only && pref_ipv6))) {
  380. return 0;
  381. }
  382. /* Clients and Servers won't use IPv6 unless it's enabled (and in most
  383. * cases, IPv6 must also be preferred before it will be used). */
  384. if (tor_addr_family(addr) == AF_INET6 &&
  385. (!fascist_firewall_use_ipv6(options) || (pref_only && !pref_ipv6))) {
  386. return 0;
  387. }
  388. return addr_policy_permits_tor_addr(addr, port,
  389. firewall_policy);
  390. }
  391. /** Is this client configured to use IPv6?
  392. * Returns true if the client might use IPv6 for some of its connections
  393. * (including dual-stack and IPv6-only clients), and false if it will never
  394. * use IPv6 for any connections.
  395. * Use node_ipv6_or/dir_preferred() when checking a specific node and OR/Dir
  396. * port: it supports bridge client per-node IPv6 preferences.
  397. */
  398. int
  399. fascist_firewall_use_ipv6(const or_options_t *options)
  400. {
  401. /* Clients use IPv6 if it's set, or they use bridges, or they don't use
  402. * IPv4, or they prefer it.
  403. * ClientPreferIPv6DirPort is deprecated, but check it anyway. */
  404. return (options->ClientUseIPv6 == 1 || options->ClientUseIPv4 == 0 ||
  405. options->ClientPreferIPv6ORPort == 1 ||
  406. options->ClientPreferIPv6DirPort == 1 || options->UseBridges == 1);
  407. }
  408. /** Do we prefer to connect to IPv6, ignoring ClientPreferIPv6ORPort and
  409. * ClientPreferIPv6DirPort?
  410. * If we're unsure, return -1, otherwise, return 1 for IPv6 and 0 for IPv4.
  411. */
  412. static int
  413. fascist_firewall_prefer_ipv6_impl(const or_options_t *options)
  414. {
  415. /*
  416. Cheap implementation of config options ClientUseIPv4 & ClientUseIPv6 --
  417. If we're a server or IPv6 is disabled, use IPv4.
  418. If IPv4 is disabled, use IPv6.
  419. */
  420. if (server_mode(options) || !fascist_firewall_use_ipv6(options)) {
  421. return 0;
  422. }
  423. if (!options->ClientUseIPv4) {
  424. return 1;
  425. }
  426. return -1;
  427. }
  428. /** Do we prefer to connect to IPv6 ORPorts?
  429. * Use node_ipv6_or_preferred() whenever possible: it supports bridge client
  430. * per-node IPv6 preferences.
  431. */
  432. int
  433. fascist_firewall_prefer_ipv6_orport(const or_options_t *options)
  434. {
  435. int pref_ipv6 = fascist_firewall_prefer_ipv6_impl(options);
  436. if (pref_ipv6 >= 0) {
  437. return pref_ipv6;
  438. }
  439. /* We can use both IPv4 and IPv6 - which do we prefer? */
  440. if (options->ClientPreferIPv6ORPort == 1) {
  441. return 1;
  442. }
  443. return 0;
  444. }
  445. /** Do we prefer to connect to IPv6 DirPorts?
  446. *
  447. * (node_ipv6_dir_preferred() doesn't support bridge client per-node IPv6
  448. * preferences. There's no reason to use it instead of this function.)
  449. */
  450. int
  451. fascist_firewall_prefer_ipv6_dirport(const or_options_t *options)
  452. {
  453. int pref_ipv6 = fascist_firewall_prefer_ipv6_impl(options);
  454. if (pref_ipv6 >= 0) {
  455. return pref_ipv6;
  456. }
  457. /* We can use both IPv4 and IPv6 - which do we prefer? */
  458. if (options->ClientPreferIPv6DirPort == 1) {
  459. return 1;
  460. }
  461. return 0;
  462. }
  463. /** Return true iff we think our firewall will let us make a connection to
  464. * addr:port. Uses ReachableORAddresses or ReachableDirAddresses based on
  465. * fw_connection.
  466. * If pref_only is true, return true if addr is in the client's preferred
  467. * address family, which is IPv6 if pref_ipv6 is true, and IPv4 otherwise.
  468. * If pref_only is false, ignore pref_ipv6, and return true if addr is allowed.
  469. */
  470. int
  471. fascist_firewall_allows_address_addr(const tor_addr_t *addr, uint16_t port,
  472. firewall_connection_t fw_connection,
  473. int pref_only, int pref_ipv6)
  474. {
  475. if (fw_connection == FIREWALL_OR_CONNECTION) {
  476. return fascist_firewall_allows_address(addr, port,
  477. reachable_or_addr_policy,
  478. pref_only, pref_ipv6);
  479. } else if (fw_connection == FIREWALL_DIR_CONNECTION) {
  480. return fascist_firewall_allows_address(addr, port,
  481. reachable_dir_addr_policy,
  482. pref_only, pref_ipv6);
  483. } else {
  484. log_warn(LD_BUG, "Bad firewall_connection_t value %d.",
  485. fw_connection);
  486. return 0;
  487. }
  488. }
  489. /** Return true iff we think our firewall will let us make a connection to
  490. * addr:port (ap). Uses ReachableORAddresses or ReachableDirAddresses based on
  491. * fw_connection.
  492. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr().
  493. */
  494. static int
  495. fascist_firewall_allows_address_ap(const tor_addr_port_t *ap,
  496. firewall_connection_t fw_connection,
  497. int pref_only, int pref_ipv6)
  498. {
  499. tor_assert(ap);
  500. return fascist_firewall_allows_address_addr(&ap->addr, ap->port,
  501. fw_connection, pref_only,
  502. pref_ipv6);
  503. }
  504. /* Return true iff we think our firewall will let us make a connection to
  505. * ipv4h_or_addr:ipv4_or_port. ipv4h_or_addr is interpreted in host order.
  506. * Uses ReachableORAddresses or ReachableDirAddresses based on
  507. * fw_connection.
  508. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr().
  509. */
  510. static int
  511. fascist_firewall_allows_address_ipv4h(uint32_t ipv4h_or_addr,
  512. uint16_t ipv4_or_port,
  513. firewall_connection_t fw_connection,
  514. int pref_only, int pref_ipv6)
  515. {
  516. tor_addr_t ipv4_or_addr;
  517. tor_addr_from_ipv4h(&ipv4_or_addr, ipv4h_or_addr);
  518. return fascist_firewall_allows_address_addr(&ipv4_or_addr, ipv4_or_port,
  519. fw_connection, pref_only,
  520. pref_ipv6);
  521. }
  522. /** Return true iff we think our firewall will let us make a connection to
  523. * ipv4h_addr/ipv6_addr. Uses ipv4_orport/ipv6_orport/ReachableORAddresses or
  524. * ipv4_dirport/ipv6_dirport/ReachableDirAddresses based on IPv4/IPv6 and
  525. * <b>fw_connection</b>.
  526. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr().
  527. */
  528. static int
  529. fascist_firewall_allows_base(uint32_t ipv4h_addr, uint16_t ipv4_orport,
  530. uint16_t ipv4_dirport,
  531. const tor_addr_t *ipv6_addr, uint16_t ipv6_orport,
  532. uint16_t ipv6_dirport,
  533. firewall_connection_t fw_connection,
  534. int pref_only, int pref_ipv6)
  535. {
  536. if (fascist_firewall_allows_address_ipv4h(ipv4h_addr,
  537. (fw_connection == FIREWALL_OR_CONNECTION
  538. ? ipv4_orport
  539. : ipv4_dirport),
  540. fw_connection,
  541. pref_only, pref_ipv6)) {
  542. return 1;
  543. }
  544. if (fascist_firewall_allows_address_addr(ipv6_addr,
  545. (fw_connection == FIREWALL_OR_CONNECTION
  546. ? ipv6_orport
  547. : ipv6_dirport),
  548. fw_connection,
  549. pref_only, pref_ipv6)) {
  550. return 1;
  551. }
  552. return 0;
  553. }
  554. /** Like fascist_firewall_allows_base(), but takes ri. */
  555. static int
  556. fascist_firewall_allows_ri_impl(const routerinfo_t *ri,
  557. firewall_connection_t fw_connection,
  558. int pref_only, int pref_ipv6)
  559. {
  560. if (!ri) {
  561. return 0;
  562. }
  563. /* Assume IPv4 and IPv6 DirPorts are the same */
  564. return fascist_firewall_allows_base(ri->addr, ri->or_port, ri->dir_port,
  565. &ri->ipv6_addr, ri->ipv6_orport,
  566. ri->dir_port, fw_connection, pref_only,
  567. pref_ipv6);
  568. }
  569. /** Like fascist_firewall_allows_rs, but takes pref_ipv6. */
  570. static int
  571. fascist_firewall_allows_rs_impl(const routerstatus_t *rs,
  572. firewall_connection_t fw_connection,
  573. int pref_only, int pref_ipv6)
  574. {
  575. if (!rs) {
  576. return 0;
  577. }
  578. /* Assume IPv4 and IPv6 DirPorts are the same */
  579. return fascist_firewall_allows_base(rs->addr, rs->or_port, rs->dir_port,
  580. &rs->ipv6_addr, rs->ipv6_orport,
  581. rs->dir_port, fw_connection, pref_only,
  582. pref_ipv6);
  583. }
  584. /** Like fascist_firewall_allows_base(), but takes rs.
  585. * When rs is a fake_status from a dir_server_t, it can have a reachable
  586. * address, even when the corresponding node does not.
  587. * nodes can be missing addresses when there's no consensus (IPv4 and IPv6),
  588. * or when there is a microdescriptor consensus, but no microdescriptors
  589. * (microdescriptors have IPv6, the microdesc consensus does not). */
  590. int
  591. fascist_firewall_allows_rs(const routerstatus_t *rs,
  592. firewall_connection_t fw_connection, int pref_only)
  593. {
  594. if (!rs) {
  595. return 0;
  596. }
  597. /* We don't have access to the node-specific IPv6 preference, so use the
  598. * generic IPv6 preference instead. */
  599. const or_options_t *options = get_options();
  600. int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION
  601. ? fascist_firewall_prefer_ipv6_orport(options)
  602. : fascist_firewall_prefer_ipv6_dirport(options));
  603. return fascist_firewall_allows_rs_impl(rs, fw_connection, pref_only,
  604. pref_ipv6);
  605. }
  606. /** Return true iff we think our firewall will let us make a connection to
  607. * ipv6_addr:ipv6_orport based on ReachableORAddresses.
  608. * If <b>fw_connection</b> is FIREWALL_DIR_CONNECTION, returns 0.
  609. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr().
  610. */
  611. static int
  612. fascist_firewall_allows_md_impl(const microdesc_t *md,
  613. firewall_connection_t fw_connection,
  614. int pref_only, int pref_ipv6)
  615. {
  616. if (!md) {
  617. return 0;
  618. }
  619. /* Can't check dirport, it doesn't have one */
  620. if (fw_connection == FIREWALL_DIR_CONNECTION) {
  621. return 0;
  622. }
  623. /* Also can't check IPv4, doesn't have that either */
  624. return fascist_firewall_allows_address_addr(&md->ipv6_addr, md->ipv6_orport,
  625. fw_connection, pref_only,
  626. pref_ipv6);
  627. }
  628. /** Like fascist_firewall_allows_base(), but takes node, and looks up pref_ipv6
  629. * from node_ipv6_or/dir_preferred(). */
  630. int
  631. fascist_firewall_allows_node(const node_t *node,
  632. firewall_connection_t fw_connection,
  633. int pref_only)
  634. {
  635. if (!node) {
  636. return 0;
  637. }
  638. node_assert_ok(node);
  639. const int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION
  640. ? node_ipv6_or_preferred(node)
  641. : node_ipv6_dir_preferred(node));
  642. /* Sometimes, the rs is missing the IPv6 address info, and we need to go
  643. * all the way to the md */
  644. if (node->ri && fascist_firewall_allows_ri_impl(node->ri, fw_connection,
  645. pref_only, pref_ipv6)) {
  646. return 1;
  647. } else if (node->rs && fascist_firewall_allows_rs_impl(node->rs,
  648. fw_connection,
  649. pref_only,
  650. pref_ipv6)) {
  651. return 1;
  652. } else if (node->md && fascist_firewall_allows_md_impl(node->md,
  653. fw_connection,
  654. pref_only,
  655. pref_ipv6)) {
  656. return 1;
  657. } else {
  658. /* If we know nothing, assume it's unreachable, we'll never get an address
  659. * to connect to. */
  660. return 0;
  661. }
  662. }
  663. /** Like fascist_firewall_allows_rs(), but takes ds. */
  664. int
  665. fascist_firewall_allows_dir_server(const dir_server_t *ds,
  666. firewall_connection_t fw_connection,
  667. int pref_only)
  668. {
  669. if (!ds) {
  670. return 0;
  671. }
  672. /* A dir_server_t always has a fake_status. As long as it has the same
  673. * addresses/ports in both fake_status and dir_server_t, this works fine.
  674. * (See #17867.)
  675. * fascist_firewall_allows_rs only checks the addresses in fake_status. */
  676. return fascist_firewall_allows_rs(&ds->fake_status, fw_connection,
  677. pref_only);
  678. }
  679. /** If a and b are both valid and allowed by fw_connection,
  680. * choose one based on want_a and return it.
  681. * Otherwise, return whichever is allowed.
  682. * Otherwise, return NULL.
  683. * pref_only and pref_ipv6 work as in fascist_firewall_allows_address_addr().
  684. */
  685. static const tor_addr_port_t *
  686. fascist_firewall_choose_address_impl(const tor_addr_port_t *a,
  687. const tor_addr_port_t *b,
  688. int want_a,
  689. firewall_connection_t fw_connection,
  690. int pref_only, int pref_ipv6)
  691. {
  692. const tor_addr_port_t *use_a = NULL;
  693. const tor_addr_port_t *use_b = NULL;
  694. if (fascist_firewall_allows_address_ap(a, fw_connection, pref_only,
  695. pref_ipv6)) {
  696. use_a = a;
  697. }
  698. if (fascist_firewall_allows_address_ap(b, fw_connection, pref_only,
  699. pref_ipv6)) {
  700. use_b = b;
  701. }
  702. /* If both are allowed */
  703. if (use_a && use_b) {
  704. /* Choose a if we want it */
  705. return (want_a ? use_a : use_b);
  706. } else {
  707. /* Choose a if we have it */
  708. return (use_a ? use_a : use_b);
  709. }
  710. }
  711. /** If a and b are both valid and preferred by fw_connection,
  712. * choose one based on want_a and return it.
  713. * Otherwise, return whichever is preferred.
  714. * If neither are preferred, and pref_only is false:
  715. * - If a and b are both allowed by fw_connection,
  716. * choose one based on want_a and return it.
  717. * - Otherwise, return whichever is preferred.
  718. * Otherwise, return NULL. */
  719. STATIC const tor_addr_port_t *
  720. fascist_firewall_choose_address(const tor_addr_port_t *a,
  721. const tor_addr_port_t *b,
  722. int want_a,
  723. firewall_connection_t fw_connection,
  724. int pref_only, int pref_ipv6)
  725. {
  726. const tor_addr_port_t *pref = fascist_firewall_choose_address_impl(
  727. a, b, want_a,
  728. fw_connection,
  729. 1, pref_ipv6);
  730. if (pref_only || pref) {
  731. /* If there is a preferred address, use it. If we can only use preferred
  732. * addresses, and neither address is preferred, pref will be NULL, and we
  733. * want to return NULL, so return it. */
  734. return pref;
  735. } else {
  736. /* If there's no preferred address, and we can return addresses that are
  737. * not preferred, use an address that's allowed */
  738. return fascist_firewall_choose_address_impl(a, b, want_a, fw_connection,
  739. 0, pref_ipv6);
  740. }
  741. }
  742. /** Copy an address and port into <b>ap</b> that we think our firewall will
  743. * let us connect to. Uses ipv4_addr/ipv6_addr and
  744. * ipv4_orport/ipv6_orport/ReachableORAddresses or
  745. * ipv4_dirport/ipv6_dirport/ReachableDirAddresses based on IPv4/IPv6 and
  746. * <b>fw_connection</b>.
  747. * If pref_only, only choose preferred addresses. In either case, choose
  748. * a preferred address before an address that's not preferred.
  749. * If both addresses could be chosen (they are both preferred or both allowed)
  750. * choose IPv6 if pref_ipv6 is true, otherwise choose IPv4.
  751. * If neither address is chosen, return 0, else return 1. */
  752. static int
  753. fascist_firewall_choose_address_base(const tor_addr_t *ipv4_addr,
  754. uint16_t ipv4_orport,
  755. uint16_t ipv4_dirport,
  756. const tor_addr_t *ipv6_addr,
  757. uint16_t ipv6_orport,
  758. uint16_t ipv6_dirport,
  759. firewall_connection_t fw_connection,
  760. int pref_only,
  761. int pref_ipv6,
  762. tor_addr_port_t* ap)
  763. {
  764. const tor_addr_port_t *result = NULL;
  765. const int want_ipv4 = !pref_ipv6;
  766. tor_assert(ipv6_addr);
  767. tor_assert(ap);
  768. tor_addr_port_t ipv4_ap;
  769. tor_addr_copy(&ipv4_ap.addr, ipv4_addr);
  770. ipv4_ap.port = (fw_connection == FIREWALL_OR_CONNECTION
  771. ? ipv4_orport
  772. : ipv4_dirport);
  773. tor_addr_port_t ipv6_ap;
  774. tor_addr_copy(&ipv6_ap.addr, ipv6_addr);
  775. ipv6_ap.port = (fw_connection == FIREWALL_OR_CONNECTION
  776. ? ipv6_orport
  777. : ipv6_dirport);
  778. result = fascist_firewall_choose_address(&ipv4_ap, &ipv6_ap,
  779. want_ipv4,
  780. fw_connection, pref_only,
  781. pref_ipv6);
  782. if (result) {
  783. tor_addr_copy(&ap->addr, &result->addr);
  784. ap->port = result->port;
  785. return 1;
  786. } else {
  787. tor_addr_make_null(&ap->addr, AF_UNSPEC);
  788. ap->port = 0;
  789. return 0;
  790. }
  791. }
  792. /** Like fascist_firewall_choose_address_base(), but takes a host-order IPv4
  793. * address as the first parameter. */
  794. static int
  795. fascist_firewall_choose_address_ipv4h(uint32_t ipv4h_addr,
  796. uint16_t ipv4_orport,
  797. uint16_t ipv4_dirport,
  798. const tor_addr_t *ipv6_addr,
  799. uint16_t ipv6_orport,
  800. uint16_t ipv6_dirport,
  801. firewall_connection_t fw_connection,
  802. int pref_only,
  803. int pref_ipv6,
  804. tor_addr_port_t* ap)
  805. {
  806. tor_addr_t ipv4_addr;
  807. tor_addr_from_ipv4h(&ipv4_addr, ipv4h_addr);
  808. return fascist_firewall_choose_address_base(&ipv4_addr, ipv4_orport,
  809. ipv4_dirport, ipv6_addr,
  810. ipv6_orport, ipv6_dirport,
  811. fw_connection, pref_only,
  812. pref_ipv6, ap);
  813. }
  814. /* Some microdescriptor consensus methods have no IPv6 addresses in rs: they
  815. * are in the microdescriptors. For these consensus methods, we can't rely on
  816. * the node's IPv6 address until its microdescriptor is available (when using
  817. * microdescs).
  818. * But for bridges, rewrite_node_address_for_bridge() updates node->ri with
  819. * the configured address, so we can trust bridge addresses.
  820. * (Bridges could gain an IPv6 address if their microdescriptor arrives, but
  821. * this will never be their preferred address: that is in the config.)
  822. * Returns true if the node needs a microdescriptor for its IPv6 address, and
  823. * false if the addresses in the node are already up-to-date.
  824. */
  825. static int
  826. node_awaiting_ipv6(const or_options_t* options, const node_t *node)
  827. {
  828. tor_assert(node);
  829. /* There's no point waiting for an IPv6 address if we'd never use it */
  830. if (!fascist_firewall_use_ipv6(options)) {
  831. return 0;
  832. }
  833. /* If the node has an IPv6 address, we're not waiting */
  834. if (node_has_ipv6_addr(node)) {
  835. return 0;
  836. }
  837. /* If the current consensus method and flavour has IPv6 addresses, we're not
  838. * waiting */
  839. if (networkstatus_consensus_has_ipv6(options)) {
  840. return 0;
  841. }
  842. /* Bridge clients never use the address from a bridge's md, so there's no
  843. * need to wait for it. */
  844. if (node_is_a_configured_bridge(node)) {
  845. return 0;
  846. }
  847. /* We are waiting if we_use_microdescriptors_for_circuits() and we have no
  848. * md. */
  849. return (!node->md && we_use_microdescriptors_for_circuits(options));
  850. }
  851. /** Like fascist_firewall_choose_address_base(), but takes <b>rs</b>.
  852. * Consults the corresponding node, then falls back to rs if node is NULL.
  853. * This should only happen when there's no valid consensus, and rs doesn't
  854. * correspond to a bridge client's bridge.
  855. */
  856. int
  857. fascist_firewall_choose_address_rs(const routerstatus_t *rs,
  858. firewall_connection_t fw_connection,
  859. int pref_only, tor_addr_port_t* ap)
  860. {
  861. if (!rs) {
  862. return 0;
  863. }
  864. tor_assert(ap);
  865. const or_options_t *options = get_options();
  866. const node_t *node = node_get_by_id(rs->identity_digest);
  867. if (node && !node_awaiting_ipv6(options, node)) {
  868. return fascist_firewall_choose_address_node(node, fw_connection, pref_only,
  869. ap);
  870. } else {
  871. /* There's no node-specific IPv6 preference, so use the generic IPv6
  872. * preference instead. */
  873. int pref_ipv6 = (fw_connection == FIREWALL_OR_CONNECTION
  874. ? fascist_firewall_prefer_ipv6_orport(options)
  875. : fascist_firewall_prefer_ipv6_dirport(options));
  876. /* Assume IPv4 and IPv6 DirPorts are the same.
  877. * Assume the IPv6 OR and Dir addresses are the same. */
  878. return fascist_firewall_choose_address_ipv4h(rs->addr,
  879. rs->or_port,
  880. rs->dir_port,
  881. &rs->ipv6_addr,
  882. rs->ipv6_orport,
  883. rs->dir_port,
  884. fw_connection,
  885. pref_only,
  886. pref_ipv6,
  887. ap);
  888. }
  889. }
  890. /** Like fascist_firewall_choose_address_base(), but takes <b>node</b>, and
  891. * looks up the node's IPv6 preference rather than taking an argument
  892. * for pref_ipv6. */
  893. int
  894. fascist_firewall_choose_address_node(const node_t *node,
  895. firewall_connection_t fw_connection,
  896. int pref_only, tor_addr_port_t *ap)
  897. {
  898. if (!node) {
  899. return 0;
  900. }
  901. node_assert_ok(node);
  902. /* Calling fascist_firewall_choose_address_node() when the node is missing
  903. * IPv6 information breaks IPv6-only clients.
  904. * If the node is a hard-coded fallback directory or authority, call
  905. * fascist_firewall_choose_address_rs() on the fake (hard-coded) routerstatus
  906. * for the node.
  907. * If it is not hard-coded, check that the node has a microdescriptor, full
  908. * descriptor (routerinfo), or is one of our configured bridges before
  909. * calling this function. */
  910. if (BUG(node_awaiting_ipv6(get_options(), node))) {
  911. return 0;
  912. }
  913. const int pref_ipv6_node = (fw_connection == FIREWALL_OR_CONNECTION
  914. ? node_ipv6_or_preferred(node)
  915. : node_ipv6_dir_preferred(node));
  916. tor_addr_port_t ipv4_or_ap;
  917. node_get_prim_orport(node, &ipv4_or_ap);
  918. tor_addr_port_t ipv4_dir_ap;
  919. node_get_prim_dirport(node, &ipv4_dir_ap);
  920. tor_addr_port_t ipv6_or_ap;
  921. node_get_pref_ipv6_orport(node, &ipv6_or_ap);
  922. tor_addr_port_t ipv6_dir_ap;
  923. node_get_pref_ipv6_dirport(node, &ipv6_dir_ap);
  924. /* Assume the IPv6 OR and Dir addresses are the same. */
  925. return fascist_firewall_choose_address_base(&ipv4_or_ap.addr,
  926. ipv4_or_ap.port,
  927. ipv4_dir_ap.port,
  928. &ipv6_or_ap.addr,
  929. ipv6_or_ap.port,
  930. ipv6_dir_ap.port,
  931. fw_connection,
  932. pref_only,
  933. pref_ipv6_node,
  934. ap);
  935. }
  936. /** Like fascist_firewall_choose_address_rs(), but takes <b>ds</b>. */
  937. int
  938. fascist_firewall_choose_address_dir_server(const dir_server_t *ds,
  939. firewall_connection_t fw_connection,
  940. int pref_only,
  941. tor_addr_port_t *ap)
  942. {
  943. if (!ds) {
  944. return 0;
  945. }
  946. /* A dir_server_t always has a fake_status. As long as it has the same
  947. * addresses/ports in both fake_status and dir_server_t, this works fine.
  948. * (See #17867.)
  949. * This function relies on fascist_firewall_choose_address_rs looking up the
  950. * node if it can, because that will get the latest info for the relay. */
  951. return fascist_firewall_choose_address_rs(&ds->fake_status, fw_connection,
  952. pref_only, ap);
  953. }
  954. /** Return 1 if <b>addr</b> is permitted to connect to our dir port,
  955. * based on <b>dir_policy</b>. Else return 0.
  956. */
  957. int
  958. dir_policy_permits_address(const tor_addr_t *addr)
  959. {
  960. return addr_policy_permits_tor_addr(addr, 1, dir_policy);
  961. }
  962. /** Return 1 if <b>addr</b> is permitted to connect to our socks port,
  963. * based on <b>socks_policy</b>. Else return 0.
  964. */
  965. int
  966. socks_policy_permits_address(const tor_addr_t *addr)
  967. {
  968. return addr_policy_permits_tor_addr(addr, 1, socks_policy);
  969. }
  970. /** Return true iff the address <b>addr</b> is in a country listed in the
  971. * case-insensitive list of country codes <b>cc_list</b>. */
  972. static int
  973. addr_is_in_cc_list(uint32_t addr, const smartlist_t *cc_list)
  974. {
  975. country_t country;
  976. const char *name;
  977. tor_addr_t tar;
  978. if (!cc_list)
  979. return 0;
  980. /* XXXXipv6 */
  981. tor_addr_from_ipv4h(&tar, addr);
  982. country = geoip_get_country_by_addr(&tar);
  983. name = geoip_get_country_name(country);
  984. return smartlist_contains_string_case(cc_list, name);
  985. }
  986. /** Return 1 if <b>addr</b>:<b>port</b> is permitted to publish to our
  987. * directory, based on <b>authdir_reject_policy</b>. Else return 0.
  988. */
  989. int
  990. authdir_policy_permits_address(uint32_t addr, uint16_t port)
  991. {
  992. if (! addr_policy_permits_address(addr, port, authdir_reject_policy))
  993. return 0;
  994. return !addr_is_in_cc_list(addr, get_options()->AuthDirRejectCCs);
  995. }
  996. /** Return 1 if <b>addr</b>:<b>port</b> is considered valid in our
  997. * directory, based on <b>authdir_invalid_policy</b>. Else return 0.
  998. */
  999. int
  1000. authdir_policy_valid_address(uint32_t addr, uint16_t port)
  1001. {
  1002. if (! addr_policy_permits_address(addr, port, authdir_invalid_policy))
  1003. return 0;
  1004. return !addr_is_in_cc_list(addr, get_options()->AuthDirInvalidCCs);
  1005. }
  1006. /** Return 1 if <b>addr</b>:<b>port</b> should be marked as a bad exit,
  1007. * based on <b>authdir_badexit_policy</b>. Else return 0.
  1008. */
  1009. int
  1010. authdir_policy_badexit_address(uint32_t addr, uint16_t port)
  1011. {
  1012. if (! addr_policy_permits_address(addr, port, authdir_badexit_policy))
  1013. return 1;
  1014. return addr_is_in_cc_list(addr, get_options()->AuthDirBadExitCCs);
  1015. }
  1016. #define REJECT(arg) \
  1017. STMT_BEGIN *msg = tor_strdup(arg); goto err; STMT_END
  1018. /** Config helper: If there's any problem with the policy configuration
  1019. * options in <b>options</b>, return -1 and set <b>msg</b> to a newly
  1020. * allocated description of the error. Else return 0. */
  1021. int
  1022. validate_addr_policies(const or_options_t *options, char **msg)
  1023. {
  1024. /* XXXX Maybe merge this into parse_policies_from_options, to make sure
  1025. * that the two can't go out of sync. */
  1026. smartlist_t *addr_policy=NULL;
  1027. *msg = NULL;
  1028. if (policies_parse_exit_policy_from_options(options,0,NULL,&addr_policy)) {
  1029. REJECT("Error in ExitPolicy entry.");
  1030. }
  1031. static int warned_about_exitrelay = 0;
  1032. const int exitrelay_setting_is_auto = options->ExitRelay == -1;
  1033. const int policy_accepts_something =
  1034. ! (policy_is_reject_star(addr_policy, AF_INET, 1) &&
  1035. policy_is_reject_star(addr_policy, AF_INET6, 1));
  1036. if (server_mode(options) &&
  1037. ! warned_about_exitrelay &&
  1038. exitrelay_setting_is_auto &&
  1039. policy_accepts_something) {
  1040. /* Policy accepts something */
  1041. warned_about_exitrelay = 1;
  1042. log_warn(LD_CONFIG,
  1043. "Tor is running as an exit relay%s. If you did not want this "
  1044. "behavior, please set the ExitRelay option to 0. If you do "
  1045. "want to run an exit Relay, please set the ExitRelay option "
  1046. "to 1 to disable this warning, and for forward compatibility.",
  1047. options->ExitPolicy == NULL ?
  1048. " with the default exit policy" : "");
  1049. if (options->ExitPolicy == NULL && options->ReducedExitPolicy == 0) {
  1050. log_warn(LD_CONFIG,
  1051. "In a future version of Tor, ExitRelay 0 may become the "
  1052. "default when no ExitPolicy is given.");
  1053. }
  1054. }
  1055. /* The rest of these calls *append* to addr_policy. So don't actually
  1056. * use the results for anything other than checking if they parse! */
  1057. if (parse_addr_policy(options->DirPolicy, &addr_policy, -1))
  1058. REJECT("Error in DirPolicy entry.");
  1059. if (parse_addr_policy(options->SocksPolicy, &addr_policy, -1))
  1060. REJECT("Error in SocksPolicy entry.");
  1061. if (parse_addr_policy(options->AuthDirReject, &addr_policy,
  1062. ADDR_POLICY_REJECT))
  1063. REJECT("Error in AuthDirReject entry.");
  1064. if (parse_addr_policy(options->AuthDirInvalid, &addr_policy,
  1065. ADDR_POLICY_REJECT))
  1066. REJECT("Error in AuthDirInvalid entry.");
  1067. if (parse_addr_policy(options->AuthDirBadExit, &addr_policy,
  1068. ADDR_POLICY_REJECT))
  1069. REJECT("Error in AuthDirBadExit entry.");
  1070. if (parse_addr_policy(options->ReachableAddresses, &addr_policy,
  1071. ADDR_POLICY_ACCEPT))
  1072. REJECT("Error in ReachableAddresses entry.");
  1073. if (parse_addr_policy(options->ReachableORAddresses, &addr_policy,
  1074. ADDR_POLICY_ACCEPT))
  1075. REJECT("Error in ReachableORAddresses entry.");
  1076. if (parse_addr_policy(options->ReachableDirAddresses, &addr_policy,
  1077. ADDR_POLICY_ACCEPT))
  1078. REJECT("Error in ReachableDirAddresses entry.");
  1079. err:
  1080. addr_policy_list_free(addr_policy);
  1081. return *msg ? -1 : 0;
  1082. #undef REJECT
  1083. }
  1084. /** Parse <b>string</b> in the same way that the exit policy
  1085. * is parsed, and put the processed version in *<b>policy</b>.
  1086. * Ignore port specifiers.
  1087. */
  1088. static int
  1089. load_policy_from_option(config_line_t *config, const char *option_name,
  1090. smartlist_t **policy,
  1091. int assume_action)
  1092. {
  1093. int r;
  1094. int killed_any_ports = 0;
  1095. addr_policy_list_free(*policy);
  1096. *policy = NULL;
  1097. r = parse_addr_policy(config, policy, assume_action);
  1098. if (r < 0) {
  1099. return -1;
  1100. }
  1101. if (*policy) {
  1102. SMARTLIST_FOREACH_BEGIN(*policy, addr_policy_t *, n) {
  1103. /* ports aren't used in these. */
  1104. if (n->prt_min > 1 || n->prt_max != 65535) {
  1105. addr_policy_t newp, *c;
  1106. memcpy(&newp, n, sizeof(newp));
  1107. newp.prt_min = 1;
  1108. newp.prt_max = 65535;
  1109. newp.is_canonical = 0;
  1110. c = addr_policy_get_canonical_entry(&newp);
  1111. SMARTLIST_REPLACE_CURRENT(*policy, n, c);
  1112. addr_policy_free(n);
  1113. killed_any_ports = 1;
  1114. }
  1115. } SMARTLIST_FOREACH_END(n);
  1116. }
  1117. if (killed_any_ports) {
  1118. log_warn(LD_CONFIG, "Ignoring ports in %s option.", option_name);
  1119. }
  1120. return 0;
  1121. }
  1122. /** Set all policies based on <b>options</b>, which should have been validated
  1123. * first by validate_addr_policies. */
  1124. int
  1125. policies_parse_from_options(const or_options_t *options)
  1126. {
  1127. int ret = 0;
  1128. if (load_policy_from_option(options->SocksPolicy, "SocksPolicy",
  1129. &socks_policy, -1) < 0)
  1130. ret = -1;
  1131. if (load_policy_from_option(options->DirPolicy, "DirPolicy",
  1132. &dir_policy, -1) < 0)
  1133. ret = -1;
  1134. if (load_policy_from_option(options->AuthDirReject, "AuthDirReject",
  1135. &authdir_reject_policy, ADDR_POLICY_REJECT) < 0)
  1136. ret = -1;
  1137. if (load_policy_from_option(options->AuthDirInvalid, "AuthDirInvalid",
  1138. &authdir_invalid_policy, ADDR_POLICY_REJECT) < 0)
  1139. ret = -1;
  1140. if (load_policy_from_option(options->AuthDirBadExit, "AuthDirBadExit",
  1141. &authdir_badexit_policy, ADDR_POLICY_REJECT) < 0)
  1142. ret = -1;
  1143. if (parse_reachable_addresses() < 0)
  1144. ret = -1;
  1145. return ret;
  1146. }
  1147. /** Compare two provided address policy items, and renturn -1, 0, or 1
  1148. * if the first is less than, equal to, or greater than the second. */
  1149. static int
  1150. single_addr_policy_eq(const addr_policy_t *a, const addr_policy_t *b)
  1151. {
  1152. int r;
  1153. #define CMP_FIELD(field) do { \
  1154. if (a->field != b->field) { \
  1155. return 0; \
  1156. } \
  1157. } while (0)
  1158. CMP_FIELD(policy_type);
  1159. CMP_FIELD(is_private);
  1160. /* refcnt and is_canonical are irrelevant to equality,
  1161. * they are hash table implementation details */
  1162. if ((r=tor_addr_compare(&a->addr, &b->addr, CMP_EXACT)))
  1163. return 0;
  1164. CMP_FIELD(maskbits);
  1165. CMP_FIELD(prt_min);
  1166. CMP_FIELD(prt_max);
  1167. #undef CMP_FIELD
  1168. return 1;
  1169. }
  1170. /** As single_addr_policy_eq, but compare every element of two policies.
  1171. */
  1172. int
  1173. addr_policies_eq(const smartlist_t *a, const smartlist_t *b)
  1174. {
  1175. int i;
  1176. int len_a = a ? smartlist_len(a) : 0;
  1177. int len_b = b ? smartlist_len(b) : 0;
  1178. if (len_a != len_b)
  1179. return 0;
  1180. for (i = 0; i < len_a; ++i) {
  1181. if (! single_addr_policy_eq(smartlist_get(a, i), smartlist_get(b, i)))
  1182. return 0;
  1183. }
  1184. return 1;
  1185. }
  1186. /** Node in hashtable used to store address policy entries. */
  1187. typedef struct policy_map_ent_t {
  1188. HT_ENTRY(policy_map_ent_t) node;
  1189. addr_policy_t *policy;
  1190. } policy_map_ent_t;
  1191. /* DOCDOC policy_root */
  1192. static HT_HEAD(policy_map, policy_map_ent_t) policy_root = HT_INITIALIZER();
  1193. /** Return true iff a and b are equal. */
  1194. static inline int
  1195. policy_eq(policy_map_ent_t *a, policy_map_ent_t *b)
  1196. {
  1197. return single_addr_policy_eq(a->policy, b->policy);
  1198. }
  1199. /** Return a hashcode for <b>ent</b> */
  1200. static unsigned int
  1201. policy_hash(const policy_map_ent_t *ent)
  1202. {
  1203. const addr_policy_t *a = ent->policy;
  1204. addr_policy_t aa;
  1205. memset(&aa, 0, sizeof(aa));
  1206. aa.prt_min = a->prt_min;
  1207. aa.prt_max = a->prt_max;
  1208. aa.maskbits = a->maskbits;
  1209. aa.policy_type = a->policy_type;
  1210. aa.is_private = a->is_private;
  1211. if (a->is_private) {
  1212. aa.is_private = 1;
  1213. } else {
  1214. tor_addr_copy_tight(&aa.addr, &a->addr);
  1215. }
  1216. return (unsigned) siphash24g(&aa, sizeof(aa));
  1217. }
  1218. HT_PROTOTYPE(policy_map, policy_map_ent_t, node, policy_hash,
  1219. policy_eq)
  1220. HT_GENERATE2(policy_map, policy_map_ent_t, node, policy_hash,
  1221. policy_eq, 0.6, tor_reallocarray_, tor_free_)
  1222. /** Given a pointer to an addr_policy_t, return a copy of the pointer to the
  1223. * "canonical" copy of that addr_policy_t; the canonical copy is a single
  1224. * reference-counted object. */
  1225. addr_policy_t *
  1226. addr_policy_get_canonical_entry(addr_policy_t *e)
  1227. {
  1228. policy_map_ent_t search, *found;
  1229. if (e->is_canonical)
  1230. return e;
  1231. search.policy = e;
  1232. found = HT_FIND(policy_map, &policy_root, &search);
  1233. if (!found) {
  1234. found = tor_malloc_zero(sizeof(policy_map_ent_t));
  1235. found->policy = tor_memdup(e, sizeof(addr_policy_t));
  1236. found->policy->is_canonical = 1;
  1237. found->policy->refcnt = 0;
  1238. HT_INSERT(policy_map, &policy_root, found);
  1239. }
  1240. tor_assert(single_addr_policy_eq(found->policy, e));
  1241. ++found->policy->refcnt;
  1242. return found->policy;
  1243. }
  1244. /** Helper for compare_tor_addr_to_addr_policy. Implements the case where
  1245. * addr and port are both known. */
  1246. static addr_policy_result_t
  1247. compare_known_tor_addr_to_addr_policy(const tor_addr_t *addr, uint16_t port,
  1248. const smartlist_t *policy)
  1249. {
  1250. /* We know the address and port, and we know the policy, so we can just
  1251. * compute an exact match. */
  1252. SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) {
  1253. if (tmpe->addr.family == AF_UNSPEC) {
  1254. log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only "
  1255. "matches other AF_UNSPEC addresses.");
  1256. }
  1257. /* Address is known */
  1258. if (!tor_addr_compare_masked(addr, &tmpe->addr, tmpe->maskbits,
  1259. CMP_EXACT)) {
  1260. if (port >= tmpe->prt_min && port <= tmpe->prt_max) {
  1261. /* Exact match for the policy */
  1262. return tmpe->policy_type == ADDR_POLICY_ACCEPT ?
  1263. ADDR_POLICY_ACCEPTED : ADDR_POLICY_REJECTED;
  1264. }
  1265. }
  1266. } SMARTLIST_FOREACH_END(tmpe);
  1267. /* accept all by default. */
  1268. return ADDR_POLICY_ACCEPTED;
  1269. }
  1270. /** Helper for compare_tor_addr_to_addr_policy. Implements the case where
  1271. * addr is known but port is not. */
  1272. static addr_policy_result_t
  1273. compare_known_tor_addr_to_addr_policy_noport(const tor_addr_t *addr,
  1274. const smartlist_t *policy)
  1275. {
  1276. /* We look to see if there's a definite match. If so, we return that
  1277. match's value, unless there's an intervening possible match that says
  1278. something different. */
  1279. int maybe_accept = 0, maybe_reject = 0;
  1280. SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) {
  1281. if (tmpe->addr.family == AF_UNSPEC) {
  1282. log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only "
  1283. "matches other AF_UNSPEC addresses.");
  1284. }
  1285. if (!tor_addr_compare_masked(addr, &tmpe->addr, tmpe->maskbits,
  1286. CMP_EXACT)) {
  1287. if (tmpe->prt_min <= 1 && tmpe->prt_max >= 65535) {
  1288. /* Definitely matches, since it covers all ports. */
  1289. if (tmpe->policy_type == ADDR_POLICY_ACCEPT) {
  1290. /* If we already hit a clause that might trigger a 'reject', than we
  1291. * can't be sure of this certain 'accept'.*/
  1292. return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED :
  1293. ADDR_POLICY_ACCEPTED;
  1294. } else {
  1295. return maybe_accept ? ADDR_POLICY_PROBABLY_REJECTED :
  1296. ADDR_POLICY_REJECTED;
  1297. }
  1298. } else {
  1299. /* Might match. */
  1300. if (tmpe->policy_type == ADDR_POLICY_REJECT)
  1301. maybe_reject = 1;
  1302. else
  1303. maybe_accept = 1;
  1304. }
  1305. }
  1306. } SMARTLIST_FOREACH_END(tmpe);
  1307. /* accept all by default. */
  1308. return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED;
  1309. }
  1310. /** Helper for compare_tor_addr_to_addr_policy. Implements the case where
  1311. * port is known but address is not. */
  1312. static addr_policy_result_t
  1313. compare_unknown_tor_addr_to_addr_policy(uint16_t port,
  1314. const smartlist_t *policy)
  1315. {
  1316. /* We look to see if there's a definite match. If so, we return that
  1317. match's value, unless there's an intervening possible match that says
  1318. something different. */
  1319. int maybe_accept = 0, maybe_reject = 0;
  1320. SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, tmpe) {
  1321. if (tmpe->addr.family == AF_UNSPEC) {
  1322. log_warn(LD_BUG, "Policy contains an AF_UNSPEC address, which only "
  1323. "matches other AF_UNSPEC addresses.");
  1324. }
  1325. if (tmpe->prt_min <= port && port <= tmpe->prt_max) {
  1326. if (tmpe->maskbits == 0) {
  1327. /* Definitely matches, since it covers all addresses. */
  1328. if (tmpe->policy_type == ADDR_POLICY_ACCEPT) {
  1329. /* If we already hit a clause that might trigger a 'reject', than we
  1330. * can't be sure of this certain 'accept'.*/
  1331. return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED :
  1332. ADDR_POLICY_ACCEPTED;
  1333. } else {
  1334. return maybe_accept ? ADDR_POLICY_PROBABLY_REJECTED :
  1335. ADDR_POLICY_REJECTED;
  1336. }
  1337. } else {
  1338. /* Might match. */
  1339. if (tmpe->policy_type == ADDR_POLICY_REJECT)
  1340. maybe_reject = 1;
  1341. else
  1342. maybe_accept = 1;
  1343. }
  1344. }
  1345. } SMARTLIST_FOREACH_END(tmpe);
  1346. /* accept all by default. */
  1347. return maybe_reject ? ADDR_POLICY_PROBABLY_ACCEPTED : ADDR_POLICY_ACCEPTED;
  1348. }
  1349. /** Decide whether a given addr:port is definitely accepted,
  1350. * definitely rejected, probably accepted, or probably rejected by a
  1351. * given policy. If <b>addr</b> is 0, we don't know the IP of the
  1352. * target address. If <b>port</b> is 0, we don't know the port of the
  1353. * target address. (At least one of <b>addr</b> and <b>port</b> must be
  1354. * provided. If you want to know whether a policy would definitely reject
  1355. * an unknown address:port, use policy_is_reject_star().)
  1356. *
  1357. * We could do better by assuming that some ranges never match typical
  1358. * addresses (127.0.0.1, and so on). But we'll try this for now.
  1359. */
  1360. MOCK_IMPL(addr_policy_result_t,
  1361. compare_tor_addr_to_addr_policy,(const tor_addr_t *addr, uint16_t port,
  1362. const smartlist_t *policy))
  1363. {
  1364. if (!policy) {
  1365. /* no policy? accept all. */
  1366. return ADDR_POLICY_ACCEPTED;
  1367. } else if (addr == NULL || tor_addr_is_null(addr)) {
  1368. if (port == 0) {
  1369. log_info(LD_BUG, "Rejecting null address with 0 port (family %d)",
  1370. addr ? tor_addr_family(addr) : -1);
  1371. return ADDR_POLICY_REJECTED;
  1372. }
  1373. return compare_unknown_tor_addr_to_addr_policy(port, policy);
  1374. } else if (port == 0) {
  1375. return compare_known_tor_addr_to_addr_policy_noport(addr, policy);
  1376. } else {
  1377. return compare_known_tor_addr_to_addr_policy(addr, port, policy);
  1378. }
  1379. }
  1380. /** Return true iff the address policy <b>a</b> covers every case that
  1381. * would be covered by <b>b</b>, so that a,b is redundant. */
  1382. static int
  1383. addr_policy_covers(addr_policy_t *a, addr_policy_t *b)
  1384. {
  1385. if (tor_addr_family(&a->addr) != tor_addr_family(&b->addr)) {
  1386. /* You can't cover a different family. */
  1387. return 0;
  1388. }
  1389. /* We can ignore accept/reject, since "accept *:80, reject *:80" reduces
  1390. * to "accept *:80". */
  1391. if (a->maskbits > b->maskbits) {
  1392. /* a has more fixed bits than b; it can't possibly cover b. */
  1393. return 0;
  1394. }
  1395. if (tor_addr_compare_masked(&a->addr, &b->addr, a->maskbits, CMP_EXACT)) {
  1396. /* There's a fixed bit in a that's set differently in b. */
  1397. return 0;
  1398. }
  1399. return (a->prt_min <= b->prt_min && a->prt_max >= b->prt_max);
  1400. }
  1401. /** Return true iff the address policies <b>a</b> and <b>b</b> intersect,
  1402. * that is, there exists an address/port that is covered by <b>a</b> that
  1403. * is also covered by <b>b</b>.
  1404. */
  1405. static int
  1406. addr_policy_intersects(addr_policy_t *a, addr_policy_t *b)
  1407. {
  1408. maskbits_t minbits;
  1409. /* All the bits we care about are those that are set in both
  1410. * netmasks. If they are equal in a and b's networkaddresses
  1411. * then the networks intersect. If there is a difference,
  1412. * then they do not. */
  1413. if (a->maskbits < b->maskbits)
  1414. minbits = a->maskbits;
  1415. else
  1416. minbits = b->maskbits;
  1417. if (tor_addr_compare_masked(&a->addr, &b->addr, minbits, CMP_EXACT))
  1418. return 0;
  1419. if (a->prt_max < b->prt_min || b->prt_max < a->prt_min)
  1420. return 0;
  1421. return 1;
  1422. }
  1423. /** Add the exit policy described by <b>more</b> to <b>policy</b>.
  1424. */
  1425. STATIC void
  1426. append_exit_policy_string(smartlist_t **policy, const char *more)
  1427. {
  1428. config_line_t tmp;
  1429. tmp.key = NULL;
  1430. tmp.value = (char*) more;
  1431. tmp.next = NULL;
  1432. if (parse_addr_policy(&tmp, policy, -1)<0) {
  1433. log_warn(LD_BUG, "Unable to parse internally generated policy %s",more);
  1434. }
  1435. }
  1436. /** Add "reject <b>addr</b>:*" to <b>dest</b>, creating the list as needed. */
  1437. void
  1438. addr_policy_append_reject_addr(smartlist_t **dest, const tor_addr_t *addr)
  1439. {
  1440. tor_assert(dest);
  1441. tor_assert(addr);
  1442. addr_policy_t p, *add;
  1443. memset(&p, 0, sizeof(p));
  1444. p.policy_type = ADDR_POLICY_REJECT;
  1445. p.maskbits = tor_addr_family(addr) == AF_INET6 ? 128 : 32;
  1446. tor_addr_copy(&p.addr, addr);
  1447. p.prt_min = 1;
  1448. p.prt_max = 65535;
  1449. add = addr_policy_get_canonical_entry(&p);
  1450. if (!*dest)
  1451. *dest = smartlist_new();
  1452. smartlist_add(*dest, add);
  1453. log_debug(LD_CONFIG, "Adding a reject ExitPolicy 'reject %s:*'",
  1454. fmt_addr(addr));
  1455. }
  1456. /* Is addr public for the purposes of rejection? */
  1457. static int
  1458. tor_addr_is_public_for_reject(const tor_addr_t *addr)
  1459. {
  1460. return (!tor_addr_is_null(addr) && !tor_addr_is_internal(addr, 0)
  1461. && !tor_addr_is_multicast(addr));
  1462. }
  1463. /* Add "reject <b>addr</b>:*" to <b>dest</b>, creating the list as needed.
  1464. * Filter the address, only adding an IPv4 reject rule if ipv4_rules
  1465. * is true, and similarly for ipv6_rules. Check each address returns true for
  1466. * tor_addr_is_public_for_reject before adding it.
  1467. */
  1468. static void
  1469. addr_policy_append_reject_addr_filter(smartlist_t **dest,
  1470. const tor_addr_t *addr,
  1471. int ipv4_rules,
  1472. int ipv6_rules)
  1473. {
  1474. tor_assert(dest);
  1475. tor_assert(addr);
  1476. /* Only reject IP addresses which are public */
  1477. if (tor_addr_is_public_for_reject(addr)) {
  1478. /* Reject IPv4 addresses and IPv6 addresses based on the filters */
  1479. int is_ipv4 = tor_addr_is_v4(addr);
  1480. if ((is_ipv4 && ipv4_rules) || (!is_ipv4 && ipv6_rules)) {
  1481. addr_policy_append_reject_addr(dest, addr);
  1482. }
  1483. }
  1484. }
  1485. /** Add "reject addr:*" to <b>dest</b>, for each addr in addrs, creating the
  1486. * list as needed. */
  1487. void
  1488. addr_policy_append_reject_addr_list(smartlist_t **dest,
  1489. const smartlist_t *addrs)
  1490. {
  1491. tor_assert(dest);
  1492. tor_assert(addrs);
  1493. SMARTLIST_FOREACH_BEGIN(addrs, tor_addr_t *, addr) {
  1494. addr_policy_append_reject_addr(dest, addr);
  1495. } SMARTLIST_FOREACH_END(addr);
  1496. }
  1497. /** Add "reject addr:*" to <b>dest</b>, for each addr in addrs, creating the
  1498. * list as needed. Filter using */
  1499. static void
  1500. addr_policy_append_reject_addr_list_filter(smartlist_t **dest,
  1501. const smartlist_t *addrs,
  1502. int ipv4_rules,
  1503. int ipv6_rules)
  1504. {
  1505. tor_assert(dest);
  1506. tor_assert(addrs);
  1507. SMARTLIST_FOREACH_BEGIN(addrs, tor_addr_t *, addr) {
  1508. addr_policy_append_reject_addr_filter(dest, addr, ipv4_rules, ipv6_rules);
  1509. } SMARTLIST_FOREACH_END(addr);
  1510. }
  1511. /** Detect and excise "dead code" from the policy *<b>dest</b>. */
  1512. static void
  1513. exit_policy_remove_redundancies(smartlist_t *dest)
  1514. {
  1515. addr_policy_t *ap, *tmp;
  1516. int i, j;
  1517. /* Step one: kill every ipv4 thing after *4:*, every IPv6 thing after *6:*
  1518. */
  1519. {
  1520. int kill_v4=0, kill_v6=0;
  1521. for (i = 0; i < smartlist_len(dest); ++i) {
  1522. sa_family_t family;
  1523. ap = smartlist_get(dest, i);
  1524. family = tor_addr_family(&ap->addr);
  1525. if ((family == AF_INET && kill_v4) ||
  1526. (family == AF_INET6 && kill_v6)) {
  1527. smartlist_del_keeporder(dest, i--);
  1528. addr_policy_free(ap);
  1529. continue;
  1530. }
  1531. if (ap->maskbits == 0 && ap->prt_min <= 1 && ap->prt_max >= 65535) {
  1532. /* This is a catch-all line -- later lines are unreachable. */
  1533. if (family == AF_INET) {
  1534. kill_v4 = 1;
  1535. } else if (family == AF_INET6) {
  1536. kill_v6 = 1;
  1537. }
  1538. }
  1539. }
  1540. }
  1541. /* Step two: for every entry, see if there's a redundant entry
  1542. * later on, and remove it. */
  1543. for (i = 0; i < smartlist_len(dest)-1; ++i) {
  1544. ap = smartlist_get(dest, i);
  1545. for (j = i+1; j < smartlist_len(dest); ++j) {
  1546. tmp = smartlist_get(dest, j);
  1547. tor_assert(j > i);
  1548. if (addr_policy_covers(ap, tmp)) {
  1549. char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN];
  1550. policy_write_item(p1, sizeof(p1), tmp, 0);
  1551. policy_write_item(p2, sizeof(p2), ap, 0);
  1552. log_debug(LD_CONFIG, "Removing exit policy %s (%d). It is made "
  1553. "redundant by %s (%d).", p1, j, p2, i);
  1554. smartlist_del_keeporder(dest, j--);
  1555. addr_policy_free(tmp);
  1556. }
  1557. }
  1558. }
  1559. /* Step three: for every entry A, see if there's an entry B making this one
  1560. * redundant later on. This is the case if A and B are of the same type
  1561. * (accept/reject), A is a subset of B, and there is no other entry of
  1562. * different type in between those two that intersects with A.
  1563. *
  1564. * Anybody want to double-check the logic here? XXX
  1565. */
  1566. for (i = 0; i < smartlist_len(dest)-1; ++i) {
  1567. ap = smartlist_get(dest, i);
  1568. for (j = i+1; j < smartlist_len(dest); ++j) {
  1569. // tor_assert(j > i); // j starts out at i+1; j only increases; i only
  1570. // // decreases.
  1571. tmp = smartlist_get(dest, j);
  1572. if (ap->policy_type != tmp->policy_type) {
  1573. if (addr_policy_intersects(ap, tmp))
  1574. break;
  1575. } else { /* policy_types are equal. */
  1576. if (addr_policy_covers(tmp, ap)) {
  1577. char p1[POLICY_BUF_LEN], p2[POLICY_BUF_LEN];
  1578. policy_write_item(p1, sizeof(p1), ap, 0);
  1579. policy_write_item(p2, sizeof(p2), tmp, 0);
  1580. log_debug(LD_CONFIG, "Removing exit policy %s. It is already "
  1581. "covered by %s.", p1, p2);
  1582. smartlist_del_keeporder(dest, i--);
  1583. addr_policy_free(ap);
  1584. break;
  1585. }
  1586. }
  1587. }
  1588. }
  1589. }
  1590. /** Reject private helper for policies_parse_exit_policy_internal: rejects
  1591. * publicly routable addresses on this exit relay.
  1592. *
  1593. * Add reject entries to the linked list *<b>dest</b>:
  1594. * <ul>
  1595. * <li>if configured_addresses is non-NULL, add entries that reject each
  1596. * tor_addr_t in the list as a destination.
  1597. * <li>if reject_interface_addresses is true, add entries that reject each
  1598. * public IPv4 and IPv6 address of each interface on this machine.
  1599. * <li>if reject_configured_port_addresses is true, add entries that reject
  1600. * each IPv4 and IPv6 address configured for a port.
  1601. * </ul>
  1602. *
  1603. * IPv6 entries are only added if ipv6_exit is true. (All IPv6 addresses are
  1604. * already blocked by policies_parse_exit_policy_internal if ipv6_exit is
  1605. * false.)
  1606. *
  1607. * The list in <b>dest</b> is created as needed.
  1608. */
  1609. void
  1610. policies_parse_exit_policy_reject_private(
  1611. smartlist_t **dest,
  1612. int ipv6_exit,
  1613. const smartlist_t *configured_addresses,
  1614. int reject_interface_addresses,
  1615. int reject_configured_port_addresses)
  1616. {
  1617. tor_assert(dest);
  1618. /* Reject configured addresses, if they are from public netblocks. */
  1619. if (configured_addresses) {
  1620. addr_policy_append_reject_addr_list_filter(dest, configured_addresses,
  1621. 1, ipv6_exit);
  1622. }
  1623. /* Reject configured port addresses, if they are from public netblocks. */
  1624. if (reject_configured_port_addresses) {
  1625. const smartlist_t *port_addrs = get_configured_ports();
  1626. SMARTLIST_FOREACH_BEGIN(port_addrs, port_cfg_t *, port) {
  1627. /* Only reject port IP addresses, not port unix sockets */
  1628. if (!port->is_unix_addr) {
  1629. addr_policy_append_reject_addr_filter(dest, &port->addr, 1, ipv6_exit);
  1630. }
  1631. } SMARTLIST_FOREACH_END(port);
  1632. }
  1633. /* Reject local addresses from public netblocks on any interface. */
  1634. if (reject_interface_addresses) {
  1635. smartlist_t *public_addresses = NULL;
  1636. /* Reject public IPv4 addresses on any interface */
  1637. public_addresses = get_interface_address6_list(LOG_INFO, AF_INET, 0);
  1638. addr_policy_append_reject_addr_list_filter(dest, public_addresses, 1, 0);
  1639. interface_address6_list_free(public_addresses);
  1640. /* Don't look for IPv6 addresses if we're configured as IPv4-only */
  1641. if (ipv6_exit) {
  1642. /* Reject public IPv6 addresses on any interface */
  1643. public_addresses = get_interface_address6_list(LOG_INFO, AF_INET6, 0);
  1644. addr_policy_append_reject_addr_list_filter(dest, public_addresses, 0, 1);
  1645. interface_address6_list_free(public_addresses);
  1646. }
  1647. }
  1648. /* If addresses were added multiple times, remove all but one of them. */
  1649. if (*dest) {
  1650. exit_policy_remove_redundancies(*dest);
  1651. }
  1652. }
  1653. /**
  1654. * Iterate through <b>policy</b> looking for redundant entries. Log a
  1655. * warning message with the first redundant entry, if any is found.
  1656. */
  1657. static void
  1658. policies_log_first_redundant_entry(const smartlist_t *policy)
  1659. {
  1660. int found_final_effective_entry = 0;
  1661. int first_redundant_entry = 0;
  1662. tor_assert(policy);
  1663. SMARTLIST_FOREACH_BEGIN(policy, const addr_policy_t *, p) {
  1664. sa_family_t family;
  1665. int found_ipv4_wildcard = 0, found_ipv6_wildcard = 0;
  1666. const int i = p_sl_idx;
  1667. /* Look for accept/reject *[4|6|]:* entires */
  1668. if (p->prt_min <= 1 && p->prt_max == 65535 && p->maskbits == 0) {
  1669. family = tor_addr_family(&p->addr);
  1670. /* accept/reject *:* may have already been expanded into
  1671. * accept/reject *4:*,accept/reject *6:*
  1672. * But handle both forms.
  1673. */
  1674. if (family == AF_INET || family == AF_UNSPEC) {
  1675. found_ipv4_wildcard = 1;
  1676. }
  1677. if (family == AF_INET6 || family == AF_UNSPEC) {
  1678. found_ipv6_wildcard = 1;
  1679. }
  1680. }
  1681. /* We also find accept *4:*,reject *6:* ; and
  1682. * accept *4:*,<other policies>,accept *6:* ; and similar.
  1683. * That's ok, because they make any subsequent entries redundant. */
  1684. if (found_ipv4_wildcard && found_ipv6_wildcard) {
  1685. found_final_effective_entry = 1;
  1686. /* if we're not on the final entry in the list */
  1687. if (i < smartlist_len(policy) - 1) {
  1688. first_redundant_entry = i + 1;
  1689. }
  1690. break;
  1691. }
  1692. } SMARTLIST_FOREACH_END(p);
  1693. /* Work out if there are redundant trailing entries in the policy list */
  1694. if (found_final_effective_entry && first_redundant_entry > 0) {
  1695. const addr_policy_t *p;
  1696. /* Longest possible policy is
  1697. * "accept6 ffff:ffff:..255/128:10000-65535",
  1698. * which contains a max-length IPv6 address, plus 24 characters. */
  1699. char line[TOR_ADDR_BUF_LEN + 32];
  1700. tor_assert(first_redundant_entry < smartlist_len(policy));
  1701. p = smartlist_get(policy, first_redundant_entry);
  1702. /* since we've already parsed the policy into an addr_policy_t struct,
  1703. * we might not log exactly what the user typed in */
  1704. policy_write_item(line, TOR_ADDR_BUF_LEN + 32, p, 0);
  1705. log_warn(LD_DIR, "Exit policy '%s' and all following policies are "
  1706. "redundant, as it follows accept/reject *:* rules for both "
  1707. "IPv4 and IPv6. They will be removed from the exit policy. (Use "
  1708. "accept/reject *:* as the last entry in any exit policy.)",
  1709. line);
  1710. }
  1711. }
  1712. #define DEFAULT_EXIT_POLICY \
  1713. "reject *:25,reject *:119,reject *:135-139,reject *:445," \
  1714. "reject *:563,reject *:1214,reject *:4661-4666," \
  1715. "reject *:6346-6429,reject *:6699,reject *:6881-6999,accept *:*"
  1716. #define REDUCED_EXIT_POLICY \
  1717. "accept *:20-23,accept *:43,accept *:53,accept *:79-81,accept *:88," \
  1718. "accept *:110,accept *:143,accept *:194,accept *:220,accept *:389," \
  1719. "accept *:443,accept *:464,accept *:465,accept *:531,accept *:543-544," \
  1720. "accept *:554,accept *:563,accept *:587,accept *:636,accept *:706," \
  1721. "accept *:749,accept *:873,accept *:902-904,accept *:981,accept *:989-995," \
  1722. "accept *:1194,accept *:1220,accept *:1293,accept *:1500,accept *:1533," \
  1723. "accept *:1677,accept *:1723,accept *:1755,accept *:1863," \
  1724. "accept *:2082-2083,accept *:2086-2087,accept *:2095-2096," \
  1725. "accept *:2102-2104,accept *:3128,accept *:3389,accept *:3690," \
  1726. "accept *:4321,accept *:4643,accept *:5050,accept *:5190," \
  1727. "accept *:5222-5223,accept *:5228,accept *:5900,accept *:6660-6669," \
  1728. "accept *:6679,accept *:6697,accept *:8000,accept *:8008,accept *:8074," \
  1729. "accept *:8080,accept *:8082,accept *:8087-8088,accept *:8232-8233," \
  1730. "accept *:8332-8333,accept *:8443,accept *:8888,accept *:9418," \
  1731. "accept *:9999,accept *:10000,accept *:11371,accept *:19294," \
  1732. "accept *:19638,accept *:50002,accept *:64738,reject *:*"
  1733. /** Parse the exit policy <b>cfg</b> into the linked list *<b>dest</b>.
  1734. *
  1735. * If <b>ipv6_exit</b> is false, prepend "reject *6:*" to the policy.
  1736. *
  1737. * If <b>configured_addresses</b> contains addresses:
  1738. * - prepend entries that reject the addresses in this list. These may be the
  1739. * advertised relay addresses and/or the outbound bind addresses,
  1740. * depending on the ExitPolicyRejectPrivate and
  1741. * ExitPolicyRejectLocalInterfaces settings.
  1742. * If <b>rejectprivate</b> is true:
  1743. * - prepend "reject private:*" to the policy.
  1744. * If <b>reject_interface_addresses</b> is true:
  1745. * - prepend entries that reject publicly routable interface addresses on
  1746. * this exit relay by calling policies_parse_exit_policy_reject_private
  1747. * If <b>reject_configured_port_addresses</b> is true:
  1748. * - prepend entries that reject all configured port addresses
  1749. *
  1750. * If cfg doesn't end in an absolute accept or reject and if
  1751. * <b>add_default_policy</b> is true, add the default exit
  1752. * policy afterwards.
  1753. *
  1754. * Return -1 if we can't parse cfg, else return 0.
  1755. *
  1756. * This function is used to parse the exit policy from our torrc. For
  1757. * the functions used to parse the exit policy from a router descriptor,
  1758. * see router_add_exit_policy.
  1759. */
  1760. static int
  1761. policies_parse_exit_policy_internal(config_line_t *cfg,
  1762. smartlist_t **dest,
  1763. int ipv6_exit,
  1764. int rejectprivate,
  1765. const smartlist_t *configured_addresses,
  1766. int reject_interface_addresses,
  1767. int reject_configured_port_addresses,
  1768. int add_default_policy,
  1769. int add_reduced_policy)
  1770. {
  1771. if (!ipv6_exit) {
  1772. append_exit_policy_string(dest, "reject *6:*");
  1773. }
  1774. if (rejectprivate) {
  1775. /* Reject IPv4 and IPv6 reserved private netblocks */
  1776. append_exit_policy_string(dest, "reject private:*");
  1777. }
  1778. /* Consider rejecting IPv4 and IPv6 advertised relay addresses, outbound bind
  1779. * addresses, publicly routable addresses, and configured port addresses
  1780. * on this exit relay */
  1781. policies_parse_exit_policy_reject_private(dest, ipv6_exit,
  1782. configured_addresses,
  1783. reject_interface_addresses,
  1784. reject_configured_port_addresses);
  1785. if (parse_addr_policy(cfg, dest, -1))
  1786. return -1;
  1787. /* Before we add the default policy and final rejects, check to see if
  1788. * there are any lines after accept *:* or reject *:*. These lines have no
  1789. * effect, and are most likely an error. */
  1790. policies_log_first_redundant_entry(*dest);
  1791. if (add_reduced_policy) {
  1792. append_exit_policy_string(dest, REDUCED_EXIT_POLICY);
  1793. } else if (add_default_policy) {
  1794. append_exit_policy_string(dest, DEFAULT_EXIT_POLICY);
  1795. } else {
  1796. append_exit_policy_string(dest, "reject *4:*");
  1797. append_exit_policy_string(dest, "reject *6:*");
  1798. }
  1799. exit_policy_remove_redundancies(*dest);
  1800. return 0;
  1801. }
  1802. /** Parse exit policy in <b>cfg</b> into <b>dest</b> smartlist.
  1803. *
  1804. * Prepend an entry that rejects all IPv6 destinations unless
  1805. * <b>EXIT_POLICY_IPV6_ENABLED</b> bit is set in <b>options</b> bitmask.
  1806. *
  1807. * If <b>EXIT_POLICY_REJECT_PRIVATE</b> bit is set in <b>options</b>:
  1808. * - prepend an entry that rejects all destinations in all netblocks
  1809. * reserved for private use.
  1810. * - prepend entries that reject the advertised relay addresses in
  1811. * configured_addresses
  1812. * If <b>EXIT_POLICY_REJECT_LOCAL_INTERFACES</b> bit is set in <b>options</b>:
  1813. * - prepend entries that reject publicly routable addresses on this exit
  1814. * relay by calling policies_parse_exit_policy_internal
  1815. * - prepend entries that reject the outbound bind addresses in
  1816. * configured_addresses
  1817. * - prepend entries that reject all configured port addresses
  1818. *
  1819. * If <b>EXIT_POLICY_ADD_DEFAULT</b> bit is set in <b>options</b>, append
  1820. * default exit policy entries to <b>result</b> smartlist.
  1821. */
  1822. int
  1823. policies_parse_exit_policy(config_line_t *cfg, smartlist_t **dest,
  1824. exit_policy_parser_cfg_t options,
  1825. const smartlist_t *configured_addresses)
  1826. {
  1827. int ipv6_enabled = (options & EXIT_POLICY_IPV6_ENABLED) ? 1 : 0;
  1828. int reject_private = (options & EXIT_POLICY_REJECT_PRIVATE) ? 1 : 0;
  1829. int add_default = (options & EXIT_POLICY_ADD_DEFAULT) ? 1 : 0;
  1830. int reject_local_interfaces = (options &
  1831. EXIT_POLICY_REJECT_LOCAL_INTERFACES) ? 1 : 0;
  1832. int add_reduced = (options & EXIT_POLICY_ADD_REDUCED) ? 1 : 0;
  1833. return policies_parse_exit_policy_internal(cfg,dest,ipv6_enabled,
  1834. reject_private,
  1835. configured_addresses,
  1836. reject_local_interfaces,
  1837. reject_local_interfaces,
  1838. add_default,
  1839. add_reduced);
  1840. }
  1841. /** Helper function that adds a copy of addr to a smartlist as long as it is
  1842. * non-NULL and not tor_addr_is_null().
  1843. *
  1844. * The caller is responsible for freeing all the tor_addr_t* in the smartlist.
  1845. */
  1846. static void
  1847. policies_copy_addr_to_smartlist(smartlist_t *addr_list, const tor_addr_t *addr)
  1848. {
  1849. if (addr && !tor_addr_is_null(addr)) {
  1850. tor_addr_t *addr_copy = tor_malloc(sizeof(tor_addr_t));
  1851. tor_addr_copy(addr_copy, addr);
  1852. smartlist_add(addr_list, addr_copy);
  1853. }
  1854. }
  1855. /** Helper function that adds ipv4h_addr to a smartlist as a tor_addr_t *,
  1856. * as long as it is not tor_addr_is_null(), by converting it to a tor_addr_t
  1857. * and passing it to policies_add_addr_to_smartlist.
  1858. *
  1859. * The caller is responsible for freeing all the tor_addr_t* in the smartlist.
  1860. */
  1861. static void
  1862. policies_copy_ipv4h_to_smartlist(smartlist_t *addr_list, uint32_t ipv4h_addr)
  1863. {
  1864. if (ipv4h_addr) {
  1865. tor_addr_t ipv4_tor_addr;
  1866. tor_addr_from_ipv4h(&ipv4_tor_addr, ipv4h_addr);
  1867. policies_copy_addr_to_smartlist(addr_list, &ipv4_tor_addr);
  1868. }
  1869. }
  1870. /** Helper function that adds copies of or_options->OutboundBindAddresses
  1871. * to a smartlist as tor_addr_t *, as long as or_options is non-NULL, and
  1872. * the addresses are not tor_addr_is_null(), by passing them to
  1873. * policies_add_addr_to_smartlist.
  1874. *
  1875. * The caller is responsible for freeing all the tor_addr_t* in the smartlist.
  1876. */
  1877. static void
  1878. policies_copy_outbound_addresses_to_smartlist(smartlist_t *addr_list,
  1879. const or_options_t *or_options)
  1880. {
  1881. if (or_options) {
  1882. for (int i=0;i<OUTBOUND_ADDR_MAX;i++) {
  1883. for (int j=0;j<2;j++) {
  1884. if (!tor_addr_is_null(&or_options->OutboundBindAddresses[i][j])) {
  1885. policies_copy_addr_to_smartlist(addr_list,
  1886. &or_options->OutboundBindAddresses[i][j]);
  1887. }
  1888. }
  1889. }
  1890. }
  1891. }
  1892. /** Parse <b>ExitPolicy</b> member of <b>or_options</b> into <b>result</b>
  1893. * smartlist.
  1894. * If <b>or_options->IPv6Exit</b> is false, prepend an entry that
  1895. * rejects all IPv6 destinations.
  1896. *
  1897. * If <b>or_options->ExitPolicyRejectPrivate</b> is true:
  1898. * - prepend an entry that rejects all destinations in all netblocks reserved
  1899. * for private use.
  1900. * - if local_address is non-zero, treat it as a host-order IPv4 address, and
  1901. * add it to the list of configured addresses.
  1902. * - if ipv6_local_address is non-NULL, and not the null tor_addr_t, add it
  1903. * to the list of configured addresses.
  1904. * If <b>or_options->ExitPolicyRejectLocalInterfaces</b> is true:
  1905. * - if or_options->OutboundBindAddresses[][0] (=IPv4) is not the null
  1906. * tor_addr_t, add it to the list of configured addresses.
  1907. * - if or_options->OutboundBindAddresses[][1] (=IPv6) is not the null
  1908. * tor_addr_t, add it to the list of configured addresses.
  1909. *
  1910. * If <b>or_options->BridgeRelay</b> is false, append entries of default
  1911. * Tor exit policy into <b>result</b> smartlist.
  1912. *
  1913. * If or_options->ExitRelay is false, then make our exit policy into
  1914. * "reject *:*" regardless.
  1915. */
  1916. int
  1917. policies_parse_exit_policy_from_options(const or_options_t *or_options,
  1918. uint32_t local_address,
  1919. const tor_addr_t *ipv6_local_address,
  1920. smartlist_t **result)
  1921. {
  1922. exit_policy_parser_cfg_t parser_cfg = 0;
  1923. smartlist_t *configured_addresses = NULL;
  1924. int rv = 0;
  1925. /* Short-circuit for non-exit relays */
  1926. if (or_options->ExitRelay == 0) {
  1927. append_exit_policy_string(result, "reject *4:*");
  1928. append_exit_policy_string(result, "reject *6:*");
  1929. return 0;
  1930. }
  1931. configured_addresses = smartlist_new();
  1932. /* Configure the parser */
  1933. if (or_options->IPv6Exit) {
  1934. parser_cfg |= EXIT_POLICY_IPV6_ENABLED;
  1935. }
  1936. if (or_options->ExitPolicyRejectPrivate) {
  1937. parser_cfg |= EXIT_POLICY_REJECT_PRIVATE;
  1938. }
  1939. if (!or_options->BridgeRelay) {
  1940. if (or_options->ReducedExitPolicy)
  1941. parser_cfg |= EXIT_POLICY_ADD_REDUCED;
  1942. else
  1943. parser_cfg |= EXIT_POLICY_ADD_DEFAULT;
  1944. }
  1945. if (or_options->ExitPolicyRejectLocalInterfaces) {
  1946. parser_cfg |= EXIT_POLICY_REJECT_LOCAL_INTERFACES;
  1947. }
  1948. /* Copy the configured addresses into the tor_addr_t* list */
  1949. if (or_options->ExitPolicyRejectPrivate) {
  1950. policies_copy_ipv4h_to_smartlist(configured_addresses, local_address);
  1951. policies_copy_addr_to_smartlist(configured_addresses, ipv6_local_address);
  1952. }
  1953. if (or_options->ExitPolicyRejectLocalInterfaces) {
  1954. policies_copy_outbound_addresses_to_smartlist(configured_addresses,
  1955. or_options);
  1956. }
  1957. rv = policies_parse_exit_policy(or_options->ExitPolicy, result, parser_cfg,
  1958. configured_addresses);
  1959. SMARTLIST_FOREACH(configured_addresses, tor_addr_t *, a, tor_free(a));
  1960. smartlist_free(configured_addresses);
  1961. return rv;
  1962. }
  1963. /** Add "reject *:*" to the end of the policy in *<b>dest</b>, allocating
  1964. * *<b>dest</b> as needed. */
  1965. void
  1966. policies_exit_policy_append_reject_star(smartlist_t **dest)
  1967. {
  1968. append_exit_policy_string(dest, "reject *4:*");
  1969. append_exit_policy_string(dest, "reject *6:*");
  1970. }
  1971. /** Replace the exit policy of <b>node</b> with reject *:* */
  1972. void
  1973. policies_set_node_exitpolicy_to_reject_all(node_t *node)
  1974. {
  1975. node->rejects_all = 1;
  1976. }
  1977. /** Return 1 if there is at least one /8 subnet in <b>policy</b> that
  1978. * allows exiting to <b>port</b>. Otherwise, return 0. */
  1979. static int
  1980. exit_policy_is_general_exit_helper(smartlist_t *policy, int port)
  1981. {
  1982. uint32_t mask, ip, i;
  1983. /* Is this /8 rejected (1), or undecided (0)? */
  1984. char subnet_status[256];
  1985. memset(subnet_status, 0, sizeof(subnet_status));
  1986. SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, p) {
  1987. if (tor_addr_family(&p->addr) != AF_INET)
  1988. continue; /* IPv4 only for now */
  1989. if (p->prt_min > port || p->prt_max < port)
  1990. continue; /* Doesn't cover our port. */
  1991. mask = 0;
  1992. tor_assert(p->maskbits <= 32);
  1993. if (p->maskbits)
  1994. mask = UINT32_MAX<<(32-p->maskbits);
  1995. ip = tor_addr_to_ipv4h(&p->addr);
  1996. /* Calculate the first and last subnet that this exit policy touches
  1997. * and set it as loop boundaries. */
  1998. for (i = ((mask & ip)>>24); i <= (~((mask & ip) ^ mask)>>24); ++i) {
  1999. tor_addr_t addr;
  2000. if (subnet_status[i] != 0)
  2001. continue; /* We already reject some part of this /8 */
  2002. tor_addr_from_ipv4h(&addr, i<<24);
  2003. if (tor_addr_is_internal(&addr, 0) &&
  2004. !get_options()->DirAllowPrivateAddresses) {
  2005. continue; /* Local or non-routable addresses */
  2006. }
  2007. if (p->policy_type == ADDR_POLICY_ACCEPT) {
  2008. if (p->maskbits > 8)
  2009. continue; /* Narrower than a /8. */
  2010. /* We found an allowed subnet of at least size /8. Done
  2011. * for this port! */
  2012. return 1;
  2013. } else if (p->policy_type == ADDR_POLICY_REJECT) {
  2014. subnet_status[i] = 1;
  2015. }
  2016. }
  2017. } SMARTLIST_FOREACH_END(p);
  2018. return 0;
  2019. }
  2020. /** Return true iff <b>ri</b> is "useful as an exit node", meaning
  2021. * it allows exit to at least one /8 address space for each of ports 80
  2022. * and 443. */
  2023. int
  2024. exit_policy_is_general_exit(smartlist_t *policy)
  2025. {
  2026. if (!policy) /*XXXX disallow NULL policies? */
  2027. return 0;
  2028. return (exit_policy_is_general_exit_helper(policy, 80) &&
  2029. exit_policy_is_general_exit_helper(policy, 443));
  2030. }
  2031. /** Return false if <b>policy</b> might permit access to some addr:port;
  2032. * otherwise if we are certain it rejects everything, return true. If no
  2033. * part of <b>policy</b> matches, return <b>default_reject</b>.
  2034. * NULL policies are allowed, and treated as empty. */
  2035. int
  2036. policy_is_reject_star(const smartlist_t *policy, sa_family_t family,
  2037. int default_reject)
  2038. {
  2039. if (!policy)
  2040. return default_reject;
  2041. SMARTLIST_FOREACH_BEGIN(policy, const addr_policy_t *, p) {
  2042. if (p->policy_type == ADDR_POLICY_ACCEPT &&
  2043. (tor_addr_family(&p->addr) == family ||
  2044. tor_addr_family(&p->addr) == AF_UNSPEC)) {
  2045. return 0;
  2046. } else if (p->policy_type == ADDR_POLICY_REJECT &&
  2047. p->prt_min <= 1 && p->prt_max == 65535 &&
  2048. p->maskbits == 0 &&
  2049. (tor_addr_family(&p->addr) == family ||
  2050. tor_addr_family(&p->addr) == AF_UNSPEC)) {
  2051. return 1;
  2052. }
  2053. } SMARTLIST_FOREACH_END(p);
  2054. return default_reject;
  2055. }
  2056. /** Write a single address policy to the buf_len byte buffer at buf. Return
  2057. * the number of characters written, or -1 on failure. */
  2058. int
  2059. policy_write_item(char *buf, size_t buflen, const addr_policy_t *policy,
  2060. int format_for_desc)
  2061. {
  2062. size_t written = 0;
  2063. char addrbuf[TOR_ADDR_BUF_LEN];
  2064. const char *addrpart;
  2065. int result;
  2066. const int is_accept = policy->policy_type == ADDR_POLICY_ACCEPT;
  2067. const sa_family_t family = tor_addr_family(&policy->addr);
  2068. const int is_ip6 = (family == AF_INET6);
  2069. tor_addr_to_str(addrbuf, &policy->addr, sizeof(addrbuf), 1);
  2070. /* write accept/reject 1.2.3.4 */
  2071. if (policy->is_private) {
  2072. addrpart = "private";
  2073. } else if (policy->maskbits == 0) {
  2074. if (format_for_desc)
  2075. addrpart = "*";
  2076. else if (family == AF_INET6)
  2077. addrpart = "*6";
  2078. else if (family == AF_INET)
  2079. addrpart = "*4";
  2080. else
  2081. addrpart = "*";
  2082. } else {
  2083. addrpart = addrbuf;
  2084. }
  2085. result = tor_snprintf(buf, buflen, "%s%s %s",
  2086. is_accept ? "accept" : "reject",
  2087. (is_ip6&&format_for_desc)?"6":"",
  2088. addrpart);
  2089. if (result < 0)
  2090. return -1;
  2091. written += strlen(buf);
  2092. /* If the maskbits is 32 (IPv4) or 128 (IPv6) we don't need to give it. If
  2093. the mask is 0, we already wrote "*". */
  2094. if (policy->maskbits < (is_ip6?128:32) && policy->maskbits > 0) {
  2095. if (tor_snprintf(buf+written, buflen-written, "/%d", policy->maskbits)<0)
  2096. return -1;
  2097. written += strlen(buf+written);
  2098. }
  2099. if (policy->prt_min <= 1 && policy->prt_max == 65535) {
  2100. /* There is no port set; write ":*" */
  2101. if (written+4 > buflen)
  2102. return -1;
  2103. strlcat(buf+written, ":*", buflen-written);
  2104. written += 2;
  2105. } else if (policy->prt_min == policy->prt_max) {
  2106. /* There is only one port; write ":80". */
  2107. result = tor_snprintf(buf+written, buflen-written, ":%d", policy->prt_min);
  2108. if (result<0)
  2109. return -1;
  2110. written += result;
  2111. } else {
  2112. /* There is a range of ports; write ":79-80". */
  2113. result = tor_snprintf(buf+written, buflen-written, ":%d-%d",
  2114. policy->prt_min, policy->prt_max);
  2115. if (result<0)
  2116. return -1;
  2117. written += result;
  2118. }
  2119. if (written < buflen)
  2120. buf[written] = '\0';
  2121. else
  2122. return -1;
  2123. return (int)written;
  2124. }
  2125. /** Create a new exit policy summary, initially only with a single
  2126. * port 1-64k item */
  2127. /* XXXX This entire thing will do most stuff in O(N^2), or worse. Use an
  2128. * RB-tree if that turns out to matter. */
  2129. static smartlist_t *
  2130. policy_summary_create(void)
  2131. {
  2132. smartlist_t *summary;
  2133. policy_summary_item_t* item;
  2134. item = tor_malloc_zero(sizeof(policy_summary_item_t));
  2135. item->prt_min = 1;
  2136. item->prt_max = 65535;
  2137. item->reject_count = 0;
  2138. item->accepted = 0;
  2139. summary = smartlist_new();
  2140. smartlist_add(summary, item);
  2141. return summary;
  2142. }
  2143. /** Split the summary item in <b>item</b> at the port <b>new_starts</b>.
  2144. * The current item is changed to end at new-starts - 1, the new item
  2145. * copies reject_count and accepted from the old item,
  2146. * starts at new_starts and ends at the port where the original item
  2147. * previously ended.
  2148. */
  2149. static policy_summary_item_t*
  2150. policy_summary_item_split(policy_summary_item_t* old, uint16_t new_starts)
  2151. {
  2152. policy_summary_item_t* new;
  2153. new = tor_malloc_zero(sizeof(policy_summary_item_t));
  2154. new->prt_min = new_starts;
  2155. new->prt_max = old->prt_max;
  2156. new->reject_count = old->reject_count;
  2157. new->accepted = old->accepted;
  2158. old->prt_max = new_starts-1;
  2159. tor_assert(old->prt_min <= old->prt_max);
  2160. tor_assert(new->prt_min <= new->prt_max);
  2161. return new;
  2162. }
  2163. /* XXXX Nick says I'm going to hell for this. If he feels charitably towards
  2164. * my immortal soul, he can clean it up himself. */
  2165. #define AT(x) ((policy_summary_item_t*)smartlist_get(summary, x))
  2166. #define IPV4_BITS (32)
  2167. /* Every IPv4 address is counted as one rejection */
  2168. #define REJECT_CUTOFF_SCALE_IPV4 (0)
  2169. /* Ports are rejected in an IPv4 summary if they are rejected in more than two
  2170. * IPv4 /8 address blocks */
  2171. #define REJECT_CUTOFF_COUNT_IPV4 (U64_LITERAL(1) << \
  2172. (IPV4_BITS - REJECT_CUTOFF_SCALE_IPV4 - 7))
  2173. #define IPV6_BITS (128)
  2174. /* IPv6 /64s are counted as one rejection, anything smaller is ignored */
  2175. #define REJECT_CUTOFF_SCALE_IPV6 (64)
  2176. /* Ports are rejected in an IPv6 summary if they are rejected in more than one
  2177. * IPv6 /16 address block.
  2178. * This is roughly equivalent to the IPv4 cutoff, as only five IPv6 /12s (and
  2179. * some scattered smaller blocks) have been allocated to the RIRs.
  2180. * Network providers are typically allocated one or more IPv6 /32s.
  2181. */
  2182. #define REJECT_CUTOFF_COUNT_IPV6 (U64_LITERAL(1) << \
  2183. (IPV6_BITS - REJECT_CUTOFF_SCALE_IPV6 - 16))
  2184. /** Split an exit policy summary so that prt_min and prt_max
  2185. * fall at exactly the start and end of an item respectively.
  2186. */
  2187. static int
  2188. policy_summary_split(smartlist_t *summary,
  2189. uint16_t prt_min, uint16_t prt_max)
  2190. {
  2191. int start_at_index;
  2192. int i = 0;
  2193. while (AT(i)->prt_max < prt_min)
  2194. i++;
  2195. if (AT(i)->prt_min != prt_min) {
  2196. policy_summary_item_t* new_item;
  2197. new_item = policy_summary_item_split(AT(i), prt_min);
  2198. smartlist_insert(summary, i+1, new_item);
  2199. i++;
  2200. }
  2201. start_at_index = i;
  2202. while (AT(i)->prt_max < prt_max)
  2203. i++;
  2204. if (AT(i)->prt_max != prt_max) {
  2205. policy_summary_item_t* new_item;
  2206. new_item = policy_summary_item_split(AT(i), prt_max+1);
  2207. smartlist_insert(summary, i+1, new_item);
  2208. }
  2209. return start_at_index;
  2210. }
  2211. /** Mark port ranges as accepted if they are below the reject_count for family
  2212. */
  2213. static void
  2214. policy_summary_accept(smartlist_t *summary,
  2215. uint16_t prt_min, uint16_t prt_max,
  2216. sa_family_t family)
  2217. {
  2218. tor_assert_nonfatal_once(family == AF_INET || family == AF_INET6);
  2219. uint64_t family_reject_count = ((family == AF_INET) ?
  2220. REJECT_CUTOFF_COUNT_IPV4 :
  2221. REJECT_CUTOFF_COUNT_IPV6);
  2222. int i = policy_summary_split(summary, prt_min, prt_max);
  2223. while (i < smartlist_len(summary) &&
  2224. AT(i)->prt_max <= prt_max) {
  2225. if (!AT(i)->accepted &&
  2226. AT(i)->reject_count <= family_reject_count)
  2227. AT(i)->accepted = 1;
  2228. i++;
  2229. }
  2230. tor_assert(i < smartlist_len(summary) || prt_max==65535);
  2231. }
  2232. /** Count the number of addresses in a network in family with prefixlen
  2233. * maskbits against the given portrange. */
  2234. static void
  2235. policy_summary_reject(smartlist_t *summary,
  2236. maskbits_t maskbits,
  2237. uint16_t prt_min, uint16_t prt_max,
  2238. sa_family_t family)
  2239. {
  2240. tor_assert_nonfatal_once(family == AF_INET || family == AF_INET6);
  2241. int i = policy_summary_split(summary, prt_min, prt_max);
  2242. /* The length of a single address mask */
  2243. int addrbits = (family == AF_INET) ? IPV4_BITS : IPV6_BITS;
  2244. tor_assert_nonfatal_once(addrbits >= maskbits);
  2245. /* We divide IPv6 address counts by (1 << scale) to keep them in a uint64_t
  2246. */
  2247. int scale = ((family == AF_INET) ?
  2248. REJECT_CUTOFF_SCALE_IPV4 :
  2249. REJECT_CUTOFF_SCALE_IPV6);
  2250. tor_assert_nonfatal_once(addrbits >= scale);
  2251. if (maskbits > (addrbits - scale)) {
  2252. tor_assert_nonfatal_once(family == AF_INET6);
  2253. /* The address range is so small, we'd need billions of them to reach the
  2254. * rejection limit. So we ignore this range in the reject count. */
  2255. return;
  2256. }
  2257. uint64_t count = 0;
  2258. if (addrbits - scale - maskbits >= 64) {
  2259. tor_assert_nonfatal_once(family == AF_INET6);
  2260. /* The address range is so large, it's an automatic rejection for all ports
  2261. * in the range. */
  2262. count = UINT64_MAX;
  2263. } else {
  2264. count = (U64_LITERAL(1) << (addrbits - scale - maskbits));
  2265. }
  2266. tor_assert_nonfatal_once(count > 0);
  2267. while (i < smartlist_len(summary) &&
  2268. AT(i)->prt_max <= prt_max) {
  2269. if (AT(i)->reject_count <= UINT64_MAX - count) {
  2270. AT(i)->reject_count += count;
  2271. } else {
  2272. /* IPv4 would require a 4-billion address redundant policy to get here,
  2273. * but IPv6 just needs to have ::/0 */
  2274. if (family == AF_INET) {
  2275. tor_assert_nonfatal_unreached_once();
  2276. }
  2277. /* If we do get here, use saturating arithmetic */
  2278. AT(i)->reject_count = UINT64_MAX;
  2279. }
  2280. i++;
  2281. }
  2282. tor_assert(i < smartlist_len(summary) || prt_max==65535);
  2283. }
  2284. /** Add a single exit policy item to our summary:
  2285. *
  2286. * If it is an accept, ignore it unless it is for all IP addresses
  2287. * ("*", i.e. its prefixlen/maskbits is 0). Otherwise call
  2288. * policy_summary_accept().
  2289. *
  2290. * If it is a reject, ignore it if it is about one of the private
  2291. * networks. Otherwise call policy_summary_reject().
  2292. */
  2293. static void
  2294. policy_summary_add_item(smartlist_t *summary, addr_policy_t *p)
  2295. {
  2296. if (p->policy_type == ADDR_POLICY_ACCEPT) {
  2297. if (p->maskbits == 0) {
  2298. policy_summary_accept(summary, p->prt_min, p->prt_max, p->addr.family);
  2299. }
  2300. } else if (p->policy_type == ADDR_POLICY_REJECT) {
  2301. int is_private = 0;
  2302. int i;
  2303. for (i = 0; private_nets[i]; ++i) {
  2304. tor_addr_t addr;
  2305. maskbits_t maskbits;
  2306. if (tor_addr_parse_mask_ports(private_nets[i], 0, &addr,
  2307. &maskbits, NULL, NULL)<0) {
  2308. tor_assert(0);
  2309. }
  2310. if (tor_addr_compare(&p->addr, &addr, CMP_EXACT) == 0 &&
  2311. p->maskbits == maskbits) {
  2312. is_private = 1;
  2313. break;
  2314. }
  2315. }
  2316. if (!is_private) {
  2317. policy_summary_reject(summary, p->maskbits, p->prt_min, p->prt_max,
  2318. p->addr.family);
  2319. }
  2320. } else
  2321. tor_assert(0);
  2322. }
  2323. /** Create a string representing a summary for an exit policy.
  2324. * The summary will either be an "accept" plus a comma-separated list of port
  2325. * ranges or a "reject" plus port-ranges, depending on which is shorter.
  2326. *
  2327. * If no exits are allowed at all then "reject 1-65535" is returned. If no
  2328. * ports are blocked instead of "reject " we return "accept 1-65535". (These
  2329. * are an exception to the shorter-representation-wins rule).
  2330. */
  2331. char *
  2332. policy_summarize(smartlist_t *policy, sa_family_t family)
  2333. {
  2334. smartlist_t *summary = policy_summary_create();
  2335. smartlist_t *accepts, *rejects;
  2336. int i, last, start_prt;
  2337. size_t accepts_len, rejects_len;
  2338. char *accepts_str = NULL, *rejects_str = NULL, *shorter_str, *result;
  2339. const char *prefix;
  2340. tor_assert(policy);
  2341. /* Create the summary list */
  2342. SMARTLIST_FOREACH_BEGIN(policy, addr_policy_t *, p) {
  2343. sa_family_t f = tor_addr_family(&p->addr);
  2344. if (f != AF_INET && f != AF_INET6) {
  2345. log_warn(LD_BUG, "Weird family when summarizing address policy");
  2346. }
  2347. if (f != family)
  2348. continue;
  2349. policy_summary_add_item(summary, p);
  2350. } SMARTLIST_FOREACH_END(p);
  2351. /* Now create two lists of strings, one for accepted and one
  2352. * for rejected ports. We take care to merge ranges so that
  2353. * we avoid getting stuff like "1-4,5-9,10", instead we want
  2354. * "1-10"
  2355. */
  2356. i = 0;
  2357. start_prt = 1;
  2358. accepts = smartlist_new();
  2359. rejects = smartlist_new();
  2360. while (1) {
  2361. last = i == smartlist_len(summary)-1;
  2362. if (last ||
  2363. AT(i)->accepted != AT(i+1)->accepted) {
  2364. char buf[POLICY_BUF_LEN];
  2365. if (start_prt == AT(i)->prt_max)
  2366. tor_snprintf(buf, sizeof(buf), "%d", start_prt);
  2367. else
  2368. tor_snprintf(buf, sizeof(buf), "%d-%d", start_prt, AT(i)->prt_max);
  2369. if (AT(i)->accepted)
  2370. smartlist_add_strdup(accepts, buf);
  2371. else
  2372. smartlist_add_strdup(rejects, buf);
  2373. if (last)
  2374. break;
  2375. start_prt = AT(i+1)->prt_min;
  2376. };
  2377. i++;
  2378. };
  2379. /* Figure out which of the two stringlists will be shorter and use
  2380. * that to build the result
  2381. */
  2382. if (smartlist_len(accepts) == 0) { /* no exits at all */
  2383. result = tor_strdup("reject 1-65535");
  2384. goto cleanup;
  2385. }
  2386. if (smartlist_len(rejects) == 0) { /* no rejects at all */
  2387. result = tor_strdup("accept 1-65535");
  2388. goto cleanup;
  2389. }
  2390. accepts_str = smartlist_join_strings(accepts, ",", 0, &accepts_len);
  2391. rejects_str = smartlist_join_strings(rejects, ",", 0, &rejects_len);
  2392. if (rejects_len > MAX_EXITPOLICY_SUMMARY_LEN-strlen("reject")-1 &&
  2393. accepts_len > MAX_EXITPOLICY_SUMMARY_LEN-strlen("accept")-1) {
  2394. char *c;
  2395. shorter_str = accepts_str;
  2396. prefix = "accept";
  2397. c = shorter_str + (MAX_EXITPOLICY_SUMMARY_LEN-strlen(prefix)-1);
  2398. while (*c != ',' && c >= shorter_str)
  2399. c--;
  2400. tor_assert(c >= shorter_str);
  2401. tor_assert(*c == ',');
  2402. *c = '\0';
  2403. } else if (rejects_len < accepts_len) {
  2404. shorter_str = rejects_str;
  2405. prefix = "reject";
  2406. } else {
  2407. shorter_str = accepts_str;
  2408. prefix = "accept";
  2409. }
  2410. tor_asprintf(&result, "%s %s", prefix, shorter_str);
  2411. cleanup:
  2412. /* cleanup */
  2413. SMARTLIST_FOREACH(summary, policy_summary_item_t *, s, tor_free(s));
  2414. smartlist_free(summary);
  2415. tor_free(accepts_str);
  2416. SMARTLIST_FOREACH(accepts, char *, s, tor_free(s));
  2417. smartlist_free(accepts);
  2418. tor_free(rejects_str);
  2419. SMARTLIST_FOREACH(rejects, char *, s, tor_free(s));
  2420. smartlist_free(rejects);
  2421. return result;
  2422. }
  2423. /** Convert a summarized policy string into a short_policy_t. Return NULL
  2424. * if the string is not well-formed. */
  2425. short_policy_t *
  2426. parse_short_policy(const char *summary)
  2427. {
  2428. const char *orig_summary = summary;
  2429. short_policy_t *result;
  2430. int is_accept;
  2431. int n_entries;
  2432. short_policy_entry_t entries[MAX_EXITPOLICY_SUMMARY_LEN]; /* overkill */
  2433. const char *next;
  2434. if (!strcmpstart(summary, "accept ")) {
  2435. is_accept = 1;
  2436. summary += strlen("accept ");
  2437. } else if (!strcmpstart(summary, "reject ")) {
  2438. is_accept = 0;
  2439. summary += strlen("reject ");
  2440. } else {
  2441. log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Unrecognized policy summary keyword");
  2442. return NULL;
  2443. }
  2444. n_entries = 0;
  2445. for ( ; *summary; summary = next) {
  2446. const char *comma = strchr(summary, ',');
  2447. unsigned low, high;
  2448. char dummy;
  2449. char ent_buf[32];
  2450. size_t len;
  2451. next = comma ? comma+1 : strchr(summary, '\0');
  2452. len = comma ? (size_t)(comma - summary) : strlen(summary);
  2453. if (n_entries == MAX_EXITPOLICY_SUMMARY_LEN) {
  2454. log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Impossibly long policy summary %s",
  2455. escaped(orig_summary));
  2456. return NULL;
  2457. }
  2458. if (! TOR_ISDIGIT(*summary) || len > (sizeof(ent_buf)-1)) {
  2459. /* unrecognized entry format. skip it. */
  2460. continue;
  2461. }
  2462. if (len < 1) {
  2463. /* empty; skip it. */
  2464. /* XXX This happens to be unreachable, since if len==0, then *summary is
  2465. * ',' or '\0', and the TOR_ISDIGIT test above would have failed. */
  2466. continue;
  2467. }
  2468. memcpy(ent_buf, summary, len);
  2469. ent_buf[len] = '\0';
  2470. if (tor_sscanf(ent_buf, "%u-%u%c", &low, &high, &dummy) == 2) {
  2471. if (low<1 || low>65535 || high<1 || high>65535 || low>high) {
  2472. log_fn(LOG_PROTOCOL_WARN, LD_DIR,
  2473. "Found bad entry in policy summary %s", escaped(orig_summary));
  2474. return NULL;
  2475. }
  2476. } else if (tor_sscanf(ent_buf, "%u%c", &low, &dummy) == 1) {
  2477. if (low<1 || low>65535) {
  2478. log_fn(LOG_PROTOCOL_WARN, LD_DIR,
  2479. "Found bad entry in policy summary %s", escaped(orig_summary));
  2480. return NULL;
  2481. }
  2482. high = low;
  2483. } else {
  2484. log_fn(LOG_PROTOCOL_WARN, LD_DIR,"Found bad entry in policy summary %s",
  2485. escaped(orig_summary));
  2486. return NULL;
  2487. }
  2488. entries[n_entries].min_port = low;
  2489. entries[n_entries].max_port = high;
  2490. n_entries++;
  2491. }
  2492. if (n_entries == 0) {
  2493. log_fn(LOG_PROTOCOL_WARN, LD_DIR,
  2494. "Found no port-range entries in summary %s", escaped(orig_summary));
  2495. return NULL;
  2496. }
  2497. {
  2498. size_t size = offsetof(short_policy_t, entries) +
  2499. sizeof(short_policy_entry_t)*(n_entries);
  2500. result = tor_malloc_zero(size);
  2501. tor_assert( (char*)&result->entries[n_entries-1] < ((char*)result)+size);
  2502. }
  2503. result->is_accept = is_accept;
  2504. result->n_entries = n_entries;
  2505. memcpy(result->entries, entries, sizeof(short_policy_entry_t)*n_entries);
  2506. return result;
  2507. }
  2508. /** Write <b>policy</b> back out into a string. */
  2509. char *
  2510. write_short_policy(const short_policy_t *policy)
  2511. {
  2512. int i;
  2513. char *answer;
  2514. smartlist_t *sl = smartlist_new();
  2515. smartlist_add_asprintf(sl, "%s", policy->is_accept ? "accept " : "reject ");
  2516. for (i=0; i < policy->n_entries; i++) {
  2517. const short_policy_entry_t *e = &policy->entries[i];
  2518. if (e->min_port == e->max_port) {
  2519. smartlist_add_asprintf(sl, "%d", e->min_port);
  2520. } else {
  2521. smartlist_add_asprintf(sl, "%d-%d", e->min_port, e->max_port);
  2522. }
  2523. if (i < policy->n_entries-1)
  2524. smartlist_add_strdup(sl, ",");
  2525. }
  2526. answer = smartlist_join_strings(sl, "", 0, NULL);
  2527. SMARTLIST_FOREACH(sl, char *, a, tor_free(a));
  2528. smartlist_free(sl);
  2529. return answer;
  2530. }
  2531. /** Release all storage held in <b>policy</b>. */
  2532. void
  2533. short_policy_free_(short_policy_t *policy)
  2534. {
  2535. tor_free(policy);
  2536. }
  2537. /** See whether the <b>addr</b>:<b>port</b> address is likely to be accepted
  2538. * or rejected by the summarized policy <b>policy</b>. Return values are as
  2539. * for compare_tor_addr_to_addr_policy. Unlike the regular addr_policy
  2540. * functions, requires the <b>port</b> be specified. */
  2541. addr_policy_result_t
  2542. compare_tor_addr_to_short_policy(const tor_addr_t *addr, uint16_t port,
  2543. const short_policy_t *policy)
  2544. {
  2545. int i;
  2546. int found_match = 0;
  2547. int accept_;
  2548. tor_assert(port != 0);
  2549. if (addr && tor_addr_is_null(addr))
  2550. addr = NULL; /* Unspec means 'no address at all,' in this context. */
  2551. if (addr && get_options()->ClientRejectInternalAddresses &&
  2552. (tor_addr_is_internal(addr, 0) || tor_addr_is_loopback(addr)))
  2553. return ADDR_POLICY_REJECTED;
  2554. for (i=0; i < policy->n_entries; ++i) {
  2555. const short_policy_entry_t *e = &policy->entries[i];
  2556. if (e->min_port <= port && port <= e->max_port) {
  2557. found_match = 1;
  2558. break;
  2559. }
  2560. }
  2561. if (found_match)
  2562. accept_ = policy->is_accept;
  2563. else
  2564. accept_ = ! policy->is_accept;
  2565. /* ???? are these right? -NM */
  2566. /* We should be sure not to return ADDR_POLICY_ACCEPTED in the accept
  2567. * case here, because it would cause clients to believe that the node
  2568. * allows exit enclaving. Trying it anyway would open up a cool attack
  2569. * where the node refuses due to exitpolicy, the client reacts in
  2570. * surprise by rewriting the node's exitpolicy to reject *:*, and then
  2571. * an adversary targets users by causing them to attempt such connections
  2572. * to 98% of the exits.
  2573. *
  2574. * Once microdescriptors can handle addresses in special cases (e.g. if
  2575. * we ever solve ticket 1774), we can provide certainty here. -RD */
  2576. if (accept_)
  2577. return ADDR_POLICY_PROBABLY_ACCEPTED;
  2578. else
  2579. return ADDR_POLICY_REJECTED;
  2580. }
  2581. /** Return true iff <b>policy</b> seems reject all ports */
  2582. int
  2583. short_policy_is_reject_star(const short_policy_t *policy)
  2584. {
  2585. /* This doesn't need to be as much on the lookout as policy_is_reject_star,
  2586. * since policy summaries are from the consensus or from consensus
  2587. * microdescs.
  2588. */
  2589. tor_assert(policy);
  2590. /* Check for an exact match of "reject 1-65535". */
  2591. return (policy->is_accept == 0 && policy->n_entries == 1 &&
  2592. policy->entries[0].min_port == 1 &&
  2593. policy->entries[0].max_port == 65535);
  2594. }
  2595. /** Decide whether addr:port is probably or definitely accepted or rejected by
  2596. * <b>node</b>. See compare_tor_addr_to_addr_policy for details on addr/port
  2597. * interpretation. */
  2598. addr_policy_result_t
  2599. compare_tor_addr_to_node_policy(const tor_addr_t *addr, uint16_t port,
  2600. const node_t *node)
  2601. {
  2602. if (node->rejects_all)
  2603. return ADDR_POLICY_REJECTED;
  2604. if (addr && tor_addr_family(addr) == AF_INET6) {
  2605. const short_policy_t *p = NULL;
  2606. if (node->ri)
  2607. p = node->ri->ipv6_exit_policy;
  2608. else if (node->md)
  2609. p = node->md->ipv6_exit_policy;
  2610. if (p)
  2611. return compare_tor_addr_to_short_policy(addr, port, p);
  2612. else
  2613. return ADDR_POLICY_REJECTED;
  2614. }
  2615. if (node->ri) {
  2616. return compare_tor_addr_to_addr_policy(addr, port, node->ri->exit_policy);
  2617. } else if (node->md) {
  2618. if (node->md->exit_policy == NULL)
  2619. return ADDR_POLICY_REJECTED;
  2620. else
  2621. return compare_tor_addr_to_short_policy(addr, port,
  2622. node->md->exit_policy);
  2623. } else {
  2624. return ADDR_POLICY_PROBABLY_REJECTED;
  2625. }
  2626. }
  2627. /**
  2628. * Given <b>policy_list</b>, a list of addr_policy_t, produce a string
  2629. * representation of the list.
  2630. * If <b>include_ipv4</b> is true, include IPv4 entries.
  2631. * If <b>include_ipv6</b> is true, include IPv6 entries.
  2632. */
  2633. char *
  2634. policy_dump_to_string(const smartlist_t *policy_list,
  2635. int include_ipv4,
  2636. int include_ipv6)
  2637. {
  2638. smartlist_t *policy_string_list;
  2639. char *policy_string = NULL;
  2640. policy_string_list = smartlist_new();
  2641. SMARTLIST_FOREACH_BEGIN(policy_list, addr_policy_t *, tmpe) {
  2642. char *pbuf;
  2643. int bytes_written_to_pbuf;
  2644. if ((tor_addr_family(&tmpe->addr) == AF_INET6) && (!include_ipv6)) {
  2645. continue; /* Don't include IPv6 parts of address policy */
  2646. }
  2647. if ((tor_addr_family(&tmpe->addr) == AF_INET) && (!include_ipv4)) {
  2648. continue; /* Don't include IPv4 parts of address policy */
  2649. }
  2650. pbuf = tor_malloc(POLICY_BUF_LEN);
  2651. bytes_written_to_pbuf = policy_write_item(pbuf,POLICY_BUF_LEN, tmpe, 1);
  2652. if (bytes_written_to_pbuf < 0) {
  2653. log_warn(LD_BUG, "policy_dump_to_string ran out of room!");
  2654. tor_free(pbuf);
  2655. goto done;
  2656. }
  2657. smartlist_add(policy_string_list,pbuf);
  2658. } SMARTLIST_FOREACH_END(tmpe);
  2659. policy_string = smartlist_join_strings(policy_string_list, "\n", 0, NULL);
  2660. done:
  2661. SMARTLIST_FOREACH(policy_string_list, char *, str, tor_free(str));
  2662. smartlist_free(policy_string_list);
  2663. return policy_string;
  2664. }
  2665. /** Implementation for GETINFO control command: knows the answer for questions
  2666. * about "exit-policy/..." */
  2667. int
  2668. getinfo_helper_policies(control_connection_t *conn,
  2669. const char *question, char **answer,
  2670. const char **errmsg)
  2671. {
  2672. (void) conn;
  2673. (void) errmsg;
  2674. if (!strcmp(question, "exit-policy/default")) {
  2675. *answer = tor_strdup(DEFAULT_EXIT_POLICY);
  2676. } else if (!strcmp(question, "exit-policy/reject-private/default")) {
  2677. smartlist_t *private_policy_strings;
  2678. const char **priv = private_nets;
  2679. private_policy_strings = smartlist_new();
  2680. while (*priv != NULL) {
  2681. /* IPv6 addresses are in "[]" and contain ":",
  2682. * IPv4 addresses are not in "[]" and contain "." */
  2683. smartlist_add_asprintf(private_policy_strings, "reject %s:*", *priv);
  2684. priv++;
  2685. }
  2686. *answer = smartlist_join_strings(private_policy_strings,
  2687. ",", 0, NULL);
  2688. SMARTLIST_FOREACH(private_policy_strings, char *, str, tor_free(str));
  2689. smartlist_free(private_policy_strings);
  2690. } else if (!strcmp(question, "exit-policy/reject-private/relay")) {
  2691. const or_options_t *options = get_options();
  2692. const routerinfo_t *me = router_get_my_routerinfo();
  2693. if (!me) {
  2694. *errmsg = "router_get_my_routerinfo returned NULL";
  2695. return -1;
  2696. }
  2697. if (!options->ExitPolicyRejectPrivate &&
  2698. !options->ExitPolicyRejectLocalInterfaces) {
  2699. *answer = tor_strdup("");
  2700. return 0;
  2701. }
  2702. smartlist_t *private_policy_list = smartlist_new();
  2703. smartlist_t *configured_addresses = smartlist_new();
  2704. /* Copy the configured addresses into the tor_addr_t* list */
  2705. if (options->ExitPolicyRejectPrivate) {
  2706. policies_copy_ipv4h_to_smartlist(configured_addresses, me->addr);
  2707. policies_copy_addr_to_smartlist(configured_addresses, &me->ipv6_addr);
  2708. }
  2709. if (options->ExitPolicyRejectLocalInterfaces) {
  2710. policies_copy_outbound_addresses_to_smartlist(configured_addresses,
  2711. options);
  2712. }
  2713. policies_parse_exit_policy_reject_private(
  2714. &private_policy_list,
  2715. options->IPv6Exit,
  2716. configured_addresses,
  2717. options->ExitPolicyRejectLocalInterfaces,
  2718. options->ExitPolicyRejectLocalInterfaces);
  2719. *answer = policy_dump_to_string(private_policy_list, 1, 1);
  2720. addr_policy_list_free(private_policy_list);
  2721. SMARTLIST_FOREACH(configured_addresses, tor_addr_t *, a, tor_free(a));
  2722. smartlist_free(configured_addresses);
  2723. } else if (!strcmpstart(question, "exit-policy/")) {
  2724. const routerinfo_t *me = router_get_my_routerinfo();
  2725. int include_ipv4 = 0;
  2726. int include_ipv6 = 0;
  2727. if (!strcmp(question, "exit-policy/ipv4")) {
  2728. include_ipv4 = 1;
  2729. } else if (!strcmp(question, "exit-policy/ipv6")) {
  2730. include_ipv6 = 1;
  2731. } else if (!strcmp(question, "exit-policy/full")) {
  2732. include_ipv4 = include_ipv6 = 1;
  2733. } else {
  2734. return 0; /* No such key. */
  2735. }
  2736. if (!me) {
  2737. *errmsg = "router_get_my_routerinfo returned NULL";
  2738. return -1;
  2739. }
  2740. *answer = router_dump_exit_policy_to_string(me,include_ipv4,include_ipv6);
  2741. }
  2742. return 0;
  2743. }
  2744. /** Release all storage held by <b>p</b>. */
  2745. void
  2746. addr_policy_list_free_(smartlist_t *lst)
  2747. {
  2748. if (!lst)
  2749. return;
  2750. SMARTLIST_FOREACH(lst, addr_policy_t *, policy, addr_policy_free(policy));
  2751. smartlist_free(lst);
  2752. }
  2753. /** Release all storage held by <b>p</b>. */
  2754. void
  2755. addr_policy_free_(addr_policy_t *p)
  2756. {
  2757. if (!p)
  2758. return;
  2759. if (--p->refcnt <= 0) {
  2760. if (p->is_canonical) {
  2761. policy_map_ent_t search, *found;
  2762. search.policy = p;
  2763. found = HT_REMOVE(policy_map, &policy_root, &search);
  2764. if (found) {
  2765. tor_assert(p == found->policy);
  2766. tor_free(found);
  2767. }
  2768. }
  2769. tor_free(p);
  2770. }
  2771. }
  2772. /** Release all storage held by policy variables. */
  2773. void
  2774. policies_free_all(void)
  2775. {
  2776. addr_policy_list_free(reachable_or_addr_policy);
  2777. reachable_or_addr_policy = NULL;
  2778. addr_policy_list_free(reachable_dir_addr_policy);
  2779. reachable_dir_addr_policy = NULL;
  2780. addr_policy_list_free(socks_policy);
  2781. socks_policy = NULL;
  2782. addr_policy_list_free(dir_policy);
  2783. dir_policy = NULL;
  2784. addr_policy_list_free(authdir_reject_policy);
  2785. authdir_reject_policy = NULL;
  2786. addr_policy_list_free(authdir_invalid_policy);
  2787. authdir_invalid_policy = NULL;
  2788. addr_policy_list_free(authdir_badexit_policy);
  2789. authdir_badexit_policy = NULL;
  2790. if (!HT_EMPTY(&policy_root)) {
  2791. policy_map_ent_t **ent;
  2792. int n = 0;
  2793. char buf[POLICY_BUF_LEN];
  2794. log_warn(LD_MM, "Still had %d address policies cached at shutdown.",
  2795. (int)HT_SIZE(&policy_root));
  2796. /* Note the first 10 cached policies to try to figure out where they
  2797. * might be coming from. */
  2798. HT_FOREACH(ent, policy_map, &policy_root) {
  2799. if (++n > 10)
  2800. break;
  2801. if (policy_write_item(buf, sizeof(buf), (*ent)->policy, 0) >= 0)
  2802. log_warn(LD_MM," %d [%d]: %s", n, (*ent)->policy->refcnt, buf);
  2803. }
  2804. }
  2805. HT_CLEAR(policy_map, &policy_root);
  2806. }