relay.c 107 KB

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  1. /* Copyright (c) 2001 Matej Pfajfar.
  2. * Copyright (c) 2001-2004, Roger Dingledine.
  3. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
  4. * Copyright (c) 2007-2017, The Tor Project, Inc. */
  5. /* See LICENSE for licensing information */
  6. /**
  7. * \file relay.c
  8. * \brief Handle relay cell encryption/decryption, plus packaging and
  9. * receiving from circuits, plus queuing on circuits.
  10. *
  11. * This is a core modules that makes Tor work. It's responsible for
  12. * dealing with RELAY cells (the ones that travel more than one hop along a
  13. * circuit), by:
  14. * <ul>
  15. * <li>constructing relays cells,
  16. * <li>encrypting relay cells,
  17. * <li>decrypting relay cells,
  18. * <li>demultiplexing relay cells as they arrive on a connection,
  19. * <li>queueing relay cells for retransmission,
  20. * <li>or handling relay cells that are for us to receive (as an exit or a
  21. * client).
  22. * </ul>
  23. *
  24. * RELAY cells are generated throughout the code at the client or relay side,
  25. * using relay_send_command_from_edge() or one of the functions like
  26. * connection_edge_send_command() that calls it. Of particular interest is
  27. * connection_edge_package_raw_inbuf(), which takes information that has
  28. * arrived on an edge connection socket, and packages it as a RELAY_DATA cell
  29. * -- this is how information is actually sent across the Tor network. The
  30. * cryptography for these functions is handled deep in
  31. * circuit_package_relay_cell(), which either adds a single layer of
  32. * encryption (if we're an exit), or multiple layers (if we're the origin of
  33. * the circuit). After construction and encryption, the RELAY cells are
  34. * passed to append_cell_to_circuit_queue(), which queues them for
  35. * transmission and tells the circuitmux (see circuitmux.c) that the circuit
  36. * is waiting to send something.
  37. *
  38. * Incoming RELAY cells arrive at circuit_receive_relay_cell(), called from
  39. * command.c. There they are decrypted and, if they are for us, are passed to
  40. * connection_edge_process_relay_cell(). If they're not for us, they're
  41. * re-queued for retransmission again with append_cell_to_circuit_queue().
  42. *
  43. * The connection_edge_process_relay_cell() function handles all the different
  44. * types of relay cells, launching requests or transmitting data as needed.
  45. **/
  46. #define RELAY_PRIVATE
  47. #include "or.h"
  48. #include "addressmap.h"
  49. #include "buffers.h"
  50. #include "channel.h"
  51. #include "circpathbias.h"
  52. #include "circuitbuild.h"
  53. #include "circuitlist.h"
  54. #include "circuituse.h"
  55. #include "compress.h"
  56. #include "config.h"
  57. #include "connection.h"
  58. #include "connection_edge.h"
  59. #include "connection_or.h"
  60. #include "control.h"
  61. #include "geoip.h"
  62. #include "hs_cache.h"
  63. #include "main.h"
  64. #include "networkstatus.h"
  65. #include "nodelist.h"
  66. #include "onion.h"
  67. #include "policies.h"
  68. #include "reasons.h"
  69. #include "relay.h"
  70. #include "rendcache.h"
  71. #include "rendcommon.h"
  72. #include "router.h"
  73. #include "routerlist.h"
  74. #include "routerparse.h"
  75. #include "scheduler.h"
  76. static edge_connection_t *relay_lookup_conn(circuit_t *circ, cell_t *cell,
  77. cell_direction_t cell_direction,
  78. crypt_path_t *layer_hint);
  79. static int connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
  80. edge_connection_t *conn,
  81. crypt_path_t *layer_hint);
  82. static void circuit_consider_sending_sendme(circuit_t *circ,
  83. crypt_path_t *layer_hint);
  84. static void circuit_resume_edge_reading(circuit_t *circ,
  85. crypt_path_t *layer_hint);
  86. static int circuit_resume_edge_reading_helper(edge_connection_t *conn,
  87. circuit_t *circ,
  88. crypt_path_t *layer_hint);
  89. static int circuit_consider_stop_edge_reading(circuit_t *circ,
  90. crypt_path_t *layer_hint);
  91. static int circuit_queue_streams_are_blocked(circuit_t *circ);
  92. static void adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
  93. entry_connection_t *conn,
  94. node_t *node,
  95. const tor_addr_t *addr);
  96. #if 0
  97. static int get_max_middle_cells(void);
  98. #endif
  99. /** Stop reading on edge connections when we have this many cells
  100. * waiting on the appropriate queue. */
  101. #define CELL_QUEUE_HIGHWATER_SIZE 256
  102. /** Start reading from edge connections again when we get down to this many
  103. * cells. */
  104. #define CELL_QUEUE_LOWWATER_SIZE 64
  105. /** Stats: how many relay cells have originated at this hop, or have
  106. * been relayed onward (not recognized at this hop)?
  107. */
  108. uint64_t stats_n_relay_cells_relayed = 0;
  109. /** Stats: how many relay cells have been delivered to streams at this
  110. * hop?
  111. */
  112. uint64_t stats_n_relay_cells_delivered = 0;
  113. /** Used to tell which stream to read from first on a circuit. */
  114. static tor_weak_rng_t stream_choice_rng = TOR_WEAK_RNG_INIT;
  115. /** Update digest from the payload of cell. Assign integrity part to
  116. * cell.
  117. */
  118. static void
  119. relay_set_digest(crypto_digest_t *digest, cell_t *cell)
  120. {
  121. char integrity[4];
  122. relay_header_t rh;
  123. crypto_digest_add_bytes(digest, (char*)cell->payload, CELL_PAYLOAD_SIZE);
  124. crypto_digest_get_digest(digest, integrity, 4);
  125. // log_fn(LOG_DEBUG,"Putting digest of %u %u %u %u into relay cell.",
  126. // integrity[0], integrity[1], integrity[2], integrity[3]);
  127. relay_header_unpack(&rh, cell->payload);
  128. memcpy(rh.integrity, integrity, 4);
  129. relay_header_pack(cell->payload, &rh);
  130. }
  131. /** Does the digest for this circuit indicate that this cell is for us?
  132. *
  133. * Update digest from the payload of cell (with the integrity part set
  134. * to 0). If the integrity part is valid, return 1, else restore digest
  135. * and cell to their original state and return 0.
  136. */
  137. static int
  138. relay_digest_matches(crypto_digest_t *digest, cell_t *cell)
  139. {
  140. uint32_t received_integrity, calculated_integrity;
  141. relay_header_t rh;
  142. crypto_digest_t *backup_digest=NULL;
  143. backup_digest = crypto_digest_dup(digest);
  144. relay_header_unpack(&rh, cell->payload);
  145. memcpy(&received_integrity, rh.integrity, 4);
  146. memset(rh.integrity, 0, 4);
  147. relay_header_pack(cell->payload, &rh);
  148. // log_fn(LOG_DEBUG,"Reading digest of %u %u %u %u from relay cell.",
  149. // received_integrity[0], received_integrity[1],
  150. // received_integrity[2], received_integrity[3]);
  151. crypto_digest_add_bytes(digest, (char*) cell->payload, CELL_PAYLOAD_SIZE);
  152. crypto_digest_get_digest(digest, (char*) &calculated_integrity, 4);
  153. if (calculated_integrity != received_integrity) {
  154. // log_fn(LOG_INFO,"Recognized=0 but bad digest. Not recognizing.");
  155. // (%d vs %d).", received_integrity, calculated_integrity);
  156. /* restore digest to its old form */
  157. crypto_digest_assign(digest, backup_digest);
  158. /* restore the relay header */
  159. memcpy(rh.integrity, &received_integrity, 4);
  160. relay_header_pack(cell->payload, &rh);
  161. crypto_digest_free(backup_digest);
  162. return 0;
  163. }
  164. crypto_digest_free(backup_digest);
  165. return 1;
  166. }
  167. /** Apply <b>cipher</b> to CELL_PAYLOAD_SIZE bytes of <b>in</b>
  168. * (in place).
  169. *
  170. * If <b>encrypt_mode</b> is 1 then encrypt, else decrypt.
  171. *
  172. * Returns 0.
  173. */
  174. static int
  175. relay_crypt_one_payload(crypto_cipher_t *cipher, uint8_t *in,
  176. int encrypt_mode)
  177. {
  178. (void)encrypt_mode;
  179. crypto_cipher_crypt_inplace(cipher, (char*) in, CELL_PAYLOAD_SIZE);
  180. return 0;
  181. }
  182. /** Receive a relay cell:
  183. * - Crypt it (encrypt if headed toward the origin or if we <b>are</b> the
  184. * origin; decrypt if we're headed toward the exit).
  185. * - Check if recognized (if exitward).
  186. * - If recognized and the digest checks out, then find if there's a stream
  187. * that the cell is intended for, and deliver it to the right
  188. * connection_edge.
  189. * - If not recognized, then we need to relay it: append it to the appropriate
  190. * cell_queue on <b>circ</b>.
  191. *
  192. * Return -<b>reason</b> on failure.
  193. */
  194. int
  195. circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
  196. cell_direction_t cell_direction)
  197. {
  198. channel_t *chan = NULL;
  199. crypt_path_t *layer_hint=NULL;
  200. char recognized=0;
  201. int reason;
  202. tor_assert(cell);
  203. tor_assert(circ);
  204. tor_assert(cell_direction == CELL_DIRECTION_OUT ||
  205. cell_direction == CELL_DIRECTION_IN);
  206. if (circ->marked_for_close)
  207. return 0;
  208. if (relay_crypt(circ, cell, cell_direction, &layer_hint, &recognized) < 0) {
  209. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  210. "relay crypt failed. Dropping connection.");
  211. return -END_CIRC_REASON_INTERNAL;
  212. }
  213. if (recognized) {
  214. edge_connection_t *conn = NULL;
  215. if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
  216. pathbias_check_probe_response(circ, cell);
  217. /* We need to drop this cell no matter what to avoid code that expects
  218. * a certain purpose (such as the hidserv code). */
  219. return 0;
  220. }
  221. conn = relay_lookup_conn(circ, cell, cell_direction, layer_hint);
  222. if (cell_direction == CELL_DIRECTION_OUT) {
  223. ++stats_n_relay_cells_delivered;
  224. log_debug(LD_OR,"Sending away from origin.");
  225. if ((reason=connection_edge_process_relay_cell(cell, circ, conn, NULL))
  226. < 0) {
  227. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  228. "connection_edge_process_relay_cell (away from origin) "
  229. "failed.");
  230. return reason;
  231. }
  232. }
  233. if (cell_direction == CELL_DIRECTION_IN) {
  234. ++stats_n_relay_cells_delivered;
  235. log_debug(LD_OR,"Sending to origin.");
  236. if ((reason = connection_edge_process_relay_cell(cell, circ, conn,
  237. layer_hint)) < 0) {
  238. /* If a client is trying to connect to unknown hidden service port,
  239. * END_CIRC_AT_ORIGIN is sent back so we can then close the circuit.
  240. * Do not log warn as this is an expected behavior for a service. */
  241. if (reason != END_CIRC_AT_ORIGIN) {
  242. log_warn(LD_OR,
  243. "connection_edge_process_relay_cell (at origin) failed.");
  244. }
  245. return reason;
  246. }
  247. }
  248. return 0;
  249. }
  250. /* not recognized. pass it on. */
  251. if (cell_direction == CELL_DIRECTION_OUT) {
  252. cell->circ_id = circ->n_circ_id; /* switch it */
  253. chan = circ->n_chan;
  254. } else if (! CIRCUIT_IS_ORIGIN(circ)) {
  255. cell->circ_id = TO_OR_CIRCUIT(circ)->p_circ_id; /* switch it */
  256. chan = TO_OR_CIRCUIT(circ)->p_chan;
  257. } else {
  258. log_fn(LOG_PROTOCOL_WARN, LD_OR,
  259. "Dropping unrecognized inbound cell on origin circuit.");
  260. /* If we see unrecognized cells on path bias testing circs,
  261. * it's bad mojo. Those circuits need to die.
  262. * XXX: Shouldn't they always die? */
  263. if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
  264. TO_ORIGIN_CIRCUIT(circ)->path_state = PATH_STATE_USE_FAILED;
  265. return -END_CIRC_REASON_TORPROTOCOL;
  266. } else {
  267. return 0;
  268. }
  269. }
  270. if (!chan) {
  271. // XXXX Can this splice stuff be done more cleanly?
  272. if (! CIRCUIT_IS_ORIGIN(circ) &&
  273. TO_OR_CIRCUIT(circ)->rend_splice &&
  274. cell_direction == CELL_DIRECTION_OUT) {
  275. or_circuit_t *splice_ = TO_OR_CIRCUIT(circ)->rend_splice;
  276. tor_assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
  277. tor_assert(splice_->base_.purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
  278. cell->circ_id = splice_->p_circ_id;
  279. cell->command = CELL_RELAY; /* can't be relay_early anyway */
  280. if ((reason = circuit_receive_relay_cell(cell, TO_CIRCUIT(splice_),
  281. CELL_DIRECTION_IN)) < 0) {
  282. log_warn(LD_REND, "Error relaying cell across rendezvous; closing "
  283. "circuits");
  284. /* XXXX Do this here, or just return -1? */
  285. circuit_mark_for_close(circ, -reason);
  286. return reason;
  287. }
  288. return 0;
  289. }
  290. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  291. "Didn't recognize cell, but circ stops here! Closing circ.");
  292. return -END_CIRC_REASON_TORPROTOCOL;
  293. }
  294. log_debug(LD_OR,"Passing on unrecognized cell.");
  295. ++stats_n_relay_cells_relayed; /* XXXX no longer quite accurate {cells}
  296. * we might kill the circ before we relay
  297. * the cells. */
  298. append_cell_to_circuit_queue(circ, chan, cell, cell_direction, 0);
  299. return 0;
  300. }
  301. /** Do the appropriate en/decryptions for <b>cell</b> arriving on
  302. * <b>circ</b> in direction <b>cell_direction</b>.
  303. *
  304. * If cell_direction == CELL_DIRECTION_IN:
  305. * - If we're at the origin (we're the OP), for hops 1..N,
  306. * decrypt cell. If recognized, stop.
  307. * - Else (we're not the OP), encrypt one hop. Cell is not recognized.
  308. *
  309. * If cell_direction == CELL_DIRECTION_OUT:
  310. * - decrypt one hop. Check if recognized.
  311. *
  312. * If cell is recognized, set *recognized to 1, and set
  313. * *layer_hint to the hop that recognized it.
  314. *
  315. * Return -1 to indicate that we should mark the circuit for close,
  316. * else return 0.
  317. */
  318. int
  319. relay_crypt(circuit_t *circ, cell_t *cell, cell_direction_t cell_direction,
  320. crypt_path_t **layer_hint, char *recognized)
  321. {
  322. relay_header_t rh;
  323. tor_assert(circ);
  324. tor_assert(cell);
  325. tor_assert(recognized);
  326. tor_assert(cell_direction == CELL_DIRECTION_IN ||
  327. cell_direction == CELL_DIRECTION_OUT);
  328. if (cell_direction == CELL_DIRECTION_IN) {
  329. if (CIRCUIT_IS_ORIGIN(circ)) { /* We're at the beginning of the circuit.
  330. * We'll want to do layered decrypts. */
  331. crypt_path_t *thishop, *cpath = TO_ORIGIN_CIRCUIT(circ)->cpath;
  332. thishop = cpath;
  333. if (thishop->state != CPATH_STATE_OPEN) {
  334. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  335. "Relay cell before first created cell? Closing.");
  336. return -1;
  337. }
  338. do { /* Remember: cpath is in forward order, that is, first hop first. */
  339. tor_assert(thishop);
  340. if (relay_crypt_one_payload(thishop->b_crypto, cell->payload, 0) < 0)
  341. return -1;
  342. relay_header_unpack(&rh, cell->payload);
  343. if (rh.recognized == 0) {
  344. /* it's possibly recognized. have to check digest to be sure. */
  345. if (relay_digest_matches(thishop->b_digest, cell)) {
  346. *recognized = 1;
  347. *layer_hint = thishop;
  348. return 0;
  349. }
  350. }
  351. thishop = thishop->next;
  352. } while (thishop != cpath && thishop->state == CPATH_STATE_OPEN);
  353. log_fn(LOG_PROTOCOL_WARN, LD_OR,
  354. "Incoming cell at client not recognized. Closing.");
  355. return -1;
  356. } else { /* we're in the middle. Just one crypt. */
  357. if (relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->p_crypto,
  358. cell->payload, 1) < 0)
  359. return -1;
  360. // log_fn(LOG_DEBUG,"Skipping recognized check, because we're not "
  361. // "the client.");
  362. }
  363. } else /* cell_direction == CELL_DIRECTION_OUT */ {
  364. /* we're in the middle. Just one crypt. */
  365. if (relay_crypt_one_payload(TO_OR_CIRCUIT(circ)->n_crypto,
  366. cell->payload, 0) < 0)
  367. return -1;
  368. relay_header_unpack(&rh, cell->payload);
  369. if (rh.recognized == 0) {
  370. /* it's possibly recognized. have to check digest to be sure. */
  371. if (relay_digest_matches(TO_OR_CIRCUIT(circ)->n_digest, cell)) {
  372. *recognized = 1;
  373. return 0;
  374. }
  375. }
  376. }
  377. return 0;
  378. }
  379. /** Package a relay cell from an edge:
  380. * - Encrypt it to the right layer
  381. * - Append it to the appropriate cell_queue on <b>circ</b>.
  382. */
  383. static int
  384. circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
  385. cell_direction_t cell_direction,
  386. crypt_path_t *layer_hint, streamid_t on_stream,
  387. const char *filename, int lineno)
  388. {
  389. channel_t *chan; /* where to send the cell */
  390. if (cell_direction == CELL_DIRECTION_OUT) {
  391. crypt_path_t *thishop; /* counter for repeated crypts */
  392. chan = circ->n_chan;
  393. if (!chan) {
  394. log_warn(LD_BUG,"outgoing relay cell sent from %s:%d has n_chan==NULL."
  395. " Dropping.", filename, lineno);
  396. return 0; /* just drop it */
  397. }
  398. if (!CIRCUIT_IS_ORIGIN(circ)) {
  399. log_warn(LD_BUG,"outgoing relay cell sent from %s:%d on non-origin "
  400. "circ. Dropping.", filename, lineno);
  401. return 0; /* just drop it */
  402. }
  403. relay_set_digest(layer_hint->f_digest, cell);
  404. thishop = layer_hint;
  405. /* moving from farthest to nearest hop */
  406. do {
  407. tor_assert(thishop);
  408. /* XXXX RD This is a bug, right? */
  409. log_debug(LD_OR,"crypting a layer of the relay cell.");
  410. if (relay_crypt_one_payload(thishop->f_crypto, cell->payload, 1) < 0) {
  411. return -1;
  412. }
  413. thishop = thishop->prev;
  414. } while (thishop != TO_ORIGIN_CIRCUIT(circ)->cpath->prev);
  415. } else { /* incoming cell */
  416. or_circuit_t *or_circ;
  417. if (CIRCUIT_IS_ORIGIN(circ)) {
  418. /* We should never package an _incoming_ cell from the circuit
  419. * origin; that means we messed up somewhere. */
  420. log_warn(LD_BUG,"incoming relay cell at origin circuit. Dropping.");
  421. assert_circuit_ok(circ);
  422. return 0; /* just drop it */
  423. }
  424. or_circ = TO_OR_CIRCUIT(circ);
  425. chan = or_circ->p_chan;
  426. relay_set_digest(or_circ->p_digest, cell);
  427. if (relay_crypt_one_payload(or_circ->p_crypto, cell->payload, 1) < 0)
  428. return -1;
  429. }
  430. ++stats_n_relay_cells_relayed;
  431. append_cell_to_circuit_queue(circ, chan, cell, cell_direction, on_stream);
  432. return 0;
  433. }
  434. /** If cell's stream_id matches the stream_id of any conn that's
  435. * attached to circ, return that conn, else return NULL.
  436. */
  437. static edge_connection_t *
  438. relay_lookup_conn(circuit_t *circ, cell_t *cell,
  439. cell_direction_t cell_direction, crypt_path_t *layer_hint)
  440. {
  441. edge_connection_t *tmpconn;
  442. relay_header_t rh;
  443. relay_header_unpack(&rh, cell->payload);
  444. if (!rh.stream_id)
  445. return NULL;
  446. /* IN or OUT cells could have come from either direction, now
  447. * that we allow rendezvous *to* an OP.
  448. */
  449. if (CIRCUIT_IS_ORIGIN(circ)) {
  450. for (tmpconn = TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
  451. tmpconn=tmpconn->next_stream) {
  452. if (rh.stream_id == tmpconn->stream_id &&
  453. !tmpconn->base_.marked_for_close &&
  454. tmpconn->cpath_layer == layer_hint) {
  455. log_debug(LD_APP,"found conn for stream %d.", rh.stream_id);
  456. return tmpconn;
  457. }
  458. }
  459. } else {
  460. for (tmpconn = TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
  461. tmpconn=tmpconn->next_stream) {
  462. if (rh.stream_id == tmpconn->stream_id &&
  463. !tmpconn->base_.marked_for_close) {
  464. log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
  465. if (cell_direction == CELL_DIRECTION_OUT ||
  466. connection_edge_is_rendezvous_stream(tmpconn))
  467. return tmpconn;
  468. }
  469. }
  470. for (tmpconn = TO_OR_CIRCUIT(circ)->resolving_streams; tmpconn;
  471. tmpconn=tmpconn->next_stream) {
  472. if (rh.stream_id == tmpconn->stream_id &&
  473. !tmpconn->base_.marked_for_close) {
  474. log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
  475. return tmpconn;
  476. }
  477. }
  478. }
  479. return NULL; /* probably a begin relay cell */
  480. }
  481. /** Pack the relay_header_t host-order structure <b>src</b> into
  482. * network-order in the buffer <b>dest</b>. See tor-spec.txt for details
  483. * about the wire format.
  484. */
  485. void
  486. relay_header_pack(uint8_t *dest, const relay_header_t *src)
  487. {
  488. set_uint8(dest, src->command);
  489. set_uint16(dest+1, htons(src->recognized));
  490. set_uint16(dest+3, htons(src->stream_id));
  491. memcpy(dest+5, src->integrity, 4);
  492. set_uint16(dest+9, htons(src->length));
  493. }
  494. /** Unpack the network-order buffer <b>src</b> into a host-order
  495. * relay_header_t structure <b>dest</b>.
  496. */
  497. void
  498. relay_header_unpack(relay_header_t *dest, const uint8_t *src)
  499. {
  500. dest->command = get_uint8(src);
  501. dest->recognized = ntohs(get_uint16(src+1));
  502. dest->stream_id = ntohs(get_uint16(src+3));
  503. memcpy(dest->integrity, src+5, 4);
  504. dest->length = ntohs(get_uint16(src+9));
  505. }
  506. /** Convert the relay <b>command</b> into a human-readable string. */
  507. static const char *
  508. relay_command_to_string(uint8_t command)
  509. {
  510. static char buf[64];
  511. switch (command) {
  512. case RELAY_COMMAND_BEGIN: return "BEGIN";
  513. case RELAY_COMMAND_DATA: return "DATA";
  514. case RELAY_COMMAND_END: return "END";
  515. case RELAY_COMMAND_CONNECTED: return "CONNECTED";
  516. case RELAY_COMMAND_SENDME: return "SENDME";
  517. case RELAY_COMMAND_EXTEND: return "EXTEND";
  518. case RELAY_COMMAND_EXTENDED: return "EXTENDED";
  519. case RELAY_COMMAND_TRUNCATE: return "TRUNCATE";
  520. case RELAY_COMMAND_TRUNCATED: return "TRUNCATED";
  521. case RELAY_COMMAND_DROP: return "DROP";
  522. case RELAY_COMMAND_RESOLVE: return "RESOLVE";
  523. case RELAY_COMMAND_RESOLVED: return "RESOLVED";
  524. case RELAY_COMMAND_BEGIN_DIR: return "BEGIN_DIR";
  525. case RELAY_COMMAND_ESTABLISH_INTRO: return "ESTABLISH_INTRO";
  526. case RELAY_COMMAND_ESTABLISH_RENDEZVOUS: return "ESTABLISH_RENDEZVOUS";
  527. case RELAY_COMMAND_INTRODUCE1: return "INTRODUCE1";
  528. case RELAY_COMMAND_INTRODUCE2: return "INTRODUCE2";
  529. case RELAY_COMMAND_RENDEZVOUS1: return "RENDEZVOUS1";
  530. case RELAY_COMMAND_RENDEZVOUS2: return "RENDEZVOUS2";
  531. case RELAY_COMMAND_INTRO_ESTABLISHED: return "INTRO_ESTABLISHED";
  532. case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
  533. return "RENDEZVOUS_ESTABLISHED";
  534. case RELAY_COMMAND_INTRODUCE_ACK: return "INTRODUCE_ACK";
  535. case RELAY_COMMAND_EXTEND2: return "EXTEND2";
  536. case RELAY_COMMAND_EXTENDED2: return "EXTENDED2";
  537. default:
  538. tor_snprintf(buf, sizeof(buf), "Unrecognized relay command %u",
  539. (unsigned)command);
  540. return buf;
  541. }
  542. }
  543. /** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and send
  544. * it onto the open circuit <b>circ</b>. <b>stream_id</b> is the ID on
  545. * <b>circ</b> for the stream that's sending the relay cell, or 0 if it's a
  546. * control cell. <b>cpath_layer</b> is NULL for OR->OP cells, or the
  547. * destination hop for OP->OR cells.
  548. *
  549. * If you can't send the cell, mark the circuit for close and return -1. Else
  550. * return 0.
  551. */
  552. MOCK_IMPL(int,
  553. relay_send_command_from_edge_,(streamid_t stream_id, circuit_t *circ,
  554. uint8_t relay_command, const char *payload,
  555. size_t payload_len, crypt_path_t *cpath_layer,
  556. const char *filename, int lineno))
  557. {
  558. cell_t cell;
  559. relay_header_t rh;
  560. cell_direction_t cell_direction;
  561. /* XXXX NM Split this function into a separate versions per circuit type? */
  562. tor_assert(circ);
  563. tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
  564. memset(&cell, 0, sizeof(cell_t));
  565. cell.command = CELL_RELAY;
  566. if (CIRCUIT_IS_ORIGIN(circ)) {
  567. tor_assert(cpath_layer);
  568. cell.circ_id = circ->n_circ_id;
  569. cell_direction = CELL_DIRECTION_OUT;
  570. } else {
  571. tor_assert(! cpath_layer);
  572. cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
  573. cell_direction = CELL_DIRECTION_IN;
  574. }
  575. memset(&rh, 0, sizeof(rh));
  576. rh.command = relay_command;
  577. rh.stream_id = stream_id;
  578. rh.length = payload_len;
  579. relay_header_pack(cell.payload, &rh);
  580. if (payload_len)
  581. memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len);
  582. log_debug(LD_OR,"delivering %d cell %s.", relay_command,
  583. cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward");
  584. /* If we are sending an END cell and this circuit is used for a tunneled
  585. * directory request, advance its state. */
  586. if (relay_command == RELAY_COMMAND_END && circ->dirreq_id)
  587. geoip_change_dirreq_state(circ->dirreq_id, DIRREQ_TUNNELED,
  588. DIRREQ_END_CELL_SENT);
  589. if (cell_direction == CELL_DIRECTION_OUT && circ->n_chan) {
  590. /* if we're using relaybandwidthrate, this conn wants priority */
  591. channel_timestamp_client(circ->n_chan);
  592. }
  593. if (cell_direction == CELL_DIRECTION_OUT) {
  594. origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
  595. if (origin_circ->remaining_relay_early_cells > 0 &&
  596. (relay_command == RELAY_COMMAND_EXTEND ||
  597. relay_command == RELAY_COMMAND_EXTEND2 ||
  598. cpath_layer != origin_circ->cpath)) {
  599. /* If we've got any relay_early cells left and (we're sending
  600. * an extend cell or we're not talking to the first hop), use
  601. * one of them. Don't worry about the conn protocol version:
  602. * append_cell_to_circuit_queue will fix it up. */
  603. cell.command = CELL_RELAY_EARLY;
  604. --origin_circ->remaining_relay_early_cells;
  605. log_debug(LD_OR, "Sending a RELAY_EARLY cell; %d remaining.",
  606. (int)origin_circ->remaining_relay_early_cells);
  607. /* Memorize the command that is sent as RELAY_EARLY cell; helps debug
  608. * task 878. */
  609. origin_circ->relay_early_commands[
  610. origin_circ->relay_early_cells_sent++] = relay_command;
  611. } else if (relay_command == RELAY_COMMAND_EXTEND ||
  612. relay_command == RELAY_COMMAND_EXTEND2) {
  613. /* If no RELAY_EARLY cells can be sent over this circuit, log which
  614. * commands have been sent as RELAY_EARLY cells before; helps debug
  615. * task 878. */
  616. smartlist_t *commands_list = smartlist_new();
  617. int i = 0;
  618. char *commands = NULL;
  619. for (; i < origin_circ->relay_early_cells_sent; i++)
  620. smartlist_add(commands_list, (char *)
  621. relay_command_to_string(origin_circ->relay_early_commands[i]));
  622. commands = smartlist_join_strings(commands_list, ",", 0, NULL);
  623. log_warn(LD_BUG, "Uh-oh. We're sending a RELAY_COMMAND_EXTEND cell, "
  624. "but we have run out of RELAY_EARLY cells on that circuit. "
  625. "Commands sent before: %s", commands);
  626. tor_free(commands);
  627. smartlist_free(commands_list);
  628. }
  629. }
  630. if (circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer,
  631. stream_id, filename, lineno) < 0) {
  632. log_warn(LD_BUG,"circuit_package_relay_cell failed. Closing.");
  633. circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
  634. return -1;
  635. }
  636. return 0;
  637. }
  638. /** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and
  639. * send it onto the open circuit <b>circ</b>. <b>fromconn</b> is the stream
  640. * that's sending the relay cell, or NULL if it's a control cell.
  641. * <b>cpath_layer</b> is NULL for OR->OP cells, or the destination hop
  642. * for OP->OR cells.
  643. *
  644. * If you can't send the cell, mark the circuit for close and
  645. * return -1. Else return 0.
  646. */
  647. int
  648. connection_edge_send_command(edge_connection_t *fromconn,
  649. uint8_t relay_command, const char *payload,
  650. size_t payload_len)
  651. {
  652. /* XXXX NM Split this function into a separate versions per circuit type? */
  653. circuit_t *circ;
  654. crypt_path_t *cpath_layer = fromconn->cpath_layer;
  655. tor_assert(fromconn);
  656. circ = fromconn->on_circuit;
  657. if (fromconn->base_.marked_for_close) {
  658. log_warn(LD_BUG,
  659. "called on conn that's already marked for close at %s:%d.",
  660. fromconn->base_.marked_for_close_file,
  661. fromconn->base_.marked_for_close);
  662. return 0;
  663. }
  664. if (!circ) {
  665. if (fromconn->base_.type == CONN_TYPE_AP) {
  666. log_info(LD_APP,"no circ. Closing conn.");
  667. connection_mark_unattached_ap(EDGE_TO_ENTRY_CONN(fromconn),
  668. END_STREAM_REASON_INTERNAL);
  669. } else {
  670. log_info(LD_EXIT,"no circ. Closing conn.");
  671. fromconn->edge_has_sent_end = 1; /* no circ to send to */
  672. fromconn->end_reason = END_STREAM_REASON_INTERNAL;
  673. connection_mark_for_close(TO_CONN(fromconn));
  674. }
  675. return -1;
  676. }
  677. #ifdef MEASUREMENTS_21206
  678. /* Keep track of the number of RELAY_DATA cells sent for directory
  679. * connections. */
  680. connection_t *linked_conn = TO_CONN(fromconn)->linked_conn;
  681. if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
  682. ++(TO_DIR_CONN(linked_conn)->data_cells_sent);
  683. }
  684. #endif
  685. return relay_send_command_from_edge(fromconn->stream_id, circ,
  686. relay_command, payload,
  687. payload_len, cpath_layer);
  688. }
  689. /** How many times will I retry a stream that fails due to DNS
  690. * resolve failure or misc error?
  691. */
  692. #define MAX_RESOLVE_FAILURES 3
  693. /** Return 1 if reason is something that you should retry if you
  694. * get the end cell before you've connected; else return 0. */
  695. static int
  696. edge_reason_is_retriable(int reason)
  697. {
  698. return reason == END_STREAM_REASON_HIBERNATING ||
  699. reason == END_STREAM_REASON_RESOURCELIMIT ||
  700. reason == END_STREAM_REASON_EXITPOLICY ||
  701. reason == END_STREAM_REASON_RESOLVEFAILED ||
  702. reason == END_STREAM_REASON_MISC ||
  703. reason == END_STREAM_REASON_NOROUTE;
  704. }
  705. /** Called when we receive an END cell on a stream that isn't open yet,
  706. * from the client side.
  707. * Arguments are as for connection_edge_process_relay_cell().
  708. */
  709. static int
  710. connection_ap_process_end_not_open(
  711. relay_header_t *rh, cell_t *cell, origin_circuit_t *circ,
  712. entry_connection_t *conn, crypt_path_t *layer_hint)
  713. {
  714. node_t *exitrouter;
  715. int reason = *(cell->payload+RELAY_HEADER_SIZE);
  716. int control_reason;
  717. edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
  718. (void) layer_hint; /* unused */
  719. if (rh->length > 0) {
  720. if (reason == END_STREAM_REASON_TORPROTOCOL ||
  721. reason == END_STREAM_REASON_DESTROY) {
  722. /* Both of these reasons could mean a failed tag
  723. * hit the exit and it complained. Do not probe.
  724. * Fail the circuit. */
  725. circ->path_state = PATH_STATE_USE_FAILED;
  726. return -END_CIRC_REASON_TORPROTOCOL;
  727. } else if (reason == END_STREAM_REASON_INTERNAL) {
  728. /* We can't infer success or failure, since older Tors report
  729. * ENETUNREACH as END_STREAM_REASON_INTERNAL. */
  730. } else {
  731. /* Path bias: If we get a valid reason code from the exit,
  732. * it wasn't due to tagging.
  733. *
  734. * We rely on recognized+digest being strong enough to make
  735. * tags unlikely to allow us to get tagged, yet 'recognized'
  736. * reason codes here. */
  737. pathbias_mark_use_success(circ);
  738. }
  739. }
  740. if (rh->length == 0) {
  741. reason = END_STREAM_REASON_MISC;
  742. }
  743. control_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
  744. if (edge_reason_is_retriable(reason) &&
  745. /* avoid retry if rend */
  746. !connection_edge_is_rendezvous_stream(edge_conn)) {
  747. const char *chosen_exit_digest =
  748. circ->build_state->chosen_exit->identity_digest;
  749. log_info(LD_APP,"Address '%s' refused due to '%s'. Considering retrying.",
  750. safe_str(conn->socks_request->address),
  751. stream_end_reason_to_string(reason));
  752. exitrouter = node_get_mutable_by_id(chosen_exit_digest);
  753. switch (reason) {
  754. case END_STREAM_REASON_EXITPOLICY: {
  755. tor_addr_t addr;
  756. tor_addr_make_unspec(&addr);
  757. if (rh->length >= 5) {
  758. int ttl = -1;
  759. tor_addr_make_unspec(&addr);
  760. if (rh->length == 5 || rh->length == 9) {
  761. tor_addr_from_ipv4n(&addr,
  762. get_uint32(cell->payload+RELAY_HEADER_SIZE+1));
  763. if (rh->length == 9)
  764. ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+5));
  765. } else if (rh->length == 17 || rh->length == 21) {
  766. tor_addr_from_ipv6_bytes(&addr,
  767. (char*)(cell->payload+RELAY_HEADER_SIZE+1));
  768. if (rh->length == 21)
  769. ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+17));
  770. }
  771. if (tor_addr_is_null(&addr)) {
  772. log_info(LD_APP,"Address '%s' resolved to 0.0.0.0. Closing,",
  773. safe_str(conn->socks_request->address));
  774. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  775. return 0;
  776. }
  777. if ((tor_addr_family(&addr) == AF_INET &&
  778. !conn->entry_cfg.ipv4_traffic) ||
  779. (tor_addr_family(&addr) == AF_INET6 &&
  780. !conn->entry_cfg.ipv6_traffic)) {
  781. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  782. "Got an EXITPOLICY failure on a connection with a "
  783. "mismatched family. Closing.");
  784. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  785. return 0;
  786. }
  787. if (get_options()->ClientDNSRejectInternalAddresses &&
  788. tor_addr_is_internal(&addr, 0)) {
  789. log_info(LD_APP,"Address '%s' resolved to internal. Closing,",
  790. safe_str(conn->socks_request->address));
  791. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  792. return 0;
  793. }
  794. client_dns_set_addressmap(conn,
  795. conn->socks_request->address, &addr,
  796. conn->chosen_exit_name, ttl);
  797. {
  798. char new_addr[TOR_ADDR_BUF_LEN];
  799. tor_addr_to_str(new_addr, &addr, sizeof(new_addr), 1);
  800. if (strcmp(conn->socks_request->address, new_addr)) {
  801. strlcpy(conn->socks_request->address, new_addr,
  802. sizeof(conn->socks_request->address));
  803. control_event_stream_status(conn, STREAM_EVENT_REMAP, 0);
  804. }
  805. }
  806. }
  807. /* check if the exit *ought* to have allowed it */
  808. adjust_exit_policy_from_exitpolicy_failure(circ,
  809. conn,
  810. exitrouter,
  811. &addr);
  812. if (conn->chosen_exit_optional ||
  813. conn->chosen_exit_retries) {
  814. /* stop wanting a specific exit */
  815. conn->chosen_exit_optional = 0;
  816. /* A non-zero chosen_exit_retries can happen if we set a
  817. * TrackHostExits for this address under a port that the exit
  818. * relay allows, but then try the same address with a different
  819. * port that it doesn't allow to exit. We shouldn't unregister
  820. * the mapping, since it is probably still wanted on the
  821. * original port. But now we give away to the exit relay that
  822. * we probably have a TrackHostExits on it. So be it. */
  823. conn->chosen_exit_retries = 0;
  824. tor_free(conn->chosen_exit_name); /* clears it */
  825. }
  826. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  827. return 0;
  828. /* else, conn will get closed below */
  829. break;
  830. }
  831. case END_STREAM_REASON_CONNECTREFUSED:
  832. if (!conn->chosen_exit_optional)
  833. break; /* break means it'll close, below */
  834. /* Else fall through: expire this circuit, clear the
  835. * chosen_exit_name field, and try again. */
  836. case END_STREAM_REASON_RESOLVEFAILED:
  837. case END_STREAM_REASON_TIMEOUT:
  838. case END_STREAM_REASON_MISC:
  839. case END_STREAM_REASON_NOROUTE:
  840. if (client_dns_incr_failures(conn->socks_request->address)
  841. < MAX_RESOLVE_FAILURES) {
  842. /* We haven't retried too many times; reattach the connection. */
  843. circuit_log_path(LOG_INFO,LD_APP,circ);
  844. /* Mark this circuit "unusable for new streams". */
  845. mark_circuit_unusable_for_new_conns(circ);
  846. if (conn->chosen_exit_optional) {
  847. /* stop wanting a specific exit */
  848. conn->chosen_exit_optional = 0;
  849. tor_free(conn->chosen_exit_name); /* clears it */
  850. }
  851. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  852. return 0;
  853. /* else, conn will get closed below */
  854. } else {
  855. log_notice(LD_APP,
  856. "Have tried resolving or connecting to address '%s' "
  857. "at %d different places. Giving up.",
  858. safe_str(conn->socks_request->address),
  859. MAX_RESOLVE_FAILURES);
  860. /* clear the failures, so it will have a full try next time */
  861. client_dns_clear_failures(conn->socks_request->address);
  862. }
  863. break;
  864. case END_STREAM_REASON_HIBERNATING:
  865. case END_STREAM_REASON_RESOURCELIMIT:
  866. if (exitrouter) {
  867. policies_set_node_exitpolicy_to_reject_all(exitrouter);
  868. }
  869. if (conn->chosen_exit_optional) {
  870. /* stop wanting a specific exit */
  871. conn->chosen_exit_optional = 0;
  872. tor_free(conn->chosen_exit_name); /* clears it */
  873. }
  874. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  875. return 0;
  876. /* else, will close below */
  877. break;
  878. } /* end switch */
  879. log_info(LD_APP,"Giving up on retrying; conn can't be handled.");
  880. }
  881. log_info(LD_APP,
  882. "Edge got end (%s) before we're connected. Marking for close.",
  883. stream_end_reason_to_string(rh->length > 0 ? reason : -1));
  884. circuit_log_path(LOG_INFO,LD_APP,circ);
  885. /* need to test because of detach_retriable */
  886. if (!ENTRY_TO_CONN(conn)->marked_for_close)
  887. connection_mark_unattached_ap(conn, control_reason);
  888. return 0;
  889. }
  890. /** Called when we have gotten an END_REASON_EXITPOLICY failure on <b>circ</b>
  891. * for <b>conn</b>, while attempting to connect via <b>node</b>. If the node
  892. * told us which address it rejected, then <b>addr</b> is that address;
  893. * otherwise it is AF_UNSPEC.
  894. *
  895. * If we are sure the node should have allowed this address, mark the node as
  896. * having a reject *:* exit policy. Otherwise, mark the circuit as unusable
  897. * for this particular address.
  898. **/
  899. static void
  900. adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
  901. entry_connection_t *conn,
  902. node_t *node,
  903. const tor_addr_t *addr)
  904. {
  905. int make_reject_all = 0;
  906. const sa_family_t family = tor_addr_family(addr);
  907. if (node) {
  908. tor_addr_t tmp;
  909. int asked_for_family = tor_addr_parse(&tmp, conn->socks_request->address);
  910. if (family == AF_UNSPEC) {
  911. make_reject_all = 1;
  912. } else if (node_exit_policy_is_exact(node, family) &&
  913. asked_for_family != -1 && !conn->chosen_exit_name) {
  914. make_reject_all = 1;
  915. }
  916. if (make_reject_all) {
  917. log_info(LD_APP,
  918. "Exitrouter %s seems to be more restrictive than its exit "
  919. "policy. Not using this router as exit for now.",
  920. node_describe(node));
  921. policies_set_node_exitpolicy_to_reject_all(node);
  922. }
  923. }
  924. if (family != AF_UNSPEC)
  925. addr_policy_append_reject_addr(&circ->prepend_policy, addr);
  926. }
  927. /** Helper: change the socks_request-&gt;address field on conn to the
  928. * dotted-quad representation of <b>new_addr</b>,
  929. * and send an appropriate REMAP event. */
  930. static void
  931. remap_event_helper(entry_connection_t *conn, const tor_addr_t *new_addr)
  932. {
  933. tor_addr_to_str(conn->socks_request->address, new_addr,
  934. sizeof(conn->socks_request->address),
  935. 1);
  936. control_event_stream_status(conn, STREAM_EVENT_REMAP,
  937. REMAP_STREAM_SOURCE_EXIT);
  938. }
  939. /** Extract the contents of a connected cell in <b>cell</b>, whose relay
  940. * header has already been parsed into <b>rh</b>. On success, set
  941. * <b>addr_out</b> to the address we're connected to, and <b>ttl_out</b> to
  942. * the ttl of that address, in seconds, and return 0. On failure, return
  943. * -1. */
  944. STATIC int
  945. connected_cell_parse(const relay_header_t *rh, const cell_t *cell,
  946. tor_addr_t *addr_out, int *ttl_out)
  947. {
  948. uint32_t bytes;
  949. const uint8_t *payload = cell->payload + RELAY_HEADER_SIZE;
  950. tor_addr_make_unspec(addr_out);
  951. *ttl_out = -1;
  952. if (rh->length == 0)
  953. return 0;
  954. if (rh->length < 4)
  955. return -1;
  956. bytes = ntohl(get_uint32(payload));
  957. /* If bytes is 0, this is maybe a v6 address. Otherwise it's a v4 address */
  958. if (bytes != 0) {
  959. /* v4 address */
  960. tor_addr_from_ipv4h(addr_out, bytes);
  961. if (rh->length >= 8) {
  962. bytes = ntohl(get_uint32(payload + 4));
  963. if (bytes <= INT32_MAX)
  964. *ttl_out = bytes;
  965. }
  966. } else {
  967. if (rh->length < 25) /* 4 bytes of 0s, 1 addr, 16 ipv4, 4 ttl. */
  968. return -1;
  969. if (get_uint8(payload + 4) != 6)
  970. return -1;
  971. tor_addr_from_ipv6_bytes(addr_out, (char*)(payload + 5));
  972. bytes = ntohl(get_uint32(payload + 21));
  973. if (bytes <= INT32_MAX)
  974. *ttl_out = (int) bytes;
  975. }
  976. return 0;
  977. }
  978. /** Drop all storage held by <b>addr</b>. */
  979. STATIC void
  980. address_ttl_free(address_ttl_t *addr)
  981. {
  982. if (!addr)
  983. return;
  984. tor_free(addr->hostname);
  985. tor_free(addr);
  986. }
  987. /** Parse a resolved cell in <b>cell</b>, with parsed header in <b>rh</b>.
  988. * Return -1 on parse error. On success, add one or more newly allocated
  989. * address_ttl_t to <b>addresses_out</b>; set *<b>errcode_out</b> to
  990. * one of 0, RESOLVED_TYPE_ERROR, or RESOLVED_TYPE_ERROR_TRANSIENT, and
  991. * return 0. */
  992. STATIC int
  993. resolved_cell_parse(const cell_t *cell, const relay_header_t *rh,
  994. smartlist_t *addresses_out, int *errcode_out)
  995. {
  996. const uint8_t *cp;
  997. uint8_t answer_type;
  998. size_t answer_len;
  999. address_ttl_t *addr;
  1000. size_t remaining;
  1001. int errcode = 0;
  1002. smartlist_t *addrs;
  1003. tor_assert(cell);
  1004. tor_assert(rh);
  1005. tor_assert(addresses_out);
  1006. tor_assert(errcode_out);
  1007. *errcode_out = 0;
  1008. if (rh->length > RELAY_PAYLOAD_SIZE)
  1009. return -1;
  1010. addrs = smartlist_new();
  1011. cp = cell->payload + RELAY_HEADER_SIZE;
  1012. remaining = rh->length;
  1013. while (remaining) {
  1014. const uint8_t *cp_orig = cp;
  1015. if (remaining < 2)
  1016. goto err;
  1017. answer_type = *cp++;
  1018. answer_len = *cp++;
  1019. if (remaining < 2 + answer_len + 4) {
  1020. goto err;
  1021. }
  1022. if (answer_type == RESOLVED_TYPE_IPV4) {
  1023. if (answer_len != 4) {
  1024. goto err;
  1025. }
  1026. addr = tor_malloc_zero(sizeof(*addr));
  1027. tor_addr_from_ipv4n(&addr->addr, get_uint32(cp));
  1028. cp += 4;
  1029. addr->ttl = ntohl(get_uint32(cp));
  1030. cp += 4;
  1031. smartlist_add(addrs, addr);
  1032. } else if (answer_type == RESOLVED_TYPE_IPV6) {
  1033. if (answer_len != 16)
  1034. goto err;
  1035. addr = tor_malloc_zero(sizeof(*addr));
  1036. tor_addr_from_ipv6_bytes(&addr->addr, (const char*) cp);
  1037. cp += 16;
  1038. addr->ttl = ntohl(get_uint32(cp));
  1039. cp += 4;
  1040. smartlist_add(addrs, addr);
  1041. } else if (answer_type == RESOLVED_TYPE_HOSTNAME) {
  1042. if (answer_len == 0) {
  1043. goto err;
  1044. }
  1045. addr = tor_malloc_zero(sizeof(*addr));
  1046. addr->hostname = tor_memdup_nulterm(cp, answer_len);
  1047. cp += answer_len;
  1048. addr->ttl = ntohl(get_uint32(cp));
  1049. cp += 4;
  1050. smartlist_add(addrs, addr);
  1051. } else if (answer_type == RESOLVED_TYPE_ERROR_TRANSIENT ||
  1052. answer_type == RESOLVED_TYPE_ERROR) {
  1053. errcode = answer_type;
  1054. /* Ignore the error contents */
  1055. cp += answer_len + 4;
  1056. } else {
  1057. cp += answer_len + 4;
  1058. }
  1059. tor_assert(((ssize_t)remaining) >= (cp - cp_orig));
  1060. remaining -= (cp - cp_orig);
  1061. }
  1062. if (errcode && smartlist_len(addrs) == 0) {
  1063. /* Report an error only if there were no results. */
  1064. *errcode_out = errcode;
  1065. }
  1066. smartlist_add_all(addresses_out, addrs);
  1067. smartlist_free(addrs);
  1068. return 0;
  1069. err:
  1070. /* On parse error, don't report any results */
  1071. SMARTLIST_FOREACH(addrs, address_ttl_t *, a, address_ttl_free(a));
  1072. smartlist_free(addrs);
  1073. return -1;
  1074. }
  1075. /** Helper for connection_edge_process_resolved_cell: given an error code,
  1076. * an entry_connection, and a list of address_ttl_t *, report the best answer
  1077. * to the entry_connection. */
  1078. static void
  1079. connection_ap_handshake_socks_got_resolved_cell(entry_connection_t *conn,
  1080. int error_code,
  1081. smartlist_t *results)
  1082. {
  1083. address_ttl_t *addr_ipv4 = NULL;
  1084. address_ttl_t *addr_ipv6 = NULL;
  1085. address_ttl_t *addr_hostname = NULL;
  1086. address_ttl_t *addr_best = NULL;
  1087. /* If it's an error code, that's easy. */
  1088. if (error_code) {
  1089. tor_assert(error_code == RESOLVED_TYPE_ERROR ||
  1090. error_code == RESOLVED_TYPE_ERROR_TRANSIENT);
  1091. connection_ap_handshake_socks_resolved(conn,
  1092. error_code,0,NULL,-1,-1);
  1093. return;
  1094. }
  1095. /* Get the first answer of each type. */
  1096. SMARTLIST_FOREACH_BEGIN(results, address_ttl_t *, addr) {
  1097. if (addr->hostname) {
  1098. if (!addr_hostname) {
  1099. addr_hostname = addr;
  1100. }
  1101. } else if (tor_addr_family(&addr->addr) == AF_INET) {
  1102. if (!addr_ipv4 && conn->entry_cfg.ipv4_traffic) {
  1103. addr_ipv4 = addr;
  1104. }
  1105. } else if (tor_addr_family(&addr->addr) == AF_INET6) {
  1106. if (!addr_ipv6 && conn->entry_cfg.ipv6_traffic) {
  1107. addr_ipv6 = addr;
  1108. }
  1109. }
  1110. } SMARTLIST_FOREACH_END(addr);
  1111. /* Now figure out which type we wanted to deliver. */
  1112. if (conn->socks_request->command == SOCKS_COMMAND_RESOLVE_PTR) {
  1113. if (addr_hostname) {
  1114. connection_ap_handshake_socks_resolved(conn,
  1115. RESOLVED_TYPE_HOSTNAME,
  1116. strlen(addr_hostname->hostname),
  1117. (uint8_t*)addr_hostname->hostname,
  1118. addr_hostname->ttl,-1);
  1119. } else {
  1120. connection_ap_handshake_socks_resolved(conn,
  1121. RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
  1122. }
  1123. return;
  1124. }
  1125. if (conn->entry_cfg.prefer_ipv6) {
  1126. addr_best = addr_ipv6 ? addr_ipv6 : addr_ipv4;
  1127. } else {
  1128. addr_best = addr_ipv4 ? addr_ipv4 : addr_ipv6;
  1129. }
  1130. /* Now convert it to the ugly old interface */
  1131. if (! addr_best) {
  1132. connection_ap_handshake_socks_resolved(conn,
  1133. RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
  1134. return;
  1135. }
  1136. connection_ap_handshake_socks_resolved_addr(conn,
  1137. &addr_best->addr,
  1138. addr_best->ttl,
  1139. -1);
  1140. remap_event_helper(conn, &addr_best->addr);
  1141. }
  1142. /** Handle a RELAY_COMMAND_RESOLVED cell that we received on a non-open AP
  1143. * stream. */
  1144. STATIC int
  1145. connection_edge_process_resolved_cell(edge_connection_t *conn,
  1146. const cell_t *cell,
  1147. const relay_header_t *rh)
  1148. {
  1149. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1150. smartlist_t *resolved_addresses = NULL;
  1151. int errcode = 0;
  1152. if (conn->base_.state != AP_CONN_STATE_RESOLVE_WAIT) {
  1153. log_fn(LOG_PROTOCOL_WARN, LD_APP, "Got a 'resolved' cell while "
  1154. "not in state resolve_wait. Dropping.");
  1155. return 0;
  1156. }
  1157. tor_assert(SOCKS_COMMAND_IS_RESOLVE(entry_conn->socks_request->command));
  1158. resolved_addresses = smartlist_new();
  1159. if (resolved_cell_parse(cell, rh, resolved_addresses, &errcode)) {
  1160. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1161. "Dropping malformed 'resolved' cell");
  1162. connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
  1163. goto done;
  1164. }
  1165. if (get_options()->ClientDNSRejectInternalAddresses) {
  1166. int orig_len = smartlist_len(resolved_addresses);
  1167. SMARTLIST_FOREACH_BEGIN(resolved_addresses, address_ttl_t *, addr) {
  1168. if (addr->hostname == NULL && tor_addr_is_internal(&addr->addr, 0)) {
  1169. log_info(LD_APP, "Got a resolved cell with answer %s; dropping that "
  1170. "answer.",
  1171. safe_str_client(fmt_addr(&addr->addr)));
  1172. address_ttl_free(addr);
  1173. SMARTLIST_DEL_CURRENT(resolved_addresses, addr);
  1174. }
  1175. } SMARTLIST_FOREACH_END(addr);
  1176. if (orig_len && smartlist_len(resolved_addresses) == 0) {
  1177. log_info(LD_APP, "Got a resolved cell with only private addresses; "
  1178. "dropping it.");
  1179. connection_ap_handshake_socks_resolved(entry_conn,
  1180. RESOLVED_TYPE_ERROR_TRANSIENT,
  1181. 0, NULL, 0, TIME_MAX);
  1182. connection_mark_unattached_ap(entry_conn,
  1183. END_STREAM_REASON_TORPROTOCOL);
  1184. goto done;
  1185. }
  1186. }
  1187. connection_ap_handshake_socks_got_resolved_cell(entry_conn,
  1188. errcode,
  1189. resolved_addresses);
  1190. connection_mark_unattached_ap(entry_conn,
  1191. END_STREAM_REASON_DONE |
  1192. END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
  1193. done:
  1194. SMARTLIST_FOREACH(resolved_addresses, address_ttl_t *, addr,
  1195. address_ttl_free(addr));
  1196. smartlist_free(resolved_addresses);
  1197. return 0;
  1198. }
  1199. /** An incoming relay cell has arrived from circuit <b>circ</b> to
  1200. * stream <b>conn</b>.
  1201. *
  1202. * The arguments here are the same as in
  1203. * connection_edge_process_relay_cell() below; this function is called
  1204. * from there when <b>conn</b> is defined and not in an open state.
  1205. */
  1206. static int
  1207. connection_edge_process_relay_cell_not_open(
  1208. relay_header_t *rh, cell_t *cell, circuit_t *circ,
  1209. edge_connection_t *conn, crypt_path_t *layer_hint)
  1210. {
  1211. if (rh->command == RELAY_COMMAND_END) {
  1212. if (CIRCUIT_IS_ORIGIN(circ) && conn->base_.type == CONN_TYPE_AP) {
  1213. return connection_ap_process_end_not_open(rh, cell,
  1214. TO_ORIGIN_CIRCUIT(circ),
  1215. EDGE_TO_ENTRY_CONN(conn),
  1216. layer_hint);
  1217. } else {
  1218. /* we just got an 'end', don't need to send one */
  1219. conn->edge_has_sent_end = 1;
  1220. conn->end_reason = *(cell->payload+RELAY_HEADER_SIZE) |
  1221. END_STREAM_REASON_FLAG_REMOTE;
  1222. connection_mark_for_close(TO_CONN(conn));
  1223. return 0;
  1224. }
  1225. }
  1226. if (conn->base_.type == CONN_TYPE_AP &&
  1227. rh->command == RELAY_COMMAND_CONNECTED) {
  1228. tor_addr_t addr;
  1229. int ttl;
  1230. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1231. tor_assert(CIRCUIT_IS_ORIGIN(circ));
  1232. if (conn->base_.state != AP_CONN_STATE_CONNECT_WAIT) {
  1233. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1234. "Got 'connected' while not in state connect_wait. Dropping.");
  1235. return 0;
  1236. }
  1237. CONNECTION_AP_EXPECT_NONPENDING(entry_conn);
  1238. conn->base_.state = AP_CONN_STATE_OPEN;
  1239. log_info(LD_APP,"'connected' received for circid %u streamid %d "
  1240. "after %d seconds.",
  1241. (unsigned)circ->n_circ_id,
  1242. rh->stream_id,
  1243. (int)(time(NULL) - conn->base_.timestamp_lastread));
  1244. if (connected_cell_parse(rh, cell, &addr, &ttl) < 0) {
  1245. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1246. "Got a badly formatted connected cell. Closing.");
  1247. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1248. connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
  1249. }
  1250. if (tor_addr_family(&addr) != AF_UNSPEC) {
  1251. const sa_family_t family = tor_addr_family(&addr);
  1252. if (tor_addr_is_null(&addr) ||
  1253. (get_options()->ClientDNSRejectInternalAddresses &&
  1254. tor_addr_is_internal(&addr, 0))) {
  1255. log_info(LD_APP, "...but it claims the IP address was %s. Closing.",
  1256. fmt_addr(&addr));
  1257. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1258. connection_mark_unattached_ap(entry_conn,
  1259. END_STREAM_REASON_TORPROTOCOL);
  1260. return 0;
  1261. }
  1262. if ((family == AF_INET && ! entry_conn->entry_cfg.ipv4_traffic) ||
  1263. (family == AF_INET6 && ! entry_conn->entry_cfg.ipv6_traffic)) {
  1264. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1265. "Got a connected cell to %s with unsupported address family."
  1266. " Closing.", fmt_addr(&addr));
  1267. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1268. connection_mark_unattached_ap(entry_conn,
  1269. END_STREAM_REASON_TORPROTOCOL);
  1270. return 0;
  1271. }
  1272. client_dns_set_addressmap(entry_conn,
  1273. entry_conn->socks_request->address, &addr,
  1274. entry_conn->chosen_exit_name, ttl);
  1275. remap_event_helper(entry_conn, &addr);
  1276. }
  1277. circuit_log_path(LOG_INFO,LD_APP,TO_ORIGIN_CIRCUIT(circ));
  1278. /* don't send a socks reply to transparent conns */
  1279. tor_assert(entry_conn->socks_request != NULL);
  1280. if (!entry_conn->socks_request->has_finished)
  1281. connection_ap_handshake_socks_reply(entry_conn, NULL, 0, 0);
  1282. /* Was it a linked dir conn? If so, a dir request just started to
  1283. * fetch something; this could be a bootstrap status milestone. */
  1284. log_debug(LD_APP, "considering");
  1285. if (TO_CONN(conn)->linked_conn &&
  1286. TO_CONN(conn)->linked_conn->type == CONN_TYPE_DIR) {
  1287. connection_t *dirconn = TO_CONN(conn)->linked_conn;
  1288. log_debug(LD_APP, "it is! %d", dirconn->purpose);
  1289. switch (dirconn->purpose) {
  1290. case DIR_PURPOSE_FETCH_CERTIFICATE:
  1291. if (consensus_is_waiting_for_certs())
  1292. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_KEYS, 0);
  1293. break;
  1294. case DIR_PURPOSE_FETCH_CONSENSUS:
  1295. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_STATUS, 0);
  1296. break;
  1297. case DIR_PURPOSE_FETCH_SERVERDESC:
  1298. case DIR_PURPOSE_FETCH_MICRODESC:
  1299. if (TO_DIR_CONN(dirconn)->router_purpose == ROUTER_PURPOSE_GENERAL)
  1300. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
  1301. count_loading_descriptors_progress());
  1302. break;
  1303. }
  1304. }
  1305. /* This is definitely a success, so forget about any pending data we
  1306. * had sent. */
  1307. if (entry_conn->pending_optimistic_data) {
  1308. buf_free(entry_conn->pending_optimistic_data);
  1309. entry_conn->pending_optimistic_data = NULL;
  1310. }
  1311. /* handle anything that might have queued */
  1312. if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
  1313. /* (We already sent an end cell if possible) */
  1314. connection_mark_for_close(TO_CONN(conn));
  1315. return 0;
  1316. }
  1317. return 0;
  1318. }
  1319. if (conn->base_.type == CONN_TYPE_AP &&
  1320. rh->command == RELAY_COMMAND_RESOLVED) {
  1321. return connection_edge_process_resolved_cell(conn, cell, rh);
  1322. }
  1323. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1324. "Got an unexpected relay command %d, in state %d (%s). Dropping.",
  1325. rh->command, conn->base_.state,
  1326. conn_state_to_string(conn->base_.type, conn->base_.state));
  1327. return 0; /* for forward compatibility, don't kill the circuit */
  1328. // connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1329. // connection_mark_for_close(conn);
  1330. // return -1;
  1331. }
  1332. /** An incoming relay cell has arrived on circuit <b>circ</b>. If
  1333. * <b>conn</b> is NULL this is a control cell, else <b>cell</b> is
  1334. * destined for <b>conn</b>.
  1335. *
  1336. * If <b>layer_hint</b> is defined, then we're the origin of the
  1337. * circuit, and it specifies the hop that packaged <b>cell</b>.
  1338. *
  1339. * Return -reason if you want to warn and tear down the circuit, else 0.
  1340. */
  1341. static int
  1342. connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
  1343. edge_connection_t *conn,
  1344. crypt_path_t *layer_hint)
  1345. {
  1346. static int num_seen=0;
  1347. relay_header_t rh;
  1348. unsigned domain = layer_hint?LD_APP:LD_EXIT;
  1349. int reason;
  1350. int optimistic_data = 0; /* Set to 1 if we receive data on a stream
  1351. * that's in the EXIT_CONN_STATE_RESOLVING
  1352. * or EXIT_CONN_STATE_CONNECTING states. */
  1353. tor_assert(cell);
  1354. tor_assert(circ);
  1355. relay_header_unpack(&rh, cell->payload);
  1356. // log_fn(LOG_DEBUG,"command %d stream %d", rh.command, rh.stream_id);
  1357. num_seen++;
  1358. log_debug(domain, "Now seen %d relay cells here (command %d, stream %d).",
  1359. num_seen, rh.command, rh.stream_id);
  1360. if (rh.length > RELAY_PAYLOAD_SIZE) {
  1361. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1362. "Relay cell length field too long. Closing circuit.");
  1363. return - END_CIRC_REASON_TORPROTOCOL;
  1364. }
  1365. if (rh.stream_id == 0) {
  1366. switch (rh.command) {
  1367. case RELAY_COMMAND_BEGIN:
  1368. case RELAY_COMMAND_CONNECTED:
  1369. case RELAY_COMMAND_END:
  1370. case RELAY_COMMAND_RESOLVE:
  1371. case RELAY_COMMAND_RESOLVED:
  1372. case RELAY_COMMAND_BEGIN_DIR:
  1373. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay command %d with zero "
  1374. "stream_id. Dropping.", (int)rh.command);
  1375. return 0;
  1376. default:
  1377. ;
  1378. }
  1379. }
  1380. /* either conn is NULL, in which case we've got a control cell, or else
  1381. * conn points to the recognized stream. */
  1382. if (conn && !connection_state_is_open(TO_CONN(conn))) {
  1383. if (conn->base_.type == CONN_TYPE_EXIT &&
  1384. (conn->base_.state == EXIT_CONN_STATE_CONNECTING ||
  1385. conn->base_.state == EXIT_CONN_STATE_RESOLVING) &&
  1386. rh.command == RELAY_COMMAND_DATA) {
  1387. /* Allow DATA cells to be delivered to an exit node in state
  1388. * EXIT_CONN_STATE_CONNECTING or EXIT_CONN_STATE_RESOLVING.
  1389. * This speeds up HTTP, for example. */
  1390. optimistic_data = 1;
  1391. } else if (rh.stream_id == 0 && rh.command == RELAY_COMMAND_DATA) {
  1392. log_warn(LD_BUG, "Somehow I had a connection that matched a "
  1393. "data cell with stream ID 0.");
  1394. } else {
  1395. return connection_edge_process_relay_cell_not_open(
  1396. &rh, cell, circ, conn, layer_hint);
  1397. }
  1398. }
  1399. switch (rh.command) {
  1400. case RELAY_COMMAND_DROP:
  1401. // log_info(domain,"Got a relay-level padding cell. Dropping.");
  1402. return 0;
  1403. case RELAY_COMMAND_BEGIN:
  1404. case RELAY_COMMAND_BEGIN_DIR:
  1405. if (layer_hint &&
  1406. circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
  1407. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1408. "Relay begin request unsupported at AP. Dropping.");
  1409. return 0;
  1410. }
  1411. if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED &&
  1412. layer_hint != TO_ORIGIN_CIRCUIT(circ)->cpath->prev) {
  1413. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1414. "Relay begin request to Hidden Service "
  1415. "from intermediary node. Dropping.");
  1416. return 0;
  1417. }
  1418. if (conn) {
  1419. log_fn(LOG_PROTOCOL_WARN, domain,
  1420. "Begin cell for known stream. Dropping.");
  1421. return 0;
  1422. }
  1423. if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
  1424. /* Assign this circuit and its app-ward OR connection a unique ID,
  1425. * so that we can measure download times. The local edge and dir
  1426. * connection will be assigned the same ID when they are created
  1427. * and linked. */
  1428. static uint64_t next_id = 0;
  1429. circ->dirreq_id = ++next_id;
  1430. TO_OR_CIRCUIT(circ)->p_chan->dirreq_id = circ->dirreq_id;
  1431. }
  1432. return connection_exit_begin_conn(cell, circ);
  1433. case RELAY_COMMAND_DATA:
  1434. ++stats_n_data_cells_received;
  1435. if (( layer_hint && --layer_hint->deliver_window < 0) ||
  1436. (!layer_hint && --circ->deliver_window < 0)) {
  1437. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1438. "(relay data) circ deliver_window below 0. Killing.");
  1439. if (conn) {
  1440. /* XXXX Do we actually need to do this? Will killing the circuit
  1441. * not send an END and mark the stream for close as appropriate? */
  1442. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1443. connection_mark_for_close(TO_CONN(conn));
  1444. }
  1445. return -END_CIRC_REASON_TORPROTOCOL;
  1446. }
  1447. log_debug(domain,"circ deliver_window now %d.", layer_hint ?
  1448. layer_hint->deliver_window : circ->deliver_window);
  1449. circuit_consider_sending_sendme(circ, layer_hint);
  1450. if (rh.stream_id == 0) {
  1451. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay data cell with zero "
  1452. "stream_id. Dropping.");
  1453. return 0;
  1454. } else if (!conn) {
  1455. log_info(domain,"data cell dropped, unknown stream (streamid %d).",
  1456. rh.stream_id);
  1457. return 0;
  1458. }
  1459. if (--conn->deliver_window < 0) { /* is it below 0 after decrement? */
  1460. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1461. "(relay data) conn deliver_window below 0. Killing.");
  1462. return -END_CIRC_REASON_TORPROTOCOL;
  1463. }
  1464. stats_n_data_bytes_received += rh.length;
  1465. connection_write_to_buf((char*)(cell->payload + RELAY_HEADER_SIZE),
  1466. rh.length, TO_CONN(conn));
  1467. #ifdef MEASUREMENTS_21206
  1468. /* Count number of RELAY_DATA cells received on a linked directory
  1469. * connection. */
  1470. connection_t *linked_conn = TO_CONN(conn)->linked_conn;
  1471. if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
  1472. ++(TO_DIR_CONN(linked_conn)->data_cells_received);
  1473. }
  1474. #endif
  1475. if (!optimistic_data) {
  1476. /* Only send a SENDME if we're not getting optimistic data; otherwise
  1477. * a SENDME could arrive before the CONNECTED.
  1478. */
  1479. connection_edge_consider_sending_sendme(conn);
  1480. }
  1481. return 0;
  1482. case RELAY_COMMAND_END:
  1483. reason = rh.length > 0 ?
  1484. get_uint8(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
  1485. if (!conn) {
  1486. log_info(domain,"end cell (%s) dropped, unknown stream.",
  1487. stream_end_reason_to_string(reason));
  1488. return 0;
  1489. }
  1490. /* XXX add to this log_fn the exit node's nickname? */
  1491. log_info(domain,TOR_SOCKET_T_FORMAT": end cell (%s) for stream %d. "
  1492. "Removing stream.",
  1493. conn->base_.s,
  1494. stream_end_reason_to_string(reason),
  1495. conn->stream_id);
  1496. if (conn->base_.type == CONN_TYPE_AP) {
  1497. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1498. if (entry_conn->socks_request &&
  1499. !entry_conn->socks_request->has_finished)
  1500. log_warn(LD_BUG,
  1501. "open stream hasn't sent socks answer yet? Closing.");
  1502. }
  1503. /* We just *got* an end; no reason to send one. */
  1504. conn->edge_has_sent_end = 1;
  1505. if (!conn->end_reason)
  1506. conn->end_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
  1507. if (!conn->base_.marked_for_close) {
  1508. /* only mark it if not already marked. it's possible to
  1509. * get the 'end' right around when the client hangs up on us. */
  1510. connection_mark_and_flush(TO_CONN(conn));
  1511. }
  1512. return 0;
  1513. case RELAY_COMMAND_EXTEND:
  1514. case RELAY_COMMAND_EXTEND2: {
  1515. static uint64_t total_n_extend=0, total_nonearly=0;
  1516. total_n_extend++;
  1517. if (rh.stream_id) {
  1518. log_fn(LOG_PROTOCOL_WARN, domain,
  1519. "'extend' cell received for non-zero stream. Dropping.");
  1520. return 0;
  1521. }
  1522. if (cell->command != CELL_RELAY_EARLY &&
  1523. !networkstatus_get_param(NULL,"AllowNonearlyExtend",0,0,1)) {
  1524. #define EARLY_WARNING_INTERVAL 3600
  1525. static ratelim_t early_warning_limit =
  1526. RATELIM_INIT(EARLY_WARNING_INTERVAL);
  1527. char *m;
  1528. if (cell->command == CELL_RELAY) {
  1529. ++total_nonearly;
  1530. if ((m = rate_limit_log(&early_warning_limit, approx_time()))) {
  1531. double percentage = ((double)total_nonearly)/total_n_extend;
  1532. percentage *= 100;
  1533. log_fn(LOG_PROTOCOL_WARN, domain, "EXTEND cell received, "
  1534. "but not via RELAY_EARLY. Dropping.%s", m);
  1535. log_fn(LOG_PROTOCOL_WARN, domain, " (We have dropped %.02f%% of "
  1536. "all EXTEND cells for this reason)", percentage);
  1537. tor_free(m);
  1538. }
  1539. } else {
  1540. log_fn(LOG_WARN, domain,
  1541. "EXTEND cell received, in a cell with type %d! Dropping.",
  1542. cell->command);
  1543. }
  1544. return 0;
  1545. }
  1546. return circuit_extend(cell, circ);
  1547. }
  1548. case RELAY_COMMAND_EXTENDED:
  1549. case RELAY_COMMAND_EXTENDED2:
  1550. if (!layer_hint) {
  1551. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1552. "'extended' unsupported at non-origin. Dropping.");
  1553. return 0;
  1554. }
  1555. log_debug(domain,"Got an extended cell! Yay.");
  1556. {
  1557. extended_cell_t extended_cell;
  1558. if (extended_cell_parse(&extended_cell, rh.command,
  1559. (const uint8_t*)cell->payload+RELAY_HEADER_SIZE,
  1560. rh.length)<0) {
  1561. log_warn(LD_PROTOCOL,
  1562. "Can't parse EXTENDED cell; killing circuit.");
  1563. return -END_CIRC_REASON_TORPROTOCOL;
  1564. }
  1565. if ((reason = circuit_finish_handshake(TO_ORIGIN_CIRCUIT(circ),
  1566. &extended_cell.created_cell)) < 0) {
  1567. circuit_mark_for_close(circ, -reason);
  1568. return 0; /* We don't want to cause a warning, so we mark the circuit
  1569. * here. */
  1570. }
  1571. }
  1572. if ((reason=circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ)))<0) {
  1573. log_info(domain,"circuit_send_next_onion_skin() failed.");
  1574. return reason;
  1575. }
  1576. return 0;
  1577. case RELAY_COMMAND_TRUNCATE:
  1578. if (layer_hint) {
  1579. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1580. "'truncate' unsupported at origin. Dropping.");
  1581. return 0;
  1582. }
  1583. if (circ->n_hop) {
  1584. if (circ->n_chan)
  1585. log_warn(LD_BUG, "n_chan and n_hop set on the same circuit!");
  1586. extend_info_free(circ->n_hop);
  1587. circ->n_hop = NULL;
  1588. tor_free(circ->n_chan_create_cell);
  1589. circuit_set_state(circ, CIRCUIT_STATE_OPEN);
  1590. }
  1591. if (circ->n_chan) {
  1592. uint8_t trunc_reason = get_uint8(cell->payload + RELAY_HEADER_SIZE);
  1593. circuit_clear_cell_queue(circ, circ->n_chan);
  1594. channel_send_destroy(circ->n_circ_id, circ->n_chan,
  1595. trunc_reason);
  1596. circuit_set_n_circid_chan(circ, 0, NULL);
  1597. }
  1598. log_debug(LD_EXIT, "Processed 'truncate', replying.");
  1599. {
  1600. char payload[1];
  1601. payload[0] = (char)END_CIRC_REASON_REQUESTED;
  1602. relay_send_command_from_edge(0, circ, RELAY_COMMAND_TRUNCATED,
  1603. payload, sizeof(payload), NULL);
  1604. }
  1605. return 0;
  1606. case RELAY_COMMAND_TRUNCATED:
  1607. if (!layer_hint) {
  1608. log_fn(LOG_PROTOCOL_WARN, LD_EXIT,
  1609. "'truncated' unsupported at non-origin. Dropping.");
  1610. return 0;
  1611. }
  1612. circuit_truncated(TO_ORIGIN_CIRCUIT(circ), layer_hint,
  1613. get_uint8(cell->payload + RELAY_HEADER_SIZE));
  1614. return 0;
  1615. case RELAY_COMMAND_CONNECTED:
  1616. if (conn) {
  1617. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1618. "'connected' unsupported while open. Closing circ.");
  1619. return -END_CIRC_REASON_TORPROTOCOL;
  1620. }
  1621. log_info(domain,
  1622. "'connected' received on circid %u for streamid %d, "
  1623. "no conn attached anymore. Ignoring.",
  1624. (unsigned)circ->n_circ_id, rh.stream_id);
  1625. return 0;
  1626. case RELAY_COMMAND_SENDME:
  1627. if (!rh.stream_id) {
  1628. if (layer_hint) {
  1629. if (layer_hint->package_window + CIRCWINDOW_INCREMENT >
  1630. CIRCWINDOW_START_MAX) {
  1631. static struct ratelim_t exit_warn_ratelim = RATELIM_INIT(600);
  1632. log_fn_ratelim(&exit_warn_ratelim, LOG_WARN, LD_PROTOCOL,
  1633. "Unexpected sendme cell from exit relay. "
  1634. "Closing circ.");
  1635. return -END_CIRC_REASON_TORPROTOCOL;
  1636. }
  1637. layer_hint->package_window += CIRCWINDOW_INCREMENT;
  1638. log_debug(LD_APP,"circ-level sendme at origin, packagewindow %d.",
  1639. layer_hint->package_window);
  1640. circuit_resume_edge_reading(circ, layer_hint);
  1641. } else {
  1642. if (circ->package_window + CIRCWINDOW_INCREMENT >
  1643. CIRCWINDOW_START_MAX) {
  1644. static struct ratelim_t client_warn_ratelim = RATELIM_INIT(600);
  1645. log_fn_ratelim(&client_warn_ratelim,LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1646. "Unexpected sendme cell from client. "
  1647. "Closing circ (window %d).",
  1648. circ->package_window);
  1649. return -END_CIRC_REASON_TORPROTOCOL;
  1650. }
  1651. circ->package_window += CIRCWINDOW_INCREMENT;
  1652. log_debug(LD_APP,
  1653. "circ-level sendme at non-origin, packagewindow %d.",
  1654. circ->package_window);
  1655. circuit_resume_edge_reading(circ, layer_hint);
  1656. }
  1657. return 0;
  1658. }
  1659. if (!conn) {
  1660. log_info(domain,"sendme cell dropped, unknown stream (streamid %d).",
  1661. rh.stream_id);
  1662. return 0;
  1663. }
  1664. conn->package_window += STREAMWINDOW_INCREMENT;
  1665. log_debug(domain,"stream-level sendme, packagewindow now %d.",
  1666. conn->package_window);
  1667. if (circuit_queue_streams_are_blocked(circ)) {
  1668. /* Still waiting for queue to flush; don't touch conn */
  1669. return 0;
  1670. }
  1671. connection_start_reading(TO_CONN(conn));
  1672. /* handle whatever might still be on the inbuf */
  1673. if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
  1674. /* (We already sent an end cell if possible) */
  1675. connection_mark_for_close(TO_CONN(conn));
  1676. return 0;
  1677. }
  1678. return 0;
  1679. case RELAY_COMMAND_RESOLVE:
  1680. if (layer_hint) {
  1681. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1682. "resolve request unsupported at AP; dropping.");
  1683. return 0;
  1684. } else if (conn) {
  1685. log_fn(LOG_PROTOCOL_WARN, domain,
  1686. "resolve request for known stream; dropping.");
  1687. return 0;
  1688. } else if (circ->purpose != CIRCUIT_PURPOSE_OR) {
  1689. log_fn(LOG_PROTOCOL_WARN, domain,
  1690. "resolve request on circ with purpose %d; dropping",
  1691. circ->purpose);
  1692. return 0;
  1693. }
  1694. connection_exit_begin_resolve(cell, TO_OR_CIRCUIT(circ));
  1695. return 0;
  1696. case RELAY_COMMAND_RESOLVED:
  1697. if (conn) {
  1698. log_fn(LOG_PROTOCOL_WARN, domain,
  1699. "'resolved' unsupported while open. Closing circ.");
  1700. return -END_CIRC_REASON_TORPROTOCOL;
  1701. }
  1702. log_info(domain,
  1703. "'resolved' received, no conn attached anymore. Ignoring.");
  1704. return 0;
  1705. case RELAY_COMMAND_ESTABLISH_INTRO:
  1706. case RELAY_COMMAND_ESTABLISH_RENDEZVOUS:
  1707. case RELAY_COMMAND_INTRODUCE1:
  1708. case RELAY_COMMAND_INTRODUCE2:
  1709. case RELAY_COMMAND_INTRODUCE_ACK:
  1710. case RELAY_COMMAND_RENDEZVOUS1:
  1711. case RELAY_COMMAND_RENDEZVOUS2:
  1712. case RELAY_COMMAND_INTRO_ESTABLISHED:
  1713. case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
  1714. rend_process_relay_cell(circ, layer_hint,
  1715. rh.command, rh.length,
  1716. cell->payload+RELAY_HEADER_SIZE);
  1717. return 0;
  1718. }
  1719. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1720. "Received unknown relay command %d. Perhaps the other side is using "
  1721. "a newer version of Tor? Dropping.",
  1722. rh.command);
  1723. return 0; /* for forward compatibility, don't kill the circuit */
  1724. }
  1725. /** How many relay_data cells have we built, ever? */
  1726. uint64_t stats_n_data_cells_packaged = 0;
  1727. /** How many bytes of data have we put in relay_data cells have we built,
  1728. * ever? This would be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if
  1729. * every relay cell we ever sent were completely full of data. */
  1730. uint64_t stats_n_data_bytes_packaged = 0;
  1731. /** How many relay_data cells have we received, ever? */
  1732. uint64_t stats_n_data_cells_received = 0;
  1733. /** How many bytes of data have we received relay_data cells, ever? This would
  1734. * be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if every relay cell we
  1735. * ever received were completely full of data. */
  1736. uint64_t stats_n_data_bytes_received = 0;
  1737. /** If <b>conn</b> has an entire relay payload of bytes on its inbuf (or
  1738. * <b>package_partial</b> is true), and the appropriate package windows aren't
  1739. * empty, grab a cell and send it down the circuit.
  1740. *
  1741. * If *<b>max_cells</b> is given, package no more than max_cells. Decrement
  1742. * *<b>max_cells</b> by the number of cells packaged.
  1743. *
  1744. * Return -1 (and send a RELAY_COMMAND_END cell if necessary) if conn should
  1745. * be marked for close, else return 0.
  1746. */
  1747. int
  1748. connection_edge_package_raw_inbuf(edge_connection_t *conn, int package_partial,
  1749. int *max_cells)
  1750. {
  1751. size_t bytes_to_process, length;
  1752. char payload[CELL_PAYLOAD_SIZE];
  1753. circuit_t *circ;
  1754. const unsigned domain = conn->base_.type == CONN_TYPE_AP ? LD_APP : LD_EXIT;
  1755. int sending_from_optimistic = 0;
  1756. entry_connection_t *entry_conn =
  1757. conn->base_.type == CONN_TYPE_AP ? EDGE_TO_ENTRY_CONN(conn) : NULL;
  1758. const int sending_optimistically =
  1759. entry_conn &&
  1760. conn->base_.type == CONN_TYPE_AP &&
  1761. conn->base_.state != AP_CONN_STATE_OPEN;
  1762. crypt_path_t *cpath_layer = conn->cpath_layer;
  1763. tor_assert(conn);
  1764. if (conn->base_.marked_for_close) {
  1765. log_warn(LD_BUG,
  1766. "called on conn that's already marked for close at %s:%d.",
  1767. conn->base_.marked_for_close_file, conn->base_.marked_for_close);
  1768. return 0;
  1769. }
  1770. if (max_cells && *max_cells <= 0)
  1771. return 0;
  1772. repeat_connection_edge_package_raw_inbuf:
  1773. circ = circuit_get_by_edge_conn(conn);
  1774. if (!circ) {
  1775. log_info(domain,"conn has no circuit! Closing.");
  1776. conn->end_reason = END_STREAM_REASON_CANT_ATTACH;
  1777. return -1;
  1778. }
  1779. if (circuit_consider_stop_edge_reading(circ, cpath_layer))
  1780. return 0;
  1781. if (conn->package_window <= 0) {
  1782. log_info(domain,"called with package_window %d. Skipping.",
  1783. conn->package_window);
  1784. connection_stop_reading(TO_CONN(conn));
  1785. return 0;
  1786. }
  1787. sending_from_optimistic = entry_conn &&
  1788. entry_conn->sending_optimistic_data != NULL;
  1789. if (PREDICT_UNLIKELY(sending_from_optimistic)) {
  1790. bytes_to_process = buf_datalen(entry_conn->sending_optimistic_data);
  1791. if (PREDICT_UNLIKELY(!bytes_to_process)) {
  1792. log_warn(LD_BUG, "sending_optimistic_data was non-NULL but empty");
  1793. bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
  1794. sending_from_optimistic = 0;
  1795. }
  1796. } else {
  1797. bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
  1798. }
  1799. if (!bytes_to_process)
  1800. return 0;
  1801. if (!package_partial && bytes_to_process < RELAY_PAYLOAD_SIZE)
  1802. return 0;
  1803. if (bytes_to_process > RELAY_PAYLOAD_SIZE) {
  1804. length = RELAY_PAYLOAD_SIZE;
  1805. } else {
  1806. length = bytes_to_process;
  1807. }
  1808. stats_n_data_bytes_packaged += length;
  1809. stats_n_data_cells_packaged += 1;
  1810. if (PREDICT_UNLIKELY(sending_from_optimistic)) {
  1811. /* XXXX We could be more efficient here by sometimes packing
  1812. * previously-sent optimistic data in the same cell with data
  1813. * from the inbuf. */
  1814. fetch_from_buf(payload, length, entry_conn->sending_optimistic_data);
  1815. if (!buf_datalen(entry_conn->sending_optimistic_data)) {
  1816. buf_free(entry_conn->sending_optimistic_data);
  1817. entry_conn->sending_optimistic_data = NULL;
  1818. }
  1819. } else {
  1820. connection_fetch_from_buf(payload, length, TO_CONN(conn));
  1821. }
  1822. log_debug(domain,TOR_SOCKET_T_FORMAT": Packaging %d bytes (%d waiting).",
  1823. conn->base_.s,
  1824. (int)length, (int)connection_get_inbuf_len(TO_CONN(conn)));
  1825. if (sending_optimistically && !sending_from_optimistic) {
  1826. /* This is new optimistic data; remember it in case we need to detach and
  1827. retry */
  1828. if (!entry_conn->pending_optimistic_data)
  1829. entry_conn->pending_optimistic_data = buf_new();
  1830. write_to_buf(payload, length, entry_conn->pending_optimistic_data);
  1831. }
  1832. if (connection_edge_send_command(conn, RELAY_COMMAND_DATA,
  1833. payload, length) < 0 )
  1834. /* circuit got marked for close, don't continue, don't need to mark conn */
  1835. return 0;
  1836. if (!cpath_layer) { /* non-rendezvous exit */
  1837. tor_assert(circ->package_window > 0);
  1838. circ->package_window--;
  1839. } else { /* we're an AP, or an exit on a rendezvous circ */
  1840. tor_assert(cpath_layer->package_window > 0);
  1841. cpath_layer->package_window--;
  1842. }
  1843. if (--conn->package_window <= 0) { /* is it 0 after decrement? */
  1844. connection_stop_reading(TO_CONN(conn));
  1845. log_debug(domain,"conn->package_window reached 0.");
  1846. circuit_consider_stop_edge_reading(circ, cpath_layer);
  1847. return 0; /* don't process the inbuf any more */
  1848. }
  1849. log_debug(domain,"conn->package_window is now %d",conn->package_window);
  1850. if (max_cells) {
  1851. *max_cells -= 1;
  1852. if (*max_cells <= 0)
  1853. return 0;
  1854. }
  1855. /* handle more if there's more, or return 0 if there isn't */
  1856. goto repeat_connection_edge_package_raw_inbuf;
  1857. }
  1858. /** Called when we've just received a relay data cell, when
  1859. * we've just finished flushing all bytes to stream <b>conn</b>,
  1860. * or when we've flushed *some* bytes to the stream <b>conn</b>.
  1861. *
  1862. * If conn->outbuf is not too full, and our deliver window is
  1863. * low, send back a suitable number of stream-level sendme cells.
  1864. */
  1865. void
  1866. connection_edge_consider_sending_sendme(edge_connection_t *conn)
  1867. {
  1868. circuit_t *circ;
  1869. if (connection_outbuf_too_full(TO_CONN(conn)))
  1870. return;
  1871. circ = circuit_get_by_edge_conn(conn);
  1872. if (!circ) {
  1873. /* this can legitimately happen if the destroy has already
  1874. * arrived and torn down the circuit */
  1875. log_info(LD_APP,"No circuit associated with conn. Skipping.");
  1876. return;
  1877. }
  1878. while (conn->deliver_window <= STREAMWINDOW_START - STREAMWINDOW_INCREMENT) {
  1879. log_debug(conn->base_.type == CONN_TYPE_AP ?LD_APP:LD_EXIT,
  1880. "Outbuf %d, Queuing stream sendme.",
  1881. (int)conn->base_.outbuf_flushlen);
  1882. conn->deliver_window += STREAMWINDOW_INCREMENT;
  1883. if (connection_edge_send_command(conn, RELAY_COMMAND_SENDME,
  1884. NULL, 0) < 0) {
  1885. log_warn(LD_APP,"connection_edge_send_command failed. Skipping.");
  1886. return; /* the circuit's closed, don't continue */
  1887. }
  1888. }
  1889. }
  1890. /** The circuit <b>circ</b> has received a circuit-level sendme
  1891. * (on hop <b>layer_hint</b>, if we're the OP). Go through all the
  1892. * attached streams and let them resume reading and packaging, if
  1893. * their stream windows allow it.
  1894. */
  1895. static void
  1896. circuit_resume_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
  1897. {
  1898. if (circuit_queue_streams_are_blocked(circ)) {
  1899. log_debug(layer_hint?LD_APP:LD_EXIT,"Too big queue, no resuming");
  1900. return;
  1901. }
  1902. log_debug(layer_hint?LD_APP:LD_EXIT,"resuming");
  1903. if (CIRCUIT_IS_ORIGIN(circ))
  1904. circuit_resume_edge_reading_helper(TO_ORIGIN_CIRCUIT(circ)->p_streams,
  1905. circ, layer_hint);
  1906. else
  1907. circuit_resume_edge_reading_helper(TO_OR_CIRCUIT(circ)->n_streams,
  1908. circ, layer_hint);
  1909. }
  1910. void
  1911. stream_choice_seed_weak_rng(void)
  1912. {
  1913. crypto_seed_weak_rng(&stream_choice_rng);
  1914. }
  1915. /** A helper function for circuit_resume_edge_reading() above.
  1916. * The arguments are the same, except that <b>conn</b> is the head
  1917. * of a linked list of edge streams that should each be considered.
  1918. */
  1919. static int
  1920. circuit_resume_edge_reading_helper(edge_connection_t *first_conn,
  1921. circuit_t *circ,
  1922. crypt_path_t *layer_hint)
  1923. {
  1924. edge_connection_t *conn;
  1925. int n_packaging_streams, n_streams_left;
  1926. int packaged_this_round;
  1927. int cells_on_queue;
  1928. int cells_per_conn;
  1929. edge_connection_t *chosen_stream = NULL;
  1930. int max_to_package;
  1931. if (first_conn == NULL) {
  1932. /* Don't bother to try to do the rest of this if there are no connections
  1933. * to resume. */
  1934. return 0;
  1935. }
  1936. /* How many cells do we have space for? It will be the minimum of
  1937. * the number needed to exhaust the package window, and the minimum
  1938. * needed to fill the cell queue. */
  1939. max_to_package = circ->package_window;
  1940. if (CIRCUIT_IS_ORIGIN(circ)) {
  1941. cells_on_queue = circ->n_chan_cells.n;
  1942. } else {
  1943. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  1944. cells_on_queue = or_circ->p_chan_cells.n;
  1945. }
  1946. if (CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue < max_to_package)
  1947. max_to_package = CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue;
  1948. /* Once we used to start listening on the streams in the order they
  1949. * appeared in the linked list. That leads to starvation on the
  1950. * streams that appeared later on the list, since the first streams
  1951. * would always get to read first. Instead, we just pick a random
  1952. * stream on the list, and enable reading for streams starting at that
  1953. * point (and wrapping around as if the list were circular). It would
  1954. * probably be better to actually remember which streams we've
  1955. * serviced in the past, but this is simple and effective. */
  1956. /* Select a stream uniformly at random from the linked list. We
  1957. * don't need cryptographic randomness here. */
  1958. {
  1959. int num_streams = 0;
  1960. for (conn = first_conn; conn; conn = conn->next_stream) {
  1961. num_streams++;
  1962. if (tor_weak_random_one_in_n(&stream_choice_rng, num_streams)) {
  1963. chosen_stream = conn;
  1964. }
  1965. /* Invariant: chosen_stream has been chosen uniformly at random from
  1966. * among the first num_streams streams on first_conn.
  1967. *
  1968. * (Note that we iterate over every stream on the circuit, so that after
  1969. * we've considered the first stream, we've chosen it with P=1; and
  1970. * after we consider the second stream, we've switched to it with P=1/2
  1971. * and stayed with the first stream with P=1/2; and after we've
  1972. * considered the third stream, we've switched to it with P=1/3 and
  1973. * remained with one of the first two streams with P=(2/3), giving each
  1974. * one P=(1/2)(2/3) )=(1/3).) */
  1975. }
  1976. }
  1977. /* Count how many non-marked streams there are that have anything on
  1978. * their inbuf, and enable reading on all of the connections. */
  1979. n_packaging_streams = 0;
  1980. /* Activate reading starting from the chosen stream */
  1981. for (conn=chosen_stream; conn; conn = conn->next_stream) {
  1982. /* Start reading for the streams starting from here */
  1983. if (conn->base_.marked_for_close || conn->package_window <= 0)
  1984. continue;
  1985. if (!layer_hint || conn->cpath_layer == layer_hint) {
  1986. connection_start_reading(TO_CONN(conn));
  1987. if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
  1988. ++n_packaging_streams;
  1989. }
  1990. }
  1991. /* Go back and do the ones we skipped, circular-style */
  1992. for (conn = first_conn; conn != chosen_stream; conn = conn->next_stream) {
  1993. if (conn->base_.marked_for_close || conn->package_window <= 0)
  1994. continue;
  1995. if (!layer_hint || conn->cpath_layer == layer_hint) {
  1996. connection_start_reading(TO_CONN(conn));
  1997. if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
  1998. ++n_packaging_streams;
  1999. }
  2000. }
  2001. if (n_packaging_streams == 0) /* avoid divide-by-zero */
  2002. return 0;
  2003. again:
  2004. cells_per_conn = CEIL_DIV(max_to_package, n_packaging_streams);
  2005. packaged_this_round = 0;
  2006. n_streams_left = 0;
  2007. /* Iterate over all connections. Package up to cells_per_conn cells on
  2008. * each. Update packaged_this_round with the total number of cells
  2009. * packaged, and n_streams_left with the number that still have data to
  2010. * package.
  2011. */
  2012. for (conn=first_conn; conn; conn=conn->next_stream) {
  2013. if (conn->base_.marked_for_close || conn->package_window <= 0)
  2014. continue;
  2015. if (!layer_hint || conn->cpath_layer == layer_hint) {
  2016. int n = cells_per_conn, r;
  2017. /* handle whatever might still be on the inbuf */
  2018. r = connection_edge_package_raw_inbuf(conn, 1, &n);
  2019. /* Note how many we packaged */
  2020. packaged_this_round += (cells_per_conn-n);
  2021. if (r<0) {
  2022. /* Problem while packaging. (We already sent an end cell if
  2023. * possible) */
  2024. connection_mark_for_close(TO_CONN(conn));
  2025. continue;
  2026. }
  2027. /* If there's still data to read, we'll be coming back to this stream. */
  2028. if (connection_get_inbuf_len(TO_CONN(conn)))
  2029. ++n_streams_left;
  2030. /* If the circuit won't accept any more data, return without looking
  2031. * at any more of the streams. Any connections that should be stopped
  2032. * have already been stopped by connection_edge_package_raw_inbuf. */
  2033. if (circuit_consider_stop_edge_reading(circ, layer_hint))
  2034. return -1;
  2035. /* XXXX should we also stop immediately if we fill up the cell queue?
  2036. * Probably. */
  2037. }
  2038. }
  2039. /* If we made progress, and we are willing to package more, and there are
  2040. * any streams left that want to package stuff... try again!
  2041. */
  2042. if (packaged_this_round && packaged_this_round < max_to_package &&
  2043. n_streams_left) {
  2044. max_to_package -= packaged_this_round;
  2045. n_packaging_streams = n_streams_left;
  2046. goto again;
  2047. }
  2048. return 0;
  2049. }
  2050. /** Check if the package window for <b>circ</b> is empty (at
  2051. * hop <b>layer_hint</b> if it's defined).
  2052. *
  2053. * If yes, tell edge streams to stop reading and return 1.
  2054. * Else return 0.
  2055. */
  2056. static int
  2057. circuit_consider_stop_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
  2058. {
  2059. edge_connection_t *conn = NULL;
  2060. unsigned domain = layer_hint ? LD_APP : LD_EXIT;
  2061. if (!layer_hint) {
  2062. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  2063. log_debug(domain,"considering circ->package_window %d",
  2064. circ->package_window);
  2065. if (circ->package_window <= 0) {
  2066. log_debug(domain,"yes, not-at-origin. stopped.");
  2067. for (conn = or_circ->n_streams; conn; conn=conn->next_stream)
  2068. connection_stop_reading(TO_CONN(conn));
  2069. return 1;
  2070. }
  2071. return 0;
  2072. }
  2073. /* else, layer hint is defined, use it */
  2074. log_debug(domain,"considering layer_hint->package_window %d",
  2075. layer_hint->package_window);
  2076. if (layer_hint->package_window <= 0) {
  2077. log_debug(domain,"yes, at-origin. stopped.");
  2078. for (conn = TO_ORIGIN_CIRCUIT(circ)->p_streams; conn;
  2079. conn=conn->next_stream) {
  2080. if (conn->cpath_layer == layer_hint)
  2081. connection_stop_reading(TO_CONN(conn));
  2082. }
  2083. return 1;
  2084. }
  2085. return 0;
  2086. }
  2087. /** Check if the deliver_window for circuit <b>circ</b> (at hop
  2088. * <b>layer_hint</b> if it's defined) is low enough that we should
  2089. * send a circuit-level sendme back down the circuit. If so, send
  2090. * enough sendmes that the window would be overfull if we sent any
  2091. * more.
  2092. */
  2093. static void
  2094. circuit_consider_sending_sendme(circuit_t *circ, crypt_path_t *layer_hint)
  2095. {
  2096. // log_fn(LOG_INFO,"Considering: layer_hint is %s",
  2097. // layer_hint ? "defined" : "null");
  2098. while ((layer_hint ? layer_hint->deliver_window : circ->deliver_window) <=
  2099. CIRCWINDOW_START - CIRCWINDOW_INCREMENT) {
  2100. log_debug(LD_CIRC,"Queuing circuit sendme.");
  2101. if (layer_hint)
  2102. layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
  2103. else
  2104. circ->deliver_window += CIRCWINDOW_INCREMENT;
  2105. if (relay_send_command_from_edge(0, circ, RELAY_COMMAND_SENDME,
  2106. NULL, 0, layer_hint) < 0) {
  2107. log_warn(LD_CIRC,
  2108. "relay_send_command_from_edge failed. Circuit's closed.");
  2109. return; /* the circuit's closed, don't continue */
  2110. }
  2111. }
  2112. }
  2113. #ifdef ACTIVE_CIRCUITS_PARANOIA
  2114. #define assert_cmux_ok_paranoid(chan) \
  2115. assert_circuit_mux_okay(chan)
  2116. #else
  2117. #define assert_cmux_ok_paranoid(chan)
  2118. #endif
  2119. /** The total number of cells we have allocated. */
  2120. static size_t total_cells_allocated = 0;
  2121. /** Release storage held by <b>cell</b>. */
  2122. static inline void
  2123. packed_cell_free_unchecked(packed_cell_t *cell)
  2124. {
  2125. --total_cells_allocated;
  2126. tor_free(cell);
  2127. }
  2128. /** Allocate and return a new packed_cell_t. */
  2129. STATIC packed_cell_t *
  2130. packed_cell_new(void)
  2131. {
  2132. ++total_cells_allocated;
  2133. return tor_malloc_zero(sizeof(packed_cell_t));
  2134. }
  2135. /** Return a packed cell used outside by channel_t lower layer */
  2136. void
  2137. packed_cell_free(packed_cell_t *cell)
  2138. {
  2139. if (!cell)
  2140. return;
  2141. packed_cell_free_unchecked(cell);
  2142. }
  2143. /** Log current statistics for cell pool allocation at log level
  2144. * <b>severity</b>. */
  2145. void
  2146. dump_cell_pool_usage(int severity)
  2147. {
  2148. int n_circs = 0;
  2149. int n_cells = 0;
  2150. SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, c) {
  2151. n_cells += c->n_chan_cells.n;
  2152. if (!CIRCUIT_IS_ORIGIN(c))
  2153. n_cells += TO_OR_CIRCUIT(c)->p_chan_cells.n;
  2154. ++n_circs;
  2155. }
  2156. SMARTLIST_FOREACH_END(c);
  2157. tor_log(severity, LD_MM,
  2158. "%d cells allocated on %d circuits. %d cells leaked.",
  2159. n_cells, n_circs, (int)total_cells_allocated - n_cells);
  2160. }
  2161. /** Allocate a new copy of packed <b>cell</b>. */
  2162. static inline packed_cell_t *
  2163. packed_cell_copy(const cell_t *cell, int wide_circ_ids)
  2164. {
  2165. packed_cell_t *c = packed_cell_new();
  2166. cell_pack(c, cell, wide_circ_ids);
  2167. return c;
  2168. }
  2169. /** Append <b>cell</b> to the end of <b>queue</b>. */
  2170. void
  2171. cell_queue_append(cell_queue_t *queue, packed_cell_t *cell)
  2172. {
  2173. TOR_SIMPLEQ_INSERT_TAIL(&queue->head, cell, next);
  2174. ++queue->n;
  2175. }
  2176. /** Append a newly allocated copy of <b>cell</b> to the end of the
  2177. * <b>exitward</b> (or app-ward) <b>queue</b> of <b>circ</b>. If
  2178. * <b>use_stats</b> is true, record statistics about the cell.
  2179. */
  2180. void
  2181. cell_queue_append_packed_copy(circuit_t *circ, cell_queue_t *queue,
  2182. int exitward, const cell_t *cell,
  2183. int wide_circ_ids, int use_stats)
  2184. {
  2185. packed_cell_t *copy = packed_cell_copy(cell, wide_circ_ids);
  2186. (void)circ;
  2187. (void)exitward;
  2188. (void)use_stats;
  2189. copy->inserted_time = (uint32_t) monotime_coarse_absolute_msec();
  2190. cell_queue_append(queue, copy);
  2191. }
  2192. /** Initialize <b>queue</b> as an empty cell queue. */
  2193. void
  2194. cell_queue_init(cell_queue_t *queue)
  2195. {
  2196. memset(queue, 0, sizeof(cell_queue_t));
  2197. TOR_SIMPLEQ_INIT(&queue->head);
  2198. }
  2199. /** Remove and free every cell in <b>queue</b>. */
  2200. void
  2201. cell_queue_clear(cell_queue_t *queue)
  2202. {
  2203. packed_cell_t *cell;
  2204. while ((cell = TOR_SIMPLEQ_FIRST(&queue->head))) {
  2205. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2206. packed_cell_free_unchecked(cell);
  2207. }
  2208. TOR_SIMPLEQ_INIT(&queue->head);
  2209. queue->n = 0;
  2210. }
  2211. /** Extract and return the cell at the head of <b>queue</b>; return NULL if
  2212. * <b>queue</b> is empty. */
  2213. STATIC packed_cell_t *
  2214. cell_queue_pop(cell_queue_t *queue)
  2215. {
  2216. packed_cell_t *cell = TOR_SIMPLEQ_FIRST(&queue->head);
  2217. if (!cell)
  2218. return NULL;
  2219. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2220. --queue->n;
  2221. return cell;
  2222. }
  2223. /** Return the total number of bytes used for each packed_cell in a queue.
  2224. * Approximate. */
  2225. size_t
  2226. packed_cell_mem_cost(void)
  2227. {
  2228. return sizeof(packed_cell_t);
  2229. }
  2230. /* DOCDOC */
  2231. STATIC size_t
  2232. cell_queues_get_total_allocation(void)
  2233. {
  2234. return total_cells_allocated * packed_cell_mem_cost();
  2235. }
  2236. /** How long after we've been low on memory should we try to conserve it? */
  2237. #define MEMORY_PRESSURE_INTERVAL (30*60)
  2238. /** The time at which we were last low on memory. */
  2239. static time_t last_time_under_memory_pressure = 0;
  2240. /** Check whether we've got too much space used for cells. If so,
  2241. * call the OOM handler and return 1. Otherwise, return 0. */
  2242. STATIC int
  2243. cell_queues_check_size(void)
  2244. {
  2245. size_t alloc = cell_queues_get_total_allocation();
  2246. alloc += buf_get_total_allocation();
  2247. alloc += tor_compress_get_total_allocation();
  2248. const size_t rend_cache_total = rend_cache_get_total_allocation();
  2249. alloc += rend_cache_total;
  2250. if (alloc >= get_options()->MaxMemInQueues_low_threshold) {
  2251. last_time_under_memory_pressure = approx_time();
  2252. if (alloc >= get_options()->MaxMemInQueues) {
  2253. /* If we're spending over 20% of the memory limit on hidden service
  2254. * descriptors, free them until we're down to 10%.
  2255. */
  2256. if (rend_cache_total > get_options()->MaxMemInQueues / 5) {
  2257. const size_t bytes_to_remove =
  2258. rend_cache_total - (size_t)(get_options()->MaxMemInQueues / 10);
  2259. alloc -= hs_cache_handle_oom(time(NULL), bytes_to_remove);
  2260. }
  2261. circuits_handle_oom(alloc);
  2262. return 1;
  2263. }
  2264. }
  2265. return 0;
  2266. }
  2267. /** Return true if we've been under memory pressure in the last
  2268. * MEMORY_PRESSURE_INTERVAL seconds. */
  2269. int
  2270. have_been_under_memory_pressure(void)
  2271. {
  2272. return last_time_under_memory_pressure + MEMORY_PRESSURE_INTERVAL
  2273. < approx_time();
  2274. }
  2275. /**
  2276. * Update the number of cells available on the circuit's n_chan or p_chan's
  2277. * circuit mux.
  2278. */
  2279. void
  2280. update_circuit_on_cmux_(circuit_t *circ, cell_direction_t direction,
  2281. const char *file, int lineno)
  2282. {
  2283. channel_t *chan = NULL;
  2284. or_circuit_t *or_circ = NULL;
  2285. circuitmux_t *cmux = NULL;
  2286. tor_assert(circ);
  2287. /* Okay, get the channel */
  2288. if (direction == CELL_DIRECTION_OUT) {
  2289. chan = circ->n_chan;
  2290. } else {
  2291. or_circ = TO_OR_CIRCUIT(circ);
  2292. chan = or_circ->p_chan;
  2293. }
  2294. tor_assert(chan);
  2295. tor_assert(chan->cmux);
  2296. /* Now get the cmux */
  2297. cmux = chan->cmux;
  2298. /* Cmux sanity check */
  2299. if (! circuitmux_is_circuit_attached(cmux, circ)) {
  2300. log_warn(LD_BUG, "called on non-attached circuit from %s:%d",
  2301. file, lineno);
  2302. return;
  2303. }
  2304. tor_assert(circuitmux_attached_circuit_direction(cmux, circ) == direction);
  2305. assert_cmux_ok_paranoid(chan);
  2306. /* Update the number of cells we have for the circuit mux */
  2307. if (direction == CELL_DIRECTION_OUT) {
  2308. circuitmux_set_num_cells(cmux, circ, circ->n_chan_cells.n);
  2309. } else {
  2310. circuitmux_set_num_cells(cmux, circ, or_circ->p_chan_cells.n);
  2311. }
  2312. assert_cmux_ok_paranoid(chan);
  2313. }
  2314. /** Remove all circuits from the cmux on <b>chan</b>.
  2315. *
  2316. * If <b>circuits_out</b> is non-NULL, add all detached circuits to
  2317. * <b>circuits_out</b>.
  2318. **/
  2319. void
  2320. channel_unlink_all_circuits(channel_t *chan, smartlist_t *circuits_out)
  2321. {
  2322. tor_assert(chan);
  2323. tor_assert(chan->cmux);
  2324. circuitmux_detach_all_circuits(chan->cmux, circuits_out);
  2325. chan->num_n_circuits = 0;
  2326. chan->num_p_circuits = 0;
  2327. }
  2328. /** Block (if <b>block</b> is true) or unblock (if <b>block</b> is false)
  2329. * every edge connection that is using <b>circ</b> to write to <b>chan</b>,
  2330. * and start or stop reading as appropriate.
  2331. *
  2332. * If <b>stream_id</b> is nonzero, block only the edge connection whose
  2333. * stream_id matches it.
  2334. *
  2335. * Returns the number of streams whose status we changed.
  2336. */
  2337. static int
  2338. set_streams_blocked_on_circ(circuit_t *circ, channel_t *chan,
  2339. int block, streamid_t stream_id)
  2340. {
  2341. edge_connection_t *edge = NULL;
  2342. int n = 0;
  2343. if (circ->n_chan == chan) {
  2344. circ->streams_blocked_on_n_chan = block;
  2345. if (CIRCUIT_IS_ORIGIN(circ))
  2346. edge = TO_ORIGIN_CIRCUIT(circ)->p_streams;
  2347. } else {
  2348. circ->streams_blocked_on_p_chan = block;
  2349. tor_assert(!CIRCUIT_IS_ORIGIN(circ));
  2350. edge = TO_OR_CIRCUIT(circ)->n_streams;
  2351. }
  2352. for (; edge; edge = edge->next_stream) {
  2353. connection_t *conn = TO_CONN(edge);
  2354. if (stream_id && edge->stream_id != stream_id)
  2355. continue;
  2356. if (edge->edge_blocked_on_circ != block) {
  2357. ++n;
  2358. edge->edge_blocked_on_circ = block;
  2359. }
  2360. if (!conn->read_event) {
  2361. /* This connection is a placeholder for something; probably a DNS
  2362. * request. It can't actually stop or start reading.*/
  2363. continue;
  2364. }
  2365. if (block) {
  2366. if (connection_is_reading(conn))
  2367. connection_stop_reading(conn);
  2368. } else {
  2369. /* Is this right? */
  2370. if (!connection_is_reading(conn))
  2371. connection_start_reading(conn);
  2372. }
  2373. }
  2374. return n;
  2375. }
  2376. /** Extract the command from a packed cell. */
  2377. static uint8_t
  2378. packed_cell_get_command(const packed_cell_t *cell, int wide_circ_ids)
  2379. {
  2380. if (wide_circ_ids) {
  2381. return get_uint8(cell->body+4);
  2382. } else {
  2383. return get_uint8(cell->body+2);
  2384. }
  2385. }
  2386. /** Extract the circuit ID from a packed cell. */
  2387. circid_t
  2388. packed_cell_get_circid(const packed_cell_t *cell, int wide_circ_ids)
  2389. {
  2390. if (wide_circ_ids) {
  2391. return ntohl(get_uint32(cell->body));
  2392. } else {
  2393. return ntohs(get_uint16(cell->body));
  2394. }
  2395. }
  2396. /** Pull as many cells as possible (but no more than <b>max</b>) from the
  2397. * queue of the first active circuit on <b>chan</b>, and write them to
  2398. * <b>chan</b>-&gt;outbuf. Return the number of cells written. Advance
  2399. * the active circuit pointer to the next active circuit in the ring. */
  2400. MOCK_IMPL(int,
  2401. channel_flush_from_first_active_circuit, (channel_t *chan, int max))
  2402. {
  2403. circuitmux_t *cmux = NULL;
  2404. int n_flushed = 0;
  2405. cell_queue_t *queue, *destroy_queue=NULL;
  2406. circuit_t *circ;
  2407. or_circuit_t *or_circ;
  2408. int streams_blocked;
  2409. packed_cell_t *cell;
  2410. /* Get the cmux */
  2411. tor_assert(chan);
  2412. tor_assert(chan->cmux);
  2413. cmux = chan->cmux;
  2414. /* Main loop: pick a circuit, send a cell, update the cmux */
  2415. while (n_flushed < max) {
  2416. circ = circuitmux_get_first_active_circuit(cmux, &destroy_queue);
  2417. if (destroy_queue) {
  2418. /* this code is duplicated from some of the logic below. Ugly! XXXX */
  2419. tor_assert(destroy_queue->n > 0);
  2420. cell = cell_queue_pop(destroy_queue);
  2421. channel_write_packed_cell(chan, cell);
  2422. /* Update the cmux destroy counter */
  2423. circuitmux_notify_xmit_destroy(cmux);
  2424. cell = NULL;
  2425. ++n_flushed;
  2426. continue;
  2427. }
  2428. /* If it returns NULL, no cells left to send */
  2429. if (!circ) break;
  2430. assert_cmux_ok_paranoid(chan);
  2431. if (circ->n_chan == chan) {
  2432. queue = &circ->n_chan_cells;
  2433. streams_blocked = circ->streams_blocked_on_n_chan;
  2434. } else {
  2435. or_circ = TO_OR_CIRCUIT(circ);
  2436. tor_assert(or_circ->p_chan == chan);
  2437. queue = &TO_OR_CIRCUIT(circ)->p_chan_cells;
  2438. streams_blocked = circ->streams_blocked_on_p_chan;
  2439. }
  2440. /* Circuitmux told us this was active, so it should have cells */
  2441. if (/*BUG(*/ queue->n == 0 /*)*/) {
  2442. log_warn(LD_BUG, "Found a supposedly active circuit with no cells "
  2443. "to send. Trying to recover.");
  2444. circuitmux_set_num_cells(cmux, circ, 0);
  2445. if (! circ->marked_for_close)
  2446. circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
  2447. continue;
  2448. }
  2449. tor_assert(queue->n > 0);
  2450. /*
  2451. * Get just one cell here; once we've sent it, that can change the circuit
  2452. * selection, so we have to loop around for another even if this circuit
  2453. * has more than one.
  2454. */
  2455. cell = cell_queue_pop(queue);
  2456. /* Calculate the exact time that this cell has spent in the queue. */
  2457. if (get_options()->CellStatistics ||
  2458. get_options()->TestingEnableCellStatsEvent) {
  2459. uint32_t msec_waiting;
  2460. uint32_t msec_now = (uint32_t)monotime_coarse_absolute_msec();
  2461. msec_waiting = msec_now - cell->inserted_time;
  2462. if (get_options()->CellStatistics && !CIRCUIT_IS_ORIGIN(circ)) {
  2463. or_circ = TO_OR_CIRCUIT(circ);
  2464. or_circ->total_cell_waiting_time += msec_waiting;
  2465. or_circ->processed_cells++;
  2466. }
  2467. if (get_options()->TestingEnableCellStatsEvent) {
  2468. uint8_t command = packed_cell_get_command(cell, chan->wide_circ_ids);
  2469. testing_cell_stats_entry_t *ent =
  2470. tor_malloc_zero(sizeof(testing_cell_stats_entry_t));
  2471. ent->command = command;
  2472. ent->waiting_time = msec_waiting / 10;
  2473. ent->removed = 1;
  2474. if (circ->n_chan == chan)
  2475. ent->exitward = 1;
  2476. if (!circ->testing_cell_stats)
  2477. circ->testing_cell_stats = smartlist_new();
  2478. smartlist_add(circ->testing_cell_stats, ent);
  2479. }
  2480. }
  2481. /* If we just flushed our queue and this circuit is used for a
  2482. * tunneled directory request, possibly advance its state. */
  2483. if (queue->n == 0 && chan->dirreq_id)
  2484. geoip_change_dirreq_state(chan->dirreq_id,
  2485. DIRREQ_TUNNELED,
  2486. DIRREQ_CIRC_QUEUE_FLUSHED);
  2487. /* Now send the cell */
  2488. channel_write_packed_cell(chan, cell);
  2489. cell = NULL;
  2490. /*
  2491. * Don't packed_cell_free_unchecked(cell) here because the channel will
  2492. * do so when it gets out of the channel queue (probably already did, in
  2493. * which case that was an immediate double-free bug).
  2494. */
  2495. /* Update the counter */
  2496. ++n_flushed;
  2497. /*
  2498. * Now update the cmux; tell it we've just sent a cell, and how many
  2499. * we have left.
  2500. */
  2501. circuitmux_notify_xmit_cells(cmux, circ, 1);
  2502. circuitmux_set_num_cells(cmux, circ, queue->n);
  2503. if (queue->n == 0)
  2504. log_debug(LD_GENERAL, "Made a circuit inactive.");
  2505. /* Is the cell queue low enough to unblock all the streams that are waiting
  2506. * to write to this circuit? */
  2507. if (streams_blocked && queue->n <= CELL_QUEUE_LOWWATER_SIZE)
  2508. set_streams_blocked_on_circ(circ, chan, 0, 0); /* unblock streams */
  2509. /* If n_flushed < max still, loop around and pick another circuit */
  2510. }
  2511. /* Okay, we're done sending now */
  2512. assert_cmux_ok_paranoid(chan);
  2513. return n_flushed;
  2514. }
  2515. #if 0
  2516. /** Indicate the current preferred cap for middle circuits; zero disables
  2517. * the cap. Right now it's just a constant, ORCIRC_MAX_MIDDLE_CELLS, but
  2518. * the logic in append_cell_to_circuit_queue() is written to be correct
  2519. * if we want to base it on a consensus param or something that might change
  2520. * in the future.
  2521. */
  2522. static int
  2523. get_max_middle_cells(void)
  2524. {
  2525. return ORCIRC_MAX_MIDDLE_CELLS;
  2526. }
  2527. #endif
  2528. /** Add <b>cell</b> to the queue of <b>circ</b> writing to <b>chan</b>
  2529. * transmitting in <b>direction</b>. */
  2530. void
  2531. append_cell_to_circuit_queue(circuit_t *circ, channel_t *chan,
  2532. cell_t *cell, cell_direction_t direction,
  2533. streamid_t fromstream)
  2534. {
  2535. or_circuit_t *orcirc = NULL;
  2536. cell_queue_t *queue;
  2537. int streams_blocked;
  2538. #if 0
  2539. uint32_t tgt_max_middle_cells, p_len, n_len, tmp, hard_max_middle_cells;
  2540. #endif
  2541. int exitward;
  2542. if (circ->marked_for_close)
  2543. return;
  2544. exitward = (direction == CELL_DIRECTION_OUT);
  2545. if (exitward) {
  2546. queue = &circ->n_chan_cells;
  2547. streams_blocked = circ->streams_blocked_on_n_chan;
  2548. } else {
  2549. orcirc = TO_OR_CIRCUIT(circ);
  2550. queue = &orcirc->p_chan_cells;
  2551. streams_blocked = circ->streams_blocked_on_p_chan;
  2552. }
  2553. /*
  2554. * Disabling this for now because of a possible guard discovery attack
  2555. */
  2556. #if 0
  2557. /* Are we a middle circuit about to exceed ORCIRC_MAX_MIDDLE_CELLS? */
  2558. if ((circ->n_chan != NULL) && CIRCUIT_IS_ORCIRC(circ)) {
  2559. orcirc = TO_OR_CIRCUIT(circ);
  2560. if (orcirc->p_chan) {
  2561. /* We are a middle circuit if we have both n_chan and p_chan */
  2562. /* We'll need to know the current preferred maximum */
  2563. tgt_max_middle_cells = get_max_middle_cells();
  2564. if (tgt_max_middle_cells > 0) {
  2565. /* Do we need to initialize middle_max_cells? */
  2566. if (orcirc->max_middle_cells == 0) {
  2567. orcirc->max_middle_cells = tgt_max_middle_cells;
  2568. } else {
  2569. if (tgt_max_middle_cells > orcirc->max_middle_cells) {
  2570. /* If we want to increase the cap, we can do so right away */
  2571. orcirc->max_middle_cells = tgt_max_middle_cells;
  2572. } else if (tgt_max_middle_cells < orcirc->max_middle_cells) {
  2573. /*
  2574. * If we're shrinking the cap, we can't shrink past either queue;
  2575. * compare tgt_max_middle_cells rather than tgt_max_middle_cells *
  2576. * ORCIRC_MAX_MIDDLE_KILL_THRESH so the queues don't shrink enough
  2577. * to generate spurious warnings, either.
  2578. */
  2579. n_len = circ->n_chan_cells.n;
  2580. p_len = orcirc->p_chan_cells.n;
  2581. tmp = tgt_max_middle_cells;
  2582. if (tmp < n_len) tmp = n_len;
  2583. if (tmp < p_len) tmp = p_len;
  2584. orcirc->max_middle_cells = tmp;
  2585. }
  2586. /* else no change */
  2587. }
  2588. } else {
  2589. /* tgt_max_middle_cells == 0 indicates we should disable the cap */
  2590. orcirc->max_middle_cells = 0;
  2591. }
  2592. /* Now we know orcirc->max_middle_cells is set correctly */
  2593. if (orcirc->max_middle_cells > 0) {
  2594. hard_max_middle_cells =
  2595. (uint32_t)(((double)orcirc->max_middle_cells) *
  2596. ORCIRC_MAX_MIDDLE_KILL_THRESH);
  2597. if ((unsigned)queue->n + 1 >= hard_max_middle_cells) {
  2598. /* Queueing this cell would put queue over the kill theshold */
  2599. log_warn(LD_CIRC,
  2600. "Got a cell exceeding the hard cap of %u in the "
  2601. "%s direction on middle circ ID %u on chan ID "
  2602. U64_FORMAT "; killing the circuit.",
  2603. hard_max_middle_cells,
  2604. (direction == CELL_DIRECTION_OUT) ? "n" : "p",
  2605. (direction == CELL_DIRECTION_OUT) ?
  2606. circ->n_circ_id : orcirc->p_circ_id,
  2607. U64_PRINTF_ARG(
  2608. (direction == CELL_DIRECTION_OUT) ?
  2609. circ->n_chan->global_identifier :
  2610. orcirc->p_chan->global_identifier));
  2611. circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
  2612. return;
  2613. } else if ((unsigned)queue->n + 1 == orcirc->max_middle_cells) {
  2614. /* Only use ==, not >= for this test so we don't spam the log */
  2615. log_warn(LD_CIRC,
  2616. "While trying to queue a cell, reached the soft cap of %u "
  2617. "in the %s direction on middle circ ID %u "
  2618. "on chan ID " U64_FORMAT ".",
  2619. orcirc->max_middle_cells,
  2620. (direction == CELL_DIRECTION_OUT) ? "n" : "p",
  2621. (direction == CELL_DIRECTION_OUT) ?
  2622. circ->n_circ_id : orcirc->p_circ_id,
  2623. U64_PRINTF_ARG(
  2624. (direction == CELL_DIRECTION_OUT) ?
  2625. circ->n_chan->global_identifier :
  2626. orcirc->p_chan->global_identifier));
  2627. }
  2628. }
  2629. }
  2630. }
  2631. #endif
  2632. cell_queue_append_packed_copy(circ, queue, exitward, cell,
  2633. chan->wide_circ_ids, 1);
  2634. if (PREDICT_UNLIKELY(cell_queues_check_size())) {
  2635. /* We ran the OOM handler */
  2636. if (circ->marked_for_close)
  2637. return;
  2638. }
  2639. /* If we have too many cells on the circuit, we should stop reading from
  2640. * the edge streams for a while. */
  2641. if (!streams_blocked && queue->n >= CELL_QUEUE_HIGHWATER_SIZE)
  2642. set_streams_blocked_on_circ(circ, chan, 1, 0); /* block streams */
  2643. if (streams_blocked && fromstream) {
  2644. /* This edge connection is apparently not blocked; block it. */
  2645. set_streams_blocked_on_circ(circ, chan, 1, fromstream);
  2646. }
  2647. update_circuit_on_cmux(circ, direction);
  2648. if (queue->n == 1) {
  2649. /* This was the first cell added to the queue. We just made this
  2650. * circuit active. */
  2651. log_debug(LD_GENERAL, "Made a circuit active.");
  2652. }
  2653. /* New way: mark this as having waiting cells for the scheduler */
  2654. scheduler_channel_has_waiting_cells(chan);
  2655. }
  2656. /** Append an encoded value of <b>addr</b> to <b>payload_out</b>, which must
  2657. * have at least 18 bytes of free space. The encoding is, as specified in
  2658. * tor-spec.txt:
  2659. * RESOLVED_TYPE_IPV4 or RESOLVED_TYPE_IPV6 [1 byte]
  2660. * LENGTH [1 byte]
  2661. * ADDRESS [length bytes]
  2662. * Return the number of bytes added, or -1 on error */
  2663. int
  2664. append_address_to_payload(uint8_t *payload_out, const tor_addr_t *addr)
  2665. {
  2666. uint32_t a;
  2667. switch (tor_addr_family(addr)) {
  2668. case AF_INET:
  2669. payload_out[0] = RESOLVED_TYPE_IPV4;
  2670. payload_out[1] = 4;
  2671. a = tor_addr_to_ipv4n(addr);
  2672. memcpy(payload_out+2, &a, 4);
  2673. return 6;
  2674. case AF_INET6:
  2675. payload_out[0] = RESOLVED_TYPE_IPV6;
  2676. payload_out[1] = 16;
  2677. memcpy(payload_out+2, tor_addr_to_in6_addr8(addr), 16);
  2678. return 18;
  2679. case AF_UNSPEC:
  2680. default:
  2681. return -1;
  2682. }
  2683. }
  2684. /** Given <b>payload_len</b> bytes at <b>payload</b>, starting with an address
  2685. * encoded as by append_address_to_payload(), try to decode the address into
  2686. * *<b>addr_out</b>. Return the next byte in the payload after the address on
  2687. * success, or NULL on failure. */
  2688. const uint8_t *
  2689. decode_address_from_payload(tor_addr_t *addr_out, const uint8_t *payload,
  2690. int payload_len)
  2691. {
  2692. if (payload_len < 2)
  2693. return NULL;
  2694. if (payload_len < 2+payload[1])
  2695. return NULL;
  2696. switch (payload[0]) {
  2697. case RESOLVED_TYPE_IPV4:
  2698. if (payload[1] != 4)
  2699. return NULL;
  2700. tor_addr_from_ipv4n(addr_out, get_uint32(payload+2));
  2701. break;
  2702. case RESOLVED_TYPE_IPV6:
  2703. if (payload[1] != 16)
  2704. return NULL;
  2705. tor_addr_from_ipv6_bytes(addr_out, (char*)(payload+2));
  2706. break;
  2707. default:
  2708. tor_addr_make_unspec(addr_out);
  2709. break;
  2710. }
  2711. return payload + 2 + payload[1];
  2712. }
  2713. /** Remove all the cells queued on <b>circ</b> for <b>chan</b>. */
  2714. void
  2715. circuit_clear_cell_queue(circuit_t *circ, channel_t *chan)
  2716. {
  2717. cell_queue_t *queue;
  2718. cell_direction_t direction;
  2719. if (circ->n_chan == chan) {
  2720. queue = &circ->n_chan_cells;
  2721. direction = CELL_DIRECTION_OUT;
  2722. } else {
  2723. or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
  2724. tor_assert(orcirc->p_chan == chan);
  2725. queue = &orcirc->p_chan_cells;
  2726. direction = CELL_DIRECTION_IN;
  2727. }
  2728. /* Clear the queue */
  2729. cell_queue_clear(queue);
  2730. /* Update the cell counter in the cmux */
  2731. if (chan->cmux && circuitmux_is_circuit_attached(chan->cmux, circ))
  2732. update_circuit_on_cmux(circ, direction);
  2733. }
  2734. /** Fail with an assert if the circuit mux on chan is corrupt
  2735. */
  2736. void
  2737. assert_circuit_mux_okay(channel_t *chan)
  2738. {
  2739. tor_assert(chan);
  2740. tor_assert(chan->cmux);
  2741. circuitmux_assert_okay(chan->cmux);
  2742. }
  2743. /** Return 1 if we shouldn't restart reading on this circuit, even if
  2744. * we get a SENDME. Else return 0.
  2745. */
  2746. static int
  2747. circuit_queue_streams_are_blocked(circuit_t *circ)
  2748. {
  2749. if (CIRCUIT_IS_ORIGIN(circ)) {
  2750. return circ->streams_blocked_on_n_chan;
  2751. } else {
  2752. return circ->streams_blocked_on_p_chan;
  2753. }
  2754. }