relay.c 109 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556155715581559156015611562156315641565156615671568156915701571157215731574157515761577157815791580158115821583158415851586158715881589159015911592159315941595159615971598159916001601160216031604160516061607160816091610161116121613161416151616161716181619162016211622162316241625162616271628162916301631163216331634163516361637163816391640164116421643164416451646164716481649165016511652165316541655165616571658165916601661166216631664166516661667166816691670167116721673167416751676167716781679168016811682168316841685168616871688168916901691169216931694169516961697169816991700170117021703170417051706170717081709171017111712171317141715171617171718171917201721172217231724172517261727172817291730173117321733173417351736173717381739174017411742174317441745174617471748174917501751175217531754175517561757175817591760176117621763176417651766176717681769177017711772177317741775177617771778177917801781178217831784178517861787178817891790179117921793179417951796179717981799180018011802180318041805180618071808180918101811181218131814181518161817181818191820182118221823182418251826182718281829183018311832183318341835183618371838183918401841184218431844184518461847184818491850185118521853185418551856185718581859186018611862186318641865186618671868186918701871187218731874187518761877187818791880188118821883188418851886188718881889189018911892189318941895189618971898189919001901190219031904190519061907190819091910191119121913191419151916191719181919192019211922192319241925192619271928192919301931193219331934193519361937193819391940194119421943194419451946194719481949195019511952195319541955195619571958195919601961196219631964196519661967196819691970197119721973197419751976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027202820292030203120322033203420352036203720382039204020412042204320442045204620472048204920502051205220532054205520562057205820592060206120622063206420652066206720682069207020712072207320742075207620772078207920802081208220832084208520862087208820892090209120922093209420952096209720982099210021012102210321042105210621072108210921102111211221132114211521162117211821192120212121222123212421252126212721282129213021312132213321342135213621372138213921402141214221432144214521462147214821492150215121522153215421552156215721582159216021612162216321642165216621672168216921702171217221732174217521762177217821792180218121822183218421852186218721882189219021912192219321942195219621972198219922002201220222032204220522062207220822092210221122122213221422152216221722182219222022212222222322242225222622272228222922302231223222332234223522362237223822392240224122422243224422452246224722482249225022512252225322542255225622572258225922602261226222632264226522662267226822692270227122722273227422752276227722782279228022812282228322842285228622872288228922902291229222932294229522962297229822992300230123022303230423052306230723082309231023112312231323142315231623172318231923202321232223232324232523262327232823292330233123322333233423352336233723382339234023412342234323442345234623472348234923502351235223532354235523562357235823592360236123622363236423652366236723682369237023712372237323742375237623772378237923802381238223832384238523862387238823892390239123922393239423952396239723982399240024012402240324042405240624072408240924102411241224132414241524162417241824192420242124222423242424252426242724282429243024312432243324342435243624372438243924402441244224432444244524462447244824492450245124522453245424552456245724582459246024612462246324642465246624672468246924702471247224732474247524762477247824792480248124822483248424852486248724882489249024912492249324942495249624972498249925002501250225032504250525062507250825092510251125122513251425152516251725182519252025212522252325242525252625272528252925302531253225332534253525362537253825392540254125422543254425452546254725482549255025512552255325542555255625572558255925602561256225632564256525662567256825692570257125722573257425752576257725782579258025812582258325842585258625872588258925902591259225932594259525962597259825992600260126022603260426052606260726082609261026112612261326142615261626172618261926202621262226232624262526262627262826292630263126322633263426352636263726382639264026412642264326442645264626472648264926502651265226532654265526562657265826592660266126622663266426652666266726682669267026712672267326742675267626772678267926802681268226832684268526862687268826892690269126922693269426952696269726982699270027012702270327042705270627072708270927102711271227132714271527162717271827192720272127222723272427252726272727282729273027312732273327342735273627372738273927402741274227432744274527462747274827492750275127522753275427552756275727582759276027612762276327642765276627672768276927702771277227732774277527762777277827792780278127822783278427852786278727882789279027912792279327942795279627972798279928002801280228032804280528062807280828092810281128122813281428152816281728182819282028212822282328242825282628272828282928302831283228332834283528362837283828392840284128422843284428452846284728482849285028512852285328542855285628572858285928602861286228632864286528662867286828692870287128722873287428752876287728782879288028812882288328842885288628872888288928902891289228932894289528962897289828992900290129022903290429052906290729082909291029112912291329142915291629172918291929202921292229232924292529262927292829292930293129322933293429352936293729382939294029412942294329442945294629472948294929502951295229532954295529562957295829592960296129622963296429652966296729682969297029712972297329742975297629772978297929802981298229832984298529862987298829892990299129922993299429952996299729982999300030013002300330043005300630073008300930103011301230133014301530163017301830193020302130223023302430253026302730283029303030313032303330343035303630373038303930403041304230433044304530463047304830493050305130523053305430553056305730583059306030613062
  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 "backtrace.h"
  50. #include "buffers.h"
  51. #include "channel.h"
  52. #include "circpathbias.h"
  53. #include "circuitbuild.h"
  54. #include "circuitlist.h"
  55. #include "circuituse.h"
  56. #include "compress.h"
  57. #include "config.h"
  58. #include "connection.h"
  59. #include "connection_edge.h"
  60. #include "connection_or.h"
  61. #include "control.h"
  62. #include "crypto_rand.h"
  63. #include "crypto_util.h"
  64. #include "directory.h"
  65. #include "geoip.h"
  66. #include "hs_cache.h"
  67. #include "main.h"
  68. #include "networkstatus.h"
  69. #include "nodelist.h"
  70. #include "onion.h"
  71. #include "policies.h"
  72. #include "reasons.h"
  73. #include "relay.h"
  74. #include "relay_crypto.h"
  75. #include "rendcache.h"
  76. #include "rendcommon.h"
  77. #include "router.h"
  78. #include "routerlist.h"
  79. #include "routerparse.h"
  80. #include "scheduler.h"
  81. #include "rephist.h"
  82. #include "cpath_build_state_st.h"
  83. #include "dir_connection_st.h"
  84. #include "entry_connection_st.h"
  85. #include "or_circuit_st.h"
  86. #include "origin_circuit_st.h"
  87. #include "socks_request_st.h"
  88. static edge_connection_t *relay_lookup_conn(circuit_t *circ, cell_t *cell,
  89. cell_direction_t cell_direction,
  90. crypt_path_t *layer_hint);
  91. static void circuit_consider_sending_sendme(circuit_t *circ,
  92. crypt_path_t *layer_hint);
  93. static void circuit_resume_edge_reading(circuit_t *circ,
  94. crypt_path_t *layer_hint);
  95. static int circuit_resume_edge_reading_helper(edge_connection_t *conn,
  96. circuit_t *circ,
  97. crypt_path_t *layer_hint);
  98. static int circuit_consider_stop_edge_reading(circuit_t *circ,
  99. crypt_path_t *layer_hint);
  100. static int circuit_queue_streams_are_blocked(circuit_t *circ);
  101. static void adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
  102. entry_connection_t *conn,
  103. node_t *node,
  104. const tor_addr_t *addr);
  105. /** Stop reading on edge connections when we have this many cells
  106. * waiting on the appropriate queue. */
  107. #define CELL_QUEUE_HIGHWATER_SIZE 256
  108. /** Start reading from edge connections again when we get down to this many
  109. * cells. */
  110. #define CELL_QUEUE_LOWWATER_SIZE 64
  111. /** Stats: how many relay cells have originated at this hop, or have
  112. * been relayed onward (not recognized at this hop)?
  113. */
  114. uint64_t stats_n_relay_cells_relayed = 0;
  115. /** Stats: how many relay cells have been delivered to streams at this
  116. * hop?
  117. */
  118. uint64_t stats_n_relay_cells_delivered = 0;
  119. /** Stats: how many circuits have we closed due to the cell queue limit being
  120. * reached (see append_cell_to_circuit_queue()) */
  121. uint64_t stats_n_circ_max_cell_reached = 0;
  122. /** Used to tell which stream to read from first on a circuit. */
  123. static tor_weak_rng_t stream_choice_rng = TOR_WEAK_RNG_INIT;
  124. /**
  125. * Update channel usage state based on the type of relay cell and
  126. * circuit properties.
  127. *
  128. * This is needed to determine if a client channel is being
  129. * used for application traffic, and if a relay channel is being
  130. * used for multihop circuits and application traffic. The decision
  131. * to pad in channelpadding.c depends upon this info (as well as
  132. * consensus parameters) to decide what channels to pad.
  133. */
  134. static void
  135. circuit_update_channel_usage(circuit_t *circ, cell_t *cell)
  136. {
  137. if (CIRCUIT_IS_ORIGIN(circ)) {
  138. /*
  139. * The client state was first set much earlier in
  140. * circuit_send_next_onion_skin(), so we can start padding as early as
  141. * possible.
  142. *
  143. * However, if padding turns out to be expensive, we may want to not do
  144. * it until actual application traffic starts flowing (which is controlled
  145. * via consensus param nf_pad_before_usage).
  146. *
  147. * So: If we're an origin circuit and we've created a full length circuit,
  148. * then any CELL_RELAY cell means application data. Increase the usage
  149. * state of the channel to indicate this.
  150. *
  151. * We want to wait for CELL_RELAY specifically here, so we know that
  152. * the channel was definitely being used for data and not for extends.
  153. * By default, we pad as soon as a channel has been used for *any*
  154. * circuits, so this state is irrelevant to the padding decision in
  155. * the default case. However, if padding turns out to be expensive,
  156. * we would like the ability to avoid padding until we're absolutely
  157. * sure that a channel is used for enough application data to be worth
  158. * padding.
  159. *
  160. * (So it does not matter that CELL_RELAY_EARLY can actually contain
  161. * application data. This is only a load reducing option and that edge
  162. * case does not matter if we're desperately trying to reduce overhead
  163. * anyway. See also consensus parameter nf_pad_before_usage).
  164. */
  165. if (BUG(!circ->n_chan))
  166. return;
  167. if (circ->n_chan->channel_usage == CHANNEL_USED_FOR_FULL_CIRCS &&
  168. cell->command == CELL_RELAY) {
  169. circ->n_chan->channel_usage = CHANNEL_USED_FOR_USER_TRAFFIC;
  170. }
  171. } else {
  172. /* If we're a relay circuit, the question is more complicated. Basically:
  173. * we only want to pad connections that carry multihop (anonymous)
  174. * circuits.
  175. *
  176. * We assume we're more than one hop if either the previous hop
  177. * is not a client, or if the previous hop is a client and there's
  178. * a next hop. Then, circuit traffic starts at RELAY_EARLY, and
  179. * user application traffic starts when we see RELAY cells.
  180. */
  181. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  182. if (BUG(!or_circ->p_chan))
  183. return;
  184. if (!channel_is_client(or_circ->p_chan) ||
  185. (channel_is_client(or_circ->p_chan) && circ->n_chan)) {
  186. if (cell->command == CELL_RELAY_EARLY) {
  187. if (or_circ->p_chan->channel_usage < CHANNEL_USED_FOR_FULL_CIRCS) {
  188. or_circ->p_chan->channel_usage = CHANNEL_USED_FOR_FULL_CIRCS;
  189. }
  190. } else if (cell->command == CELL_RELAY) {
  191. or_circ->p_chan->channel_usage = CHANNEL_USED_FOR_USER_TRAFFIC;
  192. }
  193. }
  194. }
  195. }
  196. /** Receive a relay cell:
  197. * - Crypt it (encrypt if headed toward the origin or if we <b>are</b> the
  198. * origin; decrypt if we're headed toward the exit).
  199. * - Check if recognized (if exitward).
  200. * - If recognized and the digest checks out, then find if there's a stream
  201. * that the cell is intended for, and deliver it to the right
  202. * connection_edge.
  203. * - If not recognized, then we need to relay it: append it to the appropriate
  204. * cell_queue on <b>circ</b>.
  205. *
  206. * Return -<b>reason</b> on failure.
  207. */
  208. int
  209. circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
  210. cell_direction_t cell_direction)
  211. {
  212. channel_t *chan = NULL;
  213. crypt_path_t *layer_hint=NULL;
  214. char recognized=0;
  215. int reason;
  216. tor_assert(cell);
  217. tor_assert(circ);
  218. tor_assert(cell_direction == CELL_DIRECTION_OUT ||
  219. cell_direction == CELL_DIRECTION_IN);
  220. if (circ->marked_for_close)
  221. return 0;
  222. if (relay_decrypt_cell(circ, cell, cell_direction, &layer_hint, &recognized)
  223. < 0) {
  224. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  225. "relay crypt failed. Dropping connection.");
  226. return -END_CIRC_REASON_INTERNAL;
  227. }
  228. circuit_update_channel_usage(circ, cell);
  229. if (recognized) {
  230. edge_connection_t *conn = NULL;
  231. if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
  232. pathbias_check_probe_response(circ, cell);
  233. /* We need to drop this cell no matter what to avoid code that expects
  234. * a certain purpose (such as the hidserv code). */
  235. return 0;
  236. }
  237. conn = relay_lookup_conn(circ, cell, cell_direction, layer_hint);
  238. if (cell_direction == CELL_DIRECTION_OUT) {
  239. ++stats_n_relay_cells_delivered;
  240. log_debug(LD_OR,"Sending away from origin.");
  241. if ((reason=connection_edge_process_relay_cell(cell, circ, conn, NULL))
  242. < 0) {
  243. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  244. "connection_edge_process_relay_cell (away from origin) "
  245. "failed.");
  246. return reason;
  247. }
  248. }
  249. if (cell_direction == CELL_DIRECTION_IN) {
  250. ++stats_n_relay_cells_delivered;
  251. log_debug(LD_OR,"Sending to origin.");
  252. if ((reason = connection_edge_process_relay_cell(cell, circ, conn,
  253. layer_hint)) < 0) {
  254. /* If a client is trying to connect to unknown hidden service port,
  255. * END_CIRC_AT_ORIGIN is sent back so we can then close the circuit.
  256. * Do not log warn as this is an expected behavior for a service. */
  257. if (reason != END_CIRC_AT_ORIGIN) {
  258. log_warn(LD_OR,
  259. "connection_edge_process_relay_cell (at origin) failed.");
  260. }
  261. return reason;
  262. }
  263. }
  264. return 0;
  265. }
  266. /* not recognized. pass it on. */
  267. if (cell_direction == CELL_DIRECTION_OUT) {
  268. cell->circ_id = circ->n_circ_id; /* switch it */
  269. chan = circ->n_chan;
  270. } else if (! CIRCUIT_IS_ORIGIN(circ)) {
  271. cell->circ_id = TO_OR_CIRCUIT(circ)->p_circ_id; /* switch it */
  272. chan = TO_OR_CIRCUIT(circ)->p_chan;
  273. } else {
  274. log_fn(LOG_PROTOCOL_WARN, LD_OR,
  275. "Dropping unrecognized inbound cell on origin circuit.");
  276. /* If we see unrecognized cells on path bias testing circs,
  277. * it's bad mojo. Those circuits need to die.
  278. * XXX: Shouldn't they always die? */
  279. if (circ->purpose == CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
  280. TO_ORIGIN_CIRCUIT(circ)->path_state = PATH_STATE_USE_FAILED;
  281. return -END_CIRC_REASON_TORPROTOCOL;
  282. } else {
  283. return 0;
  284. }
  285. }
  286. if (!chan) {
  287. // XXXX Can this splice stuff be done more cleanly?
  288. if (! CIRCUIT_IS_ORIGIN(circ) &&
  289. TO_OR_CIRCUIT(circ)->rend_splice &&
  290. cell_direction == CELL_DIRECTION_OUT) {
  291. or_circuit_t *splice_ = TO_OR_CIRCUIT(circ)->rend_splice;
  292. tor_assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
  293. tor_assert(splice_->base_.purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
  294. cell->circ_id = splice_->p_circ_id;
  295. cell->command = CELL_RELAY; /* can't be relay_early anyway */
  296. if ((reason = circuit_receive_relay_cell(cell, TO_CIRCUIT(splice_),
  297. CELL_DIRECTION_IN)) < 0) {
  298. log_warn(LD_REND, "Error relaying cell across rendezvous; closing "
  299. "circuits");
  300. /* XXXX Do this here, or just return -1? */
  301. circuit_mark_for_close(circ, -reason);
  302. return reason;
  303. }
  304. return 0;
  305. }
  306. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  307. "Didn't recognize cell, but circ stops here! Closing circ.");
  308. return -END_CIRC_REASON_TORPROTOCOL;
  309. }
  310. log_debug(LD_OR,"Passing on unrecognized cell.");
  311. ++stats_n_relay_cells_relayed; /* XXXX no longer quite accurate {cells}
  312. * we might kill the circ before we relay
  313. * the cells. */
  314. append_cell_to_circuit_queue(circ, chan, cell, cell_direction, 0);
  315. return 0;
  316. }
  317. /** Package a relay cell from an edge:
  318. * - Encrypt it to the right layer
  319. * - Append it to the appropriate cell_queue on <b>circ</b>.
  320. */
  321. static int
  322. circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
  323. cell_direction_t cell_direction,
  324. crypt_path_t *layer_hint, streamid_t on_stream,
  325. const char *filename, int lineno)
  326. {
  327. channel_t *chan; /* where to send the cell */
  328. if (circ->marked_for_close) {
  329. /* Circuit is marked; send nothing. */
  330. return 0;
  331. }
  332. if (cell_direction == CELL_DIRECTION_OUT) {
  333. chan = circ->n_chan;
  334. if (!chan) {
  335. log_warn(LD_BUG,"outgoing relay cell sent from %s:%d has n_chan==NULL."
  336. " Dropping. Circuit is in state %s (%d), and is "
  337. "%smarked for close. (%s:%d, %d)", filename, lineno,
  338. circuit_state_to_string(circ->state), circ->state,
  339. circ->marked_for_close ? "" : "not ",
  340. circ->marked_for_close_file?circ->marked_for_close_file:"",
  341. circ->marked_for_close, circ->marked_for_close_reason);
  342. if (CIRCUIT_IS_ORIGIN(circ)) {
  343. circuit_log_path(LOG_WARN, LD_BUG, TO_ORIGIN_CIRCUIT(circ));
  344. }
  345. log_backtrace(LOG_WARN,LD_BUG,"");
  346. return 0; /* just drop it */
  347. }
  348. if (!CIRCUIT_IS_ORIGIN(circ)) {
  349. log_warn(LD_BUG,"outgoing relay cell sent from %s:%d on non-origin "
  350. "circ. Dropping.", filename, lineno);
  351. log_backtrace(LOG_WARN,LD_BUG,"");
  352. return 0; /* just drop it */
  353. }
  354. relay_encrypt_cell_outbound(cell, TO_ORIGIN_CIRCUIT(circ), layer_hint);
  355. /* Update circ written totals for control port */
  356. origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
  357. ocirc->n_written_circ_bw = tor_add_u32_nowrap(ocirc->n_written_circ_bw,
  358. CELL_PAYLOAD_SIZE);
  359. } else { /* incoming cell */
  360. if (CIRCUIT_IS_ORIGIN(circ)) {
  361. /* We should never package an _incoming_ cell from the circuit
  362. * origin; that means we messed up somewhere. */
  363. log_warn(LD_BUG,"incoming relay cell at origin circuit. Dropping.");
  364. assert_circuit_ok(circ);
  365. return 0; /* just drop it */
  366. }
  367. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  368. relay_encrypt_cell_inbound(cell, or_circ);
  369. chan = or_circ->p_chan;
  370. }
  371. ++stats_n_relay_cells_relayed;
  372. append_cell_to_circuit_queue(circ, chan, cell, cell_direction, on_stream);
  373. return 0;
  374. }
  375. /** If cell's stream_id matches the stream_id of any conn that's
  376. * attached to circ, return that conn, else return NULL.
  377. */
  378. static edge_connection_t *
  379. relay_lookup_conn(circuit_t *circ, cell_t *cell,
  380. cell_direction_t cell_direction, crypt_path_t *layer_hint)
  381. {
  382. edge_connection_t *tmpconn;
  383. relay_header_t rh;
  384. relay_header_unpack(&rh, cell->payload);
  385. if (!rh.stream_id)
  386. return NULL;
  387. /* IN or OUT cells could have come from either direction, now
  388. * that we allow rendezvous *to* an OP.
  389. */
  390. if (CIRCUIT_IS_ORIGIN(circ)) {
  391. for (tmpconn = TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn;
  392. tmpconn=tmpconn->next_stream) {
  393. if (rh.stream_id == tmpconn->stream_id &&
  394. !tmpconn->base_.marked_for_close &&
  395. tmpconn->cpath_layer == layer_hint) {
  396. log_debug(LD_APP,"found conn for stream %d.", rh.stream_id);
  397. return tmpconn;
  398. }
  399. }
  400. } else {
  401. for (tmpconn = TO_OR_CIRCUIT(circ)->n_streams; tmpconn;
  402. tmpconn=tmpconn->next_stream) {
  403. if (rh.stream_id == tmpconn->stream_id &&
  404. !tmpconn->base_.marked_for_close) {
  405. log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
  406. if (cell_direction == CELL_DIRECTION_OUT ||
  407. connection_edge_is_rendezvous_stream(tmpconn))
  408. return tmpconn;
  409. }
  410. }
  411. for (tmpconn = TO_OR_CIRCUIT(circ)->resolving_streams; tmpconn;
  412. tmpconn=tmpconn->next_stream) {
  413. if (rh.stream_id == tmpconn->stream_id &&
  414. !tmpconn->base_.marked_for_close) {
  415. log_debug(LD_EXIT,"found conn for stream %d.", rh.stream_id);
  416. return tmpconn;
  417. }
  418. }
  419. }
  420. return NULL; /* probably a begin relay cell */
  421. }
  422. /** Pack the relay_header_t host-order structure <b>src</b> into
  423. * network-order in the buffer <b>dest</b>. See tor-spec.txt for details
  424. * about the wire format.
  425. */
  426. void
  427. relay_header_pack(uint8_t *dest, const relay_header_t *src)
  428. {
  429. set_uint8(dest, src->command);
  430. set_uint16(dest+1, htons(src->recognized));
  431. set_uint16(dest+3, htons(src->stream_id));
  432. memcpy(dest+5, src->integrity, 4);
  433. set_uint16(dest+9, htons(src->length));
  434. }
  435. /** Unpack the network-order buffer <b>src</b> into a host-order
  436. * relay_header_t structure <b>dest</b>.
  437. */
  438. void
  439. relay_header_unpack(relay_header_t *dest, const uint8_t *src)
  440. {
  441. dest->command = get_uint8(src);
  442. dest->recognized = ntohs(get_uint16(src+1));
  443. dest->stream_id = ntohs(get_uint16(src+3));
  444. memcpy(dest->integrity, src+5, 4);
  445. dest->length = ntohs(get_uint16(src+9));
  446. }
  447. /** Convert the relay <b>command</b> into a human-readable string. */
  448. static const char *
  449. relay_command_to_string(uint8_t command)
  450. {
  451. static char buf[64];
  452. switch (command) {
  453. case RELAY_COMMAND_BEGIN: return "BEGIN";
  454. case RELAY_COMMAND_DATA: return "DATA";
  455. case RELAY_COMMAND_END: return "END";
  456. case RELAY_COMMAND_CONNECTED: return "CONNECTED";
  457. case RELAY_COMMAND_SENDME: return "SENDME";
  458. case RELAY_COMMAND_EXTEND: return "EXTEND";
  459. case RELAY_COMMAND_EXTENDED: return "EXTENDED";
  460. case RELAY_COMMAND_TRUNCATE: return "TRUNCATE";
  461. case RELAY_COMMAND_TRUNCATED: return "TRUNCATED";
  462. case RELAY_COMMAND_DROP: return "DROP";
  463. case RELAY_COMMAND_RESOLVE: return "RESOLVE";
  464. case RELAY_COMMAND_RESOLVED: return "RESOLVED";
  465. case RELAY_COMMAND_BEGIN_DIR: return "BEGIN_DIR";
  466. case RELAY_COMMAND_ESTABLISH_INTRO: return "ESTABLISH_INTRO";
  467. case RELAY_COMMAND_ESTABLISH_RENDEZVOUS: return "ESTABLISH_RENDEZVOUS";
  468. case RELAY_COMMAND_INTRODUCE1: return "INTRODUCE1";
  469. case RELAY_COMMAND_INTRODUCE2: return "INTRODUCE2";
  470. case RELAY_COMMAND_RENDEZVOUS1: return "RENDEZVOUS1";
  471. case RELAY_COMMAND_RENDEZVOUS2: return "RENDEZVOUS2";
  472. case RELAY_COMMAND_INTRO_ESTABLISHED: return "INTRO_ESTABLISHED";
  473. case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
  474. return "RENDEZVOUS_ESTABLISHED";
  475. case RELAY_COMMAND_INTRODUCE_ACK: return "INTRODUCE_ACK";
  476. case RELAY_COMMAND_EXTEND2: return "EXTEND2";
  477. case RELAY_COMMAND_EXTENDED2: return "EXTENDED2";
  478. default:
  479. tor_snprintf(buf, sizeof(buf), "Unrecognized relay command %u",
  480. (unsigned)command);
  481. return buf;
  482. }
  483. }
  484. /** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and send
  485. * it onto the open circuit <b>circ</b>. <b>stream_id</b> is the ID on
  486. * <b>circ</b> for the stream that's sending the relay cell, or 0 if it's a
  487. * control cell. <b>cpath_layer</b> is NULL for OR->OP cells, or the
  488. * destination hop for OP->OR cells.
  489. *
  490. * If you can't send the cell, mark the circuit for close and return -1. Else
  491. * return 0.
  492. */
  493. MOCK_IMPL(int,
  494. relay_send_command_from_edge_,(streamid_t stream_id, circuit_t *circ,
  495. uint8_t relay_command, const char *payload,
  496. size_t payload_len, crypt_path_t *cpath_layer,
  497. const char *filename, int lineno))
  498. {
  499. cell_t cell;
  500. relay_header_t rh;
  501. cell_direction_t cell_direction;
  502. /* XXXX NM Split this function into a separate versions per circuit type? */
  503. tor_assert(circ);
  504. tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
  505. memset(&cell, 0, sizeof(cell_t));
  506. cell.command = CELL_RELAY;
  507. if (CIRCUIT_IS_ORIGIN(circ)) {
  508. tor_assert(cpath_layer);
  509. cell.circ_id = circ->n_circ_id;
  510. cell_direction = CELL_DIRECTION_OUT;
  511. } else {
  512. tor_assert(! cpath_layer);
  513. cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
  514. cell_direction = CELL_DIRECTION_IN;
  515. }
  516. memset(&rh, 0, sizeof(rh));
  517. rh.command = relay_command;
  518. rh.stream_id = stream_id;
  519. rh.length = payload_len;
  520. relay_header_pack(cell.payload, &rh);
  521. if (payload_len)
  522. memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len);
  523. log_debug(LD_OR,"delivering %d cell %s.", relay_command,
  524. cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward");
  525. if (relay_command == RELAY_COMMAND_DROP)
  526. rep_hist_padding_count_write(PADDING_TYPE_DROP);
  527. /* If we are sending an END cell and this circuit is used for a tunneled
  528. * directory request, advance its state. */
  529. if (relay_command == RELAY_COMMAND_END && circ->dirreq_id)
  530. geoip_change_dirreq_state(circ->dirreq_id, DIRREQ_TUNNELED,
  531. DIRREQ_END_CELL_SENT);
  532. if (cell_direction == CELL_DIRECTION_OUT && circ->n_chan) {
  533. /* if we're using relaybandwidthrate, this conn wants priority */
  534. channel_timestamp_client(circ->n_chan);
  535. }
  536. if (cell_direction == CELL_DIRECTION_OUT) {
  537. origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
  538. if (origin_circ->remaining_relay_early_cells > 0 &&
  539. (relay_command == RELAY_COMMAND_EXTEND ||
  540. relay_command == RELAY_COMMAND_EXTEND2 ||
  541. cpath_layer != origin_circ->cpath)) {
  542. /* If we've got any relay_early cells left and (we're sending
  543. * an extend cell or we're not talking to the first hop), use
  544. * one of them. Don't worry about the conn protocol version:
  545. * append_cell_to_circuit_queue will fix it up. */
  546. cell.command = CELL_RELAY_EARLY;
  547. --origin_circ->remaining_relay_early_cells;
  548. log_debug(LD_OR, "Sending a RELAY_EARLY cell; %d remaining.",
  549. (int)origin_circ->remaining_relay_early_cells);
  550. /* Memorize the command that is sent as RELAY_EARLY cell; helps debug
  551. * task 878. */
  552. origin_circ->relay_early_commands[
  553. origin_circ->relay_early_cells_sent++] = relay_command;
  554. } else if (relay_command == RELAY_COMMAND_EXTEND ||
  555. relay_command == RELAY_COMMAND_EXTEND2) {
  556. /* If no RELAY_EARLY cells can be sent over this circuit, log which
  557. * commands have been sent as RELAY_EARLY cells before; helps debug
  558. * task 878. */
  559. smartlist_t *commands_list = smartlist_new();
  560. int i = 0;
  561. char *commands = NULL;
  562. for (; i < origin_circ->relay_early_cells_sent; i++)
  563. smartlist_add(commands_list, (char *)
  564. relay_command_to_string(origin_circ->relay_early_commands[i]));
  565. commands = smartlist_join_strings(commands_list, ",", 0, NULL);
  566. log_warn(LD_BUG, "Uh-oh. We're sending a RELAY_COMMAND_EXTEND cell, "
  567. "but we have run out of RELAY_EARLY cells on that circuit. "
  568. "Commands sent before: %s", commands);
  569. tor_free(commands);
  570. smartlist_free(commands_list);
  571. }
  572. /* Let's assume we're well-behaved: Anything that we decide to send is
  573. * valid, delivered data. */
  574. circuit_sent_valid_data(origin_circ, rh.length);
  575. }
  576. if (circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer,
  577. stream_id, filename, lineno) < 0) {
  578. log_warn(LD_BUG,"circuit_package_relay_cell failed. Closing.");
  579. circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
  580. return -1;
  581. }
  582. return 0;
  583. }
  584. /** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and
  585. * send it onto the open circuit <b>circ</b>. <b>fromconn</b> is the stream
  586. * that's sending the relay cell, or NULL if it's a control cell.
  587. * <b>cpath_layer</b> is NULL for OR->OP cells, or the destination hop
  588. * for OP->OR cells.
  589. *
  590. * If you can't send the cell, mark the circuit for close and
  591. * return -1. Else return 0.
  592. */
  593. int
  594. connection_edge_send_command(edge_connection_t *fromconn,
  595. uint8_t relay_command, const char *payload,
  596. size_t payload_len)
  597. {
  598. /* XXXX NM Split this function into a separate versions per circuit type? */
  599. circuit_t *circ;
  600. crypt_path_t *cpath_layer = fromconn->cpath_layer;
  601. tor_assert(fromconn);
  602. circ = fromconn->on_circuit;
  603. if (fromconn->base_.marked_for_close) {
  604. log_warn(LD_BUG,
  605. "called on conn that's already marked for close at %s:%d.",
  606. fromconn->base_.marked_for_close_file,
  607. fromconn->base_.marked_for_close);
  608. return 0;
  609. }
  610. if (!circ) {
  611. if (fromconn->base_.type == CONN_TYPE_AP) {
  612. log_info(LD_APP,"no circ. Closing conn.");
  613. connection_mark_unattached_ap(EDGE_TO_ENTRY_CONN(fromconn),
  614. END_STREAM_REASON_INTERNAL);
  615. } else {
  616. log_info(LD_EXIT,"no circ. Closing conn.");
  617. fromconn->edge_has_sent_end = 1; /* no circ to send to */
  618. fromconn->end_reason = END_STREAM_REASON_INTERNAL;
  619. connection_mark_for_close(TO_CONN(fromconn));
  620. }
  621. return -1;
  622. }
  623. if (circ->marked_for_close) {
  624. /* The circuit has been marked, but not freed yet. When it's freed, it
  625. * will mark this connection for close. */
  626. return -1;
  627. }
  628. #ifdef MEASUREMENTS_21206
  629. /* Keep track of the number of RELAY_DATA cells sent for directory
  630. * connections. */
  631. connection_t *linked_conn = TO_CONN(fromconn)->linked_conn;
  632. if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
  633. ++(TO_DIR_CONN(linked_conn)->data_cells_sent);
  634. }
  635. #endif /* defined(MEASUREMENTS_21206) */
  636. return relay_send_command_from_edge(fromconn->stream_id, circ,
  637. relay_command, payload,
  638. payload_len, cpath_layer);
  639. }
  640. /** How many times will I retry a stream that fails due to DNS
  641. * resolve failure or misc error?
  642. */
  643. #define MAX_RESOLVE_FAILURES 3
  644. /** Return 1 if reason is something that you should retry if you
  645. * get the end cell before you've connected; else return 0. */
  646. static int
  647. edge_reason_is_retriable(int reason)
  648. {
  649. return reason == END_STREAM_REASON_HIBERNATING ||
  650. reason == END_STREAM_REASON_RESOURCELIMIT ||
  651. reason == END_STREAM_REASON_EXITPOLICY ||
  652. reason == END_STREAM_REASON_RESOLVEFAILED ||
  653. reason == END_STREAM_REASON_MISC ||
  654. reason == END_STREAM_REASON_NOROUTE;
  655. }
  656. /** Called when we receive an END cell on a stream that isn't open yet,
  657. * from the client side.
  658. * Arguments are as for connection_edge_process_relay_cell().
  659. */
  660. static int
  661. connection_ap_process_end_not_open(
  662. relay_header_t *rh, cell_t *cell, origin_circuit_t *circ,
  663. entry_connection_t *conn, crypt_path_t *layer_hint)
  664. {
  665. node_t *exitrouter;
  666. int reason = *(cell->payload+RELAY_HEADER_SIZE);
  667. int control_reason;
  668. edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
  669. (void) layer_hint; /* unused */
  670. if (rh->length > 0) {
  671. if (reason == END_STREAM_REASON_TORPROTOCOL ||
  672. reason == END_STREAM_REASON_DESTROY) {
  673. /* Both of these reasons could mean a failed tag
  674. * hit the exit and it complained. Do not probe.
  675. * Fail the circuit. */
  676. circ->path_state = PATH_STATE_USE_FAILED;
  677. return -END_CIRC_REASON_TORPROTOCOL;
  678. } else if (reason == END_STREAM_REASON_INTERNAL) {
  679. /* We can't infer success or failure, since older Tors report
  680. * ENETUNREACH as END_STREAM_REASON_INTERNAL. */
  681. } else {
  682. /* Path bias: If we get a valid reason code from the exit,
  683. * it wasn't due to tagging.
  684. *
  685. * We rely on recognized+digest being strong enough to make
  686. * tags unlikely to allow us to get tagged, yet 'recognized'
  687. * reason codes here. */
  688. pathbias_mark_use_success(circ);
  689. }
  690. }
  691. /* This end cell is now valid. */
  692. circuit_read_valid_data(circ, rh->length);
  693. if (rh->length == 0) {
  694. reason = END_STREAM_REASON_MISC;
  695. }
  696. control_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
  697. if (edge_reason_is_retriable(reason) &&
  698. /* avoid retry if rend */
  699. !connection_edge_is_rendezvous_stream(edge_conn)) {
  700. const char *chosen_exit_digest =
  701. circ->build_state->chosen_exit->identity_digest;
  702. log_info(LD_APP,"Address '%s' refused due to '%s'. Considering retrying.",
  703. safe_str(conn->socks_request->address),
  704. stream_end_reason_to_string(reason));
  705. exitrouter = node_get_mutable_by_id(chosen_exit_digest);
  706. switch (reason) {
  707. case END_STREAM_REASON_EXITPOLICY: {
  708. tor_addr_t addr;
  709. tor_addr_make_unspec(&addr);
  710. if (rh->length >= 5) {
  711. int ttl = -1;
  712. tor_addr_make_unspec(&addr);
  713. if (rh->length == 5 || rh->length == 9) {
  714. tor_addr_from_ipv4n(&addr,
  715. get_uint32(cell->payload+RELAY_HEADER_SIZE+1));
  716. if (rh->length == 9)
  717. ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+5));
  718. } else if (rh->length == 17 || rh->length == 21) {
  719. tor_addr_from_ipv6_bytes(&addr,
  720. (char*)(cell->payload+RELAY_HEADER_SIZE+1));
  721. if (rh->length == 21)
  722. ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+17));
  723. }
  724. if (tor_addr_is_null(&addr)) {
  725. log_info(LD_APP,"Address '%s' resolved to 0.0.0.0. Closing,",
  726. safe_str(conn->socks_request->address));
  727. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  728. return 0;
  729. }
  730. if ((tor_addr_family(&addr) == AF_INET &&
  731. !conn->entry_cfg.ipv4_traffic) ||
  732. (tor_addr_family(&addr) == AF_INET6 &&
  733. !conn->entry_cfg.ipv6_traffic)) {
  734. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  735. "Got an EXITPOLICY failure on a connection with a "
  736. "mismatched family. Closing.");
  737. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  738. return 0;
  739. }
  740. if (get_options()->ClientDNSRejectInternalAddresses &&
  741. tor_addr_is_internal(&addr, 0)) {
  742. log_info(LD_APP,"Address '%s' resolved to internal. Closing,",
  743. safe_str(conn->socks_request->address));
  744. connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
  745. return 0;
  746. }
  747. client_dns_set_addressmap(conn,
  748. conn->socks_request->address, &addr,
  749. conn->chosen_exit_name, ttl);
  750. {
  751. char new_addr[TOR_ADDR_BUF_LEN];
  752. tor_addr_to_str(new_addr, &addr, sizeof(new_addr), 1);
  753. if (strcmp(conn->socks_request->address, new_addr)) {
  754. strlcpy(conn->socks_request->address, new_addr,
  755. sizeof(conn->socks_request->address));
  756. control_event_stream_status(conn, STREAM_EVENT_REMAP, 0);
  757. }
  758. }
  759. }
  760. /* check if the exit *ought* to have allowed it */
  761. adjust_exit_policy_from_exitpolicy_failure(circ,
  762. conn,
  763. exitrouter,
  764. &addr);
  765. if (conn->chosen_exit_optional ||
  766. conn->chosen_exit_retries) {
  767. /* stop wanting a specific exit */
  768. conn->chosen_exit_optional = 0;
  769. /* A non-zero chosen_exit_retries can happen if we set a
  770. * TrackHostExits for this address under a port that the exit
  771. * relay allows, but then try the same address with a different
  772. * port that it doesn't allow to exit. We shouldn't unregister
  773. * the mapping, since it is probably still wanted on the
  774. * original port. But now we give away to the exit relay that
  775. * we probably have a TrackHostExits on it. So be it. */
  776. conn->chosen_exit_retries = 0;
  777. tor_free(conn->chosen_exit_name); /* clears it */
  778. }
  779. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  780. return 0;
  781. /* else, conn will get closed below */
  782. break;
  783. }
  784. case END_STREAM_REASON_CONNECTREFUSED:
  785. if (!conn->chosen_exit_optional)
  786. break; /* break means it'll close, below */
  787. /* Else fall through: expire this circuit, clear the
  788. * chosen_exit_name field, and try again. */
  789. /* Falls through. */
  790. case END_STREAM_REASON_RESOLVEFAILED:
  791. case END_STREAM_REASON_TIMEOUT:
  792. case END_STREAM_REASON_MISC:
  793. case END_STREAM_REASON_NOROUTE:
  794. if (client_dns_incr_failures(conn->socks_request->address)
  795. < MAX_RESOLVE_FAILURES) {
  796. /* We haven't retried too many times; reattach the connection. */
  797. circuit_log_path(LOG_INFO,LD_APP,circ);
  798. /* Mark this circuit "unusable for new streams". */
  799. mark_circuit_unusable_for_new_conns(circ);
  800. if (conn->chosen_exit_optional) {
  801. /* stop wanting a specific exit */
  802. conn->chosen_exit_optional = 0;
  803. tor_free(conn->chosen_exit_name); /* clears it */
  804. }
  805. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  806. return 0;
  807. /* else, conn will get closed below */
  808. } else {
  809. log_notice(LD_APP,
  810. "Have tried resolving or connecting to address '%s' "
  811. "at %d different places. Giving up.",
  812. safe_str(conn->socks_request->address),
  813. MAX_RESOLVE_FAILURES);
  814. /* clear the failures, so it will have a full try next time */
  815. client_dns_clear_failures(conn->socks_request->address);
  816. }
  817. break;
  818. case END_STREAM_REASON_HIBERNATING:
  819. case END_STREAM_REASON_RESOURCELIMIT:
  820. if (exitrouter) {
  821. policies_set_node_exitpolicy_to_reject_all(exitrouter);
  822. }
  823. if (conn->chosen_exit_optional) {
  824. /* stop wanting a specific exit */
  825. conn->chosen_exit_optional = 0;
  826. tor_free(conn->chosen_exit_name); /* clears it */
  827. }
  828. if (connection_ap_detach_retriable(conn, circ, control_reason) >= 0)
  829. return 0;
  830. /* else, will close below */
  831. break;
  832. } /* end switch */
  833. log_info(LD_APP,"Giving up on retrying; conn can't be handled.");
  834. }
  835. log_info(LD_APP,
  836. "Edge got end (%s) before we're connected. Marking for close.",
  837. stream_end_reason_to_string(rh->length > 0 ? reason : -1));
  838. circuit_log_path(LOG_INFO,LD_APP,circ);
  839. /* need to test because of detach_retriable */
  840. if (!ENTRY_TO_CONN(conn)->marked_for_close)
  841. connection_mark_unattached_ap(conn, control_reason);
  842. return 0;
  843. }
  844. /** Called when we have gotten an END_REASON_EXITPOLICY failure on <b>circ</b>
  845. * for <b>conn</b>, while attempting to connect via <b>node</b>. If the node
  846. * told us which address it rejected, then <b>addr</b> is that address;
  847. * otherwise it is AF_UNSPEC.
  848. *
  849. * If we are sure the node should have allowed this address, mark the node as
  850. * having a reject *:* exit policy. Otherwise, mark the circuit as unusable
  851. * for this particular address.
  852. **/
  853. static void
  854. adjust_exit_policy_from_exitpolicy_failure(origin_circuit_t *circ,
  855. entry_connection_t *conn,
  856. node_t *node,
  857. const tor_addr_t *addr)
  858. {
  859. int make_reject_all = 0;
  860. const sa_family_t family = tor_addr_family(addr);
  861. if (node) {
  862. tor_addr_t tmp;
  863. int asked_for_family = tor_addr_parse(&tmp, conn->socks_request->address);
  864. if (family == AF_UNSPEC) {
  865. make_reject_all = 1;
  866. } else if (node_exit_policy_is_exact(node, family) &&
  867. asked_for_family != -1 && !conn->chosen_exit_name) {
  868. make_reject_all = 1;
  869. }
  870. if (make_reject_all) {
  871. log_info(LD_APP,
  872. "Exitrouter %s seems to be more restrictive than its exit "
  873. "policy. Not using this router as exit for now.",
  874. node_describe(node));
  875. policies_set_node_exitpolicy_to_reject_all(node);
  876. }
  877. }
  878. if (family != AF_UNSPEC)
  879. addr_policy_append_reject_addr(&circ->prepend_policy, addr);
  880. }
  881. /** Helper: change the socks_request-&gt;address field on conn to the
  882. * dotted-quad representation of <b>new_addr</b>,
  883. * and send an appropriate REMAP event. */
  884. static void
  885. remap_event_helper(entry_connection_t *conn, const tor_addr_t *new_addr)
  886. {
  887. tor_addr_to_str(conn->socks_request->address, new_addr,
  888. sizeof(conn->socks_request->address),
  889. 1);
  890. control_event_stream_status(conn, STREAM_EVENT_REMAP,
  891. REMAP_STREAM_SOURCE_EXIT);
  892. }
  893. /** Extract the contents of a connected cell in <b>cell</b>, whose relay
  894. * header has already been parsed into <b>rh</b>. On success, set
  895. * <b>addr_out</b> to the address we're connected to, and <b>ttl_out</b> to
  896. * the ttl of that address, in seconds, and return 0. On failure, return
  897. * -1.
  898. *
  899. * Note that the resulting address can be UNSPEC if the connected cell had no
  900. * address (as for a stream to an union service or a tunneled directory
  901. * connection), and that the ttl can be absent (in which case <b>ttl_out</b>
  902. * is set to -1). */
  903. STATIC int
  904. connected_cell_parse(const relay_header_t *rh, const cell_t *cell,
  905. tor_addr_t *addr_out, int *ttl_out)
  906. {
  907. uint32_t bytes;
  908. const uint8_t *payload = cell->payload + RELAY_HEADER_SIZE;
  909. tor_addr_make_unspec(addr_out);
  910. *ttl_out = -1;
  911. if (rh->length == 0)
  912. return 0;
  913. if (rh->length < 4)
  914. return -1;
  915. bytes = ntohl(get_uint32(payload));
  916. /* If bytes is 0, this is maybe a v6 address. Otherwise it's a v4 address */
  917. if (bytes != 0) {
  918. /* v4 address */
  919. tor_addr_from_ipv4h(addr_out, bytes);
  920. if (rh->length >= 8) {
  921. bytes = ntohl(get_uint32(payload + 4));
  922. if (bytes <= INT32_MAX)
  923. *ttl_out = bytes;
  924. }
  925. } else {
  926. if (rh->length < 25) /* 4 bytes of 0s, 1 addr, 16 ipv4, 4 ttl. */
  927. return -1;
  928. if (get_uint8(payload + 4) != 6)
  929. return -1;
  930. tor_addr_from_ipv6_bytes(addr_out, (char*)(payload + 5));
  931. bytes = ntohl(get_uint32(payload + 21));
  932. if (bytes <= INT32_MAX)
  933. *ttl_out = (int) bytes;
  934. }
  935. return 0;
  936. }
  937. /** Drop all storage held by <b>addr</b>. */
  938. STATIC void
  939. address_ttl_free_(address_ttl_t *addr)
  940. {
  941. if (!addr)
  942. return;
  943. tor_free(addr->hostname);
  944. tor_free(addr);
  945. }
  946. /** Parse a resolved cell in <b>cell</b>, with parsed header in <b>rh</b>.
  947. * Return -1 on parse error. On success, add one or more newly allocated
  948. * address_ttl_t to <b>addresses_out</b>; set *<b>errcode_out</b> to
  949. * one of 0, RESOLVED_TYPE_ERROR, or RESOLVED_TYPE_ERROR_TRANSIENT, and
  950. * return 0. */
  951. STATIC int
  952. resolved_cell_parse(const cell_t *cell, const relay_header_t *rh,
  953. smartlist_t *addresses_out, int *errcode_out)
  954. {
  955. const uint8_t *cp;
  956. uint8_t answer_type;
  957. size_t answer_len;
  958. address_ttl_t *addr;
  959. size_t remaining;
  960. int errcode = 0;
  961. smartlist_t *addrs;
  962. tor_assert(cell);
  963. tor_assert(rh);
  964. tor_assert(addresses_out);
  965. tor_assert(errcode_out);
  966. *errcode_out = 0;
  967. if (rh->length > RELAY_PAYLOAD_SIZE)
  968. return -1;
  969. addrs = smartlist_new();
  970. cp = cell->payload + RELAY_HEADER_SIZE;
  971. remaining = rh->length;
  972. while (remaining) {
  973. const uint8_t *cp_orig = cp;
  974. if (remaining < 2)
  975. goto err;
  976. answer_type = *cp++;
  977. answer_len = *cp++;
  978. if (remaining < 2 + answer_len + 4) {
  979. goto err;
  980. }
  981. if (answer_type == RESOLVED_TYPE_IPV4) {
  982. if (answer_len != 4) {
  983. goto err;
  984. }
  985. addr = tor_malloc_zero(sizeof(*addr));
  986. tor_addr_from_ipv4n(&addr->addr, get_uint32(cp));
  987. cp += 4;
  988. addr->ttl = ntohl(get_uint32(cp));
  989. cp += 4;
  990. smartlist_add(addrs, addr);
  991. } else if (answer_type == RESOLVED_TYPE_IPV6) {
  992. if (answer_len != 16)
  993. goto err;
  994. addr = tor_malloc_zero(sizeof(*addr));
  995. tor_addr_from_ipv6_bytes(&addr->addr, (const char*) cp);
  996. cp += 16;
  997. addr->ttl = ntohl(get_uint32(cp));
  998. cp += 4;
  999. smartlist_add(addrs, addr);
  1000. } else if (answer_type == RESOLVED_TYPE_HOSTNAME) {
  1001. if (answer_len == 0) {
  1002. goto err;
  1003. }
  1004. addr = tor_malloc_zero(sizeof(*addr));
  1005. addr->hostname = tor_memdup_nulterm(cp, answer_len);
  1006. cp += answer_len;
  1007. addr->ttl = ntohl(get_uint32(cp));
  1008. cp += 4;
  1009. smartlist_add(addrs, addr);
  1010. } else if (answer_type == RESOLVED_TYPE_ERROR_TRANSIENT ||
  1011. answer_type == RESOLVED_TYPE_ERROR) {
  1012. errcode = answer_type;
  1013. /* Ignore the error contents */
  1014. cp += answer_len + 4;
  1015. } else {
  1016. cp += answer_len + 4;
  1017. }
  1018. tor_assert(((ssize_t)remaining) >= (cp - cp_orig));
  1019. remaining -= (cp - cp_orig);
  1020. }
  1021. if (errcode && smartlist_len(addrs) == 0) {
  1022. /* Report an error only if there were no results. */
  1023. *errcode_out = errcode;
  1024. }
  1025. smartlist_add_all(addresses_out, addrs);
  1026. smartlist_free(addrs);
  1027. return 0;
  1028. err:
  1029. /* On parse error, don't report any results */
  1030. SMARTLIST_FOREACH(addrs, address_ttl_t *, a, address_ttl_free(a));
  1031. smartlist_free(addrs);
  1032. return -1;
  1033. }
  1034. /** Helper for connection_edge_process_resolved_cell: given an error code,
  1035. * an entry_connection, and a list of address_ttl_t *, report the best answer
  1036. * to the entry_connection. */
  1037. static void
  1038. connection_ap_handshake_socks_got_resolved_cell(entry_connection_t *conn,
  1039. int error_code,
  1040. smartlist_t *results)
  1041. {
  1042. address_ttl_t *addr_ipv4 = NULL;
  1043. address_ttl_t *addr_ipv6 = NULL;
  1044. address_ttl_t *addr_hostname = NULL;
  1045. address_ttl_t *addr_best = NULL;
  1046. /* If it's an error code, that's easy. */
  1047. if (error_code) {
  1048. tor_assert(error_code == RESOLVED_TYPE_ERROR ||
  1049. error_code == RESOLVED_TYPE_ERROR_TRANSIENT);
  1050. connection_ap_handshake_socks_resolved(conn,
  1051. error_code,0,NULL,-1,-1);
  1052. return;
  1053. }
  1054. /* Get the first answer of each type. */
  1055. SMARTLIST_FOREACH_BEGIN(results, address_ttl_t *, addr) {
  1056. if (addr->hostname) {
  1057. if (!addr_hostname) {
  1058. addr_hostname = addr;
  1059. }
  1060. } else if (tor_addr_family(&addr->addr) == AF_INET) {
  1061. if (!addr_ipv4 && conn->entry_cfg.ipv4_traffic) {
  1062. addr_ipv4 = addr;
  1063. }
  1064. } else if (tor_addr_family(&addr->addr) == AF_INET6) {
  1065. if (!addr_ipv6 && conn->entry_cfg.ipv6_traffic) {
  1066. addr_ipv6 = addr;
  1067. }
  1068. }
  1069. } SMARTLIST_FOREACH_END(addr);
  1070. /* Now figure out which type we wanted to deliver. */
  1071. if (conn->socks_request->command == SOCKS_COMMAND_RESOLVE_PTR) {
  1072. if (addr_hostname) {
  1073. connection_ap_handshake_socks_resolved(conn,
  1074. RESOLVED_TYPE_HOSTNAME,
  1075. strlen(addr_hostname->hostname),
  1076. (uint8_t*)addr_hostname->hostname,
  1077. addr_hostname->ttl,-1);
  1078. } else {
  1079. connection_ap_handshake_socks_resolved(conn,
  1080. RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
  1081. }
  1082. return;
  1083. }
  1084. if (conn->entry_cfg.prefer_ipv6) {
  1085. addr_best = addr_ipv6 ? addr_ipv6 : addr_ipv4;
  1086. } else {
  1087. addr_best = addr_ipv4 ? addr_ipv4 : addr_ipv6;
  1088. }
  1089. /* Now convert it to the ugly old interface */
  1090. if (! addr_best) {
  1091. connection_ap_handshake_socks_resolved(conn,
  1092. RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
  1093. return;
  1094. }
  1095. connection_ap_handshake_socks_resolved_addr(conn,
  1096. &addr_best->addr,
  1097. addr_best->ttl,
  1098. -1);
  1099. remap_event_helper(conn, &addr_best->addr);
  1100. }
  1101. /** Handle a RELAY_COMMAND_RESOLVED cell that we received on a non-open AP
  1102. * stream. */
  1103. STATIC int
  1104. connection_edge_process_resolved_cell(edge_connection_t *conn,
  1105. const cell_t *cell,
  1106. const relay_header_t *rh)
  1107. {
  1108. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1109. smartlist_t *resolved_addresses = NULL;
  1110. int errcode = 0;
  1111. if (conn->base_.state != AP_CONN_STATE_RESOLVE_WAIT) {
  1112. log_fn(LOG_PROTOCOL_WARN, LD_APP, "Got a 'resolved' cell while "
  1113. "not in state resolve_wait. Dropping.");
  1114. return 0;
  1115. }
  1116. tor_assert(SOCKS_COMMAND_IS_RESOLVE(entry_conn->socks_request->command));
  1117. resolved_addresses = smartlist_new();
  1118. if (resolved_cell_parse(cell, rh, resolved_addresses, &errcode)) {
  1119. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1120. "Dropping malformed 'resolved' cell");
  1121. connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
  1122. goto done;
  1123. }
  1124. if (get_options()->ClientDNSRejectInternalAddresses) {
  1125. int orig_len = smartlist_len(resolved_addresses);
  1126. SMARTLIST_FOREACH_BEGIN(resolved_addresses, address_ttl_t *, addr) {
  1127. if (addr->hostname == NULL && tor_addr_is_internal(&addr->addr, 0)) {
  1128. log_info(LD_APP, "Got a resolved cell with answer %s; dropping that "
  1129. "answer.",
  1130. safe_str_client(fmt_addr(&addr->addr)));
  1131. address_ttl_free(addr);
  1132. SMARTLIST_DEL_CURRENT(resolved_addresses, addr);
  1133. }
  1134. } SMARTLIST_FOREACH_END(addr);
  1135. if (orig_len && smartlist_len(resolved_addresses) == 0) {
  1136. log_info(LD_APP, "Got a resolved cell with only private addresses; "
  1137. "dropping it.");
  1138. connection_ap_handshake_socks_resolved(entry_conn,
  1139. RESOLVED_TYPE_ERROR_TRANSIENT,
  1140. 0, NULL, 0, TIME_MAX);
  1141. connection_mark_unattached_ap(entry_conn,
  1142. END_STREAM_REASON_TORPROTOCOL);
  1143. goto done;
  1144. }
  1145. }
  1146. /* This is valid data at this point. Count it */
  1147. if (conn->on_circuit && CIRCUIT_IS_ORIGIN(conn->on_circuit)) {
  1148. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(conn->on_circuit),
  1149. rh->length);
  1150. }
  1151. connection_ap_handshake_socks_got_resolved_cell(entry_conn,
  1152. errcode,
  1153. resolved_addresses);
  1154. connection_mark_unattached_ap(entry_conn,
  1155. END_STREAM_REASON_DONE |
  1156. END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
  1157. done:
  1158. SMARTLIST_FOREACH(resolved_addresses, address_ttl_t *, addr,
  1159. address_ttl_free(addr));
  1160. smartlist_free(resolved_addresses);
  1161. return 0;
  1162. }
  1163. /** An incoming relay cell has arrived from circuit <b>circ</b> to
  1164. * stream <b>conn</b>.
  1165. *
  1166. * The arguments here are the same as in
  1167. * connection_edge_process_relay_cell() below; this function is called
  1168. * from there when <b>conn</b> is defined and not in an open state.
  1169. */
  1170. static int
  1171. connection_edge_process_relay_cell_not_open(
  1172. relay_header_t *rh, cell_t *cell, circuit_t *circ,
  1173. edge_connection_t *conn, crypt_path_t *layer_hint)
  1174. {
  1175. if (rh->command == RELAY_COMMAND_END) {
  1176. if (CIRCUIT_IS_ORIGIN(circ) && conn->base_.type == CONN_TYPE_AP) {
  1177. return connection_ap_process_end_not_open(rh, cell,
  1178. TO_ORIGIN_CIRCUIT(circ),
  1179. EDGE_TO_ENTRY_CONN(conn),
  1180. layer_hint);
  1181. } else {
  1182. /* we just got an 'end', don't need to send one */
  1183. conn->edge_has_sent_end = 1;
  1184. conn->end_reason = *(cell->payload+RELAY_HEADER_SIZE) |
  1185. END_STREAM_REASON_FLAG_REMOTE;
  1186. connection_mark_for_close(TO_CONN(conn));
  1187. return 0;
  1188. }
  1189. }
  1190. if (conn->base_.type == CONN_TYPE_AP &&
  1191. rh->command == RELAY_COMMAND_CONNECTED) {
  1192. tor_addr_t addr;
  1193. int ttl;
  1194. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1195. tor_assert(CIRCUIT_IS_ORIGIN(circ));
  1196. if (conn->base_.state != AP_CONN_STATE_CONNECT_WAIT) {
  1197. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1198. "Got 'connected' while not in state connect_wait. Dropping.");
  1199. return 0;
  1200. }
  1201. CONNECTION_AP_EXPECT_NONPENDING(entry_conn);
  1202. conn->base_.state = AP_CONN_STATE_OPEN;
  1203. log_info(LD_APP,"'connected' received for circid %u streamid %d "
  1204. "after %d seconds.",
  1205. (unsigned)circ->n_circ_id,
  1206. rh->stream_id,
  1207. (int)(time(NULL) - conn->base_.timestamp_last_read_allowed));
  1208. if (connected_cell_parse(rh, cell, &addr, &ttl) < 0) {
  1209. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1210. "Got a badly formatted connected cell. Closing.");
  1211. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1212. connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TORPROTOCOL);
  1213. return 0;
  1214. }
  1215. if (tor_addr_family(&addr) != AF_UNSPEC) {
  1216. /* The family is not UNSPEC: so we were given an address in the
  1217. * connected cell. (This is normal, except for BEGINDIR and onion
  1218. * service streams.) */
  1219. const sa_family_t family = tor_addr_family(&addr);
  1220. if (tor_addr_is_null(&addr) ||
  1221. (get_options()->ClientDNSRejectInternalAddresses &&
  1222. tor_addr_is_internal(&addr, 0))) {
  1223. log_info(LD_APP, "...but it claims the IP address was %s. Closing.",
  1224. fmt_addr(&addr));
  1225. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1226. connection_mark_unattached_ap(entry_conn,
  1227. END_STREAM_REASON_TORPROTOCOL);
  1228. return 0;
  1229. }
  1230. if ((family == AF_INET && ! entry_conn->entry_cfg.ipv4_traffic) ||
  1231. (family == AF_INET6 && ! entry_conn->entry_cfg.ipv6_traffic)) {
  1232. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1233. "Got a connected cell to %s with unsupported address family."
  1234. " Closing.", fmt_addr(&addr));
  1235. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1236. connection_mark_unattached_ap(entry_conn,
  1237. END_STREAM_REASON_TORPROTOCOL);
  1238. return 0;
  1239. }
  1240. client_dns_set_addressmap(entry_conn,
  1241. entry_conn->socks_request->address, &addr,
  1242. entry_conn->chosen_exit_name, ttl);
  1243. remap_event_helper(entry_conn, &addr);
  1244. }
  1245. circuit_log_path(LOG_INFO,LD_APP,TO_ORIGIN_CIRCUIT(circ));
  1246. /* don't send a socks reply to transparent conns */
  1247. tor_assert(entry_conn->socks_request != NULL);
  1248. if (!entry_conn->socks_request->has_finished) {
  1249. connection_ap_handshake_socks_reply(entry_conn, NULL, 0, 0);
  1250. }
  1251. /* Was it a linked dir conn? If so, a dir request just started to
  1252. * fetch something; this could be a bootstrap status milestone. */
  1253. log_debug(LD_APP, "considering");
  1254. if (TO_CONN(conn)->linked_conn &&
  1255. TO_CONN(conn)->linked_conn->type == CONN_TYPE_DIR) {
  1256. connection_t *dirconn = TO_CONN(conn)->linked_conn;
  1257. log_debug(LD_APP, "it is! %d", dirconn->purpose);
  1258. switch (dirconn->purpose) {
  1259. case DIR_PURPOSE_FETCH_CERTIFICATE:
  1260. if (consensus_is_waiting_for_certs())
  1261. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_KEYS, 0);
  1262. break;
  1263. case DIR_PURPOSE_FETCH_CONSENSUS:
  1264. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_STATUS, 0);
  1265. break;
  1266. case DIR_PURPOSE_FETCH_SERVERDESC:
  1267. case DIR_PURPOSE_FETCH_MICRODESC:
  1268. if (TO_DIR_CONN(dirconn)->router_purpose == ROUTER_PURPOSE_GENERAL)
  1269. control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
  1270. count_loading_descriptors_progress());
  1271. break;
  1272. }
  1273. }
  1274. /* This is definitely a success, so forget about any pending data we
  1275. * had sent. */
  1276. if (entry_conn->pending_optimistic_data) {
  1277. buf_free(entry_conn->pending_optimistic_data);
  1278. entry_conn->pending_optimistic_data = NULL;
  1279. }
  1280. /* This is valid data at this point. Count it */
  1281. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh->length);
  1282. /* handle anything that might have queued */
  1283. if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
  1284. /* (We already sent an end cell if possible) */
  1285. connection_mark_for_close(TO_CONN(conn));
  1286. return 0;
  1287. }
  1288. return 0;
  1289. }
  1290. if (conn->base_.type == CONN_TYPE_AP &&
  1291. rh->command == RELAY_COMMAND_RESOLVED) {
  1292. return connection_edge_process_resolved_cell(conn, cell, rh);
  1293. }
  1294. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1295. "Got an unexpected relay command %d, in state %d (%s). Dropping.",
  1296. rh->command, conn->base_.state,
  1297. conn_state_to_string(conn->base_.type, conn->base_.state));
  1298. return 0; /* for forward compatibility, don't kill the circuit */
  1299. // connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1300. // connection_mark_for_close(conn);
  1301. // return -1;
  1302. }
  1303. /** An incoming relay cell has arrived on circuit <b>circ</b>. If
  1304. * <b>conn</b> is NULL this is a control cell, else <b>cell</b> is
  1305. * destined for <b>conn</b>.
  1306. *
  1307. * If <b>layer_hint</b> is defined, then we're the origin of the
  1308. * circuit, and it specifies the hop that packaged <b>cell</b>.
  1309. *
  1310. * Return -reason if you want to warn and tear down the circuit, else 0.
  1311. */
  1312. STATIC int
  1313. connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
  1314. edge_connection_t *conn,
  1315. crypt_path_t *layer_hint)
  1316. {
  1317. static int num_seen=0;
  1318. relay_header_t rh;
  1319. unsigned domain = layer_hint?LD_APP:LD_EXIT;
  1320. int reason;
  1321. int optimistic_data = 0; /* Set to 1 if we receive data on a stream
  1322. * that's in the EXIT_CONN_STATE_RESOLVING
  1323. * or EXIT_CONN_STATE_CONNECTING states. */
  1324. tor_assert(cell);
  1325. tor_assert(circ);
  1326. relay_header_unpack(&rh, cell->payload);
  1327. // log_fn(LOG_DEBUG,"command %d stream %d", rh.command, rh.stream_id);
  1328. num_seen++;
  1329. log_debug(domain, "Now seen %d relay cells here (command %d, stream %d).",
  1330. num_seen, rh.command, rh.stream_id);
  1331. if (rh.length > RELAY_PAYLOAD_SIZE) {
  1332. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1333. "Relay cell length field too long. Closing circuit.");
  1334. return - END_CIRC_REASON_TORPROTOCOL;
  1335. }
  1336. if (rh.stream_id == 0) {
  1337. switch (rh.command) {
  1338. case RELAY_COMMAND_BEGIN:
  1339. case RELAY_COMMAND_CONNECTED:
  1340. case RELAY_COMMAND_END:
  1341. case RELAY_COMMAND_RESOLVE:
  1342. case RELAY_COMMAND_RESOLVED:
  1343. case RELAY_COMMAND_BEGIN_DIR:
  1344. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay command %d with zero "
  1345. "stream_id. Dropping.", (int)rh.command);
  1346. return 0;
  1347. default:
  1348. ;
  1349. }
  1350. }
  1351. /* either conn is NULL, in which case we've got a control cell, or else
  1352. * conn points to the recognized stream. */
  1353. if (conn && !connection_state_is_open(TO_CONN(conn))) {
  1354. if (conn->base_.type == CONN_TYPE_EXIT &&
  1355. (conn->base_.state == EXIT_CONN_STATE_CONNECTING ||
  1356. conn->base_.state == EXIT_CONN_STATE_RESOLVING) &&
  1357. rh.command == RELAY_COMMAND_DATA) {
  1358. /* Allow DATA cells to be delivered to an exit node in state
  1359. * EXIT_CONN_STATE_CONNECTING or EXIT_CONN_STATE_RESOLVING.
  1360. * This speeds up HTTP, for example. */
  1361. optimistic_data = 1;
  1362. } else if (rh.stream_id == 0 && rh.command == RELAY_COMMAND_DATA) {
  1363. log_warn(LD_BUG, "Somehow I had a connection that matched a "
  1364. "data cell with stream ID 0.");
  1365. } else {
  1366. return connection_edge_process_relay_cell_not_open(
  1367. &rh, cell, circ, conn, layer_hint);
  1368. }
  1369. }
  1370. switch (rh.command) {
  1371. case RELAY_COMMAND_DROP:
  1372. rep_hist_padding_count_read(PADDING_TYPE_DROP);
  1373. // log_info(domain,"Got a relay-level padding cell. Dropping.");
  1374. return 0;
  1375. case RELAY_COMMAND_BEGIN:
  1376. case RELAY_COMMAND_BEGIN_DIR:
  1377. if (layer_hint &&
  1378. circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
  1379. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1380. "Relay begin request unsupported at AP. Dropping.");
  1381. return 0;
  1382. }
  1383. if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED &&
  1384. layer_hint != TO_ORIGIN_CIRCUIT(circ)->cpath->prev) {
  1385. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1386. "Relay begin request to Hidden Service "
  1387. "from intermediary node. Dropping.");
  1388. return 0;
  1389. }
  1390. if (conn) {
  1391. log_fn(LOG_PROTOCOL_WARN, domain,
  1392. "Begin cell for known stream. Dropping.");
  1393. return 0;
  1394. }
  1395. if (rh.command == RELAY_COMMAND_BEGIN_DIR &&
  1396. circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
  1397. /* Assign this circuit and its app-ward OR connection a unique ID,
  1398. * so that we can measure download times. The local edge and dir
  1399. * connection will be assigned the same ID when they are created
  1400. * and linked. */
  1401. static uint64_t next_id = 0;
  1402. circ->dirreq_id = ++next_id;
  1403. TO_OR_CIRCUIT(circ)->p_chan->dirreq_id = circ->dirreq_id;
  1404. }
  1405. return connection_exit_begin_conn(cell, circ);
  1406. case RELAY_COMMAND_DATA:
  1407. ++stats_n_data_cells_received;
  1408. if (( layer_hint && --layer_hint->deliver_window < 0) ||
  1409. (!layer_hint && --circ->deliver_window < 0)) {
  1410. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1411. "(relay data) circ deliver_window below 0. Killing.");
  1412. if (conn) {
  1413. /* XXXX Do we actually need to do this? Will killing the circuit
  1414. * not send an END and mark the stream for close as appropriate? */
  1415. connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL);
  1416. connection_mark_for_close(TO_CONN(conn));
  1417. }
  1418. return -END_CIRC_REASON_TORPROTOCOL;
  1419. }
  1420. log_debug(domain,"circ deliver_window now %d.", layer_hint ?
  1421. layer_hint->deliver_window : circ->deliver_window);
  1422. circuit_consider_sending_sendme(circ, layer_hint);
  1423. if (rh.stream_id == 0) {
  1424. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Relay data cell with zero "
  1425. "stream_id. Dropping.");
  1426. return 0;
  1427. } else if (!conn) {
  1428. log_info(domain,"data cell dropped, unknown stream (streamid %d).",
  1429. rh.stream_id);
  1430. return 0;
  1431. }
  1432. if (--conn->deliver_window < 0) { /* is it below 0 after decrement? */
  1433. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1434. "(relay data) conn deliver_window below 0. Killing.");
  1435. return -END_CIRC_REASON_TORPROTOCOL;
  1436. }
  1437. /* Total all valid application bytes delivered */
  1438. if (CIRCUIT_IS_ORIGIN(circ) && rh.length > 0) {
  1439. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
  1440. }
  1441. stats_n_data_bytes_received += rh.length;
  1442. connection_buf_add((char*)(cell->payload + RELAY_HEADER_SIZE),
  1443. rh.length, TO_CONN(conn));
  1444. #ifdef MEASUREMENTS_21206
  1445. /* Count number of RELAY_DATA cells received on a linked directory
  1446. * connection. */
  1447. connection_t *linked_conn = TO_CONN(conn)->linked_conn;
  1448. if (linked_conn && linked_conn->type == CONN_TYPE_DIR) {
  1449. ++(TO_DIR_CONN(linked_conn)->data_cells_received);
  1450. }
  1451. #endif /* defined(MEASUREMENTS_21206) */
  1452. if (!optimistic_data) {
  1453. /* Only send a SENDME if we're not getting optimistic data; otherwise
  1454. * a SENDME could arrive before the CONNECTED.
  1455. */
  1456. connection_edge_consider_sending_sendme(conn);
  1457. }
  1458. return 0;
  1459. case RELAY_COMMAND_END:
  1460. reason = rh.length > 0 ?
  1461. get_uint8(cell->payload+RELAY_HEADER_SIZE) : END_STREAM_REASON_MISC;
  1462. if (!conn) {
  1463. log_info(domain,"end cell (%s) dropped, unknown stream.",
  1464. stream_end_reason_to_string(reason));
  1465. return 0;
  1466. }
  1467. /* XXX add to this log_fn the exit node's nickname? */
  1468. log_info(domain,TOR_SOCKET_T_FORMAT": end cell (%s) for stream %d. "
  1469. "Removing stream.",
  1470. conn->base_.s,
  1471. stream_end_reason_to_string(reason),
  1472. conn->stream_id);
  1473. if (conn->base_.type == CONN_TYPE_AP) {
  1474. entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
  1475. if (entry_conn->socks_request &&
  1476. !entry_conn->socks_request->has_finished)
  1477. log_warn(LD_BUG,
  1478. "open stream hasn't sent socks answer yet? Closing.");
  1479. }
  1480. /* We just *got* an end; no reason to send one. */
  1481. conn->edge_has_sent_end = 1;
  1482. if (!conn->end_reason)
  1483. conn->end_reason = reason | END_STREAM_REASON_FLAG_REMOTE;
  1484. if (!conn->base_.marked_for_close) {
  1485. /* only mark it if not already marked. it's possible to
  1486. * get the 'end' right around when the client hangs up on us. */
  1487. connection_mark_and_flush(TO_CONN(conn));
  1488. /* Total all valid application bytes delivered */
  1489. if (CIRCUIT_IS_ORIGIN(circ)) {
  1490. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
  1491. }
  1492. }
  1493. return 0;
  1494. case RELAY_COMMAND_EXTEND:
  1495. case RELAY_COMMAND_EXTEND2: {
  1496. static uint64_t total_n_extend=0, total_nonearly=0;
  1497. total_n_extend++;
  1498. if (rh.stream_id) {
  1499. log_fn(LOG_PROTOCOL_WARN, domain,
  1500. "'extend' cell received for non-zero stream. Dropping.");
  1501. return 0;
  1502. }
  1503. if (cell->command != CELL_RELAY_EARLY &&
  1504. !networkstatus_get_param(NULL,"AllowNonearlyExtend",0,0,1)) {
  1505. #define EARLY_WARNING_INTERVAL 3600
  1506. static ratelim_t early_warning_limit =
  1507. RATELIM_INIT(EARLY_WARNING_INTERVAL);
  1508. char *m;
  1509. if (cell->command == CELL_RELAY) {
  1510. ++total_nonearly;
  1511. if ((m = rate_limit_log(&early_warning_limit, approx_time()))) {
  1512. double percentage = ((double)total_nonearly)/total_n_extend;
  1513. percentage *= 100;
  1514. log_fn(LOG_PROTOCOL_WARN, domain, "EXTEND cell received, "
  1515. "but not via RELAY_EARLY. Dropping.%s", m);
  1516. log_fn(LOG_PROTOCOL_WARN, domain, " (We have dropped %.02f%% of "
  1517. "all EXTEND cells for this reason)", percentage);
  1518. tor_free(m);
  1519. }
  1520. } else {
  1521. log_fn(LOG_WARN, domain,
  1522. "EXTEND cell received, in a cell with type %d! Dropping.",
  1523. cell->command);
  1524. }
  1525. return 0;
  1526. }
  1527. return circuit_extend(cell, circ);
  1528. }
  1529. case RELAY_COMMAND_EXTENDED:
  1530. case RELAY_COMMAND_EXTENDED2:
  1531. if (!layer_hint) {
  1532. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1533. "'extended' unsupported at non-origin. Dropping.");
  1534. return 0;
  1535. }
  1536. log_debug(domain,"Got an extended cell! Yay.");
  1537. {
  1538. extended_cell_t extended_cell;
  1539. if (extended_cell_parse(&extended_cell, rh.command,
  1540. (const uint8_t*)cell->payload+RELAY_HEADER_SIZE,
  1541. rh.length)<0) {
  1542. log_warn(LD_PROTOCOL,
  1543. "Can't parse EXTENDED cell; killing circuit.");
  1544. return -END_CIRC_REASON_TORPROTOCOL;
  1545. }
  1546. if ((reason = circuit_finish_handshake(TO_ORIGIN_CIRCUIT(circ),
  1547. &extended_cell.created_cell)) < 0) {
  1548. circuit_mark_for_close(circ, -reason);
  1549. return 0; /* We don't want to cause a warning, so we mark the circuit
  1550. * here. */
  1551. }
  1552. }
  1553. if ((reason=circuit_send_next_onion_skin(TO_ORIGIN_CIRCUIT(circ)))<0) {
  1554. log_info(domain,"circuit_send_next_onion_skin() failed.");
  1555. return reason;
  1556. }
  1557. /* Total all valid bytes delivered. */
  1558. if (CIRCUIT_IS_ORIGIN(circ)) {
  1559. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
  1560. }
  1561. return 0;
  1562. case RELAY_COMMAND_TRUNCATE:
  1563. if (layer_hint) {
  1564. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1565. "'truncate' unsupported at origin. Dropping.");
  1566. return 0;
  1567. }
  1568. if (circ->n_hop) {
  1569. if (circ->n_chan)
  1570. log_warn(LD_BUG, "n_chan and n_hop set on the same circuit!");
  1571. extend_info_free(circ->n_hop);
  1572. circ->n_hop = NULL;
  1573. tor_free(circ->n_chan_create_cell);
  1574. circuit_set_state(circ, CIRCUIT_STATE_OPEN);
  1575. }
  1576. if (circ->n_chan) {
  1577. uint8_t trunc_reason = get_uint8(cell->payload + RELAY_HEADER_SIZE);
  1578. circuit_clear_cell_queue(circ, circ->n_chan);
  1579. channel_send_destroy(circ->n_circ_id, circ->n_chan,
  1580. trunc_reason);
  1581. circuit_set_n_circid_chan(circ, 0, NULL);
  1582. }
  1583. log_debug(LD_EXIT, "Processed 'truncate', replying.");
  1584. {
  1585. char payload[1];
  1586. payload[0] = (char)END_CIRC_REASON_REQUESTED;
  1587. relay_send_command_from_edge(0, circ, RELAY_COMMAND_TRUNCATED,
  1588. payload, sizeof(payload), NULL);
  1589. }
  1590. return 0;
  1591. case RELAY_COMMAND_TRUNCATED:
  1592. if (!layer_hint) {
  1593. log_fn(LOG_PROTOCOL_WARN, LD_EXIT,
  1594. "'truncated' unsupported at non-origin. Dropping.");
  1595. return 0;
  1596. }
  1597. circuit_truncated(TO_ORIGIN_CIRCUIT(circ), layer_hint,
  1598. get_uint8(cell->payload + RELAY_HEADER_SIZE));
  1599. return 0;
  1600. case RELAY_COMMAND_CONNECTED:
  1601. if (conn) {
  1602. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1603. "'connected' unsupported while open. Closing circ.");
  1604. return -END_CIRC_REASON_TORPROTOCOL;
  1605. }
  1606. log_info(domain,
  1607. "'connected' received on circid %u for streamid %d, "
  1608. "no conn attached anymore. Ignoring.",
  1609. (unsigned)circ->n_circ_id, rh.stream_id);
  1610. return 0;
  1611. case RELAY_COMMAND_SENDME:
  1612. if (!rh.stream_id) {
  1613. if (layer_hint) {
  1614. if (layer_hint->package_window + CIRCWINDOW_INCREMENT >
  1615. CIRCWINDOW_START_MAX) {
  1616. static struct ratelim_t exit_warn_ratelim = RATELIM_INIT(600);
  1617. log_fn_ratelim(&exit_warn_ratelim, LOG_WARN, LD_PROTOCOL,
  1618. "Unexpected sendme cell from exit relay. "
  1619. "Closing circ.");
  1620. return -END_CIRC_REASON_TORPROTOCOL;
  1621. }
  1622. layer_hint->package_window += CIRCWINDOW_INCREMENT;
  1623. log_debug(LD_APP,"circ-level sendme at origin, packagewindow %d.",
  1624. layer_hint->package_window);
  1625. circuit_resume_edge_reading(circ, layer_hint);
  1626. /* We count circuit-level sendme's as valid delivered data because
  1627. * they are rate limited. Note that we cannot count stream
  1628. * sendme's because the other end could send as many as they like.
  1629. */
  1630. if (CIRCUIT_IS_ORIGIN(circ)) {
  1631. circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ),
  1632. rh.length);
  1633. }
  1634. } else {
  1635. if (circ->package_window + CIRCWINDOW_INCREMENT >
  1636. CIRCWINDOW_START_MAX) {
  1637. static struct ratelim_t client_warn_ratelim = RATELIM_INIT(600);
  1638. log_fn_ratelim(&client_warn_ratelim,LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1639. "Unexpected sendme cell from client. "
  1640. "Closing circ (window %d).",
  1641. circ->package_window);
  1642. return -END_CIRC_REASON_TORPROTOCOL;
  1643. }
  1644. circ->package_window += CIRCWINDOW_INCREMENT;
  1645. log_debug(LD_APP,
  1646. "circ-level sendme at non-origin, packagewindow %d.",
  1647. circ->package_window);
  1648. circuit_resume_edge_reading(circ, layer_hint);
  1649. }
  1650. return 0;
  1651. }
  1652. if (!conn) {
  1653. log_info(domain,"sendme cell dropped, unknown stream (streamid %d).",
  1654. rh.stream_id);
  1655. return 0;
  1656. }
  1657. conn->package_window += STREAMWINDOW_INCREMENT;
  1658. log_debug(domain,"stream-level sendme, packagewindow now %d.",
  1659. conn->package_window);
  1660. if (circuit_queue_streams_are_blocked(circ)) {
  1661. /* Still waiting for queue to flush; don't touch conn */
  1662. return 0;
  1663. }
  1664. connection_start_reading(TO_CONN(conn));
  1665. /* handle whatever might still be on the inbuf */
  1666. if (connection_edge_package_raw_inbuf(conn, 1, NULL) < 0) {
  1667. /* (We already sent an end cell if possible) */
  1668. connection_mark_for_close(TO_CONN(conn));
  1669. return 0;
  1670. }
  1671. return 0;
  1672. case RELAY_COMMAND_RESOLVE:
  1673. if (layer_hint) {
  1674. log_fn(LOG_PROTOCOL_WARN, LD_APP,
  1675. "resolve request unsupported at AP; dropping.");
  1676. return 0;
  1677. } else if (conn) {
  1678. log_fn(LOG_PROTOCOL_WARN, domain,
  1679. "resolve request for known stream; dropping.");
  1680. return 0;
  1681. } else if (circ->purpose != CIRCUIT_PURPOSE_OR) {
  1682. log_fn(LOG_PROTOCOL_WARN, domain,
  1683. "resolve request on circ with purpose %d; dropping",
  1684. circ->purpose);
  1685. return 0;
  1686. }
  1687. connection_exit_begin_resolve(cell, TO_OR_CIRCUIT(circ));
  1688. return 0;
  1689. case RELAY_COMMAND_RESOLVED:
  1690. if (conn) {
  1691. log_fn(LOG_PROTOCOL_WARN, domain,
  1692. "'resolved' unsupported while open. Closing circ.");
  1693. return -END_CIRC_REASON_TORPROTOCOL;
  1694. }
  1695. log_info(domain,
  1696. "'resolved' received, no conn attached anymore. Ignoring.");
  1697. return 0;
  1698. case RELAY_COMMAND_ESTABLISH_INTRO:
  1699. case RELAY_COMMAND_ESTABLISH_RENDEZVOUS:
  1700. case RELAY_COMMAND_INTRODUCE1:
  1701. case RELAY_COMMAND_INTRODUCE2:
  1702. case RELAY_COMMAND_INTRODUCE_ACK:
  1703. case RELAY_COMMAND_RENDEZVOUS1:
  1704. case RELAY_COMMAND_RENDEZVOUS2:
  1705. case RELAY_COMMAND_INTRO_ESTABLISHED:
  1706. case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED:
  1707. rend_process_relay_cell(circ, layer_hint,
  1708. rh.command, rh.length,
  1709. cell->payload+RELAY_HEADER_SIZE);
  1710. return 0;
  1711. }
  1712. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  1713. "Received unknown relay command %d. Perhaps the other side is using "
  1714. "a newer version of Tor? Dropping.",
  1715. rh.command);
  1716. return 0; /* for forward compatibility, don't kill the circuit */
  1717. }
  1718. /** How many relay_data cells have we built, ever? */
  1719. uint64_t stats_n_data_cells_packaged = 0;
  1720. /** How many bytes of data have we put in relay_data cells have we built,
  1721. * ever? This would be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if
  1722. * every relay cell we ever sent were completely full of data. */
  1723. uint64_t stats_n_data_bytes_packaged = 0;
  1724. /** How many relay_data cells have we received, ever? */
  1725. uint64_t stats_n_data_cells_received = 0;
  1726. /** How many bytes of data have we received relay_data cells, ever? This would
  1727. * be RELAY_PAYLOAD_SIZE*stats_n_data_cells_packaged if every relay cell we
  1728. * ever received were completely full of data. */
  1729. uint64_t stats_n_data_bytes_received = 0;
  1730. /** If <b>conn</b> has an entire relay payload of bytes on its inbuf (or
  1731. * <b>package_partial</b> is true), and the appropriate package windows aren't
  1732. * empty, grab a cell and send it down the circuit.
  1733. *
  1734. * If *<b>max_cells</b> is given, package no more than max_cells. Decrement
  1735. * *<b>max_cells</b> by the number of cells packaged.
  1736. *
  1737. * Return -1 (and send a RELAY_COMMAND_END cell if necessary) if conn should
  1738. * be marked for close, else return 0.
  1739. */
  1740. int
  1741. connection_edge_package_raw_inbuf(edge_connection_t *conn, int package_partial,
  1742. int *max_cells)
  1743. {
  1744. size_t bytes_to_process, length;
  1745. char payload[CELL_PAYLOAD_SIZE];
  1746. circuit_t *circ;
  1747. const unsigned domain = conn->base_.type == CONN_TYPE_AP ? LD_APP : LD_EXIT;
  1748. int sending_from_optimistic = 0;
  1749. entry_connection_t *entry_conn =
  1750. conn->base_.type == CONN_TYPE_AP ? EDGE_TO_ENTRY_CONN(conn) : NULL;
  1751. const int sending_optimistically =
  1752. entry_conn &&
  1753. conn->base_.type == CONN_TYPE_AP &&
  1754. conn->base_.state != AP_CONN_STATE_OPEN;
  1755. crypt_path_t *cpath_layer = conn->cpath_layer;
  1756. tor_assert(conn);
  1757. if (conn->base_.marked_for_close) {
  1758. log_warn(LD_BUG,
  1759. "called on conn that's already marked for close at %s:%d.",
  1760. conn->base_.marked_for_close_file, conn->base_.marked_for_close);
  1761. return 0;
  1762. }
  1763. if (max_cells && *max_cells <= 0)
  1764. return 0;
  1765. repeat_connection_edge_package_raw_inbuf:
  1766. circ = circuit_get_by_edge_conn(conn);
  1767. if (!circ) {
  1768. log_info(domain,"conn has no circuit! Closing.");
  1769. conn->end_reason = END_STREAM_REASON_CANT_ATTACH;
  1770. return -1;
  1771. }
  1772. if (circuit_consider_stop_edge_reading(circ, cpath_layer))
  1773. return 0;
  1774. if (conn->package_window <= 0) {
  1775. log_info(domain,"called with package_window %d. Skipping.",
  1776. conn->package_window);
  1777. connection_stop_reading(TO_CONN(conn));
  1778. return 0;
  1779. }
  1780. sending_from_optimistic = entry_conn &&
  1781. entry_conn->sending_optimistic_data != NULL;
  1782. if (PREDICT_UNLIKELY(sending_from_optimistic)) {
  1783. bytes_to_process = buf_datalen(entry_conn->sending_optimistic_data);
  1784. if (PREDICT_UNLIKELY(!bytes_to_process)) {
  1785. log_warn(LD_BUG, "sending_optimistic_data was non-NULL but empty");
  1786. bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
  1787. sending_from_optimistic = 0;
  1788. }
  1789. } else {
  1790. bytes_to_process = connection_get_inbuf_len(TO_CONN(conn));
  1791. }
  1792. if (!bytes_to_process)
  1793. return 0;
  1794. if (!package_partial && bytes_to_process < RELAY_PAYLOAD_SIZE)
  1795. return 0;
  1796. if (bytes_to_process > RELAY_PAYLOAD_SIZE) {
  1797. length = RELAY_PAYLOAD_SIZE;
  1798. } else {
  1799. length = bytes_to_process;
  1800. }
  1801. stats_n_data_bytes_packaged += length;
  1802. stats_n_data_cells_packaged += 1;
  1803. if (PREDICT_UNLIKELY(sending_from_optimistic)) {
  1804. /* XXXX We could be more efficient here by sometimes packing
  1805. * previously-sent optimistic data in the same cell with data
  1806. * from the inbuf. */
  1807. buf_get_bytes(entry_conn->sending_optimistic_data, payload, length);
  1808. if (!buf_datalen(entry_conn->sending_optimistic_data)) {
  1809. buf_free(entry_conn->sending_optimistic_data);
  1810. entry_conn->sending_optimistic_data = NULL;
  1811. }
  1812. } else {
  1813. connection_buf_get_bytes(payload, length, TO_CONN(conn));
  1814. }
  1815. log_debug(domain,TOR_SOCKET_T_FORMAT": Packaging %d bytes (%d waiting).",
  1816. conn->base_.s,
  1817. (int)length, (int)connection_get_inbuf_len(TO_CONN(conn)));
  1818. if (sending_optimistically && !sending_from_optimistic) {
  1819. /* This is new optimistic data; remember it in case we need to detach and
  1820. retry */
  1821. if (!entry_conn->pending_optimistic_data)
  1822. entry_conn->pending_optimistic_data = buf_new();
  1823. buf_add(entry_conn->pending_optimistic_data, payload, length);
  1824. }
  1825. if (connection_edge_send_command(conn, RELAY_COMMAND_DATA,
  1826. payload, length) < 0 )
  1827. /* circuit got marked for close, don't continue, don't need to mark conn */
  1828. return 0;
  1829. if (!cpath_layer) { /* non-rendezvous exit */
  1830. tor_assert(circ->package_window > 0);
  1831. circ->package_window--;
  1832. } else { /* we're an AP, or an exit on a rendezvous circ */
  1833. tor_assert(cpath_layer->package_window > 0);
  1834. cpath_layer->package_window--;
  1835. }
  1836. if (--conn->package_window <= 0) { /* is it 0 after decrement? */
  1837. connection_stop_reading(TO_CONN(conn));
  1838. log_debug(domain,"conn->package_window reached 0.");
  1839. circuit_consider_stop_edge_reading(circ, cpath_layer);
  1840. return 0; /* don't process the inbuf any more */
  1841. }
  1842. log_debug(domain,"conn->package_window is now %d",conn->package_window);
  1843. if (max_cells) {
  1844. *max_cells -= 1;
  1845. if (*max_cells <= 0)
  1846. return 0;
  1847. }
  1848. /* handle more if there's more, or return 0 if there isn't */
  1849. goto repeat_connection_edge_package_raw_inbuf;
  1850. }
  1851. /** Called when we've just received a relay data cell, when
  1852. * we've just finished flushing all bytes to stream <b>conn</b>,
  1853. * or when we've flushed *some* bytes to the stream <b>conn</b>.
  1854. *
  1855. * If conn->outbuf is not too full, and our deliver window is
  1856. * low, send back a suitable number of stream-level sendme cells.
  1857. */
  1858. void
  1859. connection_edge_consider_sending_sendme(edge_connection_t *conn)
  1860. {
  1861. circuit_t *circ;
  1862. if (connection_outbuf_too_full(TO_CONN(conn)))
  1863. return;
  1864. circ = circuit_get_by_edge_conn(conn);
  1865. if (!circ) {
  1866. /* this can legitimately happen if the destroy has already
  1867. * arrived and torn down the circuit */
  1868. log_info(LD_APP,"No circuit associated with conn. Skipping.");
  1869. return;
  1870. }
  1871. while (conn->deliver_window <= STREAMWINDOW_START - STREAMWINDOW_INCREMENT) {
  1872. log_debug(conn->base_.type == CONN_TYPE_AP ?LD_APP:LD_EXIT,
  1873. "Outbuf %d, Queuing stream sendme.",
  1874. (int)conn->base_.outbuf_flushlen);
  1875. conn->deliver_window += STREAMWINDOW_INCREMENT;
  1876. if (connection_edge_send_command(conn, RELAY_COMMAND_SENDME,
  1877. NULL, 0) < 0) {
  1878. log_warn(LD_APP,"connection_edge_send_command failed. Skipping.");
  1879. return; /* the circuit's closed, don't continue */
  1880. }
  1881. }
  1882. }
  1883. /** The circuit <b>circ</b> has received a circuit-level sendme
  1884. * (on hop <b>layer_hint</b>, if we're the OP). Go through all the
  1885. * attached streams and let them resume reading and packaging, if
  1886. * their stream windows allow it.
  1887. */
  1888. static void
  1889. circuit_resume_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
  1890. {
  1891. if (circuit_queue_streams_are_blocked(circ)) {
  1892. log_debug(layer_hint?LD_APP:LD_EXIT,"Too big queue, no resuming");
  1893. return;
  1894. }
  1895. log_debug(layer_hint?LD_APP:LD_EXIT,"resuming");
  1896. if (CIRCUIT_IS_ORIGIN(circ))
  1897. circuit_resume_edge_reading_helper(TO_ORIGIN_CIRCUIT(circ)->p_streams,
  1898. circ, layer_hint);
  1899. else
  1900. circuit_resume_edge_reading_helper(TO_OR_CIRCUIT(circ)->n_streams,
  1901. circ, layer_hint);
  1902. }
  1903. void
  1904. stream_choice_seed_weak_rng(void)
  1905. {
  1906. crypto_seed_weak_rng(&stream_choice_rng);
  1907. }
  1908. /** A helper function for circuit_resume_edge_reading() above.
  1909. * The arguments are the same, except that <b>conn</b> is the head
  1910. * of a linked list of edge streams that should each be considered.
  1911. */
  1912. static int
  1913. circuit_resume_edge_reading_helper(edge_connection_t *first_conn,
  1914. circuit_t *circ,
  1915. crypt_path_t *layer_hint)
  1916. {
  1917. edge_connection_t *conn;
  1918. int n_packaging_streams, n_streams_left;
  1919. int packaged_this_round;
  1920. int cells_on_queue;
  1921. int cells_per_conn;
  1922. edge_connection_t *chosen_stream = NULL;
  1923. int max_to_package;
  1924. if (first_conn == NULL) {
  1925. /* Don't bother to try to do the rest of this if there are no connections
  1926. * to resume. */
  1927. return 0;
  1928. }
  1929. /* How many cells do we have space for? It will be the minimum of
  1930. * the number needed to exhaust the package window, and the minimum
  1931. * needed to fill the cell queue. */
  1932. max_to_package = circ->package_window;
  1933. if (CIRCUIT_IS_ORIGIN(circ)) {
  1934. cells_on_queue = circ->n_chan_cells.n;
  1935. } else {
  1936. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  1937. cells_on_queue = or_circ->p_chan_cells.n;
  1938. }
  1939. if (CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue < max_to_package)
  1940. max_to_package = CELL_QUEUE_HIGHWATER_SIZE - cells_on_queue;
  1941. /* Once we used to start listening on the streams in the order they
  1942. * appeared in the linked list. That leads to starvation on the
  1943. * streams that appeared later on the list, since the first streams
  1944. * would always get to read first. Instead, we just pick a random
  1945. * stream on the list, and enable reading for streams starting at that
  1946. * point (and wrapping around as if the list were circular). It would
  1947. * probably be better to actually remember which streams we've
  1948. * serviced in the past, but this is simple and effective. */
  1949. /* Select a stream uniformly at random from the linked list. We
  1950. * don't need cryptographic randomness here. */
  1951. {
  1952. int num_streams = 0;
  1953. for (conn = first_conn; conn; conn = conn->next_stream) {
  1954. num_streams++;
  1955. if (tor_weak_random_one_in_n(&stream_choice_rng, num_streams)) {
  1956. chosen_stream = conn;
  1957. }
  1958. /* Invariant: chosen_stream has been chosen uniformly at random from
  1959. * among the first num_streams streams on first_conn.
  1960. *
  1961. * (Note that we iterate over every stream on the circuit, so that after
  1962. * we've considered the first stream, we've chosen it with P=1; and
  1963. * after we consider the second stream, we've switched to it with P=1/2
  1964. * and stayed with the first stream with P=1/2; and after we've
  1965. * considered the third stream, we've switched to it with P=1/3 and
  1966. * remained with one of the first two streams with P=(2/3), giving each
  1967. * one P=(1/2)(2/3) )=(1/3).) */
  1968. }
  1969. }
  1970. /* Count how many non-marked streams there are that have anything on
  1971. * their inbuf, and enable reading on all of the connections. */
  1972. n_packaging_streams = 0;
  1973. /* Activate reading starting from the chosen stream */
  1974. for (conn=chosen_stream; conn; conn = conn->next_stream) {
  1975. /* Start reading for the streams starting from here */
  1976. if (conn->base_.marked_for_close || conn->package_window <= 0)
  1977. continue;
  1978. if (!layer_hint || conn->cpath_layer == layer_hint) {
  1979. connection_start_reading(TO_CONN(conn));
  1980. if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
  1981. ++n_packaging_streams;
  1982. }
  1983. }
  1984. /* Go back and do the ones we skipped, circular-style */
  1985. for (conn = first_conn; conn != chosen_stream; conn = conn->next_stream) {
  1986. if (conn->base_.marked_for_close || conn->package_window <= 0)
  1987. continue;
  1988. if (!layer_hint || conn->cpath_layer == layer_hint) {
  1989. connection_start_reading(TO_CONN(conn));
  1990. if (connection_get_inbuf_len(TO_CONN(conn)) > 0)
  1991. ++n_packaging_streams;
  1992. }
  1993. }
  1994. if (n_packaging_streams == 0) /* avoid divide-by-zero */
  1995. return 0;
  1996. again:
  1997. cells_per_conn = CEIL_DIV(max_to_package, n_packaging_streams);
  1998. packaged_this_round = 0;
  1999. n_streams_left = 0;
  2000. /* Iterate over all connections. Package up to cells_per_conn cells on
  2001. * each. Update packaged_this_round with the total number of cells
  2002. * packaged, and n_streams_left with the number that still have data to
  2003. * package.
  2004. */
  2005. for (conn=first_conn; conn; conn=conn->next_stream) {
  2006. if (conn->base_.marked_for_close || conn->package_window <= 0)
  2007. continue;
  2008. if (!layer_hint || conn->cpath_layer == layer_hint) {
  2009. int n = cells_per_conn, r;
  2010. /* handle whatever might still be on the inbuf */
  2011. r = connection_edge_package_raw_inbuf(conn, 1, &n);
  2012. /* Note how many we packaged */
  2013. packaged_this_round += (cells_per_conn-n);
  2014. if (r<0) {
  2015. /* Problem while packaging. (We already sent an end cell if
  2016. * possible) */
  2017. connection_mark_for_close(TO_CONN(conn));
  2018. continue;
  2019. }
  2020. /* If there's still data to read, we'll be coming back to this stream. */
  2021. if (connection_get_inbuf_len(TO_CONN(conn)))
  2022. ++n_streams_left;
  2023. /* If the circuit won't accept any more data, return without looking
  2024. * at any more of the streams. Any connections that should be stopped
  2025. * have already been stopped by connection_edge_package_raw_inbuf. */
  2026. if (circuit_consider_stop_edge_reading(circ, layer_hint))
  2027. return -1;
  2028. /* XXXX should we also stop immediately if we fill up the cell queue?
  2029. * Probably. */
  2030. }
  2031. }
  2032. /* If we made progress, and we are willing to package more, and there are
  2033. * any streams left that want to package stuff... try again!
  2034. */
  2035. if (packaged_this_round && packaged_this_round < max_to_package &&
  2036. n_streams_left) {
  2037. max_to_package -= packaged_this_round;
  2038. n_packaging_streams = n_streams_left;
  2039. goto again;
  2040. }
  2041. return 0;
  2042. }
  2043. /** Check if the package window for <b>circ</b> is empty (at
  2044. * hop <b>layer_hint</b> if it's defined).
  2045. *
  2046. * If yes, tell edge streams to stop reading and return 1.
  2047. * Else return 0.
  2048. */
  2049. static int
  2050. circuit_consider_stop_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
  2051. {
  2052. edge_connection_t *conn = NULL;
  2053. unsigned domain = layer_hint ? LD_APP : LD_EXIT;
  2054. if (!layer_hint) {
  2055. or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
  2056. log_debug(domain,"considering circ->package_window %d",
  2057. circ->package_window);
  2058. if (circ->package_window <= 0) {
  2059. log_debug(domain,"yes, not-at-origin. stopped.");
  2060. for (conn = or_circ->n_streams; conn; conn=conn->next_stream)
  2061. connection_stop_reading(TO_CONN(conn));
  2062. return 1;
  2063. }
  2064. return 0;
  2065. }
  2066. /* else, layer hint is defined, use it */
  2067. log_debug(domain,"considering layer_hint->package_window %d",
  2068. layer_hint->package_window);
  2069. if (layer_hint->package_window <= 0) {
  2070. log_debug(domain,"yes, at-origin. stopped.");
  2071. for (conn = TO_ORIGIN_CIRCUIT(circ)->p_streams; conn;
  2072. conn=conn->next_stream) {
  2073. if (conn->cpath_layer == layer_hint)
  2074. connection_stop_reading(TO_CONN(conn));
  2075. }
  2076. return 1;
  2077. }
  2078. return 0;
  2079. }
  2080. /** Check if the deliver_window for circuit <b>circ</b> (at hop
  2081. * <b>layer_hint</b> if it's defined) is low enough that we should
  2082. * send a circuit-level sendme back down the circuit. If so, send
  2083. * enough sendmes that the window would be overfull if we sent any
  2084. * more.
  2085. */
  2086. static void
  2087. circuit_consider_sending_sendme(circuit_t *circ, crypt_path_t *layer_hint)
  2088. {
  2089. // log_fn(LOG_INFO,"Considering: layer_hint is %s",
  2090. // layer_hint ? "defined" : "null");
  2091. while ((layer_hint ? layer_hint->deliver_window : circ->deliver_window) <=
  2092. CIRCWINDOW_START - CIRCWINDOW_INCREMENT) {
  2093. log_debug(LD_CIRC,"Queuing circuit sendme.");
  2094. if (layer_hint)
  2095. layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
  2096. else
  2097. circ->deliver_window += CIRCWINDOW_INCREMENT;
  2098. if (relay_send_command_from_edge(0, circ, RELAY_COMMAND_SENDME,
  2099. NULL, 0, layer_hint) < 0) {
  2100. log_warn(LD_CIRC,
  2101. "relay_send_command_from_edge failed. Circuit's closed.");
  2102. return; /* the circuit's closed, don't continue */
  2103. }
  2104. }
  2105. }
  2106. /** The total number of cells we have allocated. */
  2107. static size_t total_cells_allocated = 0;
  2108. /** Release storage held by <b>cell</b>. */
  2109. static inline void
  2110. packed_cell_free_unchecked(packed_cell_t *cell)
  2111. {
  2112. --total_cells_allocated;
  2113. tor_free(cell);
  2114. }
  2115. /** Allocate and return a new packed_cell_t. */
  2116. STATIC packed_cell_t *
  2117. packed_cell_new(void)
  2118. {
  2119. ++total_cells_allocated;
  2120. return tor_malloc_zero(sizeof(packed_cell_t));
  2121. }
  2122. /** Return a packed cell used outside by channel_t lower layer */
  2123. void
  2124. packed_cell_free_(packed_cell_t *cell)
  2125. {
  2126. if (!cell)
  2127. return;
  2128. packed_cell_free_unchecked(cell);
  2129. }
  2130. /** Log current statistics for cell pool allocation at log level
  2131. * <b>severity</b>. */
  2132. void
  2133. dump_cell_pool_usage(int severity)
  2134. {
  2135. int n_circs = 0;
  2136. int n_cells = 0;
  2137. SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, c) {
  2138. n_cells += c->n_chan_cells.n;
  2139. if (!CIRCUIT_IS_ORIGIN(c))
  2140. n_cells += TO_OR_CIRCUIT(c)->p_chan_cells.n;
  2141. ++n_circs;
  2142. }
  2143. SMARTLIST_FOREACH_END(c);
  2144. tor_log(severity, LD_MM,
  2145. "%d cells allocated on %d circuits. %d cells leaked.",
  2146. n_cells, n_circs, (int)total_cells_allocated - n_cells);
  2147. }
  2148. /** Allocate a new copy of packed <b>cell</b>. */
  2149. static inline packed_cell_t *
  2150. packed_cell_copy(const cell_t *cell, int wide_circ_ids)
  2151. {
  2152. packed_cell_t *c = packed_cell_new();
  2153. cell_pack(c, cell, wide_circ_ids);
  2154. return c;
  2155. }
  2156. /** Append <b>cell</b> to the end of <b>queue</b>. */
  2157. void
  2158. cell_queue_append(cell_queue_t *queue, packed_cell_t *cell)
  2159. {
  2160. TOR_SIMPLEQ_INSERT_TAIL(&queue->head, cell, next);
  2161. ++queue->n;
  2162. }
  2163. /** Append a newly allocated copy of <b>cell</b> to the end of the
  2164. * <b>exitward</b> (or app-ward) <b>queue</b> of <b>circ</b>. If
  2165. * <b>use_stats</b> is true, record statistics about the cell.
  2166. */
  2167. void
  2168. cell_queue_append_packed_copy(circuit_t *circ, cell_queue_t *queue,
  2169. int exitward, const cell_t *cell,
  2170. int wide_circ_ids, int use_stats)
  2171. {
  2172. packed_cell_t *copy = packed_cell_copy(cell, wide_circ_ids);
  2173. (void)circ;
  2174. (void)exitward;
  2175. (void)use_stats;
  2176. copy->inserted_timestamp = monotime_coarse_get_stamp();
  2177. cell_queue_append(queue, copy);
  2178. }
  2179. /** Initialize <b>queue</b> as an empty cell queue. */
  2180. void
  2181. cell_queue_init(cell_queue_t *queue)
  2182. {
  2183. memset(queue, 0, sizeof(cell_queue_t));
  2184. TOR_SIMPLEQ_INIT(&queue->head);
  2185. }
  2186. /** Remove and free every cell in <b>queue</b>. */
  2187. void
  2188. cell_queue_clear(cell_queue_t *queue)
  2189. {
  2190. packed_cell_t *cell;
  2191. while ((cell = TOR_SIMPLEQ_FIRST(&queue->head))) {
  2192. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2193. packed_cell_free_unchecked(cell);
  2194. }
  2195. TOR_SIMPLEQ_INIT(&queue->head);
  2196. queue->n = 0;
  2197. }
  2198. /** Extract and return the cell at the head of <b>queue</b>; return NULL if
  2199. * <b>queue</b> is empty. */
  2200. STATIC packed_cell_t *
  2201. cell_queue_pop(cell_queue_t *queue)
  2202. {
  2203. packed_cell_t *cell = TOR_SIMPLEQ_FIRST(&queue->head);
  2204. if (!cell)
  2205. return NULL;
  2206. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2207. --queue->n;
  2208. return cell;
  2209. }
  2210. /** Initialize <b>queue</b> as an empty cell queue. */
  2211. void
  2212. destroy_cell_queue_init(destroy_cell_queue_t *queue)
  2213. {
  2214. memset(queue, 0, sizeof(destroy_cell_queue_t));
  2215. TOR_SIMPLEQ_INIT(&queue->head);
  2216. }
  2217. /** Remove and free every cell in <b>queue</b>. */
  2218. void
  2219. destroy_cell_queue_clear(destroy_cell_queue_t *queue)
  2220. {
  2221. destroy_cell_t *cell;
  2222. while ((cell = TOR_SIMPLEQ_FIRST(&queue->head))) {
  2223. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2224. tor_free(cell);
  2225. }
  2226. TOR_SIMPLEQ_INIT(&queue->head);
  2227. queue->n = 0;
  2228. }
  2229. /** Extract and return the cell at the head of <b>queue</b>; return NULL if
  2230. * <b>queue</b> is empty. */
  2231. STATIC destroy_cell_t *
  2232. destroy_cell_queue_pop(destroy_cell_queue_t *queue)
  2233. {
  2234. destroy_cell_t *cell = TOR_SIMPLEQ_FIRST(&queue->head);
  2235. if (!cell)
  2236. return NULL;
  2237. TOR_SIMPLEQ_REMOVE_HEAD(&queue->head, next);
  2238. --queue->n;
  2239. return cell;
  2240. }
  2241. /** Append a destroy cell for <b>circid</b> to <b>queue</b>. */
  2242. void
  2243. destroy_cell_queue_append(destroy_cell_queue_t *queue,
  2244. circid_t circid,
  2245. uint8_t reason)
  2246. {
  2247. destroy_cell_t *cell = tor_malloc_zero(sizeof(destroy_cell_t));
  2248. cell->circid = circid;
  2249. cell->reason = reason;
  2250. /* Not yet used, but will be required for OOM handling. */
  2251. cell->inserted_timestamp = monotime_coarse_get_stamp();
  2252. TOR_SIMPLEQ_INSERT_TAIL(&queue->head, cell, next);
  2253. ++queue->n;
  2254. }
  2255. /** Convert a destroy_cell_t to a newly allocated cell_t. Frees its input. */
  2256. static packed_cell_t *
  2257. destroy_cell_to_packed_cell(destroy_cell_t *inp, int wide_circ_ids)
  2258. {
  2259. packed_cell_t *packed = packed_cell_new();
  2260. cell_t cell;
  2261. memset(&cell, 0, sizeof(cell));
  2262. cell.circ_id = inp->circid;
  2263. cell.command = CELL_DESTROY;
  2264. cell.payload[0] = inp->reason;
  2265. cell_pack(packed, &cell, wide_circ_ids);
  2266. tor_free(inp);
  2267. return packed;
  2268. }
  2269. /** Return the total number of bytes used for each packed_cell in a queue.
  2270. * Approximate. */
  2271. size_t
  2272. packed_cell_mem_cost(void)
  2273. {
  2274. return sizeof(packed_cell_t);
  2275. }
  2276. /* DOCDOC */
  2277. size_t
  2278. cell_queues_get_total_allocation(void)
  2279. {
  2280. return total_cells_allocated * packed_cell_mem_cost();
  2281. }
  2282. /** How long after we've been low on memory should we try to conserve it? */
  2283. #define MEMORY_PRESSURE_INTERVAL (30*60)
  2284. /** The time at which we were last low on memory. */
  2285. static time_t last_time_under_memory_pressure = 0;
  2286. /** Check whether we've got too much space used for cells. If so,
  2287. * call the OOM handler and return 1. Otherwise, return 0. */
  2288. STATIC int
  2289. cell_queues_check_size(void)
  2290. {
  2291. time_t now = time(NULL);
  2292. size_t alloc = cell_queues_get_total_allocation();
  2293. alloc += buf_get_total_allocation();
  2294. alloc += tor_compress_get_total_allocation();
  2295. const size_t rend_cache_total = rend_cache_get_total_allocation();
  2296. alloc += rend_cache_total;
  2297. const size_t geoip_client_cache_total =
  2298. geoip_client_cache_total_allocation();
  2299. alloc += geoip_client_cache_total;
  2300. if (alloc >= get_options()->MaxMemInQueues_low_threshold) {
  2301. last_time_under_memory_pressure = approx_time();
  2302. if (alloc >= get_options()->MaxMemInQueues) {
  2303. /* If we're spending over 20% of the memory limit on hidden service
  2304. * descriptors, free them until we're down to 10%. Do the same for geoip
  2305. * client cache. */
  2306. if (rend_cache_total > get_options()->MaxMemInQueues / 5) {
  2307. const size_t bytes_to_remove =
  2308. rend_cache_total - (size_t)(get_options()->MaxMemInQueues / 10);
  2309. alloc -= hs_cache_handle_oom(now, bytes_to_remove);
  2310. }
  2311. if (geoip_client_cache_total > get_options()->MaxMemInQueues / 5) {
  2312. const size_t bytes_to_remove =
  2313. geoip_client_cache_total -
  2314. (size_t)(get_options()->MaxMemInQueues / 10);
  2315. alloc -= geoip_client_cache_handle_oom(now, bytes_to_remove);
  2316. }
  2317. circuits_handle_oom(alloc);
  2318. return 1;
  2319. }
  2320. }
  2321. return 0;
  2322. }
  2323. /** Return true if we've been under memory pressure in the last
  2324. * MEMORY_PRESSURE_INTERVAL seconds. */
  2325. int
  2326. have_been_under_memory_pressure(void)
  2327. {
  2328. return last_time_under_memory_pressure + MEMORY_PRESSURE_INTERVAL
  2329. < approx_time();
  2330. }
  2331. /**
  2332. * Update the number of cells available on the circuit's n_chan or p_chan's
  2333. * circuit mux.
  2334. */
  2335. void
  2336. update_circuit_on_cmux_(circuit_t *circ, cell_direction_t direction,
  2337. const char *file, int lineno)
  2338. {
  2339. channel_t *chan = NULL;
  2340. or_circuit_t *or_circ = NULL;
  2341. circuitmux_t *cmux = NULL;
  2342. tor_assert(circ);
  2343. /* Okay, get the channel */
  2344. if (direction == CELL_DIRECTION_OUT) {
  2345. chan = circ->n_chan;
  2346. } else {
  2347. or_circ = TO_OR_CIRCUIT(circ);
  2348. chan = or_circ->p_chan;
  2349. }
  2350. tor_assert(chan);
  2351. tor_assert(chan->cmux);
  2352. /* Now get the cmux */
  2353. cmux = chan->cmux;
  2354. /* Cmux sanity check */
  2355. if (! circuitmux_is_circuit_attached(cmux, circ)) {
  2356. log_warn(LD_BUG, "called on non-attached circuit from %s:%d",
  2357. file, lineno);
  2358. return;
  2359. }
  2360. tor_assert(circuitmux_attached_circuit_direction(cmux, circ) == direction);
  2361. /* Update the number of cells we have for the circuit mux */
  2362. if (direction == CELL_DIRECTION_OUT) {
  2363. circuitmux_set_num_cells(cmux, circ, circ->n_chan_cells.n);
  2364. } else {
  2365. circuitmux_set_num_cells(cmux, circ, or_circ->p_chan_cells.n);
  2366. }
  2367. }
  2368. /** Remove all circuits from the cmux on <b>chan</b>.
  2369. *
  2370. * If <b>circuits_out</b> is non-NULL, add all detached circuits to
  2371. * <b>circuits_out</b>.
  2372. **/
  2373. void
  2374. channel_unlink_all_circuits(channel_t *chan, smartlist_t *circuits_out)
  2375. {
  2376. tor_assert(chan);
  2377. tor_assert(chan->cmux);
  2378. circuitmux_detach_all_circuits(chan->cmux, circuits_out);
  2379. chan->num_n_circuits = 0;
  2380. chan->num_p_circuits = 0;
  2381. }
  2382. /** Block (if <b>block</b> is true) or unblock (if <b>block</b> is false)
  2383. * every edge connection that is using <b>circ</b> to write to <b>chan</b>,
  2384. * and start or stop reading as appropriate.
  2385. *
  2386. * If <b>stream_id</b> is nonzero, block only the edge connection whose
  2387. * stream_id matches it.
  2388. *
  2389. * Returns the number of streams whose status we changed.
  2390. */
  2391. static int
  2392. set_streams_blocked_on_circ(circuit_t *circ, channel_t *chan,
  2393. int block, streamid_t stream_id)
  2394. {
  2395. edge_connection_t *edge = NULL;
  2396. int n = 0;
  2397. if (circ->n_chan == chan) {
  2398. circ->streams_blocked_on_n_chan = block;
  2399. if (CIRCUIT_IS_ORIGIN(circ))
  2400. edge = TO_ORIGIN_CIRCUIT(circ)->p_streams;
  2401. } else {
  2402. circ->streams_blocked_on_p_chan = block;
  2403. tor_assert(!CIRCUIT_IS_ORIGIN(circ));
  2404. edge = TO_OR_CIRCUIT(circ)->n_streams;
  2405. }
  2406. for (; edge; edge = edge->next_stream) {
  2407. connection_t *conn = TO_CONN(edge);
  2408. if (stream_id && edge->stream_id != stream_id)
  2409. continue;
  2410. if (edge->edge_blocked_on_circ != block) {
  2411. ++n;
  2412. edge->edge_blocked_on_circ = block;
  2413. }
  2414. if (!conn->read_event) {
  2415. /* This connection is a placeholder for something; probably a DNS
  2416. * request. It can't actually stop or start reading.*/
  2417. continue;
  2418. }
  2419. if (block) {
  2420. if (connection_is_reading(conn))
  2421. connection_stop_reading(conn);
  2422. } else {
  2423. /* Is this right? */
  2424. if (!connection_is_reading(conn))
  2425. connection_start_reading(conn);
  2426. }
  2427. }
  2428. return n;
  2429. }
  2430. /** Extract the command from a packed cell. */
  2431. static uint8_t
  2432. packed_cell_get_command(const packed_cell_t *cell, int wide_circ_ids)
  2433. {
  2434. if (wide_circ_ids) {
  2435. return get_uint8(cell->body+4);
  2436. } else {
  2437. return get_uint8(cell->body+2);
  2438. }
  2439. }
  2440. /** Extract the circuit ID from a packed cell. */
  2441. circid_t
  2442. packed_cell_get_circid(const packed_cell_t *cell, int wide_circ_ids)
  2443. {
  2444. if (wide_circ_ids) {
  2445. return ntohl(get_uint32(cell->body));
  2446. } else {
  2447. return ntohs(get_uint16(cell->body));
  2448. }
  2449. }
  2450. /** Pull as many cells as possible (but no more than <b>max</b>) from the
  2451. * queue of the first active circuit on <b>chan</b>, and write them to
  2452. * <b>chan</b>-&gt;outbuf. Return the number of cells written. Advance
  2453. * the active circuit pointer to the next active circuit in the ring. */
  2454. MOCK_IMPL(int,
  2455. channel_flush_from_first_active_circuit, (channel_t *chan, int max))
  2456. {
  2457. circuitmux_t *cmux = NULL;
  2458. int n_flushed = 0;
  2459. cell_queue_t *queue;
  2460. destroy_cell_queue_t *destroy_queue=NULL;
  2461. circuit_t *circ;
  2462. or_circuit_t *or_circ;
  2463. int streams_blocked;
  2464. packed_cell_t *cell;
  2465. /* Get the cmux */
  2466. tor_assert(chan);
  2467. tor_assert(chan->cmux);
  2468. cmux = chan->cmux;
  2469. /* Main loop: pick a circuit, send a cell, update the cmux */
  2470. while (n_flushed < max) {
  2471. circ = circuitmux_get_first_active_circuit(cmux, &destroy_queue);
  2472. if (destroy_queue) {
  2473. destroy_cell_t *dcell;
  2474. /* this code is duplicated from some of the logic below. Ugly! XXXX */
  2475. /* If we are given a destroy_queue here, then it is required to be
  2476. * nonempty... */
  2477. tor_assert(destroy_queue->n > 0);
  2478. dcell = destroy_cell_queue_pop(destroy_queue);
  2479. /* ...and pop() will always yield a cell from a nonempty queue. */
  2480. tor_assert(dcell);
  2481. /* frees dcell */
  2482. cell = destroy_cell_to_packed_cell(dcell, chan->wide_circ_ids);
  2483. /* Send the DESTROY cell. It is very unlikely that this fails but just
  2484. * in case, get rid of the channel. */
  2485. if (channel_write_packed_cell(chan, cell) < 0) {
  2486. /* The cell has been freed. */
  2487. channel_mark_for_close(chan);
  2488. continue;
  2489. }
  2490. /* Update the cmux destroy counter */
  2491. circuitmux_notify_xmit_destroy(cmux);
  2492. cell = NULL;
  2493. ++n_flushed;
  2494. continue;
  2495. }
  2496. /* If it returns NULL, no cells left to send */
  2497. if (!circ) break;
  2498. if (circ->n_chan == chan) {
  2499. queue = &circ->n_chan_cells;
  2500. streams_blocked = circ->streams_blocked_on_n_chan;
  2501. } else {
  2502. or_circ = TO_OR_CIRCUIT(circ);
  2503. tor_assert(or_circ->p_chan == chan);
  2504. queue = &TO_OR_CIRCUIT(circ)->p_chan_cells;
  2505. streams_blocked = circ->streams_blocked_on_p_chan;
  2506. }
  2507. /* Circuitmux told us this was active, so it should have cells */
  2508. if (/*BUG(*/ queue->n == 0 /*)*/) {
  2509. log_warn(LD_BUG, "Found a supposedly active circuit with no cells "
  2510. "to send. Trying to recover.");
  2511. circuitmux_set_num_cells(cmux, circ, 0);
  2512. if (! circ->marked_for_close)
  2513. circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
  2514. continue;
  2515. }
  2516. tor_assert(queue->n > 0);
  2517. /*
  2518. * Get just one cell here; once we've sent it, that can change the circuit
  2519. * selection, so we have to loop around for another even if this circuit
  2520. * has more than one.
  2521. */
  2522. cell = cell_queue_pop(queue);
  2523. /* Calculate the exact time that this cell has spent in the queue. */
  2524. if (get_options()->CellStatistics ||
  2525. get_options()->TestingEnableCellStatsEvent) {
  2526. uint32_t timestamp_now = monotime_coarse_get_stamp();
  2527. uint32_t msec_waiting =
  2528. (uint32_t) monotime_coarse_stamp_units_to_approx_msec(
  2529. timestamp_now - cell->inserted_timestamp);
  2530. if (get_options()->CellStatistics && !CIRCUIT_IS_ORIGIN(circ)) {
  2531. or_circ = TO_OR_CIRCUIT(circ);
  2532. or_circ->total_cell_waiting_time += msec_waiting;
  2533. or_circ->processed_cells++;
  2534. }
  2535. if (get_options()->TestingEnableCellStatsEvent) {
  2536. uint8_t command = packed_cell_get_command(cell, chan->wide_circ_ids);
  2537. testing_cell_stats_entry_t *ent =
  2538. tor_malloc_zero(sizeof(testing_cell_stats_entry_t));
  2539. ent->command = command;
  2540. ent->waiting_time = msec_waiting / 10;
  2541. ent->removed = 1;
  2542. if (circ->n_chan == chan)
  2543. ent->exitward = 1;
  2544. if (!circ->testing_cell_stats)
  2545. circ->testing_cell_stats = smartlist_new();
  2546. smartlist_add(circ->testing_cell_stats, ent);
  2547. }
  2548. }
  2549. /* If we just flushed our queue and this circuit is used for a
  2550. * tunneled directory request, possibly advance its state. */
  2551. if (queue->n == 0 && chan->dirreq_id)
  2552. geoip_change_dirreq_state(chan->dirreq_id,
  2553. DIRREQ_TUNNELED,
  2554. DIRREQ_CIRC_QUEUE_FLUSHED);
  2555. /* Now send the cell. It is very unlikely that this fails but just in
  2556. * case, get rid of the channel. */
  2557. if (channel_write_packed_cell(chan, cell) < 0) {
  2558. /* The cell has been freed at this point. */
  2559. channel_mark_for_close(chan);
  2560. continue;
  2561. }
  2562. cell = NULL;
  2563. /*
  2564. * Don't packed_cell_free_unchecked(cell) here because the channel will
  2565. * do so when it gets out of the channel queue (probably already did, in
  2566. * which case that was an immediate double-free bug).
  2567. */
  2568. /* Update the counter */
  2569. ++n_flushed;
  2570. /*
  2571. * Now update the cmux; tell it we've just sent a cell, and how many
  2572. * we have left.
  2573. */
  2574. circuitmux_notify_xmit_cells(cmux, circ, 1);
  2575. circuitmux_set_num_cells(cmux, circ, queue->n);
  2576. if (queue->n == 0)
  2577. log_debug(LD_GENERAL, "Made a circuit inactive.");
  2578. /* Is the cell queue low enough to unblock all the streams that are waiting
  2579. * to write to this circuit? */
  2580. if (streams_blocked && queue->n <= CELL_QUEUE_LOWWATER_SIZE)
  2581. set_streams_blocked_on_circ(circ, chan, 0, 0); /* unblock streams */
  2582. /* If n_flushed < max still, loop around and pick another circuit */
  2583. }
  2584. /* Okay, we're done sending now */
  2585. return n_flushed;
  2586. }
  2587. /* Minimum value is the maximum circuit window size.
  2588. *
  2589. * SENDME cells makes it that we can control how many cells can be inflight on
  2590. * a circuit from end to end. This logic makes it that on any circuit cell
  2591. * queue, we have a maximum of cells possible.
  2592. *
  2593. * Because the Tor protocol allows for a client to exit at any hop in a
  2594. * circuit and a circuit can be of a maximum of 8 hops, so in theory the
  2595. * normal worst case will be the circuit window start value times the maximum
  2596. * number of hops (8). Having more cells then that means something is wrong.
  2597. *
  2598. * However, because padding cells aren't counted in the package window, we set
  2599. * the maximum size to a reasonably large size for which we expect that we'll
  2600. * never reach in theory. And if we ever do because of future changes, we'll
  2601. * be able to control it with a consensus parameter.
  2602. *
  2603. * XXX: Unfortunately, END cells aren't accounted for in the circuit window
  2604. * which means that for instance if a client opens 8001 streams, the 8001
  2605. * following END cells will queue up in the circuit which will get closed if
  2606. * the max limit is 8000. Which is sad because it is allowed by the Tor
  2607. * protocol. But, we need an upper bound on circuit queue in order to avoid
  2608. * DoS memory pressure so the default size is a middle ground between not
  2609. * having any limit and having a very restricted one. This is why we can also
  2610. * control it through a consensus parameter. */
  2611. #define RELAY_CIRC_CELL_QUEUE_SIZE_MIN CIRCWINDOW_START_MAX
  2612. /* We can't have a consensus parameter above this value. */
  2613. #define RELAY_CIRC_CELL_QUEUE_SIZE_MAX INT32_MAX
  2614. /* Default value is set to a large value so we can handle padding cells
  2615. * properly which aren't accounted for in the SENDME window. Default is 50000
  2616. * allowed cells in the queue resulting in ~25MB. */
  2617. #define RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT \
  2618. (50 * RELAY_CIRC_CELL_QUEUE_SIZE_MIN)
  2619. /* The maximum number of cell a circuit queue can contain. This is updated at
  2620. * every new consensus and controlled by a parameter. */
  2621. static int32_t max_circuit_cell_queue_size =
  2622. RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT;
  2623. /* Called when the consensus has changed. At this stage, the global consensus
  2624. * object has NOT been updated. It is called from
  2625. * notify_before_networkstatus_changes(). */
  2626. void
  2627. relay_consensus_has_changed(const networkstatus_t *ns)
  2628. {
  2629. tor_assert(ns);
  2630. /* Update the circuit max cell queue size from the consensus. */
  2631. max_circuit_cell_queue_size =
  2632. networkstatus_get_param(ns, "circ_max_cell_queue_size",
  2633. RELAY_CIRC_CELL_QUEUE_SIZE_DEFAULT,
  2634. RELAY_CIRC_CELL_QUEUE_SIZE_MIN,
  2635. RELAY_CIRC_CELL_QUEUE_SIZE_MAX);
  2636. }
  2637. /** Add <b>cell</b> to the queue of <b>circ</b> writing to <b>chan</b>
  2638. * transmitting in <b>direction</b>.
  2639. *
  2640. * The given <b>cell</b> is copied onto the circuit queue so the caller must
  2641. * cleanup the memory.
  2642. *
  2643. * This function is part of the fast path. */
  2644. void
  2645. append_cell_to_circuit_queue(circuit_t *circ, channel_t *chan,
  2646. cell_t *cell, cell_direction_t direction,
  2647. streamid_t fromstream)
  2648. {
  2649. or_circuit_t *orcirc = NULL;
  2650. cell_queue_t *queue;
  2651. int streams_blocked;
  2652. int exitward;
  2653. if (circ->marked_for_close)
  2654. return;
  2655. exitward = (direction == CELL_DIRECTION_OUT);
  2656. if (exitward) {
  2657. queue = &circ->n_chan_cells;
  2658. streams_blocked = circ->streams_blocked_on_n_chan;
  2659. } else {
  2660. orcirc = TO_OR_CIRCUIT(circ);
  2661. queue = &orcirc->p_chan_cells;
  2662. streams_blocked = circ->streams_blocked_on_p_chan;
  2663. }
  2664. if (PREDICT_UNLIKELY(queue->n >= max_circuit_cell_queue_size)) {
  2665. log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
  2666. "%s circuit has %d cells in its queue, maximum allowed is %d. "
  2667. "Closing circuit for safety reasons.",
  2668. (exitward) ? "Outbound" : "Inbound", queue->n,
  2669. max_circuit_cell_queue_size);
  2670. circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
  2671. stats_n_circ_max_cell_reached++;
  2672. return;
  2673. }
  2674. /* Very important that we copy to the circuit queue because all calls to
  2675. * this function use the stack for the cell memory. */
  2676. cell_queue_append_packed_copy(circ, queue, exitward, cell,
  2677. chan->wide_circ_ids, 1);
  2678. /* Check and run the OOM if needed. */
  2679. if (PREDICT_UNLIKELY(cell_queues_check_size())) {
  2680. /* We ran the OOM handler which might have closed this circuit. */
  2681. if (circ->marked_for_close)
  2682. return;
  2683. }
  2684. /* If we have too many cells on the circuit, we should stop reading from
  2685. * the edge streams for a while. */
  2686. if (!streams_blocked && queue->n >= CELL_QUEUE_HIGHWATER_SIZE)
  2687. set_streams_blocked_on_circ(circ, chan, 1, 0); /* block streams */
  2688. if (streams_blocked && fromstream) {
  2689. /* This edge connection is apparently not blocked; block it. */
  2690. set_streams_blocked_on_circ(circ, chan, 1, fromstream);
  2691. }
  2692. update_circuit_on_cmux(circ, direction);
  2693. if (queue->n == 1) {
  2694. /* This was the first cell added to the queue. We just made this
  2695. * circuit active. */
  2696. log_debug(LD_GENERAL, "Made a circuit active.");
  2697. }
  2698. /* New way: mark this as having waiting cells for the scheduler */
  2699. scheduler_channel_has_waiting_cells(chan);
  2700. }
  2701. /** Append an encoded value of <b>addr</b> to <b>payload_out</b>, which must
  2702. * have at least 18 bytes of free space. The encoding is, as specified in
  2703. * tor-spec.txt:
  2704. * RESOLVED_TYPE_IPV4 or RESOLVED_TYPE_IPV6 [1 byte]
  2705. * LENGTH [1 byte]
  2706. * ADDRESS [length bytes]
  2707. * Return the number of bytes added, or -1 on error */
  2708. int
  2709. append_address_to_payload(uint8_t *payload_out, const tor_addr_t *addr)
  2710. {
  2711. uint32_t a;
  2712. switch (tor_addr_family(addr)) {
  2713. case AF_INET:
  2714. payload_out[0] = RESOLVED_TYPE_IPV4;
  2715. payload_out[1] = 4;
  2716. a = tor_addr_to_ipv4n(addr);
  2717. memcpy(payload_out+2, &a, 4);
  2718. return 6;
  2719. case AF_INET6:
  2720. payload_out[0] = RESOLVED_TYPE_IPV6;
  2721. payload_out[1] = 16;
  2722. memcpy(payload_out+2, tor_addr_to_in6_addr8(addr), 16);
  2723. return 18;
  2724. case AF_UNSPEC:
  2725. default:
  2726. return -1;
  2727. }
  2728. }
  2729. /** Given <b>payload_len</b> bytes at <b>payload</b>, starting with an address
  2730. * encoded as by append_address_to_payload(), try to decode the address into
  2731. * *<b>addr_out</b>. Return the next byte in the payload after the address on
  2732. * success, or NULL on failure. */
  2733. const uint8_t *
  2734. decode_address_from_payload(tor_addr_t *addr_out, const uint8_t *payload,
  2735. int payload_len)
  2736. {
  2737. if (payload_len < 2)
  2738. return NULL;
  2739. if (payload_len < 2+payload[1])
  2740. return NULL;
  2741. switch (payload[0]) {
  2742. case RESOLVED_TYPE_IPV4:
  2743. if (payload[1] != 4)
  2744. return NULL;
  2745. tor_addr_from_ipv4n(addr_out, get_uint32(payload+2));
  2746. break;
  2747. case RESOLVED_TYPE_IPV6:
  2748. if (payload[1] != 16)
  2749. return NULL;
  2750. tor_addr_from_ipv6_bytes(addr_out, (char*)(payload+2));
  2751. break;
  2752. default:
  2753. tor_addr_make_unspec(addr_out);
  2754. break;
  2755. }
  2756. return payload + 2 + payload[1];
  2757. }
  2758. /** Remove all the cells queued on <b>circ</b> for <b>chan</b>. */
  2759. void
  2760. circuit_clear_cell_queue(circuit_t *circ, channel_t *chan)
  2761. {
  2762. cell_queue_t *queue;
  2763. cell_direction_t direction;
  2764. if (circ->n_chan == chan) {
  2765. queue = &circ->n_chan_cells;
  2766. direction = CELL_DIRECTION_OUT;
  2767. } else {
  2768. or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
  2769. tor_assert(orcirc->p_chan == chan);
  2770. queue = &orcirc->p_chan_cells;
  2771. direction = CELL_DIRECTION_IN;
  2772. }
  2773. /* Clear the queue */
  2774. cell_queue_clear(queue);
  2775. /* Update the cell counter in the cmux */
  2776. if (chan->cmux && circuitmux_is_circuit_attached(chan->cmux, circ))
  2777. update_circuit_on_cmux(circ, direction);
  2778. }
  2779. /** Return 1 if we shouldn't restart reading on this circuit, even if
  2780. * we get a SENDME. Else return 0.
  2781. */
  2782. static int
  2783. circuit_queue_streams_are_blocked(circuit_t *circ)
  2784. {
  2785. if (CIRCUIT_IS_ORIGIN(circ)) {
  2786. return circ->streams_blocked_on_n_chan;
  2787. } else {
  2788. return circ->streams_blocked_on_p_chan;
  2789. }
  2790. }