123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686 |
- /* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- #include "or.h"
- extern or_options_t options; /* command-line and config-file options */
- static int relay_crypt(circuit_t *circ, cell_t *cell, int cell_direction,
- crypt_path_t **layer_hint, char *recognized);
- static connection_t *relay_lookup_conn(circuit_t *circ, cell_t *cell, int cell_direction);
- static void circuit_free_cpath_node(crypt_path_t *victim);
- static uint16_t get_unique_circ_id_by_conn(connection_t *conn, int circ_id_type);
- static void circuit_rep_hist_note_result(circuit_t *circ);
- static void circuit_is_open(circuit_t *circ);
- static void circuit_build_failed(circuit_t *circ);
- static circuit_t *circuit_establish_circuit(uint8_t purpose, const char *exit_nickname);
- unsigned long stats_n_relay_cells_relayed = 0;
- unsigned long stats_n_relay_cells_delivered = 0;
- /********* START VARIABLES **********/
- static int circuitlist_len=0;
- static circuit_t *global_circuitlist=NULL;
- char *circuit_state_to_string[] = {
- "doing handshakes", /* 0 */
- "processing the onion", /* 1 */
- "connecting to firsthop", /* 2 */
- "open" /* 3 */
- };
- /********* END VARIABLES ************/
- void circuit_add(circuit_t *circ) {
- if(!global_circuitlist) { /* first one */
- global_circuitlist = circ;
- circ->next = NULL;
- } else {
- circ->next = global_circuitlist;
- global_circuitlist = circ;
- }
- ++circuitlist_len;
- }
- void circuit_remove(circuit_t *circ) {
- circuit_t *tmpcirc;
- assert(circ && global_circuitlist);
- if(global_circuitlist == circ) {
- global_circuitlist = global_circuitlist->next;
- --circuitlist_len;
- return;
- }
- for(tmpcirc = global_circuitlist;tmpcirc->next;tmpcirc = tmpcirc->next) {
- if(tmpcirc->next == circ) {
- tmpcirc->next = circ->next;
- --circuitlist_len;
- return;
- }
- }
- }
- void circuit_close_all_marked()
- {
- circuit_t *tmp,*m;
- while (global_circuitlist && global_circuitlist->marked_for_close) {
- tmp = global_circuitlist->next;
- circuit_free(global_circuitlist);
- global_circuitlist = tmp;
- }
- tmp = global_circuitlist;
- while (tmp && tmp->next) {
- if (tmp->next->marked_for_close) {
- m = tmp->next->next;
- circuit_free(tmp->next);
- tmp->next = m;
- /* Need to check new tmp->next; don't advance tmp. */
- } else {
- /* Advance tmp. */
- tmp = tmp->next;
- }
- }
- }
- circuit_t *circuit_new(uint16_t p_circ_id, connection_t *p_conn) {
- circuit_t *circ;
- circ = tor_malloc_zero(sizeof(circuit_t));
- circ->magic = CIRCUIT_MAGIC;
- circ->timestamp_created = time(NULL);
- circ->p_circ_id = p_circ_id;
- circ->p_conn = p_conn;
- circ->state = CIRCUIT_STATE_ONIONSKIN_PENDING;
- /* CircIDs */
- circ->p_circ_id = p_circ_id;
- /* circ->n_circ_id remains 0 because we haven't identified the next hop yet */
- circ->package_window = CIRCWINDOW_START;
- circ->deliver_window = CIRCWINDOW_START;
- circ->next_stream_id = crypto_pseudo_rand_int(1<<16);
- circuit_add(circ);
- return circ;
- }
- void circuit_free(circuit_t *circ) {
- assert(circ);
- assert(circ->magic == CIRCUIT_MAGIC);
- if (circ->n_crypto)
- crypto_free_cipher_env(circ->n_crypto);
- if (circ->p_crypto)
- crypto_free_cipher_env(circ->p_crypto);
- if (circ->n_digest)
- crypto_free_digest_env(circ->n_digest);
- if (circ->p_digest)
- crypto_free_digest_env(circ->p_digest);
- if(circ->build_state) {
- tor_free(circ->build_state->chosen_exit);
- if (circ->build_state->pending_final_cpath)
- circuit_free_cpath_node(circ->build_state->pending_final_cpath);
- }
- tor_free(circ->build_state);
- circuit_free_cpath(circ->cpath);
- if (circ->rend_splice) {
- circ->rend_splice->rend_splice = NULL;
- }
- memset(circ, 0xAA, sizeof(circuit_t)); /* poison memory */
- free(circ);
- }
- void circuit_free_cpath(crypt_path_t *cpath) {
- crypt_path_t *victim, *head=cpath;
- if(!cpath)
- return;
- /* it's a doubly linked list, so we have to notice when we've
- * gone through it once. */
- while(cpath->next && cpath->next != head) {
- victim = cpath;
- cpath = victim->next;
- circuit_free_cpath_node(victim);
- }
- circuit_free_cpath_node(cpath);
- }
- static void circuit_free_cpath_node(crypt_path_t *victim) {
- if(victim->f_crypto)
- crypto_free_cipher_env(victim->f_crypto);
- if(victim->b_crypto)
- crypto_free_cipher_env(victim->b_crypto);
- if(victim->f_digest)
- crypto_free_digest_env(victim->f_digest);
- if(victim->b_digest)
- crypto_free_digest_env(victim->b_digest);
- if(victim->handshake_state)
- crypto_dh_free(victim->handshake_state);
- free(victim);
- }
- /* return 0 if can't get a unique circ_id. */
- static uint16_t get_unique_circ_id_by_conn(connection_t *conn, int circ_id_type) {
- uint16_t test_circ_id;
- int attempts=0;
- uint16_t high_bit;
- assert(conn && conn->type == CONN_TYPE_OR);
- high_bit = (circ_id_type == CIRC_ID_TYPE_HIGHER) ? 1<<15 : 0;
- do {
- /* Sequentially iterate over test_circ_id=1...1<<15-1 until we find a
- * circID such that (high_bit|test_circ_id) is not already used. */
- test_circ_id = conn->next_circ_id++;
- if (test_circ_id == 0 || test_circ_id >= 1<<15) {
- test_circ_id = 1;
- conn->next_circ_id = 2;
- }
- if(++attempts > 1<<15) {
- /* Make sure we don't loop forever if all circ_id's are used. This
- * matters because it's an external DoS vulnerability.
- */
- log_fn(LOG_WARN,"No unused circ IDs. Failing.");
- return 0;
- }
- test_circ_id |= high_bit;
- } while(circuit_get_by_circ_id_conn(test_circ_id, conn));
- return test_circ_id;
- }
- circuit_t *circuit_get_by_circ_id_conn(uint16_t circ_id, connection_t *conn) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if (circ->marked_for_close)
- continue;
- if(circ->p_circ_id == circ_id) {
- if(circ->p_conn == conn)
- return circ;
- for(tmpconn = circ->p_streams; tmpconn; tmpconn = tmpconn->next_stream) {
- if(tmpconn == conn)
- return circ;
- }
- }
- if(circ->n_circ_id == circ_id) {
- if(circ->n_conn == conn)
- return circ;
- for(tmpconn = circ->n_streams; tmpconn; tmpconn = tmpconn->next_stream) {
- if(tmpconn == conn)
- return circ;
- }
- }
- }
- return NULL;
- }
- circuit_t *circuit_get_by_conn(connection_t *conn) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if (circ->marked_for_close)
- continue;
- if(circ->p_conn == conn)
- return circ;
- if(circ->n_conn == conn)
- return circ;
- for(tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream)
- if(tmpconn == conn)
- return circ;
- for(tmpconn = circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream)
- if(tmpconn == conn)
- return circ;
- }
- return NULL;
- }
- /* Return 1 iff 'c' could be returned by circuit_get_best.
- */
- static int circuit_is_acceptable(circuit_t *circ,
- connection_t *conn,
- int must_be_open,
- uint8_t purpose,
- time_t now)
- {
- routerinfo_t *exitrouter;
- if (!CIRCUIT_IS_ORIGIN(circ))
- return 0; /* this circ doesn't start at us */
- if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_conn))
- return 0; /* ignore non-open circs */
- if (circ->marked_for_close)
- return 0;
- /* if this circ isn't our purpose, skip. */
- if(purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) {
- if(circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
- circ->purpose != CIRCUIT_PURPOSE_C_REND_READY &&
- circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED)
- return 0;
- } else {
- if(purpose != circ->purpose)
- return 0;
- }
- if(purpose == CIRCUIT_PURPOSE_C_GENERAL)
- if(circ->timestamp_dirty &&
- circ->timestamp_dirty+options.NewCircuitPeriod < now)
- return 0;
- if(conn) {
- /* decide if this circ is suitable for this conn */
- // if(circ->state == CIRCUIT_STATE_OPEN && circ->n_conn) /* open */
- // exitrouter = router_get_by_addr_port(circ->cpath->prev->addr,
- // circ->cpath->prev->port);
- // else /* not open */
- /* for rend circs, circ->cpath->prev is not the last router in the
- * circuit, it's the magical extra bob hop. so just check the nickname
- * of the one we meant to finish at.
- */
- exitrouter = router_get_by_nickname(circ->build_state->chosen_exit);
- if(!exitrouter) {
- log_fn(LOG_INFO,"Skipping broken circ (exit router vanished)");
- return 0; /* this circuit is screwed and doesn't know it yet */
- }
- if(purpose == CIRCUIT_PURPOSE_C_GENERAL) {
- if(connection_ap_can_use_exit(conn, exitrouter) == ADDR_POLICY_REJECTED) {
- /* can't exit from this router */
- return 0;
- }
- } else { /* not general */
- if(rend_cmp_service_ids(conn->rend_query, circ->rend_query)) {
- /* this circ is not for this conn */
- return 0;
- }
- }
- }
- return 1;
- }
- /* Return 1 iff circuit 'a' is better than circuit 'b' for purpose. Used by
- * circuit_get_best
- */
- static int circuit_is_better(circuit_t *a, circuit_t *b, uint8_t purpose)
- {
- switch(purpose) {
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* if it's used but less dirty it's best;
- * else if it's more recently created it's best
- */
- if(b->timestamp_dirty) {
- if(a->timestamp_dirty &&
- a->timestamp_dirty > b->timestamp_dirty)
- return 1;
- } else {
- if(a->timestamp_dirty ||
- a->timestamp_created > b->timestamp_created)
- return 1;
- }
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- /* more recently created is best */
- if(a->timestamp_created > b->timestamp_created)
- return 1;
- break;
- case CIRCUIT_PURPOSE_C_REND_JOINED:
- /* the closer it is to rend_joined the better it is */
- if(a->purpose > b->purpose)
- return 1;
- break;
- }
- return 0;
- }
- /* Find the best circ that conn can use, preferably one which is
- * dirty. Circ must not be too old.
- * If !conn, return newest.
- *
- * If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN.
- *
- * circ_purpose specifies what sort of circuit we must have.
- * It can be C_GENERAL, C_INTRODUCING, or C_REND_JOINED.
- *
- * If it's REND_JOINED and must_be_open==0, then return the closest
- * rendezvous-purposed circuit that you can find.
- *
- * If circ_purpose is not GENERAL, then conn must be defined.
- */
- circuit_t *circuit_get_best(connection_t *conn,
- int must_be_open, uint8_t purpose) {
- circuit_t *circ, *best=NULL;
- time_t now = time(NULL);
- assert(purpose == CIRCUIT_PURPOSE_C_GENERAL ||
- purpose == CIRCUIT_PURPOSE_C_INTRODUCING ||
- purpose == CIRCUIT_PURPOSE_C_REND_JOINED);
- for (circ=global_circuitlist;circ;circ = circ->next) {
- if (!circuit_is_acceptable(circ,conn,must_be_open,purpose,now))
- continue;
- /* now this is an acceptable circ to hand back. but that doesn't
- * mean it's the *best* circ to hand back. try to decide.
- */
- if(!best || circuit_is_better(circ,best,purpose))
- best = circ;
- }
- return best;
- }
- /* Return the first circuit in global_circuitlist after 'start' whose
- * rend_pk_digest field is 'digest' and whose purpose is purpose. Returns
- * NULL if no circuit is found. If 'start' is null, begin at the start of
- * the list.
- */
- circuit_t *circuit_get_next_by_pk_and_purpose(circuit_t *start,
- const char *digest, uint8_t purpose)
- {
- circuit_t *circ;
- if (start == NULL)
- circ = global_circuitlist;
- else
- circ = start->next;
- for( ; circ; circ = circ->next) {
- if (circ->marked_for_close)
- continue;
- if (circ->purpose != purpose)
- continue;
- if (!memcmp(circ->rend_pk_digest, digest, DIGEST_LEN))
- return circ;
- }
- return NULL;
- }
- /* Return the circuit waiting for a rendezvous with the provided cookie.
- * Return NULL if no such circuit is found.
- */
- circuit_t *circuit_get_rendezvous(const char *cookie)
- {
- circuit_t *circ;
- for (circ = global_circuitlist; circ; circ = circ->next) {
- if (! circ->marked_for_close &&
- circ->purpose == CIRCUIT_PURPOSE_REND_POINT_WAITING &&
- ! memcmp(circ->rend_cookie, cookie, REND_COOKIE_LEN) )
- return circ;
- }
- return NULL;
- }
- #define MIN_SECONDS_BEFORE_EXPIRING_CIRC 20
- /* circuits that were born at the end of their second might be expired
- * after 10.1 seconds; circuits born at the beginning might be expired
- * after closer to 11 seconds.
- */
- /* close all circuits that start at us, aren't open, and were born
- * at least MIN_SECONDS_BEFORE_EXPIRING_CIRC seconds ago */
- void circuit_expire_building(void) {
- int now = time(NULL);
- circuit_t *victim, *circ = global_circuitlist;
- while(circ) {
- victim = circ;
- circ = circ->next;
- if(!CIRCUIT_IS_ORIGIN(victim))
- continue; /* didn't originate here */
- if(victim->marked_for_close)
- continue; /* don't mess with marked circs */
- if(victim->timestamp_created + MIN_SECONDS_BEFORE_EXPIRING_CIRC > now)
- continue; /* it's young still, don't mess with it */
- /* if circ is !open, or if it's open but purpose is est intro or est rend,
- * then mark it for close */
- if(victim->state != CIRCUIT_STATE_OPEN ||
- victim->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND ||
- victim->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) {
- if(victim->n_conn)
- log_fn(LOG_INFO,"Abandoning circ %s:%d:%d (state %d:%s)",
- victim->n_conn->address, victim->n_port, victim->n_circ_id,
- victim->state, circuit_state_to_string[victim->state]);
- else
- log_fn(LOG_INFO,"Abandoning circ %d (state %d:%s)", victim->n_circ_id,
- victim->state, circuit_state_to_string[victim->state]);
- circuit_log_path(LOG_INFO,victim);
- circuit_mark_for_close(victim);
- }
- }
- }
- /* count the number of circs starting at us that aren't open */
- int circuit_count_building(void) {
- circuit_t *circ;
- int num=0;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(CIRCUIT_IS_ORIGIN(circ)
- && circ->state != CIRCUIT_STATE_OPEN
- && !circ->marked_for_close)
- num++;
- }
- return num;
- }
- #define MIN_CIRCUITS_HANDLING_STREAM 2
- /* return 1 if at least MIN_CIRCUITS_HANDLING_STREAM non-open
- * general-purpose circuits will have an acceptable exit node for
- * conn. Else return 0.
- */
- int circuit_stream_is_being_handled(connection_t *conn) {
- circuit_t *circ;
- routerinfo_t *exitrouter;
- int num=0;
- time_t now = time(NULL);
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(CIRCUIT_IS_ORIGIN(circ) && circ->state != CIRCUIT_STATE_OPEN &&
- !circ->marked_for_close && circ->purpose == CIRCUIT_PURPOSE_C_GENERAL &&
- (!circ->timestamp_dirty ||
- circ->timestamp_dirty + options.NewCircuitPeriod < now)) {
- exitrouter = router_get_by_nickname(circ->build_state->chosen_exit);
- if(exitrouter && connection_ap_can_use_exit(conn, exitrouter) != ADDR_POLICY_REJECTED)
- if(++num >= MIN_CIRCUITS_HANDLING_STREAM)
- return 1;
- }
- }
- return 0;
- }
- /* update digest from the payload of cell. assign integrity part to cell. */
- static void relay_set_digest(crypto_digest_env_t *digest, cell_t *cell) {
- char integrity[4];
- relay_header_t rh;
- crypto_digest_add_bytes(digest, cell->payload, CELL_PAYLOAD_SIZE);
- crypto_digest_get_digest(digest, integrity, 4);
- // log_fn(LOG_DEBUG,"Putting digest of %u %u %u %u into relay cell.",
- // integrity[0], integrity[1], integrity[2], integrity[3]);
- relay_header_unpack(&rh, cell->payload);
- memcpy(rh.integrity, integrity, 4);
- relay_header_pack(cell->payload, &rh);
- }
- /* update digest from the payload of cell (with the integrity part set
- * to 0). If the integrity part is valid return 1, else restore digest
- * and cell to their original state and return 0.
- */
- static int relay_digest_matches(crypto_digest_env_t *digest, cell_t *cell) {
- char received_integrity[4], calculated_integrity[4];
- relay_header_t rh;
- crypto_digest_env_t *backup_digest=NULL;
- backup_digest = crypto_digest_dup(digest);
- relay_header_unpack(&rh, cell->payload);
- memcpy(received_integrity, rh.integrity, 4);
- memset(rh.integrity, 0, 4);
- relay_header_pack(cell->payload, &rh);
- // log_fn(LOG_DEBUG,"Reading digest of %u %u %u %u from relay cell.",
- // received_integrity[0], received_integrity[1],
- // received_integrity[2], received_integrity[3]);
- crypto_digest_add_bytes(digest, cell->payload, CELL_PAYLOAD_SIZE);
- crypto_digest_get_digest(digest, calculated_integrity, 4);
- if(memcmp(received_integrity, calculated_integrity, 4)) {
- // log_fn(LOG_INFO,"Recognized=0 but bad digest. Not recognizing.");
- // (%d vs %d).", received_integrity, calculated_integrity);
- /* restore digest to its old form */
- crypto_digest_assign(digest, backup_digest);
- /* restore the relay header */
- memcpy(rh.integrity, received_integrity, 4);
- relay_header_pack(cell->payload, &rh);
- crypto_free_digest_env(backup_digest);
- return 0;
- }
- crypto_free_digest_env(backup_digest);
- return 1;
- }
- static int relay_crypt_one_payload(crypto_cipher_env_t *cipher, char *in,
- int encrypt_mode) {
- char out[CELL_PAYLOAD_SIZE]; /* 'in' must be this size too */
- relay_header_t rh;
- relay_header_unpack(&rh, in);
- // log_fn(LOG_DEBUG,"before crypt: %d",rh.recognized);
- if(( encrypt_mode && crypto_cipher_encrypt(cipher, in, CELL_PAYLOAD_SIZE, out)) ||
- (!encrypt_mode && crypto_cipher_decrypt(cipher, in, CELL_PAYLOAD_SIZE, out))) {
- log_fn(LOG_WARN,"Error during crypt: %s", crypto_perror());
- return -1;
- }
- memcpy(in,out,CELL_PAYLOAD_SIZE);
- relay_header_unpack(&rh, in);
- // log_fn(LOG_DEBUG,"after crypt: %d",rh.recognized);
- return 0;
- }
- /*
- receive a relay cell:
- - crypt it (encrypt APward, decrypt at AP, decrypt exitward)
- - check if recognized (if exitward)
- - if recognized, check digest, find right conn, deliver to edge.
- - else connection_or_write_cell_to_buf to the right conn
- */
- int circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
- int cell_direction) {
- connection_t *conn=NULL;
- crypt_path_t *layer_hint=NULL;
- char recognized=0;
- assert(cell && circ);
- assert(cell_direction == CELL_DIRECTION_OUT || cell_direction == CELL_DIRECTION_IN);
- if (circ->marked_for_close)
- return 0;
- if(relay_crypt(circ, cell, cell_direction, &layer_hint, &recognized) < 0) {
- log_fn(LOG_WARN,"relay crypt failed. Dropping connection.");
- return -1;
- }
- if(recognized) {
- conn = relay_lookup_conn(circ, cell, cell_direction);
- if(cell_direction == CELL_DIRECTION_OUT) {
- ++stats_n_relay_cells_delivered;
- log_fn(LOG_DEBUG,"Sending to exit.");
- if (connection_edge_process_relay_cell(cell, circ, conn, EDGE_EXIT, NULL) < 0) {
- log_fn(LOG_WARN,"connection_edge_process_relay_cell (at exit) failed.");
- return -1;
- }
- }
- if(cell_direction == CELL_DIRECTION_IN) {
- ++stats_n_relay_cells_delivered;
- log_fn(LOG_DEBUG,"Sending to AP.");
- if (connection_edge_process_relay_cell(cell, circ, conn, EDGE_AP, layer_hint) < 0) {
- log_fn(LOG_WARN,"connection_edge_process_relay_cell (at AP) failed.");
- return -1;
- }
- }
- return 0;
- }
- /* not recognized. pass it on. */
- if(cell_direction == CELL_DIRECTION_OUT) {
- cell->circ_id = circ->n_circ_id; /* switch it */
- conn = circ->n_conn;
- } else {
- cell->circ_id = circ->p_circ_id; /* switch it */
- conn = circ->p_conn;
- }
- if(!conn) {
- if (circ->rend_splice && cell_direction == CELL_DIRECTION_OUT) {
- assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
- assert(circ->rend_splice->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
- cell->circ_id = circ->rend_splice->p_circ_id;
- if (circuit_receive_relay_cell(cell, circ->rend_splice, CELL_DIRECTION_IN)<0) {
- log_fn(LOG_WARN, "Error relaying cell across rendezvous; closing circuits");
- circuit_mark_for_close(circ); /* XXXX Do this here, or just return -1? */
- return -1;
- }
- return 0;
- }
- log_fn(LOG_WARN,"Didn't recognize cell, but circ stops here! Closing circ.");
- return -1;
- }
- log_fn(LOG_DEBUG,"Passing on unrecognized cell.");
- ++stats_n_relay_cells_relayed;
- connection_or_write_cell_to_buf(cell, conn);
- return 0;
- }
- /* wrap this into receive_relay_cell one day */
- static int relay_crypt(circuit_t *circ, cell_t *cell, int cell_direction,
- crypt_path_t **layer_hint, char *recognized) {
- crypt_path_t *thishop;
- relay_header_t rh;
- assert(circ && cell && recognized);
- assert(cell_direction == CELL_DIRECTION_IN || cell_direction == CELL_DIRECTION_OUT);
- if(cell_direction == CELL_DIRECTION_IN) {
- if(CIRCUIT_IS_ORIGIN(circ)) { /* we're at the beginning of the circuit.
- We'll want to do layered crypts. */
- assert(circ->cpath);
- thishop = circ->cpath;
- if(thishop->state != CPATH_STATE_OPEN) {
- log_fn(LOG_WARN,"Relay cell before first created cell? Closing.");
- return -1;
- }
- do { /* Remember: cpath is in forward order, that is, first hop first. */
- assert(thishop);
- if(relay_crypt_one_payload(thishop->b_crypto, cell->payload, 0) < 0)
- return -1;
- relay_header_unpack(&rh, cell->payload);
- if(rh.recognized == 0) {
- /* it's possibly recognized. have to check digest to be sure. */
- if(relay_digest_matches(thishop->b_digest, cell)) {
- *recognized = 1;
- *layer_hint = thishop;
- return 0;
- }
- }
- thishop = thishop->next;
- } while(thishop != circ->cpath && thishop->state == CPATH_STATE_OPEN);
- log_fn(LOG_WARN,"in-cell at OP not recognized. Closing.");
- return -1;
- } else { /* we're in the middle. Just one crypt. */
- if(relay_crypt_one_payload(circ->p_crypto, cell->payload, 1) < 0)
- return -1;
- // log_fn(LOG_DEBUG,"Skipping recognized check, because we're not the OP.");
- }
- } else /* cell_direction == CELL_DIRECTION_OUT */ {
- /* we're in the middle. Just one crypt. */
- if(relay_crypt_one_payload(circ->n_crypto, cell->payload, 0) < 0)
- return -1;
- relay_header_unpack(&rh, cell->payload);
- if (rh.recognized == 0) {
- /* it's possibly recognized. have to check digest to be sure. */
- if(relay_digest_matches(circ->n_digest, cell)) {
- *recognized = 1;
- return 0;
- }
- }
- }
- return 0;
- }
- /*
- package a relay cell:
- 1) encrypt it to the right conn
- 2) connection_or_write_cell_to_buf to the right conn
- */
- int
- circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
- int cell_direction,
- crypt_path_t *layer_hint)
- {
- connection_t *conn; /* where to send the cell */
- crypt_path_t *thishop; /* counter for repeated crypts */
- if(cell_direction == CELL_DIRECTION_OUT) {
- conn = circ->n_conn;
- if(!conn) {
- log_fn(LOG_WARN,"outgoing relay cell has n_conn==NULL. Dropping.");
- return 0; /* just drop it */
- }
- relay_set_digest(layer_hint->f_digest, cell);
- thishop = layer_hint;
- /* moving from farthest to nearest hop */
- do {
- assert(thishop);
- log_fn(LOG_DEBUG,"crypting a layer of the relay cell.");
- if(relay_crypt_one_payload(thishop->f_crypto, cell->payload, 1) < 0) {
- return -1;
- }
- thishop = thishop->prev;
- } while (thishop != circ->cpath->prev);
- } else { /* incoming cell */
- conn = circ->p_conn;
- if(!conn) {
- log_fn(LOG_WARN,"incoming relay cell has p_conn==NULL. Dropping.");
- return 0; /* just drop it */
- }
- relay_set_digest(circ->p_digest, cell);
- if(relay_crypt_one_payload(circ->p_crypto, cell->payload, 1) < 0)
- return -1;
- }
- ++stats_n_relay_cells_relayed;
- connection_or_write_cell_to_buf(cell, conn);
- return 0;
- }
- static connection_t *
- relay_lookup_conn(circuit_t *circ, cell_t *cell, int cell_direction)
- {
- connection_t *tmpconn;
- relay_header_t rh;
- relay_header_unpack(&rh, cell->payload);
- if(!rh.stream_id)
- return NULL;
- /* IN or OUT cells could have come from either direction, now
- * that we allow rendezvous *to* an OP.
- */
- for(tmpconn = circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(rh.stream_id == tmpconn->stream_id) {
- log_fn(LOG_DEBUG,"found conn for stream %d.", rh.stream_id);
- if(cell_direction == CELL_DIRECTION_OUT ||
- connection_edge_is_rendezvous_stream(tmpconn))
- return tmpconn;
- }
- }
- for(tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(rh.stream_id == tmpconn->stream_id) {
- log_fn(LOG_DEBUG,"found conn for stream %d.", rh.stream_id);
- return tmpconn;
- }
- }
- return NULL; /* probably a begin relay cell */
- }
- void circuit_resume_edge_reading(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- connection_t *conn;
- assert(edge_type == EDGE_EXIT || edge_type == EDGE_AP);
- log_fn(LOG_DEBUG,"resuming");
- if(edge_type == EDGE_EXIT)
- conn = circ->n_streams;
- else
- conn = circ->p_streams;
- for( ; conn; conn=conn->next_stream) {
- if((edge_type == EDGE_EXIT && conn->package_window > 0) ||
- (edge_type == EDGE_AP && conn->package_window > 0 && conn->cpath_layer == layer_hint)) {
- connection_start_reading(conn);
- connection_edge_package_raw_inbuf(conn); /* handle whatever might still be on the inbuf */
- /* If the circuit won't accept any more data, return without looking
- * at any more of the streams. Any connections that should be stopped
- * have already been stopped by connection_edge_package_raw_inbuf. */
- if(circuit_consider_stop_edge_reading(circ, edge_type, layer_hint))
- return;
- }
- }
- }
- /* returns 1 if the window is empty, else 0. If it's empty, tell edge conns to stop reading. */
- int circuit_consider_stop_edge_reading(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- connection_t *conn = NULL;
- assert(edge_type == EDGE_EXIT || edge_type == EDGE_AP);
- assert(edge_type == EDGE_EXIT || layer_hint);
- log_fn(LOG_DEBUG,"considering");
- if(edge_type == EDGE_EXIT && circ->package_window <= 0)
- conn = circ->n_streams;
- else if(edge_type == EDGE_AP && layer_hint->package_window <= 0)
- conn = circ->p_streams;
- else
- return 0;
- for( ; conn; conn=conn->next_stream)
- if(!layer_hint || conn->cpath_layer == layer_hint)
- connection_stop_reading(conn);
- log_fn(LOG_DEBUG,"yes. stopped.");
- return 1;
- }
- void circuit_consider_sending_sendme(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- while((edge_type == EDGE_AP ? layer_hint->deliver_window : circ->deliver_window) <
- CIRCWINDOW_START - CIRCWINDOW_INCREMENT) {
- log_fn(LOG_DEBUG,"Queueing circuit sendme.");
- if(edge_type == EDGE_AP)
- layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
- else
- circ->deliver_window += CIRCWINDOW_INCREMENT;
- if(connection_edge_send_command(NULL, circ, RELAY_COMMAND_SENDME,
- NULL, 0, layer_hint) < 0) {
- log_fn(LOG_WARN,"connection_edge_send_command failed. Circuit's closed.");
- return; /* the circuit's closed, don't continue */
- }
- }
- }
- int _circuit_mark_for_close(circuit_t *circ) {
- connection_t *conn;
- assert_circuit_ok(circ);
- if (circ->marked_for_close < 0)
- return -1;
- if(circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) {
- onion_pending_remove(circ);
- }
- /* If the circuit ever became OPEN, we sent it to the reputation history
- * module then. If it isn't OPEN, we send it there now to remember which
- * links worked and which didn't.
- */
- if (circ->state != CIRCUIT_STATE_OPEN) {
- if(circ->cpath) //XXX
- circuit_build_failed(circ); /* take actions if necessary */
- circuit_rep_hist_note_result(circ);
- }
- if(circ->n_conn)
- connection_send_destroy(circ->n_circ_id, circ->n_conn);
- for(conn=circ->n_streams; conn; conn=conn->next_stream) {
- connection_edge_destroy(circ->n_circ_id, conn);
- }
- if(circ->p_conn)
- connection_send_destroy(circ->n_circ_id, circ->p_conn);
- for(conn=circ->p_streams; conn; conn=conn->next_stream) {
- connection_edge_destroy(circ->p_circ_id, conn);
- }
- circ->marked_for_close = 1;
- if (circ->rend_splice && !circ->rend_splice->marked_for_close) {
- /* do this after marking this circuit, to avoid infinite recursion. */
- circuit_mark_for_close(circ->rend_splice);
- circ->rend_splice = NULL;
- }
- return 0;
- }
- void circuit_detach_stream(circuit_t *circ, connection_t *conn) {
- connection_t *prevconn;
- assert(circ);
- assert(conn);
- if(conn == circ->p_streams) {
- circ->p_streams = conn->next_stream;
- return;
- }
- if(conn == circ->n_streams) {
- circ->n_streams = conn->next_stream;
- return;
- }
- for(prevconn = circ->p_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ;
- if(prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- return;
- }
- for(prevconn = circ->n_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ;
- if(prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- return;
- }
- log_fn(LOG_ERR,"edge conn not in circuit's list?");
- assert(0); /* should never get here */
- }
- void circuit_about_to_close_connection(connection_t *conn) {
- /* send destroys for all circuits using conn */
- /* currently, we assume it's too late to flush conn's buf here.
- * down the road, maybe we'll consider that eof doesn't mean can't-write
- */
- circuit_t *circ;
- switch(conn->type) {
- case CONN_TYPE_OR:
- /* We must close all the circuits on it. */
- while((circ = circuit_get_by_conn(conn))) {
- if(circ->n_conn == conn) /* it's closing in front of us */
- circ->n_conn = NULL;
- if(circ->p_conn == conn) /* it's closing behind us */
- circ->p_conn = NULL;
- circuit_mark_for_close(circ);
- }
- return;
- case CONN_TYPE_AP:
- case CONN_TYPE_EXIT:
- /* It's an edge conn. Need to remove it from the linked list of
- * conn's for this circuit. Confirm that 'end' relay command has
- * been sent. But don't kill the circuit.
- */
- circ = circuit_get_by_conn(conn);
- if(!circ)
- return;
- if(!conn->has_sent_end) {
- log_fn(LOG_WARN,"Edge connection hasn't sent end yet? Bug.");
- connection_mark_for_close(conn, END_STREAM_REASON_MISC);
- }
- circuit_detach_stream(circ, conn);
- } /* end switch */
- }
- void circuit_log_path(int severity, circuit_t *circ) {
- char buf[1024];
- char *s = buf;
- struct crypt_path_t *hop;
- char *states[] = {"closed", "waiting for keys", "open"};
- routerinfo_t *router;
- assert(CIRCUIT_IS_ORIGIN(circ) && circ->cpath);
- snprintf(s, sizeof(buf)-1, "circ (length %d, exit %s): ",
- circ->build_state->desired_path_len, circ->build_state->chosen_exit);
- hop=circ->cpath;
- do {
- s = buf + strlen(buf);
- router = router_get_by_addr_port(hop->addr,hop->port);
- if(router) {
- snprintf(s, sizeof(buf) - (s - buf), "%s(%s) ",
- router->nickname, states[hop->state]);
- } else {
- if(circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
- snprintf(s, sizeof(buf) - (s - buf), "(rendjoin hop)");
- } else {
- snprintf(s, sizeof(buf) - (s - buf), "UNKNOWN ");
- }
- }
- hop=hop->next;
- } while(hop!=circ->cpath);
- log_fn(severity,"%s",buf);
- }
- /* Tell the rep(utation)hist(ory) module about the status of the links
- * in circ. Hops that have become OPEN are marked as successfully
- * extended; the _first_ hop that isn't open (if any) is marked as
- * unable to extend.
- */
- static void
- circuit_rep_hist_note_result(circuit_t *circ)
- {
- struct crypt_path_t *hop;
- char *prev_nickname = NULL;
- routerinfo_t *router;
- hop = circ->cpath;
- if(!hop) {
- /* XXX
- * if !hop, then we're not the beginning of this circuit.
- * for now, just forget about it. later, we should remember when
- * extends-through-us failed, too.
- */
- return;
- }
- if (options.ORPort) {
- prev_nickname = options.Nickname;
- }
- do {
- router = router_get_by_addr_port(hop->addr,hop->port);
- if (router) {
- if (prev_nickname) {
- if (hop->state == CPATH_STATE_OPEN)
- rep_hist_note_extend_succeeded(prev_nickname, router->nickname);
- else {
- rep_hist_note_extend_failed(prev_nickname, router->nickname);
- break;
- }
- }
- prev_nickname = router->nickname;
- } else {
- prev_nickname = NULL;
- }
- hop=hop->next;
- } while (hop!=circ->cpath);
- }
- static void
- circuit_dump_details(int severity, circuit_t *circ, int poll_index,
- char *type, int this_circid, int other_circid) {
- struct crypt_path_t *hop;
- log(severity,"Conn %d has %s circuit: circID %d (other side %d), state %d (%s), born %d",
- poll_index, type, this_circid, other_circid, circ->state,
- circuit_state_to_string[circ->state], (int)circ->timestamp_created);
- if(CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */
- if(circ->state == CIRCUIT_STATE_BUILDING)
- log(severity,"Building: desired len %d, planned exit node %s.",
- circ->build_state->desired_path_len, circ->build_state->chosen_exit);
- for(hop=circ->cpath;hop->next != circ->cpath; hop=hop->next)
- log(severity,"hop: state %d, addr 0x%.8x, port %d", hop->state,
- (unsigned int)hop->addr,
- (int)hop->port);
- }
- }
- void circuit_dump_by_conn(connection_t *conn, int severity) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn)
- circuit_dump_details(severity, circ, conn->poll_index, "App-ward",
- circ->p_circ_id, circ->n_circ_id);
- for(tmpconn=circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(tmpconn == conn) {
- circuit_dump_details(severity, circ, conn->poll_index, "App-ward",
- circ->p_circ_id, circ->n_circ_id);
- }
- }
- if(circ->n_conn == conn)
- circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward",
- circ->n_circ_id, circ->p_circ_id);
- for(tmpconn=circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(tmpconn == conn) {
- circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward",
- circ->n_circ_id, circ->p_circ_id);
- }
- }
- }
- }
- /* Don't keep more than 10 unused open circuits around. */
- #define MAX_UNUSED_OPEN_CIRCUITS 10
- void circuit_expire_unused_circuits(void) {
- circuit_t *circ;
- time_t now = time(NULL);
- smartlist_t *unused_open_circs;
- int i;
- unused_open_circs = smartlist_create();
- for (circ = global_circuitlist; circ; circ = circ->next) {
- if (circ->marked_for_close)
- continue;
- /* If the circuit has been dirty for too long, and there are no streams
- * on it, mark it for close.
- */
- if (circ->timestamp_dirty &&
- circ->timestamp_dirty + options.NewCircuitPeriod < now &&
- !circ->p_conn &&
- !circ->p_streams) {
- log_fn(LOG_DEBUG,"Closing n_circ_id %d",circ->n_circ_id);
- circuit_mark_for_close(circ);
- } else if (!circ->timestamp_dirty && CIRCUIT_IS_ORIGIN(circ) &&
- circ->state == CIRCUIT_STATE_OPEN) {
- /* Also, gather a list of open unused circuits that we created.
- * Because we add elements to the front of global_circuitlist,
- * the last elements of unused_open_circs will be the oldest
- * ones.
- */
- smartlist_add(unused_open_circs, circ);
- }
- }
- for (i = MAX_UNUSED_OPEN_CIRCUITS; i < smartlist_len(unused_open_circs); ++i) {
- circuit_t *circ = smartlist_get(unused_open_circs, i);
- circuit_mark_for_close(circ);
- }
- smartlist_free(unused_open_circs);
- }
- static void circuit_is_open(circuit_t *circ) {
- switch(circ->purpose) {
- case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
- rend_client_rendcirc_is_open(circ);
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- rend_client_introcirc_is_open(circ);
- break;
- case CIRCUIT_PURPOSE_C_GENERAL:
- /* Tell any AP connections that have been waiting for a new
- * circuit that one is ready. */
- connection_ap_attach_pending();
- break;
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- /* at Bob, waiting for introductions */
- rend_service_intro_is_ready(circ);
- break;
- case CIRCUIT_PURPOSE_S_CONNECT_REND:
- /* at Bob, connecting to rend point */
- rend_service_rendezvous_is_ready(circ);
- break;
- default:
- log_fn(LOG_ERR,"unhandled purpose %d",circ->purpose);
- assert(0);
- }
- }
- /* Called whenever a circuit could not be successfully built.
- */
- static void circuit_build_failed(circuit_t *circ) {
- /* we should examine circ and see if it failed because of
- * the last hop or an earlier hop. then use this info below.
- */
- //int failed_at_last_hop;
- switch(circ->purpose) {
- case CIRCUIT_PURPOSE_C_GENERAL:
- if (circ->state != CIRCUIT_STATE_OPEN) {
- /* If we never built the circuit, note it as a failure. */
- /* Note that we can't just check circ->cpath here, because if
- * circuit-building failed immediately, it won't be set yet. */
- circuit_increment_failure_count();
- }
- break;
- case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO:
- /* at Bob, waiting for introductions */
- if (circ->state != CIRCUIT_STATE_OPEN) {
- circuit_increment_failure_count();
- }
- /* no need to care here, because bob will rebuild intro
- * points periodically. */
- break;
- case CIRCUIT_PURPOSE_C_INTRODUCING:
- /* at Alice, connecting to intro point */
- /* Don't increment failure count, since Bob may have picked
- * the introduction point maliciously */
- /* Alice will pick a new intro point when this one dies, if
- * the stream in question still cares. No need to act here. */
- break;
- case CIRCUIT_PURPOSE_C_ESTABLISH_REND:
- /* at Alice, waiting for Bob */
- if (circ->state != CIRCUIT_STATE_OPEN) {
- circuit_increment_failure_count();
- }
- /* Alice will pick a new rend point when this one dies, if
- * the stream in question still cares. No need to act here. */
- break;
- case CIRCUIT_PURPOSE_S_CONNECT_REND:
- /* at Bob, connecting to rend point */
- /* Don't increment failure count, since Alice may have picked
- * the rendezvous point maliciously */
- log_fn(LOG_INFO,"Couldn't connect to Alice's chosen rend point %s. Sucks to be Alice.", circ->build_state->chosen_exit);
- break;
- default:
- /* Other cases are impossible, since this function is only called with
- * unbuilt circuits. */
- assert(0);
- }
- }
- /* Number of consecutive failures so far; should only be touched by
- * circuit_launch_new and circuit_*_failure_count.
- */
- static int n_circuit_failures = 0;
- /* Don't retry launching a new circuit if we try this many times with no
- * success. */
- #define MAX_CIRCUIT_FAILURES 5
- /* Launch a new circuit and return a pointer to it. Return NULL if you failed. */
- circuit_t *circuit_launch_new(uint8_t purpose, const char *exit_nickname) {
- if (n_circuit_failures > MAX_CIRCUIT_FAILURES) {
- /* too many failed circs in a row. don't try. */
- // log_fn(LOG_INFO,"%d failures so far, not trying.",n_circuit_failures);
- return NULL;
- }
- /* try a circ. if it fails, circuit_mark_for_close will increment n_circuit_failures */
- return circuit_establish_circuit(purpose, exit_nickname);
- }
- void circuit_increment_failure_count(void) {
- ++n_circuit_failures;
- log_fn(LOG_DEBUG,"n_circuit_failures now %d.",n_circuit_failures);
- }
- void circuit_reset_failure_count(void) {
- n_circuit_failures = 0;
- }
- static circuit_t *circuit_establish_circuit(uint8_t purpose,
- const char *exit_nickname) {
- routerinfo_t *firsthop;
- connection_t *n_conn;
- circuit_t *circ;
- circ = circuit_new(0, NULL); /* sets circ->p_circ_id and circ->p_conn */
- circ->state = CIRCUIT_STATE_OR_WAIT;
- circ->build_state = onion_new_cpath_build_state(purpose, exit_nickname);
- circ->purpose = purpose;
- if (! circ->build_state) {
- log_fn(LOG_INFO,"Generating cpath failed.");
- circuit_mark_for_close(circ);
- return NULL;
- }
- onion_extend_cpath(&circ->cpath, circ->build_state, &firsthop);
- if(!CIRCUIT_IS_ORIGIN(circ)) {
- log_fn(LOG_INFO,"Generating first cpath hop failed.");
- circuit_mark_for_close(circ);
- return NULL;
- }
- /* now see if we're already connected to the first OR in 'route' */
- log_fn(LOG_DEBUG,"Looking for firsthop '%s:%u'",
- firsthop->address,firsthop->or_port);
- n_conn = connection_twin_get_by_addr_port(firsthop->addr,firsthop->or_port);
- if(!n_conn || n_conn->state != OR_CONN_STATE_OPEN) { /* not currently connected */
- circ->n_addr = firsthop->addr;
- circ->n_port = firsthop->or_port;
- if(!n_conn) { /* launch the connection */
- n_conn = connection_or_connect(firsthop);
- if(!n_conn) { /* connect failed, forget the whole thing */
- log_fn(LOG_INFO,"connect to firsthop failed. Closing.");
- circuit_mark_for_close(circ);
- return NULL;
- }
- }
- log_fn(LOG_DEBUG,"connecting in progress (or finished). Good.");
- /* return success. The onion/circuit/etc will be taken care of automatically
- * (may already have been) whenever n_conn reaches OR_CONN_STATE_OPEN.
- */
- return circ;
- } else { /* it (or a twin) is already open. use it. */
- circ->n_addr = n_conn->addr;
- circ->n_port = n_conn->port;
- circ->n_conn = n_conn;
- log_fn(LOG_DEBUG,"Conn open. Delivering first onion skin.");
- if(circuit_send_next_onion_skin(circ) < 0) {
- log_fn(LOG_INFO,"circuit_send_next_onion_skin failed.");
- circuit_mark_for_close(circ);
- return NULL;
- }
- }
- return circ;
- }
- /* find circuits that are waiting on me, if any, and get them to send the onion */
- void circuit_n_conn_open(connection_t *or_conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if (circ->marked_for_close)
- continue;
- if(CIRCUIT_IS_ORIGIN(circ) && circ->n_addr == or_conn->addr && circ->n_port == or_conn->port) {
- assert(circ->state == CIRCUIT_STATE_OR_WAIT);
- log_fn(LOG_DEBUG,"Found circ %d, sending onion skin.", circ->n_circ_id);
- circ->n_conn = or_conn;
- if(circuit_send_next_onion_skin(circ) < 0) {
- log_fn(LOG_INFO,"send_next_onion_skin failed; circuit marked for closing.");
- circuit_mark_for_close(circ);
- continue;
- /* XXX could this be bad, eg if next_onion_skin failed because conn died? */
- }
- }
- }
- }
- extern int has_completed_circuit;
- int circuit_send_next_onion_skin(circuit_t *circ) {
- cell_t cell;
- crypt_path_t *hop;
- routerinfo_t *router;
- int r;
- int circ_id_type;
- char payload[2+4+ONIONSKIN_CHALLENGE_LEN];
- assert(circ && CIRCUIT_IS_ORIGIN(circ));
- if(circ->cpath->state == CPATH_STATE_CLOSED) {
- assert(circ->n_conn && circ->n_conn->type == CONN_TYPE_OR);
- log_fn(LOG_DEBUG,"First skin; sending create cell.");
- circ_id_type = decide_circ_id_type(options.Nickname,
- circ->n_conn->nickname);
- circ->n_circ_id = get_unique_circ_id_by_conn(circ->n_conn, circ_id_type);
- memset(&cell, 0, sizeof(cell_t));
- cell.command = CELL_CREATE;
- cell.circ_id = circ->n_circ_id;
- if(onion_skin_create(circ->n_conn->onion_pkey,
- &(circ->cpath->handshake_state),
- cell.payload) < 0) {
- log_fn(LOG_WARN,"onion_skin_create (first hop) failed.");
- return -1;
- }
- connection_or_write_cell_to_buf(&cell, circ->n_conn);
- circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
- circ->state = CIRCUIT_STATE_BUILDING;
- log_fn(LOG_DEBUG,"first skin; finished sending create cell.");
- } else {
- assert(circ->cpath->state == CPATH_STATE_OPEN);
- assert(circ->state == CIRCUIT_STATE_BUILDING);
- log_fn(LOG_DEBUG,"starting to send subsequent skin.");
- r = onion_extend_cpath(&circ->cpath, circ->build_state, &router);
- if (r==1) {
- /* done building the circuit. whew. */
- circ->state = CIRCUIT_STATE_OPEN;
- log_fn(LOG_INFO,"circuit built!");
- circuit_reset_failure_count();
- if(!has_completed_circuit) {
- has_completed_circuit=1;
- log_fn(LOG_NOTICE,"Tor has successfully opened a circuit. Looks like it's working.");
- }
- circuit_rep_hist_note_result(circ);
- circuit_is_open(circ); /* do other actions as necessary */
- return 0;
- } else if (r<0) {
- log_fn(LOG_INFO,"Unable to extend circuit path.");
- return -1;
- }
- hop = circ->cpath->prev;
- *(uint32_t*)payload = htonl(hop->addr);
- *(uint16_t*)(payload+4) = htons(hop->port);
- if(onion_skin_create(router->onion_pkey, &(hop->handshake_state), payload+6) < 0) {
- log_fn(LOG_WARN,"onion_skin_create failed.");
- return -1;
- }
- log_fn(LOG_DEBUG,"Sending extend relay cell.");
- /* send it to hop->prev, because it will transfer
- * it to a create cell and then send to hop */
- if(connection_edge_send_command(NULL, circ, RELAY_COMMAND_EXTEND,
- payload, sizeof(payload), hop->prev) < 0)
- return 0; /* circuit is closed */
- hop->state = CPATH_STATE_AWAITING_KEYS;
- }
- return 0;
- }
- /* take the 'extend' cell, pull out addr/port plus the onion skin. Make
- * sure we're connected to the next hop, and pass it the onion skin in
- * a create cell.
- */
- int circuit_extend(cell_t *cell, circuit_t *circ) {
- connection_t *n_conn;
- int circ_id_type;
- cell_t newcell;
- if(circ->n_conn) {
- log_fn(LOG_WARN,"n_conn already set. Bug/attack. Closing.");
- return -1;
- }
- circ->n_addr = ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE));
- circ->n_port = ntohs(get_uint16(cell->payload+RELAY_HEADER_SIZE+4));
- n_conn = connection_twin_get_by_addr_port(circ->n_addr,circ->n_port);
- if(!n_conn || n_conn->type != CONN_TYPE_OR) {
- /* I've disabled making connections through OPs, but it's definitely
- * possible here. I'm not sure if it would be a bug or a feature.
- *
- * Note also that this will close circuits where the onion has the same
- * router twice in a row in the path. I think that's ok.
- */
- struct in_addr in;
- in.s_addr = htonl(circ->n_addr);
- log_fn(LOG_INFO,"Next router (%s:%d) not connected. Closing.", inet_ntoa(in), circ->n_port);
- connection_edge_send_command(NULL, circ, RELAY_COMMAND_TRUNCATED,
- NULL, 0, NULL);
- return 0;
- }
- circ->n_addr = n_conn->addr; /* these are different if we found a twin instead */
- circ->n_port = n_conn->port;
- circ->n_conn = n_conn;
- log_fn(LOG_DEBUG,"n_conn is %s:%u",n_conn->address,n_conn->port);
- circ_id_type = decide_circ_id_type(options.Nickname, n_conn->nickname);
- // log_fn(LOG_DEBUG,"circ_id_type = %u.",circ_id_type);
- circ->n_circ_id = get_unique_circ_id_by_conn(circ->n_conn, circ_id_type);
- if(!circ->n_circ_id) {
- log_fn(LOG_WARN,"failed to get unique circID.");
- return -1;
- }
- log_fn(LOG_DEBUG,"Chosen circID %u.",circ->n_circ_id);
- memset(&newcell, 0, sizeof(cell_t));
- newcell.command = CELL_CREATE;
- newcell.circ_id = circ->n_circ_id;
- memcpy(newcell.payload, cell->payload+RELAY_HEADER_SIZE+2+4,
- ONIONSKIN_CHALLENGE_LEN);
- connection_or_write_cell_to_buf(&newcell, circ->n_conn);
- return 0;
- }
- /* Initialize cpath->{f|b}_{crypto|digest} from the key material in
- * key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are
- * used as follows:
- * 20 to initialize f_digest
- * 20 to initialize b_digest
- * 16 to key f_crypto
- * 16 to key b_crypto
- *
- * (If 'reverse' is true, then f_XX and b_XX are swapped.)
- */
- int circuit_init_cpath_crypto(crypt_path_t *cpath, char *key_data, int reverse)
- {
- unsigned char iv[CIPHER_IV_LEN];
- crypto_digest_env_t *tmp_digest;
- crypto_cipher_env_t *tmp_crypto;
- assert(cpath && key_data);
- assert(!(cpath->f_crypto || cpath->b_crypto ||
- cpath->f_digest || cpath->b_digest));
- memset(iv, 0, CIPHER_IV_LEN);
- log_fn(LOG_DEBUG,"hop init digest forward 0x%.8x, backward 0x%.8x.",
- (unsigned int)*(uint32_t*)key_data, (unsigned int)*(uint32_t*)(key_data+20));
- cpath->f_digest = crypto_new_digest_env();
- crypto_digest_add_bytes(cpath->f_digest, key_data, DIGEST_LEN);
- cpath->b_digest = crypto_new_digest_env();
- crypto_digest_add_bytes(cpath->b_digest, key_data+DIGEST_LEN, DIGEST_LEN);
- log_fn(LOG_DEBUG,"hop init cipher forward 0x%.8x, backward 0x%.8x.",
- (unsigned int)*(uint32_t*)(key_data+40), (unsigned int)*(uint32_t*)(key_data+40+16));
- if (!(cpath->f_crypto =
- crypto_create_init_cipher(key_data+(2*DIGEST_LEN),iv,1))) {
- log(LOG_WARN,"forward cipher initialization failed.");
- return -1;
- }
- if (!(cpath->b_crypto =
- crypto_create_init_cipher(key_data+(2*DIGEST_LEN)+CIPHER_KEY_LEN,iv,0))) {
- log(LOG_WARN,"backward cipher initialization failed.");
- return -1;
- }
- if (reverse) {
- tmp_digest = cpath->f_digest;
- cpath->f_digest = cpath->b_digest;
- cpath->b_digest = tmp_digest;
- tmp_crypto = cpath->f_crypto;
- cpath->f_crypto = cpath->b_crypto;
- cpath->b_crypto = tmp_crypto;
- }
- return 0;
- }
- int circuit_finish_handshake(circuit_t *circ, char *reply) {
- unsigned char keys[CPATH_KEY_MATERIAL_LEN];
- crypt_path_t *hop;
- assert(CIRCUIT_IS_ORIGIN(circ));
- if(circ->cpath->state == CPATH_STATE_AWAITING_KEYS)
- hop = circ->cpath;
- else {
- for(hop=circ->cpath->next;
- hop != circ->cpath && hop->state == CPATH_STATE_OPEN;
- hop=hop->next) ;
- if(hop == circ->cpath) { /* got an extended when we're all done? */
- log_fn(LOG_WARN,"got extended when circ already built? Closing.");
- return -1;
- }
- }
- assert(hop->state == CPATH_STATE_AWAITING_KEYS);
- if(onion_skin_client_handshake(hop->handshake_state, reply, keys,
- DIGEST_LEN*2+CIPHER_KEY_LEN*2) < 0) {
- log_fn(LOG_WARN,"onion_skin_client_handshake failed.");
- return -1;
- }
- crypto_dh_free(hop->handshake_state); /* don't need it anymore */
- hop->handshake_state = NULL;
- /* Remember hash of g^xy */
- memcpy(hop->handshake_digest, reply+DH_KEY_LEN, DIGEST_LEN);
- if (circuit_init_cpath_crypto(hop, keys, 0)<0) {
- return -1;
- }
- hop->state = CPATH_STATE_OPEN;
- log_fn(LOG_INFO,"finished");
- circuit_log_path(LOG_INFO,circ);
- return 0;
- }
- int circuit_truncated(circuit_t *circ, crypt_path_t *layer) {
- crypt_path_t *victim;
- connection_t *stream;
- assert(circ && CIRCUIT_IS_ORIGIN(circ));
- assert(layer);
- /* XXX Since we don't ask for truncates currently, getting a truncated
- * means that a connection broke or an extend failed. For now,
- * just give up.
- */
- circuit_mark_for_close(circ);
- return 0;
- while(layer->next != circ->cpath) {
- /* we need to clear out layer->next */
- victim = layer->next;
- log_fn(LOG_DEBUG, "Killing a layer of the cpath.");
- for(stream = circ->p_streams; stream; stream=stream->next_stream) {
- if(stream->cpath_layer == victim) {
- log_fn(LOG_INFO, "Marking stream %d for close.", stream->stream_id);
- /* no need to send 'end' relay cells,
- * because the other side's already dead
- */
- connection_mark_for_close(stream,0);
- }
- }
- layer->next = victim->next;
- circuit_free_cpath_node(victim);
- }
- log_fn(LOG_INFO, "finished");
- return 0;
- }
- void assert_cpath_layer_ok(const crypt_path_t *cp)
- {
- assert(cp->f_crypto);
- assert(cp->b_crypto);
- // assert(cp->addr); /* these are zero for rendezvous extra-hops */
- // assert(cp->port);
- switch(cp->state)
- {
- case CPATH_STATE_CLOSED:
- case CPATH_STATE_OPEN:
- assert(!cp->handshake_state);
- break;
- case CPATH_STATE_AWAITING_KEYS:
- assert(cp->handshake_state);
- break;
- default:
- assert(0);
- }
- assert(cp->package_window >= 0);
- assert(cp->deliver_window >= 0);
- }
- void assert_cpath_ok(const crypt_path_t *cp)
- {
- while(cp->prev)
- cp = cp->prev;
- while(cp->next) {
- assert_cpath_layer_ok(cp);
- /* layers must be in sequence of: "open* awaiting? closed*" */
- if (cp->prev) {
- if (cp->prev->state == CPATH_STATE_OPEN) {
- assert(cp->state == CPATH_STATE_CLOSED ||
- cp->state == CPATH_STATE_AWAITING_KEYS);
- } else {
- assert(cp->state == CPATH_STATE_CLOSED);
- }
- }
- cp = cp->next;
- }
- }
- void assert_circuit_ok(const circuit_t *c)
- {
- connection_t *conn;
- assert(c);
- assert(c->magic == CIRCUIT_MAGIC);
- assert(c->purpose >= _CIRCUIT_PURPOSE_MIN &&
- c->purpose <= _CIRCUIT_PURPOSE_MAX);
- if (c->n_conn)
- assert(c->n_conn->type == CONN_TYPE_OR);
- if (c->p_conn)
- assert(c->p_conn->type == CONN_TYPE_OR);
- for (conn = c->p_streams; conn; conn = conn->next_stream)
- assert(conn->type == CONN_TYPE_AP);
- for (conn = c->n_streams; conn; conn = conn->next_stream)
- assert(conn->type == CONN_TYPE_EXIT);
- assert(c->deliver_window >= 0);
- assert(c->package_window >= 0);
- if (c->state == CIRCUIT_STATE_OPEN) {
- if (c->cpath) {
- assert(CIRCUIT_IS_ORIGIN(c));
- assert(!c->n_crypto);
- assert(!c->p_crypto);
- assert(!c->n_digest);
- assert(!c->p_digest);
- } else {
- assert(!CIRCUIT_IS_ORIGIN(c));
- assert(c->n_crypto);
- assert(c->p_crypto);
- assert(c->n_digest);
- assert(c->p_digest);
- }
- }
- if (c->cpath) {
- //XXX assert_cpath_ok(c->cpath);
- }
- if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) {
- if (!c->marked_for_close) {
- assert(c->rend_splice);
- assert(c->rend_splice->rend_splice == c);
- }
- assert(c->rend_splice != c);
- } else {
- assert(!c->rend_splice);
- }
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
|