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- /* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- #include "or.h"
- /********* START VARIABLES **********/
- static circuit_t *global_circuitlist=NULL;
- char *circuit_state_to_string[] = {
- "receiving the onion", /* 0 */
- "connecting to firsthop", /* 1 */
- "open" /* 2 */
- };
- /********* 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;
- }
- }
- void circuit_remove(circuit_t *circ) {
- circuit_t *tmpcirc;
- assert(circ && global_circuitlist);
- if(global_circuitlist == circ) {
- global_circuitlist = global_circuitlist->next;
- return;
- }
- for(tmpcirc = global_circuitlist;tmpcirc->next;tmpcirc = tmpcirc->next) {
- if(tmpcirc->next == circ) {
- tmpcirc->next = circ->next;
- return;
- }
- }
- }
- circuit_t *circuit_new(aci_t p_aci, connection_t *p_conn) {
- circuit_t *circ;
- circ = (circuit_t *)malloc(sizeof(circuit_t));
- if(!circ)
- return NULL;
- memset(circ,0,sizeof(circuit_t)); /* zero it out */
- circ->p_aci = p_aci;
- circ->p_conn = p_conn;
- circ->state = CIRCUIT_STATE_OPEN_WAIT;
- /* ACIs */
- circ->p_aci = p_aci;
- /* circ->n_aci remains 0 because we haven't identified the next hop yet */
- circ->n_receive_window = RECEIVE_WINDOW_START;
- circ->p_receive_window = RECEIVE_WINDOW_START;
- circuit_add(circ);
- return circ;
- }
- void circuit_free(circuit_t *circ) {
-
- if (circ->n_crypto)
- crypto_free_cipher_env(circ->n_crypto);
- if (circ->p_crypto)
- crypto_free_cipher_env(circ->p_crypto);
- if(circ->onion)
- free(circ->onion);
- if(circ->cpath)
- circuit_free_cpath(circ->cpath, circ->cpathlen);
- free(circ);
- }
- void circuit_free_cpath(crypt_path_t **cpath, int cpathlen) {
- int i;
- for(i=0;i<cpathlen;i++)
- free(cpath[i]);
- free(cpath);
- }
- aci_t get_unique_aci_by_addr_port(uint32_t addr, uint16_t port, int aci_type) {
- aci_t test_aci;
- connection_t *conn;
- log(LOG_DEBUG,"get_unique_aci_by_addr_port() trying to get a unique aci");
- crypto_pseudo_rand(2, (unsigned char *)&test_aci);
- if(aci_type == ACI_TYPE_LOWER)
- test_aci &= htons(0x00FF);
- if(aci_type == ACI_TYPE_HIGHER)
- test_aci &= htons(0xFF00);
- /* if aci_type == ACI_BOTH, don't filter any of it */
- if(test_aci == 0)
- return get_unique_aci_by_addr_port(addr, port, aci_type); /* try again */
- conn = connection_exact_get_by_addr_port(addr,port);
- if(!conn) /* there can't be a conflict -- no connection of that sort yet */
- return test_aci;
- if(circuit_get_by_aci_conn(test_aci, conn))
- return get_unique_aci_by_addr_port(addr, port, aci_type); /* try again */
- return test_aci;
-
- }
- int circuit_init(circuit_t *circ, int aci_type) {
- onion_layer_t *ol;
- unsigned char iv[16];
- unsigned char digest1[20];
- unsigned char digest2[20];
- assert(circ);
- ol = (onion_layer_t *)circ->onion;
- assert(ol);
- log(LOG_DEBUG,"circuit_init(): starting");
- circ->n_addr = ol->addr;
- circ->n_port = ol->port;
- log(LOG_DEBUG,"circuit_init(): Set port to %u.",ol->port);
- circ->p_f = ol->backf;
- log(LOG_DEBUG,"circuit_init(): Set BACKF to %u.",ol->backf);
- circ->n_f = ol->forwf;
- log(LOG_DEBUG,"circuit_init(): Set FORWF to %u.",ol->forwf);
- circ->state = CIRCUIT_STATE_OPEN;
- log(LOG_DEBUG,"circuit_init(): aci_type = %u.",aci_type);
- circ->n_aci = get_unique_aci_by_addr_port(circ->n_addr, circ->n_port, aci_type);
- log(LOG_DEBUG,"circuit_init(): Chosen ACI %u.",circ->n_aci);
- /* keys */
- memset((void *)iv, 0, 16);
- crypto_SHA_digest(ol->keyseed,16,digest1);
- crypto_SHA_digest(digest1,20,digest2);
- crypto_SHA_digest(digest2,20,digest1);
- log(LOG_DEBUG,"circuit_init(): Computed keys.");
- if (!(circ->p_crypto = create_onion_cipher(circ->p_f,digest2,iv,1))) {
- log(LOG_ERR,"Cipher initialization failed (ACI %u).",circ->n_aci);
- return -1;
- }
-
- if (!(circ->n_crypto = create_onion_cipher(circ->n_f, digest1, iv, 0))) {
- log(LOG_ERR,"Cipher initialization failed (ACI %u).",circ->n_aci);
- return -1;
- }
- log(LOG_DEBUG,"circuit_init(): Cipher initialization complete.");
- circ->expire = ol->expire;
- return 0;
- }
- circuit_t *circuit_enumerate_by_naddr_nport(circuit_t *circ, uint32_t naddr, uint16_t nport) {
- if(!circ) /* use circ if it's defined, else start from the beginning */
- circ = global_circuitlist;
- else
- circ = circ->next;
- for( ;circ;circ = circ->next) {
- if(circ->n_addr == naddr && circ->n_port == nport)
- return circ;
- }
- return NULL;
- }
- circuit_t *circuit_get_by_aci_conn(aci_t aci, connection_t *conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn && circ->p_aci == aci)
- return circ;
- if(circ->n_conn == conn && circ->n_aci == aci)
- return circ;
- }
- return NULL;
- }
- circuit_t *circuit_get_by_conn(connection_t *conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn)
- return circ;
- if(circ->n_conn == conn)
- return circ;
- }
- return NULL;
- }
- int circuit_deliver_data_cell(cell_t *cell, circuit_t *circ, connection_t *conn, int crypt_type) {
- /* first decrypt cell->length */
- if(circuit_crypt(circ, &(cell->length), 1, crypt_type) < 0) {
- log(LOG_DEBUG,"circuit_deliver_data_cell(): length decryption failed. Dropping connection.");
- return -1;
- }
- /* then decrypt the payload */
- if(circuit_crypt(circ, (char *)&(cell->payload), CELL_PAYLOAD_SIZE, crypt_type) < 0) {
- log(LOG_DEBUG,"circuit_deliver_data_cell(): payload decryption failed. Dropping connection.");
- return -1;
- }
- if(conn->type == CONN_TYPE_EXIT) { /* send payload directly */
- // log(LOG_DEBUG,"circuit_deliver_data_cell(): Sending to exit.");
- return connection_exit_process_data_cell(cell, conn);
- }
- if(conn->type == CONN_TYPE_AP) { /* send payload directly */
- // log(LOG_DEBUG,"circuit_deliver_data_cell(): Sending to AP.");
- return connection_ap_process_data_cell(cell, conn);
- }
- /* else send it as a cell */
- // log(LOG_DEBUG,"circuit_deliver_data_cell(): Sending to connection.");
- return connection_write_cell_to_buf(cell, conn);
- }
- int circuit_crypt(circuit_t *circ, char *in, int inlen, char crypt_type) {
- char *out;
- int i;
- crypt_path_t *thishop;
- assert(circ && in);
- out = (char *)malloc(inlen);
- if(!out)
- return -1;
- if(crypt_type == 'e') {
- // log(LOG_DEBUG,"circuit_crypt(): Encrypting %d bytes.",inlen);
- if(circ->cpath) { /* we're at the beginning of the circuit. We'll want to do layered crypts. */
- /* 'e' means we're preparing to send it out. */
- for (i=0; i < circ->cpathlen; i++) /* moving from last to first hop
- * Remember : cpath is in reverse order, i.e. last hop first
- */
- {
- // log(LOG_DEBUG,"circuit_crypt() : Encrypting via cpath: Processing hop %u",circ->cpathlen-i);
- thishop = circ->cpath[i];
-
- /* encrypt */
- if(crypto_cipher_encrypt(thishop->f_crypto, in, inlen, (unsigned char *)out)) {
- log(LOG_ERR,"Error performing encryption:%s",crypto_perror());
- free(out);
- return -1;
- }
- /* copy ciphertext back to buf */
- memcpy(in,out,inlen);
- }
- } else { /* we're in the middle. Just one crypt. */
- if(crypto_cipher_encrypt(circ->p_crypto,in, inlen, out)) {
- log(LOG_ERR,"circuit_encrypt(): Encryption failed for ACI : %u (%s).",
- circ->p_aci, crypto_perror());
- free(out);
- return -1;
- }
- memcpy(in,out,inlen);
- }
- } else if(crypt_type == 'd') {
- // log(LOG_DEBUG,"circuit_crypt(): Decrypting %d bytes.",inlen);
- if(circ->cpath) { /* we're at the beginning of the circuit. We'll want to do layered crypts. */
- for (i=circ->cpathlen-1; i >= 0; i--) /* moving from first to last hop
- * Remember : cpath is in reverse order, i.e. last hop first
- */
- {
- // log(LOG_DEBUG,"circuit_crypt() : Decrypting via cpath: Processing hop %u",circ->cpathlen-i);
- thishop = circ->cpath[i];
- /* encrypt */
- if(crypto_cipher_decrypt(thishop->b_crypto, in, inlen, out)) {
- log(LOG_ERR,"Error performing decryption:%s",crypto_perror());
- free(out);
- return -1;
- }
- /* copy ciphertext back to buf */
- memcpy(in,out,inlen);
- }
- } else { /* we're in the middle. Just one crypt. */
- if(crypto_cipher_decrypt(circ->n_crypto,in, inlen, out)) {
- log(LOG_ERR,"circuit_crypt(): Decryption failed for ACI : %u (%s).",
- circ->n_aci, crypto_perror());
- free(out);
- return -1;
- }
- memcpy(in,out,inlen);
- }
- }
- free(out);
- return 0;
- }
- void circuit_close(circuit_t *circ) {
- circuit_remove(circ);
- if(circ->n_conn)
- connection_send_destroy(circ->n_aci, circ->n_conn);
- if(circ->p_conn)
- connection_send_destroy(circ->p_aci, circ->p_conn);
- circuit_free(circ);
- }
- 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;
- while((circ = circuit_get_by_conn(conn))) {
- circuit_remove(circ);
- if(circ->n_conn == conn) /* it's closing in front of us */
- connection_send_destroy(circ->p_aci, circ->p_conn);
- if(circ->p_conn == conn) /* it's closing behind us */
- connection_send_destroy(circ->n_aci, circ->n_conn);
- circuit_free(circ);
- }
- }
- void circuit_dump_by_conn(connection_t *conn) {
- circuit_t *circ;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn) {
- printf("Conn %d has App-ward circuit: aci %d (other side %d), state %d (%s)\n",
- conn->poll_index, circ->p_aci, circ->n_aci, circ->state, circuit_state_to_string[circ->state]);
- }
- if(circ->n_conn == conn) {
- printf("Conn %d has Exit-ward circuit: aci %d (other side %d), state %d (%s)\n",
- conn->poll_index, circ->n_aci, circ->p_aci, circ->state, circuit_state_to_string[circ->state]);
- }
- }
- }
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