break part of circuit.c into relay.c

svn:r1854

1 files changed, 1 insertions, 339 deletions

diff --git a/src/or/circuit.c b/src/or/circuit.c
index 85e88e0755..1347b807a3 100644
--- a/src/or/circuit.c
+++ b/src/or/circuit.c
@@ -4,17 +4,13 @@
 
 /**
  * \file circuit.c
- * \brief Manage circuits and the global circuit list. Also handle
- * relay cell encryption/decryption.
+ * \brief Manage circuits and the global circuit list.
  **/
 
 #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 int circuit_resume_edge_reading_helper(connection_t *conn,
                                               circuit_t *circ,
                                               crypt_path_t *layer_hint);
@@ -27,15 +23,6 @@ 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);
 
-/** Stats: how many relay cells have originated at this hop, or have
- * been relayed onward (not recognized at this hop)?
- */
-unsigned long stats_n_relay_cells_relayed = 0;
-/** Stats: how many relay cells have been delivered to streams at this
- * hop?
- */
-unsigned long stats_n_relay_cells_delivered = 0;
-
 /********* START VARIABLES **********/
 
 /** A global (within this file) list of all circuits at this hop. */
@@ -675,331 +662,6 @@ void circuit_build_needed_circs(time_t now) {
   /* XXX count idle rendezvous circs and build more */
 }
 
-/** 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);
-}
-
-/** Does the digest for this circuit indicate that this cell is for us?
- *
- * 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;
-}
-
-/** Apply <b>cipher</b> to CELL_PAYLOAD_SIZE bytes of <b>in</b>
- * (in place).
- *
- * If <b>encrypt_mode</b> is 1 then encrypt, else decrypt.
- *
- * Return -1 if the crypto fails, else return 0.
- */
-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 relay encryption");
-    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 and the digest checks out, then find if there's
- *    a conn that the cell is intended for, and deliver it to 
- *    connection_edge.
- *  - Else connection_or_write_cell_to_buf to the conn on the other
- *    side of the circuit.
- */
-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;
-
-  tor_assert(cell && circ);
-  tor_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 away from origin.");
-      if (connection_edge_process_relay_cell(cell, circ, conn, NULL) < 0) {
-        log_fn(LOG_WARN,"connection_edge_process_relay_cell (away from origin) failed.");
-        return -1;
-      }
-    }
-    if(cell_direction == CELL_DIRECTION_IN) {
-      ++stats_n_relay_cells_delivered;
-      log_fn(LOG_DEBUG,"Sending to origin.");
-      if (connection_edge_process_relay_cell(cell, circ, conn, layer_hint) < 0) {
-        log_fn(LOG_WARN,"connection_edge_process_relay_cell (at origin) 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) {
-      tor_assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
-      tor_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;
-}
-
-/** Do the appropriate en/decryptions for <b>cell</b> arriving on
- * <b>circ</b> in direction <b>cell_direction</b>.
- *
- * If cell_direction == CELL_DIRECTION_IN:
- *   - If we're at the origin (we're the OP), for hops 1..N,
- *     decrypt cell. If recognized, stop.
- *   - Else (we're not the OP), encrypt one hop. Cell is not recognized.
- *
- * If cell_direction == CELL_DIRECTION_OUT:
- *   - decrypt one hop. Check if recognized.
- *
- * If cell is recognized, set *recognized to 1, and set
- * *layer_hint to the hop that recognized it.
- *
- * Return -1 to indicate that we should mark the circuit for close,
- * else 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;
-
-  tor_assert(circ && cell && recognized);
-  tor_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 decrypts. */
-      tor_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. */
-        tor_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:
- *  - Encrypt it to the right layer
- *  - 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 {
-      tor_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;
-}
-
-/** If cell's stream_id matches the stream_id of any conn that's
- * attached to circ, return that conn, else return NULL.
- */
-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;
-    }
-  }
-  for(tmpconn = circ->resolving_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 */
-}
-
 /** The circuit <b>circ</b> has received a circuit-level sendme
  * (on hop <b>layer_hint</b>, if we're the OP). Go through all the
  * attached streams and let them resume reading and packaging, if