Commit 21478985 authored by Roger Dingledine's avatar Roger Dingledine
Browse files

Implemented router twins

I modified new_route so we don't pick twins back-to-back in the path.

I also had to patch my previous uses of connection_twin_get_by_addr_port()
because they assumed that "addr" and "port" would be the same for a twin
as for the original router.


svn:r56
parent 0a8d5813
......@@ -287,14 +287,14 @@ int circuit_crypt(circuit_t *circ, char *in, size_t inlen, char crypt_type) {
return -1;
if(crypt_type == 'e') {
log(LOG_DEBUG,"circuit_crypt(): Encrypting %d bytes.",inlen);
// 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);
// log(LOG_DEBUG,"circuit_crypt() : Encrypting via cpath: Processing hop %u",circ->cpathlen-i);
thishop = circ->cpath[i];
/* encrypt */
......@@ -317,13 +317,13 @@ int circuit_crypt(circuit_t *circ, char *in, size_t inlen, char crypt_type) {
memcpy(in,out,inlen);
}
} else if(crypt_type == 'd') {
log(LOG_DEBUG,"circuit_crypt(): Decrypting %d bytes.",inlen);
// 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);
// log(LOG_DEBUG,"circuit_crypt() : Decrypting via cpath: Processing hop %u",circ->cpathlen-i);
thishop = circ->cpath[i];
/* encrypt */
......
......@@ -111,6 +111,10 @@ void command_process_create_cell(cell_t *cell, connection_t *conn) {
circuit_close(circ);
return;
}
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(LOG_DEBUG,"command_process_create_cell(): n_conn is %s:%u",n_conn->address,ntohs(n_conn->port));
......
......@@ -195,8 +195,6 @@ int ap_handshake_establish_circuit(connection_t *conn, unsigned int *route, int
free(route); /* we don't need it anymore */
circ = circuit_new(0, conn); /* sets circ->p_aci and circ->p_conn */
circ->n_addr = firsthop->addr;
circ->n_port = firsthop->or_port;
circ->state = CIRCUIT_STATE_OR_WAIT;
circ->onion = onion;
circ->onionlen = onionlen;
......@@ -207,6 +205,8 @@ int ap_handshake_establish_circuit(connection_t *conn, unsigned int *route, int
firsthop->address,ntohs(firsthop->or_port));
n_conn = connection_twin_get_by_addr_port(firsthop->addr,firsthop->or_port);
if(!n_conn) { /* not currently connected */
circ->n_addr = firsthop->addr;
circ->n_port = firsthop->or_port;
if(global_role & ROLE_OR_CONNECT_ALL) { /* we would be connected if he were up. but he's not. */
log(LOG_DEBUG,"ap_handshake_establish_circuit(): Route's firsthop isn't connected.");
circuit_close(circ);
......@@ -221,11 +221,13 @@ int ap_handshake_establish_circuit(connection_t *conn, unsigned int *route, int
return -1;
}
conn->state = AP_CONN_STATE_OR_WAIT;
connection_watch_events(conn, 0); /* Stop listening for input from the AP! */
connection_stop_reading(conn); /* Stop listening for input from the AP! */
return 0; /* return success. The onion/circuit/etc will be taken care of automatically
* (may already have been) whenever n_conn reaches OR_CONN_STATE_OPEN.
*/
} else { /* it's already open. use it. */
} else { /* it (or a twin) is already open. use it. */
circ->n_addr = n_conn->addr;
circ->n_port = n_conn->port;
return ap_handshake_send_onion(conn, n_conn, circ);
}
}
......@@ -237,12 +239,12 @@ int ap_handshake_n_conn_open(connection_t *or_conn) {
log(LOG_DEBUG,"ap_handshake_n_conn_open(): Starting.");
circ = circuit_get_by_naddr_nport(or_conn->addr, or_conn->port);
if(!circ)
return 0; /* i'm ok with that */
return 0; /* i'm ok with that. no need to close the connection or anything. */
if(circ->p_conn->state != AP_CONN_STATE_OR_WAIT) {
log(LOG_DEBUG,"Bug: ap_handshake_n_conn_open() got an ap_conn not in OR_WAIT state.");
}
connection_watch_events(or_conn, POLLIN); /* resume listening for reads */
connection_start_reading(circ->p_conn); /* resume listening for reads */
log(LOG_DEBUG,"ap_handshake_n_conn_open(): Found circ, sending onion.");
return ap_handshake_send_onion(circ->p_conn, or_conn, circ);
}
......@@ -332,7 +334,7 @@ int ap_handshake_send_onion(connection_t *ap_conn, connection_t *n_conn, circuit
/* now we want to give the AP a "0" byte, because it wants to hear
* back from us */
connection_write_to_buf(&zero, 1, ap_conn);
connection_write_to_buf(&zero, 1, ap_conn); /* this does connection_start_writing() too */
return 0;
}
......
......@@ -91,6 +91,22 @@ int connection_remove(connection_t *conn) {
return 0;
}
int pkey_cmp(RSA *a, RSA *b) {
/* return 0 if a and b are "the same key". Return non-0 otherwise. */
int result;
if(!a || !b)
return -1;
assert(a->n && a->e && b->n && b->e);
result = BN_cmp(a->n, b->n);
if(result)
return result;
return BN_cmp(a->e, b->e);
}
connection_t *connection_twin_get_by_addr_port(uint32_t addr, uint16_t port) {
/* Find a connection to the router described by addr and port,
* or alternately any router which knows its key.
......@@ -99,16 +115,29 @@ connection_t *connection_twin_get_by_addr_port(uint32_t addr, uint16_t port) {
*/
int i;
connection_t *conn;
routerinfo_t *router;
/* first check if it's there exactly */
conn = connection_exact_get_by_addr_port(addr,port);
if(conn && connection_state_is_open(conn)) {
log(LOG_DEBUG,"connection_twin_get_by_addr_port(): Found exact match.");
return conn;
}
/* now check if any of the other open connections are a twin for this one */
/* XXX */
router = router_get_by_addr_port(addr,port);
if(!router)
return NULL;
for(i=0;i<nfds;i++) {
conn = connection_array[i];
assert(conn);
if(connection_state_is_open(conn) && !pkey_cmp(conn->pkey, router->pkey)) {
log(LOG_DEBUG,"connection_twin_get_by_addr_port(): Found twin (%s).",conn->address);
return conn;
}
}
/* guess not */
return NULL;
......
......@@ -131,9 +131,9 @@ unsigned int *new_route(double cw, routerinfo_t **rarray, size_t rarray_len, siz
choice = choice % (rarray_len);
log(LOG_DEBUG,"new_route() : Chosen router %u.",choice);
if (choice == oldchoice) /* same router */
{
/* try again */
if (choice == oldchoice ||
(oldchoice < rarray_len && !pkey_cmp(rarray[choice]->pkey, rarray[oldchoice]->pkey))) {
/* same router, or router twin. try again. */
i--;
continue;
}
......
......@@ -509,6 +509,7 @@ int connection_add(connection_t *conn);
int connection_remove(connection_t *conn);
void connection_set_poll_socket(connection_t *conn);
int pkey_cmp(RSA *a, RSA *b);
connection_t *connection_twin_get_by_addr_port(uint32_t addr, uint16_t port);
connection_t *connection_exact_get_by_addr_port(uint32_t addr, uint16_t port);
......
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