/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2008, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/* $Id$ */
const char connection_or_c_id[] =
"$Id$";
/**
* \file connection_or.c
* \brief Functions to handle OR connections, TLS handshaking, and
* cells on the network.
**/
#include "or.h"
static int connection_tls_finish_handshake(or_connection_t *conn);
static int connection_or_process_cells_from_inbuf(or_connection_t *conn);
static int connection_or_send_versions(or_connection_t *conn);
static int connection_init_or_handshake_state(or_connection_t *conn,
int started_here);
static int connection_or_check_valid_tls_handshake(or_connection_t *conn,
int started_here,
char *digest_rcvd_out);
/**************************************************************/
/** Map from identity digest of connected OR or desired OR to a connection_t
* with that identity digest. If there is more than one such connection_t,
* they form a linked list, with next_with_same_id as the next pointer. */
static digestmap_t *orconn_identity_map = NULL;
/** If conn is listed in orconn_identity_map, remove it, and clear
* conn->identity_digest. Otherwise do nothing. */
void
connection_or_remove_from_identity_map(or_connection_t *conn)
{
or_connection_t *tmp;
tor_assert(conn);
if (!orconn_identity_map)
return;
tmp = digestmap_get(orconn_identity_map, conn->identity_digest);
if (!tmp) {
if (!tor_digest_is_zero(conn->identity_digest)) {
log_warn(LD_BUG, "Didn't find connection '%s' on identity map when "
"trying to remove it.",
conn->nickname ? conn->nickname : "NULL");
}
return;
}
if (conn == tmp) {
if (conn->next_with_same_id)
digestmap_set(orconn_identity_map, conn->identity_digest,
conn->next_with_same_id);
else
digestmap_remove(orconn_identity_map, conn->identity_digest);
} else {
while (tmp->next_with_same_id) {
if (tmp->next_with_same_id == conn) {
tmp->next_with_same_id = conn->next_with_same_id;
break;
}
tmp = tmp->next_with_same_id;
}
}
memset(conn->identity_digest, 0, DIGEST_LEN);
conn->next_with_same_id = NULL;
}
/** Remove all entries from the identity-to-orconn map, and clear
* all identities in OR conns.*/
void
connection_or_clear_identity_map(void)
{
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH(conns, connection_t *, conn,
{
if (conn->type == CONN_TYPE_OR) {
or_connection_t *or_conn = TO_OR_CONN(conn);
memset(or_conn->identity_digest, 0, DIGEST_LEN);
or_conn->next_with_same_id = NULL;
}
});
if (orconn_identity_map) {
digestmap_free(orconn_identity_map, NULL);
orconn_identity_map = NULL;
}
}
/** Change conn->identity_digest to digest, and add conn into
* orconn_digest_map. */
static void
connection_or_set_identity_digest(or_connection_t *conn, const char *digest)
{
or_connection_t *tmp;
tor_assert(conn);
tor_assert(digest);
if (!orconn_identity_map)
orconn_identity_map = digestmap_new();
if (!memcmp(conn->identity_digest, digest, DIGEST_LEN))
return;
/* If the identity was set previously, remove the old mapping. */
if (! tor_digest_is_zero(conn->identity_digest))
connection_or_remove_from_identity_map(conn);
memcpy(conn->identity_digest, digest, DIGEST_LEN);
/* If we're setting the ID to zero, don't add a mapping. */
if (tor_digest_is_zero(digest))
return;
tmp = digestmap_set(orconn_identity_map, digest, conn);
conn->next_with_same_id = tmp;
#if 1
/* Testing code to check for bugs in representation. */
for (; tmp; tmp = tmp->next_with_same_id) {
tor_assert(!memcmp(tmp->identity_digest, digest, DIGEST_LEN));
tor_assert(tmp != conn);
}
#endif
}
/** Pack the cell_t host-order structure <b>src</b> into network-order
* in the buffer <b>dest</b>. See tor-spec.txt for details about the
* wire format.
*
* Note that this function doesn't touch <b>dst</b>-\>next: the caller
* should set it or clear it as appropriate.
*/
void
cell_pack(packed_cell_t *dst, const cell_t *src)
{
char *dest = dst->body;
*(uint16_t*)dest = htons(src->circ_id);
*(uint8_t*)(dest+2) = src->command;
memcpy(dest+3, src->payload, CELL_PAYLOAD_SIZE);
}
/** Unpack the network-order buffer <b>src</b> into a host-order
* cell_t structure <b>dest</b>.
*/
static void
cell_unpack(cell_t *dest, const char *src)
{
dest->circ_id = ntohs(*(uint16_t*)(src));
dest->command = *(uint8_t*)(src+2);
memcpy(dest->payload, src+3, CELL_PAYLOAD_SIZE);
}
/** Write the header of <b>cell</b> into the first VAR_CELL_HEADER_SIZE
* bytes of <b>hdr_out</b>. */
void
var_cell_pack_header(const var_cell_t *cell, char *hdr_out)
{
*(uint16_t*)(hdr_out) = htons(cell->circ_id);
*(uint8_t*)(hdr_out+2) = cell->command;
set_uint16(hdr_out+3, htons(cell->payload_len));
}
/** Allocate and return a new var_cell_t with <b>payload_len</b> bytes of
* payload space. */
var_cell_t *
var_cell_new(uint16_t payload_len)
{
var_cell_t *cell = tor_malloc(sizeof(var_cell_t)+payload_len-1);
cell->payload_len = payload_len;
cell->command = 0;
cell->circ_id = 0;
return cell;
}
/** Release all space held by <b>cell</b>. */
void
var_cell_free(var_cell_t *cell)
{
tor_free(cell);
}
/** We've received an EOF from <b>conn</b>. Mark it for close and return. */
int
connection_or_reached_eof(or_connection_t *conn)
{
log_info(LD_OR,"OR connection reached EOF. Closing.");
connection_mark_for_close(TO_CONN(conn));
return 0;
}
/** Read conn's inbuf. If the http response from the proxy is all
* here, make sure it's good news, and begin the tls handshake. If
* it's bad news, close the connection and return -1. Else return 0
* and hope for better luck next time.
*/
static int
connection_or_read_proxy_response(or_connection_t *or_conn)
{
char *headers;
char *reason=NULL;
int status_code;
time_t date_header;
connection_t *conn = TO_CONN(or_conn);
switch (fetch_from_buf_http(conn->inbuf,
&headers, MAX_HEADERS_SIZE,
NULL, NULL, 10000, 0)) {
case -1: /* overflow */
log_warn(LD_PROTOCOL,
"Your https proxy sent back an oversized response. Closing.");
return -1;
case 0:
log_info(LD_OR,"https proxy response not all here yet. Waiting.");
return 0;
/* case 1, fall through */
}
if (parse_http_response(headers, &status_code, &date_header,
NULL, &reason) < 0) {
log_warn(LD_OR,
"Unparseable headers from proxy (connecting to '%s'). Closing.",
conn->address);
tor_free(headers);
return -1;
}
if (!reason) reason = tor_strdup("[no reason given]");
if (status_code == 200) {
log_info(LD_OR,
"HTTPS connect to '%s' successful! (200 %s) Starting TLS.",
conn->address, escaped(reason));
tor_free(reason);
if (connection_tls_start_handshake(or_conn, 0) < 0) {
/* TLS handshaking error of some kind. */
connection_mark_for_close(conn);
return -1;
}
return 0;
}
/* else, bad news on the status code */
log_warn(LD_OR,
"The https proxy sent back an unexpected status code %d (%s). "
"Closing.",
status_code, escaped(reason));
tor_free(reason);
connection_mark_for_close(conn);
return -1;
}
/** Handle any new bytes that have come in on connection <b>conn</b>.
* If conn is in 'open' state, hand it to
* connection_or_process_cells_from_inbuf()
* (else do nothing).
*/
int
connection_or_process_inbuf(or_connection_t *conn)
{
tor_assert(conn);
switch (conn->_base.state) {
case OR_CONN_STATE_PROXY_READING:
return connection_or_read_proxy_response(conn);
case OR_CONN_STATE_OPEN:
case OR_CONN_STATE_OR_HANDSHAKING:
return connection_or_process_cells_from_inbuf(conn);
default:
return 0; /* don't do anything */
}
}
/** When adding cells to an OR connection's outbuf, keep adding until the
* outbuf is at least this long, or we run out of cells. */
#define OR_CONN_HIGHWATER (32*1024)
/** Add cells to an OR connection's outbuf whenever the outbuf's data length
* drops below this size. */
#define OR_CONN_LOWWATER (16*1024)
/** Called whenever we have flushed some data on an or_conn: add more data
* from active circuits. */
int
connection_or_flushed_some(or_connection_t *conn)
{
size_t datalen = buf_datalen(conn->_base.outbuf);
/* If we're under the low water mark, add cells until we're just over the
* high water mark. */
if (datalen < OR_CONN_LOWWATER) {
int n = (OR_CONN_HIGHWATER - datalen + CELL_NETWORK_SIZE-1)
/ CELL_NETWORK_SIZE;
while (conn->active_circuits && n > 0) {
int flushed = connection_or_flush_from_first_active_circuit(conn, 1);
n -= flushed;
}
}
return 0;
}
/** Connection <b>conn</b> has finished writing and has no bytes left on
* its outbuf.
*
* Otherwise it's in state "open": stop writing and return.
*
* If <b>conn</b> is broken, mark it for close and return -1, else
* return 0.
*/
int
connection_or_finished_flushing(or_connection_t *conn)
{
tor_assert(conn);
assert_connection_ok(TO_CONN(conn),0);
switch (conn->_base.state) {
case OR_CONN_STATE_PROXY_FLUSHING:
log_debug(LD_OR,"finished sending CONNECT to proxy.");
conn->_base.state = OR_CONN_STATE_PROXY_READING;
connection_stop_writing(TO_CONN(conn));
break;
case OR_CONN_STATE_OPEN:
case OR_CONN_STATE_OR_HANDSHAKING:
connection_stop_writing(TO_CONN(conn));
break;
default:
log_err(LD_BUG,"Called in unexpected state %d.", conn->_base.state);
tor_fragile_assert();
return -1;
}
return 0;
}
/** Connected handler for OR connections: begin the TLS handshake.
*/
int
connection_or_finished_connecting(or_connection_t *or_conn)
{
connection_t *conn;
tor_assert(or_conn);
conn = TO_CONN(or_conn);
tor_assert(conn->state == OR_CONN_STATE_CONNECTING);
log_debug(LD_OR,"OR connect() to router at %s:%u finished.",
conn->address,conn->port);
if (get_options()->HttpsProxy) {
char buf[1024];
char addrbuf[INET_NTOA_BUF_LEN];
struct in_addr in;
char *base64_authenticator=NULL;
const char *authenticator = get_options()->HttpsProxyAuthenticator;
in.s_addr = htonl(conn->addr);
tor_inet_ntoa(&in, addrbuf, sizeof(addrbuf));
if (authenticator) {
base64_authenticator = alloc_http_authenticator(authenticator);
if (!base64_authenticator)
log_warn(LD_OR, "Encoding https authenticator failed");
}
if (base64_authenticator) {
tor_snprintf(buf, sizeof(buf), "CONNECT %s:%d HTTP/1.1\r\n"
"Proxy-Authorization: Basic %s\r\n\r\n", addrbuf,
conn->port, base64_authenticator);
tor_free(base64_authenticator);
} else {
tor_snprintf(buf, sizeof(buf), "CONNECT %s:%d HTTP/1.0\r\n\r\n",
addrbuf, conn->port);
}
connection_write_to_buf(buf, strlen(buf), conn);
conn->state = OR_CONN_STATE_PROXY_FLUSHING;
return 0;
}
if (connection_tls_start_handshake(or_conn, 0) < 0) {
/* TLS handshaking error of some kind. */
connection_mark_for_close(conn);
return -1;
}
return 0;
}
/** If we don't necessarily know the router we're connecting to, but we
* have an addr/port/id_digest, then fill in as much as we can. Start
* by checking to see if this describes a router we know. */
static void
connection_or_init_conn_from_address(or_connection_t *conn,
uint32_t addr, uint16_t port,
const char *id_digest,
int started_here)
{
or_options_t *options = get_options();
routerinfo_t *r = router_get_by_digest(id_digest);
conn->bandwidthrate = (int)options->BandwidthRate;
conn->read_bucket = conn->bandwidthburst = (int)options->BandwidthBurst;
connection_or_set_identity_digest(conn, id_digest);
conn->_base.addr = addr;
conn->_base.port = port;
conn->real_addr = addr;
if (r) {
if (conn->_base.addr == r->addr)
conn->is_canonical = 1;
if (!started_here) {
/* Override the addr/port, so our log messages will make sense.
* This is dangerous, since if we ever try looking up a conn by
* its actual addr/port, we won't remember. Careful! */
/* XXXX020 arma: this is stupid, and it's the reason we need real_addr
* to track is_canonical properly. What requires it? */
conn->_base.addr = r->addr;
conn->_base.port = r->or_port;
}
conn->nickname = tor_strdup(r->nickname);
tor_free(conn->_base.address);
conn->_base.address = tor_strdup(r->address);
} else {
const char *n;
/* If we're an authoritative directory server, we may know a
* nickname for this router. */
n = dirserv_get_nickname_by_digest(id_digest);
if (n) {
conn->nickname = tor_strdup(n);
} else {
conn->nickname = tor_malloc(HEX_DIGEST_LEN+2);
conn->nickname[0] = '$';
base16_encode(conn->nickname+1, HEX_DIGEST_LEN+1,
conn->identity_digest, DIGEST_LEN);
}
tor_free(conn->_base.address);
conn->_base.address = tor_dup_addr(addr);
}
}
/** Return the best connection of type OR with the
* digest <b>digest</b> that we have, or NULL if we have none.
*
* 1) Don't return it if it's marked for close.
* 2) If there are any open conns, ignore non-open conns.
* 3) If there are any non-obsolete conns, ignore obsolete conns.
* 4) Then if there are any non-empty conns, ignore empty conns.
* 5) Of the remaining conns, prefer newer conns.
*/
or_connection_t *
connection_or_get_by_identity_digest(const char *digest)
{
int newer;
or_connection_t *conn, *best=NULL;
if (!orconn_identity_map)
return NULL;
conn = digestmap_get(orconn_identity_map, digest);
for (; conn; conn = conn->next_with_same_id) {
tor_assert(conn->_base.magic == OR_CONNECTION_MAGIC);
tor_assert(conn->_base.type == CONN_TYPE_OR);
tor_assert(!memcmp(conn->identity_digest, digest, DIGEST_LEN));
if (conn->_base.marked_for_close)
continue;
if (!best) {
best = conn; /* whatever it is, it's better than nothing. */
continue;
}
if (best->_base.state == OR_CONN_STATE_OPEN &&
conn->_base.state != OR_CONN_STATE_OPEN)
continue; /* avoid non-open conns if we can */
newer = best->_base.timestamp_created < conn->_base.timestamp_created;
if (best->is_canonical && !conn->is_canonical)
continue; /* A canonical connection is best. */
if (!best->_base.or_is_obsolete && conn->_base.or_is_obsolete)
continue; /* We never prefer obsolete over non-obsolete connections. */
if (
/* We prefer non-obsolete connections: */
(best->_base.or_is_obsolete && !conn->_base.or_is_obsolete) ||
/* If both have circuits we prefer the newer: */
(best->n_circuits && conn->n_circuits && newer) ||
/* If neither has circuits we prefer the newer: */
(!best->n_circuits && !conn->n_circuits && newer) ||
/* We prefer connections with circuits: */
(!best->n_circuits && conn->n_circuits)) {
best = conn;
};
}
return best;
}
/** Launch a new OR connection to <b>addr</b>:<b>port</b> and expect to
* handshake with an OR with identity digest <b>id_digest</b>.
*
* If <b>id_digest</b> is me, do nothing. If we're already connected to it,
* return that connection. If the connect() is in progress, set the
* new conn's state to 'connecting' and return it. If connect() succeeds,
* call connection_tls_start_handshake() on it.
*
* This function is called from router_retry_connections(), for
* ORs connecting to ORs, and circuit_establish_circuit(), for
* OPs connecting to ORs.
*
* Return the launched conn, or NULL if it failed.
*/
or_connection_t *
connection_or_connect(uint32_t addr, uint16_t port, const char *id_digest)
{
or_connection_t *conn;
or_options_t *options = get_options();
tor_assert(id_digest);
if (server_mode(options) && router_digest_is_me(id_digest)) {
log_info(LD_PROTOCOL,"Client asked me to connect to myself. Refusing.");
return NULL;
}
conn = TO_OR_CONN(connection_new(CONN_TYPE_OR, AF_INET));
/* set up conn so it's got all the data we need to remember */
connection_or_init_conn_from_address(conn, addr, port, id_digest, 1);
conn->_base.state = OR_CONN_STATE_CONNECTING;
control_event_or_conn_status(conn, OR_CONN_EVENT_LAUNCHED, 0);
if (options->HttpsProxy) {
/* we shouldn't connect directly. use the https proxy instead. */
addr = options->HttpsProxyAddr;
port = options->HttpsProxyPort;
}
switch (connection_connect(TO_CONN(conn), conn->_base.address, addr, port)) {
case -1:
/* If the connection failed immediately, and we're using
* an https proxy, our https proxy is down. Don't blame the
* Tor server. */
if (!options->HttpsProxy) {
entry_guard_register_connect_status(conn->identity_digest, 0,
time(NULL));
router_set_status(conn->identity_digest, 0);
}
control_event_or_conn_status(conn, OR_CONN_EVENT_FAILED,
END_OR_CONN_REASON_TCP_REFUSED);
connection_free(TO_CONN(conn));
return NULL;
case 0:
connection_watch_events(TO_CONN(conn), EV_READ | EV_WRITE);
/* writable indicates finish, readable indicates broken link,
error indicates broken link on windows */
return conn;
/* case 1: fall through */
}
if (connection_or_finished_connecting(conn) < 0) {
/* already marked for close */
return NULL;
}
return conn;
}
/** Begin the tls handshake with <b>conn</b>. <b>receiving</b> is 0 if
* we initiated the connection, else it's 1.
*
* Assign a new tls object to conn->tls, begin reading on <b>conn</b>, and
* pass <b>conn</b> to connection_tls_continue_handshake().
*
* Return -1 if <b>conn</b> is broken, else return 0.
*/
int
connection_tls_start_handshake(or_connection_t *conn, int receiving)
{
conn->_base.state = OR_CONN_STATE_TLS_HANDSHAKING;
conn->tls = tor_tls_new(conn->_base.s, receiving);
if (!conn->tls) {
log_warn(LD_BUG,"tor_tls_new failed. Closing.");
return -1;
}
connection_start_reading(TO_CONN(conn));
log_debug(LD_OR,"starting TLS handshake on fd %d", conn->_base.s);
note_crypto_pk_op(receiving ? TLS_HANDSHAKE_S : TLS_HANDSHAKE_C);
if (connection_tls_continue_handshake(conn) < 0) {
return -1;
}
return 0;
}
/** Invoked on the server side from inside tor_tls_read() when the server
* gets a successful TLS renegotiation from the client. */
static void
connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn)
{
or_connection_t *conn = _conn;
(void)tls;
/* Don't invoke this again. */
tor_tls_set_renegotiate_callback(tls, NULL, NULL);
if (connection_tls_finish_handshake(conn) < 0) {
/* XXXX_TLS double-check that it's ok to do this from inside read. */
/* XXXX_TLS double-check that this verifies certificates. */
connection_mark_for_close(TO_CONN(conn));
}
}
/** Move forward with the tls handshake. If it finishes, hand
* <b>conn</b> to connection_tls_finish_handshake().
*
* Return -1 if <b>conn</b> is broken, else return 0.
*/
int
connection_tls_continue_handshake(or_connection_t *conn)
{
int result;
check_no_tls_errors();
again:
if (conn->_base.state == OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING) {
// log_notice(LD_OR, "Renegotiate with %p", conn->tls);
result = tor_tls_renegotiate(conn->tls);
// log_notice(LD_OR, "Result: %d", result);
} else {
tor_assert(conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING);
// log_notice(LD_OR, "Continue handshake with %p", conn->tls);
result = tor_tls_handshake(conn->tls);
// log_notice(LD_OR, "Result: %d", result);
}
switch (result) {
CASE_TOR_TLS_ERROR_ANY:
log_info(LD_OR,"tls error [%s]. breaking connection.",
tor_tls_err_to_string(result));
return -1;
case TOR_TLS_DONE:
if (! tor_tls_used_v1_handshake(conn->tls)) {
if (!tor_tls_is_server(conn->tls)) {
if (conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING) {
// log_notice(LD_OR,"Done. state was TLS_HANDSHAKING.");
conn->_base.state = OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING;
goto again;
}
// log_notice(LD_OR,"Done. state was %d.", conn->_base.state);
} else {
/* improved handshake, but not a client. */
tor_tls_set_renegotiate_callback(conn->tls,
connection_or_tls_renegotiated_cb,
conn);
conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING;
connection_stop_writing(TO_CONN(conn));
connection_start_reading(TO_CONN(conn));
return 0;
}
}
return connection_tls_finish_handshake(conn);
case TOR_TLS_WANTWRITE:
connection_start_writing(TO_CONN(conn));
log_debug(LD_OR,"wanted write");
return 0;
case TOR_TLS_WANTREAD: /* handshaking conns are *always* reading */
log_debug(LD_OR,"wanted read");
return 0;
case TOR_TLS_CLOSE:
log_info(LD_OR,"tls closed. breaking connection.");
return -1;
}
return 0;
}
/** Return 1 if we initiated this connection, or 0 if it started
* out as an incoming connection.
*/
int
connection_or_nonopen_was_started_here(or_connection_t *conn)
{
tor_assert(conn->_base.type == CONN_TYPE_OR);
if (!conn->tls)
return 1; /* it's still in proxy states or something */
if (conn->handshake_state)
return conn->handshake_state->started_here;
return !tor_tls_is_server(conn->tls);
}
/** <b>Conn</b> just completed its handshake. Return 0 if all is well, and
* return -1 if he is lying, broken, or otherwise something is wrong.
*
* If we initiated this connection (<b>started_here</b> is true), make sure
* the other side sent sent a correctly formed certificate. If I initiated the
* connection, make sure it's the right guy.
*
* Otherwise (if we _didn't_ initiate this connection), it's okay for
* the certificate to be weird or absent.
*
* If we return 0, and the certificate is as expected, write a hash of the
* identity key into digest_rcvd, which must have DIGEST_LEN space in it. (If
* we return -1 this buffer is undefined.) If the certificate is invalid
* or missing on an incoming connection, we return 0 and set digest_rcvd to
* DIGEST_LEN 0 bytes.
*
* As side effects,
* 1) Set conn->circ_id_type according to tor-spec.txt.
* 2) If we're an authdirserver and we initiated the connection: drop all
* descriptors that claim to be on that IP/port but that aren't
* this guy; and note that this guy is reachable.
*/
static int
connection_or_check_valid_tls_handshake(or_connection_t *conn,
int started_here,
char *digest_rcvd_out)
{
crypto_pk_env_t *identity_rcvd=NULL;
or_options_t *options = get_options();
int severity = server_mode(options) ? LOG_PROTOCOL_WARN : LOG_WARN;
const char *safe_address =
started_here ? conn->_base.address : safe_str(conn->_base.address);
const char *conn_type = started_here ? "outgoing" : "incoming";
int has_cert = 0, has_identity=0;
check_no_tls_errors();
has_cert = tor_tls_peer_has_cert(conn->tls);
if (started_here && !has_cert) {
log_info(LD_PROTOCOL,"Tried connecting to router at %s:%d, but it didn't "
"send a cert! Closing.",
safe_address, conn->_base.port);
return -1;
} else if (!has_cert) {
log_debug(LD_PROTOCOL,"Got incoming connection with no certificate. "
"That's ok.");
}
check_no_tls_errors();
if (has_cert) {
int v = tor_tls_verify(started_here?severity:LOG_INFO,
conn->tls, &identity_rcvd);
if (started_here && v<0) {
log_fn(severity,LD_OR,"Tried connecting to router at %s:%d: It"
" has a cert but it's invalid. Closing.",
safe_address, conn->_base.port);
return -1;
} else if (v<0) {
log_info(LD_PROTOCOL,"Incoming connection gave us an invalid cert "
"chain; ignoring.");
} else {
log_debug(LD_OR,"The certificate seems to be valid on %s connection "
"with %s:%d", conn_type, safe_address, conn->_base.port);
}
check_no_tls_errors();
}
if (identity_rcvd) {
has_identity = 1;
crypto_pk_get_digest(identity_rcvd, digest_rcvd_out);
if (crypto_pk_cmp_keys(get_identity_key(), identity_rcvd)<0) {
conn->circ_id_type = CIRC_ID_TYPE_LOWER;
} else {
conn->circ_id_type = CIRC_ID_TYPE_HIGHER;
}
crypto_free_pk_env(identity_rcvd);
} else {
memset(digest_rcvd_out, 0, DIGEST_LEN);
conn->circ_id_type = CIRC_ID_TYPE_NEITHER;
}
if (started_here && tor_digest_is_zero(conn->identity_digest)) {
connection_or_set_identity_digest(conn, digest_rcvd_out);
tor_free(conn->nickname);
conn->nickname = tor_malloc(HEX_DIGEST_LEN+2);
conn->nickname[0] = '$';
base16_encode(conn->nickname+1, HEX_DIGEST_LEN+1,
conn->identity_digest, DIGEST_LEN);
log_info(LD_OR, "Connected to router %s at %s:%d without knowing "
"its key. Hoping for the best.",
conn->nickname, conn->_base.address, conn->_base.port);
}
if (started_here) {
int as_advertised = 1;
tor_assert(has_cert);
tor_assert(has_identity);
if (memcmp(digest_rcvd_out, conn->identity_digest, DIGEST_LEN)) {
/* I was aiming for a particular digest. I didn't get it! */
char seen[HEX_DIGEST_LEN+1];
char expected[HEX_DIGEST_LEN+1];
base16_encode(seen, sizeof(seen), digest_rcvd_out, DIGEST_LEN);
base16_encode(expected, sizeof(expected), conn->identity_digest,
DIGEST_LEN);
log_fn(severity, LD_OR,
"Tried connecting to router at %s:%d, but identity key was not "
"as expected: wanted %s but got %s.",
conn->_base.address, conn->_base.port, expected, seen);
entry_guard_register_connect_status(conn->identity_digest,0,time(NULL));
router_set_status(conn->identity_digest, 0);
control_event_or_conn_status(conn, OR_CONN_EVENT_FAILED,
END_OR_CONN_REASON_OR_IDENTITY);
as_advertised = 0;
}
if (authdir_mode_tests_reachability(options)) {
/* We initiated this connection to address:port. Drop all routers
* with the same address:port and a different key.
*/
dirserv_orconn_tls_done(conn->_base.address, conn->_base.port,
digest_rcvd_out, as_advertised);
}
if (!as_advertised)
return -1;
}
return 0;
}
/** The tls handshake is finished.
*
* Make sure we are happy with the person we just handshaked with.
*
* If he initiated the connection, make sure he's not already connected,
* then initialize conn from the information in router.
*
* If all is successful, call circuit_n_conn_done() to handle events
* that have been pending on the <tls handshake completion. Also set the
* directory to be dirty (only matters if I'm an authdirserver).
*/
static int
connection_tls_finish_handshake(or_connection_t *conn)
{
char digest_rcvd[DIGEST_LEN];
int started_here = connection_or_nonopen_was_started_here(conn);
log_debug(LD_OR,"tls handshake with %s done. verifying.",
conn->_base.address);
directory_set_dirty();
if (connection_or_check_valid_tls_handshake(conn, started_here,
digest_rcvd) < 0)
return -1;
if (tor_tls_used_v1_handshake(conn->tls)) {
conn->link_proto = 1;
if (!started_here) {
connection_or_init_conn_from_address(conn,conn->_base.addr,
conn->_base.port, digest_rcvd, 0);
}
return connection_or_set_state_open(conn);
} else {
conn->_base.state = OR_CONN_STATE_OR_HANDSHAKING;
if (connection_init_or_handshake_state(conn, started_here) < 0)
return -1;
if (!started_here) {
connection_or_init_conn_from_address(conn,conn->_base.addr,
conn->_base.port, digest_rcvd, 0);
}
return connection_or_send_versions(conn);
}
}
/** Allocate a new connection handshake state for the connection
* <b>conn</b>. Return 0 on success, -1 on failure. */
static int
connection_init_or_handshake_state(or_connection_t *conn, int started_here)
{
or_handshake_state_t *s;
s = conn->handshake_state = tor_malloc_zero(sizeof(or_handshake_state_t));
s->started_here = started_here ? 1 : 0;
return 0;
}
/** Free all storage held by <b>state</b>. */
void
or_handshake_state_free(or_handshake_state_t *state)
{
tor_assert(state);
memset(state, 0xBE, sizeof(or_handshake_state_t));
tor_free(state);
}
/** Set <b>conn</b>'s state to OR_CONN_STATE_OPEN, and tell other subsystems
* as appropriate. Called when we are done with all TLS and OR handshaking.
*/
int
connection_or_set_state_open(or_connection_t *conn)
{
int started_here = connection_or_nonopen_was_started_here(conn);
time_t now = time(NULL);
conn->_base.state = OR_CONN_STATE_OPEN;
control_event_or_conn_status(conn, OR_CONN_EVENT_CONNECTED, 0);
if (started_here) {
rep_hist_note_connect_succeeded(conn->identity_digest, now);
if (entry_guard_register_connect_status(conn->identity_digest,
1, now) < 0) {
/* pending circs get closed in circuit_about_to_close_connection() */
return -1;
}
router_set_status(conn->identity_digest, 1);
} else {
/* only report it to the geoip module if it's not a known router */
if (!router_get_by_digest(conn->identity_digest))
geoip_note_client_seen(TO_CONN(conn)->addr, now);
}
if (conn->handshake_state) {
or_handshake_state_free(conn->handshake_state);
conn->handshake_state = NULL;
}
connection_start_reading(TO_CONN(conn));
circuit_n_conn_done(conn, 1); /* send the pending creates, if any. */
return 0;
}
/** Pack <b>cell</b> into wire-format, and write it onto <b>conn</b>'s outbuf.
* For cells that use or affect a circuit, this should only be called by
* connection_or_flush_from_first_active_circuit().
*/
void
connection_or_write_cell_to_buf(const cell_t *cell, or_connection_t *conn)
{
packed_cell_t networkcell;
tor_assert(cell);
tor_assert(conn);
cell_pack(&networkcell, cell);
connection_write_to_buf(networkcell.body, CELL_NETWORK_SIZE, TO_CONN(conn));
if (cell->command != CELL_PADDING)
conn->timestamp_last_added_nonpadding = time(NULL);
}
/** Pack a variable-length <b>cell</b> into wire-format, and write it onto
* <b>conn</b>'s outbuf. Right now, this <em>DOES NOT</em> support cells that
* affect a circuit.
*/
void
connection_or_write_var_cell_to_buf(const var_cell_t *cell,
or_connection_t *conn)
{
char hdr[VAR_CELL_HEADER_SIZE];
tor_assert(cell);
tor_assert(conn);
var_cell_pack_header(cell, hdr);
connection_write_to_buf(hdr, sizeof(hdr), TO_CONN(conn));
connection_write_to_buf(cell->payload, cell->payload_len, TO_CONN(conn));
if (cell->command != CELL_PADDING)
conn->timestamp_last_added_nonpadding = time(NULL);
}
/** See whether there's a variable-length cell waiting on <b>conn</b>'s
* inbuf. Return values as for fetch_var_cell_from_buf(). */
static int
connection_fetch_var_cell_from_buf(or_connection_t *conn, var_cell_t **out)
{
return fetch_var_cell_from_buf(conn->_base.inbuf, out, conn->link_proto);
}
/** Process cells from <b>conn</b>'s inbuf.
*
* Loop: while inbuf contains a cell, pull it off the inbuf, unpack it,
* and hand it to command_process_cell().
*
* Always return 0.
*/
static int
connection_or_process_cells_from_inbuf(or_connection_t *conn)
{
var_cell_t *var_cell;
while (1) {
log_debug(LD_OR,
"%d: starting, inbuf_datalen %d (%d pending in tls object).",
conn->_base.s,(int)buf_datalen(conn->_base.inbuf),
tor_tls_get_pending_bytes(conn->tls));
if (connection_fetch_var_cell_from_buf(conn, &var_cell)) {
if (!var_cell)
return 0; /* not yet. */
command_process_var_cell(var_cell, conn);
var_cell_free(var_cell);
} else {
char buf[CELL_NETWORK_SIZE];
cell_t cell;
if (buf_datalen(conn->_base.inbuf) < CELL_NETWORK_SIZE) /* whole response
available? */
return 0; /* not yet */
connection_fetch_from_buf(buf, CELL_NETWORK_SIZE, TO_CONN(conn));
/* retrieve cell info from buf (create the host-order struct from the
* network-order string) */
cell_unpack(&cell, buf);
command_process_cell(&cell, conn);
}
}
}
/** Write a destroy cell with circ ID <b>circ_id</b> and reason <b>reason</b>
* onto OR connection <b>conn</b>. Don't perform range-checking on reason:
* we may want to propagate reasons from other cells.
*
* Return 0.
*/
int
connection_or_send_destroy(uint16_t circ_id, or_connection_t *conn, int reason)
{
cell_t cell;
tor_assert(conn);
memset(&cell, 0, sizeof(cell_t));
cell.circ_id = circ_id;
cell.command = CELL_DESTROY;
cell.payload[0] = (uint8_t) reason;
log_debug(LD_OR,"Sending destroy (circID %d).", circ_id);
/* XXXX It's possible that under some circumstances, we want the destroy
* to take precedence over other data waiting on the circuit's cell queue.
*/
connection_or_write_cell_to_buf(&cell, conn);
return 0;
}
/** Array of recognized link protocol versions. */
static const uint16_t or_protocol_versions[] = { 1, 2 };
/** Number of versions in <b>or_protocol_versions</b>. */
static const int n_or_protocol_versions =
sizeof(or_protocol_versions)/sizeof(uint16_t);
/** Return true iff <b>v</b> is a link protocol version that this Tor
* implementation believes it can support. */
int
is_or_protocol_version_known(uint16_t v)
{
int i;
for (i = 0; i < n_or_protocol_versions; ++i) {
if (or_protocol_versions[i] == v)
return 1;
}
return 0;
}
/** Send a VERSIONS cell on <b>conn</b>, telling the other host about the
* link protocol versions that this Tor can support. */
static int
connection_or_send_versions(or_connection_t *conn)
{
var_cell_t *cell;
int i;
tor_assert(conn->handshake_state &&
!conn->handshake_state->sent_versions_at);
cell = var_cell_new(n_or_protocol_versions * 2);
cell->command = CELL_VERSIONS;
for (i = 0; i < n_or_protocol_versions; ++i) {
uint16_t v = or_protocol_versions[i];
set_uint16(cell->payload+(2*i), htons(v));
}
connection_or_write_var_cell_to_buf(cell, conn);
conn->handshake_state->sent_versions_at = time(NULL);
var_cell_free(cell);
return 0;
}
/** Send a NETINFO cell on <b>conn</b>, telling the other server what we know
* about their address, our address, and the current time. */
int
connection_or_send_netinfo(or_connection_t *conn)
{
cell_t cell;
time_t now = time(NULL);
routerinfo_t *me;
memset(&cell, 0, sizeof(cell_t));
cell.command = CELL_NETINFO;
/* Their address. */
set_uint32(cell.payload, htonl(now));
cell.payload[4] = RESOLVED_TYPE_IPV4;
cell.payload[5] = 4;
set_uint32(cell.payload+6, htonl(conn->_base.addr));
/* My address. */
if ((me = router_get_my_routerinfo())) {
cell.payload[10] = 1; /* only one address is supported. */
cell.payload[11] = RESOLVED_TYPE_IPV4;
cell.payload[12] = 4;
set_uint32(cell.payload+13, htonl(me->addr));
} else {
cell.payload[10] = 0;
}
connection_or_write_cell_to_buf(&cell, conn);
return 0;
}