Commit a6a45b77 authored by Nick Mathewson's avatar Nick Mathewson 🎨
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Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells. Also, add a...

Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells.  Also, add a missing ntohl in connection_ap_handshake_socks_resolved.


svn:r4894
parent 93179f4e
......@@ -469,8 +469,16 @@ TODO: (very soon)
address cannot be resolved, or a connection can't be established, the
exit node replies with a RELAY_END cell. (See 5.4 below.)
Otherwise, the exit node replies with a RELAY_CONNECTED cell, whose
payload is the 4-byte IPv4 address or the 16-byte IPv6 address to which
the connection was made.
payload is in one of the following formats:
The IPv4 address to which the connection was made [4 octets]
A number of seconds (TTL) for which the address may be cached [4 octets]
or
Four zero-valued octets [4 octets]
An address type (6) [1 octet]
The IPv6 address to which the connection was made [16 octets]
A number of seconds (TTL) for which the address may be cached [4 octets]
[XXXX Versions of Tor before 0.1.1.6 ignore and do not generate the TTL
field. No version of Tor currently generates the IPv6 format.]
The OP waits for a RELAY_CONNECTED cell before sending any data.
Once a connection has been established, the OP and exit node
......@@ -511,7 +519,8 @@ TODO: (very soon)
Tor protocol violations.)
(With REASON_EXITPOLICY, the 4-byte IPv4 address or 16-byte IPv6 address
forms the optional data; no other reason currently has extra data.)
forms the optional data; no other reason currently has extra data.
As of 0.1.1.6, the body also contains a 4-byte TTL.)
OPs and ORs MUST accept reasons not on the above list, since future
versions of Tor may provide more fine-grained reasons.
......@@ -558,6 +567,7 @@ TODO: (very soon)
Type (1 octet)
Length (1 octet)
Value (variable-width)
TTL (4 octets)
"Length" is the length of the Value field.
"Type" is one of:
0x00 -- Hostname
......
......@@ -48,7 +48,7 @@ _connection_mark_unattached_ap(connection_t *conn, int endreason,
if (conn->socks_request->command == SOCKS_COMMAND_CONNECT)
connection_ap_handshake_socks_reply(conn, NULL, 0, socksreason);
else
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL);
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
}
_connection_mark_for_close(conn, line, file);
......@@ -194,7 +194,8 @@ connection_edge_end(connection_t *conn, char reason, crypt_path_t *cpath_layer)
/* this is safe even for rend circs, because they never fail
* because of exitpolicy */
set_uint32(payload+1, htonl(conn->addr));
payload_len += 4;
set_uint32(payload+5, htonl(MAX_DNS_ENTRY_AGE)); /* XXXXfill with a real TTL*/
payload_len += 8;
}
circ = circuit_get_by_edge_conn(conn);
......@@ -266,7 +267,6 @@ connection_edge_finished_flushing(connection_t *conn)
int
connection_edge_finished_connecting(connection_t *conn)
{
char connected_payload[4];
char valbuf[INET_NTOA_BUF_LEN];
struct in_addr in;
......@@ -289,9 +289,12 @@ connection_edge_finished_connecting(connection_t *conn)
RELAY_COMMAND_CONNECTED, NULL, 0, conn->cpath_layer) < 0)
return 0; /* circuit is closed, don't continue */
} else {
*(uint32_t*)connected_payload = htonl(conn->addr);
char connected_payload[8];
set_uint32(connected_payload, htonl(htonl(conn->addr)));
set_uint32(connected_payload+4,
htonl(MAX_DNS_ENTRY_AGE)); /* XXXX fill with a real TTL */
if (connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED, connected_payload, 4, conn->cpath_layer) < 0)
RELAY_COMMAND_CONNECTED, connected_payload, 8, conn->cpath_layer) < 0)
return 0; /* circuit is closed, don't continue */
}
tor_assert(conn->package_window > 0);
......@@ -683,9 +686,13 @@ client_dns_clear_failures(const char *address)
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds.
*/
void
client_dns_set_addressmap(const char *address, uint32_t val, const char *exitname)
client_dns_set_addressmap(const char *address, uint32_t val, const char *exitname,
int ttl)
{
struct in_addr in;
char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_HEX_NICKNAME_LEN+10];
......@@ -694,6 +701,9 @@ client_dns_set_addressmap(const char *address, uint32_t val, const char *exitnam
tor_assert(address); tor_assert(val);
if (ttl<0 || ttl>MAX_DNS_ENTRY_AGE)
ttl = MAX_DNS_ENTRY_AGE;
if (tor_inet_aton(address, &in))
return; /* If address was an IP address already, don't add a mapping. */
in.s_addr = htonl(val);
......@@ -709,8 +719,7 @@ client_dns_set_addressmap(const char *address, uint32_t val, const char *exitnam
tor_snprintf(extendedval, sizeof(extendedval),
"%s", valbuf);
}
addressmap_register(extendedaddress, tor_strdup(extendedval),
time(NULL) + MAX_DNS_ENTRY_AGE);
addressmap_register(extendedaddress, tor_strdup(extendedval), time(NULL) + ttl);
}
/* Currently, we hand out 127.192.0.1 through 127.254.254.254.
......@@ -1019,14 +1028,14 @@ connection_ap_handshake_process_socks(connection_t *conn)
/* Reply to resolves immediately if we can. */
if (strlen(socks->address) > RELAY_PAYLOAD_SIZE) {
log_fn(LOG_WARN,"Address to be resolved is too large. Failing.");
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL);
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return -1;
}
if (tor_inet_aton(socks->address, &in)) { /* see if it's an IP already */
answer = in.s_addr; /* leave it in network order */
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
(char*)&answer);
(char*)&answer,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return 0;
}
......@@ -1075,7 +1084,7 @@ connection_ap_handshake_process_socks(connection_t *conn)
/* if it's a resolve request, fail it right now, rather than
* building all the circuits and then realizing it won't work. */
log_fn(LOG_WARN,"Resolve requests to hidden services not allowed. Failing.");
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL);
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL,-1);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return -1;
}
......@@ -1299,16 +1308,17 @@ void
connection_ap_handshake_socks_resolved(connection_t *conn,
int answer_type,
size_t answer_len,
const char *answer)
const char *answer,
int ttl)
{
char buf[256];
size_t replylen;
if (answer_type == RESOLVED_TYPE_IPV4) {
uint32_t a = get_uint32(answer);
uint32_t a = ntohl(get_uint32(answer));
if (a)
client_dns_set_addressmap(conn->socks_request->address, ntohl(a),
conn->chosen_exit_name);
conn->chosen_exit_name, ttl);
}
if (conn->socks_request->socks_version == 4) {
......@@ -1581,7 +1591,6 @@ connection_exit_begin_resolve(cell_t *cell, circuit_t *circ)
void
connection_exit_connect(connection_t *conn)
{
char connected_payload[4];
uint32_t addr;
uint16_t port;
......@@ -1649,10 +1658,13 @@ connection_exit_connect(connection_t *conn)
NULL, 0, conn->cpath_layer);
} else { /* normal stream */
/* This must be the original address, not the redirected address. */
*(uint32_t*)connected_payload = htonl(conn->addr);
char connected_payload[8];
set_uint32(connected_payload, htonl(htonl(conn->addr)));
set_uint32(connected_payload+4,
htonl(MAX_DNS_ENTRY_AGE)); /* XXXX fill with a real TTL */
connection_edge_send_command(conn, circuit_get_by_edge_conn(conn),
RELAY_COMMAND_CONNECTED,
connected_payload, 4, conn->cpath_layer);
connected_payload, 8, conn->cpath_layer);
}
}
......
......@@ -192,14 +192,21 @@ send_resolved_cell(connection_t *conn, uint8_t answer_type)
case RESOLVED_TYPE_IPV4:
buf[1] = 4;
set_uint32(buf+2, htonl(conn->addr));
buflen = 6;
set_uint32(buf+6, htonl(MAX_DNS_ENTRY_AGE)); /*XXXX send a real TTL*/
buflen = 10;
break;
case RESOLVED_TYPE_ERROR_TRANSIENT:
case RESOLVED_TYPE_ERROR:
buf[1] = 24; /* length of "error resolving hostname" */
strlcpy(buf+2, "error resolving hostname", sizeof(buf)-2);
buflen = 26;
{
const char *errmsg = "Error resolving hostname";
int msglen = strlen(errmsg);
int ttl = (answer_type == RESOLVED_TYPE_ERROR ? MAX_DNS_ENTRY_AGE : 0);
buf[1] = msglen;
strlcpy(buf+2, errmsg, sizeof(buf)-2);
set_uint32(buf+2+msglen, htonl((uint32_t)ttl));
buflen = 6+msglen;
break;
}
default:
tor_assert(0);
}
......
......@@ -640,14 +640,19 @@ connection_edge_process_end_not_open(
case END_STREAM_REASON_EXITPOLICY:
if (rh->length >= 5) {
uint32_t addr = ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+1));
int ttl;
if (!addr) {
log_fn(LOG_INFO,"Address '%s' resolved to 0.0.0.0. Closing,",
safe_str(conn->socks_request->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return 0;
}
if (rh->length >= 9)
ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+5));
else
ttl = -1;
client_dns_set_addressmap(conn->socks_request->address, addr,
conn->chosen_exit_name);
conn->chosen_exit_name, ttl);
}
/* check if he *ought* to have allowed it */
if (exitrouter &&
......@@ -735,14 +740,19 @@ connection_edge_process_relay_cell_not_open(
(int)(time(NULL) - conn->timestamp_lastread));
if (rh->length >= 4) {
uint32_t addr = ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE));
int ttl;
if (!addr) {
log_fn(LOG_INFO,"...but it claims the IP address was 0.0.0.0. Closing.");
connection_edge_end(conn, END_STREAM_REASON_TORPROTOCOL, conn->cpath_layer);
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return 0;
}
if (rh->length >= 8)
ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+8));
else
ttl = -1;
client_dns_set_addressmap(conn->socks_request->address, addr,
conn->chosen_exit_name);
conn->chosen_exit_name, ttl);
}
circuit_log_path(LOG_INFO,circ);
connection_ap_handshake_socks_reply(conn, NULL, 0, SOCKS5_SUCCEEDED);
......@@ -755,20 +765,28 @@ connection_edge_process_relay_cell_not_open(
return 0;
}
if (conn->type == CONN_TYPE_AP && rh->command == RELAY_COMMAND_RESOLVED) {
int ttl;
int answer_len;
if (conn->state != AP_CONN_STATE_RESOLVE_WAIT) {
log_fn(LOG_WARN,"Got a 'resolved' cell while not in state resolve_wait. Dropping.");
return 0;
}
tor_assert(conn->socks_request->command == SOCKS_COMMAND_RESOLVE);
if (rh->length < 2 || cell->payload[RELAY_HEADER_SIZE+1]+2>rh->length) {
answer_len = cell->payload[RELAY_HEADER_SIZE+1];
if (rh->length < 2 || answer_len+2>rh->length) {
log_fn(LOG_WARN, "Dropping malformed 'resolved' cell");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return 0;
}
if (rh->length >= answer_len+6)
ttl = (int)ntohl(get_uint32(cell->payload+RELAY_HEADER_SIZE+6));
else
ttl = -1;
connection_ap_handshake_socks_resolved(conn,
cell->payload[RELAY_HEADER_SIZE], /*answer_type*/
cell->payload[RELAY_HEADER_SIZE+1], /*answer_len*/
cell->payload+RELAY_HEADER_SIZE+2); /* answer */
cell->payload+RELAY_HEADER_SIZE+2,
ttl); /* answer */
connection_mark_unattached_ap(conn, END_STREAM_REASON_ALREADY_SOCKS_REPLIED);
return 0;
}
......
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