Commit 462ebb27 authored by Nick Mathewson's avatar Nick Mathewson
Browse files

Refactor begin cell parsing into its own function, with tests.

Add 'flags' argument to begin cells, per proposal 208.
parent ca8843df
......@@ -8,6 +8,7 @@
* \file connection_edge.c
* \brief Handle edge streams.
**/
#define CONNECTION_EDGE_PRIVATE
#include "or.h"
#include "addressmap.h"
......@@ -2059,6 +2060,64 @@ connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
return;
}
/* DOCDOC */
/* static */ int
begin_cell_parse(const cell_t *cell, begin_cell_t *bcell,
uint8_t *end_reason_out)
{
relay_header_t rh;
const uint8_t *body, *nul;
memset(bcell, 0, sizeof(*bcell));
*end_reason_out = END_STREAM_REASON_MISC;
relay_header_unpack(&rh, cell->payload);
if (rh.length > RELAY_PAYLOAD_SIZE) {
return -2; /*XXXX why not TORPROTOL? */
}
bcell->stream_id = rh.stream_id;
if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
bcell->is_begindir = 1;
return 0;
} else if (rh.command != RELAY_COMMAND_BEGIN) {
log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
*end_reason_out = END_STREAM_REASON_INTERNAL;
return -1;
}
body = cell->payload + RELAY_HEADER_SIZE;
nul = memchr(body, 0, rh.length);
if (! nul) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell has no \\0. Closing.");
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (tor_addr_port_split(LOG_PROTOCOL_WARN,
(char*)(body),
&bcell->address,&bcell->port)<0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Unable to parse addr:port in relay begin cell. Closing.");
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (bcell->port == 0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Missing port in relay begin cell. Closing.");
tor_free(bcell->address);
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (body + rh.length >= nul + 4)
bcell->flags = ntohl(get_uint32(nul+1));
return 0;
}
/** A relay 'begin' or 'begin_dir' cell has arrived, and either we are
* an exit hop for the circuit, or we are the origin and it is a
* rendezvous begin.
......@@ -2082,10 +2141,13 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
{
edge_connection_t *n_stream;
relay_header_t rh;
char *address=NULL;
uint16_t port;
char *address = NULL;
uint16_t port = 0;
or_circuit_t *or_circ = NULL;
const or_options_t *options = get_options();
begin_cell_t bcell;
int r;
uint8_t end_reason=0;
assert_circuit_ok(circ);
if (!CIRCUIT_IS_ORIGIN(circ))
......@@ -2109,31 +2171,20 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
return 0;
}
if (rh.command == RELAY_COMMAND_BEGIN) {
if (!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell has no \\0. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
return 0;
}
if (tor_addr_port_split(LOG_PROTOCOL_WARN,
(char*)(cell->payload+RELAY_HEADER_SIZE),
&address,&port)<0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Unable to parse addr:port in relay begin cell. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
return 0;
}
if (port==0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Missing port in relay begin cell. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
tor_free(address);
return 0;
}
r = begin_cell_parse(cell, &bcell, &end_reason);
if (r < -1) {
return -1;
} else if (r == -1) {
tor_free(bcell.address);
relay_send_end_cell_from_edge(rh.stream_id, circ, end_reason, NULL);
return 0;
}
if (! bcell.is_begindir) {
/* Steal reference */
address = bcell.address;
port = bcell.port;
if (or_circ && or_circ->p_chan) {
if (!options->AllowSingleHopExits &&
(or_circ->is_first_hop ||
......
......@@ -91,5 +91,20 @@ int connection_edge_update_circuit_isolation(const entry_connection_t *conn,
int dry_run);
void circuit_clear_isolation(origin_circuit_t *circ);
#ifdef CONNECTION_EDGE_PRIVATE
/*DOCDOC*/
typedef struct begin_cell_t {
char *address;
uint32_t flags;
uint16_t port;
uint16_t stream_id;
unsigned is_begindir : 1;
} begin_cell_t;
int begin_cell_parse(const cell_t *cell, begin_cell_t *bcell,
uint8_t *end_reason_out);
#endif
#endif
......@@ -14,6 +14,7 @@ src_test_AM_CPPFLAGS = -DSHARE_DATADIR="\"$(datadir)\"" \
src_test_test_SOURCES = \
src/test/test.c \
src/test/test_addr.c \
src/test/test_cell_formats.c \
src/test/test_containers.c \
src/test/test_crypto.c \
src/test/test_data.c \
......
......@@ -1983,6 +1983,7 @@ extern struct testcase_t pt_tests[];
extern struct testcase_t config_tests[];
extern struct testcase_t introduce_tests[];
extern struct testcase_t replaycache_tests[];
extern struct testcase_t cell_format_tests[];
static struct testgroup_t testgroups[] = {
{ "", test_array },
......@@ -1991,6 +1992,7 @@ static struct testgroup_t testgroups[] = {
{ "crypto/", crypto_tests },
{ "container/", container_tests },
{ "util/", util_tests },
{ "cellfmt/", cell_format_tests },
{ "dir/", dir_tests },
{ "dir/md/", microdesc_tests },
{ "pt/", pt_tests },
......
/* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2012, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "orconfig.h"
#define CONNECTION_EDGE_PRIVATE
#include "or.h"
#include "connection_edge.h"
#include "relay.h"
#include "test.h"
#include <stdlib.h>
#include <string.h>
static void
test_cfmt_relay_header(void *arg)
{
relay_header_t rh;
const uint8_t hdr_1[RELAY_HEADER_SIZE] =
"\x03" "\x00\x00" "\x21\x22" "ABCD" "\x01\x03";
uint8_t hdr_out[RELAY_HEADER_SIZE];
(void)arg;
tt_int_op(sizeof(hdr_1), ==, RELAY_HEADER_SIZE);
relay_header_unpack(&rh, hdr_1);
tt_int_op(rh.command, ==, 3);
tt_int_op(rh.recognized, ==, 0);
tt_int_op(rh.stream_id, ==, 0x2122);
test_mem_op(rh.integrity, ==, "ABCD", 4);
tt_int_op(rh.length, ==, 0x103);
relay_header_pack(hdr_out, &rh);
test_mem_op(hdr_out, ==, hdr_1, RELAY_HEADER_SIZE);
done:
;
}
static void
make_relay_cell(cell_t *out, uint8_t command,
const void *body, size_t bodylen)
{
relay_header_t rh;
memset(&rh, 0, sizeof(rh));
rh.stream_id = 5;
rh.command = command;
rh.length = bodylen;
out->command = CELL_RELAY;
out->circ_id = 10;
relay_header_pack(out->payload, &rh);
memcpy(out->payload + RELAY_HEADER_SIZE, body, bodylen);
}
static void
test_cfmt_begin_cells(void *arg)
{
cell_t cell;
begin_cell_t bcell;
uint8_t end_reason;
(void)arg;
/* Try begindir. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN_DIR, "", 0);
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_ptr_op(NULL, ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(0, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(1, ==, bcell.is_begindir);
/* A Begindir with extra stuff. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN_DIR, "12345", 5);
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_ptr_op(NULL, ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(0, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(1, ==, bcell.is_begindir);
/* A short but valid begin cell */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:9", 6);
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("a.b", ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(9, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* A significantly loner begin cell */
memset(&bcell, 0x7f, sizeof(bcell));
{
const char c[] = "here-is-a-nice-long.hostname.com:65535";
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, c, strlen(c)+1);
}
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("here-is-a-nice-long.hostname.com", ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(65535, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* An IPv4 begin cell. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "18.9.22.169:80", 15);
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("18.9.22.169", ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(80, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* An IPv6 begin cell. Let's make sure we handle colons*/
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN,
"[2620::6b0:b:1a1a:0:26e5:480e]:80", 34);
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("[2620::6b0:b:1a1a:0:26e5:480e]", ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(80, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* a begin cell with extra junk but not enough for flags. */
memset(&bcell, 0x7f, sizeof(bcell));
{
const char c[] = "another.example.com:80\x00\x01\x02";
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, c, sizeof(c)-1);
}
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("another.example.com", ==, bcell.address);
tt_int_op(0, ==, bcell.flags);
tt_int_op(80, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* a begin cell with flags. */
memset(&bcell, 0x7f, sizeof(bcell));
{
const char c[] = "another.example.com:443\x00\x01\x02\x03\x04";
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, c, sizeof(c)-1);
}
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("another.example.com", ==, bcell.address);
tt_int_op(0x1020304, ==, bcell.flags);
tt_int_op(443, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* a begin cell with flags and even more cruft after that. */
memset(&bcell, 0x7f, sizeof(bcell));
{
const char c[] = "a-further.example.com:22\x00\xee\xaa\x00\xffHi mom";
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, c, sizeof(c)-1);
}
tt_int_op(0, ==, begin_cell_parse(&cell, &bcell, &end_reason));
tt_str_op("a-further.example.com", ==, bcell.address);
tt_int_op(0xeeaa00ff, ==, bcell.flags);
tt_int_op(22, ==, bcell.port);
tt_int_op(5, ==, bcell.stream_id);
tt_int_op(0, ==, bcell.is_begindir);
tor_free(bcell.address);
/* bad begin cell: impossible length. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:80", 7);
cell.payload[9] = 0x01; /* Set length to 510 */
cell.payload[10] = 0xfe;
{
relay_header_t rh;
relay_header_unpack(&rh, cell.payload);
tt_int_op(rh.length, ==, 510);
}
tt_int_op(-2, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* Bad begin cell: no body. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "", 0);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* bad begin cell: no body. */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "", 0);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* bad begin cell: no colon */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b", 4);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* bad begin cell: no ports */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:", 5);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* bad begin cell: bad port */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:xyz", 8);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:100000", 11);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
/* bad begin cell: no nul */
memset(&bcell, 0x7f, sizeof(bcell));
make_relay_cell(&cell, RELAY_COMMAND_BEGIN, "a.b:80", 6);
tt_int_op(-1, ==, begin_cell_parse(&cell, &bcell, &end_reason));
done:
tor_free(bcell.address);
}
#define TEST(name, flags) \
{ #name, test_cfmt_ ## name, flags, 0, NULL }
struct testcase_t cell_format_tests[] = {
TEST(relay_header, 0),
TEST(begin_cells, 0),
END_OF_TESTCASES
};
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