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

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Add 'flags' argument to begin cells, per proposal 208.
This commit is contained in:
Nick Mathewson 2012-10-22 11:28:37 -04:00
parent ca8843df0a
commit 462ebb270a
5 changed files with 330 additions and 27 deletions
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105
src/or/connection_edge.c
View File

@ -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 ||

15
src/or/connection_edge.h
View File

@ -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

1
src/test/include.am
View File

@ -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 \

2
src/test/test.c
View File

@ -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 },

234
src/test/test_cell_formats.c Normal file
View File

@ -0,0 +1,234 @@
/* 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
};