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Write unittests to check basic vanguard path selection. 

Adds two unittests:
- First checks the path selection of basic Tor circs.
- Second checks the path selection of vanguard circs.

There is a TODO on the second unittest that we might want to test sooner than
later, but it's not trivial to do it right now.

To do these unittests we needed the following mods:
- Make some functions STATIC.
- Add some more fields to the big fake network nodes of test_entrynodes.c
- Switch fake node nicknames to base32 (because base64 does not produce valid nicknames).
This commit is contained in:
George Kadianakis 2018-04-27 15:27:17 +03:00 committed by Mike Perry
parent 98dea0bc63
commit 627d2fdbf0
3 changed files with 199 additions and 16 deletions
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7
src/or/circuitbuild.c
View File

@ -72,10 +72,7 @@ static channel_t * channel_connect_for_circuit(const tor_addr_t *addr,
static int circuit_deliver_create_cell(circuit_t *circ,
const create_cell_t *create_cell,
int relayed);
static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit,
int is_hs_v3_rp_circuit);
static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath);
static int onion_extend_cpath(origin_circuit_t *circ);
STATIC int onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice);
static int circuit_send_first_onion_skin(origin_circuit_t *circ);
static int circuit_build_no_more_hops(origin_circuit_t *circ);
@ -2285,7 +2282,7 @@ warn_if_last_router_excluded(origin_circuit_t *circ,
* be used as an HS v3 rendezvous point.
*
* Return 0 if ok, -1 if circuit should be closed. */
static int
STATIC int
onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei,
int is_hs_v3_rp_circuit)
{
@ -2719,7 +2716,7 @@ onion_next_hop_in_cpath(crypt_path_t *cpath)
* Return 1 if the path is complete, 0 if we successfully added a hop,
* and -1 on error.
*/
static int
STATIC int
onion_extend_cpath(origin_circuit_t *circ)
{
uint8_t purpose = circ->base_.purpose;

7
src/or/circuitbuild.h
View File

@ -83,6 +83,13 @@ STATIC circid_t get_unique_circ_id_by_chan(channel_t *chan);
STATIC int new_route_len(uint8_t purpose, extend_info_t *exit_ei,
smartlist_t *nodes);
MOCK_DECL(STATIC int, count_acceptable_nodes, (smartlist_t *nodes));
STATIC int onion_extend_cpath(origin_circuit_t *circ);
STATIC int
onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei,
int is_hs_v3_rp_circuit);
#if defined(ENABLE_TOR2WEB_MODE) || defined(TOR_UNIT_TESTS)
STATIC const node_t *pick_tor2web_rendezvous_node(router_crn_flags_t flags,
const or_options_t *options);

201
src/test/test_entrynodes.c
View File

@ -4,6 +4,7 @@
#include "orconfig.h"
#define CIRCUITLIST_PRIVATE
#define CIRCUITBUILD_PRIVATE
#define STATEFILE_PRIVATE
#define ENTRYNODES_PRIVATE
#define ROUTERLIST_PRIVATE
@ -14,6 +15,7 @@
#include "bridges.h"
#include "circuitlist.h"
#include "circuitbuild.h"
#include "config.h"
#include "confparse.h"
#include "directory.h"
@ -74,6 +76,17 @@ bfn_mock_node_get_by_id(const char *id)
return NULL;
}
/* Helper function to free a test node. */
static void
test_node_free(node_t *n)
{
tor_free(n->rs);
tor_free(n->md->onion_curve25519_pkey);
short_policy_free(n->md->exit_policy);
tor_free(n->md);
tor_free(n);
}
/* Unittest cleanup function: Cleanup the fake network. */
static int
big_fake_network_cleanup(const struct testcase_t *testcase, void *ptr)
@ -83,9 +96,7 @@ big_fake_network_cleanup(const struct testcase_t *testcase, void *ptr)
if (big_fake_net_nodes) {
SMARTLIST_FOREACH(big_fake_net_nodes, node_t *, n, {
tor_free(n->rs);
tor_free(n->md);
tor_free(n);
test_node_free(n);
});
smartlist_free(big_fake_net_nodes);
}
@ -113,9 +124,18 @@ big_fake_network_setup(const struct testcase_t *testcase)
big_fake_net_nodes = smartlist_new();
for (i = 0; i < N_NODES; ++i) {
curve25519_secret_key_t curve25519_secret_key;
node_t *n = tor_malloc_zero(sizeof(node_t));
n->md = tor_malloc_zero(sizeof(microdesc_t));
/* Generate curve25519 key for this node */
n->md->onion_curve25519_pkey =
tor_malloc_zero(sizeof(curve25519_public_key_t));
curve25519_secret_key_generate(&curve25519_secret_key, 0);
curve25519_public_key_generate(n->md->onion_curve25519_pkey,
&curve25519_secret_key);
crypto_rand(n->identity, sizeof(n->identity));
n->rs = tor_malloc_zero(sizeof(routerstatus_t));
@ -135,8 +155,8 @@ big_fake_network_setup(const struct testcase_t *testcase)
{
char nickname_binary[8];
crypto_rand(nickname_binary, sizeof(nickname_binary));
base64_encode(n->rs->nickname, sizeof(n->rs->nickname),
nickname_binary, sizeof(nickname_binary), 0);
base32_encode(n->rs->nickname, sizeof(n->rs->nickname),
nickname_binary, sizeof(nickname_binary));
}
/* Call half of the nodes a possible guard. */
@ -144,6 +164,12 @@ big_fake_network_setup(const struct testcase_t *testcase)
n->is_possible_guard = 1;
n->rs->guardfraction_percentage = 100;
n->rs->has_guardfraction = 1;
n->rs->is_possible_guard = 1;
}
/* Make some of these nodes a possible exit */
if (i % 7 == 0) {
n->md->exit_policy = parse_short_policy("accept 443");
}
smartlist_add(big_fake_net_nodes, n);
@ -1075,9 +1101,7 @@ test_entry_guard_expand_sample_small_net(void *arg)
/* Fun corner case: not enough guards to make up our whole sample size. */
SMARTLIST_FOREACH(big_fake_net_nodes, node_t *, n, {
if (n_sl_idx >= 15) {
tor_free(n->rs);
tor_free(n->md);
tor_free(n);
test_node_free(n);
SMARTLIST_DEL_CURRENT(big_fake_net_nodes, n);
} else {
n->rs->addr = 0; // make the filter reject this.
@ -1171,9 +1195,7 @@ test_entry_guard_update_from_consensus_status(void *arg)
entry_guard_t *g = smartlist_get(gs->sampled_entry_guards, 5);
node_t *n = (node_t*) bfn_mock_node_get_by_id(g->identity);
smartlist_remove(big_fake_net_nodes, n);
tor_free(n->rs);
tor_free(n->md);
tor_free(n);
test_node_free(n);
}
update_approx_time(start + 300);
sampled_guards_update_from_consensus(gs);
@ -2787,6 +2809,161 @@ test_entry_guard_outdated_dirserver_exclusion(void *arg)
}
}
/** Test helper to extend the <b>oc</b> circuit path <b>n</b> times and then
* ensure that the circuit is now complete. */
static void
helper_extend_circuit_path_n_times(origin_circuit_t *oc, int n)
{
int retval;
int i;
/* Extend path n times */
for (i = 0 ; i < n ; i++) {
retval = onion_extend_cpath(oc);
tt_int_op(retval, OP_EQ, 0);
tt_int_op(circuit_get_cpath_len(oc), OP_EQ, i+1);
}
/* Now do it one last time and see that circ is complete */
retval = onion_extend_cpath(oc);
tt_int_op(retval, OP_EQ, 1);
done:
;
}
/** Test for basic Tor path selection. Makes sure we build 3-hop circuits. */
static void
test_entry_guard_basic_path_selection(void *arg)
{
(void) arg;
int retval;
/* Enable entry guards */
or_options_t *options = get_options_mutable();
options->UseEntryGuards = 1;
/* disables /16 check since all nodes have the same addr... */
options->EnforceDistinctSubnets = 0;
/* Create our circuit */
circuit_t *circ = dummy_origin_circuit_new(30);
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ);
oc->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));
/* First pick the exit and pin it on the build_state */
retval = onion_pick_cpath_exit(oc, NULL, 0);
tt_int_op(retval, OP_EQ, 0);
/* Extend path 3 times. First we pick guard, then middle, then exit. */
helper_extend_circuit_path_n_times(oc, 3);
done:
circuit_free_(circ);
}
/** Test helper to build an L2 and L3 vanguard list. The vanguard lists
* produced should be completely disjoint. */
static void
helper_setup_vanguard_list(or_options_t *options)
{
int i = 0;
/* Add some nodes to the vanguard L2 list */
options->HSLayer2Nodes = routerset_new();
for (i = 0; i < 10 ; i += 2) {
node_t *vanguard_node = smartlist_get(big_fake_net_nodes, i);
tt_assert(vanguard_node->is_possible_guard);
routerset_parse(options->HSLayer2Nodes, vanguard_node->rs->nickname, "l2");
}
/* also add some nodes to vanguard L3 list
* (L2 list and L3 list should be disjoint for this test to work) */
options->HSLayer3Nodes = routerset_new();
for (i = 10; i < 20 ; i += 2) {
node_t *vanguard_node = smartlist_get(big_fake_net_nodes, i);
tt_assert(vanguard_node->is_possible_guard);
routerset_parse(options->HSLayer3Nodes, vanguard_node->rs->nickname, "l3");
}
done:
;
}
/** Test to ensure that vanguard path selection works properly. Ensures that
* default vanguard circuits are 4 hops, and that path selection works
* correctly given the vanguard settings. */
static void
test_entry_guard_vanguard_path_selection(void *arg)
{
(void) arg;
int retval;
/* Enable entry guards */
or_options_t *options = get_options_mutable();
options->UseEntryGuards = 1;
/* XXX disables /16 check */
options->EnforceDistinctSubnets = 0;
/* Setup our vanguard list */
helper_setup_vanguard_list(options);
/* Create our circuit */
circuit_t *circ = dummy_origin_circuit_new(30);
origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(circ);
oc->build_state = tor_malloc_zero(sizeof(cpath_build_state_t));
oc->build_state->is_internal = 1;
/* Switch circuit purpose to vanguards */
circ->purpose = CIRCUIT_PURPOSE_HS_VANGUARDS;
/* First pick the exit and pin it on the build_state */
tt_int_op(oc->build_state->desired_path_len, OP_EQ, 0);
retval = onion_pick_cpath_exit(oc, NULL, 0);
tt_int_op(retval, OP_EQ, 0);
/* Ensure that vanguards make 4-hop circuits by default */
tt_int_op(oc->build_state->desired_path_len, OP_EQ, 4);
/* Extend path as many times as needed to have complete circ. */
helper_extend_circuit_path_n_times(oc, oc->build_state->desired_path_len);
/* Test that the cpath linked list is set correctly. */
crypt_path_t *l1_node = oc->cpath;
crypt_path_t *l2_node = l1_node->next;
crypt_path_t *l3_node = l2_node->next;
crypt_path_t *l4_node = l3_node->next;
crypt_path_t *l1_node_again = l4_node->next;
tt_ptr_op(l1_node, OP_EQ, l1_node_again);
/* Test that L2 is indeed HSLayer2Node */
retval = routerset_contains_extendinfo(options->HSLayer2Nodes,
l2_node->extend_info);
tt_int_op(retval, OP_EQ, 4);
/* test that L3 node is _not_ contained in HSLayer2Node */
retval = routerset_contains_extendinfo(options->HSLayer2Nodes,
l3_node->extend_info);
tt_int_op(retval, OP_LT, 4);
/* Test that L3 is indeed HSLayer3Node */
retval = routerset_contains_extendinfo(options->HSLayer3Nodes,
l3_node->extend_info);
tt_int_op(retval, OP_EQ, 4);
/* test that L2 node is _not_ contained in HSLayer3Node */
retval = routerset_contains_extendinfo(options->HSLayer3Nodes,
l2_node->extend_info);
tt_int_op(retval, OP_LT, 4);
/* TODO: Test that L1 can be the same as exit. To test this we need start
enforcing EnforceDistinctSubnets again, which means that we need to give
each test node a different address which currently breaks some tests. */
done:
circuit_free_(circ);
}
static const struct testcase_setup_t big_fake_network = {
big_fake_network_setup, big_fake_network_cleanup
};
@ -2848,6 +3025,8 @@ struct testcase_t entrynodes_tests[] = {
BFN_TEST(select_and_cancel),
BFN_TEST(drop_guards),
BFN_TEST(outdated_dirserver_exclusion),
BFN_TEST(basic_path_selection),
BFN_TEST(vanguard_path_selection),
UPGRADE_TEST(upgrade_a_circuit, "c1-done c2-done"),
UPGRADE_TEST(upgrade_blocked_by_live_primary_guards, "c1-done c2-done"),