commit c3c2b55decc80028728780422fe2766ec6517246 Author: George Kadianakis desnacked@riseup.net Date: Thu Jan 25 16:38:59 2018 -0500

test: Add unit tests for the DoS subsystem

Signed-off-by: David Goulet dgoulet@torproject.org --- src/or/channel.c | 4 +- src/or/channel.h | 3 +- src/test/include.am | 1 + src/test/test.c | 1 + src/test/test.h | 1 + src/test/test_dos.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 255 insertions(+), 3 deletions(-)

diff --git a/src/or/channel.c b/src/or/channel.c index fdd3f81e8..54e10666d 100644 --- a/src/or/channel.c +++ b/src/or/channel.c @@ -3845,8 +3845,8 @@ channel_get_canonical_remote_descr(channel_t *chan) * supports this operation, and return 1. Return 0 if the underlying transport * doesn't let us do this. */ -int -channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out) +MOCK_IMPL(int, +channel_get_addr_if_possible,(channel_t *chan, tor_addr_t *addr_out)) { tor_assert(chan); tor_assert(addr_out); diff --git a/src/or/channel.h b/src/or/channel.h index a711b56d4..bcd345e8d 100644 --- a/src/or/channel.h +++ b/src/or/channel.h @@ -550,7 +550,8 @@ MOCK_DECL(void, channel_dump_statistics, (channel_t *chan, int severity)); void channel_dump_transport_statistics(channel_t *chan, int severity); const char * channel_get_actual_remote_descr(channel_t *chan); const char * channel_get_actual_remote_address(channel_t *chan); -int channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out); +MOCK_DECL(int, channel_get_addr_if_possible, (channel_t *chan, + tor_addr_t *addr_out)); const char * channel_get_canonical_remote_descr(channel_t *chan); int channel_has_queued_writes(channel_t *chan); int channel_is_bad_for_new_circs(channel_t *chan); diff --git a/src/test/include.am b/src/test/include.am index 8ecfaf10c..91b0a5910 100644 --- a/src/test/include.am +++ b/src/test/include.am @@ -87,6 +87,7 @@ src_test_test_SOURCES = \ src/test/test_controller.c \ src/test/test_controller_events.c \ src/test/test_crypto.c \ + src/test/test_dos.c \ src/test/test_data.c \ src/test/test_dir.c \ src/test/test_dir_common.c \ diff --git a/src/test/test.c b/src/test/test.c index 9a41b976b..f66dee2d0 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -1197,6 +1197,7 @@ struct testgroup_t testgroups[] = { { "control/", controller_tests }, { "control/event/", controller_event_tests }, { "crypto/", crypto_tests }, + { "dos/", dos_tests }, { "dir/", dir_tests }, { "dir_handle_get/", dir_handle_get_tests }, { "dir/md/", microdesc_tests }, diff --git a/src/test/test.h b/src/test/test.h index 25336ac83..41df6b134 100644 --- a/src/test/test.h +++ b/src/test/test.h @@ -190,6 +190,7 @@ extern struct testcase_t container_tests[]; extern struct testcase_t controller_tests[]; extern struct testcase_t controller_event_tests[]; extern struct testcase_t crypto_tests[]; +extern struct testcase_t dos_tests[]; extern struct testcase_t dir_tests[]; extern struct testcase_t dir_handle_get_tests[]; extern struct testcase_t entryconn_tests[]; diff --git a/src/test/test_dos.c b/src/test/test_dos.c new file mode 100644 index 000000000..5a8474ad8 --- /dev/null +++ b/src/test/test_dos.c @@ -0,0 +1,248 @@ +/* Copyright (c) 2018, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +#define DOS_PRIVATE +#define TOR_CHANNEL_INTERNAL_ +#define CIRCUITLIST_PRIVATE + +#include "or.h" +#include "dos.h" +#include "circuitlist.h" +#include "geoip.h" +#include "channel.h" +#include "test.h" +#include "log_test_helpers.h" + +static unsigned int +mock_enable_dos_protection(const networkstatus_t *ns) +{ + (void) ns; + return 1; +} + +/** Test that the connection tracker of the DoS subsystem will block clients + * who try to establish too many connections */ +static void +test_dos_conn_creation(void *arg) +{ + (void) arg; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + + /* Initialize test data */ + or_connection_t or_conn; + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Get DoS subsystem limits */ + dos_init(); + uint32_t max_concurrent_conns = get_param_conn_max_concurrent_count(NULL); + + /* Introduce new client */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + { /* Register many conns from this client but not enough to get it blocked */ + unsigned int i; + for (i = 0; i < max_concurrent_conns; i++) { + dos_new_client_conn(&or_conn); + } + } + + /* Check that new conns are still permitted */ + tt_int_op(DOS_CONN_DEFENSE_NONE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Register another conn and check that new conns are not allowed anymore */ + dos_new_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Close a client conn and see that a new conn will be permitted again */ + dos_close_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_NONE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + /* Register another conn and see that defense measures get reactivated */ + dos_new_client_conn(&or_conn); + tt_int_op(DOS_CONN_DEFENSE_CLOSE, OP_EQ, + dos_conn_addr_get_defense_type(addr)); + + done: + dos_free_all(); +} + +/** Helper mock: Place a fake IP addr for this channel in <b>addr_out</b> */ +static int +mock_channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out) +{ + (void)chan; + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(addr_out, "18.0.0.1"));; + return 1; + + done: + return 0; +} + +/** Test that the circuit tracker of the DoS subsystem will block clients who + * try to establish too many circuits. */ +static void +test_dos_circuit_creation(void *arg) +{ + (void) arg; + unsigned int i; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + MOCK(channel_get_addr_if_possible, + mock_channel_get_addr_if_possible); + + /* Initialize channels/conns/circs that will be used */ + channel_t *chan = tor_malloc_zero(sizeof(channel_t)); + channel_init(chan); + chan->is_client = 1; + + /* Initialize test data */ + or_connection_t or_conn; + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Get DoS subsystem limits */ + dos_init(); + uint32_t max_circuit_count = get_param_cc_circuit_burst(NULL); + uint32_t min_conc_conns_for_cc = + get_param_cc_min_concurrent_connection(NULL); + + /* Introduce new client and establish enough connections to activate the + * circuit counting subsystem */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + for (i = 0; i < min_conc_conns_for_cc ; i++) { + dos_new_client_conn(&or_conn); + } + + /* Register new circuits for this client and conn, but not enough to get + * detected as dos */ + for (i=0; i < max_circuit_count-1; i++) { + dos_cc_new_create_cell(chan); + } + /* see that we didn't get detected for dosing */ + tt_int_op(DOS_CC_DEFENSE_NONE, OP_EQ, dos_cc_get_defense_type(chan)); + + /* Register another CREATE cell that will push us over the limit. Check that + * the cell gets refused. */ + dos_cc_new_create_cell(chan); + tt_int_op(DOS_CC_DEFENSE_REFUSE_CELL, OP_EQ, dos_cc_get_defense_type(chan)); + + /* TODO: Wait a few seconds before sending the cell, and check that the + buckets got refilled properly. */ + /* TODO: Actually send a Tor cell (instead of calling the DoS function) and + * check that it will get refused */ + + done: + tor_free(chan); + dos_free_all(); +} + +/** Test that the DoS subsystem properly refills the circuit token buckets. */ +static void +test_dos_bucket_refill(void *arg) +{ + (void) arg; + int i; + /* For this test, this variable is set to the current circ count of the token + * bucket. */ + uint32_t current_circ_count; + + MOCK(get_param_cc_enabled, mock_enable_dos_protection); + MOCK(get_param_conn_enabled, mock_enable_dos_protection); + MOCK(channel_get_addr_if_possible, + mock_channel_get_addr_if_possible); + + time_t now = 1281533250; /* 2010-08-11 13:27:30 UTC */ + update_approx_time(now); + + /* Initialize channels/conns/circs that will be used */ + channel_t *chan = tor_malloc_zero(sizeof(channel_t)); + channel_init(chan); + chan->is_client = 1; + or_connection_t or_conn; + tt_int_op(AF_INET,OP_EQ, tor_addr_parse(&or_conn.real_addr, + "18.0.0.1")); + tor_addr_t *addr = &or_conn.real_addr; + + /* Initialize DoS subsystem and get relevant limits */ + dos_init(); + uint32_t max_circuit_count = get_param_cc_circuit_burst(NULL); + int circ_rate = tor_lround(get_circuit_rate_per_second()); + /* Check that the circuit rate is a positive number and smaller than the max + * circuit count */ + tt_int_op(circ_rate, OP_GT, 1); + tt_int_op(circ_rate, OP_LT, max_circuit_count); + + /* Register this client */ + geoip_note_client_seen(GEOIP_CLIENT_CONNECT, addr, NULL, now); + dos_new_client_conn(&or_conn); + + /* Fetch this client from the geoip cache and get its DoS structs */ + clientmap_entry_t *entry = geoip_lookup_client(addr, NULL, + GEOIP_CLIENT_CONNECT); + tt_assert(entry); + dos_client_stats_t* dos_stats = &entry->dos_stats; + /* Check that the circuit bucket is still uninitialized */ + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, 0); + + /* Send a create cell: then check that the circ token bucket got initialized + * and one circ was subtracted. */ + dos_cc_new_create_cell(chan); + current_circ_count = max_circuit_count - 1; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send 29 more CREATEs and ensure that the bucket is missing 30 + * tokens */ + for (i=0; i < 29; i++) { + dos_cc_new_create_cell(chan); + current_circ_count--; + } + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* OK! Progress time forward one sec, refill the bucket and check that the + * refill happened correctly. */ + now += 1; + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + /* check refill */ + current_circ_count += circ_rate; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now send as many CREATE cells as needed to deplete our token bucket + * completely */ + for (; current_circ_count != 0; current_circ_count--) { + dos_cc_new_create_cell(chan); + } + tt_uint_op(current_circ_count, OP_EQ, 0); + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + /* Now progress time a week forward, and check that the token bucket does not + * have more than max_circs allowance, even tho we let it simmer for so + * long. */ + now += 604800; /* a week */ + update_approx_time(now); + cc_stats_refill_bucket(&dos_stats->cc_stats, addr); + current_circ_count += max_circuit_count; + tt_uint_op(dos_stats->cc_stats.circuit_bucket, OP_EQ, current_circ_count); + + done: + tor_free(chan); + dos_free_all(); +} + +struct testcase_t dos_tests[] = { + { "conn_creation", test_dos_conn_creation, TT_FORK, NULL, NULL }, + { "circuit_creation", test_dos_circuit_creation, TT_FORK, NULL, NULL }, + { "bucket_refill", test_dos_bucket_refill, TT_FORK, NULL, NULL }, + END_OF_TESTCASES +}; +