commit 4a0749596cc21198dd853bb0c631e9658db7fe2d Author: Nick Mathewson <nickm@torproject.org> Date: Thu Oct 3 08:54:17 2019 -0400 Add a mock replacement for blocking hostname resolution Based on examination of our tests, this mock function accepts "localhost" and "torproject.org", and rejects everything else. --- src/test/include.am | 2 + src/test/resolve_test_helpers.c | 85 +++++++++++++++++++++++++++++++++++++++++ src/test/resolve_test_helpers.h | 18 +++++++++ 3 files changed, 105 insertions(+) diff --git a/src/test/include.am b/src/test/include.am index 2dd4d8c58..acd0824d0 100644 --- a/src/test/include.am +++ b/src/test/include.am @@ -102,6 +102,7 @@ src_test_test_SOURCES += \ src/test/log_test_helpers.c \ src/test/hs_test_helpers.c \ src/test/rend_test_helpers.c \ + src/test/resolve_test_helpers.c \ src/test/rng_test_helpers.c \ src/test/test.c \ src/test/test_accounting.c \ @@ -340,6 +341,7 @@ noinst_HEADERS+= \ src/test/hs_test_helpers.h \ src/test/log_test_helpers.h \ src/test/rend_test_helpers.h \ + src/test/resolve_test_helpers.h \ src/test/rng_test_helpers.h \ src/test/test.h \ src/test/ptr_helpers.h \ diff --git a/src/test/resolve_test_helpers.c b/src/test/resolve_test_helpers.c new file mode 100644 index 000000000..73ea73014 --- /dev/null +++ b/src/test/resolve_test_helpers.c @@ -0,0 +1,85 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * @file resolve_test_helpers.c + * @brief Helper functions for mocking libc's blocking hostname lookup + * facilities. + **/ + +#define RESOLVE_PRIVATE +#include "orconfig.h" +#include "test/resolve_test_helpers.h" +#include "lib/net/address.h" +#include "lib/net/resolve.h" +#include "test/test.h" + +#include <stdio.h> +#include <string.h> + +/** + * Mock replacement for our getaddrinfo/gethostbyname wrapper. + **/ +static int +replacement_host_lookup(const char *name, uint16_t family, tor_addr_t *addr) +{ + static const struct lookup_table_ent { + const char *name; + const char *ipv4; + const char *ipv6; + } entries[] = { + { "localhost", "127.0.0.1", "::1" }, + { "torproject.org", "198.51.100.6", "2001:DB8::700" }, + { NULL, NULL, NULL }, + }; + + int r = -1; + + for (unsigned i = 0; entries[i].name != NULL; ++i) { + if (!strcasecmp(name, entries[i].name)) { + if (family == AF_INET6) { + int s = tor_addr_parse(addr, entries[i].ipv6); + tt_int_op(s, OP_EQ, AF_INET6); + } else { + int s = tor_addr_parse(addr, entries[i].ipv4); + tt_int_op(s, OP_EQ, AF_INET); + } + r = 0; + break; + } + } + + log_debug(LD_GENERAL, "resolve(%s,%d) => %s", + name, family, r == 0 ? fmt_addr(addr) : "-1"); + + return r; + done: + return -1; +} + +/** + * Set up a mock replacement for our wrapper on libc's resolver code. + * + * According to our replacement, only "localhost" and "torproject.org" + * are real addresses; everything else doesn't exist. + * + * Use this function to avoid using the DNS resolver during unit tests; + * call unmock_hostname_resolver() when you're done. + **/ +void +mock_hostname_resolver(void) +{ + MOCK(tor_addr_lookup_host_impl, replacement_host_lookup); +} + +/** + * Unmock our wrappers for libc's blocking hostname resolver code. + **/ +void +unmock_hostname_resolver(void) +{ + UNMOCK(tor_addr_lookup_host_impl); +} diff --git a/src/test/resolve_test_helpers.h b/src/test/resolve_test_helpers.h new file mode 100644 index 000000000..e7d2e2937 --- /dev/null +++ b/src/test/resolve_test_helpers.h @@ -0,0 +1,18 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * @file resolve_test_helpers.h + * @brief Header for test/resolve_test_helpers.c + **/ + +#ifndef TOR_TEST_RESOLVE_TEST_HELPERS_H +#define TOR_TEST_RESOLVE_TEST_HELPERS_H + +void mock_hostname_resolver(void); +void unmock_hostname_resolver(void); + +#endif /* !defined(TOR_TEST_RESOLVE_TEST_HELPERS_H) */