src/test/resolve_test_helpers.c

   1 /* Copyright (c) 2001 Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2020, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 /**
   8  * @file resolve_test_helpers.c
   9  * @brief Helper functions for mocking libc's blocking hostname lookup
  10  *   facilities.
  11  **/
  12
  13 #define RESOLVE_PRIVATE
  14 #include "orconfig.h"
  15 #include "test/resolve_test_helpers.h"
  16 #include "lib/net/address.h"
  17 #include "lib/net/resolve.h"
  18 #include "test/test.h"
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22
  23 /**
  24  * Mock replacement for our getaddrinfo/gethostbyname wrapper.
  25  **/
  26 static int
  27 replacement_host_lookup(const char *name, uint16_t family, tor_addr_t *addr)
  28 {
  29   static const struct lookup_table_ent {
  30     const char *name;
  31     const char *ipv4;
  32     const char *ipv6;
  33   } entries[] = {
  34     { "localhost", "127.0.0.1", "::1" },
  35     { "torproject.org", "198.51.100.6", "2001:DB8::700" },
  36     { NULL, NULL, NULL },
  37   };
  38
  39   int r = -1;
  40
  41   for (unsigned i = 0; entries[i].name != NULL; ++i) {
  42     if (!strcasecmp(name, entries[i].name)) {
  43       if (family == AF_INET6) {
  44         int s = tor_addr_parse(addr, entries[i].ipv6);
  45         tt_int_op(s, OP_EQ, AF_INET6);
  46       } else {
  47         int s = tor_addr_parse(addr, entries[i].ipv4);
  48         tt_int_op(s, OP_EQ, AF_INET);
  49       }
  50       r = 0;
  51       break;
  52     }
  53   }
  54
  55   log_debug(LD_GENERAL, "resolve(%s,%d) => %s",
  56             name, family, r == 0 ? fmt_addr(addr) : "-1");
  57
  58   return r;
  59  done:
  60   return -1;
  61 }
  62
  63 /**
  64  * Set up a mock replacement for our wrapper on libc's resolver code.
  65  *
  66  * According to our replacement, only "localhost" and "torproject.org"
  67  * are real addresses; everything else doesn't exist.
  68  *
  69  * Use this function to avoid using the DNS resolver during unit tests;
  70  * call unmock_hostname_resolver() when you're done.
  71  **/
  72 void
  73 mock_hostname_resolver(void)
  74 {
  75   MOCK(tor_addr_lookup_host_impl, replacement_host_lookup);
  76 }
  77
  78 /**
  79  * Unmock our wrappers for libc's blocking hostname resolver code.
  80  **/
  81 void
  82 unmock_hostname_resolver(void)
  83 {
  84   UNMOCK(tor_addr_lookup_host_impl);
  85 }