resolv/tst-resolv-rotate.c

   1 /* Check that RES_ROTATE works with few nameserver entries (bug 13028).
   2    Copyright (C) 2017-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <netdb.h>
  20 #include <resolv.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <support/check.h>
  24 #include <support/check_nss.h>
  25 #include <support/resolv_test.h>
  26 #include <support/test-driver.h>
  27
  28 static volatile int drop_server = -1;
  29 static volatile unsigned int query_counts[resolv_max_test_servers];
  30
  31 static const char address_ipv4[4] = {192, 0, 2, 1};
  32 static const char address_ipv6[16]
  33   = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
  34
  35 static void
  36 response (const struct resolv_response_context *ctx,
  37           struct resolv_response_builder *b,
  38           const char *qname, uint16_t qclass, uint16_t qtype)
  39 {
  40   if (ctx->server_index == drop_server)
  41     {
  42       resolv_response_drop (b);
  43       resolv_response_close (b);
  44       return;
  45     }
  46
  47   bool force_tcp = strncmp (qname, "2.", 2) == 0;
  48   struct resolv_response_flags flags = {.tc = force_tcp && !ctx->tcp};
  49   resolv_response_init (b, flags);
  50   resolv_response_add_question (b, qname, qclass, qtype);
  51   if (flags.tc)
  52     return;
  53
  54   TEST_VERIFY_EXIT (ctx->server_index < resolv_max_test_servers);
  55   ++query_counts[ctx->server_index];
  56
  57   resolv_response_section (b, ns_s_an);
  58   resolv_response_open_record (b, qname, qclass, qtype, 0);
  59   switch (qtype)
  60     {
  61     case T_A:
  62       {
  63         char addr[sizeof (address_ipv4)];
  64         memcpy (addr, address_ipv4, sizeof (address_ipv4));
  65         addr[3] = 1 + ctx->tcp;
  66         resolv_response_add_data (b, addr, sizeof (addr));
  67       }
  68       break;
  69     case T_AAAA:
  70       {
  71         char addr[sizeof (address_ipv6)];
  72         memcpy (addr, address_ipv6, sizeof (address_ipv6));
  73         addr[15] = 1 + ctx->tcp;
  74         resolv_response_add_data (b, addr, sizeof (addr));
  75       }
  76       break;
  77     case T_PTR:
  78       if (force_tcp)
  79         resolv_response_add_name (b, "2.host.example");
  80       else
  81         resolv_response_add_name (b, "host.example");
  82       break;
  83     default:
  84       FAIL_EXIT1 ("unexpected QTYPE: %s/%u/%u", qname, qclass, qtype);
  85     }
  86   resolv_response_close_record (b);
  87 }
  88
  89 static void
  90 check_forward_1 (const char *name, int family)
  91 {
  92   unsigned char lsb;
  93   if (strncmp (name, "2.", 2) == 0)
  94     lsb = 2;
  95   else
  96     lsb = 1;
  97
  98   char expected_hostent_v4[200];
  99   snprintf (expected_hostent_v4, sizeof (expected_hostent_v4),
 100             "name: %s\naddress: 192.0.2.%d\n", name, lsb);
 101   char expected_hostent_v6[200];
 102   snprintf (expected_hostent_v6, sizeof (expected_hostent_v6),
 103             "name: %s\naddress: 2001:db8::%d\n", name, lsb);
 104   char expected_ai[200];
 105
 106   unsigned char address[16];
 107   size_t address_length;
 108
 109   char *expected_hostent;
 110   switch (family)
 111     {
 112     case AF_INET:
 113       expected_hostent = expected_hostent_v4;
 114       snprintf (expected_ai, sizeof (expected_ai),
 115                 "address: STREAM/TCP 192.0.2.%d 80\n", lsb);
 116       TEST_VERIFY_EXIT (sizeof (address_ipv4) == sizeof (struct in_addr));
 117       memcpy (address, address_ipv4, sizeof (address_ipv4));
 118       address_length = sizeof (address_ipv4);
 119       break;
 120     case AF_INET6:
 121       expected_hostent = expected_hostent_v6;
 122       snprintf (expected_ai, sizeof (expected_ai),
 123                 "address: STREAM/TCP 2001:db8::%d 80\n", lsb);
 124       TEST_VERIFY_EXIT (sizeof (address_ipv6) == sizeof (struct in6_addr));
 125       memcpy (address, address_ipv6, sizeof (address_ipv6));
 126       address_length = sizeof (address_ipv6);
 127       break;
 128     case AF_UNSPEC:
 129       expected_hostent = NULL;
 130       snprintf (expected_ai, sizeof (expected_ai),
 131                 "address: STREAM/TCP 192.0.2.%d 80\n"
 132                 "address: STREAM/TCP 2001:db8::%d 80\n",
 133                 lsb, lsb);
 134       address_length = 0;
 135       break;
 136     default:
 137       FAIL_EXIT1 ("unknown address family %d", family);
 138     }
 139
 140
 141   if (family == AF_INET)
 142     {
 143       struct hostent *e = gethostbyname (name);
 144       check_hostent (name, e, expected_hostent_v4);
 145     }
 146
 147   if (family != AF_UNSPEC)
 148     {
 149       struct hostent *e = gethostbyname2 (name, family);
 150       check_hostent (name, e, expected_hostent);
 151     }
 152
 153   if (address_length > 0)
 154     {
 155       address[address_length - 1] = lsb;
 156       struct hostent *e = gethostbyaddr (address, address_length, family);
 157       check_hostent (name, e, expected_hostent);
 158     }
 159
 160   struct addrinfo hints =
 161     {
 162       .ai_family = family,
 163       .ai_socktype = SOCK_STREAM,
 164       .ai_protocol = IPPROTO_TCP,
 165     };
 166   struct addrinfo *ai;
 167   int ret = getaddrinfo (name, "80", &hints, &ai);
 168   check_addrinfo (name, ai, ret, expected_ai);
 169   if (ret == 0)
 170     {
 171       for (struct addrinfo *p = ai; p != NULL; p = p->ai_next)
 172         {
 173           char host[200];
 174           ret = getnameinfo (p->ai_addr, p->ai_addrlen,
 175                              host, sizeof (host),
 176                              NULL, 0, /* service */
 177                              0);
 178           if (ret != 0)
 179             {
 180               support_record_failure ();
 181               printf ("error: getnameinfo: %d\n", ret);
 182             }
 183           else
 184             {
 185               if (lsb == 1)
 186                 TEST_VERIFY (strcmp (host, "host.example") == 0);
 187               else
 188                 TEST_VERIFY (strcmp (host, "2.host.example") == 0);
 189             }
 190         }
 191       freeaddrinfo (ai);
 192     }
 193 }
 194
 195 static void
 196 check_forward (int family)
 197 {
 198   check_forward_1 ("host.example", family);
 199   check_forward_1 ("2.host.example", family);
 200 }
 201
 202 static int
 203 do_test (void)
 204 {
 205   for (int force_tcp = 0; force_tcp < 2; ++force_tcp)
 206     for (int nscount = 1; nscount <= 3; ++nscount)
 207       for (int disable_server = -1; disable_server < nscount; ++disable_server)
 208         for (drop_server = -1; drop_server < nscount; ++drop_server)
 209           {
 210             /* A disabled server will never receive queries and
 211                therefore cannot drop them.  */
 212             if (drop_server >= 0 && drop_server == disable_server)
 213               continue;
 214             /* No servers remaining to query, all queries are expected
 215                to fail.  */
 216             int broken_servers = (disable_server >= 0) + (drop_server >= 0);
 217             if (nscount <= broken_servers)
 218               continue;
 219
 220             if (test_verbose > 0)
 221               printf ("info: tcp=%d nscount=%d disable=%d drop=%d\n",
 222                       force_tcp, nscount, disable_server, drop_server);
 223             struct resolv_redirect_config config =
 224               {
 225                 .response_callback = response,
 226                 .nscount = nscount
 227               };
 228             if (disable_server >= 0)
 229               {
 230                 config.servers[disable_server].disable_udp = true;
 231                 config.servers[disable_server].disable_tcp = true;
 232               }
 233
 234             struct resolv_test *aux = resolv_test_start (config);
 235             _res.options |= RES_ROTATE;
 236
 237             /* Run a few queries to make sure that all of them
 238                succeed.  We always perform more than nscount queries,
 239                so we cover all active servers due to RES_ROTATE.  */
 240             for (size_t i = 0; i < resolv_max_test_servers; ++i)
 241               query_counts[i] = 0;
 242             check_forward (AF_INET);
 243             check_forward (AF_INET6);
 244             check_forward (AF_UNSPEC);
 245
 246             for (int i = 0; i < nscount; ++i)
 247               {
 248                 if (i != disable_server && i != drop_server
 249                     && query_counts[i] == 0)
 250                   {
 251                     support_record_failure ();
 252                     printf ("error: nscount=%d, but no query to server %d\n",
 253                             nscount, i);
 254                   }
 255               }
 256
 257             resolv_test_end (aux);
 258           }
 259   return 0;
 260 }
 261
 262 #define TIMEOUT 300
 263 #include <support/test-driver.c>