resolv/tst-resolv-threads.c

   1 /* Test basic nss_dns functionality with multiple threads.
   2    Copyright (C) 2016-2022 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 /* Unlike tst-resolv-basic, this test does not overwrite the _res
  20    structure and relies on namespaces to achieve the redirection to
  21    the test servers with a custom /etc/resolv.conf file.  */
  22
  23 #include <dlfcn.h>
  24 #include <errno.h>
  25 #include <gnu/lib-names.h>
  26 #include <netdb.h>
  27 #include <resolv/resolv-internal.h>
  28 #include <resolv/resolv_context.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <support/check.h>
  33 #include <support/namespace.h>
  34 #include <support/resolv_test.h>
  35 #include <support/support.h>
  36 #include <support/temp_file.h>
  37 #include <support/test-driver.h>
  38 #include <support/xthread.h>
  39 #include <support/xunistd.h>
  40
  41 /* Each client thread sends this many queries.  */
  42 enum { queries_per_thread = 500 };
  43
  44 /* Return a small positive number identifying this thread.  */
  45 static int
  46 get_thread_number (void)
  47 {
  48   static int __thread local;
  49   if (local != 0)
  50     return local;
  51   static int global = 1;
  52   local = __atomic_fetch_add (&global, 1, __ATOMIC_RELAXED);
  53   return local;
  54 }
  55
  56 static void
  57 response (const struct resolv_response_context *ctx,
  58           struct resolv_response_builder *b,
  59           const char *qname, uint16_t qclass, uint16_t qtype)
  60 {
  61   TEST_VERIFY_EXIT (qname != NULL);
  62
  63   int counter = 0;
  64   int thread = 0;
  65   int dummy = 0;
  66   TEST_VERIFY (sscanf (qname, "counter%d.thread%d.example.com%n",
  67                        &counter, &thread, &dummy) == 2);
  68   TEST_VERIFY (dummy > 0);
  69
  70   struct resolv_response_flags flags = { 0 };
  71   resolv_response_init (b, flags);
  72   resolv_response_add_question (b, qname, qclass, qtype);
  73
  74   resolv_response_section (b, ns_s_an);
  75   resolv_response_open_record (b, qname, qclass, qtype, 0);
  76   switch (qtype)
  77     {
  78     case T_A:
  79       {
  80         char ipv4[4] = {10, 0, counter, thread};
  81         resolv_response_add_data (b, &ipv4, sizeof (ipv4));
  82       }
  83       break;
  84     case T_AAAA:
  85       {
  86         char ipv6[16]
  87           = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0,
  88              counter, 0, thread, 0, 0};
  89         resolv_response_add_data (b, &ipv6, sizeof (ipv6));
  90       }
  91       break;
  92     default:
  93       support_record_failure ();
  94       printf ("error: unexpected QTYPE: %s/%u/%u\n",
  95               qname, qclass, qtype);
  96     }
  97   resolv_response_close_record (b);
  98 }
  99
 100 /* Check that the resolver configuration for this thread has an
 101    extended resolver configuration.  */
 102 static void
 103 check_have_conf (void)
 104 {
 105   struct resolv_context *ctx = __resolv_context_get ();
 106   TEST_VERIFY_EXIT (ctx != NULL);
 107   TEST_VERIFY (ctx->conf != NULL);
 108   __resolv_context_put (ctx);
 109 }
 110
 111 /* Verify that E matches the expected response for FAMILY and
 112    COUNTER.  */
 113 static void
 114 check_hostent (const char *caller, const char *function, const char *qname,
 115                int ret, struct hostent *e, int family, int counter)
 116 {
 117   if (ret != 0)
 118     {
 119       errno = ret;
 120       support_record_failure ();
 121       printf ("error: %s: %s for %s failed: %m\n", caller, function, qname);
 122       return;
 123     }
 124
 125   TEST_VERIFY_EXIT (e != NULL);
 126   TEST_VERIFY (strcmp (qname, e->h_name) == 0);
 127   TEST_VERIFY (e->h_addrtype == family);
 128   TEST_VERIFY_EXIT (e->h_addr_list[0] != NULL);
 129   TEST_VERIFY (e->h_addr_list[1] == NULL);
 130   switch (family)
 131     {
 132     case AF_INET:
 133       {
 134         char addr[4] = {10, 0, counter, get_thread_number ()};
 135         TEST_VERIFY (e->h_length == sizeof (addr));
 136         TEST_VERIFY (memcmp (e->h_addr_list[0], addr, sizeof (addr)) == 0);
 137       }
 138       break;
 139     case AF_INET6:
 140       {
 141       char addr[16]
 142         = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0,
 143            0, counter, 0, get_thread_number (), 0, 0};
 144       TEST_VERIFY (e->h_length == sizeof (addr));
 145       TEST_VERIFY (memcmp (e->h_addr_list[0], addr, sizeof (addr)) == 0);
 146       }
 147       break;
 148     default:
 149       FAIL_EXIT1 ("%s: invalid address family %d", caller, family);
 150     }
 151   check_have_conf ();
 152 }
 153
 154 /* Check a getaddrinfo result.  */
 155 static void
 156 check_addrinfo (const char *caller, const char *qname,
 157                 int ret, struct addrinfo *ai, int family, int counter)
 158 {
 159   if (ret != 0)
 160     {
 161       support_record_failure ();
 162       printf ("error: %s: getaddrinfo for %s failed: %s\n",
 163               caller, qname, gai_strerror (ret));
 164       return;
 165     }
 166
 167   TEST_VERIFY_EXIT (ai != NULL);
 168
 169   /* Check that available data matches the requirements.  */
 170   bool have_ipv4 = false;
 171   bool have_ipv6 = false;
 172   for (struct addrinfo *p = ai; p != NULL; p = p->ai_next)
 173     {
 174       TEST_VERIFY (p->ai_socktype == SOCK_STREAM);
 175       TEST_VERIFY (p->ai_protocol == IPPROTO_TCP);
 176       TEST_VERIFY_EXIT (p->ai_addr != NULL);
 177       TEST_VERIFY (p->ai_addr->sa_family == p->ai_family);
 178
 179       switch (p->ai_family)
 180         {
 181         case AF_INET:
 182           {
 183             TEST_VERIFY (!have_ipv4);
 184             have_ipv4 = true;
 185             struct sockaddr_in *sa = (struct sockaddr_in *) p->ai_addr;
 186             TEST_VERIFY (p->ai_addrlen == sizeof (*sa));
 187             char addr[4] = {10, 0, counter, get_thread_number ()};
 188             TEST_VERIFY (memcmp (&sa->sin_addr, addr, sizeof (addr)) == 0);
 189             TEST_VERIFY (ntohs (sa->sin_port) == 80);
 190           }
 191           break;
 192         case AF_INET6:
 193           {
 194             TEST_VERIFY (!have_ipv6);
 195             have_ipv6 = true;
 196             struct sockaddr_in6 *sa = (struct sockaddr_in6 *) p->ai_addr;
 197             TEST_VERIFY (p->ai_addrlen == sizeof (*sa));
 198             char addr[16]
 199               = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0,
 200                  0, counter, 0, get_thread_number (), 0, 0};
 201             TEST_VERIFY (memcmp (&sa->sin6_addr, addr, sizeof (addr)) == 0);
 202             TEST_VERIFY (ntohs (sa->sin6_port) == 80);
 203           }
 204           break;
 205         default:
 206           FAIL_EXIT1 ("%s: invalid address family %d", caller, family);
 207         }
 208     }
 209
 210   switch (family)
 211     {
 212       case AF_INET:
 213         TEST_VERIFY (have_ipv4);
 214         TEST_VERIFY (!have_ipv6);
 215         break;
 216       case AF_INET6:
 217         TEST_VERIFY (!have_ipv4);
 218         TEST_VERIFY (have_ipv6);
 219         break;
 220       case AF_UNSPEC:
 221         TEST_VERIFY (have_ipv4);
 222         TEST_VERIFY (have_ipv6);
 223         break;
 224     default:
 225       FAIL_EXIT1 ("%s: invalid address family %d", caller, family);
 226     }
 227
 228   check_have_conf ();
 229 }
 230
 231 /* This barrier ensures that all test threads begin their work
 232    simultaneously.  */
 233 static pthread_barrier_t barrier;
 234
 235 /* Test gethostbyname2_r (if do_2 is false) or gethostbyname2_r with
 236    AF_INET (if do_2 is true).  */
 237 static void *
 238 byname (bool do_2)
 239 {
 240   int this_thread = get_thread_number ();
 241   xpthread_barrier_wait (&barrier);
 242   for (int i = 0; i < queries_per_thread; ++i)
 243     {
 244       char qname[100];
 245       snprintf (qname, sizeof (qname), "counter%d.thread%d.example.com",
 246                 i, this_thread);
 247       struct hostent storage;
 248       char buf[1000];
 249       struct hostent *e = NULL;
 250       int herrno;
 251       int ret;
 252       if (do_2)
 253         ret = gethostbyname_r (qname, &storage, buf, sizeof (buf),
 254                                &e, &herrno);
 255       else
 256         ret = gethostbyname2_r (qname, AF_INET, &storage, buf, sizeof (buf),
 257                                 &e, &herrno);
 258       check_hostent (__func__, do_2 ? "gethostbyname2_r" : "gethostbyname_r",
 259                      qname, ret, e, AF_INET, i);
 260     }
 261   check_have_conf ();
 262   return NULL;
 263 }
 264
 265 /* Test gethostbyname_r.  */
 266 static void *
 267 thread_byname (void *closure)
 268 {
 269   return byname (false);
 270 }
 271
 272 /* Test gethostbyname2_r with AF_INET.  */
 273 static void *
 274 thread_byname2 (void *closure)
 275 {
 276   return byname (true);
 277 }
 278
 279 /* Test gethostbyname2_r with AF_INET6.  */
 280 static void *
 281 thread_byname2_af_inet6 (void *closure)
 282 {
 283   int this_thread = get_thread_number ();
 284   xpthread_barrier_wait (&barrier);
 285   for (int i = 0; i < queries_per_thread; ++i)
 286     {
 287       char qname[100];
 288       snprintf (qname, sizeof (qname), "counter%d.thread%d.example.com",
 289                 i, this_thread);
 290       struct hostent storage;
 291       char buf[1000];
 292       struct hostent *e = NULL;
 293       int herrno;
 294       int ret = gethostbyname2_r (qname, AF_INET6, &storage, buf, sizeof (buf),
 295                                   &e, &herrno);
 296       check_hostent (__func__, "gethostbyname2_r", qname, ret, e, AF_INET6, i);
 297     }
 298   return NULL;
 299 }
 300
 301 /* Run getaddrinfo tests for FAMILY.  */
 302 static void *
 303 gai (int family)
 304 {
 305   int this_thread = get_thread_number ();
 306   xpthread_barrier_wait (&barrier);
 307   for (int i = 0; i < queries_per_thread; ++i)
 308     {
 309       char qname[100];
 310       snprintf (qname, sizeof (qname), "counter%d.thread%d.example.com",
 311                 i, this_thread);
 312       struct addrinfo hints =
 313         {
 314           .ai_family = family,
 315           .ai_socktype = SOCK_STREAM,
 316           .ai_protocol = IPPROTO_TCP,
 317         };
 318       struct addrinfo *ai;
 319       int ret = getaddrinfo (qname, "80", &hints, &ai);
 320       check_addrinfo (__func__, qname, ret, ai, family, i);
 321       if (ret == 0)
 322         freeaddrinfo (ai);
 323     }
 324   return NULL;
 325 }
 326
 327 /* Test getaddrinfo with AF_INET.  */
 328 static void *
 329 thread_gai_inet (void *closure)
 330 {
 331   return gai (AF_INET);
 332 }
 333
 334 /* Test getaddrinfo with AF_INET6.  */
 335 static void *
 336 thread_gai_inet6 (void *closure)
 337 {
 338   return gai (AF_INET6);
 339 }
 340
 341 /* Test getaddrinfo with AF_UNSPEC.  */
 342 static void *
 343 thread_gai_unspec (void *closure)
 344 {
 345   return gai (AF_UNSPEC);
 346 }
 347
 348 /* Description of the chroot environment used to run the tests.  */
 349 static struct support_chroot *chroot_env;
 350
 351 /* Set up the chroot environment.  */
 352 static void
 353 prepare (int argc, char **argv)
 354 {
 355   chroot_env = support_chroot_create
 356     ((struct support_chroot_configuration)
 357      {
 358        .resolv_conf =
 359          "search example.com\n"
 360          "nameserver 127.0.0.1\n"
 361          "nameserver 127.0.0.2\n"
 362          "nameserver 127.0.0.3\n",
 363      });
 364 }
 365
 366 static int
 367 do_test (void)
 368 {
 369   support_become_root ();
 370   if (!support_enter_network_namespace ())
 371     return EXIT_UNSUPPORTED;
 372   if (!support_can_chroot ())
 373     return EXIT_UNSUPPORTED;
 374
 375   /* Load the shared object outside of the chroot.  */
 376   TEST_VERIFY (dlopen (LIBNSS_DNS_SO, RTLD_LAZY) != NULL);
 377
 378   xchroot (chroot_env->path_chroot);
 379   TEST_VERIFY_EXIT (chdir ("/") == 0);
 380
 381   struct sockaddr_in server_address =
 382     {
 383       .sin_family = AF_INET,
 384       .sin_addr = { .s_addr = htonl (INADDR_LOOPBACK) },
 385       .sin_port = htons (53)
 386     };
 387   const struct sockaddr *server_addresses[1] =
 388     { (const struct sockaddr *) &server_address };
 389
 390   struct resolv_test *aux = resolv_test_start
 391     ((struct resolv_redirect_config)
 392      {
 393        .response_callback = response,
 394        .nscount = 1,
 395        .disable_redirect = true,
 396        .server_address_overrides = server_addresses,
 397      });
 398
 399   enum { thread_count = 6 };
 400   xpthread_barrier_init (&barrier, NULL, thread_count + 1);
 401   pthread_t threads[thread_count];
 402   typedef void *(*thread_func) (void *);
 403   thread_func thread_funcs[thread_count] =
 404     {
 405       thread_byname,
 406       thread_byname2,
 407       thread_byname2_af_inet6,
 408       thread_gai_inet,
 409       thread_gai_inet6,
 410       thread_gai_unspec,
 411     };
 412   for (int i = 0; i < thread_count; ++i)
 413     threads[i] = xpthread_create (NULL, thread_funcs[i], NULL);
 414   xpthread_barrier_wait (&barrier); /* Start the test threads.  */
 415   for (int i = 0; i < thread_count; ++i)
 416     xpthread_join (threads[i]);
 417
 418   resolv_test_end (aux);
 419   support_chroot_free (chroot_env);
 420
 421   return 0;
 422 }
 423
 424 #define PREPARE prepare
 425 #include <support/test-driver.c>