/* Enumerate /etc/hosts with a long line (bug 18991).

   Copyright (C) 2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <dlfcn.h>

#include <errno.h>

#include <gnu/lib-names.h>

#include <netdb.h>

#include <nss.h>

#include <stdlib.h>

#include <stdio.h>

#include <support/check.h>

#include <support/check_nss.h>

#include <support/namespace.h>

#include <support/support.h>

#include <support/test-driver.h>

#include <support/xmemstream.h>

#include <support/xstdio.h>

#include <support/xunistd.h>

struct support_chroot *chroot_env;

/* Number of alias names in the long line.  This is varied to catch

   different cases where the ERANGE handling can go wrong (line buffer

   length, alias buffer).  */

static int name_count;

/* Write /etc/hosts, from outside of the chroot.  */

static void

write_hosts (void)

{

  FILE *fp = xfopen (chroot_env->path_hosts, "w");

  fputs ("127.0.0.1   localhost localhost.localdomain\n", fp);

  fputs ("192.0.2.2 host2.example.com\n", fp);

  fputs ("192.0.2.1", fp);

  for (int i = 0; i < name_count; ++i)

    fprintf (fp, " host%d.example.com", i);

  fputs ("\n192.0.2.80 www.example.com\n"

         "192.0.2.5 host5.example.com\n"

         "192.0.2.81 www1.example.com\n", fp);

  xfclose (fp);

}

const char *host1_expected =

  "name: localhost\n"

  "alias: localhost.localdomain\n"

  "address: 127.0.0.1\n";

const char *host2_expected =

  "name: host2.example.com\n"

  "address: 192.0.2.2\n";

const char *host4_expected =

  "name: www.example.com\n"

  "address: 192.0.2.80\n";

const char *host5_expected =

  "name: host5.example.com\n"

  "address: 192.0.2.5\n";

const char *host6_expected =

  "name: www1.example.com\n"

  "address: 192.0.2.81\n";

static void

prepare (int argc, char **argv)

{

  chroot_env = support_chroot_create

    ((struct support_chroot_configuration)

     {

       .resolv_conf = "",

       .hosts = "",             /* Filled in by write_hosts.  */

       .host_conf = "multi on\n",

     });

}

/* If -1, no sethostent call.  Otherwise, pass do_stayopen as the

   sethostent argument.  */

static int do_stayopen;

/* If non-zero, perform an endostent call.  */

static int do_endent;

static void

subprocess_getent (void *closure)

{

  xchroot (chroot_env->path_chroot);

  errno = 0;

  if (do_stayopen >= 0)

    sethostent (do_stayopen);

  TEST_VERIFY (errno == 0);

  int i = 0;

  while (true)

    {

      struct xmemstream expected;

      xopen_memstream (&expected);

      switch (++i)

        {

        case 1:

          fputs (host1_expected, expected.out);

          break;

        case 2:

          fputs (host2_expected, expected.out);

          break;

        case 3:

          fputs ("name: host0.example.com\n", expected.out);

          for (int j = 1; j < name_count; ++j)

            fprintf (expected.out, "alias: host%d.example.com\n", j);

          fputs ("address: 192.0.2.1\n", expected.out);

          break;

        case 4:

          fputs (host4_expected, expected.out);

          break;

        case 5:

          fputs (host5_expected, expected.out);

          break;

        case 6:

          fputs (host6_expected, expected.out);

          break;

        default:

          fprintf (expected.out, "*** unexpected host %d ***\n", i);

          break;

        }

      xfclose_memstream (&expected);

      char *context = xasprintf ("do_stayopen=%d host=%d", do_stayopen, i);

      errno = 0;

      struct hostent *e = gethostent ();

      if (e == NULL)

        {

          TEST_VERIFY (errno == 0);

          break;

        }

      check_hostent (context, e, expected.buffer);

      free (context);

      free (expected.buffer);

    }

  errno = 0;

  if (do_endent)

    endhostent ();

  TEST_VERIFY (errno == 0);

  /* Exercise process termination.   */

  exit (0);

}

/* getaddrinfo test.  To be run from a subprocess.  */

static void

test_gai (int family)

{

  struct addrinfo hints =

    {

      .ai_family = family,

      .ai_protocol = IPPROTO_TCP,

      .ai_socktype = SOCK_STREAM,

    };

  struct addrinfo *ai;

  int ret = getaddrinfo ("host2.example.com", "80", &hints, &ai;;

  check_addrinfo ("host2.example.com", ai, ret,

                  "address: STREAM/TCP 192.0.2.2 80\n"

                  "address: STREAM/TCP 192.0.2.1 80\n");

  ret = getaddrinfo ("host5.example.com", "80", &hints, &ai;;

  check_addrinfo ("host5.example.com", ai, ret,

                  "address: STREAM/TCP 192.0.2.1 80\n"

                  "address: STREAM/TCP 192.0.2.5 80\n");

  ret = getaddrinfo ("www.example.com", "80", &hints, &ai;;

  check_addrinfo ("www.example.com", ai, ret,

                  "address: STREAM/TCP 192.0.2.80 80\n");

  ret = getaddrinfo ("www1.example.com", "80", &hints, &ai;;

  check_addrinfo ("www1.example.com", ai, ret,

                  "address: STREAM/TCP 192.0.2.81 80\n");

}

/* Subprocess routine for gethostbyname/getaddrinfo testing.  */

static void

subprocess_gethost (void *closure)

{

  xchroot (chroot_env->path_chroot);

  /* This tests enlarging the read buffer in the multi case.  */

  struct xmemstream expected;

  xopen_memstream (&expected);

  fputs ("name: host2.example.com\n", expected.out);

  for (int j = 1; j < name_count; ++j)

    /* NB: host2 is duplicated in the alias list.  */

    fprintf (expected.out, "alias: host%d.example.com\n", j);

  fputs ("alias: host0.example.com\n"

         "address: 192.0.2.2\n"

         "address: 192.0.2.1\n",

         expected.out);

  xfclose_memstream (&expected);

  check_hostent ("host2.example.com",

                 gethostbyname ("host2.example.com"),

                 expected.buffer);

  free (expected.buffer);

  /* Similarly, but with a different order in the /etc/hosts file.  */

  xopen_memstream (&expected);

  fputs ("name: host0.example.com\n", expected.out);

  for (int j = 1; j < name_count; ++j)

    fprintf (expected.out, "alias: host%d.example.com\n", j);

  /* NB: host5 is duplicated in the alias list.  */

  fputs ("alias: host5.example.com\n"

         "address: 192.0.2.1\n"

         "address: 192.0.2.5\n",

         expected.out);

  xfclose_memstream (&expected);

  check_hostent ("host5.example.com",

                 gethostbyname ("host5.example.com"),

                 expected.buffer);

  free (expected.buffer);

  check_hostent ("www.example.com",

                 gethostbyname ("www.example.com"),

                 host4_expected);

  check_hostent ("www1.example.com",

                 gethostbyname ("www1.example.com"),

                 host6_expected);

  test_gai (AF_INET);

  test_gai (AF_UNSPEC);

}

static int

do_test (void)

{

  support_become_root ();

  if (!support_can_chroot ())

    return EXIT_UNSUPPORTED;

  __nss_configure_lookup ("hosts", "files");

  if (dlopen (LIBNSS_FILES_SO, RTLD_LAZY) == NULL)

    FAIL_EXIT1 ("could not load " LIBNSS_DNS_SO ": %s", dlerror ());

  /* Each name takes about 20 bytes, so this covers a wide range of

     buffer sizes, from less than 1000 bytes to about 18000 bytes.  */

  for (name_count = 40; name_count <= 850; ++name_count)

    {

      write_hosts ();

      for (do_stayopen = -1; do_stayopen < 2; ++do_stayopen)

        for (do_endent = 0; do_endent < 2; ++do_endent)

          {

            if (test_verbose > 0)

              printf ("info: name_count=%d do_stayopen=%d do_endent=%d\n",

                      name_count, do_stayopen, do_endent);

            support_isolate_in_subprocess (subprocess_getent, NULL);

          }

      support_isolate_in_subprocess (subprocess_gethost, NULL);

    }

  support_chroot_free (chroot_env);

  return 0;

}

#define PREPARE prepare

#include <support/test-driver.c>