[PATCH COMMITTED] getnameinfo: Refactor and fix memory leak [BZ #19642]

Florian Weimer fweimer@redhat.com
Fri Apr 29 15:35:00 GMT 2016


Split getnameinfo into separate functions for host and service lookups, 
and for different address families.

I preserved some pre-existing long lines for now.

Validated with the new and attached nss_files test (which depends on the 
nss_files testing framework I posted earlier) and with the external 
libresolv test suite.

Florian
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/* Test getnameinfo using nss_files.
   Copyright (C) 2016 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 "tst-nss-aux.h"
#include "tst-nss-files-aux.h"

#include <netdb.h>
#include <string.h>
#include <sys/un.h>
#include <unistd.h>

/* create_file_callback for /etc/hosts.  */
static void
create_hosts (const char *name, FILE *out, void *closure)
{
  fputs ("127.0.0.1 localhost localhost.localdomain localhost4\n", out);
  fputs ("::1 localhost localhost.localdomain localhost6\n", out);
  fputs ("192.0.2.1 reverse-ipv4 reverse-ipv4.example\n", out);
  fputs ("2001:db8::1 reverse-ipv6 reverse-ipv6.example\n", out);
  fputs ("192.0.2.2 reverse reverse.example\n", out);
  fputs ("2001:db8::2 reverse reverse.example\n", out);
  fputs ("192.0.2.3 other-ipv4.example other-ipv4\n", out);
  fputs ("2001:db8::3 other-ipv6.example other-ipv6\n", out);
  fputs ("192.0.2.4 other.example other\n", out);
  fputs ("2001:db8::4 other.example other\n", out);
}

static void
create_services (const char *name, FILE *out, void *closure)
{
  fputs ("www 80/tcp\n", out);
  fputs ("exec 512/tcp\n", out);
  fputs ("biff 512/udp comsat\n", out);
}

static bool
check_gni_match (int line, const char *kind, int flags,
                 const char *expected, const char *actual)
{
  if (expected != NULL && strcmp (actual, expected) != 0)
    {
      record_delayed_failure ();
      printf ("%1$s:%2$d: error: %3$s mismatch (flags 0x%6$x)\n"
              "%1$s:%2$d: error:   expected: %4$s\n"
              "%1$s:%2$d: error:   actual:   %5$s\n",
              __FILE__, line, kind, expected, actual, flags);
      return false;
    }
  return true;
}

static void
check_getnameinfo (const void *addr, size_t addrlen, int flags,
                   const char *expected_host,
                   const char *expected_service, int line)
{
  size_t hostlen = 0;
  char *host = NULL;
  if (expected_host != NULL)
    {
      hostlen = strlen (expected_host) + 1;
      host = xmalloc (hostlen);
    }
  size_t servlen = 0;
  char *serv = NULL;
  if (expected_service != NULL)
    {
      servlen = strlen (expected_service) + 1;
      serv = xmalloc (servlen);
    }
  int ret = getnameinfo (addr, addrlen, host, hostlen, serv, servlen, flags);
  if (ret != 0)
    {
      record_delayed_failure ();
      printf ("%s:%d: error: unexpected error %s (%d) with flags 0x%x\n",
              __FILE__, line, gai_strerror (ret), ret, flags);
    }
  else
    {
      check_gni_match (line, "host", flags, expected_host, host);
      check_gni_match (line, "service", flags, expected_service, serv);
    }
  free (serv);
  free (host);
}

#define CHECK_GETNAMEINFO(addr, addrlen, flags, exp_host, exp_service) \
  check_getnameinfo (addr, addrlen, flags, exp_host, exp_service, __LINE__)

static void
check_getnameinfo_error (const void *addr, size_t addrlen, int flags,
                         int expected_error, int line)
{
  char host[NI_MAXHOST];
  char serv[NI_MAXSERV];
  int ret = getnameinfo (addr, addrlen, host, sizeof (host),
                         serv, sizeof (serv), flags);
  if (ret != expected_error)
    {
      record_delayed_failure ();
      printf ("%s:%d: error: expected error %s (%d), got %s (%d),"
              " with flags 0x%x\n",
              __FILE__, line,
              gai_strerror (expected_error), expected_error,
              gai_strerror (ret), ret, flags);
    }
}

#define CHECK_GETNAMEINFO_ERROR(addr, addrlen, flags, expected_error)   \
  check_getnameinfo_error (addr, addrlen, flags, expected_error, __LINE__)

static void
set_host_name (void)
{
  if (is_in_uts_namespace ())
    {
      const char *name = "host.example";
      if (sethostname (name, strlen (name)) != 0)
        printf ("warning: sethostname (\"%s\"): %m\n", name);
    }
}

static void
test_getnameinfo_inet (void)
{
  set_host_name ();

  struct sockaddr_in sin =
    {
      .sin_family = AF_INET,
      .sin_addr = {ntohl (0xc0000200)},
      .sin_port = ntohs (512)
    };
  struct sockaddr_in6 sin6 =
    {
      .sin6_family = AF_INET6,
      .sin6_port = ntohs (512)
    };
  memcpy (&sin6.sin6_addr,
          "\x20\x01\x0d\xb8\0\0\0\0\0\0\0\0\0\0\0\0", 16);
  for (int use_ipv6 = 0; use_ipv6 < 2; ++use_ipv6)
    for (int address = 1; address <= 5; ++address)
      for (int use_numerichost = 0; use_numerichost < 2; ++use_numerichost)
        for (int use_namereqd = 0; use_namereqd < 2; ++use_namereqd)
          for (int use_numericserv = 0; use_numericserv < 2; ++use_numericserv)
            for (int use_nofqdn = 0; use_nofqdn < 2; ++use_nofqdn)
              for (int use_dgram = 0; use_dgram < 2; ++use_dgram)
                {
                  /* Address without reverse lookup.  */
                  bool nxdomain = address == 5;

                  ((char *)&sin.sin_addr.s_addr)[3] = address;
                  ((char *)&sin6.sin6_addr.s6_addr)[15] = address;
                  void *sa;
                  socklen_t salen;
                  if (use_ipv6)
                    {
                      sa = &sin6;
                      salen = sizeof (sin6);
                    }
                  else
                    {
                      sa = &sin;
                      salen = sizeof (sin);
                    }

                  char numeric_host[] = "192.0.2.0";
                  numeric_host[strlen (numeric_host) - 1] += address;
                  char numeric_host6[] = "2001:db8::0";
                  numeric_host6[strlen (numeric_host6) - 1] += address;

                  int flags = 0;
                  if (use_numerichost)
                    flags |= NI_NUMERICHOST;
                  if (use_namereqd)
                    flags |= NI_NAMEREQD;
                  if (use_numericserv)
                    flags |= NI_NUMERICSERV;
                  if (use_nofqdn)
                    flags |= NI_NOFQDN;
                  if (use_dgram)
                    flags |= NI_DGRAM;

                  /* NI_NUMERICHOST with NI_NAMEREQD is not allowed.
                     NI_NAMEREQD without a reverse lookup results in
                     EAI_NONAME.  */
                  if ((use_numerichost && use_namereqd)
                      || (use_namereqd && nxdomain))
                    {
                      CHECK_GETNAMEINFO_ERROR
                        (sa, salen, flags, EAI_NONAME);
                      continue;
                    }

                  const char *exp_host;
                  if (use_numerichost || nxdomain)
                    {
                      /* Number output requested, or no reverse
                         lookup.  */
                      if (use_ipv6)
                        exp_host = numeric_host6;
                      else
                        exp_host = numeric_host;
                    }
                  else
                    /* Determine the expected address.  1 & 3 have
                       different names for IPv4 and IPv6.  1/2 and 3/4
                       have different order of the aliases, and the
                       first entry counts.  */
                    switch (address)
                      {
                      case 1:
                        if (use_ipv6)
                          exp_host = "reverse-ipv6";
                        else
                          exp_host = "reverse-ipv4";
                        break;
                      case 2:
                        exp_host = "reverse";
                        break;
                      case 3:
                        if (use_nofqdn)
                          {
                            if (use_ipv6)
                              exp_host = "other-ipv6";
                            else
                              exp_host = "other-ipv4";
                          }
                        else
                          {
                            if (use_ipv6)
                              exp_host = "other-ipv6.example";
                            else
                              exp_host = "other-ipv4.example";
                          }
                        break;
                      case 4:
                        if (use_nofqdn)
                          exp_host = "other";
                        else
                          exp_host = "other.example";
                        break;
                      default:
                        abort ();
                      }

                  const char *exp_serv;
                  if (use_numericserv)
                    exp_serv = "512";
                  else if (use_dgram)
                    exp_serv = "biff";
                  else
                    exp_serv = "exec";
                  CHECK_GETNAMEINFO
                    (sa, salen, flags, exp_host, exp_serv);
                }
}

static void
test_getnameinfo_local (void)
{
  set_host_name ();
  char *expected_hostname = xgethostname ();

  struct sockaddr_un sun =
    {
      .sun_family = AF_LOCAL,
      .sun_path = "/tmp/.X11-unix/X0"
    };
  for (int use_numerichost = 0; use_numerichost < 2; ++use_numerichost)
    for (int use_namereqd = 0; use_namereqd < 2; ++use_namereqd)
      for (int use_numericserv = 0; use_numericserv < 2; ++use_numericserv)
      for (int use_nofqdn = 0; use_nofqdn < 2; ++use_nofqdn)
        for (int use_dgram = 0; use_dgram < 2; ++use_dgram)
          {
            int flags = 0;
            const char *exp_host = expected_hostname;
            if (use_numerichost)
              {
                flags |= NI_NUMERICHOST;
                exp_host = "localhost";
              }
            if (use_namereqd)
              flags |= NI_NAMEREQD;
            if (use_numericserv)
              flags |= NI_NUMERICSERV;
            if (use_nofqdn)
              flags |= NI_NOFQDN;
            if (use_dgram)
              flags |= NI_DGRAM;
            if (use_numerichost && use_namereqd)
              {
                CHECK_GETNAMEINFO_ERROR (&sun, sizeof (sun),
                                         flags, EAI_NONAME);
                continue;
              }
            CHECK_GETNAMEINFO (&sun, sizeof (sun), flags,
                               exp_host, "/tmp/.X11-unix/X0");
          }

  free (expected_hostname);
}


static int
do_test (void)
{
  configure_nss_files ();

  char *root = create_chroot ();
  create_etc_file (root, "hosts", create_hosts, NULL);
  create_etc_file (root, "services", create_services, NULL);
  isolate_in_subprocess (root, test_getnameinfo_inet);
  isolate_in_subprocess (root, test_getnameinfo_local);
  free (root);
  return 0;
}

#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"


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