res_data.c 2.3 KB

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  1. /* Miscellaneous definitions for libresolv.
  2. Copyright (C) 1995-2019 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <http://www.gnu.org/licenses/>. */
  15. /*
  16. * Copyright (c) 1995-1999 by Internet Software Consortium.
  17. *
  18. * Permission to use, copy, modify, and distribute this software for any
  19. * purpose with or without fee is hereby granted, provided that the above
  20. * copyright notice and this permission notice appear in all copies.
  21. *
  22. * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  23. * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  24. * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  25. * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  26. * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  27. * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  28. * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  29. * SOFTWARE.
  30. */
  31. #include <resolv.h>
  32. /* This function belongs to libresolv, which is why it is not included
  33. in res-close.c. */
  34. void
  35. __res_close (void)
  36. {
  37. /* Some programs call res_close before res_init. Since _res._vcsock
  38. isn't explicitly initialized, these means that we could call
  39. close (0), which might lead to some security problems. Therefore
  40. we check if res_init was called before by looking at the RES_INIT
  41. bit in _res.options. If it hasn't been set we bail out
  42. early. */
  43. if ((_res.options & RES_INIT) == 0)
  44. return;
  45. /* We don't free the name server addresses because we never did it
  46. and it would be done implicitly on shutdown. */
  47. __res_iclose (&_res, false);
  48. }