/net/netfilter/xt_connmark.c

https://gitlab.com/davod/ddfgdfgd · C · 87 lines · 54 code · 11 blank · 22 comment · 4 complexity · 61c72e1b20dc1e9ff96a1f9f9af9f7ab MD5 · raw file

  1. /*
  2. * xt_connmark - Netfilter module to match connection mark values
  3. *
  4. * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
  5. * by Henrik Nordstrom <hno@marasystems.com>
  6. * Copyright © CC Computer Consultants GmbH, 2007 - 2008
  7. * Jan Engelhardt <jengelh@computergmbh.de>
  8. *
  9. * This program is free software; you can redistribute it and/or modify
  10. * it under the terms of the GNU General Public License as published by
  11. * the Free Software Foundation; either version 2 of the License, or
  12. * (at your option) any later version.
  13. *
  14. * This program is distributed in the hope that it will be useful,
  15. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17. * GNU General Public License for more details.
  18. *
  19. * You should have received a copy of the GNU General Public License
  20. * along with this program; if not, write to the Free Software
  21. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22. */
  23. #include <linux/module.h>
  24. #include <linux/skbuff.h>
  25. #include <net/netfilter/nf_conntrack.h>
  26. #include <linux/netfilter/x_tables.h>
  27. #include <linux/netfilter/xt_connmark.h>
  28. MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
  29. MODULE_DESCRIPTION("Xtables: connection mark match");
  30. MODULE_LICENSE("GPL");
  31. MODULE_ALIAS("ipt_connmark");
  32. MODULE_ALIAS("ip6t_connmark");
  33. static bool
  34. connmark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
  35. {
  36. const struct xt_connmark_mtinfo1 *info = par->matchinfo;
  37. enum ip_conntrack_info ctinfo;
  38. const struct nf_conn *ct;
  39. ct = nf_ct_get(skb, &ctinfo);
  40. if (ct == NULL)
  41. return false;
  42. return ((ct->mark & info->mask) == info->mark) ^ info->invert;
  43. }
  44. static bool connmark_mt_check(const struct xt_mtchk_param *par)
  45. {
  46. if (nf_ct_l3proto_try_module_get(par->family) < 0) {
  47. printk(KERN_WARNING "cannot load conntrack support for "
  48. "proto=%u\n", par->family);
  49. return false;
  50. }
  51. return true;
  52. }
  53. static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
  54. {
  55. nf_ct_l3proto_module_put(par->family);
  56. }
  57. static struct xt_match connmark_mt_reg __read_mostly = {
  58. .name = "connmark",
  59. .revision = 1,
  60. .family = NFPROTO_UNSPEC,
  61. .checkentry = connmark_mt_check,
  62. .match = connmark_mt,
  63. .matchsize = sizeof(struct xt_connmark_mtinfo1),
  64. .destroy = connmark_mt_destroy,
  65. .me = THIS_MODULE,
  66. };
  67. static int __init connmark_mt_init(void)
  68. {
  69. return xt_register_match(&connmark_mt_reg);
  70. }
  71. static void __exit connmark_mt_exit(void)
  72. {
  73. xt_unregister_match(&connmark_mt_reg);
  74. }
  75. module_init(connmark_mt_init);
  76. module_exit(connmark_mt_exit);