net/netfilter/xt_NFLOG.c

   1 /*
   2  * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/skbuff.h>
  12
  13 #include <linux/netfilter/x_tables.h>
  14 #include <linux/netfilter/xt_NFLOG.h>
  15 #include <net/netfilter/nf_log.h>
  16
  17 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  18 MODULE_DESCRIPTION("Xtables: packet logging to netlink using NFLOG");
  19 MODULE_LICENSE("GPL");
  20 MODULE_ALIAS("ipt_NFLOG");
  21 MODULE_ALIAS("ip6t_NFLOG");
  22
  23 static unsigned int
  24 nflog_tg(struct sk_buff *skb, const struct xt_action_param *par)
  25 {
  26         const struct xt_nflog_info *info = par->targinfo;
  27         struct net *net = xt_net(par);
  28         struct nf_loginfo li;
  29
  30         li.type              = NF_LOG_TYPE_ULOG;
  31         li.u.ulog.copy_len   = info->len;
  32         li.u.ulog.group      = info->group;
  33         li.u.ulog.qthreshold = info->threshold;
  34         li.u.ulog.flags      = 0;
  35
  36         if (info->flags & XT_NFLOG_F_COPY_LEN)
  37                 li.u.ulog.flags |= NF_LOG_F_COPY_LEN;
  38
  39         nf_log_packet(net, xt_family(par), xt_hooknum(par), skb, xt_in(par),
  40                       xt_out(par), &li, "%s", info->prefix);
  41
  42         return XT_CONTINUE;
  43 }
  44
  45 static int nflog_tg_check(const struct xt_tgchk_param *par)
  46 {
  47         const struct xt_nflog_info *info = par->targinfo;
  48
  49         if (info->flags & ~XT_NFLOG_MASK)
  50                 return -EINVAL;
  51         if (info->prefix[sizeof(info->prefix) - 1] != '\0')
  52                 return -EINVAL;
  53
  54         return nf_logger_find_get(par->family, NF_LOG_TYPE_ULOG);
  55 }
  56
  57 static void nflog_tg_destroy(const struct xt_tgdtor_param *par)
  58 {
  59         nf_logger_put(par->family, NF_LOG_TYPE_ULOG);
  60 }
  61
  62 static struct xt_target nflog_tg_reg __read_mostly = {
  63         .name       = "NFLOG",
  64         .revision   = 0,
  65         .family     = NFPROTO_UNSPEC,
  66         .checkentry = nflog_tg_check,
  67         .destroy    = nflog_tg_destroy,
  68         .target     = nflog_tg,
  69         .targetsize = sizeof(struct xt_nflog_info),
  70         .me         = THIS_MODULE,
  71 };
  72
  73 static int __init nflog_tg_init(void)
  74 {
  75         return xt_register_target(&nflog_tg_reg);
  76 }
  77
  78 static void __exit nflog_tg_exit(void)
  79 {
  80         xt_unregister_target(&nflog_tg_reg);
  81 }
  82
  83 module_init(nflog_tg_init);
  84 module_exit(nflog_tg_exit);