LXR linux/net/netfilter/xt

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>
   4 */
   5
   6#include <linux/module.h>
   7#include <linux/skbuff.h>
   8#include <linux/netdevice.h>
   9
  10#include <linux/netfilter/xt_devgroup.h>
  11#include <linux/netfilter/x_tables.h>
  12
  13MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
  14MODULE_LICENSE("GPL");
  15MODULE_DESCRIPTION("Xtables: Device group match");
  16MODULE_ALIAS("ipt_devgroup");
  17MODULE_ALIAS("ip6t_devgroup");
  18
  19static bool devgroup_mt(const struct sk_buff *skb, struct xt_action_param *par)
  20{
  21        const struct xt_devgroup_info *info = par->matchinfo;
  22
  23        if (info->flags & XT_DEVGROUP_MATCH_SRC &&
  24            (((info->src_group ^ xt_in(par)->group) & info->src_mask ? 1 : 0) ^
  25             ((info->flags & XT_DEVGROUP_INVERT_SRC) ? 1 : 0)))
  26                return false;
  27
  28        if (info->flags & XT_DEVGROUP_MATCH_DST &&
  29            (((info->dst_group ^ xt_out(par)->group) & info->dst_mask ? 1 : 0) ^
  30             ((info->flags & XT_DEVGROUP_INVERT_DST) ? 1 : 0)))
  31                return false;
  32
  33        return true;
  34}
  35
  36static int devgroup_mt_checkentry(const struct xt_mtchk_param *par)
  37{
  38        const struct xt_devgroup_info *info = par->matchinfo;
  39
  40        if (info->flags & ~(XT_DEVGROUP_MATCH_SRC | XT_DEVGROUP_INVERT_SRC |
  41                            XT_DEVGROUP_MATCH_DST | XT_DEVGROUP_INVERT_DST))
  42                return -EINVAL;
  43
  44        if (info->flags & XT_DEVGROUP_MATCH_SRC &&
  45            par->hook_mask & ~((1 << NF_INET_PRE_ROUTING) |
  46                               (1 << NF_INET_LOCAL_IN) |
  47                               (1 << NF_INET_FORWARD)))
  48                return -EINVAL;
  49
  50        if (info->flags & XT_DEVGROUP_MATCH_DST &&
  51            par->hook_mask & ~((1 << NF_INET_FORWARD) |
  52                               (1 << NF_INET_LOCAL_OUT) |
  53                               (1 << NF_INET_POST_ROUTING)))
  54                return -EINVAL;
  55
  56        return 0;
  57}
  58
  59static struct xt_match devgroup_mt_reg __read_mostly = {
  60        .name           = "devgroup",
  61        .match          = devgroup_mt,
  62        .checkentry     = devgroup_mt_checkentry,
  63        .matchsize      = sizeof(struct xt_devgroup_info),
  64        .family         = NFPROTO_UNSPEC,
  65        .me             = THIS_MODULE
  66};
  67
  68static int __init devgroup_mt_init(void)
  69{
  70        return xt_register_match(&devgroup_mt_reg);
  71}
  72
  73static void __exit devgroup_mt_exit(void)
  74{
  75        xt_unregister_match(&devgroup_mt_reg);
  76}
  77
  78module_init(devgroup_mt_init);
  79module_exit(devgroup_mt_exit);
  80