| 1 | |
| 2 | |
| 3 | * Copyright (c) 2011 Patrick McHardy <[email protected]>
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| 4 |
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| 5 |
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| 6 | #include <linux/module.h>
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| 7 | #include <linux/skbuff.h>
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| 8 | #include <linux/netdevice.h>
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| 9 |
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| 10 | #include <linux/netfilter/xt_devgroup.h>
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| 11 | #include <linux/netfilter/x_tables.h>
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| 12 |
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| 13 | MODULE_AUTHOR("Patrick McHardy <[email protected]>");
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| 14 | MODULE_LICENSE("GPL");
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| 15 | MODULE_DESCRIPTION("Xtables: Device group match");
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| 16 | MODULE_ALIAS("ipt_devgroup");
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| 17 | MODULE_ALIAS("ip6t_devgroup");
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| 18 |
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| 19 | static bool devgroup_mt(const struct sk_buff *skb, struct xt_action_param *par)
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| 20 | {
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| 21 | const struct xt_devgroup_info *info = par->matchinfo;
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| 22 |
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| 23 | if (info->flags & XT_DEVGROUP_MATCH_SRC &&
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| 24 | (((info->src_group ^ xt_in(par)->group) & info->src_mask ? 1 : 0) ^
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| 25 | ((info->flags & XT_DEVGROUP_INVERT_SRC) ? 1 : 0)))
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| 26 | return false;
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| 27 |
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| 28 | if (info->flags & XT_DEVGROUP_MATCH_DST &&
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| 29 | (((info->dst_group ^ xt_out(par)->group) & info->dst_mask ? 1 : 0) ^
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| 30 | ((info->flags & XT_DEVGROUP_INVERT_DST) ? 1 : 0)))
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| 31 | return false;
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| 32 |
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| 33 | return true;
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| 34 | }
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| 35 |
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| 36 | static int devgroup_mt_check_hooks(const struct xt_mtchk_param *par)
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| 37 | {
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| 38 | const struct xt_devgroup_info *info = par->matchinfo;
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| 39 |
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| 40 | if (info->flags & XT_DEVGROUP_MATCH_SRC &&
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| 41 | par->hook_mask & ~((1 << NF_INET_PRE_ROUTING) |
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| 42 | (1 << NF_INET_LOCAL_IN) |
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| 43 | (1 << NF_INET_FORWARD)))
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| 44 | return -EINVAL;
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| 45 |
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| 46 | if (info->flags & XT_DEVGROUP_MATCH_DST &&
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| 47 | par->hook_mask & ~((1 << NF_INET_FORWARD) |
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| 48 | (1 << NF_INET_LOCAL_OUT) |
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| 49 | (1 << NF_INET_POST_ROUTING)))
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| 50 | return -EINVAL;
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| 51 |
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| 52 | return 0;
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| 53 | }
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| 54 |
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| 55 | static int devgroup_mt_checkentry(const struct xt_mtchk_param *par)
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| 56 | {
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| 57 | const struct xt_devgroup_info *info = par->matchinfo;
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| 58 |
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| 59 | if (info->flags & ~(XT_DEVGROUP_MATCH_SRC | XT_DEVGROUP_INVERT_SRC |
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| 60 | XT_DEVGROUP_MATCH_DST | XT_DEVGROUP_INVERT_DST))
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| 61 | return -EINVAL;
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| 62 |
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| 63 | return 0;
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| 64 | }
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| 65 |
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| 66 | static struct xt_match devgroup_mt_reg __read_mostly = {
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| 67 | .name = "devgroup",
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| 68 | .match = devgroup_mt,
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| 69 | .check_hooks = devgroup_mt_check_hooks,
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| 70 | .checkentry = devgroup_mt_checkentry,
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| 71 | .matchsize = sizeof(struct xt_devgroup_info),
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| 72 | .family = NFPROTO_UNSPEC,
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| 73 | .me = THIS_MODULE
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| 74 | };
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| 75 |
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| 76 | static int __init devgroup_mt_init(void)
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| 77 | {
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| 78 | return xt_register_match(&devgroup_mt_reg);
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| 79 | }
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| 80 |
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| 81 | static void __exit devgroup_mt_exit(void)
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| 82 | {
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| 83 | xt_unregister_match(&devgroup_mt_reg);
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| 84 | }
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| 85 |
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| 86 | module_init(devgroup_mt_init);
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| 87 | module_exit(devgroup_mt_exit);
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