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c539f017 FW |
1 | /* |
2 | * (C) 2013 Astaro GmbH & Co KG | |
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/skbuff.h> | |
11 | #include <net/netfilter/nf_conntrack.h> | |
12 | #include <net/netfilter/nf_conntrack_labels.h> | |
13 | #include <linux/netfilter/x_tables.h> | |
14 | ||
15 | MODULE_LICENSE("GPL"); | |
16 | MODULE_AUTHOR("Florian Westphal <fw@strlen.de>"); | |
17 | MODULE_DESCRIPTION("Xtables: add/match connection trackling labels"); | |
18 | MODULE_ALIAS("ipt_connlabel"); | |
19 | MODULE_ALIAS("ip6t_connlabel"); | |
20 | ||
b4ef1599 FW |
21 | static bool connlabel_match(const struct nf_conn *ct, u16 bit) |
22 | { | |
23 | struct nf_conn_labels *labels = nf_ct_labels_find(ct); | |
24 | ||
25 | if (!labels) | |
26 | return false; | |
27 | ||
28 | return BIT_WORD(bit) < labels->words && test_bit(bit, labels->bits); | |
29 | } | |
30 | ||
c539f017 FW |
31 | static bool |
32 | connlabel_mt(const struct sk_buff *skb, struct xt_action_param *par) | |
33 | { | |
34 | const struct xt_connlabel_mtinfo *info = par->matchinfo; | |
35 | enum ip_conntrack_info ctinfo; | |
36 | struct nf_conn *ct; | |
37 | bool invert = info->options & XT_CONNLABEL_OP_INVERT; | |
38 | ||
39 | ct = nf_ct_get(skb, &ctinfo); | |
40 | if (ct == NULL || nf_ct_is_untracked(ct)) | |
41 | return invert; | |
42 | ||
43 | if (info->options & XT_CONNLABEL_OP_SET) | |
44 | return (nf_connlabel_set(ct, info->bit) == 0) ^ invert; | |
45 | ||
b4ef1599 | 46 | return connlabel_match(ct, info->bit) ^ invert; |
c539f017 FW |
47 | } |
48 | ||
49 | static int connlabel_mt_check(const struct xt_mtchk_param *par) | |
50 | { | |
51 | const int options = XT_CONNLABEL_OP_INVERT | | |
52 | XT_CONNLABEL_OP_SET; | |
53 | struct xt_connlabel_mtinfo *info = par->matchinfo; | |
54 | int ret; | |
c539f017 FW |
55 | |
56 | if (info->options & ~options) { | |
57 | pr_err("Unknown options in mask %x\n", info->options); | |
58 | return -EINVAL; | |
59 | } | |
60 | ||
61 | ret = nf_ct_l3proto_try_module_get(par->family); | |
62 | if (ret < 0) { | |
63 | pr_info("cannot load conntrack support for proto=%u\n", | |
64 | par->family); | |
65 | return ret; | |
66 | } | |
67 | ||
86ca02e7 JS |
68 | ret = nf_connlabels_get(par->net, info->bit + 1); |
69 | if (ret < 0) | |
70 | nf_ct_l3proto_module_put(par->family); | |
c539f017 FW |
71 | return ret; |
72 | } | |
73 | ||
74 | static void connlabel_mt_destroy(const struct xt_mtdtor_param *par) | |
75 | { | |
86ca02e7 | 76 | nf_connlabels_put(par->net); |
c539f017 FW |
77 | nf_ct_l3proto_module_put(par->family); |
78 | } | |
79 | ||
80 | static struct xt_match connlabels_mt_reg __read_mostly = { | |
81 | .name = "connlabel", | |
82 | .family = NFPROTO_UNSPEC, | |
83 | .checkentry = connlabel_mt_check, | |
84 | .match = connlabel_mt, | |
85 | .matchsize = sizeof(struct xt_connlabel_mtinfo), | |
86 | .destroy = connlabel_mt_destroy, | |
87 | .me = THIS_MODULE, | |
88 | }; | |
89 | ||
90 | static int __init connlabel_mt_init(void) | |
91 | { | |
92 | return xt_register_match(&connlabels_mt_reg); | |
93 | } | |
94 | ||
95 | static void __exit connlabel_mt_exit(void) | |
96 | { | |
97 | xt_unregister_match(&connlabels_mt_reg); | |
98 | } | |
99 | ||
100 | module_init(connlabel_mt_init); | |
101 | module_exit(connlabel_mt_exit); |