x25: use limited socket backlog
[linux-2.6.git] / net / netfilter / xt_dscp.c
1 /* IP tables module for matching the value of the IPv4/IPv6 DSCP field
2  *
3  * (C) 2002 by Harald Welte <laforge@netfilter.org>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/ip.h>
13 #include <linux/ipv6.h>
14 #include <net/dsfield.h>
15
16 #include <linux/netfilter/x_tables.h>
17 #include <linux/netfilter/xt_dscp.h>
18
19 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
20 MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
21 MODULE_LICENSE("GPL");
22 MODULE_ALIAS("ipt_dscp");
23 MODULE_ALIAS("ip6t_dscp");
24 MODULE_ALIAS("ipt_tos");
25 MODULE_ALIAS("ip6t_tos");
26
27 static bool
28 dscp_mt(const struct sk_buff *skb, const struct xt_match_param *par)
29 {
30         const struct xt_dscp_info *info = par->matchinfo;
31         u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
32
33         return (dscp == info->dscp) ^ !!info->invert;
34 }
35
36 static bool
37 dscp_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
38 {
39         const struct xt_dscp_info *info = par->matchinfo;
40         u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
41
42         return (dscp == info->dscp) ^ !!info->invert;
43 }
44
45 static bool dscp_mt_check(const struct xt_mtchk_param *par)
46 {
47         const struct xt_dscp_info *info = par->matchinfo;
48
49         if (info->dscp > XT_DSCP_MAX) {
50                 printk(KERN_ERR "xt_dscp: dscp %x out of range\n", info->dscp);
51                 return false;
52         }
53
54         return true;
55 }
56
57 static bool tos_mt(const struct sk_buff *skb, const struct xt_match_param *par)
58 {
59         const struct xt_tos_match_info *info = par->matchinfo;
60
61         if (par->match->family == NFPROTO_IPV4)
62                 return ((ip_hdr(skb)->tos & info->tos_mask) ==
63                        info->tos_value) ^ !!info->invert;
64         else
65                 return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
66                        info->tos_value) ^ !!info->invert;
67 }
68
69 static struct xt_match dscp_mt_reg[] __read_mostly = {
70         {
71                 .name           = "dscp",
72                 .family         = NFPROTO_IPV4,
73                 .checkentry     = dscp_mt_check,
74                 .match          = dscp_mt,
75                 .matchsize      = sizeof(struct xt_dscp_info),
76                 .me             = THIS_MODULE,
77         },
78         {
79                 .name           = "dscp",
80                 .family         = NFPROTO_IPV6,
81                 .checkentry     = dscp_mt_check,
82                 .match          = dscp_mt6,
83                 .matchsize      = sizeof(struct xt_dscp_info),
84                 .me             = THIS_MODULE,
85         },
86         {
87                 .name           = "tos",
88                 .revision       = 1,
89                 .family         = NFPROTO_IPV4,
90                 .match          = tos_mt,
91                 .matchsize      = sizeof(struct xt_tos_match_info),
92                 .me             = THIS_MODULE,
93         },
94         {
95                 .name           = "tos",
96                 .revision       = 1,
97                 .family         = NFPROTO_IPV6,
98                 .match          = tos_mt,
99                 .matchsize      = sizeof(struct xt_tos_match_info),
100                 .me             = THIS_MODULE,
101         },
102 };
103
104 static int __init dscp_mt_init(void)
105 {
106         return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
107 }
108
109 static void __exit dscp_mt_exit(void)
110 {
111         xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
112 }
113
114 module_init(dscp_mt_init);
115 module_exit(dscp_mt_exit);