[NETFILTER]: nf_conntrack: use extension infrastructure for helper
[linux-2.6] / 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/xt_dscp.h>
17 #include <linux/netfilter/x_tables.h>
18
19 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
20 MODULE_DESCRIPTION("x_tables DSCP matching module");
21 MODULE_LICENSE("GPL");
22 MODULE_ALIAS("ipt_dscp");
23 MODULE_ALIAS("ip6t_dscp");
24
25 static bool match(const struct sk_buff *skb,
26                   const struct net_device *in,
27                   const struct net_device *out,
28                   const struct xt_match *match,
29                   const void *matchinfo,
30                   int offset,
31                   unsigned int protoff,
32                   bool *hotdrop)
33 {
34         const struct xt_dscp_info *info = matchinfo;
35         u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
36
37         return (dscp == info->dscp) ^ !!info->invert;
38 }
39
40 static bool match6(const struct sk_buff *skb,
41                    const struct net_device *in,
42                    const struct net_device *out,
43                    const struct xt_match *match,
44                    const void *matchinfo,
45                    int offset,
46                    unsigned int protoff,
47                    bool *hotdrop)
48 {
49         const struct xt_dscp_info *info = matchinfo;
50         u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
51
52         return (dscp == info->dscp) ^ !!info->invert;
53 }
54
55 static bool checkentry(const char *tablename,
56                        const void *info,
57                        const struct xt_match *match,
58                        void *matchinfo,
59                        unsigned int hook_mask)
60 {
61         const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp;
62
63         if (dscp > XT_DSCP_MAX) {
64                 printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp);
65                 return false;
66         }
67
68         return true;
69 }
70
71 static struct xt_match xt_dscp_match[] __read_mostly = {
72         {
73                 .name           = "dscp",
74                 .family         = AF_INET,
75                 .checkentry     = checkentry,
76                 .match          = match,
77                 .matchsize      = sizeof(struct xt_dscp_info),
78                 .me             = THIS_MODULE,
79         },
80         {
81                 .name           = "dscp",
82                 .family         = AF_INET6,
83                 .checkentry     = checkentry,
84                 .match          = match6,
85                 .matchsize      = sizeof(struct xt_dscp_info),
86                 .me             = THIS_MODULE,
87         },
88 };
89
90 static int __init xt_dscp_match_init(void)
91 {
92         return xt_register_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
93 }
94
95 static void __exit xt_dscp_match_fini(void)
96 {
97         xt_unregister_matches(xt_dscp_match, ARRAY_SIZE(xt_dscp_match));
98 }
99
100 module_init(xt_dscp_match_init);
101 module_exit(xt_dscp_match_fini);