Merge branches 'release' and 'ppc-workaround' into release
[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/x_tables.h>
17 #include <linux/netfilter/xt_dscp.h>
18 #include <linux/netfilter_ipv4/ipt_tos.h>
19
20 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
21 MODULE_DESCRIPTION("Xtables: DSCP/TOS field match");
22 MODULE_LICENSE("GPL");
23 MODULE_ALIAS("ipt_dscp");
24 MODULE_ALIAS("ip6t_dscp");
25 MODULE_ALIAS("ipt_tos");
26 MODULE_ALIAS("ip6t_tos");
27
28 static bool
29 dscp_mt(const struct sk_buff *skb, const struct net_device *in,
30         const struct net_device *out, const struct xt_match *match,
31         const void *matchinfo, int offset, unsigned int protoff, bool *hotdrop)
32 {
33         const struct xt_dscp_info *info = matchinfo;
34         u_int8_t dscp = ipv4_get_dsfield(ip_hdr(skb)) >> XT_DSCP_SHIFT;
35
36         return (dscp == info->dscp) ^ !!info->invert;
37 }
38
39 static bool
40 dscp_mt6(const struct sk_buff *skb, const struct net_device *in,
41          const struct net_device *out, const struct xt_match *match,
42          const void *matchinfo, int offset, unsigned int protoff,
43          bool *hotdrop)
44 {
45         const struct xt_dscp_info *info = matchinfo;
46         u_int8_t dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> XT_DSCP_SHIFT;
47
48         return (dscp == info->dscp) ^ !!info->invert;
49 }
50
51 static bool
52 dscp_mt_check(const char *tablename, const void *info,
53               const struct xt_match *match, void *matchinfo,
54               unsigned int hook_mask)
55 {
56         const u_int8_t dscp = ((struct xt_dscp_info *)matchinfo)->dscp;
57
58         if (dscp > XT_DSCP_MAX) {
59                 printk(KERN_ERR "xt_dscp: dscp %x out of range\n", dscp);
60                 return false;
61         }
62
63         return true;
64 }
65
66 static bool tos_mt_v0(const struct sk_buff *skb, const struct net_device *in,
67                       const struct net_device *out,
68                       const struct xt_match *match, const void *matchinfo,
69                       int offset, unsigned int protoff, bool *hotdrop)
70 {
71         const struct ipt_tos_info *info = matchinfo;
72
73         return (ip_hdr(skb)->tos == info->tos) ^ info->invert;
74 }
75
76 static bool tos_mt(const struct sk_buff *skb, const struct net_device *in,
77                    const struct net_device *out, const struct xt_match *match,
78                    const void *matchinfo, int offset, unsigned int protoff,
79                    bool *hotdrop)
80 {
81         const struct xt_tos_match_info *info = matchinfo;
82
83         if (match->family == AF_INET)
84                 return ((ip_hdr(skb)->tos & info->tos_mask) ==
85                        info->tos_value) ^ !!info->invert;
86         else
87                 return ((ipv6_get_dsfield(ipv6_hdr(skb)) & info->tos_mask) ==
88                        info->tos_value) ^ !!info->invert;
89 }
90
91 static struct xt_match dscp_mt_reg[] __read_mostly = {
92         {
93                 .name           = "dscp",
94                 .family         = AF_INET,
95                 .checkentry     = dscp_mt_check,
96                 .match          = dscp_mt,
97                 .matchsize      = sizeof(struct xt_dscp_info),
98                 .me             = THIS_MODULE,
99         },
100         {
101                 .name           = "dscp",
102                 .family         = AF_INET6,
103                 .checkentry     = dscp_mt_check,
104                 .match          = dscp_mt6,
105                 .matchsize      = sizeof(struct xt_dscp_info),
106                 .me             = THIS_MODULE,
107         },
108         {
109                 .name           = "tos",
110                 .revision       = 0,
111                 .family         = AF_INET,
112                 .match          = tos_mt_v0,
113                 .matchsize      = sizeof(struct ipt_tos_info),
114                 .me             = THIS_MODULE,
115         },
116         {
117                 .name           = "tos",
118                 .revision       = 1,
119                 .family         = AF_INET,
120                 .match          = tos_mt,
121                 .matchsize      = sizeof(struct xt_tos_match_info),
122                 .me             = THIS_MODULE,
123         },
124         {
125                 .name           = "tos",
126                 .revision       = 1,
127                 .family         = AF_INET6,
128                 .match          = tos_mt,
129                 .matchsize      = sizeof(struct xt_tos_match_info),
130                 .me             = THIS_MODULE,
131         },
132 };
133
134 static int __init dscp_mt_init(void)
135 {
136         return xt_register_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
137 }
138
139 static void __exit dscp_mt_exit(void)
140 {
141         xt_unregister_matches(dscp_mt_reg, ARRAY_SIZE(dscp_mt_reg));
142 }
143
144 module_init(dscp_mt_init);
145 module_exit(dscp_mt_exit);