netfilter: xtables: move extension arguments into compound structure (4/6)
[linux-2.6] / net / bridge / netfilter / ebt_ip.c
1 /*
2  *  ebt_ip
3  *
4  *      Authors:
5  *      Bart De Schuymer <bdschuym@pandora.be>
6  *
7  *  April, 2002
8  *
9  *  Changes:
10  *    added ip-sport and ip-dport
11  *    Innominate Security Technologies AG <mhopf@innominate.com>
12  *    September, 2002
13  */
14 #include <linux/ip.h>
15 #include <net/ip.h>
16 #include <linux/in.h>
17 #include <linux/module.h>
18 #include <linux/netfilter/x_tables.h>
19 #include <linux/netfilter_bridge/ebtables.h>
20 #include <linux/netfilter_bridge/ebt_ip.h>
21
22 struct tcpudphdr {
23         __be16 src;
24         __be16 dst;
25 };
26
27 static bool
28 ebt_ip_mt(const struct sk_buff *skb, const struct xt_match_param *par)
29 {
30         const struct ebt_ip_info *info = par->matchinfo;
31         const struct iphdr *ih;
32         struct iphdr _iph;
33         const struct tcpudphdr *pptr;
34         struct tcpudphdr _ports;
35
36         ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
37         if (ih == NULL)
38                 return false;
39         if (info->bitmask & EBT_IP_TOS &&
40            FWINV(info->tos != ih->tos, EBT_IP_TOS))
41                 return false;
42         if (info->bitmask & EBT_IP_SOURCE &&
43            FWINV((ih->saddr & info->smsk) !=
44            info->saddr, EBT_IP_SOURCE))
45                 return false;
46         if ((info->bitmask & EBT_IP_DEST) &&
47            FWINV((ih->daddr & info->dmsk) !=
48            info->daddr, EBT_IP_DEST))
49                 return false;
50         if (info->bitmask & EBT_IP_PROTO) {
51                 if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO))
52                         return false;
53                 if (!(info->bitmask & EBT_IP_DPORT) &&
54                     !(info->bitmask & EBT_IP_SPORT))
55                         return true;
56                 if (ntohs(ih->frag_off) & IP_OFFSET)
57                         return false;
58                 pptr = skb_header_pointer(skb, ih->ihl*4,
59                                           sizeof(_ports), &_ports);
60                 if (pptr == NULL)
61                         return false;
62                 if (info->bitmask & EBT_IP_DPORT) {
63                         u32 dst = ntohs(pptr->dst);
64                         if (FWINV(dst < info->dport[0] ||
65                                   dst > info->dport[1],
66                                   EBT_IP_DPORT))
67                         return false;
68                 }
69                 if (info->bitmask & EBT_IP_SPORT) {
70                         u32 src = ntohs(pptr->src);
71                         if (FWINV(src < info->sport[0] ||
72                                   src > info->sport[1],
73                                   EBT_IP_SPORT))
74                         return false;
75                 }
76         }
77         return true;
78 }
79
80 static bool ebt_ip_mt_check(const struct xt_mtchk_param *par)
81 {
82         const struct ebt_ip_info *info = par->matchinfo;
83         const struct ebt_entry *e = par->entryinfo;
84
85         if (e->ethproto != htons(ETH_P_IP) ||
86            e->invflags & EBT_IPROTO)
87                 return false;
88         if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK)
89                 return false;
90         if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) {
91                 if (info->invflags & EBT_IP_PROTO)
92                         return false;
93                 if (info->protocol != IPPROTO_TCP &&
94                     info->protocol != IPPROTO_UDP &&
95                     info->protocol != IPPROTO_UDPLITE &&
96                     info->protocol != IPPROTO_SCTP &&
97                     info->protocol != IPPROTO_DCCP)
98                          return false;
99         }
100         if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1])
101                 return false;
102         if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1])
103                 return false;
104         return true;
105 }
106
107 static struct xt_match ebt_ip_mt_reg __read_mostly = {
108         .name           = "ip",
109         .revision       = 0,
110         .family         = NFPROTO_BRIDGE,
111         .match          = ebt_ip_mt,
112         .checkentry     = ebt_ip_mt_check,
113         .matchsize      = XT_ALIGN(sizeof(struct ebt_ip_info)),
114         .me             = THIS_MODULE,
115 };
116
117 static int __init ebt_ip_init(void)
118 {
119         return xt_register_match(&ebt_ip_mt_reg);
120 }
121
122 static void __exit ebt_ip_fini(void)
123 {
124         xt_unregister_match(&ebt_ip_mt_reg);
125 }
126
127 module_init(ebt_ip_init);
128 module_exit(ebt_ip_fini);
129 MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match");
130 MODULE_LICENSE("GPL");