[IPV4] net/ipv4/arp.c: trivial annotations
[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
15 #include <linux/netfilter_bridge/ebtables.h>
16 #include <linux/netfilter_bridge/ebt_ip.h>
17 #include <linux/ip.h>
18 #include <net/ip.h>
19 #include <linux/in.h>
20 #include <linux/module.h>
21
22 struct tcpudphdr {
23         uint16_t src;
24         uint16_t dst;
25 };
26
27 static int ebt_filter_ip(const struct sk_buff *skb, const struct net_device *in,
28    const struct net_device *out, const void *data,
29    unsigned int datalen)
30 {
31         struct ebt_ip_info *info = (struct ebt_ip_info *)data;
32         struct iphdr _iph, *ih;
33         struct tcpudphdr _ports, *pptr;
34
35         ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
36         if (ih == NULL)
37                 return EBT_NOMATCH;
38         if (info->bitmask & EBT_IP_TOS &&
39            FWINV(info->tos != ih->tos, EBT_IP_TOS))
40                 return EBT_NOMATCH;
41         if (info->bitmask & EBT_IP_SOURCE &&
42            FWINV((ih->saddr & info->smsk) !=
43            info->saddr, EBT_IP_SOURCE))
44                 return EBT_NOMATCH;
45         if ((info->bitmask & EBT_IP_DEST) &&
46            FWINV((ih->daddr & info->dmsk) !=
47            info->daddr, EBT_IP_DEST))
48                 return EBT_NOMATCH;
49         if (info->bitmask & EBT_IP_PROTO) {
50                 if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO))
51                         return EBT_NOMATCH;
52                 if (!(info->bitmask & EBT_IP_DPORT) &&
53                     !(info->bitmask & EBT_IP_SPORT))
54                         return EBT_MATCH;
55                 if (ntohs(ih->frag_off) & IP_OFFSET)
56                         return EBT_NOMATCH;
57                 pptr = skb_header_pointer(skb, ih->ihl*4,
58                                           sizeof(_ports), &_ports);
59                 if (pptr == NULL)
60                         return EBT_NOMATCH;
61                 if (info->bitmask & EBT_IP_DPORT) {
62                         u32 dst = ntohs(pptr->dst);
63                         if (FWINV(dst < info->dport[0] ||
64                                   dst > info->dport[1],
65                                   EBT_IP_DPORT))
66                         return EBT_NOMATCH;
67                 }
68                 if (info->bitmask & EBT_IP_SPORT) {
69                         u32 src = ntohs(pptr->src);
70                         if (FWINV(src < info->sport[0] ||
71                                   src > info->sport[1],
72                                   EBT_IP_SPORT))
73                         return EBT_NOMATCH;
74                 }
75         }
76         return EBT_MATCH;
77 }
78
79 static int ebt_ip_check(const char *tablename, unsigned int hookmask,
80    const struct ebt_entry *e, void *data, unsigned int datalen)
81 {
82         struct ebt_ip_info *info = (struct ebt_ip_info *)data;
83
84         if (datalen != EBT_ALIGN(sizeof(struct ebt_ip_info)))
85                 return -EINVAL;
86         if (e->ethproto != htons(ETH_P_IP) ||
87            e->invflags & EBT_IPROTO)
88                 return -EINVAL;
89         if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK)
90                 return -EINVAL;
91         if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) {
92                 if (info->invflags & EBT_IP_PROTO)
93                         return -EINVAL;
94                 if (info->protocol != IPPROTO_TCP &&
95                     info->protocol != IPPROTO_UDP &&
96                     info->protocol != IPPROTO_SCTP &&
97                     info->protocol != IPPROTO_DCCP)
98                          return -EINVAL;
99         }
100         if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1])
101                 return -EINVAL;
102         if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1])
103                 return -EINVAL;
104         return 0;
105 }
106
107 static struct ebt_match filter_ip =
108 {
109         .name           = EBT_IP_MATCH,
110         .match          = ebt_filter_ip,
111         .check          = ebt_ip_check,
112         .me             = THIS_MODULE,
113 };
114
115 static int __init ebt_ip_init(void)
116 {
117         return ebt_register_match(&filter_ip);
118 }
119
120 static void __exit ebt_ip_fini(void)
121 {
122         ebt_unregister_match(&filter_ip);
123 }
124
125 module_init(ebt_ip_init);
126 module_exit(ebt_ip_fini);
127 MODULE_LICENSE("GPL");