netfilter: ebtables: avoid explicit XT_ALIGN() in match/targets
[linux-2.6.git] / net / bridge / netfilter / ebt_ip6.c
1 /*
2  *  ebt_ip6
3  *
4  *      Authors:
5  *      Manohar Castelino <manohar.r.castelino@intel.com>
6  *      Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
7  *      Jan Engelhardt <jengelh@computergmbh.de>
8  *
9  * Summary:
10  * This is just a modification of the IPv4 code written by
11  * Bart De Schuymer <bdschuym@pandora.be>
12  * with the changes required to support IPv6
13  *
14  *  Jan, 2008
15  */
16 #include <linux/ipv6.h>
17 #include <net/ipv6.h>
18 #include <linux/in.h>
19 #include <linux/module.h>
20 #include <net/dsfield.h>
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter_bridge/ebtables.h>
23 #include <linux/netfilter_bridge/ebt_ip6.h>
24
25 struct tcpudphdr {
26         __be16 src;
27         __be16 dst;
28 };
29
30 static bool
31 ebt_ip6_mt(const struct sk_buff *skb, const struct xt_match_param *par)
32 {
33         const struct ebt_ip6_info *info = par->matchinfo;
34         const struct ipv6hdr *ih6;
35         struct ipv6hdr _ip6h;
36         const struct tcpudphdr *pptr;
37         struct tcpudphdr _ports;
38         struct in6_addr tmp_addr;
39         int i;
40
41         ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
42         if (ih6 == NULL)
43                 return false;
44         if (info->bitmask & EBT_IP6_TCLASS &&
45            FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
46                 return false;
47         for (i = 0; i < 4; i++)
48                 tmp_addr.in6_u.u6_addr32[i] = ih6->saddr.in6_u.u6_addr32[i] &
49                         info->smsk.in6_u.u6_addr32[i];
50         if (info->bitmask & EBT_IP6_SOURCE &&
51                 FWINV((ipv6_addr_cmp(&tmp_addr, &info->saddr) != 0),
52                         EBT_IP6_SOURCE))
53                 return false;
54         for (i = 0; i < 4; i++)
55                 tmp_addr.in6_u.u6_addr32[i] = ih6->daddr.in6_u.u6_addr32[i] &
56                         info->dmsk.in6_u.u6_addr32[i];
57         if (info->bitmask & EBT_IP6_DEST &&
58            FWINV((ipv6_addr_cmp(&tmp_addr, &info->daddr) != 0), EBT_IP6_DEST))
59                 return false;
60         if (info->bitmask & EBT_IP6_PROTO) {
61                 uint8_t nexthdr = ih6->nexthdr;
62                 int offset_ph;
63
64                 offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr);
65                 if (offset_ph == -1)
66                         return false;
67                 if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
68                         return false;
69                 if (!(info->bitmask & EBT_IP6_DPORT) &&
70                     !(info->bitmask & EBT_IP6_SPORT))
71                         return true;
72                 pptr = skb_header_pointer(skb, offset_ph, sizeof(_ports),
73                                           &_ports);
74                 if (pptr == NULL)
75                         return false;
76                 if (info->bitmask & EBT_IP6_DPORT) {
77                         u32 dst = ntohs(pptr->dst);
78                         if (FWINV(dst < info->dport[0] ||
79                                   dst > info->dport[1], EBT_IP6_DPORT))
80                                 return false;
81                 }
82                 if (info->bitmask & EBT_IP6_SPORT) {
83                         u32 src = ntohs(pptr->src);
84                         if (FWINV(src < info->sport[0] ||
85                                   src > info->sport[1], EBT_IP6_SPORT))
86                         return false;
87                 }
88                 return true;
89         }
90         return true;
91 }
92
93 static bool ebt_ip6_mt_check(const struct xt_mtchk_param *par)
94 {
95         const struct ebt_entry *e = par->entryinfo;
96         struct ebt_ip6_info *info = par->matchinfo;
97
98         if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
99                 return false;
100         if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
101                 return false;
102         if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
103                 if (info->invflags & EBT_IP6_PROTO)
104                         return false;
105                 if (info->protocol != IPPROTO_TCP &&
106                     info->protocol != IPPROTO_UDP &&
107                     info->protocol != IPPROTO_UDPLITE &&
108                     info->protocol != IPPROTO_SCTP &&
109                     info->protocol != IPPROTO_DCCP)
110                         return false;
111         }
112         if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
113                 return false;
114         if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
115                 return false;
116         return true;
117 }
118
119 static struct xt_match ebt_ip6_mt_reg __read_mostly = {
120         .name           = "ip6",
121         .revision       = 0,
122         .family         = NFPROTO_BRIDGE,
123         .match          = ebt_ip6_mt,
124         .checkentry     = ebt_ip6_mt_check,
125         .matchsize      = sizeof(struct ebt_ip6_info),
126         .me             = THIS_MODULE,
127 };
128
129 static int __init ebt_ip6_init(void)
130 {
131         return xt_register_match(&ebt_ip6_mt_reg);
132 }
133
134 static void __exit ebt_ip6_fini(void)
135 {
136         xt_unregister_match(&ebt_ip6_mt_reg);
137 }
138
139 module_init(ebt_ip6_init);
140 module_exit(ebt_ip6_fini);
141 MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
142 MODULE_LICENSE("GPL");