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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
25union pkthdr {
26 struct {
27 __be16 src;
28 __be16 dst;
29 } tcpudphdr;
30 struct {
31 u8 type;
32 u8 code;
33 } icmphdr;
34};
35
36static bool
37ebt_ip6_mt(const struct sk_buff *skb, struct xt_action_param *par)
38{
39 const struct ebt_ip6_info *info = par->matchinfo;
40 const struct ipv6hdr *ih6;
41 struct ipv6hdr _ip6h;
42 const union pkthdr *pptr;
43 union pkthdr _pkthdr;
44
45 ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
46 if (ih6 == NULL)
47 return false;
48 if (info->bitmask & EBT_IP6_TCLASS &&
49 FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
50 return false;
51 if ((info->bitmask & EBT_IP6_SOURCE &&
52 FWINV(ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk,
53 &info->saddr), EBT_IP6_SOURCE)) ||
54 (info->bitmask & EBT_IP6_DEST &&
55 FWINV(ipv6_masked_addr_cmp(&ih6->daddr, &info->dmsk,
56 &info->daddr), EBT_IP6_DEST)))
57 return false;
58 if (info->bitmask & EBT_IP6_PROTO) {
59 uint8_t nexthdr = ih6->nexthdr;
60 __be16 frag_off;
61 int offset_ph;
62
63 offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr, &frag_off);
64 if (offset_ph == -1)
65 return false;
66 if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
67 return false;
68 if (!(info->bitmask & ( EBT_IP6_DPORT |
69 EBT_IP6_SPORT | EBT_IP6_ICMP6)))
70 return true;
71
72
73 pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr),
74 &_pkthdr);
75 if (pptr == NULL)
76 return false;
77 if (info->bitmask & EBT_IP6_DPORT) {
78 u16 dst = ntohs(pptr->tcpudphdr.dst);
79 if (FWINV(dst < info->dport[0] ||
80 dst > info->dport[1], EBT_IP6_DPORT))
81 return false;
82 }
83 if (info->bitmask & EBT_IP6_SPORT) {
84 u16 src = ntohs(pptr->tcpudphdr.src);
85 if (FWINV(src < info->sport[0] ||
86 src > info->sport[1], EBT_IP6_SPORT))
87 return false;
88 }
89 if ((info->bitmask & EBT_IP6_ICMP6) &&
90 FWINV(pptr->icmphdr.type < info->icmpv6_type[0] ||
91 pptr->icmphdr.type > info->icmpv6_type[1] ||
92 pptr->icmphdr.code < info->icmpv6_code[0] ||
93 pptr->icmphdr.code > info->icmpv6_code[1],
94 EBT_IP6_ICMP6))
95 return false;
96 }
97 return true;
98}
99
100static int ebt_ip6_mt_check(const struct xt_mtchk_param *par)
101{
102 const struct ebt_entry *e = par->entryinfo;
103 struct ebt_ip6_info *info = par->matchinfo;
104
105 if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
106 return -EINVAL;
107 if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
108 return -EINVAL;
109 if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
110 if (info->invflags & EBT_IP6_PROTO)
111 return -EINVAL;
112 if (info->protocol != IPPROTO_TCP &&
113 info->protocol != IPPROTO_UDP &&
114 info->protocol != IPPROTO_UDPLITE &&
115 info->protocol != IPPROTO_SCTP &&
116 info->protocol != IPPROTO_DCCP)
117 return -EINVAL;
118 }
119 if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
120 return -EINVAL;
121 if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
122 return -EINVAL;
123 if (info->bitmask & EBT_IP6_ICMP6) {
124 if ((info->invflags & EBT_IP6_PROTO) ||
125 info->protocol != IPPROTO_ICMPV6)
126 return -EINVAL;
127 if (info->icmpv6_type[0] > info->icmpv6_type[1] ||
128 info->icmpv6_code[0] > info->icmpv6_code[1])
129 return -EINVAL;
130 }
131 return 0;
132}
133
134static struct xt_match ebt_ip6_mt_reg __read_mostly = {
135 .name = "ip6",
136 .revision = 0,
137 .family = NFPROTO_BRIDGE,
138 .match = ebt_ip6_mt,
139 .checkentry = ebt_ip6_mt_check,
140 .matchsize = sizeof(struct ebt_ip6_info),
141 .me = THIS_MODULE,
142};
143
144static int __init ebt_ip6_init(void)
145{
146 return xt_register_match(&ebt_ip6_mt_reg);
147}
148
149static void __exit ebt_ip6_fini(void)
150{
151 xt_unregister_match(&ebt_ip6_mt_reg);
152}
153
154module_init(ebt_ip6_init);
155module_exit(ebt_ip6_fini);
156MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
157MODULE_AUTHOR("Kuo-Lang Tseng <kuo-lang.tseng@intel.com>");
158MODULE_LICENSE("GPL");
159
