1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* ebt_ip6
*
* Authors:
* Manohar Castelino <manohar.r.castelino@intel.com>
* Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
* Jan Engelhardt <jengelh@medozas.de>
*
* Summary:
* This is just a modification of the IPv4 code written by
* Bart De Schuymer <bdschuym@pandora.be>
* with the changes required to support IPv6
*
* Jan, 2008
*/
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <linux/in.h>
#include <linux/module.h>
#include <net/dsfield.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_ip6.h>
union pkthdr {
struct {
__be16 src;
__be16 dst;
} tcpudphdr;
struct {
u8 type;
u8 code;
} icmphdr;
};
static bool
ebt_ip6_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct ebt_ip6_info *info = par->matchinfo;
const struct ipv6hdr *ih6;
struct ipv6hdr _ip6h;
const union pkthdr *pptr;
union pkthdr _pkthdr;
ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
if (ih6 == NULL)
return false;
if (info->bitmask & EBT_IP6_TCLASS &&
FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
return false;
if ((info->bitmask & EBT_IP6_SOURCE &&
FWINV(ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk,
&info->saddr), EBT_IP6_SOURCE)) ||
(info->bitmask & EBT_IP6_DEST &&
FWINV(ipv6_masked_addr_cmp(&ih6->daddr, &info->dmsk,
&info->daddr), EBT_IP6_DEST)))
return false;
if (info->bitmask & EBT_IP6_PROTO) {
uint8_t nexthdr = ih6->nexthdr;
__be16 frag_off;
int offset_ph;
offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr, &frag_off);
if (offset_ph == -1)
return false;
if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
return false;
if (!(info->bitmask & (EBT_IP6_DPORT |
EBT_IP6_SPORT | EBT_IP6_ICMP6)))
return true;
/* min icmpv6 headersize is 4, so sizeof(_pkthdr) is ok. */
pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr),
&_pkthdr);
if (pptr == NULL)
return false;
if (info->bitmask & EBT_IP6_DPORT) {
u16 dst = ntohs(pptr->tcpudphdr.dst);
if (FWINV(dst < info->dport[0] ||
dst > info->dport[1], EBT_IP6_DPORT))
return false;
}
if (info->bitmask & EBT_IP6_SPORT) {
u16 src = ntohs(pptr->tcpudphdr.src);
if (FWINV(src < info->sport[0] ||
src > info->sport[1], EBT_IP6_SPORT))
return false;
}
if ((info->bitmask & EBT_IP6_ICMP6) &&
FWINV(pptr->icmphdr.type < info->icmpv6_type[0] ||
pptr->icmphdr.type > info->icmpv6_type[1] ||
pptr->icmphdr.code < info->icmpv6_code[0] ||
pptr->icmphdr.code > info->icmpv6_code[1],
EBT_IP6_ICMP6))
return false;
}
return true;
}
static int ebt_ip6_mt_check(const struct xt_mtchk_param *par)
{
const struct ebt_entry *e = par->entryinfo;
struct ebt_ip6_info *info = par->matchinfo;
if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
return -EINVAL;
if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
return -EINVAL;
if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
if (info->invflags & EBT_IP6_PROTO)
return -EINVAL;
if (info->protocol != IPPROTO_TCP &&
info->protocol != IPPROTO_UDP &&
info->protocol != IPPROTO_UDPLITE &&
info->protocol != IPPROTO_SCTP &&
info->protocol != IPPROTO_DCCP)
return -EINVAL;
}
if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
return -EINVAL;
if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
return -EINVAL;
if (info->bitmask & EBT_IP6_ICMP6) {
if ((info->invflags & EBT_IP6_PROTO) ||
info->protocol != IPPROTO_ICMPV6)
return -EINVAL;
if (info->icmpv6_type[0] > info->icmpv6_type[1] ||
info->icmpv6_code[0] > info->icmpv6_code[1])
return -EINVAL;
}
return 0;
}
static struct xt_match ebt_ip6_mt_reg __read_mostly = {
.name = "ip6",
.revision = 0,
.family = NFPROTO_BRIDGE,
.match = ebt_ip6_mt,
.checkentry = ebt_ip6_mt_check,
.matchsize = sizeof(struct ebt_ip6_info),
.me = THIS_MODULE,
};
static int __init ebt_ip6_init(void)
{
return xt_register_match(&ebt_ip6_mt_reg);
}
static void __exit ebt_ip6_fini(void)
{
xt_unregister_match(&ebt_ip6_mt_reg);
}
module_init(ebt_ip6_init);
module_exit(ebt_ip6_fini);
MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
MODULE_AUTHOR("Kuo-Lang Tseng <kuo-lang.tseng@intel.com>");
MODULE_LICENSE("GPL");
|
