Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | */ | |
1da177e4 | 14 | #include <linux/ip.h> |
8a4c8a96 | 15 | #include <net/ip.h> |
1da177e4 LT |
16 | #include <linux/in.h> |
17 | #include <linux/module.h> | |
18219d3f JE |
18 | #include <linux/netfilter/x_tables.h> |
19 | #include <linux/netfilter_bridge/ebtables.h> | |
20 | #include <linux/netfilter_bridge/ebt_ip.h> | |
1da177e4 LT |
21 | |
22 | struct tcpudphdr { | |
47c183fa AV |
23 | __be16 src; |
24 | __be16 dst; | |
1da177e4 LT |
25 | }; |
26 | ||
2d06d4a5 | 27 | static bool |
62fc8051 | 28 | ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) |
1da177e4 | 29 | { |
f7108a20 | 30 | const struct ebt_ip_info *info = par->matchinfo; |
abfdf1c4 JE |
31 | const struct iphdr *ih; |
32 | struct iphdr _iph; | |
33 | const struct tcpudphdr *pptr; | |
34 | struct tcpudphdr _ports; | |
1da177e4 LT |
35 | |
36 | ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); | |
37 | if (ih == NULL) | |
8cc784ee | 38 | return false; |
1da177e4 LT |
39 | if (info->bitmask & EBT_IP_TOS && |
40 | FWINV(info->tos != ih->tos, EBT_IP_TOS)) | |
8cc784ee | 41 | return false; |
1da177e4 LT |
42 | if (info->bitmask & EBT_IP_SOURCE && |
43 | FWINV((ih->saddr & info->smsk) != | |
44 | info->saddr, EBT_IP_SOURCE)) | |
8cc784ee | 45 | return false; |
1da177e4 LT |
46 | if ((info->bitmask & EBT_IP_DEST) && |
47 | FWINV((ih->daddr & info->dmsk) != | |
48 | info->daddr, EBT_IP_DEST)) | |
8cc784ee | 49 | return false; |
1da177e4 LT |
50 | if (info->bitmask & EBT_IP_PROTO) { |
51 | if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO)) | |
8cc784ee | 52 | return false; |
1da177e4 LT |
53 | if (!(info->bitmask & EBT_IP_DPORT) && |
54 | !(info->bitmask & EBT_IP_SPORT)) | |
8cc784ee | 55 | return true; |
8a4c8a96 | 56 | if (ntohs(ih->frag_off) & IP_OFFSET) |
8cc784ee | 57 | return false; |
1da177e4 LT |
58 | pptr = skb_header_pointer(skb, ih->ihl*4, |
59 | sizeof(_ports), &_ports); | |
60 | if (pptr == NULL) | |
8cc784ee | 61 | return false; |
1da177e4 LT |
62 | if (info->bitmask & EBT_IP_DPORT) { |
63 | u32 dst = ntohs(pptr->dst); | |
64 | if (FWINV(dst < info->dport[0] || | |
9d6f229f YH |
65 | dst > info->dport[1], |
66 | EBT_IP_DPORT)) | |
8cc784ee | 67 | return false; |
1da177e4 LT |
68 | } |
69 | if (info->bitmask & EBT_IP_SPORT) { | |
70 | u32 src = ntohs(pptr->src); | |
71 | if (FWINV(src < info->sport[0] || | |
9d6f229f YH |
72 | src > info->sport[1], |
73 | EBT_IP_SPORT)) | |
8cc784ee | 74 | return false; |
1da177e4 LT |
75 | } |
76 | } | |
8cc784ee | 77 | return true; |
1da177e4 LT |
78 | } |
79 | ||
b0f38452 | 80 | static int ebt_ip_mt_check(const struct xt_mtchk_param *par) |
1da177e4 | 81 | { |
9b4fce7a JE |
82 | const struct ebt_ip_info *info = par->matchinfo; |
83 | const struct ebt_entry *e = par->entryinfo; | |
1da177e4 | 84 | |
1da177e4 LT |
85 | if (e->ethproto != htons(ETH_P_IP) || |
86 | e->invflags & EBT_IPROTO) | |
bd414ee6 | 87 | return -EINVAL; |
1da177e4 | 88 | if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK) |
bd414ee6 | 89 | return -EINVAL; |
1da177e4 LT |
90 | if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) { |
91 | if (info->invflags & EBT_IP_PROTO) | |
bd414ee6 | 92 | return -EINVAL; |
1da177e4 | 93 | if (info->protocol != IPPROTO_TCP && |
ab67a4d5 | 94 | info->protocol != IPPROTO_UDP && |
a8d0f952 | 95 | info->protocol != IPPROTO_UDPLITE && |
ab67a4d5 PM |
96 | info->protocol != IPPROTO_SCTP && |
97 | info->protocol != IPPROTO_DCCP) | |
bd414ee6 | 98 | return -EINVAL; |
1da177e4 LT |
99 | } |
100 | if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1]) | |
bd414ee6 | 101 | return -EINVAL; |
1da177e4 | 102 | if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1]) |
bd414ee6 JE |
103 | return -EINVAL; |
104 | return 0; | |
1da177e4 LT |
105 | } |
106 | ||
043ef46c JE |
107 | static struct xt_match ebt_ip_mt_reg __read_mostly = { |
108 | .name = "ip", | |
001a18d3 JE |
109 | .revision = 0, |
110 | .family = NFPROTO_BRIDGE, | |
2d06d4a5 JE |
111 | .match = ebt_ip_mt, |
112 | .checkentry = ebt_ip_mt_check, | |
fc0e3df4 | 113 | .matchsize = sizeof(struct ebt_ip_info), |
1da177e4 LT |
114 | .me = THIS_MODULE, |
115 | }; | |
116 | ||
65b4b4e8 | 117 | static int __init ebt_ip_init(void) |
1da177e4 | 118 | { |
043ef46c | 119 | return xt_register_match(&ebt_ip_mt_reg); |
1da177e4 LT |
120 | } |
121 | ||
65b4b4e8 | 122 | static void __exit ebt_ip_fini(void) |
1da177e4 | 123 | { |
043ef46c | 124 | xt_unregister_match(&ebt_ip_mt_reg); |
1da177e4 LT |
125 | } |
126 | ||
65b4b4e8 AM |
127 | module_init(ebt_ip_init); |
128 | module_exit(ebt_ip_fini); | |
f776c4cd | 129 | MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match"); |
1da177e4 | 130 | MODULE_LICENSE("GPL"); |