Commit | Line | Data |
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73e4022f KK |
1 | /* (C) 1999-2001 Paul `Rusty' Russell |
2 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | ||
9 | #include <linux/types.h> | |
10 | #include <linux/ip.h> | |
11 | #include <linux/netfilter.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <net/route.h> | |
15 | #include <net/ip.h> | |
16 | ||
8fa9ff68 | 17 | #include <linux/netfilter_bridge.h> |
73e4022f KK |
18 | #include <linux/netfilter_ipv4.h> |
19 | #include <net/netfilter/ipv4/nf_defrag_ipv4.h> | |
20 | ||
21 | /* Returns new sk_buff, or NULL */ | |
22 | static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) | |
23 | { | |
24 | int err; | |
25 | ||
26 | skb_orphan(skb); | |
27 | ||
28 | local_bh_disable(); | |
29 | err = ip_defrag(skb, user); | |
30 | local_bh_enable(); | |
31 | ||
32 | if (!err) | |
33 | ip_send_check(ip_hdr(skb)); | |
34 | ||
35 | return err; | |
36 | } | |
37 | ||
8fa9ff68 PM |
38 | static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum, |
39 | struct sk_buff *skb) | |
40 | { | |
41 | #ifdef CONFIG_BRIDGE_NETFILTER | |
42 | if (skb->nf_bridge && | |
43 | skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING) | |
44 | return IP_DEFRAG_CONNTRACK_BRIDGE_IN; | |
45 | #endif | |
46 | if (hooknum == NF_INET_PRE_ROUTING) | |
47 | return IP_DEFRAG_CONNTRACK_IN; | |
48 | else | |
49 | return IP_DEFRAG_CONNTRACK_OUT; | |
50 | } | |
51 | ||
73e4022f KK |
52 | static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, |
53 | struct sk_buff *skb, | |
54 | const struct net_device *in, | |
55 | const struct net_device *out, | |
56 | int (*okfn)(struct sk_buff *)) | |
57 | { | |
58 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
38f7ac3e | 59 | #if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE) |
73e4022f KK |
60 | /* Previously seen (loopback)? Ignore. Do this before |
61 | fragment check. */ | |
b2a15a60 | 62 | if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct)) |
73e4022f KK |
63 | return NF_ACCEPT; |
64 | #endif | |
38f7ac3e | 65 | #endif |
73e4022f KK |
66 | /* Gather fragments. */ |
67 | if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { | |
8fa9ff68 PM |
68 | enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb); |
69 | if (nf_ct_ipv4_gather_frags(skb, user)) | |
73e4022f KK |
70 | return NF_STOLEN; |
71 | } | |
72 | return NF_ACCEPT; | |
73 | } | |
74 | ||
75 | static struct nf_hook_ops ipv4_defrag_ops[] = { | |
76 | { | |
77 | .hook = ipv4_conntrack_defrag, | |
78 | .owner = THIS_MODULE, | |
79 | .pf = PF_INET, | |
80 | .hooknum = NF_INET_PRE_ROUTING, | |
81 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, | |
82 | }, | |
83 | { | |
84 | .hook = ipv4_conntrack_defrag, | |
85 | .owner = THIS_MODULE, | |
86 | .pf = PF_INET, | |
87 | .hooknum = NF_INET_LOCAL_OUT, | |
88 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, | |
89 | }, | |
90 | }; | |
91 | ||
92 | static int __init nf_defrag_init(void) | |
93 | { | |
94 | return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); | |
95 | } | |
96 | ||
97 | static void __exit nf_defrag_fini(void) | |
98 | { | |
99 | nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); | |
100 | } | |
101 | ||
102 | void nf_defrag_ipv4_enable(void) | |
103 | { | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); | |
106 | ||
107 | module_init(nf_defrag_init); | |
108 | module_exit(nf_defrag_fini); | |
109 | ||
110 | MODULE_LICENSE("GPL"); |