git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| 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"); |