KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 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 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 17 | #include <linux/netfilter_bridge.h> |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 18 | #include <linux/netfilter_ipv4.h> |
| 19 | #include <net/netfilter/ipv4/nf_defrag_ipv4.h> |
Patrick McHardy | 37ee3d5 | 2010-02-18 19:04:44 +0100 | [diff] [blame] | 20 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
Florian Westphal | 7678037 | 2010-02-08 15:39:16 +0100 | [diff] [blame] | 21 | #include <net/netfilter/nf_conntrack.h> |
Patrick McHardy | 37ee3d5 | 2010-02-18 19:04:44 +0100 | [diff] [blame] | 22 | #endif |
| 23 | #include <net/netfilter/nf_conntrack_zones.h> |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 24 | |
| 25 | /* Returns new sk_buff, or NULL */ |
| 26 | static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) |
| 27 | { |
| 28 | int err; |
| 29 | |
| 30 | skb_orphan(skb); |
| 31 | |
| 32 | local_bh_disable(); |
| 33 | err = ip_defrag(skb, user); |
| 34 | local_bh_enable(); |
| 35 | |
| 36 | if (!err) |
| 37 | ip_send_check(ip_hdr(skb)); |
| 38 | |
| 39 | return err; |
| 40 | } |
| 41 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 42 | static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum, |
| 43 | struct sk_buff *skb) |
| 44 | { |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 45 | u16 zone = NF_CT_DEFAULT_ZONE; |
| 46 | |
Patrick McHardy | 37ee3d5 | 2010-02-18 19:04:44 +0100 | [diff] [blame] | 47 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 48 | if (skb->nfct) |
| 49 | zone = nf_ct_zone((struct nf_conn *)skb->nfct); |
Patrick McHardy | 37ee3d5 | 2010-02-18 19:04:44 +0100 | [diff] [blame] | 50 | #endif |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 51 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 52 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 53 | if (skb->nf_bridge && |
| 54 | skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING) |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 55 | return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone; |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 56 | #endif |
| 57 | if (hooknum == NF_INET_PRE_ROUTING) |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 58 | return IP_DEFRAG_CONNTRACK_IN + zone; |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 59 | else |
Patrick McHardy | 5d0aa2c | 2010-02-15 18:13:33 +0100 | [diff] [blame] | 60 | return IP_DEFRAG_CONNTRACK_OUT + zone; |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 61 | } |
| 62 | |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 63 | static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, |
| 64 | struct sk_buff *skb, |
| 65 | const struct net_device *in, |
| 66 | const struct net_device *out, |
| 67 | int (*okfn)(struct sk_buff *)) |
| 68 | { |
Jiri Olsa | cbdd769 | 2010-09-21 21:17:34 +0000 | [diff] [blame] | 69 | struct sock *sk = skb->sk; |
Jiri Olsa | 7b2ff18 | 2010-06-15 01:07:31 +0000 | [diff] [blame] | 70 | struct inet_sock *inet = inet_sk(skb->sk); |
| 71 | |
Jiri Olsa | cbdd769 | 2010-09-21 21:17:34 +0000 | [diff] [blame] | 72 | if (sk && (sk->sk_family == PF_INET) && |
| 73 | inet->nodefrag) |
Jiri Olsa | 7b2ff18 | 2010-06-15 01:07:31 +0000 | [diff] [blame] | 74 | return NF_ACCEPT; |
| 75 | |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 76 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
Patrick McHardy | 38f7ac3 | 2008-10-14 11:56:59 -0700 | [diff] [blame] | 77 | #if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 78 | /* Previously seen (loopback)? Ignore. Do this before |
| 79 | fragment check. */ |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 80 | if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct)) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 81 | return NF_ACCEPT; |
| 82 | #endif |
Patrick McHardy | 38f7ac3 | 2008-10-14 11:56:59 -0700 | [diff] [blame] | 83 | #endif |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 84 | /* Gather fragments. */ |
Paul Gortmaker | 56f8a75 | 2011-06-21 20:33:34 -0700 | [diff] [blame] | 85 | if (ip_is_fragment(ip_hdr(skb))) { |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 86 | enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb); |
| 87 | if (nf_ct_ipv4_gather_frags(skb, user)) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 88 | return NF_STOLEN; |
| 89 | } |
| 90 | return NF_ACCEPT; |
| 91 | } |
| 92 | |
| 93 | static struct nf_hook_ops ipv4_defrag_ops[] = { |
| 94 | { |
| 95 | .hook = ipv4_conntrack_defrag, |
| 96 | .owner = THIS_MODULE, |
Alban Crequy | 89a48e3 | 2012-05-14 03:56:37 +0000 | [diff] [blame] | 97 | .pf = NFPROTO_IPV4, |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 98 | .hooknum = NF_INET_PRE_ROUTING, |
| 99 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, |
| 100 | }, |
| 101 | { |
| 102 | .hook = ipv4_conntrack_defrag, |
| 103 | .owner = THIS_MODULE, |
Alban Crequy | 89a48e3 | 2012-05-14 03:56:37 +0000 | [diff] [blame] | 104 | .pf = NFPROTO_IPV4, |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 105 | .hooknum = NF_INET_LOCAL_OUT, |
| 106 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, |
| 107 | }, |
| 108 | }; |
| 109 | |
| 110 | static int __init nf_defrag_init(void) |
| 111 | { |
| 112 | return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); |
| 113 | } |
| 114 | |
| 115 | static void __exit nf_defrag_fini(void) |
| 116 | { |
| 117 | nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); |
| 118 | } |
| 119 | |
| 120 | void nf_defrag_ipv4_enable(void) |
| 121 | { |
| 122 | } |
| 123 | EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); |
| 124 | |
| 125 | module_init(nf_defrag_init); |
| 126 | module_exit(nf_defrag_fini); |
| 127 | |
| 128 | MODULE_LICENSE("GPL"); |