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> |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 20 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
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 | |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 25 | static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) |
| 26 | { |
| 27 | int err; |
| 28 | |
| 29 | skb_orphan(skb); |
| 30 | |
| 31 | local_bh_disable(); |
| 32 | err = ip_defrag(skb, user); |
| 33 | local_bh_enable(); |
| 34 | |
Florian Westphal | 895162b | 2014-05-02 15:32:16 +0200 | [diff] [blame] | 35 | if (!err) { |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 36 | ip_send_check(ip_hdr(skb)); |
WANG Cong | 60ff746 | 2014-05-04 16:39:18 -0700 | [diff] [blame] | 37 | skb->ignore_df = 1; |
Florian Westphal | 895162b | 2014-05-02 15:32:16 +0200 | [diff] [blame] | 38 | } |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 39 | |
| 40 | return err; |
| 41 | } |
| 42 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 43 | static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum, |
| 44 | struct sk_buff *skb) |
| 45 | { |
Daniel Borkmann | 308ac91 | 2015-08-08 21:40:01 +0200 | [diff] [blame] | 46 | u16 zone_id = NF_CT_DEFAULT_ZONE_ID; |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 47 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
Daniel Borkmann | deedb59 | 2015-08-14 16:03:39 +0200 | [diff] [blame] | 48 | if (skb->nfct) { |
| 49 | enum ip_conntrack_info ctinfo; |
| 50 | const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); |
| 51 | |
| 52 | zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo)); |
| 53 | } |
Patrick McHardy | 37ee3d5 | 2010-02-18 19:04:44 +0100 | [diff] [blame] | 54 | #endif |
Florian Westphal | 72b1e5e | 2015-07-23 16:21:30 +0200 | [diff] [blame] | 55 | if (nf_bridge_in_prerouting(skb)) |
Daniel Borkmann | 308ac91 | 2015-08-08 21:40:01 +0200 | [diff] [blame] | 56 | return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id; |
Florian Westphal | 72b1e5e | 2015-07-23 16:21:30 +0200 | [diff] [blame] | 57 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 58 | if (hooknum == NF_INET_PRE_ROUTING) |
Daniel Borkmann | 308ac91 | 2015-08-08 21:40:01 +0200 | [diff] [blame] | 59 | return IP_DEFRAG_CONNTRACK_IN + zone_id; |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 60 | else |
Daniel Borkmann | 308ac91 | 2015-08-08 21:40:01 +0200 | [diff] [blame] | 61 | return IP_DEFRAG_CONNTRACK_OUT + zone_id; |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 62 | } |
| 63 | |
Patrick McHardy | 795aa6e | 2013-10-10 09:21:55 +0200 | [diff] [blame] | 64 | static unsigned int ipv4_conntrack_defrag(const struct nf_hook_ops *ops, |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 65 | struct sk_buff *skb, |
David S. Miller | 238e54c | 2015-04-03 20:32:56 -0400 | [diff] [blame] | 66 | const struct nf_hook_state *state) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 67 | { |
Jiri Olsa | cbdd769 | 2010-09-21 21:17:34 +0000 | [diff] [blame] | 68 | struct sock *sk = skb->sk; |
Jiri Olsa | 7b2ff18 | 2010-06-15 01:07:31 +0000 | [diff] [blame] | 69 | struct inet_sock *inet = inet_sk(skb->sk); |
| 70 | |
Jiri Olsa | cbdd769 | 2010-09-21 21:17:34 +0000 | [diff] [blame] | 71 | if (sk && (sk->sk_family == PF_INET) && |
| 72 | inet->nodefrag) |
Jiri Olsa | 7b2ff18 | 2010-06-15 01:07:31 +0000 | [diff] [blame] | 73 | return NF_ACCEPT; |
| 74 | |
Duan Jiong | 24de3d3 | 2014-06-30 09:19:32 +0800 | [diff] [blame] | 75 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
| 76 | #if !IS_ENABLED(CONFIG_NF_NAT) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 77 | /* Previously seen (loopback)? Ignore. Do this before |
| 78 | fragment check. */ |
Patrick McHardy | b2a15a6 | 2010-02-03 14:13:03 +0100 | [diff] [blame] | 79 | if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct)) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 80 | return NF_ACCEPT; |
| 81 | #endif |
Patrick McHardy | 38f7ac3 | 2008-10-14 11:56:59 -0700 | [diff] [blame] | 82 | #endif |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 83 | /* Gather fragments. */ |
Paul Gortmaker | 56f8a75 | 2011-06-21 20:33:34 -0700 | [diff] [blame] | 84 | if (ip_is_fragment(ip_hdr(skb))) { |
Patrick McHardy | 795aa6e | 2013-10-10 09:21:55 +0200 | [diff] [blame] | 85 | enum ip_defrag_users user = |
| 86 | nf_ct_defrag_user(ops->hooknum, skb); |
| 87 | |
Patrick McHardy | 8fa9ff6 | 2009-12-15 16:59:59 +0100 | [diff] [blame] | 88 | if (nf_ct_ipv4_gather_frags(skb, user)) |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 89 | return NF_STOLEN; |
| 90 | } |
| 91 | return NF_ACCEPT; |
| 92 | } |
| 93 | |
| 94 | static struct nf_hook_ops ipv4_defrag_ops[] = { |
| 95 | { |
| 96 | .hook = ipv4_conntrack_defrag, |
| 97 | .owner = THIS_MODULE, |
Alban Crequy | 89a48e3 | 2012-05-14 03:56:37 +0000 | [diff] [blame] | 98 | .pf = NFPROTO_IPV4, |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 99 | .hooknum = NF_INET_PRE_ROUTING, |
| 100 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, |
| 101 | }, |
| 102 | { |
| 103 | .hook = ipv4_conntrack_defrag, |
| 104 | .owner = THIS_MODULE, |
Alban Crequy | 89a48e3 | 2012-05-14 03:56:37 +0000 | [diff] [blame] | 105 | .pf = NFPROTO_IPV4, |
KOVACS Krisztian | 73e4022 | 2008-10-08 11:35:12 +0200 | [diff] [blame] | 106 | .hooknum = NF_INET_LOCAL_OUT, |
| 107 | .priority = NF_IP_PRI_CONNTRACK_DEFRAG, |
| 108 | }, |
| 109 | }; |
| 110 | |
| 111 | static int __init nf_defrag_init(void) |
| 112 | { |
| 113 | return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); |
| 114 | } |
| 115 | |
| 116 | static void __exit nf_defrag_fini(void) |
| 117 | { |
| 118 | nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); |
| 119 | } |
| 120 | |
| 121 | void nf_defrag_ipv4_enable(void) |
| 122 | { |
| 123 | } |
| 124 | EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); |
| 125 | |
| 126 | module_init(nf_defrag_init); |
| 127 | module_exit(nf_defrag_fini); |
| 128 | |
| 129 | MODULE_LICENSE("GPL"); |