Pablo Neira Ayuso | 7c62234 | 2012-06-19 02:10:57 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * (C) 2012 by Pablo Neira Ayuso <pablo@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 | |
| 10 | #include <linux/skbuff.h> |
| 11 | #include <linux/netfilter.h> |
| 12 | #include <linux/netfilter/nfnetlink.h> |
| 13 | #include <linux/netfilter/nfnetlink_queue.h> |
| 14 | #include <net/netfilter/nf_conntrack.h> |
| 15 | |
| 16 | struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size, |
| 17 | enum ip_conntrack_info *ctinfo) |
| 18 | { |
| 19 | struct nfq_ct_hook *nfq_ct; |
| 20 | struct nf_conn *ct; |
| 21 | |
| 22 | /* rcu_read_lock()ed by __nf_queue already. */ |
| 23 | nfq_ct = rcu_dereference(nfq_ct_hook); |
| 24 | if (nfq_ct == NULL) |
| 25 | return NULL; |
| 26 | |
| 27 | ct = nf_ct_get(entskb, ctinfo); |
| 28 | if (ct) { |
| 29 | if (!nf_ct_is_untracked(ct)) |
| 30 | *size += nfq_ct->build_size(ct); |
| 31 | else |
| 32 | ct = NULL; |
| 33 | } |
| 34 | return ct; |
| 35 | } |
| 36 | |
| 37 | struct nf_conn * |
| 38 | nfqnl_ct_parse(const struct sk_buff *skb, const struct nlattr *attr, |
| 39 | enum ip_conntrack_info *ctinfo) |
| 40 | { |
| 41 | struct nfq_ct_hook *nfq_ct; |
| 42 | struct nf_conn *ct; |
| 43 | |
| 44 | /* rcu_read_lock()ed by __nf_queue already. */ |
| 45 | nfq_ct = rcu_dereference(nfq_ct_hook); |
| 46 | if (nfq_ct == NULL) |
| 47 | return NULL; |
| 48 | |
| 49 | ct = nf_ct_get(skb, ctinfo); |
| 50 | if (ct && !nf_ct_is_untracked(ct)) |
| 51 | nfq_ct->parse(attr, ct); |
| 52 | |
| 53 | return ct; |
| 54 | } |
| 55 | |
| 56 | int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct, |
| 57 | enum ip_conntrack_info ctinfo) |
| 58 | { |
| 59 | struct nfq_ct_hook *nfq_ct; |
| 60 | struct nlattr *nest_parms; |
| 61 | u_int32_t tmp; |
| 62 | |
| 63 | nfq_ct = rcu_dereference(nfq_ct_hook); |
| 64 | if (nfq_ct == NULL) |
| 65 | return 0; |
| 66 | |
| 67 | nest_parms = nla_nest_start(skb, NFQA_CT | NLA_F_NESTED); |
| 68 | if (!nest_parms) |
| 69 | goto nla_put_failure; |
| 70 | |
| 71 | if (nfq_ct->build(skb, ct) < 0) |
| 72 | goto nla_put_failure; |
| 73 | |
| 74 | nla_nest_end(skb, nest_parms); |
| 75 | |
| 76 | tmp = ctinfo; |
| 77 | if (nla_put_be32(skb, NFQA_CT_INFO, htonl(tmp))) |
| 78 | goto nla_put_failure; |
| 79 | |
| 80 | return 0; |
| 81 | |
| 82 | nla_put_failure: |
| 83 | return -1; |
| 84 | } |
| 85 | |
| 86 | void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct, |
| 87 | enum ip_conntrack_info ctinfo, int diff) |
| 88 | { |
| 89 | struct nfq_ct_hook *nfq_ct; |
| 90 | |
| 91 | nfq_ct = rcu_dereference(nfq_ct_hook); |
| 92 | if (nfq_ct == NULL) |
| 93 | return; |
| 94 | |
| 95 | if ((ct->status & IPS_NAT_MASK) && diff) |
| 96 | nfq_ct->seq_adjust(skb, ct, ctinfo, diff); |
| 97 | } |