net/netfilter/nfnetlink_queue_ct.c

   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 #include <net/netfilter/nfnetlink_queue.h>
  16
  17 struct nf_conn *nfqnl_ct_get(struct sk_buff *entskb, size_t *size,
  18                              enum ip_conntrack_info *ctinfo)
  19 {
  20         struct nfq_ct_hook *nfq_ct;
  21         struct nf_conn *ct;
  22
  23         /* rcu_read_lock()ed by __nf_queue already. */
  24         nfq_ct = rcu_dereference(nfq_ct_hook);
  25         if (nfq_ct == NULL)
  26                 return NULL;
  27
  28         ct = nf_ct_get(entskb, ctinfo);
  29         if (ct) {
  30                 if (!nf_ct_is_untracked(ct))
  31                         *size += nfq_ct->build_size(ct);
  32                 else
  33                         ct = NULL;
  34         }
  35         return ct;
  36 }
  37
  38 struct nf_conn *
  39 nfqnl_ct_parse(const struct sk_buff *skb, const struct nlattr *attr,
  40                enum ip_conntrack_info *ctinfo)
  41 {
  42         struct nfq_ct_hook *nfq_ct;
  43         struct nf_conn *ct;
  44
  45         /* rcu_read_lock()ed by __nf_queue already. */
  46         nfq_ct = rcu_dereference(nfq_ct_hook);
  47         if (nfq_ct == NULL)
  48                 return NULL;
  49
  50         ct = nf_ct_get(skb, ctinfo);
  51         if (ct && !nf_ct_is_untracked(ct))
  52                 nfq_ct->parse(attr, ct);
  53
  54         return ct;
  55 }
  56
  57 int nfqnl_ct_put(struct sk_buff *skb, struct nf_conn *ct,
  58                  enum ip_conntrack_info ctinfo)
  59 {
  60         struct nfq_ct_hook *nfq_ct;
  61         struct nlattr *nest_parms;
  62         u_int32_t tmp;
  63
  64         nfq_ct = rcu_dereference(nfq_ct_hook);
  65         if (nfq_ct == NULL)
  66                 return 0;
  67
  68         nest_parms = nla_nest_start(skb, NFQA_CT | NLA_F_NESTED);
  69         if (!nest_parms)
  70                 goto nla_put_failure;
  71
  72         if (nfq_ct->build(skb, ct) < 0)
  73                 goto nla_put_failure;
  74
  75         nla_nest_end(skb, nest_parms);
  76
  77         tmp = ctinfo;
  78         if (nla_put_be32(skb, NFQA_CT_INFO, htonl(tmp)))
  79                 goto nla_put_failure;
  80
  81         return 0;
  82
  83 nla_put_failure:
  84         return -1;
  85 }
  86
  87 void nfqnl_ct_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
  88                          enum ip_conntrack_info ctinfo, int diff)
  89 {
  90         struct nfq_ct_nat_hook *nfq_nat_ct;
  91
  92         nfq_nat_ct = rcu_dereference(nfq_ct_nat_hook);
  93         if (nfq_nat_ct == NULL)
  94                 return;
  95
  96         if ((ct->status & IPS_NAT_MASK) && diff)
  97                 nfq_nat_ct->seq_adjust(skb, ct, ctinfo, diff);
  98 }