diff options
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index fda2ca17135e..13857df1dae1 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1671,6 +1671,52 @@ csum_err: } EXPORT_SYMBOL(tcp_v4_do_rcv); +int tcp_v4_early_demux(struct sk_buff *skb) +{ + struct net *net = dev_net(skb->dev); + const struct iphdr *iph; + const struct tcphdr *th; + struct sock *sk; + int err; + + err = -ENOENT; + if (skb->pkt_type != PACKET_HOST) + goto out_err; + + if (!pskb_may_pull(skb, ip_hdrlen(skb) + sizeof(struct tcphdr))) + goto out_err; + + iph = ip_hdr(skb); + th = (struct tcphdr *) ((char *)iph + ip_hdrlen(skb)); + + if (th->doff < sizeof(struct tcphdr) / 4) + goto out_err; + + if (!pskb_may_pull(skb, ip_hdrlen(skb) + th->doff * 4)) + goto out_err; + + sk = __inet_lookup_established(net, &tcp_hashinfo, + iph->saddr, th->source, + iph->daddr, th->dest, + skb->dev->ifindex); + if (sk) { + skb->sk = sk; + skb->destructor = sock_edemux; + if (sk->sk_state != TCP_TIME_WAIT) { + struct dst_entry *dst = sk->sk_rx_dst; + if (dst) + dst = dst_check(dst, 0); + if (dst) { + skb_dst_set_noref(skb, dst); + err = 0; + } + } + } + +out_err: + return err; +} + /* * From tcp_input.c */ |