From 4c507d2897bd9be810b3403ade73b04cf6fdfd4a Mon Sep 17 00:00:00 2001
From: Jiri Benc <jbenc@redhat.com>
Date: Thu, 9 Feb 2012 09:35:49 +0000
Subject: net: implement IP_RECVTOS for IP_PKTOPTIONS
Currently, it is not easily possible to get TOS/DSCP value of packets from
an incoming TCP stream. The mechanism is there, IP_PKTOPTIONS getsockopt
with IP_RECVTOS set, the same way as incoming TTL can be queried. This is
not actually implemented for TOS, though.
This patch adds this functionality, both for IPv4 (IP_PKTOPTIONS) and IPv6
(IPV6_2292PKTOPTIONS). For IPv4, like in the IP_RECVTTL case, the value of
the TOS field is stored from the other party's ACK.
This is needed for proxies which require DSCP transparency. One such example
is at http://zph.bratcheda.org/.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv6/tcp_ipv6.c | 4 ++++
1 file changed, 4 insertions(+)
(limited to 'net/ipv6/tcp_ipv6.c')
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d16414cb3421..12c6ece67f39 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1282,6 +1282,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+ newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
/*
* No need to charge this sock to the relevant IPv6 refcnt debug socks count
@@ -1360,6 +1361,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newnp->opt = NULL;
newnp->mcast_oif = inet6_iif(skb);
newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+ newnp->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
/* Clone native IPv6 options from listening socket (if any)
@@ -1562,6 +1564,8 @@ ipv6_pktoptions:
np->mcast_oif = inet6_iif(opt_skb);
if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
+ if (np->rxopt.bits.rxtclass)
+ np->rcv_tclass = ipv6_tclass(ipv6_hdr(skb));
if (ipv6_opt_accepted(sk, opt_skb)) {
skb_set_owner_r(opt_skb, sk);
opt_skb = xchg(&np->pktoptions, opt_skb);
--
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