diff options
| author | Wei Wang <weiwan@google.com> | 2020-12-08 18:55:08 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-12-10 01:08:23 +0100 |
| commit | 8ef44b6fe49d2b8d03ba9aa69063612b474f963b (patch) | |
| tree | 74f6edf6c6e959406b20c0abbc457929040e6431 /net/ipv6/tcp_ipv6.c | |
| parent | ethtool: fix stack overflow in ethnl_parse_bitset() (diff) | |
| download | linux-8ef44b6fe49d2b8d03ba9aa69063612b474f963b.tar.xz linux-8ef44b6fe49d2b8d03ba9aa69063612b474f963b.zip | |
tcp: Retain ECT bits for tos reflection
For DCTCP, we have to retain the ECT bits set by the congestion control
algorithm on the socket when reflecting syn TOS in syn-ack, in order to
make ECN work properly.
Fixes: ac8f1710c12b ("tcp: reflect tos value received in SYN to the socket")
Reported-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 992cbf3eb9e3..991dc36f95ff 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -528,7 +528,8 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ? - tcp_rsk(req)->syn_tos & ~INET_ECN_MASK : + (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | + (np->tclass & INET_ECN_MASK) : np->tclass; if (!INET_ECN_is_capable(tclass) && @@ -1320,7 +1321,9 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * if (np->repflow) newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); - /* Set ToS of the new socket based upon the value of incoming SYN. */ + /* Set ToS of the new socket based upon the value of incoming SYN. + * ECT bits are set later in tcp_init_transfer(). + */ if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; |