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| author |   Eric Dumazet <edumazet@google.com> | 2015-09-15 15:24:20 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2015-09-17 21:01:04 -0700 |
| commit | 58d607d3e52f2b15902f58a1161da9fb3b0f6d47 (patch) | |
| tree | 1949d88eb7d541878079ddafa607c31017099349 /net/ipv4/tcp_output.c | |
| parent | Merge branch 'nf_hook_netns' (diff) | |
| download | linux-dev-58d607d3e52f2b15902f58a1161da9fb3b0f6d47.tar.xz linux-dev-58d607d3e52f2b15902f58a1161da9fb3b0f6d47.zip | |
tcp: provide skb->hash to synack packets
In commit b73c3d0e4f0e ("net: Save TX flow hash in sock and set in skbuf
on xmit"), Tom provided a l4 hash to most outgoing TCP packets.
We'd like to provide one as well for SYNACK packets, so that all packets
of a given flow share same txhash, to later enable bonding driver to
also use skb->hash to perform slave selection.
Note that a SYNACK retransmit shuffles the tx hash, as Tom did
in commit 265f94ff54d62 ("net: Recompute sk_txhash on negative routing
advice") for established sockets.
This has nice effect making TCP flows resilient to some kind of black
holes, even at connection establish phase.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f9a8a12b62ee..d0ad3554c333 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2987,6 +2987,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, rcu_read_lock(); md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req)); #endif + skb_set_hash(skb, tcp_rsk(req)->txhash, PKT_HASH_TYPE_L4); tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5, foc) + sizeof(*th); @@ -3505,6 +3506,7 @@ int tcp_rtx_synack(struct sock *sk, struct request_sock *req) struct flowi fl; int res; + tcp_rsk(req)->txhash = net_tx_rndhash(); res = af_ops->send_synack(sk, NULL, &fl, req, 0, NULL); if (!res) { TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); |