tcp: add TCP_CC_INFO socket option
authorEric Dumazet <edumazet@google.com>
Tue, 28 Apr 2015 23:23:49 +0000 (16:23 -0700)
committerDavid S. Miller <davem@davemloft.net>
Wed, 29 Apr 2015 21:10:38 +0000 (17:10 -0400)
commit6e9250f59ef9efb932c84850cd221f22c2a03c4a
tree8492e1b4724aa12b31675b45e3bb681f860213f0
parent64f40ff5bbdb1b679fb3c4dbc8230d6517d2b8dc
tcp: add TCP_CC_INFO socket option

Some Congestion Control modules can provide per flow information,
but current way to get this information is to use netlink.

Like TCP_INFO, let's add TCP_CC_INFO so that applications can
issue a getsockopt() if they have a socket file descriptor,
instead of playing complex netlink games.

Sample usage would be :

  union tcp_cc_info info;
  socklen_t len = sizeof(info);

  if (getsockopt(fd, SOL_TCP, TCP_CC_INFO, &info, &len) == -1)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/uapi/linux/tcp.h
net/ipv4/tcp.c