Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6e9250f5 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarEric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 64f40ff5

include/uapi/linux/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ enum { 
#define TCP_FASTOPEN		23	/* Enable FastOpen on listeners */

#define TCP_TIMESTAMP		24

#define TCP_NOTSENT_LOWAT	25	/* limit number of unsent bytes in write queue */

#define TCP_CC_INFO		26	/* Get Congestion Control (optional) info */



struct tcp_repair_opt {

	__u32	opt_code;

net/ipv4/tcp.c

+21 −0
Original line number Diff line number Diff line
@@ -252,6 +252,7 @@ 
#include <linux/types.h>

#include <linux/fcntl.h>

#include <linux/poll.h>

#include <linux/inet_diag.h>

#include <linux/init.h>

#include <linux/fs.h>

#include <linux/skbuff.h>
@@ -2739,6 +2740,26 @@ static int do_tcp_getsockopt(struct sock *sk, int level, 
			return -EFAULT;

		return 0;

	}

	case TCP_CC_INFO: {

		const struct tcp_congestion_ops *ca_ops;

		union tcp_cc_info info;

		size_t sz = 0;

		int attr;



		if (get_user(len, optlen))

			return -EFAULT;



		ca_ops = icsk->icsk_ca_ops;

		if (ca_ops && ca_ops->get_info)

			sz = ca_ops->get_info(sk, ~0U, &attr, &info);



		len = min_t(unsigned int, len, sz);

		if (put_user(len, optlen))

			return -EFAULT;

		if (copy_to_user(optval, &info, len))

			return -EFAULT;

		return 0;

	}

	case TCP_QUICKACK:

		val = !icsk->icsk_ack.pingpong;

		break;