tcp: add TCP_CC_INFO socket option (6e9250f5) · Commits · 戴 / test

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

+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;

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