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

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
...@@ -112,6 +112,7 @@ enum { ...@@ -112,6 +112,7 @@ enum {
#define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ #define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */
#define TCP_TIMESTAMP 24 #define TCP_TIMESTAMP 24
#define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */ #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 { struct tcp_repair_opt {
__u32 opt_code; __u32 opt_code;
......
...@@ -252,6 +252,7 @@ ...@@ -252,6 +252,7 @@
#include <linux/types.h> #include <linux/types.h>
#include <linux/fcntl.h> #include <linux/fcntl.h>
#include <linux/poll.h> #include <linux/poll.h>
#include <linux/inet_diag.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/fs.h> #include <linux/fs.h>
#include <linux/skbuff.h> #include <linux/skbuff.h>
...@@ -2739,6 +2740,26 @@ static int do_tcp_getsockopt(struct sock *sk, int level, ...@@ -2739,6 +2740,26 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
return -EFAULT; return -EFAULT;
return 0; 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: case TCP_QUICKACK:
val = !icsk->icsk_ack.pingpong; val = !icsk->icsk_ack.pingpong;
break; break;
......
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