inet_diag: report delayed ack timer information

inet_sk_diag_fill() populates r->idiag_timer with the following
precedence order:

1 - Retransmit timer.
4 - Probe0 timer.
2 - Keepalive timer.

This patch adds a new value, last in the list, if other timers
are not active.

5 - Delayed ACK timer.

A corresponding iproute2 patch will follow to replace "unknown"
with "delack":

ESTAB 10     0   [2002:a05:6830:1f86::]:12875 [2002:a05:6830:1f85::]:50438

    timer:(unknown,003ms,0) ino:152178 sk:3004 cgroup:unreachable:189 <->

    skmem:(r1344,rb12780520,t0,tb262144,f2752,w0,o250,bl0,d0) ts usec_ts
    ...

Also add the following enum in uapi/linux/inet_diag.h
as suggested by David Ahern.

enum {
	IDIAG_TIMER_OFF,
	IDIAG_TIMER_ON,
	IDIAG_TIMER_KEEPALIVE,
	IDIAG_TIMER_TIMEWAIT,
	IDIAG_TIMER_PROBE0,
	IDIAG_TIMER_DELACK,
};

Neal Cardwell suggested to test for ICSK_ACK_TIMER:
inet_csk_clear_xmit_timer() does not call sk_stop_timer()
because INET_CSK_CLEAR_TIMERS is unset.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260305114829.2163276-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index 86bb2e8b17c9f197fd49cf7996d5e4f555a9b8e8..21f0d735fbae206cf2e1e573912a324bb2eb64d9 100644 (file)
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -129,6 +129,15 @@ struct inet_diag_msg {
        __u32   idiag_inode;
 };
 
+enum {
+       IDIAG_TIMER_OFF,
+       IDIAG_TIMER_ON,
+       IDIAG_TIMER_KEEPALIVE,
+       IDIAG_TIMER_TIMEWAIT,
+       IDIAG_TIMER_PROBE0,
+       IDIAG_TIMER_DELACK,
+};
+
 /* Extensions */
 
 enum {

diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 9d215485b5c7e7ba29dd53c924f0245439d74af5..34b77aa87d0a48bcbceb7f2935a210a347812cc6 100644 (file)
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -241,7 +241,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
 
        inet_diag_msg_common_fill(r, sk);
        r->idiag_state = sk->sk_state;
-       r->idiag_timer = 0;
+       r->idiag_timer = IDIAG_TIMER_OFF;
        r->idiag_retrans = 0;
        r->idiag_expires = 0;
 
@@ -284,20 +284,25 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
        if (icsk_pending == ICSK_TIME_RETRANS ||
            icsk_pending == ICSK_TIME_REO_TIMEOUT ||
            icsk_pending == ICSK_TIME_LOSS_PROBE) {
-               r->idiag_timer = 1;
+               r->idiag_timer = IDIAG_TIMER_ON;
                r->idiag_retrans = READ_ONCE(icsk->icsk_retransmits);
                r->idiag_expires =
                        jiffies_delta_to_msecs(tcp_timeout_expires(sk) - jiffies);
        } else if (icsk_pending == ICSK_TIME_PROBE0) {
-               r->idiag_timer = 4;
+               r->idiag_timer = IDIAG_TIMER_PROBE0;
                r->idiag_retrans = READ_ONCE(icsk->icsk_probes_out);
                r->idiag_expires =
                        jiffies_delta_to_msecs(tcp_timeout_expires(sk) - jiffies);
        } else if (timer_pending(&icsk->icsk_keepalive_timer)) {
-               r->idiag_timer = 2;
+               r->idiag_timer = IDIAG_TIMER_KEEPALIVE;
                r->idiag_retrans = READ_ONCE(icsk->icsk_probes_out);
                r->idiag_expires =
                        jiffies_delta_to_msecs(icsk->icsk_keepalive_timer.expires - jiffies);
+       } else if ((READ_ONCE(icsk->icsk_ack.pending) & ICSK_ACK_TIMER) &&
+                  timer_pending(&icsk->icsk_delack_timer)) {
+               r->idiag_timer = IDIAG_TIMER_DELACK;
+               r->idiag_expires =
+                       jiffies_delta_to_msecs(icsk_delack_timeout(icsk) - jiffies);
        }
 
        if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {

diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 7935702e394b26d1ea2f2a990f645e0a681c6fbd..ba1fdbe9807fd2942460d71744f2147fa4638313 100644 (file)
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -212,7 +212,7 @@ static int tcp_twsk_diag_fill(struct sock *sk,
        r->idiag_retrans      = 0;
 
        r->idiag_state        = READ_ONCE(tw->tw_substate);
-       r->idiag_timer        = 3;
+       r->idiag_timer        = IDIAG_TIMER_TIMEWAIT;
        tmo = tw->tw_timer.expires - jiffies;
        r->idiag_expires      = jiffies_delta_to_msecs(tmo);
        r->idiag_rqueue       = 0;
@@ -247,7 +247,7 @@ static int tcp_req_diag_fill(struct sock *sk, struct sk_buff *skb,
        r = nlmsg_data(nlh);
        inet_diag_msg_common_fill(r, sk);
        r->idiag_state = TCP_SYN_RECV;
-       r->idiag_timer = 1;
+       r->idiag_timer = IDIAG_TIMER_ON;
        r->idiag_retrans = READ_ONCE(reqsk->num_retrans);
 
        BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=