git: d1b07f36a2aa - main - TCP complete end status work.

The branch main has been updated by rrs:

URL: https://cgit.FreeBSD.org/src/commit/?id=d1b07f36a2aa37591cd2b81bc8d0628ddb1f7a73

commit d1b07f36a2aa37591cd2b81bc8d0628ddb1f7a73
Author:     Randall Stewart <rrs@FreeBSD.org>
AuthorDate: 2022-09-26 19:20:18 +0000
Commit:     Randall Stewart <rrs@FreeBSD.org>
CommitDate: 2022-09-26 19:20:18 +0000

    TCP complete end status work.
    
    The ending of a connection can tell us a lot about what happened i.e. did
    it fail to setup, did it timeout, was it a normal close. Often times this is
    useful information to help analyze and debug issues. Rack has had
    end status for some time but the base stack as not. Lets go a ahead
    and add in the missing bits to populate the end status.
    
    Reviewed by: tuexen, rscheff
    Sponsored by: Netflix Inc
    Differential Revision: https://reviews.freebsd.org/D36712
---
 sys/netinet/tcp_input.c | 13 +++++++++++++
 sys/netinet/tcp_timer.c |  5 +++++
 2 files changed, 18 insertions(+)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 03941e2bb9a7..8c9b171e4eb5 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -1604,6 +1604,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
 		rstreason = BANDLIM_UNLIMITED;
+		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
 
@@ -1615,6 +1616,8 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	tp->t_rcvtime = ticks;
 
+	if (thflags & TH_FIN)
+		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
 	/*
 	 * Scale up the window into a 32-bit value.
 	 * For the SYN_SENT state the scale is zero.
@@ -1988,6 +1991,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
 		     SEQ_GT(th->th_ack, tp->snd_max))) {
 				rstreason = BANDLIM_RST_OPENPORT;
+				tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 				goto dropwithreset;
 		}
 		if (IS_FASTOPEN(tp->t_flags)) {
@@ -2000,6 +2004,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 			 */
 			if ((thflags & (TH_SYN|TH_ACK)) == (TH_SYN|TH_ACK)) {
 				rstreason = BANDLIM_RST_OPENPORT;
+				tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 				goto dropwithreset;
 			} else if (thflags & TH_SYN) {
 				/* non-initial SYN is ignored */
@@ -2031,6 +2036,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if ((thflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) {
 			TCP_PROBE5(connect__refused, NULL, tp,
 			    m, tp, th);
+			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 			tp = tcp_drop(tp, ECONNREFUSED);
 		}
 		if (thflags & TH_RST)
@@ -2193,6 +2199,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 				close:
 					/* FALLTHROUGH */
 				default:
+					tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_RST);
 					tp = tcp_close(tp);
 				}
 			} else {
@@ -2217,6 +2224,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 		if (V_tcp_insecure_syn &&
 		    SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
 		    SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) {
+			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 			tp = tcp_drop(tp, ECONNRESET);
 			rstreason = BANDLIM_UNLIMITED;
 		} else {
@@ -2268,6 +2276,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 	 */
 	if (tp->t_state == TCPS_SYN_RECEIVED && SEQ_LT(th->th_seq, tp->irs)) {
 		rstreason = BANDLIM_RST_OPENPORT;
+		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
 
@@ -2341,6 +2350,9 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 			    s, __func__, tcpstates[tp->t_state], tlen);
 			free(s, M_TCPLOG);
 		}
+		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
+		/* tcp_close will kill the inp pre-log the Reset */
+		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
 		tp = tcp_close(tp);
 		TCPSTAT_INC(tcps_rcvafterclose);
 		rstreason = BANDLIM_UNLIMITED;
@@ -3332,6 +3344,7 @@ dropafterack:
 	    (SEQ_GT(tp->snd_una, th->th_ack) ||
 	     SEQ_GT(th->th_ack, tp->snd_max)) ) {
 		rstreason = BANDLIM_RST_OPENPORT;
+		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
 		goto dropwithreset;
 	}
 #ifdef TCPDEBUG
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 6828364deea1..dea53e67c29b 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -327,6 +327,7 @@ tcp_timer_2msl(void *xtp)
 	inp = tp->t_inpcb;
 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
 	INP_WLOCK(inp);
+	tcp_log_end_status(tp, TCP_EI_STATUS_2MSL);
 	tcp_free_sackholes(tp);
 	if (callout_pending(&tp->t_timers->tt_2msl) ||
 	    !callout_active(&tp->t_timers->tt_2msl)) {
@@ -490,6 +491,7 @@ tcp_timer_keep(void *xtp)
 dropit:
 	TCPSTAT_INC(tcps_keepdrops);
 	NET_EPOCH_ENTER(et);
+	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
 	tp = tcp_drop(tp, ETIMEDOUT);
 
 #ifdef TCPDEBUG
@@ -550,6 +552,7 @@ tcp_timer_persist(void *xtp)
 	     ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
 		TCPSTAT_INC(tcps_persistdrop);
 		NET_EPOCH_ENTER(et);
+		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
 		tp = tcp_drop(tp, ETIMEDOUT);
 		NET_EPOCH_EXIT(et);
 		tcp_inpinfo_lock_del(inp, tp);
@@ -563,6 +566,7 @@ tcp_timer_persist(void *xtp)
 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
 		TCPSTAT_INC(tcps_persistdrop);
 		NET_EPOCH_ENTER(et);
+		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
 		tp = tcp_drop(tp, ETIMEDOUT);
 		NET_EPOCH_EXIT(et);
 		tcp_inpinfo_lock_del(inp, tp);
@@ -631,6 +635,7 @@ tcp_timer_rexmt(void * xtp)
 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
 		TCPSTAT_INC(tcps_timeoutdrop);
 		NET_EPOCH_ENTER(et);
+		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
 		tp = tcp_drop(tp, ETIMEDOUT);
 		NET_EPOCH_EXIT(et);
 		tcp_inpinfo_lock_del(inp, tp);