The output from tcp debug sockets was incomplete. After detach tp

was NULL and nothing was traced.  So save the old tcpcb and use
that to retrieve some information.  Note that otb may be freed and
must not be dereferenced.  Use a heuristic for cases where the
address family is in the IP header but not provided in the PCB.
OK visa@

1 files changed, 39 insertions, 24 deletions

diff --git a/sys/netinet/tcp_debug.c b/sys/netinet/tcp_debug.c
index 89f6b6567bd..8997019dabd 100644
--- a/sys/netinet/tcp_debug.c
+++ b/sys/netinet/tcp_debug.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tcp_debug.c,v 1.26 2018/05/10 13:30:25 bluhm Exp $	*/
+/*	$OpenBSD: tcp_debug.c,v 1.27 2018/06/11 07:40:26 bluhm Exp $	*/
 /*	$NetBSD: tcp_debug.c,v 1.10 1996/02/13 23:43:36 christos Exp $	*/
 
 /*
@@ -110,18 +110,19 @@ int	tcp_debx;
  * Tcp debug routines
  */
 void
-tcp_trace(short act, short ostate, struct tcpcb *tp, caddr_t headers,
-   int req, int len)
+tcp_trace(short act, short ostate, struct tcpcb *tp, struct tcpcb *otp,
+    caddr_t headers, int req, int len)
 {
 #ifdef TCPDEBUG
 	tcp_seq seq, ack;
 	int flags;
 #endif
+	int pf = PF_UNSPEC;
 	struct tcp_debug *td = &tcp_debug[tcp_debx++];
 	struct tcpiphdr *ti = (struct tcpiphdr *)headers;
 	struct tcphdr *th;
 #ifdef INET6
-	struct tcpipv6hdr *ti6 = (struct tcpipv6hdr *)ti;
+	struct tcpipv6hdr *ti6 = (struct tcpipv6hdr *)headers;
 #endif
 
 	if (tcp_debx == TCP_NDEBUG)
@@ -129,40 +130,54 @@ tcp_trace(short act, short ostate, struct tcpcb *tp, caddr_t headers,
 	td->td_time = iptime();
 	td->td_act = act;
 	td->td_ostate = ostate;
-	td->td_tcb = (caddr_t)tp;
-	if (tp)
+	td->td_tcb = (caddr_t)otp;
+	if (tp) {
+		pf = tp->pf;
 		td->td_cb = *tp;
-	else
+	} else
 		bzero((caddr_t)&td->td_cb, sizeof (*tp));
-	switch (tp->pf) {
+
+	bzero(&td->td_ti6, sizeof(struct tcpipv6hdr));
+	bzero(&td->td_ti, sizeof(struct tcpiphdr));
+	if (headers) {
+		/* The address family may be in tcpcb or ip header. */
+		if (pf == PF_UNSPEC) {
+			switch (ti6->ti6_i.ip6_vfc & IPV6_VERSION_MASK) {
 #ifdef INET6
-	case PF_INET6:
-		if (ti6) {
+			case IPV6_VERSION:
+				pf = PF_INET6;
+				break;
+#endif /* INET6 */
+			case IPVERSION:
+				pf = PF_INET;
+				break;
+			}
+		}
+		switch (pf) {
+#ifdef INET6
+		case PF_INET6:
 			th = &ti6->ti6_t;
 			td->td_ti6 = *ti6;
 			td->td_ti6.ti6_plen = len;
-		} else
-			bzero(&td->td_ti6, sizeof(struct tcpipv6hdr));
-		break;
+			break;
 #endif /* INET6 */
-	case PF_INET:
-		if (ti) {
+		case PF_INET:
 			th = &ti->ti_t;
 			td->td_ti = *ti;
 			td->td_ti.ti_len = len;
-		} else
-			bzero(&td->td_ti, sizeof(struct tcpiphdr));
-		break;
-	default:
-		return;
+			break;
+		default:
+			headers = NULL;
+			break;
+		}
 	}
 
 	td->td_req = req;
 #ifdef TCPDEBUG
 	if (tcpconsdebug == 0)
 		return;
-	if (tp)
-		printf("%p %s:", tp, tcpstates[ostate]);
+	if (otp)
+		printf("%p %s:", otp, tcpstates[ostate]);
 	else
 		printf("???????? ");
 	printf("%s ", tanames[act]);
@@ -171,7 +186,7 @@ tcp_trace(short act, short ostate, struct tcpcb *tp, caddr_t headers,
 	case TA_INPUT:
 	case TA_OUTPUT:
 	case TA_DROP:
-		if (ti == 0)
+		if (headers == NULL)
 			break;
 		seq = th->th_seq;
 		ack = th->th_ack;
@@ -205,7 +220,7 @@ tcp_trace(short act, short ostate, struct tcpcb *tp, caddr_t headers,
 		printf(" -> %s", tcpstates[tp->t_state]);
 	/* print out internal state of tp !?! */
 	printf("\n");
-	if (tp == 0)
+	if (tp == NULL)
 		return;
 	printf("\trcv_(nxt,wnd,up) (%x,%lx,%x) snd_(una,nxt,max) (%x,%x,%x)\n",
 	    tp->rcv_nxt, tp->rcv_wnd, tp->rcv_up, tp->snd_una, tp->snd_nxt,