From 4e64d49b299b035a80413de9c2614f79e6e7fea5 Mon Sep 17 00:00:00 2001
From: bluhm <bluhm@openbsd.org>
Date: Mon, 11 Jun 2018 07:40:26 +0000
Subject: 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@

---
 sys/netinet/tcp_debug.c | 63 ++++++++++++++++++++++++++++++-------------------
 1 file changed, 39 insertions(+), 24 deletions(-)

(limited to 'sys/netinet/tcp_debug.c')

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,
-- 
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