Explicitly assert socket pointer is non-NULL in tcp_input() so as to

provide better debugging information.

Prefer explicit comparison to NULL for tcpcb pointers rather than
treating them as booleans.

MFC after:	1 month

3 files changed, 16 insertions, 14 deletions

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 836181d..18ccc34 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -784,6 +784,7 @@ findpcb:
 		goto drop;
 #endif
 	so = inp->inp_socket;
+	KASSERT(so != NULL, ("tcp_input: so == NULL"));
 #ifdef TCPDEBUG
 	if (so->so_options & SO_DEBUG) {
 		ostate = tp->t_state;
@@ -2552,7 +2553,7 @@ dropwithreset:
 			    (tcp_seq)0, TH_RST|TH_ACK);
 	}
 
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	if (headlocked)
 		INP_INFO_WUNLOCK(&tcbinfo);
@@ -2563,11 +2564,11 @@ drop:
 	 * Drop space held by incoming segment and return.
 	 */
 #ifdef TCPDEBUG
-	if (tp == 0 || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+	if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen,
 			  &tcp_savetcp, 0);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	if (headlocked)
 		INP_INFO_WUNLOCK(&tcbinfo);
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index 836181d..18ccc34 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -784,6 +784,7 @@ findpcb:
 		goto drop;
 #endif
 	so = inp->inp_socket;
+	KASSERT(so != NULL, ("tcp_input: so == NULL"));
 #ifdef TCPDEBUG
 	if (so->so_options & SO_DEBUG) {
 		ostate = tp->t_state;
@@ -2552,7 +2553,7 @@ dropwithreset:
 			    (tcp_seq)0, TH_RST|TH_ACK);
 	}
 
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	if (headlocked)
 		INP_INFO_WUNLOCK(&tcbinfo);
@@ -2563,11 +2564,11 @@ drop:
 	 * Drop space held by incoming segment and return.
 	 */
 #ifdef TCPDEBUG
-	if (tp == 0 || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+	if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen,
 			  &tcp_savetcp, 0);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	if (headlocked)
 		INP_INFO_WUNLOCK(&tcbinfo);
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index b9d24a8..45808af 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -195,11 +195,11 @@ tcp_timer_2msl(xtp)
 		tp = tcp_close(tp);
 
 #ifdef TCPDEBUG
-	if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+	if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
 			  PRU_SLOWTIMO);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	INP_INFO_WUNLOCK(&tcbinfo);
 }
@@ -353,11 +353,11 @@ dropit:
 	tp = tcp_drop(tp, ETIMEDOUT);
 
 #ifdef TCPDEBUG
-	if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+	if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
 			  PRU_SLOWTIMO);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(tp->t_inpcb);
 	INP_INFO_WUNLOCK(&tcbinfo);
 }
@@ -412,11 +412,11 @@ tcp_timer_persist(xtp)
 
 out:
 #ifdef TCPDEBUG
-	if (tp && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
+	if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
 		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
 			  PRU_SLOWTIMO);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	INP_INFO_WUNLOCK(&tcbinfo);
 }
@@ -560,11 +560,11 @@ tcp_timer_rexmt(xtp)
 
 out:
 #ifdef TCPDEBUG
-	if (tp && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
+	if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
 		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
 			  PRU_SLOWTIMO);
 #endif
-	if (tp)
+	if (tp != NULL)
 		INP_UNLOCK(inp);
 	if (headlocked)
 		INP_INFO_WUNLOCK(&tcbinfo);