In ether_input() scheduling the soft interrupt and queueing the

packet have to be protected by the same splnet.  Otherwise on
architectures where soft interrupts are executed immediately, the
interrupt is processed before the packet is in the queue.

On real hardware interfaces this was not a problem as ether_input()
is called at splnet anyway.  But when sending to a tun interface
the packet got delayed.

ok beck@ miod@ henning@ mpf@ markus@

1 files changed, 14 insertions, 10 deletions

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 89cab499a31..7ea08f926be 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ethersubr.c,v 1.112 2007/11/22 01:21:40 mpf Exp $	*/
+/*	$OpenBSD: if_ethersubr.c,v 1.113 2008/01/17 17:50:59 bluhm Exp $	*/
 /*	$NetBSD: if_ethersubr.c,v 1.19 1996/05/07 02:40:30 thorpej Exp $	*/
 
 /*
@@ -597,6 +597,10 @@ ether_input(ifp, eh, m)
 		}
 	}
 
+	/*
+	 * Schedule softnet interrupt and enqueue packet within the same spl.
+	 */
+	s = splnet();
 decapsulate:
 
 	switch (etype) {
@@ -617,7 +621,7 @@ decapsulate:
 		if (ifp->if_flags & IFF_NOARP)
 			goto dropanyway;
 		revarpinput(m);	/* XXX queue? */
-		return;
+		goto done;
 
 #endif
 #ifdef INET6
@@ -638,7 +642,7 @@ decapsulate:
 		/* probably this should be done with a NETISR as well */
 		/* XXX queue this */
 		aarpinput((struct arpcom *)ifp, m);
-		return;
+		goto done;
 #endif
 #if NPPPOE > 0
 	case ETHERTYPE_PPPOEDISC:
@@ -647,18 +651,18 @@ decapsulate:
 		/*
 		if (m->m_flags & M_PROMISC) {
 			m_freem(m);
-			return;
+			goto done;
 		}
 		*/
 #ifndef PPPOE_SERVER
 		if (m->m_flags & (M_MCAST | M_BCAST)) {
 			m_freem(m);
-			return;
+			goto done;
 		}
 #endif
 		M_PREPEND(m, sizeof(*eh), M_DONTWAIT);
 		if (m == NULL)
-			return;
+			goto done;
 
 		eh_tmp = mtod(m, struct ether_header *);
 		bcopy(eh, eh_tmp, sizeof(struct ether_header));
@@ -705,7 +709,7 @@ decapsulate:
 				m_adj(m, AT_LLC_SIZE);
 				/* XXX Really this should use netisr too */
 				aarpinput((struct arpcom *)ifp, m);
-				return;
+				goto done;
 			}
 #endif /* NETATALK */
 			if (l->llc_control == LLC_UI &&
@@ -719,7 +723,7 @@ decapsulate:
 				m->m_pkthdr.len -= 6;	/* XXX */
 				M_PREPEND(m, sizeof(*eh), M_DONTWAIT);
 				if (m == 0)
-					return;
+					goto done;
 				*mtod(m, struct ether_header *) = *eh;
 				goto decapsulate;
 			}
@@ -727,12 +731,12 @@ decapsulate:
 		dropanyway:
 		default:
 			m_freem(m);
-			return;
+			goto done;
 		}
 	}
 
-	s = splnet();
 	IF_INPUT_ENQUEUE(inq, m);
+done:
 	splx(s);
 }