Lock down the network interface queues. The queue mutex must be obtained

before adding/removing packets from the queue.  Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.

IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue.  An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.

Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.

1 files changed, 2 insertions, 4 deletions

diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index beb620b..63e10c8 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -235,6 +235,7 @@ ip_init()
 
 	ip_id = time_second & 0xffff;
 	ipintrq.ifq_maxlen = ipqmaxlen;
+	mtx_init(&ipintrq.ifq_mtx, "ip_inq", MTX_DEF);
 
 	register_netisr(NETISR_IP, ipintr);
 }
@@ -745,13 +746,10 @@ bad:
 static void
 ipintr(void)
 {
-	int s;
 	struct mbuf *m;
 
-	while(1) {
-		s = splimp();
+	while (1) {
 		IF_DEQUEUE(&ipintrq, m);
-		splx(s);
 		if (m == 0)
 			return;
 		ip_input(m);