Split up ip_drain() into an outer lock and iterator part and

a "locked" version that will only handle a single network stack
instance. The latter is called directly from ip_destroy().

Hook up an ip_destroy() function to release resources from the
legacy IP network layer upon virtual network stack teardown.

Sponsored by:	ISPsystem
Reviewed by:	rwatson
MFC After:	5 days

3 files changed, 40 insertions, 8 deletions

diff --git a/sys/netinet/in_proto.c b/sys/netinet/in_proto.c
index 2bc6ca9..d9cab84 100644
--- a/sys/netinet/in_proto.c
+++ b/sys/netinet/in_proto.c
@@ -114,6 +114,9 @@ struct protosw inetsw[] = {
 	.pr_domain =		&inetdomain,
 	.pr_protocol =		IPPROTO_IP,
 	.pr_init =		ip_init,
+#ifdef VIMAGE
+	.pr_destroy =		ip_destroy,
+#endif
 	.pr_slowtimo =		ip_slowtimo,
 	.pr_drain =		ip_drain,
 	.pr_usrreqs =		&nousrreqs
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 8ffa01a..084bac0 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -199,6 +199,7 @@ static struct mtx ipqlock;
 
 static void	maxnipq_update(void);
 static void	ipq_zone_change(void *);
+static void	ip_drain_locked(void);
 
 SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD,
     &VNET_NAME(nipq), 0,
@@ -368,6 +369,22 @@ ip_init(void)
 	netisr_register(&ip_nh);
 }
 
+#ifdef VIMAGE
+void
+ip_destroy(void)
+{
+
+	/* Cleanup in_ifaddr hash table; should be empty. */
+	hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
+
+	IPQ_LOCK();
+	ip_drain_locked();
+	IPQ_UNLOCK();
+
+	uma_zdestroy(V_ipq_zone);
+}
+#endif
+
 void
 ip_fini(void *xtp)
 {
@@ -1237,23 +1254,32 @@ ip_slowtimo(void)
 /*
  * Drain off all datagram fragments.
  */
+static void
+ip_drain_locked(void)
+{
+	int     i;
+
+	IPQ_LOCK_ASSERT();
+
+	for (i = 0; i < IPREASS_NHASH; i++) {
+		while(!TAILQ_EMPTY(&V_ipq[i])) {
+			IPSTAT_ADD(ips_fragdropped,
+			    TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
+			ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
+		}
+	}
+}
+
 void
 ip_drain(void)
 {
 	VNET_ITERATOR_DECL(vnet_iter);
-	int     i;
 
 	VNET_LIST_RLOCK_NOSLEEP();
 	IPQ_LOCK();
 	VNET_FOREACH(vnet_iter) {
 		CURVNET_SET(vnet_iter);
-		for (i = 0; i < IPREASS_NHASH; i++) {
-			while(!TAILQ_EMPTY(&V_ipq[i])) {
-				IPSTAT_ADD(ips_fragdropped,
-				    TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
-				ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
-			}
-		}
+		ip_drain_locked();
 		CURVNET_RESTORE();
 	}
 	IPQ_UNLOCK();
diff --git a/sys/netinet/ip_var.h b/sys/netinet/ip_var.h
index d041dd3..389ad6e 100644
--- a/sys/netinet/ip_var.h
+++ b/sys/netinet/ip_var.h
@@ -212,6 +212,9 @@ int	ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
 	    u_long if_hwassist_flags, int sw_csum);
 void	ip_forward(struct mbuf *m, int srcrt);
 void	ip_init(void);
+#ifdef VIMAGE
+void	ip_destroy(void);
+#endif
 extern int
 	(*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
 	    struct ip_moptions *);