Recursive splsoftnet() in PMTU

[Martin Pieuchot]

Timers configured with rt_timer_add(9) are always run under splsoftnet()
so no need to take it recursively.

ok?

Index: netinet/ip_icmp.c
===================================================================
RCS file: /cvs/src/sys/netinet/ip_icmp.c,v
retrieving revision 1.152
diff -u -p -r1.152 ip_icmp.c
--- netinet/ip_icmp.c   22 Aug 2016 15:37:23 -0000      1.152
+++ netinet/ip_icmp.c   7 Nov 2016 09:23:47 -0000
@@ -1046,7 +1046,8 @@ void
 icmp_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
 {
        struct ifnet *ifp;
-       int s;
+
+       splsoftassert(IPL_SOFTNET);
 
        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
@@ -1058,7 +1059,6 @@ icmp_mtudisc_timeout(struct rtentry *rt,
 
                sin = *satosin(rt_key(rt));
 
-               s = splsoftnet();
                rtdeletemsg(rt, ifp, r->rtt_tableid);
 
                /* Notify TCP layer of increased Path MTU estimate */
@@ -1066,7 +1066,6 @@ icmp_mtudisc_timeout(struct rtentry *rt,
                if (ctlfunc)
                        (*ctlfunc)(PRC_MTUINC, sintosa(&sin),
                            r->rtt_tableid, NULL);
-               splx(s);
        } else {
                if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
                        rt->rt_rmx.rmx_mtu = 0;
@@ -1097,16 +1096,15 @@ void
 icmp_redirect_timeout(struct rtentry *rt, struct rttimer *r)
 {
        struct ifnet *ifp;
-       int s;
+
+       splsoftassert(IPL_SOFTNET);
 
        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                return;
 
        if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) {
-               s = splsoftnet();
                rtdeletemsg(rt, ifp, r->rtt_tableid);
-               splx(s);
        }
 
        if_put(ifp);
Index: netinet6/icmp6.c
===================================================================
RCS file: /cvs/src/sys/netinet6/icmp6.c,v
retrieving revision 1.190
diff -u -p -r1.190 icmp6.c
--- netinet6/icmp6.c    24 Aug 2016 09:38:29 -0000      1.190
+++ netinet6/icmp6.c    7 Nov 2016 09:24:37 -0000
@@ -1947,16 +1947,15 @@ void
 icmp6_mtudisc_timeout(struct rtentry *rt, struct rttimer *r)
 {
        struct ifnet *ifp;
-       int s;
+
+       splsoftassert(IPL_SOFTNET);
 
        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                return;
 
        if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) {
-               s = splsoftnet();
                rtdeletemsg(rt, ifp, r->rtt_tableid);
-               splx(s);
        } else {
                if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
                        rt->rt_rmx.rmx_mtu = 0;
@@ -1969,16 +1968,15 @@ void
 icmp6_redirect_timeout(struct rtentry *rt, struct rttimer *r)
 {
        struct ifnet *ifp;
-       int s;
+
+       splsoftassert(IPL_SOFTNET);
 
        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                return;
 
        if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) {
-               s = splsoftnet();
                rtdeletemsg(rt, ifp, r->rtt_tableid);
-               splx(s);
        }
 
        if_put(ifp);
Index: net/route.c
===================================================================
RCS file: /cvs/src/sys/net/route.c,v
retrieving revision 1.333
diff -u -p -r1.333 route.c
--- net/route.c 6 Oct 2016 19:09:08 -0000       1.333
+++ net/route.c 7 Nov 2016 09:22:11 -0000
@@ -1498,6 +1498,8 @@ rt_timer_queue_destroy(struct rttimer_qu
 {
        struct rttimer  *r;
 
+       splsoftassert(IPL_SOFTNET);
+
        while ((r = TAILQ_FIRST(&rtq->rtq_head)) != NULL) {
                LIST_REMOVE(r, rtt_link);
                TAILQ_REMOVE(&rtq->rtq_head, r, rtt_next);