On 05/06/17(Mon) 16:52, Martin Pieuchot wrote:
> On 05/06/17(Mon) 12:12, Martin Pieuchot wrote:
> > Routing sockets are not protected by the NET_LOCK().  That's one of the
> > boundaries of the network stack.  That's whhy claudio@ sent some diffs
> > to no longer require the KERNEL_LOCK() to protect them.
> > 
> > But right now some rtm_* functions can be executed without
> > KERNEL_LOCK().  That's wrong.  Diff below fixes that and move the
> > KERNEL_LOCK() further down in rtrequest(9) since the NET_LOCK() is
> > enough to protect the other data structures.
> > 
> > The scariest bits come from default router advertisements, but I guess
> > that slaacd(8) saved us ;)
> 
> Also change a KERNEL_ASSERT_LOCKED() into a NET_ASSERT_LOCK() in
> rt_{set,put}gwroute().  Theses can now be called without KERNEL_LOCK()
> when inserting an ARP entry.

Hrvoje Popovski found the hard way that rtrequest(RTM_RESOLVE...) still
need the KERNEL_LOCK() for malloc(9)/free(9).

Here's a more conservative diff.  ok?

Index: net/route.c
===================================================================
RCS file: /cvs/src/sys/net/route.c,v
retrieving revision 1.357
diff -u -p -r1.357 route.c
--- net/route.c 27 May 2017 09:51:18 -0000      1.357
+++ net/route.c 6 Jun 2017 11:01:05 -0000
@@ -385,7 +385,7 @@ rt_setgwroute(struct rtentry *rt, u_int 
 {
        struct rtentry *nhrt;
 
-       KERNEL_ASSERT_LOCKED();
+       NET_ASSERT_LOCKED();
 
        KASSERT(ISSET(rt->rt_flags, RTF_GATEWAY));
 
@@ -442,7 +442,7 @@ rt_putgwroute(struct rtentry *rt)
 {
        struct rtentry *nhrt = rt->rt_gwroute;
 
-       KERNEL_ASSERT_LOCKED();
+       NET_ASSERT_LOCKED();
 
        if (!ISSET(rt->rt_flags, RTF_GATEWAY) || nhrt == NULL)
                return;
@@ -624,7 +624,9 @@ out:
        info.rti_info[RTAX_DST] = dst;
        info.rti_info[RTAX_GATEWAY] = gateway;
        info.rti_info[RTAX_AUTHOR] = src;
+       KERNEL_LOCK();
        rtm_miss(RTM_REDIRECT, &info, flags, prio, ifidx, error, rdomain);
+       KERNEL_UNLOCK();
 }
 
 /*
@@ -653,8 +655,10 @@ rtdeletemsg(struct rtentry *rt, struct i
        info.rti_flags = rt->rt_flags;
        ifidx = rt->rt_ifidx;
        error = rtrequest_delete(&info, rt->rt_priority, ifp, &rt, tableid);
+       KERNEL_LOCK();
        rtm_miss(RTM_DELETE, &info, info.rti_flags, rt->rt_priority, ifidx,
            error, tableid);
+       KERNEL_UNLOCK();
        if (error == 0)
                rtfree(rt);
        return (error);
Index: netinet/in_pcb.c
===================================================================
RCS file: /cvs/src/sys/netinet/in_pcb.c,v
retrieving revision 1.220
diff -u -p -r1.220 in_pcb.c
--- netinet/in_pcb.c    7 Mar 2017 16:59:40 -0000       1.220
+++ netinet/in_pcb.c    6 Jun 2017 10:56:17 -0000
@@ -716,8 +716,11 @@ in_losing(struct inpcb *inp)
                info.rti_info[RTAX_DST] = &inp->inp_route.ro_dst;
                info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
                info.rti_info[RTAX_NETMASK] = rt_plen2mask(rt, &sa_mask);
+
+               KERNEL_LOCK();
                rtm_miss(RTM_LOSING, &info, rt->rt_flags, rt->rt_priority,
                    rt->rt_ifidx, 0, inp->inp_rtableid);
+               KERNEL_UNLOCK();
                if (rt->rt_flags & RTF_DYNAMIC)
                        (void)rtrequest(RTM_DELETE, &info, rt->rt_priority,
                            NULL, inp->inp_rtableid);
Index: netinet6/nd6_rtr.c
===================================================================
RCS file: /cvs/src/sys/netinet6/nd6_rtr.c,v
retrieving revision 1.159
diff -u -p -r1.159 nd6_rtr.c
--- netinet6/nd6_rtr.c  30 May 2017 08:58:34 -0000      1.159
+++ netinet6/nd6_rtr.c  6 Jun 2017 10:56:17 -0000
@@ -613,7 +613,9 @@ defrouter_addreq(struct nd_defrouter *ne
        error = rtrequest(RTM_ADD, &info, RTP_DEFAULT, &rt,
            new->ifp->if_rdomain);
        if (error == 0) {
+               KERNEL_LOCK();
                rtm_send(rt, RTM_ADD, new->ifp->if_rdomain);
+               KERNEL_UNLOCK();
                rtfree(rt);
                new->installed = 1;
        }
@@ -717,7 +719,9 @@ defrouter_delreq(struct nd_defrouter *dr
        error = rtrequest(RTM_DELETE, &info, RTP_DEFAULT, &rt,
            dr->ifp->if_rdomain);
        if (error == 0) {
+               KERNEL_LOCK();
                rtm_send(rt, RTM_DELETE, dr->ifp->if_rdomain);
+               KERNEL_UNLOCK();
                rtfree(rt);
        }
 

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