[src/netbsd-8]: src Pull up following revision(s) (requested by ozaki-r in ti...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0e827cff7f63
branches:  netbsd-8
changeset: 452466:0e827cff7f63
user:      martin <martin%NetBSD.org@localhost>
date:      Mon Jul 08 16:30:58 2019 +0000

description:
Pull up following revision(s) (requested by ozaki-r in ticket #1285):

        sys/netinet6/nd6.c: revision 1.255
        tests/net/ndp/t_ndp.sh: revision 1.32

nd6: restore a missing reachability confirmation

On sending a packet over a STALE cache, the cache should be tried a reachability
confirmation, which is described in RFC 2461/4861 7.3.3.  On the fast path in
nd6_resolve, however, the treatment for STALE caches has been skipped
accidentally.  So STALE caches never be back to the REACHABLE state.

To fix the issue, branch to the fast path only when the cache entry is the
REACHABLE state and leave other caches to the slow path that includes the
treatment.  To this end we need to allow to return a link-layer address if a
valid address is available on the slow path too, which is the same behavior as
FreeBSD and OpenBSD.

tests: test state transitions of neighbor caches

diffstat:

 sys/netinet6/nd6.c     |  20 ++++++++++--
 tests/net/ndp/t_ndp.sh |  78 +++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 93 insertions(+), 5 deletions(-)

diffs (145 lines):

diff -r 743e1b7d70a4 -r 0e827cff7f63 sys/netinet6/nd6.c
--- a/sys/netinet6/nd6.c        Mon Jul 08 16:28:36 2019 +0000
+++ b/sys/netinet6/nd6.c        Mon Jul 08 16:30:58 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nd6.c,v 1.232.2.9 2018/11/06 14:38:58 martin Exp $     */
+/*     $NetBSD: nd6.c,v 1.232.2.10 2019/07/08 16:30:58 martin Exp $    */
 /*     $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $   */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.232.2.9 2018/11/06 14:38:58 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.232.2.10 2019/07/08 16:30:58 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -2311,8 +2311,8 @@
        /* Look up the neighbor cache for the nexthop */
        ln = nd6_lookup(&dst->sin6_addr, ifp, false);
 
-       if (ln != NULL && (ln->la_flags & LLE_VALID) != 0) {
-               KASSERT(ln->ln_state > ND6_LLINFO_INCOMPLETE);
+       if (ln != NULL && (ln->la_flags & LLE_VALID) != 0 &&
+           ln->ln_state == ND6_LLINFO_REACHABLE) {
                /* Fast path */
                memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen));
                LLE_RUNLOCK(ln);
@@ -2375,6 +2375,18 @@
        }
 
        /*
+        * If the neighbor cache entry has a state other than INCOMPLETE
+        * (i.e. its link-layer address is already resolved), just
+        * send the packet.
+        */
+       if (ln->ln_state > ND6_LLINFO_INCOMPLETE) {
+               KASSERT((ln->la_flags & LLE_VALID) != 0);
+               memcpy(lldst, &ln->ll_addr, MIN(dstsize, ifp->if_addrlen));
+               LLE_WUNLOCK(ln);
+               return 0;
+       }
+
+       /*
         * There is a neighbor cache entry, but no ethernet address
         * response yet.  Append this latest packet to the end of the
         * packet queue in the mbuf, unless the number of the packet
diff -r 743e1b7d70a4 -r 0e827cff7f63 tests/net/ndp/t_ndp.sh
--- a/tests/net/ndp/t_ndp.sh    Mon Jul 08 16:28:36 2019 +0000
+++ b/tests/net/ndp/t_ndp.sh    Mon Jul 08 16:30:58 2019 +0000
@@ -1,4 +1,4 @@
-#      $NetBSD: t_ndp.sh,v 1.19.2.2 2018/04/02 09:51:58 martin Exp $
+#      $NetBSD: t_ndp.sh,v 1.19.2.3 2019/07/08 16:30:58 martin Exp $
 #
 # Copyright (c) 2015 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -675,6 +675,81 @@
        cleanup
 }
 
+atf_test_case ndp_cache_state cleanup
+ndp_stray_entries_head()
+{
+
+       atf_set "descr" "Tests states of neighbor cache entries"
+       atf_set "require.progs" "rump_server"
+}
+
+check_cache_state()
+{
+       local dst=$1
+       local state=$2
+
+       $DEBUG && rump.ndp -n $dst
+       atf_check -s exit:0 -o match:"^$dst.*$state " rump.ndp -n $dst
+}
+
+wait_until_stalled()
+{
+       local dst=$1
+       local state=$2
+
+       $DEBUG && rump.ndp -n $dst
+       while true; do
+                rump.ndp -n $dst | grep -q "^$dst.*S " && break
+                sleep 1
+       done
+       $DEBUG && rump.ndp -n $dst
+}
+
+ndp_cache_state_body()
+{
+
+       rump_server_start $SOCKSRC netinet6
+       rump_server_start $SOCKDST netinet6
+
+       setup_dst_server
+       setup_src_server
+
+       export RUMP_SERVER=$SOCKSRC
+
+       #
+       # Reachability confirmation (RFC 4861 7.3.3)
+       #
+       atf_check -s exit:0 -o ignore rump.ping6 -n -X $TIMEOUT -c 1 $IP6DST
+
+       # Receiving a solicited NA packet changes the state of the cache to REACHABLE
+       check_cache_state $IP6DST R
+
+       # The state of the cache transits to STALE after a while
+       wait_until_stalled $IP6DST
+
+       # Sending a packet on the cache will run a reachability confirmation
+       atf_check -s exit:0 -o ignore rump.ping6 -n -X $TIMEOUT -c 1 $IP6DST
+
+       sleep 1
+
+       # The state of the cache is changed to DELAY and stay for 5s, then
+       # send a NS packet and change the state to PROBE
+       check_cache_state $IP6DST D
+
+       sleep $((5 + 1))
+
+       # If the reachability confirmation is success, the state of the cache
+       # is changed to REACHABLE
+       check_cache_state $IP6DST R
+}
+
+ndp_cache_state_cleanup()
+{
+
+       $DEBUG && dump
+       cleanup
+}
+
 atf_init_test_cases()
 {
        atf_add_test_case ndp_cache_expiration
@@ -687,4 +762,5 @@
        atf_add_test_case ndp_purge_on_route_delete
        atf_add_test_case ndp_purge_on_ifdown
        atf_add_test_case ndp_stray_entries
+       atf_add_test_case ndp_cache_state
 }