Module Name: src
Committed By: roy
Date: Sun Sep 1 19:26:22 UTC 2019
Modified Files:
src/sys/netinet6: nd6.c nd6.h
Log Message:
inet6: Re-introduce ND6_LLINFO_WAITDELETE so we can return EHOSTDOWN
Once we've sent nd6_mmaxtries NS messages, send RTM_MISS and move to the
ND6_LLINFO_WAITDELETE state rather than freeing the llentry right away.
Wait for a probe cycle and then free the llentry.
If a connection attempts to re-use the llentry during ND6_LLINFO_WAITDELETE,
return EHOSTDOWN (or EHOSTUNREACH if a gateway) to match inet behaviour.
Continue to ND6_LLINFO_INCOMPLETE and send another NS probe in hope of a
reply. Rinse and repeat.
This reverts part of nd6.c r1.14 - an 18 year old commit!
To generate a diff of this commit:
cvs rdiff -u -r1.262 -r1.263 src/sys/netinet6/nd6.c
cvs rdiff -u -r1.86 -r1.87 src/sys/netinet6/nd6.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/netinet6/nd6.c
diff -u src/sys/netinet6/nd6.c:1.262 src/sys/netinet6/nd6.c:1.263
--- src/sys/netinet6/nd6.c:1.262 Sun Sep 1 18:54:38 2019
+++ src/sys/netinet6/nd6.c Sun Sep 1 19:26:21 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: nd6.c,v 1.262 2019/09/01 18:54:38 roy Exp $ */
+/* $NetBSD: nd6.c,v 1.263 2019/09/01 19:26:21 roy 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 1.262 2019/09/01 18:54:38 roy Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.263 2019/09/01 19:26:21 roy Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -480,9 +480,14 @@ nd6_llinfo_timer(void *arg)
ndi = ND_IFINFO(ifp);
switch (ln->ln_state) {
+ case ND6_LLINFO_WAITDELETE:
+ LLE_REMREF(ln);
+ nd6_free(ln, 0);
+ ln = NULL;
+ break;
+
case ND6_LLINFO_INCOMPLETE:
- if (ln->ln_asked < nd6_mmaxtries) {
- ln->ln_asked++;
+ if (ln->ln_asked++ < nd6_mmaxtries) {
send_ns = true;
break;
}
@@ -506,9 +511,17 @@ nd6_llinfo_timer(void *arg)
sockaddr_in6_init(&sin6, taddr6, 0, 0, 0);
rt_clonedmsg(RTM_MISS, sin6tosa(&sin6), NULL, ifp);
- LLE_REMREF(ln);
- nd6_free(ln, 0);
- ln = NULL;
+ /*
+ * Move to the ND6_LLINFO_WAITDELETE state for another
+ * interval at which point the llentry will be freed
+ * unless it's attempted to be used again and we'll
+ * resend NS again, rinse and repeat.
+ */
+ ln->ln_state = ND6_LLINFO_WAITDELETE;
+ if (ln->ln_asked == nd6_mmaxtries)
+ nd6_llinfo_settimer(ln, ndi->retrans * hz / 1000);
+ else
+ send_ns = true;
break;
case ND6_LLINFO_REACHABLE:
@@ -2312,6 +2325,7 @@ nd6_resolve(struct ifnet *ifp, const str
struct llentry *ln = NULL;
bool created = false;
const struct sockaddr_in6 *dst = satocsin6(_dst);
+ int error;
/* discard the packet if IPv6 operation is disabled on the interface */
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
@@ -2406,7 +2420,8 @@ nd6_resolve(struct ifnet *ifp, const str
* does not exceed nd6_maxqueuelen. When it exceeds nd6_maxqueuelen,
* the oldest packet in the queue will be removed.
*/
- if (ln->ln_state == ND6_LLINFO_NOSTATE)
+ if (ln->ln_state == ND6_LLINFO_NOSTATE ||
+ ln->ln_state == ND6_LLINFO_WAITDELETE)
ln->ln_state = ND6_LLINFO_INCOMPLETE;
if (ln->ln_hold) {
struct mbuf *m_hold;
@@ -2430,6 +2445,12 @@ nd6_resolve(struct ifnet *ifp, const str
ln->ln_hold = m;
}
+ if (ln->ln_asked >= nd6_mmaxtries)
+ error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ?
+ EHOSTUNREACH : EHOSTDOWN;
+ else
+ error = EWOULDBLOCK;
+
/*
* If there has been no NS for the neighbor after entering the
* INCOMPLETE state, send the first solicitation.
@@ -2448,7 +2469,7 @@ nd6_resolve(struct ifnet *ifp, const str
if (created)
nd6_gc_neighbors(LLTABLE6(ifp), &dst->sin6_addr);
- return EWOULDBLOCK;
+ return error;
}
int
Index: src/sys/netinet6/nd6.h
diff -u src/sys/netinet6/nd6.h:1.86 src/sys/netinet6/nd6.h:1.87
--- src/sys/netinet6/nd6.h:1.86 Tue Mar 6 10:57:00 2018
+++ src/sys/netinet6/nd6.h Sun Sep 1 19:26:21 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: nd6.h,v 1.86 2018/03/06 10:57:00 roy Exp $ */
+/* $NetBSD: nd6.h,v 1.87 2019/09/01 19:26:21 roy Exp $ */
/* $KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $ */
/*
@@ -38,14 +38,7 @@
#define ND6_LLINFO_PURGE -3
#define ND6_LLINFO_NOSTATE -2
-/*
- * We don't need the WAITDELETE state any more, but we keep the definition
- * in a comment line instead of removing it. This is necessary to avoid
- * unintentionally reusing the value for another purpose, which might
- * affect backward compatibility with old applications.
- * (20000711 jin...@kame.net)
- */
-/* #define ND6_LLINFO_WAITDELETE -1 */
+#define ND6_LLINFO_WAITDELETE -1
#define ND6_LLINFO_INCOMPLETE 0
#define ND6_LLINFO_REACHABLE 1
#define ND6_LLINFO_STALE 2
