PR/60071 CVS commit: src/sys

["Ryota Ozaki" <ozaki-r%netbsd.org@localhost>]

The following reply was made to PR kern/60071; it has been noted by GNATS.

From: "Ryota Ozaki" <ozaki-r%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/60071 CVS commit: src/sys
Date: Thu, 26 Mar 2026 04:35:18 +0000

 Module Name:	src
 Committed By:	ozaki-r
 Date:		Thu Mar 26 04:35:17 UTC 2026
 
 Modified Files:
 	src/sys/net: if_llatbl.h nd.c
 	src/sys/netinet: if_arp.c
 	src/sys/netinet6: nd6.c
 
 Log Message:
 commit 27c3de6c8063a7850ef0efbea0d83f314e541ce8
 Author: Ryota Ozaki <ozaki-r%iij.ad.jp@localhost>
 Date:   Thu Mar 12 12:42:03 2026 +0900
 
     nd: reset ln_asked on state reset
 
     Even if a userland program such as ping continuously sends packets
     to a (temporarily) unreachable host, the ND resolver only sends
     request packets up to nd_mmaxtries times. This change allows ND
     request packets to continue being sent while the userland process
     is still sending packets.
 
     Additionally, introduce LLE_UNRESOLVED to fix another issue.
     nd_resolve may incorrectly return an error immediately after sending
     the last ND request packet. For example, if nd_mmaxtries = 1 and two
     packets arrive simultaneously, nd_resolve returns an error for the
     second packet. This occurs because ln_asked is used to determine
     whether the ND resolution is still in progress.
 
     Instead, use the new LLE_UNRESOLVED state. It is set when the state
     transitions to WAITDELETE, i.e., one second after the last request
     is sent without successful address resolution.
 
     PR kern/60071
 
 diff --git a/sys/net/if_llatbl.h b/sys/net/if_llatbl.h
 index a83f31cac70..31a3ebef30b 100644
 --- a/sys/net/if_llatbl.h
 +++ b/sys/net/if_llatbl.h
 @@ -249,6 +249,7 @@ MALLOC_DECLARE(M_LLTABLE);
  #define	LLE_VALID	0x0008	/* ll_addr is valid */
  #define	LLE_PUB		0x0020	/* publish entry ??? */
  #define	LLE_LINKED	0x0040	/* linked to lookup structure */
 +#define	LLE_UNRESOLVED	0x0080	/* address unresolved */
  /* LLE request flags */
  #define	LLE_EXCLUSIVE	0x2000	/* return lle xlocked  */
 
 diff --git a/sys/net/nd.c b/sys/net/nd.c
 index 8ebc5fe5338..8d12c1d7b58 100644
 --- a/sys/net/nd.c
 +++ b/sys/net/nd.c
 @@ -113,6 +113,7 @@ nd_timer(void *arg)
 
  		missed = ND_LLINFO_INCOMPLETE;
  		ln->ln_state = ND_LLINFO_WAITDELETE;
 +		ln->la_flags |= LLE_UNRESOLVED;
  		break;
 
  	case ND_LLINFO_REACHABLE:
 @@ -360,8 +361,10 @@ nd_resolve(struct llentry *ln, const struct rtentry *rt, struct mbuf *m,
  	 * the oldest packet in the queue will be removed.
  	 */
  	if (ln->ln_state == ND_LLINFO_NOSTATE ||
 -	    ln->ln_state == ND_LLINFO_WAITDELETE)
 +	    ln->ln_state == ND_LLINFO_WAITDELETE) {
 +		ln->ln_asked = 0;
  		ln->ln_state = ND_LLINFO_INCOMPLETE;
 +	}
 
  #ifdef MBUFTRACE
  	m_claimm(m, ln->lle_tbl->llt_mowner);
 @@ -398,7 +401,7 @@ nd_resolve(struct llentry *ln, const struct rtentry *rt, struct mbuf *m,
  	    ln->la_numheld, nd->nd_maxqueuelen);
  	ln->la_numheld++;
 
 -	if (ln->ln_asked >= nd->nd_mmaxtries)
 +	if ((ln->la_flags & LLE_UNRESOLVED) != 0)
  		error = (rt != NULL && rt->rt_flags & RTF_GATEWAY) ?
  		    EHOSTUNREACH : EHOSTDOWN;
  	else
 diff --git a/sys/netinet/if_arp.c b/sys/netinet/if_arp.c
 index 2934534efb1..fc4d0252a74 100644
 --- a/sys/netinet/if_arp.c
 +++ b/sys/netinet/if_arp.c
 @@ -1056,6 +1056,7 @@ again:
  	KASSERT(sizeof(la->ll_addr) >= ifp->if_addrlen);
  	memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
  	la->la_flags |= LLE_VALID;
 +	la->la_flags &= ~LLE_UNRESOLVED;
  	la->ln_asked = 0;
  	if (new_state != 0) {
  		la->ln_state = new_state;
 diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
 index aeaef609a79..1920759ecbc 100644
 --- a/sys/netinet6/nd6.c
 +++ b/sys/netinet6/nd6.c
 @@ -1400,6 +1400,7 @@ nd6_cache_lladdr(
  		 */
  		memcpy(&ln->ll_addr, lladdr, ifp->if_addrlen);
  		ln->la_flags |= LLE_VALID;
 +		ln->la_flags &= ~LLE_UNRESOLVED;
  	}
 
  	if (!is_newentry) {
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.19 -r1.20 src/sys/net/if_llatbl.h
 cvs rdiff -u -r1.9 -r1.10 src/sys/net/nd.c
 cvs rdiff -u -r1.318 -r1.319 src/sys/netinet/if_arp.c
 cvs rdiff -u -r1.285 -r1.286 src/sys/netinet6/nd6.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.