Pull up following revision(s) (requested by ozaki-r in ticket #1164):

	sys/net/link_proto.c: revision 1.41
	sys/netinet6/in6.c: revision 1.293
	sys/net/if.h: revision 1.307
	sys/netinet/ip_icmp.c: revision 1.180
	sys/dev/vmt/vmt_subr.c: revision 1.11
	sys/netinet6/in6_var.h: revision 1.105
	sys/netinet6/in6_var.h: revision 1.106
	sys/net/if.c: revision 1.532
	sys/net/if.c: revision 1.533
	sys/netinet6/mld6.c: revision 1.102
	sys/netinet/in_var.h: revision 1.104
	sys/net/if_spppsubr.c: revision 1.270
	sys/net/if_spppsubr.c: revision 1.271
	sys/netinet6/nd6.c: revision 1.284

if: introduce if_first_addr() (and psref variant)

It returns a first address (ifa) of a given family on a given interface.

It will replace a bunch of open codes and make their intent clear.
Apply if_first_addr() and if_first_addr_psref()

in6: introduce in6ifa_first_lladdr() (and psref variant)

It returns a first link-local address (ifa) on a given interface.
Apply in6ifa_first_lladdr() and in6ifa_first_lladdr_psref()

Author: MartinHusemann

sys/dev/vmt/vmt_subr.c

@@ -1,4 +1,4 @@
-/* $NetBSD: vmt_subr.c,v 1.3.16.1 2024/09/11 15:52:17 martin Exp $ */
+/* $NetBSD: vmt_subr.c,v 1.3.16.2 2025/10/01 14:58:37 martin Exp $ */
 /* $OpenBSD: vmt.c,v 1.11 2011/01/27 21:29:25 dtucker Exp $ */
 
 /*
@@ -711,17 +711,12 @@ vmt_tclo_broadcastip(struct vmt_softc *sc)
 			continue;
 		}
 
-		IFADDR_READER_FOREACH(iface_addr, iface) {
-			if (iface_addr->ifa_addr->sa_family != AF_INET) {
-				continue;
-			}
-
+		iface_addr = if_first_addr_psref(iface, AF_INET, &psref);
+		if (iface_addr != NULL) {
 			guest_ip = satosin(iface_addr->ifa_addr);
-			ifa_acquire(iface_addr, &psref);
-			goto got;
+			break;
 		}
 	}
-got:
 	pserialize_read_exit(s);
 
 	if (guest_ip != NULL) {

sys/net/if.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: if.c,v 1.528.2.1 2025/07/14 18:31:54 martin Exp $	*/
+/*	$NetBSD: if.c,v 1.528.2.2 2025/10/01 14:58:36 martin Exp $	*/
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.528.2.1 2025/07/14 18:31:54 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.528.2.2 2025/10/01 14:58:36 martin Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -2099,6 +2099,33 @@ ifa_ifwithladdr_psref(const struct sockaddr *addr, struct psref *psref)
 	return ifa;
 }
 
+struct ifaddr *
+if_first_addr(const struct ifnet *ifp, const int af)
+{
+	struct ifaddr *ifa = NULL;
+
+	IFADDR_READER_FOREACH(ifa, ifp) {
+		if (ifa->ifa_addr->sa_family == af)
+			break;
+	}
+	return ifa;
+}
+
+struct ifaddr *
+if_first_addr_psref(const struct ifnet *ifp, const int af, struct psref *psref)
+{
+	struct ifaddr *ifa;
+	int s;
+
+	s = pserialize_read_enter();
+	ifa = if_first_addr(ifp, af);
+	if (ifa != NULL)
+		ifa_acquire(ifa, psref);
+	pserialize_read_exit(s);
+
+	return ifa;
+}
+
 /*
  * Find an interface using a specific address family
  */
@@ -2113,12 +2140,10 @@ ifa_ifwithaf(int af)
 	IFNET_READER_FOREACH(ifp) {
 		if (if_is_deactivated(ifp))
 			continue;
-		IFADDR_READER_FOREACH(ifa, ifp) {
-			if (ifa->ifa_addr->sa_family == af)
-				goto out;
-		}
+		ifa = if_first_addr(ifp, af);
+		if (ifa != NULL)
+			break;
 	}
-out:
 	pserialize_read_exit(s);
 	return ifa;
 }

sys/net/if.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: if.h,v 1.304 2022/11/25 08:39:32 knakahara Exp $	*/
+/*	$NetBSD: if.h,v 1.304.2.1 2025/10/01 14:58:36 martin Exp $	*/
 
 /*-
  * Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -1230,6 +1230,9 @@ struct	ifaddr *ifaof_ifpforaddr_psref(const struct sockaddr *, struct ifnet *,
 void	link_rtrequest(int, struct rtentry *, const struct rt_addrinfo *);
 void	p2p_rtrequest(int, struct rtentry *, const struct rt_addrinfo *);
 
+struct ifaddr *if_first_addr(const struct ifnet *ifp, const int af);
+struct ifaddr *if_first_addr_psref(const struct ifnet *ifp, const int af, struct psref *psref);
+
 void	if_clone_attach(struct if_clone *);
 void	if_clone_detach(struct if_clone *);
 

sys/net/if_spppsubr.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: if_spppsubr.c,v 1.266 2022/09/03 02:47:59 thorpej Exp $	 */
+/*	$NetBSD: if_spppsubr.c,v 1.266.4.1 2025/10/01 14:58:36 martin Exp $	 */
 
 /*
  * Synchronous PPP/Cisco link level subroutines.
@@ -41,7 +41,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.266 2022/09/03 02:47:59 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.266.4.1 2025/10/01 14:58:36 martin Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -5567,39 +5567,27 @@ sppp_get_ip_addrs(struct sppp *sp, uint32_t *src, uint32_t *dst, uint32_t *srcma
 {
 	struct ifnet *ifp = &sp->pp_if;
 	struct ifaddr *ifa;
-	struct sockaddr_in *si, *sm;
 	uint32_t ssrc, ddst;
-	int bound, s;
+	int bound;
 	struct psref psref;
 
-	sm = NULL;
 	ssrc = ddst = 0;
 	/*
 	 * Pick the first AF_INET address from the list,
 	 * aliases don't make any sense on a p2p link anyway.
 	 */
-	si = 0;
 	bound = curlwp_bind();
-	s = pserialize_read_enter();
-	IFADDR_READER_FOREACH(ifa, ifp) {
-		if (ifa->ifa_addr->sa_family == AF_INET) {
-			si = (struct sockaddr_in *)ifa->ifa_addr;
-			sm = (struct sockaddr_in *)ifa->ifa_netmask;
-			if (si) {
-				ifa_acquire(ifa, &psref);
-				break;
-			}
-		}
-	}
-	pserialize_read_exit(s);
-	if (ifa) {
-		if (si && si->sin_addr.s_addr) {
+	ifa = if_first_addr_psref(ifp, AF_INET, &psref);
+	if (ifa != NULL) {
+		struct sockaddr_in *si = satosin(ifa->ifa_addr);
+		struct sockaddr_in *sm = satosin(ifa->ifa_netmask);
+		if (si->sin_addr.s_addr) {
 			ssrc = si->sin_addr.s_addr;
 			if (srcmask)
 				*srcmask = ntohl(sm->sin_addr.s_addr);
 		}
 
-		si = (struct sockaddr_in *)ifa->ifa_dstaddr;
+		si = satosin(ifa->ifa_dstaddr);
 		if (si && si->sin_addr.s_addr)
 			ddst = si->sin_addr.s_addr;
 		ifa_release(ifa, &psref);
@@ -5621,7 +5609,7 @@ sppp_set_ip_addrs(struct sppp *sp)
 	struct ifaddr *ifa;
 	struct sockaddr_in *si, *dest;
 	uint32_t myaddr = 0, hisaddr = 0;
-	int s;
+	struct psref psref;
 
 	KASSERT(SPPP_WLOCKED(sp));
 
@@ -5636,15 +5624,11 @@ sppp_set_ip_addrs(struct sppp *sp)
 	 * aliases don't make any sense on a p2p link anyway.
 	 */
 	si = dest = NULL;
-	s = pserialize_read_enter();
-	IFADDR_READER_FOREACH(ifa, ifp) {
-		if (ifa->ifa_addr->sa_family == AF_INET) {
-			si = (struct sockaddr_in *)ifa->ifa_addr;
-			dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
-			break;
-		}
+	ifa = if_first_addr_psref(ifp, AF_INET, &psref);
+	if (ifa != NULL) {
+		si = satosin(ifa->ifa_addr);
+		dest = satosin(ifa->ifa_dstaddr);
 	}
-	pserialize_read_exit(s);
 
 	if ((sp->ipcp.flags & IPCP_MYADDR_DYN) && (sp->ipcp.flags & IPCP_MYADDR_SEEN))
 		myaddr = sp->ipcp.req_myaddr;
@@ -5682,6 +5666,8 @@ sppp_set_ip_addrs(struct sppp *sp)
 			pfil_run_addrhooks(if_pfil, SIOCAIFADDR, ifa);
 		}
 	}
+	if (ifa != NULL)
+		ifa_release(ifa, &psref);
 
 	IFNET_UNLOCK(ifp);
 
@@ -5697,7 +5683,7 @@ sppp_clear_ip_addrs(struct sppp *sp)
 	struct ifnet *ifp;
 	struct ifaddr *ifa;
 	struct sockaddr_in *si, *dest;
-	int s;
+	struct psref psref;
 
 	KASSERT(SPPP_WLOCKED(sp));
 
@@ -5712,15 +5698,16 @@ sppp_clear_ip_addrs(struct sppp *sp)
 	 * aliases don't make any sense on a p2p link anyway.
 	 */
 	si = dest = NULL;
-	s = pserialize_read_enter();
-	IFADDR_READER_FOREACH(ifa, ifp) {
-		if (ifa->ifa_addr->sa_family == AF_INET) {
-			si = (struct sockaddr_in *)ifa->ifa_addr;
-			dest = (struct sockaddr_in *)ifa->ifa_dstaddr;
-			break;
-		}
+	ifa = if_first_addr_psref(ifp, AF_INET, &psref);
+	if (ifa != NULL) {
+		si = satosin(ifa->ifa_addr);
+		dest = satosin(ifa->ifa_dstaddr);
+		/*
+		 * ignore "0.0.0.0" which means ppp is not opened yet.
+		 */
+		if (si->sin_addr.s_addr == INADDR_ANY)
+			si = NULL;
 	}
-	pserialize_read_exit(s);
 
 	if (si != NULL) {
 		struct sockaddr_in new_sin = *si;
@@ -5746,6 +5733,8 @@ sppp_clear_ip_addrs(struct sppp *sp)
 			pfil_run_addrhooks(if_pfil, SIOCAIFADDR, ifa);
 		}
 	}
+	if (ifa != NULL)
+		ifa_release(ifa, &psref);
 
 	IFNET_UNLOCK(ifp);
 }
@@ -5761,35 +5750,22 @@ sppp_get_ip6_addrs(struct sppp *sp, struct in6_addr *src, struct in6_addr *dst,
 {
 	struct ifnet *ifp = &sp->pp_if;
 	struct ifaddr *ifa;
-	struct sockaddr_in6 *si, *sm;
 	struct in6_addr ssrc, ddst;
-	int bound, s;
+	int bound;
 	struct psref psref;
 
-	sm = NULL;
 	memset(&ssrc, 0, sizeof(ssrc));
 	memset(&ddst, 0, sizeof(ddst));
 	/*
 	 * Pick the first link-local AF_INET6 address from the list,
 	 * aliases don't make any sense on a p2p link anyway.
 	 */
-	si = 0;
 	bound = curlwp_bind();
-	s = pserialize_read_enter();
-	IFADDR_READER_FOREACH(ifa, ifp) {
-		if (ifa->ifa_addr->sa_family == AF_INET6) {
-			si = (struct sockaddr_in6 *)ifa->ifa_addr;
-			sm = (struct sockaddr_in6 *)ifa->ifa_netmask;
-			if (si && IN6_IS_ADDR_LINKLOCAL(&si->sin6_addr)) {
-				ifa_acquire(ifa, &psref);
-				break;
-			}
-		}
-	}
-	pserialize_read_exit(s);
-
-	if (ifa) {
-		if (si && !IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
+	ifa = in6ifa_first_lladdr_psref(ifp, &psref);
+	if (ifa != NULL) {
+		struct sockaddr_in6 *si = satosin6(ifa->ifa_addr);
+		struct sockaddr_in6 *sm = satosin6(ifa->ifa_netmask);
+		if (!IN6_IS_ADDR_UNSPECIFIED(&si->sin6_addr)) {
 			memcpy(&ssrc, &si->sin6_addr, sizeof(ssrc));
 			if (srcmask) {
 				memcpy(srcmask, &sm->sin6_addr,
@@ -5828,7 +5804,6 @@ sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src)
 {
 	struct ifnet *ifp;
 	struct ifaddr *ifa;
-	struct sockaddr_in6 *sin6;
 	int s;
 	struct psref psref;
 
@@ -5845,25 +5820,11 @@ sppp_set_ip6_addr(struct sppp *sp, const struct in6_addr *src)
 	 * aliases don't make any sense on a p2p link anyway.
 	 */
 
-	sin6 = NULL;
-	s = pserialize_read_enter();
-	IFADDR_READER_FOREACH(ifa, ifp)
-	{
-		if (ifa->ifa_addr->sa_family == AF_INET6)
-		{
-			sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
-			if (sin6 && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
-				ifa_acquire(ifa, &psref);
-				break;
-			}
-		}
-	}
-	pserialize_read_exit(s);
-
-	if (ifa && sin6)
-	{
-		int error;
+	ifa = in6ifa_first_lladdr_psref(ifp, &psref);
+	if (ifa != NULL) {
+		struct sockaddr_in6 *sin6 = satosin6(ifa->ifa_addr);
 		struct sockaddr_in6 new_sin6 = *sin6;
+		int error;
 
 		memcpy(&new_sin6.sin6_addr, src, sizeof(new_sin6.sin6_addr));
 		error = in6_ifinit(ifp, ifatoia6(ifa), &new_sin6, 1);

sys/net/link_proto.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: link_proto.c,v 1.40 2021/12/31 14:25:24 riastradh Exp $	*/
+/*	$NetBSD: link_proto.c,v 1.40.4.1 2025/10/01 14:58:36 martin Exp $	*/
 
 /*-
  * Copyright (c) 1982, 1986, 1993
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: link_proto.c,v 1.40 2021/12/31 14:25:24 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: link_proto.c,v 1.40.4.1 2025/10/01 14:58:36 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/socket.h>
@@ -182,12 +182,8 @@ link_control(struct socket *so, unsigned long cmd, void *data,
 		case SIOCGLIFADDR:
 			ifa_release(ifa, &psref);
 			s = pserialize_read_enter();
-			if ((iflr->flags & IFLR_PREFIX) == 0) {
-				IFADDR_READER_FOREACH(ifa, ifp) {
-					if (ifa->ifa_addr->sa_family == AF_LINK)
-						break;
-				}
-			}
+			if ((iflr->flags & IFLR_PREFIX) == 0)
+				ifa = if_first_addr(ifp, AF_LINK);
 			if (ifa == NULL) {
 				pserialize_read_exit(s);
 				error = EADDRNOTAVAIL;

sys/netinet/in_var.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: in_var.h,v 1.103.2.1 2025/07/29 09:35:28 martin Exp $	*/
+/*	$NetBSD: in_var.h,v 1.103.2.2 2025/10/01 14:58:37 martin Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -327,11 +327,7 @@ in_get_ia_from_ifp(struct ifnet *ifp)
 {
 	struct ifaddr *ifa;
 
-	IFADDR_READER_FOREACH(ifa, ifp) {
-		if (ifa->ifa_addr->sa_family == AF_INET)
-			break;
-	}
-
+	ifa = if_first_addr(ifp, AF_INET);
 	return ifatoia(ifa);
 }