From: Alexander Bluhm <bluhm@openbsd.org>
Subject: replace macro IFP_TO_IA with function in_ifp2ia
To: tech@openbsd.org
Date: Tue, 2 Dec 2025 14:15:32 +0100

Hi,

Can we replace macro IFP_TO_IA() with function in_ifp2ia() ?
Adding locks will be easier when you don't have to do it in a header
file.

ok?

bluhm

Index: netinet/igmp.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/igmp.c,v
diff -u -p -r1.92 igmp.c
--- netinet/igmp.c	17 Nov 2025 23:53:57 -0000	1.92
+++ netinet/igmp.c	2 Dec 2025 10:33:17 -0000
@@ -427,7 +427,7 @@ igmp_input_if(struct ifnet *ifp, struct 
 		 * determine the arrival interface of an incoming packet.
 		 */
 		if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
-			IFP_TO_IA(ifp, ia);
+			ia = in_ifp2ia(ifp);
 			if (ia)
 				ip->ip_src.s_addr = ia->ia_net;
 		}
@@ -466,7 +466,7 @@ igmp_input_if(struct ifnet *ifp, struct 
 		 * leave requires knowing that we are the only member of a
 		 * group.
 		 */
-		IFP_TO_IA(ifp, ia);
+		ia = in_ifp2ia(ifp);
 		if (ia && ip->ip_src.s_addr == ia->ia_addr.sin_addr.s_addr)
 			break;
 #endif
@@ -494,7 +494,7 @@ igmp_input_if(struct ifnet *ifp, struct 
 		 */
 		if ((ip->ip_src.s_addr & IN_CLASSA_NET) == 0) {
 #ifndef MROUTING
-			IFP_TO_IA(ifp, ia);
+			ia = in_ifp2ia(ifp);
 #endif
 			if (ia)
 				ip->ip_src.s_addr = ia->ia_net;
Index: netinet/in.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in.c,v
diff -u -p -r1.189 in.c
--- netinet/in.c	13 Nov 2025 23:30:01 -0000	1.189
+++ netinet/in.c	2 Dec 2025 10:29:18 -0000
@@ -193,6 +193,28 @@ in_sa2sin(struct sockaddr *sa, struct so
 	return 0;
 }
 
+/*
+ * Finding the internet address structure (in_ifaddr) corresponding
+ * to a given interface (ifnet structure).
+ */
+struct in_ifaddr *
+in_ifp2ia(struct ifnet *ifp)
+{
+	struct in_ifaddr *ia = NULL;
+	struct ifaddr *ifa;
+
+	NET_ASSERT_LOCKED();
+
+	TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
+		if (ifa->ifa_addr->sa_family != AF_INET)
+			continue;
+		ia = ifatoia(ifa);
+		break;
+	}
+
+	return (ia);
+}
+
 int
 in_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp)
 {
Index: netinet/in_pcb.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in_pcb.c,v
diff -u -p -r1.321 in_pcb.c
--- netinet/in_pcb.c	24 Oct 2025 15:09:56 -0000	1.321
+++ netinet/in_pcb.c	2 Dec 2025 10:33:59 -0000
@@ -1024,7 +1024,7 @@ in_pcbselsrc(struct in_addr *insrc, cons
 		ifp = if_get(mopts->imo_ifidx);
 		if (ifp != NULL) {
 			if (ifp->if_rdomain == rtable_l2(rtableid))
-				IFP_TO_IA(ifp, ia);
+				ia = in_ifp2ia(ifp);
 			if (ia == NULL) {
 				if_put(ifp);
 				return (EADDRNOTAVAIL);
Index: netinet/in_var.h
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/in_var.h,v
diff -u -p -r1.43 in_var.h
--- netinet/in_var.h	12 Nov 2025 11:37:08 -0000	1.43
+++ netinet/in_var.h	2 Dec 2025 10:30:44 -0000
@@ -76,23 +76,6 @@ struct	in_aliasreq {
 };
 
 #ifdef _KERNEL
-/*
- * Macro for finding the internet address structure (in_ifaddr) corresponding
- * to a given interface (ifnet structure).
- */
-#define IFP_TO_IA(ifp, ia)						\
-	/* struct ifnet *ifp; */					\
-	/* struct in_ifaddr *ia; */					\
-do {									\
-	struct ifaddr *ifa;						\
-	NET_ASSERT_LOCKED();						\
-	TAILQ_FOREACH(ifa, &(ifp)->if_addrlist, ifa_list) {		\
-		if (ifa->ifa_addr->sa_family == AF_INET)		\
-			break;						\
-	}								\
-	(ia) = ifatoia(ifa);						\
-} while (/* CONSTCOND */ 0)
-
 struct router_info;
 
 /*
@@ -119,6 +102,7 @@ ifmatoinm(struct ifmaddr *ifma)
        return ((struct in_multi *)(ifma));
 }
 
+struct	in_ifaddr *in_ifp2ia(struct ifnet *);
 int	in_ifinit(struct ifnet *,
 	    struct in_ifaddr *, struct sockaddr_in *, int);
 struct	in_multi *in_lookupmulti(const struct in_addr *, struct ifnet *);
Index: netinet/ip_output.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/ip_output.c,v
diff -u -p -r1.414 ip_output.c
--- netinet/ip_output.c	11 Nov 2025 16:57:06 -0000	1.414
+++ netinet/ip_output.c	2 Dec 2025 10:34:36 -0000
@@ -175,7 +175,7 @@ reroute:
 		if (ip->ip_src.s_addr == INADDR_ANY) {
 			struct in_ifaddr *ia;
 
-			IFP_TO_IA(ifp, ia);
+			ia = in_ifp2ia(ifp);
 			if (ia != NULL)
 				ip->ip_src = ia->ia_addr.sin_addr;
 		}
@@ -293,7 +293,7 @@ reroute:
 		if (ip->ip_src.s_addr == INADDR_ANY) {
 			struct in_ifaddr *ia;
 
-			IFP_TO_IA(ifp, ia);
+			ia = in_ifp2ia(ifp);
 			if (ia != NULL)
 				ip->ip_src = ia->ia_addr.sin_addr;
 		}
@@ -1702,9 +1702,9 @@ ip_getmoptions(int optname, struct ip_mo
 		if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL)
 			addr->s_addr = INADDR_ANY;
 		else {
-			IFP_TO_IA(ifp, ia);
-			addr->s_addr = (ia == NULL) ? INADDR_ANY
-					: ia->ia_addr.sin_addr.s_addr;
+			ia = in_ifp2ia(ifp);
+			addr->s_addr = (ia == NULL) ? INADDR_ANY :
+			    ia->ia_addr.sin_addr.s_addr;
 			if_put(ifp);
 		}
 		return (0);