From: Claudio Jeker <cjeker@diehard.n-r-g.com>
Subject: Re: replace macro IFP_TO_IA with function in_ifp2ia
To: Alexander Bluhm <bluhm@openbsd.org>
Cc: tech@openbsd.org
Date: Tue, 2 Dec 2025 14:18:12 +0100

On Tue, Dec 02, 2025 at 02:15:32PM +0100, Alexander Bluhm wrote:
> 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?

OK claudio@
 
> 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);
> 

-- 
:wq Claudio