From e296dd2e517cc79321176833d84ca616132cc5bb Mon Sep 17 00:00:00 2001
From: maxv <maxv@NetBSD.org>
Date: Tue, 13 Feb 2018 08:43:26 +0000
Subject: [PATCH] Define ar_* as inlined functions, not as macros. Makes it
 easier to understand why ARPHRD_IEEE1394 needs to be handled with care - it
 doesn't have ar_tha.

---
 sys/net/if_arp.h | 45 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/sys/net/if_arp.h b/sys/net/if_arp.h
index ddcc62250d66..ee7d322b26b6 100644
--- a/sys/net/if_arp.h
+++ b/sys/net/if_arp.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: if_arp.h,v 1.30 2015/08/31 08:05:20 ozaki-r Exp $	*/
+/*	$NetBSD: if_arp.h,v 1.31 2018/02/13 08:43:26 maxv Exp $	*/
 
 /*
  * Copyright (c) 1986, 1993
@@ -68,20 +68,43 @@ struct	arphdr {
 #ifdef COMMENT_ONLY
 	uint8_t  ar_sha[];	/* sender hardware address */
 	uint8_t  ar_spa[];	/* sender protocol address */
-	uint8_t  ar_tha[];	/* target hardware address */
+	uint8_t  ar_tha[];	/* target hardware address (!IEEE1394) */
 	uint8_t  ar_tpa[];	/* target protocol address */
 #endif
-#define ar_sha(ap) (((char *)((ap)+1))+0)
-#define ar_spa(ap) (((char *)((ap)+1))+(ap)->ar_hln)
-#define ar_tha(ap) \
-	(ntohs((ap)->ar_hrd) == ARPHRD_IEEE1394 \
-		? NULL : (((char *)((ap)+1))+(ap)->ar_hln+(ap)->ar_pln))
-#define ar_tpa(ap) \
-	(ntohs((ap)->ar_hrd) == ARPHRD_IEEE1394 \
-		? (((char *)((ap)+1))+(ap)->ar_hln+(ap)->ar_pln) \
-		: (((char *)((ap)+1))+(ap)->ar_hln+(ap)->ar_pln+(ap)->ar_hln))
 } __packed;
 
+static inline uint8_t *
+ar_sha(struct arphdr *ap)
+{
+	return ((uint8_t *)(ap + 1)) + 0;
+}
+
+static inline uint8_t *
+ar_spa(struct arphdr *ap)
+{
+	return ((uint8_t *)(ap + 1)) + ap->ar_hln;
+}
+
+static inline uint8_t *
+ar_tha(struct arphdr *ap)
+{
+	if (ntohs(ap->ar_hrd) == ARPHRD_IEEE1394) {
+		return NULL;
+	} else {
+		return ((uint8_t *)(ap + 1)) + ap->ar_hln + ap->ar_pln;
+	}
+}
+
+static inline uint8_t *
+ar_tpa(struct arphdr *ap)
+{
+	if (ntohs(ap->ar_hrd) == ARPHRD_IEEE1394) {
+		return ((uint8_t *)(ap + 1)) + ap->ar_hln + ap->ar_pln;
+	} else {
+		return ((uint8_t *)(ap + 1)) + ap->ar_hln + ap->ar_pln +
+		    ap->ar_hln;
+	}
+}
 
 /*
  * ARP ioctl request