arphrd-util: introduce arphrd_to_hw_addr_len()

src/basic/arphrd-util.c

@@ -1,7 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <errno.h>
+#include <netinet/in.h>
 #include <linux/if_arp.h>
+#include <linux/if_infiniband.h>
 #include <string.h>
 
 #include "arphrd-util.h"
@@ -23,3 +25,21 @@ int arphrd_from_name(const char *name) {
 
         return sc->id;
 }
+
+size_t arphrd_to_hw_addr_len(uint16_t arphrd) {
+        switch (arphrd) {
+        case ARPHRD_ETHER:
+                return ETH_ALEN;
+        case ARPHRD_INFINIBAND:
+                return INFINIBAND_ALEN;
+        case ARPHRD_TUNNEL:
+        case ARPHRD_SIT:
+        case ARPHRD_IPGRE:
+                return sizeof(struct in_addr);
+        case ARPHRD_TUNNEL6:
+        case ARPHRD_IP6GRE:
+                return sizeof(struct in6_addr);
+        default:
+                return 0;
+        }
+}

src/basic/arphrd-util.h

@@ -1,5 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include <inttypes.h>
+#include <stddef.h>
+
 const char *arphrd_to_name(int id);
 int arphrd_from_name(const char *name);
+
+size_t arphrd_to_hw_addr_len(uint16_t arphrd);