Go back to original SA_LEN macro.

Due to some circular dependencies on Solaris, this needs to be defined
as a macro. We should just remove SA_LEN usage here next.

include/Makefile.am

@@ -1,8 +1,8 @@
 noinst_HEADERS =
 noinst_HEADERS += signal.h
 noinst_HEADERS += unistd.h
-noinst_HEADERS += netinet/in.h
 noinst_HEADERS += sys/queue.h
+noinst_HEADERS += sys/socket.h
 noinst_HEADERS += sys/types.h
 noinst_HEADERS += sys/time.h
 noinst_HEADERS += err.h

include/netinet/in.h

@@ -1,24 +0,0 @@
-/*
- * Public domain
- * netinet/in.h compatibility shim
- */
-
-#include_next <netinet/in.h>
-
-#ifndef SA_LEN
-static inline socklen_t sockaddr_len(void *a)
-{
-	struct sockaddr *sa = a;
-	switch (sa->sa_family) {
-	case AF_INET:
-		return sizeof(struct sockaddr_in);
-	case AF_INET6:
-		return sizeof(struct sockaddr_in6);
-	case AF_UNSPEC:
-		return sizeof(struct sockaddr);
-	default:
-		return 0;
-	}
-}
-#define SA_LEN(X) sockaddr_len(X)
-#endif

include/sys/socket.h

@@ -0,0 +1,14 @@
+/*
+ * Public domain
+ * sys/socket.h compatibility shim
+ */
+
+#include_next <sys/socket.h>
+
+#ifndef SA_LEN
+#define SA_LEN(X) \
+	(((struct sockaddr*)(X))->sa_family == AF_INET ? sizeof(struct sockaddr_in) : \
+	 ((struct sockaddr*)(X))->sa_family == AF_INET6 ? sizeof(struct sockaddr_in6) : \
+	 ((struct sockaddr*)(X))->sa_family == AF_UNSPEC ? sizeof(struct sockaddr) : \
+	   sizeof(struct sockaddr))
+#endif