lib: Breakout sendmmsg into it's own header

The only 2 places sendmmsg is used is in zlog_5424.c
and zlog_live.c.  Why is the rest of the entire system
paying for this compilation?

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

lib/frrsendmmsg.h

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * FRR sendmmsg wrapper
+ * Copyright (C) 2024 by Nvidia, Inc.
+ *                       Donald Sharp
+ */
+#ifndef __FRRSENDMMSG_H__
+#define __FRRSENDMMSG_H__
+
+#if !defined(HAVE_STRUCT_MMSGHDR_MSG_HDR) || !defined(HAVE_SENDMMSG)
+/* avoid conflicts in case we have partial support */
+#define mmsghdr	 frr_mmsghdr
+#define sendmmsg frr_sendmmsg
+
+struct mmsghdr {
+	struct msghdr msg_hdr;
+	unsigned int msg_len;
+};
+
+/* just go 1 at a time here, the loop this is used in will handle the rest */
+static inline int sendmmsg(int fd, struct mmsghdr *mmh, unsigned int len,
+			   int flags)
+{
+	int rv = sendmsg(fd, &mmh->msg_hdr, 0);
+
+	return rv > 0 ? 1 : rv;
+}
+#endif
+
+#endif

lib/subdir.am

@@ -227,6 +227,7 @@ pkginclude_HEADERS += \
 	lib/frr_pthread.h \
 	lib/frratomic.h \
 	lib/frrcu.h \
+	lib/frrsendmmsg.h \
 	lib/frrstr.h \
 	lib/graph.h \
 	lib/hash.h \

lib/zebra.h

@@ -203,26 +203,6 @@ size_t strlcpy(char *__restrict dest,
 void explicit_bzero(void *buf, size_t len);
 #endif
 
-#if !defined(HAVE_STRUCT_MMSGHDR_MSG_HDR) || !defined(HAVE_SENDMMSG)
-/* avoid conflicts in case we have partial support */
-#define mmsghdr frr_mmsghdr
-#define sendmmsg frr_sendmmsg
-
-struct mmsghdr {
-	struct msghdr msg_hdr;
-	unsigned int msg_len;
-};
-
-/* just go 1 at a time here, the loop this is used in will handle the rest */
-static inline int sendmmsg(int fd, struct mmsghdr *mmh, unsigned int len,
-			   int flags)
-{
-	int rv = sendmsg(fd, &mmh->msg_hdr, 0);
-
-	return rv > 0 ? 1 : rv;
-}
-#endif
-
 /*
  * RFC 3542 defines several macros for using struct cmsghdr.
  * Here, we define those that are not present

lib/zlog_5424.c

@@ -14,6 +14,8 @@
 
 #include "zebra.h"
 
+#include "frrsendmmsg.h"
+
 #include "zlog_5424.h"
 
 #include <sys/un.h>

lib/zlog_live.c

@@ -5,6 +5,8 @@
 
 #include "zebra.h"
 
+#include "frrsendmmsg.h"
+
 #include "zlog_live.h"
 
 #include "memory.h"