[BusyBox] [PATCH] macadddr command

[systems engineer]

the warewulf project uses busybox for its ramdisk image (which works
great), with which they have a standalone mac-addr binary that simply
emits the mac address of an interface specified on the command line. i'm
working on better integration, so have ported mac-addr to busybox (but
without the hypen :) resulting in the following patch, submitted in hopes
that it will be useful.

two pieces: macaddr.c (goes in networking) and the glue. (new to
subversion; it didn't give me macaddr.c in diff, probably showing where i
didn't know to include an additional step...)


-------------- next part --------------
Index: networking/Makefile.in
===================================================================
--- networking/Makefile.in	(revision 10867)
+++ networking/Makefile.in	(working copy)
@@ -39,6 +39,7 @@
 NETWORKING-$(CONFIG_IPLINK)       += iplink.o
 NETWORKING-$(CONFIG_IPROUTE)      += iproute.o
 NETWORKING-$(CONFIG_IPTUNNEL)     += iptunnel.o
+NETWORKING-$(CONFIG_MACADDR)      += macaddr.o
 NETWORKING-$(CONFIG_NAMEIF)       += nameif.o
 NETWORKING-$(CONFIG_NC)           += nc.o
 NETWORKING-$(CONFIG_NETSTAT)      += netstat.o
Index: networking/Config.in
===================================================================
--- networking/Config.in	(revision 10867)
+++ networking/Config.in	(working copy)
@@ -407,6 +407,12 @@
 	help
 	  Equivalent to selecting tunnel support to "ip", above.
 
+config CONFIG_MACADDR
+	bool "macaddr"
+	default n
+	help
+	  Return the mac address of a given interface, for use in scripts.
+
 config CONFIG_NAMEIF
 	bool "nameif"
 	default n
Index: include/usage.h
===================================================================
--- include/usage.h	(revision 10867)
+++ include/usage.h	(working copy)
@@ -1648,6 +1648,11 @@
 #define lsmod_full_usage \
 	"List the currently loaded kernel modules."
 
+#define macaddr_trivial_usage \
+	"[INTERFACE]"
+#define macaddr_full_usage \
+	"Returns the MAC address of a given interface."
+
 #ifdef CONFIG_FEATURE_MAKEDEVS_LEAF
 #define makedevs_trivial_usage \
 	"NAME TYPE MAJOR MINOR FIRST LAST [s]"
Index: include/applets.h
===================================================================
--- include/applets.h	(revision 10867)
+++ include/applets.h	(working copy)
@@ -389,6 +389,9 @@
 #ifdef CONFIG_LSMOD
 	APPLET(lsmod, lsmod_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_MACADDR
+	APPLET(macaddr, macaddr_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_MAKEDEVS
 	APPLET(makedevs, makedevs_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
-------------- next part --------------
/*
 * macaddr.c	print the mac address of a given interface
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Lance Davis
 *
 * Changes:
 *
 * Greg Kurtzer <greg at caosity.org> added argument support
 * ozone <ozone at cname.com> grafted it into busybox, rewrote for(printf()) loop
 */


#include <stdio.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include "busybox.h"

int macaddr_main(int argc, char **argv) {
	int s;
	struct ifreq devea;

	if (argc == 2) {
		 strcpy(devea.ifr_name,argv[1]);
	} else {
		 printf("Usage: %s device\n",argv[0]);
		 exit(1);
	}

	s = socket(AF_INET,SOCK_DGRAM,0);

	if (s < 0) {
		 perror("socket");
		 exit(1);
	}

	if (ioctl(s,SIOCGIFHWADDR,&devea) < 0) {
		 perror(&devea.ifr_name[0]);
		 exit(1);
	}

	for (s = 0; s < 6; s++) {
		printf("%.2X%c",
			devea.ifr_ifru.ifru_hwaddr.sa_data[s]&0xff,
			s == 5 ? '\n' : ':');
	}

	return (0);
}