iplink: support add/delete

[Oliver Metz]

> As said, please send in a patch with a proper Signed-Off-By.
> TIA,

Your wish is my command...

This patch makes ip applets address and link compile again with older kernel versions.

Regards
Oliver

Signed-off-by: Oliver Metz <oliver.metz at web.de>

--- busybox-1.17.1-orig/networking/libiproute/ipaddress.c	2010-07-25 00:12:43.000000000 +0200
+++ busybox-1.17.1/networking/libiproute/ipaddress.c	2010-08-05 11:33:47.000000000 +0200
@@ -164,6 +164,7 @@
 		printf("master %s ", ll_idx_n2a(*(int*)RTA_DATA(tb[IFLA_MASTER]), b1));
 	}
 #endif
+#ifdef IFLA_OPERSTATE
 	if (tb[IFLA_OPERSTATE]) {
 		static const char operstate_labels[] ALIGN1 =
 			"UNKNOWN\0""NOTPRESENT\0""DOWN\0""LOWERLAYERDOWN\0"
@@ -171,6 +172,7 @@
 		printf("state %s ", nth_string(operstate_labels,
 					*(uint8_t *)RTA_DATA(tb[IFLA_OPERSTATE])));
 	}
+#endif
 	if (G_filter.showqueue)
 		print_queuelen((char*)RTA_DATA(tb[IFLA_IFNAME]));
 
--- busybox-1.17.1-orig/networking/libiproute/iplink.c	2010-07-25 00:12:43.000000000 +0200
+++ busybox-1.17.1/networking/libiproute/iplink.c	2010-08-05 11:39:03.000000000 +0200
@@ -274,6 +274,7 @@
 	return ipaddr_list_or_flush(argv, 0);
 }
 
+#ifdef IFLA_LINKINFO
 #ifndef NLMSG_TAIL
 #define NLMSG_TAIL(nmsg) \
 	((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
@@ -360,20 +361,29 @@
 		return 2;
 	return 0;
 }
+#endif
 
 /* Return value becomes exitcode. It's okay to not return at all */
 int do_iplink(char **argv)
 {
 	static const char keywords[] ALIGN1 =
+#ifdef IFLA_LINKINFO
 		"add\0""delete\0""set\0""show\0""lst\0""list\0";
+#else
+		"set\0""show\0""lst\0""list\0";
+#endif
 	if (*argv) {
 		smalluint key = index_in_substrings(keywords, *argv);
 		if (key > 5) /* invalid argument */
 			bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 		argv++;
+#ifdef IFLA_LINKINFO
 		if (key <= 1) /* add/delete */
 			return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK);
 		else if (key == 2) /* set */
+#else
+		if (key == 0) /* set */
+#endif
 			return do_set(argv);
 	}
 	/* show, lst, list */