IP applet by Bastian Blank <waldi@debian.org>
diff --git a/networking/libiproute/iplink.c b/networking/libiproute/iplink.c
new file mode 100644
index 0000000..90d60b4
--- /dev/null
+++ b/networking/libiproute/iplink.c
@@ -0,0 +1,349 @@
+/*
+ * iplink.c		"ip link".
+ *
+ *		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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <linux/if.h>
+#include <linux/if_packet.h>
+#include <linux/if_ether.h>
+#include <linux/sockios.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <linux/sockios.h>
+
+#include "rt_names.h"
+#include "utils.h"
+#include "ip_common.h"
+
+#include "busybox.h"
+
+static int on_off(char *msg)
+{
+	fprintf(stderr, "Error: argument of \"%s\" must be \"on\" or \"off\"\n", msg);
+	return -1;
+}
+
+static int get_ctl_fd(void)
+{
+	int s_errno;
+	int fd;
+
+	fd = socket(PF_INET, SOCK_DGRAM, 0);
+	if (fd >= 0)
+		return fd;
+	s_errno = errno;
+	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
+	if (fd >= 0)
+		return fd;
+	fd = socket(PF_INET6, SOCK_DGRAM, 0);
+	if (fd >= 0)
+		return fd;
+	errno = s_errno;
+	perror("Cannot create control socket");
+	return -1;
+}
+
+static int do_chflags(char *dev, __u32 flags, __u32 mask)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	strcpy(ifr.ifr_name, dev);
+	fd = get_ctl_fd();
+	if (fd < 0)
+		return -1;
+	err = ioctl(fd, SIOCGIFFLAGS, &ifr);
+	if (err) {
+		perror("SIOCGIFFLAGS");
+		close(fd);
+		return -1;
+	}
+	if ((ifr.ifr_flags^flags)&mask) {
+		ifr.ifr_flags &= ~mask;
+		ifr.ifr_flags |= mask&flags;
+		err = ioctl(fd, SIOCSIFFLAGS, &ifr);
+		if (err)
+			perror("SIOCSIFFLAGS");
+	}
+	close(fd);
+	return err;
+}
+
+static int do_changename(char *dev, char *newdev)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	strcpy(ifr.ifr_name, dev);
+	strcpy(ifr.ifr_newname, newdev);
+	fd = get_ctl_fd();
+	if (fd < 0)
+		return -1;
+	err = ioctl(fd, SIOCSIFNAME, &ifr);
+	if (err) {
+		perror("SIOCSIFNAME");
+		close(fd);
+		return -1;
+	}
+	close(fd);
+	return err;
+}
+
+static int set_qlen(char *dev, int qlen)
+{
+	struct ifreq ifr;
+	int s;
+
+	s = get_ctl_fd();
+	if (s < 0)
+		return -1;
+
+	memset(&ifr, 0, sizeof(ifr));
+	strcpy(ifr.ifr_name, dev); 
+	ifr.ifr_qlen = qlen; 
+	if (ioctl(s, SIOCSIFTXQLEN, &ifr) < 0) {
+		perror("SIOCSIFXQLEN");
+		close(s);
+		return -1;
+	}
+	close(s);
+
+	return 0; 
+}
+
+static int set_mtu(char *dev, int mtu)
+{
+	struct ifreq ifr;
+	int s;
+
+	s = get_ctl_fd();
+	if (s < 0)
+		return -1;
+
+	memset(&ifr, 0, sizeof(ifr));
+	strcpy(ifr.ifr_name, dev); 
+	ifr.ifr_mtu = mtu; 
+	if (ioctl(s, SIOCSIFMTU, &ifr) < 0) {
+		perror("SIOCSIFMTU");
+		close(s);
+		return -1;
+	}
+	close(s);
+
+	return 0; 
+}
+
+static int get_address(char *dev, int *htype)
+{
+	struct ifreq ifr;
+	struct sockaddr_ll me;
+	int alen;
+	int s;
+
+	s = socket(PF_PACKET, SOCK_DGRAM, 0);
+	if (s < 0) { 
+		perror("socket(PF_PACKET)");
+		return -1;
+	}
+
+	memset(&ifr, 0, sizeof(ifr));
+	strcpy(ifr.ifr_name, dev);
+	if (ioctl(s, SIOCGIFINDEX, &ifr) < 0) {
+		perror("SIOCGIFINDEX");
+		close(s);
+		return -1;
+	}
+
+	memset(&me, 0, sizeof(me));
+	me.sll_family = AF_PACKET;
+	me.sll_ifindex = ifr.ifr_ifindex;
+	me.sll_protocol = htons(ETH_P_LOOP);
+	if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) {
+		perror("bind");
+		close(s);
+		return -1;
+	}
+
+	alen = sizeof(me);
+	if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) {
+		perror("getsockname");
+		close(s);
+		return -1;
+	}
+	close(s);
+	*htype = me.sll_hatype;
+	return me.sll_halen;
+}
+
+static int parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr)
+{
+	int alen;
+
+	memset(ifr, 0, sizeof(*ifr));
+	strcpy(ifr->ifr_name, dev);
+	ifr->ifr_hwaddr.sa_family = hatype;
+	alen = ll_addr_a2n(ifr->ifr_hwaddr.sa_data, 14, lla);
+	if (alen < 0)
+		return -1;
+	if (alen != halen) {
+		fprintf(stderr, "Wrong address (%s) length: expected %d bytes\n", lla, halen);
+		return -1;
+	}
+	return 0; 
+}
+
+static int set_address(struct ifreq *ifr, int brd)
+{
+	int s;
+
+	s = get_ctl_fd();
+	if (s < 0)
+		return -1;
+	if (ioctl(s, brd?SIOCSIFHWBROADCAST:SIOCSIFHWADDR, ifr) < 0) {
+		perror(brd?"SIOCSIFHWBROADCAST":"SIOCSIFHWADDR");
+		close(s);
+		return -1;
+	}
+	close(s);
+	return 0; 
+}
+
+
+static int do_set(int argc, char **argv)
+{
+	char *dev = NULL;
+	__u32 mask = 0;
+	__u32 flags = 0;
+	int qlen = -1;
+	int mtu = -1;
+	char *newaddr = NULL;
+	char *newbrd = NULL;
+	struct ifreq ifr0, ifr1;
+	char *newname = NULL;
+	int htype, halen;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "up") == 0) {
+			mask |= IFF_UP;
+			flags |= IFF_UP;
+		} else if (strcmp(*argv, "down") == 0) {
+			mask |= IFF_UP;
+			flags &= ~IFF_UP;
+		} else if (strcmp(*argv, "name") == 0) {
+			NEXT_ARG();
+			newname = *argv;
+		} else if (strcmp(*argv, "mtu") == 0) {
+			NEXT_ARG();
+			if (mtu != -1)
+				duparg("mtu", *argv);
+			if (get_integer(&mtu, *argv, 0))
+				invarg("Invalid \"mtu\" value\n", *argv);
+		} else if (strcmp(*argv, "multicast") == 0) {
+			NEXT_ARG();
+			mask |= IFF_MULTICAST;
+			if (strcmp(*argv, "on") == 0) {
+				flags |= IFF_MULTICAST;
+			} else if (strcmp(*argv, "off") == 0) {
+				flags &= ~IFF_MULTICAST;
+			} else
+				return on_off("multicast");
+		} else if (strcmp(*argv, "arp") == 0) {
+			NEXT_ARG();
+			mask |= IFF_NOARP;
+			if (strcmp(*argv, "on") == 0) {
+				flags &= ~IFF_NOARP;
+			} else if (strcmp(*argv, "off") == 0) {
+				flags |= IFF_NOARP;
+			} else
+				return on_off("noarp");
+		} else {
+                        if (strcmp(*argv, "dev") == 0) {
+				NEXT_ARG();
+			}
+			if (dev)
+				duparg2("dev", *argv);
+			dev = *argv;
+		}
+		argc--; argv++;
+	}
+
+	if (!dev) {
+		fprintf(stderr, "Not enough of information: \"dev\" argument is required.\n");
+		exit(-1);
+	}
+
+	if (newaddr || newbrd) {
+		halen = get_address(dev, &htype);
+		if (halen < 0)
+			return -1;
+		if (newaddr) {
+			if (parse_address(dev, htype, halen, newaddr, &ifr0) < 0)
+				return -1;
+		}
+		if (newbrd) {
+			if (parse_address(dev, htype, halen, newbrd, &ifr1) < 0)
+				return -1; 
+		}
+	}
+
+	if (newname && strcmp(dev, newname)) {
+		if (do_changename(dev, newname) < 0)
+			return -1;
+		dev = newname;
+	}
+	if (qlen != -1) { 
+		if (set_qlen(dev, qlen) < 0)
+			return -1; 
+	}
+	if (mtu != -1) { 
+		if (set_mtu(dev, mtu) < 0)
+			return -1; 
+	}
+	if (newaddr || newbrd) {
+		if (newbrd) {
+			if (set_address(&ifr1, 1) < 0)
+				return -1; 
+		}
+		if (newaddr) {
+			if (set_address(&ifr0, 0) < 0)
+				return -1;
+		}
+	}
+	if (mask)
+		return do_chflags(dev, flags, mask);
+	return 0;
+}
+
+int do_iplink(int argc, char **argv)
+{
+	if (argc > 0) {
+		if (matches(*argv, "set") == 0)
+			return do_set(argc-1, argv+1);
+		if (matches(*argv, "show") == 0 ||
+		    matches(*argv, "lst") == 0 ||
+		    matches(*argv, "list") == 0)
+			return ipaddr_list_link(argc-1, argv+1);
+	} else
+		return ipaddr_list_link(0, NULL);
+
+	fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n", *argv);
+	exit(-1);
+}