networking/libiproute/iplink.c

/* vi: set sw=4 ts=4: */
/*
 * iplink.c "ip link".
 *
 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
#include <net/if.h>
#include <net/if_packet.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>

#include "ip_common.h"  /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"

/* taken from linux/sockios.h */
#define SIOCSIFNAME	0x8923		/* set interface name */

/* Exits on error */
static int get_ctl_fd(void)
{
	int fd;

	fd = socket(PF_INET, SOCK_DGRAM, 0);
	if (fd >= 0)
		return fd;
	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
	if (fd >= 0)
		return fd;
	return xsocket(PF_INET6, SOCK_DGRAM, 0);
}

/* Exits on error */
static void do_chflags(char *dev, uint32_t flags, uint32_t mask)
{
	struct ifreq ifr;
	int fd;

	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
	fd = get_ctl_fd();
	xioctl(fd, SIOCGIFFLAGS, &ifr);
	if ((ifr.ifr_flags ^ flags) & mask) {
		ifr.ifr_flags &= ~mask;
		ifr.ifr_flags |= mask & flags;
		xioctl(fd, SIOCSIFFLAGS, &ifr);
	}
	close(fd);
}

/* Exits on error */
static void do_changename(char *dev, char *newdev)
{
	struct ifreq ifr;
	int fd;

	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
	strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);
	fd = get_ctl_fd();
	xioctl(fd, SIOCSIFNAME, &ifr);
	close(fd);
}

/* Exits on error */
static void set_qlen(char *dev, int qlen)
{
	struct ifreq ifr;
	int s;

	s = get_ctl_fd();
	memset(&ifr, 0, sizeof(ifr));
	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
	ifr.ifr_qlen = qlen;
	xioctl(s, SIOCSIFTXQLEN, &ifr);
	close(s);
}

/* Exits on error */
static void set_mtu(char *dev, int mtu)
{
	struct ifreq ifr;
	int s;

	s = get_ctl_fd();
	memset(&ifr, 0, sizeof(ifr));
	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
	ifr.ifr_mtu = mtu;
	xioctl(s, SIOCSIFMTU, &ifr);
	close(s);
}

/* Exits on error */
static int get_address(char *dev, int *htype)
{
	struct ifreq ifr;
	struct sockaddr_ll me;
	socklen_t alen;
	int s;

	s = xsocket(PF_PACKET, SOCK_DGRAM, 0);

	memset(&ifr, 0, sizeof(ifr));
	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
	xioctl(s, SIOCGIFINDEX, &ifr);

	memset(&me, 0, sizeof(me));
	me.sll_family = AF_PACKET;
	me.sll_ifindex = ifr.ifr_ifindex;
	me.sll_protocol = htons(ETH_P_LOOP);
	xbind(s, (struct sockaddr*)&me, sizeof(me));
	alen = sizeof(me);
	getsockname(s, (struct sockaddr*)&me, &alen);
	//never happens:
	//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
	//	bb_perror_msg_and_die("getsockname");
	close(s);
	*htype = me.sll_hatype;
	return me.sll_halen;
}

/* Exits on error */
static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr)
{
	int alen;

	memset(ifr, 0, sizeof(*ifr));
	strncpy_IFNAMSIZ(ifr->ifr_name, dev);
	ifr->ifr_hwaddr.sa_family = hatype;

	alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/;
	alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);
	if (alen < 0)
		exit(EXIT_FAILURE);
	if (alen != halen) {
		bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);
	}
}

/* Exits on error */
static void set_address(struct ifreq *ifr, int brd)
{
	int s;

	s = get_ctl_fd();
	if (brd)
		xioctl(s, SIOCSIFHWBROADCAST, ifr);
	else
		xioctl(s, SIOCSIFHWADDR, ifr);
	close(s);
}


static void die_must_be_on_off(const char *msg) NORETURN;
static void die_must_be_on_off(const char *msg)
{
	bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg);
}

/* Return value becomes exitcode. It's okay to not return at all */
static int do_set(char **argv)
{
	char *dev = NULL;
	uint32_t mask = 0;
	uint32_t flags = 0;
	int qlen = -1;
	int mtu = -1;
	char *newaddr = NULL;
	char *newbrd = NULL;
	struct ifreq ifr0, ifr1;
	char *newname = NULL;
	int htype, halen;
	static const char keywords[] ALIGN1 =
		"up\0""down\0""name\0""mtu\0""qlen\0""multicast\0"
		"arp\0""address\0""dev\0";
	enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast,
		ARG_arp, ARG_addr, ARG_dev };
	static const char str_on_off[] ALIGN1 = "on\0""off\0";
	enum { PARM_on = 0, PARM_off };
	smalluint key;

	while (*argv) {
		/* substring search ensures that e.g. "addr" and "address"
		 * are both accepted */
		key = index_in_substrings(keywords, *argv);
		if (key == ARG_up) {
			mask |= IFF_UP;
			flags |= IFF_UP;
		} else if (key == ARG_down) {
			mask |= IFF_UP;
			flags &= ~IFF_UP;
		} else if (key == ARG_name) {
			NEXT_ARG();
			newname = *argv;
		} else if (key == ARG_mtu) {
			NEXT_ARG();
			if (mtu != -1)
				duparg("mtu", *argv);
			mtu = get_unsigned(*argv, "mtu");
		} else if (key == ARG_qlen) {
			NEXT_ARG();
			if (qlen != -1)
				duparg("qlen", *argv);
			qlen = get_unsigned(*argv, "qlen");
		} else if (key == ARG_addr) {
			NEXT_ARG();
			newaddr = *argv;
		} else if (key >= ARG_dev) {
			if (key == ARG_dev) {
				NEXT_ARG();
			}
			if (dev)
				duparg2("dev", *argv);
			dev = *argv;
		} else {
			int param;
			NEXT_ARG();
			param = index_in_strings(str_on_off, *argv);
			if (key == ARG_multicast) {
				if (param < 0)
					die_must_be_on_off("multicast");
				mask |= IFF_MULTICAST;
				if (param == PARM_on)
					flags |= IFF_MULTICAST;
				else
					flags &= ~IFF_MULTICAST;
			} else if (key == ARG_arp) {
				if (param < 0)
					die_must_be_on_off("arp");
				mask |= IFF_NOARP;
				if (param == PARM_on)
					flags &= ~IFF_NOARP;
				else
					flags |= IFF_NOARP;
			}
		}
		argv++;
	}

	if (!dev) {
		bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\"");
	}

	if (newaddr || newbrd) {
		halen = get_address(dev, &htype);
		if (newaddr) {
			parse_address(dev, htype, halen, newaddr, &ifr0);
			set_address(&ifr0, 0);
		}
		if (newbrd) {
			parse_address(dev, htype, halen, newbrd, &ifr1);
			set_address(&ifr1, 1);
		}
	}

	if (newname && strcmp(dev, newname)) {
		do_changename(dev, newname);
		dev = newname;
	}
	if (qlen != -1) {
		set_qlen(dev, qlen);
	}
	if (mtu != -1) {
		set_mtu(dev, mtu);
	}
	if (mask)
		do_chflags(dev, flags, mask);
	return 0;
}

static int ipaddr_list_link(char **argv)
{
	preferred_family = AF_PACKET;
	return ipaddr_list_or_flush(argv, 0);
}

#ifndef NLMSG_TAIL
#define NLMSG_TAIL(nmsg) \
	((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
#endif
/* Return value becomes exitcode. It's okay to not return at all */
static int do_change(char **argv, const unsigned rtm)
{
	static const char keywords[] ALIGN1 =
		"link\0""name\0""type\0""dev\0";
	enum {
		ARG_link,
		ARG_name,
		ARG_type,
		ARG_dev,
	};
	struct rtnl_handle rth;
	struct {
		struct nlmsghdr		n;
		struct ifinfomsg	i;
		char			buf[1024];
	} req;
	smalluint arg;
	char *name_str = NULL, *link_str = NULL, *type_str = NULL, *dev_str = NULL;

	memset(&req, 0, sizeof(req));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = rtm;
	req.i.ifi_family = preferred_family;
	if (rtm == RTM_NEWLINK)
		req.n.nlmsg_flags |= NLM_F_CREATE|NLM_F_EXCL;

	while (*argv) {
		arg = index_in_substrings(keywords, *argv);
		if (arg == ARG_link) {
			NEXT_ARG();
			link_str = *argv;
		} else if (arg == ARG_name) {
			NEXT_ARG();
			name_str = *argv;
		} else if (arg == ARG_type) {
			NEXT_ARG();
			type_str = *argv;
		} else {
			if (arg == ARG_dev) {
				if (dev_str)
					duparg(*argv, "dev");
				NEXT_ARG();
			}
			dev_str = *argv;
		}
		argv++;
	}
	xrtnl_open(&rth);
	ll_init_map(&rth);
	if (type_str) {
		struct rtattr *linkinfo = NLMSG_TAIL(&req.n);

		addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
		addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type_str,
				strlen(type_str));
		linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
	}
	if (rtm != RTM_NEWLINK) {
		if (!dev_str)
			return 1; /* Need a device to delete */
		req.i.ifi_index = xll_name_to_index(dev_str);
	} else {
		if (!name_str)
			name_str = dev_str;
		if (link_str) {
			int idx = xll_name_to_index(link_str);
			addattr_l(&req.n, sizeof(req), IFLA_LINK, &idx, 4);
		}
	}
	if (name_str) {
		const size_t name_len = strlen(name_str) + 1;
		if (name_len < 2 || name_len > IFNAMSIZ)
			invarg(name_str, "name");
		addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name_str, name_len);
	}
	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
		return 2;
	return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iplink(char **argv)
{
	static const char keywords[] ALIGN1 =
		"add\0""delete\0""set\0""show\0""lst\0""list\0";
	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++;
		if (key <= 1) /* add/delete */
			return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK);
		else if (key == 2) /* set */
			return do_set(argv);
	}
	/* show, lst, list */
	return ipaddr_list_link(argv);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* iplink.c "ip link".
4	*
5	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6	*
7	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8	*/
9	#include <net/if.h>
10	#include <net/if_packet.h>
11	#include <netpacket/packet.h>
12	#include <net/ethernet.h>
13
14	#include "ip_common.h" /* #include "libbb.h" is inside */
15	#include "rt_names.h"
16	#include "utils.h"
17
18	/* taken from linux/sockios.h */
19	#define SIOCSIFNAME 0x8923 /* set interface name */
20
21	/* Exits on error */
22	static int get_ctl_fd(void)
23	{
24	int fd;
25
26	fd = socket(PF_INET, SOCK_DGRAM, 0);
27	if (fd >= 0)
28	return fd;
29	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
30	if (fd >= 0)
31	return fd;
32	return xsocket(PF_INET6, SOCK_DGRAM, 0);
33	}
34
35	/* Exits on error */
36	static void do_chflags(char *dev, uint32_t flags, uint32_t mask)
37	{
38	struct ifreq ifr;
39	int fd;
40
41	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
42	fd = get_ctl_fd();
43	xioctl(fd, SIOCGIFFLAGS, &ifr);
44	if ((ifr.ifr_flags ^ flags) & mask) {
45	ifr.ifr_flags &= ~mask;
46	ifr.ifr_flags \|= mask & flags;
47	xioctl(fd, SIOCSIFFLAGS, &ifr);
48	}
49	close(fd);
50	}
51
52	/* Exits on error */
53	static void do_changename(char dev, char newdev)
54	{
55	struct ifreq ifr;
56	int fd;
57
58	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
59	strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);
60	fd = get_ctl_fd();
61	xioctl(fd, SIOCSIFNAME, &ifr);
62	close(fd);
63	}
64
65	/* Exits on error */
66	static void set_qlen(char *dev, int qlen)
67	{
68	struct ifreq ifr;
69	int s;
70
71	s = get_ctl_fd();
72	memset(&ifr, 0, sizeof(ifr));
73	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
74	ifr.ifr_qlen = qlen;
75	xioctl(s, SIOCSIFTXQLEN, &ifr);
76	close(s);
77	}
78
79	/* Exits on error */
80	static void set_mtu(char *dev, int mtu)
81	{
82	struct ifreq ifr;
83	int s;
84
85	s = get_ctl_fd();
86	memset(&ifr, 0, sizeof(ifr));
87	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
88	ifr.ifr_mtu = mtu;
89	xioctl(s, SIOCSIFMTU, &ifr);
90	close(s);
91	}
92
93	/* Exits on error */
94	static int get_address(char dev, int htype)
95	{
96	struct ifreq ifr;
97	struct sockaddr_ll me;
98	socklen_t alen;
99	int s;
100
101	s = xsocket(PF_PACKET, SOCK_DGRAM, 0);
102
103	memset(&ifr, 0, sizeof(ifr));
104	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
105	xioctl(s, SIOCGIFINDEX, &ifr);
106
107	memset(&me, 0, sizeof(me));
108	me.sll_family = AF_PACKET;
109	me.sll_ifindex = ifr.ifr_ifindex;
110	me.sll_protocol = htons(ETH_P_LOOP);
111	xbind(s, (struct sockaddr*)&me, sizeof(me));
112	alen = sizeof(me);
113	getsockname(s, (struct sockaddr*)&me, &alen);
114	//never happens:
115	//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
116	// bb_perror_msg_and_die("getsockname");
117	close(s);
118	*htype = me.sll_hatype;
119	return me.sll_halen;
120	}
121
122	/* Exits on error */
123	static void parse_address(char dev, int hatype, int halen, char lla, struct ifreq *ifr)
124	{
125	int alen;
126
127	memset(ifr, 0, sizeof(*ifr));
128	strncpy_IFNAMSIZ(ifr->ifr_name, dev);
129	ifr->ifr_hwaddr.sa_family = hatype;
130
131	alen = hatype == 1/ARPHRD_ETHER/ ? 14/ETH_HLEN/ : 19/INFINIBAND_HLEN/;
132	alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);
133	if (alen < 0)
134	exit(EXIT_FAILURE);
135	if (alen != halen) {
136	bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);
137	}
138	}
139
140	/* Exits on error */
141	static void set_address(struct ifreq *ifr, int brd)
142	{
143	int s;
144
145	s = get_ctl_fd();
146	if (brd)
147	xioctl(s, SIOCSIFHWBROADCAST, ifr);
148	else
149	xioctl(s, SIOCSIFHWADDR, ifr);
150	close(s);
151	}
152
153
154	static void die_must_be_on_off(const char *msg) NORETURN;
155	static void die_must_be_on_off(const char *msg)
156	{
157	bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg);
158	}
159
160	/* Return value becomes exitcode. It's okay to not return at all */
161	static int do_set(char **argv)
162	{
163	char *dev = NULL;
164	uint32_t mask = 0;
165	uint32_t flags = 0;
166	int qlen = -1;
167	int mtu = -1;
168	char *newaddr = NULL;
169	char *newbrd = NULL;
170	struct ifreq ifr0, ifr1;
171	char *newname = NULL;
172	int htype, halen;
173	static const char keywords[] ALIGN1 =
174	"up\0""down\0""name\0""mtu\0""qlen\0""multicast\0"
175	"arp\0""address\0""dev\0";
176	enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_qlen, ARG_multicast,
177	ARG_arp, ARG_addr, ARG_dev };
178	static const char str_on_off[] ALIGN1 = "on\0""off\0";
179	enum { PARM_on = 0, PARM_off };
180	smalluint key;
181
182	while (*argv) {
183	/* substring search ensures that e.g. "addr" and "address"
184	* are both accepted */
185	key = index_in_substrings(keywords, *argv);
186	if (key == ARG_up) {
187	mask \|= IFF_UP;
188	flags \|= IFF_UP;
189	} else if (key == ARG_down) {
190	mask \|= IFF_UP;
191	flags &= ~IFF_UP;
192	} else if (key == ARG_name) {
193	NEXT_ARG();
194	newname = *argv;
195	} else if (key == ARG_mtu) {
196	NEXT_ARG();
197	if (mtu != -1)
198	duparg("mtu", *argv);
199	mtu = get_unsigned(*argv, "mtu");
200	} else if (key == ARG_qlen) {
201	NEXT_ARG();
202	if (qlen != -1)
203	duparg("qlen", *argv);
204	qlen = get_unsigned(*argv, "qlen");
205	} else if (key == ARG_addr) {
206	NEXT_ARG();
207	newaddr = *argv;
208	} else if (key >= ARG_dev) {
209	if (key == ARG_dev) {
210	NEXT_ARG();
211	}
212	if (dev)
213	duparg2("dev", *argv);
214	dev = *argv;
215	} else {
216	int param;
217	NEXT_ARG();
218	param = index_in_strings(str_on_off, *argv);
219	if (key == ARG_multicast) {
220	if (param < 0)
221	die_must_be_on_off("multicast");
222	mask \|= IFF_MULTICAST;
223	if (param == PARM_on)
224	flags \|= IFF_MULTICAST;
225	else
226	flags &= ~IFF_MULTICAST;
227	} else if (key == ARG_arp) {
228	if (param < 0)
229	die_must_be_on_off("arp");
230	mask \|= IFF_NOARP;
231	if (param == PARM_on)
232	flags &= ~IFF_NOARP;
233	else
234	flags \|= IFF_NOARP;
235	}
236	}
237	argv++;
238	}
239
240	if (!dev) {
241	bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\"");
242	}
243
244	if (newaddr \|\| newbrd) {
245	halen = get_address(dev, &htype);
246	if (newaddr) {
247	parse_address(dev, htype, halen, newaddr, &ifr0);
248	set_address(&ifr0, 0);
249	}
250	if (newbrd) {
251	parse_address(dev, htype, halen, newbrd, &ifr1);
252	set_address(&ifr1, 1);
253	}
254	}
255
256	if (newname && strcmp(dev, newname)) {
257	do_changename(dev, newname);
258	dev = newname;
259	}
260	if (qlen != -1) {
261	set_qlen(dev, qlen);
262	}
263	if (mtu != -1) {
264	set_mtu(dev, mtu);
265	}
266	if (mask)
267	do_chflags(dev, flags, mask);
268	return 0;
269	}
270
271	static int ipaddr_list_link(char **argv)
272	{
273	preferred_family = AF_PACKET;
274	return ipaddr_list_or_flush(argv, 0);
275	}
276
277	#ifndef NLMSG_TAIL
278	#define NLMSG_TAIL(nmsg) \
279	((struct rtattr ) (((void ) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
280	#endif
281	/* Return value becomes exitcode. It's okay to not return at all */
282	static int do_change(char **argv, const unsigned rtm)
283	{
284	static const char keywords[] ALIGN1 =
285	"link\0""name\0""type\0""dev\0";
286	enum {
287	ARG_link,
288	ARG_name,
289	ARG_type,
290	ARG_dev,
291	};
292	struct rtnl_handle rth;
293	struct {
294	struct nlmsghdr n;
295	struct ifinfomsg i;
296	char buf[1024];
297	} req;
298	smalluint arg;
299	char name_str = NULL, link_str = NULL, type_str = NULL, dev_str = NULL;
300
301	memset(&req, 0, sizeof(req));
302
303	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
304	req.n.nlmsg_flags = NLM_F_REQUEST;
305	req.n.nlmsg_type = rtm;
306	req.i.ifi_family = preferred_family;
307	if (rtm == RTM_NEWLINK)
308	req.n.nlmsg_flags \|= NLM_F_CREATE\|NLM_F_EXCL;
309
310	while (*argv) {
311	arg = index_in_substrings(keywords, *argv);
312	if (arg == ARG_link) {
313	NEXT_ARG();
314	link_str = *argv;
315	} else if (arg == ARG_name) {
316	NEXT_ARG();
317	name_str = *argv;
318	} else if (arg == ARG_type) {
319	NEXT_ARG();
320	type_str = *argv;
321	} else {
322	if (arg == ARG_dev) {
323	if (dev_str)
324	duparg(*argv, "dev");
325	NEXT_ARG();
326	}
327	dev_str = *argv;
328	}
329	argv++;
330	}
331	xrtnl_open(&rth);
332	ll_init_map(&rth);
333	if (type_str) {
334	struct rtattr *linkinfo = NLMSG_TAIL(&req.n);
335
336	addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
337	addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, type_str,
338	strlen(type_str));
339	linkinfo->rta_len = (void )NLMSG_TAIL(&req.n) - (void )linkinfo;
340	}
341	if (rtm != RTM_NEWLINK) {
342	if (!dev_str)
343	return 1; /* Need a device to delete */
344	req.i.ifi_index = xll_name_to_index(dev_str);
345	} else {
346	if (!name_str)
347	name_str = dev_str;
348	if (link_str) {
349	int idx = xll_name_to_index(link_str);
350	addattr_l(&req.n, sizeof(req), IFLA_LINK, &idx, 4);
351	}
352	}
353	if (name_str) {
354	const size_t name_len = strlen(name_str) + 1;
355	if (name_len < 2 \|\| name_len > IFNAMSIZ)
356	invarg(name_str, "name");
357	addattr_l(&req.n, sizeof(req), IFLA_IFNAME, name_str, name_len);
358	}
359	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
360	return 2;
361	return 0;
362	}
363
364	/* Return value becomes exitcode. It's okay to not return at all */
365	int do_iplink(char **argv)
366	{
367	static const char keywords[] ALIGN1 =
368	"add\0""delete\0""set\0""show\0""lst\0""list\0";
369	if (*argv) {
370	smalluint key = index_in_substrings(keywords, *argv);
371	if (key > 5) /* invalid argument */
372	bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
373	argv++;
374	if (key <= 1) /* add/delete */
375	return do_change(argv, key ? RTM_DELLINK : RTM_NEWLINK);
376	else if (key == 2) /* set */
377	return do_set(argv);
378	}
379	/* show, lst, list */
380	return ipaddr_list_link(argv);
381	}