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 <sys/ioctl.h>
//#include <sys/socket.h>
#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""multicast\0"
		"arp\0""address\0""dev\0";
	enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, 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;
		}
		if (key == ARG_down) {
			mask |= IFF_UP;
			flags &= ~IFF_UP;
		}
		if (key == ARG_name) {
			NEXT_ARG();
			newname = *argv;
		}
		if (key == ARG_mtu) {
			NEXT_ARG();
			if (mtu != -1)
				duparg("mtu", *argv);
			mtu = get_unsigned(*argv, "mtu");
		}
		if (key == ARG_multicast) {
			int param;
			NEXT_ARG();
			mask |= IFF_MULTICAST;
			param = index_in_strings(str_on_off, *argv);
			if (param < 0)
				die_must_be_on_off("multicast");
			if (param == PARM_on)
				flags |= IFF_MULTICAST;
			else
				flags &= ~IFF_MULTICAST;
		}
		if (key == ARG_arp) {
			int param;
			NEXT_ARG();
			mask |= IFF_NOARP;
			param = index_in_strings(str_on_off, *argv);
			if (param < 0)
				die_must_be_on_off("arp");
			if (param == PARM_on)
				flags &= ~IFF_NOARP;
			else
				flags |= IFF_NOARP;
		}
		if (key == ARG_addr) {
			NEXT_ARG();
			newaddr = *argv;
		}
		if (key >= ARG_dev) {
			if (key == ARG_dev) {
				NEXT_ARG();
			}
			if (dev)
				duparg2("dev", *argv);
			dev = *argv;
		}
		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);
		}
		if (newbrd) {
			parse_address(dev, htype, halen, newbrd, &ifr1);
		}
	}

	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 (newaddr || newbrd) {
		if (newbrd) {
			set_address(&ifr1, 1);
		}
		if (newaddr) {
			set_address(&ifr0, 0);
		}
	}
	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);
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iplink(char **argv)
{
	static const char keywords[] ALIGN1 =
		"set\0""show\0""lst\0""list\0";
	int key;
	if (!*argv)
		return ipaddr_list_link(argv);
	key = index_in_substrings(keywords, *argv);
	if (key < 0)
		bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
	argv++;
	if (key == 0) /* 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
10	//#include <sys/ioctl.h>
11	//#include <sys/socket.h>
12	#include <net/if.h>
13	#include <net/if_packet.h>
14	#include <netpacket/packet.h>
15	#include <net/ethernet.h>
16
17	#include "ip_common.h" /* #include "libbb.h" is inside */
18	#include "rt_names.h"
19	#include "utils.h"
20
21	/* taken from linux/sockios.h */
22	#define SIOCSIFNAME 0x8923 /* set interface name */
23
24	/* Exits on error */
25	static int get_ctl_fd(void)
26	{
27	int fd;
28
29	fd = socket(PF_INET, SOCK_DGRAM, 0);
30	if (fd >= 0)
31	return fd;
32	fd = socket(PF_PACKET, SOCK_DGRAM, 0);
33	if (fd >= 0)
34	return fd;
35	return xsocket(PF_INET6, SOCK_DGRAM, 0);
36	}
37
38	/* Exits on error */
39	static void do_chflags(char *dev, uint32_t flags, uint32_t mask)
40	{
41	struct ifreq ifr;
42	int fd;
43
44	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
45	fd = get_ctl_fd();
46	xioctl(fd, SIOCGIFFLAGS, &ifr);
47	if ((ifr.ifr_flags ^ flags) & mask) {
48	ifr.ifr_flags &= ~mask;
49	ifr.ifr_flags \|= mask & flags;
50	xioctl(fd, SIOCSIFFLAGS, &ifr);
51	}
52	close(fd);
53	}
54
55	/* Exits on error */
56	static void do_changename(char dev, char newdev)
57	{
58	struct ifreq ifr;
59	int fd;
60
61	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
62	strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);
63	fd = get_ctl_fd();
64	xioctl(fd, SIOCSIFNAME, &ifr);
65	close(fd);
66	}
67
68	/* Exits on error */
69	static void set_qlen(char *dev, int qlen)
70	{
71	struct ifreq ifr;
72	int s;
73
74	s = get_ctl_fd();
75	memset(&ifr, 0, sizeof(ifr));
76	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
77	ifr.ifr_qlen = qlen;
78	xioctl(s, SIOCSIFTXQLEN, &ifr);
79	close(s);
80	}
81
82	/* Exits on error */
83	static void set_mtu(char *dev, int mtu)
84	{
85	struct ifreq ifr;
86	int s;
87
88	s = get_ctl_fd();
89	memset(&ifr, 0, sizeof(ifr));
90	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
91	ifr.ifr_mtu = mtu;
92	xioctl(s, SIOCSIFMTU, &ifr);
93	close(s);
94	}
95
96	/* Exits on error */
97	static int get_address(char dev, int htype)
98	{
99	struct ifreq ifr;
100	struct sockaddr_ll me;
101	socklen_t alen;
102	int s;
103
104	s = xsocket(PF_PACKET, SOCK_DGRAM, 0);
105
106	memset(&ifr, 0, sizeof(ifr));
107	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
108	xioctl(s, SIOCGIFINDEX, &ifr);
109
110	memset(&me, 0, sizeof(me));
111	me.sll_family = AF_PACKET;
112	me.sll_ifindex = ifr.ifr_ifindex;
113	me.sll_protocol = htons(ETH_P_LOOP);
114	xbind(s, (struct sockaddr*)&me, sizeof(me));
115	alen = sizeof(me);
116	getsockname(s, (struct sockaddr*)&me, &alen);
117	//never happens:
118	//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)
119	// bb_perror_msg_and_die("getsockname");
120	close(s);
121	*htype = me.sll_hatype;
122	return me.sll_halen;
123	}
124
125	/* Exits on error */
126	static void parse_address(char dev, int hatype, int halen, char lla, struct ifreq *ifr)
127	{
128	int alen;
129
130	memset(ifr, 0, sizeof(*ifr));
131	strncpy_IFNAMSIZ(ifr->ifr_name, dev);
132	ifr->ifr_hwaddr.sa_family = hatype;
133
134	alen = hatype == 1/ARPHRD_ETHER/ ? 14/ETH_HLEN/ : 19/INFINIBAND_HLEN/;
135	alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);
136	if (alen < 0)
137	exit(EXIT_FAILURE);
138	if (alen != halen) {
139	bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);
140	}
141	}
142
143	/* Exits on error */
144	static void set_address(struct ifreq *ifr, int brd)
145	{
146	int s;
147
148	s = get_ctl_fd();
149	if (brd)
150	xioctl(s, SIOCSIFHWBROADCAST, ifr);
151	else
152	xioctl(s, SIOCSIFHWADDR, ifr);
153	close(s);
154	}
155
156
157	static void die_must_be_on_off(const char *msg) NORETURN;
158	static void die_must_be_on_off(const char *msg)
159	{
160	bb_error_msg_and_die("argument of \"%s\" must be \"on\" or \"off\"", msg);
161	}
162
163	/* Return value becomes exitcode. It's okay to not return at all */
164	static int do_set(char **argv)
165	{
166	char *dev = NULL;
167	uint32_t mask = 0;
168	uint32_t flags = 0;
169	int qlen = -1;
170	int mtu = -1;
171	char *newaddr = NULL;
172	char *newbrd = NULL;
173	struct ifreq ifr0, ifr1;
174	char *newname = NULL;
175	int htype, halen;
176	static const char keywords[] ALIGN1 =
177	"up\0""down\0""name\0""mtu\0""multicast\0"
178	"arp\0""address\0""dev\0";
179	enum { ARG_up = 0, ARG_down, ARG_name, ARG_mtu, ARG_multicast,
180	ARG_arp, ARG_addr, ARG_dev };
181	static const char str_on_off[] ALIGN1 = "on\0""off\0";
182	enum { PARM_on = 0, PARM_off };
183	smalluint key;
184
185	while (*argv) {
186	/* substring search ensures that e.g. "addr" and "address"
187	* are both accepted */
188	key = index_in_substrings(keywords, *argv);
189	if (key == ARG_up) {
190	mask \|= IFF_UP;
191	flags \|= IFF_UP;
192	}
193	if (key == ARG_down) {
194	mask \|= IFF_UP;
195	flags &= ~IFF_UP;
196	}
197	if (key == ARG_name) {
198	NEXT_ARG();
199	newname = *argv;
200	}
201	if (key == ARG_mtu) {
202	NEXT_ARG();
203	if (mtu != -1)
204	duparg("mtu", *argv);
205	mtu = get_unsigned(*argv, "mtu");
206	}
207	if (key == ARG_multicast) {
208	int param;
209	NEXT_ARG();
210	mask \|= IFF_MULTICAST;
211	param = index_in_strings(str_on_off, *argv);
212	if (param < 0)
213	die_must_be_on_off("multicast");
214	if (param == PARM_on)
215	flags \|= IFF_MULTICAST;
216	else
217	flags &= ~IFF_MULTICAST;
218	}
219	if (key == ARG_arp) {
220	int param;
221	NEXT_ARG();
222	mask \|= IFF_NOARP;
223	param = index_in_strings(str_on_off, *argv);
224	if (param < 0)
225	die_must_be_on_off("arp");
226	if (param == PARM_on)
227	flags &= ~IFF_NOARP;
228	else
229	flags \|= IFF_NOARP;
230	}
231	if (key == ARG_addr) {
232	NEXT_ARG();
233	newaddr = *argv;
234	}
235	if (key >= ARG_dev) {
236	if (key == ARG_dev) {
237	NEXT_ARG();
238	}
239	if (dev)
240	duparg2("dev", *argv);
241	dev = *argv;
242	}
243	argv++;
244	}
245
246	if (!dev) {
247	bb_error_msg_and_die(bb_msg_requires_arg, "\"dev\"");
248	}
249
250	if (newaddr \|\| newbrd) {
251	halen = get_address(dev, &htype);
252	if (newaddr) {
253	parse_address(dev, htype, halen, newaddr, &ifr0);
254	}
255	if (newbrd) {
256	parse_address(dev, htype, halen, newbrd, &ifr1);
257	}
258	}
259
260	if (newname && strcmp(dev, newname)) {
261	do_changename(dev, newname);
262	dev = newname;
263	}
264	if (qlen != -1) {
265	set_qlen(dev, qlen);
266	}
267	if (mtu != -1) {
268	set_mtu(dev, mtu);
269	}
270	if (newaddr \|\| newbrd) {
271	if (newbrd) {
272	set_address(&ifr1, 1);
273	}
274	if (newaddr) {
275	set_address(&ifr0, 0);
276	}
277	}
278	if (mask)
279	do_chflags(dev, flags, mask);
280	return 0;
281	}
282
283	static int ipaddr_list_link(char **argv)
284	{
285	preferred_family = AF_PACKET;
286	return ipaddr_list_or_flush(argv, 0);
287	}
288
289	/* Return value becomes exitcode. It's okay to not return at all */
290	int do_iplink(char **argv)
291	{
292	static const char keywords[] ALIGN1 =
293	"set\0""show\0""lst\0""list\0";
294	int key;
295	if (!*argv)
296	return ipaddr_list_link(argv);
297	key = index_in_substrings(keywords, *argv);
298	if (key < 0)
299	bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
300	argv++;
301	if (key == 0) /* set */
302	return do_set(argv);
303	/* show, lst, list */
304	return ipaddr_list_link(argv);
305	}