summaryrefslogtreecommitdiffhomepage
path: root/networking/nameif.c
blob: dcc5ec097851264d1f2d5994e4568ad63c7a8faf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 * nameif.c - Naming Interfaces based on MAC address for busybox.
 *
 * Written 2000 by Andi Kleen.
 * Busybox port 2002 by Nick Fedchik <nick@fedchik.org.ua>
 *			Glenn McGrath <bug1@optushome.com.au>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307 USA
 *
 */


#include <sys/syslog.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include <net/if.h>
#include <netinet/ether.h>

#include "busybox.h"

/* Older versions of net/if.h do not appear to define IF_NAMESIZE. */
#ifndef IF_NAMESIZE
#  ifdef IFNAMSIZ
#    define IF_NAMESIZE IFNAMSIZ
#  else
#    define IF_NAMESIZE 16
#  endif
#endif

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

/* Octets in one Ethernet addr, from <linux/if_ether.h> */
#define ETH_ALEN	6

#ifndef ifr_newname
#define ifr_newname ifr_ifru.ifru_slave
#endif

typedef struct mactable_s {
	struct mactable_s *next;
	struct mactable_s *prev;
	char *ifname;
	struct ether_addr *mac;
} mactable_t;

static unsigned char use_syslog;

static void serror(const char *s, ...) __attribute__ ((noreturn));

static void serror(const char *s, ...)
{
	va_list ap;

	va_start(ap, s);

	if (use_syslog) {
		openlog(bb_applet_name, 0, LOG_LOCAL0);
		vsyslog(LOG_ERR, s, ap);
		closelog();
	} else {
		bb_verror_msg(s, ap);
		putc('\n', stderr);
	}

	va_end(ap);

	exit(EXIT_FAILURE);
}

/* Check ascii str_macaddr, convert and copy to *mac */
struct ether_addr *cc_macaddr(char *str_macaddr)
{
	struct ether_addr *lmac, *mac;

	lmac = ether_aton(str_macaddr);
	if (lmac == NULL)
		serror("cannot parse MAC %s", str_macaddr);
	mac = xmalloc(ETH_ALEN);
	memcpy(mac, lmac, ETH_ALEN);

	return mac;
}

int nameif_main(int argc, char **argv)
{
	mactable_t *clist = NULL;
	FILE *ifh;
	const char *fname = "/etc/mactab";
	char *line;
	int ctl_sk;
	int opt;
	int if_index = 1;
	mactable_t *ch;


	while ((opt = getopt(argc, argv, "c:s")) != -1) {
		switch (opt) {
		case 'c':
			fname = optarg;
			break;
		case 's':
			use_syslog = 1;
			break;
		default:
			bb_show_usage();
		}
	}

	if ((argc - optind) & 1)
		bb_show_usage();

	if (optind < argc) {
		char **a = argv + optind;

		while (*a) {

			if (strlen(*a) > IF_NAMESIZE)
				serror("interface name `%s' too long", *a);
			ch = xcalloc(1, sizeof(mactable_t));
			ch->ifname = bb_xstrdup(*a++);
			ch->mac = cc_macaddr(*a++);
			if (clist)
				clist->prev = ch;
			ch->next = clist;
			clist = ch;
		}
	} else {
		ifh = bb_xfopen(fname, "r");

		while ((line = bb_get_line_from_file(ifh)) != NULL) {
			char *line_ptr;
			size_t name_length;

			line_ptr = line + strspn(line, " \t");
			if ((line_ptr[0] == '#') || (line_ptr[0] == '\n'))
				continue;
			name_length = strcspn(line_ptr, " \t");
			ch = xcalloc(1, sizeof(mactable_t));
			ch->ifname = bb_xstrndup(line_ptr, name_length);
			if (name_length > IF_NAMESIZE)
				serror("interface name `%s' too long", ch->ifname);
			line_ptr += name_length;
			line_ptr += strspn(line_ptr, " \t");
			name_length = strspn(line_ptr, "0123456789ABCDEFabcdef:");
			line_ptr[name_length] = '\0';
			ch->mac = cc_macaddr(line_ptr);
			if (clist)
				clist->prev = ch;
			ch->next = clist;
			clist = ch;
			free(line);
		}
		fclose(ifh);
	}

	if ((ctl_sk = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
		serror("socket: %m");

	while (clist) {
		struct ifreq ifr;

		bzero(&ifr, sizeof(struct ifreq));
		if_index++;
		ifr.ifr_ifindex = if_index;

		/* Get ifname by index or die */
		if (ioctl(ctl_sk, SIOCGIFNAME, &ifr))
			break;

		/* Has this device hwaddr? */
		if (ioctl(ctl_sk, SIOCGIFHWADDR, &ifr))
			continue;

		/* Search for mac like in ifr.ifr_hwaddr.sa_data */
		for (ch = clist; ch; ch = ch->next)
			if (!memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN))
				break;

		/* Nothing found for current ifr.ifr_hwaddr.sa_data */
		if (ch == NULL)
			continue;

		strcpy(ifr.ifr_newname, ch->ifname);
		if (ioctl(ctl_sk, SIOCSIFNAME, &ifr) < 0)
			serror("cannot change ifname %s to %s: %m",
				   ifr.ifr_name, ch->ifname);

		/* Remove list entry of renamed interface */
		if (ch->prev != NULL) {
			(ch->prev)->next = ch->next;
		} else {
			clist = ch->next;
		}
		if (ch->next != NULL)
			(ch->next)->prev = ch->prev;
#ifdef CONFIG_FEATURE_CLEAN_UP
		free(ch->ifname);
		free(ch->mac);
		free(ch);
#endif
	}

	return 0;
}