summaryrefslogtreecommitdiffhomepage
path: root/networking/nameif.c
blob: 0369c0807af2eda674954a498ad5b9e32f89cb42 (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
/* vi: set sw=4 ts=4: */
/*
 * 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 
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "libbb.h"
#include <syslog.h>
#include <net/if.h>
#include <netinet/ether.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;

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

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

	return mac;
}

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

	if (1 & getopt32(argv, "sc:", &fname)) {
		openlog(applet_name, 0, LOG_LOCAL0);
		logmode = LOGMODE_SYSLOG;
	}

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

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

		while (*a) {
			if (strlen(*a) > IF_NAMESIZE)
				bb_error_msg_and_die("interface name '%s' "
					    "too long", *a);
			ch = xzalloc(sizeof(mactable_t));
			ch->ifname = xstrdup(*a++);
			ch->mac = cc_macaddr(*a++);
			if (clist)
				clist->prev = ch;
			ch->next = clist;
			clist = ch;
		}
	} else {
		ifh = xfopen(fname, "r");

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

			line_ptr = line + strspn(line, " \t");
			if ((line_ptr[0] == '#') || (line_ptr[0] == '\n')) {
				free(line);
				continue;
			}
			name_length = strcspn(line_ptr, " \t");
			ch = xzalloc(sizeof(mactable_t));
			ch->ifname = xstrndup(line_ptr, name_length);
			if (name_length > IF_NAMESIZE)
				bb_error_msg_and_die("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);
	}

	ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);

	while (clist) {
		struct ifreq ifr;

		memset(&ifr, 0, 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);
		ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
					"cannot change ifname %s to %s",
					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;
		if (ENABLE_FEATURE_CLEAN_UP) {
			free(ch->ifname);
			free(ch->mac);
			free(ch);
		}
	}

	return 0;
}