aboutsummaryrefslogtreecommitdiff
path: root/networking/nameif.c
blob: afc88917ed640e2b7a3a9f3098aee4733eb0a193 (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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/* 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
 * Extended matching support 2008 by Nico Erfurth <masta@perlgolf.de>
 *
 * 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>
#include <linux/sockios.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 ethtable_s {
	struct ethtable_s *next;
	struct ethtable_s *prev;
	char *ifname;
	struct ether_addr *mac;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
	char *bus_info;
	char *driver;
#endif
} ethtable_t;

#if ENABLE_FEATURE_NAMEIF_EXTENDED
/* Cut'n'paste from ethtool.h */
#define ETHTOOL_BUSINFO_LEN 32
/* these strings are set to whatever the driver author decides... */
struct ethtool_drvinfo {
	uint32_t cmd;
	char  driver[32]; /* driver short name, "tulip", "eepro100" */
	char  version[32];  /* driver version string */
	char  fw_version[32]; /* firmware version string, if applicable */
	char  bus_info[ETHTOOL_BUSINFO_LEN];  /* Bus info for this IF. */
	/* For PCI devices, use pci_dev->slot_name. */
	char  reserved1[32];
	char  reserved2[16];
	uint32_t n_stats;  /* number of u64's from ETHTOOL_GSTATS */
	uint32_t testinfo_len;
	uint32_t eedump_len; /* Size of data from ETHTOOL_GEEPROM (bytes) */
	uint32_t regdump_len;  /* Size of data from ETHTOOL_GREGS (bytes) */
};
#define ETHTOOL_GDRVINFO  0x00000003 /* Get driver info. */
#endif


static void nameif_parse_selector(ethtable_t *ch, char *selector)
{
	struct ether_addr *lmac;
#if ENABLE_FEATURE_NAMEIF_EXTENDED
	int found_selector = 0;

	while (*selector) {
		char *next;
#endif
		selector = skip_whitespace(selector);
#if ENABLE_FEATURE_NAMEIF_EXTENDED
		if (*selector == '\0')
			break;
		/* Search for the end .... */
		next = skip_non_whitespace(selector);
		if (*next)
			*next++ = '\0';
		/* Check for selectors, mac= is assumed */
		if (strncmp(selector, "bus=", 4) == 0) {
			ch->bus_info = xstrdup(selector + 4);
			found_selector++;
		} else if (strncmp(selector, "driver=", 7) == 0) {
			ch->driver = xstrdup(selector + 7);
			found_selector++;
		} else {
#endif
			lmac = xmalloc(ETH_ALEN);
			ch->mac = ether_aton_r(selector + (strncmp(selector, "mac=", 4) ? 0 : 4), lmac);
			if (ch->mac == NULL)
				bb_error_msg_and_die("cannot parse %s", selector);
#if  ENABLE_FEATURE_NAMEIF_EXTENDED
			found_selector++;
		};
		selector = next;
	}
	if (found_selector == 0)
		bb_error_msg_and_die("no selectors found for %s", ch->ifname);
#endif
}

static void prepend_new_eth_table(ethtable_t **clist, char *ifname, char *selector)
{
	ethtable_t *ch;
	if (strlen(ifname) >= IF_NAMESIZE)
		bb_error_msg_and_die("interface name '%s' too long", ifname);
	ch = xzalloc(sizeof(*ch));
	ch->ifname = xstrdup(ifname);
	nameif_parse_selector(ch, selector);
	ch->next = *clist;
	if (*clist)
		(*clist)->prev = ch;
	*clist = ch;
}

#if ENABLE_FEATURE_CLEAN_UP
static void delete_eth_table(ethtable_t *ch)
{
	free(ch->ifname);
#if ENABLE_FEATURE_NAMEIF_EXTENDED
	free(ch->bus_info);
	free(ch->driver);
#endif
	free(ch->mac);
	free(ch);
};
#else
void delete_eth_table(ethtable_t *ch);
#endif

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

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

	if (argc & 1)
		bb_show_usage();

	if (argc) {
		while (*argv) {
			char *ifname = xstrdup(*argv++);
			prepend_new_eth_table(&clist, ifname, *argv++);
		}
	} else {
		ifh = xfopen(fname, "r");
		while ((line = xmalloc_fgets(ifh)) != NULL) {
			char *next;

			line_ptr = skip_whitespace(line);
			if ((line_ptr[0] == '#') || (line_ptr[0] == '\n'))
				goto read_next_line;
			next = skip_non_whitespace(line_ptr);
			if (*next)
				*next++ = '\0';
			prepend_new_eth_table(&clist, line_ptr, next);
			read_next_line:
			free(line);
		}
		fclose(ifh);
	}

	ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
	ifh = xfopen("/proc/net/dev", "r");

	linenum = 0;
	while (clist) {
		struct ifreq ifr;
#if  ENABLE_FEATURE_NAMEIF_EXTENDED
		struct ethtool_drvinfo drvinfo;
#endif

		line = xmalloc_fgets(ifh);
		if (line == NULL)
			break; /* Seems like we're done */
		if (linenum++ < 2 )
			goto next_line; /* Skip the first two lines */

		/* Find the current interface name and copy it to ifr.ifr_name */
		line_ptr = skip_whitespace(line);
		*strpbrk(line_ptr, " \t\n:") = '\0';

		memset(&ifr, 0, sizeof(struct ifreq));
		strncpy(ifr.ifr_name, line_ptr, sizeof(ifr.ifr_name));

#if ENABLE_FEATURE_NAMEIF_EXTENDED
		/* Check for driver etc. */
		memset(&drvinfo, 0, sizeof(struct ethtool_drvinfo));
		drvinfo.cmd = ETHTOOL_GDRVINFO;
		ifr.ifr_data = (caddr_t) &drvinfo;
		/* Get driver and businfo first, so we have it in drvinfo */
		ioctl(ctl_sk, SIOCETHTOOL, &ifr);
#endif
		ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);

		/* Search the list for a matching device */
		for (ch = clist; ch; ch = ch->next) {
#if ENABLE_FEATURE_NAMEIF_EXTENDED
			if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)
				continue;
			if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)
				continue;
#endif
			if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)
				continue;
			/* if we came here, all selectors have matched */
			goto found;
		}
		/* Nothing found for current interface */
		goto next_line;
 found:
		if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
			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)
			delete_eth_table(ch);
 next_line:
		free(line);
	}
	if (ENABLE_FEATURE_CLEAN_UP) {
		for (ch = clist; ch; ch = ch->next)
			delete_eth_table(ch);
		fclose(ifh);
	};

	return 0;
}