aboutsummaryrefslogtreecommitdiff
path: root/networking/nameif.c
blob: 1f26954952961fad583ed08318af3131bf39b01d (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
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
/* 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 GPLv2 or later, see file LICENSE in this source tree.
 */

//config:config NAMEIF
//config:	bool "nameif (6.6 kb)"
//config:	default y
//config:	select PLATFORM_LINUX
//config:	select FEATURE_SYSLOG
//config:	help
//config:	nameif is used to rename network interface by its MAC address.
//config:	Renamed interfaces MUST be in the down state.
//config:	It is possible to use a file (default: /etc/mactab)
//config:	with list of new interface names and MACs.
//config:	Maximum interface name length: IFNAMSIZ = 16
//config:	File fields are separated by space or tab.
//config:	File format:
//config:		# Comment
//config:		new_interface_name  XX:XX:XX:XX:XX:XX
//config:
//config:config FEATURE_NAMEIF_EXTENDED
//config:	bool "Extended nameif"
//config:	default y
//config:	depends on NAMEIF
//config:	help
//config:	This extends the nameif syntax to support the bus_info, driver,
//config:	phyaddr selectors. The syntax is compatible to the normal nameif.
//config:	File format:
//config:		new_interface_name  driver=asix bus=usb-0000:00:08.2-3
//config:		new_interface_name  bus=usb-0000:00:08.2-3 00:80:C8:38:91:B5
//config:		new_interface_name  phy_address=2 00:80:C8:38:91:B5
//config:		new_interface_name  mac=00:80:C8:38:91:B5
//config:		new_interface_name  00:80:C8:38:91:B5

//applet:IF_NAMEIF(APPLET_NOEXEC(nameif, nameif, BB_DIR_SBIN, BB_SUID_DROP, nameif))

//kbuild:lib-$(CONFIG_NAMEIF) += nameif.o

//usage:#define nameif_trivial_usage
//usage:	IF_NOT_FEATURE_NAMEIF_EXTENDED(
//usage:		"[-s] [-c FILE] [IFNAME HWADDR]..."
//usage:	)
//usage:	IF_FEATURE_NAMEIF_EXTENDED(
//usage:		"[-s] [-c FILE] [IFNAME SELECTOR]..."
//usage:	)
//usage:#define nameif_full_usage "\n\n"
//usage:	"Rename network interface while it in the down state."
//usage:	IF_NOT_FEATURE_NAMEIF_EXTENDED(
//usage:     "\nThe device with address HWADDR is renamed to IFACE."
//usage:	)
//usage:	IF_FEATURE_NAMEIF_EXTENDED(
//usage:     "\nThe device matched by SELECTOR is renamed to IFACE."
//usage:     "\nSELECTOR can be a combination of:"
//usage:     "\n	driver=STRING"
//usage:     "\n	bus=STRING"
//usage:     "\n	phy_address=NUM"
//usage:     "\n	[mac=]XX:XX:XX:XX:XX:XX"
//usage:	)
//usage:     "\n"
//usage:     "\n	-c FILE	Configuration file (default: /etc/mactab)"
//usage:     "\n	-s	Log to syslog"
//usage:
//usage:#define nameif_example_usage
//usage:       "$ nameif -s dmz0 00:A0:C9:8C:F6:3F\n"
//usage:       " or\n"
//usage:       "$ nameif -c /etc/my_mactab_file\n"

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

#ifndef IFNAMSIZ
#define IFNAMSIZ 16
#endif

/* Taken 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;
	int32_t phy_address;
#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) */
};

struct ethtool_cmd {
	uint32_t   cmd;
	uint32_t   supported;      /* Features this interface supports */
	uint32_t   advertising;    /* Features this interface advertises */
	uint16_t   speed;          /* The forced speed, 10Mb, 100Mb, gigabit */
	uint8_t    duplex;         /* Duplex, half or full */
	uint8_t    port;           /* Which connector port */
	uint8_t    phy_address;
	uint8_t    transceiver;    /* Which transceiver to use */
	uint8_t    autoneg;        /* Enable or disable autonegotiation */
	uint32_t   maxtxpkt;       /* Tx pkts before generating tx int */
	uint32_t   maxrxpkt;       /* Rx pkts before generating rx int */
	uint16_t   speed_hi;
	uint16_t   reserved2;
	uint32_t   reserved[3];
};

#define ETHTOOL_GSET      0x00000001 /* Get settings. */
#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
		ch->phy_address = -1;
		if (*selector == '\0')
			break;
		/* Search for the end .... */
		next = skip_non_whitespace(selector);
		if (*next)
			*next++ = '\0';
		/* Check for selectors, mac= is assumed */
		if (is_prefixed_with(selector, "bus=")) {
			ch->bus_info = xstrdup(selector + 4);
			found_selector++;
		} else if (is_prefixed_with(selector, "driver=")) {
			ch->driver = xstrdup(selector + 7);
			found_selector++;
		} else if (is_prefixed_with(selector, "phyaddr=")) {
			ch->phy_address = xatoi_positive(selector + 8);
			found_selector++;
		} else {
#endif
			lmac = xmalloc(ETH_ALEN);
			ch->mac = ether_aton_r(selector + (is_prefixed_with(selector, "mac=") ? 4 : 0), lmac);
			if (ch->mac == NULL)
				bb_error_msg_and_die("can't 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) >= IFNAMSIZ)
		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 UNUSED_PARAM, char **argv)
{
	ethtable_t *clist = NULL;
	const char *fname = "/etc/mactab";
	int ctl_sk;
	ethtable_t *ch;
	parser_t *parser;
	char *token[2];

	if (1 & getopt32(argv, "sc:", &fname)) {
		openlog(applet_name, 0, LOG_LOCAL0);
		/* Why not just "="? I assume logging to stderr
		 * can't hurt. 2>/dev/null if you don't like it: */
		logmode |= LOGMODE_SYSLOG;
	}
	argv += optind;

	if (argv[0]) {
		do {
			if (!argv[1])
				bb_show_usage();
			prepend_new_eth_table(&clist, argv[0], argv[1]);
			argv += 2;
		} while (*argv);
	} else {
		parser = config_open(fname);
		while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL))
			prepend_new_eth_table(&clist, token[0], token[1]);
		config_close(parser);
	}

	ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);
	parser = config_open2("/proc/net/dev", xfopen_for_read);

	while (clist && config_read(parser, token, 2, 2, "\0: \t", PARSE_NORMAL)) {
		struct ifreq ifr;
#if  ENABLE_FEATURE_NAMEIF_EXTENDED
		struct ethtool_drvinfo drvinfo;
		struct ethtool_cmd eth_settings;
#endif
		if (parser->lineno <= 2)
			continue; /* Skip the first two lines */

		/* Find the current interface name and copy it to ifr.ifr_name */
		memset(&ifr, 0, sizeof(struct ifreq));
		strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);

#if ENABLE_FEATURE_NAMEIF_EXTENDED
		/* Check for phy address */
		memset(&eth_settings, 0, sizeof(eth_settings));
		eth_settings.cmd = ETHTOOL_GSET;
		ifr.ifr_data = (caddr_t) &eth_settings;
		ioctl(ctl_sk, SIOCETHTOOL, &ifr);

		/* Check for driver etc. */
		memset(&drvinfo, 0, sizeof(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;
			if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)
				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 */
		continue;
 found:
		if (strcmp(ifr.ifr_name, ch->ifname) != 0) {
			strcpy(ifr.ifr_newname, ch->ifname);
			ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,
					"can't 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);
	} /* while */

	if (ENABLE_FEATURE_CLEAN_UP) {
		ethtable_t *next;
		for (ch = clist; ch; ch = next) {
			next = ch->next;
			delete_eth_table(ch);
		}
		config_close(parser);
	};

	return 0;
}