summaryrefslogtreecommitdiff
path: root/networking/ifenslave.c
blob: 44839868abfb607fae2079ff326479adcda915f4 (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
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
/* Mode: C;
 *
 * Mini ifenslave implementation for busybox
 * Copyright (C) 2005 by Marc Leeman <marc.leeman@barco.com>
 *
 * ifenslave.c: Configure network interfaces for parallel routing.
 *
 *      This program controls the Linux implementation of running multiple
 *      network interfaces in parallel.
 *
 * Author:      Donald Becker <becker@cesdis.gsfc.nasa.gov>
 *              Copyright 1994-1996 Donald Becker
 *
 *              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.
 *
 *      The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
 *      Center of Excellence in Space Data and Information Sciences
 *         Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
 *
 *  Changes :
 *    - 2000/10/02 Willy Tarreau <willy at meta-x.org> :
 *       - few fixes. Master's MAC address is now correctly taken from
 *         the first device when not previously set ;
 *       - detach support : call BOND_RELEASE to detach an enslaved interface.
 *       - give a mini-howto from command-line help : # ifenslave -h
 *
 *    - 2001/02/16 Chad N. Tindel <ctindel at ieee dot org> :
 *       - Master is now brought down before setting the MAC address.  In
 *         the 2.4 kernel you can't change the MAC address while the device is
 *         up because you get EBUSY.
 *
 *    - 2001/09/13 Takao Indoh <indou dot takao at jp dot fujitsu dot com>
 *       - Added the ability to change the active interface on a mode 1 bond
 *         at runtime.
 *
 *    - 2001/10/23 Chad N. Tindel <ctindel at ieee dot org> :
 *       - No longer set the MAC address of the master.  The bond device will
 *         take care of this itself
 *       - Try the SIOC*** versions of the bonding ioctls before using the
 *         old versions
 *    - 2002/02/18 Erik Habbinga <erik_habbinga @ hp dot com> :
 *       - ifr2.ifr_flags was not initialized in the hwaddr_notset case,
 *         SIOCGIFFLAGS now called before hwaddr_notset test
 *
 *    - 2002/10/31 Tony Cureington <tony.cureington * hp_com> :
 *       - If the master does not have a hardware address when the first slave
 *         is enslaved, the master is assigned the hardware address of that
 *         slave - there is a comment in bonding.c stating "ifenslave takes
 *         care of this now." This corrects the problem of slaves having
 *         different hardware addresses in active-backup mode when
 *         multiple interfaces are specified on a single ifenslave command
 *         (ifenslave bond0 eth0 eth1).
 *
 *    - 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
 *                   Shmulik Hen <shmulik.hen at intel dot com>
 *       - Moved setting the slave's mac address and openning it, from
 *         the application to the driver. This enables support of modes
 *         that need to use the unique mac address of each slave.
 *         The driver also takes care of closing the slave and restoring its
 *         original mac address upon release.
 *         In addition, block possibility of enslaving before the master is up.
 *         This prevents putting the system in an undefined state.
 *
 *    - 2003/05/01 - Amir Noam <amir.noam at intel dot com>
 *       - Added ABI version control to restore compatibility between
 *         new/old ifenslave and new/old bonding.
 *       - Prevent adding an adapter that is already a slave.
 *         Fixes the problem of stalling the transmission and leaving
 *         the slave in a down state.
 *
 *    - 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
 *       - Prevent enslaving if the bond device is down.
 *         Fixes the problem of leaving the system in unstable state and
 *         halting when trying to remove the module.
 *       - Close socket on all abnormal exists.
 *       - Add versioning scheme that follows that of the bonding driver.
 *         current version is 1.0.0 as a base line.
 *
 *    - 2003/05/22 - Jay Vosburgh <fubar at us dot ibm dot com>
 *       - ifenslave -c was broken; it's now fixed
 *       - Fixed problem with routes vanishing from master during enslave
 *         processing.
 *
 *    - 2003/05/27 - Amir Noam <amir.noam at intel dot com>
 *       - Fix backward compatibility issues:
 *         For drivers not using ABI versions, slave was set down while
 *         it should be left up before enslaving.
 *         Also, master was not set down and the default set_mac_address()
 *         would fail and generate an error message in the system log.
 *       - For opt_c: slave should not be set to the master's setting
 *         while it is running. It was already set during enslave. To
 *         simplify things, it is now handeled separately.
 *
 *    - 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
 *       - Code cleanup and style changes
 *         set version to 1.1.0
 */

#include "libbb.h"

#include <net/if_arp.h>
#include <linux/if_bonding.h>
#include <linux/sockios.h>

typedef unsigned long long u64; /* hack, so we may include kernel's ethtool.h */
typedef uint32_t u32;           /* ditto */
typedef uint16_t u16;           /* ditto */
typedef uint8_t u8;             /* ditto */
#include <linux/ethtool.h>


struct dev_data {
	struct ifreq mtu, flags, hwaddr;
};


enum { skfd = 3 };      /* AF_INET socket for ioctl() calls. */
struct globals {
	unsigned abi_ver;       /* userland - kernel ABI version */
	smallint hwaddr_set;    /* Master's hwaddr is set */
	struct dev_data master;
	struct dev_data slave;
};
#define G (*ptr_to_globals)
#define abi_ver    (G.abi_ver   )
#define hwaddr_set (G.hwaddr_set)
#define master     (G.master    )
#define slave      (G.slave     )
#define INIT_G() do { \
	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


/* NOINLINEs are placed where it results in smaller code (gcc 4.3.1) */

static void strncpy_IFNAMSIZ(char *dst, const char *src)
{
	strncpy(dst, src, IFNAMSIZ);
}

static int ioctl_on_skfd(unsigned request, struct ifreq *ifr)
{
	return ioctl(skfd, request, ifr);
}

static int set_ifrname_and_do_ioctl(unsigned request, struct ifreq *ifr, const char *ifname)
{
        strncpy_IFNAMSIZ(ifr->ifr_name, ifname);
	return ioctl_on_skfd(request, ifr);
}

static int get_if_settings(char *ifname, struct dev_data *dd)
{
	int res;

	res = set_ifrname_and_do_ioctl(SIOCGIFMTU, &dd->mtu, ifname);
	res |= set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &dd->flags, ifname);
	res |= set_ifrname_and_do_ioctl(SIOCGIFHWADDR, &dd->hwaddr, ifname);

	return res;
}

static int get_slave_flags(char *slave_ifname)
{
	return set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &slave.flags, slave_ifname);
}

static int set_hwaddr(char *ifname, struct sockaddr *hwaddr)
{
	struct ifreq ifr;

	memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(*hwaddr));
	return set_ifrname_and_do_ioctl(SIOCSIFHWADDR, &ifr, ifname);
}

static int set_mtu(char *ifname, int mtu)
{
	struct ifreq ifr;

	ifr.ifr_mtu = mtu;
	return set_ifrname_and_do_ioctl(SIOCSIFMTU, &ifr, ifname);
}

static int set_if_flags(char *ifname, int flags)
{
	struct ifreq ifr;

	ifr.ifr_flags = flags;
	return set_ifrname_and_do_ioctl(SIOCSIFFLAGS, &ifr, ifname);
}

static int set_if_up(char *ifname, int flags)
{
	int res = set_if_flags(ifname, flags | IFF_UP);
	if (res)
		bb_perror_msg("%s: can't up", ifname);
	return res;
}

static int set_if_down(char *ifname, int flags)
{
	int res = set_if_flags(ifname, flags & ~IFF_UP);
	if (res)
		bb_perror_msg("%s: can't down", ifname);
	return res;
}

static int clear_if_addr(char *ifname)
{
	struct ifreq ifr;

	ifr.ifr_addr.sa_family = AF_INET;
	memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
	return set_ifrname_and_do_ioctl(SIOCSIFADDR, &ifr, ifname);
}

static int set_if_addr(char *master_ifname, char *slave_ifname)
{
#if (SIOCGIFADDR | SIOCSIFADDR \
  | SIOCGIFDSTADDR | SIOCSIFDSTADDR \
  | SIOCGIFBRDADDR | SIOCSIFBRDADDR \
  | SIOCGIFNETMASK | SIOCSIFNETMASK) <= 0xffff
#define INT uint16_t
#else
#define INT int
#endif
	static const struct {
		INT g_ioctl;
		INT s_ioctl;
	} ifra[] = {
		{ SIOCGIFADDR,    SIOCSIFADDR    },
		{ SIOCGIFDSTADDR, SIOCSIFDSTADDR },
		{ SIOCGIFBRDADDR, SIOCSIFBRDADDR },
		{ SIOCGIFNETMASK, SIOCSIFNETMASK },
	};

	struct ifreq ifr;
	int res;
	unsigned i;

	for (i = 0; i < ARRAY_SIZE(ifra); i++) {
		res = set_ifrname_and_do_ioctl(ifra[i].g_ioctl, &ifr, master_ifname);
		if (res < 0) {
			ifr.ifr_addr.sa_family = AF_INET;
			memset(ifr.ifr_addr.sa_data, 0,
			       sizeof(ifr.ifr_addr.sa_data));
		}

		res = set_ifrname_and_do_ioctl(ifra[i].s_ioctl, &ifr, slave_ifname);
		if (res < 0)
			return res;
	}

	return 0;
}

static void change_active(char *master_ifname, char *slave_ifname)
{
	struct ifreq ifr;

	if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
		bb_error_msg_and_die(
			"%s is not a slave",
			slave_ifname);
	}

	strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
	if (set_ifrname_and_do_ioctl(SIOCBONDCHANGEACTIVE, &ifr, master_ifname)
	 && ioctl_on_skfd(BOND_CHANGE_ACTIVE_OLD, &ifr)
	) {
		bb_perror_msg_and_die(
			"master %s, slave %s: can't "
			"change active",
			master_ifname, slave_ifname);
	}
}

static NOINLINE int enslave(char *master_ifname, char *slave_ifname)
{
	struct ifreq ifr;
	int res;

	if (slave.flags.ifr_flags & IFF_SLAVE) {
		bb_error_msg(
			"%s is already a slave",
			slave_ifname);
		return 1;
	}

	res = set_if_down(slave_ifname, slave.flags.ifr_flags);
	if (res)
		return res;

	if (abi_ver < 2) {
		/* Older bonding versions would panic if the slave has no IP
		 * address, so get the IP setting from the master.
		 */
		res = set_if_addr(master_ifname, slave_ifname);
		if (res) {
			bb_perror_msg("%s: can't set address", slave_ifname);
			return res;
		}
	} else {
		res = clear_if_addr(slave_ifname);
		if (res) {
			bb_perror_msg("%s: can't clear address", slave_ifname);
			return res;
		}
	}

	if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
		res = set_mtu(slave_ifname, master.mtu.ifr_mtu);
		if (res) {
			bb_perror_msg("%s: can't set MTU", slave_ifname);
			return res;
		}
	}

	if (hwaddr_set) {
		/* Master already has an hwaddr
		 * so set it's hwaddr to the slave
		 */
		if (abi_ver < 1) {
			/* The driver is using an old ABI, so
			 * the application sets the slave's
			 * hwaddr
			 */
			if (set_hwaddr(slave_ifname, &(master.hwaddr.ifr_hwaddr))) {
				bb_perror_msg("%s: can't set hw address",
						slave_ifname);
				goto undo_mtu;
			}

			/* For old ABI the application needs to bring the
			 * slave back up
			 */
			if (set_if_up(slave_ifname, slave.flags.ifr_flags))
				goto undo_slave_mac;
		}
		/* The driver is using a new ABI,
		 * so the driver takes care of setting
		 * the slave's hwaddr and bringing
		 * it up again
		 */
	} else {
		/* No hwaddr for master yet, so
		 * set the slave's hwaddr to it
		 */
		if (abi_ver < 1) {
			/* For old ABI, the master needs to be
			 * down before setting it's hwaddr
			 */
			if (set_if_down(master_ifname, master.flags.ifr_flags))
				goto undo_mtu;
		}

		if (set_hwaddr(master_ifname, &(slave.hwaddr.ifr_hwaddr))) {
			bb_error_msg("%s: can't set hw address",
				master_ifname);
			goto undo_mtu;
		}

		if (abi_ver < 1) {
			/* For old ABI, bring the master
			 * back up
			 */
			if (set_if_up(master_ifname, master.flags.ifr_flags))
				goto undo_master_mac;
		}

		hwaddr_set = 1;
	}

	/* Do the real thing */
	strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
	if (set_ifrname_and_do_ioctl(SIOCBONDENSLAVE, &ifr, master_ifname)
	 && ioctl_on_skfd(BOND_ENSLAVE_OLD, &ifr)
	) {
		goto undo_master_mac;
	}

	return 0;

/* rollback (best effort) */
 undo_master_mac:
	set_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
	hwaddr_set = 0;
	goto undo_mtu;

 undo_slave_mac:
	set_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
 undo_mtu:
	set_mtu(slave_ifname, slave.mtu.ifr_mtu);
	return 1;
}

static int release(char *master_ifname, char *slave_ifname)
{
	struct ifreq ifr;
	int res = 0;

	if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
		bb_error_msg("%s is not a slave",
			slave_ifname);
		return 1;
	}

	strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
	if (set_ifrname_and_do_ioctl(SIOCBONDRELEASE, &ifr, master_ifname) < 0
	 && ioctl_on_skfd(BOND_RELEASE_OLD, &ifr) < 0
	) {
		return 1;
	}
	if (abi_ver < 1) {
		/* The driver is using an old ABI, so we'll set the interface
		 * down to avoid any conflicts due to same MAC/IP
		 */
		res = set_if_down(slave_ifname, slave.flags.ifr_flags);
	}

	/* set to default mtu */
	set_mtu(slave_ifname, 1500);

	return res;
}

static NOINLINE void get_drv_info(char *master_ifname)
{
	struct ifreq ifr;
	struct ethtool_drvinfo info;

	memset(&ifr, 0, sizeof(ifr));
	ifr.ifr_data = (caddr_t)&info;
	info.cmd = ETHTOOL_GDRVINFO;
	strncpy(info.driver, "ifenslave", 32);
	snprintf(info.fw_version, 32, "%d", BOND_ABI_VERSION);
	if (set_ifrname_and_do_ioctl(SIOCETHTOOL, &ifr, master_ifname) < 0) {
		if (errno == EOPNOTSUPP)
			return;
		bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
	}

	abi_ver = bb_strtou(info.fw_version, NULL, 0);
	if (errno)
		bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
}

int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ifenslave_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
	char *master_ifname, *slave_ifname;
	int rv;
	int res;
	unsigned opt;
	enum {
		OPT_c = (1 << 0),
		OPT_d = (1 << 1),
		OPT_f = (1 << 2),
	};
#if ENABLE_GETOPT_LONG
	static const char ifenslave_longopts[] ALIGN1 =
		"change-active\0" No_argument "c"
		"detach\0"        No_argument "d"
		"force\0"         No_argument "f"
		;

	applet_long_options = ifenslave_longopts;
#endif
	INIT_G();

	opt = getopt32(argv, "cdf");
	argv += optind;
	if (opt & (opt-1)) /* options check */
		bb_show_usage();

	master_ifname = *argv++;

	/* No interface names - show all interfaces. */
	if (!master_ifname) {
		display_interfaces(NULL);
		return EXIT_SUCCESS;
	}

	/* Open a basic socket */
	xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);

	/* Exchange abi version with bonding module */
	get_drv_info(master_ifname);

	slave_ifname = *argv++;
	if (!slave_ifname) {
		if (opt & (OPT_d|OPT_c)) {
			/* --change or --detach, and no slaves given -
			 * show all interfaces. */
			display_interfaces(slave_ifname /* == NULL */);
			return 2; /* why 2? */
		}
		/* A single arg means show the
		 * configuration for this interface
		 */
		display_interfaces(master_ifname);
		return EXIT_SUCCESS;
	}

	res = get_if_settings(master_ifname, &master);
	if (res) {
		/* Probably a good reason not to go on */
		bb_perror_msg_and_die("%s: can't get settings", master_ifname);
	}

	/* check if master is indeed a master;
	 * if not then fail any operation
	 */
	if (!(master.flags.ifr_flags & IFF_MASTER))
		bb_error_msg_and_die("%s is not a master", master_ifname);

	/* check if master is up; if not then fail any operation */
	if (!(master.flags.ifr_flags & IFF_UP))
		bb_error_msg_and_die("%s is not up", master_ifname);

	/* No opts: neither -c[hange] nor -d[etach] -> it's "enslave" then;
	 * and -f[orce] is not there too */
	if (!opt) {
		/* The family '1' is ARPHRD_ETHER for ethernet. */
		if (master.hwaddr.ifr_hwaddr.sa_family != 1) {
			bb_error_msg_and_die(
				"%s is not ethernet-like (-f overrides)",
				master_ifname);
		}
	}

	/* Accepts only one slave */
	if (opt & OPT_c) {
		/* change active slave */
		if (get_slave_flags(slave_ifname)) {
			bb_perror_msg_and_die(
				"%s: can't get flags", slave_ifname);
		}
		change_active(master_ifname, slave_ifname);
		return EXIT_SUCCESS;
	}

	/* Accept multiple slaves */
	res = 0;
	do {
		if (opt & OPT_d) {
			/* detach a slave interface from the master */
			rv = get_slave_flags(slave_ifname);
			if (rv) {
				/* Can't work with this slave, */
				/* remember the error and skip it */
				bb_perror_msg(
					"skipping %s: can't get flags",
					slave_ifname);
				res = rv;
				continue;
			}
			rv = release(master_ifname, slave_ifname);
			if (rv) {
				bb_perror_msg(
					"master %s, slave %s: "
					"can't release",
					master_ifname, slave_ifname);
				res = rv;
			}
		} else {
			/* attach a slave interface to the master */
			rv = get_if_settings(slave_ifname, &slave);
			if (rv) {
				/* Can't work with this slave, */
				/* remember the error and skip it */
				bb_perror_msg(
					"skipping %s: can't get settings",
					slave_ifname);
				res = rv;
				continue;
			}
			rv = enslave(master_ifname, slave_ifname);
			if (rv) {
				bb_perror_msg(
					"master %s, slave %s: "
					"can't enslave",
					master_ifname, slave_ifname);
				res = rv;
			}
		}
	} while ((slave_ifname = *argv++) != NULL);

	if (ENABLE_FEATURE_CLEAN_UP) {
		close(skfd);
	}

	return res;
}