aboutsummaryrefslogtreecommitdiff
path: root/networking/brctl.c
blob: 25640246d13b6a19d3b571c24f6689006f9c0dc7 (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
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
/* vi: set sw=4 ts=4: */
/*
 * Small implementation of brctl for busybox.
 *
 * Copyright (C) 2008 by Bernhard Reutner-Fischer
 *
 * Some helper functions from bridge-utils are
 * Copyright (C) 2000 Lennert Buytenhek
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config BRCTL
//config:	bool "brctl (4.7 kb)"
//config:	default y
//config:	select PLATFORM_LINUX
//config:	help
//config:	Manage ethernet bridges.
//config:	Supports addbr/delbr and addif/delif.
//config:
//config:config FEATURE_BRCTL_FANCY
//config:	bool "Fancy options"
//config:	default y
//config:	depends on BRCTL
//config:	help
//config:	Add support for extended option like:
//config:		setageing, setfd, sethello, setmaxage,
//config:		setpathcost, setportprio, setbridgeprio,
//config:		stp
//config:	This adds about 600 bytes.
//config:
//config:config FEATURE_BRCTL_SHOW
//config:	bool "Support show"
//config:	default y
//config:	depends on BRCTL && FEATURE_BRCTL_FANCY
//config:	help
//config:	Add support for option which prints the current config:
//config:		show

//applet:IF_BRCTL(APPLET_NOEXEC(brctl, brctl, BB_DIR_USR_SBIN, BB_SUID_DROP, brctl))

//kbuild:lib-$(CONFIG_BRCTL) += brctl.o

//usage:#define brctl_trivial_usage
//usage:       "COMMAND [BRIDGE [ARGS]]"
//usage:#define brctl_full_usage "\n\n"
//usage:       "Manage ethernet bridges"
//usage:     "\nCommands:"
//usage:	IF_FEATURE_BRCTL_SHOW(
//usage:     "\n	show [BRIDGE]...	Show bridges"
//usage:	)
//usage:     "\n	addbr BRIDGE		Create BRIDGE"
//usage:     "\n	delbr BRIDGE		Delete BRIDGE"
//usage:     "\n	addif BRIDGE IFACE	Add IFACE to BRIDGE"
//usage:     "\n	delif BRIDGE IFACE	Delete IFACE from BRIDGE"
//usage:	IF_FEATURE_BRCTL_FANCY(
//usage:     "\n	showmacs BRIDGE			List MAC addresses"
//usage:     "\n	showstp	BRIDGE			Show STP info"
//usage:     "\n	stp BRIDGE 1/yes/on|0/no/off	Set STP on/off"
//usage:     "\n	setageing BRIDGE SECONDS	Set ageing time"
//usage:     "\n	setfd BRIDGE SECONDS		Set bridge forward delay"
//usage:     "\n	sethello BRIDGE SECONDS		Set hello time"
//usage:     "\n	setmaxage BRIDGE SECONDS	Set max message age"
//usage:     "\n	setbridgeprio BRIDGE PRIO	Set bridge priority"
//usage:     "\n	setportprio BRIDGE IFACE PRIO	Set port priority"
//usage:     "\n	setpathcost BRIDGE IFACE COST	Set path cost"
//usage:	)
// Not yet implemented:
//			hairpin BRIDGE IFACE on|off	Set hairpin on/off

#include "libbb.h"
#include "common_bufsiz.h"
#include <linux/sockios.h>
#include <net/if.h>

#ifndef SIOCBRADDBR
# define SIOCBRADDBR BRCTL_ADD_BRIDGE
#endif
#ifndef SIOCBRDELBR
# define SIOCBRDELBR BRCTL_DEL_BRIDGE
#endif
#ifndef SIOCBRADDIF
# define SIOCBRADDIF BRCTL_ADD_IF
#endif
#ifndef SIOCBRDELIF
# define SIOCBRDELIF BRCTL_DEL_IF
#endif

#if ENABLE_FEATURE_BRCTL_FANCY
static unsigned str_to_jiffies(const char *time_str)
{
	double dd;
	char *endptr;
	dd = /*bb_*/strtod(time_str, &endptr);
	if (endptr == time_str || dd < 0)
		bb_error_msg_and_die(bb_msg_invalid_arg_to, time_str, "timespec");

	dd *= 100;
	/* For purposes of brctl,
	 * capping SECONDS by ~20 million seconds is quite enough:
	 */
	if (dd > INT_MAX)
		dd = INT_MAX;

	return dd;
}
#endif

#define filedata bb_common_bufsiz1

#if ENABLE_FEATURE_BRCTL_SHOW
static int read_file(const char *name)
{
	int n = open_read_close(name, filedata, COMMON_BUFSIZE - 1);
	if (n < 0) {
		filedata[0] = '\0';
	} else {
		filedata[n] = '\0';
		if (n != 0 && filedata[n - 1] == '\n')
			filedata[--n] = '\0';
	}
	return n;
}

/* NB: we are in /sys/class/net
 */
static int show_bridge(const char *name, int need_hdr)
{
/* Output:
 *bridge name	bridge id		STP enabled	interfaces
 *br0		8000.000000000000	no		eth0
 */
	char pathbuf[IFNAMSIZ + sizeof("/bridge/bridge_id") + 8];
	int tabs;
	DIR *ifaces;
	struct dirent *ent;
	char *sfx;

#if IFNAMSIZ == 16
	sfx = pathbuf + sprintf(pathbuf, "%.16s/bridge/", name);
#else
	sfx = pathbuf + sprintf(pathbuf, "%.*s/bridge/", (int)IFNAMSIZ, name);
#endif
	strcpy(sfx, "bridge_id");
	if (read_file(pathbuf) < 0)
		return -1; /* this iface is not a bridge */

	if (need_hdr)
		puts("bridge name\tbridge id\t\tSTP enabled\tinterfaces");
	printf("%s\t\t%s\t", name, filedata);

	strcpy(sfx, "stp_state");
	read_file(pathbuf);
	if (LONE_CHAR(filedata, '0'))
		strcpy(filedata, "no");
	else
	if (LONE_CHAR(filedata, '1'))
		strcpy(filedata, "yes");
	fputs(filedata, stdout);

	/* sfx points past "BR/bridge/", turn it into "BR/brif": */
	sfx[-4] = 'f'; sfx[-3] = '\0';
	tabs = 0;
	ifaces = opendir(pathbuf);
	if (ifaces) {
		while ((ent = readdir(ifaces)) != NULL) {
			if (DOT_OR_DOTDOT(ent->d_name))
				continue; /* . or .. */
			if (tabs)
				printf("\t\t\t\t\t");
			else
				tabs = 1;
			printf("\t\t%s\n", ent->d_name);
		}
		closedir(ifaces);
	}
	if (!tabs)  /* bridge has no interfaces */
		bb_putchar('\n');
	return 0;
}
#endif

#if ENABLE_FEATURE_BRCTL_FANCY
static void write_uint(const char *name, const char *leaf, unsigned val)
{
	char pathbuf[IFNAMSIZ + sizeof("/bridge/bridge_id") + 32];
	int fd, n;

#if IFNAMSIZ == 16
	sprintf(pathbuf, "%.16s/%s", name, leaf);
#else
	sprintf(pathbuf, "%.*s/%s", (int)IFNAMSIZ, name, leaf);
#endif
	fd = xopen(pathbuf, O_WRONLY);
	n = sprintf(filedata, "%u\n", val);
	if (write(fd, filedata, n) < 0)
		bb_simple_perror_msg_and_die(name);
	/* So far all callers exit very soon after calling us.
	 * Do not bother closing fd (unless debugging):
	 */
	if (ENABLE_FEATURE_CLEAN_UP)
		close(fd);
}

struct fdb_entry {
	uint8_t mac_addr[6];
	uint8_t port_no;
	uint8_t is_local;
	uint32_t ageing_timer_value;
	uint8_t port_hi;
	uint8_t pad0;
	uint16_t unused;
};

static int compare_fdbs(const void *_f0, const void *_f1)
{
	const struct fdb_entry *f0 = _f0;
	const struct fdb_entry *f1 = _f1;

	return memcmp(f0->mac_addr, f1->mac_addr, 6);
}

static size_t read_bridge_forward_db(const char *name, struct fdb_entry **_fdb)
{
	char pathbuf[IFNAMSIZ + sizeof("/brforward") + 8];
	struct fdb_entry *fdb;
	size_t nentries;
	int fd;
	ssize_t cc;

#if IFNAMSIZ == 16
	sprintf(pathbuf, "%.16s/brforward", name);
#else
	sprintf(pathbuf, "%.*s/brforward", (int)IFNAMSIZ, name);
#endif
	fd = open(pathbuf, O_RDONLY);
	if (fd < 0)
		bb_error_msg_and_die("bridge %s does not exist", name);

	fdb = NULL;
	nentries = 0;
	for (;;) {
		fdb = xrealloc_vector(fdb, 4, nentries);
		cc = full_read(fd, &fdb[nentries], sizeof(*fdb));
		if (cc == 0) {
			break;
		}
		if (cc != sizeof(*fdb)) {
			bb_perror_msg_and_die("can't read bridge %s forward db", name);
		}
		++nentries;
	}

	if (ENABLE_FEATURE_CLEAN_UP)
		close(fd);

	qsort(fdb, nentries, sizeof(*fdb), compare_fdbs);

	*_fdb = fdb;
	return nentries;
}

static void show_bridge_macs(const char *name)
{
	struct fdb_entry *fdb;
	size_t nentries;
	size_t i;

	nentries = read_bridge_forward_db(name, &fdb);

	printf("port no\tmac addr\t\tis local?\tageing timer\n");
	for (i = 0; i < nentries; ++i) {
		const struct fdb_entry *f = &fdb[i];
		unsigned tv_sec = f->ageing_timer_value / 100;
		unsigned tv_csec = f->ageing_timer_value % 100;
		printf("%3u\t"
			"%.2x:%.2x:%.2x:%.2x:%.2x:%.2x\t"
			"%s\t\t"
			"%4u.%.2u\n",
			f->port_no,
			f->mac_addr[0], f->mac_addr[1], f->mac_addr[2],
			f->mac_addr[3], f->mac_addr[4], f->mac_addr[5],
			(f->is_local ? "yes" : "no"),
			tv_sec, tv_csec
		);
	}

	if (ENABLE_FEATURE_CLEAN_UP)
		free(fdb);
}

static void show_bridge_timer(const char *msg)
{
	unsigned long long centisec = xstrtoull(filedata, 0);
	unsigned tv_sec = centisec / 100;
	unsigned tv_csec = centisec % 100;
	printf("%s%4u.%.2u", msg, tv_sec, tv_csec);
}

static const char *show_bridge_state(unsigned state)
{
	/* See linux/if_bridge.h, BR_STATE_ constants */
	static const char state_names[] ALIGN1 =
		"disabled\0"	//BR_STATE_DISABLED   0
		"listening\0"   //BR_STATE_LISTENING  1
		"learning\0"    //BR_STATE_LEARNING   2
		"forwarding\0"  //BR_STATE_FORWARDING 3
		"blocking"      //BR_STATE_BLOCKING   4
	;
	if (state < 5)
		return nth_string(state_names, state);
	return utoa(state);
}

static void printf_xstrtou(const char *fmt)
{
	printf(fmt, xstrtou(filedata, 0));
}

static void show_bridge_port(const char *name)
{
	char pathbuf[IFNAMSIZ + sizeof("/brport/forward_delay_timer") + 8];
	char *sfx;

#if IFNAMSIZ == 16
	sfx = pathbuf + sprintf(pathbuf, "%.16s/brport/", name);
#else
	sfx = pathbuf + sprintf(pathbuf, "%.*s/brport/", (int)IFNAMSIZ, name);
#endif

	strcpy(sfx, "port_no");
	read_file(pathbuf);
	printf("%s (%u)\n", name, xstrtou(filedata, 0));

	strcpy(sfx + 5, "id"); // "port_id"
	read_file(pathbuf);
	printf_xstrtou(" port id\t\t%.4x");

	strcpy(sfx, "state");
	read_file(pathbuf);
	printf("\t\t\tstate\t\t%15s\n", show_bridge_state(xstrtou(filedata, 0)));

	strcpy(sfx, "designated_root");
	read_file(pathbuf);
	printf(" designated root\t%s", filedata);

	strcpy(sfx, "path_cost");
	read_file(pathbuf);
	printf_xstrtou("\tpath cost\t\t%4u\n");

	strcpy(sfx, "designated_bridge");
	read_file(pathbuf);
	printf(" designated bridge\t%s", filedata);

	strcpy(sfx, "message_age_timer");
	read_file(pathbuf);
	show_bridge_timer("\tmessage age timer\t");

	strcpy(sfx, "designated_port");
	read_file(pathbuf);
	printf_xstrtou("\n designated port\t%.4x");

	strcpy(sfx, "forward_delay_timer");
	read_file(pathbuf);
	show_bridge_timer("\t\t\tforward delay timer\t");

	strcpy(sfx, "designated_cost");
	read_file(pathbuf);
	printf_xstrtou("\n designated cost\t%4u");

	strcpy(sfx, "hold_timer");
	read_file(pathbuf);
	show_bridge_timer("\t\t\thold timer\t\t");

	printf("\n flags\t\t\t");

	strcpy(sfx, "config_pending");
	read_file(pathbuf);
	if (!LONE_CHAR(filedata, '0'))
		printf("CONFIG_PENDING ");

	strcpy(sfx, "change_ack");
	read_file(pathbuf);
	if (!LONE_CHAR(filedata, '0'))
		printf("TOPOLOGY_CHANGE_ACK ");

	strcpy(sfx, "hairpin_mode");
	read_file(pathbuf);
	if (!LONE_CHAR(filedata, '0'))
		printf_xstrtou("\n hairpin mode\t\t%4u");

	printf("\n\n");
}

static void show_bridge_stp(const char *name)
{
	char pathbuf[IFNAMSIZ + sizeof("/bridge/topology_change_timer") + 8];
	char *sfx;

#if IFNAMSIZ == 16
	sfx = pathbuf + sprintf(pathbuf, "%.16s/bridge/", name);
#else
	sfx = pathbuf + sprintf(pathbuf, "%.*s/bridge/", (int)IFNAMSIZ, name);
#endif

	strcpy(sfx, "bridge_id");
	if (read_file(pathbuf) < 0)
		bb_error_msg_and_die("bridge %s does not exist", name);

	printf("%s\n"
		" bridge id\t\t%s", name, filedata);

	strcpy(sfx, "root_id");
	read_file(pathbuf);
	printf("\n designated root\t%s", filedata);

	strcpy(sfx + 5, "port"); // "root_port"
	read_file(pathbuf);
	printf_xstrtou("\n root port\t\t%4u\t\t\t");

	strcpy(sfx + 6, "ath_cost"); // "root_path_cost"
	read_file(pathbuf);
	printf_xstrtou("path cost\t\t%4u\n");

	strcpy(sfx, "max_age");
	read_file(pathbuf);
	show_bridge_timer(" max age\t\t");
	show_bridge_timer("\t\t\tbridge max age\t\t");

	strcpy(sfx, "hello_time");
	read_file(pathbuf);
	show_bridge_timer("\n hello time\t\t");
	show_bridge_timer("\t\t\tbridge hello time\t");

	strcpy(sfx, "forward_delay");
	read_file(pathbuf);
	show_bridge_timer("\n forward delay\t\t");
	show_bridge_timer("\t\t\tbridge forward delay\t");

	strcpy(sfx, "ageing_time");
	read_file(pathbuf);
	show_bridge_timer("\n ageing time\t\t");

	strcpy(sfx, "hello_timer");
	read_file(pathbuf);
	show_bridge_timer("\n hello timer\t\t");

	strcpy(sfx, "tcn_timer");
	read_file(pathbuf);
	show_bridge_timer("\t\t\ttcn timer\t\t");

	strcpy(sfx, "topology_change_timer");
	read_file(pathbuf);
	show_bridge_timer("\n topology change timer\t");

	strcpy(sfx, "gc_timer");
	read_file(pathbuf);
	show_bridge_timer("\t\t\tgc timer\t\t");

	printf("\n flags\t\t\t");

	strcpy(sfx, "topology_change");
	read_file(pathbuf);
	if (!LONE_CHAR(filedata, '0'))
		printf("TOPOLOGY_CHANGE ");

	strcpy(sfx, "topology_change_detected");
	read_file(pathbuf);
	if (!LONE_CHAR(filedata, '0'))
		printf("TOPOLOGY_CHANGE_DETECTED ");
	printf("\n\n\n");

	/* Show bridge ports */
	{
		DIR *ifaces;

		/* sfx points past "BR/bridge/", turn it into "BR/brif": */
		sfx[-4] = 'f'; sfx[-3] = '\0';
		ifaces = opendir(pathbuf);
		if (ifaces) {
			struct dirent *ent;
			while ((ent = readdir(ifaces)) != NULL) {
				if (DOT_OR_DOTDOT(ent->d_name))
					continue; /* . or .. */
				show_bridge_port(ent->d_name);
			}
			if (ENABLE_FEATURE_CLEAN_UP)
				closedir(ifaces);
		}
	}
}
#endif

int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int brctl_main(int argc UNUSED_PARAM, char **argv)
{
	static const char keywords[] ALIGN1 =
		"addbr\0" "delbr\0" "addif\0" "delif\0"
	IF_FEATURE_BRCTL_FANCY(
		"stp\0"
		"showstp\0"
		"setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
		"setpathcost\0" "setportprio\0"
		"setbridgeprio\0"
		"showmacs\0"
	)
	IF_FEATURE_BRCTL_SHOW("show\0");
	enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
		IF_FEATURE_BRCTL_FANCY(,
			ARG_stp,
			ARG_showstp,
			ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
			ARG_setpathcost, ARG_setportprio,
			ARG_setbridgeprio,
			ARG_showmacs
		)
		IF_FEATURE_BRCTL_SHOW(, ARG_show)
	};
	int key;
	char *br;

	argv++;
	if (!*argv) {
		/* bare "brctl" shows --help */
		bb_show_usage();
	}

	xchdir("/sys/class/net");

	key = index_in_strings(keywords, *argv);
	if (key == -1) /* no match found in keywords array, bail out. */
		bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
	argv++;

#if ENABLE_FEATURE_BRCTL_SHOW
	if (key == ARG_show) { /* show [BR]... */
		DIR *net;
		struct dirent *ent;
		int need_hdr = 1;
		int exitcode = EXIT_SUCCESS;

		if (*argv) {
			/* "show BR1 BR2 BR3" */
			do {
				if (show_bridge(*argv, need_hdr) >= 0) {
					need_hdr = 0;
				} else {
					bb_error_msg("bridge %s does not exist", *argv);
//TODO: if device exists, but is not a BR, brctl from bridge-utils 1.6
//says this instead: "device eth0 is not a bridge"
					exitcode = EXIT_FAILURE;
				}
			} while (*++argv != NULL);
			return exitcode;
		}

		/* "show" (if no ifaces, shows nothing, not even header) */
		net = xopendir(".");
		while ((ent = readdir(net)) != NULL) {
			if (DOT_OR_DOTDOT(ent->d_name))
				continue; /* . or .. */
			if (show_bridge(ent->d_name, need_hdr) >= 0)
				need_hdr = 0;
		}
		if (ENABLE_FEATURE_CLEAN_UP)
			closedir(net);
		return exitcode;
	}
#endif

	if (!*argv) /* All of the below need at least one argument */
		bb_show_usage();

	br = *argv++;

	if (key == ARG_addbr || key == ARG_delbr) {
		/* brctl from bridge-utils 1.6 still uses ioctl
		 * for SIOCBRADDBR / SIOCBRDELBR, not /sys accesses
		 */
		int fd = xsocket(AF_INET, SOCK_STREAM, 0);
		ioctl_or_perror_and_die(fd,
			key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
			br, "bridge %s", br
		);
		//close(fd);
		//goto done;
		/* bridge-utils 1.6 simply ignores trailing args:
		 * "brctl addbr BR1 ARGS" ignores ARGS
		 */
		if (ENABLE_FEATURE_CLEAN_UP)
			close(fd);
		return EXIT_SUCCESS;
	}

	if (key == ARG_showmacs) {
		show_bridge_macs(br);
		return EXIT_SUCCESS;
	}
	if (key == ARG_showstp) {
		show_bridge_stp(br);
		return EXIT_SUCCESS;
	}

	if (!*argv) /* All of the below need at least two arguments */
		bb_show_usage();

#if ENABLE_FEATURE_BRCTL_FANCY
	if (key == ARG_stp) {
		static const char no_yes[] ALIGN1 =
			"0\0" "off\0" "n\0" "no\0"   /* 0 .. 3 */
			"1\0" "on\0"  "y\0" "yes\0"; /* 4 .. 7 */
		int onoff = index_in_strings(no_yes, *argv);
		if (onoff < 0)
			bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
		onoff = (unsigned)onoff / 4;
		write_uint(br, "bridge/stp_state", onoff);
		return EXIT_SUCCESS;
	}

	if ((unsigned)(key - ARG_setageing) < 4) { /* time related ops */
		/* setageing BR N: "N*100\n" to /sys/class/net/BR/bridge/ageing_time
		 * setfd BR N:     "N*100\n" to /sys/class/net/BR/bridge/forward_delay
		 * sethello BR N:  "N*100\n" to /sys/class/net/BR/bridge/hello_time
		 * setmaxage BR N: "N*100\n" to /sys/class/net/BR/bridge/max_age
		 */
		write_uint(br,
			nth_string(
				"bridge/ageing_time"  "\0" /* ARG_setageing */
				"bridge/forward_delay""\0" /* ARG_setfd     */
				"bridge/hello_time"   "\0" /* ARG_sethello  */
				"bridge/max_age",          /* ARG_setmaxage */
				key - ARG_setageing
			),
			str_to_jiffies(*argv)
		);
		return EXIT_SUCCESS;
	}

	if (key == ARG_setbridgeprio) {
		write_uint(br, "bridge/priority", xatoi_positive(*argv));
		return EXIT_SUCCESS;
	}

	if (key == ARG_setpathcost
	 || key == ARG_setportprio
	) {
		if (!argv[1])
			bb_show_usage();
		/* BR is not used (and ignored!) for these commands:
		 * "setpathcost BR PORT N" writes "N\n" to
		 * /sys/class/net/PORT/brport/path_cost
		 * "setportprio BR PORT N" writes "N\n" to
		 * /sys/class/net/PORT/brport/priority
		 */
		write_uint(argv[0],
			nth_string(
				"brport/path_cost" "\0" /* ARG_setpathcost */
				"brport/priority",      /* ARG_setportprio */
				key - ARG_setpathcost
			),
			xatoi_positive(argv[1])
		);
		return EXIT_SUCCESS;
	}
#endif
	/* always true: if (key == ARG_addif || key == ARG_delif) */ {
		struct ifreq ifr;
		int fd = xsocket(AF_INET, SOCK_STREAM, 0);

		strncpy_IFNAMSIZ(ifr.ifr_name, br);
		ifr.ifr_ifindex = if_nametoindex(*argv);
		if (ifr.ifr_ifindex == 0) {
			bb_perror_msg_and_die("iface %s", *argv);
		}
		ioctl_or_perror_and_die(fd,
			key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
			&ifr, "bridge %s", br
		);
		if (ENABLE_FEATURE_CLEAN_UP)
			close(fd);
	}

	return EXIT_SUCCESS;
}