1 /* Mode: C;
2 *
3 * Mini ifenslave implementation for busybox
4 * Copyright (C) 2005 by Marc Leeman <marc.leeman@barco.com>
5 *
6 * ifenslave.c: Configure network interfaces for parallel routing.
7 *
8 * This program controls the Linux implementation of running multiple
9 * network interfaces in parallel.
10 *
11 * Author: Donald Becker <becker@cesdis.gsfc.nasa.gov>
12 * Copyright 1994-1996 Donald Becker
13 *
14 * This program is free software; you can redistribute it
15 * and/or modify it under the terms of the GNU General Public
16 * License as published by the Free Software Foundation.
17 *
18 * The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
19 * Center of Excellence in Space Data and Information Sciences
20 * Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771
21 *
22 * Changes :
23 * - 2000/10/02 Willy Tarreau <willy at meta-x.org> :
24 * - few fixes. Master's MAC address is now correctly taken from
25 * the first device when not previously set ;
26 * - detach support : call BOND_RELEASE to detach an enslaved interface.
27 * - give a mini-howto from command-line help : # ifenslave -h
28 *
29 * - 2001/02/16 Chad N. Tindel <ctindel at ieee dot org> :
30 * - Master is now brought down before setting the MAC address. In
31 * the 2.4 kernel you can't change the MAC address while the device is
32 * up because you get EBUSY.
33 *
34 * - 2001/09/13 Takao Indoh <indou dot takao at jp dot fujitsu dot com>
35 * - Added the ability to change the active interface on a mode 1 bond
36 * at runtime.
37 *
38 * - 2001/10/23 Chad N. Tindel <ctindel at ieee dot org> :
39 * - No longer set the MAC address of the master. The bond device will
40 * take care of this itself
41 * - Try the SIOC*** versions of the bonding ioctls before using the
42 * old versions
43 * - 2002/02/18 Erik Habbinga <erik_habbinga @ hp dot com> :
44 * - ifr2.ifr_flags was not initialized in the hwaddr_notset case,
45 * SIOCGIFFLAGS now called before hwaddr_notset test
46 *
47 * - 2002/10/31 Tony Cureington <tony.cureington * hp_com> :
48 * - If the master does not have a hardware address when the first slave
49 * is enslaved, the master is assigned the hardware address of that
50 * slave - there is a comment in bonding.c stating "ifenslave takes
51 * care of this now." This corrects the problem of slaves having
52 * different hardware addresses in active-backup mode when
53 * multiple interfaces are specified on a single ifenslave command
54 * (ifenslave bond0 eth0 eth1).
55 *
56 * - 2003/03/18 - Tsippy Mendelson <tsippy.mendelson at intel dot com> and
57 * Shmulik Hen <shmulik.hen at intel dot com>
58 * - Moved setting the slave's mac address and opening it, from
59 * the application to the driver. This enables support of modes
60 * that need to use the unique mac address of each slave.
61 * The driver also takes care of closing the slave and restoring its
62 * original mac address upon release.
63 * In addition, block possibility of enslaving before the master is up.
64 * This prevents putting the system in an undefined state.
65 *
66 * - 2003/05/01 - Amir Noam <amir.noam at intel dot com>
67 * - Added ABI version control to restore compatibility between
68 * new/old ifenslave and new/old bonding.
69 * - Prevent adding an adapter that is already a slave.
70 * Fixes the problem of stalling the transmission and leaving
71 * the slave in a down state.
72 *
73 * - 2003/05/01 - Shmulik Hen <shmulik.hen at intel dot com>
74 * - Prevent enslaving if the bond device is down.
75 * Fixes the problem of leaving the system in unstable state and
76 * halting when trying to remove the module.
77 * - Close socket on all abnormal exists.
78 * - Add versioning scheme that follows that of the bonding driver.
79 * current version is 1.0.0 as a base line.
80 *
81 * - 2003/05/22 - Jay Vosburgh <fubar at us dot ibm dot com>
82 * - ifenslave -c was broken; it's now fixed
83 * - Fixed problem with routes vanishing from master during enslave
84 * processing.
85 *
86 * - 2003/05/27 - Amir Noam <amir.noam at intel dot com>
87 * - Fix backward compatibility issues:
88 * For drivers not using ABI versions, slave was set down while
89 * it should be left up before enslaving.
90 * Also, master was not set down and the default set_mac_address()
91 * would fail and generate an error message in the system log.
92 * - For opt_c: slave should not be set to the master's setting
93 * while it is running. It was already set during enslave. To
94 * simplify things, it is now handeled separately.
95 *
96 * - 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
97 * - Code cleanup and style changes
98 * set version to 1.1.0
99 */
100 //config:config IFENSLAVE
101 //config: bool "ifenslave (13 kb)"
102 //config: default y
103 //config: help
104 //config: Userspace application to bind several interfaces
105 //config: to a logical interface (use with kernel bonding driver).
106
107 //applet:IF_IFENSLAVE(APPLET_NOEXEC(ifenslave, ifenslave, BB_DIR_SBIN, BB_SUID_DROP, ifenslave))
108
109 //kbuild:lib-$(CONFIG_IFENSLAVE) += ifenslave.o interface.o
110
111 //usage:#define ifenslave_trivial_usage
112 //usage: "[-cdf] MASTER_IFACE SLAVE_IFACE..."
113 //usage:#define ifenslave_full_usage "\n\n"
114 //usage: "Configure network interfaces for parallel routing\n"
115 //usage: "\n -c Change active slave"
116 //usage: "\n -d Remove slave interface from bonding device"
117 //usage: "\n -f Force, even if interface is not Ethernet"
118 /* //usage: "\n -r Create a receive-only slave" */
119 //usage:
120 //usage:#define ifenslave_example_usage
121 //usage: "To create a bond device, simply follow these three steps:\n"
122 //usage: "- ensure that the required drivers are properly loaded:\n"
123 //usage: " # modprobe bonding ; modprobe <3c59x|eepro100|pcnet32|tulip|...>\n"
124 //usage: "- assign an IP address to the bond device:\n"
125 //usage: " # ifconfig bond0 <addr> netmask <mask> broadcast <bcast>\n"
126 //usage: "- attach all the interfaces you need to the bond device:\n"
127 //usage: " # ifenslave bond0 eth0 eth1 eth2\n"
128 //usage: " If bond0 didn't have a MAC address, it will take eth0's. Then, all\n"
129 //usage: " interfaces attached AFTER this assignment will get the same MAC addr.\n\n"
130 //usage: " To detach a dead interface without setting the bond device down:\n"
131 //usage: " # ifenslave -d bond0 eth1\n\n"
132 //usage: " To set the bond device down and automatically release all the slaves:\n"
133 //usage: " # ifconfig bond0 down\n\n"
134 //usage: " To change active slave:\n"
135 //usage: " # ifenslave -c bond0 eth0\n"
136
137 #include "libbb.h"
138
139 /* #include <net/if.h> - no. linux/if_bonding.h pulls in linux/if.h */
140 #include <linux/if.h>
141 //#include <net/if_arp.h> - not needed?
142 #include <linux/if_bonding.h>
143 #include <linux/sockios.h>
144 #include "fix_u32.h" /* hack, so we may include kernel's ethtool.h */
145 #include <linux/ethtool.h>
146 #ifndef BOND_ABI_VERSION
147 # define BOND_ABI_VERSION 2
148 #endif
149 #ifndef IFNAMSIZ
150 # define IFNAMSIZ 16
151 #endif
152
153
154 struct dev_data {
155 struct ifreq mtu, flags, hwaddr;
156 };
157
158
159 enum { skfd = 3 }; /* AF_INET socket for ioctl() calls. */
160 struct globals {
161 unsigned abi_ver; /* userland - kernel ABI version */
162 smallint hwaddr_set; /* Master's hwaddr is set */
163 struct dev_data master;
164 struct dev_data slave;
165 };
166 #define G (*ptr_to_globals)
167 #define abi_ver (G.abi_ver )
168 #define hwaddr_set (G.hwaddr_set)
169 #define master (G.master )
170 #define slave (G.slave )
171 #define INIT_G() do { \
172 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
173 } while (0)
174
175
176 /* NOINLINEs are placed where it results in smaller code (gcc 4.3.1) */
177
ioctl_on_skfd(unsigned request,struct ifreq * ifr)178 static int ioctl_on_skfd(unsigned request, struct ifreq *ifr)
179 {
180 return ioctl(skfd, request, ifr);
181 }
182
set_ifrname_and_do_ioctl(unsigned request,struct ifreq * ifr,const char * ifname)183 static int set_ifrname_and_do_ioctl(unsigned request, struct ifreq *ifr, const char *ifname)
184 {
185 strncpy_IFNAMSIZ(ifr->ifr_name, ifname);
186 return ioctl_on_skfd(request, ifr);
187 }
188
get_if_settings(char * ifname,struct dev_data * dd)189 static int get_if_settings(char *ifname, struct dev_data *dd)
190 {
191 int res;
192
193 res = set_ifrname_and_do_ioctl(SIOCGIFMTU, &dd->mtu, ifname);
194 res |= set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &dd->flags, ifname);
195 res |= set_ifrname_and_do_ioctl(SIOCGIFHWADDR, &dd->hwaddr, ifname);
196
197 return res;
198 }
199
get_slave_flags(char * slave_ifname)200 static int get_slave_flags(char *slave_ifname)
201 {
202 return set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &slave.flags, slave_ifname);
203 }
204
set_hwaddr(char * ifname,struct sockaddr * hwaddr)205 static int set_hwaddr(char *ifname, struct sockaddr *hwaddr)
206 {
207 struct ifreq ifr;
208
209 memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(*hwaddr));
210 return set_ifrname_and_do_ioctl(SIOCSIFHWADDR, &ifr, ifname);
211 }
212
set_mtu(char * ifname,int mtu)213 static int set_mtu(char *ifname, int mtu)
214 {
215 struct ifreq ifr;
216
217 ifr.ifr_mtu = mtu;
218 return set_ifrname_and_do_ioctl(SIOCSIFMTU, &ifr, ifname);
219 }
220
set_if_flags(char * ifname,int flags)221 static int set_if_flags(char *ifname, int flags)
222 {
223 struct ifreq ifr;
224
225 ifr.ifr_flags = flags;
226 return set_ifrname_and_do_ioctl(SIOCSIFFLAGS, &ifr, ifname);
227 }
228
set_if_up(char * ifname,int flags)229 static int set_if_up(char *ifname, int flags)
230 {
231 int res = set_if_flags(ifname, flags | IFF_UP);
232 if (res)
233 bb_perror_msg("%s: can't up", ifname);
234 return res;
235 }
236
set_if_down(char * ifname,int flags)237 static int set_if_down(char *ifname, int flags)
238 {
239 int res = set_if_flags(ifname, flags & ~IFF_UP);
240 if (res)
241 bb_perror_msg("%s: can't down", ifname);
242 return res;
243 }
244
clear_if_addr(char * ifname)245 static int clear_if_addr(char *ifname)
246 {
247 struct ifreq ifr;
248
249 ifr.ifr_addr.sa_family = AF_INET;
250 memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
251 return set_ifrname_and_do_ioctl(SIOCSIFADDR, &ifr, ifname);
252 }
253
set_if_addr(char * master_ifname,char * slave_ifname)254 static int set_if_addr(char *master_ifname, char *slave_ifname)
255 {
256 #if (SIOCGIFADDR | SIOCSIFADDR \
257 | SIOCGIFDSTADDR | SIOCSIFDSTADDR \
258 | SIOCGIFBRDADDR | SIOCSIFBRDADDR \
259 | SIOCGIFNETMASK | SIOCSIFNETMASK) <= 0xffff
260 #define INT uint16_t
261 #else
262 #define INT int
263 #endif
264 static const struct {
265 INT g_ioctl;
266 INT s_ioctl;
267 } ifra[] = {
268 { SIOCGIFADDR, SIOCSIFADDR },
269 { SIOCGIFDSTADDR, SIOCSIFDSTADDR },
270 { SIOCGIFBRDADDR, SIOCSIFBRDADDR },
271 { SIOCGIFNETMASK, SIOCSIFNETMASK },
272 };
273
274 struct ifreq ifr;
275 int res;
276 unsigned i;
277
278 for (i = 0; i < ARRAY_SIZE(ifra); i++) {
279 res = set_ifrname_and_do_ioctl(ifra[i].g_ioctl, &ifr, master_ifname);
280 if (res < 0) {
281 ifr.ifr_addr.sa_family = AF_INET;
282 memset(ifr.ifr_addr.sa_data, 0,
283 sizeof(ifr.ifr_addr.sa_data));
284 }
285
286 res = set_ifrname_and_do_ioctl(ifra[i].s_ioctl, &ifr, slave_ifname);
287 if (res < 0)
288 return res;
289 }
290
291 return 0;
292 }
293
change_active(char * master_ifname,char * slave_ifname)294 static void change_active(char *master_ifname, char *slave_ifname)
295 {
296 struct ifreq ifr;
297
298 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
299 bb_error_msg_and_die("%s is not a slave", slave_ifname);
300 }
301
302 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
303 if (set_ifrname_and_do_ioctl(SIOCBONDCHANGEACTIVE, &ifr, master_ifname)
304 && ioctl_on_skfd(BOND_CHANGE_ACTIVE_OLD, &ifr)
305 ) {
306 bb_perror_msg_and_die(
307 "master %s, slave %s: can't "
308 "change active",
309 master_ifname, slave_ifname);
310 }
311 }
312
enslave(char * master_ifname,char * slave_ifname)313 static NOINLINE int enslave(char *master_ifname, char *slave_ifname)
314 {
315 struct ifreq ifr;
316 int res;
317
318 if (slave.flags.ifr_flags & IFF_SLAVE) {
319 bb_error_msg(
320 "%s is already a slave",
321 slave_ifname);
322 return 1;
323 }
324
325 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
326 if (res)
327 return res;
328
329 if (abi_ver < 2) {
330 /* Older bonding versions would panic if the slave has no IP
331 * address, so get the IP setting from the master.
332 */
333 res = set_if_addr(master_ifname, slave_ifname);
334 if (res) {
335 bb_perror_msg("%s: can't set address", slave_ifname);
336 return res;
337 }
338 } else {
339 res = clear_if_addr(slave_ifname);
340 if (res) {
341 bb_perror_msg("%s: can't clear address", slave_ifname);
342 return res;
343 }
344 }
345
346 if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
347 res = set_mtu(slave_ifname, master.mtu.ifr_mtu);
348 if (res) {
349 bb_perror_msg("%s: can't set MTU", slave_ifname);
350 return res;
351 }
352 }
353
354 if (hwaddr_set) {
355 /* Master already has an hwaddr
356 * so set it's hwaddr to the slave
357 */
358 if (abi_ver < 1) {
359 /* The driver is using an old ABI, so
360 * the application sets the slave's
361 * hwaddr
362 */
363 if (set_hwaddr(slave_ifname, &(master.hwaddr.ifr_hwaddr))) {
364 bb_perror_msg("%s: can't set hw address",
365 slave_ifname);
366 goto undo_mtu;
367 }
368
369 /* For old ABI the application needs to bring the
370 * slave back up
371 */
372 if (set_if_up(slave_ifname, slave.flags.ifr_flags))
373 goto undo_slave_mac;
374 }
375 /* The driver is using a new ABI,
376 * so the driver takes care of setting
377 * the slave's hwaddr and bringing
378 * it up again
379 */
380 } else {
381 /* No hwaddr for master yet, so
382 * set the slave's hwaddr to it
383 */
384 if (abi_ver < 1) {
385 /* For old ABI, the master needs to be
386 * down before setting it's hwaddr
387 */
388 if (set_if_down(master_ifname, master.flags.ifr_flags))
389 goto undo_mtu;
390 }
391
392 if (set_hwaddr(master_ifname, &(slave.hwaddr.ifr_hwaddr))) {
393 bb_error_msg("%s: can't set hw address",
394 master_ifname);
395 goto undo_mtu;
396 }
397
398 if (abi_ver < 1) {
399 /* For old ABI, bring the master
400 * back up
401 */
402 if (set_if_up(master_ifname, master.flags.ifr_flags))
403 goto undo_master_mac;
404 }
405
406 hwaddr_set = 1;
407 }
408
409 /* Do the real thing */
410 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
411 if (set_ifrname_and_do_ioctl(SIOCBONDENSLAVE, &ifr, master_ifname)
412 && ioctl_on_skfd(BOND_ENSLAVE_OLD, &ifr)
413 ) {
414 goto undo_master_mac;
415 }
416
417 return 0;
418
419 /* rollback (best effort) */
420 undo_master_mac:
421 set_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
422 hwaddr_set = 0;
423 goto undo_mtu;
424
425 undo_slave_mac:
426 set_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
427 undo_mtu:
428 set_mtu(slave_ifname, slave.mtu.ifr_mtu);
429 return 1;
430 }
431
release(char * master_ifname,char * slave_ifname)432 static int release(char *master_ifname, char *slave_ifname)
433 {
434 struct ifreq ifr;
435 int res = 0;
436
437 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
438 bb_error_msg("%s is not a slave", slave_ifname);
439 return 1;
440 }
441
442 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
443 if (set_ifrname_and_do_ioctl(SIOCBONDRELEASE, &ifr, master_ifname) < 0
444 && ioctl_on_skfd(BOND_RELEASE_OLD, &ifr) < 0
445 ) {
446 return 1;
447 }
448 if (abi_ver < 1) {
449 /* The driver is using an old ABI, so we'll set the interface
450 * down to avoid any conflicts due to same MAC/IP
451 */
452 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
453 }
454
455 /* set to default mtu */
456 set_mtu(slave_ifname, 1500);
457
458 return res;
459 }
460
get_drv_info(char * master_ifname)461 static NOINLINE void get_drv_info(char *master_ifname)
462 {
463 struct ifreq ifr;
464 struct ethtool_drvinfo info;
465
466 memset(&ifr, 0, sizeof(ifr));
467 ifr.ifr_data = (caddr_t)&info;
468 info.cmd = ETHTOOL_GDRVINFO;
469 /* both fields are 32 bytes long (long enough) */
470 strcpy(info.driver, "ifenslave");
471 strcpy(info.fw_version, utoa(BOND_ABI_VERSION));
472 if (set_ifrname_and_do_ioctl(SIOCETHTOOL, &ifr, master_ifname) < 0) {
473 if (errno == EOPNOTSUPP)
474 return;
475 bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
476 }
477
478 abi_ver = bb_strtou(info.fw_version, NULL, 0);
479 if (errno)
480 bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
481 }
482
483 int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
ifenslave_main(int argc UNUSED_PARAM,char ** argv)484 int ifenslave_main(int argc UNUSED_PARAM, char **argv)
485 {
486 char *master_ifname, *slave_ifname;
487 int rv;
488 int res;
489 unsigned opt;
490 enum {
491 OPT_c = (1 << 0),
492 OPT_d = (1 << 1),
493 OPT_f = (1 << 2),
494 };
495
496 INIT_G();
497
498 opt = getopt32long(argv, "cdfa",
499 "change-active\0" No_argument "c"
500 "detach\0" No_argument "d"
501 "force\0" No_argument "f"
502 /* "all-interfaces\0" No_argument "a" */
503 );
504 argv += optind;
505 if (opt & (opt-1)) /* Only one option can be given */
506 bb_show_usage();
507
508 master_ifname = *argv++;
509
510 /* No interface names - show all interfaces. */
511 if (!master_ifname) {
512 display_interfaces(NULL);
513 return EXIT_SUCCESS;
514 }
515
516 /* Open a basic socket */
517 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);
518
519 /* Exchange abi version with bonding module */
520 get_drv_info(master_ifname);
521
522 slave_ifname = *argv++;
523 if (!slave_ifname) {
524 if (opt & (OPT_d|OPT_c)) {
525 /* --change or --detach, and no slaves given -
526 * show all interfaces. */
527 display_interfaces(slave_ifname /* == NULL */);
528 return 2; /* why 2? */
529 }
530 /* A single arg means show the
531 * configuration for this interface
532 */
533 display_interfaces(master_ifname);
534 return EXIT_SUCCESS;
535 }
536
537 if (get_if_settings(master_ifname, &master)) {
538 /* Probably a good reason not to go on */
539 bb_perror_msg_and_die("%s: can't get settings", master_ifname);
540 }
541
542 /* Check if master is indeed a master;
543 * if not then fail any operation
544 */
545 if (!(master.flags.ifr_flags & IFF_MASTER))
546 bb_error_msg_and_die("%s is not a master", master_ifname);
547
548 /* Check if master is up; if not then fail any operation */
549 if (!(master.flags.ifr_flags & IFF_UP))
550 bb_error_msg_and_die("%s is not up", master_ifname);
551
552 #ifdef WHY_BOTHER
553 /* Neither -c[hange] nor -d[etach] -> it's "enslave" then;
554 * and -f[orce] is not there too. Check that it's ethernet. */
555 if (!(opt & (OPT_d|OPT_c|OPT_f))) {
556 /* The family '1' is ARPHRD_ETHER for ethernet. */
557 if (master.hwaddr.ifr_hwaddr.sa_family != 1) {
558 bb_error_msg_and_die(
559 "%s is not ethernet-like (-f overrides)",
560 master_ifname);
561 }
562 }
563 #endif
564
565 /* Accepts only one slave */
566 if (opt & OPT_c) {
567 /* Change active slave */
568 if (get_slave_flags(slave_ifname)) {
569 bb_perror_msg_and_die(
570 "%s: can't get flags", slave_ifname);
571 }
572 change_active(master_ifname, slave_ifname);
573 return EXIT_SUCCESS;
574 }
575
576 /* Accepts multiple slaves */
577 res = 0;
578 do {
579 if (opt & OPT_d) {
580 /* Detach a slave interface from the master */
581 rv = get_slave_flags(slave_ifname);
582 if (rv) {
583 /* Can't work with this slave, */
584 /* remember the error and skip it */
585 bb_perror_msg(
586 "skipping %s: can't get %s",
587 slave_ifname, "flags");
588 res = rv;
589 continue;
590 }
591 rv = release(master_ifname, slave_ifname);
592 if (rv) {
593 bb_perror_msg("can't release %s from %s",
594 slave_ifname, master_ifname);
595 res = rv;
596 }
597 } else {
598 /* Attach a slave interface to the master */
599 rv = get_if_settings(slave_ifname, &slave);
600 if (rv) {
601 /* Can't work with this slave, */
602 /* remember the error and skip it */
603 bb_perror_msg(
604 "skipping %s: can't get %s",
605 slave_ifname, "settings");
606 res = rv;
607 continue;
608 }
609 rv = enslave(master_ifname, slave_ifname);
610 if (rv) {
611 bb_perror_msg("can't enslave %s to %s",
612 slave_ifname, master_ifname);
613 res = rv;
614 }
615 }
616 } while ((slave_ifname = *argv++) != NULL);
617
618 if (ENABLE_FEATURE_CLEAN_UP) {
619 close(skfd);
620 }
621
622 return res;
623 }
624