3 * Mini ifenslave implementation for busybox
4 * Copyright (C) 2005 by Marc Leeman <marc.leeman@barco.com>
6 * ifenslave.c: Configure network interfaces for parallel routing.
8 * This program controls the Linux implementation of running multiple
9 * network interfaces in parallel.
11 * Author: Donald Becker <becker@cesdis.gsfc.nasa.gov>
12 * Copyright 1994-1996 Donald Becker
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.
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
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
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.
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
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
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
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).
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 openning 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.
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.
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.
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
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.
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
103 #include <net/if_arp.h>
104 #include <linux/if_bonding.h>
105 #include <linux/sockios.h>
107 typedef unsigned long long u64; /* hack, so we may include kernel's ethtool.h */
108 typedef uint32_t u32; /* ditto */
109 typedef uint16_t u16; /* ditto */
110 typedef uint8_t u8; /* ditto */
111 #include <linux/ethtool.h>
115 struct ifreq mtu, flags, hwaddr;
119 enum { skfd = 3 }; /* AF_INET socket for ioctl() calls.*/
121 unsigned abi_ver; /* userland - kernel ABI version */
122 smallint hwaddr_set; /* Master's hwaddr is set */
123 struct dev_data master;
124 struct dev_data slave;
126 #define G (*ptr_to_globals)
127 #define abi_ver (G.abi_ver )
128 #define hwaddr_set (G.hwaddr_set)
129 #define master (G.master )
130 #define slave (G.slave )
131 #define INIT_G() do { \
132 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
136 static void get_drv_info(char *master_ifname);
137 static int get_if_settings(char *ifname, struct dev_data *dd);
138 static int get_slave_flags(char *slave_ifname);
139 static int set_master_hwaddr(char *master_ifname, struct sockaddr *hwaddr);
140 static int set_slave_hwaddr(char *slave_ifname, struct sockaddr *hwaddr);
141 static int set_slave_mtu(char *slave_ifname, int mtu);
142 static int set_if_flags(char *ifname, short flags);
143 static int set_if_up(char *ifname, short flags);
144 static int set_if_down(char *ifname, short flags);
145 static int clear_if_addr(char *ifname);
146 static int set_if_addr(char *master_ifname, char *slave_ifname);
147 static void change_active(char *master_ifname, char *slave_ifname);
148 static int enslave(char *master_ifname, char *slave_ifname);
149 static int release(char *master_ifname, char *slave_ifname);
151 static void strncpy_IFNAMSIZ(char *dst, const char *src)
153 strncpy(dst, src, IFNAMSIZ);
156 int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
157 int ifenslave_main(int argc ATTRIBUTE_UNUSED, char **argv)
159 char *master_ifname, *slave_ifname;
168 #if ENABLE_GETOPT_LONG
169 static const char ifenslave_longopts[] ALIGN1 =
170 "change-active" No_argument "c"
171 "detach" No_argument "d"
172 "force" No_argument "f"
175 applet_long_options = ifenslave_longopts;
177 opt = getopt32(argv, "cdf");
179 if (opt & (opt-1)) /* options check */
182 /* Copy the interface name */
183 master_ifname = *argv++;
185 /* No remaining args means show all interfaces. */
186 if (!master_ifname) {
187 display_interfaces(NULL);
191 /* Open a basic socket */
192 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);
194 /* exchange abi version with bonding module */
195 get_drv_info(master_ifname);
197 slave_ifname = *argv++;
199 if (opt & (OPT_d|OPT_c)) {
200 display_interfaces(slave_ifname);
203 /* A single arg means show the
204 * configuration for this interface
206 display_interfaces(master_ifname);
210 res = get_if_settings(master_ifname, &master);
212 /* Probably a good reason not to go on */
213 bb_perror_msg_and_die("%s: can't get settings", master_ifname);
216 /* check if master is indeed a master;
217 * if not then fail any operation
219 if (!(master.flags.ifr_flags & IFF_MASTER))
220 bb_error_msg_and_die("%s is not a master", master_ifname);
222 /* check if master is up; if not then fail any operation */
223 if (!(master.flags.ifr_flags & IFF_UP))
224 bb_error_msg_and_die("%s is not up", master_ifname);
226 /* Only for enslaving */
227 if (!(opt & (OPT_c|OPT_d))) {
228 sa_family_t master_family = master.hwaddr.ifr_hwaddr.sa_family;
230 /* The family '1' is ARPHRD_ETHER for ethernet. */
231 if (master_family != 1 && !(opt & OPT_f)) {
232 bb_error_msg_and_die(
233 "%s is not ethernet-like (-f overrides)",
238 /* Accepts only one slave */
240 /* change active slave */
241 res = get_slave_flags(slave_ifname);
243 bb_perror_msg_and_die(
244 "%s: can't get flags", slave_ifname);
246 change_active(master_ifname, slave_ifname);
250 /* Accept multiple slaves */
254 /* detach a slave interface from the master */
255 rv = get_slave_flags(slave_ifname);
257 /* Can't work with this slave. */
258 /* remember the error and skip it*/
260 "skipping %s: can't get flags",
265 rv = release(master_ifname, slave_ifname);
268 "master %s, slave %s: "
270 master_ifname, slave_ifname);
274 /* attach a slave interface to the master */
275 rv = get_if_settings(slave_ifname, &slave);
277 /* Can't work with this slave. */
278 /* remember the error and skip it*/
280 "skipping %s: can't get settings",
285 rv = enslave(master_ifname, slave_ifname);
288 "master %s, slave %s: "
290 master_ifname, slave_ifname);
294 } while ((slave_ifname = *argv++) != NULL);
296 if (ENABLE_FEATURE_CLEAN_UP) {
303 static void get_drv_info(char *master_ifname)
306 struct ethtool_drvinfo info;
308 memset(&ifr, 0, sizeof(ifr));
309 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
310 ifr.ifr_data = (caddr_t)&info;
312 info.cmd = ETHTOOL_GDRVINFO;
313 strncpy(info.driver, "ifenslave", 32);
314 snprintf(info.fw_version, 32, "%d", BOND_ABI_VERSION);
316 if (ioctl(skfd, SIOCETHTOOL, &ifr) < 0) {
317 if (errno == EOPNOTSUPP)
319 bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
322 abi_ver = bb_strtou(info.fw_version, NULL, 0);
324 bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
329 static void change_active(char *master_ifname, char *slave_ifname)
333 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
334 bb_error_msg_and_die(
339 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
340 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
341 if (ioctl(skfd, SIOCBONDCHANGEACTIVE, &ifr) < 0
342 && ioctl(skfd, BOND_CHANGE_ACTIVE_OLD, &ifr) < 0
344 bb_perror_msg_and_die(
345 "master %s, slave %s: can't "
347 master_ifname, slave_ifname);
351 static int enslave(char *master_ifname, char *slave_ifname)
356 if (slave.flags.ifr_flags & IFF_SLAVE) {
358 "%s is already a slave",
363 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
368 /* Older bonding versions would panic if the slave has no IP
369 * address, so get the IP setting from the master.
371 res = set_if_addr(master_ifname, slave_ifname);
373 bb_perror_msg("%s: can't set address", slave_ifname);
377 res = clear_if_addr(slave_ifname);
379 bb_perror_msg("%s: can't clear address", slave_ifname);
384 if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
385 res = set_slave_mtu(slave_ifname, master.mtu.ifr_mtu);
387 bb_perror_msg("%s: can't set MTU", slave_ifname);
393 /* Master already has an hwaddr
394 * so set it's hwaddr to the slave
397 /* The driver is using an old ABI, so
398 * the application sets the slave's
401 res = set_slave_hwaddr(slave_ifname,
402 &(master.hwaddr.ifr_hwaddr));
404 bb_perror_msg("%s: can't set hw address",
409 /* For old ABI the application needs to bring the
412 res = set_if_up(slave_ifname, slave.flags.ifr_flags);
416 /* The driver is using a new ABI,
417 * so the driver takes care of setting
418 * the slave's hwaddr and bringing
422 /* No hwaddr for master yet, so
423 * set the slave's hwaddr to it
426 /* For old ABI, the master needs to be
427 * down before setting it's hwaddr
429 res = set_if_down(master_ifname, master.flags.ifr_flags);
434 res = set_master_hwaddr(master_ifname,
435 &(slave.hwaddr.ifr_hwaddr));
437 bb_error_msg("%s: can't set hw address",
443 /* For old ABI, bring the master
446 res = set_if_up(master_ifname, master.flags.ifr_flags);
448 goto undo_master_mac;
454 /* Do the real thing */
455 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
456 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
457 if (ioctl(skfd, SIOCBONDENSLAVE, &ifr) < 0
458 && ioctl(skfd, BOND_ENSLAVE_OLD, &ifr) < 0
464 goto undo_master_mac;
468 /* rollback (best effort) */
470 set_master_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
474 set_slave_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
476 set_slave_mtu(slave_ifname, slave.mtu.ifr_mtu);
480 static int release(char *master_ifname, char *slave_ifname)
485 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
486 bb_error_msg("%s is not a slave",
491 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
492 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
493 if (ioctl(skfd, SIOCBONDRELEASE, &ifr) < 0
494 && ioctl(skfd, BOND_RELEASE_OLD, &ifr) < 0
499 /* The driver is using an old ABI, so we'll set the interface
500 * down to avoid any conflicts due to same MAC/IP
502 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
505 /* set to default mtu */
506 set_slave_mtu(slave_ifname, 1500);
511 static int get_if_settings(char *ifname, struct dev_data *dd)
515 strncpy_IFNAMSIZ(dd->mtu.ifr_name, ifname);
516 res = ioctl(skfd, SIOCGIFMTU, &dd->mtu);
517 strncpy_IFNAMSIZ(dd->flags.ifr_name, ifname);
518 res |= ioctl(skfd, SIOCGIFFLAGS, &dd->flags);
519 strncpy_IFNAMSIZ(dd->hwaddr.ifr_name, ifname);
520 res |= ioctl(skfd, SIOCGIFHWADDR, &dd->hwaddr);
525 static int get_slave_flags(char *slave_ifname)
527 strncpy_IFNAMSIZ(slave.flags.ifr_name, slave_ifname);
528 return ioctl(skfd, SIOCGIFFLAGS, &slave.flags);
531 static int set_master_hwaddr(char *master_ifname, struct sockaddr *hwaddr)
535 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
536 memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
537 return ioctl(skfd, SIOCSIFHWADDR, &ifr);
540 static int set_slave_hwaddr(char *slave_ifname, struct sockaddr *hwaddr)
544 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
545 memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
546 return ioctl(skfd, SIOCSIFHWADDR, &ifr);
549 static int set_slave_mtu(char *slave_ifname, int mtu)
554 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
555 return ioctl(skfd, SIOCSIFMTU, &ifr);
558 static int set_if_flags(char *ifname, short flags)
562 ifr.ifr_flags = flags;
563 strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
564 return ioctl(skfd, SIOCSIFFLAGS, &ifr);
567 static int set_if_up(char *ifname, short flags)
569 int res = set_if_flags(ifname, flags | IFF_UP);
571 bb_perror_msg("%s: can't up", ifname);
575 static int set_if_down(char *ifname, short flags)
577 int res = set_if_flags(ifname, flags & ~IFF_UP);
579 bb_perror_msg("%s: can't down", ifname);
583 static int clear_if_addr(char *ifname)
587 strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
588 ifr.ifr_addr.sa_family = AF_INET;
589 memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
590 return ioctl(skfd, SIOCSIFADDR, &ifr);
593 static int set_if_addr(char *master_ifname, char *slave_ifname)
595 static const struct {
599 { SIOCGIFADDR, SIOCSIFADDR },
600 { SIOCGIFDSTADDR, SIOCSIFDSTADDR },
601 { SIOCGIFBRDADDR, SIOCSIFBRDADDR },
602 { SIOCGIFNETMASK, SIOCSIFNETMASK },
609 for (i = 0; i < ARRAY_SIZE(ifra); i++) {
610 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
611 res = ioctl(skfd, ifra[i].g_ioctl, &ifr);
613 ifr.ifr_addr.sa_family = AF_INET;
614 memset(ifr.ifr_addr.sa_data, 0,
615 sizeof(ifr.ifr_addr.sa_data));
618 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
619 res = ioctl(skfd, ifra[i].s_ioctl, &ifr);