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;
179 opt = getopt32(argv, "cdf");
181 if (opt & (opt-1)) /* options check */
184 /* Copy the interface name */
185 master_ifname = *argv++;
187 /* No remaining args means show all interfaces. */
188 if (!master_ifname) {
189 display_interfaces(NULL);
193 /* Open a basic socket */
194 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);
196 /* exchange abi version with bonding module */
197 get_drv_info(master_ifname);
199 slave_ifname = *argv++;
201 if (opt & (OPT_d|OPT_c)) {
202 display_interfaces(slave_ifname);
205 /* A single arg means show the
206 * configuration for this interface
208 display_interfaces(master_ifname);
212 res = get_if_settings(master_ifname, &master);
214 /* Probably a good reason not to go on */
215 bb_perror_msg_and_die("%s: can't get settings", master_ifname);
218 /* check if master is indeed a master;
219 * if not then fail any operation
221 if (!(master.flags.ifr_flags & IFF_MASTER))
222 bb_error_msg_and_die("%s is not a master", master_ifname);
224 /* check if master is up; if not then fail any operation */
225 if (!(master.flags.ifr_flags & IFF_UP))
226 bb_error_msg_and_die("%s is not up", master_ifname);
228 /* Only for enslaving */
229 if (!(opt & (OPT_c|OPT_d))) {
230 sa_family_t master_family = master.hwaddr.ifr_hwaddr.sa_family;
232 /* The family '1' is ARPHRD_ETHER for ethernet. */
233 if (master_family != 1 && !(opt & OPT_f)) {
234 bb_error_msg_and_die(
235 "%s is not ethernet-like (-f overrides)",
240 /* Accepts only one slave */
242 /* change active slave */
243 res = get_slave_flags(slave_ifname);
245 bb_perror_msg_and_die(
246 "%s: can't get flags", slave_ifname);
248 change_active(master_ifname, slave_ifname);
252 /* Accept multiple slaves */
256 /* detach a slave interface from the master */
257 rv = get_slave_flags(slave_ifname);
259 /* Can't work with this slave. */
260 /* remember the error and skip it*/
262 "skipping %s: can't get flags",
267 rv = release(master_ifname, slave_ifname);
270 "master %s, slave %s: "
272 master_ifname, slave_ifname);
276 /* attach a slave interface to the master */
277 rv = get_if_settings(slave_ifname, &slave);
279 /* Can't work with this slave. */
280 /* remember the error and skip it*/
282 "skipping %s: can't get settings",
287 rv = enslave(master_ifname, slave_ifname);
290 "master %s, slave %s: "
292 master_ifname, slave_ifname);
296 } while ((slave_ifname = *argv++) != NULL);
298 if (ENABLE_FEATURE_CLEAN_UP) {
305 static void get_drv_info(char *master_ifname)
308 struct ethtool_drvinfo info;
310 memset(&ifr, 0, sizeof(ifr));
311 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
312 ifr.ifr_data = (caddr_t)&info;
314 info.cmd = ETHTOOL_GDRVINFO;
315 strncpy(info.driver, "ifenslave", 32);
316 snprintf(info.fw_version, 32, "%d", BOND_ABI_VERSION);
318 if (ioctl(skfd, SIOCETHTOOL, &ifr) < 0) {
319 if (errno == EOPNOTSUPP)
321 bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
324 abi_ver = bb_strtou(info.fw_version, NULL, 0);
326 bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
331 static void change_active(char *master_ifname, char *slave_ifname)
335 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
336 bb_error_msg_and_die(
341 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
342 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
343 if (ioctl(skfd, SIOCBONDCHANGEACTIVE, &ifr) < 0
344 && ioctl(skfd, BOND_CHANGE_ACTIVE_OLD, &ifr) < 0
346 bb_perror_msg_and_die(
347 "master %s, slave %s: can't "
349 master_ifname, slave_ifname);
353 static int enslave(char *master_ifname, char *slave_ifname)
358 if (slave.flags.ifr_flags & IFF_SLAVE) {
360 "%s is already a slave",
365 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
370 /* Older bonding versions would panic if the slave has no IP
371 * address, so get the IP setting from the master.
373 res = set_if_addr(master_ifname, slave_ifname);
375 bb_perror_msg("%s: can't set address", slave_ifname);
379 res = clear_if_addr(slave_ifname);
381 bb_perror_msg("%s: can't clear address", slave_ifname);
386 if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
387 res = set_slave_mtu(slave_ifname, master.mtu.ifr_mtu);
389 bb_perror_msg("%s: can't set MTU", slave_ifname);
395 /* Master already has an hwaddr
396 * so set it's hwaddr to the slave
399 /* The driver is using an old ABI, so
400 * the application sets the slave's
403 res = set_slave_hwaddr(slave_ifname,
404 &(master.hwaddr.ifr_hwaddr));
406 bb_perror_msg("%s: can't set hw address",
411 /* For old ABI the application needs to bring the
414 res = set_if_up(slave_ifname, slave.flags.ifr_flags);
418 /* The driver is using a new ABI,
419 * so the driver takes care of setting
420 * the slave's hwaddr and bringing
424 /* No hwaddr for master yet, so
425 * set the slave's hwaddr to it
428 /* For old ABI, the master needs to be
429 * down before setting it's hwaddr
431 res = set_if_down(master_ifname, master.flags.ifr_flags);
436 res = set_master_hwaddr(master_ifname,
437 &(slave.hwaddr.ifr_hwaddr));
439 bb_error_msg("%s: can't set hw address",
445 /* For old ABI, bring the master
448 res = set_if_up(master_ifname, master.flags.ifr_flags);
450 goto undo_master_mac;
456 /* Do the real thing */
457 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
458 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
459 if (ioctl(skfd, SIOCBONDENSLAVE, &ifr) < 0
460 && ioctl(skfd, BOND_ENSLAVE_OLD, &ifr) < 0
466 goto undo_master_mac;
470 /* rollback (best effort) */
472 set_master_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
476 set_slave_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
478 set_slave_mtu(slave_ifname, slave.mtu.ifr_mtu);
482 static int release(char *master_ifname, char *slave_ifname)
487 if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
488 bb_error_msg("%s is not a slave",
493 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
494 strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
495 if (ioctl(skfd, SIOCBONDRELEASE, &ifr) < 0
496 && ioctl(skfd, BOND_RELEASE_OLD, &ifr) < 0
501 /* The driver is using an old ABI, so we'll set the interface
502 * down to avoid any conflicts due to same MAC/IP
504 res = set_if_down(slave_ifname, slave.flags.ifr_flags);
507 /* set to default mtu */
508 set_slave_mtu(slave_ifname, 1500);
513 static int get_if_settings(char *ifname, struct dev_data *dd)
517 strncpy_IFNAMSIZ(dd->mtu.ifr_name, ifname);
518 res = ioctl(skfd, SIOCGIFMTU, &dd->mtu);
519 strncpy_IFNAMSIZ(dd->flags.ifr_name, ifname);
520 res |= ioctl(skfd, SIOCGIFFLAGS, &dd->flags);
521 strncpy_IFNAMSIZ(dd->hwaddr.ifr_name, ifname);
522 res |= ioctl(skfd, SIOCGIFHWADDR, &dd->hwaddr);
527 static int get_slave_flags(char *slave_ifname)
529 strncpy_IFNAMSIZ(slave.flags.ifr_name, slave_ifname);
530 return ioctl(skfd, SIOCGIFFLAGS, &slave.flags);
533 static int set_master_hwaddr(char *master_ifname, struct sockaddr *hwaddr)
537 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
538 memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
539 return ioctl(skfd, SIOCSIFHWADDR, &ifr);
542 static int set_slave_hwaddr(char *slave_ifname, struct sockaddr *hwaddr)
546 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
547 memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
548 return ioctl(skfd, SIOCSIFHWADDR, &ifr);
551 static int set_slave_mtu(char *slave_ifname, int mtu)
556 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
557 return ioctl(skfd, SIOCSIFMTU, &ifr);
560 static int set_if_flags(char *ifname, short flags)
564 ifr.ifr_flags = flags;
565 strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
566 return ioctl(skfd, SIOCSIFFLAGS, &ifr);
569 static int set_if_up(char *ifname, short flags)
571 int res = set_if_flags(ifname, flags | IFF_UP);
573 bb_perror_msg("%s: can't up", ifname);
577 static int set_if_down(char *ifname, short flags)
579 int res = set_if_flags(ifname, flags & ~IFF_UP);
581 bb_perror_msg("%s: can't down", ifname);
585 static int clear_if_addr(char *ifname)
589 strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
590 ifr.ifr_addr.sa_family = AF_INET;
591 memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
592 return ioctl(skfd, SIOCSIFADDR, &ifr);
595 static int set_if_addr(char *master_ifname, char *slave_ifname)
597 static const struct {
601 { SIOCGIFADDR, SIOCSIFADDR },
602 { SIOCGIFDSTADDR, SIOCSIFDSTADDR },
603 { SIOCGIFBRDADDR, SIOCSIFBRDADDR },
604 { SIOCGIFNETMASK, SIOCSIFNETMASK },
611 for (i = 0; i < ARRAY_SIZE(ifra); i++) {
612 strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
613 res = ioctl(skfd, ifra[i].g_ioctl, &ifr);
615 ifr.ifr_addr.sa_family = AF_INET;
616 memset(ifr.ifr_addr.sa_data, 0,
617 sizeof(ifr.ifr_addr.sa_data));
620 strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
621 res = ioctl(skfd, ifra[i].s_ioctl, &ifr);