busybox/networking/ifenslave.c

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/* 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.
*
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* This program controls the Linux implementation of running multiple
* network interfaces in parallel.
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*
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* Author: Donald Becker <becker@cesdis.gsfc.nasa.gov>
* Copyright 1994-1996 Donald Becker
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*
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* 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.
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*
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* 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
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*
* 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>
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* - ifenslave -c was broken; it's now fixed
* - Fixed problem with routes vanishing from master during enslave
* processing.
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*
* - 2003/05/27 - Amir Noam <amir.noam at intel dot com>
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* - 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.
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*
* - 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
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* - Code cleanup and style changes
* set version to 1.1.0
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*/
#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 { \
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SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
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} while (0)
static void get_drv_info(char *master_ifname);
static int get_if_settings(char *ifname, struct dev_data *dd);
static int get_slave_flags(char *slave_ifname);
static int set_master_hwaddr(char *master_ifname, struct sockaddr *hwaddr);
static int set_slave_hwaddr(char *slave_ifname, struct sockaddr *hwaddr);
static int set_slave_mtu(char *slave_ifname, int mtu);
static int set_if_flags(char *ifname, short flags);
static int set_if_up(char *ifname, short flags);
static int set_if_down(char *ifname, short flags);
static int clear_if_addr(char *ifname);
static int set_if_addr(char *master_ifname, char *slave_ifname);
static void change_active(char *master_ifname, char *slave_ifname);
static int enslave(char *master_ifname, char *slave_ifname);
static int release(char *master_ifname, char *slave_ifname);
static void strncpy_IFNAMSIZ(char *dst, const char *src)
{
strncpy(dst, src, IFNAMSIZ);
}
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int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ifenslave_main(int argc ATTRIBUTE_UNUSED, char **argv)
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{
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" No_argument "c"
"detach" No_argument "d"
"force" No_argument "f"
;
applet_long_options = ifenslave_longopts;
#endif
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INIT_G();
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opt = getopt32(argv, "cdf");
argv += optind;
if (opt & (opt-1)) /* options check */
bb_show_usage();
/* Copy the interface name */
master_ifname = *argv++;
/* No remaining args means 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)) {
display_interfaces(slave_ifname);
return 2; /* why? */
}
/* 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);
/* Only for enslaving */
if (!(opt & (OPT_c|OPT_d))) {
sa_family_t master_family = master.hwaddr.ifr_hwaddr.sa_family;
/* The family '1' is ARPHRD_ETHER for ethernet. */
if (master_family != 1 && !(opt & OPT_f)) {
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 */
res = get_slave_flags(slave_ifname);
if (res) {
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;
}
static void get_drv_info(char *master_ifname)
{
struct ifreq ifr;
struct ethtool_drvinfo info;
memset(&ifr, 0, sizeof(ifr));
strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
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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 (ioctl(skfd, SIOCETHTOOL, &ifr) < 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);
return;
}
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_name, master_ifname);
strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
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if (ioctl(skfd, SIOCBONDCHANGEACTIVE, &ifr) < 0
&& ioctl(skfd, BOND_CHANGE_ACTIVE_OLD, &ifr) < 0
) {
bb_perror_msg_and_die(
"master %s, slave %s: can't "
"change active",
master_ifname, slave_ifname);
}
}
static 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_slave_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
*/
res = set_slave_hwaddr(slave_ifname,
&(master.hwaddr.ifr_hwaddr));
if (res) {
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
*/
res = set_if_up(slave_ifname, slave.flags.ifr_flags);
if (res)
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
*/
res = set_if_down(master_ifname, master.flags.ifr_flags);
if (res)
goto undo_mtu;
}
res = set_master_hwaddr(master_ifname,
&(slave.hwaddr.ifr_hwaddr));
if (res) {
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
*/
res = set_if_up(master_ifname, master.flags.ifr_flags);
if (res)
goto undo_master_mac;
}
hwaddr_set = 1;
}
/* Do the real thing */
strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
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if (ioctl(skfd, SIOCBONDENSLAVE, &ifr) < 0
&& ioctl(skfd, BOND_ENSLAVE_OLD, &ifr) < 0
) {
res = 1;
}
if (res)
goto undo_master_mac;
return 0;
/* rollback (best effort) */
undo_master_mac:
set_master_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
hwaddr_set = 0;
goto undo_mtu;
undo_slave_mac:
set_slave_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
undo_mtu:
set_slave_mtu(slave_ifname, slave.mtu.ifr_mtu);
return res;
}
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_name, master_ifname);
strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
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if (ioctl(skfd, SIOCBONDRELEASE, &ifr) < 0
&& ioctl(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_slave_mtu(slave_ifname, 1500);
return res;
}
static int get_if_settings(char *ifname, struct dev_data *dd)
{
int res;
strncpy_IFNAMSIZ(dd->mtu.ifr_name, ifname);
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res = ioctl(skfd, SIOCGIFMTU, &dd->mtu);
strncpy_IFNAMSIZ(dd->flags.ifr_name, ifname);
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res |= ioctl(skfd, SIOCGIFFLAGS, &dd->flags);
strncpy_IFNAMSIZ(dd->hwaddr.ifr_name, ifname);
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res |= ioctl(skfd, SIOCGIFHWADDR, &dd->hwaddr);
return res;
}
static int get_slave_flags(char *slave_ifname)
{
strncpy_IFNAMSIZ(slave.flags.ifr_name, slave_ifname);
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return ioctl(skfd, SIOCGIFFLAGS, &slave.flags);
}
static int set_master_hwaddr(char *master_ifname, struct sockaddr *hwaddr)
{
struct ifreq ifr;
strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
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memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
return ioctl(skfd, SIOCSIFHWADDR, &ifr);
}
static int set_slave_hwaddr(char *slave_ifname, struct sockaddr *hwaddr)
{
struct ifreq ifr;
strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
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memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(struct sockaddr));
return ioctl(skfd, SIOCSIFHWADDR, &ifr);
}
static int set_slave_mtu(char *slave_ifname, int mtu)
{
struct ifreq ifr;
ifr.ifr_mtu = mtu;
strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
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return ioctl(skfd, SIOCSIFMTU, &ifr);
}
static int set_if_flags(char *ifname, short flags)
{
struct ifreq ifr;
ifr.ifr_flags = flags;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
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return ioctl(skfd, SIOCSIFFLAGS, &ifr);
}
static int set_if_up(char *ifname, short 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, short 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;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
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ifr.ifr_addr.sa_family = AF_INET;
memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
return ioctl(skfd, SIOCSIFADDR, &ifr);
}
static int set_if_addr(char *master_ifname, char *slave_ifname)
{
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;
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for (i = 0; i < ARRAY_SIZE(ifra); i++) {
strncpy_IFNAMSIZ(ifr.ifr_name, master_ifname);
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res = ioctl(skfd, ifra[i].g_ioctl, &ifr);
if (res < 0) {
ifr.ifr_addr.sa_family = AF_INET;
memset(ifr.ifr_addr.sa_data, 0,
sizeof(ifr.ifr_addr.sa_data));
}
strncpy_IFNAMSIZ(ifr.ifr_name, slave_ifname);
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res = ioctl(skfd, ifra[i].s_ioctl, &ifr);
if (res < 0)
return res;
}
return 0;
}