hush/networking/ifenslave.c
Denis Vlasenko 048897c971 ifenslave: small shrink
text    data     bss     dec     hex filename
 809731     624    7060  817415   c7907 busybox_old
 809629     624    7060  817313   c78a1 busybox_unstripped
2008-06-08 08:01:12 +00:00

593 lines
16 KiB
C

/* 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.
*
* This program controls the Linux implementation of running multiple
* network interfaces in parallel.
*
* Author: Donald Becker <becker@cesdis.gsfc.nasa.gov>
* Copyright 1994-1996 Donald Becker
*
* 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.
*
* 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
*
* 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>
* - ifenslave -c was broken; it's now fixed
* - Fixed problem with routes vanishing from master during enslave
* processing.
*
* - 2003/05/27 - Amir Noam <amir.noam at intel dot com>
* - 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.
*
* - 2003/12/01 - Shmulik Hen <shmulik.hen at intel dot com>
* - Code cleanup and style changes
* set version to 1.1.0
*/
#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 { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)
/* NOINLINEs are placed where it results in smaller code (gcc 4.3.1) */
static void strncpy_IFNAMSIZ(char *dst, const char *src)
{
strncpy(dst, src, IFNAMSIZ);
}
static int ioctl_on_skfd(unsigned request, struct ifreq *ifr)
{
return ioctl(skfd, request, ifr);
}
static int set_ifrname_and_do_ioctl(unsigned request, struct ifreq *ifr, const char *ifname)
{
strncpy_IFNAMSIZ(ifr->ifr_name, ifname);
return ioctl_on_skfd(request, ifr);
}
static int get_if_settings(char *ifname, struct dev_data *dd)
{
int res;
res = set_ifrname_and_do_ioctl(SIOCGIFMTU, &dd->mtu, ifname);
res |= set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &dd->flags, ifname);
res |= set_ifrname_and_do_ioctl(SIOCGIFHWADDR, &dd->hwaddr, ifname);
return res;
}
static int get_slave_flags(char *slave_ifname)
{
return set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &slave.flags, slave_ifname);
}
static int set_hwaddr(char *ifname, struct sockaddr *hwaddr)
{
struct ifreq ifr;
memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(*hwaddr));
return set_ifrname_and_do_ioctl(SIOCSIFHWADDR, &ifr, ifname);
}
static int set_mtu(char *ifname, int mtu)
{
struct ifreq ifr;
ifr.ifr_mtu = mtu;
return set_ifrname_and_do_ioctl(SIOCSIFMTU, &ifr, ifname);
}
static int set_if_flags(char *ifname, int flags)
{
struct ifreq ifr;
ifr.ifr_flags = flags;
return set_ifrname_and_do_ioctl(SIOCSIFFLAGS, &ifr, ifname);
}
static int set_if_up(char *ifname, int 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, int 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;
ifr.ifr_addr.sa_family = AF_INET;
memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
return set_ifrname_and_do_ioctl(SIOCSIFADDR, &ifr, ifname);
}
static int set_if_addr(char *master_ifname, char *slave_ifname)
{
#if (SIOCGIFADDR | SIOCSIFADDR \
| SIOCGIFDSTADDR | SIOCSIFDSTADDR \
| SIOCGIFBRDADDR | SIOCSIFBRDADDR \
| SIOCGIFNETMASK | SIOCSIFNETMASK) <= 0xffff
#define INT uint16_t
#else
#define INT int
#endif
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;
for (i = 0; i < ARRAY_SIZE(ifra); i++) {
res = set_ifrname_and_do_ioctl(ifra[i].g_ioctl, &ifr, master_ifname);
if (res < 0) {
ifr.ifr_addr.sa_family = AF_INET;
memset(ifr.ifr_addr.sa_data, 0,
sizeof(ifr.ifr_addr.sa_data));
}
res = set_ifrname_and_do_ioctl(ifra[i].s_ioctl, &ifr, slave_ifname);
if (res < 0)
return res;
}
return 0;
}
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_slave, slave_ifname);
if (set_ifrname_and_do_ioctl(SIOCBONDCHANGEACTIVE, &ifr, master_ifname)
&& ioctl_on_skfd(BOND_CHANGE_ACTIVE_OLD, &ifr)
) {
bb_perror_msg_and_die(
"master %s, slave %s: can't "
"change active",
master_ifname, slave_ifname);
}
}
static NOINLINE 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_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
*/
if (set_hwaddr(slave_ifname, &(master.hwaddr.ifr_hwaddr))) {
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
*/
if (set_if_up(slave_ifname, slave.flags.ifr_flags))
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
*/
if (set_if_down(master_ifname, master.flags.ifr_flags))
goto undo_mtu;
}
if (set_hwaddr(master_ifname, &(slave.hwaddr.ifr_hwaddr))) {
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
*/
if (set_if_up(master_ifname, master.flags.ifr_flags))
goto undo_master_mac;
}
hwaddr_set = 1;
}
/* Do the real thing */
strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
if (set_ifrname_and_do_ioctl(SIOCBONDENSLAVE, &ifr, master_ifname)
&& ioctl_on_skfd(BOND_ENSLAVE_OLD, &ifr)
) {
goto undo_master_mac;
}
return 0;
/* rollback (best effort) */
undo_master_mac:
set_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
hwaddr_set = 0;
goto undo_mtu;
undo_slave_mac:
set_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
undo_mtu:
set_mtu(slave_ifname, slave.mtu.ifr_mtu);
return 1;
}
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_slave, slave_ifname);
if (set_ifrname_and_do_ioctl(SIOCBONDRELEASE, &ifr, master_ifname) < 0
&& ioctl_on_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_mtu(slave_ifname, 1500);
return res;
}
static NOINLINE void get_drv_info(char *master_ifname)
{
struct ifreq ifr;
struct ethtool_drvinfo info;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_data = (caddr_t)&info;
info.cmd = ETHTOOL_GDRVINFO;
/* both fields are 32 bytes long (long enough) */
strcpy(info.driver, "ifenslave");
strcpy(info.fw_version, utoa(BOND_ABI_VERSION));
if (set_ifrname_and_do_ioctl(SIOCETHTOOL, &ifr, master_ifname) < 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);
}
int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ifenslave_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
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\0" No_argument "c"
"detach\0" No_argument "d"
"force\0" No_argument "f"
/* "all-interfaces\0" No_argument "a" */
;
applet_long_options = ifenslave_longopts;
#endif
INIT_G();
opt = getopt32(argv, "cdfa");
argv += optind;
if (opt & (opt-1)) /* Only one option can be given */
bb_show_usage();
master_ifname = *argv++;
/* No interface names - 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)) {
/* --change or --detach, and no slaves given -
* show all interfaces. */
display_interfaces(slave_ifname /* == NULL */);
return 2; /* why 2? */
}
/* A single arg means show the
* configuration for this interface
*/
display_interfaces(master_ifname);
return EXIT_SUCCESS;
}
if (get_if_settings(master_ifname, &master)) {
/* 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);
#ifdef WHY_BOTHER
/* Neither -c[hange] nor -d[etach] -> it's "enslave" then;
* and -f[orce] is not there too. Check that it's ethernet. */
if (!(opt & (OPT_d|OPT_c|OPT_f)) {
/* The family '1' is ARPHRD_ETHER for ethernet. */
if (master.hwaddr.ifr_hwaddr.sa_family != 1) {
bb_error_msg_and_die(
"%s is not ethernet-like (-f overrides)",
master_ifname);
}
}
#endif
/* Accepts only one slave */
if (opt & OPT_c) {
/* Change active slave */
if (get_slave_flags(slave_ifname)) {
bb_perror_msg_and_die(
"%s: can't get flags", slave_ifname);
}
change_active(master_ifname, slave_ifname);
return EXIT_SUCCESS;
}
/* Accepts 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("can't release %s from %s",
slave_ifname, master_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("can't enslave %s to %s",
slave_ifname, master_ifname);
res = rv;
}
}
} while ((slave_ifname = *argv++) != NULL);
if (ENABLE_FEATURE_CLEAN_UP) {
close(skfd);
}
return res;
}