source: branches/3.2/mindi-busybox/networking/ifenslave.c @ 3186

Last change on this file since 3186 was 2725, checked in by bruno, 8 years ago
  • Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3
  • Property svn:eol-style set to native
File size: 16.5 KB
Line 
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 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.
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
101#include "libbb.h"
102
103/* #include <net/if.h> - no. linux/if_bonding.h pulls in linux/if.h */
104#include <linux/if.h>
105//#include <net/if_arp.h> - not needed?
106#include <linux/if_bonding.h>
107#include <linux/sockios.h>
108#include "fix_u32.h" /* hack, so we may include kernel's ethtool.h */
109#include <linux/ethtool.h>
110#ifndef BOND_ABI_VERSION
111# define BOND_ABI_VERSION 2
112#endif
113#ifndef IFNAMSIZ
114# define IFNAMSIZ 16
115#endif
116
117
118struct dev_data {
119    struct ifreq mtu, flags, hwaddr;
120};
121
122
123enum { skfd = 3 };      /* AF_INET socket for ioctl() calls. */
124struct globals {
125    unsigned abi_ver;       /* userland - kernel ABI version */
126    smallint hwaddr_set;    /* Master's hwaddr is set */
127    struct dev_data master;
128    struct dev_data slave;
129};
130#define G (*ptr_to_globals)
131#define abi_ver    (G.abi_ver   )
132#define hwaddr_set (G.hwaddr_set)
133#define master     (G.master    )
134#define slave      (G.slave     )
135#define INIT_G() do { \
136    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
137} while (0)
138
139
140/* NOINLINEs are placed where it results in smaller code (gcc 4.3.1) */
141
142static int ioctl_on_skfd(unsigned request, struct ifreq *ifr)
143{
144    return ioctl(skfd, request, ifr);
145}
146
147static int set_ifrname_and_do_ioctl(unsigned request, struct ifreq *ifr, const char *ifname)
148{
149    strncpy_IFNAMSIZ(ifr->ifr_name, ifname);
150    return ioctl_on_skfd(request, ifr);
151}
152
153static int get_if_settings(char *ifname, struct dev_data *dd)
154{
155    int res;
156
157    res = set_ifrname_and_do_ioctl(SIOCGIFMTU, &dd->mtu, ifname);
158    res |= set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &dd->flags, ifname);
159    res |= set_ifrname_and_do_ioctl(SIOCGIFHWADDR, &dd->hwaddr, ifname);
160
161    return res;
162}
163
164static int get_slave_flags(char *slave_ifname)
165{
166    return set_ifrname_and_do_ioctl(SIOCGIFFLAGS, &slave.flags, slave_ifname);
167}
168
169static int set_hwaddr(char *ifname, struct sockaddr *hwaddr)
170{
171    struct ifreq ifr;
172
173    memcpy(&(ifr.ifr_hwaddr), hwaddr, sizeof(*hwaddr));
174    return set_ifrname_and_do_ioctl(SIOCSIFHWADDR, &ifr, ifname);
175}
176
177static int set_mtu(char *ifname, int mtu)
178{
179    struct ifreq ifr;
180
181    ifr.ifr_mtu = mtu;
182    return set_ifrname_and_do_ioctl(SIOCSIFMTU, &ifr, ifname);
183}
184
185static int set_if_flags(char *ifname, int flags)
186{
187    struct ifreq ifr;
188
189    ifr.ifr_flags = flags;
190    return set_ifrname_and_do_ioctl(SIOCSIFFLAGS, &ifr, ifname);
191}
192
193static int set_if_up(char *ifname, int flags)
194{
195    int res = set_if_flags(ifname, flags | IFF_UP);
196    if (res)
197        bb_perror_msg("%s: can't up", ifname);
198    return res;
199}
200
201static int set_if_down(char *ifname, int flags)
202{
203    int res = set_if_flags(ifname, flags & ~IFF_UP);
204    if (res)
205        bb_perror_msg("%s: can't down", ifname);
206    return res;
207}
208
209static int clear_if_addr(char *ifname)
210{
211    struct ifreq ifr;
212
213    ifr.ifr_addr.sa_family = AF_INET;
214    memset(ifr.ifr_addr.sa_data, 0, sizeof(ifr.ifr_addr.sa_data));
215    return set_ifrname_and_do_ioctl(SIOCSIFADDR, &ifr, ifname);
216}
217
218static int set_if_addr(char *master_ifname, char *slave_ifname)
219{
220#if (SIOCGIFADDR | SIOCSIFADDR \
221  | SIOCGIFDSTADDR | SIOCSIFDSTADDR \
222  | SIOCGIFBRDADDR | SIOCSIFBRDADDR \
223  | SIOCGIFNETMASK | SIOCSIFNETMASK) <= 0xffff
224#define INT uint16_t
225#else
226#define INT int
227#endif
228    static const struct {
229        INT g_ioctl;
230        INT s_ioctl;
231    } ifra[] = {
232        { SIOCGIFADDR,    SIOCSIFADDR    },
233        { SIOCGIFDSTADDR, SIOCSIFDSTADDR },
234        { SIOCGIFBRDADDR, SIOCSIFBRDADDR },
235        { SIOCGIFNETMASK, SIOCSIFNETMASK },
236    };
237
238    struct ifreq ifr;
239    int res;
240    unsigned i;
241
242    for (i = 0; i < ARRAY_SIZE(ifra); i++) {
243        res = set_ifrname_and_do_ioctl(ifra[i].g_ioctl, &ifr, master_ifname);
244        if (res < 0) {
245            ifr.ifr_addr.sa_family = AF_INET;
246            memset(ifr.ifr_addr.sa_data, 0,
247                   sizeof(ifr.ifr_addr.sa_data));
248        }
249
250        res = set_ifrname_and_do_ioctl(ifra[i].s_ioctl, &ifr, slave_ifname);
251        if (res < 0)
252            return res;
253    }
254
255    return 0;
256}
257
258static void change_active(char *master_ifname, char *slave_ifname)
259{
260    struct ifreq ifr;
261
262    if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
263        bb_error_msg_and_die("%s is not a slave", slave_ifname);
264    }
265
266    strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
267    if (set_ifrname_and_do_ioctl(SIOCBONDCHANGEACTIVE, &ifr, master_ifname)
268     && ioctl_on_skfd(BOND_CHANGE_ACTIVE_OLD, &ifr)
269    ) {
270        bb_perror_msg_and_die(
271            "master %s, slave %s: can't "
272            "change active",
273            master_ifname, slave_ifname);
274    }
275}
276
277static NOINLINE int enslave(char *master_ifname, char *slave_ifname)
278{
279    struct ifreq ifr;
280    int res;
281
282    if (slave.flags.ifr_flags & IFF_SLAVE) {
283        bb_error_msg(
284            "%s is already a slave",
285            slave_ifname);
286        return 1;
287    }
288
289    res = set_if_down(slave_ifname, slave.flags.ifr_flags);
290    if (res)
291        return res;
292
293    if (abi_ver < 2) {
294        /* Older bonding versions would panic if the slave has no IP
295         * address, so get the IP setting from the master.
296         */
297        res = set_if_addr(master_ifname, slave_ifname);
298        if (res) {
299            bb_perror_msg("%s: can't set address", slave_ifname);
300            return res;
301        }
302    } else {
303        res = clear_if_addr(slave_ifname);
304        if (res) {
305            bb_perror_msg("%s: can't clear address", slave_ifname);
306            return res;
307        }
308    }
309
310    if (master.mtu.ifr_mtu != slave.mtu.ifr_mtu) {
311        res = set_mtu(slave_ifname, master.mtu.ifr_mtu);
312        if (res) {
313            bb_perror_msg("%s: can't set MTU", slave_ifname);
314            return res;
315        }
316    }
317
318    if (hwaddr_set) {
319        /* Master already has an hwaddr
320         * so set it's hwaddr to the slave
321         */
322        if (abi_ver < 1) {
323            /* The driver is using an old ABI, so
324             * the application sets the slave's
325             * hwaddr
326             */
327            if (set_hwaddr(slave_ifname, &(master.hwaddr.ifr_hwaddr))) {
328                bb_perror_msg("%s: can't set hw address",
329                        slave_ifname);
330                goto undo_mtu;
331            }
332
333            /* For old ABI the application needs to bring the
334             * slave back up
335             */
336            if (set_if_up(slave_ifname, slave.flags.ifr_flags))
337                goto undo_slave_mac;
338        }
339        /* The driver is using a new ABI,
340         * so the driver takes care of setting
341         * the slave's hwaddr and bringing
342         * it up again
343         */
344    } else {
345        /* No hwaddr for master yet, so
346         * set the slave's hwaddr to it
347         */
348        if (abi_ver < 1) {
349            /* For old ABI, the master needs to be
350             * down before setting it's hwaddr
351             */
352            if (set_if_down(master_ifname, master.flags.ifr_flags))
353                goto undo_mtu;
354        }
355
356        if (set_hwaddr(master_ifname, &(slave.hwaddr.ifr_hwaddr))) {
357            bb_error_msg("%s: can't set hw address",
358                master_ifname);
359            goto undo_mtu;
360        }
361
362        if (abi_ver < 1) {
363            /* For old ABI, bring the master
364             * back up
365             */
366            if (set_if_up(master_ifname, master.flags.ifr_flags))
367                goto undo_master_mac;
368        }
369
370        hwaddr_set = 1;
371    }
372
373    /* Do the real thing */
374    strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
375    if (set_ifrname_and_do_ioctl(SIOCBONDENSLAVE, &ifr, master_ifname)
376     && ioctl_on_skfd(BOND_ENSLAVE_OLD, &ifr)
377    ) {
378        goto undo_master_mac;
379    }
380
381    return 0;
382
383/* rollback (best effort) */
384 undo_master_mac:
385    set_hwaddr(master_ifname, &(master.hwaddr.ifr_hwaddr));
386    hwaddr_set = 0;
387    goto undo_mtu;
388
389 undo_slave_mac:
390    set_hwaddr(slave_ifname, &(slave.hwaddr.ifr_hwaddr));
391 undo_mtu:
392    set_mtu(slave_ifname, slave.mtu.ifr_mtu);
393    return 1;
394}
395
396static int release(char *master_ifname, char *slave_ifname)
397{
398    struct ifreq ifr;
399    int res = 0;
400
401    if (!(slave.flags.ifr_flags & IFF_SLAVE)) {
402        bb_error_msg("%s is not a slave", slave_ifname);
403        return 1;
404    }
405
406    strncpy_IFNAMSIZ(ifr.ifr_slave, slave_ifname);
407    if (set_ifrname_and_do_ioctl(SIOCBONDRELEASE, &ifr, master_ifname) < 0
408     && ioctl_on_skfd(BOND_RELEASE_OLD, &ifr) < 0
409    ) {
410        return 1;
411    }
412    if (abi_ver < 1) {
413        /* The driver is using an old ABI, so we'll set the interface
414         * down to avoid any conflicts due to same MAC/IP
415         */
416        res = set_if_down(slave_ifname, slave.flags.ifr_flags);
417    }
418
419    /* set to default mtu */
420    set_mtu(slave_ifname, 1500);
421
422    return res;
423}
424
425static NOINLINE void get_drv_info(char *master_ifname)
426{
427    struct ifreq ifr;
428    struct ethtool_drvinfo info;
429
430    memset(&ifr, 0, sizeof(ifr));
431    ifr.ifr_data = (caddr_t)&info;
432    info.cmd = ETHTOOL_GDRVINFO;
433    /* both fields are 32 bytes long (long enough) */
434    strcpy(info.driver, "ifenslave");
435    strcpy(info.fw_version, utoa(BOND_ABI_VERSION));
436    if (set_ifrname_and_do_ioctl(SIOCETHTOOL, &ifr, master_ifname) < 0) {
437        if (errno == EOPNOTSUPP)
438            return;
439        bb_perror_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
440    }
441
442    abi_ver = bb_strtou(info.fw_version, NULL, 0);
443    if (errno)
444        bb_error_msg_and_die("%s: SIOCETHTOOL error", master_ifname);
445}
446
447int ifenslave_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
448int ifenslave_main(int argc UNUSED_PARAM, char **argv)
449{
450    char *master_ifname, *slave_ifname;
451    int rv;
452    int res;
453    unsigned opt;
454    enum {
455        OPT_c = (1 << 0),
456        OPT_d = (1 << 1),
457        OPT_f = (1 << 2),
458    };
459#if ENABLE_LONG_OPTS
460    static const char ifenslave_longopts[] ALIGN1 =
461        "change-active\0"  No_argument "c"
462        "detach\0"         No_argument "d"
463        "force\0"          No_argument "f"
464        /* "all-interfaces\0" No_argument "a" */
465        ;
466
467    applet_long_options = ifenslave_longopts;
468#endif
469    INIT_G();
470
471    opt = getopt32(argv, "cdfa");
472    argv += optind;
473    if (opt & (opt-1)) /* Only one option can be given */
474        bb_show_usage();
475
476    master_ifname = *argv++;
477
478    /* No interface names - show all interfaces. */
479    if (!master_ifname) {
480        display_interfaces(NULL);
481        return EXIT_SUCCESS;
482    }
483
484    /* Open a basic socket */
485    xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), skfd);
486
487    /* Exchange abi version with bonding module */
488    get_drv_info(master_ifname);
489
490    slave_ifname = *argv++;
491    if (!slave_ifname) {
492        if (opt & (OPT_d|OPT_c)) {
493            /* --change or --detach, and no slaves given -
494             * show all interfaces. */
495            display_interfaces(slave_ifname /* == NULL */);
496            return 2; /* why 2? */
497        }
498        /* A single arg means show the
499         * configuration for this interface
500         */
501        display_interfaces(master_ifname);
502        return EXIT_SUCCESS;
503    }
504
505    if (get_if_settings(master_ifname, &master)) {
506        /* Probably a good reason not to go on */
507        bb_perror_msg_and_die("%s: can't get settings", master_ifname);
508    }
509
510    /* Check if master is indeed a master;
511     * if not then fail any operation
512     */
513    if (!(master.flags.ifr_flags & IFF_MASTER))
514        bb_error_msg_and_die("%s is not a master", master_ifname);
515
516    /* Check if master is up; if not then fail any operation */
517    if (!(master.flags.ifr_flags & IFF_UP))
518        bb_error_msg_and_die("%s is not up", master_ifname);
519
520#ifdef WHY_BOTHER
521    /* Neither -c[hange] nor -d[etach] -> it's "enslave" then;
522     * and -f[orce] is not there too. Check that it's ethernet. */
523    if (!(opt & (OPT_d|OPT_c|OPT_f)) {
524        /* The family '1' is ARPHRD_ETHER for ethernet. */
525        if (master.hwaddr.ifr_hwaddr.sa_family != 1) {
526            bb_error_msg_and_die(
527                "%s is not ethernet-like (-f overrides)",
528                master_ifname);
529        }
530    }
531#endif
532
533    /* Accepts only one slave */
534    if (opt & OPT_c) {
535        /* Change active slave */
536        if (get_slave_flags(slave_ifname)) {
537            bb_perror_msg_and_die(
538                "%s: can't get flags", slave_ifname);
539        }
540        change_active(master_ifname, slave_ifname);
541        return EXIT_SUCCESS;
542    }
543
544    /* Accepts multiple slaves */
545    res = 0;
546    do {
547        if (opt & OPT_d) {
548            /* Detach a slave interface from the master */
549            rv = get_slave_flags(slave_ifname);
550            if (rv) {
551                /* Can't work with this slave, */
552                /* remember the error and skip it */
553                bb_perror_msg(
554                    "skipping %s: can't get flags",
555                    slave_ifname);
556                res = rv;
557                continue;
558            }
559            rv = release(master_ifname, slave_ifname);
560            if (rv) {
561                bb_perror_msg("can't release %s from %s",
562                    slave_ifname, master_ifname);
563                res = rv;
564            }
565        } else {
566            /* Attach a slave interface to the master */
567            rv = get_if_settings(slave_ifname, &slave);
568            if (rv) {
569                /* Can't work with this slave, */
570                /* remember the error and skip it */
571                bb_perror_msg(
572                    "skipping %s: can't get settings",
573                    slave_ifname);
574                res = rv;
575                continue;
576            }
577            rv = enslave(master_ifname, slave_ifname);
578            if (rv) {
579                bb_perror_msg("can't enslave %s to %s",
580                    slave_ifname, master_ifname);
581                res = rv;
582            }
583        }
584    } while ((slave_ifname = *argv++) != NULL);
585
586    if (ENABLE_FEATURE_CLEAN_UP) {
587        close(skfd);
588    }
589
590    return res;
591}
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