LXR busybox/networking/brctl.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Small implementation of brctl for busybox.
   4 *
   5 * Copyright (C) 2008 by Bernhard Reutner-Fischer
   6 *
   7 * Some helper functions from bridge-utils are
   8 * Copyright (C) 2000 Lennert Buytenhek
   9 *
  10 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  11 */
  12/* This applet currently uses only the ioctl interface and no sysfs at all.
  13 * At the time of this writing this was considered a feature.
  14 */
  15//config:config BRCTL
  16//config:       bool "brctl (4.7 kb)"
  17//config:       default y
  18//config:       select PLATFORM_LINUX
  19//config:       help
  20//config:       Manage ethernet bridges.
  21//config:       Supports addbr/delbr and addif/delif.
  22//config:
  23//config:config FEATURE_BRCTL_FANCY
  24//config:       bool "Fancy options"
  25//config:       default y
  26//config:       depends on BRCTL
  27//config:       help
  28//config:       Add support for extended option like:
  29//config:               setageing, setfd, sethello, setmaxage,
  30//config:               setpathcost, setportprio, setbridgeprio,
  31//config:               stp
  32//config:       This adds about 600 bytes.
  33//config:
  34//config:config FEATURE_BRCTL_SHOW
  35//config:       bool "Support show"
  36//config:       default y
  37//config:       depends on BRCTL && FEATURE_BRCTL_FANCY
  38//config:       help
  39//config:       Add support for option which prints the current config:
  40//config:               show
  41
  42//applet:IF_BRCTL(APPLET_NOEXEC(brctl, brctl, BB_DIR_USR_SBIN, BB_SUID_DROP, brctl))
  43
  44//kbuild:lib-$(CONFIG_BRCTL) += brctl.o
  45
  46//usage:#define brctl_trivial_usage
  47//usage:       "COMMAND [BRIDGE [INTERFACE]]"
  48//usage:#define brctl_full_usage "\n\n"
  49//usage:       "Manage ethernet bridges\n"
  50//usage:     "\nCommands:"
  51//usage:        IF_FEATURE_BRCTL_SHOW(
  52//usage:     "\n        show                    Show a list of bridges"
  53//usage:        )
  54//usage:     "\n        addbr BRIDGE            Create BRIDGE"
  55//usage:     "\n        delbr BRIDGE            Delete BRIDGE"
  56//usage:     "\n        addif BRIDGE IFACE      Add IFACE to BRIDGE"
  57//usage:     "\n        delif BRIDGE IFACE      Delete IFACE from BRIDGE"
  58//usage:        IF_FEATURE_BRCTL_FANCY(
  59//usage:     "\n        setageing BRIDGE TIME           Set ageing time"
  60//usage:     "\n        setfd BRIDGE TIME               Set bridge forward delay"
  61//usage:     "\n        sethello BRIDGE TIME            Set hello time"
  62//usage:     "\n        setmaxage BRIDGE TIME           Set max message age"
  63//usage:     "\n        setpathcost BRIDGE COST         Set path cost"
  64//usage:     "\n        setportprio BRIDGE PRIO         Set port priority"
  65//usage:     "\n        setbridgeprio BRIDGE PRIO       Set bridge priority"
  66//usage:     "\n        stp BRIDGE [1/yes/on|0/no/off]  STP on/off"
  67//usage:        )
  68
  69#include "libbb.h"
  70#include <linux/sockios.h>
  71#include <net/if.h>
  72
  73#ifndef SIOCBRADDBR
  74# define SIOCBRADDBR BRCTL_ADD_BRIDGE
  75#endif
  76#ifndef SIOCBRDELBR
  77# define SIOCBRDELBR BRCTL_DEL_BRIDGE
  78#endif
  79#ifndef SIOCBRADDIF
  80# define SIOCBRADDIF BRCTL_ADD_IF
  81#endif
  82#ifndef SIOCBRDELIF
  83# define SIOCBRDELIF BRCTL_DEL_IF
  84#endif
  85
  86
  87/* Maximum number of ports supported per bridge interface.  */
  88#ifndef MAX_PORTS
  89# define MAX_PORTS 32
  90#endif
  91
  92/* Use internal number parsing and not the "exact" conversion.  */
  93/* #define BRCTL_USE_INTERNAL 0 */ /* use exact conversion */
  94#define BRCTL_USE_INTERNAL 1
  95
  96#if ENABLE_FEATURE_BRCTL_FANCY
  97/* #include <linux/if_bridge.h>
  98 * breaks on musl: we already included netinet/in.h in libbb.h,
  99 * if we include <linux/if_bridge.h> here, we get this:
 100 * In file included from /usr/include/linux/if_bridge.h:18,
 101 *                  from networking/brctl.c:67:
 102 * /usr/include/linux/in6.h:32: error: redefinition of 'struct in6_addr'
 103 * /usr/include/linux/in6.h:49: error: redefinition of 'struct sockaddr_in6'
 104 * /usr/include/linux/in6.h:59: error: redefinition of 'struct ipv6_mreq'
 105 */
 106/* From <linux/if_bridge.h> */
 107#define BRCTL_GET_VERSION 0
 108#define BRCTL_GET_BRIDGES 1
 109#define BRCTL_ADD_BRIDGE 2
 110#define BRCTL_DEL_BRIDGE 3
 111#define BRCTL_ADD_IF 4
 112#define BRCTL_DEL_IF 5
 113#define BRCTL_GET_BRIDGE_INFO 6
 114#define BRCTL_GET_PORT_LIST 7
 115#define BRCTL_SET_BRIDGE_FORWARD_DELAY 8
 116#define BRCTL_SET_BRIDGE_HELLO_TIME 9
 117#define BRCTL_SET_BRIDGE_MAX_AGE 10
 118#define BRCTL_SET_AGEING_TIME 11
 119#define BRCTL_SET_GC_INTERVAL 12
 120#define BRCTL_GET_PORT_INFO 13
 121#define BRCTL_SET_BRIDGE_STP_STATE 14
 122#define BRCTL_SET_BRIDGE_PRIORITY 15
 123#define BRCTL_SET_PORT_PRIORITY 16
 124#define BRCTL_SET_PATH_COST 17
 125#define BRCTL_GET_FDB_ENTRIES 18
 126struct __bridge_info {
 127        uint64_t designated_root;
 128        uint64_t bridge_id;
 129        uint32_t root_path_cost;
 130        uint32_t max_age;
 131        uint32_t hello_time;
 132        uint32_t forward_delay;
 133        uint32_t bridge_max_age;
 134        uint32_t bridge_hello_time;
 135        uint32_t bridge_forward_delay;
 136        uint8_t  topology_change;
 137        uint8_t  topology_change_detected;
 138        uint8_t  root_port;
 139        uint8_t  stp_enabled;
 140        uint32_t ageing_time;
 141        uint32_t gc_interval;
 142        uint32_t hello_timer_value;
 143        uint32_t tcn_timer_value;
 144        uint32_t topology_change_timer_value;
 145        uint32_t gc_timer_value;
 146};
 147/* end <linux/if_bridge.h> */
 148
 149/* FIXME: These 4 funcs are not really clean and could be improved */
 150static ALWAYS_INLINE void bb_strtotimeval(struct timeval *tv,
 151                const char *time_str)
 152{
 153        double secs;
 154# if BRCTL_USE_INTERNAL
 155        char *endptr;
 156        secs = /*bb_*/strtod(time_str, &endptr);
 157        if (endptr == time_str)
 158# else
 159        if (sscanf(time_str, "%lf", &secs) != 1)
 160# endif
 161                bb_error_msg_and_die(bb_msg_invalid_arg_to, time_str, "timespec");
 162        tv->tv_sec = secs;
 163        tv->tv_usec = 1000000 * (secs - tv->tv_sec);
 164}
 165
 166static ALWAYS_INLINE unsigned long tv_to_jiffies(const struct timeval *tv)
 167{
 168        unsigned long long jif;
 169
 170        jif = 1000000ULL * tv->tv_sec + tv->tv_usec;
 171
 172        return jif/10000;
 173}
 174# if 0
 175static void jiffies_to_tv(struct timeval *tv, unsigned long jiffies)
 176{
 177        unsigned long long tvusec;
 178
 179        tvusec = 10000ULL*jiffies;
 180        tv->tv_sec = tvusec/1000000;
 181        tv->tv_usec = tvusec - 1000000 * tv->tv_sec;
 182}
 183# endif
 184static unsigned long str_to_jiffies(const char *time_str)
 185{
 186        struct timeval tv;
 187        bb_strtotimeval(&tv, time_str);
 188        return tv_to_jiffies(&tv);
 189}
 190
 191static void arm_ioctl(unsigned long *args,
 192                unsigned long arg0, unsigned long arg1, unsigned long arg2)
 193{
 194        args[0] = arg0;
 195        args[1] = arg1;
 196        args[2] = arg2;
 197        args[3] = 0;
 198}
 199#endif
 200
 201
 202int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 203int brctl_main(int argc UNUSED_PARAM, char **argv)
 204{
 205        static const char keywords[] ALIGN1 =
 206                "addbr\0" "delbr\0" "addif\0" "delif\0"
 207        IF_FEATURE_BRCTL_FANCY(
 208                "stp\0"
 209                "setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
 210                "setpathcost\0" "setportprio\0" "setbridgeprio\0"
 211        )
 212        IF_FEATURE_BRCTL_SHOW("show\0");
 213
 214        enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
 215                IF_FEATURE_BRCTL_FANCY(,
 216                        ARG_stp,
 217                        ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
 218                        ARG_setpathcost, ARG_setportprio, ARG_setbridgeprio
 219                )
 220                IF_FEATURE_BRCTL_SHOW(, ARG_show)
 221        };
 222
 223        int fd;
 224        smallint key;
 225        struct ifreq ifr;
 226        char *br, *brif;
 227
 228        argv++;
 229        while (*argv) {
 230#if ENABLE_FEATURE_BRCTL_FANCY
 231                int ifidx[MAX_PORTS];
 232                unsigned long args[4];
 233                ifr.ifr_data = (char *) &args;
 234#endif
 235
 236                key = index_in_strings(keywords, *argv);
 237                if (key == -1) /* no match found in keywords array, bail out. */
 238                        bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
 239                argv++;
 240                fd = xsocket(AF_INET, SOCK_STREAM, 0);
 241
 242#if ENABLE_FEATURE_BRCTL_SHOW
 243                if (key == ARG_show) { /* show */
 244                        char brname[IFNAMSIZ];
 245                        int bridx[MAX_PORTS];
 246                        int i, num;
 247                        arm_ioctl(args, BRCTL_GET_BRIDGES,
 248                                                (unsigned long) bridx, MAX_PORTS);
 249                        num = xioctl(fd, SIOCGIFBR, args);
 250                        puts("bridge name\tbridge id\t\tSTP enabled\tinterfaces");
 251                        for (i = 0; i < num; i++) {
 252                                char ifname[IFNAMSIZ];
 253                                int j, tabs;
 254                                struct __bridge_info bi;
 255                                unsigned char *x;
 256
 257                                if (!if_indextoname(bridx[i], brname))
 258                                        bb_perror_msg_and_die("can't get bridge name for index %d", i);
 259                                strncpy_IFNAMSIZ(ifr.ifr_name, brname);
 260
 261                                arm_ioctl(args, BRCTL_GET_BRIDGE_INFO,
 262                                                        (unsigned long) &bi, 0);
 263                                xioctl(fd, SIOCDEVPRIVATE, &ifr);
 264                                printf("%s\t\t", brname);
 265
 266                                /* print bridge id */
 267                                x = (unsigned char *) &bi.bridge_id;
 268                                for (j = 0; j < 8; j++) {
 269                                        printf("%02x", x[j]);
 270                                        if (j == 1)
 271                                                bb_putchar('.');
 272                                }
 273                                printf(bi.stp_enabled ? "\tyes" : "\tno");
 274
 275                                /* print interface list */
 276                                arm_ioctl(args, BRCTL_GET_PORT_LIST,
 277                                                        (unsigned long) ifidx, MAX_PORTS);
 278                                xioctl(fd, SIOCDEVPRIVATE, &ifr);
 279                                tabs = 0;
 280                                for (j = 0; j < MAX_PORTS; j++) {
 281                                        if (!ifidx[j])
 282                                                continue;
 283                                        if (!if_indextoname(ifidx[j], ifname))
 284                                                bb_perror_msg_and_die("can't get interface name for index %d", j);
 285                                        if (tabs)
 286                                                printf("\t\t\t\t\t");
 287                                        else
 288                                                tabs = 1;
 289                                        printf("\t\t%s\n", ifname);
 290                                }
 291                                if (!tabs)  /* bridge has no interfaces */
 292                                        bb_putchar('\n');
 293                        }
 294                        goto done;
 295                }
 296#endif
 297
 298                if (!*argv) /* all but 'show' need at least one argument */
 299                        bb_show_usage();
 300
 301                br = *argv++;
 302
 303                if (key == ARG_addbr || key == ARG_delbr) { /* addbr or delbr */
 304                        ioctl_or_perror_and_die(fd,
 305                                        key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
 306                                        br, "bridge %s", br);
 307                        goto done;
 308                }
 309
 310                if (!*argv) /* all but 'addbr/delbr' need at least two arguments */
 311                        bb_show_usage();
 312
 313                strncpy_IFNAMSIZ(ifr.ifr_name, br);
 314                if (key == ARG_addif || key == ARG_delif) { /* addif or delif */
 315                        brif = *argv;
 316                        ifr.ifr_ifindex = if_nametoindex(brif);
 317                        if (!ifr.ifr_ifindex) {
 318                                bb_perror_msg_and_die("iface %s", brif);
 319                        }
 320                        ioctl_or_perror_and_die(fd,
 321                                        key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
 322                                        &ifr, "bridge %s", br);
 323                        goto done_next_argv;
 324                }
 325#if ENABLE_FEATURE_BRCTL_FANCY
 326                if (key == ARG_stp) { /* stp */
 327                        static const char no_yes[] ALIGN1 =
 328                                "0\0" "off\0" "n\0" "no\0"   /* 0 .. 3 */
 329                                "1\0" "on\0"  "y\0" "yes\0"; /* 4 .. 7 */
 330                        int onoff = index_in_strings(no_yes, *argv);
 331                        if (onoff < 0)
 332                                bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
 333                        onoff = (unsigned)onoff / 4;
 334                        arm_ioctl(args, BRCTL_SET_BRIDGE_STP_STATE, onoff, 0);
 335                        goto fire;
 336                }
 337                if ((unsigned)(key - ARG_setageing) < 4) { /* time related ops */
 338                        static const uint8_t ops[] ALIGN1 = {
 339                                BRCTL_SET_AGEING_TIME,          /* ARG_setageing */
 340                                BRCTL_SET_BRIDGE_FORWARD_DELAY, /* ARG_setfd     */
 341                                BRCTL_SET_BRIDGE_HELLO_TIME,    /* ARG_sethello  */
 342                                BRCTL_SET_BRIDGE_MAX_AGE        /* ARG_setmaxage */
 343                        };
 344                        arm_ioctl(args, ops[key - ARG_setageing], str_to_jiffies(*argv), 0);
 345                        goto fire;
 346                }
 347                if (key == ARG_setpathcost
 348                 || key == ARG_setportprio
 349                 || key == ARG_setbridgeprio
 350                ) {
 351                        static const uint8_t ops[] ALIGN1 = {
 352                                BRCTL_SET_PATH_COST,      /* ARG_setpathcost   */
 353                                BRCTL_SET_PORT_PRIORITY,  /* ARG_setportprio   */
 354                                BRCTL_SET_BRIDGE_PRIORITY /* ARG_setbridgeprio */
 355                        };
 356                        int port = -1;
 357                        unsigned arg1, arg2;
 358
 359                        if (key != ARG_setbridgeprio) {
 360                                /* get portnum */
 361                                unsigned i;
 362
 363                                port = if_nametoindex(*argv++);
 364                                if (!port)
 365                                        bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, "port");
 366                                memset(ifidx, 0, sizeof ifidx);
 367                                arm_ioctl(args, BRCTL_GET_PORT_LIST, (unsigned long)ifidx,
 368                                                MAX_PORTS);
 369                                xioctl(fd, SIOCDEVPRIVATE, &ifr);
 370                                for (i = 0; i < MAX_PORTS; i++) {
 371                                        if (ifidx[i] == port) {
 372                                                port = i;
 373                                                break;
 374                                        }
 375                                }
 376                        }
 377                        arg1 = port;
 378                        arg2 = xatoi_positive(*argv);
 379                        if (key == ARG_setbridgeprio) {
 380                                arg1 = arg2;
 381                                arg2 = 0;
 382                        }
 383                        arm_ioctl(args, ops[key - ARG_setpathcost], arg1, arg2);
 384                }
 385 fire:
 386                /* Execute the previously set command */
 387                xioctl(fd, SIOCDEVPRIVATE, &ifr);
 388#endif
 389 done_next_argv:
 390                argv++;
 391 done:
 392                close(fd);
 393        }
 394
 395        return EXIT_SUCCESS;
 396}
 397