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
 126 struct __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 */
 150 static 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
 166 static 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
 175 static 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
 184 static 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
 191 static 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
 202 int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 203 int 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 }