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