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 tarball for details.
  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 #include "libbb.h"
  16 #include <linux/sockios.h>
  17 #include <net/if.h>
  18
  19 #ifndef SIOCBRADDBR
  20 # define SIOCBRADDBR BRCTL_ADD_BRIDGE
  21 #endif
  22 #ifndef SIOCBRDELBR
  23 # define SIOCBRDELBR BRCTL_DEL_BRIDGE
  24 #endif
  25 #ifndef SIOCBRADDIF
  26 # define SIOCBRADDIF BRCTL_ADD_IF
  27 #endif
  28 #ifndef SIOCBRDELIF
  29 # define SIOCBRDELIF BRCTL_DEL_IF
  30 #endif
  31
  32
  33 /* Maximum number of ports supported per bridge interface.  */
  34 #ifndef MAX_PORTS
  35 #define MAX_PORTS 32
  36 #endif
  37
  38 /* Use internal number parsing and not the "exact" conversion.  */
  39 /* #define BRCTL_USE_INTERNAL 0 */ /* use exact conversion */
  40 #define BRCTL_USE_INTERNAL 1
  41
  42 #if ENABLE_FEATURE_BRCTL_FANCY
  43 #include <linux/if_bridge.h>
  44
  45 /* FIXME: These 4 funcs are not really clean and could be improved */
  46 static ALWAYS_INLINE void strtotimeval(struct timeval *tv,
  47                 const char *time_str)
  48 {
  49         double secs;
  50 #if BRCTL_USE_INTERNAL
  51         char *endptr;
  52         secs = /*bb_*/strtod(time_str, &endptr);
  53         if (endptr == time_str)
  54 #else
  55         if (sscanf(time_str, "%lf", &secs) != 1)
  56 #endif
  57                 bb_error_msg_and_die (bb_msg_invalid_arg, time_str, "timespec");
  58         tv->tv_sec = secs;
  59         tv->tv_usec = 1000000 * (secs - tv->tv_sec);
  60 }
  61
  62 static ALWAYS_INLINE unsigned long __tv_to_jiffies(const struct timeval *tv)
  63 {
  64         unsigned long long jif;
  65
  66         jif = 1000000ULL * tv->tv_sec + tv->tv_usec;
  67
  68         return jif/10000;
  69 }
  70 # if 0
  71 static void __jiffies_to_tv(struct timeval *tv, unsigned long jiffies)
  72 {
  73         unsigned long long tvusec;
  74
  75         tvusec = 10000ULL*jiffies;
  76         tv->tv_sec = tvusec/1000000;
  77         tv->tv_usec = tvusec - 1000000 * tv->tv_sec;
  78 }
  79 # endif
  80 static unsigned long str_to_jiffies(const char *time_str)
  81 {
  82         struct timeval tv;
  83         strtotimeval(&tv, time_str);
  84         return __tv_to_jiffies(&tv);
  85 }
  86
  87 static void arm_ioctl(unsigned long *args,
  88                 unsigned long arg0, unsigned long arg1, unsigned long arg2)
  89 {
  90         args[0] = arg0;
  91         args[1] = arg1;
  92         args[2] = arg2;
  93         args[3] = 0;
  94 }
  95 #endif
  96
  97
  98 int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  99 int brctl_main(int argc UNUSED_PARAM, char **argv)
 100 {
 101         static const char keywords[] ALIGN1 =
 102                 "addbr\0" "delbr\0" "addif\0" "delif\0"
 103         IF_FEATURE_BRCTL_FANCY(
 104                 "stp\0"
 105                 "setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
 106                 "setpathcost\0" "setportprio\0" "setbridgeprio\0"
 107         )
 108         IF_FEATURE_BRCTL_SHOW("showmacs\0" "show\0");
 109
 110         enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
 111                 IF_FEATURE_BRCTL_FANCY(,
 112                    ARG_stp,
 113                    ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
 114                    ARG_setpathcost, ARG_setportprio, ARG_setbridgeprio
 115                 )
 116                 IF_FEATURE_BRCTL_SHOW(, ARG_showmacs, ARG_show)
 117         };
 118
 119         int fd;
 120         smallint key;
 121         struct ifreq ifr;
 122         char *br, *brif;
 123
 124         argv++;
 125         while (*argv) {
 126 #if ENABLE_FEATURE_BRCTL_FANCY
 127                 int ifidx[MAX_PORTS];
 128                 unsigned long args[4];
 129                 ifr.ifr_data = (char *) &args;
 130 #endif
 131
 132                 key = index_in_strings(keywords, *argv);
 133                 if (key == -1) /* no match found in keywords array, bail out. */
 134                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 135                 argv++;
 136                 fd = xsocket(AF_INET, SOCK_STREAM, 0);
 137
 138 #if ENABLE_FEATURE_BRCTL_SHOW
 139                 if (key == ARG_show) { /* show */
 140                         char brname[IFNAMSIZ];
 141                         int bridx[MAX_PORTS];
 142                         int i, num;
 143                         arm_ioctl(args, BRCTL_GET_BRIDGES,
 144                                                 (unsigned long) bridx, MAX_PORTS);
 145                         num = xioctl(fd, SIOCGIFBR, args);
 146                         printf("bridge name\tbridge id\t\tSTP enabled\tinterfaces\n");
 147                         for (i = 0; i < num; i++) {
 148                                 char ifname[IFNAMSIZ];
 149                                 int j, tabs;
 150                                 struct __bridge_info bi;
 151                                 unsigned char *x;
 152
 153                                 if (!if_indextoname(bridx[i], brname))
 154                                         bb_perror_msg_and_die("can't get bridge name for index %d", i);
 155                                 strncpy_IFNAMSIZ(ifr.ifr_name, brname);
 156
 157                                 arm_ioctl(args, BRCTL_GET_BRIDGE_INFO,
 158                                                         (unsigned long) &bi, 0);
 159                                 xioctl(fd, SIOCDEVPRIVATE, &ifr);
 160                                 printf("%s\t\t", brname);
 161
 162                                 /* print bridge id */
 163                                 x = (unsigned char *) &bi.bridge_id;
 164                                 for (j = 0; j < 8; j++) {
 165                                         printf("%.2x", x[j]);
 166                                         if (j == 1)
 167                                                 bb_putchar('.');
 168                                 }
 169                                 printf(bi.stp_enabled ? "\tyes" : "\tno");
 170
 171                                 /* print interface list */
 172                                 arm_ioctl(args, BRCTL_GET_PORT_LIST,
 173                                                         (unsigned long) ifidx, MAX_PORTS);
 174                                 xioctl(fd, SIOCDEVPRIVATE, &ifr);
 175                                 tabs = 0;
 176                                 for (j = 0; j < MAX_PORTS; j++) {
 177                                         if (!ifidx[j])
 178                                                 continue;
 179                                         if (!if_indextoname(ifidx[j], ifname))
 180                                                 bb_perror_msg_and_die("can't get interface name for index %d", j);
 181                                         if (tabs)
 182                                                 printf("\t\t\t\t\t");
 183                                         else
 184                                                 tabs = 1;
 185                                         printf("\t\t%s\n", ifname);
 186                                 }
 187                                 if (!tabs)      /* bridge has no interfaces */
 188                                         bb_putchar('\n');
 189                         }
 190                         goto done;
 191                 }
 192 #endif
 193
 194                 if (!*argv) /* all but 'show' need at least one argument */
 195                         bb_show_usage();
 196
 197                 br = *argv++;
 198
 199                 if (key == ARG_addbr || key == ARG_delbr) { /* addbr or delbr */
 200                         ioctl_or_perror_and_die(fd,
 201                                         key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
 202                                         br, "bridge %s", br);
 203                         goto done;
 204                 }
 205
 206                 if (!*argv) /* all but 'addbr/delbr' need at least two arguments */
 207                         bb_show_usage();
 208
 209                 strncpy_IFNAMSIZ(ifr.ifr_name, br);
 210                 if (key == ARG_addif || key == ARG_delif) { /* addif or delif */
 211                         brif = *argv;
 212                         ifr.ifr_ifindex = if_nametoindex(brif);
 213                         if (!ifr.ifr_ifindex) {
 214                                 bb_perror_msg_and_die("iface %s", brif);
 215                         }
 216                         ioctl_or_perror_and_die(fd,
 217                                         key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
 218                                         &ifr, "bridge %s", br);
 219                         goto done_next_argv;
 220                 }
 221 #if ENABLE_FEATURE_BRCTL_FANCY
 222                 if (key == ARG_stp) { /* stp */
 223                         /* FIXME: parsing yes/y/on/1 versus no/n/off/0 is too involved */
 224                         arm_ioctl(args, BRCTL_SET_BRIDGE_STP_STATE,
 225                                           (unsigned)(**argv - '0'), 0);
 226                         goto fire;
 227                 }
 228                 if ((unsigned)(key - ARG_setageing) < 4) { /* time related ops */
 229                         static const uint8_t ops[] ALIGN1 = {
 230                                 BRCTL_SET_AGEING_TIME,          /* ARG_setageing */
 231                                 BRCTL_SET_BRIDGE_FORWARD_DELAY, /* ARG_setfd     */
 232                                 BRCTL_SET_BRIDGE_HELLO_TIME,    /* ARG_sethello  */
 233                                 BRCTL_SET_BRIDGE_MAX_AGE        /* ARG_setmaxage */
 234                         };
 235                         arm_ioctl(args, ops[key - ARG_setageing], str_to_jiffies(*argv), 0);
 236                         goto fire;
 237                 }
 238                 if (key == ARG_setpathcost
 239                  || key == ARG_setportprio
 240                  || key == ARG_setbridgeprio
 241                 ) {
 242                         static const uint8_t ops[] ALIGN1 = {
 243                                 BRCTL_SET_PATH_COST,      /* ARG_setpathcost   */
 244                                 BRCTL_SET_PORT_PRIORITY,  /* ARG_setportprio   */
 245                                 BRCTL_SET_BRIDGE_PRIORITY /* ARG_setbridgeprio */
 246                         };
 247                         int port = -1;
 248                         unsigned arg1, arg2;
 249
 250                         if (key != ARG_setbridgeprio) {
 251                                 /* get portnum */
 252                                 unsigned i;
 253
 254                                 port = if_nametoindex(*argv++);
 255                                 if (!port)
 256                                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, "port");
 257                                 memset(ifidx, 0, sizeof ifidx);
 258                                 arm_ioctl(args, BRCTL_GET_PORT_LIST, (unsigned long)ifidx,
 259                                                   MAX_PORTS);
 260                                 xioctl(fd, SIOCDEVPRIVATE, &ifr);
 261                                 for (i = 0; i < MAX_PORTS; i++) {
 262                                         if (ifidx[i] == port) {
 263                                                 port = i;
 264                                                 break;
 265                                         }
 266                                 }
 267                         }
 268                         arg1 = port;
 269                         arg2 = xatoi_u(*argv);
 270                         if (key == ARG_setbridgeprio) {
 271                                 arg1 = arg2;
 272                                 arg2 = 0;
 273                         }
 274                         arm_ioctl(args, ops[key - ARG_setpathcost], arg1, arg2);
 275                 }
 276  fire:
 277                 /* Execute the previously set command */
 278                 xioctl(fd, SIOCDEVPRIVATE, &ifr);
 279 #endif
 280  done_next_argv:
 281                 argv++;
 282  done:
 283                 close(fd);
 284         }
 285
 286         return EXIT_SUCCESS;
 287 }