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 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 /* Maximum number of ports supported per bridge interface.  */
  20 #ifndef MAX_PORTS
  21 #define MAX_PORTS 32
  22 #endif
  23
  24 /* Use internal number parsing and not the "exact" conversion.  */
  25 /* #define BRCTL_USE_INTERNAL 0 */ /* use exact conversion */
  26 #define BRCTL_USE_INTERNAL 1
  27
  28 #ifdef ENABLE_FEATURE_BRCTL_SHOW
  29 #error Remove these
  30 #endif
  31 #define ENABLE_FEATURE_BRCTL_SHOW 0
  32 #define USE_FEATURE_BRCTL_SHOW(...)
  33
  34 #if ENABLE_FEATURE_BRCTL_FANCY
  35 #include <linux/if_bridge.h>
  36 /* FIXME: These 4 funcs are not really clean and could be improved */
  37 static inline ALWAYS_INLINE void strtotimeval(struct timeval *tv,
  38                                                                                           const char *time_str)
  39 {
  40         double secs;
  41 #if BRCTL_USE_INTERNAL
  42         if (!(secs = /*bb_*/strtod(time_str, NULL)))
  43 #else
  44         if (sscanf(time_str, "%lf", &secs) != 1)
  45 #endif
  46                 bb_error_msg_and_die (bb_msg_invalid_arg, time_str, "timespec");
  47         tv->tv_sec = secs;
  48         tv->tv_usec = 1000000 * (secs - tv->tv_sec);
  49 }
  50
  51 static inline ALWAYS_INLINE unsigned long __tv_to_jiffies(const struct timeval *tv)
  52 {
  53         unsigned long long jif;
  54
  55         jif = 1000000ULL * tv->tv_sec + tv->tv_usec;
  56
  57         return jif/10000;
  58 }
  59 # if 00
  60 static void __jiffies_to_tv(struct timeval *tv, unsigned long jiffies)
  61 {
  62         unsigned long long tvusec;
  63
  64         tvusec = 10000ULL*jiffies;
  65         tv->tv_sec = tvusec/1000000;
  66         tv->tv_usec = tvusec - 1000000 * tv->tv_sec;
  67 }
  68 # endif
  69 static unsigned long str_to_jiffies(const char *time_str)
  70 {
  71         struct timeval tv;
  72         strtotimeval(&tv, time_str);
  73         return __tv_to_jiffies(&tv);
  74 }
  75
  76 static void arm_ioctl(unsigned long *args,
  77                                  unsigned long arg0, unsigned long arg1, unsigned long arg2)
  78 {
  79         args[0] = arg0;
  80         args[1] = arg1;
  81         args[2] = arg2;
  82         args[3] = 0;
  83 }
  84 #endif
  85
  86
  87 int brctl_main(int argc ATTRIBUTE_UNUSED, char **argv) MAIN_EXTERNALLY_VISIBLE;
  88 int brctl_main(int argc ATTRIBUTE_UNUSED, char **argv)
  89 {
  90         int fd;
  91         static const char keywords[] ALIGN1 =
  92                 "addbr\0" "delbr\0" "addif\0" "delif\0"
  93         USE_FEATURE_BRCTL_FANCY(
  94                 "stp\0"
  95                 "setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
  96                 "setpathcost\0" "setportprio\0" "setbridgeprio\0"
  97         )
  98                 USE_FEATURE_BRCTL_SHOW("showmacs\0" "show\0");
  99         enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
 100                 USE_FEATURE_BRCTL_FANCY(,
 101                    ARG_stp,
 102                    ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
 103                    ARG_setpathcost, ARG_setportprio, ARG_setbridgeprio
 104                 )
 105                   USE_FEATURE_BRCTL_SHOW(, ARG_showmacs, ARG_show) };
 106         smallint key;
 107         struct ifreq ifr;
 108         static char info[] = "bridge %s\0 iface %s";
 109         char *br, *brif;
 110 #if ENABLE_FEATURE_BRCTL_FANCY
 111         unsigned long args[4] = {0, 0, 0, 0};
 112         int port;
 113         int tmp;
 114 #endif
 115
 116         argv++;
 117         while (*argv) {
 118                 key = index_in_strings(keywords, *argv);
 119                 if (key == -1) /* no match found in keywords array, bail out. */
 120                         bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
 121                 argv++;
 122 #if ENABLE_FEATURE_BRCTL_SHOW
 123                 if (key == ARG_show) { /* show */
 124                         goto out; /* FIXME: implement me! :) */
 125                 }
 126 #endif
 127                 fd = xsocket(AF_INET, SOCK_STREAM, 0);
 128                 br = *(argv++);
 129
 130                 if (key == ARG_addbr || key == ARG_delbr) { /* addbr or delbr */
 131                         ioctl_or_perror_and_die(fd,
 132                                                                 key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
 133                                                                 br, info, br);
 134                         goto done;
 135                 }
 136                 if (!*argv) /* all but 'show' need at least one argument */
 137                         bb_show_usage();
 138                 safe_strncpy(ifr.ifr_name, br, IFNAMSIZ);
 139                 if (key == ARG_addif || key == ARG_delif) { /* addif or delif */
 140                         brif = *(argv++);
 141                         if (!(ifr.ifr_ifindex = if_nametoindex(brif))) {
 142                                 bb_perror_msg_and_die(info+11, brif);
 143                         }
 144                         ioctl_or_perror_and_die(fd,
 145                                                                   key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
 146                                                                   &ifr, info, br);
 147                         goto done;
 148                 }
 149 #if ENABLE_FEATURE_BRCTL_FANCY
 150                 ifr.ifr_data = (char *) &args;
 151                 if (key == ARG_stp) { /* stp */
 152                         /* FIXME: parsing yes/y/on/1 versus no/n/off/0 is too involved */
 153                         arm_ioctl(args, BRCTL_SET_BRIDGE_STP_STATE,
 154                                           (unsigned)(**argv - '0'), 0);
 155                         goto fire;
 156                 }
 157                 if ((unsigned)(key - ARG_stp) < 5) { /* time related ops */
 158                         unsigned long op = (key == ARG_setageing) ? BRCTL_SET_AGEING_TIME :
 159                                                         (key == ARG_setfd) ? BRCTL_SET_BRIDGE_FORWARD_DELAY:
 160                                                         (key == ARG_sethello) ? BRCTL_SET_BRIDGE_HELLO_TIME:
 161                                                         (key == ARG_setmaxage) ? BRCTL_SET_BRIDGE_MAX_AGE :
 162                                                         -1/* will never be used */;
 163                         arm_ioctl(args, op, str_to_jiffies (*argv), 0);
 164                         goto fire;
 165                 }
 166                 port = -1;
 167                 if (key == ARG_setpathcost || key == ARG_setportprio) {/* get portnum */
 168                         int ifidx[MAX_PORTS];
 169                         unsigned i;
 170
 171                         if (!(port = if_nametoindex(*argv)))
 172                                 bb_error_msg_and_die(bb_msg_invalid_arg, *argv, "port");
 173                         argv++;
 174                         memset(ifidx, 0, sizeof ifidx);
 175                         arm_ioctl(args, BRCTL_GET_PORT_LIST, (unsigned long)ifidx,
 176                                           MAX_PORTS);
 177                         xioctl(fd, SIOCDEVPRIVATE, &ifr);
 178                         for (i = 0; i < MAX_PORTS; i++)
 179                                 if (ifidx[i] == port) {
 180                                         port = i;
 181                                         break;
 182                                 }
 183                 }
 184                 if (key == ARG_setpathcost
 185                         || key == ARG_setportprio || key == ARG_setbridgeprio) {
 186                         unsigned long op = (key == ARG_setpathcost) ? BRCTL_SET_PATH_COST :
 187                                                 (key == ARG_setportprio) ? BRCTL_SET_PORT_PRIORITY :
 188                                                 (key == ARG_setbridgeprio) ? BRCTL_SET_BRIDGE_PRIORITY :
 189                                                 -1/* will never be used */;
 190                         unsigned long arg1 = port;
 191                         unsigned long arg2;
 192 # if BRCTL_USE_INTERNAL
 193                         tmp = xatoi(*argv);
 194 # else
 195                         if (sscanf(*argv, "%i", &tmp) != 1)
 196                                 bb_error_msg_and_die(bb_msg_invalid_arg, *argv,
 197                                                                          key == ARG_setpathcost ? "cost" : "prio");
 198 # endif
 199                         if (key == ARG_setbridgeprio) {
 200                                 arg1 = tmp;
 201                                 arg2 = 0;
 202                         } else
 203                                 arg2 = tmp;
 204                         arm_ioctl(args, op, arg1, arg2);
 205                 }
 206  fire:
 207                 /* Execute the previously set command.  */
 208                 xioctl(fd, SIOCDEVPRIVATE, &ifr);
 209                 argv++;
 210 #endif
 211  done:
 212                 if (ENABLE_FEATURE_CLEAN_UP)
 213                         close(fd);
 214         }
 215 USE_FEATURE_BRCTL_SHOW(out:)
 216         return EXIT_SUCCESS;
 217 }