package/ead/src/libbridge_init.c

   1 /*
   2  * Copyright (C) 2000 Lennert Buytenhek
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <errno.h>
  23 #include <string.h>
  24 #include <dirent.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27
  28 #include "libbridge.h"
  29 #include "libbridge_private.h"
  30
  31 int br_socket_fd = -1;
  32
  33 static int br_init(void)
  34 {
  35         if ((br_socket_fd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0)
  36                 return errno;
  37         return 0;
  38 }
  39
  40 static void br_shutdown(void)
  41 {
  42         close(br_socket_fd);
  43         br_socket_fd = -1;
  44 }
  45
  46 /* If /sys/class/net/XXX/bridge exists then it must be a bridge */
  47 static int isbridge(const struct dirent *entry)
  48 {
  49         char path[SYSFS_PATH_MAX];
  50         struct stat st;
  51
  52         snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/bridge", entry->d_name);
  53         return stat(path, &st) == 0 && S_ISDIR(st.st_mode);
  54 }
  55
  56 /*
  57  * New interface uses sysfs to find bridges
  58  */
  59 static int new_foreach_bridge(int (*iterator)(const char *name, void *),
  60                               void *arg)
  61 {
  62         struct dirent **namelist;
  63         int i, count = 0;
  64
  65         count = scandir(SYSFS_CLASS_NET, &namelist, isbridge, alphasort);
  66         if (count < 0)
  67                 return -1;
  68
  69         for (i = 0; i < count; i++) {
  70                 if (iterator(namelist[i]->d_name, arg))
  71                         break;
  72         }
  73
  74         for (i = 0; i < count; i++)
  75                 free(namelist[i]);
  76         free(namelist);
  77
  78         return count;
  79 }
  80
  81 /*
  82  * Old interface uses ioctl
  83  */
  84 static int old_foreach_bridge(int (*iterator)(const char *, void *),
  85                               void *iarg)
  86 {
  87         int i, ret=0, num;
  88         char ifname[IFNAMSIZ];
  89         int ifindices[MAX_BRIDGES];
  90         unsigned long args[3] = { BRCTL_GET_BRIDGES,
  91                                  (unsigned long)ifindices, MAX_BRIDGES };
  92
  93         num = ioctl(br_socket_fd, SIOCGIFBR, args);
  94         if (num < 0) {
  95                 dprintf("Get bridge indices failed: %s\n",
  96                         strerror(errno));
  97                 return -errno;
  98         }
  99
 100         for (i = 0; i < num; i++) {
 101                 if (!if_indextoname(ifindices[i], ifname)) {
 102                         dprintf("get find name for ifindex %d\n",
 103                                 ifindices[i]);
 104                         return -errno;
 105                 }
 106
 107                 ++ret;
 108                 if(iterator(ifname, iarg))
 109                         break;
 110         }
 111
 112         return ret;
 113
 114 }
 115
 116 /*
 117  * Go over all bridges and call iterator function.
 118  * if iterator returns non-zero then stop.
 119  */
 120 static int br_foreach_bridge(int (*iterator)(const char *, void *),
 121                      void *arg)
 122 {
 123         int ret;
 124
 125         ret = new_foreach_bridge(iterator, arg);
 126         if (ret <= 0)
 127                 ret = old_foreach_bridge(iterator, arg);
 128
 129         return ret;
 130 }
 131
 132 /*
 133  * Only used if sysfs is not available.
 134  */
 135 static int old_foreach_port(const char *brname,
 136                             int (*iterator)(const char *br, const char *port,
 137                                             void *arg),
 138                             void *arg)
 139 {
 140         int i, err, count;
 141         struct ifreq ifr;
 142         char ifname[IFNAMSIZ];
 143         int ifindices[MAX_PORTS];
 144         unsigned long args[4] = { BRCTL_GET_PORT_LIST,
 145                                   (unsigned long)ifindices, MAX_PORTS, 0 };
 146
 147         memset(ifindices, 0, sizeof(ifindices));
 148         strncpy(ifr.ifr_name, brname, IFNAMSIZ);
 149         ifr.ifr_data = (char *) &args;
 150
 151         err = ioctl(br_socket_fd, SIOCDEVPRIVATE, &ifr);
 152         if (err < 0) {
 153                 dprintf("list ports for bridge:'%s' failed: %s\n",
 154                         brname, strerror(errno));
 155                 return -errno;
 156         }
 157
 158         count = 0;
 159         for (i = 0; i < MAX_PORTS; i++) {
 160                 if (!ifindices[i])
 161                         continue;
 162
 163                 if (!if_indextoname(ifindices[i], ifname)) {
 164                         dprintf("can't find name for ifindex:%d\n",
 165                                 ifindices[i]);
 166                         continue;
 167                 }
 168
 169                 ++count;
 170                 if (iterator(brname, ifname, arg))
 171                         break;
 172         }
 173
 174         return count;
 175 }
 176
 177 /*
 178  * Iterate over all ports in bridge (using sysfs).
 179  */
 180 static int br_foreach_port(const char *brname,
 181                     int (*iterator)(const char *br, const char *port, void *arg),
 182                     void *arg)
 183 {
 184         int i, count;
 185         struct dirent **namelist;
 186         char path[SYSFS_PATH_MAX];
 187
 188         snprintf(path, SYSFS_PATH_MAX, SYSFS_CLASS_NET "%s/brif", brname);
 189         count = scandir(path, &namelist, 0, alphasort);
 190         if (count < 0)
 191                 return old_foreach_port(brname, iterator, arg);
 192
 193         for (i = 0; i < count; i++) {
 194                 if (namelist[i]->d_name[0] == '.'
 195                     && (namelist[i]->d_name[1] == '\0'
 196                         || (namelist[i]->d_name[1] == '.'
 197                             && namelist[i]->d_name[2] == '\0')))
 198                         continue;
 199
 200                 if (iterator(brname, namelist[i]->d_name, arg))
 201                         break;
 202         }
 203         for (i = 0; i < count; i++)
 204                 free(namelist[i]);
 205         free(namelist);
 206
 207         return count;
 208 }