src/lxc/tools/lxc_device.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * Authors:
   5  * Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include <stdio.h>
  22 #include <unistd.h>
  23 #include <sys/types.h>
  24 #include <libgen.h>
  25 #include <string.h>
  26 #include <limits.h>
  27
  28 #include <lxc/lxccontainer.h>
  29
  30 #include "utils.h"
  31 #include "lxc.h"
  32 #include "log.h"
  33
  34 #include "arguments.h"
  35
  36 #if HAVE_IFADDRS_H
  37 #include <ifaddrs.h>
  38 #else
  39 #include <../include/ifaddrs.h>
  40 #endif
  41
  42 lxc_log_define(lxc_device, lxc);
  43
  44 static const struct option my_longopts[] = {
  45         LXC_COMMON_OPTIONS
  46 };
  47
  48 static struct lxc_arguments my_args = {
  49         .progname = "lxc-device",
  50         .help     = "\
  51 --name=NAME -- add|del DEV\n\
  52 \n\
  53 lxc-device attach or detach DEV to or from container.\n\
  54 \n\
  55 Options :\n\
  56   -n, --name=NAME      NAME of the container\n\
  57   --rcfile=FILE        Load configuration file FILE\n",
  58         .options  = my_longopts,
  59         .parser   = NULL,
  60         .checker  = NULL,
  61 };
  62
  63 static bool is_interface(const char* dev_name, pid_t pid)
  64 {
  65         pid_t p = fork();
  66
  67         if (p < 0) {
  68                 SYSERROR("failed to fork task.");
  69                 exit(EXIT_FAILURE);
  70         }
  71
  72         if (p == 0) {
  73                 struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
  74
  75                 if (!switch_to_ns(pid, "net")) {
  76                         ERROR("failed to enter netns of container.");
  77                         exit(-1);
  78                 }
  79
  80                 /* Grab the list of interfaces */
  81                 if (getifaddrs(&interfaceArray)) {
  82                         ERROR("failed to get interfaces list");
  83                         exit(-1);
  84                 }
  85
  86                 /* Iterate through the interfaces */
  87                 for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
  88                         if (strcmp(tempIfAddr->ifa_name, dev_name) == 0) {
  89                                 exit(EXIT_SUCCESS);
  90                         }
  91                 }
  92                 exit(EXIT_FAILURE);
  93         }
  94
  95         if (wait_for_pid(p) == 0) {
  96                 return true;
  97         }
  98         return false;
  99 }
 100
 101 int main(int argc, char *argv[])
 102 {
 103         struct lxc_container *c;
 104         char *cmd, *dev_name, *dst_name;
 105         int ret = 1;
 106
 107         if (geteuid() != 0) {
 108                 ERROR("%s must be run as root", argv[0]);
 109                 exit(EXIT_FAILURE);
 110         }
 111
 112         if (lxc_arguments_parse(&my_args, argc, argv))
 113                 goto err;
 114
 115         if (!my_args.log_file)
 116                 my_args.log_file = "none";
 117
 118         if (lxc_log_init(my_args.name, my_args.log_file, my_args.log_priority,
 119                          my_args.progname, my_args.quiet, my_args.lxcpath[0]))
 120                 goto err;
 121         lxc_log_options_no_override();
 122
 123         c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
 124         if (!c) {
 125                 ERROR("%s doesn't exist", my_args.name);
 126                 goto err;
 127         }
 128
 129         if (my_args.rcfile) {
 130                 c->clear_config(c);
 131                 if (!c->load_config(c, my_args.rcfile)) {
 132                         ERROR("Failed to load rcfile");
 133                         goto err1;
 134                 }
 135                 c->configfile = strdup(my_args.rcfile);
 136                 if (!c->configfile) {
 137                         ERROR("Out of memory setting new config filename");
 138                         goto err1;
 139                 }
 140         }
 141
 142         if (!c->is_running(c)) {
 143                 ERROR("Container %s is not running.", c->name);
 144                 goto err1;
 145         }
 146
 147         if (my_args.argc < 2) {
 148                 ERROR("Error: no command given (Please see --help output)");
 149                 goto err1;
 150         }
 151
 152         cmd = my_args.argv[0];
 153         dev_name = my_args.argv[1];
 154         if (my_args.argc < 3)
 155                 dst_name = dev_name;
 156         else
 157                 dst_name = my_args.argv[2];
 158
 159         if (strcmp(cmd, "add") == 0) {
 160                 if (is_interface(dev_name, 1)) {
 161                         ret = c->attach_interface(c, dev_name, dst_name);
 162                 } else {
 163                         ret = c->add_device_node(c, dev_name, dst_name);
 164                 }
 165                 if (ret != true) {
 166                         ERROR("Failed to add %s to %s.", dev_name, c->name);
 167                         ret = 1;
 168                         goto err1;
 169                 }
 170                 INFO("Add %s to %s.", dev_name, c->name);
 171         } else if (strcmp(cmd, "del") == 0) {
 172                 if (is_interface(dev_name, c->init_pid(c))) {
 173                         ret = c->detach_interface(c, dev_name, dst_name);
 174                 } else {
 175                         ret = c->remove_device_node(c, dev_name, dst_name);
 176                 }
 177                 if (ret != true) {
 178                         ERROR("Failed to del %s from %s.", dev_name, c->name);
 179                         ret = 1;
 180                         goto err1;
 181                 }
 182                 INFO("Delete %s from %s.", dev_name, c->name);
 183         } else {
 184                 ERROR("Error: Please use add or del (Please see --help output)");
 185                 goto err1;
 186         }
 187         exit(EXIT_SUCCESS);
 188 err1:
 189         lxc_container_put(c);
 190 err:
 191         exit(EXIT_FAILURE);
 192 }