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 static const struct option my_longopts[] = {
  43         LXC_COMMON_OPTIONS
  44 };
  45
  46 static struct lxc_arguments my_args = {
  47         .progname = "lxc-device",
  48         .help     = "\
  49 --name=NAME -- add|del DEV\n\
  50 \n\
  51 lxc-device attach or detach DEV to or from container.\n\
  52 \n\
  53 Options :\n\
  54   -n, --name=NAME      NAME of the container\n\
  55   --rcfile=FILE        Load configuration file FILE\n",
  56         .options  = my_longopts,
  57         .parser   = NULL,
  58         .checker  = NULL,
  59 };
  60
  61 static bool is_interface(const char* dev_name, pid_t pid)
  62 {
  63         pid_t p = fork();
  64
  65         if (p < 0) {
  66                 fprintf(stderr, "failed to fork task.\n");
  67                 exit(EXIT_FAILURE);
  68         }
  69
  70         if (p == 0) {
  71                 struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
  72
  73                 if (!switch_to_ns(pid, "net")) {
  74                         fprintf(stderr, "failed to enter netns of container.\n");
  75                         exit(-1);
  76                 }
  77
  78                 /* Grab the list of interfaces */
  79                 if (getifaddrs(&interfaceArray)) {
  80                         fprintf(stderr, "failed to get interfaces list\n");
  81                         exit(-1);
  82                 }
  83
  84                 /* Iterate through the interfaces */
  85                 for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
  86                         if (strcmp(tempIfAddr->ifa_name, dev_name) == 0) {
  87                                 exit(EXIT_SUCCESS);
  88                         }
  89                 }
  90                 exit(EXIT_FAILURE);
  91         }
  92
  93         if (wait_for_pid(p) == 0) {
  94                 return true;
  95         }
  96         return false;
  97 }
  98
  99 int main(int argc, char *argv[])
 100 {
 101         struct lxc_container *c;
 102         struct lxc_log log;
 103         char *cmd, *dev_name, *dst_name;
 104         bool ret = false;
 105
 106         if (geteuid() != 0) {
 107                 fprintf(stderr, "%s must be run as root\n", argv[0]);
 108                 exit(EXIT_FAILURE);
 109         }
 110
 111         if (lxc_arguments_parse(&my_args, argc, argv))
 112                 goto err;
 113
 114         if (!my_args.log_file)
 115                 my_args.log_file = "none";
 116
 117         log.name = my_args.name;
 118         log.file = my_args.log_file;
 119         log.level = my_args.log_priority;
 120         log.prefix = my_args.progname;
 121         log.quiet = my_args.quiet;
 122         log.lxcpath = my_args.lxcpath[0];
 123
 124         if (lxc_log_init(&log))
 125                 goto err;
 126         lxc_log_options_no_override();
 127
 128         /* REMOVE IN LXC 3.0 */
 129         setenv("LXC_UPDATE_CONFIG_FORMAT", "1", 0);
 130
 131         c = lxc_container_new(my_args.name, my_args.lxcpath[0]);
 132         if (!c) {
 133                 fprintf(stderr, "%s doesn't exist\n", my_args.name);
 134                 goto err;
 135         }
 136
 137         if (my_args.rcfile) {
 138                 c->clear_config(c);
 139                 if (!c->load_config(c, my_args.rcfile)) {
 140                         fprintf(stderr, "Failed to load rcfile\n");
 141                         goto err1;
 142                 }
 143                 c->configfile = strdup(my_args.rcfile);
 144                 if (!c->configfile) {
 145                         fprintf(stderr, "Out of memory setting new config filename\n");
 146                         goto err1;
 147                 }
 148         }
 149
 150         if (!c->is_running(c)) {
 151                 fprintf(stderr, "Container %s is not running.\n", c->name);
 152                 goto err1;
 153         }
 154
 155         if (my_args.argc < 2) {
 156                 fprintf(stderr, "Error: no command given (Please see --help output)\n");
 157                 goto err1;
 158         }
 159
 160         cmd = my_args.argv[0];
 161         dev_name = my_args.argv[1];
 162         if (my_args.argc < 3)
 163                 dst_name = dev_name;
 164         else
 165                 dst_name = my_args.argv[2];
 166
 167         if (strcmp(cmd, "add") == 0) {
 168                 if (is_interface(dev_name, 1)) {
 169                         ret = c->attach_interface(c, dev_name, dst_name);
 170                 } else {
 171                         ret = c->add_device_node(c, dev_name, dst_name);
 172                 }
 173                 if (ret != true) {
 174                         fprintf(stderr, "Failed to add %s to %s.\n", dev_name, c->name);
 175                         goto err1;
 176                 }
 177         } else if (strcmp(cmd, "del") == 0) {
 178                 if (is_interface(dev_name, c->init_pid(c))) {
 179                         ret = c->detach_interface(c, dev_name, dst_name);
 180                 } else {
 181                         ret = c->remove_device_node(c, dev_name, dst_name);
 182                 }
 183                 if (ret != true) {
 184                         fprintf(stderr, "Failed to del %s from %s.\n", dev_name, c->name);
 185                         goto err1;
 186                 }
 187         } else {
 188                 fprintf(stderr, "Error: Please use add or del (Please see --help output)\n");
 189                 goto err1;
 190         }
 191         exit(EXIT_SUCCESS);
 192 err1:
 193         lxc_container_put(c);
 194 err:
 195         exit(EXIT_FAILURE);
 196 }