src/lxc/lxc_start.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <dlezcano at fr.ibm.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #define _GNU_SOURCE
  24 #include <stdio.h>
  25 #undef _GNU_SOURCE
  26 #include <libgen.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <string.h>
  30 #include <termios.h>
  31 #include <errno.h>
  32 #include <fcntl.h>
  33 #include <signal.h>
  34 #include <sys/param.h>
  35 #include <sys/utsname.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <sys/stat.h>
  39 #include <arpa/inet.h>
  40 #include <netinet/in.h>
  41 #include <net/if.h>
  42
  43 #include "log.h"
  44 #include "caps.h"
  45 #include "lxc.h"
  46 #include "conf.h"
  47 #include "cgroup.h"
  48 #include "utils.h"
  49 #include "config.h"
  50 #include "confile.h"
  51 #include "arguments.h"
  52
  53 lxc_log_define(lxc_start_ui, lxc_start);
  54
  55 static struct lxc_list defines;
  56
  57 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  58 {
  59         switch (c) {
  60         case 'c': args->console = arg; break;
  61         case 'd': args->daemonize = 1; args->close_all_fds = 1; break;
  62         case 'f': args->rcfile = arg; break;
  63         case 'C': args->close_all_fds = 1; break;
  64         case 's': return lxc_config_define_add(&defines, arg);
  65         }
  66         return 0;
  67 }
  68
  69 static const struct option my_longopts[] = {
  70         {"daemon", no_argument, 0, 'd'},
  71         {"rcfile", required_argument, 0, 'f'},
  72         {"define", required_argument, 0, 's'},
  73         {"console", required_argument, 0, 'c'},
  74         {"close-all-fds", no_argument, 0, 'C'},
  75         LXC_COMMON_OPTIONS
  76 };
  77
  78 static struct lxc_arguments my_args = {
  79         .progname = "lxc-start",
  80         .help     = "\
  81 --name=NAME -- COMMAND\n\
  82 \n\
  83 lxc-start start COMMAND in specified container NAME\n\
  84 \n\
  85 Options :\n\
  86   -n, --name=NAME      NAME for name of the container\n\
  87   -d, --daemon         daemonize the container\n\
  88   -f, --rcfile=FILE    Load configuration file FILE\n\
  89   -c, --console=FILE   Set the file output for the container console\n\
  90   -C, --close-all-fds  If any fds are inherited, close them\n\
  91                        If not specified, exit with failure instead\n\
  92                        Note: --daemon implies --close-all-fds\n\
  93   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
  94         .options   = my_longopts,
  95         .parser    = my_parser,
  96         .checker   = NULL,
  97         .daemonize = 0,
  98 };
  99
 100 int main(int argc, char *argv[])
 101 {
 102         int err = -1;
 103         struct lxc_conf *conf;
 104         char *const *args;
 105         char *rcfile = NULL;
 106         char *const default_args[] = {
 107                 "/sbin/init",
 108                 '\0',
 109         };
 110
 111         lxc_list_init(&defines);
 112
 113         if (lxc_caps_init())
 114                 return err;
 115
 116         if (lxc_arguments_parse(&my_args, argc, argv))
 117                 return err;
 118
 119         if (!my_args.argc)
 120                 args = default_args;
 121         else
 122                 args = my_args.argv;
 123
 124         if (lxc_log_init(my_args.log_file, my_args.log_priority,
 125                          my_args.progname, my_args.quiet))
 126                 return err;
 127
 128         if (putenv("container=lxc")) {
 129                 SYSERROR("failed to set environment variable");
 130                 return err;
 131         }
 132
 133         /* rcfile is specified in the cli option */
 134         if (my_args.rcfile)
 135                 rcfile = (char *)my_args.rcfile;
 136         else {
 137                 int rc;
 138
 139                 rc = asprintf(&rcfile, LXCPATH "/%s/config", my_args.name);
 140                 if (rc == -1) {
 141                         SYSERROR("failed to allocate memory");
 142                         return err;
 143                 }
 144
 145                 /* container configuration does not exist */
 146                 if (access(rcfile, F_OK)) {
 147                         free(rcfile);
 148                         rcfile = NULL;
 149                 }
 150         }
 151
 152         conf = lxc_conf_init();
 153         if (!conf) {
 154                 ERROR("failed to initialize configuration");
 155                 return err;
 156         }
 157
 158         if (rcfile && lxc_config_read(rcfile, conf)) {
 159                 ERROR("failed to read configuration file");
 160                 return err;
 161         }
 162
 163         if (lxc_config_define_load(&defines, conf))
 164                 return err;
 165
 166         if (!rcfile && !strcmp("/sbin/init", args[0])) {
 167                 ERROR("no configuration file for '/sbin/init' (may crash the host)");
 168                 return err;
 169         }
 170
 171         if (my_args.console) {
 172
 173                 char *console, fd;
 174
 175                 if (access(my_args.console, W_OK)) {
 176
 177                         fd = creat(my_args.console, 0600);
 178                         if (fd < 0) {
 179                                 SYSERROR("failed to touch file '%s'",
 180                                          my_args.console);
 181                                 return err;
 182                         }
 183                         close(fd);
 184                 }
 185
 186                 console = realpath(my_args.console, NULL);
 187                 if (!console) {
 188                         SYSERROR("failed to get the real path of '%s'",
 189                                  my_args.console);
 190                         return err;
 191                 }
 192
 193                 conf->console.path = strdup(console);
 194                 if (!conf->console.path) {
 195                         ERROR("failed to dup string '%s'", console);
 196                         return err;
 197                 }
 198
 199                 free(console);
 200         }
 201
 202         if (my_args.daemonize) {
 203                 /* do an early check for needed privs, since otherwise the
 204                  * user won't see the error */
 205
 206                 if (!lxc_caps_check()) {
 207                         ERROR("Not running with sufficient privilege");
 208                         return err;
 209                 }
 210
 211                 if (daemon(0, 0)) {
 212                         SYSERROR("failed to daemonize '%s'", my_args.name);
 213                         return err;
 214                 }
 215         }
 216
 217         if (my_args.close_all_fds)
 218                 conf->close_all_fds = 1;
 219
 220         err = lxc_start(my_args.name, args, conf);
 221
 222         /*
 223          * exec ourself, that requires to have all opened fd
 224          * with the close-on-exec flag set
 225          */
 226         if (conf->reboot) {
 227                 INFO("rebooting container");
 228                 execvp(argv[0], argv);
 229                 SYSERROR("failed to exec");
 230                 err = -1;
 231         }
 232
 233         return err;
 234 }
 235