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 ensure_path(char **confpath, const char *path)
  58 {
  59         int err = -1, fd;
  60         char *fullpath = NULL;
  61
  62         if (path) {
  63                 if (access(path, W_OK)) {
  64                         fd = creat(path, 0600);
  65                         if (fd < 0) {
  66                                 SYSERROR("failed to create '%s'", path);
  67                                 goto err;
  68                         }
  69                         close(fd);
  70                 }
  71
  72                 fullpath = realpath(path, NULL);
  73                 if (!fullpath) {
  74                         SYSERROR("failed to get the real path of '%s'", path);
  75                         goto err;
  76                 }
  77
  78                 *confpath = strdup(fullpath);
  79                 if (!*confpath) {
  80                         ERROR("failed to dup string '%s'", fullpath);
  81                         goto err;
  82                 }
  83         }
  84         err = 0;
  85
  86 err:
  87         if (fullpath)
  88                 free(fullpath);
  89         return err;
  90 }
  91
  92 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  93 {
  94         switch (c) {
  95         case 'c': args->console = arg; break;
  96         case 'L': args->console_log = arg; break;
  97         case 'd': args->daemonize = 1; args->close_all_fds = 1; break;
  98         case 'f': args->rcfile = arg; break;
  99         case 'C': args->close_all_fds = 1; break;
 100         case 's': return lxc_config_define_add(&defines, arg);
 101         case 'p': args->pidfile = arg; break;
 102         }
 103         return 0;
 104 }
 105
 106 static const struct option my_longopts[] = {
 107         {"daemon", no_argument, 0, 'd'},
 108         {"rcfile", required_argument, 0, 'f'},
 109         {"define", required_argument, 0, 's'},
 110         {"console", required_argument, 0, 'c'},
 111         {"console-log", required_argument, 0, 'L'},
 112         {"close-all-fds", no_argument, 0, 'C'},
 113         {"pidfile", required_argument, 0, 'p'},
 114         LXC_COMMON_OPTIONS
 115 };
 116
 117 static struct lxc_arguments my_args = {
 118         .progname = "lxc-start",
 119         .help     = "\
 120 --name=NAME -- COMMAND\n\
 121 \n\
 122 lxc-start start COMMAND in specified container NAME\n\
 123 \n\
 124 Options :\n\
 125   -n, --name=NAME        NAME for name of the container\n\
 126   -d, --daemon           daemonize the container\n\
 127   -p, --pidfile=FILE     Create a file with the process id\n\
 128   -f, --rcfile=FILE      Load configuration file FILE\n\
 129   -c, --console=FILE     Use specified FILE for the container console\n\
 130   -L, --console-log=FILE Log container console output to FILE\n\
 131   -C, --close-all-fds    If any fds are inherited, close them\n\
 132                          If not specified, exit with failure instead\n\
 133                          Note: --daemon implies --close-all-fds\n\
 134   -s, --define KEY=VAL   Assign VAL to configuration variable KEY\n",
 135         .options   = my_longopts,
 136         .parser    = my_parser,
 137         .checker   = NULL,
 138         .daemonize = 0,
 139         .pidfile = NULL,
 140 };
 141
 142 int main(int argc, char *argv[])
 143 {
 144         int err = -1;
 145         struct lxc_conf *conf;
 146         char *const *args;
 147         char *rcfile = NULL;
 148         char *const default_args[] = {
 149                 "/sbin/init",
 150                 '\0',
 151         };
 152         FILE *pid_fp = NULL;
 153
 154         lxc_list_init(&defines);
 155
 156         if (lxc_caps_init())
 157                 return err;
 158
 159         if (lxc_arguments_parse(&my_args, argc, argv))
 160                 return err;
 161
 162         if (!my_args.argc)
 163                 args = default_args;
 164         else
 165                 args = my_args.argv;
 166
 167         if (lxc_log_init(my_args.log_file, my_args.log_priority,
 168                          my_args.progname, my_args.quiet))
 169                 return err;
 170
 171         /* rcfile is specified in the cli option */
 172         if (my_args.rcfile)
 173                 rcfile = (char *)my_args.rcfile;
 174         else {
 175                 int rc;
 176
 177                 rc = asprintf(&rcfile, LXCPATH "/%s/config", my_args.name);
 178                 if (rc == -1) {
 179                         SYSERROR("failed to allocate memory");
 180                         return err;
 181                 }
 182
 183                 /* container configuration does not exist */
 184                 if (access(rcfile, F_OK)) {
 185                         free(rcfile);
 186                         rcfile = NULL;
 187                 }
 188         }
 189
 190         conf = lxc_conf_init();
 191         if (!conf) {
 192                 ERROR("failed to initialize configuration");
 193                 return err;
 194         }
 195
 196         if (rcfile && lxc_config_read(rcfile, conf)) {
 197                 ERROR("failed to read configuration file");
 198                 return err;
 199         }
 200
 201         if (lxc_config_define_load(&defines, conf))
 202                 return err;
 203
 204         if (!rcfile && !strcmp("/sbin/init", args[0])) {
 205                 ERROR("no configuration file for '/sbin/init' (may crash the host)");
 206                 return err;
 207         }
 208
 209         if (ensure_path(&conf->console.path, my_args.console) < 0) {
 210                 ERROR("failed to ensure console path '%s'", my_args.console);
 211                 return err;
 212         }
 213
 214         if (ensure_path(&conf->console.log_path, my_args.console_log) < 0) {
 215                 ERROR("failed to ensure console log '%s'", my_args.console_log);
 216                 return err;
 217         }
 218
 219         if (my_args.pidfile != NULL) {
 220                 pid_fp = fopen(my_args.pidfile, "w");
 221                 if (pid_fp == NULL) {
 222                         SYSERROR("failed to create pidfile '%s' for '%s'",
 223                                  my_args.pidfile, my_args.name);
 224                         return err;
 225                 }
 226         }
 227
 228         if (my_args.daemonize) {
 229                 /* do an early check for needed privs, since otherwise the
 230                  * user won't see the error */
 231
 232                 if (!lxc_caps_check()) {
 233                         ERROR("Not running with sufficient privilege");
 234                         return err;
 235                 }
 236
 237                 if (daemon(0, 0)) {
 238                         SYSERROR("failed to daemonize '%s'", my_args.name);
 239                         return err;
 240                 }
 241         }
 242
 243         if (pid_fp != NULL) {
 244                 if (fprintf(pid_fp, "%d\n", getpid()) < 0) {
 245                         SYSERROR("failed to write '%s'", my_args.pidfile);
 246                         return err;
 247                 }
 248                 fclose(pid_fp);
 249         }
 250
 251         if (my_args.close_all_fds)
 252                 conf->close_all_fds = 1;
 253
 254         err = lxc_start(my_args.name, args, conf);
 255
 256         /*
 257          * exec ourself, that requires to have all opened fd
 258          * with the close-on-exec flag set
 259          */
 260         if (conf->reboot) {
 261                 INFO("rebooting container");
 262                 execvp(argv[0], argv);
 263                 SYSERROR("failed to exec");
 264                 err = -1;
 265         }
 266
 267         if (my_args.pidfile)
 268                 unlink(my_args.pidfile);
 269
 270         return err;
 271 }
 272