src/lxc/lxc_restart.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2010
   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 <stdlib.h>
  27 #include <unistd.h>
  28 #include <errno.h>
  29 #include <sys/types.h>
  30 #include <fcntl.h>
  31
  32 #include "log.h"
  33 #include "lxc.h"
  34 #include "conf.h"
  35 #include "config.h"
  36 #include "confile.h"
  37 #include "arguments.h"
  38
  39 lxc_log_define(lxc_restart_ui, lxc_restart);
  40
  41 static struct lxc_list defines;
  42
  43 static int my_checker(const struct lxc_arguments* args)
  44 {
  45         if ((!args->statefile) && (args->statefd == -1)) {
  46                 lxc_error(args, "no statefile specified");
  47                 return -1;
  48         }
  49
  50         if ((args->statefile) && (args->statefd != -1)) {
  51                 lxc_error(args, "--statefile AND --statefd abnormally set");
  52                 return -1;
  53         }
  54
  55         return 0;
  56 }
  57
  58 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  59 {
  60         switch (c) {
  61         case 'S': args->statefile = arg; break;
  62         case 'f': args->rcfile = arg; break;
  63         case 'p': args->flags = LXC_FLAG_PAUSE; break;
  64         case 's': return lxc_config_define_add(&defines, arg);
  65         case 'd': {
  66                         int fd;
  67                         fd = lxc_arguments_str_to_int(args, arg);
  68                         if (fd < 0)
  69                                 return -1;
  70
  71                         args->statefd = fd;
  72                         break;
  73                 }
  74         }
  75
  76         return 0;
  77 }
  78
  79 static const struct option my_longopts[] = {
  80         {"statefile", required_argument, 0, 'S'},
  81         {"statefd", required_argument, 0, 'd'},
  82         {"rcfile", required_argument, 0, 'f'},
  83         {"pause", no_argument, 0, 'p'},
  84         {"define", required_argument, 0, 's'},
  85         LXC_COMMON_OPTIONS
  86 };
  87
  88 static struct lxc_arguments my_args = {
  89         .progname = "lxc-restart",
  90         .help     = "\
  91 --name=NAME --statefile FILE\n\
  92 \n\
  93 lxc-restart restarts from FILE the NAME container\n\
  94 \n\
  95 Options :\n\
  96   -n, --name=NAME      NAME for name of the container\n\
  97   -p, --pause          do not unfreeze the container after the restart\n\
  98   -S, --statefile=FILE read the container state from this file, or\n\
  99   -d, --statefd=FD read the container state from this file descriptor\n\
 100   -f, --rcfile=FILE Load configuration file FILE\n\
 101   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
 102         .options  = my_longopts,
 103         .parser   = my_parser,
 104         .checker  = my_checker,
 105
 106         .statefd  = -1,
 107 };
 108
 109 int main(int argc, char *argv[])
 110 {
 111         int sfd = -1;
 112         int ret;
 113         char *rcfile = NULL;
 114         struct lxc_conf *conf;
 115
 116         lxc_list_init(&defines);
 117
 118         if (lxc_arguments_parse(&my_args, argc, argv))
 119                 return -1;
 120
 121         if (lxc_log_init(my_args.log_file, my_args.log_priority,
 122                          my_args.progname, my_args.quiet))
 123                 return -1;
 124
 125         /* rcfile is specified in the cli option */
 126         if (my_args.rcfile)
 127                 rcfile = (char *)my_args.rcfile;
 128         else {
 129                 if (!asprintf(&rcfile, LXCPATH "/%s/config", my_args.name)) {
 130                         SYSERROR("failed to allocate memory");
 131                         return -1;
 132                 }
 133
 134                 /* container configuration does not exist */
 135                 if (access(rcfile, F_OK)) {
 136                         free(rcfile);
 137                         rcfile = NULL;
 138                 }
 139         }
 140
 141         conf = lxc_conf_init();
 142         if (!conf) {
 143                 ERROR("failed to initialize configuration");
 144                 return -1;
 145         }
 146
 147         if (rcfile && lxc_config_read(rcfile, conf)) {
 148                 ERROR("failed to read configuration file");
 149                 return -1;
 150         }
 151
 152         if (lxc_config_define_load(&defines, conf))
 153                 return -1;
 154
 155         if (my_args.statefd != -1)
 156                 sfd = my_args.statefd;
 157
 158 #define OPEN_READ_MODE O_RDONLY | O_CLOEXEC | O_LARGEFILE
 159         if (my_args.statefile) {
 160                 sfd = open(my_args.statefile, OPEN_READ_MODE, 0);
 161                 if (sfd < 0) {
 162                         ERROR("'%s' open failure : %m", my_args.statefile);
 163                         return sfd;
 164                 }
 165         }
 166
 167         ret = lxc_restart(my_args.name, sfd, conf, my_args.flags);
 168
 169         if (my_args.statefile)
 170                 close(sfd);
 171         return ret;
 172 }