src/lxc/lxc_wait.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 #include <stdio.h>
  24 #include <string.h>
  25 #include <libgen.h>
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <signal.h>
  29 #include <sys/types.h>
  30
  31 #include <lxc/lxc.h>
  32 #include <lxc/log.h>
  33 #include <lxc/monitor.h>
  34 #include "arguments.h"
  35
  36 lxc_log_define(lxc_wait_ui, lxc_monitor);
  37
  38 static int my_checker(const struct lxc_arguments* args)
  39 {
  40         if (!args->states) {
  41                 lxc_error(args, "missing state option to wait for.");
  42                 return -1;
  43         }
  44         return 0;
  45 }
  46
  47 static int my_parser(struct lxc_arguments* args, int c, char* arg)
  48 {
  49         switch (c) {
  50         case 's': args->states = optarg; break;
  51         case 't': args->timeout = atol(optarg); break;
  52         }
  53         return 0;
  54 }
  55
  56 static const struct option my_longopts[] = {
  57         {"state", required_argument, 0, 's'},
  58         {"timeout", required_argument, 0, 't'},
  59         LXC_COMMON_OPTIONS
  60 };
  61
  62 static struct lxc_arguments my_args = {
  63         .progname = "lxc-wait",
  64         .help     = "\
  65 --name=NAME --state=STATE\n\
  66 \n\
  67 lxc-wait waits for NAME container state to reach STATE\n\
  68 \n\
  69 Options :\n\
  70   -n, --name=NAME   NAME for name of the container\n\
  71   -s, --state=STATE ORed states to wait for\n\
  72                     STOPPED, STARTING, RUNNING, STOPPING,\n\
  73                     ABORTING, FREEZING, FROZEN\n\
  74   -t, --timeout=TMO Seconds to wait for state changes\n",
  75         .options  = my_longopts,
  76         .parser   = my_parser,
  77         .checker  = my_checker,
  78 };
  79
  80 static int fillwaitedstates(char *strstates, int *states)
  81 {
  82         char *token, *saveptr = NULL;
  83         int state;
  84
  85         token = strtok_r(strstates, "|", &saveptr);
  86         while (token) {
  87
  88                 state = lxc_str2state(token);
  89                 if (state < 0)
  90                         return -1;
  91
  92                 states[state] = 1;
  93
  94                 token = strtok_r(NULL, "|", &saveptr);
  95         }
  96         return 0;
  97 }
  98
  99 static void timeout_handler(int signal)
 100 {
 101         exit(-1);
 102 }
 103
 104 int main(int argc, char *argv[])
 105 {
 106         struct lxc_msg msg;
 107         int s[MAX_STATE] = { }, fd;
 108         int state, ret;
 109
 110         if (lxc_arguments_parse(&my_args, argc, argv))
 111                 return -1;
 112
 113         if (lxc_log_init(my_args.log_file, my_args.log_priority,
 114                          my_args.progname, my_args.quiet))
 115                 return -1;
 116
 117         if (fillwaitedstates(my_args.states, s))
 118                 return -1;
 119
 120         fd = lxc_monitor_open();
 121         if (fd < 0)
 122                 return -1;
 123
 124         /*
 125          * if container present,
 126          * then check if already in requested state
 127          */
 128         ret = -1;
 129         state = lxc_getstate(my_args.name);
 130         if (state < 0) {
 131                 goto out_close;
 132         } else if ((state >= 0) && (s[state])) {
 133                 ret = 0;
 134                 goto out_close;
 135         }
 136
 137         signal(SIGALRM, timeout_handler);
 138         alarm(my_args.timeout);
 139
 140         for (;;) {
 141                 if (lxc_monitor_read(fd, &msg) < 0)
 142                         goto out_close;
 143
 144                 if (strcmp(my_args.name, msg.name))
 145                         continue;
 146
 147                 switch (msg.type) {
 148                 case lxc_msg_state:
 149                         if (msg.value < 0 || msg.value >= MAX_STATE) {
 150                                 ERROR("Receive an invalid state number '%d'",
 151                                         msg.value);
 152                                 goto out_close;
 153                         }
 154
 155                         if (s[msg.value]) {
 156                                 alarm(0);
 157                                 ret = 0;
 158                                 goto out_close;
 159                         }
 160                         break;
 161                 default:
 162                         /* just ignore garbage */
 163                         break;
 164                 }
 165         }
 166
 167 out_close:
 168         lxc_monitor_close(fd);
 169         return ret;
 170 }