src/lxc/state.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <unistd.h>
  29 #include <sys/types.h>
  30 #include <sys/socket.h>
  31 #include <sys/param.h>
  32 #include <sys/stat.h>
  33 #include <sys/file.h>
  34
  35 #include <lxc/lxc.h>
  36 #include <lxc/log.h>
  37 #include <lxc/start.h>
  38 #include <lxc/cgroup.h>
  39 #include <lxc/monitor.h>
  40 #include "commands.h"
  41 #include "config.h"
  42
  43 lxc_log_define(lxc_state, lxc);
  44
  45 static char *strstate[] = {
  46         "STOPPED", "STARTING", "RUNNING", "STOPPING",
  47         "ABORTING", "FREEZING", "FROZEN", "THAWED",
  48 };
  49
  50 const char *lxc_state2str(lxc_state_t state)
  51 {
  52         if (state < STOPPED || state > MAX_STATE - 1)
  53                 return NULL;
  54         return strstate[state];
  55 }
  56
  57 lxc_state_t lxc_str2state(const char *state)
  58 {
  59         size_t len;
  60         lxc_state_t i;
  61         len = sizeof(strstate)/sizeof(strstate[0]);
  62         for (i = 0; i < len; i++)
  63                 if (!strcmp(strstate[i], state))
  64                         return i;
  65
  66         ERROR("invalid state '%s'", state);
  67         return -1;
  68 }
  69
  70 static lxc_state_t freezer_state(const char *name, const char *lxcpath)
  71 {
  72         char *cgabspath = NULL;
  73         char freezer[MAXPATHLEN];
  74         char status[MAXPATHLEN];
  75         FILE *file;
  76         int ret;
  77
  78         cgabspath = lxc_cgroup_path_get("freezer", name, lxcpath);
  79         if (!cgabspath)
  80                 return -1;
  81
  82         ret = snprintf(freezer, MAXPATHLEN, "%s/freezer.state", cgabspath);
  83         if (ret < 0 || ret >= MAXPATHLEN)
  84                 goto out;
  85
  86         file = fopen(freezer, "r");
  87         if (!file) {
  88                 ret = -1;
  89                 goto out;
  90         }
  91
  92         ret = fscanf(file, "%s", status);
  93         fclose(file);
  94
  95         if (ret == EOF) {
  96                 SYSERROR("failed to read %s", freezer);
  97                 ret = -1;
  98                 goto out;
  99         }
 100
 101         ret = lxc_str2state(status);
 102
 103 out:
 104         free(cgabspath);
 105         return ret;
 106 }
 107
 108 lxc_state_t lxc_getstate(const char *name, const char *lxcpath)
 109 {
 110         lxc_state_t state = freezer_state(name, lxcpath);
 111         if (state != FROZEN && state != FREEZING)
 112                 state = lxc_cmd_get_state(name, lxcpath);
 113         return state;
 114 }
 115
 116 static int fillwaitedstates(const char *strstates, int *states)
 117 {
 118         char *token, *saveptr = NULL;
 119         char *strstates_dup = strdup(strstates);
 120         int state;
 121
 122         if (!strstates_dup)
 123                 return -1;
 124
 125         token = strtok_r(strstates_dup, "|", &saveptr);
 126         while (token) {
 127
 128                 state = lxc_str2state(token);
 129                 if (state < 0) {
 130                         free(strstates_dup);
 131                         return -1;
 132                 }
 133
 134                 states[state] = 1;
 135
 136                 token = strtok_r(NULL, "|", &saveptr);
 137         }
 138         free(strstates_dup);
 139         return 0;
 140 }
 141
 142 extern int lxc_wait(const char *lxcname, const char *states, int timeout, const char *lxcpath)
 143 {
 144         struct lxc_msg msg;
 145         int state, ret;
 146         int s[MAX_STATE] = { }, fd;
 147
 148         if (fillwaitedstates(states, s))
 149                 return -1;
 150
 151         if (lxc_monitord_spawn(lxcpath))
 152                 return -1;
 153
 154         fd = lxc_monitor_open(lxcpath);
 155         if (fd < 0)
 156                 return -1;
 157
 158         /*
 159          * if container present,
 160          * then check if already in requested state
 161          */
 162         ret = -1;
 163         state = lxc_getstate(lxcname, lxcpath);
 164         if (state < 0) {
 165                 goto out_close;
 166         } else if ((state >= 0) && (s[state])) {
 167                 ret = 0;
 168                 goto out_close;
 169         }
 170
 171         for (;;) {
 172                 int elapsed_time, curtime = 0;
 173                 struct timeval tv;
 174                 int stop = 0;
 175                 int retval;
 176
 177                 if (timeout != -1) {
 178                         retval = gettimeofday(&tv, NULL);
 179                         if (retval)
 180                                 goto out_close;
 181                         curtime = tv.tv_sec;
 182                 }
 183                 if (lxc_monitor_read_timeout(fd, &msg, timeout) < 0) {
 184                         /* try again if select interrupted by signal */
 185                         if (errno != EINTR)
 186                                 goto out_close;
 187                 }
 188
 189                 if (timeout != -1) {
 190                         retval = gettimeofday(&tv, NULL);
 191                         if (retval)
 192                                 goto out_close;
 193                         elapsed_time = tv.tv_sec - curtime;
 194                         if (timeout - elapsed_time <= 0)
 195                                 stop = 1;
 196                         timeout -= elapsed_time;
 197                 }
 198
 199                 if (strcmp(lxcname, msg.name)) {
 200                         if (stop) {
 201                                 ret = -2;
 202                                 goto out_close;
 203                         }
 204                         continue;
 205                 }
 206
 207                 switch (msg.type) {
 208                 case lxc_msg_state:
 209                         if (msg.value < 0 || msg.value >= MAX_STATE) {
 210                                 ERROR("Receive an invalid state number '%d'",
 211                                         msg.value);
 212                                 goto out_close;
 213                         }
 214
 215                         if (s[msg.value]) {
 216                                 ret = 0;
 217                                 goto out_close;
 218                         }
 219                         break;
 220                 default:
 221                         if (stop) {
 222                                 ret = -2;
 223                                 goto out_close;
 224                         }
 225                         /* just ignore garbage */
 226                         break;
 227                 }
 228         }
 229
 230 out_close:
 231         lxc_monitor_close(fd);
 232         return ret;
 233 }