src/lxc/execute.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
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29
  30 #include "conf.h"
  31 #include "log.h"
  32 #include "start.h"
  33 #include "utils.h"
  34
  35 lxc_log_define(lxc_execute, lxc_start);
  36
  37 struct execute_args {
  38         char *const *argv;
  39         int quiet;
  40 };
  41
  42 /* historically lxc-init has been under /usr/lib/lxc and under
  43  * /usr/lib/$ARCH/lxc.  It now lives as $prefix/sbin/init.lxc.
  44  */
  45 static char *choose_init(void)
  46 {
  47         char *retv = NULL;
  48         int ret, env_set = 0;
  49         struct stat mystat;
  50
  51         if (!getenv("PATH")) {
  52                 if (setenv("PATH", "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", 0))
  53                         SYSERROR("Failed to setenv");
  54                 env_set = 1;
  55         }
  56
  57         retv = on_path("init.lxc");
  58
  59         if (env_set) {
  60                 if (unsetenv("PATH"))
  61                         SYSERROR("Failed to unsetenv");
  62         }
  63
  64         if (retv)
  65                 return retv;
  66
  67         retv = malloc(PATH_MAX);
  68         if (!retv)
  69                 return NULL;
  70
  71         ret = snprintf(retv, PATH_MAX, SBINDIR "/init.lxc");
  72         if (ret < 0 || ret >= PATH_MAX) {
  73                 ERROR("pathname too long");
  74                 goto out1;
  75         }
  76
  77         ret = stat(retv, &mystat);
  78         if (ret == 0)
  79                 return retv;
  80
  81         ret = snprintf(retv, PATH_MAX, LXCINITDIR "/lxc/lxc-init");
  82         if (ret < 0 || ret >= PATH_MAX) {
  83                 ERROR("pathname too long");
  84                 goto out1;
  85         }
  86
  87         ret = stat(retv, &mystat);
  88         if (ret == 0)
  89                 return retv;
  90
  91         ret = snprintf(retv, PATH_MAX, "/usr/lib/lxc/lxc-init");
  92         if (ret < 0 || ret >= PATH_MAX) {
  93                 ERROR("pathname too long");
  94                 goto out1;
  95         }
  96         ret = stat(retv, &mystat);
  97         if (ret == 0)
  98                 return retv;
  99         ret = snprintf(retv, PATH_MAX, "/sbin/lxc-init");
 100         if (ret < 0 || ret >= PATH_MAX) {
 101                 ERROR("pathname too long");
 102                 goto out1;
 103         }
 104         ret = stat(retv, &mystat);
 105         if (ret == 0)
 106                 return retv;
 107 out1:
 108         free(retv);
 109         return NULL;
 110 }
 111
 112 static int execute_start(struct lxc_handler *handler, void* data)
 113 {
 114         int j, i = 0;
 115         struct execute_args *my_args = data;
 116         char **argv;
 117         int argc = 0, argc_add;
 118         char *initpath;
 119
 120         while (my_args->argv[argc++]);
 121
 122         argc_add = 4;
 123         if (my_args->quiet)
 124                 argc_add++;
 125         if (!handler->conf->rootfs.path) {
 126                 argc_add += 4;
 127                 if (lxc_log_has_valid_level())
 128                         argc_add += 2;
 129         }
 130
 131         argv = malloc((argc + argc_add) * sizeof(*argv));
 132         if (!argv)
 133                 goto out1;
 134
 135         initpath = choose_init();
 136         if (!initpath) {
 137                 ERROR("Failed to find an lxc-init");
 138                 goto out2;
 139         }
 140         argv[i++] = initpath;
 141         if (my_args->quiet)
 142                 argv[i++] = "--quiet";
 143         if (!handler->conf->rootfs.path) {
 144                 argv[i++] = "--name";
 145                 argv[i++] = (char *)handler->name;
 146                 argv[i++] = "--lxcpath";
 147                 argv[i++] = (char *)handler->lxcpath;
 148
 149                 if (lxc_log_has_valid_level()) {
 150                         argv[i++] = "--logpriority";
 151                         argv[i++] = (char *)
 152                                 lxc_log_priority_to_string(lxc_log_get_level());
 153                 }
 154         }
 155         argv[i++] = "--";
 156         for (j = 0; j < argc; j++)
 157                 argv[i++] = my_args->argv[j];
 158         argv[i++] = NULL;
 159
 160         NOTICE("exec'ing '%s'", my_args->argv[0]);
 161
 162         execvp(argv[0], argv);
 163         SYSERROR("failed to exec %s", argv[0]);
 164         free(initpath);
 165 out2:
 166         free(argv);
 167 out1:
 168         return 1;
 169 }
 170
 171 static int execute_post_start(struct lxc_handler *handler, void* data)
 172 {
 173         struct execute_args *my_args = data;
 174         NOTICE("'%s' started with pid '%d'", my_args->argv[0], handler->pid);
 175         return 0;
 176 }
 177
 178 static struct lxc_operations execute_start_ops = {
 179         .start = execute_start,
 180         .post_start = execute_post_start
 181 };
 182
 183 int lxc_execute(const char *name, char *const argv[], int quiet,
 184                 struct lxc_conf *conf, const char *lxcpath)
 185 {
 186         struct execute_args args = {
 187                 .argv = argv,
 188                 .quiet = quiet
 189         };
 190
 191         if (lxc_check_inherited(conf, -1))
 192                 return -1;
 193
 194         conf->is_execute = 1;
 195         return __lxc_start(name, conf, &execute_start_ops, &args, lxcpath);
 196 }