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 #ifndef _GNU_SOURCE
  25 #define _GNU_SOURCE 1
  26 #endif
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32 #include <unistd.h>
  33
  34 #include "conf.h"
  35 #include "config.h"
  36 #include "log.h"
  37 #include "start.h"
  38 #include "raw_syscalls.h"
  39 #include "utils.h"
  40
  41 lxc_log_define(execute, start);
  42
  43 static int execute_start(struct lxc_handler *handler, void* data)
  44 {
  45         int argc_add, j;
  46         char **argv;
  47         int argc = 0, i = 0;
  48         struct execute_args *my_args = data;
  49
  50         while (my_args->argv[argc++]);
  51
  52         /* lxc-init -n name -- [argc] NULL -> 5 */
  53         argc_add = 5;
  54         if (my_args->quiet)
  55                 argc_add++;
  56
  57         if (!handler->conf->rootfs.path)
  58                 argc_add += 2;
  59
  60         argv = malloc((argc + argc_add) * sizeof(*argv));
  61         if (!argv) {
  62                 SYSERROR("Allocating init args failed");
  63                 goto out1;
  64         }
  65
  66         if (my_args->init_path)
  67                 argv[i++] = my_args->init_path;
  68         else
  69                 argv[i++] = "lxc-init";
  70
  71         argv[i++] = "-n";
  72         argv[i++] = (char *)handler->name;
  73
  74         if (my_args->quiet)
  75                 argv[i++] = "--quiet";
  76
  77         if (!handler->conf->rootfs.path) {
  78                 argv[i++] = "-P";
  79                 argv[i++] = (char *)handler->lxcpath;
  80         }
  81
  82         argv[i++] = "--";
  83         for (j = 0; j < argc; j++)
  84                 argv[i++] = my_args->argv[j];
  85         argv[i++] = NULL;
  86
  87         NOTICE("Exec'ing \"%s\"", my_args->argv[0]);
  88
  89         if (my_args->init_fd >= 0)
  90                 lxc_raw_execveat(my_args->init_fd, "", argv, environ, AT_EMPTY_PATH);
  91         else
  92                 execvp(argv[0], argv);
  93         SYSERROR("Failed to exec %s", argv[0]);
  94
  95         free(argv);
  96 out1:
  97         return 1;
  98 }
  99
 100 static int execute_post_start(struct lxc_handler *handler, void* data)
 101 {
 102         struct execute_args *my_args = data;
 103         NOTICE("'%s' started with pid '%d'", my_args->argv[0], handler->pid);
 104         return 0;
 105 }
 106
 107 static struct lxc_operations execute_start_ops = {
 108         .start = execute_start,
 109         .post_start = execute_post_start
 110 };
 111
 112 int lxc_execute(const char *name, char *const argv[], int quiet,
 113                 struct lxc_handler *handler, const char *lxcpath,
 114                 bool daemonize, int *error_num)
 115 {
 116         struct execute_args args = {.argv = argv, .quiet = quiet};
 117
 118         TRACE("Doing lxc_execute");
 119         handler->conf->is_execute = true;
 120         return __lxc_start(name, handler, &execute_start_ops, &args, lxcpath,
 121                            daemonize, error_num);
 122 }