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 #define _GNU_SOURCE
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <errno.h>
  28 #include <unistd.h>
  29 #include <stdlib.h>
  30 #include <stdio.h>
  31
  32 #include "conf.h"
  33 #include "log.h"
  34 #include "start.h"
  35 #include "utils.h"
  36
  37 lxc_log_define(lxc_execute, lxc_start);
  38
  39 static int execute_start(struct lxc_handler *handler, void* data)
  40 {
  41         int j, i = 0, log = -1;
  42         struct execute_args *my_args = data;
  43         char **argv, *logfd;
  44         int argc = 0, argc_add;
  45
  46         while (my_args->argv[argc++]);
  47
  48         /* lxc-init -n name -- [argc] NULL -> 5 */
  49         argc_add = 5;
  50         if (my_args->quiet)
  51                 argc_add++;
  52         if (!handler->conf->rootfs.path)
  53                 argc_add += 2;
  54         if (lxc_log_has_valid_level())
  55                 argc_add += 2;
  56
  57         argv = malloc((argc + argc_add) * sizeof(*argv));
  58         if (!argv)
  59                 goto out1;
  60
  61         if (!my_args->init_path)
  62                 goto out2;
  63
  64         argv[i++] = my_args->init_path;
  65
  66         argv[i++] = "-n";
  67         argv[i++] = (char *)handler->name;
  68
  69         if (lxc_log_has_valid_level()) {
  70                 argv[i++] = "-l";
  71                 argv[i++] = (char *)lxc_log_priority_to_string(lxc_log_get_level());
  72         }
  73
  74         if (current_config->logfd != -1 || lxc_log_fd != -1) {
  75                 int to_dup = current_config->logfd;
  76
  77                 if (current_config->logfd == -1)
  78                         to_dup = lxc_log_fd;
  79
  80                 log = dup(to_dup);
  81                 if (log < 0) {
  82                         SYSERROR("dup of log fd failed");
  83                         goto out2;
  84                 }
  85
  86                 if (asprintf(&logfd, "/proc/1/fd/%d", log) < 0) {
  87                         ERROR("Couldn't allocate memory for log string");
  88                         goto out3;
  89                 }
  90
  91                 argv[i++] = "-o";
  92                 argv[i++] = logfd;
  93         }
  94
  95         if (my_args->quiet)
  96                 argv[i++] = "--quiet";
  97
  98         if (!handler->conf->rootfs.path) {
  99                 argv[i++] = "-P";
 100                 argv[i++] = (char *)handler->lxcpath;
 101         }
 102
 103         argv[i++] = "--";
 104         for (j = 0; j < argc; j++)
 105                 argv[i++] = my_args->argv[j];
 106         argv[i++] = NULL;
 107
 108         NOTICE("Exec'ing \"%s\"", my_args->argv[0]);
 109
 110         execvp(argv[0], argv);
 111         SYSERROR("Failed to exec %s", argv[0]);
 112
 113         free(logfd);
 114 out3:
 115         close(log);
 116 out2:
 117         free(argv);
 118 out1:
 119         return 1;
 120 }
 121
 122 static int execute_post_start(struct lxc_handler *handler, void* data)
 123 {
 124         struct execute_args *my_args = data;
 125         NOTICE("'%s' started with pid '%d'", my_args->argv[0], handler->pid);
 126         return 0;
 127 }
 128
 129 static struct lxc_operations execute_start_ops = {
 130         .start = execute_start,
 131         .post_start = execute_post_start
 132 };
 133
 134 int lxc_execute(const char *name, char *const argv[], int quiet,
 135                 struct lxc_handler *handler, const char *lxcpath,
 136                 bool backgrounded, int *error_num)
 137 {
 138         struct execute_args args = {.argv = argv, .quiet = quiet};
 139
 140         if (lxc_check_inherited(handler->conf, false, &handler->conf->maincmd_fd, 1))
 141                 return -1;
 142
 143         handler->conf->is_execute = 1;
 144         return __lxc_start(name, handler, &execute_start_ops, &args, lxcpath,
 145                            backgrounded, error_num);
 146 }