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 argc_add, j;
  42         char **argv;
  43         int argc = 0, i = 0, logfd = -1;
  44         struct execute_args *my_args = data;
  45         char logfile[LXC_PROC_PID_FD_LEN];
  46
  47         while (my_args->argv[argc++]);
  48
  49         /* lxc-init -n name -- [argc] NULL -> 5 */
  50         argc_add = 5;
  51         if (my_args->quiet)
  52                 argc_add++;
  53
  54         if (!handler->conf->rootfs.path)
  55                 argc_add += 2;
  56
  57         if (lxc_log_has_valid_level())
  58                 argc_add += 2;
  59
  60         if (current_config->logfd != -1 || lxc_log_fd != -1)
  61                 argc_add += 2;
  62
  63         argv = malloc((argc + argc_add) * sizeof(*argv));
  64         if (!argv) {
  65                 SYSERROR("Allocating init args failed");
  66                 goto out1;
  67         }
  68
  69         if (!my_args->init_path) {
  70                 ERROR("Init path missing");
  71                 goto out2;
  72         }
  73
  74         argv[i++] = my_args->init_path;
  75
  76         argv[i++] = "-n";
  77         argv[i++] = (char *)handler->name;
  78
  79         if (lxc_log_has_valid_level()) {
  80                 argv[i++] = "-l";
  81                 argv[i++] = (char *)lxc_log_priority_to_string(lxc_log_get_level());
  82         }
  83
  84         if (current_config->logfd != -1 || lxc_log_fd != -1) {
  85                 int ret;
  86                 int to_dup = current_config->logfd;
  87
  88                 if (current_config->logfd == -1)
  89                         to_dup = lxc_log_fd;
  90
  91                 logfd = dup(to_dup);
  92                 if (logfd < 0) {
  93                         SYSERROR("Failed to duplicate log file descriptor");
  94                         goto out2;
  95                 }
  96
  97                 ret = snprintf(logfile, sizeof(logfile), "/proc/1/fd/%d", logfd);
  98                 if (ret < 0 || (size_t)ret >= sizeof(logfile))
  99                         goto out3;
 100
 101                 argv[i++] = "-o";
 102                 argv[i++] = logfile;
 103         }
 104
 105         if (my_args->quiet)
 106                 argv[i++] = "--quiet";
 107
 108         if (!handler->conf->rootfs.path) {
 109                 argv[i++] = "-P";
 110                 argv[i++] = (char *)handler->lxcpath;
 111         }
 112
 113         argv[i++] = "--";
 114         for (j = 0; j < argc; j++)
 115                 argv[i++] = my_args->argv[j];
 116         argv[i++] = NULL;
 117
 118         NOTICE("Exec'ing \"%s\"", my_args->argv[0]);
 119
 120         execvp(argv[0], argv);
 121         SYSERROR("Failed to exec %s", argv[0]);
 122
 123 out3:
 124         close(logfd);
 125 out2:
 126         free(argv);
 127 out1:
 128         return 1;
 129 }
 130
 131 static int execute_post_start(struct lxc_handler *handler, void* data)
 132 {
 133         struct execute_args *my_args = data;
 134         NOTICE("'%s' started with pid '%d'", my_args->argv[0], handler->pid);
 135         return 0;
 136 }
 137
 138 static struct lxc_operations execute_start_ops = {
 139         .start = execute_start,
 140         .post_start = execute_post_start
 141 };
 142
 143 int lxc_execute(const char *name, char *const argv[], int quiet,
 144                 struct lxc_handler *handler, const char *lxcpath,
 145                 bool backgrounded, int *error_num)
 146 {
 147         struct execute_args args = {.argv = argv, .quiet = quiet};
 148
 149         TRACE("Doing lxc_execute");
 150         handler->conf->is_execute = 1;
 151         return __lxc_start(name, handler, &execute_start_ops, &args, lxcpath,
 152                            backgrounded, error_num);
 153 }