summaryrefslogtreecommitdiffstats
path: root/daemon/command.c
blob: b2b5ef91d8f1fb0c52cbdb885cd26f3c5f05dbee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
/* libguestfs - the guestfsd daemon
 * Copyright (C) 2009 Red Hat Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../src/guestfs_protocol.h"
#include "daemon.h"
#include "actions.h"

char *
do_command (char *const *argv)
{
  char *out, *err;
  int r;
  char *sysroot_dev, *sysroot_dev_pts, *sysroot_proc,
    *sysroot_selinux, *sysroot_sys;
  int dev_ok, dev_pts_ok, proc_ok, selinux_ok, sys_ok;

  /* We need a root filesystem mounted to do this. */
  NEED_ROOT (return NULL);

  /* Conveniently, argv is already a NULL-terminated argv-style array
   * of parameters, so we can pass it straight in to our internal
   * commandv.  We just have to check the list is non-empty.
   */
  if (argv[0] == NULL) {
    reply_with_error ("command: passed an empty list");
    return NULL;
  }

  /* While running the command, bind-mount /dev, /proc, /sys
   * into the chroot.  However we must be careful to unmount them
   * afterwards because otherwise they would interfere with
   * future mount and unmount operations.
   *
   * We deliberately allow these commands to fail silently, BUT
   * if a mount fails, don't unmount the corresponding mount.
   */
  sysroot_dev = sysroot_path ("/dev");
  sysroot_dev_pts = sysroot_path ("/dev/pts");
  sysroot_proc = sysroot_path ("/proc");
  sysroot_selinux = sysroot_path ("/selinux");
  sysroot_sys = sysroot_path ("/sys");

  if (sysroot_dev == NULL || sysroot_dev_pts == NULL ||
      sysroot_proc == NULL || sysroot_selinux == NULL ||
      sysroot_sys == NULL) {
    reply_with_perror ("malloc");
    free (sysroot_dev);
    free (sysroot_dev_pts);
    free (sysroot_proc);
    free (sysroot_selinux);
    free (sysroot_sys);
    return NULL;
  }

  r = command (NULL, NULL, "mount", "--bind", "/dev", sysroot_dev, NULL);
  dev_ok = r != -1;
  r = command (NULL, NULL, "mount", "--bind", "/dev/pts", sysroot_dev_pts, NULL);
  dev_pts_ok = r != -1;
  r = command (NULL, NULL, "mount", "--bind", "/proc", sysroot_proc, NULL);
  proc_ok = r != -1;
  r = command (NULL, NULL, "mount", "--bind", "/selinux", sysroot_selinux, NULL);
  selinux_ok = r != -1;
  r = command (NULL, NULL, "mount", "--bind", "/sys", sysroot_sys, NULL);
  sys_ok = r != -1;

  CHROOT_IN;
  r = commandv (&out, &err, argv);
  CHROOT_OUT;

  if (sys_ok) command (NULL, NULL, "umount", sysroot_sys, NULL);
  if (selinux_ok) command (NULL, NULL, "umount", sysroot_selinux, NULL);
  if (proc_ok) command (NULL, NULL, "umount", sysroot_proc, NULL);
  if (dev_pts_ok) command (NULL, NULL, "umount", sysroot_dev_pts, NULL);
  if (dev_ok) command (NULL, NULL, "umount", sysroot_dev, NULL);

  free (sysroot_dev);
  free (sysroot_dev_pts);
  free (sysroot_proc);
  free (sysroot_selinux);
  free (sysroot_sys);

  if (r == -1) {
    reply_with_error ("%s", err);
    free (out);
    free (err);
    return NULL;
  }

  free (err);

  return out;			/* Caller frees. */
}

char **
do_command_lines (char *const *argv)
{
  char *out;
  char **lines;

  out = do_command (argv);
  if (out == NULL)
    return NULL;

  lines = split_lines (out);
  free (out);

  if (lines == NULL)
    return NULL;

  return lines;			/* Caller frees. */
}

char *
do_sh (const char *cmd)
{
  const char *argv[] = { "/bin/sh", "-c", cmd, NULL };

  return do_command ((char **) argv);
}

char **
do_sh_lines (const char *cmd)
{
  const char *argv[] = { "/bin/sh", "-c", cmd, NULL };

  return do_command_lines ((char **) argv);
}