Fix FileIn cmds losing synch if both ends send cancel messages (RHBZ#576879).

[libguestfs.git] / daemon / command.c

diff --git a/daemon/command.c b/daemon/command.c
index 589ca76..48bed2d 100644 (file)
--- a/daemon/command.c
+++ b/daemon/command.c
@@ -1,5 +1,5 @@
 /* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc. 
+ * 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
@@ -27,27 +27,79 @@
 #include "actions.h"
 
 char *
-do_command (char * const * const argv)
+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 (NULL);
+  NEED_ROOT (0, 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");
+    reply_with_error ("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);
+  r = commandv (&out, &err, (const char * const *) 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);
@@ -61,41 +113,36 @@ do_command (char * const * const argv)
 }
 
 char **
-do_command_lines (char * const * const argv)
+do_command_lines (char *const *argv)
 {
   char *out;
-  char **lines = NULL;
-  int size = 0, alloc = 0;
-  char *p, *pend;
+  char **lines;
 
   out = do_command (argv);
   if (out == NULL)
     return NULL;
 
-  /* Now convert the output to a list of lines. */
-  p = out;
-  while (p) {
-    pend = strchr (p, '\n');
-    if (pend) {
-      *pend = '\0';
-      pend++;
-    }
+  lines = split_lines (out);
+  free (out);
 
-    /* Final \n?  Don't return an empty final element. */
-    if (pend && *pend == '\0') break;
+  if (lines == NULL)
+    return NULL;
 
-    if (add_string (&lines, &size, &alloc, p) == -1) {
-      free (out);
-      return NULL;
-    }
+  return lines;                        /* Caller frees. */
+}
 
-    p = pend;
-  }
+char *
+do_sh (const char *cmd)
+{
+  const char *argv[] = { "/bin/sh", "-c", cmd, NULL };
 
-  free (out);
+  return do_command ((char **) argv);
+}
 
-  if (add_string (&lines, &size, &alloc, NULL) == -1)
-    return NULL;
+char **
+do_sh_lines (const char *cmd)
+{
+  const char *argv[] = { "/bin/sh", "-c", cmd, NULL };
 
-  return lines;
+  return do_command_lines ((char **) argv);
 }