Fix upload losing synchronization if root not mounted (RHBZ#576879).

Modify the generator so that it can correctly handle early
cancellation for Pathname|Device|.. parameters.  This fixes
the upload command, but consequently we need to fix the
parameters for tar_in and t?z_in commands.  This should also
mean that 'win:' can now be used as the second argument of
tar_in and t?z_in commands in guestfish, whereas previously
this wouldn't have worked.

Adds a regression test for the original problem.

8 files changed, 34 insertions, 51 deletions

diff --git a/daemon/command.c b/daemon/command.c
index ca06478c..5e870673 100644
--- a/daemon/command.c
+++ b/daemon/command.c
@@ -36,7 +36,7 @@ do_command (char *const *argv)
   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);
+  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
diff --git a/daemon/daemon.h b/daemon/daemon.h
index ebbeaa2e..81a9f366 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -68,7 +68,7 @@ extern char **split_lines (char *str);
 
 extern void trim (char *str);
 
-extern int device_name_translation (char *device, const char *func);
+extern int device_name_translation (char *device);
 
 extern int prog_exists (const char *prog);
 
@@ -155,9 +155,10 @@ extern void reply (xdrproc_t xdrp, char *ret);
 /* Helper for functions that need a root filesystem mounted.
  * NB. Cannot be used for FileIn functions.
  */
-#define NEED_ROOT(fail_stmt)						\
+#define NEED_ROOT(cancel_stmt,fail_stmt)                                \
   do {									\
     if (!root_mounted) {						\
+      cancel_stmt;                                                      \
       reply_with_error ("%s: you must call 'mount' first to mount the root filesystem", __func__); \
       fail_stmt;							\
     }									\
@@ -167,9 +168,10 @@ extern void reply (xdrproc_t xdrp, char *ret);
 /* Helper for functions that need an argument ("path") that is absolute.
  * NB. Cannot be used for FileIn functions.
  */
-#define ABS_PATH(path,fail_stmt)					\
+#define ABS_PATH(path,cancel_stmt,fail_stmt)                            \
   do {									\
     if ((path)[0] != '/') {						\
+      cancel_stmt;							\
       reply_with_error ("%s: path must start with a / character", __func__); \
       fail_stmt;							\
     }									\
@@ -182,14 +184,20 @@ extern void reply (xdrproc_t xdrp, char *ret);
  *
  * NB. Cannot be used for FileIn functions.
  */
-#define RESOLVE_DEVICE(path,fail_stmt)					\
+#define RESOLVE_DEVICE(path,cancel_stmt,fail_stmt)                      \
   do {									\
     if (STRNEQLEN ((path), "/dev/", 5)) {				\
+      cancel_stmt;							\
       reply_with_error ("%s: %s: expecting a device name", __func__, (path)); \
       fail_stmt;							\
     }									\
-    if (device_name_translation ((path), __func__) == -1)		\
+    if (device_name_translation ((path)) == -1) {                       \
+      int err = errno;                                                  \
+      cancel_stmt;                                                      \
+      errno = err;                                                      \
+      reply_with_perror ("%s: %s", __func__, path);                     \
       fail_stmt;							\
+    }                                                                   \
   } while (0)
 
 /* Helper for functions which need either an absolute path in the
@@ -202,13 +210,13 @@ extern void reply (xdrproc_t xdrp, char *ret);
  * because we intend in future to make device parameters a distinct
  * type from filenames.
  */
-#define REQUIRE_ROOT_OR_RESOLVE_DEVICE(path,fail_stmt)			\
+#define REQUIRE_ROOT_OR_RESOLVE_DEVICE(path,cancel_stmt,fail_stmt)      \
   do {									\
     if (STREQLEN ((path), "/dev/", 5))                                  \
-      RESOLVE_DEVICE ((path), fail_stmt);				\
+      RESOLVE_DEVICE ((path), cancel_stmt, fail_stmt);                  \
     else {								\
-      NEED_ROOT (fail_stmt);						\
-      ABS_PATH ((path),fail_stmt);					\
+      NEED_ROOT (cancel_stmt, fail_stmt);                               \
+      ABS_PATH ((path), cancel_stmt, fail_stmt);                        \
     }									\
   } while (0)
 
diff --git a/daemon/df.c b/daemon/df.c
index b5c4980c..7aa6f4fd 100644
--- a/daemon/df.c
+++ b/daemon/df.c
@@ -33,7 +33,7 @@ do_df (void)
   int r;
   char *out, *err;
 
-  NEED_ROOT (return NULL);
+  NEED_ROOT (, return NULL);
 
   r = command (&out, &err, "df", NULL);
   if (r == -1) {
@@ -54,7 +54,7 @@ do_df_h (void)
   int r;
   char *out, *err;
 
-  NEED_ROOT (return NULL);
+  NEED_ROOT (, return NULL);
 
   r = command (&out, &err, "df", "-h", NULL);
   if (r == -1) {
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 69baf9e8..06ad702e 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -1022,42 +1022,36 @@ print_arginfo (const struct printf_info *info, size_t n, int *argtypes)
  * the device nodes themselves will exist in the appliance.
  */
 int
-device_name_translation (char *device, const char *func)
+device_name_translation (char *device)
 {
   int fd;
 
   fd = open (device, O_RDONLY);
   if (fd >= 0) {
+  close_ok:
     close (fd);
     return 0;
   }
 
-  if (errno != ENXIO && errno != ENOENT) {
-  error:
-    reply_with_perror ("%s: %s", func, device);
+  if (errno != ENXIO && errno != ENOENT)
     return -1;
-  }
 
   /* If the name begins with "/dev/sd" then try the alternatives. */
   if (STRNEQLEN (device, "/dev/sd", 7))
-    goto error;
+    return -1;
 
   device[5] = 'h';		/* /dev/hd (old IDE driver) */
   fd = open (device, O_RDONLY);
-  if (fd >= 0) {
-    close (fd);
-    return 0;
-  }
+  if (fd >= 0)
+    goto close_ok;
 
   device[5] = 'v';		/* /dev/vd (for virtio devices) */
   fd = open (device, O_RDONLY);
-  if (fd >= 0) {
-    close (fd);
-    return 0;
-  }
+  if (fd >= 0)
+    goto close_ok;
 
   device[5] = 's';		/* Restore original device name. */
-  goto error;
+  return -1;
 }
 
 /* Check program exists and is executable on $PATH.  Actually, we
diff --git a/daemon/inotify.c b/daemon/inotify.c
index ec3aa64f..104fa60b 100644
--- a/daemon/inotify.c
+++ b/daemon/inotify.c
@@ -70,7 +70,7 @@ do_inotify_init (int max_events)
 #ifdef HAVE_SYS_INOTIFY_H
   FILE *fp;
 
-  NEED_ROOT (return -1);
+  NEED_ROOT (, return -1);
 
   if (max_events < 0) {
     reply_with_error ("max_events < 0");
diff --git a/daemon/mount.c b/daemon/mount.c
index 838bef86..8927c6c2 100644
--- a/daemon/mount.c
+++ b/daemon/mount.c
@@ -48,7 +48,7 @@ do_mount_vfs (const char *options, const char *vfstype,
   char *mp;
   char *error;
 
-  ABS_PATH (mountpoint, return -1);
+  ABS_PATH (mountpoint, , return -1);
 
   is_root = STREQ (mountpoint, "/");
 
@@ -121,7 +121,7 @@ do_umount (const char *pathordevice)
   }
 
   if (is_dev)
-    RESOLVE_DEVICE (buf, { free (buf); return -1; });
+    RESOLVE_DEVICE (buf, , { free (buf); return -1; });
 
   r = command (NULL, &err, "umount", buf, NULL);
   free (buf);
@@ -356,7 +356,7 @@ do_mkmountpoint (const char *path)
   int r;
 
   /* NEED_ROOT (return -1); - we don't want this test for this call. */
-  ABS_PATH (path, return -1);
+  ABS_PATH (path, , return -1);
 
   CHROOT_IN;
   r = mkdir (path, 0777);
@@ -381,7 +381,7 @@ do_rmmountpoint (const char *path)
   int r;
 
   /* NEED_ROOT (return -1); - we don't want this test for this call. */
-  ABS_PATH (path, return -1);
+  ABS_PATH (path, , return -1);
 
   CHROOT_IN;
   r = rmdir (path);
diff --git a/daemon/tar.c b/daemon/tar.c
index 5b73599a..26a0d302 100644
--- a/daemon/tar.c
+++ b/daemon/tar.c
@@ -42,12 +42,6 @@ do_tar_in (const char *dir)
   FILE *fp;
   char *cmd;
 
-  if (!root_mounted || dir[0] != '/') {
-    cancel_receive ();
-    reply_with_error ("root must be mounted and path must be absolute");
-    return -1;
-  }
-
   /* "tar -C /sysroot%s -xf -" but we have to quote the dir. */
   if (asprintf_nowarn (&cmd, "tar -C %R -xf -", dir) == -1) {
     err = errno;
@@ -165,12 +159,6 @@ do_tXz_in (const char *dir, char filter)
   FILE *fp;
   char *cmd;
 
-  if (!root_mounted || dir[0] != '/') {
-    cancel_receive ();
-    reply_with_error ("root must be mounted and path must be absolute");
-    return -1;
-  }
-
   /* "tar -C /sysroot%s -zxf -" but we have to quote the dir. */
   if (asprintf_nowarn (&cmd, "tar -C %R -%cxf -", dir, filter) == -1) {
     err = errno;
diff --git a/daemon/upload.c b/daemon/upload.c
index 3c20d6f0..d93a5ade 100644
--- a/daemon/upload.c
+++ b/daemon/upload.c
@@ -41,13 +41,6 @@ do_upload (const char *filename)
   int err, fd, r, is_dev;
 
   is_dev = STRPREFIX (filename, "/dev/");
-  if (!is_dev) {
-    if (!root_mounted || filename[0] != '/') {
-      cancel_receive ();
-      reply_with_error ("root must be mounted and path must be absolute");
-      return -1;
-    }
-  }
 
   if (!is_dev) CHROOT_IN;
   fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666);