X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fgenerator.ml;h=de3b4f62a819fe41addbcf6a93bd60f6d9335ec7;hp=0904afc0435e63dcc854277753e88b0cce1d9d12;hb=23e6fc3f61294acf1bce2003dc4060df25e899f9;hpb=745f1d9ee8480b3a38f778fcc4506ce86da473a6

diff --git a/src/generator.ml b/src/generator.ml
index 0904afc..de3b4f6 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -24,8 +24,9 @@
  * this one to describe the interface (see the big table below), and
  * daemon/<somefile>.c to write the implementation.
  *
- * After editing this file, run it (./src/generator.ml) to regenerate
- * all the output files.
+ * After editing this file, run it (./src/generator.ml) to regenerate all the
+ * output files.  Note that if you are using a separate build directory you
+ * must run generator.ml from the _source_ directory.
  *
  * IMPORTANT: This script should NOT print any warnings.  If it prints
  * warnings, you should treat them as errors.
@@ -84,6 +85,20 @@ and ret =
      * inefficient.  Keys should be unique.  NULLs are not permitted.
      *)
   | RHashtable of string
+    (* "RBufferOut" is handled almost exactly like RString, but
+     * it allows the string to contain arbitrary 8 bit data including
+     * ASCII NUL.  In the C API this causes an implicit extra parameter
+     * to be added of type <size_t *size_r>.  The extra parameter
+     * returns the actual size of the return buffer in bytes.
+     *
+     * Other programming languages support strings with arbitrary 8 bit
+     * data.
+     *
+     * At the RPC layer we have to use the opaque<> type instead of
+     * string<>.  Returned data is still limited to the max message
+     * size (ie. ~ 2 MB).
+     *)
+  | RBufferOut of string
 
 and args = argt list	(* Function parameters, guestfs handle is implicit. *)
 
@@ -110,6 +125,18 @@ and argt =
      *)
   | FileIn of string
   | FileOut of string
+(* Not implemented:
+    (* Opaque buffer which can contain arbitrary 8 bit data.
+     * In the C API, this is expressed as <char *, int> pair.
+     * Most other languages have a string type which can contain
+     * ASCII NUL.  We use whatever type is appropriate for each
+     * language.
+     * Buffers are limited by the total message size.  To transfer
+     * large blocks of data, use FileIn/FileOut parameters instead.
+     * To return an arbitrary buffer, use RBufferOut.
+     *)
+  | BufferIn of string
+*)
 
 type flags =
   | ProtocolLimitWarning  (* display warning about protocol size limits *)
@@ -183,6 +210,10 @@ and test =
      *)
   | TestOutputInt of seq * int
     (* Run the command sequence and expect the output of the final
+     * command to be <op> <int>, eg. ">=", "1".
+     *)
+  | TestOutputIntOp of seq * string * int
+    (* Run the command sequence and expect the output of the final
      * command to be a true value (!= 0 or != NULL).
      *)
   | TestOutputTrue of seq
@@ -206,6 +237,7 @@ and test =
 
 and test_field_compare =
   | CompareWithInt of string * int
+  | CompareWithIntOp of string * string * int
   | CompareWithString of string * string
   | CompareFieldsIntEq of string * string
   | CompareFieldsStrEq of string * string
@@ -442,7 +474,8 @@ environment variable.
 Setting C<qemu> to C<NULL> restores the default qemu binary.");
 
   ("get_qemu", (RConstString "qemu", []), -1, [],
-   [],
+   [InitNone, Always, TestRun (
+      [["get_qemu"]])],
    "get the qemu binary",
    "\
 Return the current qemu binary.
@@ -462,7 +495,8 @@ C<LIBGUESTFS_PATH> environment variable.
 Setting C<path> to C<NULL> restores the default path.");
 
   ("get_path", (RConstString "path", []), -1, [],
-   [],
+   [InitNone, Always, TestRun (
+      [["get_path"]])],
    "get the search path",
    "\
 Return the current search path.
@@ -470,7 +504,7 @@ Return the current search path.
 This is always non-NULL.  If it wasn't set already, then this will
 return the default path.");
 
-  ("set_append", (RErr, [String "append"]), -1, [FishAlias "append"],
+  ("set_append", (RErr, [OptString "append"]), -1, [FishAlias "append"],
    [],
    "add options to kernel command line",
    "\
@@ -484,6 +518,10 @@ Setting C<append> to C<NULL> means I<no> additional options
 are passed (libguestfs always adds a few of its own).");
 
   ("get_append", (RConstString "append", []), -1, [],
+   (* This cannot be tested with the current framework.  The
+    * function can return NULL in normal operations, which the
+    * test framework interprets as an error.
+    *)
    [],
    "get the additional kernel options",
    "\
@@ -505,7 +543,8 @@ This is disabled by default (except in guestfish where it is
 enabled by default).");
 
   ("get_autosync", (RBool "autosync", []), -1, [],
-   [],
+   [InitNone, Always, TestRun (
+      [["get_autosync"]])],
    "get autosync mode",
    "\
 Get the autosync flag.");
@@ -526,7 +565,8 @@ C<LIBGUESTFS_DEBUG> is defined and set to C<1>.");
 This returns the verbose messages flag.");
 
   ("is_ready", (RBool "ready", []), -1, [],
-   [],
+   [InitNone, Always, TestOutputTrue (
+      [["is_ready"]])],
    "is ready to accept commands",
    "\
 This returns true iff this handle is ready to accept commands
@@ -535,7 +575,8 @@ This returns true iff this handle is ready to accept commands
 For more information on states, see L<guestfs(3)>.");
 
   ("is_config", (RBool "config", []), -1, [],
-   [],
+   [InitNone, Always, TestOutputFalse (
+      [["is_config"]])],
    "is in configuration state",
    "\
 This returns true iff this handle is being configured
@@ -544,7 +585,8 @@ This returns true iff this handle is being configured
 For more information on states, see L<guestfs(3)>.");
 
   ("is_launching", (RBool "launching", []), -1, [],
-   [],
+   [InitNone, Always, TestOutputFalse (
+      [["is_launching"]])],
    "is launching subprocess",
    "\
 This returns true iff this handle is launching the subprocess
@@ -553,7 +595,8 @@ This returns true iff this handle is launching the subprocess
 For more information on states, see L<guestfs(3)>.");
 
   ("is_busy", (RBool "busy", []), -1, [],
-   [],
+   [InitNone, Always, TestOutputFalse (
+      [["is_busy"]])],
    "is busy processing a command",
    "\
 This returns true iff this handle is busy processing a command
@@ -599,7 +642,9 @@ actions using the low-level API.
 For more information on states, see L<guestfs(3)>.");
 
   ("set_memsize", (RErr, [Int "memsize"]), -1, [FishAlias "memsize"],
-   [],
+   [InitNone, Always, TestOutputInt (
+      [["set_memsize"; "500"];
+       ["get_memsize"]], 500)],
    "set memory allocated to the qemu subprocess",
    "\
 This sets the memory size in megabytes allocated to the
@@ -614,7 +659,8 @@ For more information on the architecture of libguestfs,
 see L<guestfs(3)>.");
 
   ("get_memsize", (RInt "memsize", []), -1, [],
-   [],
+   [InitNone, Always, TestOutputIntOp (
+      [["get_memsize"]], ">=", 256)],
    "get memory allocated to the qemu subprocess",
    "\
 This gets the memory size in megabytes allocated to the
@@ -628,7 +674,8 @@ For more information on the architecture of libguestfs,
 see L<guestfs(3)>.");
 
   ("get_pid", (RInt "pid", []), -1, [FishAlias "pid"],
-   [],
+   [InitNone, Always, TestOutputIntOp (
+      [["get_pid"]], ">=", 1)],
    "get PID of qemu subprocess",
    "\
 Return the process ID of the qemu subprocess.  If there is no
@@ -637,7 +684,7 @@ qemu subprocess, then this will return an error.
 This is an internal call used for debugging and testing.");
 
   ("version", (RStruct ("version", "version"), []), -1, [],
-   [InitBasicFS, Always, TestOutputStruct (
+   [InitNone, Always, TestOutputStruct (
       [["version"]], [CompareWithInt ("major", 1)])],
    "get the library version number",
    "\
@@ -729,8 +776,8 @@ Return the contents of the file named C<path>.
 
 Note that this function cannot correctly handle binary files
 (specifically, files containing C<\\0> character which is treated
-as end of string).  For those you need to use the C<guestfs_download>
-function which has a more complex interface.");
+as end of string).  For those you need to use the C<guestfs_read_file>
+or C<guestfs_download> functions which have a more complex interface.");
 
   ("ll", (RString "listing", [String "directory"]), 5, [],
    [], (* XXX Tricky to test because it depends on the exact format
@@ -1327,7 +1374,9 @@ contains the filesystem.");
 This returns the list of currently mounted filesystems.  It returns
 the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
 
-Some internal mounts are not shown.");
+Some internal mounts are not shown.
+
+See also: C<guestfs_mountpoints>");
 
   ("umount_all", (RErr, []), 47, [FishAlias "unmount-all"],
    [InitBasicFS, Always, TestOutputList (
@@ -1674,8 +1723,8 @@ This uses the L<blockdev(8)> command.");
   ("upload", (RErr, [FileIn "filename"; String "remotefilename"]), 66, [],
    [InitBasicFS, Always, TestOutput (
       (* Pick a file from cwd which isn't likely to change. *)
-    [["upload"; "../COPYING.LIB"; "/COPYING.LIB"];
-     ["checksum"; "md5"; "/COPYING.LIB"]], "e3eda01d9815f8d24aae2dbd89b68b06")],
+      [["upload"; "../COPYING.LIB"; "/COPYING.LIB"];
+       ["checksum"; "md5"; "/COPYING.LIB"]], "e3eda01d9815f8d24aae2dbd89b68b06")],
    "upload a file from the local machine",
    "\
 Upload local file C<filename> to C<remotefilename> on the
@@ -1688,10 +1737,10 @@ See also C<guestfs_download>.");
   ("download", (RErr, [String "remotefilename"; FileOut "filename"]), 67, [],
    [InitBasicFS, Always, TestOutput (
       (* Pick a file from cwd which isn't likely to change. *)
-    [["upload"; "../COPYING.LIB"; "/COPYING.LIB"];
-     ["download"; "/COPYING.LIB"; "testdownload.tmp"];
-     ["upload"; "testdownload.tmp"; "/upload"];
-     ["checksum"; "md5"; "/upload"]], "e3eda01d9815f8d24aae2dbd89b68b06")],
+      [["upload"; "../COPYING.LIB"; "/COPYING.LIB"];
+       ["download"; "/COPYING.LIB"; "testdownload.tmp"];
+       ["upload"; "testdownload.tmp"; "/upload"];
+       ["checksum"; "md5"; "/upload"]], "e3eda01d9815f8d24aae2dbd89b68b06")],
    "download a file to the local machine",
    "\
 Download file C<remotefilename> and save it as C<filename>
@@ -2313,19 +2362,19 @@ are activated or deactivated.");
 
   ("lvresize", (RErr, [String "device"; Int "mbytes"]), 105, [],
    [InitNone, Always, TestOutput (
-    [["sfdiskM"; "/dev/sda"; ","];
-     ["pvcreate"; "/dev/sda1"];
-     ["vgcreate"; "VG"; "/dev/sda1"];
-     ["lvcreate"; "LV"; "VG"; "10"];
-     ["mkfs"; "ext2"; "/dev/VG/LV"];
-     ["mount"; "/dev/VG/LV"; "/"];
-     ["write_file"; "/new"; "test content"; "0"];
-     ["umount"; "/"];
-     ["lvresize"; "/dev/VG/LV"; "20"];
-     ["e2fsck_f"; "/dev/VG/LV"];
-     ["resize2fs"; "/dev/VG/LV"];
-     ["mount"; "/dev/VG/LV"; "/"];
-     ["cat"; "/new"]], "test content")],
+      [["sfdiskM"; "/dev/sda"; ","];
+       ["pvcreate"; "/dev/sda1"];
+       ["vgcreate"; "VG"; "/dev/sda1"];
+       ["lvcreate"; "LV"; "VG"; "10"];
+       ["mkfs"; "ext2"; "/dev/VG/LV"];
+       ["mount"; "/dev/VG/LV"; "/"];
+       ["write_file"; "/new"; "test content"; "0"];
+       ["umount"; "/"];
+       ["lvresize"; "/dev/VG/LV"; "20"];
+       ["e2fsck_f"; "/dev/VG/LV"];
+       ["resize2fs"; "/dev/VG/LV"];
+       ["mount"; "/dev/VG/LV"; "/"];
+       ["cat"; "/new"]], "test content")],
    "resize an LVM logical volume",
    "\
 This resizes (expands or shrinks) an existing LVM logical
@@ -2397,7 +2446,7 @@ This command is only needed because of C<guestfs_resize2fs>
 
   ("sleep", (RErr, [Int "secs"]), 109, [],
    [InitNone, Always, TestRun (
-    [["sleep"; "1"]])],
+      [["sleep"; "1"]])],
    "sleep for some seconds",
    "\
 Sleep for C<secs> seconds.");
@@ -2797,6 +2846,50 @@ All entries in the directory are returned, including C<.> and
 C<..>.  The entries are I<not> sorted, but returned in the same
 order as the underlying filesystem.
 
+Also this call returns basic file type information about each
+file.  The C<ftyp> field will contain one of the following characters:
+
+=over 4
+
+=item 'b'
+
+Block special
+
+=item 'c'
+
+Char special
+
+=item 'd'
+
+Directory
+
+=item 'f'
+
+FIFO (named pipe)
+
+=item 'l'
+
+Symbolic link
+
+=item 'r'
+
+Regular file
+
+=item 's'
+
+Socket
+
+=item 'u'
+
+Unknown file type
+
+=item '?'
+
+The L<readdir(3)> returned a C<d_type> field with an
+unexpected value
+
+=back
+
 This function is primarily intended for use by programs.  To
 get a simple list of names, use C<guestfs_ls>.  To get a printable
 directory for human consumption, use C<guestfs_ll>.");
@@ -2813,6 +2906,134 @@ were rarely if ever used anyway.
 
 See also C<guestfs_sfdisk> and the L<sfdisk(8)> manpage.");
 
+  ("zfile", (RString "description", [String "method"; String "path"]), 140, [],
+   [],
+   "determine file type inside a compressed file",
+   "\
+This command runs C<file> after first decompressing C<path>
+using C<method>.
+
+C<method> must be one of C<gzip>, C<compress> or C<bzip2>.
+
+See also: C<guestfs_file>");
+
+  ("getxattrs", (RStructList ("xattrs", "xattr"), [String "path"]), 141, [],
+   [],
+   "list extended attributes of a file or directory",
+   "\
+This call lists the extended attributes of the file or directory
+C<path>.
+
+At the system call level, this is a combination of the
+L<listxattr(2)> and L<getxattr(2)> calls.
+
+See also: C<guestfs_lgetxattrs>, L<attr(5)>.");
+
+  ("lgetxattrs", (RStructList ("xattrs", "xattr"), [String "path"]), 142, [],
+   [],
+   "list extended attributes of a file or directory",
+   "\
+This is the same as C<guestfs_getxattrs>, but if C<path>
+is a symbolic link, then it returns the extended attributes
+of the link itself.");
+
+  ("setxattr", (RErr, [String "xattr";
+		       String "val"; Int "vallen"; (* will be BufferIn *)
+		       String "path"]), 143, [],
+   [],
+   "set extended attribute of a file or directory",
+   "\
+This call sets the extended attribute named C<xattr>
+of the file C<path> to the value C<val> (of length C<vallen>).
+The value is arbitrary 8 bit data.
+
+See also: C<guestfs_lsetxattr>, L<attr(5)>.");
+
+  ("lsetxattr", (RErr, [String "xattr";
+			String "val"; Int "vallen"; (* will be BufferIn *)
+			String "path"]), 144, [],
+   [],
+   "set extended attribute of a file or directory",
+   "\
+This is the same as C<guestfs_setxattr>, but if C<path>
+is a symbolic link, then it sets an extended attribute
+of the link itself.");
+
+  ("removexattr", (RErr, [String "xattr"; String "path"]), 145, [],
+   [],
+   "remove extended attribute of a file or directory",
+   "\
+This call removes the extended attribute named C<xattr>
+of the file C<path>.
+
+See also: C<guestfs_lremovexattr>, L<attr(5)>.");
+
+  ("lremovexattr", (RErr, [String "xattr"; String "path"]), 146, [],
+   [],
+   "remove extended attribute of a file or directory",
+   "\
+This is the same as C<guestfs_removexattr>, but if C<path>
+is a symbolic link, then it removes an extended attribute
+of the link itself.");
+
+  ("mountpoints", (RHashtable "mps", []), 147, [],
+   [],
+   "show mountpoints",
+   "\
+This call is similar to C<guestfs_mounts>.  That call returns
+a list of devices.  This one returns a hash table (map) of
+device name to directory where the device is mounted.");
+
+  ("mkmountpoint", (RErr, [String "path"]), 148, [],
+   [],
+   "create a mountpoint",
+   "\
+C<guestfs_mkmountpoint> and C<guestfs_rmmountpoint> are
+specialized calls that can be used to create extra mountpoints
+before mounting the first filesystem.
+
+These calls are I<only> necessary in some very limited circumstances,
+mainly the case where you want to mount a mix of unrelated and/or
+read-only filesystems together.
+
+For example, live CDs often contain a \"Russian doll\" nest of
+filesystems, an ISO outer layer, with a squashfs image inside, with
+an ext2/3 image inside that.  You can unpack this as follows
+in guestfish:
+
+ add-ro Fedora-11-i686-Live.iso
+ run
+ mkmountpoint /cd
+ mkmountpoint /squash
+ mkmountpoint /ext3
+ mount /dev/sda /cd
+ mount-loop /cd/LiveOS/squashfs.img /squash
+ mount-loop /squash/LiveOS/ext3fs.img /ext3
+
+The inner filesystem is now unpacked under the /ext3 mountpoint.");
+
+  ("rmmountpoint", (RErr, [String "path"]), 149, [],
+   [],
+   "remove a mountpoint",
+   "\
+This calls removes a mountpoint that was previously created
+with C<guestfs_mkmountpoint>.  See C<guestfs_mkmountpoint>
+for full details.");
+
+  ("read_file", (RBufferOut "content", [String "path"]), 150, [ProtocolLimitWarning],
+   [InitBasicFS, Always, TestOutput (
+      [["write_file"; "/new"; "new file contents"; "0"];
+       ["read_file"; "/new"]], "new file contents")],
+   "read a file",
+   "\
+This calls returns the contents of the file C<path> as a
+buffer.
+
+Unlike C<guestfs_cat>, this function can correctly
+handle files that contain embedded ASCII NUL characters.
+However unlike C<guestfs_download>, this function is limited
+in the total size of file that can be handled.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
@@ -2828,6 +3049,7 @@ let all_functions_sorted =
 type field =
   | FChar			(* C 'char' (really, a 7 bit byte). *)
   | FString			(* nul-terminated ASCII string. *)
+  | FBuffer			(* opaque buffer of bytes, (char *, int) pair *)
   | FUInt32
   | FInt32
   | FUInt64
@@ -2966,6 +3188,12 @@ let structs = [
     "release", FInt64;
     "extra", FString;
   ];
+
+  (* Extended attribute. *)
+  "xattr", [
+    "attrname", FString;
+    "attrval", FBuffer;
+  ];
 ] (* end of structs *)
 
 (* Ugh, Java has to be different ..
@@ -2980,6 +3208,7 @@ let java_structs = [
   "statvfs", "StatVFS";
   "dirent", "Dirent";
   "version", "Version";
+  "xattr", "XAttr";
 ]
 
 (* Used for testing language bindings. *)
@@ -3130,7 +3359,8 @@ let cols_of_struct typ =
 let seq_of_test = function
   | TestRun s | TestOutput (s, _) | TestOutputList (s, _)
   | TestOutputListOfDevices (s, _)
-  | TestOutputInt (s, _) | TestOutputTrue s | TestOutputFalse s
+  | TestOutputInt (s, _) | TestOutputIntOp (s, _, _)
+  | TestOutputTrue s | TestOutputFalse s
   | TestOutputLength (s, _) | TestOutputStruct (s, _)
   | TestLastFail s -> s
 
@@ -3187,7 +3417,7 @@ let check_functions () =
        | RErr -> ()
        | RInt n | RInt64 n | RBool n | RConstString n | RString n
        | RStringList n | RStruct (n, _) | RStructList (n, _)
-       | RHashtable n ->
+       | RHashtable n | RBufferOut n ->
 	   check_arg_ret_name n
       );
       List.iter (fun arg -> check_arg_ret_name (name_of_argt arg)) (snd style)
@@ -3369,6 +3599,10 @@ strings, or NULL if there was an error.
 The array of strings will always have length C<2n+1>, where
 C<n> keys and values alternate, followed by the trailing NULL entry.
 I<The caller must free the strings and the array after use>.\n\n"
+	 | RBufferOut _ ->
+	     pr "This function returns a buffer, or NULL on error.
+The size of the returned buffer is written to C<*size_r>.
+I<The caller must free the returned buffer after use>.\n\n"
 	);
 	if List.mem ProtocolLimitWarning flags then
 	  pr "%s\n\n" protocol_limit_warning;
@@ -3392,6 +3626,10 @@ and generate_structs_pod () =
 	| name, (FUInt64|FBytes) -> pr "   uint64_t %s;\n" name
 	| name, FInt64 -> pr "   int64_t %s;\n" name
 	| name, FString -> pr "   char *%s;\n" name
+	| name, FBuffer ->
+	    pr "   /* The next two fields describe a byte array. */\n";
+	    pr "   uint32_t %s_len;\n" name;
+	    pr "   char *%s;\n" name
 	| name, FUUID ->
 	    pr "   /* The next field is NOT nul-terminated, be careful when printing it: */\n";
 	    pr "   char %s[32];\n" name
@@ -3435,6 +3673,7 @@ and generate_xdr () =
 	List.iter (function
 		   | name, FChar -> pr "  char %s;\n" name
 		   | name, FString -> pr "  string %s<>;\n" name
+		   | name, FBuffer -> pr "  opaque %s<>;\n" name
 		   | name, FUUID -> pr "  opaque %s[32];\n" name
 		   | name, (FInt32|FUInt32) -> pr "  int %s;\n" name
 		   | name, (FInt64|FUInt64|FBytes) -> pr "  hyper %s;\n" name
@@ -3501,6 +3740,10 @@ and generate_xdr () =
 	   pr "struct %s_ret {\n" name;
 	   pr "  str %s<>;\n" n;
 	   pr "};\n\n"
+       | RBufferOut n ->
+	   pr "struct %s_ret {\n" name;
+	   pr "  opaque %s<>;\n" n;
+	   pr "};\n\n"
       );
   ) daemon_functions;
 
@@ -3596,6 +3839,9 @@ and generate_structs_h () =
 	function
 	| name, FChar -> pr "  char %s;\n" name
 	| name, FString -> pr "  char *%s;\n" name
+	| name, FBuffer ->
+	    pr "  uint32_t %s_len;\n" name;
+	    pr "  char *%s;\n" name
 	| name, FUUID -> pr "  char %s[32]; /* this is NOT nul-terminated, be careful when printing */\n" name
 	| name, FUInt32 -> pr "  uint32_t %s;\n" name
 	| name, FInt32 -> pr "  int32_t %s;\n" name
@@ -3681,7 +3927,7 @@ check_state (guestfs_h *g, const char *caller)
 {
   if (!guestfs_is_ready (g)) {
     if (guestfs_is_config (g))
-      error (g, \"%%s: call launch() before using this function\",
+      error (g, \"%%s: call launch before using this function\\n(in guestfish, don't forget to use the 'run' command)\",
         caller);
     else if (guestfs_is_launching (g))
       error (g, \"%%s: call wait_ready() before using this function\",
@@ -3719,7 +3965,7 @@ check_state (guestfs_h *g, const char *caller)
        | RInt _ | RInt64 _
        | RBool _ | RString _ | RStringList _
        | RStruct _ | RStructList _
-       | RHashtable _ ->
+       | RHashtable _ | RBufferOut _ ->
 	   pr "  struct %s_ret ret;\n" name
       );
       pr "};\n";
@@ -3760,7 +4006,7 @@ check_state (guestfs_h *g, const char *caller)
        | RInt _ | RInt64 _
        | RBool _ | RString _ | RStringList _
        | RStruct _ | RStructList _
-       | RHashtable _ ->
+       | RHashtable _ | RBufferOut _ ->
 	   pr "  if (!xdr_%s_ret (xdr, &ctx->ret)) {\n" name;
 	   pr "    error (g, \"%%s: failed to parse reply\", \"%s\");\n" name;
 	   pr "    return;\n";
@@ -3782,7 +4028,7 @@ check_state (guestfs_h *g, const char *caller)
 	    failwithf "RConstString cannot be returned from a daemon function"
 	| RString _ | RStringList _
 	| RStruct _ | RStructList _
-	| RHashtable _ ->
+	| RHashtable _ | RBufferOut _ ->
 	    "NULL" in
 
       pr "{\n";
@@ -3920,6 +4166,9 @@ check_state (guestfs_h *g, const char *caller)
        | RStructList (n, _) ->
 	   pr "  /* caller will free this */\n";
 	   pr "  return safe_memdup (g, &ctx.ret.%s, sizeof (ctx.ret.%s));\n" n n
+       | RBufferOut n ->
+	   pr "  *size_r = ctx.ret.%s.%s_len;\n" n n;
+	   pr "  return ctx.ret.%s.%s_val; /* caller will free */\n" n n
       );
 
       pr "}\n\n"
@@ -4000,7 +4249,11 @@ and generate_daemon_actions () =
 	| RString _ -> pr "  char *r;\n"; "NULL"
 	| RStringList _ | RHashtable _ -> pr "  char **r;\n"; "NULL"
 	| RStruct (_, typ) -> pr "  guestfs_int_%s *r;\n" typ; "NULL"
-	| RStructList (_, typ) -> pr "  guestfs_int_%s_list *r;\n" typ; "NULL" in
+	| RStructList (_, typ) -> pr "  guestfs_int_%s_list *r;\n" typ; "NULL"
+	| RBufferOut _ ->
+	    pr "  size_t size;\n";
+	    pr "  char *r;\n";
+	    "NULL" in
 
       (match snd style with
        | [] -> ()
@@ -4054,11 +4307,11 @@ and generate_daemon_actions () =
       (* Don't want to call the impl with any FileIn or FileOut
        * parameters, since these go "outside" the RPC protocol.
        *)
-      let argsnofile =
+      let args' =
 	List.filter (function FileIn _ | FileOut _ -> false | _ -> true)
 	  (snd style) in
       pr "  r = do_%s " name;
-      generate_call_args argsnofile;
+      generate_c_call_args (fst style, args');
       pr ";\n";
 
       pr "  if (r == %s)\n" error_code;
@@ -4110,6 +4363,13 @@ and generate_daemon_actions () =
 	      name;
 	    pr "  xdr_free ((xdrproc_t) xdr_guestfs_%s_ret, (char *) &ret);\n"
 	      name
+	| RBufferOut n ->
+	    pr "  struct guestfs_%s_ret ret;\n" name;
+	    pr "  ret.%s.%s_val = r;\n" n n;
+	    pr "  ret.%s.%s_len = size;\n" n n;
+	    pr "  reply ((xdrproc_t) &xdr_guestfs_%s_ret, (char *) &ret);\n"
+	      name;
+	    pr "  free (r);\n"
       );
 
       (* Free the args. *)
@@ -4213,7 +4473,7 @@ and generate_daemon_actions () =
 		 pr "    fprintf (stderr, \"%%s: failed to parse float '%%s' from token %%s\\n\", __func__, tok, \"%s\");\n" name;
 		 pr "    return -1;\n";
 		 pr "  }\n";
-	     | FInt32 | FUInt32 | FUInt64 | FChar ->
+	     | FBuffer | FInt32 | FUInt32 | FUInt64 | FChar ->
 		 assert false (* can never be an LVM column *)
 	    );
 	    pr "  tok = next;\n";
@@ -4621,7 +4881,11 @@ static int %s (void)
 
 and generate_one_test_body name i test_name init test =
   (match init with
-   | InitNone
+   | InitNone (* XXX at some point, InitNone and InitEmpty became
+	       * folded together as the same thing.  Really we should
+	       * make InitNone do nothing at all, but the tests may
+	       * need to be checked to make sure this is OK.
+	       *)
    | InitEmpty ->
        pr "  /* InitNone|InitEmpty for %s */\n" test_name;
        List.iter (generate_test_command_call test_name)
@@ -4747,6 +5011,19 @@ and generate_one_test_body name i test_name init test =
       in
       List.iter (generate_test_command_call test_name) seq;
       generate_test_command_call ~test test_name last
+  | TestOutputIntOp (seq, op, expected) ->
+      pr "  /* TestOutputIntOp for %s (%d) */\n" name i;
+      let seq, last = get_seq_last seq in
+      let test () =
+	pr "    if (! (r %s %d)) {\n" op expected;
+	pr "      fprintf (stderr, \"%s: expected %s %d but got %%d\\n\","
+	  test_name op expected;
+	pr "               (int) r);\n";
+	pr "      return -1;\n";
+	pr "    }\n"
+      in
+      List.iter (generate_test_command_call test_name) seq;
+      generate_test_command_call ~test test_name last
   | TestOutputTrue seq ->
       pr "  /* TestOutputTrue for %s (%d) */\n" name i;
       let seq, last = get_seq_last seq in
@@ -4805,6 +5082,13 @@ and generate_one_test_body name i test_name init test =
 	      pr "               (int) r->%s);\n" field;
 	      pr "      return -1;\n";
 	      pr "    }\n"
+	  | CompareWithIntOp (field, op, expected) ->
+	      pr "    if (!(r->%s %s %d)) {\n" field op expected;
+	      pr "      fprintf (stderr, \"%s: %s was %%d, expected %s %d\\n\",\n"
+		test_name field op expected;
+	      pr "               (int) r->%s);\n" field;
+	      pr "      return -1;\n";
+	      pr "    }\n"
 	  | CompareWithString (field, expected) ->
 	      pr "    if (strcmp (r->%s, \"%s\") != 0) {\n" field expected;
 	      pr "      fprintf (stderr, \"%s: %s was \"%%s\", expected \"%s\"\\n\",\n"
@@ -4894,7 +5178,11 @@ and generate_test_command_call ?(expect_error = false) ?test test_name cmd =
 	| RStruct (_, typ) ->
 	    pr "    struct guestfs_%s *r;\n" typ; "NULL"
 	| RStructList (_, typ) ->
-	    pr "    struct guestfs_%s_list *r;\n" typ; "NULL" in
+	    pr "    struct guestfs_%s_list *r;\n" typ; "NULL"
+	| RBufferOut _ ->
+	    pr "    char *r;\n";
+	    pr "    size_t size;\n";
+	    "NULL" in
 
       pr "    suppress_error = %d;\n" (if expect_error then 1 else 0);
       pr "    r = guestfs_%s (g" name;
@@ -4920,7 +5208,13 @@ and generate_test_command_call ?(expect_error = false) ?test test_name cmd =
 	    let b = bool_of_string arg in pr ", %d" (if b then 1 else 0)
       ) (List.combine (snd style) args);
 
+      (match fst style with
+       | RBufferOut _ -> pr ", &size"
+       | _ -> ()
+      );
+
       pr ");\n";
+
       if not expect_error then
 	pr "    if (r == %s)\n" error_code
       else
@@ -4935,7 +5229,7 @@ and generate_test_command_call ?(expect_error = false) ?test test_name cmd =
 
       (match fst style with
        | RErr | RInt _ | RInt64 _ | RBool _ | RConstString _ -> ()
-       | RString _ -> pr "    free (r);\n"
+       | RString _ | RBufferOut _ -> pr "    free (r);\n"
        | RStringList _ | RHashtable _ ->
 	   pr "    for (i = 0; r[i] != NULL; ++i)\n";
 	   pr "      free (r[i]);\n";
@@ -4972,6 +5266,7 @@ and generate_fish_cmds () =
   pr "#include <stdlib.h>\n";
   pr "#include <string.h>\n";
   pr "#include <inttypes.h>\n";
+  pr "#include <ctype.h>\n";
   pr "\n";
   pr "#include <guestfs.h>\n";
   pr "#include \"fish.h\"\n";
@@ -5049,7 +5344,7 @@ and generate_fish_cmds () =
   List.iter (
     fun (typ, cols) ->
       let needs_i =
-        List.exists (function (_, FUUID) -> true | _ -> false) cols in
+        List.exists (function (_, (FUUID|FBuffer)) -> true | _ -> false) cols in
 
       pr "static void print_%s (struct guestfs_%s *%s)\n" typ typ typ;
       pr "{\n";
@@ -5066,6 +5361,14 @@ and generate_fish_cmds () =
 	    pr "  for (i = 0; i < 32; ++i)\n";
 	    pr "    printf (\"%%c\", %s->%s[i]);\n" typ name;
 	    pr "  printf (\"\\n\");\n"
+	| name, FBuffer ->
+	    pr "  printf (\"%s: \");\n" name;
+	    pr "  for (i = 0; i < %s->%s_len; ++i)\n" typ name;
+	    pr "    if (isprint (%s->%s[i]))\n" typ name;
+	    pr "      printf (\"%%c\", %s->%s[i]);\n" typ name;
+	    pr "    else\n";
+	    pr "      printf (\"\\\\x%%02x\", %s->%s[i]);\n" typ name;
+	    pr "  printf (\"\\n\");\n"
 	| name, (FUInt64|FBytes) ->
 	    pr "  printf (\"%s: %%\" PRIu64 \"\\n\", %s->%s);\n" name typ name
 	| name, FInt64 ->
@@ -5109,6 +5412,9 @@ and generate_fish_cmds () =
        | RStringList _ | RHashtable _ -> pr "  char **r;\n"
        | RStruct (_, typ) -> pr "  struct guestfs_%s *r;\n" typ
        | RStructList (_, typ) -> pr "  struct guestfs_%s_list *r;\n" typ
+       | RBufferOut _ ->
+	   pr "  char *r;\n";
+	   pr "  size_t size;\n";
       );
       List.iter (
 	function
@@ -5155,7 +5461,7 @@ and generate_fish_cmds () =
 	try find_map (function FishAction n -> Some n | _ -> None) flags
 	with Not_found -> sprintf "guestfs_%s" name in
       pr "  r = %s " fn;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" style;
       pr ";\n";
 
       (* Check return value for errors and display command results. *)
@@ -5202,6 +5508,11 @@ and generate_fish_cmds () =
 	   pr "  print_table (r);\n";
 	   pr "  free_strings (r);\n";
 	   pr "  return 0;\n"
+       | RBufferOut _ ->
+	   pr "  if (r == NULL) return -1;\n";
+	   pr "  fwrite (r, size, 1, stdout);\n";
+	   pr "  free (r);\n";
+	   pr "  return 0;\n"
       );
       pr "}\n";
       pr "\n"
@@ -5392,7 +5703,7 @@ and generate_prototype ?(extern = true) ?(static = false) ?(semicolon = true)
    | RInt64 _ -> pr "int64_t "
    | RBool _ -> pr "int "
    | RConstString _ -> pr "const char *"
-   | RString _ -> pr "char *"
+   | RString _ | RBufferOut _ -> pr "char *"
    | RStringList _ | RHashtable _ -> pr "char **"
    | RStruct (_, typ) ->
        if not in_daemon then pr "struct guestfs_%s *" typ
@@ -5401,8 +5712,9 @@ and generate_prototype ?(extern = true) ?(static = false) ?(semicolon = true)
        if not in_daemon then pr "struct guestfs_%s_list *" typ
        else pr "guestfs_int_%s_list *" typ
   );
+  let is_RBufferOut = match fst style with RBufferOut _ -> true | _ -> false in
   pr "%s%s (" prefix name;
-  if handle = None && List.length (snd style) = 0 then
+  if handle = None && List.length (snd style) = 0 && not is_RBufferOut then
     pr "void"
   else (
     let comma = ref false in
@@ -5433,25 +5745,37 @@ and generate_prototype ?(extern = true) ?(static = false) ?(semicolon = true)
       | FileOut n ->
 	  if not in_daemon then (next (); pr "const char *%s" n)
     ) (snd style);
+    if is_RBufferOut then (next (); pr "size_t *size_r");
   );
   pr ")";
   if semicolon then pr ";";
   if newline then pr "\n"
 
 (* Generate C call arguments, eg "(handle, foo, bar)" *)
-and generate_call_args ?handle args =
+and generate_c_call_args ?handle ?(decl = false) style =
   pr "(";
   let comma = ref false in
+  let next () =
+    if !comma then pr ", ";
+    comma := true
+  in
   (match handle with
    | None -> ()
    | Some handle -> pr "%s" handle; comma := true
   );
   List.iter (
     fun arg ->
-      if !comma then pr ", ";
-      comma := true;
+      next ();
       pr "%s" (name_of_argt arg)
-  ) args;
+  ) (snd style);
+  (* For RBufferOut calls, add implicit &size parameter. *)
+  if not decl then (
+    match fst style with
+    | RBufferOut _ ->
+	next ();
+	pr "&size"
+    | _ -> ()
+  );
   pr ")"
 
 (* Generate the OCaml bindings interface. *)
@@ -5581,6 +5905,10 @@ copy_table (char * const * argv)
 	  (match col with
 	   | name, FString ->
 	       pr "  v = caml_copy_string (%s->%s);\n" typ name
+	   | name, FBuffer ->
+	       pr "  v = caml_alloc_string (%s->%s_len);\n" typ name;
+	       pr "  memcpy (String_val (v), %s->%s, %s->%s_len);\n"
+		 typ name typ name
 	   | name, FUUID ->
 	       pr "  v = caml_alloc_string (32);\n";
 	       pr "  memcpy (String_val (v), %s->%s, 32);\n" typ name
@@ -5692,12 +6020,16 @@ copy_table (char * const * argv)
 	| RHashtable _ ->
 	    pr "  int i;\n";
 	    pr "  char **r;\n";
+	    "NULL"
+	| RBufferOut _ ->
+	    pr "  char *r;\n";
+	    pr "  size_t size;\n";
 	    "NULL" in
       pr "\n";
 
       pr "  caml_enter_blocking_section ();\n";
       pr "  r = guestfs_%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" style;
       pr ";\n";
       pr "  caml_leave_blocking_section ();\n";
 
@@ -5736,6 +6068,9 @@ copy_table (char * const * argv)
 	   pr "  rv = copy_table (r);\n";
 	   pr "  for (i = 0; r[i] != NULL; ++i) free (r[i]);\n";
 	   pr "  free (r);\n";
+       | RBufferOut _ ->
+	   pr "  rv = caml_alloc_string (size);\n";
+	   pr "  memcpy (String_val (rv), r, size);\n";
       );
 
       pr "  CAMLreturn (rv);\n";
@@ -5761,6 +6096,7 @@ and generate_ocaml_structure_decls () =
       List.iter (
 	function
 	| name, FString -> pr "  %s : string;\n" name
+	| name, FBuffer -> pr "  %s : string;\n" name
 	| name, FUUID -> pr "  %s : string;\n" name
 	| name, (FBytes|FInt64|FUInt64) -> pr "  %s : int64;\n" name
 	| name, (FInt32|FUInt32) -> pr "  %s : int32;\n" name
@@ -5788,7 +6124,7 @@ and generate_ocaml_prototype ?(is_external = false) name style =
    | RInt64 _ -> pr "int64"
    | RBool _ -> pr "bool"
    | RConstString _ -> pr "string"
-   | RString _ -> pr "string"
+   | RString _ | RBufferOut _ -> pr "string"
    | RStringList _ -> pr "string array"
    | RStruct (_, typ) -> pr "%s" typ
    | RStructList (_, typ) -> pr "%s array" typ
@@ -5905,6 +6241,7 @@ DESTROY (g)
        | RBool _ -> pr "SV *\n"
        | RConstString _ -> pr "SV *\n"
        | RString _ -> pr "SV *\n"
+       | RBufferOut _ -> pr "SV *\n"
        | RStringList _
        | RStruct _ | RStructList _
        | RHashtable _ ->
@@ -5912,7 +6249,7 @@ DESTROY (g)
       );
       (* Call and arguments. *)
       pr "%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" ~decl:true style;
       pr "\n";
       pr "      guestfs_h *g;\n";
       iteri (
@@ -5946,7 +6283,7 @@ DESTROY (g)
 	   pr "      int r;\n";
 	   pr " PPCODE:\n";
 	   pr "      r = guestfs_%s " name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (r == -1)\n";
@@ -5957,7 +6294,7 @@ DESTROY (g)
 	   pr "      int %s;\n" n;
 	   pr "   CODE:\n";
 	   pr "      %s = guestfs_%s " n name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (%s == -1)\n" n;
@@ -5970,7 +6307,7 @@ DESTROY (g)
 	   pr "      int64_t %s;\n" n;
 	   pr "   CODE:\n";
 	   pr "      %s = guestfs_%s " n name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (%s == -1)\n" n;
@@ -5983,7 +6320,7 @@ DESTROY (g)
 	   pr "      const char *%s;\n" n;
 	   pr "   CODE:\n";
 	   pr "      %s = guestfs_%s " n name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (%s == NULL)\n" n;
@@ -5996,7 +6333,7 @@ DESTROY (g)
 	   pr "      char *%s;\n" n;
 	   pr "   CODE:\n";
 	   pr "      %s = guestfs_%s " n name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (%s == NULL)\n" n;
@@ -6011,7 +6348,7 @@ DESTROY (g)
 	   pr "      int i, n;\n";
 	   pr " PPCODE:\n";
 	   pr "      %s = guestfs_%s " n name;
-	   generate_call_args ~handle:"g" (snd style);
+	   generate_c_call_args ~handle:"g" style;
 	   pr ";\n";
 	   do_cleanups ();
 	   pr "      if (%s == NULL)\n" n;
@@ -6029,6 +6366,21 @@ DESTROY (g)
        | RStructList (n, typ) ->
 	   let cols = cols_of_struct typ in
 	   generate_perl_struct_list_code typ cols name style n do_cleanups
+       | RBufferOut n ->
+	   pr "PREINIT:\n";
+	   pr "      char *%s;\n" n;
+	   pr "      size_t size;\n";
+	   pr "   CODE:\n";
+	   pr "      %s = guestfs_%s " n name;
+	   generate_c_call_args ~handle:"g" style;
+	   pr ";\n";
+	   do_cleanups ();
+	   pr "      if (%s == NULL)\n" n;
+	   pr "        croak (\"%s: %%s\", guestfs_last_error (g));\n" name;
+	   pr "      RETVAL = newSVpv (%s, size);\n" n;
+	   pr "      free (%s);\n" n;
+	   pr " OUTPUT:\n";
+	   pr "      RETVAL\n"
       );
 
       pr "\n"
@@ -6041,7 +6393,7 @@ and generate_perl_struct_list_code typ cols name style n do_cleanups =
   pr "      HV *hv;\n";
   pr " PPCODE:\n";
   pr "      %s = guestfs_%s " n name;
-  generate_call_args ~handle:"g" (snd style);
+  generate_c_call_args ~handle:"g" style;
   pr ";\n";
   do_cleanups ();
   pr "      if (%s == NULL)\n" n;
@@ -6057,6 +6409,9 @@ and generate_perl_struct_list_code typ cols name style n do_cleanups =
     | name, FUUID ->
 	pr "        (void) hv_store (hv, \"%s\", %d, newSVpv (%s->val[i].%s, 32), 0);\n"
 	  name (String.length name) n name
+    | name, FBuffer ->
+	pr "        (void) hv_store (hv, \"%s\", %d, newSVpv (%s->val[i].%s, %s->val[i].%s_len), 0);\n"
+	  name (String.length name) n name n name
     | name, (FBytes|FUInt64) ->
 	pr "        (void) hv_store (hv, \"%s\", %d, my_newSVull (%s->val[i].%s), 0);\n"
 	  name (String.length name) n name
@@ -6082,7 +6437,7 @@ and generate_perl_struct_code typ cols name style n do_cleanups =
   pr "      struct guestfs_%s *%s;\n" typ n;
   pr " PPCODE:\n";
   pr "      %s = guestfs_%s " n name;
-  generate_call_args ~handle:"g" (snd style);
+  generate_c_call_args ~handle:"g" style;
   pr ";\n";
   do_cleanups ();
   pr "      if (%s == NULL)\n" n;
@@ -6096,6 +6451,9 @@ and generate_perl_struct_code typ cols name style n do_cleanups =
       | name, FString ->
 	  pr "      PUSHs (sv_2mortal (newSVpv (%s->%s, 0)));\n"
 	    n name
+      | name, FBuffer ->
+	  pr "      PUSHs (sv_2mortal (newSVpv (%s->%s, %s->%s_len)));\n"
+	    n name n name
       | name, FUUID ->
 	  pr "      PUSHs (sv_2mortal (newSVpv (%s->%s, 32)));\n"
 	    n name
@@ -6252,7 +6610,8 @@ and generate_perl_prototype name style =
    | RInt n
    | RInt64 n
    | RConstString n
-   | RString n -> pr "$%s = " n
+   | RString n
+   | RBufferOut n -> pr "$%s = " n
    | RStruct (n,_)
    | RHashtable n -> pr "%%%s = " n
    | RStringList n
@@ -6428,6 +6787,10 @@ py_guestfs_close (PyObject *self, PyObject *args)
 	    pr "  PyDict_SetItemString (dict, \"%s\",\n" name;
 	    pr "                        PyString_FromString (%s->%s));\n"
 	      typ name
+	| name, FBuffer ->
+	    pr "  PyDict_SetItemString (dict, \"%s\",\n" name;
+	    pr "                        PyString_FromStringAndSize (%s->%s, %s->%s_len));\n"
+	      typ name typ name
 	| name, FUUID ->
 	    pr "  PyDict_SetItemString (dict, \"%s\",\n" name;
 	    pr "                        PyString_FromStringAndSize (%s->%s, 32));\n"
@@ -6499,7 +6862,11 @@ py_guestfs_close (PyObject *self, PyObject *args)
 	| RStringList _ | RHashtable _ -> pr "  char **r;\n"; "NULL"
 	| RStruct (_, typ) -> pr "  struct guestfs_%s *r;\n" typ; "NULL"
 	| RStructList (_, typ) ->
-	    pr "  struct guestfs_%s_list *r;\n" typ; "NULL" in
+	    pr "  struct guestfs_%s_list *r;\n" typ; "NULL"
+	| RBufferOut _ ->
+	    pr "  char *r;\n";
+	    pr "  size_t size;\n";
+	    "NULL" in
 
       List.iter (
 	function
@@ -6550,7 +6917,7 @@ py_guestfs_close (PyObject *self, PyObject *args)
       pr "\n";
 
       pr "  r = guestfs_%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" style;
       pr ";\n";
 
       List.iter (
@@ -6589,6 +6956,9 @@ py_guestfs_close (PyObject *self, PyObject *args)
        | RHashtable n ->
 	   pr "  py_r = put_table (r);\n";
 	   pr "  free_strings (r);\n"
+       | RBufferOut _ ->
+	   pr "  py_r = PyString_FromStringAndSize (r, size);\n";
+	   pr "  free (r);\n"
       );
 
       pr "  return py_r;\n";
@@ -6692,7 +7062,7 @@ class GuestFS:
   List.iter (
     fun (name, style, _, flags, _, _, longdesc) ->
       pr "    def %s " name;
-      generate_call_args ~handle:"self" (snd style);
+      generate_py_call_args ~handle:"self" (snd style);
       pr ":\n";
 
       if not (List.mem NotInDocs flags) then (
@@ -6700,7 +7070,7 @@ class GuestFS:
 	let doc =
           match fst style with
 	  | RErr | RInt _ | RInt64 _ | RBool _ | RConstString _
-	  | RString _ -> doc
+	  | RString _ | RBufferOut _ -> doc
 	  | RStringList _ ->
 	      doc ^ "\n\nThis function returns a list of strings."
 	  | RStruct (_, typ) ->
@@ -6723,11 +7093,17 @@ class GuestFS:
 	pr "        u\"\"\"%s\"\"\"\n" doc;
       );
       pr "        return libguestfsmod.%s " name;
-      generate_call_args ~handle:"self._o" (snd style);
+      generate_py_call_args ~handle:"self._o" (snd style);
       pr "\n";
       pr "\n";
   ) all_functions
 
+(* Generate Python call arguments, eg "(handle, foo, bar)" *)
+and generate_py_call_args ~handle args =
+  pr "(%s" handle;
+  List.iter (fun arg -> pr ", %s" (name_of_argt arg)) args;
+  pr ")"
+
 (* Useful if you need the longdesc POD text as plain text.  Returns a
  * list of lines.
  *
@@ -6880,11 +7256,15 @@ static VALUE ruby_guestfs_close (VALUE gv)
 	| RStringList _ | RHashtable _ -> pr "  char **r;\n"; "NULL"
 	| RStruct (_, typ) -> pr "  struct guestfs_%s *r;\n" typ; "NULL"
 	| RStructList (_, typ) ->
-	    pr "  struct guestfs_%s_list *r;\n" typ; "NULL" in
+	    pr "  struct guestfs_%s_list *r;\n" typ; "NULL"
+	| RBufferOut _ ->
+	    pr "  char *r;\n";
+	    pr "  size_t size;\n";
+	    "NULL" in
       pr "\n";
 
       pr "  r = guestfs_%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" style;
       pr ";\n";
 
       List.iter (
@@ -6937,6 +7317,10 @@ static VALUE ruby_guestfs_close (VALUE gv)
 	   pr "  }\n";
 	   pr "  free (r);\n";
 	   pr "  return rv;\n"
+       | RBufferOut _ ->
+	   pr "  VALUE rv = rb_str_new (r, size);\n";
+	   pr "  free (r);\n";
+	   pr "  return rv;\n";
       );
 
       pr "}\n";
@@ -6971,6 +7355,8 @@ and generate_ruby_struct_code typ cols =
     function
     | name, FString ->
 	pr "  rb_hash_aset (rv, rb_str_new2 (\"%s\"), rb_str_new2 (r->%s));\n" name name
+    | name, FBuffer ->
+	pr "  rb_hash_aset (rv, rb_str_new2 (\"%s\"), rb_str_new (r->%s, r->%s_len));\n" name name name
     | name, FUUID ->
 	pr "  rb_hash_aset (rv, rb_str_new2 (\"%s\"), rb_str_new (r->%s, 32));\n" name name
     | name, (FBytes|FUInt64) ->
@@ -6999,6 +7385,8 @@ and generate_ruby_struct_list_code typ cols =
     function
     | name, FString ->
 	pr "    rb_hash_aset (hv, rb_str_new2 (\"%s\"), rb_str_new2 (r->val[i].%s));\n" name name
+    | name, FBuffer ->
+	pr "    rb_hash_aset (hv, rb_str_new2 (\"%s\"), rb_str_new (r->val[i].%s, r->val[i].%s_len));\n" name name name
     | name, FUUID ->
 	pr "    rb_hash_aset (hv, rb_str_new2 (\"%s\"), rb_str_new (r->val[i].%s, 32));\n" name name
     | name, (FBytes|FUInt64) ->
@@ -7126,7 +7514,7 @@ public class GuestFS {
       pr "    ";
       if fst style <> RErr then pr "return ";
       pr "_%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_java_call_args ~handle:"g" (snd style);
       pr ";\n";
       pr "  }\n";
       pr "  ";
@@ -7137,6 +7525,12 @@ public class GuestFS {
 
   pr "}\n"
 
+(* Generate Java call arguments, eg "(handle, foo, bar)" *)
+and generate_java_call_args ~handle args =
+  pr "(%s" handle;
+  List.iter (fun arg -> pr ", %s" (name_of_argt arg)) args;
+  pr ")"
+
 and generate_java_prototype ?(public=false) ?(privat=false) ?(native=false)
     ?(semicolon=true) name style =
   if privat then pr "private ";
@@ -7149,7 +7543,7 @@ and generate_java_prototype ?(public=false) ?(privat=false) ?(native=false)
    | RInt _ -> pr "int ";
    | RInt64 _ -> pr "long ";
    | RBool _ -> pr "boolean ";
-   | RConstString _ | RString _ -> pr "String ";
+   | RConstString _ | RString _ | RBufferOut _ -> pr "String ";
    | RStringList _ -> pr "String[] ";
    | RStruct (_, typ) ->
        let name = java_name_of_struct typ in
@@ -7210,7 +7604,8 @@ public class %s {
   List.iter (
     function
     | name, FString
-    | name, FUUID -> pr "  public String %s;\n" name
+    | name, FUUID
+    | name, FBuffer -> pr "  public String %s;\n" name
     | name, (FBytes|FUInt64|FInt64) -> pr "  public long %s;\n" name
     | name, (FUInt32|FInt32) -> pr "  public int %s;\n" name
     | name, FChar -> pr "  public char %s;\n" name
@@ -7277,7 +7672,7 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
        | RInt _ -> pr "jint ";
        | RInt64 _ -> pr "jlong ";
        | RBool _ -> pr "jboolean ";
-       | RConstString _ | RString _ -> pr "jstring ";
+       | RConstString _ | RString _ | RBufferOut _ -> pr "jstring ";
        | RStruct _ | RHashtable _ ->
 	   pr "jobject ";
        | RStringList _ | RStructList _ ->
@@ -7332,7 +7727,12 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
 	    pr "  jfieldID fl;\n";
 	    pr "  jobject jfl;\n";
 	    pr "  struct guestfs_%s_list *r;\n" typ; "NULL", "NULL"
-	| RHashtable _ -> pr "  char **r;\n"; "NULL", "NULL" in
+	| RHashtable _ -> pr "  char **r;\n"; "NULL", "NULL"
+	| RBufferOut _ ->
+	    pr "  jstring jr;\n";
+	    pr "  char *r;\n";
+	    pr "  size_t size;\n";
+	    "NULL", "NULL" in
       List.iter (
 	function
 	| String n
@@ -7352,7 +7752,7 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
 	(match fst style with
 	 | RStringList _ | RStructList _ -> true
 	 | RErr | RBool _ | RInt _ | RInt64 _ | RConstString _
-	 | RString _ | RStruct _ | RHashtable _ -> false) ||
+	 | RString _ | RBufferOut _ | RStruct _ | RHashtable _ -> false) ||
 	  List.exists (function StringList _ -> true | _ -> false) (snd style) in
       if needs_i then
 	pr "  int i;\n";
@@ -7387,7 +7787,7 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
 
       (* Make the call. *)
       pr "  r = guestfs_%s " name;
-      generate_call_args ~handle:"g" (snd style);
+      generate_c_call_args ~handle:"g" style;
       pr ";\n";
 
       (* Release the parameters. *)
@@ -7452,6 +7852,10 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
 	   (* XXX *)
 	   pr "  throw_exception (env, \"%s: internal error: please let us know how to make a Java HashMap from JNI bindings!\");\n" name;
 	   pr "  return NULL;\n"
+       | RBufferOut _ ->
+	   pr "  jr = (*env)->NewStringUTF (env, r); /* XXX size */\n";
+	   pr "  free (r);\n";
+	   pr "  return jr;\n"
       );
 
       pr "}\n";
@@ -7474,6 +7878,15 @@ and generate_java_struct_return typ jtyp cols =
 	pr "    fl = (*env)->GetFieldID (env, cl, \"%s\", \"Ljava/lang/String;\");\n" name;
 	pr "    (*env)->SetObjectField (env, jr, fl, (*env)->NewStringUTF (env, s));\n";
 	pr "  }\n";
+    | name, FBuffer ->
+	pr "  {\n";
+	pr "    int len = r->%s_len;\n" name;
+	pr "    char s[len+1];\n";
+	pr "    memcpy (s, r->%s, len);\n" name;
+	pr "    s[len] = 0;\n";
+	pr "    fl = (*env)->GetFieldID (env, cl, \"%s\", \"Ljava/lang/String;\");\n" name;
+	pr "    (*env)->SetObjectField (env, jr, fl, (*env)->NewStringUTF (env, s));\n";
+	pr "  }\n";
     | name, (FBytes|FUInt64|FInt64) ->
 	pr "  fl = (*env)->GetFieldID (env, cl, \"%s\", \"J\");\n" name;
 	pr "  (*env)->SetLongField (env, jr, fl, r->%s);\n" name;
@@ -7508,6 +7921,15 @@ and generate_java_struct_list_return typ jtyp cols =
 	pr "      fl = (*env)->GetFieldID (env, cl, \"%s\", \"Ljava/lang/String;\");\n" name;
 	pr "      (*env)->SetObjectField (env, jfl, fl, (*env)->NewStringUTF (env, s));\n";
 	pr "    }\n";
+    | name, FBuffer ->
+	pr "    {\n";
+	pr "      int len = r->val[i].%s_len;\n" name;
+	pr "      char s[len+1];\n";
+	pr "      memcpy (s, r->val[i].%s, len);\n" name;
+	pr "      s[len] = 0;\n";
+	pr "      fl = (*env)->GetFieldID (env, cl, \"%s\", \"Ljava/lang/String;\");\n" name;
+	pr "      (*env)->SetObjectField (env, jfl, fl, (*env)->NewStringUTF (env, s));\n";
+	pr "    }\n";
     | name, (FBytes|FUInt64|FInt64) ->
 	pr "    fl = (*env)->GetFieldID (env, cl, \"%s\", \"J\");\n" name;
 	pr "    (*env)->SetLongField (env, jfl, fl, r->val[i].%s);\n" name;
@@ -7543,7 +7965,8 @@ and generate_haskell_hs () =
     | RStringList _, _
     | RStruct _, _
     | RStructList _, _
-    | RHashtable _, _ -> false in
+    | RHashtable _, _
+    | RBufferOut _, _ -> false in
 
   pr "\
 {-# INCLUDE <guestfs.h> #-}
@@ -7653,7 +8076,7 @@ last_error h = do
 	     pr "      err <- last_error h\n";
 	     pr "      fail err\n";
 	 | RConstString _ | RString _ | RStringList _ | RStruct _
-	 | RStructList _ | RHashtable _ ->
+	 | RStructList _ | RHashtable _ | RBufferOut _ ->
 	     pr "  if (r == nullPtr)\n";
 	     pr "    then do\n";
 	     pr "      err <- last_error h\n";
@@ -7673,7 +8096,8 @@ last_error h = do
 	 | RStringList _
 	 | RStruct _
 	 | RStructList _
-	 | RHashtable _ ->
+	 | RHashtable _
+	 | RBufferOut _ ->
 	     pr "    else return ()\n" (* XXXXXXXXXXXXXXXXXXXX *)
 	);
 	pr "\n";
@@ -7715,6 +8139,7 @@ and generate_haskell_prototype ~handle ?(hs = false) style =
        let name = java_name_of_struct typ in
        pr "[%s]" name
    | RHashtable _ -> pr "Hashtable"
+   | RBufferOut _ -> pr "%s" string
   );
   pr ")"
 
@@ -7838,6 +8263,8 @@ print_strings (char * const* const argv)
 	     pr "  }\n";
 	     pr "  strs[n*2] = NULL;\n";
 	     pr "  return strs;\n"
+	 | RBufferOut _ ->
+	     pr "  return strdup (val);\n"
 	);
 	pr "}\n";
 	pr "\n"
@@ -7853,7 +8280,8 @@ print_strings (char * const* const argv)
 	 | RConstString _
 	 | RString _ | RStringList _ | RStruct _
 	 | RStructList _
-	 | RHashtable _ ->
+	 | RHashtable _
+	 | RBufferOut _ ->
 	     pr "  return NULL;\n"
 	);
 	pr "}\n";
@@ -8271,6 +8699,15 @@ Run it from the top source directory using the command
       close ();
   ) java_structs;
 
+  let close = output_to "java/Makefile.inc" in
+  pr "java_built_sources =";
+  List.iter (
+    fun (typ, jtyp) ->
+        pr " com/redhat/et/libguestfs/%s.java" jtyp;
+  ) java_structs;
+  pr " com/redhat/et/libguestfs/GuestFS.java\n";
+  close ();
+
   let close = output_to "java/com_redhat_et_libguestfs_GuestFS.c" in
   generate_java_c ();
   close ();