From c07dde3ade4465dc6de99fd0761cb2707fe65ac2 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Sat, 18 Oct 2014 18:41:01 +0100

Subject: [PATCH] mllib: Enhance and rename 'detect_compression' function so it

 can detect a few more file types.

(cherry picked from commit d8e26d0e4dc3de649cf81584e8c060becd2e4531)

---

 builder/builder.ml     |  6 +++++-

 mllib/common_utils.ml  | 29 ++++++++++++++++++++---------

 mllib/common_utils.mli |  6 ++----

 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/builder/builder.ml b/builder/builder.ml

index 5195cfd..121c5fb 100644

--- a/builder/builder.ml

+++ b/builder/builder.ml

@@ -315,8 +315,12 @@ let main () =

       | None -> []

       | Some format -> [`Format, format] in

     let compression_tag =

-      match detect_compression template with

+      match detect_file_type template with

       | `XZ -> [ `XZ, "" ]

+      | `GZip | `Tar | `Zip ->

+        eprintf (f_"%s: input file (%s) has an unsupported type\n")

+          prog template;

+        exit 1

       | `Unknown -> [] in

     [ `Template, ""; `Filename, template; `Size, Int64.to_string size ] @

       format_tag @ compression_tag in

diff --git a/mllib/common_utils.ml b/mllib/common_utils.ml

index adfad3f..295981c 100644

--- a/mllib/common_utils.ml

+++ b/mllib/common_utils.ml

@@ -547,17 +547,28 @@ let rm_rf_only_files (g : Guestfs.guestfs) dir =

     List.iter g#rm files

   )

-(* Detect compression of a file.

- *

- * Only detects the formats we need in virt-builder so far.

- *)

-let detect_compression filename =

+(* Detect type of a file. *)

+let detect_file_type filename =

   let chan = open_in filename in

-  let buf = String.create 6 in

-  really_input chan buf 0 6;

+  let get start size =

+    try

+      seek_in chan start;

+      let buf = String.create size in

+      really_input chan buf 0 size;

+      Some buf

+    with End_of_file | Invalid_argument _ -> None

+  in

+  let ret =

+    if get 0 6 = Some "\2537zXZ\000" then `XZ

+    else if get 0 4 = Some "PK\003\004" then `Zip

+    else if get 0 4 = Some "PK\005\006" then `Zip

+    else if get 0 4 = Some "PK\007\008" then `Zip

+    else if get 257 6 = Some "ustar\000" then `Tar

+    else if get 257 8 = Some "ustar\x20\x20\000" then `Tar

+    else if get 0 2 = Some "\x1f\x8b" then `GZip

+    else `Unknown in

   close_in chan;

-  if buf = "\2537zXZ\000" then `XZ

-  else `Unknown

+  ret

 let is_block_device file =

   try (Unix.stat file).Unix.st_kind = Unix.S_BLK

diff --git a/mllib/common_utils.mli b/mllib/common_utils.mli

index d78fd70..112648a 100644

--- a/mllib/common_utils.mli

+++ b/mllib/common_utils.mli

@@ -118,10 +118,8 @@ val rm_rf_only_files : Guestfs.guestfs -> string -> unit

     XXX Could be faster with a specific API for doing this. *)

-val detect_compression : string -> [`Unknown | `XZ]

-(** Detect compression of a file.

-

-    XXX Only detects the formats we need in virt-builder so far. *)

+val detect_file_type : string -> [`GZip | `Tar | `XZ | `Zip | `Unknown]

+(** Detect type of a file. *)

 val is_block_device : string -> bool

 val is_char_device : string -> bool

-- 

1.8.3.1