Bug 602423

Created attachment 422705 [details]
Parmesan for the fettucini

Surely you know what to do with a shell script:

    $ wc -l rpm2cpio.sh
    51 rpm2cpio.sh

shell script doesn't work for me on a centos 5 system:

# Getting RPM
$ wget http://ftp.redhat.com/redhat/rhel/beta/6/i386/os/Packages/kernel-devel-2.6.32-19.el6.i686.rpm

# Checking if it's OK
$ rpm -K kernel-devel-2.6.32-19.el6.i686.rpmkernel-devel-2.6.32-19.el6.i686.rpm: RSA sha1 (MD5) (PGP) md5 NOT OK (MISSING KEYS: PGP#f21541eb)

# Trying to unpack
$ rpm2cpio.sh kernel-devel-2.6.32-19.el6.i686.rpm  | cpio -id
/usr/bin/unlzma: (stdin): File format not recognized
cpio: premature end of archive

# Shell trace follows
$ bash -x rpm2cpio.sh kernel-devel-2.6.32-19.el6.i686.rpm  | cpio 
cpio: You must specify one of -oipt options.
Try `cpio --help' or `cpio --usage' for more information.

+ pkg=kernel-devel-2.6.32-19.el6.i686.rpm
+ '[' kernel-devel-2.6.32-19.el6.i686.rpm = '' -o '!' -e kernel-devel-2.6.32-19.el6.i686.rpm ']'
+ leadsize=96
++ expr 96 + 8
+ o=104
++ od -j 104 -N 8 -t u1 kernel-devel-2.6.32-19.el6.i686.rpm
+ set 0000150 0 0 0 7 0 0 4 132 0000160
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 0 ')' + 7
+ il=7
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 4 ')' + 132
+ dl=1156
++ expr 8 + 16 '*' 7 + 1156
+ sigsize=1276
++ expr 104 + 1276 + '(' 8 - '(' 1276 % 8 ')' ')' % 8 + 8
+ o=1392
++ od -j 1392 -N 8 -t u1 kernel-devel-2.6.32-19.el6.i686.rpm
+ set 0002560 0 0 0 53 0 19 195 180 0002570
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 0 ')' + 53
+ il=53
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 19 ')' + 195 ')' + 180
+ dl=1295284
++ expr 8 + 16 '*' 53 + 1295284
+ hdrsize=1296140
++ expr 1392 + 1296140
+ o=1297532
+ EXTRACTOR='dd if=kernel-devel-2.6.32-19.el6.i686.rpm ibs=1297532 skip=1'
+ COMPRESSION='/dev/stdin: data'
+ echo /dev/stdin: data
+ grep -q gzip
+ echo /dev/stdin: data
+ grep -q bzip2
+ echo /dev/stdin: data
+ grep -q xz
+ echo /dev/stdin: data
+ grep -q cpio
++ which unlzma
+ DECOMPRESSOR=/usr/bin/unlzma
+ case "$DECOMPRESSOR" in
+ dd if=kernel-devel-2.6.32-19.el6.i686.rpm ibs=1297532 skip=1
+ /usr/bin/unlzma
/usr/bin/unlzma: (stdin): File format not recognized
[kir@ovzdl tmp]$ bash -x rpm2cpio.sh kernel-devel-2.6.32-19.el6.i686.rpm
+ pkg=kernel-devel-2.6.32-19.el6.i686.rpm
+ '[' kernel-devel-2.6.32-19.el6.i686.rpm = '' -o '!' -e kernel-devel-2.6.32-19.el6.i686.rpm ']'
+ leadsize=96
++ expr 96 + 8
+ o=104
++ od -j 104 -N 8 -t u1 kernel-devel-2.6.32-19.el6.i686.rpm
+ set 0000150 0 0 0 7 0 0 4 132 0000160
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 0 ')' + 7
+ il=7
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 4 ')' + 132
+ dl=1156
++ expr 8 + 16 '*' 7 + 1156
+ sigsize=1276
++ expr 104 + 1276 + '(' 8 - '(' 1276 % 8 ')' ')' % 8 + 8
+ o=1392
++ od -j 1392 -N 8 -t u1 kernel-devel-2.6.32-19.el6.i686.rpm
+ set 0002560 0 0 0 53 0 19 195 180 0002570
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 0 ')' + 0 ')' + 53
+ il=53
++ expr 256 '*' '(' 256 '*' '(' 256 '*' 0 + 19 ')' + 195 ')' + 180
+ dl=1295284
++ expr 8 + 16 '*' 53 + 1295284
+ hdrsize=1296140
++ expr 1392 + 1296140
+ o=1297532
+ EXTRACTOR='dd if=kernel-devel-2.6.32-19.el6.i686.rpm ibs=1297532 skip=1'
+ COMPRESSION='/dev/stdin: data'
+ echo /dev/stdin: data
+ grep -q gzip
+ echo /dev/stdin: data
+ grep -q bzip2
+ echo /dev/stdin: data
+ grep -q xz
+ echo /dev/stdin: data
+ grep -q cpio
++ which unlzma
+ DECOMPRESSOR=/usr/bin/unlzma
+ case "$DECOMPRESSOR" in
+ dd if=kernel-devel-2.6.32-19.el6.i686.rpm ibs=1297532 skip=1
+ /usr/bin/unlzma
/usr/bin/unlzma: (stdin): File format not recognized

Bug #528693 is related, dealing with the same problem, only from mc perspective.

Some more diags:
$ dd if=kernel-devel-2.6.32-19.el6.i686.rpm ibs=1297532 skip=1 | hexdump -C | head -1
00000000  fd 37 7a 58 5a 00 00 0a  e1 fb 0c a1 02 00 21 01  |.7zXZ.........!.|

Now it looks like the signature is from xz, the problem with rpm2cpio.sh is it uses file utility which does not recognize xz.

$ rpm -q file xz
file-4.17-15.el5_3.1
xz-4.999.9-0.3.beta.20091007git.el5

Here's my dirty workaround to the above rpm2cpio.sh script that does not work with RHEL5.5's file utility:

--- /usr/local/bin/rpm2cpio.sh.oldfile	2010-10-13 13:58:33.000000000 +0400
+++ /usr/local/bin/rpm2cpio.sh	2010-10-13 14:51:37.000000000 +0400
@@ -33,6 +33,8 @@
 	DECOMPRESSOR=unxz
 elif echo $COMPRESSION |grep -q cpio; then
 	DECOMPRESSOR=cat
+elif $EXTRACTOR | od -x | head -1 | grep -q '37fd 587a '; then
+	DECOMPRESSOR=unxz
 else
 	# Most versions of file don't support LZMA, therefore we assume
 	# anything not detected is LZMA

Created attachment 453182 [details]
patched parmezan, works for me on rhel5

*** Bug 837945 has been marked as a duplicate of this bug. ***

RHEL5 is now in the development phase 2. This limits updates to critical issues only. While this issue might be annoying it is now too late to get it fixed. Sorry.

In case anyone stumbles on this bug wanting a quick fix on RHEL5:
$ yum install xz file rpm
$ rpm -qpR foo.rpm | grep -i xz
rpmlib(PayloadIsXz) <= 5.2-1

# foo.rpm has a payload with XZ compression. Although rpm2cpio doesn't understand the xz format, it still emits the compressed file intact.

$ rpm2cpio foo.rpm | xzcat > foo.cpio
$ cpio -idmv < foo.cpio

$ cpio -idm < foo.cpio
278 blocks
$ ls -l
total 156
-rw-r--r-- 1 phil   staff 141864 Oct 31 12:33 foo.cpio
drwxr-xr-x 3 phil   staff   4096 Oct 31 12:34 usr

This problems exists on PPC / Fedora releases too