diff mbox series

[1/1] rpm2cpio.sh: update to the last 4.x version

Message ID 20230526130742.28754-1-aplanas@suse.com
State New
Headers show
Series [1/1] rpm2cpio.sh: update to the last 4.x version | expand

Commit Message

Alberto Planas Dominguez May 26, 2023, 1:07 p.m. UTC 
openSUSE RPMs are compressing the RPM payload using zstd, that
correspond to the magic ID 0x28, 0xb5, 0x2f.

This patch update the script to the last version from the rpm project,
and add support to this compression format, and extract the cpio payload
using the "unzstd" binary.

Signed-off-by: Alberto Planas <aplanas@suse.com>
---
 scripts/rpm2cpio.sh | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)
 mode change 100755 => 100644 scripts/rpm2cpio.sh
diff mbox series

Patch

diff --git a/scripts/rpm2cpio.sh b/scripts/rpm2cpio.sh
old mode 100755
new mode 100644
index 2034373fe4..8199b43784
--- a/scripts/rpm2cpio.sh
+++ b/scripts/rpm2cpio.sh
@@ -7,7 +7,7 @@  fatal() {
 }
 
 pkg="$1"
-[ -n "$pkg" -a -e "$pkg" ] ||
+[ -n "$pkg" ] && [ -e "$pkg" ] ||
 	fatal "No package supplied"
 
 _dd() {
@@ -16,14 +16,23 @@  _dd() {
 }
 
 calcsize() {
+
+	case "$(_dd $1 bs=4 count=1 | tr -d '\0')" in
+		"$(printf '\216\255\350')"*) ;; # '\x8e\xad\xe8'
+		*) fatal "File doesn't look like rpm: $pkg" ;;
+	esac
+
 	offset=$(($1 + 8))
 
 	local i b b0 b1 b2 b3 b4 b5 b6 b7
 
 	i=0
 	while [ $i -lt 8 ]; do
- 		b=$(_dd $(($offset + $i)) bs=1 count=1; echo X)
- 		b=${b%X}
+		# add . to not loose \n
+		# strip \0 as it gets dropped with warning otherwise
+		b="$(_dd $(($offset + $i)) bs=1 count=1 | tr -d '\0' ; echo .)"
+		b=${b%.}    # strip . again
+
 		[ -z "$b" ] &&
 			b="0" ||
 			b="$(exec printf '%u\n' "'$b")"
@@ -35,7 +44,7 @@  calcsize() {
 	offset=$(($offset + $rsize))
 }
 
-case "$(_dd 0 bs=8 count=1)" in
+case "$(_dd 0 bs=4 count=1 | tr -d '\0')" in
 	"$(printf '\355\253\356\333')"*) ;; # '\xed\xab\xee\xdb'
 	*) fatal "File doesn't look like rpm: $pkg" ;;
 esac
@@ -46,10 +55,11 @@  sigsize=$rsize
 calcsize $(($offset + (8 - ($sigsize % 8)) % 8))
 hdrsize=$rsize
 
-case "$(_dd $offset bs=3 count=1)" in
-	"$(printf '\102\132')"*) _dd $offset | bzip2 -d ;; # '\x42\x5a'
-	"$(printf '\037\213')"*) _dd $offset | gunzip  ;; # '\x1f\x8b'
-	"$(printf '\375\067')"*) _dd $offset | xzcat   ;; # '\xfd\x37'
-	"$(printf '\135\000')"*) _dd $offset | unlzma  ;; # '\x5d\x00'
-	*) fatal "Unrecognized rpm file: $pkg" ;;
+case "$(_dd $offset bs=2 count=1 | tr -d '\0')" in
+	"$(printf '\102\132')") _dd $offset | bunzip2 ;; # '\x42\x5a'
+	"$(printf '\037\213')") _dd $offset | gunzip  ;; # '\x1f\x8b'
+	"$(printf '\375\067')") _dd $offset | xzcat   ;; # '\xfd\x37'
+	"$(printf '\135')") _dd $offset | unlzma      ;; # '\x5d\x00'
+	"$(printf '\050\265')") _dd $offset | unzstd  ;; # '\x28\xb5'
+	*) fatal "Unrecognized payload compression format in rpm file: $pkg" ;;
 esac