diff mbox series

[v3,1/2] rpm2cpio.sh: update to the last 4.x version

Message ID 20230619064249.20642-1-aplanas@suse.com
State Accepted, archived
Commit 3aba44a75dd565b192f7328f2a0150a313de3cc1
Headers show
Series [v3,1/2] rpm2cpio.sh: update to the last 4.x version | expand

Commit Message

Alberto Planas Dominguez June 19, 2023, 6:42 a.m. UTC 
From: Alberto Planas <aplanas@suse.com>

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(-)
diff mbox series

Patch

diff --git a/scripts/rpm2cpio.sh b/scripts/rpm2cpio.sh
index 2034373fe4..8199b43784 100755
--- 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