rpm2cpio.sh: update to the last 4.x version

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>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/scripts/rpm2cpio.sh b/scripts/rpm2cpio.sh
index 2034373fe4bdbc5116e1edb459d5f4c5405eef29..8199b43784d794d00f5d89866d3d1d66f7e8fa8f 100755 (executable)
--- 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