paches/openwrt: add FilesSignature

This is variation on LinkSignature but it covers files. It should cover case when content of package changes. This can happen with OpenWrt configuration or just by mistake.

This also reworks original script for LinkSignature a bit. This is just to make both script consistent between each other.

Implements #257 (closed) and relates to turris/updater/updater#313 (closed).

patches/openwrt/hack/0019-Generate-link-signature-for-packages.patch

-From 69e54105161b74714b537ab3b80b0894bfa90fcf Mon Sep 17 00:00:00 2001
+From 4002bcfdb2474cc57746ec505735eeed92c77295 Mon Sep 17 00:00:00 2001
 From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <cynerd@email.cz>
 Date: Mon, 15 Jun 2020 21:38:58 +0200
 Subject: [PATCH] Generate link signature for packages
@@ -14,12 +14,12 @@ packages that are installed with same version from older snapshot can
 break this dependency.
 ---
  include/package-ipkg.mk       |  8 ++++++++
- scripts/gen-link-signature.sh | 23 +++++++++++++++++++++++
- 2 files changed, 31 insertions(+)
+ scripts/gen-link-signature.sh | 22 ++++++++++++++++++++++
+ 2 files changed, 30 insertions(+)
  create mode 100755 scripts/gen-link-signature.sh
 
 diff --git a/include/package-ipkg.mk b/include/package-ipkg.mk
-index 03c0383..7d5adcc 100644
+index 03c0383..866de94 100644
 --- a/include/package-ipkg.mk
 +++ b/include/package-ipkg.mk
 @@ -95,6 +95,12 @@ ifneq ($(PKG_NAME),toolchain)
@@ -30,7 +30,7 @@ index 03c0383..7d5adcc 100644
 +	LINK_SIGNATURE="$$$$( \
 +		export READELF=$(TARGET_CROSS)readelf; \
 +		$(SCRIPT_DIR)/gen-link-signature.sh "$$(IDIR_$(1))"; \
-+	)";
++	)"
 +  endef
  endif
  
@@ -48,33 +48,32 @@ index 03c0383..7d5adcc 100644
  		chmod 644 control; \
 diff --git a/scripts/gen-link-signature.sh b/scripts/gen-link-signature.sh
 new file mode 100755
-index 0000000..e54e712
+index 0000000..c46efdc
 --- /dev/null
 +++ b/scripts/gen-link-signature.sh
-@@ -0,0 +1,23 @@
+@@ -0,0 +1,22 @@
 +#!/usr/bin/env bash
 +SELF=${0##*/}
 +
 +READELF="${READELF:-readelf}"
-+TARGETS=$*
 +
-+[ -z "$TARGETS" ] && {
-+  echo "$SELF: no directories / files specified" >&2
-+  echo "usage: $SELF [PATH...]d" >&2
-+  exit 1
++[ -z "$*" ] && {
++	echo "$SELF: no directories / files specified" >&2
++	echo "usage: $SELF [PATH...]" >&2
++	exit 1
 +}
 +
-+find $TARGETS -type f -a -exec file {} \; | \
-+	sed -n -e 's/^\(.*\):.*ELF.*\(executable\|shared object\).*,.*/\1/p' | \
-+	while read -r TARGET; do
-+		# Libraries
-+		"$READELF" -d "$TARGET" | awk '$2 == "(NEEDED)" { print $NF }'
-+		# Dynamic Symbols (undefined that means provided by libraries)
-+		"$READELF" --dyn-syms "$TARGET" | awk '$7 == "UND" && $8 { print $8 }'
-+	done | \
-+	sort -u | \
-+	md5sum | \
-+	cut -d' ' -f1
++find "$@" -type f -a -exec file {} \; | \
++	sed -n -e 's/^\(.*\):.*ELF.*\(executable\|shared object\).*,.*/\1/p' \
++		| while read -r TARGET; do
++			# Libraries
++			"$READELF" -d "$TARGET" | awk '$2 == "(NEEDED)" { print $NF }'
++			# Dynamic Symbols (undefined that means provided by libraries)
++			"$READELF" --dyn-syms "$TARGET" | awk '$7 == "UND" && $8 { print $8 }'
++		done \
++		| sort -u \
++		| md5sum \
++		| cut -d' ' -f1
 -- 
-2.27.0
+2.32.0