build: Optionally provide file checksums in package metadata

This may be useful if you don't entirely trust your flash and want to be able
to check for corruptions.

Signed-off-by: Michal Hrusecky <Michal@Hrusecky.net>

config/Config-build.in

@@ -68,6 +68,14 @@ menu "Global build settings"
 		  This removes all ipkg/opkg status data files from the target directory
 		  before building the root filesystem.
 
+	config IPK_FILES_CHECKSUMS
+		bool
+		prompt "Record files checksums in package metadata"
+		default n
+		help
+		  This makes file checksums part of package metadata. It increases size
+		  but provides you with pkg_check command to check for flash coruptions.
+
 	config INCLUDE_CONFIG
 		bool "Include build configuration in firmware" if DEVEL
 		default n

include/package-ipkg.mk

@@ -199,6 +199,15 @@ $(_endef)
 	$(CheckDependencies)
 
 	$(RSTRIP) $$(IDIR_$(1))
+
+    ifneq ($$(CONFIG_IPK_FILES_CHECKSUMS),)
+	(cd $$(IDIR_$(1)); \
+		( \
+			find . -type f \! -path ./CONTROL/\* -exec sha256sum \{\} \; 2> /dev/null | \
+			sed 's|\([[:blank:]]\)\./|\1/|' > $$(IDIR_$(1))/CONTROL/files-sha256 \
+		) || true \
+	)
+    endif
 	(cd $$(IDIR_$(1))/CONTROL; \
 		( \
 			echo "$$$$CONTROL"; \

package/base-files/Makefile

@@ -195,6 +195,8 @@ define Package/base-files/install
 		mkdir -p $(1)/etc/opkg; \
 		$(call FeedSourcesAppend,$(1)/etc/opkg/distfeeds.conf); \
 		$(VERSION_SED_SCRIPT) $(1)/etc/opkg/distfeeds.conf)
+	$(if $(CONFIG_IPK_FILES_CHECKSUMS), \
+		rm -f $(1)/sbin/pkg_check,)
 endef
 
 ifneq ($(DUMP),1)

package/base-files/files/sbin/pkg_check

@@ -0,0 +1,130 @@
+#!/bin/sh
+#
+# Package checksums checking script
+# (C) 2018 CZ.NIC, z.s.p.o.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+ERRFATAL="no"
+QUIET="yes"
+MISSING=""
+SUMMARY=""
+NL="
+"
+
+# Arguments parsing
+while expr "x$1" : "x-" > /dev/null; do
+	if [ "x$1" = "x-s" ]; then
+		ERRFATAL="yes"
+		shift
+	elif [ "x$1" = "x-v" ]; then
+		QUIET="	no"
+		shift
+	else
+		echo "Usage: $(basename $0) [-s] [-v] [pkg1 pkg2 ...]"
+		echo
+		echo "   -s   Stop on first change"
+		echo "   -v   Verbose"
+		if [ "x$1" = "x-h" ]; then
+			exit 0
+		else
+			echo
+			echo "ERROR: Unknown option '$1'"
+			exit 1
+		fi
+	fi
+done
+
+# Check all packages by default
+if [ -z "$1" ]; then
+	set $(cd /usr/lib/opkg/info/; for i in *.files-sha256sum; do basename $i .files-sha256sum; done)
+fi
+
+# Iterate over packages
+while [ "$1" ]; do
+	if [ \! -f "/usr/lib/opkg/info/$1.files-sha256sum" ]; then
+		if [ "$ERRFATAL" = no ]; then
+			echo " * No checksums for $1 - skipping"
+			echo
+		else
+			echo " * No checksums for $1 - exiting"
+			exit 1
+		fi
+		if [ -z "$MISSING" ]; then
+			MISSING="$1"
+		else
+			MISSING="$MISSING, $1"
+		fi
+		shift
+		continue
+	fi
+	[ $QUIET = yes ] || echo " * Checking package $1:"
+	ERR=""
+	CHECK="`sha256sum -c /usr/lib/opkg/info/$1.files-sha256sum 2> /dev/null`"
+
+	# Are the changed files config files?
+	if [ $? -ne 0 ] && [ "`cat "/usr/lib/opkg/info/$1.files-sha256sum"`" ]; then
+		NEWCHECK="`echo "$CHECK" | grep '^.*: OK$'`"
+		for i in `echo "$CHECK" | sed -n 's|^\(.*\): FAILED$|\1|p'`; do
+			if [ "`grep "^$i\$" "/usr/lib/opkg/info/$1.conffiles" 2> /dev/null`" ] || \
+			   [ "`echo "$i" | grep "^/etc/uci-defaults/"`" ]; then
+				NEWCHECK="${NEWCHECK}${NL}${i}: CONFIGURED"
+			else
+				NEWCHECK="${NEWCHECK}${NL}${i}: FAILED"
+				ERR="y"
+			fi
+		done
+		CHECK="$NEWCHECK"
+	fi
+
+	# Do we have changed files or not?
+	if [ -z "$ERR" ]; then
+		[ $QUIET = yes ] || [ -z "`cat "/usr/lib/opkg/info/$1.files-sha256sum"`" ] || echo "$CHECK" | sed 's|^|   - |'
+		[ $QUIET = yes ] || echo " * Package $1 is ok"
+		[ $QUIET = yes ] || echo
+	else
+		if [ $QUIET = yes ]; then
+			echo " * Changes found in package $1:"
+			echo "$CHECK" | sed -n 's|^\(.*:[[:blank:]]*FAILED\)$|   - \1|p'
+		else
+			echo "$CHECK" | sed 's|^|   - |'
+			echo " * Changes found in package $1!"
+		fi
+		if [ "$ERRFATAL" = yes ]; then
+			echo
+			echo "Exiting on first change found!"
+			exit 1
+		fi
+		for i in `echo "$CHECK" | sed -n 's|^\(.*\): FAILED$|\1|p'`; do
+			SUMMARY="${SUMMARY}${NL} - $1: $i"
+		done
+		echo
+	fi
+	shift
+done
+
+# If there are changed files, report them
+if [ "$SUMMARY" ]; then
+	echo "Some packages contain changed files!"
+	echo "Maybe something worth looking into?"
+	echo "Here is the list of packages and changed files:"
+	echo "$SUMMARY"
+fi
+if [ "$MISSING" ]; then
+	echo "Following packages are missing checksums: $MISSING"
+fi
+if [ "$MISSING" ] || [ "$SUMMARY" ]; then
+	exit 1
+fi