Some download-related changes (branch yem/check-downloads)

index 0233506..97053ba 100644
@@ -305,6 +305,7 @@ HOST_MAKE_ENV=PATH=$(BR_PATH) \
 # post-images)
 EXTRA_ENV=\
 	PATH=$(BR_PATH) \
+	BR2_DL_DIR=$(BR2_DL_DIR) \
 	BUILD_DIR=$(BUILD_DIR)
 
 ################################################################################

index ccd7f3b..5293a7a 100644
@@ -574,6 +574,7 @@ $$($(2)_TARGET_PATCH):			RAWNAME=$(patsubst host-%,%,$(1))
 $$($(2)_TARGET_PATCH):			PKGDIR=$(pkgdir)
 $$($(2)_TARGET_EXTRACT):		PKG=$(2)
 $$($(2)_TARGET_SOURCE):			PKG=$(2)
+$$($(2)_TARGET_SOURCE):			PKGDIR=$(pkgdir)
 $$($(2)_TARGET_DIRCLEAN):		PKG=$(2)
 
 # Compute the name of the Kconfig option that correspond to the

index 4cfb913..888d26e 100644
@@ -12,7 +12,7 @@ WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
 SVN := $(call qstrip,$(BR2_SVN))
 CVS := $(call qstrip,$(BR2_CVS))
 BZR := $(call qstrip,$(BR2_BZR))
-GIT := $(call qstrip,$(BR2_GIT))
+export GIT := $(call qstrip,$(BR2_GIT))
 HG := $(call qstrip,$(BR2_HG)) $(QUIET)
 SCP := $(call qstrip,$(BR2_SCP)) $(QUIET)
 SSH := $(call qstrip,$(BR2_SSH)) $(QUIET)

@@ -84,19 +84,8 @@ github = https://github.com/$(1)/$(2)/archive/$(3)
 # problems
 define DOWNLOAD_GIT
 	test -e $(DL_DIR)/$($(PKG)_SOURCE) || \
-	(pushd $(DL_DIR) > /dev/null && \
-	 ((test "`git ls-remote $($(PKG)_SITE) $($(PKG)_DL_VERSION)`" && \
-	   echo "Doing shallow clone" && \
-	   $(GIT) clone --depth 1 -b $($(PKG)_DL_VERSION) --bare $($(PKG)_SITE) $($(PKG)_BASE_NAME)) || \
-	  (echo "Doing full clone" && \
-	   $(GIT) clone --bare $($(PKG)_SITE) $($(PKG)_BASE_NAME))) && \
-	pushd $($(PKG)_BASE_NAME) > /dev/null && \
-	$(GIT) archive --format=tar --prefix=$($(PKG)_BASE_NAME)/ -o $(DL_DIR)/.$($(PKG)_SOURCE).tmp $($(PKG)_DL_VERSION) && \
-	gzip -c $(DL_DIR)/.$($(PKG)_SOURCE).tmp > $(DL_DIR)/$($(PKG)_SOURCE) && \
-	rm -f $(DL_DIR)/.$($(PKG)_SOURCE).tmp && \
-	popd > /dev/null && \
-	rm -rf $($(PKG)_DL_DIR) && \
-	popd > /dev/null)
+	$(EXTRA_ENV) support/download/git $($(PKG)_SITE) $($(PKG)_DL_VERSION) \
+					  $($(PKG)_BASE_NAME) $(DL_DIR)/$($(PKG)_SOURCE)
 endef
 
 # TODO: improve to check that the given PKG_DL_VERSION exists on the remote

new file mode 100755
index 0000000..96db3a9
@@ -0,0 +1,37 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for git
+# Call it with:
+#   $1: git repo
+#   $2: git cset
+#   $3: package's basename (eg. foobar-1.2.3)
+#   $4: output file
+# And this environment:
+#   BR2_DL_DIR: path to Buildroot's download dir
+#   GIT       : the git command to call
+
+repo="${1}"
+cset="${2}"
+basename="${3}"
+output="${4}"
+
+repodir="${BR2_DL_DIR}/${basename}"
+
+if [ -n "$(${GIT} ls-remote "${repo}" "${cset}" 2>&1)" ]; then
+    printf "Doing shallow clone\n"
+    ${GIT} clone --depth 1 -b "${cset}" --bare "${repo}" "${repodir}"
+else
+    printf "Doing full clone\n"
+    ${GIT} clone --bare "${repo}" "${repodir}"
+fi
+
+pushd "${repodir}"
+${GIT} archive --prefix="${basename}/" -o "${output}.tmp" --format=tar "${cset}"
+gzip -c "${output}.tmp" >"${output}"
+rm -f "${output}.tmp"
+popd
+
+rm -rf "${repodir}"

index 888d26e..570a47b 100644
@@ -9,7 +9,7 @@
 
 # Download method commands
 WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
-SVN := $(call qstrip,$(BR2_SVN))
+export SVN := $(call qstrip,$(BR2_SVN))
 CVS := $(call qstrip,$(BR2_CVS))
 BZR := $(call qstrip,$(BR2_BZR))
 export GIT := $(call qstrip,$(BR2_GIT))

@@ -133,11 +133,8 @@ endef
 
 define DOWNLOAD_SVN
 	test -e $(DL_DIR)/$($(PKG)_SOURCE) || \
-	(pushd $(DL_DIR) > /dev/null && \
-	$(SVN) export -r $($(PKG)_DL_VERSION) $($(PKG)_SITE) $($(PKG)_DL_DIR) && \
-	$(TAR) czf $($(PKG)_SOURCE) $($(PKG)_BASE_NAME)/ && \
-	rm -rf $($(PKG)_DL_DIR) && \
-	popd > /dev/null)
+	$(EXTRA_ENV) support/download/svn $($(PKG)_SITE) $($(PKG)_DL_VERSION) \
+					  $($(PKG)_BASE_NAME) $(DL_DIR)/$($(PKG)_SOURCE)
 endef
 
 define SOURCE_CHECK_SVN

new file mode 100755
index 0000000..c3ab32c
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for svn
+# Call it with:
+#   $1: svn repo
+#   $2: svn revision
+#   $3: package's basename (eg. foobar-1.2.3)
+#   $4: output file
+# And this environment:
+#   SVN       : the svn command to call
+#   BR2_DL_DIR: path to Buildroot's download dir
+
+repo="${1}"
+rev="${2}"
+basename="${3}"
+output="${4}"
+
+pushd "${BR2_DL_DIR}"
+${SVN} export -r "${rev}" "${repo}" "${basename}"
+tar czf "${output}" "${basename}"
+rm -rf "${basename}"
+popd

index 570a47b..97a26f2 100644
@@ -10,7 +10,7 @@
 # Download method commands
 WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
 export SVN := $(call qstrip,$(BR2_SVN))
-CVS := $(call qstrip,$(BR2_CVS))
+export CVS := $(call qstrip,$(BR2_CVS))
 BZR := $(call qstrip,$(BR2_BZR))
 export GIT := $(call qstrip,$(BR2_GIT))
 HG := $(call qstrip,$(BR2_HG)) $(QUIET)

@@ -114,12 +114,9 @@ endef
 
 define DOWNLOAD_CVS
 	test -e $(DL_DIR)/$($(PKG)_SOURCE) || \
-	(pushd $(DL_DIR) > /dev/null && \
-	$(CVS) -z3 -d:pserver:anonymous@$(call stripurischeme,$(call qstrip,$($(PKG)_SITE))) \
-		co -d $($(PKG)_BASE_NAME) -r :$($(PKG)_DL_VERSION) -P $($(PKG)_RAWNAME) && \
-	$(TAR) czf $($(PKG)_SOURCE) $($(PKG)_BASE_NAME)/ && \
-	rm -rf $($(PKG)_DL_DIR) && \
-	popd > /dev/null)
+	$(EXTRA_ENV) support/download/cvs $(call stripurischeme,$(call qstrip,$($(PKG)_SITE))) \
+					  $($(PKG)_DL_VERSION) $($(PKG)_RAWNAME) \
+					  $($(PKG)_BASE_NAME) $(DL_DIR)/$($(PKG)_SOURCE)
 endef
 
 # Not all CVS servers support ls/rls, use login to see if we can connect

new file mode 100755
index 0000000..06b8647
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for cvs
+# Call it with:
+#   $1: cvs repo
+#   $2: cvs revision
+#   $3: package's name (eg. foobar)
+#   $4: package's basename (eg. foobar-1.2.3)
+#   $5: output file
+# And this environment:
+#   CVS       : the cvs command to call
+#   BR2_DL_DIR: path to Buildroot's download dir
+
+repo="${1}"
+rev="${2}"
+rawname="${3}"
+basename="${4}"
+output="${5}"
+
+cd "${BR2_DL_DIR}"
+${CVS} -z3 -d":pserver:anonymous@${repo}" \
+       co -d "${basename}" -r ":${rev}" -P "${rawname}"
+tar czf "${output}" "${basename}"
+rm -rf "${basename}"

index 97a26f2..37f0830 100644
@@ -13,7 +13,7 @@ export SVN := $(call qstrip,$(BR2_SVN))
 export CVS := $(call qstrip,$(BR2_CVS))
 BZR := $(call qstrip,$(BR2_BZR))
 export GIT := $(call qstrip,$(BR2_GIT))
-HG := $(call qstrip,$(BR2_HG)) $(QUIET)
+export HG := $(call qstrip,$(BR2_HG)) $(QUIET)
 SCP := $(call qstrip,$(BR2_SCP)) $(QUIET)
 SSH := $(call qstrip,$(BR2_SSH)) $(QUIET)
 LOCALFILES := $(call qstrip,$(BR2_LOCALFILES))

@@ -161,13 +161,8 @@ endef
 
 define DOWNLOAD_HG
 	test -e $(DL_DIR)/$($(PKG)_SOURCE) || \
-	(pushd $(DL_DIR) > /dev/null && \
-	rm -rf $($(PKG)_BASE_NAME) && \
-	$(HG) clone --noupdate --rev $($(PKG)_DL_VERSION) $($(PKG)_SITE) $($(PKG)_BASE_NAME) && \
-	$(HG) archive --repository $($(PKG)_BASE_NAME) --type tgz --prefix $($(PKG)_BASE_NAME)/ \
-	              --rev $($(PKG)_DL_VERSION) $(DL_DIR)/$($(PKG)_SOURCE) && \
-	rm -rf $($(PKG)_DL_DIR) && \
-	popd > /dev/null)
+	$(EXTRA_ENV) support/download/hg $($(PKG)_SITE) $($(PKG)_DL_VERSION) \
+					  $($(PKG)_BASE_NAME) $(DL_DIR)/$($(PKG)_SOURCE)
 endef
 
 # TODO: improve to check that the given PKG_DL_VERSION exists on the remote

new file mode 100755
index 0000000..70b49cf
@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for hg
+# Call it with:
+#   $1: hg repo
+#   $2: hg cset
+#   $3: package's basename (eg. foobar-1.2.3)
+#   $4: output file
+# And this environment:
+#   HG        : the hg command to call
+#   BR2_DL_DIR: path to Buildroot's download dir
+
+repo="${1}"
+cset="${2}"
+basename="${3}"
+output="${4}"
+
+cd "${BR2_DL_DIR}"
+${HG} clone --noupdate --rev "${cset}" "${repo}" "${basename}"
+${HG} archive --repository "${basename}" --type tgz --prefix "${basename}" \
+              --rev "${cset}" "${output}"
+rm -rf "${basename}"

index 37f0830..b495bbb 100644
@@ -8,7 +8,7 @@
 ################################################################################
 
 # Download method commands
-WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
+export WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
 export SVN := $(call qstrip,$(BR2_SVN))
 export CVS := $(call qstrip,$(BR2_CVS))
 BZR := $(call qstrip,$(BR2_BZR))

@@ -175,17 +175,10 @@ define SHOW_EXTERNAL_DEPS_HG
   echo $($(PKG)_SOURCE)
 endef
 
-# Download a file using wget. Only download the file if it doesn't
-# already exist in the download directory. If the download fails,
-# remove the file (because wget -O creates a 0-byte file even if the
-# download fails).  To handle an interrupted download as well, download
-# to a temporary file first.  The temporary file will be overwritten
-# the next time the download is tried.
+
 define DOWNLOAD_WGET
 	test -e $(DL_DIR)/$(2) || \
-	($(WGET) -O $(DL_DIR)/$(2).tmp '$(call qstrip,$(1))' && \
-	 mv $(DL_DIR)/$(2).tmp $(DL_DIR)/$(2)) || \
-	(rm -f $(DL_DIR)/$(2).tmp ; exit 1)
+	$(EXTRA_ENV) support/download/wget '$(call qstrip,$(1))' $(DL_DIR)/$(2)
 endef
 
 define SOURCE_CHECK_WGET

new file mode 100755
index 0000000..7865517
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for wget
+# Call it with:
+#   $1: URL
+#   $2: output file
+# And this environment:
+#   WGET      : the wget command to call
+
+url="${1}"
+output="${2}"
+
+if ${WGET} -O "${output}.tmp" "${url}"; then
+    mv "${output}.tmp" "${output}"
+else
+    rm -f "${output}.tmp"
+    exit 1
+fi

index b495bbb..e0dda39 100644
@@ -11,7 +11,7 @@
 export WGET := $(call qstrip,$(BR2_WGET)) $(QUIET)
 export SVN := $(call qstrip,$(BR2_SVN))
 export CVS := $(call qstrip,$(BR2_CVS))
-BZR := $(call qstrip,$(BR2_BZR))
+export BZR := $(call qstrip,$(BR2_BZR))
 export GIT := $(call qstrip,$(BR2_GIT))
 export HG := $(call qstrip,$(BR2_HG)) $(QUIET)
 SCP := $(call qstrip,$(BR2_SCP)) $(QUIET)

@@ -101,7 +101,7 @@ endef
 
 define DOWNLOAD_BZR
 	test -e $(DL_DIR)/$($(PKG)_SOURCE) || \
-	$(BZR) export $(DL_DIR)/$($(PKG)_SOURCE) $($(PKG)_SITE) -r $($(PKG)_DL_VERSION)
+	$(EXTRA_ENV) support/download/bzr $($(PKG)_SITE) $($(PKG)_DL_VERSION) $(DL_DIR)/$($(PKG)_SOURCE)
 endef
 
 define SOURCE_CHECK_BZR

new file mode 100755
index 0000000..68121f4
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+# We want to catch any command failure, and exit immediately
+set -e
+
+# Download helper for bzr
+# Call it with:
+#   $1: bzr repo
+#   $2: bzr revision
+#   $3: output file
+# And this environment:
+#   BZR       : the bzr command to call
+#   BR2_DL_DIR: path to Buildroot's download dir
+
+repo="${1}"
+rev="${2}"
+output="${3}"
+
+${BZR} export "${output}" "${repo}" -r "${rev}"

index 68121f4..e0da34c 100755
@@ -9,11 +9,26 @@ set -e
 #   $2: bzr revision
 #   $3: output file
 # And this environment:
-#   BZR       : the bzr command to call
-#   BR2_DL_DIR: path to Buildroot's download dir
+#   BZR      : the bzr command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 repo="${1}"
 rev="${2}"
 output="${3}"
 
-${BZR} export "${output}" "${repo}" -r "${rev}"
+tmp_dl="$( mktemp "${BUILD_DIR}/.XXXXXX" )"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - the we move to a temp file in the final location, so it is
+#   on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
+if ${BZR} export "${tmp_dl}" "${repo}" -r "${rev}"; then
+    tmp_output="$( mktemp "${output}.XXXXXX" )"
+    mv "${tmp_dl}" "${tmp_output}"
+    mv "${tmp_output}" "${output}"
+else
+    rm -f "${tmp_dl}"
+    exit 1
+fi

index 06b8647..edcf55c 100755
@@ -11,8 +11,8 @@ set -e
 #   $4: package's basename (eg. foobar-1.2.3)
 #   $5: output file
 # And this environment:
-#   CVS       : the cvs command to call
-#   BR2_DL_DIR: path to Buildroot's download dir
+#   CVS      : the cvs command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 repo="${1}"
 rev="${2}"

@@ -20,8 +20,21 @@ rawname="${3}"
 basename="${4}"
 output="${5}"
 
-cd "${BR2_DL_DIR}"
+repodir="${basename}.tmp-cvs-checkout"
+
+cd "${BUILD_DIR}"
+# Remove leftovers from a previous failed run
+rm -rf "${repodir}"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - then we create a temporary tarball in the final location, so it is
+#   on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
 ${CVS} -z3 -d":pserver:anonymous@${repo}" \
-       co -d "${basename}" -r ":${rev}" -P "${rawname}"
-tar czf "${output}" "${basename}"
-rm -rf "${basename}"
+       co -d "${repodir}" -r ":${rev}" -P "${rawname}"
+temp_output="$( mktemp "${output}.XXXXXX" )"
+tar czf "${temp_output}" "${repodir}"
+mv "${temp_output}" "${output}"
+rm -rf "${repodir}"

index 96db3a9..1d2493d 100755
@@ -10,15 +10,27 @@ set -e
 #   $3: package's basename (eg. foobar-1.2.3)
 #   $4: output file
 # And this environment:
-#   BR2_DL_DIR: path to Buildroot's download dir
-#   GIT       : the git command to call
+#   GIT      : the git command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 repo="${1}"
 cset="${2}"
 basename="${3}"
 output="${4}"
 
-repodir="${BR2_DL_DIR}/${basename}"
+repodir="${basename}.tmp-git-checkout"
+tmp_tar="$( mktemp "${BUILD_DIR}/.XXXXXX" )"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - then we create the uncomporessed tarball in tht same trashable location
+# - then we create a temporary compressed tarball in the final location, so
+#   it is on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
+cd "${BUILD_DIR}"
+# Remove leftovers from a previous failed run
+rm -rf "${repodir}"
 
 if [ -n "$(${GIT} ls-remote "${repo}" "${cset}" 2>&1)" ]; then
     printf "Doing shallow clone\n"

@@ -29,9 +41,10 @@ else
 fi
 
 pushd "${repodir}"
-${GIT} archive --prefix="${basename}/" -o "${output}.tmp" --format=tar "${cset}"
-gzip -c "${output}.tmp" >"${output}"
-rm -f "${output}.tmp"
+${GIT} archive --prefix="${basename}/" -o "${tmp_tar}" --format=tar "${cset}"
+tmp_output="$( mktemp "${output}.XXXXXX" )"
+gzip -c "${tmp_tar}" >"${tmp_output}"
+mv "${tmp_output}" "${output}"
 popd
 
 rm -rf "${repodir}"

index 70b49cf..bf9d4ea 100755
@@ -10,16 +10,29 @@ set -e
 #   $3: package's basename (eg. foobar-1.2.3)
 #   $4: output file
 # And this environment:
-#   HG        : the hg command to call
-#   BR2_DL_DIR: path to Buildroot's download dir
+#   HG       : the hg command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 repo="${1}"
 cset="${2}"
 basename="${3}"
 output="${4}"
 
-cd "${BR2_DL_DIR}"
-${HG} clone --noupdate --rev "${cset}" "${repo}" "${basename}"
-${HG} archive --repository "${basename}" --type tgz --prefix "${basename}" \
-              --rev "${cset}" "${output}"
-rm -rf "${basename}"
+repodir="${basename}.tmp-hg-checkout"
+
+cd "${BUILD_DIR}"
+# Remove leftovers from a previous failed run
+rm -rf "${repodir}"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - then we create a temporary tarball in the final location, so it is
+#   on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
+${HG} clone --noupdate --rev "${cset}" "${repo}" "${repodir}"
+tmp_output="$( mktemp "${output}.XXXXXX" )"
+${HG} archive --repository "${repodir}" --type tgz --prefix "${basename}" \
+              --rev "${cset}" "${tmp_output}"
+mv "${tmp_output}" "${output}"
+rm -rf "${repodir}"

index c3ab32c..3977591 100755
@@ -10,16 +10,28 @@ set -e
 #   $3: package's basename (eg. foobar-1.2.3)
 #   $4: output file
 # And this environment:
-#   SVN       : the svn command to call
-#   BR2_DL_DIR: path to Buildroot's download dir
+#   SVN      : the svn command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 repo="${1}"
 rev="${2}"
 basename="${3}"
 output="${4}"
 
-pushd "${BR2_DL_DIR}"
-${SVN} export -r "${rev}" "${repo}" "${basename}"
-tar czf "${output}" "${basename}"
-rm -rf "${basename}"
-popd
+repodir="${basename}.tmp-svn-checkout"
+
+cd "${BUILD_DIR}"
+# Remove leftovers from a previous failed run
+rm -rf "${repodir}"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - then we create a temporary tarball in the final location, so it is
+#   on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
+${SVN} export -r "${rev}" "${repo}" "${repodir}"
+tmp_output="$( mktemp "${output}.XXXXXX" )"
+tar czf "${tmp_output}" "${repodir}"
+mv "${tmp_output}" "${output}"
+rm -rf "${repodir}"

index 7865517..989829a 100755
@@ -8,14 +8,25 @@ set -e
 #   $1: URL
 #   $2: output file
 # And this environment:
-#   WGET      : the wget command to call
+#   WGET     : the wget command to call
+#   BUILD_DIR: path to Buildroot's build dir
 
 url="${1}"
 output="${2}"
 
-if ${WGET} -O "${output}.tmp" "${url}"; then
-    mv "${output}.tmp" "${output}"
+tmp_dl="$( mktemp "${BUILD_DIR}/.XXXXXX" )"
+
+# Play tic-tac-toe with temp files
+# - first, we download to a trashable location (the build-dir)
+# - then we copy to a temporary tarball in the final location, so it is
+#   on the same filesystem as the final file
+# - finally, we atomically rename to the final file
+
+if ${WGET} -O "${tmp_dl}" "${url}"; then
+    tmp_output="$( mktemp "${output}.XXXXXX" )"
+    mv "${tmp_dl}" "${tmp_output}"
+    mv "${tmp_output}" "${output}"
 else
-    rm -f "${output}.tmp"
+    rm -f "${tmp_dl}"
     exit 1
 fi

index e0dda39..dcf6b62 100644
@@ -58,6 +58,17 @@ domainseparator=$(if $(1),$(1),/)
 # github(user,package,version): returns site of GitHub repository
 github = https://github.com/$(1)/$(2)/archive/$(3)
 
+# Helper for checking a tarball's checksum
+# If the hash does not match, remove the incorrect file
+# $(1): the path to the file with the hashes
+# $(2): the full path to the file to check
+define VERIFY_HASH
+	if ! support/download/check-hash $(1) $(2); then \
+		rm -f $(2); \
+		exit 1; \
+	fi
+endef
+
 ################################################################################
 # The DOWNLOAD_* helpers are in charge of getting a working copy
 # of the source repository for their corresponding SCM,

@@ -147,7 +158,8 @@ endef
 # to prepend the path with a slash: scp://[user@]host:/absolutepath
 define DOWNLOAD_SCP
 	test -e $(DL_DIR)/$(2) || \
-	$(SCP) '$(call stripurischeme,$(call qstrip,$(1)))' $(DL_DIR)/$(2)
+	$(SCP) '$(call stripurischeme,$(call qstrip,$(1)))' $(DL_DIR)/$(2) && \
+	$(call VERIFY_HASH,$(PKGDIR)/$($(PKG)_NAME).hash,$(DL_DIR)/$(2))
 endef
 
 define SOURCE_CHECK_SCP

@@ -178,7 +190,8 @@ endef
 
 define DOWNLOAD_WGET
 	test -e $(DL_DIR)/$(2) || \
-	$(EXTRA_ENV) support/download/wget '$(call qstrip,$(1))' $(DL_DIR)/$(2)
+	$(EXTRA_ENV) support/download/wget '$(call qstrip,$(1))' $(DL_DIR)/$(2) && \
+	$(call VERIFY_HASH,$(PKGDIR)/$($(PKG)_NAME).hash,$(DL_DIR)/$(2))
 endef
 
 define SOURCE_CHECK_WGET

@@ -191,7 +204,8 @@ endef
 
 define DOWNLOAD_LOCALFILES
 	test -e $(DL_DIR)/$(2) || \
-		$(LOCALFILES) $(call stripurischeme,$(call qstrip,$(1))) $(DL_DIR)
+	$(LOCALFILES) $(call stripurischeme,$(call qstrip,$(1))) $(DL_DIR) && \
+	$(call VERIFY_HASH,$(PKGDIR)/$($(PKG)_NAME).hash,$(DL_DIR)/$(2))
 endef
 
 define SOURCE_CHECK_LOCALFILES

76 lines not on this page · raw message

index 69b012c..c2f0a1a 100644
@@ -357,3 +357,69 @@ different way, using different infrastructures:
 
 Further formatting details: see xref:writing-rules-mk[the writing
 rules].
+
+[[adding-packages-hash]]
+=== The +.hash+ file
+
+Optionally, you can add a third file, named +libfoo.hash+, that contains
+the hashes of the downloaded files for the +libfoo+ package.
+
+The hashes stored in that file are used to validate the integrity of the
+downloaded files.
+
+The format of this file is one line for each file for which to check the
+hash, each line being space-separated, with these three fields:
+
+* the type of hash, one of:
+** +sha1+, +sha224+, +sha256+, +sha384+, +sha512+
+* the hash of the file:
+** for +sha1+, 40 hexadecimal characters
+** for +sha224+, 56 hexadecimal characters
+** for +sha256+, 64 hexadecimal characters
+** for +sha384+, 96 hexadecimal characters
+** for +sha512+, 128 hexadecimal characters
+* the name of the file, without any directory component
+
+Lines starting with a +#+ sign are considered comments, and ignored. Empty
+lines are ignored.
+
+There can be more than one hash for a single file, each on its own line. In
+this case, all hashes must match.
+
+Ideally, the hashes stored in this file should match the hashes published by
+upstream, e.g. on their website, in the e-mail announcement... If upstream
+provides more than one type of hash (say, +sha1+ and +sha512+), then it is
+best to add all those hashes in the +.hash+ file. If upstream does not
+provide any hash, then compute at least one yourself, and mention this in a
+comment line above the hashes.
+
+*Note:* the number of spaces does not matter, so one can use spaces to
+properly align the different fields.
+
+The example below defines a +sha1+ and a +sha256+ published by upstream for
+the main +libfoo-1.2.3.tar.bz2+ tarball, plus two locally-computed hashes,
+a +sha256+ for a downloaded patch, and a +sha1+ for a downloaded binary blob:
+
+----
+# Hashes from: http://www.foosoftware.org/download/libfoo-1.2.3.tar.bz2.{sha1,sha256}:
+sha1   486fb55c3efa71148fe07895fd713ea3a5ae343a                         libfoo-1.2.3.tar.bz2
+sha256 efc8103cc3bcb06bda6a781532d12701eb081ad83e8f90004b39ab81b65d4369 libfoo-1.2.3.tar.bz2
+
+# No upstream hashes for the following:
+sha256 ff52101fb90bbfc3fe9475e425688c660f46216d7e751c4bbdb1dc85cdccacb9 libfoo-fix-blabla.patch
+sha1   2d608f3c318c6b7557d551a5a09314f03452f1a1                         libfoo-data.bin
+----
+
+If the +.hash+ file is present, and it contains one or more hashes for a
+downloaded file, the hash(es) computed by Buildroot (after download) must
+match the hash(es) stored in the +.hash+ file. If one or more hashes do
+not match, Buildroot considers this an error, deletes the downloaded file,
+and aborts.
+
+If the +.hash+ file is present, but it does not contain a hash for a
+downloaded file, no check is done for that file. If you set the
+environment variable +BR2_ENFORCE_CHECK_HASH+ to a non-empty value, and
+there is no hash for a downloaded file, Buildroot considers this an
+error, deletes the downloaded file, and aborts.
+
+If the +.hash+ file is missing, then no check is done at all.

index d498752..ce50e5a 100755
@@ -22,6 +22,7 @@ check_one_hash() {
     _known="${2}"
     _file="${3}"
 
+    # Note: md5 is supported, but undocumented on purpose.
     # Note: sha3 is not supported, since there is currently no implemetation
     #       (the NIST has yet to publish the parameters).
     case "${_h}" in

new file mode 100644
index 0000000..bcd0723
@@ -0,0 +1,3 @@
+# hashes from: $(CA_CERTIFICATES_SITE)/ca-certificates_$(CA_CERTIFICATES_VERSION).dsc :
+sha1   ad57a45f0422fafd78a2e8191e5204f2306cc91b                         ca-certificates_20140223.tar.xz
+sha256 815b7cd97200b0d76450bb3e7d9b65997ac494ab6467b17369f65b2ef94bcb0c ca-certificates_20140223.tar.xz