luci-mod-admin-full: restructure and fix backup, restore and sysuprade (#517)

Do not use standard post security checking for actions that require file upload
since reading the token value will trigger parsing of the http message body
before the file upload handler has been set, which causes LuCI to buffer the
entire request body in memory.

In order to simplify the code and logic flow, split action_flashops() into
separate handlers for reset, backup, restore and sysupgrade.

Let the backup restore and sysupgrade handlers use the new test_post_security()
method in luci.dispatcher to perform token checking *after* setting the upload
handler.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

modules/luci-mod-admin-full/luasrc/controller/admin/system.lua

@@ -31,9 +31,15 @@ function index()
 		entry({"admin", "system", "leds"}, cbi("admin_system/leds"), _("<abbr title=\"Light Emitting Diode\">LED</abbr> Configuration"), 60)
 	end
 
-	entry({"admin", "system", "flashops"}, post_on({ exec = "1" }, "action_flashops"), _("Backup / Flash Firmware"), 70)
+	entry({"admin", "system", "flashops"}, call("action_flashops"), _("Backup / Flash Firmware"), 70)
+	entry({"admin", "system", "flashops", "reset"}, post("action_reset"))
+	entry({"admin", "system", "flashops", "backup"}, post("action_backup"))
 	entry({"admin", "system", "flashops", "backupfiles"}, form("admin_system/backupfiles"))
 
+	-- call() instead of post() due to upload handling!
+	entry({"admin", "system", "flashops", "restore"}, call("action_restore"))
+	entry({"admin", "system", "flashops", "sysupgrade"}, call("action_sysupgrade"))
+
 	entry({"admin", "system", "reboot"}, template("admin_system/reboot"), _("Reboot"), 90)
 	entry({"admin", "system", "reboot", "call"}, post("action_reboot"))
 end
@@ -171,31 +177,25 @@ function action_packages()
 	end
 end
 
-function action_flashops()
+local function image_supported(image)
-	local http = require "luci.http"
+	return (os.execute("sysupgrade -T %q >/dev/null" % image) == 0)
-	local sys  = require "luci.sys"
-	local fs   = require "nixio.fs"
-
-	local submit = (http.formvalue("exec") == "1")
-
-	local upgrade_avail = fs.access("/lib/upgrade/platform.sh")
-	local reset_avail   = os.execute([[grep '"rootfs_data"' /proc/mtd >/dev/null 2>&1]]) == 0
-
-	local restore_cmd = "tar -xzC/ >/dev/null 2>&1"
-	local backup_cmd  = "sysupgrade --create-backup - 2>/dev/null"
-	local image_tmp   = "/tmp/firmware.img"
-
-	local function image_supported()
-		return (os.execute("sysupgrade -T %q >/dev/null" % image_tmp) == 0)
 end
 
-	local function image_checksum()
+local function image_checksum(image)
-		return (luci.sys.exec("md5sum %q" % image_tmp):match("^([^%s]+)"))
+	return (luci.sys.exec("md5sum %q" % image):match("^([^%s]+)"))
+end
+
+local function supports_sysupgrade()
+	return nixio.fs.access("/lib/upgrade/platform.sh")
+end
+
+local function supports_reset()
+	return (os.execute([[grep -sq '"rootfs_data"' /proc/mtd]]) == 0)
 end
 
 local function storage_size()
 	local size = 0
-		if fs.access("/proc/mtd") then
+	if nixio.fs.access("/proc/mtd") then
 		for l in io.lines("/proc/mtd") do
 			local d, s, e, n = l:match('^([^%s]+)%s+([^%s]+)%s+([^%s]+)%s+"([^%s]+)"')
 			if n == "linux" or n == "firmware" then
@@ -203,7 +203,7 @@ function action_flashops()
 				break
 			end
 		end
-		elseif fs.access("/proc/partitions") then
+	elseif nixio.fs.access("/proc/partitions") then
 		for l in io.lines("/proc/partitions") do
 			local x, y, b, n = l:match('^%s*(%d+)%s+(%d+)%s+([^%s]+)%s+([^%s]+)')
 			if b and n and not n:match('[0-9]') then
@@ -215,61 +215,59 @@ function action_flashops()
 	return size
 end
 
+
+function action_flashops()
 	--
-	-- Handle modifying actions
+	-- Overview
 	--
-	if submit then
+	luci.template.render("admin_system/flashops", {
+		reset_avail   = supports_reset(),
+		upgrade_avail = supports_sysupgrade()
+	})
+end
+
+function action_sysupgrade()
+	local fs = require "nixio.fs"
+	local http = require "luci.http"
+	local image_tmp = "/tmp/firmware.img"
 
 	local fp
 	http.setfilehandler(
 		function(meta, chunk, eof)
-				if not fp then
+			if not fp and meta and meta.name == "image" then
-					if meta and meta.name == "image" then
 				fp = io.open(image_tmp, "w")
-					else
-						fp = io.popen(restore_cmd, "w")
 			end
-				end
+			if fp and chunk then
-				if chunk then
 				fp:write(chunk)
 			end
-				if eof then
+			if fp and eof then
 				fp:close()
 			end
 		end
 	)
 
-		if http.formvalue("backup") then
+	if not luci.dispatcher.test_post_security() then
-			--
+		fs.unlink(image_tmp)
-			-- Assemble file list, generate backup
+		return
-			--
+	end
-			local reader = ltn12_popen(backup_cmd)
+
-			http.header('Content-Disposition', 'attachment; filename="backup-%s-%s.tar.gz"' % {
+	--
-				luci.sys.hostname(), os.date("%Y-%m-%d")})
+	-- Cancel firmware flash
-			http.prepare_content("application/x-targz")
+	--
-			luci.ltn12.pump.all(reader, http.write)
+	if http.formvalue("cancel") then
-			return
+		fs.unlink(image_tmp)
-
+		http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
-		elseif http.formvalue("restore") then
-			--
-			-- Unpack received .tar.gz
-			--
-			local upload = http.formvalue("archive")
-			if upload and #upload > 0 then
-				luci.template.render("admin_system/applyreboot")
-				luci.sys.reboot()
 		return
 	end
 
-		elseif http.formvalue("image") or http.formvalue("step") then
 	--
 	-- Initiate firmware flash
 	--
 	local step = tonumber(http.formvalue("step") or 1)
 	if step == 1 then
-				if image_supported() then
+		if image_supported(image_tmp) then
 			luci.template.render("admin_system/upgrade", {
-						checksum = image_checksum(),
+				checksum = image_checksum(image_tmp),
 				storage  = storage_size(),
 				size     = (fs.stat(image_tmp, "size") or 0),
 				keep     = (not not http.formvalue("keep"))
@@ -277,12 +275,11 @@ function action_flashops()
 		else
 			fs.unlink(image_tmp)
 			luci.template.render("admin_system/flashops", {
-						reset_avail   = reset_avail,
+				reset_avail   = supports_reset(),
-						upgrade_avail = upgrade_avail,
+				upgrade_avail = supports_sysupgrade(),
 				image_invalid = true
 			})
 		end
-				return
 	--
 	-- Start sysupgrade flash
 	--
@@ -294,29 +291,71 @@ function action_flashops()
 			addr  = (#keep > 0) and "192.168.1.1" or nil
 		})
 		fork_exec("killall dropbear uhttpd; sleep 1; /sbin/sysupgrade %s %q" %{ keep, image_tmp })
+	end
+end
+
+function action_backup()
+	local reader = ltn12_popen("sysupgrade --create-backup - 2>/dev/null")
+
+	luci.http.header(
+		'Content-Disposition', 'attachment; filename="backup-%s-%s.tar.gz"' %{
+			luci.sys.hostname(),
+			os.date("%Y-%m-%d")
+		})
+
+	luci.http.prepare_content("application/x-targz")
+	luci.ltn12.pump.all(reader, luci.http.write)
+end
+
+function action_restore()
+	local fs = require "nixio.fs"
+	local http = require "luci.http"
+	local archive_tmp = "/tmp/restore.tar.gz"
+
+	local fp
+	http.setfilehandler(
+		function(meta, chunk, eof)
+			if not fp and meta and meta.name == "archive" then
+				fp = io.open(archive_tmp, "w")
+			end
+			if fp and chunk then
+				fp:write(chunk)
+			end
+			if fp and eof then
+				fp:close()
+			end
+		end
+	)
+
+	if not luci.dispatcher.test_post_security() then
+		fs.unlink(archive_tmp)
 		return
 	end
-		elseif reset_avail and http.formvalue("reset") then
+
-			--
+	local upload = http.formvalue("archive")
-			-- Reset system
+	if upload and #upload > 0 then
-			--
+		luci.template.render("admin_system/applyreboot")
+		os.execute("tar -C / -xzf %q >/dev/null 2>&1" % archive_tmp)
+		luci.sys.reboot()
+		return
+	end
+
+	http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
+end
+
+function action_reset()
+	if supports_reset() then
 		luci.template.render("admin_system/applyreboot", {
 			title = luci.i18n.translate("Erasing..."),
 			msg   = luci.i18n.translate("The system is erasing the configuration partition now and will reboot itself when finished."),
 			addr  = "192.168.1.1"
 		})
+
 		fork_exec("killall dropbear uhttpd; sleep 1; mtd -r erase rootfs_data")
 		return
 	end
-	end
 
-	--
+	http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
-	-- Overview
-	--
-	luci.template.render("admin_system/flashops", {
-		reset_avail   = reset_avail,
-		upgrade_avail = upgrade_avail
-	})
 end
 
 function action_passwd()

modules/luci-mod-admin-full/luasrc/view/admin_system/flashops.htm

@@ -17,38 +17,43 @@
 
 	<fieldset class="cbi-section">
 		<legend><%:Backup / Restore%></legend>
-		<form method="post" action="<%=url('admin/system/flashops')%>" enctype="multipart/form-data">
-			<input type="hidden" name="exec" value="1" />
-			<input type="hidden" name="token" value="<%=token%>" />
 		<div class="cbi-section-descr"><%:Click "Generate archive" to download a tar archive of the current configuration files. To reset the firmware to its initial state, click "Perform reset" (only possible with squashfs images).%></div>
 		<div class="cbi-section-node">
+			<form class="inline" method="post" action="<%=url('admin/system/flashops/backup')%>">
+				<input type="hidden" name="token" value="<%=token%>" />
 				<div class="cbi-value<% if not reset_avail then %> cbi-value-last<% end %>">
 					<label class="cbi-value-title" for="image"><%:Download backup%>:</label>
 					<div class="cbi-value-field">
 						<input class="cbi-button cbi-button-apply" type="submit" name="backup" value="<%:Generate archive%>" />
 					</div>
 				</div>
+			</form>
 			<% if reset_avail then %>
+			<form class="inline" method="post" action="<%=url('admin/system/flashops/reset')%>">
+				<input type="hidden" name="token" value="<%=token%>" />
 				<div class="cbi-value cbi-value-last">
 					<label class="cbi-value-title"><%:Reset to defaults%>:</label>
 					<div class="cbi-value-field">
 						<input onclick="return confirm('<%:Really reset all changes?%>')" class="cbi-button cbi-button-reset" type="submit" name="reset" value="<%:Perform reset%>" />
 					</div>
 				</div>
+			</form>
 			<% end %>
 		</div>
 		<br />
 		<div class="cbi-section-descr"><%:To restore configuration files, you can upload a previously generated backup archive here.%></div>
 		<div class="cbi-section-node">
+			<form class="inline" method="post" action="<%=url('admin/system/flashops/restore')%>" enctype="multipart/form-data">
 				<div class="cbi-value cbi-value-last">
 					<label class="cbi-value-title" for="archive"><%:Restore backup%>:</label>
 					<div class="cbi-value-field">
+						<input type="hidden" name="token" value="<%=token%>" />
 						<input type="file" name="archive" id="archive" />
 						<input type="submit" class="cbi-button cbi-input-apply" name="restore" value="<%:Upload archive...%>" />
 					</div>
 				</div>
-			</div>
 			</form>
+		</div>
 	</fieldset>
 
 	<br />
@@ -56,8 +61,7 @@
 	<fieldset class="cbi-section">
 		<legend><%:Flash new firmware image%></legend>
 		<% if upgrade_avail then %>
-			<form method="post" action="<%=url('admin/system/flashops')%>" enctype="multipart/form-data">
+			<form method="post" action="<%=url('admin/system/flashops/sysupgrade')%>" enctype="multipart/form-data">
-				<input type="hidden" name="exec" value="1" />
 				<input type="hidden" name="token" value="<%=token%>" />
 				<div class="cbi-section-descr"><%:Upload a sysupgrade-compatible image here to replace the running firmware. Check "Keep settings" to retain the current configuration (requires an OpenWrt compatible firmware image).%></div>
 				<div class="cbi-section-node">

modules/luci-mod-admin-full/luasrc/view/admin_system/upgrade.htm

@@ -45,12 +45,11 @@
 </fieldset>
 
 <div class="cbi-page-actions right">
-	<form style="display:inline" action="<%=REQUEST_URI%>" method="post">
+	<form class="inline" action="<%=REQUEST_URI%>" method="post">
-		<input class="cbi-button cbi-button-reset" type="submit" value="<%:Cancel%>" />
+		<input type="hidden" name="token" value="<%=token%>" />
-	</form>
-	<form style="display:inline" action="<%=REQUEST_URI%>" method="post">
 		<input type="hidden" name="step" value="2" />
 		<input type="hidden" name="keep" value="<%=keep and "1" or ""%>" />
+		<input class="cbi-button cbi-button-reset" name="cancel" type="submit" value="<%:Cancel%>" />
 		<input class="cbi-button cbi-button-apply" type="submit" value="<%:Proceed%>" />
 	</form>
 </div>