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>

3 files changed, 187 insertions, 145 deletions

diff --git a/modules/luci-mod-admin-full/luasrc/controller/admin/system.lua b/modules/luci-mod-admin-full/luasrc/controller/admin/system.lua
index 3340b171e..cbba48cc2 100644
--- a/modules/luci-mod-admin-full/luasrc/controller/admin/system.lua
+++ b/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
@@ -171,152 +177,185 @@ function action_packages()
 	end
 end
 
-function action_flashops()
-	local http = require "luci.http"
-	local sys  = require "luci.sys"
-	local fs   = require "nixio.fs"
+local function image_supported(image)
+	return (os.execute("sysupgrade -T %q >/dev/null" % image) == 0)
+end
 
-	local submit = (http.formvalue("exec") == "1")
+local function image_checksum(image)
+	return (luci.sys.exec("md5sum %q" % image):match("^([^%s]+)"))
+end
 
-	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 function supports_sysupgrade()
+	return nixio.fs.access("/lib/upgrade/platform.sh")
+end
 
-	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 supports_reset()
+	return (os.execute([[grep -sq '"rootfs_data"' /proc/mtd]]) == 0)
+end
 
-	local function image_supported()
-		return (os.execute("sysupgrade -T %q >/dev/null" % image_tmp) == 0)
+local function storage_size()
+	local size = 0
+	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
+				size = tonumber(s, 16)
+				break
+			end
+		end
+	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
+				size = tonumber(b) * 1024
+				break
+			end
+		end
 	end
+	return size
+end
 
-	local function image_checksum()
-		return (luci.sys.exec("md5sum %q" % image_tmp):match("^([^%s]+)"))
-	end
 
-	local function storage_size()
-		local size = 0
-		if 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
-					size = tonumber(s, 16)
-					break
-				end
+function action_flashops()
+	--
+	-- Overview
+	--
+	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 and meta and meta.name == "image" then
+				fp = io.open(image_tmp, "w")
 			end
-		elseif 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
-					size = tonumber(b) * 1024
-					break
-				end
+			if fp and chunk then
+				fp:write(chunk)
+			end
+			if fp and eof then
+				fp:close()
 			end
 		end
-		return size
+	)
+
+	if not luci.dispatcher.test_post_security() then
+		fs.unlink(image_tmp)
+		return
 	end
 
 	--
-	-- Handle modifying actions
+	-- Cancel firmware flash
 	--
-	if submit then
+	if http.formvalue("cancel") then
+		fs.unlink(image_tmp)
+		http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
+		return
+	end
+
+	--
+	-- Initiate firmware flash
+	--
+	local step = tonumber(http.formvalue("step") or 1)
+	if step == 1 then
+		if image_supported(image_tmp) then
+			luci.template.render("admin_system/upgrade", {
+				checksum = image_checksum(image_tmp),
+				storage  = storage_size(),
+				size     = (fs.stat(image_tmp, "size") or 0),
+				keep     = (not not http.formvalue("keep"))
+			})
+		else
+			fs.unlink(image_tmp)
+			luci.template.render("admin_system/flashops", {
+				reset_avail   = supports_reset(),
+				upgrade_avail = supports_sysupgrade(),
+				image_invalid = true
+			})
+		end
+	--
+	-- Start sysupgrade flash
+	--
+	elseif step == 2 then
+		local keep = (http.formvalue("keep") == "1") and "" or "-n"
+		luci.template.render("admin_system/applyreboot", {
+			title = luci.i18n.translate("Flashing..."),
+			msg   = luci.i18n.translate("The system is flashing now.<br /> DO NOT POWER OFF THE DEVICE!<br /> Wait a few minutes before you try to reconnect. It might be necessary to renew the address of your computer to reach the device again, depending on your settings."),
+			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
 
-		local fp
-		http.setfilehandler(
-			function(meta, chunk, eof)
-				if not fp then
-					if meta and meta.name == "image" then
-						fp = io.open(image_tmp, "w")
-					else
-						fp = io.popen(restore_cmd, "w")
-					end
-				end
-				if chunk then
-					fp:write(chunk)
-				end
-				if eof then
-					fp:close()
-				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 http.formvalue("backup") then
-			--
-			-- Assemble file list, generate backup
-			--
-			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")})
-			http.prepare_content("application/x-targz")
-			luci.ltn12.pump.all(reader, http.write)
-			return
-
-		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
+			if fp and chunk then
+				fp:write(chunk)
 			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
-					luci.template.render("admin_system/upgrade", {
-						checksum = image_checksum(),
-						storage  = storage_size(),
-						size     = (fs.stat(image_tmp, "size") or 0),
-						keep     = (not not http.formvalue("keep"))
-					})
-				else
-					fs.unlink(image_tmp)
-					luci.template.render("admin_system/flashops", {
-						reset_avail   = reset_avail,
-						upgrade_avail = upgrade_avail,
-						image_invalid = true
-					})
-				end
-				return
-			--
-			-- Start sysupgrade flash
-			--
-			elseif step == 2 then
-				local keep = (http.formvalue("keep") == "1") and "" or "-n"
-				luci.template.render("admin_system/applyreboot", {
-					title = luci.i18n.translate("Flashing..."),
-					msg   = luci.i18n.translate("The system is flashing now.<br /> DO NOT POWER OFF THE DEVICE!<br /> Wait a few minutes before you try to reconnect. It might be necessary to renew the address of your computer to reach the device again, depending on your settings."),
-					addr  = (#keep > 0) and "192.168.1.1" or nil
-				})
-				fork_exec("killall dropbear uhttpd; sleep 1; /sbin/sysupgrade %s %q" %{ keep, image_tmp })
-				return
+			if fp and eof then
+				fp:close()
 			end
-		elseif reset_avail and http.formvalue("reset") then
-			--
-			-- Reset system
-			--
-			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
+	)
+
+	if not luci.dispatcher.test_post_security() then
+		fs.unlink(archive_tmp)
+		return
 	end
 
-	--
-	-- Overview
-	--
-	luci.template.render("admin_system/flashops", {
-		reset_avail   = reset_avail,
-		upgrade_avail = upgrade_avail
-	})
+	local upload = http.formvalue("archive")
+	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
+
+	http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
 end
 
 function action_passwd()
diff --git a/modules/luci-mod-admin-full/luasrc/view/admin_system/flashops.htm b/modules/luci-mod-admin-full/luasrc/view/admin_system/flashops.htm
index 8bf199294..82a1fdbc9 100644
--- a/modules/luci-mod-admin-full/luasrc/view/admin_system/flashops.htm
+++ b/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">
+		<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>
-				<% if reset_avail then %>
+			</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>
-				<% 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>
+			<% 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>
+			</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">
-				<input type="hidden" name="exec" value="1" />
+			<form method="post" action="<%=url('admin/system/flashops/sysupgrade')%>" enctype="multipart/form-data">
 				<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">
diff --git a/modules/luci-mod-admin-full/luasrc/view/admin_system/upgrade.htm b/modules/luci-mod-admin-full/luasrc/view/admin_system/upgrade.htm
index 198505882..5ca0398e1 100644
--- a/modules/luci-mod-admin-full/luasrc/view/admin_system/upgrade.htm
+++ b/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">
-		<input class="cbi-button cbi-button-reset" type="submit" value="<%:Cancel%>" />
-	</form>
-	<form style="display:inline" action="<%=REQUEST_URI%>" method="post">
+	<form class="inline" action="<%=REQUEST_URI%>" method="post">
+		<input type="hidden" name="token" value="<%=token%>" />
 		<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>