treewide: rework rollback/apply workflow

Rework the apply confirmation mechanism to be session agnostic in order to
circumvent cross domain restrictions which prevent the JS code from issuing
apply confirm requests in some cases, e.g. when changing the LAN IP.

Confirmation calls may now be done from unauthenticated pages, as long as a
matching confirmation token is sent along with the request.

The reasoning behind this is that there is little security impact in
confirming pending apply sessions, especially since those sessions can only
be initiated while being authenticated.

After this change, LuCI will now launch a confirmation process on every
rendered page when a rollback is pending. The confirmation will happen
regardless of whether the user is logged in or not, or if the current page
is a CBI form or static template.

A confirmation request now also requires a random one-time token which is
rendered along with the confirmation JavaScript code in order to succeed.

This token is not meant to provide security but to ensure that the confirm
was triggered from an interactive browser session and not some background
HTTP requests that happened to end up in the admin ui.

As a consequence, the different apply/confirm/rollback code paths in CBI
maps and the UCI change/revert pages have been consolidated into one common
implementation residing in the common global theme agnostic footer template.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

modules/luci-base/luasrc/dispatcher.lua

@@ -893,8 +893,6 @@ local function _cbi(self, ...)
 	local pageaction = true
 	local parsechain = { }
 
-	local is_rollback, time_remaining = uci:rollback_pending()
-
 	for i, res in ipairs(maps) do
 		if res.apply_needed and res.parsechain then
 			local c
@@ -921,8 +919,6 @@ local function _cbi(self, ...)
 	for i, res in ipairs(maps) do
 		res:render({
 			firstmap   = (i == 1),
-			applymap   = applymap,
-			confirmmap = (is_rollback and time_remaining or nil),
 			redirect   = redirect,
 			messages   = messages,
 			pageaction = pageaction,
@@ -932,11 +928,12 @@ local function _cbi(self, ...)
 
 	if not config.nofooter then
 		tpl.render("cbi/footer", {
-			flow       = config,
+			flow          = config,
-			pageaction = pageaction,
+			pageaction    = pageaction,
-			redirect   = redirect,
+			redirect      = redirect,
-			state      = state,
+			state         = state,
-			autoapply  = config.autoapply
+			autoapply     = config.autoapply,
+			trigger_apply = applymap
 		})
 	end
 end

modules/luci-base/luasrc/model/uci.lua

@@ -147,19 +147,31 @@ function apply(self, rollback)
 	local _, err
 
 	if rollback then
+		local sys = require "luci.sys"
 		local conf = require "luci.config"
-		local timeout = tonumber(conf and conf.apply and conf.apply.rollback or "") or 0
+		local timeout = tonumber(conf and conf.apply and conf.apply.rollback or 30) or 0
 
 		_, err = call("apply", {
-			timeout  = (timeout > 30) and timeout or 30,
+			timeout = (timeout > 30) and timeout or 30,
 			rollback = true
 		})
 
 		if not err then
+			local now = os.time()
+			local token = sys.uniqueid(16)
+
 			util.ubus("session", "set", {
-				ubus_rpc_session = session_id,
+				ubus_rpc_session = "00000000000000000000000000000000",
-				values = { rollback = os.time() + timeout }
+				values = {
+					rollback = {
+						token   = token,
+						session = session_id,
+						timeout = now + timeout
+					}
+				}
 			})
+
+			return token
 		end
 	else
 		_, err = call("changes", {})
@@ -184,40 +196,72 @@ function apply(self, rollback)
 	return (err == nil), ERRSTR[err]
 end
 
-function confirm(self)
+function confirm(self, token)
-	local _, err = call("confirm", {})
+	local is_pending, time_remaining, rollback_sid, rollback_token = self:rollback_pending()
-	if not err then
+
-		util.ubus("session", "set", {
+	if is_pending then
-			ubus_rpc_session = session_id,
+		if token ~= rollback_token then
-			values = { rollback = 0 }
+			return false, "Permission denied"
+		end
+
+		local _, err = util.ubus("uci", "confirm", {
+			ubus_rpc_session = rollback_sid
 		})
+
+		if not err then
+			util.ubus("session", "set", {
+				ubus_rpc_session = "00000000000000000000000000000000",
+				values = { rollback = {} }
+			})
+		end
+
+		return (err == nil), ERRSTR[err]
 	end
-	return (err == nil), ERRSTR[err]
+
+	return false, "No data"
 end
 
 function rollback(self)
-	local _, err = call("rollback", {})
+	local is_pending, time_remaining, rollback_sid = self:rollback_pending()
-	if not err then
+
-		util.ubus("session", "set", {
+	if is_pending then
-			ubus_rpc_session = session_id,
+		local _, err = util.ubus("uci", "rollback", {
-			values = { rollback = 0 }
+			ubus_rpc_session = rollback_sid
 		})
+
+		if not err then
+			util.ubus("session", "set", {
+				ubus_rpc_session = "00000000000000000000000000000000",
+				values = { rollback = {} }
+			})
+		end
+
+		return (err == nil), ERRSTR[err]
 	end
-	return (err == nil), ERRSTR[err]
+
+	return false, "No data"
 end
 
 function rollback_pending(self)
-	local deadline, err = util.ubus("session", "get", {
+	local rv, err = util.ubus("session", "get", {
-		ubus_rpc_session = session_id,
+		ubus_rpc_session = "00000000000000000000000000000000",
 		keys = { "rollback" }
 	})
 
-	if type(deadline) == "table" and
+	local now = os.time()
-	   type(deadline.values) == "table" and
+
-	   type(deadline.values.rollback) == "number" and
+	if type(rv) == "table" and
-	   deadline.values.rollback > os.time()
+	   type(rv.values) == "table" and
+	   type(rv.values.rollback) == "table" and
+	   type(rv.values.rollback.token) == "string" and
+	   type(rv.values.rollback.session) == "string" and
+	   type(rv.values.rollback.timeout) == "number" and
+	   rv.values.rollback.timeout > now
 	then
-		return true, deadline.values.rollback - os.time()
+		return true,
+			rv.values.rollback.timeout - now,
+			rv.values.rollback.session,
+			rv.values.rollback.token
 	end
 
 	return false, ERRSTR[err]

modules/luci-base/luasrc/view/cbi/apply_widget.htm

@@ -1,4 +1,4 @@
-<% export("cbi_apply_widget", function(redirect_ok) -%>
+<% export("cbi_apply_widget", function(redirect_ok, rollback_token) -%>
 <style type="text/css">
 	#cbi_apply_overlay {
 		position: absolute;
@@ -51,6 +51,7 @@
 	    uci_apply_holdoff = <%=math.max(luci.config and luci.config.apply and luci.config.apply.holdoff or 4, 1)%>,
 	    uci_apply_timeout = <%=math.max(luci.config and luci.config.apply and luci.config.apply.timeout or 5, 1)%>,
 	    uci_apply_display = <%=math.max(luci.config and luci.config.apply and luci.config.apply.display or 1.5, 1)%>,
+	    uci_confirm_auth = <% if rollback_token then %>{ token: '<%=rollback_token%>' }<% else %>null<% end %>,
 	    was_xhr_poll_running = false;
 
 	function uci_status_message(type, content) {
@@ -148,7 +149,7 @@
 
 			var delay = isNaN(duration) ? 0 : Math.max(1000 - duration, 0);
 			window.setTimeout(function() {
-				xhr.post('<%=url("admin/uci/confirm")%>', uci_apply_auth, call, uci_apply_timeout * 1000);
+				xhr.post('<%=url("admin/uci/confirm")%>', uci_confirm_auth, call, uci_apply_timeout * 1000);
 			}, delay);
 		};
 
@@ -177,8 +178,11 @@
 			'<img src="<%=resource%>/icons/loading.gif" alt="" style="vertical-align:middle" /> ' +
 			'<%:Starting configuration apply…%>');
 
-		xhr.post('<%=url("admin/uci")%>/' + (checked ? 'apply_rollback' : 'apply_unchecked'), uci_apply_auth, function(r) {
+		xhr.post('<%=url("admin/uci")%>/' + (checked ? 'apply_rollback' : 'apply_unchecked'), uci_apply_auth, function(r, tok) {
 			if (r.status === (checked ? 200 : 204)) {
+				if (checked && tok !== null && typeof(tok) === 'object' && typeof(tok.token) === 'string')
+					uci_confirm_auth = tok;
+
 				uci_confirm(checked, Date.now() + uci_apply_rollback * 1000);
 			}
 			else if (checked && r.status === 204) {

modules/luci-base/luasrc/view/cbi/map.htm

@@ -5,21 +5,6 @@
 <div class="cbi-map" id="cbi-<%=self.config%>">
 	<% if self.title and #self.title > 0 then %><h2 name="content"><%=self.title%></h2><% end %>
 	<% if self.description and #self.description > 0 then %><div class="cbi-map-descr"><%=self.description%></div><% end %>
-	<%- if firstmap and (applymap or confirmmap) then -%>
-		<%+cbi/apply_widget%>
-		<% cbi_apply_widget(redirect) %>
-		<div class="alert-message" id="cbi_apply_status" style="display:none"></div>
-		<script type="text/javascript">
-			document.addEventListener("DOMContentLoaded", function() {
-				<% if confirmmap then -%>
-					uci_confirm(true, Date.now() + <%=confirmmap%> * 1000);
-				<%- else -%>
-					uci_apply(true);
-				<%- end %>
-			});
-		</script>
-	<%- end -%>
-
 	<% if self.tabbed then %>
 		<ul class="cbi-tabmenu map">
 			<%- self.selected_tab = luci.http.formvalue("tab.m-" .. self.config) %>

modules/luci-base/luasrc/view/footer.htm

@@ -4,4 +4,27 @@
  Licensed to the public under the Apache License 2.0.
 -%>
 
-<% include("themes/" .. theme .. "/footer") %>
+<%
+	include("themes/" .. theme .. "/footer")
+
+	local is_rollback_pending, rollback_time_remaining, rollback_session, rollback_token = luci.model.uci:rollback_pending()
+
+	if is_rollback_pending or trigger_apply or trigger_revert then
+		include("cbi/apply_widget")
+		cbi_apply_widget(redirect, rollback_token)
+%>
+	<div class="alert-message" id="cbi_apply_status" style="display:none"></div>
+	<script type="text/javascript">
+		document.addEventListener("DOMContentLoaded", function() {
+			<% if trigger_apply then -%>
+				uci_apply(true);
+			<%- elseif trigger_revert then -%>
+				uci_revert();
+			<%- else -%>
+				uci_confirm(true, Date.now() + <%=rollback_time_remaining%> * 1000);
+			<%- end %>
+		});
+	</script>
+<%
+	end
+%>

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

@@ -9,7 +9,7 @@ function index()
 		or table.concat(luci.dispatcher.context.request, "/")
 
 	entry({"admin", "uci"}, nil, _("Configuration"))
-	entry({"admin", "uci", "changes"}, call("action_changes"), _("Changes"), 40).query = {redir=redir}
+	entry({"admin", "uci", "changes"}, post_on({ trigger_apply = true }, "action_changes"), _("Changes"), 40).query = {redir=redir}
 	entry({"admin", "uci", "revert"}, post("action_revert"), _("Revert"), 30).query = {redir=redir}
 
 	local node
@@ -25,9 +25,9 @@ function index()
 	node.cors = true
 	node.sysauth_authenticator = authen
 
-	node = entry({"admin", "uci", "confirm"}, post("action_confirm"), nil)
+	node = entry({"admin", "uci", "confirm"}, call("action_confirm"), nil)
 	node.cors = true
-	node.sysauth_authenticator = authen
+	node.sysauth = false
 end
 
 
@@ -36,8 +36,9 @@ function action_changes()
 	local changes = uci:changes()
 
 	luci.template.render("admin_uci/changes", {
-		changes  = next(changes) and changes,
+		changes       = next(changes) and changes,
-		timeout  = timeout
+		timeout       = timeout,
+		trigger_apply = luci.http.formvalue("trigger_apply") and true or false
 	})
 end
 
@@ -52,7 +53,8 @@ function action_revert()
 	end
 
 	luci.template.render("admin_uci/revert", {
-		changes = next(changes) and changes
+		changes        = next(changes) and changes,
+		trigger_revert = true
 	})
 end
 
@@ -84,8 +86,13 @@ end
 
 function action_apply_rollback()
 	local uci = require "luci.model.uci"
-	local _, errstr = uci:apply(true)
+	local token, errstr = uci:apply(true)
-	ubus_state_to_http(errstr)
+	if token then
+		luci.http.prepare_content("application/json")
+		luci.http.write_json({ token = token })
+	else
+		ubus_state_to_http(errstr)
+	end
 end
 
 function action_apply_unchecked()
@@ -96,6 +103,7 @@ end
 
 function action_confirm()
 	local uci = require "luci.model.uci"
-	local _, errstr = uci:confirm()
+	local token = luci.http.formvalue("token")
+	local _, errstr = uci:confirm(token)
 	ubus_state_to_http(errstr)
 end

modules/luci-mod-admin-full/luasrc/view/admin_uci/changes.htm

@@ -8,11 +8,9 @@
 
 <%-
 	local node, redir_url = luci.dispatcher.lookup(luci.http.formvalue("redir"))
+	export("redirect", redir_url or url("admin/uci/changes"))
 
-	include("cbi/apply_widget")
 	include("admin_uci/changelog")
-
-	cbi_apply_widget(redir_url or url("admin/uci/changes"))
 -%>
 
 <h2 name="content"><%:Configuration%> / <%:Changes%></h2>
@@ -32,7 +30,11 @@
 	</form>
 	<% end %>
 
-	<input class="cbi-button cbi-button-save" type="button" id="apply_button" value="<%:Save & Apply%>" onclick="uci_apply(true); this.blur()" />
+	<form method="post" action="<%=url("admin/uci/changes")%>">
+		<input type="hidden" name="token" value="<%=token%>" />
+		<input type="hidden" name="redir" value="<%=pcdata(luci.http.formvalue("redir"))%>" />
+		<input class="cbi-button cbi-button-save" type="submit" name="trigger_apply" value="<%:Save & Apply%>" />
+	</form>
 	<form method="post" action="<%=url("admin/uci/revert")%>">
 		<input type="hidden" name="token" value="<%=token%>" />
 		<input type="hidden" name="redir" value="<%=pcdata(luci.http.formvalue("redir"))%>" />

modules/luci-mod-admin-full/luasrc/view/admin_uci/revert.htm

@@ -8,11 +8,9 @@
 
 <%-
 	local node, redir_url = luci.dispatcher.lookup(luci.http.formvalue("redir"))
+	export("redirect", redir_url or url("admin/uci/changes"))
 
-	include("cbi/apply_widget")
 	include("admin_uci/changelog")
-
-	cbi_apply_widget(redir_url or url("admin/uci/revert"))
 -%>
 
 <h2 name="content"><%:Configuration%> / <%:Revert%></h2>
@@ -24,13 +22,6 @@
 	<p><strong><%:There are no pending changes to revert!%></strong></p>
 <% end %>
 
-<div class="alert-message" id="cbi_apply_status" style="display:none"></div>
-<script type="text/javascript">
-	document.addEventListener("DOMContentLoaded", function() {
-		uci_revert();
-	});
-</script>
-
 <% if redir_url then %>
 	<div class="cbi-page-actions">
 		<form class="inline" method="get" action="<%=luci.util.pcdata(redir_url)%>">