luci-base: add ubus-http gateway

Add an admin/ubus route mimicking the native uhttpd-mod-ubus protocol.

The main difference to the native protocol is that this gateway requires
no additional per-object/procedure ACL setup on the router side and that
it is located under the same prefix as LuCI itself, allowing the reuse
of the session login cookie.

This route is meant to be a transitional mechanism until client side
RPC calls are eventually migrated to uhttpd-mod-ubus completely.

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

1 files changed, 112 insertions, 0 deletions

diff --git a/modules/luci-base/luasrc/controller/admin/index.lua b/modules/luci-base/luasrc/controller/admin/index.lua
index 1f7db0cb38..259c34eee8 100644
--- a/modules/luci-base/luasrc/controller/admin/index.lua
+++ b/modules/luci-base/luasrc/controller/admin/index.lua
@@ -88,6 +88,9 @@ function index()
 	page = entry({"admin", "translations"}, call("action_translations"), nil)
 	page.leaf = true
 
+	page = entry({"admin", "ubus"}, call("action_ubus"), nil)
+	page.leaf = true
+
 	-- Logout is last
 	entry({"admin", "logout"}, call("action_logout"), _("Logout"), 999)
 end
@@ -129,6 +132,115 @@ function action_translations(lang)
 	http.write_json(i18n.dump())
 end
 
+local function ubus_reply(id, data, code, errmsg)
+	local reply = { jsonrpc = "2.0", id = id }
+	if errmsg then
+		reply.error = {
+			code = code,
+			message = errmsg
+		}
+	else
+		reply.result = { code, data }
+	end
+
+	return reply
+end
+
+local ubus_types = {
+	nil,
+	"array",
+	"object",
+	"string",
+	nil, -- INT64
+	"number",
+	nil, -- INT16,
+	"boolean",
+	"double"
+}
+
+local function ubus_request(req)
+	if type(req) ~= "table" or type(req.method) ~= "string" or type(req.params) ~= "table" or
+	   #req.params < 2 or req.jsonrpc ~= "2.0" or req.id == nil then
+		return ubus_reply(req.id, nil, -32600, "Invalid request")
+
+	elseif req.method == "call" then
+		local sid, obj, fun, arg =
+			req.params[1], req.params[2], req.params[3], req.params[4] or {}
+		if type(arg) ~= "table" or arg.ubus_rpc_session ~= nil then
+			return ubus_reply(req.id, nil, -32602, "Invalid parameters")
+		end
+
+		if sid == "00000000000000000000000000000000" then
+			sid = luci.dispatcher.context.authsession
+		end
+
+		arg.ubus_rpc_session = sid
+
+		local res, code = luci.util.ubus(obj, fun, arg)
+		return ubus_reply(req.id, res, code or 0)
+
+	elseif req.method == "list" then
+		if type(params) ~= "table" or #params == 0 then
+			local objs = { luci.util.ubus() }
+			return ubus_reply(req.id, objs, 0)
+		else
+			local n, rv = nil, {}
+			for n = 1, #params do
+				if type(params[n]) ~= "string" then
+					return ubus_reply(req.id, nil, -32602, "Invalid parameters")
+				end
+
+				local sig = luci.util.ubus(params[n])
+				if sig and type(sig) == "table" then
+					rv[params[n]] = {}
+
+					local m, p
+					for m, p in pairs(sig) do
+						if type(p) == "table" then
+							rv[params[n]][m] = {}
+
+							local pn, pt
+							for pn, pt in pairs(p) do
+								rv[params[n]][m][pn] = ubus_types[pt] or "unknown"
+							end
+						end
+					end
+				end
+			end
+			return ubus_reply(req.id, rv, 0)
+		end
+	end
+
+	return ubus_reply(req.id, nil, -32601, "Method not found")
+end
+
+function action_ubus()
+	local parser = require "luci.jsonc".new()
+	luci.http.context.request:setfilehandler(function(_, s) parser:parse(s or "") end)
+	luci.http.context.request:content()
+
+	local json = parser:get()
+	if json == nil or type(json) ~= "table" then
+		luci.http.prepare_content("application/json")
+		luci.http.write_json(ubus_reply(nil, nil, -32700, "Parse error"))
+		return
+	end
+
+	local response
+	if #json == 0 then
+		response = ubus_request(json)
+	else
+		response = {}
+
+		local _, request
+		for _, request in ipairs(json) do
+			response[_] = ubus_request(request)
+		end
+	end
+
+	luci.http.prepare_content("application/json")
+	luci.http.write_json(response)
+end
 
 function lease_status()
 	local s = require "luci.tools.status"