libs/web: introduce recursive expression support for datatypes, introduce "or" and "and" datatypes

The commit adds a recursive parser for datatype expressions which allows nesting of validators,
this allows for complex expressions like  "list(or(range(0,65535),'infinite'))" to allow a list of
values which are either integers between 0 and 65535 or the literal string "inifinite".
That change also deprecates combined datatypes like "ipaddr" ["or(ip4addr,ip6addr)"] or
"host" ["or(hostname,ip4addr,ip6addr)"]

2 files changed, 135 insertions, 45 deletions

diff --git a/libs/web/luasrc/cbi.lua b/libs/web/luasrc/cbi.lua
index ff030a268..88fb8a9b1 100644
--- a/libs/web/luasrc/cbi.lua
+++ b/libs/web/luasrc/cbi.lua
@@ -152,6 +152,78 @@ function load(cbimap, ...)
 	return maps
 end
 
+--
+-- Compile a datatype specification into a parse tree for evaluation later on
+--
+local cdt_cache = { }
+
+function compile_datatype(code)
+	local i
+	local pos = 0
+	local esc = false
+	local depth = 0
+	local stack = { }
+
+	for i = 1, #code+1 do
+		local byte = code:byte(i) or 44
+		if esc then
+			esc = false
+		elseif byte == 92 then
+			esc = true
+		elseif byte == 40 or byte == 44 then
+			if depth <= 0 then
+				if pos < i then
+					local label = code:sub(pos, i-1)
+						:gsub("\\(.)", "%1")
+						:gsub("^%s+", "")
+						:gsub("%s+$", "")
+
+					if #label > 0 and tonumber(label) then
+						stack[#stack+1] = tonumber(label)
+					elseif label:match("^'.+'$") or label:match('^".+"$') then
+						stack[#stack+1] = label:gsub("[\"'](.+)[\"']", "%1")
+					elseif type(datatypes[label]) == "function" then
+						stack[#stack+1] = datatypes[label]
+						stack[#stack+1] = { }
+					else
+						error("Datatype error, bad token %q" % label)
+					end
+				end
+				pos = i + 1
+			end
+			depth = depth + (byte == 40 and 1 or 0)
+		elseif byte == 41 then
+			depth = depth - 1
+			if depth <= 0 then
+				if type(stack[#stack-1]) ~= "function" then
+					error("Datatype error, argument list follows non-function")
+				end
+				stack[#stack] = compile_datatype(code:sub(pos, i-1))
+				pos = i + 1
+			end
+		end
+	end
+
+	return stack
+end
+
+function verify_datatype(dt, value)
+	if dt and #dt > 0 then
+		if not cdt_cache[dt] then
+			local c = compile_datatype(dt)
+			if c and type(c[1]) == "function" then
+				cdt_cache[dt] = c
+			else
+				error("Datatype error, not a function expression")
+			end
+		end
+		if cdt_cache[dt] then
+			return cdt_cache[dt][1](value, unpack(cdt_cache[dt][2]))
+		end
+	end
+	return true
+end
+
 
 -- Node pseudo abstract class
 Node = class()
@@ -1356,31 +1428,19 @@ end
 -- Validate the form value
 function AbstractValue.validate(self, value)
 	if self.datatype and value then
-		local args = { }
-		local dt, ar = self.datatype:match("^(%w+)%(([^%(%)]+)%)")
-
-		if dt and ar then
-			local a
-			for a in ar:gmatch("[^%s,]+") do
-				args[#args+1] = a
-			end
-		else
-			dt = self.datatype
-		end
-
-		if dt and datatypes[dt] then
-			if type(value) == "table" then
-				local v
-				for _, v in ipairs(value) do
-					if v and #v > 0 and not datatypes[dt](v, unpack(args)) then
-						return nil
-					end
-				end
-			else
-				if not datatypes[dt](value, unpack(args)) then
+		if type(value) == "table" then
+			local v
+			for _, v in ipairs(value) do
+				if v and #v > 0 and not verify_datatype(self.datatype, v) then
+					error('F')
 					return nil
 				end
 			end
+		else
+			if not verify_datatype(self.datatype, value) then
+				error('F')
+				return nil
+			end
 		end
 	end
 
diff --git a/libs/web/luasrc/cbi/datatypes.lua b/libs/web/luasrc/cbi/datatypes.lua
index 9f5a3eb1b..6d8715734 100644
--- a/libs/web/luasrc/cbi/datatypes.lua
+++ b/libs/web/luasrc/cbi/datatypes.lua
@@ -17,12 +17,64 @@ local fs = require "nixio.fs"
 local ip = require "luci.ip"
 local math = require "math"
 local util = require "luci.util"
-local tonumber, type = tonumber, type
+local tonumber, type, unpack, select = tonumber, type, unpack, select
 
 
 module "luci.cbi.datatypes"
 
 
+_M['or'] = function(v, ...)
+	local i
+	for i = 1, select('#', ...), 2 do
+		local f = select(i, ...)
+		local a = select(i+1, ...)
+		if type(f) ~= "function" then
+			print("COMP", f, v)
+			if f == v then
+				return true
+			end
+			i = i - 1
+		elseif f(v, unpack(a)) then
+			return true
+		end
+	end
+	return false
+end
+
+_M['and'] = function(v, ...)
+	local i
+	for i = 1, select('#', ...), 2 do
+		local f = select(i, ...)
+		local a = select(i+1, ...)
+		if type(f) ~= "function" then
+			if f ~= v then
+				return false
+			end
+			i = i - 1
+		elseif not f(v, unpack(a)) then
+			return false
+		end
+	end
+	return true
+end
+
+function neg(v, ...)
+	return _M['or'](v:gsub("^%s*!%s*", ""), ...)
+end
+
+function list(v, subvalidator, subargs)
+	if type(subvalidator) ~= "function" then
+		return false
+	end
+	local token
+	for token in v:gmatch("%S+") do
+		if not subvalidator(token, unpack(subargs)) then
+			return false
+		end
+	end
+	return true
+end
+
 function bool(val)
 	if val == "1" or val == "yes" or val == "on" or val == "true" then
 		return true
@@ -254,25 +306,3 @@ function max(val, max)
 
 	return false
 end
-
-function neg(val, what)
-	if what and type(_M[what]) == "function" then
-		return _M[what](val:gsub("^%s*!%s*", ""))
-	end
-
-	return false
-end
-
-function list(val, what, ...)
-	if type(val) == "string" and what and type(_M[what]) == "function" then
-		for val in val:gmatch("%S+") do
-			if not _M[what](val, ...) then
-				return false
-			end
-		end
-
-		return true
-	end
-
-	return false
-end