proper escaping for back-end addresses

1 files changed, 159 insertions, 0 deletions

diff --git a/aconf/path/base.lua b/aconf/path/base.lua
new file mode 100644
index 0000000..4e2bf8f
--- /dev/null
+++ b/aconf/path/base.lua
@@ -0,0 +1,159 @@
+--[[
+Copyright (c) 2012-2015 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+local M = {}
+
+
+local object = require('aconf.object')
+local class = object.class
+
+local map = require('aconf.util').map
+
+
+M.Special = class()
+function M.Special:tostring() return self.symbol end
+
+local Up = class(M.Special)
+Up.symbol = '..'
+
+local Wildcard = class(M.Special)
+Wildcard.symbol = '*'
+
+
+
+M.Syntax = class()
+
+M.Syntax.up = Up()
+M.Syntax.wildcard = Wildcard()
+
+
+function M.Syntax:get_special(comp)
+   return ({['..']=M.Syntax.up, ['*']=M.Syntax.wildcard})[comp]
+end
+
+
+function M.Syntax:is_absolute(path) return path:sub(1, 1) == '/' end
+
+
+function M.Syntax:escape(comp)
+   if type(comp) == 'table' then
+      if object.isinstance(object.toinstance(comp), M.Special) then
+	 return comp:tostring()
+      end
+   end
+   if type(comp) == 'number' then return tostring(comp) end
+   local res = comp:gsub('([\\/])', '\\%1')
+   return (self:get_special(res) or tonumber(res)) and '\\'..res or res
+end
+
+
+function M.Syntax:rawjoin(p1, p2, ...)
+   if not p2 then return p1 end
+   if not self:is_absolute(p2) then p2 = '/'..p2 end
+   return self:rawjoin((p1 == '/' and '' or p1)..p2, ...)
+end
+
+function M.Syntax:join(parent, ...)
+   local args = map(function(c) return self:escape(c) end, {...})
+   if parent > '' then table.insert(args, 1, parent) end
+   return self:rawjoin(table.unpack(args))
+end
+
+
+function M.Syntax:split(path)
+   local res = {}
+   local comp = ''
+   local escaped
+
+   local function merge(s)
+      if s > '' then
+	 table.insert(
+	    res, not escaped and (self:get_special(s) or tonumber(s)) or s
+	 )
+      end
+   end
+
+   while true do
+      local prefix, sep, suffix = path:match('([^\\/]*)([\\/])(.*)')
+      if not prefix then
+	 merge(comp..path)
+	 return res
+      end
+
+      comp = comp..prefix
+      if sep == '\\' then
+	 comp = comp..suffix:sub(1, 1)
+	 escaped = true
+	 path = suffix:sub(2, -1)
+      else
+	 merge(comp)
+	 comp = ''
+	 escaped = false
+	 path = suffix
+      end
+   end
+end
+
+
+function M.Syntax:is_unique(path)
+   for _, comp in ipairs(self:split(path)) do
+      if comp == self.wildcard then return false end
+   end
+   return true
+end
+
+function M.Syntax:is_subordinate(p1, p2)
+   p1 = self:split(p1)
+   for i, comp in ipairs(self:split(p2)) do
+      if p1[i] ~= comp then return false end
+   end
+   return true
+end
+
+
+function M.Syntax:to_absolute(path, base)
+   if not self:is_absolute(path) then
+      path = base..(base ~= '/' and '/' or '')..path
+   end
+   local comps = self:split(path)
+   local i = 1
+   while i <= #comps do
+      if comps[i] == self.up then
+	 if i == 1 then error('Invalid path: '..path) end
+	 table.remove(comps, i - 1)
+	 table.remove(comps, i - 1)
+	 i = i - 1
+      else i = i + 1 end
+   end
+   return self:join('/', table.unpack(comps))
+end
+
+
+function M.Syntax:parent(path)
+   local comps = self:split(path)
+   table.remove(comps)
+   return self:join('/', table.unpack(comps))
+end
+
+function M.Syntax:name(path)
+   local comps = self:split(path)
+   return comps[#comps]
+end
+
+
+function M.Syntax:export(mod)
+   if not mod then mod = {} end
+   for k, v in pairs(M.Syntax) do
+      if k ~= 'export' then
+	 mod[k] = type(v) == 'function' and function(...)
+	    return v(self, ...)
+         end or v
+      end
+   end
+   return mod
+end
+
+
+return M