Current File : //opt/imunify360-webshield/lualib/ngx/re.lua
-- I hereby assign copyright in this code to the lua-resty-core project,
-- to be licensed under the same terms as the rest of the code.
local base = require "resty.core.base"
local ffi = require 'ffi'
local bit = require "bit"
local core_regex = require "resty.core.regex"
if core_regex.no_pcre then
error("no support for 'ngx.re' module: OpenResty was " ..
"compiled without PCRE support", 3)
end
local C = ffi.C
local ffi_str = ffi.string
local sub = string.sub
local error = error
local type = type
local band = bit.band
local new_tab = base.new_tab
local tostring = tostring
local math_max = math.max
local math_min = math.min
local is_regex_cache_empty = core_regex.is_regex_cache_empty
local re_match_compile = core_regex.re_match_compile
local destroy_compiled_regex = core_regex.destroy_compiled_regex
local get_string_buf = base.get_string_buf
local get_size_ptr = base.get_size_ptr
local FFI_OK = base.FFI_OK
local subsystem = ngx.config.subsystem
local MAX_ERR_MSG_LEN = 128
local FLAG_DFA = 0x02
local PCRE_ERROR_NOMATCH = -1
local DEFAULT_SPLIT_RES_SIZE = 4
local split_ctx = new_tab(0, 1)
local ngx_lua_ffi_set_jit_stack_size
local ngx_lua_ffi_exec_regex
if subsystem == 'http' then
ffi.cdef[[
int ngx_http_lua_ffi_set_jit_stack_size(int size, unsigned char *errstr,
size_t *errstr_size);
]]
ngx_lua_ffi_exec_regex = C.ngx_http_lua_ffi_exec_regex
ngx_lua_ffi_set_jit_stack_size = C.ngx_http_lua_ffi_set_jit_stack_size
elseif subsystem == 'stream' then
ffi.cdef[[
int ngx_stream_lua_ffi_set_jit_stack_size(int size, unsigned char *errstr,
size_t *errstr_size);
]]
ngx_lua_ffi_exec_regex = C.ngx_stream_lua_ffi_exec_regex
ngx_lua_ffi_set_jit_stack_size = C.ngx_stream_lua_ffi_set_jit_stack_size
end
local _M = { version = base.version }
local function re_split_helper(subj, compiled, compile_once, flags, ctx)
local rc
do
local pos = math_max(ctx.pos, 0)
rc = ngx_lua_ffi_exec_regex(compiled, flags, subj, #subj, pos)
end
if rc == PCRE_ERROR_NOMATCH then
return nil, nil, nil
end
if rc < 0 then
if not compile_once then
destroy_compiled_regex(compiled)
end
return nil, nil, nil, "pcre_exec() failed: " .. rc
end
if rc == 0 then
if band(flags, FLAG_DFA) == 0 then
if not compile_once then
destroy_compiled_regex(compiled)
end
return nil, nil, nil, "capture size too small"
end
rc = 1
end
local caps = compiled.captures
local ncaps = compiled.ncaptures
local from = caps[0]
local to = caps[1]
if from < 0 or to < 0 then
return nil, nil, nil
end
if from == to then
-- empty match, skip to next char
ctx.pos = to + 1
else
ctx.pos = to
end
-- convert to Lua string indexes
from = from + 1
to = to + 1
-- retrieve the first sub-match capture if any
if ncaps > 0 and rc > 1 then
return from, to, sub(subj, caps[2] + 1, caps[3])
end
return from, to
end
function _M.split(subj, regex, opts, ctx, max, res)
-- we need to cast this to strings to avoid exceptions when they are
-- something else.
-- needed because of further calls to string.sub in this function.
subj = tostring(subj)
if not ctx then
ctx = split_ctx
ctx.pos = 1 -- set or reset upvalue field
elseif not ctx.pos then
-- ctx provided by user but missing pos field
ctx.pos = 1
end
max = max or 0
if not res then
-- limit the initial arr_n size of res to a reasonable value
-- 0 < narr <= DEFAULT_SPLIT_RES_SIZE
local narr = DEFAULT_SPLIT_RES_SIZE
if max > 0 then
-- the user specified a valid max limiter if max > 0
narr = math_min(narr, max)
end
res = new_tab(narr, 0)
elseif type(res) ~= "table" then
error("res is not a table", 2)
end
local len = #subj
if ctx.pos > len then
res[1] = nil
return res
end
-- compile regex
local compiled, compile_once, flags = re_match_compile(regex, opts)
if compiled == nil then
-- compiled_once holds the error string
return nil, compile_once
end
local sub_idx = ctx.pos
local res_idx = 0
local last_empty_match
-- update to split_helper PCRE indexes
ctx.pos = sub_idx - 1
-- splitting: with and without a max limiter
if max > 0 then
local count = 1
while count < max do
local from, to, capture, err = re_split_helper(subj, compiled,
compile_once, flags, ctx)
if err then
return nil, err
end
if not from then
break
end
if last_empty_match then
sub_idx = last_empty_match
end
if from == to then
last_empty_match = from
end
if from > sub_idx or not last_empty_match then
count = count + 1
res_idx = res_idx + 1
res[res_idx] = sub(subj, sub_idx, from - 1)
if capture then
res_idx = res_idx + 1
res[res_idx] = capture
end
sub_idx = to
if sub_idx > len then
break
end
end
end
else
while true do
local from, to, capture, err = re_split_helper(subj, compiled,
compile_once, flags, ctx)
if err then
return nil, err
end
if not from then
break
end
if last_empty_match then
sub_idx = last_empty_match
end
if from == to then
last_empty_match = from
end
if from > sub_idx or not last_empty_match then
res_idx = res_idx + 1
res[res_idx] = sub(subj, sub_idx, from - 1)
if capture then
res_idx = res_idx + 1
res[res_idx] = capture
end
sub_idx = to
if sub_idx > len then
break
end
end
end
end
if not compile_once then
destroy_compiled_regex(compiled)
end
-- trailing nil for non-cleared res tables
-- delete empty trailing ones (without max)
if max <= 0 and sub_idx > len then
for ety_idx = res_idx, 1, -1 do
if res[ety_idx] ~= "" then
res_idx = ety_idx
break
end
res[ety_idx] = nil
end
else
res_idx = res_idx + 1
res[res_idx] = sub(subj, sub_idx)
end
res[res_idx + 1] = nil
return res
end
function _M.opt(option, value)
if option == "jit_stack_size" then
if not is_regex_cache_empty() then
error("changing jit stack size is not allowed when some " ..
"regexs have already been compiled and cached", 2)
end
local errbuf = get_string_buf(MAX_ERR_MSG_LEN)
local sizep = get_size_ptr()
sizep[0] = MAX_ERR_MSG_LEN
local rc = ngx_lua_ffi_set_jit_stack_size(value, errbuf, sizep)
if rc == FFI_OK then
return
end
error(ffi_str(errbuf, sizep[0]), 2)
end
error("unrecognized option name", 2)
end
return _M
Mini Shell