paulbsd-salt/states/haproxy/scripts/http.lua

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2022-10-23 16:37:53 +02:00
--
-- HTTP 1.1 library for HAProxy Lua modules
--
-- The library is loosely modeled after Python's Requests Library
-- using the same field names and very similar calling conventions for
-- "HTTP verb" methods (where we use Lua specific named parameter support)
--
-- In addition to client side, the library also supports server side request
-- parsing, where we utilize HAProxy Lua API for all heavy lifting.
--
--
-- Copyright (c) 2017-2020. Adis Nezirović <anezirovic@haproxy.com>
-- Copyright (c) 2017-2020. HAProxy Technologies, LLC.
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
--
-- SPDX-License-Identifier: Apache-2.0
local _author = "Adis Nezirovic <anezirovic@haproxy.com>"
local _copyright = "Copyright 2017-2020. HAProxy Technologies, LLC."
local _version = "1.0.0"
local json = require "json"
-- Utility functions
-- HTTP headers fetch helper
--
-- Returns a header value(s) according to strategy (fold by default):
-- - single/string value for "fold", "first" and "last" strategies
-- - table for "all" strategy (for single value, a table with single element)
--
-- @param hdrs table Headers table as received by http.get and friends
-- @param name string Header name
-- @param strategy string "multiple header values" handling strategy
-- @return header value (string or table) or nil
local function get_header(hdrs, name, strategy)
if hdrs == nil or name == nil then return nil end
local v = hdrs[name:lower()]
if type(v) ~= "table" and strategy ~= "all" then return v end
if strategy == nil or strategy == "fold" then
return table.concat(v, ",")
elseif strategy == "first" then
return v[1]
elseif strategy == "last" then
return v[#v]
elseif strategy == "all" then
if type(v) ~= "table" then
return {v}
else
return v
end
end
end
-- HTTP headers iterator helper
--
-- Returns key/value pairs for all header, making sure that returned values
-- are always of string type (if necessary, it folds multiple headers with
-- the same name)
--
-- @param hdrs table Headers table as received by http.get and friends
-- @return header name/value iterator (suitable for use in "for" loops)
local function get_headers_folded(hdrs)
if hdrs == nil then
return function() end
end
local function iter(t, k)
local v
k, v = next(t, k)
if v ~= nil then
if type(v) ~= "table" then
return k, v
else
return k, table.concat(v, ",")
end
end
end
return iter, hdrs, nil
end
-- HTTP headers iterator
--
-- Returns key/value pairs for all headers, for multiple headers with same name
-- it will return every name/value pair
-- (i.e. you can safely use it to process responses with 'Set-Cookie' header)
--
-- @param hdrs table Headers table as received by http.get and friends
-- @return header name/value iterator (suitable for use in "for" loops)
local function get_headers_flattened(hdrs)
if hdrs == nil then
return function() end
end
local k -- top level key (string)
local k_sub = 0 -- sub table key (integer), 0 if item not a table,
-- nil after last sub table iteration
local v_sub -- sub table
return function ()
local v
if k_sub == 0 then
k, v = next(hdrs, k)
if k == nil then return end
else
k_sub, v = next(v_sub, k_sub)
if k_sub == nil then
k_sub = 0
k, v = next(hdrs, k)
end
end
if k == nil then return end
if type(v) ~= "table" then
return k, v
else
v_sub = v
k_sub = k_sub + 1
return k, v[k_sub]
end
end
end
--- Parse key/value pairs from a string
--
-- @param s Lua string with (multiple) key/value pairs (separated by 'sep')
--
-- @return Table with parsed keys and values or nil
local function parse_kv(s, sep)
if s == nil then return nil end
idx = 1
result = {}
while idx < s:len() do
i, j = s:find(sep, idx)
if i == nil then
k, v = string.match(s:sub(idx), "^(.-)=(.*)$")
if k then result[k] = v end
break
end
k, v = string.match(s:sub(idx, i-1), "^(.-)=(.*)$")
if k then result[k] = v end
idx = j + 1
end
if next(result) == nil then
return nil
else
return result
end
end
--- Make deep copy of table and it's values
--
-- Use only for simple tables (it handles nested table values), but not for
-- Lua objects or similar, or very big tables (this uses recursion).
--
-- @param t Cloned Lua table or nil
--
-- @return Cloned table or nil
local function copyTable(t)
if type(t) ~= "table" then
return nil
end
local r = {}
for k, v in pairs(t) do
if type(v) == "table" then
r[k] = copyTable(v)
else
r[k] = v
end
end
return r
end
--- Namespace object which hosts HTTP verb methods and request/response classes
local M = {}
--- HTTP response class
M.response = {}
M.response.__index = M.response
local _reason = {
[200] = "OK",
[201] = "Created",
[204] = "No Content",
[301] = "Moved Permanently",
[302] = "Found",
[400] = "Bad Request",
[403] = "Forbidden",
[404] = "Not Found",
[405] = "Method Not Allowed",
[408] = "Request Timeout",
[413] = "Payload Too Large",
[429] = "Too many requests",
[500] = "Internal Server Error",
[501] = "Not Implemented",
[502] = "Bad Gateway",
[503] = "Service Unavailable",
[504] = "Gateway Timeout"
}
--- Creates HTTP response from scratch
--
-- @param status_code HTTP status code
-- @param reason HTTP status code text (e.g. "OK" for 200 response)
-- @param headers HTTP response headers
-- @param request The HTTP request which triggered the response
-- @param encoding Default encoding for response or conversions
--
-- @return response object
function M.response.create(t)
local self = setmetatable({}, M.response)
if not t then
t = {}
end
self.status_code = t.status_code or nil
self.reason = t.reason or _reason[self.status_code] or ""
self.headers = copyTable(t.headers) or {}
self.content = t.content or ""
self.request = t.request or nil
self.encoding = t.encoding or "utf-8"
return self
end
function M.response.send(self, applet)
applet:set_status(tonumber(self.status_code), self.reason)
for k, v in pairs(self.headers) do
if type(v) == "table" then
for _, hdr_val in pairs(v) do
applet:add_header(k, hdr_val)
end
else
applet:add_header(k, v)
end
end
if not self.headers["content-type"] then
if type(self.content) == "table" then
applet:add_header("content-type", "application/json; charset=" ..
self.encoding)
if next(self.content) == nil then
-- Return empty JSON object for empty Lua tables
-- (that makes more sense then returning [])
self.content = "{}"
else
self.content = json.encode(self.content)
end
else
applet:add_header("content-type", "text/plain; charset=" ..
self.encoding)
end
end
if not self.headers["content-length"] then
applet:add_header("content-length", #tostring(self.content))
end
applet:start_response()
applet:send(tostring(self.content))
end
--- Convert response content to JSON
--
-- @return Lua table (decoded json)
function M.response.json(self)
return json.decode(self.content)
end
-- Response headers getter
--
-- Returns a header value(s) according to strategy (fold by default):
-- - single/string value for "fold", "first" and "last" strategies
-- - table for "all" strategy (for single value, a table with single element)
--
-- @param name string Header name
-- @param strategy string "multiple header values" handling strategy
-- @return header value (string or table) or nil
function M.response.get_header(self, name, strategy)
return get_header(self.headers, name, strategy)
end
-- Response headers iterator
--
-- Yields key/value pairs for all headers, making sure that returned values
-- are always of string type
--
-- @param folded boolean Specifies whether to fold headers with same name
-- @return header name/value iterator (suitable for use in "for" loops)
function M.response.get_headers(self, folded)
if folded == true then
return get_headers_folded(self.headers)
else
return get_headers_flattened(self.headers)
end
end
--- HTTP request class (client or server side, depending on the constructor)
M.request = {}
M.request.__index = M.request
--- HTTP request constructor
--
-- Parses client HTTP request (as forwarded by HAProxy)
--
-- @param applet HAProxy AppletHTTP Lua object
--
-- @return Request object
function M.request.parse(applet)
local self = setmetatable({}, M.request)
self.method = applet.method
if (applet.method == "POST" or applet.method == "PUT") and
applet.length > 0 then
self.data = applet:receive()
if self.data == "" then self.data = nil end
end
self.headers = {}
for k, v in pairs(applet.headers) do
if (v[1]) then -- (non folded header with multiple values)
self.headers[k] = {}
for _, val in pairs(v) do
table.insert(self.headers[k], val)
end
else
self.headers[k] = v[0]
end
end
if not self.headers["host"] then
return nil, "Bad request, no Host header specified"
end
self.cookies = parse_kv(self.headers["cookie"], "; ")
-- TODO: Patch ApletHTTP and add schema of request
local schema = applet.schema or "http"
local url = {schema, "://", self.headers["host"], applet.path}
self.params = {}
if applet.qs:len() > 0 then
for _, arg in ipairs(core.tokenize(applet.qs, "&", true)) do
kv = core.tokenize(arg, "=", true)
self.params[kv[1]] = kv[2]
end
url[#url+1] = "?"
url[#url+1] = applet.qs
end
self.url = table.concat(url)
return self
end
--- Escape Lua pattern chars in HTTP multipart boundary
--
-- This function escapes only minimal number of characters, which can be
-- observed in multipart boundaries, namely: -, +, ? and .
--
-- @param s string Data to escape
--
-- @return escaped data (string)
local function escape_pattern(s)
return s:gsub("%-", "%%-"):gsub("%+", "%%+"):gsub("%?", "%%?"):gsub("%.", "%%.")
end
--- Parse HTTP POST data
--
-- @return Table with submitted form data
function M.request.parse_multipart(self)
local ct = self.headers['content-type']
if ct == nil then
return nil, 'Content-Type header not present'
end
if self.data == nil then
return nil, 'Empty body'
end
local body = self.data
local result ={}
if ct:find('^multipart/form[-]data;') then
local boundary = ct:match('^multipart/form[-]data; boundary=["]?(.+)["]?$')
if boundary == nil then
return nil, 'Could not parse boundary from Content-Type'
end
-- per RFC2046, CLRF is treated as a part of boundary
-- but first one does not have it, so we're going pretend
-- it is part of the content and ignore it there (in the pattern)
boundary = string.format('%%-%%-%s.-\r\n', escape_pattern(boundary))
local i = 1
local j
local old_i
while true do
i, j = body:find(boundary, i)
if i == nil then break end
if old_i then
local part = body:sub(old_i, i - 1)
local k, fn, t, v = part:match('^[cC]ontent[-][dD]isposition: form[-]data; name[=]"(.+)"; filename="(.+)"\r\n[cC]ontent[-][tT]ype: (.+)\r\n\r\n(.+)\r\n$')
if k then
result[k] = {
filename = fn,
content_type = t,
data = v
}
else
k, v = part:match('^[cC]ontent[-][dD]isposition: form[-]data; name[=]"(.+)"\r\n\r\n(.+)\r\n$')
if k then
result[k] = v
end
end
end
i = j + 1
old_i = i
end
elseif ct == 'application/x-www-form-urlencoded' then
result = parse_kv(body, '&')
else
return nil, 'Unsupported Content-Type: ' .. ct
end
if result == nil or not next(result) then
return nil, 'Could not parse form data'
end
return result
end
--- Reads (all) chunks from a HTTP response
--
-- @param socket socket object (with already established tcp connection)
-- @param get_all boolean (true by default), collect all chunks at once
-- or yield every chunk separately.
--
-- @return Full response payload or nil and an error message
function M.receive_chunked(socket, get_all)
if socket == nil then
return nil, "http.receive_chunked: Socket is nil"
end
local data = {}
while true do
local chunk, err = socket:receive("*l")
if chunk == nil then
return nil, "http.receive_chunked(): Receive error (chunk length): " .. tostring(err)
end
local chunk_len = tonumber(chunk, 16)
if chunk_len == nil then
return nil, "http.receive_chunked(): Could not parse chunk length"
end
if chunk_len == 0 then
-- TODO: support trailers
break
end
-- Consume next chunk (including the \r\n)
chunk, err = socket:receive(chunk_len+2)
if chunk == nil then
return nil, "http.receive_chunked(): Receive error (chunk data): " .. tostring(err)
end
-- Strip the \r\n before collection
local chunk_data = string.sub(chunk, 1, -3)
if get_all == false then
return chunk_data
end
table.insert(data, chunk_data)
end
return table.concat(data)
end
-- Request headers getter
--
-- Returns a header value(s) according to strategy (fold by default):
-- - single/string value for "fold", "first" and "last" strategies
-- - table for "all" strategy (for single value, a table with single element)
--
-- @param name string Header name
-- @param strategy string "multiple header values" handling strategy
-- @return header value (string or table) or nil
function M.request.get_header(self, name, strategy)
return get_header(self.headers, name, strategy)
end
-- Request headers iterator
--
-- Yields key/value pairs for all headers, making sure that returned values
-- are always of string type
--
-- @param hdrs table Headers table as received by http.get and friends
-- @param folded boolean Specifies whether to fold headers with same name
-- @return header name/value iterator (suitable for use in "for" loops)
function M.request.get_headers(self, folded)
if folded == true then
return get_headers_folded(self.headers)
else
return get_headers_flattened(self.headers)
end
end
--- Creates HTTP request from scratch
--
-- @param method HTTP method
-- @param url Valid HTTP url
-- @param headers Lua table with request headers
-- @param data Request content
-- @param params Lua table with request url arguments
-- @param auth (username, password) tuple for HTTP auth
--
-- @return request object
function M.request.create(t)
local self = setmetatable({}, M.request)
if t.method then
self.method = t.method:lower()
else
self.method = "get"
end
self.url = t.url or nil
self.headers = copyTable(t.headers) or {}
self.data = t.data or nil
self.params = copyTable(t.params) or {}
self.auth = copyTable(t.auth) or {}
return self
end
--- HTTP HEAD request
function M.head(t)
return M.send("HEAD", t)
end
--- HTTP GET request
function M.get(t)
return M.send("GET", t)
end
--- HTTP PUT request
function M.put(t)
return M.send("PUT", t)
end
--- HTTP POST request
function M.post(t)
return M.send("POST", t)
end
--- HTTP DELETE request
function M.delete(t)
return M.send("DELETE", t)
end
--- Send HTTP request
--
-- @param method HTTP method
-- @param url Valid HTTP url (mandatory)
-- @param headers Lua table with request headers
-- @param data Request content
-- @param params Lua table with request url arguments
-- @param auth (username, password) tuple for HTTP auth
-- @param timeout Optional timeout for socket operations (5s by default)
--
-- @return Response object or tuple (nil, msg) on errors
-- Note that the prefered way to call this method is via Lua
-- "keyword arguments" convention, e.g.
-- http.get{uri="http://example.net"}
function M.send(method, t)
if type(t) ~= "table" then
return nil, "http." .. method:lower() ..
": expecting Request object for named parameters"
end
if type(t.url) ~= "string" then
return nil, "http." .. method:lower() .. ": 'url' parameter missing"
end
local socket = core.tcp()
socket:settimeout(t.timeout or 5)
local connect
if t.url:sub(1, 7) ~= "http://" and t.url:sub(1, 8) ~= "https://" then
t.url = "http://" .. t.url
end
local schema, host, req_uri = t.url:match("^(.*)://(.-)(/.*)$")
if not schema then
-- maybe path (request uri) is missing
schema, host = t.url:match("^(.*)://(.-)$")
if not schema then
return nil, "http." .. method:lower() .. ": Could not parse URL: " .. t.url
end
req_uri = "/"
end
local addr, port = host:match("(.*):(%d+)")
if schema == "http" then
connect = socket.connect
if not port then
addr = host
port = 80
end
elseif schema == "https" then
connect = socket.connect_ssl
if not port then
addr = host
port = 443
end
else
return nil, "http." .. method:lower() .. ": Invalid URL schema " .. tostring(schema)
end
local c, err = connect(socket, addr, port)
if c then
local req = {}
local hdr_tbl = {}
if t.headers then
for k, v in pairs(t.headers) do
if type(v) == "table" then
table.insert(hdr_tbl, k .. ": " .. table.concat(v, ","))
else
table.insert(hdr_tbl, k .. ": " .. tostring(v))
end
end
else
t.headers = {} -- dummy table
end
if not t.headers.host then
-- 'Host' header must be provided for HTTP/1.1
table.insert(hdr_tbl, "host: " .. host)
end
if not t.headers["accept"] then
table.insert(hdr_tbl, "accept: */*")
end
if not t.headers["user-agent"] then
table.insert(hdr_tbl, "user-agent: haproxy-lua-http/1.0")
end
if not t.headers.connection then
table.insert(hdr_tbl, "connection: close")
end
if t.data then
req[4] = t.data
if not t.headers or not t.headers["content-length"] then
table.insert(hdr_tbl, "content-length: " .. tostring(#t.data))
end
end
req[1] = method .. " " .. req_uri .. " HTTP/1.1\r\n"
req[2] = table.concat(hdr_tbl, "\r\n")
req[3] = "\r\n\r\n"
local r, e = socket:send(table.concat(req))
if not r then
socket:close()
return nil, "http." .. method:lower() .. ": " .. tostring(e)
end
local line
r = M.response.create()
while true do
line, err = socket:receive("*l")
if not line then
socket:close()
return nil, "http." .. method:lower() ..
": Receive error (headers): " .. err
end
if line == "" then break end
if not r.status_code then
_, r.status_code, r.reason =
line:match("(HTTP/1.[01]) (%d%d%d)(.*)")
if not _ then
socket:close()
return nil, "http." .. method:lower() ..
": Could not parse request line"
end
r.status_code = tonumber(r.status_code)
else
local sep = line:find(":")
local hdr_name = line:sub(1, sep-1):lower()
local hdr_val = line:sub(sep+1):match("^%s*(.*%S)%s*$") or ""
if r.headers[hdr_name] == nil then
r.headers[hdr_name] = hdr_val
elseif type(r.headers[hdr_name]) == "table" then
table.insert(r.headers[hdr_name], hdr_val)
else
r.headers[hdr_name] = {
r.headers[hdr_name],
hdr_val
}
end
end
end
if method:lower() == "head" then
r.content = nil
socket:close()
return r
end
if r.headers["content-length"] and tonumber(r.headers["content-length"]) > 0 then
r.content, err = socket:receive("*a")
if not r.content then
socket:close()
return nil, "http." .. method:lower() ..
": Receive error (content): " .. err
end
end
if r.headers["transfer-encoding"] and r.headers["transfer-encoding"] == "chunked" then
r.content, err = M.receive_chunked(socket)
if r.content == nil then
socket:close()
return nil, err
end
end
socket:close()
return r
else
return nil, "http." .. method:lower() .. ": Connection error: " .. tostring(err)
end
end
M.base64 = {}
--- URL safe base64 encoder
--
-- Padding ('=') is omited, as permited per RFC
-- https://tools.ietf.org/html/rfc4648
-- in order to follow JSON Web Signature RFC
-- https://tools.ietf.org/html/rfc7515
--
-- @param s String (can be binary data) to encode
-- @param enc Function which implements base64 encoder (e.g. HAProxy base64 fetch)
-- @return Encoded string
function M.base64.encode(s, enc)
if not s then return nil end
local u = enc(s)
if not u then
return nil
end
local pad_len = 2 - ((#s-1) % 3)
if pad_len > 0 then
return u:sub(1, - pad_len - 1):gsub('[+]', '-'):gsub('[/]', '_')
else
return u:gsub('[+]', '-'):gsub('[/]', '_')
end
end
--- URLsafe base64 decoder
--
-- @param s Base64 string to decode
-- @param dec Function which implements base64 decoder (e.g. HAProxy b64dec fetch)
-- @return Decoded string (can be binary data)
function M.base64.decode(s, dec)
if not s then return nil end
local e = s:gsub('[-]', '+'):gsub('[_]', '/')
return dec(e .. string.rep('=', 3 - ((#s - 1) % 4)))
end
return M