feature: socks5 proxy

lib/resty/requests/adapter.lua

@@ -2,6 +2,7 @@
 
 local util = require "resty.requests.util"
 local response = require "resty.requests.response"
+local proxies = require "resty.requests.proxies"
 local check_http2, http2 = pcall(require, "resty.http2")
 
 local pairs = pairs
@@ -19,7 +20,7 @@ local new_tab = util.new_tab
 local is_tab = util.is_tab
 local is_func = util.is_func
 
-local _M = { _VERSION = "0.4" }
+local _M = { _VERSION = "0.5" }
 local mt = { __index = _M }
 
 local DEFAULT_POOL_SIZE = 30
@@ -146,6 +147,10 @@ end
 
 
 local function proxy(self, request)
+    if self.socks5_proxy then
+        return proxies.socks5(self.sock, request)
+    end
+
     if not self.https_proxy then
         return true
     end
@@ -155,7 +160,7 @@ local function proxy(self, request)
 
     local message = new_tab(4, 0)
     message[1] = format("CONNECT %s HTTP/1.1\r\n", host)
-    message[2] = format("Host: %s\r\n", host)
+    message[2] = format("Host: %s:%d\r\n", request.host, request.port)
     message[3] = format("User-Agent: resty-requests\r\n")
     message[4] = format("Proxy-Connection: keep-alive\r\n\r\n")
 
@@ -242,7 +247,9 @@ local function connect(self, request)
         host = proxies[scheme].host
         port = proxies[scheme].port
         if scheme == "https" then
-            self.https_proxy = format("%s:%d", request.host, request.port)
+            self.https_proxy = true
+        elseif scheme == "socks5" then
+            self.socks5_proxy = true
         end
     else
         host = request.host
@@ -491,6 +498,7 @@ local function new(opts)
         h2_stream = nil,
 
         https_proxy = nil, -- https proxy
+        socks5_proxy = nil, -- socks5 proxy
 
         error_filter = opts.error_filter,
     }

lib/resty/requests/proxies.lua

@@ -0,0 +1,178 @@
+-- Copyright (C) Alex Zhang
+
+local bit = require "bit"
+local ffi = require "ffi"
+
+local byte = string.byte
+local char = string.char
+local band = bit.band
+local lshift = bit.lshift
+local rshift = bit.rshift
+local C = ffi.C
+
+local SOCKS5_REP = {
+    [0] = "succeeded",
+    [1] = "general socks server failure",
+    [2] = "connection not allowed by ruleset",
+    [3] = "network unreachable",
+    [4] = "host unreachable",
+    [5] = "connection refused",
+    [6] = "ttl expired",
+    [7] = "command not supported",
+    [8] = "address type not supported",
+    [9] = "to X'FF' unassigned",
+}
+
+local DOT_BYTE = byte('.')
+local COLON_BYTE = byte(':')
+local INADDR_NONE = -1
+
+local _M = { _VERSION = "0.1" }
+
+
+ffi.cdef[[
+uint32_t htonl(uint32_t hostlong);
+]]
+
+
+local function inet_addr(host)
+    local addr = 0
+    local octet = 0
+    local n = 0
+    for i = 1, #host do
+        local b = byte(host, i, i)
+        if b >= 0 and b <= 9 then
+            octet = octet * 10 + b
+            if octet > 255 then
+                return INADDR_NONE
+            end
+
+        elseif b == DOT_BYTE then
+            addr = lshift(addr, 8) + octet
+            octet = 0
+            n = n + 1
+
+        else
+            return INADDR_NONE
+        end
+    end
+
+    if n ~= 3 then
+        return INADDR_NONE
+    end
+
+    addr = lshift(addr, 8) + octet
+    return C.htonl(addr)
+end
+
+
+local function addr_type(host)
+    local ipv4 = inet_addr(host)
+    if ipv4 ~= INADDR_NONE then
+        return {
+            "1", -- type
+            char(band(rshift(host, 24), 0xff)),
+            char(band(rshift(host, 16), 0xff)),
+            char(band(rshift(host, 8), 0xff)),
+            char(band(host, 0xff)),
+        }
+    end
+
+    local colons = 0
+    for i = 1, #host do
+        if host:byte(i, i) == COLON_BYTE then
+            colons = colons + 1
+        end
+    end
+
+    if colons > 1 then
+        -- TODO support IPv6
+        error("ipv6 not supported yet")
+    end
+
+    return { "3", char(#host), host }
+end
+
+
+local function process_method(sock)
+    -- version 5, method count 1, no authentication (0)
+    local _, err = sock:send("510")
+    if err then
+        return nil, err
+    end
+
+    local data, err = sock:receive(2)
+    if err then
+        return nil, err
+    end
+
+    local ver, method = byte(data, 1, 2)
+    if ver ~= 5 then
+        return nil, "invalid socks version " .. ver
+    end
+
+    if method ~= 0 then
+        return nil, "authentication-based socks5 not supported yet"
+    end
+
+    return true
+end
+
+
+local function connect(sock, request)
+    local host = request.host
+    local port = request.port
+    local data = {
+        "510",
+        addr_type(host),
+        char(band(rshift(port, 8), 0xff)),
+        char(band(port, 0xff)),
+    }
+
+    local _, err = sock:send(data)
+    if err then
+        return nil, err
+    end
+
+    data, err = sock:receive(4)
+    if err then
+        return nil, err
+    end
+
+    local ver, rep, _, atype = byte(data, 1, 4)
+    if ver ~= 5 then
+        return nil, "invalid socks version " .. ver
+    end
+
+    if rep ~= 0 then
+        return nil, SOCKS5_REP[rep] or "unknown socks REP field"
+    end
+
+    if atype ~= 1 then
+        return nil, "socks5 server used invalid bind address type" .. atype
+    end
+
+    -- IPv4 (4 bytes) + port (2 bytes)
+    local _, err = sock:receive(6)
+    if err then
+        return nil, err
+    end
+
+    return true
+end
+
+
+local function socks5_proxy(sock, request)
+    local ok, err = process_method(sock)
+    if not ok then
+        return nil, err
+    end
+
+    return connect(sock, request)
+end
+
+
+_M.socks5 = socks5_proxy
+
+
+return _M