diff options
Diffstat (limited to 'lib/yahns/proxy_pass.rb')
| -rw-r--r-- | lib/yahns/proxy_pass.rb | 276 |
1 files changed, 150 insertions, 126 deletions
diff --git a/lib/yahns/proxy_pass.rb b/lib/yahns/proxy_pass.rb index 9c12e99..09fb884 100644 --- a/lib/yahns/proxy_pass.rb +++ b/lib/yahns/proxy_pass.rb @@ -5,110 +5,168 @@ require 'socket' require 'kgio' require 'kcar' # gem install kcar require 'rack/request' -require 'thread' require 'timeout' -# Totally synchronous and Rack 1.1-compatible, this will probably be rewritten. -# to take advantage of rack.hijack and use the non-blocking I/O facilities -# in yahns. yahns may have to grow a supported API for that... -# For now, we this blocks a worker thread; fortunately threads are reasonably -# cheap on GNU/Linux... +require_relative 'proxy_http_response' + class Yahns::ProxyPass # :nodoc: - class ConnPool - def initialize - @mtx = Mutex.new - @objs = [] - end + class ReqRes < Kgio::Socket + attr_writer :resbuf - def get - @mtx.synchronize { @objs.pop } + def req_start(c, req, input, chunked) + @hdr = @resbuf = nil + @yahns_client = c + @rrstate = input ? [ req, input, chunked ] : req + Thread.current[:yahns_queue].queue_add(self, Yahns::Queue::QEV_WR) end - def put(obj) - @mtx.synchronize { @objs << obj } + # we must reinitialize the thread-local rbuf if it may get beyond the + # current thread + def detach_rbuf! + Thread.current[:yahns_rbuf] = '' end - end - class UpstreamSocket < Kgio::Socket # :nodoc: - attr_writer :expiry + def yahns_step # yahns event loop entry point + case req = @rrstate + when Kcar::Parser # reading response... + buf = Thread.current[:yahns_rbuf] + c = @yahns_client - # called automatically by kgio_read! - def kgio_wait_readable(timeout = nil) - super(timeout || wait_time) - end + case resbuf = @resbuf # where are we at the response? + when nil # common case, catch the response header in a single read - def wait_time - tout = @expiry ? @expiry - Yahns.now : @timeout - raise Timeout::Error, "request timed out", [] if tout < 0 - tout - end + case rv = kgio_tryread(0x2000, buf) + when String + if res = req.headers(@hdr = [], rv) + return c.proxy_response_start(res, rv, req, self) + else # ugh, big headers or tricked response + buf = detach_rbuf! + @resbuf = rv + end + # continue looping in middle "case @resbuf" loop + when :wait_readable + return rv # spurious wakeup + when nil then return c.proxy_err_response(502, self, nil, nil) + end # NOT looping here - def readpartial(bytes, buf = Thread.current[:yahns_rbuf] ||= "") - case rv = kgio_read!(bytes, buf) - when String - @expiry += @timeout # bump expiry when we succeed - end - rv - end + when String # continue reading trickled response headers from upstream - def req_write(buf, timeout) - @timeout = timeout - @expiry = Yahns.now + timeout - case rv = kgio_trywrite(buf) - when :wait_writable - kgio_wait_writable(wait_time) - when nil - return - when String - buf = rv - end while true + case rv = kgio_tryread(0x2000, buf) + when String then res = req.headers(@hdr, resbuf << rv) and break + when :wait_readable then return rv + when nil then return c.proxy_err_response(502, self, nil, nil) + end while true + + return c.proxy_response_start(res, resbuf, req, self) + + when Yahns::WbufCommon # streaming/buffering the response body + + return c.proxy_response_finish(req, resbuf, self) + + end while true # case @resbuf + + when Array # [ (str|vec), rack.input, chunked? ] + send_req_body(req) # returns nil or :wait_writable + when String # buffered request header + send_req_buf(req) + end + rescue => e + c.proxy_err_response(502, self, e, nil) end - end # class UpstreamSocket - class UpstreamResponse < Kcar::Response # :nodoc: # Called by the Rack server at the end of a successful response def close - reusable = @parser.keepalive? && @parser.body_eof? + @hdr = @yahns_client = @rrstate = nil super - @pool.put(self) if reusable - nil end - # req is just a string buffer of HTTP headers - def req_write(req, timeout) - @sock.req_write(req, timeout) - end + # returns :wait_readable if complete, :wait_writable if not + def send_req_body(req) + buf, input, chunked = req - # returns true if the socket is still alive, nil if dead - def sock_alive? - @reused = (:wait_readable == (@sock.kgio_tryread(1) rescue nil)) ? - true : @sock.close - end + # get the first buffered chunk or vector + case rv = String === buf ? kgio_trywrite(buf) : kgio_trywritev(buf) + when String, Array + buf = rv # retry inner loop + when :wait_writable + req[0] = buf + return :wait_writable + when nil + break # onto writing body + end while true - # returns true if the socket was reused and thus retryable - def fail_retryable? - @sock.close - @reused + buf = Thread.current[:yahns_rbuf] + + # Note: input (env['rack.input']) is fully-buffered by default so + # we should not be waiting on a slow network resource when reading + # input. However, some weird configs may disable this on LANs + + if chunked + while input.read(0x2000, buf) + vec = [ "#{buf.size.to_s(16)}\r\n", buf, "\r\n".freeze ] + case rv = kgio_trywritev(vec) + when Array + vec = rv # partial write, retry in case loop + when :wait_writable + buf = detach_rbuf! + req[0] = vec + return :wait_writable + when nil + break # continue onto reading next chunk + end while true + end + close_req_body(input) + + # note: we do not send any trailer, they are folded into the header + # because this relies on full request buffering + send_req_buf("0\r\n\r\n".freeze) + else # identity request, easy: + while input.read(0x2000, buf) + case rv = kgio_trywrite(buf) + when String + buf = rv # partial write, retry in case loop + when :wait_writable + buf = detach_rbuf! + req[0] = buf + return :wait_writable + when nil + break # continue onto reading next block + end while true + end + + close_req_body(input) + prepare_wait_readable + end end - def initialize(sock, pool) - super(sock) - @reused = false - @pool = pool + def prepare_wait_readable + @rrstate = Kcar::Parser.new + :wait_readable # all done sending the request, wait for response end - end # class UpstreamResponse - # take a responder from the pool, we'll add the object back to the - # pool in UpstreamResponse#close - def responder_get - while obj = @pool.get - return obj if obj.sock_alive? + def close_req_body(input) + case input + when Yahns::TeeInput, IO, StringIO + input.close + end end - UpstreamResponse.new(UpstreamSocket.start(@sockaddr), @pool) - end + # n.b. buf must be a detached string not shared with + # Thread.current[:yahns_rbuf] of any thread + def send_req_buf(buf) + case rv = kgio_trywrite(buf) + when String + buf = rv # retry inner loop + when :wait_writable + @rrstate = buf + return :wait_writable + when nil + return prepare_wait_readable + end while true + end + end # class ReqRes - def initialize(dest, timeout = 5) + def initialize(dest) case dest when %r{\Aunix:([^:]+)(?::(/.*))?\z} path = $2 @@ -121,8 +179,6 @@ class Yahns::ProxyPass # :nodoc: raise ArgumentError, "destination must be an HTTP URL or unix: path" end init_path_vars(path) - @pool = ConnPool.new - @timeout = timeout end def init_path_vars(path) @@ -139,10 +195,15 @@ class Yahns::ProxyPass # :nodoc: end def call(env) - request_method = env['REQUEST_METHOD'] + # 3-way handshake for TCP backends while we generate the request header + rr = ReqRes.start(@sockaddr) + c = env['rack.hijack'].call + req = Rack::Request.new(env) - path = @path.gsub(/\$(\w+)/) { req.__send__($1) } - req = "#{request_method} #{path} HTTP/1.1\r\n" \ + req = @path.gsub(/\$(\w+)/) { req.__send__($1) } + + # start the connection asynchronously and early so TCP can do a + req = "#{env['REQUEST_METHOD']} #{req} HTTP/1.1\r\n" \ "X-Forwarded-For: #{env["REMOTE_ADDR"]}\r\n" # pass most HTTP_* headers through as-is @@ -150,61 +211,24 @@ class Yahns::ProxyPass # :nodoc: env.each do |key, val| %r{\AHTTP_(\w+)\z} =~ key or next key = $1 - next if %r{\A(?:VERSION|CONNECTION|KEEP_ALIVE|X_FORWARDED_FOR)} =~ key + # trailers are folded into the header, so do not send the Trailer: + # header in the request + next if /\A(?:VERSION|CONNECTION|KEEP_ALIVE|X_FORWARDED_FOR|TRAILER)/ =~ + key chunked = true if %r{\ATRANSFER_ENCODING} =~ key && val =~ /\bchunked\b/i - key.tr!("_", "-") + key.tr!('_'.freeze, '-'.freeze) req << "#{key}: #{val}\r\n" end # special cases which Rack does not prefix: ctype = env["CONTENT_TYPE"] and req << "Content-Type: #{ctype}\r\n" clen = env["CONTENT_LENGTH"] and req << "Content-Length: #{clen}\r\n" - req << "\r\n" - - # get an open socket and send the headers - ures = responder_get - ures.req_write(req, @timeout) + input = chunked || (clen && clen.to_i > 0) ? env['rack.input'] : nil - # send the request body if there was one - send_body(env["rack.input"], ures, chunked) if chunked || clen - - # wait for the response here - _, header, body = res = ures.rack - - # don't let the upstream Connection and Keep-Alive headers leak through - header.delete_if do |k,_| - k =~ /\A(?:Connection|Keep-Alive)\z/i - end - - case request_method - when "HEAD" - # kcar doesn't know if it's a HEAD or GET response, and HEAD - # responses have Content-Length in it which fools kcar... - body.parser.body_bytes_left = 0 - res[1] = header.dup - body.close # clobbers original header - res[2] = body = [] - end - res + # finally, prepare to emit the headers + rr.req_start(c, req << "\r\n".freeze, input, chunked) rescue => e - retry if ures && ures.fail_retryable? && request_method != "POST" Yahns::Log.exception(env['rack.logger'], 'proxy_pass', e) [ 502, [ %w(Content-Length 0), %w(Content-Type text/plain) ], [] ] end - - def send_body(input, ures, chunked) - buf = Thread.current[:yahns_rbuf] ||= "" - - if chunked # unlikely - while input.read(16384, buf) - buf.replace("#{buf.size.to_s(16)}\r\n#{buf}\r\n") - ures.req_write(buf, @timeout) - end - ures.req_write("0\r\n\r\n", @timeout) - else # common if we hit uploads - while input.read(16384, buf) - ures.req_write(buf, @timeout) - end - end - end end |