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-rw-r--r--src/net/http/fcgi/fcgi.go270
1 files changed, 270 insertions, 0 deletions
diff --git a/src/net/http/fcgi/fcgi.go b/src/net/http/fcgi/fcgi.go
new file mode 100644
index 0000000..fb822f8
--- /dev/null
+++ b/src/net/http/fcgi/fcgi.go
@@ -0,0 +1,270 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package fcgi implements the FastCGI protocol.
+//
+// See https://fast-cgi.github.io/ for an unofficial mirror of the
+// original documentation.
+//
+// Currently only the responder role is supported.
+package fcgi
+
+// This file defines the raw protocol and some utilities used by the child and
+// the host.
+
+import (
+ "bufio"
+ "bytes"
+ "encoding/binary"
+ "errors"
+ "io"
+ "sync"
+)
+
+// recType is a record type, as defined by
+// https://web.archive.org/web/20150420080736/http://www.fastcgi.com/drupal/node/6?q=node/22#S8
+type recType uint8
+
+const (
+ typeBeginRequest recType = 1
+ typeAbortRequest recType = 2
+ typeEndRequest recType = 3
+ typeParams recType = 4
+ typeStdin recType = 5
+ typeStdout recType = 6
+ typeStderr recType = 7
+ typeData recType = 8
+ typeGetValues recType = 9
+ typeGetValuesResult recType = 10
+ typeUnknownType recType = 11
+)
+
+// keep the connection between web-server and responder open after request
+const flagKeepConn = 1
+
+const (
+ maxWrite = 65535 // maximum record body
+ maxPad = 255
+)
+
+const (
+ roleResponder = iota + 1 // only Responders are implemented.
+ roleAuthorizer
+ roleFilter
+)
+
+const (
+ statusRequestComplete = iota
+ statusCantMultiplex
+ statusOverloaded
+ statusUnknownRole
+)
+
+type header struct {
+ Version uint8
+ Type recType
+ Id uint16
+ ContentLength uint16
+ PaddingLength uint8
+ Reserved uint8
+}
+
+type beginRequest struct {
+ role uint16
+ flags uint8
+ reserved [5]uint8
+}
+
+func (br *beginRequest) read(content []byte) error {
+ if len(content) != 8 {
+ return errors.New("fcgi: invalid begin request record")
+ }
+ br.role = binary.BigEndian.Uint16(content)
+ br.flags = content[2]
+ return nil
+}
+
+// for padding so we don't have to allocate all the time
+// not synchronized because we don't care what the contents are
+var pad [maxPad]byte
+
+func (h *header) init(recType recType, reqId uint16, contentLength int) {
+ h.Version = 1
+ h.Type = recType
+ h.Id = reqId
+ h.ContentLength = uint16(contentLength)
+ h.PaddingLength = uint8(-contentLength & 7)
+}
+
+// conn sends records over rwc
+type conn struct {
+ mutex sync.Mutex
+ rwc io.ReadWriteCloser
+
+ // to avoid allocations
+ buf bytes.Buffer
+ h header
+}
+
+func newConn(rwc io.ReadWriteCloser) *conn {
+ return &conn{rwc: rwc}
+}
+
+func (c *conn) Close() error {
+ c.mutex.Lock()
+ defer c.mutex.Unlock()
+ return c.rwc.Close()
+}
+
+type record struct {
+ h header
+ buf [maxWrite + maxPad]byte
+}
+
+func (rec *record) read(r io.Reader) (err error) {
+ if err = binary.Read(r, binary.BigEndian, &rec.h); err != nil {
+ return err
+ }
+ if rec.h.Version != 1 {
+ return errors.New("fcgi: invalid header version")
+ }
+ n := int(rec.h.ContentLength) + int(rec.h.PaddingLength)
+ if _, err = io.ReadFull(r, rec.buf[:n]); err != nil {
+ return err
+ }
+ return nil
+}
+
+func (r *record) content() []byte {
+ return r.buf[:r.h.ContentLength]
+}
+
+// writeRecord writes and sends a single record.
+func (c *conn) writeRecord(recType recType, reqId uint16, b []byte) error {
+ c.mutex.Lock()
+ defer c.mutex.Unlock()
+ c.buf.Reset()
+ c.h.init(recType, reqId, len(b))
+ if err := binary.Write(&c.buf, binary.BigEndian, c.h); err != nil {
+ return err
+ }
+ if _, err := c.buf.Write(b); err != nil {
+ return err
+ }
+ if _, err := c.buf.Write(pad[:c.h.PaddingLength]); err != nil {
+ return err
+ }
+ _, err := c.rwc.Write(c.buf.Bytes())
+ return err
+}
+
+func (c *conn) writeEndRequest(reqId uint16, appStatus int, protocolStatus uint8) error {
+ b := make([]byte, 8)
+ binary.BigEndian.PutUint32(b, uint32(appStatus))
+ b[4] = protocolStatus
+ return c.writeRecord(typeEndRequest, reqId, b)
+}
+
+func (c *conn) writePairs(recType recType, reqId uint16, pairs map[string]string) error {
+ w := newWriter(c, recType, reqId)
+ b := make([]byte, 8)
+ for k, v := range pairs {
+ n := encodeSize(b, uint32(len(k)))
+ n += encodeSize(b[n:], uint32(len(v)))
+ if _, err := w.Write(b[:n]); err != nil {
+ return err
+ }
+ if _, err := w.WriteString(k); err != nil {
+ return err
+ }
+ if _, err := w.WriteString(v); err != nil {
+ return err
+ }
+ }
+ w.Close()
+ return nil
+}
+
+func readSize(s []byte) (uint32, int) {
+ if len(s) == 0 {
+ return 0, 0
+ }
+ size, n := uint32(s[0]), 1
+ if size&(1<<7) != 0 {
+ if len(s) < 4 {
+ return 0, 0
+ }
+ n = 4
+ size = binary.BigEndian.Uint32(s)
+ size &^= 1 << 31
+ }
+ return size, n
+}
+
+func readString(s []byte, size uint32) string {
+ if size > uint32(len(s)) {
+ return ""
+ }
+ return string(s[:size])
+}
+
+func encodeSize(b []byte, size uint32) int {
+ if size > 127 {
+ size |= 1 << 31
+ binary.BigEndian.PutUint32(b, size)
+ return 4
+ }
+ b[0] = byte(size)
+ return 1
+}
+
+// bufWriter encapsulates bufio.Writer but also closes the underlying stream when
+// Closed.
+type bufWriter struct {
+ closer io.Closer
+ *bufio.Writer
+}
+
+func (w *bufWriter) Close() error {
+ if err := w.Writer.Flush(); err != nil {
+ w.closer.Close()
+ return err
+ }
+ return w.closer.Close()
+}
+
+func newWriter(c *conn, recType recType, reqId uint16) *bufWriter {
+ s := &streamWriter{c: c, recType: recType, reqId: reqId}
+ w := bufio.NewWriterSize(s, maxWrite)
+ return &bufWriter{s, w}
+}
+
+// streamWriter abstracts out the separation of a stream into discrete records.
+// It only writes maxWrite bytes at a time.
+type streamWriter struct {
+ c *conn
+ recType recType
+ reqId uint16
+}
+
+func (w *streamWriter) Write(p []byte) (int, error) {
+ nn := 0
+ for len(p) > 0 {
+ n := len(p)
+ if n > maxWrite {
+ n = maxWrite
+ }
+ if err := w.c.writeRecord(w.recType, w.reqId, p[:n]); err != nil {
+ return nn, err
+ }
+ nn += n
+ p = p[n:]
+ }
+ return nn, nil
+}
+
+func (w *streamWriter) Close() error {
+ // send empty record to close the stream
+ return w.c.writeRecord(w.recType, w.reqId, nil)
+}