diff options
Diffstat (limited to 'vendor/github.com/google/gopacket/tcpassembly/tcpreader/reader.go')
| -rw-r--r-- | vendor/github.com/google/gopacket/tcpassembly/tcpreader/reader.go | 210 |
1 files changed, 0 insertions, 210 deletions
diff --git a/vendor/github.com/google/gopacket/tcpassembly/tcpreader/reader.go b/vendor/github.com/google/gopacket/tcpassembly/tcpreader/reader.go deleted file mode 100644 index 092b811..0000000 --- a/vendor/github.com/google/gopacket/tcpassembly/tcpreader/reader.go +++ /dev/null @@ -1,210 +0,0 @@ -// Copyright 2012 Google, Inc. All rights reserved. -// -// Use of this source code is governed by a BSD-style license -// that can be found in the LICENSE file in the root of the source -// tree. - -// Package tcpreader provides an implementation for tcpassembly.Stream which presents -// the caller with an io.Reader for easy processing. -// -// The assembly package handles packet data reordering, but its output is -// library-specific, thus not usable by the majority of external Go libraries. -// The io.Reader interface, on the other hand, is used throughout much of Go -// code as an easy mechanism for reading in data streams and decoding them. For -// example, the net/http package provides the ReadRequest function, which can -// parase an HTTP request from a live data stream, just what we'd want when -// sniffing HTTP traffic. Using ReaderStream, this is relatively easy to set -// up: -// -// // Create our StreamFactory -// type httpStreamFactory struct {} -// func (f *httpStreamFactory) New(a, b gopacket.Flow) { -// r := tcpreader.NewReaderStream(false) -// go printRequests(r) -// return &r -// } -// func printRequests(r io.Reader) { -// // Convert to bufio, since that's what ReadRequest wants. -// buf := bufio.NewReader(r) -// for { -// if req, err := http.ReadRequest(buf); err == io.EOF { -// return -// } else if err != nil { -// log.Println("Error parsing HTTP requests:", err) -// } else { -// fmt.Println("HTTP REQUEST:", req) -// fmt.Println("Body contains", tcpreader.DiscardBytesToEOF(req.Body), "bytes") -// } -// } -// } -// -// Using just this code, we're able to reference a powerful, built-in library -// for HTTP request parsing to do all the dirty-work of parsing requests from -// the wire in real-time. Pass this stream factory to an tcpassembly.StreamPool, -// start up an tcpassembly.Assembler, and you're good to go! -package tcpreader - -import ( - "errors" - "github.com/google/gopacket/tcpassembly" - "io" -) - -var discardBuffer = make([]byte, 4096) - -// DiscardBytesToFirstError will read in all bytes up to the first error -// reported by the given reader, then return the number of bytes discarded -// and the error encountered. -func DiscardBytesToFirstError(r io.Reader) (discarded int, err error) { - for { - n, e := r.Read(discardBuffer) - discarded += n - if e != nil { - return discarded, e - } - } -} - -// DiscardBytesToEOF will read in all bytes from a Reader until it -// encounters an io.EOF, then return the number of bytes. Be careful -// of this... if used on a Reader that returns a non-io.EOF error -// consistently, this will loop forever discarding that error while -// it waits for an EOF. -func DiscardBytesToEOF(r io.Reader) (discarded int) { - for { - n, e := DiscardBytesToFirstError(r) - discarded += n - if e == io.EOF { - return - } - } -} - -// ReaderStream implements both tcpassembly.Stream and io.Reader. You can use it -// as a building block to make simple, easy stream handlers. -// -// IMPORTANT: If you use a ReaderStream, you MUST read ALL BYTES from it, -// quickly. Not reading available bytes will block TCP stream reassembly. It's -// a common pattern to do this by starting a goroutine in the factory's New -// method: -// -// type myStreamHandler struct { -// r ReaderStream -// } -// func (m *myStreamHandler) run() { -// // Do something here that reads all of the ReaderStream, or your assembly -// // will block. -// fmt.Println(tcpreader.DiscardBytesToEOF(&m.r)) -// } -// func (f *myStreamFactory) New(a, b gopacket.Flow) tcpassembly.Stream { -// s := &myStreamHandler{} -// go s.run() -// // Return the ReaderStream as the stream that assembly should populate. -// return &s.r -// } -type ReaderStream struct { - ReaderStreamOptions - reassembled chan []tcpassembly.Reassembly - done chan bool - current []tcpassembly.Reassembly - closed bool - lossReported bool - first bool - initiated bool -} - -// ReaderStreamOptions provides user-resettable options for a ReaderStream. -type ReaderStreamOptions struct { - // LossErrors determines whether this stream will return - // ReaderStreamDataLoss errors from its Read function whenever it - // determines data has been lost. - LossErrors bool -} - -// NewReaderStream returns a new ReaderStream object. -func NewReaderStream() ReaderStream { - r := ReaderStream{ - reassembled: make(chan []tcpassembly.Reassembly), - done: make(chan bool), - first: true, - initiated: true, - } - return r -} - -// Reassembled implements tcpassembly.Stream's Reassembled function. -func (r *ReaderStream) Reassembled(reassembly []tcpassembly.Reassembly) { - if !r.initiated { - panic("ReaderStream not created via NewReaderStream") - } - r.reassembled <- reassembly - <-r.done -} - -// ReassemblyComplete implements tcpassembly.Stream's ReassemblyComplete function. -func (r *ReaderStream) ReassemblyComplete() { - close(r.reassembled) - close(r.done) -} - -// stripEmpty strips empty reassembly slices off the front of its current set of -// slices. -func (r *ReaderStream) stripEmpty() { - for len(r.current) > 0 && len(r.current[0].Bytes) == 0 { - r.current = r.current[1:] - r.lossReported = false - } -} - -// DataLost is returned by the ReaderStream's Read function when it encounters -// a Reassembly with Skip != 0. -var DataLost = errors.New("lost data") - -// Read implements io.Reader's Read function. -// Given a byte slice, it will either copy a non-zero number of bytes into -// that slice and return the number of bytes and a nil error, or it will -// leave slice p as is and return 0, io.EOF. -func (r *ReaderStream) Read(p []byte) (int, error) { - if !r.initiated { - panic("ReaderStream not created via NewReaderStream") - } - var ok bool - r.stripEmpty() - for !r.closed && len(r.current) == 0 { - if r.first { - r.first = false - } else { - r.done <- true - } - if r.current, ok = <-r.reassembled; ok { - r.stripEmpty() - } else { - r.closed = true - } - } - if len(r.current) > 0 { - current := &r.current[0] - if r.LossErrors && !r.lossReported && current.Skip != 0 { - r.lossReported = true - return 0, DataLost - } - length := copy(p, current.Bytes) - current.Bytes = current.Bytes[length:] - return length, nil - } - return 0, io.EOF -} - -// Close implements io.Closer's Close function, making ReaderStream a -// io.ReadCloser. It discards all remaining bytes in the reassembly in a -// manner that's safe for the assembler (IE: it doesn't block). -func (r *ReaderStream) Close() error { - r.current = nil - r.closed = true - for { - if _, ok := <-r.reassembled; !ok { - return nil - } - r.done <- true - } -} |