chore(restructure): reorganize project layout

- Reorganize internal packages and overall project structure
- Update imports and wiring to match the new layout
- Separate HTTP parsing and streaming from the server package
- Separate middleware from the server package
- Separate session registry from the session package
- Move HTTP, HTTPS, and TCP servers to the transport package
- Session package no longer starts the TCP server directly
- Server package no longer starts HTTP/HTTPS servers on initialization
- Forwarder no longer handles accepting TCP requests
- Move session details to the types package
- HTTP/HTTPS initialization is now the responsibility of main

internal/http/header/header.go

@@ -0,0 +1,30 @@
+package header
+
+type ResponseHeader interface {
+	Value(key string) string
+	Set(key string, value string)
+	Remove(key string)
+	Finalize() []byte
+}
+
+type responseHeader struct {
+	startLine []byte
+	headers   map[string]string
+}
+
+type RequestHeader interface {
+	Value(key string) string
+	Set(key string, value string)
+	Remove(key string)
+	Finalize() []byte
+	GetMethod() string
+	GetPath() string
+	GetVersion() string
+}
+type requestHeader struct {
+	method    string
+	path      string
+	version   string
+	startLine []byte
+	headers   map[string]string
+}

internal/http/header/parser.go

@@ -0,0 +1,148 @@
+package header
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+)
+
+func setRemainingHeaders(remaining []byte, header interface {
+	Set(key string, value string)
+}) {
+	for len(remaining) > 0 {
+		lineEnd := bytes.Index(remaining, []byte("\r\n"))
+		if lineEnd == -1 {
+			lineEnd = len(remaining)
+		}
+
+		line := remaining[:lineEnd]
+
+		if len(line) == 0 {
+			break
+		}
+
+		colonIdx := bytes.IndexByte(line, ':')
+		if colonIdx != -1 {
+			key := bytes.TrimSpace(line[:colonIdx])
+			value := bytes.TrimSpace(line[colonIdx+1:])
+			header.Set(string(key), string(value))
+		}
+
+		if lineEnd == len(remaining) {
+			break
+		}
+
+		remaining = remaining[lineEnd+2:]
+	}
+}
+
+func parseHeadersFromBytes(headerData []byte) (RequestHeader, error) {
+	header := &requestHeader{
+		headers: make(map[string]string, 16),
+	}
+
+	lineEnd := bytes.Index(headerData, []byte("\r\n"))
+	if lineEnd == -1 {
+		return nil, fmt.Errorf("invalid request: no CRLF found in start line")
+	}
+
+	startLine := headerData[:lineEnd]
+	header.startLine = startLine
+	var err error
+	header.method, header.path, header.version, err = parseStartLine(startLine)
+	if err != nil {
+		return nil, err
+	}
+
+	remaining := headerData[lineEnd+2:]
+
+	setRemainingHeaders(remaining, header)
+
+	return header, nil
+}
+
+func parseStartLine(startLine []byte) (method, path, version string, err error) {
+	firstSpace := bytes.IndexByte(startLine, ' ')
+	if firstSpace == -1 {
+		return "", "", "", fmt.Errorf("invalid start line: missing method")
+	}
+
+	secondSpace := bytes.IndexByte(startLine[firstSpace+1:], ' ')
+	if secondSpace == -1 {
+		return "", "", "", fmt.Errorf("invalid start line: missing version")
+	}
+	secondSpace += firstSpace + 1
+
+	method = string(startLine[:firstSpace])
+	path = string(startLine[firstSpace+1 : secondSpace])
+	version = string(startLine[secondSpace+1:])
+
+	return method, path, version, nil
+}
+
+func parseHeadersFromReader(br *bufio.Reader) (RequestHeader, error) {
+	header := &requestHeader{
+		headers: make(map[string]string, 16),
+	}
+
+	startLineBytes, err := br.ReadSlice('\n')
+	if err != nil {
+		return nil, err
+	}
+
+	startLineBytes = bytes.TrimRight(startLineBytes, "\r\n")
+	header.startLine = make([]byte, len(startLineBytes))
+	copy(header.startLine, startLineBytes)
+
+	header.method, header.path, header.version, err = parseStartLine(header.startLine)
+	if err != nil {
+		return nil, err
+	}
+
+	for {
+		lineBytes, err := br.ReadSlice('\n')
+		if err != nil {
+			return nil, err
+		}
+
+		lineBytes = bytes.TrimRight(lineBytes, "\r\n")
+
+		if len(lineBytes) == 0 {
+			break
+		}
+
+		colonIdx := bytes.IndexByte(lineBytes, ':')
+		if colonIdx == -1 {
+			continue
+		}
+
+		key := bytes.TrimSpace(lineBytes[:colonIdx])
+		value := bytes.TrimSpace(lineBytes[colonIdx+1:])
+
+		header.headers[string(key)] = string(value)
+	}
+
+	return header, nil
+}
+
+func finalize(startLine []byte, headers map[string]string) []byte {
+	size := len(startLine) + 2
+	for key, val := range headers {
+		size += len(key) + 2 + len(val) + 2
+	}
+	size += 2
+
+	buf := make([]byte, 0, size)
+	buf = append(buf, startLine...)
+	buf = append(buf, '\r', '\n')
+
+	for key, val := range headers {
+		buf = append(buf, key...)
+		buf = append(buf, ':', ' ')
+		buf = append(buf, val...)
+		buf = append(buf, '\r', '\n')
+	}
+
+	buf = append(buf, '\r', '\n')
+	return buf
+}

internal/http/header/request.go

@@ -0,0 +1,49 @@
+package header
+
+import (
+	"bufio"
+	"fmt"
+)
+
+func NewRequest(r interface{}) (RequestHeader, error) {
+	switch v := r.(type) {
+	case []byte:
+		return parseHeadersFromBytes(v)
+	case *bufio.Reader:
+		return parseHeadersFromReader(v)
+	default:
+		return nil, fmt.Errorf("unsupported type: %T", r)
+	}
+}
+
+func (req *requestHeader) Value(key string) string {
+	val, ok := req.headers[key]
+	if !ok {
+		return ""
+	}
+	return val
+}
+
+func (req *requestHeader) Set(key string, value string) {
+	req.headers[key] = value
+}
+
+func (req *requestHeader) Remove(key string) {
+	delete(req.headers, key)
+}
+
+func (req *requestHeader) GetMethod() string {
+	return req.method
+}
+
+func (req *requestHeader) GetPath() string {
+	return req.path
+}
+
+func (req *requestHeader) GetVersion() string {
+	return req.version
+}
+
+func (req *requestHeader) Finalize() []byte {
+	return finalize(req.startLine, req.headers)
+}

internal/http/header/response.go

@@ -0,0 +1,40 @@
+package header
+
+import (
+	"bytes"
+	"fmt"
+)
+
+func NewResponse(headerData []byte) (ResponseHeader, error) {
+	header := &responseHeader{
+		startLine: nil,
+		headers:   make(map[string]string, 16),
+	}
+
+	lineEnd := bytes.Index(headerData, []byte("\r\n"))
+	if lineEnd == -1 {
+		return nil, fmt.Errorf("invalid response: no CRLF found in start line")
+	}
+
+	header.startLine = headerData[:lineEnd]
+	remaining := headerData[lineEnd+2:]
+	setRemainingHeaders(remaining, header)
+
+	return header, nil
+}
+
+func (resp *responseHeader) Value(key string) string {
+	return resp.headers[key]
+}
+
+func (resp *responseHeader) Set(key string, value string) {
+	resp.headers[key] = value
+}
+
+func (resp *responseHeader) Remove(key string) {
+	delete(resp.headers, key)
+}
+
+func (resp *responseHeader) Finalize() []byte {
+	return finalize(resp.startLine, resp.headers)
+}

internal/http/stream/parser.go

@@ -0,0 +1,29 @@
+package stream
+
+import "bytes"
+
+func splitHeaderAndBody(data []byte, delimiterIdx int) ([]byte, []byte) {
+	headerByte := data[:delimiterIdx+len(DELIMITER)]
+	body := data[delimiterIdx+len(DELIMITER):]
+	return headerByte, body
+}
+
+func isHTTPHeader(buf []byte) bool {
+	lines := bytes.Split(buf, []byte("\r\n"))
+
+	startLine := string(lines[0])
+	if !requestLine.MatchString(startLine) && !responseLine.MatchString(startLine) {
+		return false
+	}
+
+	for _, line := range lines[1:] {
+		if len(line) == 0 {
+			break
+		}
+		colonIdx := bytes.IndexByte(line, ':')
+		if colonIdx <= 0 {
+			return false
+		}
+	}
+	return true
+}

internal/http/stream/reader.go

@@ -0,0 +1,50 @@
+package stream
+
+import (
+	"bytes"
+	"tunnel_pls/internal/http/header"
+)
+
+func (hs *http) Read(p []byte) (int, error) {
+	tmp := make([]byte, len(p))
+	read, err := hs.reader.Read(tmp)
+	if read == 0 && err != nil {
+		return 0, err
+	}
+
+	tmp = tmp[:read]
+
+	headerEndIdx := bytes.Index(tmp, DELIMITER)
+	if headerEndIdx == -1 {
+		return handleNoDelimiter(p, tmp, err)
+	}
+
+	headerByte, bodyByte := splitHeaderAndBody(tmp, headerEndIdx)
+
+	if !isHTTPHeader(headerByte) {
+		copy(p, tmp)
+		return read, nil
+	}
+
+	return hs.processHTTPRequest(p, headerByte, bodyByte)
+}
+
+func (hs *http) processHTTPRequest(p, headerByte, bodyByte []byte) (int, error) {
+	reqhf, err := header.NewRequest(headerByte)
+	if err != nil {
+		return 0, err
+	}
+
+	if err = hs.ApplyRequestMiddlewares(reqhf); err != nil {
+		return 0, err
+	}
+
+	hs.reqHeader = reqhf
+	combined := append(reqhf.Finalize(), bodyByte...)
+	return copy(p, combined), nil
+}
+
+func handleNoDelimiter(p, tmp []byte, err error) (int, error) {
+	copy(p, tmp)
+	return len(tmp), err
+}

internal/http/stream/stream.go

@@ -0,0 +1,103 @@
+package stream
+
+import (
+	"io"
+	"log"
+	"net"
+	"regexp"
+	"tunnel_pls/internal/http/header"
+	"tunnel_pls/internal/middleware"
+)
+
+var DELIMITER = []byte{0x0D, 0x0A, 0x0D, 0x0A}
+var requestLine = regexp.MustCompile(`^(GET|POST|PUT|DELETE|HEAD|OPTIONS|PATCH|TRACE|CONNECT) \S+ HTTP/\d\.\d$`)
+var responseLine = regexp.MustCompile(`^HTTP/\d\.\d \d{3} .+`)
+
+type HTTP interface {
+	io.ReadWriteCloser
+	CloseWrite() error
+	RemoteAddr() net.Addr
+	UseResponseMiddleware(mw middleware.ResponseMiddleware)
+	UseRequestMiddleware(mw middleware.RequestMiddleware)
+	SetRequestHeader(header header.RequestHeader)
+	RequestMiddlewares() []middleware.RequestMiddleware
+	ResponseMiddlewares() []middleware.ResponseMiddleware
+	ApplyResponseMiddlewares(resphf header.ResponseHeader, body []byte) error
+	ApplyRequestMiddlewares(reqhf header.RequestHeader) error
+}
+
+type http struct {
+	remoteAddr net.Addr
+	writer     io.Writer
+	reader     io.Reader
+	headerBuf  []byte
+	buf        []byte
+	respHeader header.ResponseHeader
+	reqHeader  header.RequestHeader
+	respMW     []middleware.ResponseMiddleware
+	reqMW      []middleware.RequestMiddleware
+}
+
+func New(writer io.Writer, reader io.Reader, remoteAddr net.Addr) HTTP {
+	return &http{
+		remoteAddr: remoteAddr,
+		writer:     writer,
+		reader:     reader,
+		buf:        make([]byte, 0, 4096),
+	}
+}
+
+func (hs *http) RemoteAddr() net.Addr {
+	return hs.remoteAddr
+}
+
+func (hs *http) UseResponseMiddleware(mw middleware.ResponseMiddleware) {
+	hs.respMW = append(hs.respMW, mw)
+}
+
+func (hs *http) UseRequestMiddleware(mw middleware.RequestMiddleware) {
+	hs.reqMW = append(hs.reqMW, mw)
+}
+
+func (hs *http) SetRequestHeader(header header.RequestHeader) {
+	hs.reqHeader = header
+}
+
+func (hs *http) RequestMiddlewares() []middleware.RequestMiddleware {
+	return hs.reqMW
+}
+
+func (hs *http) ResponseMiddlewares() []middleware.ResponseMiddleware {
+	return hs.respMW
+}
+
+func (hs *http) Close() error {
+	return hs.writer.(io.Closer).Close()
+}
+
+func (hs *http) CloseWrite() error {
+	if closer, ok := hs.writer.(interface{ CloseWrite() error }); ok {
+		return closer.CloseWrite()
+	}
+	return hs.Close()
+}
+
+func (hs *http) ApplyRequestMiddlewares(reqhf header.RequestHeader) error {
+	for _, m := range hs.RequestMiddlewares() {
+		if err := m.HandleRequest(reqhf); err != nil {
+			log.Printf("Error when applying request middleware: %v", err)
+			return err
+		}
+	}
+	return nil
+}
+
+func (hs *http) ApplyResponseMiddlewares(resphf header.ResponseHeader, bodyByte []byte) error {
+	for _, m := range hs.ResponseMiddlewares() {
+		if err := m.HandleResponse(resphf, bodyByte); err != nil {
+			log.Printf("Cannot apply middleware: %s\n", err)
+			return err
+		}
+	}
+	return nil
+}

internal/http/stream/writer.go

@@ -0,0 +1,88 @@
+package stream
+
+import (
+	"bytes"
+	"tunnel_pls/internal/http/header"
+)
+
+func (hs *http) Write(p []byte) (int, error) {
+	if hs.shouldBypassBuffering(p) {
+		hs.respHeader = nil
+	}
+
+	if hs.respHeader != nil {
+		return hs.writer.Write(p)
+	}
+
+	hs.buf = append(hs.buf, p...)
+
+	headerEndIdx := bytes.Index(hs.buf, DELIMITER)
+	if headerEndIdx == -1 {
+		return len(p), nil
+	}
+
+	return hs.processBufferedResponse(p, headerEndIdx)
+}
+
+func (hs *http) shouldBypassBuffering(p []byte) bool {
+	return hs.respHeader != nil && len(hs.buf) == 0 && len(p) >= 5 && string(p[0:5]) == "HTTP/"
+}
+
+func (hs *http) processBufferedResponse(p []byte, delimiterIdx int) (int, error) {
+	headerByte, bodyByte := splitHeaderAndBody(hs.buf, delimiterIdx)
+
+	if !isHTTPHeader(headerByte) {
+		return hs.writeRawBuffer()
+	}
+
+	if err := hs.processHTTPResponse(headerByte, bodyByte); err != nil {
+		return 0, err
+	}
+
+	hs.buf = nil
+	return len(p), nil
+}
+
+func (hs *http) writeRawBuffer() (int, error) {
+	_, err := hs.writer.Write(hs.buf)
+	length := len(hs.buf)
+	hs.buf = nil
+	if err != nil {
+		return 0, err
+	}
+	return length, nil
+}
+
+func (hs *http) processHTTPResponse(headerByte, bodyByte []byte) error {
+	resphf, err := header.NewResponse(headerByte)
+	if err != nil {
+		return err
+	}
+
+	if err = hs.ApplyResponseMiddlewares(resphf, bodyByte); err != nil {
+		return err
+	}
+
+	hs.respHeader = resphf
+	finalHeader := resphf.Finalize()
+
+	if err = hs.writeHeaderAndBody(finalHeader, bodyByte); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (hs *http) writeHeaderAndBody(header, bodyByte []byte) error {
+	if _, err := hs.writer.Write(header); err != nil {
+		return err
+	}
+
+	if len(bodyByte) > 0 {
+		if _, err := hs.writer.Write(bodyByte); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}