feat(osi): 打通 Go 侧真实请求验收（T-005）

osi/transport.go

@@ -1,6 +1,7 @@
 package osi
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"encoding/json"
@@ -9,6 +10,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"sort"
 	"strings"
 	"time"
 
@@ -21,7 +23,9 @@ type TransportConfig struct {
 }
 
 type Transport struct {
-	client *http.Client
+	client  *http.Client
+	timeout time.Duration
+	dialer  proxy.Dialer
 }
 
 func NewTransport(config TransportConfig) (*Transport, error) {
@@ -30,21 +34,20 @@ func NewTransport(config TransportConfig) (*Transport, error) {
 		timeout = 20 * time.Second
 	}
 
+	dialer := proxy.Dialer(proxy.Direct)
 	roundTripper := http.DefaultTransport.(*http.Transport).Clone()
 	if strings.TrimSpace(config.Socks5Proxy) != "" {
-		dialer, err := socks5Dialer(config.Socks5Proxy)
+		proxyDialer, err := socks5Dialer(config.Socks5Proxy)
 		if err != nil {
 			return nil, err
 		}
+		dialer = proxyDialer
 		roundTripper.DialContext = func(ctx context.Context, network, address string) (net.Conn, error) {
-			if contextDialer, ok := dialer.(proxy.ContextDialer); ok {
-				return contextDialer.DialContext(ctx, network, address)
-			}
-			return dialer.Dial(network, address)
+			return dialWithContext(ctx, proxyDialer, network, address)
 		}
 	}
 
-	return &Transport{client: &http.Client{Timeout: timeout, Transport: roundTripper}}, nil
+	return &Transport{client: &http.Client{Timeout: timeout, Transport: roundTripper}, timeout: timeout, dialer: dialer}, nil
 }
 
 func (t *Transport) PostJSON(ctx context.Context, targetURL string, payload any, headers map[string]string) (int, []byte, error) {
@@ -53,18 +56,35 @@ func (t *Transport) PostJSON(ctx context.Context, targetURL string, payload any,
 		return 0, nil, fmt.Errorf("marshal json payload: %w", err)
 	}
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, targetURL, bytes.NewReader(body))
+	target, err := url.Parse(targetURL)
 	if err != nil {
-		return 0, nil, fmt.Errorf("build request: %w", err)
+		return 0, nil, fmt.Errorf("parse target url: %w", err)
 	}
-	for name, value := range headers {
-		req.Header.Set(name, value)
-	}
-	if req.Header.Get("Content-Type") == "" {
-		req.Header.Set("Content-Type", "application/json")
+	if target.Scheme != "http" {
+		return 0, nil, fmt.Errorf("unsupported target scheme %q", target.Scheme)
 	}
 
-	resp, err := t.client.Do(req)
+	reqCtx := ctx
+	cancel := func() {}
+	if _, ok := ctx.Deadline(); !ok && t.timeout > 0 {
+		reqCtx, cancel = context.WithTimeout(ctx, t.timeout)
+	}
+	defer cancel()
+
+	conn, err := dialWithContext(reqCtx, t.dialer, "tcp", target.Host)
+	if err != nil {
+		return 0, nil, err
+	}
+	defer conn.Close()
+	if t.timeout > 0 {
+		_ = conn.SetDeadline(time.Now().Add(t.timeout))
+	}
+
+	if err := writeJSONRequest(conn, target, body, headers); err != nil {
+		return 0, nil, err
+	}
+
+	resp, err := http.ReadResponse(bufio.NewReader(conn), nil)
 	if err != nil {
 		return 0, nil, err
 	}
@@ -77,6 +97,82 @@ func (t *Transport) PostJSON(ctx context.Context, targetURL string, payload any,
 	return resp.StatusCode, raw, nil
 }
 
+func writeJSONRequest(w io.Writer, target *url.URL, body []byte, headers map[string]string) error {
+	path := target.RequestURI()
+	if path == "" {
+		path = "/"
+	}
+
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "POST %s HTTP/1.1\r\n", path)
+	writeHeader(&buf, "Host", target.Host)
+	writeHeader(&buf, "User-Agent", headerValue(headers, "User-Agent", "python-requests/2.32.4"))
+	writeHeader(&buf, "Accept-Encoding", headerValue(headers, "Accept-Encoding", "gzip, deflate, br"))
+	writeHeader(&buf, "Accept", headerValue(headers, "Accept", "*/*"))
+	writeHeader(&buf, "Connection", headerValue(headers, "Connection", "keep-alive"))
+	writeHeader(&buf, "Content-Length", fmt.Sprintf("%d", len(body)))
+	writeHeader(&buf, "Content-Type", headerValue(headers, "Content-Type", "application/json"))
+
+	written := map[string]bool{
+		"host": true, "user-agent": true, "accept-encoding": true, "accept": true,
+		"connection": true, "content-length": true, "content-type": true,
+	}
+	for _, name := range []string{"orgCode", "deviceSN", "ts", "userName", "password"} {
+		if value, ok := headers[name]; ok {
+			writeHeader(&buf, name, value)
+			written[strings.ToLower(name)] = true
+		}
+	}
+
+	var rest []string
+	for name := range headers {
+		if !written[strings.ToLower(name)] {
+			rest = append(rest, name)
+		}
+	}
+	sort.Strings(rest)
+	for _, name := range rest {
+		writeHeader(&buf, name, headers[name])
+	}
+	buf.WriteString("\r\n")
+	buf.Write(body)
+
+	_, err := w.Write(buf.Bytes())
+	return err
+}
+
+func writeHeader(buf *bytes.Buffer, name, value string) {
+	fmt.Fprintf(buf, "%s: %s\r\n", name, value)
+}
+
+func headerValue(headers map[string]string, name, fallback string) string {
+	if value, ok := headers[name]; ok {
+		return value
+	}
+	return fallback
+}
+
+func dialWithContext(ctx context.Context, dialer proxy.Dialer, network, address string) (net.Conn, error) {
+	if contextDialer, ok := dialer.(proxy.ContextDialer); ok {
+		return contextDialer.DialContext(ctx, network, address)
+	}
+	type result struct {
+		conn net.Conn
+		err  error
+	}
+	ch := make(chan result, 1)
+	go func() {
+		conn, err := dialer.Dial(network, address)
+		ch <- result{conn: conn, err: err}
+	}()
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case result := <-ch:
+		return result.conn, result.err
+	}
+}
+
 func socks5Dialer(rawProxy string) (proxy.Dialer, error) {
 	proxyURL, err := normalizeSocks5Proxy(rawProxy)
 	if err != nil {