From 1f9ae59de7cbbe491657b79d5559772b6049a079 Mon Sep 17 00:00:00 2001 From: XOF Date: Mon, 15 Dec 2025 01:18:22 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20proxy/handler.go?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- proxy/handler.go | 214 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 214 insertions(+) create mode 100644 proxy/handler.go diff --git a/proxy/handler.go b/proxy/handler.go new file mode 100644 index 0000000..9e1d2bf --- /dev/null +++ b/proxy/handler.go @@ -0,0 +1,214 @@ +// proxy/handler.go +package proxy + +import ( + "bytes" + "fmt" + "io" + "log" + "net/http" + "net/url" + "strings" + "time" + + "siteproxy/cache" + "siteproxy/security" +) + +type ProxyHandler struct { + validator *security.RequestValidator + rateLimiter *security.RateLimiter + cache *cache.MemoryCache + client *http.Client + userAgent string + maxSize int64 +} + +func NewHandler(validator *security.RequestValidator, rateLimiter *security.RateLimiter, memCache *cache.MemoryCache, userAgent string, maxSize int64) *ProxyHandler { + return &ProxyHandler{ + validator: validator, + rateLimiter: rateLimiter, + cache: memCache, + userAgent: userAgent, + maxSize: maxSize, + client: &http.Client{ + Timeout: 30 * time.Second, + CheckRedirect: func(req *http.Request, via []*http.Request) error { + if len(via) >= 10 { + return fmt.Errorf("too many redirects") + } + return nil + }, + }, + } +} + +func (h *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) { + // 获取 session ID + cookie, err := r.Cookie("session_id") + if err != nil { + http.Error(w, "Unauthorized", http.StatusUnauthorized) + return + } + + sessionID := cookie.Value + + // 速率限制检查 + if !h.rateLimiter.Allow(sessionID) { + http.Error(w, "Rate limit exceeded", http.StatusTooManyRequests) + return + } + + // 获取目标 URL + targetURL := r.URL.Query().Get("url") + if targetURL == "" { + http.Error(w, "Missing url parameter", http.StatusBadRequest) + return + } + + // 验证 URL + if err := h.validator.ValidateURL(targetURL); err != nil { + log.Printf("URL validation failed: %v", err) + http.Error(w, "Invalid or blocked URL", http.StatusForbidden) + return + } + + // 检查缓存 + cacheKey := h.cache.GenerateKey(targetURL) + if cached, ok := h.cache.Get(cacheKey); ok { + log.Printf("Cache hit: %s", targetURL) + h.serveCached(w, cached) + return + } + + // 发起代理请求 + log.Printf("Proxying: %s", targetURL) + if err := h.proxyRequest(w, targetURL, cacheKey); err != nil { + log.Printf("Proxy error: %v", err) + http.Error(w, "Proxy request failed", http.StatusBadGateway) + return + } +} + +func (h *ProxyHandler) proxyRequest(w http.ResponseWriter, targetURL, cacheKey string) error { + // 创建请求 + req, err := http.NewRequest("GET", targetURL, nil) + if err != nil { + return err + } + + // 设置请求头 + req.Header.Set("User-Agent", h.userAgent) + req.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8") + req.Header.Set("Accept-Language", "en-US,en;q=0.9") + req.Header.Set("Accept-Encoding", "gzip, deflate, br") + req.Header.Set("DNT", "1") + req.Header.Set("Connection", "keep-alive") + req.Header.Set("Upgrade-Insecure-Requests", "1") + + // 发送请求 + resp, err := h.client.Do(req) + if err != nil { + return err + } + defer resp.Body.Close() + + // 限制响应大小 + limitedReader := io.LimitReader(resp.Body, h.maxSize) + body, err := io.ReadAll(limitedReader) + if err != nil { + return err + } + + // 检查内容类型 + contentType := resp.Header.Get("Content-Type") + + // 如果是 HTML，进行 URL 重写 + if strings.Contains(contentType, "text/html") { + body = h.rewriteHTML(body, targetURL) + } else if strings.Contains(contentType, "text/css") { + body = h.rewriteCSS(body, targetURL) + } + + // 缓存静态资源 + if h.shouldCache(contentType) { + headers := make(map[string]string) + headers["Content-Type"] = contentType + h.cache.Set(cacheKey, body, headers) + } + + // 设置响应头 + w.Header().Set("Content-Type", contentType) + w.Header().Set("X-Proxied-By", "SiteProxy") + + // 移除可能泄露的头 + for _, header := range []string{"Server", "X-Powered-By", "Set-Cookie"} { + w.Header().Del(header) + } + + w.WriteHeader(resp.StatusCode) + w.Write(body) + + return nil +} + +func (h *ProxyHandler) rewriteHTML(body []byte, baseURL string) []byte { + content := string(body) + + // 解析基础 URL + base, err := url.Parse(baseURL) + if err != nil { + return body + } + + // 重写绝对 URL + content = strings.ReplaceAll(content, `href="`+base.Scheme+`://`+base.Host, `href="/proxy?url=`+url.QueryEscape(base.Scheme+`://`+base.Host)) + content = strings.ReplaceAll(content, `src="`+base.Scheme+`://`+base.Host, `src="/proxy?url=`+url.QueryEscape(base.Scheme+`://`+base.Host)) + + // 重写相对 URL（简化版本） + // 注意：完整实现需要 HTML 解析器 + + return []byte(content) +} + +func (h *ProxyHandler) rewriteCSS(body []byte, baseURL string) []byte { + content := string(body) + + base, err := url.Parse(baseURL) + if err != nil { + return body + } + + // 重写 CSS 中的 url() + content = strings.ReplaceAll(content, `url(`+base.Scheme+`://`+base.Host, `url(/proxy?url=`+url.QueryEscape(base.Scheme+`://`+base.Host)) + + return []byte(content) +} + +func (h *ProxyHandler) shouldCache(contentType string) bool { + cacheableTypes := []string{ + "image/", + "text/css", + "application/javascript", + "application/json", + "font/", + } + + for _, t := range cacheableTypes { + if strings.Contains(contentType, t) { + return true + } + } + + return false +} + +func (h *ProxyHandler) serveCached(w http.ResponseWriter, entry *cache.CacheEntry) { + for key, value := range entry.Headers { + w.Header().Set(key, value) + } + w.Header().Set("X-Cache-Status", "HIT") + w.Header().Set("X-Proxied-By", "SiteProxy") + w.WriteHeader(http.StatusOK) + w.Write(entry.Data) +}