Github代理功能测试成功

Co-authored-by: Copilot <copilot@github.com>

main.go

@@ -0,0 +1,229 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// ========================
+// 配置区域
+// ========================
+const (
+	sizeLimit = int64(1024 * 1024 * 1024 * 1) 	// 允许的文件大小, 1GB
+	host = "127.0.0.1"
+	port = "2005"
+)
+
+// 先生效白名单再匹配黑名单
+// 每行一个规则，示例：
+// user1 # 封禁user1的所有仓库
+// user1/repo1 # 封禁user1的repo1
+// */repo1 # 封禁所有叫做repo1的仓库
+var (
+	whiteListStr = ``
+	blackListStr = ``
+)
+
+
+// ========================
+// 全局变量与预编译正则
+// ========================
+var (
+	whiteList [][]string
+	blackList [][]string
+
+
+	exp1 = regexp.MustCompile(`^(?:https?://)?github\.com/(?P<author>[^/]+)/(?P<repo>[^/]+)/(?:releases|archive)/.*$`)
+	exp2 = regexp.MustCompile(`^(?:https?://)?github\.com/(?P<author>[^/]+)/(?P<repo>[^/]+)/(?:blob|raw)/.*$`)
+	exp3 = regexp.MustCompile(`^(?:https?://)?github\.com/(?P<author>[^/]+)/(?P<repo>[^/]+)/(?:info|git-).*$`)
+	exp4 = regexp.MustCompile(`^(?:https?://)?raw\.(?:githubusercontent|github)\.com/(?P<author>[^/]+)/(?P<repo>[^/]+)/.+?/.+$`)
+	exp5 = regexp.MustCompile(`^(?:https?://)?gist\.(?:githubusercontent|github)\.com/(?P<author>[^/]+)/.+?/.+$`)
+
+	httpClient *http.Client
+)
+
+func init() {
+	// 1. 初始化列表
+	whiteList = parseList(whiteListStr)
+	blackList = parseList(blackListStr)
+
+	httpClient = &http.Client{
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+		Timeout: 0,
+	}
+}
+
+func main() {
+	http.HandleFunc("/", routeHandler)
+	addr := fmt.Sprintf("%s:%s", host, port)
+	log.Printf("服务器启动成功，正在监听 %s", addr)
+	if err := http.ListenAndServe(addr, nil); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func routeHandler(w http.ResponseWriter, r *http.Request) {
+
+	u := strings.TrimPrefix(r.URL.RequestURI(), "/")
+	if strings.HasPrefix(u, "https:/") && !strings.HasPrefix(u, "https://") {
+		u = "https://" + strings.TrimPrefix(u, "https:/")
+	} else if strings.HasPrefix(u, "http:/") && !strings.HasPrefix(u, "http://") {
+		u = "http://" + strings.TrimPrefix(u, "http:/")
+	}
+
+	if !strings.HasPrefix(u, "http") {
+		u = "https://" + u
+	}
+
+	m := checkURL(u)
+	if m == nil {
+		http.Error(w, "Invalid input.", http.StatusForbidden)
+		return 
+	}
+
+	if len(whiteList) > 0 {
+		allowed := false
+		for _, i := range whiteList {
+			if matchRule(m, i) {
+				allowed = true
+				break
+			}
+		}
+		if !allowed {
+			http.Error(w, "Forbidden by white list.", http.StatusForbidden)
+			return 
+		}
+	}
+
+	for _, i := range blackList {
+		if matchRule(m, i) {
+			http.Error(w, "Forbidden by black list.", http.StatusForbidden)
+			return
+		}
+	}
+
+	// 将网页浏览的blob链接统一替换为raw下载链接
+	if exp2.MatchString(u) {
+		u = strings.Replace(u, "/blob/", "/raw/", 1)
+	}
+
+	// 发起代理请求
+	parsedURL, err := url.Parse(u)
+	if err == nil {
+		u = parsedURL.String()
+	}
+	proxy(w, r, u)
+}
+
+func proxy(w http.ResponseWriter, r *http.Request, targetURL string) {
+	// 修正由于多重代理可能造成的 URL 格式错误
+	if strings.HasPrefix(targetURL, "https:/") && ! strings.HasPrefix(targetURL, "https://") {
+		targetURL = "https://" + targetURL[7:]
+	}
+
+	req, err := http.NewRequest(r.Method, targetURL, r.Body)
+	if err != nil {
+		http.Error(w, "server error " + err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// 拷贝 Header， 但不包含 Host
+	for k, vv := range r.Header {
+		if strings.EqualFold(k, "Host") {
+			continue
+		}
+		for _, v := range vv {
+			req.Header.Add(k, v)
+		}
+	}
+
+	resp, err := httpClient.Do(req)
+	if err != nil {
+		http.Error(w, "server error " + err.Error(), http.StatusInternalServerError)
+		return
+	}
+	defer resp.Body.Close()
+
+	// 校验大文件限制
+	if resp.ContentLength > sizeLimit {
+		http.Redirect(w, r, targetURL, http.StatusFound)
+		return
+	}
+
+	// 处理重定向 Location Header
+	if loc := resp.Header.Get("Location"); loc != "" {
+		if checkURL(loc) != nil {
+			resp.Header.Set("Location", "/"+loc)
+		} else {
+			// 如果不符合 Github 下载格式，则递归代理目标地址
+			proxy(w, r, loc)
+			return
+		}
+	}
+
+	// 拷贝响应的 Header 并写入状态码
+	for k, vv := range resp.Header {
+		for _, v := range vv {
+			w.Header().Add(k, v)
+		}
+	}
+	w.WriteHeader(resp.StatusCode)
+
+	// Go 会原生以 Stream 方式拷贝数据给 Client 端
+	io.Copy(w, resp.Body)
+}
+
+func matchRule(m []string, i []string) bool {
+	// m 通常为 [author, repo] 或 [author]
+	if len(i) == 1 {
+		return len(m) >= 1 && m[0] == i[0]
+	} else if len(i) == 2 {
+		if i[0] == "*" && len(m) >= 2 && m[1] == i[1] {
+			return true
+		}
+		return len(m) >= 2 && m[0] == i[0] && m[1] == i[1]
+	}
+	return false
+}
+
+func checkURL(u string) []string {
+	exps := []*regexp.Regexp {exp1, exp2, exp3, exp4, exp5}
+	for _, exp := range exps {
+		matches := exp.FindStringSubmatch(u)
+		if matches != nil {
+			var result []string
+			for i, name := range exp.SubexpNames() {
+				if i > 0 && name != "" {
+					result = append(result, matches[i])
+				}
+			}
+			return result
+		}
+	}	
+	return nil
+}
+
+
+func parseList(s string) [][]string {
+	var res [][]string
+	lines := strings.Split(s, "\n")
+	for _, line := range lines {
+		line =  strings.TrimSpace(line)
+		if line != "" {
+			parts := strings.Split(line, "/")
+			var cleaned []string
+			for _, p := range parts {
+				cleaned = append(cleaned, strings.ReplaceAll(p, " ", ""))
+			}
+			res = append(res, cleaned)
+		}
+	}
+	return res
+}