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-rw-r--r--contrib/persistent-https/client.go189
1 files changed, 189 insertions, 0 deletions
diff --git a/contrib/persistent-https/client.go b/contrib/persistent-https/client.go
new file mode 100644
index 0000000..71125b5
--- /dev/null
+++ b/contrib/persistent-https/client.go
@@ -0,0 +1,189 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+ "bufio"
+ "errors"
+ "fmt"
+ "net"
+ "net/url"
+ "os"
+ "os/exec"
+ "strings"
+ "syscall"
+ "time"
+)
+
+type Client struct {
+ ProxyBin string
+ Args []string
+
+ insecure bool
+}
+
+func (c *Client) Run() error {
+ if err := c.resolveArgs(); err != nil {
+ return fmt.Errorf("resolveArgs() got error: %v", err)
+ }
+
+ // Connect to the proxy.
+ uconn, hconn, addr, err := c.connect()
+ if err != nil {
+ return fmt.Errorf("connect() got error: %v", err)
+ }
+ // Keep the unix socket connection open for the duration of the request.
+ defer uconn.Close()
+ // Keep a connection to the HTTP server open, so no other user can
+ // bind on the same address so long as the process is running.
+ defer hconn.Close()
+
+ // Start the git-remote-http subprocess.
+ cargs := []string{"-c", fmt.Sprintf("http.proxy=%v", addr), "remote-http"}
+ cargs = append(cargs, c.Args...)
+ cmd := exec.Command("git", cargs...)
+
+ for _, v := range os.Environ() {
+ if !strings.HasPrefix(v, "GIT_PERSISTENT_HTTPS_SECURE=") {
+ cmd.Env = append(cmd.Env, v)
+ }
+ }
+ // Set the GIT_PERSISTENT_HTTPS_SECURE environment variable when
+ // the proxy is using a SSL connection. This allows credential helpers
+ // to identify secure proxy connections, despite being passed an HTTP
+ // scheme.
+ if !c.insecure {
+ cmd.Env = append(cmd.Env, "GIT_PERSISTENT_HTTPS_SECURE=1")
+ }
+
+ cmd.Stdin = os.Stdin
+ cmd.Stdout = os.Stdout
+ cmd.Stderr = os.Stderr
+ if err := cmd.Run(); err != nil {
+ if eerr, ok := err.(*exec.ExitError); ok {
+ if stat, ok := eerr.ProcessState.Sys().(syscall.WaitStatus); ok && stat.ExitStatus() != 0 {
+ os.Exit(stat.ExitStatus())
+ }
+ }
+ return fmt.Errorf("git-remote-http subprocess got error: %v", err)
+ }
+ return nil
+}
+
+func (c *Client) connect() (uconn net.Conn, hconn net.Conn, addr string, err error) {
+ uconn, err = DefaultSocket.Dial()
+ if err != nil {
+ if e, ok := err.(*net.OpError); ok && (os.IsNotExist(e.Err) || e.Err == syscall.ECONNREFUSED) {
+ if err = c.startProxy(); err == nil {
+ uconn, err = DefaultSocket.Dial()
+ }
+ }
+ if err != nil {
+ return
+ }
+ }
+
+ if addr, err = c.readAddr(uconn); err != nil {
+ return
+ }
+
+ // Open a tcp connection to the proxy.
+ if hconn, err = net.Dial("tcp", addr); err != nil {
+ return
+ }
+
+ // Verify the address hasn't changed ownership.
+ var addr2 string
+ if addr2, err = c.readAddr(uconn); err != nil {
+ return
+ } else if addr != addr2 {
+ err = fmt.Errorf("address changed after connect. got %q, want %q", addr2, addr)
+ return
+ }
+ return
+}
+
+func (c *Client) readAddr(conn net.Conn) (string, error) {
+ conn.SetDeadline(time.Now().Add(5 * time.Second))
+ data := make([]byte, 100)
+ n, err := conn.Read(data)
+ if err != nil {
+ return "", fmt.Errorf("error reading unix socket: %v", err)
+ } else if n == 0 {
+ return "", errors.New("empty data response")
+ }
+ conn.Write([]byte{1}) // Ack
+
+ var addr string
+ if addrs := strings.Split(string(data[:n]), "\n"); len(addrs) != 2 {
+ return "", fmt.Errorf("got %q, wanted 2 addresses", data[:n])
+ } else if c.insecure {
+ addr = addrs[1]
+ } else {
+ addr = addrs[0]
+ }
+ return addr, nil
+}
+
+func (c *Client) startProxy() error {
+ cmd := exec.Command(c.ProxyBin)
+ cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+ stdout, err := cmd.StdoutPipe()
+ if err != nil {
+ return err
+ }
+ defer stdout.Close()
+ if err := cmd.Start(); err != nil {
+ return err
+ }
+ result := make(chan error)
+ go func() {
+ bytes, _, err := bufio.NewReader(stdout).ReadLine()
+ if line := string(bytes); err == nil && line != "OK" {
+ err = fmt.Errorf("proxy returned %q, want \"OK\"", line)
+ }
+ result <- err
+ }()
+ select {
+ case err := <-result:
+ return err
+ case <-time.After(5 * time.Second):
+ return errors.New("timeout waiting for proxy to start")
+ }
+ panic("not reachable")
+}
+
+func (c *Client) resolveArgs() error {
+ if nargs := len(c.Args); nargs == 0 {
+ return errors.New("remote needed")
+ } else if nargs > 2 {
+ return fmt.Errorf("want at most 2 args, got %v", c.Args)
+ }
+
+ // Rewrite the url scheme to be http.
+ idx := len(c.Args) - 1
+ rawurl := c.Args[idx]
+ rurl, err := url.Parse(rawurl)
+ if err != nil {
+ return fmt.Errorf("invalid remote: %v", err)
+ }
+ c.insecure = rurl.Scheme == "persistent-http"
+ rurl.Scheme = "http"
+ c.Args[idx] = rurl.String()
+ if idx != 0 && c.Args[0] == rawurl {
+ c.Args[0] = c.Args[idx]
+ }
+ return nil
+}