Merge branch 'jk/list-objects-optim-wo-trees'
[git/git.git] / contrib / persistent-https / socket.go
1 // Copyright 2012 Google Inc. All Rights Reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 package main
16
17 import (
18 "fmt"
19 "log"
20 "net"
21 "os"
22 "path/filepath"
23 "syscall"
24 )
25
26 // A Socket is a wrapper around a Unix socket that verifies directory
27 // permissions.
28 type Socket struct {
29 Dir string
30 }
31
32 func defaultDir() string {
33 sockPath := ".git-credential-cache"
34 if home := os.Getenv("HOME"); home != "" {
35 return filepath.Join(home, sockPath)
36 }
37 log.Printf("socket: cannot find HOME path. using relative directory %q for socket", sockPath)
38 return sockPath
39 }
40
41 // DefaultSocket is a Socket in the $HOME/.git-credential-cache directory.
42 var DefaultSocket = Socket{Dir: defaultDir()}
43
44 // Listen announces the local network address of the unix socket. The
45 // permissions on the socket directory are verified before attempting
46 // the actual listen.
47 func (s Socket) Listen() (net.Listener, error) {
48 network, addr := "unix", s.Path()
49 if err := s.mkdir(); err != nil {
50 return nil, &net.OpError{Op: "listen", Net: network, Addr: &net.UnixAddr{Name: addr, Net: network}, Err: err}
51 }
52 return net.Listen(network, addr)
53 }
54
55 // Dial connects to the unix socket. The permissions on the socket directory
56 // are verified before attempting the actual dial.
57 func (s Socket) Dial() (net.Conn, error) {
58 network, addr := "unix", s.Path()
59 if err := s.checkPermissions(); err != nil {
60 return nil, &net.OpError{Op: "dial", Net: network, Addr: &net.UnixAddr{Name: addr, Net: network}, Err: err}
61 }
62 return net.Dial(network, addr)
63 }
64
65 // Path returns the fully specified file name of the unix socket.
66 func (s Socket) Path() string {
67 return filepath.Join(s.Dir, "persistent-https-proxy-socket")
68 }
69
70 func (s Socket) mkdir() error {
71 if err := s.checkPermissions(); err == nil {
72 return nil
73 } else if !os.IsNotExist(err) {
74 return err
75 }
76 if err := os.MkdirAll(s.Dir, 0700); err != nil {
77 return err
78 }
79 return s.checkPermissions()
80 }
81
82 func (s Socket) checkPermissions() error {
83 fi, err := os.Stat(s.Dir)
84 if err != nil {
85 return err
86 }
87 if !fi.IsDir() {
88 return fmt.Errorf("socket: got file, want directory for %q", s.Dir)
89 }
90 if fi.Mode().Perm() != 0700 {
91 return fmt.Errorf("socket: got perm %o, want 700 for %q", fi.Mode().Perm(), s.Dir)
92 }
93 if st := fi.Sys().(*syscall.Stat_t); int(st.Uid) != os.Getuid() {
94 return fmt.Errorf("socket: got uid %d, want %d for %q", st.Uid, os.Getuid(), s.Dir)
95 }
96 return nil
97 }