1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build !ts_omit_serve
package localapi
import (
"crypto/sha256"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"net/http"
"runtime"
"tailscale.com/ipn"
"tailscale.com/ipn/ipnlocal"
"tailscale.com/util/httpm"
"tailscale.com/version"
)
func init() {
Register("serve-config", (*Handler).serveServeConfig)
}
func (h *Handler) serveServeConfig(w http.ResponseWriter, r *http.Request) {
switch r.Method {
case httpm.GET:
if !h.PermitRead {
http.Error(w, "serve config denied", http.StatusForbidden)
return
}
config := h.b.ServeConfig()
bts, err := json.Marshal(config)
if err != nil {
http.Error(w, "error encoding config: "+err.Error(), http.StatusInternalServerError)
return
}
sum := sha256.Sum256(bts)
etag := hex.EncodeToString(sum[:])
w.Header().Set("Etag", etag)
w.Header().Set("Content-Type", "application/json")
w.Write(bts)
case httpm.POST:
if !h.PermitWrite {
http.Error(w, "serve config denied", http.StatusForbidden)
return
}
configIn := new(ipn.ServeConfig)
if err := json.NewDecoder(r.Body).Decode(configIn); err != nil {
WriteErrorJSON(w, fmt.Errorf("decoding config: %w", err))
return
}
// require a local admin when setting a path handler
// TODO: roll-up this Windows-specific check into either PermitWrite
// or a global admin escalation check.
if err := authorizeServeConfigForGOOSAndUserContext(runtime.GOOS, configIn, h); err != nil {
http.Error(w, err.Error(), http.StatusUnauthorized)
return
}
etag := r.Header.Get("If-Match")
if err := h.b.SetServeConfig(configIn, etag); err != nil {
if errors.Is(err, ipnlocal.ErrETagMismatch) {
http.Error(w, err.Error(), http.StatusPreconditionFailed)
return
}
WriteErrorJSON(w, fmt.Errorf("updating config: %w", err))
return
}
w.WriteHeader(http.StatusOK)
default:
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
}
}
func authorizeServeConfigForGOOSAndUserContext(goos string, configIn *ipn.ServeConfig, h *Handler) error {
switch goos {
case "windows", "linux", "darwin", "illumos", "solaris":
default:
return nil
}
// Only check for local admin on tailscaled-on-mac (based on "sudo"
// permissions). On sandboxed variants (MacSys and AppStore), tailscaled
// cannot serve files outside of the sandbox and this check is not
// relevant.
if goos == "darwin" && version.IsSandboxedMacOS() {
return nil
}
if !configIn.HasPathHandler() {
return nil
}
if h.Actor.IsLocalAdmin(h.b.OperatorUserID()) {
return nil
}
switch goos {
case "windows":
return errors.New("must be a Windows local admin to serve a path")
case "linux", "darwin", "illumos", "solaris":
return errors.New("must be root, or be an operator and able to run 'sudo tailscale' to serve a path")
default:
// We filter goos at the start of the func, this default case
// should never happen.
panic("unreachable")
}
}
|
