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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
// Copyright (C) 2024 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package api
import (
"time"
"github.com/syncthing/syncthing/lib/db"
"github.com/syncthing/syncthing/lib/rand"
"github.com/syncthing/syncthing/lib/sync"
"golang.org/x/exp/slices"
)
type tokenManager struct {
key string
miscDB *db.NamespacedKV
lifetime time.Duration
maxItems int
timeNow func() time.Time // can be overridden for testing
mut sync.Mutex
tokens *TokenSet
saveTimer *time.Timer
}
func newTokenManager(key string, miscDB *db.NamespacedKV, lifetime time.Duration, maxItems int) *tokenManager {
tokens := &TokenSet{
Tokens: make(map[string]int64),
}
if bs, ok, _ := miscDB.Bytes(key); ok {
_ = tokens.Unmarshal(bs) // best effort
}
return &tokenManager{
key: key,
miscDB: miscDB,
lifetime: lifetime,
maxItems: maxItems,
timeNow: time.Now,
mut: sync.NewMutex(),
tokens: tokens,
}
}
// Check returns true if the token is valid, and updates the token's expiry
// time. The token is removed if it is expired.
func (m *tokenManager) Check(token string) bool {
m.mut.Lock()
defer m.mut.Unlock()
expires, ok := m.tokens.Tokens[token]
if ok {
if expires < m.timeNow().UnixNano() {
// The token is expired.
m.saveLocked() // removes expired tokens
return false
}
// Give the token further life.
m.tokens.Tokens[token] = m.timeNow().Add(m.lifetime).UnixNano()
m.saveLocked()
}
return ok
}
// New creates a new token and returns it.
func (m *tokenManager) New() string {
token := rand.String(randomTokenLength)
m.mut.Lock()
defer m.mut.Unlock()
m.tokens.Tokens[token] = m.timeNow().Add(m.lifetime).UnixNano()
m.saveLocked()
return token
}
// Delete removes a token.
func (m *tokenManager) Delete(token string) {
m.mut.Lock()
defer m.mut.Unlock()
delete(m.tokens.Tokens, token)
m.saveLocked()
}
func (m *tokenManager) saveLocked() {
// Remove expired tokens.
now := m.timeNow().UnixNano()
for token, expiry := range m.tokens.Tokens {
if expiry < now {
delete(m.tokens.Tokens, token)
}
}
// If we have a limit on the number of tokens, remove the oldest ones.
if m.maxItems > 0 && len(m.tokens.Tokens) > m.maxItems {
// Sort the tokens by expiry time, oldest first.
type tokenExpiry struct {
token string
expiry int64
}
var tokens []tokenExpiry
for token, expiry := range m.tokens.Tokens {
tokens = append(tokens, tokenExpiry{token, expiry})
}
slices.SortFunc(tokens, func(i, j tokenExpiry) int {
return int(i.expiry - j.expiry)
})
// Remove the oldest tokens.
for _, token := range tokens[:len(tokens)-m.maxItems] {
delete(m.tokens.Tokens, token.token)
}
}
// Postpone saving until one second of inactivity.
if m.saveTimer == nil {
m.saveTimer = time.AfterFunc(time.Second, m.scheduledSave)
} else {
m.saveTimer.Reset(time.Second)
}
}
func (m *tokenManager) scheduledSave() {
m.mut.Lock()
defer m.mut.Unlock()
m.saveTimer = nil
bs, _ := m.tokens.Marshal() // can't fail
_ = m.miscDB.PutBytes(m.key, bs) // can fail, but what are we going to do?
}
|
