-
Notifications
You must be signed in to change notification settings - Fork 14
/
pnp.go
173 lines (146 loc) · 3.81 KB
/
pnp.go
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/* ipp-usb - HTTP reverse proxy, backed by IPP-over-USB connection to device
*
* Copyright (C) 2020 and up by Alexander Pevzner ([email protected])
* See LICENSE for license terms and conditions
*
* PnP manager
*/
package main
import (
"context"
"os"
"os/signal"
"sync"
"syscall"
"time"
)
// PnPExitReason explains why PnP manager has exited
type PnPExitReason int
// PnPExitReason constants
const (
PnPIdle PnPExitReason = iota // No more connected devices
PnPTerm // Terminating signal received
)
// pnpRetryTime returns time of next retry of failed device initialization
func pnpRetryTime(err error) time.Time {
if err == ErrBlackListed || err == ErrUnusable {
// These errors are unrecoverable.
// Forget about device for the next million hours :-)
return time.Now().Add(time.Hour * 1e6)
}
return time.Now().Add(DevInitRetryInterval)
}
// pnpRetryExpired checks if device initialization retry time expired
func pnpRetryExpired(tm time.Time) bool {
return !time.Now().Before(tm)
}
// PnPStart start PnP manager
//
// If exitWhenIdle is true, PnP manager will exit, when there is no more
// devices to serve
func PnPStart(exitWhenIdle bool) PnPExitReason {
devices := UsbAddrList{}
devByAddr := make(map[UsbAddr]*Device)
retryByAddr := make(map[UsbAddr]time.Time)
sigChan := make(chan os.Signal, 1)
ticker := time.NewTicker(DevInitRetryInterval / 4)
tickerRunning := true
signal.Notify(sigChan,
os.Signal(syscall.SIGINT),
os.Signal(syscall.SIGTERM),
os.Signal(syscall.SIGHUP))
// Start control socket server
err := CtrlsockStart()
if err == nil {
defer CtrlsockStop()
}
// Serve PnP events until terminated
loop:
for {
devDescs, err := UsbGetIppOverUsbDeviceDescs()
if err == nil {
newdevices := UsbAddrList{}
for _, desc := range devDescs {
newdevices.Add(desc.UsbAddr)
}
added, removed := devices.Diff(newdevices)
devices = newdevices
// Handle added devices
for _, addr := range added {
Log.Debug('+', "PNP %s: added", addr)
dev, err := NewDevice(devDescs[addr])
StatusSet(addr, devDescs[addr], err)
if err == nil {
devByAddr[addr] = dev
} else {
Log.Error('!', "PNP %s: %s", addr, err)
retryByAddr[addr] = pnpRetryTime(err)
}
}
// Handle removed devices
for _, addr := range removed {
Log.Debug('-', "PNP %s: removed", addr)
delete(retryByAddr, addr)
StatusDel(addr)
dev, ok := devByAddr[addr]
if ok {
dev.Close()
delete(devByAddr, addr)
}
}
// Handle devices, waiting for retry
for addr, tm := range retryByAddr {
if !pnpRetryExpired(tm) {
continue
}
Log.Debug('+', "PNP %s: retry", addr)
dev, err := NewDevice(devDescs[addr])
StatusSet(addr, devDescs[addr], err)
if err == nil {
devByAddr[addr] = dev
delete(retryByAddr, addr)
} else {
Log.Error('!', "PNP %s: %s", addr, err)
retryByAddr[addr] = pnpRetryTime(err)
}
}
}
// Handle exit when idle
if exitWhenIdle && len(devices) == 0 {
Log.Info(' ', "No IPP-over-USB devices present, exiting")
return PnPIdle
}
// Update ticker
switch {
case tickerRunning && len(retryByAddr) == 0:
ticker.Stop()
tickerRunning = false
case !tickerRunning && len(retryByAddr) != 0:
ticker = time.NewTicker(DevInitRetryInterval / 4)
tickerRunning = true
}
// Wait for the next event
select {
case <-UsbHotPlugChan:
case <-ticker.C:
case sig := <-sigChan:
Log.Info(' ', "%s signal received, exiting", sig)
break loop
}
}
// Close remaining devices
ctx, cancel := context.WithTimeout(context.Background(),
DevShutdownTimeout)
defer cancel()
var done sync.WaitGroup
for _, dev := range devByAddr {
done.Add(1)
go func(dev *Device) {
dev.Shutdown(ctx)
dev.Close()
done.Done()
}(dev)
}
done.Wait()
return PnPTerm
}