updated Salto key encoding workflow

This commit is contained in:
yurii 2025-08-11 14:57:33 +01:00
parent c8f6c57983
commit b4d16f9021
3 changed files with 113 additions and 85 deletions

View File

@ -75,120 +75,145 @@ func (lock *SaltoLockServer) BuildCommand(req DoorCardRequest, checkIn, checkOut
return nil
}
// readFrame consumes a full frame starting with firstByte (expected STX).
// It reads up to ETX and then attempts to read a trailing LRC (or CR). timeout controls read deadlines.
func (lock *SaltoLockServer) readFrame(conn net.Conn, reader *bufio.Reader, firstByte byte, timeout time.Duration) ([]byte, error) {
frame := []byte{firstByte}
for {
conn.SetReadDeadline(time.Now().Add(timeout))
b, e := reader.ReadByte()
if e != nil {
return frame, fmt.Errorf("error reading frame body: %w", e)
}
frame = append(frame, b)
if b == ETX {
break
}
}
// read trailing LRC (or CR) if present (non-blocking w/ timeout)
conn.SetReadDeadline(time.Now().Add(timeout))
if lrc, e := reader.ReadByte(); e == nil {
frame = append(frame, lrc)
} else {
// Not fatal: some devices might omit LRC/CR — just log
log.Warnf("readFrame: no trailing LRC/CR: %v", e)
}
return frame, nil
}
// waitForAck waits for ACK or NAK. If STX frames are encountered they are drained
// using readFrame. drainedCount (if non-nil) accumulates the number of drained frames.
func (lock *SaltoLockServer) waitForAck(conn net.Conn, reader *bufio.Reader, timeout time.Duration, drainedCount *int) error {
deadline := time.Now().Add(timeout)
for {
conn.SetReadDeadline(time.Now().Add(time.Until(deadline)))
b, e := reader.ReadByte()
if e != nil {
return fmt.Errorf("error waiting for ACK/NAK: %w", e)
}
switch b {
case ACK:
return nil
case NAK:
return fmt.Errorf("received NAK")
case STX:
// stale or queued full response: consume it and continue waiting
frame, fe := lock.readFrame(conn, reader, b, timeout)
if fe != nil {
// if we can't consume frame, consider it an error
return fmt.Errorf("failed to consume queued STX frame: %w", fe)
}
if drainedCount != nil {
*drainedCount++
log.Infof("Drained queued frame #%d (while waiting for ACK): %q", *drainedCount, string(frame))
} else {
log.Infof("Drained queued frame (while waiting for ACK): %q", string(frame))
}
// loop to keep waiting for ACK
default:
// Unexpected byte while waiting for ACK. Log and continue reading.
log.Warnf("waitForAck: unexpected byte 0x%X while waiting for ACK; ignoring", b)
// keep looping until timeout or ACK/NAK
}
}
}
// LockSequence performs the full ENQ/ACK handshake and command exchange
func (lock *SaltoLockServer) LockSequence(conn net.Conn) error {
log.Infof("Sending command: %q", string(lock.command))
const timeout = 10 * time.Second
var (
err error
resp []byte
resp []byte
reader = bufio.NewReader(conn)
drained = 0 // count of stale frames consumed across waits
)
reader := bufio.NewReader(conn)
// 1. Send ENQ
log.Infof("Sending ENQ")
if _, e := conn.Write([]byte{ENQ}); e != nil {
return fmt.Errorf("failed to send ENQ: %w", e)
}
// 2. Expect ACK
conn.SetReadDeadline(time.Now().Add(timeout))
if b, e := reader.ReadByte(); e != nil {
// 2. Expect ACK (but drain any queued STX frames first)
if e := lock.waitForAck(conn, reader, timeout, &drained); e != nil {
return fmt.Errorf("error awaiting ACK to ENQ: %w", e)
} else if b != ACK {
return fmt.Errorf("expected ACK after ENQ, got 0x%X", b)
}
// 3. Send command frame
log.Infof("Sending encoding command: %q", string(lock.command))
if _, e := conn.Write(lock.command); e != nil {
return fmt.Errorf("failed to send command frame: %w", e)
}
// 4. Expect ACK to command
conn.SetReadDeadline(time.Now().Add(timeout))
if b, e := reader.ReadByte(); e != nil {
// 4. Expect ACK to command (again drain any queued frames that might precede it)
if e := lock.waitForAck(conn, reader, timeout, &drained); e != nil {
return fmt.Errorf("error awaiting ACK to command: %w", e)
} else if b == NAK {
return fmt.Errorf("command rejected (NAK)")
} else if b != ACK {
return fmt.Errorf("expected ACK to command, got 0x%X", b)
}
// 5. Expect STX
conn.SetReadDeadline(time.Now().Add(timeout))
stx, e := reader.ReadByte()
if e != nil {
return fmt.Errorf("error reading STX: %w", e)
}
resp = append(resp, stx)
if stx != STX {
err = fmt.Errorf("expected STX, got 0x%X", stx)
}
// 6. Read separator after STX
conn.SetReadDeadline(time.Now().Add(timeout))
if sep, e := reader.ReadByte(); e == nil {
resp = append(resp, sep)
} else if err == nil {
err = fmt.Errorf("error reading separator after STX: %w", e)
}
// 7. Read command code (e.g., CN, TD)
conn.SetReadDeadline(time.Now().Add(timeout))
b1, e1 := reader.ReadByte()
if e1 == nil {
resp = append(resp, b1)
} else if err == nil {
err = fmt.Errorf("error reading first response byte: %w", e1)
}
b2, e2 := reader.ReadByte()
if e2 == nil {
resp = append(resp, b2)
} else if err == nil {
err = fmt.Errorf("error reading second response byte: %w", e2)
}
switch {
case b1 == 'C' && b2 == 'N':
log.Infof("LockSequence: command response is CN (normal)")
case b1 == 'C' && b2 == 'C':
log.Infof("LockSequence: command response is CC (follow-up)")
case b1 == 'T' && b2 == 'D':
log.Warnf("LockSequence: command response is TD (room does not exist)")
if err == nil {
err = fmt.Errorf("lock response indicates room does not exist")
}
default:
log.Warnf("LockSequence: unexpected command response %q", string(resp))
if err == nil {
err = fmt.Errorf("error encoding keycard, unexpected response")
}
}
// 8. Read rest of message until ETX
// 5. Now read the *next* STX frame which should be the response to our command.
for {
conn.SetReadDeadline(time.Now().Add(timeout))
c, e := reader.ReadByte()
conn.SetReadDeadline(time.Now().Add(20 * time.Second))
b, e := reader.ReadByte()
if e != nil {
if err == nil {
err = fmt.Errorf("error reading response body: %w", e)
}
break
return fmt.Errorf("error reading response start: %w", e)
}
resp = append(resp, c)
if c == ETX {
break
if b != STX {
// If anything else arrives, it might be another control byte or noise;
// log and keep consuming until we find STX.
log.Warnf("expected STX to start response but got 0x%X; ignoring", b)
continue
}
// consume full response frame
frame, fe := lock.readFrame(conn, reader, b, timeout)
if fe != nil {
return fmt.Errorf("error reading response frame: %w", fe)
}
resp = append(resp, frame...)
break
}
// 9. Optional: read trailing byte (LRC or CR)
conn.SetReadDeadline(time.Now().Add(timeout))
if lrc, e := reader.ReadByte(); e == nil {
resp = append(resp, lrc)
// parse the command code within response frame
if len(resp) >= 4 {
// The command bytes are usually at indices 2 and 3 if separator is at index 1
sepIndex := 1
b1 := resp[sepIndex+1]
b2 := resp[sepIndex+2]
switch {
case b1 == 'C' && b2 == 'N':
log.Infof("LockSequence: command response is CN (normal)")
case b1 == 'C' && b2 == 'C':
log.Infof("LockSequence: command response is CC (follow-up)")
case b1 == 'T' && b2 == 'D':
log.Warnf("LockSequence: command response is TD (room does not exist)")
return fmt.Errorf("lock response indicates room does not exist")
default:
log.Warnf("LockSequence: unexpected command response %q", string(resp))
return fmt.Errorf("error encoding keycard, unexpected response")
}
} else {
log.Warnf("LockSequence: failed to read trailing LRC/CR: %v", e)
log.Warnf("LockSequence: response too short: %q", string(resp))
return fmt.Errorf("response too short")
}
log.Infof("LockSequence: received response: %q", string(resp))
return err
return nil
}

View File

@ -30,7 +30,7 @@ import (
)
const (
buildVersion = "1.0.10"
buildVersion = "1.0.11"
serviceName = "hardlink"
customLayout = "2006-01-02 15:04:05 -0700"
transactionUrl = "http://127.0.0.1:18181/start-transaction/"

View File

@ -2,6 +2,9 @@
builtVersion is a const in main.go
#### 1.0.11 - 11 August 2024
updated Salto key encoding workflow
#### 1.0.10 - 08 August 2024
updated logging for TLJ locks