tidy up

.drone.yml

@@ -0,0 +1,41 @@
+---
+kind: pipeline
+type: docker
+name: default
+
+steps:
+ - name: build
+   image: golang
+   environment:
+     CGO_ENABLED: 0
+   commands:
+    - go vet
+    - go build
+
+ - name: upload
+   image: plugins/s3
+   settings:
+     bucket: artifacts
+     access_key:
+       from_secret: MINIO_ACCESS_KEY
+     secret_key:
+       from_secret: MINIO_SECRET_KEY
+     endpoint: https://minio.burble.dn42
+     region: fr-par1
+     path_style: true
+     source: modemulator
+     target: /modemulator/${DRONE_BRANCH}
+
+---
+kind: secret
+name: MINIO_ACCESS_KEY
+get:
+  path: burble.dn42/kv/data/drone/minio
+  name: ACCESS_KEY
+
+---
+kind: secret
+name: MINIO_SECRET_KEY
+get:
+  path: burble.dn42/kv/data/drone/minio
+  name: SECRET_KEY

README.md

@@ -1,3 +1,57 @@
 # modemulator
 
-golang modem/telnet emulator
+[![Build Status](https://ci.burble.dn42/api/badges/burble.dn42/modemulator/status.svg?ref=refs/heads/main)](https://ci.burble.dn42/burble.dn42/modemulator)
+
+modemulator is small golang server that emulates a small subset of the
+Hayes AT command set. The server can be configured to connect to other backend
+services via the telnet protocol when a user dials specific numbers. 
+
+The server is intended to be used with a serial terminal or via a virtual serial port
+in a virtual machine to emulate a modem connection to a remote server.
+
+| Port | BAUD | Port | BAUD | Port | BAUD |
+|:--|:--|:--|:--|:--|:--|
+| _10003_ | 300   | _10012_ | 1200   | _10024_ | 2400 |
+| _10048_ | 4800  | _10096_ | 9600   | _10144_ | 14400 |
+| _10192_ | 19200 | _10288_ | 28800  | _10336_ | 33600 |
+| _10560_ | 56000 | _11150_ | 115000 |
+
+## Connecting using socat and minicom
+
+Example on how to connect to the shell server using socat and minicom at 2400 baud
+
+```text
+$ socat -d -d pty,rawer tcp:dialup.burble.dn42:10024 &
+...
+... socat[xxx] N PTY is /dev/pts/2
+...
+$ minicom -D /dev/pts/2
+
+```
+
+Within minicom type **ATDT54311** to dial the shell server.
+
+```text
+Welcome to minicom 2.8
+
+OPTIONS: I18n 
+Port /dev/pts/2, 14:01:58
+
+Press CTRL-A Z for help on special keys
+
+ATDT54311
+CONNECT 2400
+Ubuntu 22.04.1 LTS
+shell-fr-par1 login: 
+```
+
+## Connecting using qemu
+
+Add a virtual serial port to QEMU using `-chardev` and `-device`.
+
+e.g. 
+
+```text
+-chardev socket,id=bdn42,port=11150,host=dialup.burble.dn42,server=off -device pci-serial,chardev=bdn42
+```
+

modemulator.go

@@ -528,7 +528,7 @@ func (m *Modem) atCmd(cmd string) {
 
 	// cope with zero length commands
 	if l == 0 {
-		m.cmdError()
+		m.cmdOK()
 		return
 	}
 
@@ -804,7 +804,7 @@ func (m *Modem) dceTelnet() {
 
 func main() {
 
-	log.SetLevel(log.DebugLevel)
+	log.SetLevel(log.InfoLevel)
 	log.Info("modemulator starting")
 
 	// startup