Client and server example

The example in examples/csp_server_client.c provides a simple server/client setup, where the client sends a request to the server and receives a reply. The code can be compiled to an executable using ./examples/buildall.py.

The example servers bind to all CSP ports and pass default service requests to csp_service_handler(). This exposes CMP management operations, including PEEK and POKE. These examples demonstrate libcsp functionality; they are not hardened services intended for exposure to an untrusted network. See CMP PEEK and POKE for the security model and deployment requirements.

The example supports these drivers and interfaces in CSP:

ZMQHUB: -z <host name|ip>

Requires no extra hardware, as it uses standard network. The zmqproxy will need to be started.
CAN: -c <can device>

Requires a physical CAN interface. There are several CAN dongles on the market, for example https://www.peak-system.com/PCAN-USB.199.0.html.

To achieve best performance and stability, following options can be set on the CAN device:
```
linux: sudo ip link set dev can0 down
linux: sudo ip link set dev can0 up type can bitrate 1000000 restart-ms 100
linux: sudo ip link set dev can0 txqueuelen 100
```
KISS: -k <serial device>

Requires a serial interface, e.g. USB dongle.

Running the example

If the example is started without any interfaces, it will use the loopback interface for communication between client and server:

libcsp$ ./build/examples/csp_server_client
Initialising CSP
Connection table
[00 0x7fbd8f574080] S:0, 0 -> 0, 0 -> 0 (17) fl 0
[01 0x7fbd8f574198] S:0, 0 -> 0, 0 -> 0 (18) fl 0
[02 0x7fbd8f5742b0] S:0, 0 -> 0, 0 -> 0 (19) fl 0
[03 0x7fbd8f5743c8] S:0, 0 -> 0, 0 -> 0 (20) fl 0
[04 0x7fbd8f5744e0] S:0, 0 -> 0, 0 -> 0 (21) fl 0
[05 0x7fbd8f5745f8] S:0, 0 -> 0, 0 -> 0 (22) fl 0
[06 0x7fbd8f574710] S:0, 0 -> 0, 0 -> 0 (23) fl 0
[07 0x7fbd8f574828] S:0, 0 -> 0, 0 -> 0 (24) fl 0
Interfaces
LOOP       addr: 0 netmask: 14 dfl: 0
           tx: 00000 rx: 00000 txe: 00000 rxe: 00000
           drop: 00000 autherr: 00000 frame: 00000
           txb: 0 (0B) rxb: 0 (0B) 

Client task started
Server task started
Ping address: 0, result 2 [mS]
reboot system request sent to address: 0
Packet received on MY_SERVER_PORT: Hello world A

Running the example with ZMQHUB interface

To run the example with ZMQHUB interfaces, start the zmqproxy, client and server in three separate processes.

libcsp$ ./build/examples/zmqproxy
Subscriber task listening on tcp://0.0.0.0:6000
Publisher task listening on tcp://0.0.0.0:7000
Capture/logging task listening on tcp://0.0.0.0:6000
Packet: Src 3, Dst 2, Dport 1, Sport 18, Pri 2, Flags 0x00, Size 100
Packet: Src 2, Dst 3, Dport 18, Sport 1, Pri 2, Flags 0x00, Size 100
Packet: Src 3, Dst 2, Dport 4, Sport 19, Pri 2, Flags 0x01, Size 8
Packet: Src 3, Dst 2, Dport 10, Sport 20, Pri 2, Flags 0x00, Size 14

libcsp$ ./build/examples/csp_server -z localhost -a 2
Initialising CSP
Connection table
[00 0x7f266ec1d080] S:0, 0 -> 0, 0 -> 0 (17) fl 0
[01 0x7f266ec1d198] S:0, 0 -> 0, 0 -> 0 (18) fl 0
[02 0x7f266ec1d2b0] S:0, 0 -> 0, 0 -> 0 (19) fl 0
[03 0x7f266ec1d3c8] S:0, 0 -> 0, 0 -> 0 (20) fl 0
[04 0x7f266ec1d4e0] S:0, 0 -> 0, 0 -> 0 (21) fl 0
[05 0x7f266ec1d5f8] S:0, 0 -> 0, 0 -> 0 (22) fl 0
[06 0x7f266ec1d710] S:0, 0 -> 0, 0 -> 0 (23) fl 0
[07 0x7f266ec1d828] S:0, 0 -> 0, 0 -> 0 (24) fl 0
Interfaces
LOOP      addr: 0 netmask: 14 dfl: 0
          tx: 00000 rx: 00000 txe: 00000 rxe: 00000
          drop: 00000 autherr: 00000 frame: 00000
          txb: 0 (0B) rxb: 0 (0B)

ZMQHUB    addr: 2 netmask: 0 dfl: 1
          tx: 00000 rx: 00000 txe: 00000 rxe: 00000
          drop: 00000 autherr: 00000 frame: 00000
          txb: 0 (0B) rxb: 0 (0B)

Server task started
Packet received on SERVER_PORT: Hello world A

libcsp$ ./build/examples/csp_client -z localhost -a 3 -C 2
Initialising CSP
Connection table
[00 0x7f471efc1080] S:0, 0 -> 0, 0 -> 0 (17) fl 0
[01 0x7f471efc1198] S:0, 0 -> 0, 0 -> 0 (18) fl 0
[02 0x7f471efc12b0] S:0, 0 -> 0, 0 -> 0 (19) fl 0
[03 0x7f471efc13c8] S:0, 0 -> 0, 0 -> 0 (20) fl 0
[04 0x7f471efc14e0] S:0, 0 -> 0, 0 -> 0 (21) fl 0
[05 0x7f471efc15f8] S:0, 0 -> 0, 0 -> 0 (22) fl 0
[06 0x7f471efc1710] S:0, 0 -> 0, 0 -> 0 (23) fl 0
[07 0x7f471efc1828] S:0, 0 -> 0, 0 -> 0 (24) fl 0
Interfaces
LOOP      addr: 0 netmask: 14 dfl: 0
          tx: 00000 rx: 00000 txe: 00000 rxe: 00000
          drop: 00000 autherr: 00000 frame: 00000
          txb: 0 (0B) rxb: 0 (0B)

ZMQHUB    addr: 3 netmask: 0 dfl: 1
          tx: 00000 rx: 00000 txe: 00000 rxe: 00000
          drop: 00000 autherr: 00000 frame: 00000
          txb: 0 (0B) rxb: 0 (0B)

Client task started
Ping address: 2, result 8 [mS]
reboot system request sent to address: 2