CP <--- CSMS GetConfig.req message Panic occurs when receiving unknown key

[libreleee]

OCPP version:
[x] 1.6
[ ] 2.0.1

I'm submitting a ...

[X] bug report
[ ] feature request

Current behavior:

CP <--- CSMS[2,"9926ce5a-5090-4ea0-ad7b-0087d6fe4ec9","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]

file : example/1.6/cp/handler.go

func (handler *ChargePointHandler) OnGetConfiguration(request *core.GetConfigurationRequest) (confirmation *core.GetConfigurationConfirmation, err error) {
var resultKeys []core.ConfigurationKey
var unknownKeys []string
for _, key := range request.Key {
configKey, ok := handler.configuration[key]
if !ok {
unknownKeys = append(unknownKeys, *configKey.Value) <<<------------ This Line *configKey.Value = nil Panic
} else {
resultKeys = append(resultKeys, configKey)
}
}

...

It is a key that does not have a value, so of course it is nil.
and A panic occurs and the program terminates.
because *configKey.Value = *string.nil

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x7ff7cdec87f1]

goroutine 27 [running]:
main.(*ChargePointHandler).OnGetConfiguration(0xc00018a2a0, 0xc000322168)
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/example/1.6/cp/handler.go:492 +0x2f1
github.com/lorenzodonini/ocpp-go/ocpp1%2e6.(*chargePoint).handleIncomingRequest(0xc0002f4000, {0x7ff7ce14f820, 0xc000322168}, {0xc000378720, 0x24}, {0xc000094410, 0x10})
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ocpp1.6/charge_point.go:432 +0x20ac
github.com/lorenzodonini/ocpp-go/ocppj.(*Client).ocppMessageHandler(0xc00026fae0, {0xc0002f6400, 0x64, 0x200})
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ocppj/client.go:310 +0xaaf
github.com/lorenzodonini/ocpp-go/ws.(*Client).readPump(0xc0002f2000)
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ws/websocket.go:999 +0x4fa
created by github.com/lorenzodonini/ocpp-go/ws.(*Client).Start in goroutine 1
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ws/websocket.go:1153 +0xc19

Expected behavior:

CP <--- CSMS[2,"314dac3e-f639-438c-8e0a-48ae26bf23c4","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
CP ---> CSMS [3,"314dac3e-f639-438c-8e0a-48ae26bf23c4",{"unknownKey":["AllowOfflineTxForUnknownId"]}]

Steps to reproduce:

Related code:

file : example/1.6/cp/handler.go

func (handler *ChargePointHandler) OnGetConfiguration(request *core.GetConfigurationRequest) (confirmation *core.GetConfigurationConfirmation, err error) {
var resultKeys []core.ConfigurationKey
var unknownKeys []string
for _, key := range request.Key {
configKey, ok := handler.configuration[key]
if !ok {
unknownKeys = append(unknownKeys, *configKey.Value) <<<------------ This Line *configKey.Value = nil Panic
} else {
resultKeys = append(resultKeys, configKey)
}

}

...

insert short code snippets here

---

Solution 1

---

I tried changing the code

...
for _, key := range request.Key {
configKey, ok := handler.configuration[key]
if !ok {
//unknownKeys = append(unknownKeys,*configKey.Value)
unknownKeys = append(unknownKeys, key) <<<-------------- *1 Code change
} else {
resultKeys = append(resultKeys, configKey)
}
}

...
unknownKeys = append(unknownKeys, *configKey.Value) -> unknownKeys = append(unknownKeys, key)

After changing, I was able to send a conf message without panic. as below
CSMS also confirmed normal reception.

CP log
Oct 9 17:06:53.338�[36m [INFO] [ocppj] �[0mrecv CP <--- CSMS[2,"643c4d80-e83a-44c2-b23a-5d2e37b08169","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
Oct 9 17:06:55.794�[36m [INFO] [GetConfiguration] �[0mreturning configuration for requested keys: [AllowOfflineTxForUnknownId]
Oct 9 17:06:55.795�[36m [INFO] [ocppj] �[0msend2 CP ---> CSMS [3,"643c4d80-e83a-44c2-b23a-5d2e37b08169",{"unknownKey":["AllowOfflineTxForUnknownId"]}]

CSMS log
[INFO ] 2024-10-09 17:06:53,336 de.rwth.idsg.steve.ocpp.ws.WebSocketLogger (SteVe-Executor-0) - [chargeBoxId=CNU_TEST_CS1, sessionId=08c43155-6e89-ba36-ac28-c45e5bc58ef3] Sending: [2,"643c4d80-e83a-44c2-b23a-5d2e37b08169","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
[INFO ] 2024-10-09 17:06:55,797 de.rwth.idsg.steve.ocpp.ws.WebSocketLogger (qtp351877391-31) - [chargeBoxId=CNU_TEST_CS1, sessionId=08c43155-6e89-ba36-ac28-c45e5bc58ef3] Received: [3,"643c4d80-e83a-44c2-b23a-5d2e37b08169",{"unknownKey":["AllowOfflineTxForUnknownId"]}]

CP <--- CSMS[2,"314dac3e-f639-438c-8e0a-48ae26bf23c4","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
CP ---> CSMS [3,"314dac3e-f639-438c-8e0a-48ae26bf23c4",{"unknownKey":["AllowOfflineTxForUnknownId"]}]

Receipt was also confirmed on the OCTT Server.
In my case, this solved it.

I think the code needs to be modified.

Or is there another good solution?

Other information:

insert the output here

[xBlaz3kx]

Could you wrap your code and logs into code blocks using ``` for better readability?

[xBlaz3kx]

As far as I understand, this has nothing to do with the library, but with the example code, which has a bug.

The real problem is that we are using the ConfigurationKey.Value instead of Key itself.

[libreleee]

I'm so happy to hear back from you.
I have summarized it again as requested.

----- code start, panic occurred -----

func (handler *ChargePointHandler) OnGetConfiguration(request *core.GetConfigurationRequest) (confirmation *core.GetConfigurationConfirmation, err error) {
var resultKeys []core.ConfigurationKey
var unknownKeys []string
for _, key := range request.Key {
configKey, ok := handler.configuration[key]
if !ok {
unknownKeys = append(unknownKeys, *configKey.Value) // panic occurred
//unknownKeys = append(unknownKeys, key)
} else {
resultKeys = append(resultKeys, configKey)
}
}
if len(request.Key) == 0 {
// Return config for all keys
for _, v := range handler.configuration {
resultKeys = append(resultKeys, v)
}
}
logDefault(request.GetFeatureName()).Infof("returning configuration for requested keys: %v", request.Key)
conf := core.NewGetConfigurationConfirmation(resultKeys)
conf.UnknownKey = unknownKeys
return conf, nil
}
----- code end -----

----- log start -----
'''
log - cp

[ocppj] recv CP <--- CSMS[2,"315b0eb2-f11e-4287-8fc7-6eeebfa28813","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xc0000005 code=0x0 addr=0x0 pc=0x7ff66a4b7711]

goroutine 6 [running]:
main.(*ChargePointHandler).OnGetConfiguration(0xc000094180, 0xc0000083f0)
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/example/1.6/cp/handler.go:550 +0x2f1
github.com/lorenzodonini/ocpp-go/ocpp1%2e6.(*chargePoint).handleIncomingRequest(0xc0000d8210, {0x7ff66a7420e0, 0xc0000083f0}, {0xc000224bd0, 0x24}, {0xc0001faff0, 0x10})
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ocpp1.6/charge_point.go:441 +0x20ac
github.com/lorenzodonini/ocpp-go/ocppj.(*Client).ocppMessageHandler(0xc0000ae820, {0xc00010ee00, 0x64, 0x200})
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ocppj/client.go:310 +0xaaf
github.com/lorenzodonini/ocpp-go/ws.(*Client).readPump(0xc000302000)
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ws/websocket.go:999 +0x4fa
created by github.com/lorenzodonini/ocpp-go/ws.(*Client).Start in goroutine 1
c:/Users/i/Documents/work/go/ocpp-go-master-vscode/ws/websocket.go:1153 +0xc19

'''
----- log end -----

[libreleee]

----- code start, No panic occurred -----

func (handler *ChargePointHandler) OnGetConfiguration(request *core.GetConfigurationRequest) (confirmation *core.GetConfigurationConfirmation, err error) {
var resultKeys []core.ConfigurationKey
var unknownKeys []string
for _, key := range request.Key {
configKey, ok := handler.configuration[key]
if !ok {
//unknownKeys = append(unknownKeys, *configKey.Value)
unknownKeys = append(unknownKeys, key) //No panic occured
} else {
resultKeys = append(resultKeys, configKey)
}
}
if len(request.Key) == 0 {
// Return config for all keys
for _, v := range handler.configuration {
resultKeys = append(resultKeys, v)
}
}
logDefault(request.GetFeatureName()).Infof("returning configuration for requested keys: %v", request.Key)
conf := core.NewGetConfigurationConfirmation(resultKeys)
conf.UnknownKey = unknownKeys
return conf, nil
}

----- log start -----

'''
log - cp

Dec 28 19:54:30.517 [INFO] [ocppj] recv CP <--- CSMS[2,"64d2495c-88df-40b7-9147-387f2f08a7e6","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
Dec 28 19:54:33.299 [INFO] [ocppj] send CP ---> CSMS[3,"64d2495c-88df-40b7-9147-387f2f08a7e6",{"unknownKey":["AllowOfflineTxForUnknownId"]}]

log - csms

INFO:ocpp: send CSMS ---> CP [2,"64d2495c-88df-40b7-9147-387f2f08a7e6","GetConfiguration",{"key":["AllowOfflineTxForUnknownId"]}]
INFO:ocpp: recv CSMS <--_ CP [3,"64d2495c-88df-40b7-9147-387f2f08a7e6",{"unknownKey":["AllowOfflineTxForUnknownId"]}]
'''
----- log end -----

[xBlaz3kx]

I see, since you found the bug and the solution to fix it, why haven't you opened a PR?

[libreleee]

First, I wanted to make sure there were other solutions and that I wasn't wrong

Over 20 years of program development experience but, I'm still not good at github activities because I'm a beginner.
My job is a programmer, but it is the most enjoyable hobby for me, This moment is fun. Thank you

I will prepare and PR.