Core Dumped when authentication plugin returns MOSQ_ERR_AUTH few times

[hasunperera]

This error popups after few seconds when authentication plugin is returning MOSQ_ERR_AUTH with mosquitto broker 1.4.14

loop.c:488: loop_handle_reads_writes: Assertion pollfds[context->pollfd_index].fd == context->sock' failed. (core dumped)`

[dhanushkad]

I also faced somewhat similar issue.

Im not a very "C" savvy person
Not sure if it breaks anything else, not having the assertion in the code worked for me to get rid of this problem. but still trying to understand if it is essential to the functionality.

"assert(pollfds[context->pollfd_index].fd == context->sock);"

@ralight Assert macro does an application abort on FALSE isnt it? Is it a good idea to have this Assert there since the broker would fail on unsuccessful assertion? Or is it an expected behavior.

[ralight]

I haven't yet managed to reproduce this, is there anything else you can tell me about the circumstances around when it happens?

[hasunperera]

@dhanushkad I was able to do the same and it solved the issue. But not sure why assert(pollfds[context->pollfd_index].fd == context->sock); returns false.

@ralight I re-created this issue by returning MOSQ_ERR_AUTH for any username or password that is passed to the auth plugin to connect to the Mosquitto broker. After trying to connect to the broker few times from a web-socket client broker gets

loop.c:488: loop_handle_reads_writes: Assertionpollfds[context->pollfd_index].fd == context->sock' failed. (core dumped)`

My auth plugin method is as below,

int mosquitto_auth_unpwd_check(void *user_data, const char *username, const char *password) {
return MOSQ_ERR_AUTH;
}

Mosquitto broker configuration file -

allow_anonymous false
persistence true
persistence_file mosquitto.db

listener 1883
protocol mqtt

listener 1884
protocol websockets
http_dir /home/hasunp/mosquitto/http
certfile /home/hasunp/certificate.crt
cafile /home/hasunp/ca_bundle.crt
keyfile /home/hasunp/private.key
require_certificate false
tls_version tlsv1.2

listener 1885
protocol mqtt
certfile /home/hasunp/certificate.crt
cafile /home/hasunp/ca_bundle.crt
keyfile /home/hasunp/private.key
require_certificate false
tls_version tlsv1.2

auth_plugin /home/hasunp/mosquitto_auth_token.so
auth_opt_http_user_uri http:https://backend:9005/user/verify
auth_opt_http_acl_uri http:https://backend:9005/user/verify
auth_opt_bypass_acl true

log_dest file /home/hasunp/mosquitto/mosquitto.log

[ralight]

Do you know what version of libwebsockets you are using?

[hasunperera]

I'm using libwebsockets-2.2.1 @ralight

[ralight]

I believe this is fixed in the commit referenced above. Would you be able to try out the fixes branch to see if it works for you?

[hasunperera]

Thank you @ralight ... I'll try out and let you know soon.

[hasunperera]

It didn't fix the issue @ralight ..... I get the same error again after returning MOSQ_ERR_AUTH few times

loop.c:489: loop_handle_reads_writes: Assertion 'pollfds[context->pollfd_index].fd == context->sock' failed. Aborted (core dumped)

[ralight]

Could you try again with this new fix please?

[hasunperera]

Thank you @ralight I'll try out now

[hasunperera]

@ralight It seems to be working now.. 👍 I'll run it for few days and report you. Thank you so much

[hasunperera]

@ralight Broker was running for few days now.. And it seems to be working fine now 👍

[kylebake]

So, I'm using the latest mosquitto (1.4.14) and libwebsockets-dev v1.7.1-1 and I'm getting this websockets core dump after a couple of failed authentications. Am I missing something? How did you get yours to work exactly @hasunperera?

[hasunperera]

@Tryforce Please build mosquitto from this bug fix with libwebsockets-2.2.1
#490

[iegomez]

Hi, I was having the same problem, building the latest libwebsockets (2.4) and then mosquitto (1.4.14) and mosquitto-auth-plug fixed it for me.

[PierreF]

Closing as the issue seems fixed in latest version. Feel free to reopen if this bug is not fixed.