Server keeps files open for bad clients

[jbwdevries]

I have one static file of 1188 bytes size that mosquitto should serve when a http request is made to the websocket listener. This worked reasonably well until last week. At that point it would refuse new connections, claiming "Too many files open". Checking with lsof revealed that it would keep a lot of instances to the static file open.

I managed to reproduce it fairly easy. In the .conf:

listener 8082
protocol websockets
http_dir /var/www/static

Then:

$ echo -en "GET / HTTP/0.9\r\n\r\n" | nc localhost 8082
HTTP/1.0 200 OK
Server: mosquitto
Content-Length: 1188

$

If you run lsof after each time you run of the line above, it will have one more line like:

mosquitto 14003 mosquitto  700r   REG   0,25      1188    196 /vagrant/www/static/index.html

Actually requesting the file with curl does not have the same problem. Only if you close the connection before receiving the whole file.

Tested with mosquitto/libwebsockets 1.4.8/1.7.8 and 1.4.10/1.7.9.

I'm not sure where this bug could be. I presume somewhere in callback_http in websockets.c, but I don't know enough about either project to know where to go.

I appreciate any tips on where to look to build a patch.

[ralight]

Thanks for reporting this, I believe it now fixed in the fixes branch.