site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com User-agent: Microsoft-Entourage/10.1.4.030702.0 Thank you all for responding:

Can it be possible to rethink the issue and wonder if instead, you could not just prevent the kext from being unloaded when the client is connected?

Your kext can, and probably should, refuse to unload if there are connections open.

Can you better outline what type of KEXT this is? What IOKit family, etc. are you based on?

The answer can depend on family / type of KEXT (but also listen to what other have already responded with).

OK, let me be more specific. My KEXT is an IP filter and I am sending selected IP packets to my client. In the KEXT _start() function I add IPv4 and IPv6 filters and then do a ctl_register with a dynamic ID. My client app opens the KEXT connection via: sockNum = socket( PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL ) ioctl( sockNum, CTLIOCGINFO, &info ) // to get the ctl_id connect( sockNum, (struct sockaddr *)&sockAddr, sizeof( struct sockaddr_ctl )) When the client starts, the KEXT gets a call in its ctl_connect_func and I save the kctlref and unit ID. When the client quits, the KEXT gets a call in its ctl_disconnect_func and I clean up any connection state that I maintain. My concern here is that my KEXT has no way of anticipating when the user (that's me) pulls the plug with kextunload while the connected app is still running. At that point the _stop funtion in my KEXT is called and I remove my IPv4 and IPv6 filters and then call ctl_deregister and deregister fails with EBUSY. So, are you all saying that in my _stop() there is a way to see if a client is connected and if so merely return KERN_FAILURE to prevent the KEXT from unloading? What api is this? There is no ctl_ call available in kern_control.h to do this ... Unless I call ctl_deregister first in my _stop() and return KERN_FAILURE immediately if I get EBUSY - is that it?

When shutting down or restarting, a non-IOKit kext will not be unloaded automatically, so you will not get a panic if your client is still connected.

This is good news for when my KEXT goes into the startup folder. -Allan _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com