December 2003 - Darwin-kernel

getattrlist Documentation
by Quinn 19 Dec '03

19 Dec '03

Greetings If you're writing a VFS plug-in for Mac OS X, you'll be interested to know that we now have official documentation for the Apple extensions to the Posix file system API, to wit getattrlist, setattrlist, getdirentriesattr, searchfs, and exchangedata. <http://developer.apple.com/qa/qa2001/qa1327.html> If your file system supports these calls, you should check your implementation against this documentation. Let me know if you see any problems. S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Technical Support * Networking, Communications, Hardware _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: Problem related kernel level socket api soaccept()
by Herry Wiputra 18 Dec '03

18 Dec '03

Hi, The reason why soaccept paniced is because soaccept() is a non-blocking call, and you call soaccept without any connections to be accepted. You need to provide your own blocking mechanism to wait until the socket has connections ready to be accepted. Please look at accept1() in Darwin source tree for more example. Regards, Herry _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: user settable preferences for a kext
by Stefan Werner 18 Dec '03

18 Dec '03

Hi, ----- Original Message ----- From: "Dean Reece" <dean.reece(a)apple.com> To: "Stefan Werner" <stefan(a)keindesign.de> Cc: <darwin-kernel(a)lists.apple.com> Sent: Wednesday, December 17, 2003 8:17 PM Subject: Re: user settable preferences for a kext > 1) Figure out a way to not need the prefs in the first place. > 2) Move out of the kernel and do your work as a daemon instead of a > kext. > 3) Have the driver not maintain prefs, but instead have the client app > push the prefs down on open. Thanks for your answer. I have figured out a way of solving my problem, which is a StartupItem that is reading the plist file in /Library/Preferences and is passing the parameters to my .kext. Since my kext is an audio driver, based on the PhantomAudio example (hence the Info.plist for configuration, that's how PhantomAudio does it), I was able to use a AudioDriverPlugin to implement custom properties and have a user-space interface to them. Funny how one always gets the ideas /after/ sending the question to a mailing list... Stefan _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: user settable preferences for a kext
by Dean Reece 17 Dec '03

17 Dec '03

On Dec 17, 2003, at 5:12 AM, Stefan Werner wrote: how can I have preference files for my kext that a "mortal" (=non-root) user can write? Is there a way a kernel extension can safely read .plist files in /Library/Preferences? The over-arching rule is that kexts should not have preferences. They can have modes/state that are set by their clients while in use. The introduction of global persistent preferences for a kext introduces a file that can become corrupt and must be maintained. The kext must always be able to do something reasonable if this file is missing or corrupt, so if you are already going to the trouble, you may as well eliminate the fragile state and always do something reasonable. A few alternative approaches: 1) Figure out a way to not need the prefs in the first place. 2) Move out of the kernel and do your work as a daemon instead of a kext. 3) Have the driver not maintain prefs, but instead have the client app push the prefs down on open. If none of these approaches will work for your product, then the only supported way is to have a daemon that coordinates all file I/O for your driver. The daemon launches at boot and searches the IORegistry for instances of your driver and uses getProperty/setProperty or your own IOUserClient to push the data down. For non-IOKit kexts, you'll have to work out your own rendezvous mechanism between the kext and the daemon (socket or a /dev node are good choices) Right now, I am using the kext's Info.plist to pass preferences to my kext, but that file can only be written by root. This is not supported, and will work differently (or not at all) on different versions of Mac OS X. The Info.plist file is considered part of the driver, and not a prefs database. For performance reasons, it is often cached, so changes you make to the Info.plist may not be noticed by the driver until the cache gets rebuilt. Future versions of the OS my detect the change in the driver and flag it as potentially corrupt. In short, don't do this in production code - it is OK for development & testing in a controlled environment only. Cheers, - Dean _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: char * varname causing kernel panics
by Quinn 17 Dec '03

17 Dec '03

At 15:23 -0700 16/12/03, Matt Jaffa wrote: Any ideas? Set up two-machine debugging (instructions for this are on our web site) and attach with the debugger before loading your KEXT. Instead of panicking, you'll drop into the debugger. S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Technical Support * Networking, Communications, Hardware _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Problem related kernel level socket api soaccept()
by Girish 17 Dec '03

17 Dec '03

Hello, While searching for kernel socket api,I got your mail realted to NetworkAudioDriver.kext. After that I looked into the code and find socket api. Then I wrote my sample kernel module using socreate(),sobind(),solisten() then it works fine.When I used soaccept() then it gave me kernel panic. Please help me to the problem. ===== GIRISH V. DUDHE [girish_dudhe(a)yahoo.com ] __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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user settable preferences for a kext
by Stefan Werner 17 Dec '03

17 Dec '03

Hi, how can I have preference files for my kext that a "mortal" (=non-root) user can write? Is there a way a kernel extension can safely read .plist files in /Library/Preferences? Right now, I am using the kext's Info.plist to pass preferences to my kext, but that file can only be written by root. Thanks, Stefan _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: char * causing kernel panics
by Justin Walker 16 Dec '03

16 Dec '03

Matt, Your messages have two problems, at least for me: 1) You never include any substantive information regarding the problem you are facing, leaving us to divine the actual problem. 2) It appears that you are thinking faster than you type, with the result that what you have typed is difficult to understand. We are happy to help, but you need to provide a little more in the way of clear, concise problem statements. Code snippets help. Be assured that declaring a variable does not cause a kernel panic. Something else is causing it. One way to figure out what the problem, on your own, is to use the kernel debugger. You can do this in two ways: 1) use remote debugging, as explained in the documentation tree; connect to the crashed system from another system, and get a stack traceback. That will start you on the path to narrowing down the search for the cause of the crash. 2) get the information from the crash, reboot, and use the debugger on your system to look at the code. You can use this information to figure out where the crash took place, and work backwards from there. Regards, Justin On Tuesday, December 16, 2003, at 02:32 PM, Matt Jaffa wrote: Hi, Never mind where ever i declare a char * or caddr_t vairable it is causing a kernel Panic when i loaded a compiled version of my KEXT, despite the fact that there are other places in the code that have these variables declared. I took example project from nke and modified it. Now why would adding char * values cause it to panic? Thanks, Matt _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored. -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | If you're not confused, | You're not paying attention *--------------------------------------*-------------------------------* _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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Re: logon Banner for OS X
by Robert J. Accettura 16 Dec '03

16 Dec '03

If I recall correctly, http://www.resexcellence.com or http://www.macosxhints.com had something similar in the past. I don't remember where offhand, but I think that might put you on the right track. Hope that helps. Robert J. Accettura robert(a)accettura.com Talwar, Puneet (NIH/NIAID) wrote: >HI, > >I would like to know if someone has created a script where when a user logs >onto the OS X workstation a logon banner pops up and user click OK after >HE/SHE sees the message of the day. > >Thanks, > >Puneet > >---------------------------------------------------------- >Puneet Talwar >Unix Administrator >_______________________________________________ >darwin-kernel mailing list | darwin-kernel(a)lists.apple.com >Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel >Do not post admin requests to the list. They will be ignored. [demime 0.98b removed an attachment of type application/x-pkcs7-signature which had a name of smime.p7s] _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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logon Banner for OS X
by Talwar, Puneet (NIH/NIAID) 16 Dec '03

16 Dec '03

HI, I would like to know if someone has created a script where when a user logs onto the OS X workstation a logon banner pops up and user click OK after HE/SHE sees the message of the day. Thanks, Puneet ---------------------------------------------------------- Puneet Talwar Unix Administrator _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.

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