March 2012 - Darwin-kernel - lists.apple.com

Re: Kernel IPC
by Quinn "The Eskimo!" 07 Mar '12

07 Mar '12

On 6 Mar 2012, at 22:13, me wrote: > I am looking for some code examples of kext to user space code. For BSD level code I generally recommend kernel control sockets, as illustrated by the tcplognke sample code. <https://developer.apple.com/library/mac/#samplecode/tcplognke/> In my experience it's very hard to get Mach messaging right and, when you get it from from kernel code, you end up rebooting a lot )-: Share and Enjoy -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Relations, Developer Technical Support, Core OS/Hardware _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Kernel IPC
by me 06 Mar '12

06 Mar '12

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Create a hard link to a vnode from the kernel
by Evgeny Yakovlev 06 Mar '12

06 Mar '12

Hello, I am writing a solution that intercepts file deletion and securely deletes it by wiping file contents according to user configuration. Currently i plan to achieve this by having a kauth kext that intercepts KAUTH_VNODE_DELETE and a user space deamon that does actual wiping. Somewhere, either in kext or in user space daemon, i want to create a new hard link to the to-be-deleted vnode in a special folder for each mount point, queue this file for wiping using this new link and return from kauth callback. I can think of creating a new hard link either in kernel (directly in kauth callback) or by notifying my user space daemon and blocking until it creates the link (otherwise there is a race condition between vnode deletion in kernel and link call from user space daemon). In the first case (create a hard link from kernel) i can't seem to figure out how to do this because VNOP_LINK is private and probably for good reason. In the second case (notifying the user space daemon) i need to synchronize properly, i.e. to wait until user space daemon creates a new hard link and then exit from kauth callback, which is not that good since i need to share some kind of a semaphore and actually block the kernel waiting for a user space event to occur. I would prefere creating a hard link from kernel, but my question is is it possible in the first case and if not what would have been a better workaround? Thanks Evgeny _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists… This email sent to site_archiver(a)lists.apple.com

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Lion FDE bypass user login screen
by Arun 04 Mar '12

04 Mar '12

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