March 2008 - Darwin-kernel - lists.apple.com

Use of asynchronous receive at kernel level
by Eddy Quicksall 24 Mar '08

24 Mar '08

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[IRQ] how to use it?
by syl 24 Mar '08

24 Mar '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; bh=Rs9V8BWsusoI9lrTujc6f3VEDYlrLbFb1TbIQ4CyXHM=; b=a7WFApIAE7nThyRZ/xZXCRJB70rA92+ALAqsRfLGKFjWgR7I0heBDGHEEZg2shuqQ/7sJke3uQtUMw8N+bDTygTovaQRMK7RSKpVaPbWL+IfoI+7STHzohvWWIrWXHcDbylZnxVOhZ8/RbSDC2LEmOPaSdKG4TRhTKeEt5r0784= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=blFa67VfByilB1+SXKZsR7iIWzM9eP5mDa5OKvjr+ZXUhlp4wAupqCAh6rpJfQUKk6lHlUbCt/0t1JMFPm+ssmSBdX7AAbTtIdbs6/rRmbpJw1cpTDg5Y8e/lfQVc4R/XpfRCZ6s/fa3WEA401eizObobpRSeMwgPkl8ay5eNJc= Hello guys. I'm trying to wrote an driver using irq and I want to do it without the IOKit. I've created my chardev with cdevsw_add and a simply driver who play on ioport seems to work fine :) I've got just one point not finish yet : Irq management. I don't found how adding an handler for my irq management, and I don't know where I can found this information and which part of the kernel do the IRQ management (BSD or mach). For information I am developing on a x86. Do you know how can I do add my handler ? Thanks for your help and sorry for my poor English. -- Gallon sylvestre Astek méchant / Assistant Cisco Rathaxes Core Developper / LSE researcher kernel developer for adeneo and OpenBSD fan http://devsyl.blogspot.com/ | www.rathaxes.eu _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Accessing the mode of a directory with its vnode and other questions
by Michael Smith 24 Mar '08

24 Mar '08

site_archiver(a)lists.apple.com Delivered-To: Darwin-kernel(a)lists.apple.com On Mar 21, 2008, at 5:08 PM, John D. wrote: goes something like this... (untested, of course:-) struct vnode_attr vattr; VATTR_INIT(&vattr); VATTR_WANTED(&vattr, va_mode); err = vnode_getattr(vp, &vattr, vfs_context_current()); Thanks. I figured it out also after reading the auditing related sources. I had some issues before I found out that you can couple multiple VATTR_WANTED calls :) I'm not sure on what's the best policy here, if I should start a new thread for some kauth related questions. I'm trying to implement a vnode scope listener that catches binary executions but so far I've only got a fileop scope listener to catch those properly. Maybe I'm simply doing something wrong. I was receiving NULL dvp (parent vnode) structures, which is impossible if we are executing a binary (ie. it must have a parent vnode, be it the root directory or the immediately top directory where the binary image / mach-o object is located). = Mike _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On Sat, Mar 22, 2008 at 12:27 AM, Rick Macklem <rmacklem(a)uoguelph.ca> wrote: For trivial things like va_mode, you will typically be OK, but you should make a habit of checking VATTR_IS_SUPPORTED() for a field before using it, as some attributes aren't universal and can't be faked up for you by the VFS. If you don't have any fallback code you can just test VATTR_ALL_SUPPORTED() and fail if it returns false. The dvp is only set for KAUTH_SCOPE_VNODE listeners when the operation being authorised has a dependency on an explicit parent (since vnodes can have an arbitrary number of parents, including zero). Currently, this is only the case for DELETE. It is nontrivial to establish the set of parent objects that a vnode has (many filesystems don't store node parent information), so your design should as a rule avoid making any assumptions about node parentage. This email sent to site_archiver(a)lists.apple.com

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Re: Accessing the mode of a directory with its vnode and other questions
by Terry Lambert 22 Mar '08

22 Mar '08

site_archiver(a)lists.apple.com Delivered-To: Darwin-kernel(a)lists.apple.com Hi, -- Terry _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On Mar 21, 2008, at 12:42 AM, John D. wrote: I'm new on the list, hopefully I'll contribute and help around as much as I can. That said, I have a few issues with some code I'm working on.... ;( I would like to know how to access the mode of a file system object (in this case, a directory) with only its vnode. I don't have access out of the box to any vfs context nor extra data besides the vnode alone. I believe I can retrieve an usable vfs context using vfs_context_current(), and then use vfs_getattr() but I can't figure out how exactly they should be used. I tried looking for FreeBSD specific documentation and reading the source a couple times, but looks like I might be missing some macro to initialize the ctx or attr variables. Also, is there any function or macro to verify if a memory address is contained within the user-land stack address space? Any cryptographic (specifically, hashing) functionality already implemented on kernel-land? (ie. if I wanted to calculate a SHA-256 of some in-kernel data). Generally, this information is intentionally difficult to obtain, since we do not want you compositing permissions on your own. The security model is that you have an actor (a vfs_context_t), and action (the operation to perform), and an object (in this case, the vnode on which you wish o perform the action). Then you use an authorization functions to ask if the specified actor is permitted to perform the specified action on the specified object. It's wrong for you to composite your own idea of whether or not an action will be permitted, since your decision may not match the decision of the system, nor of any MAC modules which may be loaded - such as SeatBelt or MCX. It also will not take into account non-POSIX style permissions which may or may not be present on the object (ACLs, and so on), for which it is practically impossible for you to get an answer without a hook into whatever security association vended your credential in the first place (Directory Services in 10.5, "memberd" in 10.4). It is almost always better to make a kauth call instead and ask "can actor do this class of action to this object?". As things go forward, this will continue to tighten up, to the point where it will be impossible to composite your own permissions, since we will simply not provide KPI for you to get the raw permissions in the first place (this is already true for certain group membership operations, and is true for ACLs). This email sent to site_archiver(a)lists.apple.com

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Internals of the dyld library insert and file descriptors
by John D. 22 Mar '08

22 Mar '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; bh=IFL5GUzAQmFHOQqvKCX2zOqamKeeYM0KNVwJVtcPiaU=; b=lC7y8eQKkfvC5q636J0MHgJOXoU0n63vO0nBW1OSlTUNZtioVKz4ZiIA4Wg53Gg4+/pxV2hSC9VeV2TP6HAAQfUIF5ooZAhh4XrlGSRkItvNNppV1kFEOJvnywgwO7hFbK5NTbIxLu5MWBo90FbXYdttwiYBvELRXPnJRTMFyms= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=rFHURw00MuFRc84PQ0OzOBiSAIF5Jkh1fvC+WN8MJzROZsRSvwkDM/FvJEIY4rAYsonGvyx/4/NmFGHgUX3iarW7g+yeEAkrx3Tx8nA5CE2WScSU6ot8AYxwMHMVMn2kEFf/mC64XhfoKm+4u1Fm3q/XWi61NcthlcsJUYp7mko= I'm looking over dyld's code to insert libraries and perform the linking, it seems to be based off mmap() and pmap(), right?. Does it rely on shared region mappings for libraries inserted by the user or via some of the environment variables? Also, I would like to know what is the best method and available API for retrieving the corresponding vnode for a specific file descriptor in a process. I will try to look this up on my own through the sources but I guess it might be helpful to other people reading the list and save them some time. cheers, -- John _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Accessing the mode of a directory with its vnode and other questions
by John D. 22 Mar '08

22 Mar '08

site_archiver(a)lists.apple.com Delivered-To: Darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; bh=VAmQs4Jvi0pF2hb8Lr36VcXmOwToUkZYmfhPg+eMd7w=; b=h7sQa3g8YsidaGYUxoIPiSoan79GtkzPFNLhmAqvgr4atMQB5g11mNxbTSx9GQ10APzMgU4DZZnM0cdnAjomE13vGsjReR8Y8AGNZdliODepem8Kn+DCv4G35BprZ4KXe7usA2lrUXNyz1c5/Q/rmBtn09MdDrE0ZY6C/rk3b5I= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Q6qiL3dUHScq/POJNZFOJxuzZBrc68JJb98Jw7ncMPT+K4qxOfHBpQDn+8+hkZQ9D/6g2S6qoBkFmxboMPtg589nzh56GRFYzwtKOx1GxgGeYonoUEqH89qjw2wNxyGpUf+GVDvV5osZkqydvk5dw/4hV64ZVelG65fGmEKfLzc= On Sat, Mar 22, 2008 at 12:27 AM, Rick Macklem <rmacklem(a)uoguelph.ca> wrote: > goes something like this... (untested, of course:-) > struct vnode_attr vattr; > > VATTR_INIT(&vattr); > VATTR_WANTED(&vattr, va_mode); > err = vnode_getattr(vp, &vattr, vfs_context_current()); Thanks. I figured it out also after reading the auditing related sources. I had some issues before I found out that you can couple multiple VATTR_WANTED calls :) > You'll find Darwin quite different than FreeBSD w.r.t. this. The doc is > use is the kernel sources (xnu-1228.tar.gz found under "Get the Source" > on http://developer.apple.com) Look in xnu-1228/bsd/nfs/nfs_serv.c for > an example. Right on, thanks again! > > Don't know the answer to the others, although you can probably figure > out what crypto functions are in the kernel by looking ay the above > sources. (If you use anything that isn't a kpi in your kext, you'll be > walking on thin ice like I do. I figure that's ok for an open source > project, but probably unwize for something that might be shipped to > customers. Others might elaborate on this.) The BSD subsystem provides AES and SHA2 related functionality apparently, so I will stick to that instead of porting my existing crypto to kernel-land. I'm not sure on what's the best policy here, if I should start a new thread for some kauth related questions. I'm trying to implement a vnode scope listener that catches binary executions but so far I've only got a fileop scope listener to catch those properly. Maybe I'm simply doing something wrong. I was receiving NULL dvp (parent vnode) structures, which is impossible if we are executing a binary (ie. it must have a parent vnode, be it the root directory or the immediately top directory where the binary image / mach-o object is located). Cheers, -- John. _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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Re: Accessing the mode of a directory with its vnode and other questions
by Rick Macklem 21 Mar '08

21 Mar '08

site_archiver(a)lists.apple.com Delivered-To: Darwin-kernel(a)lists.apple.com On Fri, 21 Mar 2008, John D. wrote: I would like to know how to access the mode of a file system object (in this case, a directory) with only its vnode. I don't have access out of the box to any vfs context nor extra data besides the vnode alone. I believe I can retrieve an usable vfs context using vfs_context_current(), and then use vfs_getattr() but I can't figure out how exactly they should be used. I tried looking for FreeBSD specific documentation and reading the source a couple times, but looks like I might be missing some macro to initialize the ctx or attr variables. goes something like this... (untested, of course:-) struct vnode_attr vattr; VATTR_INIT(&vattr); VATTR_WANTED(&vattr, va_mode); err = vnode_getattr(vp, &vattr, vfs_context_current()); Don't know the answer to the others, although you can probably figure out what crypto functions are in the kernel by looking ay the above sources. (If you use anything that isn't a kpi in your kext, you'll be walking on thin ice like I do. I figure that's ok for an open source project, but probably unwize for something that might be shipped to customers. Others might elaborate on this.) Good luck with it, rick _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… You'll find Darwin quite different than FreeBSD w.r.t. this. The doc is use is the kernel sources (xnu-1228.tar.gz found under "Get the Source" on http://developer.apple.com) Look in xnu-1228/bsd/nfs/nfs_serv.c for an example. This email sent to site_archiver(a)lists.apple.com

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Re: kernel level sockets documentation
by Justin C. Walker 21 Mar '08

21 Mar '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com You can probably do best with a carefully crafted google search :-} Justin -- Justin C. Walker, Curmudgeon at Large Director Institute for the Enhancement of the Director's Income ----------- Nobody knows the trouble I've been ----------- _______________________________________________ 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: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… On Mar 21, 2008, at 08:44 , Eddy Quicksall wrote: Where can I get good documentation on the kernel level sockets? Specifically I want to use the "so" routines (sobind, soaccept, sosend, soreceive, etc). Apple's developer website (<http://developer.apple.com>) has some documentation on NKEs, as well as sample code. You may have to join (it's free) to gain access. Amit Singh's Mac OS X book might have something on the subject (<http://www.osxbook.com >), but I've not looked at it. Stevens' "TCP/IP Illustrated, V2" is a code walkthrough of an early version of the BSD socket code which can be helpful; although the code in use today is much different, the structure of the code has not changed all that much, and the basic ideas remain.. And of course, there's the defacto 100% correct documentation: the source (see above re: Apple developer site). This email sent to site_archiver(a)lists.apple.com

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kernel level sockets documentation
by Eddy Quicksall 21 Mar '08

21 Mar '08

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Accessing the mode of a directory with its vnode and other questions
by John D. 21 Mar '08

21 Mar '08

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