June 2010 - Darwin-kernel - lists.apple.com

Re: Running .kext on iPhone OS
by Kevin Van Vechten 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com This isn't the right forum for this discussion — no one here will have answers for you. This list is intended for technical discussion and any Apple engineers on the lists are here purely on a volunteer basis. Any concerns about product feature sets should be taken up directly with DTS or Apple product evangelists. Kevin On Jun 16, 2010, at 11:35 AM, Andreas Fink wrote: > to quote DTS: > >> At this time, there isn't any new information available for this issue. I have checked with engineering, and the issue is still being investigated. > > is 5 years a normal timeframe for investigations? > How long normally do implementations take? _______________________________________________ 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: Running .kext on iPhone OS
by Andreas Fink 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com to quote DTS: > At this time, there isn't any new information available for this issue. I have checked with engineering, and the issue is still being investigated. is 5 years a normal timeframe for investigations? How long normally do implementations take? _______________________________________________ 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: Process exit notifcation in a kext
by Wade Tregaskis 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com >> "Every process has a process identification number (PID) that is >> assigned according to order it was run. The first process that runs >> has a PID of 1. The second has a PID of 2 and so on. If a process dies >> or is killed, that PID is not reused. If the computer is restarted, >> the process count begins at 1 again." This is wrong and has never been true. Mac OS X, like all BSDs, will recycle unused pids after wrapping at some predefined threshold. > What I meant to say is that I read that document, but it's simply not > true that PIDs aren't reused. You can verify this easily (the upper > bound appears to be around 100,000): That is more or less correct, it is 100,000 in Leopard and Snow Leopard. Though that includes pid 0, which symbolically means the kernel, so the highest pid actually available is 99,999. In Tiger and earlier the limit was 30,001 (i.e. highest pid was 30,000). > I assume what the document means is that PIDs aren't immediately > reused when a process exits, but will be reused when the upper bound > is hit. That's an implementation detail though, and I know Terry's > mentioned before that PID randomization may happen eventually. So it's > best to consider the potential race conditions, which it sounds like > you've already been contemplating. Pid reuse has been a problem on Mac OS X, even with the 100,000 ceiling. And you can imagine that in future it may be even moreso. There is not really a good, simple substitute. If possible you should use Mach task ports, or task name ports, but those are't always an option. You need to decide if there is a security concern in your particular use, and mitigate that appropriately. I also recommend filing radars and enhancement requests around this issue. Snow Leopard introduced unique IDs for threads, which had previously suffered from the same reuse issues, and it's trivial to imagine the same mechanism for processes. You could also file an enhancement request for monitoring thread/task creation/destruction in the kernel. Such a thing would be useful to others, as well. Wade _______________________________________________ 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: Process exit notifcation in a kext
by Ronnie Misra 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com That article is obsolete; I believe it refers to Mac OS X Server 1.0, which predates Darwin: <http://en.wikipedia.org/wiki/Mac_OS_X_Server_1.0> Ronnie On Jun 16, 2010, at 5:50 AM, Bogdan Harjoc wrote: > On Wed, Jun 16, 2010 at 3:13 PM, Dave Keck <davekeck(a)gmail.com> wrote: >> I mistakenly sent my last message off-list; you might want to put your >> reply on-list for more input. >> >>> Thank you for the reply. According to [1], PIDs are not reused, so I >>> assume there's no need to worry about races with this approach. >>> >>> [1] http://support.apple.com/kb/TA44156 >> >> I'm not sure what point that document is trying to make, but PIDs are >> most certainly reused as necessary. The only PID-reuse limitation that >> I'm aware of is that a PID can't be reused until its parent process >> has reaped it (otherwise waitpid() could fail.) > > The relevant snippet is: > > "Every process has a process identification number (PID) that is > assigned according to order it was run. The first process that runs > has a PID of 1. The second has a PID of 2 and so on. If a process dies > or is killed, that PID is not reused. If the computer is restarted, > the process count begins at 1 again." > >> Perhaps you could give some details of what you're trying to accomplish? > > I am using process exit notifications to clean up the list of PIDs for > which traffic is filtered. > > Regards, > Bogdan > _______________________________________________ > 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/rgmisra%40apple.com > > This email sent to rgmisra(a)apple.com _______________________________________________ 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: Process exit notifcation in a kext
by Dave Keck 16 Jun '10

16 Jun '10

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=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type; bh=amnjzZXiWW4/ydkqjIRFY4wf96RAznEDRThSlvMhji4=; b=djCfJmYYwj0HjDBaWZCAucRDLPYBSOWQUPRL3U7Sp5P7Iu7NEdFZb8McaaZDFALWQK JUjLCe11vohf7XtF1v97mxmZScKXLPGpm49AVeQ0AxZXyZ3O4Gh+4tjVmJTp0qf/FPta qavbboWHEf7NTOsiunewXsEnAifpQI4Bm3Yyc= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=q9rSQ5AoesW4Rwfs5xuELqM7MSe0BbAt+SW2Jatza3AMH8FTsVNEMg0+3xPeJJa06p rjznxTfpNEK1NRcsErNfG9VevKVIIb8UhRqvsPVdOy1TsPMDAblEFgrfrJe8OGUU/Na3 NUsPMjsmwMcTqSY/yb7TaFucK4AgUzb1eMEXw= > The relevant snippet is: > > "Every process has a process identification number (PID) that is > assigned according to order it was run. The first process that runs > has a PID of 1. The second has a PID of 2 and so on. If a process dies > or is killed, that PID is not reused. If the computer is restarted, > the process count begins at 1 again." What I meant to say is that I read that document, but it's simply not true that PIDs aren't reused. You can verify this easily (the upper bound appears to be around 100,000): ========================= #include <stdio.h> #include <assert.h> #include <errno.h> #include <unistd.h> #include <sys/wait.h> int main() { for (;;) { if (!fork()) printf("%d\n", getpid()), _exit(0); else { int s, wr; do errno = 0, wr = wait(&s); while (wr == -1 && errno == EINTR); } } return 0; } ========================= I assume what the document means is that PIDs aren't immediately reused when a process exits, but will be reused when the upper bound is hit. That's an implementation detail though, and I know Terry's mentioned before that PID randomization may happen eventually. So it's best to consider the potential race conditions, which it sounds like you've already been contemplating. > I am using process exit notifications to clean up the list of PIDs for > which traffic is filtered. The other more knowledgeable people on this list will probably need to help here. _______________________________________________ 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: Process exit notifcation in a kext
by Bogdan Harjoc 16 Jun '10

16 Jun '10

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=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=qSIgGFOD4qUzpD07gCNhN2L/2/IIG6SIw1ukiKGZ1mE=; b=Xsbhsf2UOQIAziTAHUCbZwmLySE7uywxkLPlea7m37tbDl5ZlG9HpLrENbI7Bk9RyB cVyrE/FtgzEJUMAvQ9/o37xORGvDDPyN9Xwg8sO1QSDJb4KzjdFH3wynPp78H14pUI24 uF7WXf92QYjAiEUilRqZjVSp+akk6GW2ITEfM= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=XBrZp3dJEnXPXuXv0fccmncNhJ6aDXlUbDhXt9VJJOv0MPp3LHwPU6ATm6RqGa3q2L t27cUrNczijzM134J0hbuBAZcQIUrsnMitEVaopbLjLKwwAsGoZRbqUD1xZvxknmo7CA /bk0/pF1Bd6nD/1jRLc3L2nqg5SPmZTq8ul1g= On Wed, Jun 16, 2010 at 3:13 PM, Dave Keck <davekeck(a)gmail.com> wrote: > I mistakenly sent my last message off-list; you might want to put your > reply on-list for more input. > >> Thank you for the reply. According to [1], PIDs are not reused, so I >> assume there's no need to worry about races with this approach. >> >> [1] http://support.apple.com/kb/TA44156 > > I'm not sure what point that document is trying to make, but PIDs are > most certainly reused as necessary. The only PID-reuse limitation that > I'm aware of is that a PID can't be reused until its parent process > has reaped it (otherwise waitpid() could fail.) The relevant snippet is: "Every process has a process identification number (PID) that is assigned according to order it was run. The first process that runs has a PID of 1. The second has a PID of 2 and so on. If a process dies or is killed, that PID is not reused. If the computer is restarted, the process count begins at 1 again." > Perhaps you could give some details of what you're trying to accomplish? I am using process exit notifications to clean up the list of PIDs for which traffic is filtered. Regards, Bogdan _______________________________________________ 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: Process exit notifcation in a kext
by Dave Keck 16 Jun '10

16 Jun '10

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=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:content-type; bh=ny8Xhq+5examSeY0cZJTJnRgVNW4vVLph5WIIaBC28g=; b=iYqEW2U1IvgyRLRwzdqz+q0b9U6Skj/izbsaGDw4mBgM8csW+aIqTiksmJ5pJ9Nu2P IZEihkawFT0wa3yJemJPDKskXWGfh1Kq4g5M07eq9EQC7sFGRQzbgijLtA7wWQi67x0p Yco/MUMKxCoz6iKY7ovbdaqD3srF50sawScG0= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; b=bIP+YCKlFc0MzeK6yGKUN77/ofSZwPrVwj/jBCLynCwEi8L/oCjppdjNV7It40GV6g SVB/J9C+2yzuP6QMFo4h65Z2fA8RuI5/QmOb+nccR8DXL4/RnhqveBB+weooedBsBuGc 1OYhg3kwSkF6BJWgtfYNGB6bVsmB7GBiu07ws= kqueue/kevent is a user-level API and cannot be used from the kernel; I suggest creating a user-level daemon or agent which can access these APIs, and have it communicate with your kext via a kernel control socket (or IOUserClient if you're writing an IOKit kext.) _______________________________________________ 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: Running .kext on iPhone OS
by Andreas Fink 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On 16.06.2010, at 12:08, Michael Tüxen wrote: > On Jun 16, 2010, at 2:17 AM, Josh Graessley wrote: > >> >> On Jun 15, 2010, at 5:01 PM, Andreas Fink wrote: >> >>> >>> On 16.06.2010, at 01:38, Josh Graessley wrote: >>> >>>> >>>> On Jun 15, 2010, at 4:29 PM, Martin Hardman wrote: >>>> >>>>> Hi >>>>> >>>>> I’m trying to find out if it’s at all possible to run a .kext (specifically an NKE) on an iPhone/iPad >>>> >>>> It is not (supposed to be) possible to load a kext on any iOS device. >>> >>> which locks out SCTP again... when will Apple finally adopt it ? (as Linux, FreeBSD, Solaris, HP/UX etc etc). >>> It's multihoming feature would REALLY be useful for iPhone OS (sorry iOS but isn't that a trademark by cisco as iPhone was?) to keep sessions up between 3G and WiFi switching. >>> >>> Radar: 3800302 is one of the oldest one I know. >> >> Cellular network NATs. > Which doesn't break SCTP/UDP/IP which is supported by the SCTP NKE... and good NAT's don't break SCTP/IP neither... Remember: There's a world outside US and AT&T. That world uses such futuristic things like IPv6, 3G networks and SCTP since more than 10 years. _______________________________________________ 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: Running .kext on iPhone OS
by Michael Tüxen 16 Jun '10

16 Jun '10

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Jun 16, 2010, at 2:17 AM, Josh Graessley wrote: > > On Jun 15, 2010, at 5:01 PM, Andreas Fink wrote: > >> >> On 16.06.2010, at 01:38, Josh Graessley wrote: >> >>> >>> On Jun 15, 2010, at 4:29 PM, Martin Hardman wrote: >>> >>>> Hi >>>> >>>> I’m trying to find out if it’s at all possible to run a .kext (specifically an NKE) on an iPhone/iPad >>> >>> It is not (supposed to be) possible to load a kext on any iOS device. >> >> which locks out SCTP again... when will Apple finally adopt it ? (as Linux, FreeBSD, Solaris, HP/UX etc etc). >> It's multihoming feature would REALLY be useful for iPhone OS (sorry iOS but isn't that a trademark by cisco as iPhone was?) to keep sessions up between 3G and WiFi switching. >> >> Radar: 3800302 is one of the oldest one I know. > > Cellular network NATs. Which doesn't break SCTP/UDP/IP which is supported by the SCTP NKE... Best regards Michael > > 'nuff said. > > -josh > > _______________________________________________ > 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/michael.tuexen%40lurch… > > This email sent to michael.tuexen(a)lurchi.franken.de > _______________________________________________ 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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Process exit notifcation in a kext
by Bogdan Harjoc 16 Jun '10

16 Jun '10

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=gamma; h=domainkey-signature:mime-version:received:received:date:message-id :subject:from:to:content-type; bh=O+GRbGaVRNYhXA7+sQSfNewAx+sjDgzFtgUtEvvsvWY=; b=x+MmeT68HQCt4s5Vk7iFRVJwCtzVIc/slgn3bzsBTkThrZIgPFyW8VxIAomp4hHOau wFhYnrzlnXmO4DntK1AQwy1CAnCINNsgeu8w6BC81goqd9UF5PHf4VUrzSwOWm2Zuxdo B31TuKAl1ypEGjcbSQH3iw10hehS2Id6UTsM8= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=csycOIoNH+JPLDMecOUdA8UkDFHQtnHWf8jLZ2+NPJk4fyF5YYLYgs1pMeTMgwaAlT 8gkuR9dH+S1RBiW6gBi7L+uymvLEIsaoLkiJP7cZUAI81gHWIfUFVL+jD1tqqa9t8Ibh vfEEbH5wNg/YNFCcNxkuutG7jCB1kkcCo5YRQ= Hello, I'm writing a kext that monitors processes based on their network traffic. One of the events I have to monitor is "process has exited". Kqueue offers a nice uniform way of doing this, but I don't see how it can be called from kernel code. My question is if kqueue can deliver events to a kext, or at least if one can start a kernel thread just for the purpose of waiting for events by calling kevent(). Regards, Bogdan Harjoc _______________________________________________ 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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