July 2002 - Darwin-kernel - lists.apple.com

Re: More Dummynet
by Justin C. Walker 17 Jul '02

17 Jul '02

On Tuesday, July 16, 2002, at 07:34 PM, Ryan Stinnett wrote: Sorry for missing the post last week, I wasn't trying to waste your time. I'm really interested in trying to get Dummynet to work. Is there any chance you could give me an idea of what needs to be done? As you said, I've tried adding an option for Dummynet to the MASTER file (along with trying to manually define it), but there's definitely more work left. Thanks for your help! The main issue, I believe, in getting dummynet to work is to rewrite its interface with the rest of the kernel to conform to what's called DLIL (the Data Link Interface layer). It's documented, after a fashion and in a somewhat out-of-date form, in the file file://Developer/Documentation/Darwin/Extensions/NKE.pdf. I'd start there, and also look at if_ethersubr.c in the FreeBSD and Darwin kernels to get a feel for what the differences are. That said, it's a significant task. If you undertake it, it will make you stronger :-}. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | It's not whether you win or lose... | It's whether *I* win or lose. *--------------------------------------*-------------------------------* _______________________________________________ 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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More Dummynet
by Ryan Stinnett 17 Jul '02

17 Jul '02

Sorry for missing the post last week, I wasn't trying to waste your time. I'm really interested in trying to get Dummynet to work. Is there any chance you could give me an idea of what needs to be done? As you said, I've tried adding an option for Dummynet to the MASTER file (along with trying to manually define it), but there's definitely more work left. Thanks for your help! -Ryan Stinnett _______________________________________________ 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: Enabling Dummynet in IPFirewall
by Justin C. Walker 15 Jul '02

15 Jul '02

On Monday, July 15, 2002, at 03:11 PM, Ryan Stinnett wrote: I'm trying to enable Dummynet in IPFirewall. I'm pretty new to Darwin, so I may be missing something simple. I downloaded the source for the IPFirewall kernel extension, added a define for Dummynet (I saw ifdefs that were checking for Dummynet, so I thought that defining it would fix the problem), and I recompiled the IPFirewall kext. I then replaced the one in /System/Library/Extensions with the one I just made. I didn't really see how to dynamically unload the old one and load up the new one, so I just rebooted. However, Dummynet is still disabled. What did I miss? Thanks! The only thing you missed is that dummynet support is illusory. The #ifdefs in the code are there to simplify life when pulling in updates from FreeBSD (i.e., we'd like as few diffs as possible). In order for dummynet support to work in the firewall (ipfw), there's a fair amount of work to get the kernel portion of the functionality to work. It's not just a simple "define and compile" exercise. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | Men are from Earth. | Women are from Earth. | Deal with it. *--------------------------------------*-------------------------------* _______________________________________________ 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: Enabling Dummynet in IPFirewall
by Eugenio Jarosiewicz 15 Jul '02

15 Jul '02

read the archives from last week ;-) -ej From: Joshua Graessley <jgraessley(a)apple.com> Date: Tue Jul 9, 2002 10:09:18 AM US/Pacific To: darwin-kernel(a)lists.apple.com Subject: Re: IPFirewall.ktext HELP Some of these options may require that the kernel be recompiled as well. For example, dummynet support requires changes to the kernel as well as the IPFirewall kext. -josh On Tuesday, July 9, 2002, at 12:16 AM, Justin C. Walker wrote: On Monday, July 8, 2002, at 08:23 PM, Alberto wrote: Please, I have to do some changes in IPFW and for others UNIXs I should recompile my kernel and add: options NETGRAPH options NETGRAPH_PPPOE options NETGRAPH_SOCKET options NETGRAPH_IFACE options IPFIREWALL options IPFIREWALL_DEFAULT_TO_ACCEPT options IPFIREWALL_VERBOSE options IPFIREWALL_FORWARD options IPDIVERT options BRIDGE options DUMMYNET What exactly I need to do? On Monday, July 15, 2002, at 03:11 PM, Ryan Stinnett wrote: I'm trying to enable Dummynet in IPFirewall. I'm pretty new to Darwin, so I may be missing something simple. I downloaded the source for the IPFirewall kernel extension, added a define for Dummynet (I saw ifdefs that were checking for Dummynet, so I thought that defining it would fix the problem), and I recompiled the IPFirewall kext. I then replaced the one in /System/Library/Extensions with the one I just made. I didn't really see how to dynamically unload the old one and load up the new one, so I just rebooted. However, Dummynet is still disabled. What did I miss? Thanks! -Ryan Stinnett _______________________________________________ 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: Enabling Dummynet in IPFirewall
by Joshua Graessley 15 Jul '02

15 Jul '02

In order to enable Dummynet, the kernel has to be recompiled with that option as well. D'oh. -josh On Monday, July 15, 2002, at 03:11 PM, Ryan Stinnett wrote: I'm trying to enable Dummynet in IPFirewall. I'm pretty new to Darwin, so I may be missing something simple. I downloaded the source for the IPFirewall kernel extension, added a define for Dummynet (I saw ifdefs that were checking for Dummynet, so I thought that defining it would fix the problem), and I recompiled the IPFirewall kext. I then replaced the one in /System/Library/Extensions with the one I just made. I didn't really see how to dynamically unload the old one and load up the new one, so I just rebooted. However, Dummynet is still disabled. What did I miss? Thanks! -Ryan Stinnett _______________________________________________ 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. _______________________________________________ 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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Enabling Dummynet in IPFirewall
by Ryan Stinnett 15 Jul '02

15 Jul '02

I'm trying to enable Dummynet in IPFirewall. I'm pretty new to Darwin, so I may be missing something simple. I downloaded the source for the IPFirewall kernel extension, added a define for Dummynet (I saw ifdefs that were checking for Dummynet, so I thought that defining it would fix the problem), and I recompiled the IPFirewall kext. I then replaced the one in /System/Library/Extensions with the one I just made. I didn't really see how to dynamically unload the old one and load up the new one, so I just rebooted. However, Dummynet is still disabled. What did I miss? Thanks! -Ryan Stinnett _______________________________________________ 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: mmap
by Umesh Vaishampayan 13 Jul '02

13 Jul '02

On Tuesday, July 9, 2002, at 04:10 PM, Louis Demers wrote: At 12:27 -0400 2002.07.09, Jim Magee wrote: On Tuesday, July 9, 2002, at 12:32 AM, Louis Demers wrote: trying to port inn news server 2.3.3 to osx and the standard distribution seems to have problems with a mmap call. A static data is mmap to a file and then porperly written (I dumped all 130180 bytes to a file and it's ok) but when unmapped, the file reverts to all zeros. I checked and the file descriptor is opened with O_RDWR, the mmap is done with PROT_WRITE|PROT_READ. Did you set the MAP_SHARED flag? GROUPheader = mmap(0, 131080, flag, MAP_SHARED, GROUPfd, 0) and the file descriptor GROUPfd was opened O_RDWR | O_CREAT. How large was the file when you mapped it, Initially the file doesn't exist sot it is created with 0 bytes. and how much of it did you map? I imagine that the call to mmap mapped all 131080 and extended the file. mmap() does not extend a file. You have to use truncate()/ftruncate() or write()/pwrite() to extend the file. See <http://www.opengroup.org/onlinepubs/007904975/toc.htm> For SUSV3 spec for mmap() "If the size of the mapped file changes after the call to mmap() as a result of some other operation on the mapped file, the effect of references to portions of the mapped region that correspond to added or removed portions of the file is unspecified." "The system shall always zero-fill any partial page at the end of an object. Further, the system shall never write out any modified portions of the last page of an object which are beyond its end." "[ENXIO] Addresses in the range [off,off+len) are invalid for the object specified by fildes." So your mmap(0, 131080, flag, MAP_SHARED, GROUPfd, 0), should have failed for the 0 sized file. However it also allows the implementation to not treat the request as "invalid" provided that: "The mmap() function can be used to map a region of memory that is larger than the current size of the object. Memory access within the mapping but beyond the current end of the underlying objects may result in SIGBUS signals being sent to the process. The reason for this is that the size of the object can be manipulated by other processes and can change at any moment. The implementation should tell the application that a memory reference is outside the object where this can be detected; otherwise, written data may be lost and read data may not reflect actual data in the object." So your store to memory should have generated a SIGBUS.... [Please file a bug]. If you read further: "Note that references beyond the end of the object do not extend the object as the new end cannot be determined precisely by most virtual memory hardware. Instead, the size can be directly manipulated by ftruncate()." Hope this helps, --Umesh -- Umesh Vaishampayan Apple Computer, Inc. Mac OS X Kernel Ph: (408) 974 0229 _______________________________________________ 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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Wanting to globally receive events in an app.
by Walter Horat 11 Jul '02

11 Jul '02

Greetings- This seemed like the most appropriate place to post. Some background: We have a carbon application that has a need to receive on a system-wide basis: Mouse moved and mouse down events. Using the carbon APIs is no good; hooking an event handler to receive mouse moved events fails when a) the mouse is down in a control and b) when your app. is in the background. It is even worse to globally receive the state of the button, in both cases you have to resort to polling and for mouse down events you have to make sure your frequency of polling is 2x the speed of a fast user click or you miss clicks. Can we solve this problem by writing some sort of 'kext' (or something!) that globally hooks event processing and lets our application have a path to receive this information? TIA for any suggestions, advice, pointers to same. Walter Horat Senior Software Engineer WebEx Communications, Inc. http://www.webex.com/ "We've got to start meeting like this!" ----- _______________________________________________ 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: mmap SOLVED (Ithink)
by Louis Demers 10 Jul '02

10 Jul '02

At 19:10 -0400 2002.07.09, Louis Demers wrote: At 12:27 -0400 2002.07.09, Jim Magee wrote: On Tuesday, July 9, 2002, at 12:32 AM, Louis Demers wrote: trying to port inn news server 2.3.3 to osx and the standard distribution seems to have problems with a mmap call. A static data is mmap to a file and then porperly written (I dumped all 130180 bytes to a file and it's ok) but when unmapped, the file reverts to all zeros. I checked and the file descriptor is opened with O_RDWR, the mmap is done with PROT_WRITE|PROT_READ. Did you msync() your changes or just munmap()? I tried msync() at various points before and after the close (GROUPfd) but always before the munmap. well, when I tried msync, I passed 0 as the length, interpreting the documentation as meaning that it would sync everything needed. Wrong. I now pass explicitly the length and it seems to write the modification to disk correctly. >From the number of systems on which this code worked, I wonder if the OSX behaviour should not be revised. shouldn't munmap sync before unmapping. It is as if we were required to call fflush before fclose to make sure our writes are comitted to the file ! Cheers. -- Louis Demers ing. LouisDemers(a)mac.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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Re: mmap
by Louis Demers 09 Jul '02

09 Jul '02

At 19:10 -0400 2002.07.09, Louis Demers wrote: At 12:27 -0400 2002.07.09, Jim Magee wrote: On Tuesday, July 9, 2002, at 12:32 AM, Louis Demers wrote: How large was the file when you mapped it, Initially the file doesn't exist sot it is created with 0 bytes. by single stepping and examining the code, if the file is detected to be too small, it is expanded to the correct size (with ftruncate) and then only is it mapped with mmap! -- Louis Demers ing. LouisDemers(a)mac.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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