April 2004 - Darwin-kernel - lists.apple.com

Re: Directories appearing as volume aliases in 10.3 Finder
by Sam Vaughan 07 Apr '04

07 Apr '04

I checked the fields we return from stat/lstat on a directory and they look OK when compared to HFS+. I then compared getdirentries output and suddenly remembered that we return a type of DT_UNKNOWN for everything. The reason for this is that we simply don't know what type the items are in vop_readdir. (IRIX doesn't have a type field in its dirent struct, Solaris doesn't either I'm told) A quick grep on xnu for DT_UNKNOWN shows that we're not the only ones doing this. See bsd/isofs/cd9660/cd9660_vnops.c for a good example. Running a ktrace on the Finder shows that it's doing lstats on the items in the directory after it does a getdirentries call, so you'd think it could correctly work out what the unknown items are. Presumably that's what Jaguar did because we had no issues there. For a laugh I tried returning DT_DIR for everything but quickly panicked due to a locking issue. I then tried DT_REG and sure enough all the dirs appeared in the Finder as files. So from this I'm concluding that the 10.3 Finder is more interested in the d_type field in the dirent than checking whether the S_IFDIR/S_ISDIR bit is set in the st_mode field of the stat structure. Any ideas on workarounds for this would be terrific! Thanks, Sam On 07/04/2004, at 9:39 AM, Sam Vaughan wrote: The 10.3 Finder is displaying directories in our file systems as aliases to network volumes. _______________________________________________ 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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Directories appearing as volume aliases in 10.3 Finder
by Sam Vaughan 06 Apr '04

06 Apr '04

The 10.3 Finder is displaying directories in our file systems as aliases to network volumes. I was wondering if anyone with access to the source code could give me a clue about why this might be happening. Presumably our vop_getattr needs some attention, or maybe it's finally time to implement vop_getattrlist. The directories are given the same globe-in-a-glass-box icon as network volumes, with a little alias arrow at the bottom left. Double clicking on one raises a dialog box with the message: The volume for "foo" cannot be found. Insert the volume for "foo" and wait for it to appear on the desktop, then try again. The directories are also displayed in this way in Open/Save dialog boxes, but they appear and work as normal in the Terminal. The same code gives regular folder icons on 10.2. Does anyone know what fields the 10.3 Finder looks in to decide it's working with network volume aliases? Thanks, Sam _______________________________________________ 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: any info on next-gen firewall (ipfw2)?
by OpenMacNews 06 Apr '04

06 Apr '04

great to hear! it'll make gateway migration to OSX from *BSD (e.g.) a bit less painful ... can you comment re: whether as built-in the kernel, or as an extension? the former (maybe?) probably has some performance advantages, but the latter could allow for the inclusion/addition of "pf" as well. i've read strong arguments on the lists for both pkgs ... thx, richard We are aware that the firewall is falling behind. We are looking at ipfw2. -josh On Apr 5, 2004, at 8:43 AM, OpenMacNews wrote: hi, can anyone provide any insight as to if/when Darwin will update its currently integrated firewall, ipfw, to a 'current' version/product --- say ipfw2, pf, etc.? or, is there an existing non-kernel port of any of them? FreeBSD has available both kernel builds and ports, but i've found nothing for OSX ... thanks, richard _______________________________________________ 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: NKE filter
by Joshua Graessley 06 Apr '04

06 Apr '04

This is possible but not easy. I think the easiest solution might be to have a userland process with an open socket. When the user attempts to connect, you could change the address their connecting to to the address your socket is listening on. Your socket would the receive the connect and the data, you could respond accordingly. If you won't know until after the connection has occurred, things get a little trickier. One solution might be to always change the connection so the socket connects to the local userland process instead of the server it's attempting to connect to. You could probably communicate the address the client was attempting to connect to and act as a proxy, opening a connection from your userland process and then forwarding the data in both directions. When you detect something you don't like, don't forward the data from the server, forward the data from your file instead. Either way, it will involve fragile code that will break with future releases of the operating system. -josh On Apr 5, 2004, at 5:41 PM, Matt Jaffa wrote: > Hi, > > I was wondering if it is possible to somehow make the current web > browsers page > go to a file stored on the HD. > > K, here is the explaination, > I have a NKE that is filtering at the socket level, If my app > determines that they are > not allowed to access that web page, I would like the web browser that > made the request > to redirect to either a local web page (prefered) or to a remote web > page. > > 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. [demime 0.98b removed an attachment of type application/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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Re: any info on next-gen firewall (ipfw2)?
by Joshua Graessley 06 Apr '04

06 Apr '04

We are aware that the firewall is falling behind. We are looking at ipfw2. -josh On Apr 5, 2004, at 8:43 AM, OpenMacNews wrote: > hi, > > can anyone provide any insight as to if/when Darwin will update its > currently integrated firewall, ipfw, to a 'current' version/product > --- say ipfw2, pf, etc.? > > or, is there an existing non-kernel port of any of them? FreeBSD has > available both kernel builds and ports, but i've found nothing for OSX > ... > > thanks, > > richard > _______________________________________________ > 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/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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Re: TCP packet interception in Mac
by Michael Cashwell 06 Apr '04

06 Apr '04

On Apr 6, 2004, at 2:52 AM, manju dogra wrote: I am a total newbie to Mac kernel and drivers. i want to develop a module which can intercept TCP packets before they reach the TCP stack and send its own modified packets to the stack. Similarly, for packets going towards the network, the packets need to be intercepted and replaced by modified packets. Could anyone help me on how to get started on this ?? Thanks Ashish A good description of the different kinds of filter NKEs can be found here: http://developer.apple.com/documentation/Darwin/Conceptual/ KernelProgramming/Networking/chapter_13_section_3.html#//apple_ref/doc/ uid/TP30000905-CH216-TPXREF102 Which I found via a search for "NKE" at Apple's Developer site (http://developer.apple.com/) I know there was some sample code related to this somewhere. (I developed an interface NKE and recall finding something that helped get things going.) I don't know if it was on Apple's site but I can't find it there now. I'll check my notes at home and if I can come up with anything useful I'll sent a link to you later. Best regards, Mike _______________________________________________ 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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TCP packet interception in Mac
by manju dogra 06 Apr '04

06 Apr '04

Hi all, I am a total newbie to Mac kernel and drivers. i want to develop a module which can intercept TCP packets before they reach the TCP stack and send its own modified packets to the stack. Similarly, for packets going towards the network, the packets need to be intercepted and replaced by modified packets. Could anyone help me on how to get started on this ?? Thanks Ashish Yahoo! Finance Tax Center - File online. File on time. _______________________________________________ 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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NKE filter
by Matt Jaffa 06 Apr '04

06 Apr '04

Hi, I was wondering if it is possible to somehow make the current web browsers page go to a file stored on the HD. K, here is the explaination, I have a NKE that is filtering at the socket level, If my app determines that they are not allowed to access that web page, I would like the web browser that made the request to redirect to either a local web page (prefered) or to a remote web page. 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.

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Supporting RFC 2395 (LZS compression for IPcomp)
by Alastair Rankine 05 Apr '04

05 Apr '04

Not sure if this is the right forum for this question... The goal is to support VPN connections using RFC 2395 (LZS compression for IPcomp). Certain VSUs are configured to compress outbound traffic using this protocol. By default, darwin (and other KAME-based IPsec implementations) do not support this protocol. Unfortunately LZS compression is patent encumbered. From the RFC: Hi/fn, Inc. holds patents on the LZS algorithm. Licenses for a reference implementation are available for use in IPPCP, IPSec, TLS and PPP applications at no cost. Source and object licenses are available on a non-discriminatory basis. My reading of this says that including an implementation of LZS compression into the darwin IPsec stack would require Apple to license it from Hi/fn. Does anyone want to comment on the likelihood of this? There may be another way however - I have heard that the linux folks are moving towards extensibility in their kernel for cases such as this. In particular, they are allowing additional compression/encryption/digest algorithms to be loaded dynamically into the kernel. This decouples the kernel from licensing restrictions for such algorithms. I understand that the changes required are quite limited in scope. In order to add LZS compression, we simply need to modify the ipcomp_algorithm struct within ipcomp_core.c with pointers to the correct compression/decompression functions. Unfortunately this seems to require a kernel rebuild. How difficult would it be to allow this struct (and possibly it's equivalents in the other *_core.c modules) to be extended at runtime? _______________________________________________ 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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any info on next-gen firewall (ipfw2)?
by OpenMacNews 05 Apr '04

05 Apr '04

hi, can anyone provide any insight as to if/when Darwin will update its currently integrated firewall, ipfw, to a 'current' version/product --- say ipfw2, pf, etc.? or, is there an existing non-kernel port of any of them? FreeBSD has available both kernel builds and ports, but i've found nothing for OSX ... thanks, richard _______________________________________________ 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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