Re: openg and path_to_handle

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From: Andreas Dilger
Date: Wednesday, December 6, 2006 - 3:09 pm

On Dec 06, 2006  13:50 -0700, Matthew Wilcox wrote:

If the server has to have processed a real "open" request, say within
the preceding 30s, then it would have a handle for openfh() to match
against.  If the server reboots, or a client tries to construct a new
handle from scratch, or even tries to use the handle after the file is
closed then the handle would be invalid.

It isn't just an encoding for "open-by-inum", but rather a handle that
references some just-created open file handle on the server.  That the
handle might contain the UID/GID is mostly irrelevant - either the
process + network is trusted to pass the handle around without snooping,
or a malicious client which intercepts the handle can spoof the UID/GID
just as easily.  Make the handle sufficiently large to avoid guessing
and it is "secure enough" until the whole filesystem is using kerberos
to avoid any number of other client/user spoofing attacks.

Considering that filesystems like GFS and OCFS allow clients DIRECT
ACCESS to the block device itself (which no amount of authentication
will fix, unless it is in the disks themselves), the risk of passing a
file handle around is pretty minimal.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

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Messages in current thread:
NFSv4/pNFS possible POSIX I/O API standards, Gary Grider, (Mon Nov 27, 9:34 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Mon Nov 27, 10:54 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Tue Nov 28, 3:54 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Anton Altaparmakov, (Tue Nov 28, 4:28 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Tue Nov 28, 8:08 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Russell Cattelan, (Tue Nov 28, 1:17 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Wendy Cheng, (Tue Nov 28, 4:28 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Brad Boyer, (Wed Nov 29, 1:26 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Wed Nov 29, 2:04 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Wed Nov 29, 2:12 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Wed Nov 29, 2:14 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Wed Nov 29, 2:48 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Anton Altaparmakov, (Wed Nov 29, 3:18 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Steven Whitehouse, (Wed Nov 29, 3:25 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Wed Nov 29, 5:23 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Wed Nov 29, 5:35 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Wed Nov 29, 5:39 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Gary Grider, (Wed Nov 29, 9:26 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Wed Nov 29, 10:18 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Thu Nov 30, 2:25 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Thu Nov 30, 5:29 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Thu Nov 30, 10:49 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Thu Nov 30, 10:26 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Fri Dec 1, 12:08 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Fri Dec 1, 7:41 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ric Wheeler, (Fri Dec 1, 8:52 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Fri Dec 1, 9:47 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Fri Dec 1, 11:07 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Fri Dec 1, 11:42 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Fri Dec 1, 12:13 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Fri Dec 1, 1:32 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Fri Dec 1, 3:29 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Latchesar Ionkov, (Fri Dec 1, 7:35 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Sat Dec 2, 6:52 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Sat Dec 2, 6:57 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Sun Dec 3, 9:10 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Mon Dec 4, 12:32 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Mon Dec 4, 8:15 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Peter Staubach, (Mon Dec 4, 11:02 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Mon Dec 4, 5:37 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Mon Dec 4, 5:59 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Gary Grider, (Mon Dec 4, 9:44 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Mon Dec 4, 10:56 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Tue Dec 5, 3:02 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Tue Dec 5, 3:05 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Tue Dec 5, 3:07 am)
Re: readdirplus() as possible POSIX I/O API, Andreas Dilger, (Tue Dec 5, 3:26 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Tue Dec 5, 7:20 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Peter Staubach, (Tue Dec 5, 7:37 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Tue Dec 5, 7:55 am)
Re: readdirplus() as possible POSIX I/O API, Trond Myklebust, (Tue Dec 5, 8:23 am)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Latchesar Ionkov, (Tue Dec 5, 9:47 am)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Latchesar Ionkov, (Tue Dec 5, 9:55 am)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Tue Dec 5, 10:01 am)
Re: Re: readdirplus() as possible POSIX I/O API, Latchesar Ionkov, (Tue Dec 5, 10:06 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Tue Dec 5, 2:44 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Peter Staubach, (Tue Dec 5, 2:50 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Tue Dec 5, 2:50 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Tue Dec 5, 3:05 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Tue Dec 5, 3:11 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Christoph Hellwig, (Tue Dec 5, 3:12 pm)
Re: readdirplus() as possible POSIX I/O API, Rob Ross, (Tue Dec 5, 3:48 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Sage Weil, (Tue Dec 5, 4:18 pm)
Re: readdirplus() as possible POSIX I/O API, Sage Weil, (Tue Dec 5, 4:20 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Tue Dec 5, 4:24 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Tue Dec 5, 4:55 pm)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, David Chinner, (Wed Dec 6, 2:48 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Wed Dec 6, 3:06 am)
Re: readdirplus() as possible POSIX I/O API, Andreas Dilger, (Wed Dec 6, 3:28 am)
openg, Christoph Hellwig, (Wed Dec 6, 4:01 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Wed Dec 6, 8:04 am)
Re: readdirplus() as possible POSIX I/O API, Trond Myklebust, (Wed Dec 6, 8:10 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Wed Dec 6, 8:14 am)
Re: openg, Trond Myklebust, (Wed Dec 6, 8:41 am)
Re: openg, Rob Ross, (Wed Dec 6, 8:42 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Wed Dec 6, 8:44 am)
Re: readdirplus() as possible POSIX I/O API, Peter Staubach, (Wed Dec 6, 8:48 am)
openg and path_to_handle, Rob Ross, (Wed Dec 6, 8:53 am)
Re: openg and path_to_handle, Matthew Wilcox, (Wed Dec 6, 9:04 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Wed Dec 6, 9:15 am)
Re: openg and path_to_handle, Rob Ross, (Wed Dec 6, 9:20 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Wed Dec 6, 9:42 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Wed Dec 6, 10:19 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Rob Ross, (Wed Dec 6, 10:27 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Wed Dec 6, 10:42 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ragnar , (Wed Dec 6, 11:01 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Wed Dec 6, 11:13 am)
Re: openg and path_to_handle, David Chinner, (Wed Dec 6, 1:40 pm)
Re: openg and path_to_handle, Matthew Wilcox, (Wed Dec 6, 1:50 pm)
Re: openg and path_to_handle, Rob Ross, (Wed Dec 6, 1:50 pm)
Re: openg and path_to_handle, David Chinner, (Wed Dec 6, 1:57 pm)
Re: openg and path_to_handle, David Chinner, (Wed Dec 6, 2:01 pm)
Re: openg and path_to_handle, David Chinner, (Wed Dec 6, 2:09 pm)
Re: openg and path_to_handle, Andreas Dilger, (Wed Dec 6, 3:09 pm)
Re: openg and path_to_handle, Matthew Wilcox, (Wed Dec 6, 3:17 pm)
Re: openg and path_to_handle, Andreas Dilger, (Wed Dec 6, 3:41 pm)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Latchesar Ionkov, (Wed Dec 6, 4:12 pm)
Re: openg and path_to_handle, Latchesar Ionkov, (Wed Dec 6, 4:19 pm)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Latchesar Ionkov, (Wed Dec 6, 4:25 pm)
Re: openg, Christoph Hellwig, (Wed Dec 6, 4:32 pm)
Re: Re: NFSv4/pNFS possible POSIX I/O API standards, Trond Myklebust, (Wed Dec 6, 4:33 pm)
Re: openg and path_to_handle, Christoph Hellwig, (Wed Dec 6, 4:39 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Wed Dec 6, 10:57 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Nikita Danilov, (Thu Dec 7, 4:39 pm)
Re: openg and path_to_handle, Rob Ross, (Thu Dec 14, 2:00 pm)
Re: openg and path_to_handle, Matthew Wilcox, (Thu Dec 14, 2:20 pm)
Re: openg and path_to_handle, Rob Ross, (Thu Dec 14, 3:52 pm)
Re: openg and path_to_handle, Rob Ross, (Thu Dec 14, 4:02 pm)
Re: openg, Rob Ross, (Thu Dec 14, 4:36 pm)
statlite(), Rob Ross, (Thu Dec 14, 4:58 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Fri Dec 15, 3:37 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Andreas Dilger, (Sat Dec 16, 11:13 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Sat Dec 16, 12:08 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ragnar , (Sun Dec 17, 7:41 am)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Sun Dec 17, 12:07 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Matthew Wilcox, (Sun Dec 17, 12:38 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ulrich Drepper, (Sun Dec 17, 2:51 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Ragnar , (Sun Dec 17, 7:57 pm)
Re: NFSv4/pNFS possible POSIX I/O API standards, Gary Grider, (Sun Dec 17, 8:54 pm)