Wireshark mailing list archives

Re: Compilation error Red Hat 3.4.3-9.EL4


From: Jakub Zawadzki <darkjames-ws () darkjames pl>
Date: Fri, 29 Apr 2011 13:36:45 +0200

On Fri, Apr 29, 2011 at 12:55:34AM -0700, Guy Harris wrote:
On Apr 29, 2011, at 12:52 AM, Jakub Zawadzki wrote:

Actually we still can do transparent access, but only when BLOCK is not inside
middle of byte.

Does that mean "we can still do fast random access to all gzipped files, but we have to change the way we choose when 
to start a new block", or does it mean "we can't do fast random access to some gzipped files"?

Sorry, don't know.

In *one* pcap file (ratio: 1.187):
  I have 2346 blocks (avg. every 37KB) from which 268 (avg. every 330KB) has bits=0.
  330 KB is still below SPAN constant (1MiB).
  (I can send C program to calculate these values for given gzip file)

But honestly, I don't care, if someone need it he can:
 1/ update zlib.
 2/ Write his own compressor and pass to deflate(..., flush):
     a/ Z_FINISH (and write new gzip header -- wiretap will always make a fast seek point).
                      And random access will work also without inflateSetDictionary.
     b/ Z_FULL_FLUSH, Z_SYNC_FLUSH (which should align block to byte boundary) every N bytes like he want (but N >= 
SPAN)
                  By using Z_FULL_FLUSH it should also be possible to
                  have random access without inflateSetDictionary.

Note that we also use inflateSetDictionary(), which appears to have been added in 1.2.2.1 (31 October 2004).

I'm aware, should I commit patch for it? (or wait when wiretap fails to build to someone?)

Btw. from zlib page:
  Version 1.2.3 (July 2005) eliminates potential security vulnerabilities in zlib 1.2.1 and 1.2.2, so all users of 
those versions should ***upgrade immediately***

So maybe it's good (read: safer for user) if wireshark fails to build with zlib support? :-)
___________________________________________________________________________
Sent via:    Wireshark-dev mailing list <wireshark-dev () wireshark org>
Archives:    http://www.wireshark.org/lists/wireshark-dev
Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev
             mailto:wireshark-dev-request () wireshark org?subject=unsubscribe


Current thread: