https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=2706
Jeff Morriss <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |[email protected] --- Comment #5 from Jeff Morriss <[email protected]> 2010-10-15 11:25:21 PDT --- (In reply to comment #3) > Created an attachment (id=5298) --> (https://bugs.wireshark.org/bugzilla/attachment.cgi?id=5298) [details] > Patch that excludes pattern type from length for TEST_TLV. > > (In reply to comment #2) > > Can you point us to the documentation where you found the recommendation to > > *not* include the pattern type field in the field length? > > I think he is right. Refer to section 9.3 LBM PDU of > http://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-Y.1731-200802-I!!PDF-E&type=items. > > In particular, from 9.3-4: "Length: Identifies size, in octets, of the Value > field containing the test pattern and CRC-32." > > Note that it does NOT state, "... of the Value field containing the pattern > type, test pattern and CRC-32." Hmmm, I think I'd disagree. If you look at figure 9.1-2, it shows that they are setting up a basic TLV message with a 1-octet Tag, a 2-octet Length, and variable-length Value. 9.3.2 goes on to say what you quoted above, but to me the Value is the Value part of the whole TLV structure; the "pattern type" is part of the Value field for this particular message. I can see the ambiguity the original author talks about because "containing the test pattern" could theoretically mean "containing only the pattern but not the 1-octet pattern type selector" but TLV encodings don't normally work that way. (In other words: why make the length different different for this message type only?) The Length definition goes on to say (emphasis mine) "In a frame where the PDU is limited to 1492 octets, the maximum length value is 1480 octets (since 12 bytes are required for 8 octets of LBM PDU overhead, *3* *octets* *of* *Test* *TLV* *overhead*, and 1 octet of end TLV)." -- Configure bugmail: https://bugs.wireshark.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. ___________________________________________________________________________ Sent via: Wireshark-bugs mailing list <[email protected]> Archives: http://www.wireshark.org/lists/wireshark-bugs Unsubscribe: https://wireshark.org/mailman/options/wireshark-bugs mailto:[email protected]?subject=unsubscribe
