[ net-snmp-Bugs-2980122 ] build_oid_segment reverses IP address bytes

[SourceForge.net <no...@so...>]

Bugs item #2980122, was opened at 2010-03-31 10:37
Message generated for change (Comment added) made by bishdogg
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=112694&aid=2980122&group_id=12694

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: library
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Darrell Bishop (bishdogg)
Assigned to: Nobody/Anonymous (nobody)
Summary: build_oid_segment reverses IP address bytes

Initial Comment:
(This probably only affects platforms where host byte order differs from network byte order, eg. Intel)
While dealing with a table having an IP address in the index, I noticed the index getting reversed.  I eventually isolated the problem:

parse_one_oid_index() reads 4 sub-identifiers from an (index) OID, building a numeric representation (in the unsigned int "uitmp").  It then converts that to network byte-order using htonl() and copies the 4 bytes yielding 4 correct bytes in var->val.string[0..3].

However, build_oid_segment treats var->val.integer (cast to an unsigned int) numerically to extract each byte value.  This part of build_oid_segment() needs to perform the inverse of the htonl() performed in parse_one_oid_index (i.e. ntohl()).  The attached patch fixed the issue for me, but someone with a larger perspective needs to make sure other net-snmp wasn't working around this bug (and would thus become broken by fixing this bug).

----------------------------------------------------------------------

>Comment By: Darrell Bishop (bishdogg)
Date: 2010-03-31 10:38

Message:
Arg, sorry, forgot to include net-snmp version: it was found and fixed (see
patch) in net-snmp 5.5.

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=112694&aid=2980122&group_id=12694