Bug 992

Summary:	Unusual (possibly incorrect assertion) in Packet::Deserialize
Product:	ns-3	Reporter:	Quincy Tse <quincy.tse>
Component:	core	Assignee:	Mathieu Lacage <mathieu.lacage>
Status:	RESOLVED FIXED
Severity:	minor	CC:	jpelkey, ns-bugs
Priority:	P5
Version:	ns-3-dev
Hardware:	All
OS:	All
Attachments:	Proposed patch Proposed patch.

Description Quincy Tse 2010-09-16 00:10:29 EDT

../src/common/packet.cc:738:3: error: comparison of unsigned
      expression >= 0 is always true [-Wtautological-compare]

Same warning was also triggered in lines 767 and 787.

In Packet::Deserialize, size is uint32_t, thus always >=0 (NS_ASSERT line does not detect the buffer overflow).

Maybe the NS_ASSERTs should be something like the following?

== NS_ASSERT (size >= nixSize);
== NS_ASSERT (size >= metaSize);
== NS_ASSERT (size >= bufSize);

Comment 1 Quincy Tse 2010-09-16 00:13:32 EDT

Created attachment 973 [details]
Proposed patch

Comment 2 Quincy Tse 2010-09-16 00:14:38 EDT

Created attachment 974 [details]
Proposed patch.

Comment 3 Josh Pelkey 2010-09-29 17:22:51 EDT

(In reply to comment #2)
> Created an attachment (id=974) [details]
> Proposed patch.

You are right, and the patch is right.  I have applied: changeset 6d5c1c19bdfe

Thanks.