K 10
svn:author
V 8
lstewart
K 8
svn:date
V 27
2011-02-01T13:32:27.913465Z
K 7
svn:log
V 839
Algorithm modules can define their own private congestion signal types in the
top 8 bits of the 32 bit signal bit field space for internal use. These private
signals should not be leaked outside of a module.

Given that many algorithm modules use the NewReno hook functions to simplify
their implementation, the obvious place such a leak would show up is in the
NewReno cong_signal hook function.

- Show the full number of significant bits in the signal type definitions in
  <netinet/cc.h>.

- Add a bitmask to simplify figuring out if a given signal is in the private or
  public bit range.

- Add a sanity check in newreno_cong_signal() to ensure private signals are not
  being leaked into the hook function.

Sponsored by:	FreeBSD Foundation
Discussed with:	David Hayes <dahayes at swin edu au>
MFC after:	1 week
X-MFC with:	r215166

END