Until now, ofpbuf_put() has been able to reallocate an ofpbuf to
expand the tailroom, but ofpbuf_push() has not been able to expand
the headroom in an analogous way. This omission is simply because
it has never been useful to do this. However, an upcoming change
will make the amount of headroom in an ofpbuf passed up from a
dpif to ofproto harder to predict. It seems that we might as well
simply implement expanding headroom, so this commit does that.
Acked-by: Jesse Gross <jesse@nicira.com>
This new function is useful in a situation where a small stack-allocated
buffer is usually appropriate but occasionally it must be expanded.
Acked-by: Jesse Gross <jesse@nicira.com>
ovs_queue doesn't seem very useful; it's just a singly-linked list. It's
more generally useful to use a general-purpose "struct list" for lists of
packets, so this commit adds such a member to "struct ofpbuf" and shifts
the existing users to use it.
Until now, ofpbuf_trim() has not handled the case where the ofpbuf has
nonzero headroom. This causes an assertion failure when pinsched_send()
queues a packet to be sent later, because such packets have been
guaranteed to have nonzero headroom since commit 43253595 "ofproto: Avoid
buffer copy in OFPT_PACKET_IN path." This commit fixes the problem by
implementing the until-now unsupported case.
This commit factors code out of ofpbuf_prealloc_tailroom() into two new
functions, ofpbuf_rebase__() and ofpbuf_resize_tailroom__(), and uses the
latter to implement both ofpbuf_prealloc_tailroom() and ofpbuf_trim().
ofpbuf_rebase__() isn't used on its own at all, but it seems potentially
useful so I made it an independent function.
Reported-by: Tom Everman <teverman@google.com>
