lib/ofp-util: Restore the check for minus sign in port number strings.

Commit 33ab38d9 (meta-flow: Simplify mf_from_ofp_port_string())
inadvertently removed a check for minus sign at the beginning of a
port number string introduced by commit 05dddba (meta-flow: Don't
allow negative port numbers).  This check is still needed, so put it
back, but to ofputil_port_from_string() this time.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Justin Pettit <jpettit@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
lib/flow: Introduce miniflow_extract().

miniflow_extract() extracts packet headers directly to a miniflow,
which is a compressed form of the struct flow.  This does not require
a large struct to be cleared to begin with, and accesses less memory.
These performance benefits should allow this to be used in the DPDK
datapath.

miniflow_extract() takes a miniflow as an input/output parameter.  On
input the buffer for values to be extracted must be properly
initialized.  On output the map contains ones for all the fields that
have been extracted.

Some struct flow fields are reordered to make miniflow_extract to
progress in the logical order.

Some explicit "inline" keywords are necessary for GCC to optimize this
properly.  Also, macros are used for same reason instead of inline
functions for pushing data to the miniflow.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
lib/flow: Add miniflow accessors and miniflow_get_tcp_flags().

Add inlined generic accessors for miniflow integer type fields, and a
new miniflow_get_tcp_flags() usinge these.  These will be used in a
later patch.

Some definitions also used in lib/packets.h had to be moved there to
resolve circular include dependencies.  Similarly, some inline
functions using struct flow are now in lib/flow.h.  IMO this is
cleaner, since now the lib/flow.h need not be included from
lib/packets.h.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
lib/flow: Possibly faster miniflow_hash_in_minimask()

Upcoming patches add classifier lookups using miniflows, this is
heavily used for it.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
classifier: Support miniflow as a key.

Support struct miniflow as a key for datapath flow lookup.

The new classifier interface classifier_lookup_miniflow_first() takes
a miniflow as a key and stops at the first match with no regard to
flow prioritites.  This works only if the classifier has no
conflicting rules (as is the case with the userspace datapath
classifier).

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
dpif-netdev: Use miniflow as a flow key.

Use miniflow as a flow key in the userspace datapath classifier.  The
miniflow is expanded for upcalls, but for existing datapath flows, the
key need not be expanded.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>