- Import infrastructure for caching flows as a means of accelerating L3 and L2 lookups

as well as providing stateful load balancing when used with RADIX_MPATH.
- Currently compiled in to i386 and amd64 but disabled by default, it can be enabled at
  runtime with 'sysctl net.inet.flowtable.enable=1'.

- Embedded users can remove it entirely from the kernel by adding 'nooption FLOWTABLE' to
  their kernel config files.

- A minimal hookup will be added to ip_output in a subsequent commit. I would like to see
  more review before bringing in changes that require more churn.

Supported by: Bitgravity Inc.

sys/amd64/conf/DEFAULTS

@@ -20,3 +20,5 @@ options 	GEOM_PART_BSD
 options 	GEOM_PART_EBR
 options 	GEOM_PART_EBR_COMPAT
 options 	GEOM_PART_MBR
+
+options		FLOWTABLE

sys/conf/NOTES

@@ -553,6 +553,9 @@ options 	LIBMCHAIN
 # libalias library, performing NAT
 options		LIBALIAS
 
+# flowtable cache
+options		FLOWTABLE
+
 #
 # SCTP is a NEW transport protocol defined by
 # RFC2960 updated by RFC3309 and RFC3758.. and

sys/conf/files

@@ -2145,6 +2145,7 @@ net/bpf_jitter.c		optional bpf_jitter
 net/bpf_filter.c		optional bpf | netgraph_bpf
 net/bpf_zerocopy.c		optional bpf
 net/bridgestp.c			optional bridge | if_bridge
+net/flowtable.c			optional flowtable
 net/ieee8023ad_lacp.c		optional lagg
 net/if.c			standard
 net/if_arcsubr.c		optional arcnet

sys/conf/options

@@ -417,6 +417,7 @@ TCP_OFFLOAD_DISABLE	opt_inet.h #Disable code to dispatch tcp offloading
 TCP_SIGNATURE		opt_inet.h
 VLAN_ARRAY		opt_vlan.h
 XBONEHACK
+FLOWTABLE		opt_route.h
 
 #
 # SCTP

sys/i386/conf/DEFAULTS

@@ -28,3 +28,5 @@ options 	GEOM_PART_MBR
 # enable support for native hardware
 options 	NATIVE
 device		atpic
+
+options		FLOWTABLE

sys/net/flowtable.h

@@ -0,0 +1,77 @@
+/**************************************************************************
+
+Copyright (c) 2008-2009, BitGravity Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+ 2. Neither the name of the BitGravity Corporation nor the names of its
+    contributors may be used to endorse or promote products derived from
+    this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+$FreeBSD$
+
+***************************************************************************/
+
+#ifndef	_NET_FLOWTABLE_H_
+#define	_NET_FLOWTABLE_H_
+
+#ifdef	_KERNEL
+#include "opt_route.h"
+
+#include <net/ethernet.h>
+#include <netinet/in.h>
+
+#define	FL_HASH_PORTS	(1<<0)	/* hash 4-tuple + protocol */
+#define	FL_PCPU		(1<<1)	/* pcpu cache */
+
+struct flowtable;
+extern struct flowtable *ip_ft;
+extern struct flowtable *ip_forward_ft;
+
+#ifdef FLOWTABLE
+struct flowtable *flowtable_alloc(int nentry, int flags);
+
+/*
+ * Given a flow table, look up the L3 and L2 information and
+ * return it in the route
+ *
+ */
+int flowtable_lookup(struct flowtable *ft, struct mbuf *m,
+    struct route *ro);
+
+#else
+static __inline struct flowtable *
+flowtable_alloc(int nentry, int flags)
+{
+
+	return (NULL);
+}
+
+static __inline int
+flowtable_lookup(struct flowtable *ft, struct mbuf *m,
+    struct route *ro)
+{
+
+	return (ENOTSUP);
+}
+#endif
+#endif
+
+#endif