Add for public examination the beginnings of the per-host cache support

which will for the basis of RTF_PRCLONING's more efficient, better-
designed replacement.

1 files changed, 83 insertions, 0 deletions

diff --git a/sys/netinet/in_hostcache.h b/sys/netinet/in_hostcache.h
new file mode 100644
index 0000000..81ae4bd
--- /dev/null
+++ b/sys/netinet/in_hostcache.h
@@ -0,0 +1,83 @@
+/*
+ * Copyright 1997 Massachusetts Institute of Technology
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby
+ * granted, provided that both the above copyright notice and this
+ * permission notice appear in all copies, that both the above
+ * copyright notice and this permission notice appear in all
+ * supporting documentation, and that the name of M.I.T. not be used
+ * in advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.  M.I.T. makes
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
+ * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
+ * SHALL M.I.T. 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.
+ *
+ *	$Id$
+ */
+
+#ifndef _NETINET_IN_HOSTCACHE_H
+#define	_NETINET_IN_HOSTCACHE_H	1
+
+/*
+ * This file defines the particular structures contained in the host cache
+ * for the use of IP.
+ */
+
+/*
+ * An IP host cache entry.  Note that we include the srtt/var here,
+ * with the expectation that it might be used to keep a persistent,
+ * cross-connection view of this statistic.
+ */
+struct in_hcentry {
+	struct	hcentry inhc_hc;
+	u_long	inhc_pmtu;
+	u_long	inhc_recvpipe;
+	u_long	inhc_sendpipe;
+	u_long	inhc_pksent;
+	u_long	inhc_flags;
+	u_long	inhc_ssthresh;
+	int	inhc_srtt;	/* VJ RTT estimator */
+	int	inhc_srttvar;	/* VJ */
+	u_int	inhc_rttmin;	/* VJ */
+	int	inhc_rxt;	/* TCP retransmit timeout */
+	u_long	inhc_cc;	/* deliberate type pun with tcp_cc */
+	u_long	inhc_ccsent;	/* as above */
+	u_short	inhc_mssopt;
+};
+
+#define	inhc_addr(inhc)	((struct sockaddr_in *)(inhc)->inhc_hc.hc_host)
+
+/* Flags for inhc_flags... */
+#define	INHC_LOCAL	0x0001	/* this address is local */
+#define	INHC_BROADCAST	0x0002	/* this address is broadcast */
+#define	INHC_MULTICAST	0x0004	/* this address is multicast */
+#define	INHC_REDUCEDMTU	0x0008	/* we reduced the mtu via PMTU discovery */
+
+#ifdef KERNEL
+/*
+ * inhc_alloc can block while adding a new entry to the cache;
+ * inhc_lookup will does not add new entries and so can be called
+ * in non-process context.
+ */
+struct	in_hcentry *inhc_alloc(struct sockaddr_in *sin);
+int	inhc_init(void);
+struct	in_hcentry *inhc_lookup(struct sockaddr_in *sin);
+#define	inhc_ref(inhc)	(hc_ref(&(inhc)->inhc_hc))
+#define	inhc_rele(inhc)	(hc_rele(&(inhc)->inhc_hc))
+#endif /* KERNEL */
+
+#endif /* _NETINET_IN_HOSTCACHE_H */