A node that implements Predictor-1 compression for PPP.

Submitted by:	Alexander Motin <mav alkar.net>

2 files changed, 781 insertions, 0 deletions

diff --git a/sys/netgraph/ng_pred1.c b/sys/netgraph/ng_pred1.c
new file mode 100644
index 0000000..28dff36
--- /dev/null
+++ b/sys/netgraph/ng_pred1.c
@@ -0,0 +1,698 @@
+/*-
+ * Copyright (c) 2006 Alexander Motin <mav@alkar.net>
+ * 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 unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Predictor-1 PPP compression netgraph node type.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/mbuf.h>
+#include <sys/malloc.h>
+#include <sys/errno.h>
+#include <sys/syslog.h>
+
+#include <netgraph/ng_message.h>
+#include <netgraph/netgraph.h>
+#include <netgraph/ng_parse.h>
+#include <netgraph/ng_pred1.h>
+
+#include "opt_netgraph.h"
+
+MALLOC_DEFINE(M_NETGRAPH_PRED1, "netgraph_pred1", "netgraph pred1 node ");
+
+/* PRED1 header length */
+#define PRED1_HDRLEN		2
+
+#define PRED1_TABLE_SIZE	0x10000
+#define PRED1_BUF_SIZE		4096
+#define PPP_INITFCS		0xffff  /* Initial FCS value */
+#define PPP_GOODFCS		0xf0b8  /* Good final FCS value */
+
+/*
+ * The following hash code is the heart of the algorithm:
+ * it builds a sliding hash sum of the previous 3-and-a-bit
+ * characters which will be used to index the guess table.
+ * A better hash function would result in additional compression,
+ * at the expense of time.
+ */
+
+#define HASH(x) priv->Hash = (priv->Hash << 4) ^ (x)
+
+/* Node private data */
+struct ng_pred1_private {
+	struct ng_pred1_config cfg;		/* configuration */
+	u_char		GuessTable[PRED1_TABLE_SIZE];	/* dictionary */
+	u_char		inbuf[PRED1_BUF_SIZE];	/* input buffer */
+	u_char		outbuf[PRED1_BUF_SIZE];	/* output buffer */
+	struct ng_pred1_stats stats;		/* statistics */
+	uint16_t	Hash;
+	ng_ID_t		ctrlnode;		/* path to controlling node */
+	uint16_t	seqnum;			/* sequence number */
+	u_char		compress;		/* compress/decompress flag */
+};
+typedef struct ng_pred1_private *priv_p;
+
+/* Netgraph node methods */
+static ng_constructor_t	ng_pred1_constructor;
+static ng_rcvmsg_t	ng_pred1_rcvmsg;
+static ng_shutdown_t	ng_pred1_shutdown;
+static ng_newhook_t	ng_pred1_newhook;
+static ng_rcvdata_t	ng_pred1_rcvdata;
+static ng_disconnect_t	ng_pred1_disconnect;
+
+/* Helper functions */
+static int	ng_pred1_compress(node_p node, struct mbuf *m,
+		    struct mbuf **resultp);
+static int	ng_pred1_decompress(node_p node, struct mbuf *m,
+		    struct mbuf **resultp);
+static void	Pred1Init(node_p node);
+static int	Pred1Compress(node_p node, u_char *source, u_char *dest,
+		    int len);
+static int	Pred1Decompress(node_p node, u_char *source, u_char *dest,
+		    int slen, int dlen);
+static void	Pred1SyncTable(node_p node, u_char *source, int len);
+static uint16_t	Crc16(uint16_t fcs, u_char *cp, int len);
+
+static const uint16_t	Crc16Table[];
+
+/* Parse type for struct ng_pred1_config. */
+static const struct ng_parse_struct_field ng_pred1_config_type_fields[]
+	= NG_PRED1_CONFIG_INFO;
+static const struct ng_parse_type ng_pred1_config_type = {
+	&ng_parse_struct_type,
+	ng_pred1_config_type_fields
+};
+
+/* Parse type for struct ng_pred1_stat. */
+static const struct ng_parse_struct_field ng_pred1_stats_type_fields[]
+	= NG_PRED1_STATS_INFO;
+static const struct ng_parse_type ng_pred1_stat_type = {
+	&ng_parse_struct_type,
+	ng_pred1_stats_type_fields
+};
+
+/* List of commands and how to convert arguments to/from ASCII. */
+static const struct ng_cmdlist ng_pred1_cmds[] = {
+	{
+	  NGM_PRED1_COOKIE,
+	  NGM_PRED1_CONFIG,
+	  "config",
+	  &ng_pred1_config_type,
+	  NULL
+	},
+	{
+	  NGM_PRED1_COOKIE,
+	  NGM_PRED1_RESETREQ,
+	  "resetreq",
+	  NULL,
+	  NULL
+	},
+	{
+	  NGM_PRED1_COOKIE,
+	  NGM_PRED1_GET_STATS,
+	  "getstats",
+	  NULL,
+	  &ng_pred1_stat_type
+	},
+	{
+	  NGM_PRED1_COOKIE,
+	  NGM_PRED1_CLR_STATS,
+	  "clrstats",
+	  NULL,
+	  NULL
+	},
+	{
+	  NGM_PRED1_COOKIE,
+	  NGM_PRED1_GETCLR_STATS,
+	  "getclrstats",
+	  NULL,
+	  &ng_pred1_stat_type
+	},
+	{ 0 }
+};
+
+/* Node type descriptor */
+static struct ng_type ng_pred1_typestruct = {
+	.version =	NG_ABI_VERSION,
+	.name =		NG_PRED1_NODE_TYPE,
+	.constructor =	ng_pred1_constructor,
+	.rcvmsg =	ng_pred1_rcvmsg,
+	.shutdown =	ng_pred1_shutdown,
+	.newhook =	ng_pred1_newhook,
+	.rcvdata =	ng_pred1_rcvdata,
+	.disconnect =	ng_pred1_disconnect,
+	.cmdlist =	ng_pred1_cmds,
+};
+NETGRAPH_INIT(pred1, &ng_pred1_typestruct);
+
+#define ERROUT(x)	do { error = (x); goto done; } while (0)
+
+/************************************************************************
+			NETGRAPH NODE STUFF
+ ************************************************************************/
+
+/*
+ * Node type constructor
+ */
+static int
+ng_pred1_constructor(node_p node)
+{
+	priv_p priv;
+
+	/* Allocate private structure. */
+	priv = malloc(sizeof(*priv), M_NETGRAPH_PRED1, M_WAITOK | M_ZERO);
+
+	NG_NODE_SET_PRIVATE(node, priv);
+
+	/* This node is not thread safe. */
+	NG_NODE_FORCE_WRITER(node);
+
+	/* Done */
+	return (0);
+}
+
+/*
+ * Give our OK for a hook to be added.
+ */
+static int
+ng_pred1_newhook(node_p node, hook_p hook, const char *name)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	if (NG_NODE_NUMHOOKS(node) > 0)
+		return (EINVAL);
+
+	if (strcmp(name, NG_PRED1_HOOK_COMP) == 0)
+		priv->compress = 1;
+	else if (strcmp(name, NG_PRED1_HOOK_DECOMP) == 0)
+		priv->compress = 0;
+	else
+		return (EINVAL);
+
+	return (0);
+}
+
+/*
+ * Receive a control message.
+ */
+static int
+ng_pred1_rcvmsg(node_p node, item_p item, hook_p lasthook)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+	struct ng_mesg *resp = NULL;
+	int error = 0;
+	struct ng_mesg *msg;
+
+	NGI_GET_MSG(item, msg);
+
+	if (msg->header.typecookie != NGM_PRED1_COOKIE)
+		ERROUT(EINVAL);
+	
+	switch (msg->header.cmd) {
+	case NGM_PRED1_CONFIG:
+	    {
+		struct ng_pred1_config *const cfg =
+		    (struct ng_pred1_config *)msg->data;
+
+		/* Check configuration. */
+		if (msg->header.arglen != sizeof(*cfg))
+			ERROUT(EINVAL);
+
+		/* Configuration is OK, reset to it. */
+		priv->cfg = *cfg;
+
+		/* Save return address so we can send reset-req's. */
+		priv->ctrlnode = NGI_RETADDR(item);
+
+		/* Clear our state. */
+		Pred1Init(node);
+
+		break;
+	    }
+	case NGM_PRED1_RESETREQ:
+		Pred1Init(node);
+		break;
+
+	case NGM_PRED1_GET_STATS:
+	case NGM_PRED1_CLR_STATS:
+	case NGM_PRED1_GETCLR_STATS:
+	    {
+		/* Create response. */
+		if (msg->header.cmd != NGM_PRED1_CLR_STATS) {
+			NG_MKRESPONSE(resp, msg,
+			    sizeof(struct ng_pred1_stats), M_NOWAIT);
+			if (resp == NULL)
+				ERROUT(ENOMEM);
+			bcopy(&priv->stats, resp->data,
+			    sizeof(struct ng_pred1_stats));	
+		}
+
+		if (msg->header.cmd != NGM_PRED1_GET_STATS)
+			bzero(&priv->stats, sizeof(struct ng_pred1_stats));
+		break;
+	    }
+
+	default:
+		error = EINVAL;
+		break;
+	}
+done:
+	NG_RESPOND_MSG(error, node, item, resp);
+	NG_FREE_MSG(msg);
+	return (error);
+}
+
+/*
+ * Receive incoming data on our hook.
+ */
+static int
+ng_pred1_rcvdata(hook_p hook, item_p item)
+{
+	const node_p node = NG_HOOK_NODE(hook);
+	const priv_p priv = NG_NODE_PRIVATE(node);
+	struct mbuf *m, *out;
+	int error;
+
+	if (!priv->cfg.enable) {
+		NG_FREE_ITEM(item);
+		return (ENXIO);
+	}
+	
+	NGI_GET_M(item, m);
+	/* Compress. */
+	if (priv->compress) {
+		if ((error = ng_pred1_compress(node, m, &out)) != 0) {
+			NG_FREE_ITEM(item);
+			log(LOG_NOTICE, "%s: error: %d\n", __func__, error);
+			return (error);
+		}
+
+	} else { /* Decompress. */
+		if ((error = ng_pred1_decompress(node, m, &out)) != 0) {
+			NG_FREE_ITEM(item);
+			log(LOG_NOTICE, "%s: error: %d\n", __func__, error);
+			if (priv->ctrlnode != 0) {
+				struct ng_mesg *msg;
+
+				/* Need to send a reset-request. */
+				NG_MKMESSAGE(msg, NGM_PRED1_COOKIE,
+				    NGM_PRED1_RESETREQ, 0, M_NOWAIT);
+				if (msg == NULL)
+					return (error);
+				NG_SEND_MSG_ID(error, node, msg,
+				    priv->ctrlnode, 0);
+			}
+			return (error);
+		}
+	}
+
+	NG_FWD_NEW_DATA(error, item, hook, out);
+	return (error);
+}
+
+/*
+ * Destroy node.
+ */
+static int
+ng_pred1_shutdown(node_p node)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	free(priv, M_NETGRAPH_PRED1);
+	NG_NODE_SET_PRIVATE(node, NULL);
+	NG_NODE_UNREF(node);		/* Let the node escape. */
+	return (0);
+}
+
+/*
+ * Hook disconnection
+ */
+static int
+ng_pred1_disconnect(hook_p hook)
+{
+	const node_p node = NG_HOOK_NODE(hook);
+
+	Pred1Init(node);
+
+	/* Go away if no longer connected. */
+	if ((NG_NODE_NUMHOOKS(node) == 0) && NG_NODE_IS_VALID(node))
+		ng_rmnode_self(node);
+	return (0);
+}
+
+/************************************************************************
+			HELPER STUFF
+ ************************************************************************/
+
+/*
+ * Compress/encrypt a packet and put the result in a new mbuf at *resultp.
+ * The original mbuf is not free'd.
+ */
+static int
+ng_pred1_compress(node_p node, struct mbuf *m, struct mbuf **resultp)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int 		outlen, inlen;
+	u_char		*out;
+	uint16_t	fcs, lenn;
+	int		len;
+
+	/* Initialize. */
+	*resultp = NULL;
+
+	inlen = m->m_pkthdr.len;
+
+	priv->stats.FramesPlain++;
+	priv->stats.InOctets += inlen;
+
+	/* Reserve space for expansion. */
+	if (inlen > (PRED1_BUF_SIZE*8/9 + 1 + 4)) {
+		priv->stats.Errors++;
+		NG_FREE_M(m);
+		return (ENOMEM);
+	}
+	
+	/* Work with contiguous regions of memory. */
+	m_copydata(m, 0, inlen, (caddr_t)(priv->inbuf + 2));
+
+	NG_FREE_M(m);
+
+	lenn = htons(inlen & 0x7FFF);
+
+	/* Compute FCS. */
+	fcs = Crc16(PPP_INITFCS, (u_char *)&lenn, 2);
+	fcs = Crc16(fcs, priv->inbuf + 2, inlen);
+	fcs = ~fcs;
+
+	/* Compress data. */
+	len = Pred1Compress(node, priv->inbuf + 2, priv->outbuf + 2, inlen);
+
+	/* What happened? */
+	if (len < inlen) {
+		out = priv->outbuf;
+		outlen = 2 + len;
+		*(uint16_t *)out = lenn;
+		*out |= 0x80;
+		priv->stats.FramesComp++;
+	} else {
+		out = priv->inbuf;
+		outlen = 2 + inlen;
+		*(uint16_t *)out = lenn;
+		priv->stats.FramesUncomp++;
+	}
+
+	/* Add FCS. */
+	(out + outlen)[0] = fcs & 0xFF;
+	(out + outlen)[1] = fcs >> 8;
+
+	/* Calculate resulting size. */
+	outlen += 2;
+
+	/* Return packet in an mbuf. */
+	*resultp = m_devget((caddr_t)out, outlen, 0, NULL, NULL);
+	if (*resultp == NULL) {
+	    priv->stats.Errors++;
+	    return (ENOMEM);
+	};
+
+	priv->stats.OutOctets += outlen;
+
+	return (0);
+}
+
+/*
+ * Decompress/decrypt packet and put the result in a new mbuf at *resultp.
+ * The original mbuf is not free'd.
+ */
+static int
+ng_pred1_decompress(node_p node, struct mbuf *m, struct mbuf **resultp)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int 		inlen;
+	uint16_t	len, len1, cf, lenn;
+	uint16_t	fcs;
+
+	/* Initialize. */
+	*resultp = NULL;
+
+	inlen = m->m_pkthdr.len;
+		
+	if (inlen > PRED1_BUF_SIZE) {
+		priv->stats.Errors++;
+		NG_FREE_M(m);
+		return (ENOMEM);
+	}
+
+	/* Work with contiguous regions of memory. */
+	m_copydata(m, 0, inlen, (caddr_t)priv->inbuf);
+
+	priv->stats.InOctets += inlen;
+    	
+	/* Get initial length value. */
+	len = priv->inbuf[0] << 8;
+	len += priv->inbuf[1];
+
+	cf = (len & 0x8000);
+	len &= 0x7fff;
+
+	/* Is data compressed or not really? */
+	if (cf) {
+		NG_FREE_M(m);
+		
+		priv->stats.FramesComp++;
+		len1 = Pred1Decompress(node, priv->inbuf + 2, priv->outbuf,
+		    inlen - 4, PRED1_BUF_SIZE);
+		if (len != len1) {
+			/* Error is detected. Send reset request */
+			priv->stats.Errors++;
+			log(LOG_NOTICE, "ng_pred1: Comp length error (%d) "
+			    "--> len (%d)\n", len, len1);
+			return (EIO);
+		}
+
+		/*
+		 * CRC check on receive is defined in RFC. It is surely required
+		 * for compressed frames to signal dictionary corruption,
+		 * but it is actually useless for uncompressed frames because
+		 * the same check has already done by HDLC and/or other layer.
+		 */
+		lenn = htons(len);
+		fcs = Crc16(PPP_INITFCS, (u_char *)&lenn, 2);
+		fcs = Crc16(fcs, priv->outbuf, len);
+		fcs = Crc16(fcs, priv->inbuf + inlen - 2, 2);
+
+		if (fcs != PPP_GOODFCS) {
+			priv->stats.Errors++;
+	    		log(LOG_NOTICE, "ng_pred1: Pred1: Bad CRC-16\n");
+			return (EIO);
+		}
+
+		/* Return packet in an mbuf. */
+		*resultp = m_devget((caddr_t)priv->outbuf, len, 0, NULL, NULL);
+		if (*resultp == NULL) {
+			priv->stats.Errors++;
+			return (ENOMEM);
+		};
+
+	} else {
+		priv->stats.FramesUncomp++;
+		if (len != (inlen - 4)) {
+			/* Wrong length. Send reset request */
+			priv->stats.Errors++;
+			log(LOG_NOTICE, "ng_pred1: Uncomp length error (%d) "
+			    "--> len (%d)\n", len, inlen - 4);
+			NG_FREE_M(m);
+			return (EIO);
+		}
+		Pred1SyncTable(node, priv->inbuf + 2, len);
+		m_adj(m, 2);	/* Strip length. */
+		m_adj(m, -2);	/* Strip fcs. */
+		*resultp = m;
+	}
+
+	priv->stats.FramesPlain++;
+	priv->stats.OutOctets += len;
+
+	return (0);
+}
+
+/*
+ * Pred1Init()
+ */
+
+static void
+Pred1Init(node_p node)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	priv->Hash = 0;
+	memset(priv->GuessTable, 0, PRED1_TABLE_SIZE);
+}
+
+/*
+ * Pred1Compress()
+ */
+
+static int
+Pred1Compress(node_p node, u_char *source, u_char *dest, int len)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int		i, bitmask;
+	u_char		flags;
+	u_char		*flagdest, *orgdest;
+
+	orgdest = dest;
+	while (len) {
+		flagdest = dest++;
+		flags = 0;	/* All guesses are wrong initially. */
+		for (bitmask = 1, i = 0; i < 8 && len; i++, bitmask <<= 1) {
+    			if (priv->GuessTable[priv->Hash] == *source)
+				/* Guess was right - don't output. */
+				flags |= bitmask;
+    			else {
+				/* Guess wrong, output char. */
+				priv->GuessTable[priv->Hash] = *source;
+				*dest++ = *source;
+    			}
+    			HASH(*source++);
+    			len--;
+		}
+		*flagdest = flags;
+	}
+	return (dest - orgdest);
+}
+
+/*
+ * Pred1Decompress()
+ *
+ * Returns decompressed size, or -1 if we ran out of space.
+ */
+
+static int
+Pred1Decompress(node_p node, u_char *source, u_char *dest, int slen, int dlen)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int		i, bitmask;
+	u_char		flags, *orgdest;
+
+	orgdest = dest;
+	while (slen) {
+		flags = *source++;
+		slen--;
+		for (i = 0, bitmask = 1; i < 8; i++, bitmask <<= 1) {
+			if (dlen <= 0)
+				return(-1);
+			if (flags & bitmask)
+				/* Guess correct */
+				*dest = priv->GuessTable[priv->Hash];
+			else {
+				if (!slen)
+					/* We seem to be really done -- cabo. */
+					break;
+
+				/* Guess wrong. */
+				priv->GuessTable[priv->Hash] = *source;
+				/* Read from source. */
+				*dest = *source++;
+				slen--;
+			}
+			HASH(*dest++);
+			dlen--;
+		}
+	}
+	return (dest - orgdest);
+}
+
+/*
+ * Pred1SyncTable()
+ */
+
+static void
+Pred1SyncTable(node_p node, u_char *source, int len)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	while (len--) {
+		priv->GuessTable[priv->Hash] = *source;
+		HASH(*source++);
+	}
+}
+
+/*
+ * Crc16()
+ *
+ * Compute the 16 bit frame check value, per RFC 1171 Appendix B,
+ * on an array of bytes.
+ */
+
+static uint16_t
+Crc16(uint16_t crc, u_char *cp, int len)
+{
+	while (len--)
+		crc = (crc >> 8) ^ Crc16Table[(crc ^ *cp++) & 0xff];
+	return (crc);
+}
+
+static const uint16_t Crc16Table[256] = {
+/* 00 */    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+/* 08 */    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+/* 10 */    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+/* 18 */    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+/* 20 */    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+/* 28 */    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+/* 30 */    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+/* 38 */    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+/* 40 */    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+/* 48 */    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+/* 50 */    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+/* 58 */    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+/* 60 */    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+/* 68 */    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+/* 70 */    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+/* 78 */    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+/* 80 */    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+/* 88 */    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+/* 90 */    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+/* 98 */    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+/* a0 */    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+/* a8 */    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+/* b0 */    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+/* b8 */    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+/* c0 */    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+/* c8 */    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+/* d0 */    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+/* d8 */    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+/* e0 */    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+/* e8 */    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+/* f0 */    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+/* f8 */    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
diff --git a/sys/netgraph/ng_pred1.h b/sys/netgraph/ng_pred1.h
new file mode 100644
index 0000000..a33d120
--- /dev/null
+++ b/sys/netgraph/ng_pred1.h
@@ -0,0 +1,83 @@
+/*-
+ * Copyright (c) 2006 Alexander Motin <mav@alkar.net>
+ * 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 unmodified, this list of conditions, and the following
+ *    disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 _NETGRAPH_NG_PRED1_H_
+#define _NETGRAPH_NG_PRED1_H_
+
+/* Node type name and magic cookie */
+#define NG_PRED1_NODE_TYPE	"pred1"
+#define NGM_PRED1_COOKIE	1166902612
+
+/* Hook names */
+#define NG_PRED1_HOOK_COMP	"comp"		/* compression hook */
+#define NG_PRED1_HOOK_DECOMP	"decomp"	/* decompression hook */
+
+/* Config struct */
+struct ng_pred1_config {
+	u_char		enable;			/* node enabled */
+};
+
+/* Keep this in sync with the above structure definition. */
+#define NG_PRED1_CONFIG_INFO	{			\
+	{ "enable",	&ng_parse_uint8_type	},	\
+	{ NULL }					\
+}
+
+/* Statistics structure for one direction. */
+struct ng_pred1_stats {
+	uint64_t	FramesPlain;
+	uint64_t	FramesComp;
+	uint64_t	FramesUncomp;
+	uint64_t	InOctets;
+	uint64_t	OutOctets;
+	uint64_t	Errors;
+};
+
+/* Keep this in sync with the above structure definition. */
+#define NG_PRED1_STATS_INFO	{				\
+	{ "FramesPlain",&ng_parse_uint64_type	},	\
+	{ "FramesComp",	&ng_parse_uint64_type	},	\
+	{ "FramesUncomp", &ng_parse_uint64_type	},	\
+	{ "InOctets",	&ng_parse_uint64_type	},	\
+	{ "OutOctets",	&ng_parse_uint64_type	},	\
+	{ "Errors",	&ng_parse_uint64_type	},	\
+	{ NULL }					\
+}
+
+/* Netgraph commands */
+enum {
+	NGM_PRED1_CONFIG = 1,
+	NGM_PRED1_RESETREQ,			/* sent either way! */
+	NGM_PRED1_GET_STATS,
+	NGM_PRED1_CLR_STATS,
+	NGM_PRED1_GETCLR_STATS,
+};
+
+#endif /* _NETGRAPH_NG_PRED1_H_ */
+