A node that implements the Deflate sub-protocols of the Compression Control

Protocol (CCP).

Submitted by:	Alexander Motin <mav alkar.net>

1 files changed, 683 insertions, 0 deletions

diff --git a/sys/netgraph/ng_deflate.c b/sys/netgraph/ng_deflate.c
new file mode 100644
index 0000000..a185a35
--- /dev/null
+++ b/sys/netgraph/ng_deflate.c
@@ -0,0 +1,683 @@
+/*-
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Deflate 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 <net/zlib.h>
+
+#include <netgraph/ng_message.h>
+#include <netgraph/netgraph.h>
+#include <netgraph/ng_parse.h>
+#include <netgraph/ng_deflate.h>
+
+#include "opt_netgraph.h"
+
+MALLOC_DEFINE(M_NETGRAPH_DEFLATE, "netgraph_deflate", "netgraph deflate node ");
+
+/* DEFLATE header length */
+#define DEFLATE_HDRLEN		2
+
+#define PROT_COMPD		0x00fd
+
+#define DEFLATE_BUF_SIZE	4096
+
+/* Node private data */
+struct ng_deflate_private {
+	struct ng_deflate_config cfg;		/* configuration */
+	u_char		inbuf[DEFLATE_BUF_SIZE];	/* input buffer */
+	u_char		outbuf[DEFLATE_BUF_SIZE];	/* output buffer */
+	z_stream 	cx;			/* compression context */
+	struct ng_deflate_stats stats;		/* statistics */
+	ng_ID_t		ctrlnode;		/* path to controlling node */
+	uint16_t	seqnum;			/* sequence number */
+	u_char		compress;		/* compress/decompress flag */
+};
+typedef struct ng_deflate_private *priv_p;
+
+/* Netgraph node methods */
+static ng_constructor_t	ng_deflate_constructor;
+static ng_rcvmsg_t	ng_deflate_rcvmsg;
+static ng_shutdown_t	ng_deflate_shutdown;
+static ng_newhook_t	ng_deflate_newhook;
+static ng_rcvdata_t	ng_deflate_rcvdata;
+static ng_disconnect_t	ng_deflate_disconnect;
+
+/* Helper functions */
+static void	*z_alloc(void *, u_int items, u_int size);
+static void	z_free(void *, void *ptr);
+static int	ng_deflate_compress(node_p node,
+		    struct mbuf *m, struct mbuf **resultp);
+static int	ng_deflate_decompress(node_p node,
+		    struct mbuf *m, struct mbuf **resultp);
+static void	ng_deflate_reset_req(node_p node);
+
+/* Parse type for struct ng_deflate_config. */
+static const struct ng_parse_struct_field ng_deflate_config_type_fields[]
+	= NG_DEFLATE_CONFIG_INFO;
+static const struct ng_parse_type ng_deflate_config_type = {
+	&ng_parse_struct_type,
+	ng_deflate_config_type_fields
+};
+
+/* Parse type for struct ng_deflate_stat. */
+static const struct ng_parse_struct_field ng_deflate_stats_type_fields[]
+	= NG_DEFLATE_STATS_INFO;
+static const struct ng_parse_type ng_deflate_stat_type = {
+	&ng_parse_struct_type,
+	ng_deflate_stats_type_fields
+};
+
+/* List of commands and how to convert arguments to/from ASCII. */
+static const struct ng_cmdlist ng_deflate_cmds[] = {
+	{
+	  NGM_DEFLATE_COOKIE,
+	  NGM_DEFLATE_CONFIG,
+	  "config",
+	  &ng_deflate_config_type,
+	  NULL
+	},
+	{
+	  NGM_DEFLATE_COOKIE,
+	  NGM_DEFLATE_RESETREQ,
+	  "resetreq",
+	  NULL,
+	  NULL
+	},
+	{
+	  NGM_DEFLATE_COOKIE,
+	  NGM_DEFLATE_GET_STATS,
+	  "getstats",
+	  NULL,
+	  &ng_deflate_stat_type
+	},
+	{
+	  NGM_DEFLATE_COOKIE,
+	  NGM_DEFLATE_CLR_STATS,
+	  "clrstats",
+	  NULL,
+	  NULL
+	},
+	{
+	  NGM_DEFLATE_COOKIE,
+	  NGM_DEFLATE_GETCLR_STATS,
+	  "getclrstats",
+	  NULL,
+	  &ng_deflate_stat_type
+	},
+	{ 0 }
+};
+
+/* Node type descriptor */
+static struct ng_type ng_deflate_typestruct = {
+	.version =	NG_ABI_VERSION,
+	.name =		NG_DEFLATE_NODE_TYPE,
+	.constructor =	ng_deflate_constructor,
+	.rcvmsg =	ng_deflate_rcvmsg,
+	.shutdown =	ng_deflate_shutdown,
+	.newhook =	ng_deflate_newhook,
+	.rcvdata =	ng_deflate_rcvdata,
+	.disconnect =	ng_deflate_disconnect,
+	.cmdlist =	ng_deflate_cmds,
+};
+NETGRAPH_INIT(deflate, &ng_deflate_typestruct);
+
+/* Depend on separate zlib module. */
+MODULE_DEPEND(ng_deflate, zlib, 1, 1, 1);
+
+#define ERROUT(x)	do { error = (x); goto done; } while (0)
+
+/************************************************************************
+			NETGRAPH NODE STUFF
+ ************************************************************************/
+
+/*
+ * Node type constructor
+ */
+static int
+ng_deflate_constructor(node_p node)
+{
+	priv_p priv;
+
+	/* Allocate private structure. */
+	priv = malloc(sizeof(*priv), M_NETGRAPH_DEFLATE, 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_deflate_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_DEFLATE_HOOK_COMP) == 0)
+		priv->compress = 1;
+	else if (strcmp(name, NG_DEFLATE_HOOK_DECOMP) == 0)
+		priv->compress = 0;
+	else
+		return (EINVAL);
+
+	return (0);
+}
+
+/*
+ * Receive a control message
+ */
+static int
+ng_deflate_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_DEFLATE_COOKIE)
+		ERROUT(EINVAL);
+	
+	switch (msg->header.cmd) {
+	case NGM_DEFLATE_CONFIG:
+	    {
+		struct ng_deflate_config *const cfg
+		    = (struct ng_deflate_config *)msg->data;
+
+		/* Check configuration. */
+		if (msg->header.arglen != sizeof(*cfg))
+			ERROUT(EINVAL);
+		if (cfg->enable) {
+		    if (cfg->windowBits < 8 || cfg->windowBits > 15)
+			ERROUT(EINVAL);
+		} else
+		    cfg->windowBits = 0;
+
+		/* Clear previous state. */
+		if (priv->cfg.enable) {
+			if (priv->compress)
+				deflateEnd(&priv->cx);
+			else
+				inflateEnd(&priv->cx);
+			priv->cfg.enable = 0;
+		}
+			
+		/* Configuration is OK, reset to it. */
+		priv->cfg = *cfg;
+
+		if (priv->cfg.enable) {
+			priv->cx.next_in = NULL;
+			priv->cx.zalloc = z_alloc;
+			priv->cx.zfree = z_free;
+			int res;
+			if (priv->compress) {
+				if ((res = deflateInit2(&priv->cx,
+				    Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+				    -cfg->windowBits, 8,
+				    Z_DEFAULT_STRATEGY)) != Z_OK) {
+					log(LOG_NOTICE,
+					    "deflateInit2: error %d, %s\n",
+					    res, priv->cx.msg);
+					priv->cfg.enable = 0;
+					ERROUT(ENOMEM);
+				}
+			} else {
+				if ((res = inflateInit2(&priv->cx,
+				    -cfg->windowBits)) != Z_OK) {
+					log(LOG_NOTICE,
+					    "inflateInit2: error %d, %s\n",
+					    res, priv->cx.msg);
+					priv->cfg.enable = 0;
+					ERROUT(ENOMEM);
+				}
+			}
+		}
+
+		/* Initialize other state. */
+		priv->seqnum = 0;
+
+		/* Save return address so we can send reset-req's */
+		priv->ctrlnode = NGI_RETADDR(item);
+		break;
+	    }
+
+	case NGM_DEFLATE_RESETREQ:
+		ng_deflate_reset_req(node);
+		break;
+
+	case NGM_DEFLATE_GET_STATS:
+	case NGM_DEFLATE_CLR_STATS:
+	case NGM_DEFLATE_GETCLR_STATS:
+		/* Create response if requested. */
+		if (msg->header.cmd != NGM_DEFLATE_CLR_STATS) {
+			NG_MKRESPONSE(resp, msg,
+			    sizeof(struct ng_deflate_stats), M_NOWAIT);
+			if (resp == NULL)
+				ERROUT(ENOMEM);
+			bcopy(&priv->stats, resp->data,
+			    sizeof(struct ng_deflate_stats));	
+		}
+
+		/* Clear stats if requested. */
+		if (msg->header.cmd != NGM_DEFLATE_GET_STATS)
+			bzero(&priv->stats,
+			    sizeof(struct ng_deflate_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_deflate_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_deflate_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_deflate_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_DEFLATE_COOKIE,
+				    NGM_DEFLATE_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_deflate_shutdown(node_p node)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	/* Take down netgraph node. */
+	if (priv->cfg.enable) {
+	    if (priv->compress)
+		deflateEnd(&priv->cx);
+	    else
+		inflateEnd(&priv->cx);
+	}
+
+	free(priv, M_NETGRAPH_DEFLATE);
+	NG_NODE_SET_PRIVATE(node, NULL);
+	NG_NODE_UNREF(node);		/* let the node escape */
+	return (0);
+}
+
+/*
+ * Hook disconnection
+ */
+static int
+ng_deflate_disconnect(hook_p hook)
+{
+	const node_p node = NG_HOOK_NODE(hook);
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	if (priv->cfg.enable) {
+	    if (priv->compress)
+		deflateEnd(&priv->cx);
+	    else
+		inflateEnd(&priv->cx);
+	    priv->cfg.enable = 0;
+	}
+
+	/* 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
+ ************************************************************************/
+
+/*
+ * Space allocation and freeing routines for use by zlib routines.
+ */
+
+static void *
+z_alloc(void *notused, u_int items, u_int size)
+{
+
+	return (malloc(items * size, M_NETGRAPH_DEFLATE, M_NOWAIT));
+}
+
+static void
+z_free(void *notused, void *ptr)
+{
+
+	free(ptr, M_NETGRAPH_DEFLATE);
+}
+
+/*
+ * Compress/encrypt a packet and put the result in a new mbuf at *resultp.
+ * The original mbuf is not free'd.
+ */
+static int
+ng_deflate_compress(node_p node, struct mbuf *m, struct mbuf **resultp)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int 		outlen, inlen;
+	int 		rtn;
+
+	/* Initialize. */
+	*resultp = NULL;
+
+	inlen = m->m_pkthdr.len;
+
+	priv->stats.FramesPlain++;
+	priv->stats.InOctets+=inlen;
+
+	if (inlen > DEFLATE_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);
+	outlen = DEFLATE_BUF_SIZE;
+
+	/* Compress "inbuf" into "outbuf". */
+	/* Prepare to compress. */
+	if (priv->inbuf[0] != 0) {
+		priv->cx.next_in = priv->inbuf;
+		priv->cx.avail_in = inlen;
+	} else {
+		priv->cx.next_in = priv->inbuf + 1; /* compress protocol */
+		priv->cx.avail_in = inlen - 1;
+	}
+	priv->cx.next_out = priv->outbuf + 2 + DEFLATE_HDRLEN;
+	priv->cx.avail_out = outlen - 2 - DEFLATE_HDRLEN;
+
+	/* Compress. */
+	rtn = deflate(&priv->cx, Z_PACKET_FLUSH);
+
+	/* Check return value. */
+	if (rtn != Z_OK) {
+		priv->stats.Errors++;
+		log(LOG_NOTICE, "ng_deflate: compression error: %d (%s)\n",
+		    rtn, priv->cx.msg);
+		NG_FREE_M(m);
+		return (EINVAL);
+	}
+
+	/* Calculate resulting size. */
+	outlen -= priv->cx.avail_out;
+
+	/* If we can't compress this packet, send it as-is. */
+	if (outlen > inlen) {
+		/* Return original packet uncompressed. */
+		*resultp = m;
+		priv->stats.FramesUncomp++;
+		priv->stats.OutOctets+=inlen;
+	} else {
+		NG_FREE_M(m);
+
+		/* Install header. */
+		((u_int16_t *)priv->outbuf)[0] = htons(PROT_COMPD);
+		((u_int16_t *)priv->outbuf)[1] = htons(priv->seqnum);
+
+		/* Return packet in an mbuf. */
+		*resultp = m_devget((caddr_t)priv->outbuf, outlen, 0, NULL,
+		    NULL);
+		if (*resultp == NULL) {
+			priv->stats.Errors++;
+			return (ENOMEM);
+		};
+		priv->stats.FramesComp++;
+		priv->stats.OutOctets+=outlen;
+	}
+
+	/* Update sequence number. */
+	priv->seqnum++;
+
+	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_deflate_decompress(node_p node, struct mbuf *m, struct mbuf **resultp)
+{
+	const priv_p 	priv = NG_NODE_PRIVATE(node);
+	int 		outlen, inlen;
+	int 		rtn;
+	uint16_t	proto;
+	int		offset;
+	uint16_t	rseqnum;
+
+	/* Initialize. */
+	*resultp = NULL;
+
+	inlen = m->m_pkthdr.len;
+		
+	if (inlen > DEFLATE_BUF_SIZE) {
+		priv->stats.Errors++;
+		NG_FREE_M(m);
+		priv->seqnum = 0;
+		return (ENOMEM);
+	}
+
+	/* Work with contiguous regions of memory. */
+	m_copydata(m, 0, inlen, (caddr_t)priv->inbuf);
+
+	/* Separate proto. */
+	if ((priv->inbuf[0] & 0x01) != 0) {
+		proto = priv->inbuf[0];
+		offset = 1;
+	} else {
+		proto = ntohs(((uint16_t *)priv->inbuf)[0]);
+		offset = 2;
+	}
+
+	/* Packet is compressed, so decompress. */
+	if (proto == PROT_COMPD) {
+		priv->stats.FramesComp++;
+		priv->stats.InOctets+=inlen;
+    	
+		/* Check sequence number. */
+		rseqnum = ntohs(((uint16_t *)(priv->inbuf + offset))[0]);
+		offset += 2;
+		if (rseqnum != priv->seqnum) {
+			priv->stats.Errors++;
+			log(LOG_NOTICE, "ng_deflate: wrong sequence: %u "
+			    "instead of %u\n", rseqnum, priv->seqnum);
+			NG_FREE_M(m);
+			priv->seqnum = 0;
+			return (EPIPE);
+		}
+
+		outlen = DEFLATE_BUF_SIZE;
+
+    		/* Decompress "inbuf" into "outbuf". */
+		/* Prepare to decompress. */
+		priv->cx.next_in = priv->inbuf + offset;
+		priv->cx.avail_in = inlen - offset;
+		/* Reserve space for protocol decompression. */
+		priv->cx.next_out = priv->outbuf + 1;
+		priv->cx.avail_out = outlen - 1;
+
+		/* Decompress. */
+		rtn = inflate(&priv->cx, Z_PACKET_FLUSH);
+
+		/* Check return value. */
+		if (rtn != Z_OK && rtn != Z_STREAM_END) {
+			priv->stats.Errors++;
+			NG_FREE_M(m);
+			priv->seqnum = 0;
+			log(LOG_NOTICE, "%s: decompression error: %d (%s)\n",
+			    __func__, rtn, priv->cx.msg);
+
+			switch (rtn) {
+			case Z_MEM_ERROR:
+				return (ENOMEM);
+			case Z_DATA_ERROR:
+				return (EIO);
+			default:
+				return (EINVAL);
+			}
+		}
+
+		/* Calculate resulting size. */
+		outlen -= priv->cx.avail_out;
+
+		NG_FREE_M(m);
+
+		/* Decompress protocol. */
+		if ((priv->outbuf[1] & 0x01) != 0) {
+			priv->outbuf[0] = 0;
+			/* Return packet in an mbuf. */
+			*resultp = m_devget((caddr_t)priv->outbuf, outlen, 0,
+			    NULL, NULL);
+		} else {
+			outlen--;
+			/* Return packet in an mbuf. */
+			*resultp = m_devget((caddr_t)(priv->outbuf + 1),
+			    outlen, 0, NULL, NULL);
+		}
+		if (*resultp == NULL) {
+			priv->stats.Errors++;
+			priv->seqnum = 0;
+			return (ENOMEM);
+		};
+		priv->stats.FramesPlain++;
+		priv->stats.OutOctets+=outlen;
+
+	} else { /* Packet is not compressed, just update dictionary. */
+		priv->stats.FramesUncomp++;
+		if (priv->inbuf[0] == 0) {
+		    priv->cx.next_in = priv->inbuf + 1; /* compress protocol */
+		    priv->cx.avail_in = inlen - 1;
+		} else {
+		    priv->cx.next_in = priv->inbuf;
+		    priv->cx.avail_in = inlen;
+		}
+
+		rtn = inflateIncomp(&priv->cx);
+
+		/* Check return value */
+		if (rtn != Z_OK) {
+			priv->stats.Errors++;
+			log(LOG_NOTICE, "%s: inflateIncomp error: %d (%s)\n",
+			    __func__, rtn, priv->cx.msg);
+			NG_FREE_M(m);
+			priv->seqnum = 0;
+			return (EINVAL);
+		}
+
+		*resultp = m;
+		priv->stats.FramesPlain++;
+		priv->stats.OutOctets += inlen;
+	}
+
+	/* Update sequence number. */
+	priv->seqnum++;
+
+	return (0);
+}
+
+/*
+ * The peer has sent us a CCP ResetRequest, so reset our transmit state.
+ */
+static void
+ng_deflate_reset_req(node_p node)
+{
+	const priv_p priv = NG_NODE_PRIVATE(node);
+
+	priv->seqnum = 0;
+	if (priv->cfg.enable) {
+	    if (priv->compress)
+		deflateReset(&priv->cx);
+	    else
+		inflateReset(&priv->cx);
+	}
+}
+