Add a netgraph node to handle ATM LLC encapsulation. This currently handles

ethernet (tested) and FDDI (not tested).  The main use for this is on ADSL (or
other ATM) connections where bridged ethernet is used, PPPoE being a prime
example.

There is no manual page as yet, I will write one shortly.

Reviewed by:	harti

1 files changed, 278 insertions, 0 deletions

diff --git a/sys/netgraph/ng_atmllc.c b/sys/netgraph/ng_atmllc.c
new file mode 100644
index 0000000..e346c7b
--- /dev/null
+++ b/sys/netgraph/ng_atmllc.c
@@ -0,0 +1,278 @@
+/*
+ * Copyright (c) 2003-2004 Benno Rice <benno@eloquent.com.au>
+ * 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. 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  ``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  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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+
+#include <netgraph/ng_message.h>
+#include <netgraph/netgraph.h>
+#include <netgraph/ng_atmllc.h>
+
+#include <net/if.h>
+#include <net/ethernet.h>	/* for M_HASFCS and ETHER_HDR_LEN */
+#include <net/if_atm.h>		/* for struct atmllc */
+
+#define	NG_ATMLLC_HEADER		"\252\252\3\0\200\302"
+#define	NG_ATMLLC_HEADER_LEN		(sizeof(struct atmllc))
+#define	NG_ATMLLC_TYPE_ETHERNET_FCS	0x0001
+#define	NG_ATMLLC_TYPE_FDDI_FCS		0x0004
+#define	NG_ATMLLC_TYPE_ETHERNET_NOFCS	0x0007
+#define	NG_ATMLLC_TYPE_FDDI_NOFCS	0x000A
+
+struct ng_atmllc_priv {
+	hook_p		atm;
+	hook_p		ether;
+	hook_p		fddi;
+};
+
+/* Netgraph methods. */
+static ng_constructor_t		ng_atmllc_constructor;
+static ng_shutdown_t		ng_atmllc_shutdown;
+static ng_rcvmsg_t		ng_atmllc_rcvmsg;
+static ng_newhook_t		ng_atmllc_newhook;
+static ng_rcvdata_t		ng_atmllc_rcvdata;
+static ng_disconnect_t		ng_atmllc_disconnect;
+
+static struct ng_type ng_atmllc_typestruct = {
+	NG_ABI_VERSION,	
+	NG_ATMLLC_NODE_TYPE,
+	NULL,
+	ng_atmllc_constructor,
+	ng_atmllc_rcvmsg,
+	ng_atmllc_shutdown,
+	ng_atmllc_newhook,
+	NULL,
+	NULL,
+	ng_atmllc_rcvdata,
+	ng_atmllc_disconnect,
+	NULL
+};
+NETGRAPH_INIT(atmllc, &ng_atmllc_typestruct);
+
+static int
+ng_atmllc_constructor(node_p node)
+{
+	struct	ng_atmllc_priv *priv;
+
+	MALLOC(priv, struct ng_atmllc_priv *, sizeof(*priv), M_NETGRAPH,
+	    M_NOWAIT | M_ZERO);
+	if (priv == NULL) {
+		return (ENOMEM);
+	}
+
+	NG_NODE_SET_PRIVATE(node, priv);
+
+	return (0);
+}
+
+static int
+ng_atmllc_rcvmsg(node_p node, item_p item, hook_p lasthook)
+{
+	struct	ng_mesg *msg;
+	int	error;
+
+	error = 0;
+	NGI_GET_MSG(item, msg);
+	msg->header.flags |= NGF_RESP;
+	NG_RESPOND_MSG(error, node, item, msg);
+	return (error);
+}
+
+static int
+ng_atmllc_shutdown(node_p node)
+{
+	struct	ng_atmllc_priv *priv;
+
+	priv = NG_NODE_PRIVATE(node);
+
+	FREE(priv, M_NETGRAPH);
+
+	NG_NODE_UNREF(node);
+
+	return (0);
+}
+
+static int
+ng_atmllc_newhook(node_p node, hook_p hook, const char *name)
+{
+	struct	ng_atmllc_priv *priv;
+
+	priv = NG_NODE_PRIVATE(node);
+
+	if (strcmp(name, NG_ATMLLC_HOOK_ATM) == 0) {
+		if (priv->atm != NULL) {
+			return (EISCONN);
+		}
+		priv->atm = hook;
+	} else if (strcmp(name, NG_ATMLLC_HOOK_ETHER) == 0) {
+		if (priv->ether != NULL) {
+			return (EISCONN);
+		}
+		priv->ether = hook;
+	} else if (strcmp(name, NG_ATMLLC_HOOK_FDDI) == 0) {
+		if (priv->fddi != NULL) {
+			return (EISCONN);
+		}
+		priv->fddi = hook;
+	} else {
+		return (EINVAL);
+	}
+
+	return (0);
+}
+
+static int
+ng_atmllc_rcvdata(hook_p hook, item_p item)
+{
+	struct	ng_atmllc_priv *priv;
+	struct	mbuf *m;
+	struct	atmllc *hdr;
+	hook_p	outhook;
+	u_int	padding;
+	int	error;
+
+	priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
+	m = NGI_M(item);
+	outhook = NULL;
+	padding = 0;
+
+	if (hook == priv->atm) {
+		/* Ditch the psuedoheader. */
+		hdr = mtod(m, struct atmllc *);
+		/* m_adj(m, sizeof(struct atm_pseudohdr)); */
+
+		/*
+		 * Make sure we have the LLC and ethernet headers.
+		 * The ethernet header size is slightly larger than the FDDI
+		 * header, which is convenient.
+		 */
+		if (m->m_len < sizeof(struct atmllc) + ETHER_HDR_LEN) {
+			m = m_pullup(m, sizeof(struct atmllc) + ETHER_HDR_LEN);
+			if (m == NULL) {
+				return (ENOMEM);
+			}
+		}
+
+		/* Decode the LLC header. */
+		hdr = mtod(m, struct atmllc *);
+		if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_ETHERNET_NOFCS) {
+			m->m_flags &= ~M_HASFCS;
+			outhook = priv->ether;
+			padding = 2;
+		} else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_ETHERNET_FCS) {
+			m->m_flags |= M_HASFCS;
+			outhook = priv->ether;
+			padding = 2;
+		} else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_FDDI_NOFCS) {
+			m->m_flags &= ~M_HASFCS;
+			outhook = priv->fddi;
+			padding = 3;
+		} else if (ATM_LLC_TYPE(hdr) == NG_ATMLLC_TYPE_FDDI_FCS) {
+			m->m_flags |= M_HASFCS;
+			outhook = priv->fddi;
+			padding = 3;
+		} else {
+			printf("ng_atmllc: unknown type: %x\n",
+			    ATM_LLC_TYPE(hdr));
+		}
+
+		/* Remove the LLC header and any padding*/
+		m_adj(m, sizeof(struct atmllc) + padding);
+	} else if (hook == priv->ether) {
+		/* Add the LLC header */
+		M_PREPEND(m, NG_ATMLLC_HEADER_LEN + 2, M_DONTWAIT);
+		if (m == NULL) {
+			printf("ng_atmllc: M_PREPEND failed\n");
+			NG_FREE_ITEM(item);
+			return (ENOMEM);
+		}
+		hdr = mtod(m, struct atmllc *);
+		bzero((void *)hdr, sizeof(struct atmllc) + 2);
+		bcopy(NG_ATMLLC_HEADER, hdr->llchdr, 6);
+		if ((m->m_flags & M_HASFCS) != 0) {
+			ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_ETHERNET_FCS);
+		} else {
+			ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_ETHERNET_NOFCS);
+		}
+		outhook = priv->atm;
+	} else if (hook == priv->fddi) {
+		/* Add the LLC header */
+		M_PREPEND(m, NG_ATMLLC_HEADER_LEN + 3, M_DONTWAIT);
+		if (m == NULL) {
+			printf("ng_atmllc: M_PREPEND failed\n");
+			NG_FREE_ITEM(item);
+			return (ENOMEM);
+		}
+		hdr = mtod(m, struct atmllc *);
+		bzero((void *)hdr, sizeof(struct atmllc) + 3);
+		bcopy(NG_ATMLLC_HEADER, hdr->llchdr, 6);
+		if ((m->m_flags & M_HASFCS) != 0) {
+			ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_FDDI_FCS);
+		} else {
+			ATM_LLC_SETTYPE(hdr, NG_ATMLLC_TYPE_FDDI_NOFCS);
+		}
+		outhook = priv->atm;
+	}
+
+	if (outhook == NULL) {
+		NG_FREE_ITEM(item);
+		return (0);
+	}
+
+	NG_FWD_NEW_DATA(error, item, outhook, m);
+	return (error);
+}
+
+static int
+ng_atmllc_disconnect(hook_p hook)
+{
+	node_p	node;
+	struct	ng_atmllc_priv *priv;
+
+	node = NG_HOOK_NODE(hook);
+	priv = NG_NODE_PRIVATE(node);
+
+	if (hook == priv->atm) {
+		priv->atm = NULL;
+	} else if (hook == priv->ether) {
+		priv->ether = NULL;
+	} else if (hook == priv->fddi) {
+		priv->fddi = NULL;
+	}
+
+	if (NG_NODE_NUMHOOKS(node) == 0 && NG_NODE_IS_VALID(node)) {
+		ng_rmnode_self(node);
+	}
+
+	return (0);
+}