Whistle's Netgraph link-layer (sometimes more) networking infrastructure.

Been in production for 3 years now. Gives Instant Frame relay to if_sr
and if_ar drivers, and PPPOE support soon. See:
ftp://ftp.whistle.com/pub/archie/netgraph/index.html
for on-line manual pages.

Reviewed by: Doug Rabson (dfr@freebsd.org)
Obtained from:  Whistle CVS tree

1 files changed, 268 insertions, 0 deletions

diff --git a/sys/netgraph/ng_tee.c b/sys/netgraph/ng_tee.c
new file mode 100644
index 0000000..476913c
--- /dev/null
+++ b/sys/netgraph/ng_tee.c
@@ -0,0 +1,268 @@
+
+/*
+ * ng_tee.c
+ *
+ * Copyright (c) 1996-1999 Whistle Communications, Inc.
+ * All rights reserved.
+ * 
+ * Subject to the following obligations and disclaimer of warranty, use and
+ * redistribution of this software, in source or object code forms, with or
+ * without modifications are expressly permitted by Whistle Communications;
+ * provided, however, that:
+ * 1. Any and all reproductions of the source or object code must include the
+ *    copyright notice above and the following disclaimer of warranties; and
+ * 2. No rights are granted, in any manner or form, to use Whistle
+ *    Communications, Inc. trademarks, including the mark "WHISTLE
+ *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
+ *    such appears in the above copyright notice or in the software.
+ * 
+ * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
+ * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
+ * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
+ * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
+ * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
+ * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
+ * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
+ * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
+ * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
+ * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
+ * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Julian Elischer <julian@whistle.com>
+ *
+ * $FreeBSD$
+ * $Whistle: ng_tee.c,v 1.16 1999/01/28 23:54:54 julian Exp $
+ */
+
+/*
+ * This node is like the tee(1) command and is useful for ``snooping.''
+ * It has 4 hooks: left, right, left2right, and right2left. Data
+ * entering from the right is passed to the left and duplicated on
+ * right2left, and data entering from the left is passed to the right
+ * and duplicated on left2right. Data entering from left2right is
+ * sent to right, and data from right2left to left.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/errno.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <netgraph/ng_message.h>
+#include <netgraph/netgraph.h>
+#include <netgraph/ng_tee.h>
+
+/* Per hook info */
+struct hookinfo {
+	hook_p  hook;
+	int     bytes;
+	int     packets;
+	int     flags;
+};
+
+/* Per node info */
+struct privdata {
+	node_p  node;
+	int     flags;
+	struct hookinfo left;
+	struct hookinfo right;
+	struct hookinfo left2right;
+	struct hookinfo right2left;
+};
+typedef struct privdata *sc_p;
+
+/* Netgraph methods */
+static int	ngt_constructor(node_p *node);
+static int	ngt_rcvmsg(node_p node, struct ng_mesg *msg,
+		    const char *retaddr, struct ng_mesg **resp);
+static int	ngt_rmnode(node_p node);
+static int	ngt_newhook(node_p node, hook_p hook, const char *name);
+static int	ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta);
+static int	ngt_disconnect(hook_p hook);
+
+/* Netgraph type descriptor */
+static struct ng_type typestruct = {
+	NG_VERSION,
+	NG_TEE_NODE_TYPE,
+	NULL,
+	ngt_constructor,
+	ngt_rcvmsg,
+	ngt_rmnode,
+	ngt_newhook,
+	NULL,
+	NULL,
+	ngt_rcvdata,
+	ngt_rcvdata,
+	ngt_disconnect
+};
+NETGRAPH_INIT(tee, &typestruct);
+
+/*
+ * Node constructor
+ */
+static int
+ngt_constructor(node_p *nodep)
+{
+	sc_p privdata;
+	int error = 0;
+
+	MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_WAITOK);
+	if (privdata == NULL)
+		return (ENOMEM);
+	bzero(privdata, sizeof(*privdata));
+
+	if ((error = ng_make_node_common(&typestruct, nodep))) {
+		FREE(privdata, M_NETGRAPH);
+		return (error);
+	}
+	(*nodep)->private = privdata;
+	privdata->node = *nodep;
+	return (0);
+}
+
+/*
+ * Add a hook
+ */
+static int
+ngt_newhook(node_p node, hook_p hook, const char *name)
+{
+	const sc_p sc = node->private;
+
+	if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
+		sc->right.hook = hook;
+		sc->right.bytes = 0;
+		sc->right.packets = 0;
+		hook->private = &sc->right;
+	} else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
+		sc->left.hook = hook;
+		sc->left.bytes = 0;
+		sc->left.packets = 0;
+		hook->private = &sc->left;
+	} else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
+		sc->right2left.hook = hook;
+		sc->right2left.bytes = 0;
+		sc->right2left.packets = 0;
+		hook->private = &sc->right2left;
+	} else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
+		sc->left2right.hook = hook;
+		sc->left2right.bytes = 0;
+		sc->left2right.packets = 0;
+		hook->private = &sc->left2right;
+	} else
+		return (EINVAL);
+	return (0);
+}
+
+/*
+ * We don't support any type-specific messages
+ */
+static int
+ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
+	   struct ng_mesg **resp)
+{
+	FREE(msg, M_NETGRAPH);
+	return (EINVAL);
+}
+
+/*
+ * Receive data on a hook
+ *
+ * If data comes in the right link send a copy out right2left, and then
+ * send the original onwards out through the left link.
+ * Do the opposite for data coming in from the left link.
+ * Data coming in right2left or left2right is forwarded
+ * on through the appropriate destination hook as if it had come
+ * from the other side.
+ */
+static int
+ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
+{
+	const sc_p sc = hook->node->private;
+	struct hookinfo *hi;
+	struct hookinfo *dest;
+	struct hookinfo *dup;
+	struct mbuf *mdup;
+	int error = 0;
+
+	if ((hi = hook->private) != NULL) {
+		if (hi == &sc->left) {
+			dup = &sc->left2right;
+			dest = &sc->right;
+		} else if (hi == &sc->right) {
+			dup = &sc->right2left;
+			dest = &sc->left;
+		} else if (hi == &sc->right2left) {
+			dup = NULL;
+			dest = &sc->left;
+		} else if (hi == &sc->left2right) {
+			dup = NULL;
+			dest = &sc->right;
+		} else
+			goto out;
+		if (dup) {
+			mdup = m_copypacket(m, M_NOWAIT);
+			if (mdup) {
+				/* XXX should we duplicate meta? */
+				/* for now no.			 */
+				void   *x = NULL;
+
+				NG_SEND_DATA(error, dup->hook, mdup, x);
+			}
+		}
+		NG_SEND_DATA(error, dest->hook, m, meta);
+	}
+
+out:
+	NG_FREE_DATA(m, meta);
+	return (error);
+}
+
+/*
+ * Shutdown processing
+ *
+ * This is tricky. If we have both a left and right hook, then we
+ * probably want to extricate ourselves and leave the two peers
+ * still linked to each other. Otherwise we should just shut down as
+ * a normal node would.
+ *
+ * To keep the scope of info correct the routine to "extract" a node
+ * from two links is in ng_base.c.
+ */
+static int
+ngt_rmnode(node_p node)
+{
+	const sc_p privdata = node->private;
+
+	node->flags |= NG_INVALID;
+	if (privdata->left.hook && privdata->right.hook)
+		ng_bypass(privdata->left.hook, privdata->right.hook);
+	ng_cutlinks(node);
+	ng_unname(node);
+	node->private = NULL;
+	ng_unref(privdata->node);
+	FREE(privdata, M_NETGRAPH);
+	return (0);
+}
+
+/*
+ * Hook disconnection
+ */
+static int
+ngt_disconnect(hook_p hook)
+{
+	struct hookinfo *hi;
+
+	if ((hi = hook->private) != NULL)
+		hi->hook = NULL;
+	if (hook->node->numhooks == 0)
+		ng_rmnode(hook->node);
+	return (0);
+}
+