A node that creates a device entry in /dev (yay devfs)

so that /dev/mumble can be the entrypoint to some networking graph,
e.g. a tunnel or a remote tape drive or whatever...

Not fully tested (by me) yet.

Submitted by:	Mark Santcroos <marks@ripe.net>
MFC after:	3 weeks

4 files changed, 689 insertions, 0 deletions

diff --git a/sys/conf/files b/sys/conf/files
index 3ce861b..b3ea208 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1112,6 +1112,7 @@ netgraph/ng_bpf.c	optional netgraph_bpf
 net/bpf_filter.c	optional netgraph_bpf
 netgraph/ng_bridge.c	optional netgraph_bridge
 netgraph/ng_cisco.c	optional netgraph_cisco
+netgraph/ng_device.c	optional netgraph_device
 netgraph/ng_echo.c	optional netgraph_echo
 netgraph/ng_ether.c	optional netgraph_ether
 netgraph/ng_frame_relay.c	optional netgraph_frame_relay
diff --git a/sys/modules/netgraph/device/Makefile b/sys/modules/netgraph/device/Makefile
new file mode 100644
index 0000000..9f85151
--- /dev/null
+++ b/sys/modules/netgraph/device/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+KMOD=   ng_device
+SRCS=   ng_device.c
+
+SRCS+=   device_if.h
+
+.include <bsd.kmod.mk>
diff --git a/sys/netgraph/ng_device.c b/sys/netgraph/ng_device.c
new file mode 100644
index 0000000..55c0606
--- /dev/null
+++ b/sys/netgraph/ng_device.c
@@ -0,0 +1,637 @@
+/*
+ * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
+ *
+ * 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.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * 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.
+ *
+ * Netgraph "device" node
+ *
+ * This node presents a /dev/ngd%d device that interfaces to an other 
+ * netgraph node.
+ *
+ * $FreeBSD$
+ *
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/mbuf.h>
+#include <sys/uio.h>
+#include <sys/queue.h>
+#include <sys/malloc.h>
+#include <sys/conf.h>
+#include <sys/poll.h>
+#include <sys/ioccom.h>
+
+#include <netgraph/ng_message.h>
+#include <netgraph/netgraph.h>
+
+#include "ng_device.h"
+
+/* turn this on for verbose messages */
+#define NGD_DEBUG
+
+/* Netgraph methods */
+static ng_constructor_t	ng_device_cons;
+static ng_rcvmsg_t	ng_device_rcvmsg;
+static ng_newhook_t	ng_device_newhook;
+static ng_connect_t 	ng_device_connect;
+static ng_rcvdata_t	ng_device_rcvdata;
+static ng_disconnect_t	ng_device_disconnect;
+static int              ng_device_mod_event(module_t mod, int event, void *data);
+
+static int ng_device_init(void);
+static int get_free_unit(void);
+
+/* Netgraph type */
+static struct ng_type typestruct = {
+	NG_ABI_VERSION,			/* version */
+	NG_DEVICE_NODE_TYPE,		/* name */
+	ng_device_mod_event,		/* modevent */
+	ng_device_cons, 		/* constructor */
+	ng_device_rcvmsg, 		/* receive msg */
+	NULL, 				/* shutdown */
+	ng_device_newhook, 		/* newhook */
+	NULL,				/* findhook */
+	ng_device_connect, 		/* connect */
+	ng_device_rcvdata, 		/* receive data */
+	ng_device_disconnect, 		/* disconnect */
+	NULL
+};
+NETGRAPH_INIT(device, &typestruct);
+
+/* per hook data */
+struct ngd_connection {
+	SLIST_ENTRY(ngd_connection) links;
+
+	dev_t 	ngddev;
+	struct 	ng_hook *active_hook;
+	char	*readq;
+	int 	loc;
+	int 	unit;
+};
+
+/* global data */
+struct ngd_softc {
+	SLIST_HEAD(, ngd_connection) head;
+
+	node_p node;
+	char nodename[NG_NODELEN + 1];
+} ngd_softc;
+
+/* helper definition */
+#define		MIN(a, b)	((a) < (b) ? (a) : (b))
+
+/* the per connection receiving queue maximum */
+#define NGD_QUEUE_SIZE (1024*10)
+
+/* Maximum number of NGD devices */
+#define MAX_NGD	25 		/* should be more than enough for now */
+
+static d_close_t ngdclose;
+static d_open_t ngdopen;
+static d_read_t ngdread;
+static d_write_t ngdwrite;
+static d_ioctl_t ngdioctl;
+static d_poll_t ngdpoll;
+
+#define NGD_CDEV_MAJOR 20
+static struct cdevsw ngd_cdevsw = {
+        /* open */      ngdopen,
+        /* close */     ngdclose,
+        /* read */      ngdread,
+        /* write */     ngdwrite,
+        /* ioctl */     ngdioctl,
+        /* poll */      ngdpoll,
+        /* mmap */      nommap,
+        /* strategy */  nostrategy,
+        /* name */      "ngd",
+        /* maj */       NGD_CDEV_MAJOR,
+        /* dump */      nodump,
+        /* psize */     nopsize,
+        /* flags */     0,
+};
+
+/* 
+ * this holds all the stuff that should be done at load time 
+ */
+static int
+ng_device_mod_event(module_t mod, int event, void *data)
+{
+	int error = 0;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	switch (event) {
+		case MOD_LOAD:
+
+			ng_device_init();
+			break;
+
+		case MOD_UNLOAD:
+			/* XXX do we need to do something specific ? */
+			/* ng_device_breakdown */
+			break;
+		
+		default:
+			error = EOPNOTSUPP;
+			break;
+	}
+
+	return(error);
+}
+
+
+static int
+ng_device_init()
+{
+        struct ngd_softc *sc = &ngd_softc;
+	
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */ 
+
+	SLIST_INIT(&sc->head);
+
+        if (ng_make_node_common(&typestruct, &sc->node) != 0) {
+                printf("%s(): ng_make_node_common failed\n",__func__);
+                return(ENXIO);
+        }
+        sprintf(sc->nodename, "%s", NG_DEVICE_NODE_TYPE);
+        if (ng_name_node(sc->node, sc->nodename)) {
+                NG_NODE_UNREF(sc->node); /* make it go away again */
+                printf("%s(): ng_name_node failed\n",__func__);
+                return(ENXIO);
+        }
+        NG_NODE_SET_PRIVATE(sc->node, sc);
+
+	return(0);
+}
+
+/* 
+ * don't allow to be created, only the device can do that 
+ */
+static int
+ng_device_cons(node_p node)
+{
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+	
+	return(EINVAL);
+}
+
+/*
+ * Receive control message. We just bounce it back as a reply.
+ */
+static int
+ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
+{
+        struct ngd_softc *sc = &ngd_softc;
+	struct ng_mesg *msg;
+	int error = 0;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection *tmp = NULL;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	NGI_GET_MSG(item, msg); 
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->active_hook == lasthook) {
+			connection = tmp;
+		}
+	}
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no hook found\n",__func__);
+		return(-1);
+	}
+
+	return(error);
+}
+
+static int
+get_free_unit()
+{
+	struct ngd_connection *tmp = NULL;
+	struct ngd_softc *sc = &ngd_softc;
+	int n = 0;
+	int unit = -1;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	/* When there is no list yet, the first device unit is always 0. */
+	if SLIST_EMPTY(&sc->head) {
+		unit = 0;
+		return(unit);
+	}
+
+	/* Just do a brute force loop to find the first free unit that is
+	 * smaller than MAX_NGD.
+	 * Set MAX_NGD to a large value, doesn't impact performance.
+	 */
+	for(n = 0;n<MAX_NGD && unit == -1;n++) {
+		SLIST_FOREACH(tmp,&sc->head,links) {
+
+			if(tmp->unit == n) {
+				unit = -1;
+				break;
+			}
+			unit = n;
+		}
+	}
+
+	return(unit);
+}
+
+/*
+ * incoming hook
+ */
+static int
+ng_device_newhook(node_p node, hook_p hook, const char *name)
+{
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * new_connection = NULL;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	new_connection = malloc(sizeof(struct ngd_connection), M_DEVBUF, M_NOWAIT);
+	if(new_connection == NULL) {
+		printf("%s(): ERROR: new_connection == NULL\n",__func__);
+		return(-1);
+	}
+
+	new_connection->unit = get_free_unit();
+	if(new_connection->unit<0) {
+		printf("%s: No free unit found by get_free_unit(), "
+				"increas MAX_NGD\n",__func__);
+		return(-1);
+	}
+	new_connection->ngddev = make_dev(&ngd_cdevsw, new_connection->unit, 0, 0,0600,"ngd%d",new_connection->unit);
+	if(new_connection->ngddev == NULL) {
+		printf("%s(): make_dev failed\n",__func__);
+		return(-1);
+	}
+
+	new_connection->readq = malloc(sizeof(char)*NGD_QUEUE_SIZE, M_DEVBUF, M_NOWAIT | M_ZERO);
+	if(new_connection->readq == NULL) {
+		printf("%s(): readq malloc failed\n",__func__);
+		return(-1);
+	}
+
+	/* point to begin of buffer */
+	new_connection->loc = 0;
+	new_connection->active_hook = hook;
+
+	SLIST_INSERT_HEAD(&sc->head, new_connection, links);
+
+	return(0);
+}
+
+/*
+ * we gave ok to a new hook
+ * now connect
+ */
+static int
+ng_device_connect(hook_p hook)
+{
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	return(0);
+}
+
+
+/*
+ * Receive data from hook
+ */
+static int
+ng_device_rcvdata(hook_p hook, item_p item)
+{
+	struct mbuf *m;
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+	char *buffer;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->active_hook == hook) {
+			connection = tmp;
+		}
+	}
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no hook found\n",__func__);
+		return(-1);
+	}
+
+	NGI_GET_M(item, m);
+	NG_FREE_ITEM(item);
+
+	m = m_pullup(m,m->m_len);
+	if(m == NULL) {
+		printf("%s(): ERROR: m_pullup failed\n",__func__);
+		return(-1);
+	}
+
+	buffer = malloc(sizeof(char)*m->m_len, M_DEVBUF, M_NOWAIT | M_ZERO);
+	if(buffer == NULL) {
+		printf("%s(): ERROR: buffer malloc failed\n",__func__);
+		return(-1);
+	}
+
+	buffer = mtod(m,char *);
+
+	if( (connection->loc+m->m_len) < NGD_QUEUE_SIZE) {
+	        memcpy(connection->readq+connection->loc, buffer, m->m_len);
+		connection->loc += m->m_len;
+	} else
+		printf("%s(): queue full, first read out a bit\n",__func__);
+
+	free(buffer,M_DEVBUF);
+
+	return(0);
+}
+
+/*
+ * Removal of the last link destroys the node
+ */
+static int
+ng_device_disconnect(hook_p hook)
+{
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->active_hook == hook) {
+			connection = tmp;
+		}
+	}
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no hook found\n",__func__);
+		return(-1);
+	}
+
+        free(connection->readq,M_DEVBUF);
+
+	destroy_dev(connection->ngddev);
+
+	SLIST_REMOVE(&sc->head,connection,ngd_connection,links);
+
+	return(0);
+}
+/*
+ * the device is opened 
+ */
+static int
+ngdopen(dev_t dev, int flag, int mode, struct thread *td)
+{
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	return(0);
+}
+
+/*
+ * the device is closed 
+ */
+static int
+ngdclose(dev_t dev, int flag, int mode, struct thread *td)
+{
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif
+
+	return(0);
+}
+
+
+/*
+ * process ioctl
+ *
+ * they are translated into netgraph messages and passed on
+ * 
+ */
+static int
+ngdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
+{
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+	int error = 0;
+	struct ng_mesg *msg;
+        struct ngd_param_s * datap;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->ngddev == dev) {
+			connection = tmp;
+		}
+	}
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no dev found\n",__func__);
+		return(-1);
+	}
+
+	/* NG_MKMESSAGE(msg, cookie, cmdid, len, how) */
+	NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s), 
+			M_NOWAIT);
+	if (msg == NULL) {
+		printf("%s(): msg == NULL\n",__func__);
+		goto nomsg;
+	}
+
+	/* pass the ioctl data into the ->data area */
+	datap = (struct ngd_param_s *)msg->data;
+        datap->p = addr;
+
+	/* NG_SEND_MSG_HOOK(error, here, msg, hook, retaddr) */
+	NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, NULL);
+	if(error)
+		printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
+
+nomsg:
+
+	return(0);
+}
+
+
+/*
+ * This function is called when a read(2) is done to our device.
+ * We pass the data available in kernelspace on into userland using
+ * uiomove.
+ */
+static int
+ngdread(dev_t dev, struct uio *uio, int flag)
+{
+	int ret = 0, amnt;
+	char buffer[uio->uio_resid+1];
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->ngddev == dev) {
+			connection = tmp;
+		}
+	}
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no dev found\n",__func__);
+		return(-1);
+	}
+
+	while ( ( uio->uio_resid > 0 ) && ( connection->loc > 0 ) ) {
+		amnt = MIN(uio->uio_resid,connection->loc);
+
+		memcpy(buffer,connection->readq, amnt);
+		memcpy(connection->readq, connection->readq+amnt,
+				connection->loc-amnt);
+		connection->loc -= amnt;
+
+		ret = uiomove((caddr_t)buffer, amnt, uio);
+		if(ret != 0)
+			goto error;
+
+	}
+	return(0);
+
+error:
+	printf("%s(): uiomove returns error %d\n",__func__,ret);
+	/* do error cleanup here */
+	return(ret);
+}
+
+
+/* 
+ * This function is called when our device is written to.
+ * We read the data from userland into our local buffer and pass it on
+ * into the remote hook.
+ *
+ */
+static int
+ngdwrite(dev_t dev, struct uio *uio, int flag)
+{
+	int ret;
+	int error = 0;
+	struct mbuf *m;
+	char buffer[uio->uio_resid];
+	int len = uio->uio_resid;
+	struct ngd_softc *sc =& ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+
+#ifdef NGD_DEBUG
+	printf("%s()\n",__func__);
+#endif /* NGD_DEBUG */
+
+	SLIST_FOREACH(tmp,&sc->head,links) {
+		if(tmp->ngddev == dev) {
+			connection = tmp;
+		}
+	}
+
+	if(connection == NULL) {
+		printf("%s(): connection is still NULL, no dev found\n",__func__);
+		return(-1);
+	}
+
+	if (len > 0) {
+		if ((ret = uiomove((caddr_t)buffer, len, uio)) != 0)
+			goto error;
+	} else
+		printf("%s(): len <= 0 : is this supposed to happen?!\n",__func__);
+
+	m = m_devget(buffer,len,0,NULL,NULL);
+
+	NG_SEND_DATA_ONLY(error,connection->active_hook,m);
+
+	return(0);
+
+error:
+	/* do error cleanup here */
+	printf("%s(): uiomove returned err: %d\n",__func__,ret);
+
+	return(ret);
+}
+
+/*
+ * we are being polled/selected
+ * check if there is data available for read
+ */
+static int
+ngdpoll(dev_t dev, int events, struct thread *td)
+{
+	int revents = 0;
+	struct ngd_softc *sc = &ngd_softc;
+	struct ngd_connection * connection = NULL;
+	struct ngd_connection * tmp;
+
+
+	if (events & (POLLIN | POLLRDNORM)) {
+		/* get the connection we have to know the loc from */
+		SLIST_FOREACH(tmp,&sc->head,links) {
+			if(tmp->ngddev == dev) {
+				connection = tmp;
+			}
+		}
+		if(connection == NULL) {
+			printf("%s(): ERROR: connection is still NULL,"
+				"no dev found\n",__func__);
+			return(-1);
+		}
+
+		if (connection->loc > 0)
+			revents |= events & (POLLIN | POLLRDNORM);
+	}
+
+	return(revents);
+}
diff --git a/sys/netgraph/ng_device.h b/sys/netgraph/ng_device.h
new file mode 100644
index 0000000..335a332
--- /dev/null
+++ b/sys/netgraph/ng_device.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
+ *
+ * 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.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * 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.
+ *
+ *
+ * $FreeBSD$
+ *
+ */
+
+#ifndef _NETGRAPH_DEVICE_H_
+#define _NETGRAPH_DEVICE_H_
+
+/* Node type name and magic cookie */
+#define NG_DEVICE_NODE_TYPE	"device"
+#define NGM_DEVICE_COOKIE	1009920473
+
+/* passing ioctl params */
+struct ngd_param_s {
+	        void * p;
+};
+
+
+#endif /* _NETGRAPH_DEVICE_H_ */