xref: /freebsd/sys/netgraph/ng_socket.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
1 
2 /*
3  * ng_socket.c
4  *
5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
6  * All rights reserved.
7  *
8  * Subject to the following obligations and disclaimer of warranty, use and
9  * redistribution of this software, in source or object code forms, with or
10  * without modifications are expressly permitted by Whistle Communications;
11  * provided, however, that:
12  * 1. Any and all reproductions of the source or object code must include the
13  *    copyright notice above and the following disclaimer of warranties; and
14  * 2. No rights are granted, in any manner or form, to use Whistle
15  *    Communications, Inc. trademarks, including the mark "WHISTLE
16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17  *    such appears in the above copyright notice or in the software.
18  *
19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35  * OF SUCH DAMAGE.
36  *
37  * Author: Julian Elischer <julian@whistle.com>
38  *
39  * $FreeBSD$
40  * $Whistle: ng_socket.c,v 1.28 1999/11/01 09:24:52 julian Exp $
41  */
42 
43 /*
44  * Netgraph socket nodes
45  *
46  * There are two types of netgraph sockets, control and data.
47  * Control sockets have a netgraph node, but data sockets are
48  * parasitic on control sockets, and have no node of their own.
49  */
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/proc.h>
54 #include <sys/domain.h>
55 #include <sys/errno.h>
56 #include <sys/kernel.h>
57 #include <sys/filedesc.h>
58 #include <sys/malloc.h>
59 #include <sys/queue.h>
60 #include <sys/mbuf.h>
61 #include <sys/protosw.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/sysctl.h>
65 #ifdef NOTYET
66 #include <sys/vnode.h>
67 #endif
68 #include <netgraph/ng_message.h>
69 #include <netgraph/netgraph.h>
70 #include <netgraph/ng_socketvar.h>
71 #include <netgraph/ng_socket.h>
72 
73 /*
74  * It's Ascii-art time!
75  *   +-------------+   +-------------+
76  *   |socket  (ctl)|   |socket (data)|
77  *   +-------------+   +-------------+
78  *          ^                 ^
79  *          |                 |
80  *          v                 v
81  *    +-----------+     +-----------+
82  *    |pcb   (ctl)|     |pcb  (data)|
83  *    +-----------+     +-----------+
84  *          ^                 ^
85  *          |                 |
86  *          v                 v
87  *      +--------------------------+
88  *      |   Socket type private    |
89  *      |       data               |
90  *      +--------------------------+
91  *                   ^
92  *                   |
93  *                   v
94  *           +----------------+
95  *           | struct ng_node |
96  *           +----------------+
97  */
98 
99 /* Netgraph node methods */
100 static ng_constructor_t	ngs_constructor;
101 static ng_rcvmsg_t	ngs_rcvmsg;
102 static ng_shutdown_t	ngs_rmnode;
103 static ng_newhook_t	ngs_newhook;
104 static ng_rcvdata_t	ngs_rcvdata;
105 static ng_disconnect_t	ngs_disconnect;
106 
107 /* Internal methods */
108 static int	ng_attach_data(struct socket *so);
109 static int	ng_attach_cntl(struct socket *so);
110 static int	ng_attach_common(struct socket *so, int type);
111 static void	ng_detach_common(struct ngpcb *pcbp, int type);
112 /*static int	ng_internalize(struct mbuf *m, struct proc *p); */
113 
114 static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
115 static int	ng_connect_cntl(struct sockaddr *nam, struct ngpcb *pcbp);
116 static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
117 
118 static int	ngs_mod_event(module_t mod, int event, void *data);
119 static int	ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg,
120 			struct sockaddr_ng *addr);
121 
122 /* Netgraph type descriptor */
123 static struct ng_type typestruct = {
124 	NG_VERSION,
125 	NG_SOCKET_NODE_TYPE,
126 	ngs_mod_event,
127 	ngs_constructor,
128 	ngs_rcvmsg,
129 	ngs_rmnode,
130 	ngs_newhook,
131 	NULL,
132 	NULL,
133 	ngs_rcvdata,
134 	ngs_rcvdata,
135 	ngs_disconnect,
136 	NULL
137 };
138 NETGRAPH_INIT(socket, &typestruct);
139 
140 /* Buffer space */
141 static u_long ngpdg_sendspace = 2 * 1024;	/* really max datagram size */
142 static u_long ngpdg_recvspace = 20 * 1024;
143 
144 /* List of all sockets */
145 LIST_HEAD(, ngpcb) ngsocklist;
146 
147 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
148 
149 /* If getting unexplained errors returned, set this to "Debugger("X"); */
150 #ifndef TRAP_ERROR
151 #define TRAP_ERROR
152 #endif
153 
154 /***************************************************************
155 	Control sockets
156 ***************************************************************/
157 
158 static int
159 ngc_attach(struct socket *so, int proto, struct proc *p)
160 {
161 	struct ngpcb *const pcbp = sotongpcb(so);
162 
163 	if (suser(p))
164 		return (EPERM);
165 	if (pcbp != NULL)
166 		return (EISCONN);
167 	return (ng_attach_cntl(so));
168 }
169 
170 static int
171 ngc_detach(struct socket *so)
172 {
173 	struct ngpcb *const pcbp = sotongpcb(so);
174 
175 	if (pcbp == NULL)
176 		return (EINVAL);
177 	ng_detach_common(pcbp, NG_CONTROL);
178 	return (0);
179 }
180 
181 static int
182 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
183 	 struct mbuf *control, struct proc *p)
184 {
185 	struct ngpcb *const pcbp = sotongpcb(so);
186 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
187 	struct ng_mesg *resp;
188 	struct mbuf *m0;
189 	char *msg, *path = NULL;
190 	int len, error = 0;
191 
192 	if (pcbp == NULL) {
193 		error = EINVAL;
194 		goto release;
195 	}
196 #ifdef	NOTYET
197 	if (control && (error = ng_internalize(control, p))) {
198 		if (pcbp->sockdata == NULL) {
199 			error = ENOTCONN;
200 			goto release;
201 		}
202 	}
203 #else	/* NOTYET */
204 	if (control) {
205 		error = EINVAL;
206 		goto release;
207 	}
208 #endif	/* NOTYET */
209 
210 	/* Require destination as there may be >= 1 hooks on this node */
211 	if (addr == NULL) {
212 		error = EDESTADDRREQ;
213 		goto release;
214 	}
215 
216 	/* Allocate an expendable buffer for the path, chop off
217 	 * the sockaddr header, and make sure it's NUL terminated */
218 	len = sap->sg_len - 2;
219 	MALLOC(path, char *, len + 1, M_NETGRAPH, M_WAITOK);
220 	if (path == NULL) {
221 		error = ENOMEM;
222 		goto release;
223 	}
224 	bcopy(sap->sg_data, path, len);
225 	path[len] = '\0';
226 
227 	/* Move the actual message out of mbufs into a linear buffer.
228 	 * Start by adding up the size of the data. (could use mh_len?) */
229 	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
230 		len += m0->m_len;
231 
232 	/* Move the data into a linear buffer as well. Messages are not
233 	 * delivered in mbufs. */
234 	MALLOC(msg, char *, len + 1, M_NETGRAPH, M_WAITOK);
235 	if (msg == NULL) {
236 		error = ENOMEM;
237 		goto release;
238 	}
239 	m_copydata(m, 0, len, msg);
240 
241 	/* The callee will free the msg when done. The addr is our business. */
242 	error = ng_send_msg(pcbp->sockdata->node,
243 			    (struct ng_mesg *) msg, path, &resp);
244 
245 	/* If the callee responded with a synchronous response, then put it
246 	 * back on the receive side of the socket; sap is source address. */
247 	if (error == 0 && resp != NULL)
248 		error = ship_msg(pcbp, resp, sap);
249 
250 release:
251 	if (path != NULL)
252 		FREE(path, M_NETGRAPH);
253 	if (control != NULL)
254 		m_freem(control);
255 	if (m != NULL)
256 		m_freem(m);
257 	return (error);
258 }
259 
260 static int
261 ngc_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
262 {
263 	struct ngpcb *const pcbp = sotongpcb(so);
264 
265 	if (pcbp == 0)
266 		return (EINVAL);
267 	return (ng_bind(nam, pcbp));
268 }
269 
270 static int
271 ngc_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
272 {
273 	struct ngpcb *const pcbp = sotongpcb(so);
274 
275 	if (pcbp == 0)
276 		return (EINVAL);
277 	return (ng_connect_cntl(nam, pcbp));
278 }
279 
280 /***************************************************************
281 	Data sockets
282 ***************************************************************/
283 
284 static int
285 ngd_attach(struct socket *so, int proto, struct proc *p)
286 {
287 	struct ngpcb *const pcbp = sotongpcb(so);
288 
289 	if (pcbp != NULL)
290 		return (EISCONN);
291 	return (ng_attach_data(so));
292 }
293 
294 static int
295 ngd_detach(struct socket *so)
296 {
297 	struct ngpcb *const pcbp = sotongpcb(so);
298 
299 	if (pcbp == NULL)
300 		return (EINVAL);
301 	ng_detach_common(pcbp, NG_DATA);
302 	return (0);
303 }
304 
305 static int
306 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
307 	 struct mbuf *control, struct proc *p)
308 {
309 	struct ngpcb *const pcbp = sotongpcb(so);
310 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
311 	meta_p  mp = NULL;
312 	int     len, error;
313 	hook_p  hook = NULL;
314 	char	hookname[NG_HOOKLEN + 1];
315 
316 	if ((pcbp == NULL) || (control != NULL)) {
317 		error = EINVAL;
318 		goto release;
319 	}
320 	if (pcbp->sockdata == NULL) {
321 		error = ENOTCONN;
322 		goto release;
323 	}
324 	/*
325 	 * If the user used any of these ways to not specify an address
326 	 * then handle specially.
327 	 */
328 	if ((sap == NULL)
329 	|| ((len = sap->sg_len) <= 2)
330 	|| (*sap->sg_data == '\0')) {
331 		if (pcbp->sockdata->node->numhooks != 1) {
332 			error = EDESTADDRREQ;
333 			goto release;
334 		}
335 		/*
336 		 * if exactly one hook exists, just use it.
337 		 * Special case to allow write(2) to work on an ng_socket.
338 		 */
339 		hook = LIST_FIRST(&pcbp->sockdata->node->hooks);
340 	} else {
341 		if (len > NG_HOOKLEN) {
342 			error = EINVAL;
343 			goto release;
344 		}
345 
346 		/*
347 		 * chop off the sockaddr header, and make sure it's NUL
348 		 * terminated
349 		 */
350 		bcopy(sap->sg_data, hookname, len);
351 		hookname[len] = '\0';
352 
353 		/* Find the correct hook from 'hookname' */
354 		LIST_FOREACH(hook, &pcbp->sockdata->node->hooks, hooks) {
355 			if (strcmp(hookname, hook->name) == 0)
356 				break;
357 		}
358 		if (hook == NULL)
359 			error = EHOSTUNREACH;
360 	}
361 
362 	/* Send data (OK if hook is NULL) */
363 	NG_SEND_DATA(error, hook, m, mp);	/* makes m NULL */
364 
365 release:
366 	if (control != NULL)
367 		m_freem(control);
368 	if (m != NULL)
369 		m_freem(m);
370 	return (error);
371 }
372 
373 static int
374 ngd_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
375 {
376 	struct ngpcb *const pcbp = sotongpcb(so);
377 
378 	if (pcbp == 0)
379 		return (EINVAL);
380 	return (ng_connect_data(nam, pcbp));
381 }
382 
383 /*
384  * Used for both data and control sockets
385  */
386 static int
387 ng_setsockaddr(struct socket *so, struct sockaddr **addr)
388 {
389 	struct ngpcb *pcbp;
390 	struct sockaddr_ng *sg;
391 	int sg_len, namelen, s;
392 
393 	/* Why isn't sg_data a `char[1]' ? :-( */
394 	sg_len = sizeof(struct sockaddr_ng) - sizeof(sg->sg_data) + 1;
395 
396 	s = splnet();
397 	pcbp = sotongpcb(so);
398 	if (pcbp == 0) {
399 		splx(s);
400 		return (EINVAL);
401 	}
402 
403 	namelen = 0;		/* silence compiler ! */
404 
405 	if (pcbp->sockdata->node->name != NULL)
406 		sg_len += namelen = strlen(pcbp->sockdata->node->name);
407 
408 	MALLOC(sg, struct sockaddr_ng *, sg_len, M_SONAME, M_WAITOK);
409 	bzero(sg, sg_len);
410 
411 	if (pcbp->sockdata->node->name != NULL)
412 		bcopy(pcbp->sockdata->node->name, sg->sg_data, namelen);
413 	splx(s);
414 
415 	sg->sg_len = sg_len;
416 	sg->sg_family = AF_NETGRAPH;
417 	*addr = (struct sockaddr *)sg;
418 
419 	return (0);
420 }
421 
422 /*
423  * Attach a socket to it's protocol specific partner.
424  * For a control socket, actually create a netgraph node and attach
425  * to it as well.
426  */
427 
428 static int
429 ng_attach_cntl(struct socket *so)
430 {
431 	struct ngsock *privdata;
432 	struct ngpcb *pcbp;
433 	int error;
434 
435 	/* Setup protocol control block */
436 	if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
437 		return (error);
438 	pcbp = sotongpcb(so);
439 
440 	/* Allocate node private info */
441 	MALLOC(privdata, struct ngsock *,
442 	    sizeof(*privdata), M_NETGRAPH, M_WAITOK);
443 	if (privdata == NULL) {
444 		ng_detach_common(pcbp, NG_CONTROL);
445 		return (ENOMEM);
446 	}
447 	bzero(privdata, sizeof(*privdata));
448 
449 	/* Make the generic node components */
450 	if ((error = ng_make_node_common(&typestruct, &privdata->node)) != 0) {
451 		FREE(privdata, M_NETGRAPH);
452 		ng_detach_common(pcbp, NG_CONTROL);
453 		return (error);
454 	}
455 	privdata->node->private = privdata;
456 
457 	/* Link the pcb and the node private data */
458 	privdata->ctlsock = pcbp;
459 	pcbp->sockdata = privdata;
460 	privdata->refs++;
461 	return (0);
462 }
463 
464 static int
465 ng_attach_data(struct socket *so)
466 {
467 	return(ng_attach_common(so, NG_DATA));
468 }
469 
470 /*
471  * Set up a socket protocol control block.
472  * This code is shared between control and data sockets.
473  */
474 static int
475 ng_attach_common(struct socket *so, int type)
476 {
477 	struct ngpcb *pcbp;
478 	int error;
479 
480 	/* Standard socket setup stuff */
481 	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
482 	if (error)
483 		return (error);
484 
485 	/* Allocate the pcb */
486 	MALLOC(pcbp, struct ngpcb *, sizeof(*pcbp), M_PCB, M_WAITOK);
487 	if (pcbp == NULL)
488 		return (ENOMEM);
489 	bzero(pcbp, sizeof(*pcbp));
490 	pcbp->type = type;
491 
492 	/* Link the pcb and the socket */
493 	so->so_pcb = (caddr_t) pcbp;
494 	pcbp->ng_socket = so;
495 
496 	/* Add the socket to linked list */
497 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
498 	return (0);
499 }
500 
501 /*
502  * Disassociate the socket from it's protocol specific
503  * partner. If it's attached to a node's private data structure,
504  * then unlink from that too. If we were the last socket attached to it,
505  * then shut down the entire node. Shared code for control and data sockets.
506  */
507 static void
508 ng_detach_common(struct ngpcb *pcbp, int which)
509 {
510 	struct ngsock *sockdata;
511 
512 	if (pcbp->sockdata) {
513 		sockdata = pcbp->sockdata;
514 		pcbp->sockdata = NULL;
515 		switch (which) {
516 		case NG_CONTROL:
517 			sockdata->ctlsock = NULL;
518 			break;
519 		case NG_DATA:
520 			sockdata->datasock = NULL;
521 			break;
522 		default:
523 			panic(__FUNCTION__);
524 		}
525 		if ((--sockdata->refs == 0) && (sockdata->node != NULL))
526 			ng_rmnode(sockdata->node);
527 	}
528 	pcbp->ng_socket->so_pcb = NULL;
529 	pcbp->ng_socket = NULL;
530 	LIST_REMOVE(pcbp, socks);
531 	FREE(pcbp, M_PCB);
532 }
533 
534 #ifdef NOTYET
535 /*
536  * File descriptors can be passed into a AF_NETGRAPH socket.
537  * Note, that file descriptors cannot be passed OUT.
538  * Only character device descriptors are accepted.
539  * Character devices are useful to connect a graph to a device,
540  * which after all is the purpose of this whole system.
541  */
542 static int
543 ng_internalize(struct mbuf *control, struct proc *p)
544 {
545 	struct filedesc *fdp = p->p_fd;
546 	struct cmsghdr *cm = mtod(control, struct cmsghdr *);
547 	struct file *fp;
548 	struct vnode *vn;
549 	int oldfds;
550 	int fd;
551 
552 	if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
553 	    cm->cmsg_len != control->m_len) {
554 		TRAP_ERROR;
555 		return (EINVAL);
556 	}
557 
558 	/* Check there is only one FD. XXX what would more than one signify? */
559 	oldfds = (cm->cmsg_len - sizeof(*cm)) / sizeof(int);
560 	if (oldfds != 1) {
561 		TRAP_ERROR;
562 		return (EINVAL);
563 	}
564 
565 	/* Check that the FD given is legit. and change it to a pointer to a
566 	 * struct file. */
567 	fd = *(int *) (cm + 1);
568 	if ((unsigned) fd >= fdp->fd_nfiles
569 	    || (fp = fdp->fd_ofiles[fd]) == NULL) {
570 		return (EBADF);
571 	}
572 
573 	/* Depending on what kind of resource it is, act differently. For
574 	 * devices, we treat it as a file. For a AF_NETGRAPH socket,
575 	 * shortcut straight to the node. */
576 	switch (fp->f_type) {
577 	case DTYPE_VNODE:
578 		vn = (struct vnode *) fp->f_data;
579 		if (vn && (vn->v_type == VCHR)) {
580 			/* for a VCHR, actually reference the FILE */
581 			fp->f_count++;
582 			/* XXX then what :) */
583 			/* how to pass on to other modules? */
584 		} else {
585 			TRAP_ERROR;
586 			return (EINVAL);
587 		}
588 		break;
589 	default:
590 		TRAP_ERROR;
591 		return (EINVAL);
592 	}
593 	return (0);
594 }
595 #endif	/* NOTYET */
596 
597 /*
598  * Connect the data socket to a named control socket node.
599  */
600 static int
601 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
602 {
603 	struct sockaddr_ng *sap;
604 	node_p farnode;
605 	struct ngsock *sockdata;
606 	int error;
607 
608 	/* If we are already connected, don't do it again */
609 	if (pcbp->sockdata != NULL)
610 		return (EISCONN);
611 
612 	/* Find the target (victim) and check it doesn't already have a data
613 	 * socket. Also check it is a 'socket' type node. */
614 	sap = (struct sockaddr_ng *) nam;
615 	if ((error = ng_path2node(NULL, sap->sg_data, &farnode, NULL)))
616 		return (error);
617 
618 	if (strcmp(farnode->type->name, NG_SOCKET_NODE_TYPE) != 0)
619 		return (EINVAL);
620 	sockdata = farnode->private;
621 	if (sockdata->datasock != NULL)
622 		return (EADDRINUSE);
623 
624 	/* Link the PCB and the private data struct. and note the extra
625 	 * reference */
626 	sockdata->datasock = pcbp;
627 	pcbp->sockdata = sockdata;
628 	sockdata->refs++;
629 	return (0);
630 }
631 
632 /*
633  * Connect the existing control socket node to a named node:hook.
634  * The hook we use on this end is the same name as the remote node name.
635  */
636 static int
637 ng_connect_cntl(struct sockaddr *nam, struct ngpcb *pcbp)
638 {
639 	struct ngsock *const sockdata = pcbp->sockdata;
640 	struct sockaddr_ng *sap;
641 	char *node, *hook;
642 	node_p farnode;
643 	int rtn, error;
644 
645 	sap = (struct sockaddr_ng *) nam;
646 	rtn = ng_path_parse(sap->sg_data, &node, NULL, &hook);
647 	if (rtn < 0 || node == NULL || hook == NULL) {
648 		TRAP_ERROR;
649 		return (EINVAL);
650 	}
651 	farnode = ng_findname(sockdata->node, node);
652 	if (farnode == NULL) {
653 		TRAP_ERROR;
654 		return (EADDRNOTAVAIL);
655 	}
656 
657 	/* Connect, using a hook name the same as the far node name. */
658 	error = ng_con_nodes(sockdata->node, node, farnode, hook);
659 	return error;
660 }
661 
662 /*
663  * Binding a socket means giving the corresponding node a name
664  */
665 static int
666 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
667 {
668 	struct ngsock *const sockdata = pcbp->sockdata;
669 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
670 
671 	if (sockdata == NULL) {
672 		TRAP_ERROR;
673 		return (EINVAL);
674 	}
675 	if (sap->sg_len < 3 || sap->sg_data[sap->sg_len - 3] != '\0') {
676 		TRAP_ERROR;
677 		return (EINVAL);
678 	}
679 	return (ng_name_node(sockdata->node, sap->sg_data));
680 }
681 
682 /*
683  * Take a message and pass it up to the control socket associated
684  * with the node.
685  */
686 static int
687 ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg, struct sockaddr_ng *addr)
688 {
689 	struct socket *const so = pcbp->ng_socket;
690 	struct mbuf *mdata;
691 	int msglen;
692 
693 	/* Copy the message itself into an mbuf chain */
694 	msglen = sizeof(struct ng_mesg) + msg->header.arglen;
695 	mdata = m_devget((caddr_t) msg, msglen, 0, NULL, NULL);
696 
697 	/* Here we free the message, as we are the end of the line.
698 	 * We need to do that regardless of whether we got mbufs. */
699 	FREE(msg, M_NETGRAPH);
700 
701 	if (mdata == NULL) {
702 		TRAP_ERROR;
703 		return (ENOBUFS);
704 	}
705 
706 	/* Send it up to the socket */
707 	if (sbappendaddr(&so->so_rcv,
708 	    (struct sockaddr *) addr, mdata, NULL) == 0) {
709 		TRAP_ERROR;
710 		m_freem(mdata);
711 		return (ENOBUFS);
712 	}
713 	sorwakeup(so);
714 	return (0);
715 }
716 
717 /*
718  * You can only create new nodes from the socket end of things.
719  */
720 static int
721 ngs_constructor(node_p *nodep)
722 {
723 	return (EINVAL);
724 }
725 
726 /*
727  * We allow any hook to be connected to the node.
728  * There is no per-hook private information though.
729  */
730 static int
731 ngs_newhook(node_p node, hook_p hook, const char *name)
732 {
733 	hook->private = node->private;
734 	return (0);
735 }
736 
737 /*
738  * Incoming messages get passed up to the control socket.
739  * Unless they are for us specifically (socket_type)
740  */
741 static int
742 ngs_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
743 	   struct ng_mesg **resp)
744 {
745 	struct ngsock *const sockdata = node->private;
746 	struct ngpcb *const pcbp = sockdata->ctlsock;
747 	struct sockaddr_ng *addr;
748 	int addrlen;
749 	int error = 0;
750 
751 	/* Only allow mesgs to be passed if we have the control socket.
752 	 * Data sockets can only support the generic messages. */
753 	if (pcbp == NULL) {
754 		TRAP_ERROR;
755 		return (EINVAL);
756 	}
757 
758 	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
759 		switch (msg->header.cmd) {
760 		case NGM_SOCK_CMD_NOLINGER:
761 			sockdata->flags |= NGS_FLAG_NOLINGER;
762 			break;
763 		case NGM_SOCK_CMD_LINGER:
764 			sockdata->flags &= ~NGS_FLAG_NOLINGER;
765 			break;
766 		default:
767 			error = EINVAL;		/* unknown command */
768 		}
769 		/* Free the message and return */
770 		FREE(msg, M_NETGRAPH);
771 		return(error);
772 
773 	}
774 	/* Get the return address into a sockaddr */
775 	if ((retaddr == NULL) || (*retaddr == '\0'))
776 		retaddr = "";
777 	addrlen = strlen(retaddr);
778 	MALLOC(addr, struct sockaddr_ng *, addrlen + 4, M_NETGRAPH, M_NOWAIT);
779 	if (addr == NULL) {
780 		TRAP_ERROR;
781 		return (ENOMEM);
782 	}
783 	addr->sg_len = addrlen + 3;
784 	addr->sg_family = AF_NETGRAPH;
785 	bcopy(retaddr, addr->sg_data, addrlen);
786 	addr->sg_data[addrlen] = '\0';
787 
788 	/* Send it up */
789 	error = ship_msg(pcbp, msg, addr);
790 	FREE(addr, M_NETGRAPH);
791 	return (error);
792 }
793 
794 /*
795  * Receive data on a hook
796  */
797 static int
798 ngs_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
799 {
800 	struct ngsock *const sockdata = hook->node->private;
801 	struct ngpcb *const pcbp = sockdata->datasock;
802 	struct socket *so;
803 	struct sockaddr_ng *addr;
804 	char *addrbuf[NG_HOOKLEN + 1 + 4];
805 	int addrlen;
806 
807 	/* If there is no data socket, black-hole it */
808 	if (pcbp == NULL) {
809 		NG_FREE_DATA(m, meta);
810 		return (0);
811 	}
812 	so = pcbp->ng_socket;
813 
814 	/* Get the return address into a sockaddr. */
815 	addrlen = strlen(hook->name);	/* <= NG_HOOKLEN */
816 	addr = (struct sockaddr_ng *) addrbuf;
817 	addr->sg_len = addrlen + 3;
818 	addr->sg_family = AF_NETGRAPH;
819 	bcopy(hook->name, addr->sg_data, addrlen);
820 	addr->sg_data[addrlen] = '\0';
821 
822 	/* We have no use for the meta data, free/clear it now. */
823 	NG_FREE_META(meta);
824 
825 	/* Try to tell the socket which hook it came in on */
826 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *) addr, m, NULL) == 0) {
827 		m_freem(m);
828 		TRAP_ERROR;
829 		return (ENOBUFS);
830 	}
831 	sorwakeup(so);
832 	return (0);
833 }
834 
835 /*
836  * Hook disconnection
837  *
838  * For this type, removal of the last link destroys the node
839  * if the NOLINGER flag is set.
840  */
841 static int
842 ngs_disconnect(hook_p hook)
843 {
844 	struct ngsock *const sockdata = hook->node->private;
845 
846 	if ((sockdata->flags & NGS_FLAG_NOLINGER )
847 	&& (hook->node->numhooks == 0)) {
848 		ng_rmnode(hook->node);
849 	}
850 	return (0);
851 }
852 
853 /*
854  * Do local shutdown processing.
855  * In this case, that involves making sure the socket
856  * knows we should be shutting down.
857  */
858 static int
859 ngs_rmnode(node_p node)
860 {
861 	struct ngsock *const sockdata = node->private;
862 	struct ngpcb *const dpcbp = sockdata->datasock;
863 	struct ngpcb *const pcbp = sockdata->ctlsock;
864 
865 	ng_cutlinks(node);
866 	ng_unname(node);
867 
868 	if (dpcbp != NULL) {
869 		soisdisconnected(dpcbp->ng_socket);
870 		dpcbp->sockdata = NULL;
871 		sockdata->datasock = NULL;
872 		sockdata->refs--;
873 	}
874 	if (pcbp != NULL) {
875 		soisdisconnected(pcbp->ng_socket);
876 		pcbp->sockdata = NULL;
877 		sockdata->ctlsock = NULL;
878 		sockdata->refs--;
879 	}
880 	node->private = NULL;
881 	ng_unref(node);
882 	FREE(sockdata, M_NETGRAPH);
883 	return (0);
884 }
885 
886 /*
887  * Control and data socket type descriptors
888  */
889 
890 static struct pr_usrreqs ngc_usrreqs = {
891 	NULL,			/* abort */
892 	pru_accept_notsupp,
893 	ngc_attach,
894 	ngc_bind,
895 	ngc_connect,
896 	pru_connect2_notsupp,
897 	pru_control_notsupp,
898 	ngc_detach,
899 	NULL,			/* disconnect */
900 	pru_listen_notsupp,
901 	NULL,			/* setpeeraddr */
902 	pru_rcvd_notsupp,
903 	pru_rcvoob_notsupp,
904 	ngc_send,
905 	pru_sense_null,
906 	NULL,			/* shutdown */
907 	ng_setsockaddr,
908 	sosend,
909 	soreceive,
910 	sopoll
911 };
912 
913 static struct pr_usrreqs ngd_usrreqs = {
914 	NULL,			/* abort */
915 	pru_accept_notsupp,
916 	ngd_attach,
917 	NULL,			/* bind */
918 	ngd_connect,
919 	pru_connect2_notsupp,
920 	pru_control_notsupp,
921 	ngd_detach,
922 	NULL,			/* disconnect */
923 	pru_listen_notsupp,
924 	NULL,			/* setpeeraddr */
925 	pru_rcvd_notsupp,
926 	pru_rcvoob_notsupp,
927 	ngd_send,
928 	pru_sense_null,
929 	NULL,			/* shutdown */
930 	ng_setsockaddr,
931 	sosend,
932 	soreceive,
933 	sopoll
934 };
935 
936 /*
937  * Definitions of protocols supported in the NETGRAPH domain.
938  */
939 
940 extern struct domain ngdomain;		/* stop compiler warnings */
941 
942 static struct protosw ngsw[] = {
943 	{
944 		SOCK_DGRAM,
945 		&ngdomain,
946 		NG_CONTROL,
947 		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
948 		0, 0, 0, 0,
949 		NULL,
950 		0, 0, 0, 0,
951 		&ngc_usrreqs
952 	},
953 	{
954 		SOCK_DGRAM,
955 		&ngdomain,
956 		NG_DATA,
957 		PR_ATOMIC | PR_ADDR,
958 		0, 0, 0, 0,
959 		NULL,
960 		0, 0, 0, 0,
961 		&ngd_usrreqs
962 	}
963 };
964 
965 struct domain ngdomain = {
966 	AF_NETGRAPH,
967 	"netgraph",
968 	0,
969 	NULL,
970 	NULL,
971 	ngsw,
972 	&ngsw[sizeof(ngsw) / sizeof(ngsw[0])],
973 	0,
974 	NULL,
975 	0,
976 	0
977 };
978 
979 /*
980  * Handle loading and unloading for this node type
981  * This is to handle auxiliary linkages (e.g protocol domain addition).
982  */
983 static int
984 ngs_mod_event(module_t mod, int event, void *data)
985 {
986 	int error = 0;
987 
988 	switch (event) {
989 	case MOD_LOAD:
990 		/* Register protocol domain */
991 		net_add_domain(&ngdomain);
992 		break;
993 	case MOD_UNLOAD:
994 		/* Insure there are no open netgraph sockets */
995 		if (!LIST_EMPTY(&ngsocklist)) {
996 			error = EBUSY;
997 			break;
998 		}
999 
1000 #ifdef NOTYET
1001 		/* Unregister protocol domain XXX can't do this yet.. */
1002 		if ((error = net_rm_domain(&ngdomain)) != 0)
1003 			break;
1004 #else
1005 		error = EBUSY;
1006 #endif
1007 		break;
1008 	default:
1009 		error = EOPNOTSUPP;
1010 		break;
1011 	}
1012 	return (error);
1013 }
1014 
1015 SYSCTL_NODE(_net, AF_NETGRAPH, graph, CTLFLAG_RW, 0, "netgraph Family");
1016 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
1017 SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
1018 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
1019 SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
1020 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
1021 
1022