xref: /freebsd/sys/netgraph/ng_socket.c (revision a14a0223ae1b172e96dd2a1d849e22026a98b692)
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/file.h>
58 #include <sys/filedesc.h>
59 #include <sys/malloc.h>
60 #include <sys/queue.h>
61 #include <sys/mbuf.h>
62 #include <sys/protosw.h>
63 #include <sys/socket.h>
64 #include <sys/socketvar.h>
65 #include <sys/sysctl.h>
66 #ifdef NOTYET
67 #include <sys/vnode.h>
68 #endif
69 #include <netgraph/ng_message.h>
70 #include <netgraph/netgraph.h>
71 #include <netgraph/ng_socketvar.h>
72 #include <netgraph/ng_socket.h>
73 
74 /*
75  * It's Ascii-art time!
76  *   +-------------+   +-------------+
77  *   |socket  (ctl)|   |socket (data)|
78  *   +-------------+   +-------------+
79  *          ^                 ^
80  *          |                 |
81  *          v                 v
82  *    +-----------+     +-----------+
83  *    |pcb   (ctl)|     |pcb  (data)|
84  *    +-----------+     +-----------+
85  *          ^                 ^
86  *          |                 |
87  *          v                 v
88  *      +--------------------------+
89  *      |   Socket type private    |
90  *      |       data               |
91  *      +--------------------------+
92  *                   ^
93  *                   |
94  *                   v
95  *           +----------------+
96  *           | struct ng_node |
97  *           +----------------+
98  */
99 
100 /* Netgraph node methods */
101 static ng_constructor_t	ngs_constructor;
102 static ng_rcvmsg_t	ngs_rcvmsg;
103 static ng_shutdown_t	ngs_rmnode;
104 static ng_newhook_t	ngs_newhook;
105 static ng_rcvdata_t	ngs_rcvdata;
106 static ng_disconnect_t	ngs_disconnect;
107 
108 /* Internal methods */
109 static int	ng_attach_data(struct socket *so);
110 static int	ng_attach_cntl(struct socket *so);
111 static int	ng_attach_common(struct socket *so, int type);
112 static void	ng_detach_common(struct ngpcb *pcbp, int type);
113 /*static int	ng_internalize(struct mbuf *m, struct proc *p); */
114 
115 static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
116 static int	ng_connect_cntl(struct sockaddr *nam, struct ngpcb *pcbp);
117 static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
118 
119 static int	ngs_mod_event(module_t mod, int event, void *data);
120 static int	ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg,
121 			struct sockaddr_ng *addr);
122 
123 /* Netgraph type descriptor */
124 static struct ng_type typestruct = {
125 	NG_VERSION,
126 	NG_SOCKET_NODE_TYPE,
127 	ngs_mod_event,
128 	ngs_constructor,
129 	ngs_rcvmsg,
130 	ngs_rmnode,
131 	ngs_newhook,
132 	NULL,
133 	NULL,
134 	ngs_rcvdata,
135 	ngs_rcvdata,
136 	ngs_disconnect
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 (pcbp != NULL)
164 		return (EISCONN);
165 	return (ng_attach_cntl(so));
166 }
167 
168 static int
169 ngc_detach(struct socket *so)
170 {
171 	struct ngpcb *const pcbp = sotongpcb(so);
172 
173 	if (pcbp == NULL)
174 		return (EINVAL);
175 	ng_detach_common(pcbp, NG_CONTROL);
176 	return (0);
177 }
178 
179 static int
180 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
181 	 struct mbuf *control, struct proc *p)
182 {
183 	struct ngpcb *const pcbp = sotongpcb(so);
184 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
185 	struct ng_mesg *resp;
186 	struct mbuf *m0;
187 	char *msg, *path = NULL;
188 	int len, error = 0;
189 
190 	if (pcbp == NULL) {
191 		error = EINVAL;
192 		goto release;
193 	}
194 #ifdef	NOTYET
195 	if (control && (error = ng_internalize(control, p))) {
196 		if (pcbp->sockdata == NULL) {
197 			error = ENOTCONN;
198 			goto release;
199 		}
200 	}
201 #else	/* NOTYET */
202 	if (control) {
203 		error = EINVAL;
204 		goto release;
205 	}
206 #endif	/* NOTYET */
207 
208 	/* Require destination as there may be >= 1 hooks on this node */
209 	if (addr == NULL) {
210 		error = EDESTADDRREQ;
211 		goto release;
212 	}
213 
214 	/* Allocate an expendable buffer for the path, chop off
215 	 * the sockaddr header, and make sure it's NUL terminated */
216 	len = sap->sg_len - 2;
217 	MALLOC(path, char *, len + 1, M_NETGRAPH, M_WAITOK);
218 	if (path == NULL) {
219 		error = ENOMEM;
220 		goto release;
221 	}
222 	bcopy(sap->sg_data, path, len);
223 	path[len] = '\0';
224 
225 	/* Move the actual message out of mbufs into a linear buffer.
226 	 * Start by adding up the size of the data. (could use mh_len?) */
227 	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
228 		len += m0->m_len;
229 
230 	/* Move the data into a linear buffer as well. Messages are not
231 	 * delivered in mbufs. */
232 	MALLOC(msg, char *, len + 1, M_NETGRAPH, M_WAITOK);
233 	if (msg == NULL) {
234 		error = ENOMEM;
235 		goto release;
236 	}
237 	m_copydata(m, 0, len, msg);
238 
239 	/* The callee will free the msg when done. The addr is our business. */
240 	error = ng_send_msg(pcbp->sockdata->node,
241 			    (struct ng_mesg *) msg, path, &resp);
242 
243 	/* If the callee responded with a synchronous response, then put it
244 	 * back on the receive side of the socket; sap is source address. */
245 	if (error == 0 && resp != NULL)
246 		error = ship_msg(pcbp, resp, sap);
247 
248 release:
249 	if (path != NULL)
250 		FREE(path, M_NETGRAPH);
251 	if (control != NULL)
252 		m_freem(control);
253 	if (m != NULL)
254 		m_freem(m);
255 	return (error);
256 }
257 
258 static int
259 ngc_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
260 {
261 	struct ngpcb *const pcbp = sotongpcb(so);
262 
263 	if (pcbp == 0)
264 		return (EINVAL);
265 	return (ng_bind(nam, pcbp));
266 }
267 
268 static int
269 ngc_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
270 {
271 	struct ngpcb *const pcbp = sotongpcb(so);
272 
273 	if (pcbp == 0)
274 		return (EINVAL);
275 	return (ng_connect_cntl(nam, pcbp));
276 }
277 
278 /***************************************************************
279 	Data sockets
280 ***************************************************************/
281 
282 static int
283 ngd_attach(struct socket *so, int proto, struct proc *p)
284 {
285 	struct ngpcb *const pcbp = sotongpcb(so);
286 
287 	if (pcbp != NULL)
288 		return (EISCONN);
289 	return (ng_attach_data(so));
290 }
291 
292 static int
293 ngd_detach(struct socket *so)
294 {
295 	struct ngpcb *const pcbp = sotongpcb(so);
296 
297 	if (pcbp == NULL)
298 		return (EINVAL);
299 	ng_detach_common(pcbp, NG_DATA);
300 	return (0);
301 }
302 
303 static int
304 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
305 	 struct mbuf *control, struct proc *p)
306 {
307 	struct ngpcb *const pcbp = sotongpcb(so);
308 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
309 	char   *hookname = NULL;
310 	meta_p  mp = NULL;
311 	int     len, error;
312 	hook_p  hook;
313 
314 	if ((pcbp == NULL) || (control != NULL)) {
315 		error = EINVAL;
316 		goto release;
317 	}
318 	if (pcbp->sockdata == NULL) {
319 		error = ENOTCONN;
320 		goto release;
321 	}
322 	if (addr == NULL) {
323 		error = EDESTADDRREQ;
324 		goto release;
325 	}
326 
327 	/* Allocate an expendable buffer for the hook name, chop off
328 	 * the sockaddr header, and make sure it's NUL terminated */
329 	len = sap->sg_len - 2;
330 	MALLOC(hookname, char *, len + 1, M_NETGRAPH, M_WAITOK);
331 	if (hookname == NULL) {
332 		error = ENOMEM;
333 		goto release;
334 	}
335 	bcopy(sap->sg_data, hookname, len);
336 	hookname[len] = '\0';
337 
338 	/* Find the correct hook from 'hookname' */
339 	LIST_FOREACH(hook, &pcbp->sockdata->node->hooks, hooks) {
340 		if (strcmp(hookname, hook->name) == 0)
341 			break;
342 	}
343 
344 	/* Send data (OK if hook is NULL) */
345 	NG_SEND_DATA(error, hook, m, mp);	/* makes m NULL */
346 
347 release:
348 	if (hookname != NULL)
349 		FREE(hookname, M_NETGRAPH);
350 	if (control != NULL)
351 		m_freem(control);
352 	if (m != NULL)
353 		m_freem(m);
354 	return (error);
355 }
356 
357 static int
358 ngd_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
359 {
360 	struct ngpcb *const pcbp = sotongpcb(so);
361 
362 	if (pcbp == 0)
363 		return (EINVAL);
364 	return (ng_connect_data(nam, pcbp));
365 }
366 
367 /*
368  * Used for both data and control sockets
369  */
370 static int
371 ng_setsockaddr(struct socket *so, struct sockaddr **addr)
372 {
373 	struct ngpcb *const pcbp = sotongpcb(so);
374 	struct sockaddr *sa;
375 	int namelen;
376 
377 	if (pcbp == 0)
378 		return (EINVAL);
379 	if (pcbp->sockdata->node->name != NULL) {
380 		namelen = strlen(pcbp->sockdata->node->name) + 3;
381 		MALLOC(sa, struct sockaddr *, namelen, M_SONAME, M_WAITOK);
382 		if (sa == NULL)
383 			return (ENOMEM);
384 		sa->sa_family = AF_NETGRAPH;
385 		sa->sa_len = namelen;
386 		strcpy(sa->sa_data, pcbp->sockdata->node->name);
387 		*addr = sa;
388 	} else
389 		*addr = NULL;		/* XXX check this makes sense */
390 	return (0);
391 }
392 
393 /*
394  * Attach a socket to it's protocol specific partner.
395  * For a control socket, actually create a netgraph node and attach
396  * to it as well.
397  */
398 
399 static int
400 ng_attach_cntl(struct socket *so)
401 {
402 	struct ngsock *privdata;
403 	struct ngpcb *pcbp;
404 	int error;
405 
406 	/* Setup protocol control block */
407 	if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
408 		return (error);
409 	pcbp = (struct ngpcb *) so->so_pcb;
410 
411 	/* Allocate node private info */
412 	MALLOC(privdata, struct ngsock *,
413 	    sizeof(*privdata), M_NETGRAPH, M_WAITOK);
414 	if (privdata == NULL) {
415 		ng_detach_common(pcbp, NG_CONTROL);
416 		return (ENOMEM);
417 	}
418 	bzero(privdata, sizeof(*privdata));
419 
420 	/* Make the generic node components */
421 	if ((error = ng_make_node_common(&typestruct, &privdata->node)) != 0) {
422 		FREE(privdata, M_NETGRAPH);
423 		ng_detach_common(pcbp, NG_CONTROL);
424 		return (error);
425 	}
426 	privdata->node->private = privdata;
427 
428 	/* Link the pcb and the node private data */
429 	privdata->ctlsock = pcbp;
430 	pcbp->sockdata = privdata;
431 	privdata->refs++;
432 	return (0);
433 }
434 
435 static int
436 ng_attach_data(struct socket *so)
437 {
438 	return(ng_attach_common(so, NG_DATA));
439 }
440 
441 /*
442  * Set up a socket protocol control block.
443  * This code is shared between control and data sockets.
444  */
445 static int
446 ng_attach_common(struct socket *so, int type)
447 {
448 	struct ngpcb *pcbp;
449 	int error;
450 
451 	/* Standard socket setup stuff */
452 	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
453 	if (error)
454 		return (error);
455 
456 	/* Allocate the pcb */
457 	MALLOC(pcbp, struct ngpcb *, sizeof(*pcbp), M_PCB, M_WAITOK);
458 	if (pcbp == NULL)
459 		return (ENOMEM);
460 	bzero(pcbp, sizeof(*pcbp));
461 	pcbp->type = type;
462 
463 	/* Link the pcb and the socket */
464 	so->so_pcb = (caddr_t) pcbp;
465 	pcbp->ng_socket = so;
466 
467 	/* Add the socket to linked list */
468 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
469 	return (0);
470 }
471 
472 /*
473  * Disassociate the socket from it's protocol specific
474  * partner. If it's attached to a node's private data structure,
475  * then unlink from that too. If we were the last socket attached to it,
476  * then shut down the entire node. Shared code for control and data sockets.
477  */
478 static void
479 ng_detach_common(struct ngpcb *pcbp, int which)
480 {
481 	struct ngsock *sockdata;
482 
483 	if (pcbp->sockdata) {
484 		sockdata = pcbp->sockdata;
485 		pcbp->sockdata = NULL;
486 		switch (which) {
487 		case NG_CONTROL:
488 			sockdata->ctlsock = NULL;
489 			break;
490 		case NG_DATA:
491 			sockdata->datasock = NULL;
492 			break;
493 		default:
494 			panic(__FUNCTION__);
495 		}
496 		if ((--sockdata->refs == 0) && (sockdata->node != NULL))
497 			ng_rmnode(sockdata->node);
498 	}
499 	pcbp->ng_socket->so_pcb = NULL;
500 	pcbp->ng_socket = NULL;
501 	LIST_REMOVE(pcbp, socks);
502 	FREE(pcbp, M_PCB);
503 }
504 
505 #ifdef NOTYET
506 /*
507  * File descriptors can be passed into a AF_NETGRAPH socket.
508  * Note, that file descriptors cannot be passed OUT.
509  * Only character device descriptors are accepted.
510  * Character devices are useful to connect a graph to a device,
511  * which after all is the purpose of this whole system.
512  */
513 static int
514 ng_internalize(struct mbuf *control, struct proc *p)
515 {
516 	struct filedesc *fdp = p->p_fd;
517 	struct cmsghdr *cm = mtod(control, struct cmsghdr *);
518 	struct file *fp;
519 	struct vnode *vn;
520 	int oldfds;
521 	int fd;
522 
523 	if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
524 	    cm->cmsg_len != control->m_len) {
525 		TRAP_ERROR;
526 		return (EINVAL);
527 	}
528 
529 	/* Check there is only one FD. XXX what would more than one signify? */
530 	oldfds = (cm->cmsg_len - sizeof(*cm)) / sizeof(int);
531 	if (oldfds != 1) {
532 		TRAP_ERROR;
533 		return (EINVAL);
534 	}
535 
536 	/* Check that the FD given is legit. and change it to a pointer to a
537 	 * struct file. */
538 	fd = *(int *) (cm + 1);
539 	if ((unsigned) fd >= fdp->fd_nfiles
540 	    || (fp = fdp->fd_ofiles[fd]) == NULL) {
541 		return (EBADF);
542 	}
543 
544 	/* Depending on what kind of resource it is, act differently. For
545 	 * devices, we treat it as a file. For a AF_NETGRAPH socket,
546 	 * shortcut straight to the node. */
547 	switch (fp->f_type) {
548 	case DTYPE_VNODE:
549 		vn = (struct vnode *) fp->f_data;
550 		if (vn && (vn->v_type == VCHR)) {
551 			/* for a VCHR, actually reference the FILE */
552 			fp->f_count++;
553 			/* XXX then what :) */
554 			/* how to pass on to other modules? */
555 		} else {
556 			TRAP_ERROR;
557 			return (EINVAL);
558 		}
559 		break;
560 	default:
561 		TRAP_ERROR;
562 		return (EINVAL);
563 	}
564 	return (0);
565 }
566 #endif	/* NOTYET */
567 
568 /*
569  * Connect the data socket to a named control socket node.
570  */
571 static int
572 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
573 {
574 	struct sockaddr_ng *sap;
575 	node_p farnode;
576 	struct ngsock *sockdata;
577 	int error;
578 
579 	/* If we are already connected, don't do it again */
580 	if (pcbp->sockdata != NULL)
581 		return (EISCONN);
582 
583 	/* Find the target (victim) and check it doesn't already have a data
584 	 * socket. Also check it is a 'socket' type node. */
585 	sap = (struct sockaddr_ng *) nam;
586 	if ((error = ng_path2node(NULL, sap->sg_data, &farnode, NULL)))
587 		return (error);
588 
589 	if (strcmp(farnode->type->name, NG_SOCKET_NODE_TYPE) != 0)
590 		return (EINVAL);
591 	sockdata = farnode->private;
592 	if (sockdata->datasock != NULL)
593 		return (EADDRINUSE);
594 
595 	/* Link the PCB and the private data struct. and note the extra
596 	 * reference */
597 	sockdata->datasock = pcbp;
598 	pcbp->sockdata = sockdata;
599 	sockdata->refs++;
600 	return (0);
601 }
602 
603 /*
604  * Connect the existing control socket node to a named node:hook.
605  * The hook we use on this end is the same name as the remote node name.
606  */
607 static int
608 ng_connect_cntl(struct sockaddr *nam, struct ngpcb *pcbp)
609 {
610 	struct ngsock *const sockdata = pcbp->sockdata;
611 	struct sockaddr_ng *sap;
612 	char *node, *hook;
613 	node_p farnode;
614 	int rtn, error;
615 
616 	sap = (struct sockaddr_ng *) nam;
617 	rtn = ng_path_parse(sap->sg_data, &node, NULL, &hook);
618 	if (rtn < 0 || node == NULL || hook == NULL) {
619 		TRAP_ERROR;
620 		return (EINVAL);
621 	}
622 	farnode = ng_findname(sockdata->node, node);
623 	if (farnode == NULL) {
624 		TRAP_ERROR;
625 		return (EADDRNOTAVAIL);
626 	}
627 
628 	/* Connect, using a hook name the same as the far node name. */
629 	error = ng_con_nodes(sockdata->node, node, farnode, hook);
630 	return error;
631 }
632 
633 /*
634  * Binding a socket means giving the corresponding node a name
635  */
636 static int
637 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
638 {
639 	struct ngsock *const sockdata = pcbp->sockdata;
640 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
641 
642 	if (sockdata == NULL) {
643 		TRAP_ERROR;
644 		return (EINVAL);
645 	}
646 	if (sap->sg_len < 3 || sap->sg_data[sap->sg_len - 3] != '\0') {
647 		TRAP_ERROR;
648 		return (EINVAL);
649 	}
650 	return (ng_name_node(sockdata->node, sap->sg_data));
651 }
652 
653 /*
654  * Take a message and pass it up to the control socket associated
655  * with the node.
656  */
657 static int
658 ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg, struct sockaddr_ng *addr)
659 {
660 	struct socket *const so = pcbp->ng_socket;
661 	struct mbuf *mdata;
662 	int msglen;
663 
664 	/* Copy the message itself into an mbuf chain */
665 	msglen = sizeof(struct ng_mesg) + msg->header.arglen;
666 	mdata = m_devget((caddr_t) msg, msglen, 0, NULL, NULL);
667 
668 	/* Here we free the message, as we are the end of the line.
669 	 * We need to do that regardless of whether we got mbufs. */
670 	FREE(msg, M_NETGRAPH);
671 
672 	if (mdata == NULL) {
673 		TRAP_ERROR;
674 		return (ENOBUFS);
675 	}
676 
677 	/* Send it up to the socket */
678 	if (sbappendaddr(&so->so_rcv,
679 	    (struct sockaddr *) addr, mdata, NULL) == 0) {
680 		TRAP_ERROR;
681 		m_freem(mdata);
682 		return (ENOBUFS);
683 	}
684 	sorwakeup(so);
685 	return (0);
686 }
687 
688 /*
689  * You can only create new nodes from the socket end of things.
690  */
691 static int
692 ngs_constructor(node_p *nodep)
693 {
694 	return (EINVAL);
695 }
696 
697 /*
698  * We allow any hook to be connected to the node.
699  * There is no per-hook private information though.
700  */
701 static int
702 ngs_newhook(node_p node, hook_p hook, const char *name)
703 {
704 	hook->private = node->private;
705 	return (0);
706 }
707 
708 /*
709  * Incoming messages get passed up to the control socket.
710  * Unless they are for us specifically (socket_type)
711  */
712 static int
713 ngs_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
714 	   struct ng_mesg **resp)
715 {
716 	struct ngsock *const sockdata = node->private;
717 	struct ngpcb *const pcbp = sockdata->ctlsock;
718 	struct sockaddr_ng *addr;
719 	int addrlen;
720 	int error = 0;
721 
722 	/* Only allow mesgs to be passed if we have the control socket.
723 	 * Data sockets can only support the generic messages. */
724 	if (pcbp == NULL) {
725 		TRAP_ERROR;
726 		return (EINVAL);
727 	}
728 
729 	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
730 		switch (msg->header.cmd) {
731 		case NGM_SOCK_CMD_NOLINGER:
732 			sockdata->flags |= NGS_FLAG_NOLINGER;
733 			break;
734 		case NGM_SOCK_CMD_LINGER:
735 			sockdata->flags &= ~NGS_FLAG_NOLINGER;
736 			break;
737 		default:
738 			error = EINVAL;		/* unknown command */
739 		}
740 		/* Free the message and return */
741 		FREE(msg, M_NETGRAPH);
742 		return(error);
743 
744 	}
745 	/* Get the return address into a sockaddr */
746 	if ((retaddr == NULL) || (*retaddr == '\0'))
747 		retaddr = "";
748 	addrlen = strlen(retaddr);
749 	MALLOC(addr, struct sockaddr_ng *, addrlen + 4, M_NETGRAPH, M_NOWAIT);
750 	if (addr == NULL) {
751 		TRAP_ERROR;
752 		return (ENOMEM);
753 	}
754 	addr->sg_len = addrlen + 3;
755 	addr->sg_family = AF_NETGRAPH;
756 	bcopy(retaddr, addr->sg_data, addrlen);
757 	addr->sg_data[addrlen] = '\0';
758 
759 	/* Send it up */
760 	error = ship_msg(pcbp, msg, addr);
761 	FREE(addr, M_NETGRAPH);
762 	return (error);
763 }
764 
765 /*
766  * Receive data on a hook
767  */
768 static int
769 ngs_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
770 {
771 	struct ngsock *const sockdata = hook->node->private;
772 	struct ngpcb *const pcbp = sockdata->datasock;
773 	struct socket *so;
774 	struct sockaddr_ng *addr;
775 	char *addrbuf[NG_HOOKLEN + 1 + 4];
776 	int addrlen;
777 
778 	/* If there is no data socket, black-hole it */
779 	if (pcbp == NULL) {
780 		NG_FREE_DATA(m, meta);
781 		return (0);
782 	}
783 	so = pcbp->ng_socket;
784 
785 	/* Get the return address into a sockaddr. */
786 	addrlen = strlen(hook->name);	/* <= NG_HOOKLEN */
787 	addr = (struct sockaddr_ng *) addrbuf;
788 	addr->sg_len = addrlen + 3;
789 	addr->sg_family = AF_NETGRAPH;
790 	bcopy(hook->name, addr->sg_data, addrlen);
791 	addr->sg_data[addrlen] = '\0';
792 
793 	/* We have no use for the meta data, free/clear it now. */
794 	NG_FREE_META(meta);
795 
796 	/* Try to tell the socket which hook it came in on */
797 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *) addr, m, NULL) == 0) {
798 		m_freem(m);
799 		TRAP_ERROR;
800 		return (ENOBUFS);
801 	}
802 	sorwakeup(so);
803 	return (0);
804 }
805 
806 /*
807  * Dook disconnection
808  *
809  * For this type, removal of the last link destroys the node
810  * if the NOLINGER flag is set.
811  */
812 static int
813 ngs_disconnect(hook_p hook)
814 {
815 	struct ngsock *const sockdata = hook->node->private;
816 
817 	if ((sockdata->flags & NGS_FLAG_NOLINGER )
818 	&& (hook->node->numhooks == 0)) {
819 		ng_rmnode(hook->node);
820 	}
821 	return (0);
822 }
823 
824 /*
825  * Do local shutdown processing.
826  * In this case, that involves making sure the socket
827  * knows we should be shutting down.
828  */
829 static int
830 ngs_rmnode(node_p node)
831 {
832 	struct ngsock *const sockdata = node->private;
833 	struct ngpcb *const dpcbp = sockdata->datasock;
834 	struct ngpcb *const pcbp = sockdata->ctlsock;
835 
836 	ng_cutlinks(node);
837 	ng_unname(node);
838 
839 	if (dpcbp != NULL) {
840 		soisdisconnected(dpcbp->ng_socket);
841 		dpcbp->sockdata = NULL;
842 		sockdata->datasock = NULL;
843 		sockdata->refs--;
844 	}
845 	if (pcbp != NULL) {
846 		soisdisconnected(pcbp->ng_socket);
847 		pcbp->sockdata = NULL;
848 		sockdata->ctlsock = NULL;
849 		sockdata->refs--;
850 	}
851 	node->private = NULL;
852 	ng_unref(node);
853 	FREE(sockdata, M_NETGRAPH);
854 	return (0);
855 }
856 
857 /*
858  * Control and data socket type descriptors
859  */
860 
861 static struct pr_usrreqs ngc_usrreqs = {
862 	NULL,			/* abort */
863 	pru_accept_notsupp,
864 	ngc_attach,
865 	ngc_bind,
866 	ngc_connect,
867 	pru_connect2_notsupp,
868 	pru_control_notsupp,
869 	ngc_detach,
870 	NULL,			/* disconnect */
871 	pru_listen_notsupp,
872 	NULL,			/* setpeeraddr */
873 	pru_rcvd_notsupp,
874 	pru_rcvoob_notsupp,
875 	ngc_send,
876 	pru_sense_null,
877 	NULL,			/* shutdown */
878 	ng_setsockaddr,
879 	sosend,
880 	soreceive,
881 	sopoll
882 };
883 
884 static struct pr_usrreqs ngd_usrreqs = {
885 	NULL,			/* abort */
886 	pru_accept_notsupp,
887 	ngd_attach,
888 	NULL,			/* bind */
889 	ngd_connect,
890 	pru_connect2_notsupp,
891 	pru_control_notsupp,
892 	ngd_detach,
893 	NULL,			/* disconnect */
894 	pru_listen_notsupp,
895 	NULL,			/* setpeeraddr */
896 	pru_rcvd_notsupp,
897 	pru_rcvoob_notsupp,
898 	ngd_send,
899 	pru_sense_null,
900 	NULL,			/* shutdown */
901 	ng_setsockaddr,
902 	sosend,
903 	soreceive,
904 	sopoll
905 };
906 
907 /*
908  * Definitions of protocols supported in the NETGRAPH domain.
909  */
910 
911 extern struct domain ngdomain;		/* stop compiler warnings */
912 
913 static struct protosw ngsw[] = {
914 	{
915 		SOCK_DGRAM,
916 		&ngdomain,
917 		NG_CONTROL,
918 		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
919 		0, 0, 0, 0,
920 		NULL,
921 		0, 0, 0, 0,
922 		&ngc_usrreqs
923 	},
924 	{
925 		SOCK_DGRAM,
926 		&ngdomain,
927 		NG_DATA,
928 		PR_ATOMIC | PR_ADDR,
929 		0, 0, 0, 0,
930 		NULL,
931 		0, 0, 0, 0,
932 		&ngd_usrreqs
933 	}
934 };
935 
936 struct domain ngdomain = {
937 	AF_NETGRAPH,
938 	"netgraph",
939 	0,
940 	NULL,
941 	NULL,
942 	ngsw,
943 	&ngsw[sizeof(ngsw) / sizeof(ngsw[0])],
944 	0,
945 	NULL,
946 	0,
947 	0
948 };
949 
950 /*
951  * Handle loading and unloading for this node type
952  * This is to handle auxiliary linkages (e.g protocol domain addition).
953  */
954 static int
955 ngs_mod_event(module_t mod, int event, void *data)
956 {
957 	int error = 0;
958 
959 	switch (event) {
960 	case MOD_LOAD:
961 		/* Register protocol domain */
962 		net_add_domain(&ngdomain);
963 		break;
964 	case MOD_UNLOAD:
965 		/* Insure there are no open netgraph sockets */
966 		if (!LIST_EMPTY(&ngsocklist)) {
967 			error = EBUSY;
968 			break;
969 		}
970 
971 #ifdef NOTYET
972 		/* Unregister protocol domain XXX can't do this yet.. */
973 		if ((error = net_rm_domain(&ngdomain)) != 0)
974 			break;
975 #else
976 		error = EBUSY;
977 #endif
978 		break;
979 	default:
980 		error = EOPNOTSUPP;
981 		break;
982 	}
983 	return (error);
984 }
985 
986 SYSCTL_NODE(_net, AF_NETGRAPH, graph, CTLFLAG_RW, 0, "netgraph Family");
987 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
988 SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
989 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
990 SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
991 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
992 
993