xref: /freebsd/sys/netgraph/ng_socket.c (revision eacee0ff7ec955b32e09515246bd97b6edcd2b0f)
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@freebsd.org>
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/domain.h>
54 #include <sys/errno.h>
55 #include <sys/kernel.h>
56 #include <sys/filedesc.h>
57 #include <sys/malloc.h>
58 #include <sys/queue.h>
59 #include <sys/mbuf.h>
60 #include <sys/protosw.h>
61 #include <sys/socket.h>
62 #include <sys/socketvar.h>
63 #include <sys/sysctl.h>
64 #ifdef NOTYET
65 #include <sys/vnode.h>
66 #endif
67 #include <netgraph/ng_message.h>
68 #include <netgraph/netgraph.h>
69 #include <netgraph/ng_socketvar.h>
70 #include <netgraph/ng_socket.h>
71 
72 #ifdef NG_SEPARATE_MALLOC
73 MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info ");
74 MALLOC_DEFINE(M_NETGRAPH_SOCK, "netgraph_sock", "netgraph socket info ");
75 #else
76 #define M_NETGRAPH_PATH M_NETGRAPH
77 #define M_NETGRAPH_SOCK M_NETGRAPH
78 #endif
79 
80 /*
81  * It's Ascii-art time!
82  *   +-------------+   +-------------+
83  *   |socket  (ctl)|   |socket (data)|
84  *   +-------------+   +-------------+
85  *          ^                 ^
86  *          |                 |
87  *          v                 v
88  *    +-----------+     +-----------+
89  *    |pcb   (ctl)|     |pcb  (data)|
90  *    +-----------+     +-----------+
91  *          ^                 ^
92  *          |                 |
93  *          v                 v
94  *      +--------------------------+
95  *      |   Socket type private    |
96  *      |       data               |
97  *      +--------------------------+
98  *                   ^
99  *                   |
100  *                   v
101  *           +----------------+
102  *           | struct ng_node |
103  *           +----------------+
104  */
105 
106 /* Netgraph node methods */
107 static ng_constructor_t	ngs_constructor;
108 static ng_rcvmsg_t	ngs_rcvmsg;
109 static ng_shutdown_t	ngs_shutdown;
110 static ng_newhook_t	ngs_newhook;
111 static ng_connect_t	ngs_connect;
112 static ng_rcvdata_t	ngs_rcvdata;
113 static ng_disconnect_t	ngs_disconnect;
114 
115 /* Internal methods */
116 static int	ng_attach_data(struct socket *so);
117 static int	ng_attach_cntl(struct socket *so);
118 static int	ng_attach_common(struct socket *so, int type);
119 static void	ng_detach_common(struct ngpcb *pcbp, int type);
120 /*static int	ng_internalize(struct mbuf *m, struct thread *p); */
121 
122 static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
123 static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
124 
125 static int	ngs_mod_event(module_t mod, int event, void *data);
126 static int	ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg,
127 			struct sockaddr_ng *addr);
128 
129 /* Netgraph type descriptor */
130 static struct ng_type typestruct = {
131 	NG_ABI_VERSION,
132 	NG_SOCKET_NODE_TYPE,
133 	ngs_mod_event,
134 	ngs_constructor,
135 	ngs_rcvmsg,
136 	ngs_shutdown,
137 	ngs_newhook,
138 	NULL,
139 	ngs_connect,
140 	ngs_rcvdata,
141 	ngs_disconnect,
142 	NULL
143 };
144 NETGRAPH_INIT(socket, &typestruct);
145 
146 /* Buffer space */
147 static u_long ngpdg_sendspace = 20 * 1024;	/* really max datagram size */
148 static u_long ngpdg_recvspace = 20 * 1024;
149 
150 /* List of all sockets */
151 static LIST_HEAD(, ngpcb) ngsocklist;
152 
153 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
154 
155 /* If getting unexplained errors returned, set this to "Debugger("X"); */
156 #ifndef TRAP_ERROR
157 #define TRAP_ERROR
158 #endif
159 
160 /***************************************************************
161 	Control sockets
162 ***************************************************************/
163 
164 static int
165 ngc_attach(struct socket *so, int proto, struct thread *td)
166 {
167 	struct ngpcb *const pcbp = sotongpcb(so);
168 
169 	if (suser_td(td))
170 		return (EPERM);
171 	if (pcbp != NULL)
172 		return (EISCONN);
173 	return (ng_attach_cntl(so));
174 }
175 
176 static int
177 ngc_detach(struct socket *so)
178 {
179 	struct ngpcb *const pcbp = sotongpcb(so);
180 
181 	if (pcbp == NULL)
182 		return (EINVAL);
183 	ng_detach_common(pcbp, NG_CONTROL);
184 	return (0);
185 }
186 
187 static int
188 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
189 	 struct mbuf *control, struct thread *td)
190 {
191 	struct ngpcb *const pcbp = sotongpcb(so);
192 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
193 	struct ng_mesg *msg;
194 	struct mbuf *m0;
195 	char *path = NULL;
196 	int len, error = 0;
197 
198 	if (pcbp == NULL) {
199 		error = EINVAL;
200 		goto release;
201 	}
202 #ifdef	NOTYET
203 	if (control && (error = ng_internalize(control, td))) {
204 		if (pcbp->sockdata == NULL) {
205 			error = ENOTCONN;
206 			goto release;
207 		}
208 	}
209 #else	/* NOTYET */
210 	if (control) {
211 		error = EINVAL;
212 		goto release;
213 	}
214 #endif	/* NOTYET */
215 
216 	/* Require destination as there may be >= 1 hooks on this node */
217 	if (addr == NULL) {
218 		error = EDESTADDRREQ;
219 		goto release;
220 	}
221 
222 	/* Allocate an expendable buffer for the path, chop off
223 	 * the sockaddr header, and make sure it's NUL terminated */
224 	len = sap->sg_len - 2;
225 	MALLOC(path, char *, len + 1, M_NETGRAPH_PATH, M_WAITOK);
226 	if (path == NULL) {
227 		error = ENOMEM;
228 		goto release;
229 	}
230 	bcopy(sap->sg_data, path, len);
231 	path[len] = '\0';
232 
233 	/* Move the actual message out of mbufs into a linear buffer.
234 	 * Start by adding up the size of the data. (could use mh_len?) */
235 	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
236 		len += m0->m_len;
237 
238 	/* Move the data into a linear buffer as well. Messages are not
239 	 * delivered in mbufs. */
240 	MALLOC(msg, struct ng_mesg *, len + 1, M_NETGRAPH_MSG, M_WAITOK);
241 	if (msg == NULL) {
242 		error = ENOMEM;
243 		goto release;
244 	}
245 	m_copydata(m, 0, len, (char *)msg);
246 
247 #ifdef TRACE_MESSAGES
248 	do {
249 		item_p item;
250 		if ((item = ng_package_msg(msg)) == NULL) {
251 			(msg) = NULL;
252 			(error) = ENOMEM;
253 printf("err=%d\n",error);
254 			break;
255 		}
256 		if (((error) = ng_address_path((pcbp->sockdata->node), (item),
257 					(path), (NULL))) == 0) {
258 printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
259 item->el_dest->nd_ID,
260 msg->header.typecookie,
261 msg->header.cmd,
262 msg->header.cmdstr,
263 msg->header.flags,
264 msg->header.token,
265 item->el_dest->nd_type->name);
266 			SAVE_LINE(item);
267 			(error) = ng_snd_item((item), 0);
268 		}
269 else {
270 printf("errx=%d\n",error);
271 }
272 		(msg) = NULL;
273 	} while (0);
274 
275 #else
276 	/* The callee will free the msg when done. The path is our business. */
277 	NG_SEND_MSG_PATH(error, pcbp->sockdata->node, msg, path, NULL);
278 #endif
279 release:
280 	if (path != NULL)
281 		FREE(path, M_NETGRAPH_PATH);
282 	if (control != NULL)
283 		m_freem(control);
284 	if (m != NULL)
285 		m_freem(m);
286 	return (error);
287 }
288 
289 static int
290 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
291 {
292 	struct ngpcb *const pcbp = sotongpcb(so);
293 
294 	if (pcbp == 0)
295 		return (EINVAL);
296 	return (ng_bind(nam, pcbp));
297 }
298 
299 static int
300 ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
301 {
302 printf(" program tried to connect control socket to remote node\n ");
303 	/*
304 	 * At this time refuse to do this.. it used to
305 	 * do something but it was undocumented and not used.
306 	 */
307 	return (EINVAL);
308 }
309 
310 /***************************************************************
311 	Data sockets
312 ***************************************************************/
313 
314 static int
315 ngd_attach(struct socket *so, int proto, struct thread *td)
316 {
317 	struct ngpcb *const pcbp = sotongpcb(so);
318 
319 	if (pcbp != NULL)
320 		return (EISCONN);
321 	return (ng_attach_data(so));
322 }
323 
324 static int
325 ngd_detach(struct socket *so)
326 {
327 	struct ngpcb *const pcbp = sotongpcb(so);
328 
329 	if (pcbp == NULL)
330 		return (EINVAL);
331 	ng_detach_common(pcbp, NG_DATA);
332 	return (0);
333 }
334 
335 static int
336 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
337 	 struct mbuf *control, struct thread *td)
338 {
339 	struct ngpcb *const pcbp = sotongpcb(so);
340 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
341 	int     len, error;
342 	hook_p  hook = NULL;
343 	char	hookname[NG_HOOKLEN + 1];
344 
345 	if ((pcbp == NULL) || (control != NULL)) {
346 		error = EINVAL;
347 		goto release;
348 	}
349 	if (pcbp->sockdata == NULL) {
350 		error = ENOTCONN;
351 		goto release;
352 	}
353 	/*
354 	 * If the user used any of these ways to not specify an address
355 	 * then handle specially.
356 	 */
357 	if ((sap == NULL)
358 	    || ((len = sap->sg_len - 2) <= 0)
359 	    || (*sap->sg_data == '\0')) {
360 		if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
361 			error = EDESTADDRREQ;
362 			goto release;
363 		}
364 		/*
365 		 * if exactly one hook exists, just use it.
366 		 * Special case to allow write(2) to work on an ng_socket.
367 		 */
368 		hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
369 	} else {
370 		if (len > NG_HOOKLEN) {
371 			error = EINVAL;
372 			goto release;
373 		}
374 
375 		/*
376 		 * chop off the sockaddr header, and make sure it's NUL
377 		 * terminated
378 		 */
379 		bcopy(sap->sg_data, hookname, len);
380 		hookname[len] = '\0';
381 
382 		/* Find the correct hook from 'hookname' */
383 		LIST_FOREACH(hook, &pcbp->sockdata->node->nd_hooks, hk_hooks) {
384 			if (strcmp(hookname, NG_HOOK_NAME(hook)) == 0) {
385 				break;
386 			}
387 		}
388 		if (hook == NULL) {
389 			error = EHOSTUNREACH;
390 		}
391 	}
392 
393 	/* Send data (OK if hook is NULL) */
394 	NG_SEND_DATA_ONLY(error, hook, m);	/* makes m NULL */
395 
396 release:
397 	if (control != NULL)
398 		m_freem(control);
399 	if (m != NULL)
400 		m_freem(m);
401 	return (error);
402 }
403 
404 static int
405 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
406 {
407 	struct ngpcb *const pcbp = sotongpcb(so);
408 
409 	if (pcbp == 0)
410 		return (EINVAL);
411 	return (ng_connect_data(nam, pcbp));
412 }
413 
414 /*
415  * Used for both data and control sockets
416  */
417 static int
418 ng_setsockaddr(struct socket *so, struct sockaddr **addr)
419 {
420 	struct ngpcb *pcbp;
421 	struct sockaddr_ng *sg;
422 	int sg_len, namelen, s;
423 
424 	/* Why isn't sg_data a `char[1]' ? :-( */
425 	sg_len = sizeof(struct sockaddr_ng) - sizeof(sg->sg_data) + 1;
426 
427 	s = splnet();
428 	pcbp = sotongpcb(so);
429 	if ((pcbp == NULL) || (pcbp->sockdata == NULL)) {
430 		splx(s);
431 		return (EINVAL);
432 	}
433 
434 	namelen = 0;		/* silence compiler ! */
435 	if ( NG_NODE_HAS_NAME(pcbp->sockdata->node))
436 		sg_len += namelen = strlen(NG_NODE_NAME(pcbp->sockdata->node));
437 
438 	MALLOC(sg, struct sockaddr_ng *, sg_len, M_SONAME, M_WAITOK | M_ZERO);
439 
440 	if (NG_NODE_HAS_NAME(pcbp->sockdata->node))
441 		bcopy(NG_NODE_NAME(pcbp->sockdata->node), sg->sg_data, namelen);
442 	splx(s);
443 
444 	sg->sg_len = sg_len;
445 	sg->sg_family = AF_NETGRAPH;
446 	*addr = (struct sockaddr *)sg;
447 
448 	return (0);
449 }
450 
451 /*
452  * Attach a socket to it's protocol specific partner.
453  * For a control socket, actually create a netgraph node and attach
454  * to it as well.
455  */
456 
457 static int
458 ng_attach_cntl(struct socket *so)
459 {
460 	struct ngsock *privdata;
461 	struct ngpcb *pcbp;
462 	int error;
463 
464 	/* Setup protocol control block */
465 	if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
466 		return (error);
467 	pcbp = sotongpcb(so);
468 
469 	/* Allocate node private info */
470 	MALLOC(privdata, struct ngsock *,
471 	    sizeof(*privdata), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
472 	if (privdata == NULL) {
473 		ng_detach_common(pcbp, NG_CONTROL);
474 		return (ENOMEM);
475 	}
476 
477 	/* Make the generic node components */
478 	if ((error = ng_make_node_common(&typestruct, &privdata->node)) != 0) {
479 		FREE(privdata, M_NETGRAPH_SOCK);
480 		ng_detach_common(pcbp, NG_CONTROL);
481 		return (error);
482 	}
483 	NG_NODE_SET_PRIVATE(privdata->node, privdata);
484 
485 	/* Link the pcb and the node private data */
486 	privdata->ctlsock = pcbp;
487 	pcbp->sockdata = privdata;
488 	privdata->refs++;
489 	return (0);
490 }
491 
492 static int
493 ng_attach_data(struct socket *so)
494 {
495 	return(ng_attach_common(so, NG_DATA));
496 }
497 
498 /*
499  * Set up a socket protocol control block.
500  * This code is shared between control and data sockets.
501  */
502 static int
503 ng_attach_common(struct socket *so, int type)
504 {
505 	struct ngpcb *pcbp;
506 	int error;
507 
508 	/* Standard socket setup stuff */
509 	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
510 	if (error)
511 		return (error);
512 
513 	/* Allocate the pcb */
514 	MALLOC(pcbp, struct ngpcb *, sizeof(*pcbp), M_PCB, M_WAITOK | M_ZERO);
515 	if (pcbp == NULL)
516 		return (ENOMEM);
517 	pcbp->type = type;
518 
519 	/* Link the pcb and the socket */
520 	so->so_pcb = (caddr_t) pcbp;
521 	pcbp->ng_socket = so;
522 
523 	/* Add the socket to linked list */
524 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
525 	return (0);
526 }
527 
528 /*
529  * Disassociate the socket from it's protocol specific
530  * partner. If it's attached to a node's private data structure,
531  * then unlink from that too. If we were the last socket attached to it,
532  * then shut down the entire node. Shared code for control and data sockets.
533  */
534 static void
535 ng_detach_common(struct ngpcb *pcbp, int which)
536 {
537 	struct ngsock *priv;
538 
539 	if (pcbp->sockdata) {
540 		priv = pcbp->sockdata;
541 		pcbp->sockdata = NULL;
542 		switch (which) {
543 		case NG_CONTROL:
544 			priv->ctlsock = NULL;
545 			break;
546 		case NG_DATA:
547 			priv->datasock = NULL;
548 			break;
549 		default:
550 			panic(__func__);
551 		}
552 		if ((--priv->refs == 0) && (priv->node != NULL))
553 			ng_rmnode_self(priv->node);
554 	}
555 	pcbp->ng_socket->so_pcb = NULL;
556 	pcbp->ng_socket = NULL;
557 	LIST_REMOVE(pcbp, socks);
558 	FREE(pcbp, M_PCB);
559 }
560 
561 #ifdef NOTYET
562 /*
563  * File descriptors can be passed into a AF_NETGRAPH socket.
564  * Note, that file descriptors cannot be passed OUT.
565  * Only character device descriptors are accepted.
566  * Character devices are useful to connect a graph to a device,
567  * which after all is the purpose of this whole system.
568  */
569 static int
570 ng_internalize(struct mbuf *control, struct thread *td)
571 {
572 	struct cmsghdr *cm = mtod(control, struct cmsghdr *);
573 	struct file *fp;
574 	struct vnode *vn;
575 	int oldfds;
576 	int fd;
577 
578 	if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
579 	    cm->cmsg_len != control->m_len) {
580 		TRAP_ERROR;
581 		return (EINVAL);
582 	}
583 
584 	/* Check there is only one FD. XXX what would more than one signify? */
585 	oldfds = ((caddr_t)cm + cm->cmsg_len - (caddr_t)data) / sizeof (int);
586 	if (oldfds != 1) {
587 		TRAP_ERROR;
588 		return (EINVAL);
589 	}
590 
591 	/* Check that the FD given is legit. and change it to a pointer to a
592 	 * struct file. */
593 	fd = CMSG_DATA(cm);
594 	if ((error = fget(td, fd, &fp)) != 0)
595 		return (error);
596 
597 	/* Depending on what kind of resource it is, act differently. For
598 	 * devices, we treat it as a file. For a AF_NETGRAPH socket,
599 	 * shortcut straight to the node. */
600 	switch (fp->f_type) {
601 	case DTYPE_VNODE:
602 		vn = (struct vnode *) fp->f_data;
603 		if (vn && (vn->v_type == VCHR)) {
604 			/* for a VCHR, actually reference the FILE */
605 			fp->f_count++;
606 			/* XXX then what :) */
607 			/* how to pass on to other modules? */
608 		} else {
609 			fdrop(fp, td);
610 			TRAP_ERROR;
611 			return (EINVAL);
612 		}
613 		break;
614 	default:
615 		fdrop(fp, td);
616 		TRAP_ERROR;
617 		return (EINVAL);
618 	}
619 	fdrop(fp, td);
620 	return (0);
621 }
622 #endif	/* NOTYET */
623 
624 /*
625  * Connect the data socket to a named control socket node.
626  */
627 static int
628 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
629 {
630 	struct sockaddr_ng *sap;
631 	node_p farnode;
632 	struct ngsock *priv;
633 	int error;
634 	item_p item;
635 
636 	/* If we are already connected, don't do it again */
637 	if (pcbp->sockdata != NULL)
638 		return (EISCONN);
639 
640 	/* Find the target (victim) and check it doesn't already have a data
641 	 * socket. Also check it is a 'socket' type node.
642 	 * Use ng_package_data() and address_path() to do this.
643 	 */
644 
645 	sap = (struct sockaddr_ng *) nam;
646 	/* The item will hold the node reference */
647 	item = ng_package_data(NULL, NULL);
648 	if (item == NULL) {
649 		return (ENOMEM);
650 	}
651 	if ((error = ng_address_path(NULL, item,  sap->sg_data, NULL)))
652 		return (error); /* item is freed on failure */
653 
654 	/*
655 	 * Extract node from item and free item. Remember we now have
656 	 * a reference on the node. The item holds it for us.
657 	 * when we free the item we release the reference.
658 	 */
659 	farnode = item->el_dest; /* shortcut */
660 	if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
661 		NG_FREE_ITEM(item); /* drop the reference to the node */
662 		return (EINVAL);
663 	}
664 	priv = NG_NODE_PRIVATE(farnode);
665 	if (priv->datasock != NULL) {
666 		NG_FREE_ITEM(item);	/* drop the reference to the node */
667 		return (EADDRINUSE);
668 	}
669 
670 	/*
671 	 * Link the PCB and the private data struct. and note the extra
672 	 * reference. Drop the extra reference on the node.
673 	 */
674 	priv->datasock = pcbp;
675 	pcbp->sockdata = priv;
676 	priv->refs++; /* XXX possible race if it's being freed */
677 	NG_FREE_ITEM(item);	/* drop the reference to the node */
678 	return (0);
679 }
680 
681 /*
682  * Binding a socket means giving the corresponding node a name
683  */
684 static int
685 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
686 {
687 	struct ngsock *const priv = pcbp->sockdata;
688 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
689 
690 	if (priv == NULL) {
691 		TRAP_ERROR;
692 		return (EINVAL);
693 	}
694 	if ((sap->sg_len < 4)
695 	||  (sap->sg_len > (NG_NODELEN + 3))
696 	||  (sap->sg_data[0] == '\0')
697 	||  (sap->sg_data[sap->sg_len - 3] != '\0')) {
698 		TRAP_ERROR;
699 		return (EINVAL);
700 	}
701 	return (ng_name_node(priv->node, sap->sg_data));
702 }
703 
704 /*
705  * Take a message and pass it up to the control socket associated
706  * with the node.
707  */
708 static int
709 ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg, struct sockaddr_ng *addr)
710 {
711 	struct socket *const so = pcbp->ng_socket;
712 	struct mbuf *mdata;
713 	int msglen;
714 
715 	/* Copy the message itself into an mbuf chain */
716 	msglen = sizeof(struct ng_mesg) + msg->header.arglen;
717 	mdata = m_devget((caddr_t) msg, msglen, 0, NULL, NULL);
718 
719 	/* Here we free the message, as we are the end of the line.
720 	 * We need to do that regardless of whether we got mbufs. */
721 	NG_FREE_MSG(msg);
722 
723 	if (mdata == NULL) {
724 		TRAP_ERROR;
725 		return (ENOBUFS);
726 	}
727 
728 	/* Send it up to the socket */
729 	if (sbappendaddr(&so->so_rcv,
730 	    (struct sockaddr *) addr, mdata, NULL) == 0) {
731 		TRAP_ERROR;
732 		m_freem(mdata);
733 		return (ENOBUFS);
734 	}
735 	sorwakeup(so);
736 	return (0);
737 }
738 
739 /*
740  * You can only create new nodes from the socket end of things.
741  */
742 static int
743 ngs_constructor(node_p nodep)
744 {
745 	return (EINVAL);
746 }
747 
748 /*
749  * We allow any hook to be connected to the node.
750  * There is no per-hook private information though.
751  */
752 static int
753 ngs_newhook(node_p node, hook_p hook, const char *name)
754 {
755 	NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
756 	return (0);
757 }
758 
759 /*
760  * if only one hook, allow read(2) and write(2) to work.
761  */
762 static int
763 ngs_connect(hook_p hook)
764 {
765 	node_p node = NG_HOOK_NODE(hook);
766 	struct ngsock *priv = NG_NODE_PRIVATE(node);
767 
768 	if ((priv->datasock)
769 	&&  (priv->datasock->ng_socket)) {
770 		if (NG_NODE_NUMHOOKS(node) == 1) {
771 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
772 		} else {
773 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
774 		}
775 	}
776 	return (0);
777 }
778 
779 /*
780  * Incoming messages get passed up to the control socket.
781  * Unless they are for us specifically (socket_type)
782  */
783 static int
784 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
785 {
786 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
787 	struct ngpcb *const pcbp = priv->ctlsock;
788 	struct sockaddr_ng *addr;
789 	int addrlen;
790 	int error = 0;
791 	struct	ng_mesg *msg;
792 	ng_ID_t	retaddr = NGI_RETADDR(item);
793 	char	retabuf[32];
794 
795 	NGI_GET_MSG(item, msg);
796 	NG_FREE_ITEM(item); /* we have all we need */
797 
798 	/* Only allow mesgs to be passed if we have the control socket.
799 	 * Data sockets can only support the generic messages. */
800 	if (pcbp == NULL) {
801 		TRAP_ERROR;
802 		return (EINVAL);
803 	}
804 #ifdef TRACE_MESSAGES
805 printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
806 retaddr,
807 msg->header.typecookie,
808 msg->header.cmd,
809 msg->header.cmdstr,
810 msg->header.flags,
811 msg->header.token);
812 
813 #endif
814 
815 	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
816 		switch (msg->header.cmd) {
817 		case NGM_SOCK_CMD_NOLINGER:
818 			priv->flags |= NGS_FLAG_NOLINGER;
819 			break;
820 		case NGM_SOCK_CMD_LINGER:
821 			priv->flags &= ~NGS_FLAG_NOLINGER;
822 			break;
823 		default:
824 			error = EINVAL;		/* unknown command */
825 		}
826 		/* Free the message and return */
827 		NG_FREE_MSG(msg);
828 		return(error);
829 
830 	}
831 	/* Get the return address into a sockaddr */
832 	sprintf(retabuf,"[%x]:", retaddr);
833 	addrlen = strlen(retabuf);
834 	MALLOC(addr, struct sockaddr_ng *, addrlen + 4, M_NETGRAPH_PATH, M_NOWAIT);
835 	if (addr == NULL) {
836 		TRAP_ERROR;
837 		return (ENOMEM);
838 	}
839 	addr->sg_len = addrlen + 3;
840 	addr->sg_family = AF_NETGRAPH;
841 	bcopy(retabuf, addr->sg_data, addrlen);
842 	addr->sg_data[addrlen] = '\0';
843 
844 	/* Send it up */
845 	error = ship_msg(pcbp, msg, addr);
846 	FREE(addr, M_NETGRAPH_PATH);
847 	return (error);
848 }
849 
850 /*
851  * Receive data on a hook
852  */
853 static int
854 ngs_rcvdata(hook_p hook, item_p item)
855 {
856 	struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
857 	struct ngpcb *const pcbp = priv->datasock;
858 	struct socket *so;
859 	struct sockaddr_ng *addr;
860 	char *addrbuf[NG_HOOKLEN + 1 + 4];
861 	int addrlen;
862 	struct mbuf *m;
863 
864 	NGI_GET_M(item, m);
865 	NG_FREE_ITEM(item);
866 	/* If there is no data socket, black-hole it */
867 	if (pcbp == NULL) {
868 		NG_FREE_M(m);
869 		return (0);
870 	}
871 	so = pcbp->ng_socket;
872 
873 	/* Get the return address into a sockaddr. */
874 	addrlen = strlen(NG_HOOK_NAME(hook));	/* <= NG_HOOKLEN */
875 	addr = (struct sockaddr_ng *) addrbuf;
876 	addr->sg_len = addrlen + 3;
877 	addr->sg_family = AF_NETGRAPH;
878 	bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
879 	addr->sg_data[addrlen] = '\0';
880 
881 	/* Try to tell the socket which hook it came in on */
882 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *) addr, m, NULL) == 0) {
883 		m_freem(m);
884 		TRAP_ERROR;
885 		return (ENOBUFS);
886 	}
887 	sorwakeup(so);
888 	return (0);
889 }
890 
891 /*
892  * Hook disconnection
893  *
894  * For this type, removal of the last link destroys the node
895  * if the NOLINGER flag is set.
896  */
897 static int
898 ngs_disconnect(hook_p hook)
899 {
900 	node_p node = NG_HOOK_NODE(hook);
901 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
902 
903 	if ((priv->datasock)
904 	&&  (priv->datasock->ng_socket)) {
905 		if (NG_NODE_NUMHOOKS(node) == 1) {
906 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
907 		} else {
908 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
909 		}
910 	}
911 
912 	if ((priv->flags & NGS_FLAG_NOLINGER )
913 	&& (NG_NODE_NUMHOOKS(node) == 0)
914 	&& (NG_NODE_IS_VALID(node))) {
915 		ng_rmnode_self(node);
916 	}
917 	return (0);
918 }
919 
920 /*
921  * Do local shutdown processing.
922  * In this case, that involves making sure the socket
923  * knows we should be shutting down.
924  */
925 static int
926 ngs_shutdown(node_p node)
927 {
928 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
929 	struct ngpcb *const dpcbp = priv->datasock;
930 	struct ngpcb *const pcbp = priv->ctlsock;
931 
932 	if (dpcbp != NULL) {
933 		soisdisconnected(dpcbp->ng_socket);
934 		dpcbp->sockdata = NULL;
935 		priv->datasock = NULL;
936 		priv->refs--;
937 	}
938 	if (pcbp != NULL) {
939 		soisdisconnected(pcbp->ng_socket);
940 		pcbp->sockdata = NULL;
941 		priv->ctlsock = NULL;
942 		priv->refs--;
943 	}
944 	NG_NODE_SET_PRIVATE(node, NULL);
945 	NG_NODE_UNREF(node);
946 	FREE(priv, M_NETGRAPH_SOCK);
947 	return (0);
948 }
949 
950 static	int
951 dummy_disconnect(struct socket *so)
952 {
953 	return (0);
954 }
955 /*
956  * Control and data socket type descriptors
957  */
958 
959 static struct pr_usrreqs ngc_usrreqs = {
960 	NULL,			/* abort */
961 	pru_accept_notsupp,
962 	ngc_attach,
963 	ngc_bind,
964 	ngc_connect,
965 	pru_connect2_notsupp,
966 	pru_control_notsupp,
967 	ngc_detach,
968 	dummy_disconnect,	/* disconnect */
969 	pru_listen_notsupp,
970 	NULL,			/* setpeeraddr */
971 	pru_rcvd_notsupp,
972 	pru_rcvoob_notsupp,
973 	ngc_send,
974 	pru_sense_null,
975 	NULL,			/* shutdown */
976 	ng_setsockaddr,
977 	sosend,
978 	soreceive,
979 	sopoll
980 };
981 
982 static struct pr_usrreqs ngd_usrreqs = {
983 	NULL,			/* abort */
984 	pru_accept_notsupp,
985 	ngd_attach,
986 	NULL,			/* bind */
987 	ngd_connect,
988 	pru_connect2_notsupp,
989 	pru_control_notsupp,
990 	ngd_detach,
991 	dummy_disconnect,	/* disconnect */
992 	pru_listen_notsupp,
993 	NULL,			/* setpeeraddr */
994 	pru_rcvd_notsupp,
995 	pru_rcvoob_notsupp,
996 	ngd_send,
997 	pru_sense_null,
998 	NULL,			/* shutdown */
999 	ng_setsockaddr,
1000 	sosend,
1001 	soreceive,
1002 	sopoll
1003 };
1004 
1005 /*
1006  * Definitions of protocols supported in the NETGRAPH domain.
1007  */
1008 
1009 extern struct domain ngdomain;		/* stop compiler warnings */
1010 
1011 static struct protosw ngsw[] = {
1012 	{
1013 		SOCK_DGRAM,		/* protocol type */
1014 		&ngdomain,		/* backpointer to domain */
1015 		NG_CONTROL,
1016 		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,	/* flags */
1017 		0, 0, 0, 0,		/* input, output, ctlinput, ctloutput */
1018 		NULL,			/* ousrreq */
1019 		0, 0, 0, 0,		/* init, fasttimeo, slowtimo, drain */
1020 		&ngc_usrreqs,		/* usrreq table (above) */
1021 		/*{NULL}*/		/* pffh (protocol filter head?) */
1022 	},
1023 	{
1024 		SOCK_DGRAM,		/* protocol type */
1025 		&ngdomain,		/* backpointer to domain */
1026 		NG_DATA,
1027 		PR_ATOMIC | PR_ADDR,	/* flags */
1028 		0, 0, 0, 0,		/* input, output, ctlinput, ctloutput */
1029 		NULL,			/* ousrreq() */
1030 		0, 0, 0, 0,		/* init, fasttimeo, slowtimo, drain */
1031 		&ngd_usrreqs,		/* usrreq table (above) */
1032 		/*{NULL}*/		/* pffh (protocol filter head?) */
1033 	}
1034 };
1035 
1036 struct domain ngdomain = {
1037 	AF_NETGRAPH,
1038 	"netgraph",
1039 	NULL,					/* init() */
1040 	NULL,					/* externalise() */
1041 	NULL,					/* dispose() */
1042 	ngsw,					/* protosw entry */
1043 	&ngsw[sizeof(ngsw) / sizeof(ngsw[0])], 	/* Number of protosw entries */
1044 	NULL,					/* next domain in list */
1045 	NULL,					/* rtattach() */
1046 	0,					/* arg to rtattach in bits */
1047 	0					/* maxrtkey */
1048 };
1049 
1050 /*
1051  * Handle loading and unloading for this node type
1052  * This is to handle auxiliary linkages (e.g protocol domain addition).
1053  */
1054 static int
1055 ngs_mod_event(module_t mod, int event, void *data)
1056 {
1057 	int error = 0;
1058 
1059 	switch (event) {
1060 	case MOD_LOAD:
1061 		/* Register protocol domain */
1062 		net_add_domain(&ngdomain);
1063 		break;
1064 	case MOD_UNLOAD:
1065 		/* Insure there are no open netgraph sockets */
1066 		if (!LIST_EMPTY(&ngsocklist)) {
1067 			error = EBUSY;
1068 			break;
1069 		}
1070 
1071 #ifdef NOTYET
1072 		if ((LIST_EMPTY(&ngsocklist)) && (typestruct.refs == 0)) {
1073 		/* Unregister protocol domain XXX can't do this yet.. */
1074 			if ((error = net_rm_domain(&ngdomain)) != 0)
1075 				break;
1076 		} else
1077 #endif
1078 			error = EBUSY;
1079 		break;
1080 	default:
1081 		error = EOPNOTSUPP;
1082 		break;
1083 	}
1084 	return (error);
1085 }
1086 
1087 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
1088 SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
1089 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
1090 SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
1091 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
1092 
1093