xref: /freebsd/sys/netgraph/ng_socket.c (revision 3d11b6c8f01e1fca5936a11d6996448467851a94)
1 /*
2  * ng_socket.c
3  */
4 
5 /*-
6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
7  * All rights reserved.
8  *
9  * Subject to the following obligations and disclaimer of warranty, use and
10  * redistribution of this software, in source or object code forms, with or
11  * without modifications are expressly permitted by Whistle Communications;
12  * provided, however, that:
13  * 1. Any and all reproductions of the source or object code must include the
14  *    copyright notice above and the following disclaimer of warranties; and
15  * 2. No rights are granted, in any manner or form, to use Whistle
16  *    Communications, Inc. trademarks, including the mark "WHISTLE
17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18  *    such appears in the above copyright notice or in the software.
19  *
20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36  * OF SUCH DAMAGE.
37  *
38  * Author: Julian Elischer <julian@freebsd.org>
39  *
40  * $FreeBSD$
41  * $Whistle: ng_socket.c,v 1.28 1999/11/01 09:24:52 julian Exp $
42  */
43 
44 /*
45  * Netgraph socket nodes
46  *
47  * There are two types of netgraph sockets, control and data.
48  * Control sockets have a netgraph node, but data sockets are
49  * parasitic on control sockets, and have no node of their own.
50  */
51 
52 #include <sys/param.h>
53 #include <sys/domain.h>
54 #include <sys/errno.h>
55 #include <sys/kdb.h>
56 #include <sys/kernel.h>
57 #include <sys/linker.h>
58 #include <sys/lock.h>
59 #include <sys/malloc.h>
60 #include <sys/mbuf.h>
61 #include <sys/mutex.h>
62 #include <sys/protosw.h>
63 #include <sys/queue.h>
64 #include <sys/signalvar.h>
65 #include <sys/socket.h>
66 #include <sys/socketvar.h>
67 #include <sys/sx.h>
68 #include <sys/sysctl.h>
69 #include <sys/systm.h>
70 #ifdef NOTYET
71 #include <sys/vnode.h>
72 #endif
73 #include <netgraph/ng_message.h>
74 #include <netgraph/netgraph.h>
75 #include <netgraph/ng_socketvar.h>
76 #include <netgraph/ng_socket.h>
77 
78 #ifdef NG_SEPARATE_MALLOC
79 MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info ");
80 MALLOC_DEFINE(M_NETGRAPH_SOCK, "netgraph_sock", "netgraph socket info ");
81 #else
82 #define M_NETGRAPH_PATH M_NETGRAPH
83 #define M_NETGRAPH_SOCK M_NETGRAPH
84 #endif
85 
86 /*
87  * It's Ascii-art time!
88  *   +-------------+   +-------------+
89  *   |socket  (ctl)|   |socket (data)|
90  *   +-------------+   +-------------+
91  *          ^                 ^
92  *          |                 |
93  *          v                 v
94  *    +-----------+     +-----------+
95  *    |pcb   (ctl)|     |pcb  (data)|
96  *    +-----------+     +-----------+
97  *          ^                 ^
98  *          |                 |
99  *          v                 v
100  *      +--------------------------+
101  *      |   Socket type private    |
102  *      |       data               |
103  *      +--------------------------+
104  *                   ^
105  *                   |
106  *                   v
107  *           +----------------+
108  *           | struct ng_node |
109  *           +----------------+
110  */
111 
112 /* Netgraph node methods */
113 static ng_constructor_t	ngs_constructor;
114 static ng_rcvmsg_t	ngs_rcvmsg;
115 static ng_shutdown_t	ngs_shutdown;
116 static ng_newhook_t	ngs_newhook;
117 static ng_connect_t	ngs_connect;
118 static ng_rcvdata_t	ngs_rcvdata;
119 static ng_disconnect_t	ngs_disconnect;
120 
121 /* Internal methods */
122 static int	ng_attach_data(struct socket *so);
123 static int	ng_attach_cntl(struct socket *so);
124 static int	ng_attach_common(struct socket *so, int type);
125 static void	ng_detach_common(struct ngpcb *pcbp, int type);
126 static void	ng_socket_free_priv(struct ngsock *priv);
127 /*static int	ng_internalize(struct mbuf *m, struct thread *p); */
128 
129 static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
130 static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
131 
132 static int	ngs_mod_event(module_t mod, int event, void *data);
133 static int	ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg,
134 			struct sockaddr_ng *addr);
135 static void	ng_socket_item_applied(void *context, int error);
136 
137 /* Netgraph type descriptor */
138 static struct ng_type typestruct = {
139 	.version =	NG_ABI_VERSION,
140 	.name =		NG_SOCKET_NODE_TYPE,
141 	.mod_event =	ngs_mod_event,
142 	.constructor =	ngs_constructor,
143 	.rcvmsg =	ngs_rcvmsg,
144 	.shutdown =	ngs_shutdown,
145 	.newhook =	ngs_newhook,
146 	.connect =	ngs_connect,
147 	.rcvdata =	ngs_rcvdata,
148 	.disconnect =	ngs_disconnect,
149 };
150 NETGRAPH_INIT_ORDERED(socket, &typestruct, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
151 
152 /* Buffer space */
153 static u_long ngpdg_sendspace = 20 * 1024;	/* really max datagram size */
154 SYSCTL_INT(_net_graph, OID_AUTO, maxdgram, CTLFLAG_RW,
155     &ngpdg_sendspace , 0, "Maximum outgoing Netgraph datagram size");
156 static u_long ngpdg_recvspace = 20 * 1024;
157 SYSCTL_INT(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
158     &ngpdg_recvspace , 0, "Maximum space for incoming Netgraph datagrams");
159 
160 /* List of all sockets */
161 static LIST_HEAD(, ngpcb) ngsocklist;
162 
163 static struct mtx	ngsocketlist_mtx;
164 
165 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
166 
167 /* If getting unexplained errors returned, set this to "kdb_enter("X"); */
168 #ifndef TRAP_ERROR
169 #define TRAP_ERROR
170 #endif
171 
172 /***************************************************************
173 	Control sockets
174 ***************************************************************/
175 
176 static int
177 ngc_attach(struct socket *so, int proto, struct thread *td)
178 {
179 	struct ngpcb *const pcbp = sotongpcb(so);
180 
181 	if (suser(td))
182 		return (EPERM);
183 	if (pcbp != NULL)
184 		return (EISCONN);
185 	return (ng_attach_cntl(so));
186 }
187 
188 static void
189 ngc_detach(struct socket *so)
190 {
191 	struct ngpcb *const pcbp = sotongpcb(so);
192 
193 	KASSERT(pcbp != NULL, ("ngc_detach: pcbp == NULL"));
194 	ng_detach_common(pcbp, NG_CONTROL);
195 }
196 
197 static int
198 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
199 	 struct mbuf *control, struct thread *td)
200 {
201 	struct ngpcb *const pcbp = sotongpcb(so);
202 	struct ngsock *const priv = NG_NODE_PRIVATE(pcbp->sockdata->node);
203 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
204 	struct ng_mesg *msg;
205 	struct mbuf *m0;
206 	item_p item;
207 	char *path = NULL;
208 	int len, error = 0;
209 
210 	if (pcbp == NULL) {
211 		error = EINVAL;
212 		goto release;
213 	}
214 #ifdef	NOTYET
215 	if (control && (error = ng_internalize(control, td))) {
216 		if (pcbp->sockdata == NULL) {
217 			error = ENOTCONN;
218 			goto release;
219 		}
220 	}
221 #else	/* NOTYET */
222 	if (control) {
223 		error = EINVAL;
224 		goto release;
225 	}
226 #endif	/* NOTYET */
227 
228 	/* Require destination as there may be >= 1 hooks on this node */
229 	if (addr == NULL) {
230 		error = EDESTADDRREQ;
231 		goto release;
232 	}
233 
234 	/* Allocate an expendable buffer for the path, chop off
235 	 * the sockaddr header, and make sure it's NUL terminated */
236 	len = sap->sg_len - 2;
237 	MALLOC(path, char *, len + 1, M_NETGRAPH_PATH, M_WAITOK);
238 	if (path == NULL) {
239 		error = ENOMEM;
240 		goto release;
241 	}
242 	bcopy(sap->sg_data, path, len);
243 	path[len] = '\0';
244 
245 	/* Move the actual message out of mbufs into a linear buffer.
246 	 * Start by adding up the size of the data. (could use mh_len?) */
247 	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
248 		len += m0->m_len;
249 
250 	/* Move the data into a linear buffer as well. Messages are not
251 	 * delivered in mbufs. */
252 	MALLOC(msg, struct ng_mesg *, len + 1, M_NETGRAPH_MSG, M_WAITOK);
253 	if (msg == NULL) {
254 		error = ENOMEM;
255 		goto release;
256 	}
257 	m_copydata(m, 0, len, (char *)msg);
258 
259 	if (msg->header.version != NG_VERSION) {
260 		error = EINVAL;
261 		goto release;
262 	}
263 
264 	/*
265 	 * Hack alert!
266 	 * We look into the message and if it mkpeers a node of unknown type, we
267 	 * try to load it. We need to do this now, in syscall thread, because if
268 	 * message gets queued and applied later we will get panic.
269 	 */
270 	if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
271 	    msg->header.cmd == NGM_MKPEER) {
272 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
273 		struct ng_type *type;
274 
275 		if ((type = ng_findtype(mkp->type)) == NULL) {
276 			char filename[NG_TYPESIZ + 3];
277 			linker_file_t lf;
278 
279 			/* Not found, try to load it as a loadable module. */
280 			snprintf(filename, sizeof(filename), "ng_%s",
281 			    mkp->type);
282 			mtx_lock(&Giant);
283 			error = linker_load_module(NULL, filename, NULL, NULL,
284 			    &lf);
285 			mtx_unlock(&Giant);
286 			if (error != 0) {
287 				FREE(msg, M_NETGRAPH_MSG);
288 				goto release;
289 			}
290 			lf->userrefs++;
291 
292 			/* See if type has been loaded successfully. */
293 			if ((type = ng_findtype(mkp->type)) == NULL) {
294 				FREE(msg, M_NETGRAPH_MSG);
295 				error =  ENXIO;
296 				goto release;
297 			}
298 		}
299 	}
300 
301 	if ((item = ng_package_msg(msg, M_WAITOK)) == NULL) {
302 		error = ENOMEM;
303 #ifdef TRACE_MESSAGES
304 		printf("ng_package_msg: err=%d\n", error);
305 #endif
306 		goto release;
307 	}
308 	if ((error = ng_address_path((pcbp->sockdata->node), item,
309 	    path, 0)) != 0) {
310 #ifdef TRACE_MESSAGES
311 		printf("ng_address_path: errx=%d\n", error);
312 #endif
313 		goto release;
314 	}
315 
316 #ifdef TRACE_MESSAGES
317 	printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
318 		item->el_dest->nd_ID,
319 		msg->header.typecookie,
320 		msg->header.cmd,
321 		msg->header.cmdstr,
322 		msg->header.flags,
323 		msg->header.token,
324 		item->el_dest->nd_type->name);
325 #endif
326 	SAVE_LINE(item);
327 	/*
328 	 * We do not want to return from syscall until the item
329 	 * is processed by destination node. We register callback
330 	 * on the item, which will update priv->error when item
331 	 * was applied.
332 	 * If ng_snd_item() has queued item, we sleep until
333 	 * callback wakes us up.
334 	 */
335 	item->apply = ng_socket_item_applied;
336 	item->context = priv;
337 	priv->error = -1;
338 
339 	error = ng_snd_item(item, NG_PROGRESS);
340 
341 	if (error == EINPROGRESS) {
342 		mtx_lock(&priv->mtx);
343 		if (priv->error == -1)
344 			msleep(priv, &priv->mtx, 0, "ngsock", 0);
345 		mtx_unlock(&priv->mtx);
346 		KASSERT(priv->error != -1,
347 		    ("ng_socket: priv->error wasn't updated"));
348 		error = priv->error;
349 	}
350 
351 release:
352 	if (path != NULL)
353 		FREE(path, M_NETGRAPH_PATH);
354 	if (control != NULL)
355 		m_freem(control);
356 	if (m != NULL)
357 		m_freem(m);
358 	return (error);
359 }
360 
361 static int
362 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
363 {
364 	struct ngpcb *const pcbp = sotongpcb(so);
365 
366 	if (pcbp == 0)
367 		return (EINVAL);
368 	return (ng_bind(nam, pcbp));
369 }
370 
371 static int
372 ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
373 {
374 printf(" program tried to connect control socket to remote node\n ");
375 	/*
376 	 * At this time refuse to do this.. it used to
377 	 * do something but it was undocumented and not used.
378 	 */
379 	return (EINVAL);
380 }
381 
382 /***************************************************************
383 	Data sockets
384 ***************************************************************/
385 
386 static int
387 ngd_attach(struct socket *so, int proto, struct thread *td)
388 {
389 	struct ngpcb *const pcbp = sotongpcb(so);
390 
391 	if (pcbp != NULL)
392 		return (EISCONN);
393 	return (ng_attach_data(so));
394 }
395 
396 static void
397 ngd_detach(struct socket *so)
398 {
399 	struct ngpcb *const pcbp = sotongpcb(so);
400 
401 	KASSERT(pcbp != NULL, ("ngd_detach: pcbp == NULL"));
402 	ng_detach_common(pcbp, NG_DATA);
403 }
404 
405 static int
406 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
407 	 struct mbuf *control, struct thread *td)
408 {
409 	struct ngpcb *const pcbp = sotongpcb(so);
410 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
411 	int     len, error;
412 	hook_p  hook = NULL;
413 	char	hookname[NG_HOOKSIZ];
414 
415 	if ((pcbp == NULL) || (control != NULL)) {
416 		error = EINVAL;
417 		goto release;
418 	}
419 	if (pcbp->sockdata == NULL) {
420 		error = ENOTCONN;
421 		goto release;
422 	}
423 
424 	if (sap == NULL)
425 		len = 0;		/* Make compiler happy. */
426 	else
427 		len = sap->sg_len - 2;
428 
429 	/*
430 	 * If the user used any of these ways to not specify an address
431 	 * then handle specially.
432 	 */
433 	if ((sap == NULL) || (len <= 0) || (*sap->sg_data == '\0')) {
434 		if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
435 			error = EDESTADDRREQ;
436 			goto release;
437 		}
438 		/*
439 		 * if exactly one hook exists, just use it.
440 		 * Special case to allow write(2) to work on an ng_socket.
441 		 */
442 		hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
443 	} else {
444 		if (len >= NG_HOOKSIZ) {
445 			error = EINVAL;
446 			goto release;
447 		}
448 
449 		/*
450 		 * chop off the sockaddr header, and make sure it's NUL
451 		 * terminated
452 		 */
453 		bcopy(sap->sg_data, hookname, len);
454 		hookname[len] = '\0';
455 
456 		/* Find the correct hook from 'hookname' */
457 		LIST_FOREACH(hook, &pcbp->sockdata->node->nd_hooks, hk_hooks) {
458 			if (strcmp(hookname, NG_HOOK_NAME(hook)) == 0) {
459 				break;
460 			}
461 		}
462 		if (hook == NULL) {
463 			error = EHOSTUNREACH;
464 		}
465 	}
466 
467 	/* Send data (OK if hook is NULL) */
468 	NG_SEND_DATA_ONLY(error, hook, m);	/* makes m NULL */
469 
470 release:
471 	if (control != NULL)
472 		m_freem(control);
473 	if (m != NULL)
474 		m_freem(m);
475 	return (error);
476 }
477 
478 static int
479 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
480 {
481 	struct ngpcb *const pcbp = sotongpcb(so);
482 
483 	if (pcbp == 0)
484 		return (EINVAL);
485 	return (ng_connect_data(nam, pcbp));
486 }
487 
488 /*
489  * Used for both data and control sockets
490  */
491 static int
492 ng_setsockaddr(struct socket *so, struct sockaddr **addr)
493 {
494 	struct ngpcb *pcbp;
495 	struct sockaddr_ng *sg;
496 	int sg_len;
497 	int error = 0;
498 
499 	/* Why isn't sg_data a `char[1]' ? :-( */
500 	sg_len = sizeof(struct sockaddr_ng) - sizeof(sg->sg_data) + 1;
501 
502 	pcbp = sotongpcb(so);
503 	if ((pcbp == NULL) || (pcbp->sockdata == NULL))
504 		/* XXXGL: can this still happen? */
505 		return (EINVAL);
506 
507 	mtx_lock(&pcbp->sockdata->mtx);
508 	if (pcbp->sockdata->node != NULL) {
509 		node_p node = pcbp->sockdata->node;
510 		int namelen = 0;	/* silence compiler! */
511 
512 		if (NG_NODE_HAS_NAME(node))
513 			sg_len += namelen = strlen(NG_NODE_NAME(node));
514 
515 		sg = malloc(sg_len, M_SONAME, M_WAITOK | M_ZERO);
516 
517 		if (NG_NODE_HAS_NAME(node))
518 			bcopy(NG_NODE_NAME(node), sg->sg_data, namelen);
519 
520 		sg->sg_len = sg_len;
521 		sg->sg_family = AF_NETGRAPH;
522 		*addr = (struct sockaddr *)sg;
523 		mtx_unlock(&pcbp->sockdata->mtx);
524 	} else {
525 		mtx_unlock(&pcbp->sockdata->mtx);
526 		error = EINVAL;
527 	}
528 
529 	return (error);
530 }
531 
532 /*
533  * Attach a socket to it's protocol specific partner.
534  * For a control socket, actually create a netgraph node and attach
535  * to it as well.
536  */
537 
538 static int
539 ng_attach_cntl(struct socket *so)
540 {
541 	struct ngsock *priv;
542 	struct ngpcb *pcbp;
543 	int error;
544 
545 	/* Allocate node private info */
546 	MALLOC(priv, struct ngsock *,
547 	    sizeof(*priv), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
548 	if (priv == NULL)
549 		return (ENOMEM);
550 
551 	/* Setup protocol control block */
552 	if ((error = ng_attach_common(so, NG_CONTROL)) != 0) {
553 		FREE(priv, M_NETGRAPH_SOCK);
554 		return (error);
555 	}
556 	pcbp = sotongpcb(so);
557 
558 	/* Link the pcb the private data. */
559 	priv->ctlsock = pcbp;
560 	pcbp->sockdata = priv;
561 	priv->refs++;
562 
563 	/* Initialize mutex. */
564 	mtx_init(&priv->mtx, "ng_socket", NULL, MTX_DEF);
565 
566 	/* Make the generic node components */
567 	if ((error = ng_make_node_common(&typestruct, &priv->node)) != 0) {
568 		FREE(priv, M_NETGRAPH_SOCK);
569 		ng_detach_common(pcbp, NG_CONTROL);
570 		return (error);
571 	}
572 
573 	/* Link the node and the private data. */
574 	NG_NODE_SET_PRIVATE(priv->node, priv);
575 	NG_NODE_REF(priv->node);
576 	priv->refs++;
577 
578 	return (0);
579 }
580 
581 static int
582 ng_attach_data(struct socket *so)
583 {
584 	return(ng_attach_common(so, NG_DATA));
585 }
586 
587 /*
588  * Set up a socket protocol control block.
589  * This code is shared between control and data sockets.
590  */
591 static int
592 ng_attach_common(struct socket *so, int type)
593 {
594 	struct ngpcb *pcbp;
595 	int error;
596 
597 	/* Standard socket setup stuff */
598 	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
599 	if (error)
600 		return (error);
601 
602 	/* Allocate the pcb */
603 	MALLOC(pcbp, struct ngpcb *, sizeof(*pcbp), M_PCB, M_WAITOK | M_ZERO);
604 	if (pcbp == NULL)
605 		return (ENOMEM);
606 	pcbp->type = type;
607 
608 	/* Link the pcb and the socket */
609 	so->so_pcb = (caddr_t) pcbp;
610 	pcbp->ng_socket = so;
611 
612 	/* Add the socket to linked list */
613 	mtx_lock(&ngsocketlist_mtx);
614 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
615 	mtx_unlock(&ngsocketlist_mtx);
616 	return (0);
617 }
618 
619 /*
620  * Disassociate the socket from it's protocol specific
621  * partner. If it's attached to a node's private data structure,
622  * then unlink from that too. If we were the last socket attached to it,
623  * then shut down the entire node. Shared code for control and data sockets.
624  */
625 static void
626 ng_detach_common(struct ngpcb *pcbp, int which)
627 {
628 	struct ngsock *priv = pcbp->sockdata;
629 
630 	if (priv != NULL) {
631 		mtx_lock(&priv->mtx);
632 
633 		switch (which) {
634 		case NG_CONTROL:
635 			priv->ctlsock = NULL;
636 			break;
637 		case NG_DATA:
638 			priv->datasock = NULL;
639 			break;
640 		default:
641 			panic(__func__);
642 		}
643 		pcbp->sockdata = NULL;
644 
645 		ng_socket_free_priv(priv);
646 	}
647 
648 	pcbp->ng_socket->so_pcb = NULL;
649 	mtx_lock(&ngsocketlist_mtx);
650 	LIST_REMOVE(pcbp, socks);
651 	mtx_unlock(&ngsocketlist_mtx);
652 	FREE(pcbp, M_PCB);
653 }
654 
655 /*
656  * Remove a reference from node private data.
657  */
658 static void
659 ng_socket_free_priv(struct ngsock *priv)
660 {
661 	mtx_assert(&priv->mtx, MA_OWNED);
662 
663 	priv->refs--;
664 
665 	if (priv->refs == 0) {
666 		mtx_destroy(&priv->mtx);
667 		FREE(priv, M_NETGRAPH_SOCK);
668 		return;
669 	}
670 
671 	if ((priv->refs == 1) && (priv->node != NULL)) {
672 		node_p node = priv->node;
673 
674 		priv->node = NULL;
675 		mtx_unlock(&priv->mtx);
676 		NG_NODE_UNREF(node);
677 		ng_rmnode_self(node);
678 	} else
679 		mtx_unlock(&priv->mtx);
680 }
681 
682 #ifdef NOTYET
683 /*
684  * File descriptors can be passed into an AF_NETGRAPH socket.
685  * Note, that file descriptors cannot be passed OUT.
686  * Only character device descriptors are accepted.
687  * Character devices are useful to connect a graph to a device,
688  * which after all is the purpose of this whole system.
689  */
690 static int
691 ng_internalize(struct mbuf *control, struct thread *td)
692 {
693 	const struct cmsghdr *cm = mtod(control, const struct cmsghdr *);
694 	struct file *fp;
695 	struct vnode *vn;
696 	int oldfds;
697 	int fd;
698 
699 	if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
700 	    cm->cmsg_len != control->m_len) {
701 		TRAP_ERROR;
702 		return (EINVAL);
703 	}
704 
705 	/* Check there is only one FD. XXX what would more than one signify? */
706 	oldfds = ((caddr_t)cm + cm->cmsg_len - (caddr_t)data) / sizeof (int);
707 	if (oldfds != 1) {
708 		TRAP_ERROR;
709 		return (EINVAL);
710 	}
711 
712 	/* Check that the FD given is legit. and change it to a pointer to a
713 	 * struct file. */
714 	fd = CMSG_DATA(cm);
715 	if ((error = fget(td, fd, &fp)) != 0)
716 		return (error);
717 
718 	/* Depending on what kind of resource it is, act differently. For
719 	 * devices, we treat it as a file. For an AF_NETGRAPH socket,
720 	 * shortcut straight to the node. */
721 	switch (fp->f_type) {
722 	case DTYPE_VNODE:
723 		vn = fp->f_data;
724 		if (vn && (vn->v_type == VCHR)) {
725 			/* for a VCHR, actually reference the FILE */
726 			fp->f_count++;
727 			/* XXX then what :) */
728 			/* how to pass on to other modules? */
729 		} else {
730 			fdrop(fp, td);
731 			TRAP_ERROR;
732 			return (EINVAL);
733 		}
734 		break;
735 	default:
736 		fdrop(fp, td);
737 		TRAP_ERROR;
738 		return (EINVAL);
739 	}
740 	fdrop(fp, td);
741 	return (0);
742 }
743 #endif	/* NOTYET */
744 
745 /*
746  * Connect the data socket to a named control socket node.
747  */
748 static int
749 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
750 {
751 	struct sockaddr_ng *sap;
752 	node_p farnode;
753 	struct ngsock *priv;
754 	int error;
755 	item_p item;
756 
757 	/* If we are already connected, don't do it again */
758 	if (pcbp->sockdata != NULL)
759 		return (EISCONN);
760 
761 	/* Find the target (victim) and check it doesn't already have a data
762 	 * socket. Also check it is a 'socket' type node.
763 	 * Use ng_package_data() and address_path() to do this.
764 	 */
765 
766 	sap = (struct sockaddr_ng *) nam;
767 	/* The item will hold the node reference */
768 	item = ng_package_data(NULL, NG_WAITOK);
769 	if (item == NULL) {
770 		return (ENOMEM);
771 	}
772 	if ((error = ng_address_path(NULL, item,  sap->sg_data, 0)))
773 		return (error); /* item is freed on failure */
774 
775 	/*
776 	 * Extract node from item and free item. Remember we now have
777 	 * a reference on the node. The item holds it for us.
778 	 * when we free the item we release the reference.
779 	 */
780 	farnode = item->el_dest; /* shortcut */
781 	if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
782 		NG_FREE_ITEM(item); /* drop the reference to the node */
783 		return (EINVAL);
784 	}
785 	priv = NG_NODE_PRIVATE(farnode);
786 	if (priv->datasock != NULL) {
787 		NG_FREE_ITEM(item);	/* drop the reference to the node */
788 		return (EADDRINUSE);
789 	}
790 
791 	/*
792 	 * Link the PCB and the private data struct. and note the extra
793 	 * reference. Drop the extra reference on the node.
794 	 */
795 	mtx_lock(&priv->mtx);
796 	priv->datasock = pcbp;
797 	pcbp->sockdata = priv;
798 	priv->refs++;
799 	mtx_unlock(&priv->mtx);
800 	NG_FREE_ITEM(item);	/* drop the reference to the node */
801 	return (0);
802 }
803 
804 /*
805  * Binding a socket means giving the corresponding node a name
806  */
807 static int
808 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
809 {
810 	struct ngsock *const priv = pcbp->sockdata;
811 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
812 
813 	if (priv == NULL) {
814 		TRAP_ERROR;
815 		return (EINVAL);
816 	}
817 	if ((sap->sg_len < 4)
818 	||  (sap->sg_len > (NG_NODESIZ + 2))
819 	||  (sap->sg_data[0] == '\0')
820 	||  (sap->sg_data[sap->sg_len - 3] != '\0')) {
821 		TRAP_ERROR;
822 		return (EINVAL);
823 	}
824 	return (ng_name_node(priv->node, sap->sg_data));
825 }
826 
827 /*
828  * Take a message and pass it up to the control socket associated
829  * with the node.
830  */
831 static int
832 ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg, struct sockaddr_ng *addr)
833 {
834 	struct socket *const so = pcbp->ng_socket;
835 	struct mbuf *mdata;
836 	int msglen;
837 	int error = 0;
838 
839 	/* Copy the message itself into an mbuf chain */
840 	msglen = sizeof(struct ng_mesg) + msg->header.arglen;
841 	mdata = m_devget((caddr_t) msg, msglen, 0, NULL, NULL);
842 
843 	/* Here we free the message, as we are the end of the line.
844 	 * We need to do that regardless of whether we got mbufs. */
845 	NG_FREE_MSG(msg);
846 
847 	if (mdata == NULL) {
848 		TRAP_ERROR;
849 		return (ENOBUFS);
850 	}
851 
852 	/* Send it up to the socket */
853 	if (sbappendaddr(&so->so_rcv,
854 	    (struct sockaddr *) addr, mdata, NULL) == 0) {
855 		TRAP_ERROR;
856 		m_freem(mdata);
857 		error = so->so_error = ENOBUFS;
858 	}
859 	sorwakeup(so);
860 	return (error);
861 }
862 
863 /***************************************************************
864 	Netgraph node
865 ***************************************************************/
866 
867 /*
868  * You can only create new nodes from the socket end of things.
869  */
870 static int
871 ngs_constructor(node_p nodep)
872 {
873 	return (EINVAL);
874 }
875 
876 /*
877  * We allow any hook to be connected to the node.
878  * There is no per-hook private information though.
879  */
880 static int
881 ngs_newhook(node_p node, hook_p hook, const char *name)
882 {
883 	NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
884 	return (0);
885 }
886 
887 /*
888  * if only one hook, allow read(2) and write(2) to work.
889  */
890 static int
891 ngs_connect(hook_p hook)
892 {
893 	node_p node = NG_HOOK_NODE(hook);
894 	struct ngsock *priv = NG_NODE_PRIVATE(node);
895 
896 	if ((priv->datasock)
897 	&&  (priv->datasock->ng_socket)) {
898 		if (NG_NODE_NUMHOOKS(node) == 1) {
899 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
900 		} else {
901 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
902 		}
903 	}
904 	return (0);
905 }
906 
907 /*
908  * Incoming messages get passed up to the control socket.
909  * Unless they are for us specifically (socket_type)
910  */
911 static int
912 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
913 {
914 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
915 	struct ngpcb *const pcbp = priv->ctlsock;
916 	struct sockaddr_ng *addr;
917 	int addrlen;
918 	int error = 0;
919 	struct	ng_mesg *msg;
920 	ng_ID_t	retaddr = NGI_RETADDR(item);
921 	char	retabuf[32];
922 
923 	NGI_GET_MSG(item, msg);
924 	NG_FREE_ITEM(item); /* we have all we need */
925 
926 	/* Only allow mesgs to be passed if we have the control socket.
927 	 * Data sockets can only support the generic messages. */
928 	if (pcbp == NULL) {
929 		TRAP_ERROR;
930 		return (EINVAL);
931 	}
932 
933 #ifdef TRACE_MESSAGES
934 	printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
935 		retaddr,
936 		msg->header.typecookie,
937 		msg->header.cmd,
938 		msg->header.cmdstr,
939 		msg->header.flags,
940 		msg->header.token);
941 #endif
942 
943 	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
944 		switch (msg->header.cmd) {
945 		case NGM_SOCK_CMD_NOLINGER:
946 			priv->flags |= NGS_FLAG_NOLINGER;
947 			break;
948 		case NGM_SOCK_CMD_LINGER:
949 			priv->flags &= ~NGS_FLAG_NOLINGER;
950 			break;
951 		default:
952 			error = EINVAL;		/* unknown command */
953 		}
954 		/* Free the message and return */
955 		NG_FREE_MSG(msg);
956 		return(error);
957 
958 	}
959 	/* Get the return address into a sockaddr */
960 	sprintf(retabuf,"[%x]:", retaddr);
961 	addrlen = strlen(retabuf);
962 	MALLOC(addr, struct sockaddr_ng *, addrlen + 4, M_NETGRAPH_PATH, M_NOWAIT);
963 	if (addr == NULL) {
964 		TRAP_ERROR;
965 		return (ENOMEM);
966 	}
967 	addr->sg_len = addrlen + 3;
968 	addr->sg_family = AF_NETGRAPH;
969 	bcopy(retabuf, addr->sg_data, addrlen);
970 	addr->sg_data[addrlen] = '\0';
971 
972 	/* Send it up */
973 	error = ship_msg(pcbp, msg, addr);
974 	FREE(addr, M_NETGRAPH_PATH);
975 	return (error);
976 }
977 
978 /*
979  * Receive data on a hook
980  */
981 static int
982 ngs_rcvdata(hook_p hook, item_p item)
983 {
984 	struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
985 	struct ngpcb *const pcbp = priv->datasock;
986 	struct socket *so;
987 	struct sockaddr_ng *addr;
988 	char *addrbuf[NG_HOOKSIZ + 4];
989 	int addrlen;
990 	struct mbuf *m;
991 
992 	NGI_GET_M(item, m);
993 	NG_FREE_ITEM(item);
994 	/* If there is no data socket, black-hole it */
995 	if (pcbp == NULL) {
996 		NG_FREE_M(m);
997 		return (0);
998 	}
999 	so = pcbp->ng_socket;
1000 
1001 	/* Get the return address into a sockaddr. */
1002 	addrlen = strlen(NG_HOOK_NAME(hook));	/* <= NG_HOOKSIZ - 1 */
1003 	addr = (struct sockaddr_ng *) addrbuf;
1004 	addr->sg_len = addrlen + 3;
1005 	addr->sg_family = AF_NETGRAPH;
1006 	bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
1007 	addr->sg_data[addrlen] = '\0';
1008 
1009 	/* Try to tell the socket which hook it came in on */
1010 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *) addr, m, NULL) == 0) {
1011 		m_freem(m);
1012 		TRAP_ERROR;
1013 		return (ENOBUFS);
1014 	}
1015 	sorwakeup(so);
1016 	return (0);
1017 }
1018 
1019 /*
1020  * Hook disconnection
1021  *
1022  * For this type, removal of the last link destroys the node
1023  * if the NOLINGER flag is set.
1024  */
1025 static int
1026 ngs_disconnect(hook_p hook)
1027 {
1028 	node_p node = NG_HOOK_NODE(hook);
1029 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
1030 
1031 	if ((priv->datasock)
1032 	&&  (priv->datasock->ng_socket)) {
1033 		if (NG_NODE_NUMHOOKS(node) == 1) {
1034 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
1035 		} else {
1036 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
1037 		}
1038 	}
1039 
1040 	if ((priv->flags & NGS_FLAG_NOLINGER )
1041 	&& (NG_NODE_NUMHOOKS(node) == 0)
1042 	&& (NG_NODE_IS_VALID(node))) {
1043 		ng_rmnode_self(node);
1044 	}
1045 	return (0);
1046 }
1047 
1048 /*
1049  * Do local shutdown processing.
1050  * In this case, that involves making sure the socket
1051  * knows we should be shutting down.
1052  */
1053 static int
1054 ngs_shutdown(node_p node)
1055 {
1056 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
1057 	struct ngpcb *const dpcbp = priv->datasock;
1058 	struct ngpcb *const pcbp = priv->ctlsock;
1059 
1060 	if (dpcbp != NULL)
1061 		soisdisconnected(dpcbp->ng_socket);
1062 
1063 	if (pcbp != NULL)
1064 		soisdisconnected(pcbp->ng_socket);
1065 
1066 	mtx_lock(&priv->mtx);
1067 	priv->node = NULL;
1068 	NG_NODE_SET_PRIVATE(node, NULL);
1069 	ng_socket_free_priv(priv);
1070 
1071 	NG_NODE_UNREF(node);
1072 	return (0);
1073 }
1074 
1075 static void
1076 ng_socket_item_applied(void *context, int error)
1077 {
1078 	struct ngsock *const priv = (struct ngsock *)context;
1079 
1080 	mtx_lock(&priv->mtx);
1081 	priv->error = error;
1082 	wakeup(priv);
1083 	mtx_unlock(&priv->mtx);
1084 
1085 }
1086 
1087 static	int
1088 dummy_disconnect(struct socket *so)
1089 {
1090 	return (0);
1091 }
1092 /*
1093  * Control and data socket type descriptors
1094  */
1095 
1096 static struct pr_usrreqs ngc_usrreqs = {
1097 	.pru_abort =		NULL,
1098 	.pru_attach =		ngc_attach,
1099 	.pru_bind =		ngc_bind,
1100 	.pru_connect =		ngc_connect,
1101 	.pru_detach =		ngc_detach,
1102 	.pru_disconnect =	dummy_disconnect,
1103 	.pru_peeraddr =		NULL,
1104 	.pru_send =		ngc_send,
1105 	.pru_shutdown =		NULL,
1106 	.pru_sockaddr =		ng_setsockaddr,
1107 };
1108 
1109 static struct pr_usrreqs ngd_usrreqs = {
1110 	.pru_abort =		NULL,
1111 	.pru_attach =		ngd_attach,
1112 	.pru_bind =		NULL,
1113 	.pru_connect =		ngd_connect,
1114 	.pru_detach =		ngd_detach,
1115 	.pru_disconnect =	dummy_disconnect,
1116 	.pru_peeraddr =		NULL,
1117 	.pru_send =		ngd_send,
1118 	.pru_shutdown =		NULL,
1119 	.pru_sockaddr =		ng_setsockaddr,
1120 };
1121 
1122 /*
1123  * Definitions of protocols supported in the NETGRAPH domain.
1124  */
1125 
1126 extern struct domain ngdomain;		/* stop compiler warnings */
1127 
1128 static struct protosw ngsw[] = {
1129 {
1130 	.pr_type =		SOCK_DGRAM,
1131 	.pr_domain =		&ngdomain,
1132 	.pr_protocol =		NG_CONTROL,
1133 	.pr_flags =		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
1134 	.pr_usrreqs =		&ngc_usrreqs
1135 },
1136 {
1137 	.pr_type =		SOCK_DGRAM,
1138 	.pr_domain =		&ngdomain,
1139 	.pr_protocol =		NG_DATA,
1140 	.pr_flags =		PR_ATOMIC | PR_ADDR,
1141 	.pr_usrreqs =		&ngd_usrreqs
1142 }
1143 };
1144 
1145 struct domain ngdomain = {
1146 	.dom_family =		AF_NETGRAPH,
1147 	.dom_name =		"netgraph",
1148 	.dom_protosw =		ngsw,
1149 	.dom_protoswNPROTOSW =	&ngsw[sizeof(ngsw) / sizeof(ngsw[0])]
1150 };
1151 
1152 /*
1153  * Handle loading and unloading for this node type
1154  * This is to handle auxiliary linkages (e.g protocol domain addition).
1155  */
1156 static int
1157 ngs_mod_event(module_t mod, int event, void *data)
1158 {
1159 	int error = 0;
1160 
1161 	switch (event) {
1162 	case MOD_LOAD:
1163 		mtx_init(&ngsocketlist_mtx, "ng_socketlist", NULL, MTX_DEF);
1164 		/* Register protocol domain */
1165 		net_add_domain(&ngdomain);
1166 		break;
1167 	case MOD_UNLOAD:
1168 		/* Insure there are no open netgraph sockets */
1169 		if (!LIST_EMPTY(&ngsocklist)) {
1170 			error = EBUSY;
1171 			break;
1172 		}
1173 
1174 #ifdef NOTYET
1175 		if ((LIST_EMPTY(&ngsocklist)) && (typestruct.refs == 0)) {
1176 		/* Unregister protocol domain XXX can't do this yet.. */
1177 			if ((error = net_rm_domain(&ngdomain)) != 0)
1178 				break;
1179 			mtx_destroy(&ngsocketlist_mtx);
1180 		} else
1181 #endif
1182 			error = EBUSY;
1183 		break;
1184 	default:
1185 		error = EOPNOTSUPP;
1186 		break;
1187 	}
1188 	return (error);
1189 }
1190 
1191 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
1192 SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
1193 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
1194 SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
1195 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
1196 
1197