xref: /freebsd/sys/netgraph/ng_socket.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 /*
2  * ng_socket.c
3  *
4  * Copyright (c) 1996-1999 Whistle Communications, Inc.
5  * All rights reserved.
6  *
7  * Subject to the following obligations and disclaimer of warranty, use and
8  * redistribution of this software, in source or object code forms, with or
9  * without modifications are expressly permitted by Whistle Communications;
10  * provided, however, that:
11  * 1. Any and all reproductions of the source or object code must include the
12  *    copyright notice above and the following disclaimer of warranties; and
13  * 2. No rights are granted, in any manner or form, to use Whistle
14  *    Communications, Inc. trademarks, including the mark "WHISTLE
15  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
16  *    such appears in the above copyright notice or in the software.
17  *
18  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
19  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
20  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
21  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
23  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
24  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
25  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
26  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
27  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
28  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
29  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
30  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
34  * OF SUCH DAMAGE.
35  *
36  * Author: Julian Elischer <julian@freebsd.org>
37  *
38  * $FreeBSD$
39  * $Whistle: ng_socket.c,v 1.28 1999/11/01 09:24:52 julian Exp $
40  */
41 
42 /*
43  * Netgraph socket nodes
44  *
45  * There are two types of netgraph sockets, control and data.
46  * Control sockets have a netgraph node, but data sockets are
47  * parasitic on control sockets, and have no node of their own.
48  */
49 
50 #include <sys/param.h>
51 #include <sys/domain.h>
52 #include <sys/errno.h>
53 #include <sys/kdb.h>
54 #include <sys/kernel.h>
55 #include <sys/linker.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mbuf.h>
59 #include <sys/mutex.h>
60 #include <sys/protosw.h>
61 #include <sys/queue.h>
62 #include <sys/signalvar.h>
63 #include <sys/socket.h>
64 #include <sys/socketvar.h>
65 #include <sys/sx.h>
66 #include <sys/sysctl.h>
67 #include <sys/systm.h>
68 #ifdef NOTYET
69 #include <sys/vnode.h>
70 #endif
71 #include <netgraph/ng_message.h>
72 #include <netgraph/netgraph.h>
73 #include <netgraph/ng_socketvar.h>
74 #include <netgraph/ng_socket.h>
75 
76 #ifdef NG_SEPARATE_MALLOC
77 MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info ");
78 MALLOC_DEFINE(M_NETGRAPH_SOCK, "netgraph_sock", "netgraph socket info ");
79 #else
80 #define M_NETGRAPH_PATH M_NETGRAPH
81 #define M_NETGRAPH_SOCK M_NETGRAPH
82 #endif
83 
84 /*
85  * It's Ascii-art time!
86  *   +-------------+   +-------------+
87  *   |socket  (ctl)|   |socket (data)|
88  *   +-------------+   +-------------+
89  *          ^                 ^
90  *          |                 |
91  *          v                 v
92  *    +-----------+     +-----------+
93  *    |pcb   (ctl)|     |pcb  (data)|
94  *    +-----------+     +-----------+
95  *          ^                 ^
96  *          |                 |
97  *          v                 v
98  *      +--------------------------+
99  *      |   Socket type private    |
100  *      |       data               |
101  *      +--------------------------+
102  *                   ^
103  *                   |
104  *                   v
105  *           +----------------+
106  *           | struct ng_node |
107  *           +----------------+
108  */
109 
110 /* Netgraph node methods */
111 static ng_constructor_t	ngs_constructor;
112 static ng_rcvmsg_t	ngs_rcvmsg;
113 static ng_shutdown_t	ngs_shutdown;
114 static ng_newhook_t	ngs_newhook;
115 static ng_connect_t	ngs_connect;
116 static ng_rcvdata_t	ngs_rcvdata;
117 static ng_disconnect_t	ngs_disconnect;
118 
119 /* Internal methods */
120 static int	ng_attach_data(struct socket *so);
121 static int	ng_attach_cntl(struct socket *so);
122 static int	ng_attach_common(struct socket *so, int type);
123 static void	ng_detach_common(struct ngpcb *pcbp, int type);
124 /*static int	ng_internalize(struct mbuf *m, struct thread *p); */
125 
126 static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
127 static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
128 
129 static int	ngs_mod_event(module_t mod, int event, void *data);
130 static int	ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg,
131 			struct sockaddr_ng *addr);
132 
133 /* Netgraph type descriptor */
134 static struct ng_type typestruct = {
135 	.version =	NG_ABI_VERSION,
136 	.name =		NG_SOCKET_NODE_TYPE,
137 	.mod_event =	ngs_mod_event,
138 	.constructor =	ngs_constructor,
139 	.rcvmsg =	ngs_rcvmsg,
140 	.shutdown =	ngs_shutdown,
141 	.newhook =	ngs_newhook,
142 	.connect =	ngs_connect,
143 	.rcvdata =	ngs_rcvdata,
144 	.disconnect =	ngs_disconnect,
145 };
146 NETGRAPH_INIT(socket, &typestruct);
147 
148 /* Buffer space */
149 static u_long ngpdg_sendspace = 20 * 1024;	/* really max datagram size */
150 SYSCTL_INT(_net_graph, OID_AUTO, maxdgram, CTLFLAG_RW,
151     &ngpdg_sendspace , 0, "Maximum outgoing Netgraph datagram size");
152 static u_long ngpdg_recvspace = 20 * 1024;
153 SYSCTL_INT(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
154     &ngpdg_recvspace , 0, "Maximum space for incoming Netgraph datagrams");
155 
156 /* List of all sockets */
157 static LIST_HEAD(, ngpcb) ngsocklist;
158 
159 static struct mtx	ngsocketlist_mtx;
160 MTX_SYSINIT(ngsocketlist, &ngsocketlist_mtx, "ng_socketlist", MTX_DEF);
161 
162 #define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
163 
164 /* If getting unexplained errors returned, set this to "kdb_enter("X"); */
165 #ifndef TRAP_ERROR
166 #define TRAP_ERROR
167 #endif
168 
169 /***************************************************************
170 	Control sockets
171 ***************************************************************/
172 
173 static int
174 ngc_attach(struct socket *so, int proto, struct thread *td)
175 {
176 	struct ngpcb *const pcbp = sotongpcb(so);
177 
178 	if (suser(td))
179 		return (EPERM);
180 	if (pcbp != NULL)
181 		return (EISCONN);
182 	return (ng_attach_cntl(so));
183 }
184 
185 static int
186 ngc_detach(struct socket *so)
187 {
188 	struct ngpcb *const pcbp = sotongpcb(so);
189 
190 	if (pcbp == NULL)
191 		return (EINVAL);
192 	ng_detach_common(pcbp, NG_CONTROL);
193 	return (0);
194 }
195 
196 static int
197 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
198 	 struct mbuf *control, struct thread *td)
199 {
200 	struct ngpcb *const pcbp = sotongpcb(so);
201 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
202 	struct ng_mesg *msg;
203 	struct mbuf *m0;
204 	char *path = NULL;
205 	int len, error = 0;
206 
207 	if (pcbp == NULL) {
208 		error = EINVAL;
209 		goto release;
210 	}
211 #ifdef	NOTYET
212 	if (control && (error = ng_internalize(control, td))) {
213 		if (pcbp->sockdata == NULL) {
214 			error = ENOTCONN;
215 			goto release;
216 		}
217 	}
218 #else	/* NOTYET */
219 	if (control) {
220 		error = EINVAL;
221 		goto release;
222 	}
223 #endif	/* NOTYET */
224 
225 	/* Require destination as there may be >= 1 hooks on this node */
226 	if (addr == NULL) {
227 		error = EDESTADDRREQ;
228 		goto release;
229 	}
230 
231 	/* Allocate an expendable buffer for the path, chop off
232 	 * the sockaddr header, and make sure it's NUL terminated */
233 	len = sap->sg_len - 2;
234 	MALLOC(path, char *, len + 1, M_NETGRAPH_PATH, M_WAITOK);
235 	if (path == NULL) {
236 		error = ENOMEM;
237 		goto release;
238 	}
239 	bcopy(sap->sg_data, path, len);
240 	path[len] = '\0';
241 
242 	/* Move the actual message out of mbufs into a linear buffer.
243 	 * Start by adding up the size of the data. (could use mh_len?) */
244 	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
245 		len += m0->m_len;
246 
247 	/* Move the data into a linear buffer as well. Messages are not
248 	 * delivered in mbufs. */
249 	MALLOC(msg, struct ng_mesg *, len + 1, M_NETGRAPH_MSG, M_WAITOK);
250 	if (msg == NULL) {
251 		error = ENOMEM;
252 		goto release;
253 	}
254 	m_copydata(m, 0, len, (char *)msg);
255 
256 #ifdef TRACE_MESSAGES
257 	do {
258 		item_p item;
259 		if ((item = ng_package_msg(msg)) == NULL) {
260 			(msg) = NULL;
261 			(error) = ENOMEM;
262 printf("err=%d\n",error);
263 			break;
264 		}
265 		if (((error) = ng_address_path((pcbp->sockdata->node), (item),
266 					(path), (NULL))) == 0) {
267 printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
268 item->el_dest->nd_ID,
269 msg->header.typecookie,
270 msg->header.cmd,
271 msg->header.cmdstr,
272 msg->header.flags,
273 msg->header.token,
274 item->el_dest->nd_type->name);
275 			SAVE_LINE(item);
276 			(error) = ng_snd_item((item), 0);
277 		}
278 else {
279 printf("errx=%d\n",error);
280 }
281 		(msg) = NULL;
282 	} while (0);
283 
284 #else
285 	/*
286 	 * Hack alert!
287 	 * We look into the message and if it mkpeers a node of unknown type, we
288 	 * try to load it. We need to do this now, in syscall thread, because if
289 	 * message gets queued and applied later we will get panic.
290 	 */
291 	if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
292 	    msg->header.cmd == NGM_MKPEER) {
293 		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
294 		struct ng_type *type;
295 
296 		if ((type = ng_findtype(mkp->type)) == NULL) {
297 			char filename[NG_TYPESIZ + 3];
298 			linker_file_t lf;
299 			int error;
300 
301 			/* Not found, try to load it as a loadable module */
302 			snprintf(filename, sizeof(filename), "ng_%s", mkp->type);
303 			error = linker_load_module(NULL, filename, NULL, NULL, &lf);
304 			if (error != 0) {
305 				FREE(msg, M_NETGRAPH_MSG);
306 				goto release;
307 			}
308 			lf->userrefs++;
309 
310 			/* Try again, as now the type should have linked itself in */
311 			if ((type = ng_findtype(mkp->type)) == NULL) {
312 				FREE(msg, M_NETGRAPH_MSG);
313 				error =  ENXIO;
314 				goto release;
315 			}
316 		}
317 	}
318 
319 	/* The callee will free the msg when done. The path is our business. */
320 	NG_SEND_MSG_PATH(error, pcbp->sockdata->node, msg, path, 0);
321 #endif
322 release:
323 	if (path != NULL)
324 		FREE(path, M_NETGRAPH_PATH);
325 	if (control != NULL)
326 		m_freem(control);
327 	if (m != NULL)
328 		m_freem(m);
329 	return (error);
330 }
331 
332 static int
333 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
334 {
335 	struct ngpcb *const pcbp = sotongpcb(so);
336 
337 	if (pcbp == 0)
338 		return (EINVAL);
339 	return (ng_bind(nam, pcbp));
340 }
341 
342 static int
343 ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
344 {
345 printf(" program tried to connect control socket to remote node\n ");
346 	/*
347 	 * At this time refuse to do this.. it used to
348 	 * do something but it was undocumented and not used.
349 	 */
350 	return (EINVAL);
351 }
352 
353 /***************************************************************
354 	Data sockets
355 ***************************************************************/
356 
357 static int
358 ngd_attach(struct socket *so, int proto, struct thread *td)
359 {
360 	struct ngpcb *const pcbp = sotongpcb(so);
361 
362 	if (pcbp != NULL)
363 		return (EISCONN);
364 	return (ng_attach_data(so));
365 }
366 
367 static int
368 ngd_detach(struct socket *so)
369 {
370 	struct ngpcb *const pcbp = sotongpcb(so);
371 
372 	if (pcbp == NULL)
373 		return (EINVAL);
374 	ng_detach_common(pcbp, NG_DATA);
375 	return (0);
376 }
377 
378 static int
379 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
380 	 struct mbuf *control, struct thread *td)
381 {
382 	struct ngpcb *const pcbp = sotongpcb(so);
383 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
384 	int     len, error;
385 	hook_p  hook = NULL;
386 	char	hookname[NG_HOOKSIZ];
387 
388 	if ((pcbp == NULL) || (control != NULL)) {
389 		error = EINVAL;
390 		goto release;
391 	}
392 	if (pcbp->sockdata == NULL) {
393 		error = ENOTCONN;
394 		goto release;
395 	}
396 	/*
397 	 * If the user used any of these ways to not specify an address
398 	 * then handle specially.
399 	 */
400 	if ((sap == NULL)
401 	    || ((len = sap->sg_len - 2) <= 0)
402 	    || (*sap->sg_data == '\0')) {
403 		if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
404 			error = EDESTADDRREQ;
405 			goto release;
406 		}
407 		/*
408 		 * if exactly one hook exists, just use it.
409 		 * Special case to allow write(2) to work on an ng_socket.
410 		 */
411 		hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
412 	} else {
413 		if (len >= NG_HOOKSIZ) {
414 			error = EINVAL;
415 			goto release;
416 		}
417 
418 		/*
419 		 * chop off the sockaddr header, and make sure it's NUL
420 		 * terminated
421 		 */
422 		bcopy(sap->sg_data, hookname, len);
423 		hookname[len] = '\0';
424 
425 		/* Find the correct hook from 'hookname' */
426 		LIST_FOREACH(hook, &pcbp->sockdata->node->nd_hooks, hk_hooks) {
427 			if (strcmp(hookname, NG_HOOK_NAME(hook)) == 0) {
428 				break;
429 			}
430 		}
431 		if (hook == NULL) {
432 			error = EHOSTUNREACH;
433 		}
434 	}
435 
436 	/* Send data (OK if hook is NULL) */
437 	NG_SEND_DATA_ONLY(error, hook, m);	/* makes m NULL */
438 
439 release:
440 	if (control != NULL)
441 		m_freem(control);
442 	if (m != NULL)
443 		m_freem(m);
444 	return (error);
445 }
446 
447 static int
448 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
449 {
450 	struct ngpcb *const pcbp = sotongpcb(so);
451 
452 	if (pcbp == 0)
453 		return (EINVAL);
454 	return (ng_connect_data(nam, pcbp));
455 }
456 
457 /*
458  * Used for both data and control sockets
459  */
460 static int
461 ng_setsockaddr(struct socket *so, struct sockaddr **addr)
462 {
463 	struct ngpcb *pcbp;
464 	struct sockaddr_ng *sg;
465 	int sg_len, namelen, s;
466 
467 	/* Why isn't sg_data a `char[1]' ? :-( */
468 	sg_len = sizeof(struct sockaddr_ng) - sizeof(sg->sg_data) + 1;
469 
470 	s = splnet();
471 	pcbp = sotongpcb(so);
472 	if ((pcbp == NULL) || (pcbp->sockdata == NULL)) {
473 		splx(s);
474 		return (EINVAL);
475 	}
476 
477 	namelen = 0;		/* silence compiler ! */
478 	if ( NG_NODE_HAS_NAME(pcbp->sockdata->node))
479 		sg_len += namelen = strlen(NG_NODE_NAME(pcbp->sockdata->node));
480 
481 	MALLOC(sg, struct sockaddr_ng *, sg_len, M_SONAME, M_WAITOK | M_ZERO);
482 
483 	if (NG_NODE_HAS_NAME(pcbp->sockdata->node))
484 		bcopy(NG_NODE_NAME(pcbp->sockdata->node), sg->sg_data, namelen);
485 	splx(s);
486 
487 	sg->sg_len = sg_len;
488 	sg->sg_family = AF_NETGRAPH;
489 	*addr = (struct sockaddr *)sg;
490 
491 	return (0);
492 }
493 
494 /*
495  * Attach a socket to it's protocol specific partner.
496  * For a control socket, actually create a netgraph node and attach
497  * to it as well.
498  */
499 
500 static int
501 ng_attach_cntl(struct socket *so)
502 {
503 	struct ngsock *privdata;
504 	struct ngpcb *pcbp;
505 	int error;
506 
507 	/* Setup protocol control block */
508 	if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
509 		return (error);
510 	pcbp = sotongpcb(so);
511 
512 	/* Allocate node private info */
513 	MALLOC(privdata, struct ngsock *,
514 	    sizeof(*privdata), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
515 	if (privdata == NULL) {
516 		ng_detach_common(pcbp, NG_CONTROL);
517 		return (ENOMEM);
518 	}
519 
520 	/* Make the generic node components */
521 	if ((error = ng_make_node_common(&typestruct, &privdata->node)) != 0) {
522 		FREE(privdata, M_NETGRAPH_SOCK);
523 		ng_detach_common(pcbp, NG_CONTROL);
524 		return (error);
525 	}
526 	NG_NODE_SET_PRIVATE(privdata->node, privdata);
527 
528 	/* Link the pcb and the node private data */
529 	privdata->ctlsock = pcbp;
530 	pcbp->sockdata = privdata;
531 	privdata->refs++;
532 	return (0);
533 }
534 
535 static int
536 ng_attach_data(struct socket *so)
537 {
538 	return(ng_attach_common(so, NG_DATA));
539 }
540 
541 /*
542  * Set up a socket protocol control block.
543  * This code is shared between control and data sockets.
544  */
545 static int
546 ng_attach_common(struct socket *so, int type)
547 {
548 	struct ngpcb *pcbp;
549 	int error;
550 
551 	/* Standard socket setup stuff */
552 	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
553 	if (error)
554 		return (error);
555 
556 	/* Allocate the pcb */
557 	MALLOC(pcbp, struct ngpcb *, sizeof(*pcbp), M_PCB, M_WAITOK | M_ZERO);
558 	if (pcbp == NULL)
559 		return (ENOMEM);
560 	pcbp->type = type;
561 
562 	/* Link the pcb and the socket */
563 	so->so_pcb = (caddr_t) pcbp;
564 	pcbp->ng_socket = so;
565 
566 	/* Add the socket to linked list */
567 	mtx_lock(&ngsocketlist_mtx);
568 	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
569 	mtx_unlock(&ngsocketlist_mtx);
570 	return (0);
571 }
572 
573 /*
574  * Disassociate the socket from it's protocol specific
575  * partner. If it's attached to a node's private data structure,
576  * then unlink from that too. If we were the last socket attached to it,
577  * then shut down the entire node. Shared code for control and data sockets.
578  */
579 static void
580 ng_detach_common(struct ngpcb *pcbp, int which)
581 {
582 	struct ngsock *priv;
583 
584 	if (pcbp->sockdata) {
585 		priv = pcbp->sockdata;
586 		pcbp->sockdata = NULL;
587 		switch (which) {
588 		case NG_CONTROL:
589 			priv->ctlsock = NULL;
590 			break;
591 		case NG_DATA:
592 			priv->datasock = NULL;
593 			break;
594 		default:
595 			panic(__func__);
596 		}
597 		if ((--priv->refs == 0) && (priv->node != NULL))
598 			ng_rmnode_self(priv->node);
599 	}
600 	pcbp->ng_socket->so_pcb = NULL;
601 	pcbp->ng_socket = NULL;
602 	mtx_lock(&ngsocketlist_mtx);
603 	LIST_REMOVE(pcbp, socks);
604 	mtx_unlock(&ngsocketlist_mtx);
605 	FREE(pcbp, M_PCB);
606 }
607 
608 #ifdef NOTYET
609 /*
610  * File descriptors can be passed into an AF_NETGRAPH socket.
611  * Note, that file descriptors cannot be passed OUT.
612  * Only character device descriptors are accepted.
613  * Character devices are useful to connect a graph to a device,
614  * which after all is the purpose of this whole system.
615  */
616 static int
617 ng_internalize(struct mbuf *control, struct thread *td)
618 {
619 	const struct cmsghdr *cm = mtod(control, const struct cmsghdr *);
620 	struct file *fp;
621 	struct vnode *vn;
622 	int oldfds;
623 	int fd;
624 
625 	if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
626 	    cm->cmsg_len != control->m_len) {
627 		TRAP_ERROR;
628 		return (EINVAL);
629 	}
630 
631 	/* Check there is only one FD. XXX what would more than one signify? */
632 	oldfds = ((caddr_t)cm + cm->cmsg_len - (caddr_t)data) / sizeof (int);
633 	if (oldfds != 1) {
634 		TRAP_ERROR;
635 		return (EINVAL);
636 	}
637 
638 	/* Check that the FD given is legit. and change it to a pointer to a
639 	 * struct file. */
640 	fd = CMSG_DATA(cm);
641 	if ((error = fget(td, fd, &fp)) != 0)
642 		return (error);
643 
644 	/* Depending on what kind of resource it is, act differently. For
645 	 * devices, we treat it as a file. For an AF_NETGRAPH socket,
646 	 * shortcut straight to the node. */
647 	switch (fp->f_type) {
648 	case DTYPE_VNODE:
649 		vn = fp->f_data;
650 		if (vn && (vn->v_type == VCHR)) {
651 			/* for a VCHR, actually reference the FILE */
652 			fp->f_count++;
653 			/* XXX then what :) */
654 			/* how to pass on to other modules? */
655 		} else {
656 			fdrop(fp, td);
657 			TRAP_ERROR;
658 			return (EINVAL);
659 		}
660 		break;
661 	default:
662 		fdrop(fp, td);
663 		TRAP_ERROR;
664 		return (EINVAL);
665 	}
666 	fdrop(fp, td);
667 	return (0);
668 }
669 #endif	/* NOTYET */
670 
671 /*
672  * Connect the data socket to a named control socket node.
673  */
674 static int
675 ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
676 {
677 	struct sockaddr_ng *sap;
678 	node_p farnode;
679 	struct ngsock *priv;
680 	int error;
681 	item_p item;
682 
683 	/* If we are already connected, don't do it again */
684 	if (pcbp->sockdata != NULL)
685 		return (EISCONN);
686 
687 	/* Find the target (victim) and check it doesn't already have a data
688 	 * socket. Also check it is a 'socket' type node.
689 	 * Use ng_package_data() and address_path() to do this.
690 	 */
691 
692 	sap = (struct sockaddr_ng *) nam;
693 	/* The item will hold the node reference */
694 	item = ng_package_data(NULL, NULL);
695 	if (item == NULL) {
696 		return (ENOMEM);
697 	}
698 	if ((error = ng_address_path(NULL, item,  sap->sg_data, 0)))
699 		return (error); /* item is freed on failure */
700 
701 	/*
702 	 * Extract node from item and free item. Remember we now have
703 	 * a reference on the node. The item holds it for us.
704 	 * when we free the item we release the reference.
705 	 */
706 	farnode = item->el_dest; /* shortcut */
707 	if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
708 		NG_FREE_ITEM(item); /* drop the reference to the node */
709 		return (EINVAL);
710 	}
711 	priv = NG_NODE_PRIVATE(farnode);
712 	if (priv->datasock != NULL) {
713 		NG_FREE_ITEM(item);	/* drop the reference to the node */
714 		return (EADDRINUSE);
715 	}
716 
717 	/*
718 	 * Link the PCB and the private data struct. and note the extra
719 	 * reference. Drop the extra reference on the node.
720 	 */
721 	priv->datasock = pcbp;
722 	pcbp->sockdata = priv;
723 	priv->refs++; /* XXX possible race if it's being freed */
724 	NG_FREE_ITEM(item);	/* drop the reference to the node */
725 	return (0);
726 }
727 
728 /*
729  * Binding a socket means giving the corresponding node a name
730  */
731 static int
732 ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
733 {
734 	struct ngsock *const priv = pcbp->sockdata;
735 	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
736 
737 	if (priv == NULL) {
738 		TRAP_ERROR;
739 		return (EINVAL);
740 	}
741 	if ((sap->sg_len < 4)
742 	||  (sap->sg_len > (NG_NODESIZ + 2))
743 	||  (sap->sg_data[0] == '\0')
744 	||  (sap->sg_data[sap->sg_len - 3] != '\0')) {
745 		TRAP_ERROR;
746 		return (EINVAL);
747 	}
748 	return (ng_name_node(priv->node, sap->sg_data));
749 }
750 
751 /*
752  * Take a message and pass it up to the control socket associated
753  * with the node.
754  */
755 static int
756 ship_msg(struct ngpcb *pcbp, struct ng_mesg *msg, struct sockaddr_ng *addr)
757 {
758 	struct socket *const so = pcbp->ng_socket;
759 	struct mbuf *mdata;
760 	int msglen;
761 
762 	/* Copy the message itself into an mbuf chain */
763 	msglen = sizeof(struct ng_mesg) + msg->header.arglen;
764 	mdata = m_devget((caddr_t) msg, msglen, 0, NULL, NULL);
765 
766 	/* Here we free the message, as we are the end of the line.
767 	 * We need to do that regardless of whether we got mbufs. */
768 	NG_FREE_MSG(msg);
769 
770 	if (mdata == NULL) {
771 		TRAP_ERROR;
772 		return (ENOBUFS);
773 	}
774 
775 	/* Send it up to the socket */
776 	if (sbappendaddr(&so->so_rcv,
777 	    (struct sockaddr *) addr, mdata, NULL) == 0) {
778 		TRAP_ERROR;
779 		m_freem(mdata);
780 		return (ENOBUFS);
781 	}
782 	sorwakeup(so);
783 	return (0);
784 }
785 
786 /*
787  * You can only create new nodes from the socket end of things.
788  */
789 static int
790 ngs_constructor(node_p nodep)
791 {
792 	return (EINVAL);
793 }
794 
795 /*
796  * We allow any hook to be connected to the node.
797  * There is no per-hook private information though.
798  */
799 static int
800 ngs_newhook(node_p node, hook_p hook, const char *name)
801 {
802 	NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
803 	return (0);
804 }
805 
806 /*
807  * if only one hook, allow read(2) and write(2) to work.
808  */
809 static int
810 ngs_connect(hook_p hook)
811 {
812 	node_p node = NG_HOOK_NODE(hook);
813 	struct ngsock *priv = NG_NODE_PRIVATE(node);
814 
815 	if ((priv->datasock)
816 	&&  (priv->datasock->ng_socket)) {
817 		if (NG_NODE_NUMHOOKS(node) == 1) {
818 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
819 		} else {
820 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
821 		}
822 	}
823 	return (0);
824 }
825 
826 /*
827  * Incoming messages get passed up to the control socket.
828  * Unless they are for us specifically (socket_type)
829  */
830 static int
831 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
832 {
833 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
834 	struct ngpcb *const pcbp = priv->ctlsock;
835 	struct sockaddr_ng *addr;
836 	int addrlen;
837 	int error = 0;
838 	struct	ng_mesg *msg;
839 	ng_ID_t	retaddr = NGI_RETADDR(item);
840 	char	retabuf[32];
841 
842 	NGI_GET_MSG(item, msg);
843 	NG_FREE_ITEM(item); /* we have all we need */
844 
845 	/* Only allow mesgs to be passed if we have the control socket.
846 	 * Data sockets can only support the generic messages. */
847 	if (pcbp == NULL) {
848 		TRAP_ERROR;
849 		return (EINVAL);
850 	}
851 #ifdef TRACE_MESSAGES
852 printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
853 retaddr,
854 msg->header.typecookie,
855 msg->header.cmd,
856 msg->header.cmdstr,
857 msg->header.flags,
858 msg->header.token);
859 
860 #endif
861 
862 	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
863 		switch (msg->header.cmd) {
864 		case NGM_SOCK_CMD_NOLINGER:
865 			priv->flags |= NGS_FLAG_NOLINGER;
866 			break;
867 		case NGM_SOCK_CMD_LINGER:
868 			priv->flags &= ~NGS_FLAG_NOLINGER;
869 			break;
870 		default:
871 			error = EINVAL;		/* unknown command */
872 		}
873 		/* Free the message and return */
874 		NG_FREE_MSG(msg);
875 		return(error);
876 
877 	}
878 	/* Get the return address into a sockaddr */
879 	sprintf(retabuf,"[%x]:", retaddr);
880 	addrlen = strlen(retabuf);
881 	MALLOC(addr, struct sockaddr_ng *, addrlen + 4, M_NETGRAPH_PATH, M_NOWAIT);
882 	if (addr == NULL) {
883 		TRAP_ERROR;
884 		return (ENOMEM);
885 	}
886 	addr->sg_len = addrlen + 3;
887 	addr->sg_family = AF_NETGRAPH;
888 	bcopy(retabuf, addr->sg_data, addrlen);
889 	addr->sg_data[addrlen] = '\0';
890 
891 	/* Send it up */
892 	error = ship_msg(pcbp, msg, addr);
893 	FREE(addr, M_NETGRAPH_PATH);
894 	return (error);
895 }
896 
897 /*
898  * Receive data on a hook
899  */
900 static int
901 ngs_rcvdata(hook_p hook, item_p item)
902 {
903 	struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
904 	struct ngpcb *const pcbp = priv->datasock;
905 	struct socket *so;
906 	struct sockaddr_ng *addr;
907 	char *addrbuf[NG_HOOKSIZ + 4];
908 	int addrlen;
909 	struct mbuf *m;
910 
911 	NGI_GET_M(item, m);
912 	NG_FREE_ITEM(item);
913 	/* If there is no data socket, black-hole it */
914 	if (pcbp == NULL) {
915 		NG_FREE_M(m);
916 		return (0);
917 	}
918 	so = pcbp->ng_socket;
919 
920 	/* Get the return address into a sockaddr. */
921 	addrlen = strlen(NG_HOOK_NAME(hook));	/* <= NG_HOOKSIZ - 1 */
922 	addr = (struct sockaddr_ng *) addrbuf;
923 	addr->sg_len = addrlen + 3;
924 	addr->sg_family = AF_NETGRAPH;
925 	bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
926 	addr->sg_data[addrlen] = '\0';
927 
928 	/* Try to tell the socket which hook it came in on */
929 	if (sbappendaddr(&so->so_rcv, (struct sockaddr *) addr, m, NULL) == 0) {
930 		m_freem(m);
931 		TRAP_ERROR;
932 		return (ENOBUFS);
933 	}
934 	sorwakeup(so);
935 	return (0);
936 }
937 
938 /*
939  * Hook disconnection
940  *
941  * For this type, removal of the last link destroys the node
942  * if the NOLINGER flag is set.
943  */
944 static int
945 ngs_disconnect(hook_p hook)
946 {
947 	node_p node = NG_HOOK_NODE(hook);
948 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
949 
950 	if ((priv->datasock)
951 	&&  (priv->datasock->ng_socket)) {
952 		if (NG_NODE_NUMHOOKS(node) == 1) {
953 			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
954 		} else {
955 			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
956 		}
957 	}
958 
959 	if ((priv->flags & NGS_FLAG_NOLINGER )
960 	&& (NG_NODE_NUMHOOKS(node) == 0)
961 	&& (NG_NODE_IS_VALID(node))) {
962 		ng_rmnode_self(node);
963 	}
964 	return (0);
965 }
966 
967 /*
968  * Do local shutdown processing.
969  * In this case, that involves making sure the socket
970  * knows we should be shutting down.
971  */
972 static int
973 ngs_shutdown(node_p node)
974 {
975 	struct ngsock *const priv = NG_NODE_PRIVATE(node);
976 	struct ngpcb *const dpcbp = priv->datasock;
977 	struct ngpcb *const pcbp = priv->ctlsock;
978 
979 	if (dpcbp != NULL) {
980 		soisdisconnected(dpcbp->ng_socket);
981 		dpcbp->sockdata = NULL;
982 		priv->datasock = NULL;
983 		priv->refs--;
984 	}
985 	if (pcbp != NULL) {
986 		soisdisconnected(pcbp->ng_socket);
987 		pcbp->sockdata = NULL;
988 		priv->ctlsock = NULL;
989 		priv->refs--;
990 	}
991 	NG_NODE_SET_PRIVATE(node, NULL);
992 	NG_NODE_UNREF(node);
993 	FREE(priv, M_NETGRAPH_SOCK);
994 	return (0);
995 }
996 
997 static	int
998 dummy_disconnect(struct socket *so)
999 {
1000 	return (0);
1001 }
1002 /*
1003  * Control and data socket type descriptors
1004  */
1005 
1006 static struct pr_usrreqs ngc_usrreqs = {
1007 	NULL,			/* abort */
1008 	pru_accept_notsupp,
1009 	ngc_attach,
1010 	ngc_bind,
1011 	ngc_connect,
1012 	pru_connect2_notsupp,
1013 	pru_control_notsupp,
1014 	ngc_detach,
1015 	dummy_disconnect,	/* disconnect */
1016 	pru_listen_notsupp,
1017 	NULL,			/* setpeeraddr */
1018 	pru_rcvd_notsupp,
1019 	pru_rcvoob_notsupp,
1020 	ngc_send,
1021 	pru_sense_null,
1022 	NULL,			/* shutdown */
1023 	ng_setsockaddr,
1024 	sosend,
1025 	soreceive,
1026 	sopoll,
1027 	pru_sosetlabel_null
1028 };
1029 
1030 static struct pr_usrreqs ngd_usrreqs = {
1031 	NULL,			/* abort */
1032 	pru_accept_notsupp,
1033 	ngd_attach,
1034 	NULL,			/* bind */
1035 	ngd_connect,
1036 	pru_connect2_notsupp,
1037 	pru_control_notsupp,
1038 	ngd_detach,
1039 	dummy_disconnect,	/* disconnect */
1040 	pru_listen_notsupp,
1041 	NULL,			/* setpeeraddr */
1042 	pru_rcvd_notsupp,
1043 	pru_rcvoob_notsupp,
1044 	ngd_send,
1045 	pru_sense_null,
1046 	NULL,			/* shutdown */
1047 	ng_setsockaddr,
1048 	sosend,
1049 	soreceive,
1050 	sopoll,
1051 	pru_sosetlabel_null
1052 };
1053 
1054 /*
1055  * Definitions of protocols supported in the NETGRAPH domain.
1056  */
1057 
1058 extern struct domain ngdomain;		/* stop compiler warnings */
1059 
1060 static struct protosw ngsw[] = {
1061 	{
1062 		SOCK_DGRAM,		/* protocol type */
1063 		&ngdomain,		/* backpointer to domain */
1064 		NG_CONTROL,
1065 		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,	/* flags */
1066 		0, 0, 0, 0,		/* input, output, ctlinput, ctloutput */
1067 		NULL,			/* ousrreq */
1068 		0, 0, 0, 0,		/* init, fasttimeo, slowtimo, drain */
1069 		&ngc_usrreqs,		/* usrreq table (above) */
1070 		/*{NULL}*/		/* pffh (protocol filter head?) */
1071 	},
1072 	{
1073 		SOCK_DGRAM,		/* protocol type */
1074 		&ngdomain,		/* backpointer to domain */
1075 		NG_DATA,
1076 		PR_ATOMIC | PR_ADDR,	/* flags */
1077 		0, 0, 0, 0,		/* input, output, ctlinput, ctloutput */
1078 		NULL,			/* ousrreq() */
1079 		0, 0, 0, 0,		/* init, fasttimeo, slowtimo, drain */
1080 		&ngd_usrreqs,		/* usrreq table (above) */
1081 		/*{NULL}*/		/* pffh (protocol filter head?) */
1082 	}
1083 };
1084 
1085 struct domain ngdomain = {
1086 	AF_NETGRAPH,
1087 	"netgraph",
1088 	NULL,					/* init() */
1089 	NULL,					/* externalise() */
1090 	NULL,					/* dispose() */
1091 	ngsw,					/* protosw entry */
1092 	&ngsw[sizeof(ngsw) / sizeof(ngsw[0])], 	/* Number of protosw entries */
1093 	NULL,					/* next domain in list */
1094 	NULL,					/* rtattach() */
1095 	0,					/* arg to rtattach in bits */
1096 	0					/* maxrtkey */
1097 };
1098 
1099 /*
1100  * Handle loading and unloading for this node type
1101  * This is to handle auxiliary linkages (e.g protocol domain addition).
1102  */
1103 static int
1104 ngs_mod_event(module_t mod, int event, void *data)
1105 {
1106 	int error = 0;
1107 
1108 	switch (event) {
1109 	case MOD_LOAD:
1110 		/* Register protocol domain */
1111 		net_add_domain(&ngdomain);
1112 		break;
1113 	case MOD_UNLOAD:
1114 		/* Insure there are no open netgraph sockets */
1115 		if (!LIST_EMPTY(&ngsocklist)) {
1116 			error = EBUSY;
1117 			break;
1118 		}
1119 
1120 #ifdef NOTYET
1121 		if ((LIST_EMPTY(&ngsocklist)) && (typestruct.refs == 0)) {
1122 		/* Unregister protocol domain XXX can't do this yet.. */
1123 			if ((error = net_rm_domain(&ngdomain)) != 0)
1124 				break;
1125 		} else
1126 #endif
1127 			error = EBUSY;
1128 		break;
1129 	default:
1130 		error = EOPNOTSUPP;
1131 		break;
1132 	}
1133 	return (error);
1134 }
1135 
1136 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, 0, AF_NETGRAPH, "");
1137 SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
1138 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, 0, NG_DATA, "");
1139 SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
1140 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, 0, NG_CONTROL, "");
1141 
1142