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/hash.h>
55#include <sys/kernel.h>
56#include <sys/linker.h>
57#include <sys/lock.h>
58#include <sys/malloc.h>
59#include <sys/mbuf.h>
60#include <sys/mutex.h>
61#include <sys/priv.h>
62#include <sys/protosw.h>
63#include <sys/queue.h>
64#include <sys/socket.h>
65#include <sys/socketvar.h>
66#include <sys/syscallsubr.h>
67#include <sys/sysctl.h>
68
69#include <net/vnet.h>
70
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
77static MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info");
78static 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 */
111static ng_constructor_t	ngs_constructor;
112static ng_rcvmsg_t	ngs_rcvmsg;
113static ng_shutdown_t	ngs_shutdown;
114static ng_newhook_t	ngs_newhook;
115static ng_connect_t	ngs_connect;
116static ng_findhook_t	ngs_findhook;
117static ng_rcvdata_t	ngs_rcvdata;
118static ng_disconnect_t	ngs_disconnect;
119
120/* Internal methods */
121static int	ng_attach_data(struct socket *so);
122static int	ng_attach_cntl(struct socket *so);
123static int	ng_attach_common(struct socket *so, int type);
124static void	ng_detach_common(struct ngpcb *pcbp, int type);
125static void	ng_socket_free_priv(struct ngsock *priv);
126static int	ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp);
127static int	ng_bind(struct sockaddr *nam, struct ngpcb *pcbp);
128
129static int	ngs_mod_event(module_t mod, int event, void *data);
130static void	ng_socket_item_applied(void *context, int error);
131
132/* Netgraph type descriptor */
133static struct ng_type typestruct = {
134	.version =	NG_ABI_VERSION,
135	.name =		NG_SOCKET_NODE_TYPE,
136	.mod_event =	ngs_mod_event,
137	.constructor =	ngs_constructor,
138	.rcvmsg =	ngs_rcvmsg,
139	.shutdown =	ngs_shutdown,
140	.newhook =	ngs_newhook,
141	.connect =	ngs_connect,
142	.findhook =	ngs_findhook,
143	.rcvdata =	ngs_rcvdata,
144	.disconnect =	ngs_disconnect,
145};
146NETGRAPH_INIT_ORDERED(socket, &typestruct, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
147
148/* Buffer space */
149static u_long ngpdg_sendspace = 20 * 1024;	/* really max datagram size */
150SYSCTL_ULONG(_net_graph, OID_AUTO, maxdgram, CTLFLAG_RW,
151    &ngpdg_sendspace , 0, "Maximum outgoing Netgraph datagram size");
152static u_long ngpdg_recvspace = 20 * 1024;
153SYSCTL_ULONG(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
154    &ngpdg_recvspace , 0, "Maximum space for incoming Netgraph datagrams");
155
156/* List of all sockets (for netstat -f netgraph) */
157static LIST_HEAD(, ngpcb) ngsocklist;
158
159static struct mtx	ngsocketlist_mtx;
160
161#define sotongpcb(so) ((struct ngpcb *)(so)->so_pcb)
162
163/* If getting unexplained errors returned, set this to "kdb_enter("X"); */
164#ifndef TRAP_ERROR
165#define TRAP_ERROR
166#endif
167
168struct hookpriv {
169	LIST_ENTRY(hookpriv)	next;
170	hook_p			hook;
171};
172LIST_HEAD(ngshash, hookpriv);
173
174/* Per-node private data */
175struct ngsock {
176	struct ng_node	*node;		/* the associated netgraph node */
177	struct ngpcb	*datasock;	/* optional data socket */
178	struct ngpcb	*ctlsock;	/* optional control socket */
179	struct ngshash	*hash;		/* hash for hook names */
180	u_long		hmask;		/* hash mask */
181	int	flags;
182	int	refs;
183	struct mtx	mtx;		/* mtx to wait on */
184	int		error;		/* place to store error */
185};
186
187#define	NGS_FLAG_NOLINGER	1	/* close with last hook */
188
189/***************************************************************
190	Control sockets
191***************************************************************/
192
193static int
194ngc_attach(struct socket *so, int proto, struct thread *td)
195{
196	struct ngpcb *const pcbp = sotongpcb(so);
197	int error;
198
199	error = priv_check(td, PRIV_NETGRAPH_CONTROL);
200	if (error)
201		return (error);
202	if (pcbp != NULL)
203		return (EISCONN);
204	return (ng_attach_cntl(so));
205}
206
207static void
208ngc_detach(struct socket *so)
209{
210	struct ngpcb *const pcbp = sotongpcb(so);
211
212	KASSERT(pcbp != NULL, ("ngc_detach: pcbp == NULL"));
213	ng_detach_common(pcbp, NG_CONTROL);
214}
215
216static int
217ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
218	 struct mbuf *control, struct thread *td)
219{
220	struct ngpcb *const pcbp = sotongpcb(so);
221	struct ngsock *const priv = NG_NODE_PRIVATE(pcbp->sockdata->node);
222	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
223	struct ng_mesg *msg;
224	struct mbuf *m0;
225	item_p item;
226	char *path = NULL;
227	int len, error = 0;
228	struct ng_apply_info apply;
229
230	if (control) {
231		error = EINVAL;
232		goto release;
233	}
234
235	/* Require destination as there may be >= 1 hooks on this node. */
236	if (addr == NULL) {
237		error = EDESTADDRREQ;
238		goto release;
239	}
240
241	/*
242	 * Allocate an expendable buffer for the path, chop off
243	 * the sockaddr header, and make sure it's NUL terminated.
244	 */
245	len = sap->sg_len - 2;
246	path = malloc(len + 1, M_NETGRAPH_PATH, M_WAITOK);
247	bcopy(sap->sg_data, path, len);
248	path[len] = '\0';
249
250	/*
251	 * Move the actual message out of mbufs into a linear buffer.
252	 * Start by adding up the size of the data. (could use mh_len?)
253	 */
254	for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
255		len += m0->m_len;
256
257	/*
258	 * Move the data into a linear buffer as well.
259	 * Messages are not delivered in mbufs.
260	 */
261	msg = malloc(len + 1, M_NETGRAPH_MSG, M_WAITOK);
262	m_copydata(m, 0, len, (char *)msg);
263
264	if (msg->header.version != NG_VERSION) {
265		free(msg, M_NETGRAPH_MSG);
266		error = EINVAL;
267		goto release;
268	}
269
270	/*
271	 * Hack alert!
272	 * We look into the message and if it mkpeers a node of unknown type, we
273	 * try to load it. We need to do this now, in syscall thread, because if
274	 * message gets queued and applied later we will get panic.
275	 */
276	if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
277	    msg->header.cmd == NGM_MKPEER) {
278		struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
279
280		if (ng_findtype(mkp->type) == NULL) {
281			char filename[NG_TYPESIZ + 3];
282			int fileid;
283
284			/* Not found, try to load it as a loadable module. */
285			snprintf(filename, sizeof(filename), "ng_%s",
286			    mkp->type);
287			error = kern_kldload(curthread, filename, &fileid);
288			if (error != 0) {
289				free(msg, M_NETGRAPH_MSG);
290				goto release;
291			}
292
293			/* See if type has been loaded successfully. */
294			if (ng_findtype(mkp->type) == NULL) {
295				free(msg, M_NETGRAPH_MSG);
296				(void)kern_kldunload(curthread, fileid,
297				    LINKER_UNLOAD_NORMAL);
298				error =  ENXIO;
299				goto release;
300			}
301		}
302	}
303
304	item = ng_package_msg(msg, NG_WAITOK);
305	if ((error = ng_address_path((pcbp->sockdata->node), item, path, 0))
306	    != 0) {
307#ifdef TRACE_MESSAGES
308		printf("ng_address_path: errx=%d\n", error);
309#endif
310		goto release;
311	}
312
313#ifdef TRACE_MESSAGES
314	printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
315		item->el_dest->nd_ID,
316		msg->header.typecookie,
317		msg->header.cmd,
318		msg->header.cmdstr,
319		msg->header.flags,
320		msg->header.token,
321		item->el_dest->nd_type->name);
322#endif
323	SAVE_LINE(item);
324	/*
325	 * We do not want to return from syscall until the item
326	 * is processed by destination node. We register callback
327	 * on the item, which will update priv->error when item
328	 * was applied.
329	 * If ng_snd_item() has queued item, we sleep until
330	 * callback wakes us up.
331	 */
332	bzero(&apply, sizeof(apply));
333	apply.apply = ng_socket_item_applied;
334	apply.context = priv;
335	item->apply = &apply;
336	priv->error = -1;
337
338	error = ng_snd_item(item, 0);
339
340	mtx_lock(&priv->mtx);
341	if (priv->error == -1)
342		msleep(priv, &priv->mtx, 0, "ngsock", 0);
343	mtx_unlock(&priv->mtx);
344	KASSERT(priv->error != -1,
345	    ("ng_socket: priv->error wasn't updated"));
346	error = priv->error;
347
348release:
349	if (path != NULL)
350		free(path, M_NETGRAPH_PATH);
351	if (control != NULL)
352		m_freem(control);
353	if (m != NULL)
354		m_freem(m);
355	return (error);
356}
357
358static int
359ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
360{
361	struct ngpcb *const pcbp = sotongpcb(so);
362
363	if (pcbp == NULL)
364		return (EINVAL);
365	return (ng_bind(nam, pcbp));
366}
367
368static int
369ngc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
370{
371	/*
372	 * At this time refuse to do this.. it used to
373	 * do something but it was undocumented and not used.
374	 */
375	printf("program tried to connect control socket to remote node\n");
376	return (EINVAL);
377}
378
379/***************************************************************
380	Data sockets
381***************************************************************/
382
383static int
384ngd_attach(struct socket *so, int proto, struct thread *td)
385{
386	struct ngpcb *const pcbp = sotongpcb(so);
387
388	if (pcbp != NULL)
389		return (EISCONN);
390	return (ng_attach_data(so));
391}
392
393static void
394ngd_detach(struct socket *so)
395{
396	struct ngpcb *const pcbp = sotongpcb(so);
397
398	KASSERT(pcbp != NULL, ("ngd_detach: pcbp == NULL"));
399	ng_detach_common(pcbp, NG_DATA);
400}
401
402static int
403ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
404	 struct mbuf *control, struct thread *td)
405{
406	struct ngpcb *const pcbp = sotongpcb(so);
407	struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
408	int	len, error;
409	hook_p  hook = NULL;
410	char	hookname[NG_HOOKSIZ];
411
412	if ((pcbp == NULL) || (control != NULL)) {
413		error = EINVAL;
414		goto release;
415	}
416	if (pcbp->sockdata == NULL) {
417		error = ENOTCONN;
418		goto release;
419	}
420
421	if (sap == NULL)
422		len = 0;		/* Make compiler happy. */
423	else
424		len = sap->sg_len - 2;
425
426	/*
427	 * If the user used any of these ways to not specify an address
428	 * then handle specially.
429	 */
430	if ((sap == NULL) || (len <= 0) || (*sap->sg_data == '\0')) {
431		if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
432			error = EDESTADDRREQ;
433			goto release;
434		}
435		/*
436		 * If exactly one hook exists, just use it.
437		 * Special case to allow write(2) to work on an ng_socket.
438		 */
439		hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
440	} else {
441		if (len >= NG_HOOKSIZ) {
442			error = EINVAL;
443			goto release;
444		}
445
446		/*
447		 * chop off the sockaddr header, and make sure it's NUL
448		 * terminated
449		 */
450		bcopy(sap->sg_data, hookname, len);
451		hookname[len] = '\0';
452
453		/* Find the correct hook from 'hookname' */
454		hook = ng_findhook(pcbp->sockdata->node, hookname);
455		if (hook == NULL) {
456			error = EHOSTUNREACH;
457			goto release;
458		}
459	}
460
461	/* Send data. */
462	NG_SEND_DATA_FLAGS(error, hook, m, NG_WAITOK);
463
464release:
465	if (control != NULL)
466		m_freem(control);
467	if (m != NULL)
468		m_freem(m);
469	return (error);
470}
471
472static int
473ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
474{
475	struct ngpcb *const pcbp = sotongpcb(so);
476
477	if (pcbp == NULL)
478		return (EINVAL);
479	return (ng_connect_data(nam, pcbp));
480}
481
482/*
483 * Used for both data and control sockets
484 */
485static int
486ng_getsockaddr(struct socket *so, struct sockaddr **addr)
487{
488	struct ngpcb *pcbp;
489	struct sockaddr_ng *sg;
490	int sg_len;
491	int error = 0;
492
493	pcbp = sotongpcb(so);
494	if ((pcbp == NULL) || (pcbp->sockdata == NULL))
495		/* XXXGL: can this still happen? */
496		return (EINVAL);
497
498	sg_len = sizeof(struct sockaddr_ng) + NG_NODESIZ -
499	    sizeof(sg->sg_data);
500	sg = malloc(sg_len, M_SONAME, M_WAITOK | M_ZERO);
501
502	mtx_lock(&pcbp->sockdata->mtx);
503	if (pcbp->sockdata->node != NULL) {
504		node_p node = pcbp->sockdata->node;
505
506		if (NG_NODE_HAS_NAME(node))
507			bcopy(NG_NODE_NAME(node), sg->sg_data,
508			    strlen(NG_NODE_NAME(node)));
509		mtx_unlock(&pcbp->sockdata->mtx);
510
511		sg->sg_len = sg_len;
512		sg->sg_family = AF_NETGRAPH;
513		*addr = (struct sockaddr *)sg;
514	} else {
515		mtx_unlock(&pcbp->sockdata->mtx);
516		free(sg, M_SONAME);
517		error = EINVAL;
518	}
519
520	return (error);
521}
522
523/*
524 * Attach a socket to it's protocol specific partner.
525 * For a control socket, actually create a netgraph node and attach
526 * to it as well.
527 */
528
529static int
530ng_attach_cntl(struct socket *so)
531{
532	struct ngsock *priv;
533	struct ngpcb *pcbp;
534	node_p node;
535	int error;
536
537	/* Setup protocol control block */
538	if ((error = ng_attach_common(so, NG_CONTROL)) != 0)
539		return (error);
540	pcbp = sotongpcb(so);
541
542	/* Make the generic node components */
543	if ((error = ng_make_node_common(&typestruct, &node)) != 0) {
544		ng_detach_common(pcbp, NG_CONTROL);
545		return (error);
546	}
547
548	/*
549	 * Allocate node private info and hash. We start
550	 * with 16 hash entries, however we may grow later
551	 * in ngs_newhook(). We can't predict how much hooks
552	 * does this node plan to have.
553	 */
554	priv = malloc(sizeof(*priv), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
555	priv->hash = hashinit(16, M_NETGRAPH_SOCK, &priv->hmask);
556
557	/* Initialize mutex. */
558	mtx_init(&priv->mtx, "ng_socket", NULL, MTX_DEF);
559
560	/* Link the pcb the private data. */
561	priv->ctlsock = pcbp;
562	pcbp->sockdata = priv;
563	priv->refs++;
564	priv->node = node;
565	pcbp->node_id = node->nd_ID;	/* hint for netstat(1) */
566
567	/* Link the node and the private data. */
568	NG_NODE_SET_PRIVATE(priv->node, priv);
569	NG_NODE_REF(priv->node);
570	priv->refs++;
571
572	return (0);
573}
574
575static int
576ng_attach_data(struct socket *so)
577{
578	return (ng_attach_common(so, NG_DATA));
579}
580
581/*
582 * Set up a socket protocol control block.
583 * This code is shared between control and data sockets.
584 */
585static int
586ng_attach_common(struct socket *so, int type)
587{
588	struct ngpcb *pcbp;
589	int error;
590
591	/* Standard socket setup stuff. */
592	error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
593	if (error)
594		return (error);
595
596	/* Allocate the pcb. */
597	pcbp = malloc(sizeof(struct ngpcb), M_PCB, M_WAITOK | M_ZERO);
598	pcbp->type = type;
599
600	/* Link the pcb and the socket. */
601	so->so_pcb = (caddr_t)pcbp;
602	pcbp->ng_socket = so;
603
604	/* Add the socket to linked list */
605	mtx_lock(&ngsocketlist_mtx);
606	LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
607	mtx_unlock(&ngsocketlist_mtx);
608	return (0);
609}
610
611/*
612 * Disassociate the socket from it's protocol specific
613 * partner. If it's attached to a node's private data structure,
614 * then unlink from that too. If we were the last socket attached to it,
615 * then shut down the entire node. Shared code for control and data sockets.
616 */
617static void
618ng_detach_common(struct ngpcb *pcbp, int which)
619{
620	struct ngsock *priv = pcbp->sockdata;
621
622	if (priv != NULL) {
623		mtx_lock(&priv->mtx);
624
625		switch (which) {
626		case NG_CONTROL:
627			priv->ctlsock = NULL;
628			break;
629		case NG_DATA:
630			priv->datasock = NULL;
631			break;
632		default:
633			panic("%s", __func__);
634		}
635		pcbp->sockdata = NULL;
636		pcbp->node_id = 0;
637
638		ng_socket_free_priv(priv);
639	}
640
641	pcbp->ng_socket->so_pcb = NULL;
642	mtx_lock(&ngsocketlist_mtx);
643	LIST_REMOVE(pcbp, socks);
644	mtx_unlock(&ngsocketlist_mtx);
645	free(pcbp, M_PCB);
646}
647
648/*
649 * Remove a reference from node private data.
650 */
651static void
652ng_socket_free_priv(struct ngsock *priv)
653{
654	mtx_assert(&priv->mtx, MA_OWNED);
655
656	priv->refs--;
657
658	if (priv->refs == 0) {
659		mtx_destroy(&priv->mtx);
660		hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
661		free(priv, M_NETGRAPH_SOCK);
662		return;
663	}
664
665	if ((priv->refs == 1) && (priv->node != NULL)) {
666		node_p node = priv->node;
667
668		priv->node = NULL;
669		mtx_unlock(&priv->mtx);
670		NG_NODE_UNREF(node);
671		ng_rmnode_self(node);
672	} else
673		mtx_unlock(&priv->mtx);
674}
675
676/*
677 * Connect the data socket to a named control socket node.
678 */
679static int
680ng_connect_data(struct sockaddr *nam, struct ngpcb *pcbp)
681{
682	struct sockaddr_ng *sap;
683	node_p farnode;
684	struct ngsock *priv;
685	int error;
686	item_p item;
687
688	/* If we are already connected, don't do it again. */
689	if (pcbp->sockdata != NULL)
690		return (EISCONN);
691
692	/*
693	 * Find the target (victim) and check it doesn't already have
694	 * a data socket. Also check it is a 'socket' type node.
695	 * Use ng_package_data() and ng_address_path() to do this.
696	 */
697
698	sap = (struct sockaddr_ng *) nam;
699	/* The item will hold the node reference. */
700	item = ng_package_data(NULL, NG_WAITOK);
701
702	if ((error = ng_address_path(NULL, item,  sap->sg_data, 0)))
703		return (error); /* item is freed on failure */
704
705	/*
706	 * Extract node from item and free item. Remember we now have
707	 * a reference on the node. The item holds it for us.
708	 * when we free the item we release the reference.
709	 */
710	farnode = item->el_dest; /* shortcut */
711	if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
712		NG_FREE_ITEM(item); /* drop the reference to the node */
713		return (EINVAL);
714	}
715	priv = NG_NODE_PRIVATE(farnode);
716	if (priv->datasock != NULL) {
717		NG_FREE_ITEM(item);	/* drop the reference to the node */
718		return (EADDRINUSE);
719	}
720
721	/*
722	 * Link the PCB and the private data struct. and note the extra
723	 * reference. Drop the extra reference on the node.
724	 */
725	mtx_lock(&priv->mtx);
726	priv->datasock = pcbp;
727	pcbp->sockdata = priv;
728	pcbp->node_id = priv->node->nd_ID;	/* hint for netstat(1) */
729	priv->refs++;
730	mtx_unlock(&priv->mtx);
731	NG_FREE_ITEM(item);	/* drop the reference to the node */
732	return (0);
733}
734
735/*
736 * Binding a socket means giving the corresponding node a name
737 */
738static int
739ng_bind(struct sockaddr *nam, struct ngpcb *pcbp)
740{
741	struct ngsock *const priv = pcbp->sockdata;
742	struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
743
744	if (priv == NULL) {
745		TRAP_ERROR;
746		return (EINVAL);
747	}
748	if ((sap->sg_len < 4) || (sap->sg_len > (NG_NODESIZ + 2)) ||
749	    (sap->sg_data[0] == '\0') ||
750	    (sap->sg_data[sap->sg_len - 3] != '\0')) {
751		TRAP_ERROR;
752		return (EINVAL);
753	}
754	return (ng_name_node(priv->node, sap->sg_data));
755}
756
757/***************************************************************
758	Netgraph node
759***************************************************************/
760
761/*
762 * You can only create new nodes from the socket end of things.
763 */
764static int
765ngs_constructor(node_p nodep)
766{
767	return (EINVAL);
768}
769
770static void
771ngs_rehash(node_p node)
772{
773	struct ngsock *priv = NG_NODE_PRIVATE(node);
774	struct ngshash *new;
775	struct hookpriv *hp;
776	hook_p hook;
777	uint32_t h;
778	u_long hmask;
779
780	new = hashinit_flags((priv->hmask + 1) * 2, M_NETGRAPH_SOCK, &hmask,
781	    HASH_NOWAIT);
782	if (new == NULL)
783		return;
784
785	LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
786		hp = NG_HOOK_PRIVATE(hook);
787#ifdef INVARIANTS
788		LIST_REMOVE(hp, next);
789#endif
790		h = hash32_str(NG_HOOK_NAME(hook), HASHINIT) & hmask;
791		LIST_INSERT_HEAD(&new[h], hp, next);
792	}
793
794	hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
795	priv->hash = new;
796	priv->hmask = hmask;
797}
798
799/*
800 * We allow any hook to be connected to the node.
801 * There is no per-hook private information though.
802 */
803static int
804ngs_newhook(node_p node, hook_p hook, const char *name)
805{
806	struct ngsock *const priv = NG_NODE_PRIVATE(node);
807	struct hookpriv *hp;
808	uint32_t h;
809
810	hp = malloc(sizeof(*hp), M_NETGRAPH_SOCK, M_NOWAIT);
811	if (hp == NULL)
812		return (ENOMEM);
813	if (node->nd_numhooks * 2 > priv->hmask)
814		ngs_rehash(node);
815	hp->hook = hook;
816	h = hash32_str(name, HASHINIT) & priv->hmask;
817	LIST_INSERT_HEAD(&priv->hash[h], hp, next);
818	NG_HOOK_SET_PRIVATE(hook, hp);
819
820	return (0);
821}
822
823/*
824 * If only one hook, allow read(2) and write(2) to work.
825 */
826static int
827ngs_connect(hook_p hook)
828{
829	node_p node = NG_HOOK_NODE(hook);
830	struct ngsock *priv = NG_NODE_PRIVATE(node);
831
832	if ((priv->datasock) && (priv->datasock->ng_socket)) {
833		if (NG_NODE_NUMHOOKS(node) == 1)
834			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
835		else
836			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
837	}
838	return (0);
839}
840
841/* Look up hook by name */
842static hook_p
843ngs_findhook(node_p node, const char *name)
844{
845	struct ngsock *priv = NG_NODE_PRIVATE(node);
846	struct hookpriv *hp;
847	uint32_t h;
848
849	/*
850	 * Microoptimisation for an ng_socket with
851	 * a single hook, which is a common case.
852	 */
853	if (node->nd_numhooks == 1) {
854		hook_p hook;
855
856		hook = LIST_FIRST(&node->nd_hooks);
857
858		if (strcmp(NG_HOOK_NAME(hook), name) == 0)
859			return (hook);
860		else
861			return (NULL);
862	}
863
864	h = hash32_str(name, HASHINIT) & priv->hmask;
865
866	LIST_FOREACH(hp, &priv->hash[h], next)
867		if (strcmp(NG_HOOK_NAME(hp->hook), name) == 0)
868			return (hp->hook);
869
870	return (NULL);
871}
872
873/*
874 * Incoming messages get passed up to the control socket.
875 * Unless they are for us specifically (socket_type)
876 */
877static int
878ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
879{
880	struct ngsock *const priv = NG_NODE_PRIVATE(node);
881	struct ngpcb *pcbp;
882	struct socket *so;
883	struct sockaddr_ng addr;
884	struct ng_mesg *msg;
885	struct mbuf *m;
886	ng_ID_t	retaddr = NGI_RETADDR(item);
887	int addrlen;
888	int error = 0;
889
890	NGI_GET_MSG(item, msg);
891	NG_FREE_ITEM(item);
892
893	/*
894	 * Grab priv->mtx here to prevent destroying of control socket
895	 * after checking that priv->ctlsock is not NULL.
896	 */
897	mtx_lock(&priv->mtx);
898	pcbp = priv->ctlsock;
899
900	/*
901	 * Only allow mesgs to be passed if we have the control socket.
902	 * Data sockets can only support the generic messages.
903	 */
904	if (pcbp == NULL) {
905		mtx_unlock(&priv->mtx);
906		TRAP_ERROR;
907		NG_FREE_MSG(msg);
908		return (EINVAL);
909	}
910	so = pcbp->ng_socket;
911	SOCKBUF_LOCK(&so->so_rcv);
912
913	/* As long as the race is handled, priv->mtx may be unlocked now. */
914	mtx_unlock(&priv->mtx);
915
916#ifdef TRACE_MESSAGES
917	printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
918		retaddr,
919		msg->header.typecookie,
920		msg->header.cmd,
921		msg->header.cmdstr,
922		msg->header.flags,
923		msg->header.token);
924#endif
925
926	if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
927		switch (msg->header.cmd) {
928		case NGM_SOCK_CMD_NOLINGER:
929			priv->flags |= NGS_FLAG_NOLINGER;
930			break;
931		case NGM_SOCK_CMD_LINGER:
932			priv->flags &= ~NGS_FLAG_NOLINGER;
933			break;
934		default:
935			error = EINVAL;		/* unknown command */
936		}
937		SOCKBUF_UNLOCK(&so->so_rcv);
938
939		/* Free the message and return. */
940		NG_FREE_MSG(msg);
941		return (error);
942	}
943
944	/* Get the return address into a sockaddr. */
945	bzero(&addr, sizeof(addr));
946	addr.sg_len = sizeof(addr);
947	addr.sg_family = AF_NETGRAPH;
948	addrlen = snprintf((char *)&addr.sg_data, sizeof(addr.sg_data),
949	    "[%x]:", retaddr);
950	if (addrlen < 0 || addrlen > sizeof(addr.sg_data)) {
951		SOCKBUF_UNLOCK(&so->so_rcv);
952		printf("%s: snprintf([%x]) failed - %d\n", __func__, retaddr,
953		    addrlen);
954		NG_FREE_MSG(msg);
955		return (EINVAL);
956	}
957
958	/* Copy the message itself into an mbuf chain. */
959	m = m_devget((caddr_t)msg, sizeof(struct ng_mesg) + msg->header.arglen,
960	    0, NULL, NULL);
961
962	/*
963	 * Here we free the message. We need to do that
964	 * regardless of whether we got mbufs.
965	 */
966	NG_FREE_MSG(msg);
967
968	if (m == NULL) {
969		SOCKBUF_UNLOCK(&so->so_rcv);
970		TRAP_ERROR;
971		return (ENOBUFS);
972	}
973
974	/* Send it up to the socket. */
975	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&addr, m,
976	    NULL) == 0) {
977		SOCKBUF_UNLOCK(&so->so_rcv);
978		TRAP_ERROR;
979		m_freem(m);
980		return (ENOBUFS);
981	}
982	sorwakeup_locked(so);
983
984	return (error);
985}
986
987/*
988 * Receive data on a hook
989 */
990static int
991ngs_rcvdata(hook_p hook, item_p item)
992{
993	struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
994	struct ngpcb *const pcbp = priv->datasock;
995	struct socket *so;
996	struct sockaddr_ng *addr;
997	char *addrbuf[NG_HOOKSIZ + 4];
998	int addrlen;
999	struct mbuf *m;
1000
1001	NGI_GET_M(item, m);
1002	NG_FREE_ITEM(item);
1003
1004	/* If there is no data socket, black-hole it. */
1005	if (pcbp == NULL) {
1006		NG_FREE_M(m);
1007		return (0);
1008	}
1009	so = pcbp->ng_socket;
1010
1011	/* Get the return address into a sockaddr. */
1012	addrlen = strlen(NG_HOOK_NAME(hook));	/* <= NG_HOOKSIZ - 1 */
1013	addr = (struct sockaddr_ng *) addrbuf;
1014	addr->sg_len = addrlen + 3;
1015	addr->sg_family = AF_NETGRAPH;
1016	bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
1017	addr->sg_data[addrlen] = '\0';
1018
1019	/* Try to tell the socket which hook it came in on. */
1020	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)addr, m, NULL) == 0) {
1021		m_freem(m);
1022		TRAP_ERROR;
1023		return (ENOBUFS);
1024	}
1025	sorwakeup(so);
1026	return (0);
1027}
1028
1029/*
1030 * Hook disconnection
1031 *
1032 * For this type, removal of the last link destroys the node
1033 * if the NOLINGER flag is set.
1034 */
1035static int
1036ngs_disconnect(hook_p hook)
1037{
1038	node_p node = NG_HOOK_NODE(hook);
1039	struct ngsock *const priv = NG_NODE_PRIVATE(node);
1040	struct hookpriv *hp = NG_HOOK_PRIVATE(hook);
1041
1042	LIST_REMOVE(hp, next);
1043	free(hp, M_NETGRAPH_SOCK);
1044
1045	if ((priv->datasock) && (priv->datasock->ng_socket)) {
1046		if (NG_NODE_NUMHOOKS(node) == 1)
1047			priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
1048		else
1049			priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
1050	}
1051
1052	if ((priv->flags & NGS_FLAG_NOLINGER) &&
1053	    (NG_NODE_NUMHOOKS(node) == 0) && (NG_NODE_IS_VALID(node)))
1054		ng_rmnode_self(node);
1055
1056	return (0);
1057}
1058
1059/*
1060 * Do local shutdown processing.
1061 * In this case, that involves making sure the socket
1062 * knows we should be shutting down.
1063 */
1064static int
1065ngs_shutdown(node_p node)
1066{
1067	struct ngsock *const priv = NG_NODE_PRIVATE(node);
1068	struct ngpcb *dpcbp, *pcbp;
1069
1070	mtx_lock(&priv->mtx);
1071	dpcbp = priv->datasock;
1072	pcbp = priv->ctlsock;
1073
1074	if (dpcbp != NULL)
1075		soisdisconnected(dpcbp->ng_socket);
1076
1077	if (pcbp != NULL)
1078		soisdisconnected(pcbp->ng_socket);
1079
1080	priv->node = NULL;
1081	NG_NODE_SET_PRIVATE(node, NULL);
1082	ng_socket_free_priv(priv);
1083
1084	NG_NODE_UNREF(node);
1085	return (0);
1086}
1087
1088static void
1089ng_socket_item_applied(void *context, int error)
1090{
1091	struct ngsock *const priv = (struct ngsock *)context;
1092
1093	mtx_lock(&priv->mtx);
1094	priv->error = error;
1095	wakeup(priv);
1096	mtx_unlock(&priv->mtx);
1097
1098}
1099
1100static	int
1101dummy_disconnect(struct socket *so)
1102{
1103	return (0);
1104}
1105/*
1106 * Control and data socket type descriptors
1107 *
1108 * XXXRW: Perhaps _close should do something?
1109 */
1110
1111static struct pr_usrreqs ngc_usrreqs = {
1112	.pru_abort =		NULL,
1113	.pru_attach =		ngc_attach,
1114	.pru_bind =		ngc_bind,
1115	.pru_connect =		ngc_connect,
1116	.pru_detach =		ngc_detach,
1117	.pru_disconnect =	dummy_disconnect,
1118	.pru_peeraddr =		NULL,
1119	.pru_send =		ngc_send,
1120	.pru_shutdown =		NULL,
1121	.pru_sockaddr =		ng_getsockaddr,
1122	.pru_close =		NULL,
1123};
1124
1125static struct pr_usrreqs ngd_usrreqs = {
1126	.pru_abort =		NULL,
1127	.pru_attach =		ngd_attach,
1128	.pru_bind =		NULL,
1129	.pru_connect =		ngd_connect,
1130	.pru_detach =		ngd_detach,
1131	.pru_disconnect =	dummy_disconnect,
1132	.pru_peeraddr =		NULL,
1133	.pru_send =		ngd_send,
1134	.pru_shutdown =		NULL,
1135	.pru_sockaddr =		ng_getsockaddr,
1136	.pru_close =		NULL,
1137};
1138
1139/*
1140 * Definitions of protocols supported in the NETGRAPH domain.
1141 */
1142
1143extern struct domain ngdomain;		/* stop compiler warnings */
1144
1145static struct protosw ngsw[] = {
1146{
1147	.pr_type =		SOCK_DGRAM,
1148	.pr_domain =		&ngdomain,
1149	.pr_protocol =		NG_CONTROL,
1150	.pr_flags =		PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
1151	.pr_usrreqs =		&ngc_usrreqs
1152},
1153{
1154	.pr_type =		SOCK_DGRAM,
1155	.pr_domain =		&ngdomain,
1156	.pr_protocol =		NG_DATA,
1157	.pr_flags =		PR_ATOMIC | PR_ADDR,
1158	.pr_usrreqs =		&ngd_usrreqs
1159}
1160};
1161
1162struct domain ngdomain = {
1163	.dom_family =		AF_NETGRAPH,
1164	.dom_name =		"netgraph",
1165	.dom_protosw =		ngsw,
1166	.dom_protoswNPROTOSW =	&ngsw[nitems(ngsw)]
1167};
1168
1169/*
1170 * Handle loading and unloading for this node type.
1171 * This is to handle auxiliary linkages (e.g protocol domain addition).
1172 */
1173static int
1174ngs_mod_event(module_t mod, int event, void *data)
1175{
1176	int error = 0;
1177
1178	switch (event) {
1179	case MOD_LOAD:
1180		mtx_init(&ngsocketlist_mtx, "ng_socketlist", NULL, MTX_DEF);
1181		break;
1182	case MOD_UNLOAD:
1183		/* Ensure there are no open netgraph sockets. */
1184		if (!LIST_EMPTY(&ngsocklist)) {
1185			error = EBUSY;
1186			break;
1187		}
1188#ifdef NOTYET
1189		/* Unregister protocol domain XXX can't do this yet.. */
1190#endif
1191		error = EBUSY;
1192		break;
1193	default:
1194		error = EOPNOTSUPP;
1195		break;
1196	}
1197	return (error);
1198}
1199
1200VNET_DOMAIN_SET(ng);
1201
1202SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, AF_NETGRAPH, "");
1203static SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW, 0, "DATA");
1204SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_DATA, "");
1205static SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW, 0, "CONTROL");
1206SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_CONTROL, "");
1207
1208