1/*
2 * ng_gif.c
3 */
4
5/*-
6 * SPDX-License-Identifier: BSD-3-Clause AND BSD-2-Clause
7 *
8 * Copyright 2001 The Aerospace Corporation.  All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions, and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions, and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of The Aerospace Corporation may not be used to endorse or
20 *    promote products derived from this software.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AEROSPACE CORPORATION BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *
35 * Copyright (c) 1996-2000 Whistle Communications, Inc.
36 * All rights reserved.
37 *
38 * Subject to the following obligations and disclaimer of warranty, use and
39 * redistribution of this software, in source or object code forms, with or
40 * without modifications are expressly permitted by Whistle Communications;
41 * provided, however, that:
42 * 1. Any and all reproductions of the source or object code must include the
43 *    copyright notice above and the following disclaimer of warranties; and
44 * 2. No rights are granted, in any manner or form, to use Whistle
45 *    Communications, Inc. trademarks, including the mark "WHISTLE
46 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
47 *    such appears in the above copyright notice or in the software.
48 *
49 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
50 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
51 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
52 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
53 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
54 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
55 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
56 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
57 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
58 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
59 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
60 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
61 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
62 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
63 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
64 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
65 * OF SUCH DAMAGE.
66 */
67
68/*
69 * ng_gif(4) netgraph node type
70 */
71#include <sys/param.h>
72#include <sys/systm.h>
73#include <sys/kernel.h>
74#include <sys/malloc.h>
75#include <sys/mbuf.h>
76#include <sys/errno.h>
77#include <sys/syslog.h>
78#include <sys/socket.h>
79
80#include <net/if.h>
81#include <net/route.h>
82#include <net/if_types.h>
83#include <net/if_var.h>
84#include <net/if_gif.h>
85#include <net/if_private.h>
86#include <net/vnet.h>
87
88#include <netgraph/ng_message.h>
89#include <netgraph/netgraph.h>
90#include <netgraph/ng_parse.h>
91#include <netgraph/ng_gif.h>
92
93#define IFP2NG(ifp)  ((struct ng_node *)((struct gif_softc *)(ifp->if_softc))->gif_netgraph)
94#define IFP2NG_SET(ifp, val)  (((struct gif_softc *)(ifp->if_softc))->gif_netgraph = (val))
95
96/* Per-node private data */
97struct private {
98	struct ifnet	*ifp;		/* associated interface */
99	hook_p		lower;		/* lower OR orphan hook connection */
100	u_char		lowerOrphan;	/* whether lower is lower or orphan */
101};
102typedef struct private *priv_p;
103
104/* Functional hooks called from if_gif.c */
105static void	ng_gif_input(struct ifnet *ifp, struct mbuf **mp, int af);
106static void	ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af);
107static void	ng_gif_attach(struct ifnet *ifp);
108static void	ng_gif_detach(struct ifnet *ifp);
109
110/* Other functions */
111static void	ng_gif_input2(node_p node, struct mbuf **mp, int af);
112static int	ng_gif_glue_af(struct mbuf **mp, int af);
113static int	ng_gif_rcv_lower(node_p node, struct mbuf *m);
114
115/* Netgraph node methods */
116static ng_constructor_t	ng_gif_constructor;
117static ng_rcvmsg_t	ng_gif_rcvmsg;
118static ng_shutdown_t	ng_gif_shutdown;
119static ng_newhook_t	ng_gif_newhook;
120static ng_connect_t	ng_gif_connect;
121static ng_rcvdata_t	ng_gif_rcvdata;
122static ng_disconnect_t	ng_gif_disconnect;
123static int		ng_gif_mod_event(module_t mod, int event, void *data);
124
125/* List of commands and how to convert arguments to/from ASCII */
126static const struct ng_cmdlist ng_gif_cmdlist[] = {
127	{
128	  NGM_GIF_COOKIE,
129	  NGM_GIF_GET_IFNAME,
130	  "getifname",
131	  NULL,
132	  &ng_parse_string_type
133	},
134	{
135	  NGM_GIF_COOKIE,
136	  NGM_GIF_GET_IFINDEX,
137	  "getifindex",
138	  NULL,
139	  &ng_parse_int32_type
140	},
141	{ 0 }
142};
143
144static struct ng_type ng_gif_typestruct = {
145	.version =	NG_ABI_VERSION,
146	.name =		NG_GIF_NODE_TYPE,
147	.mod_event =	ng_gif_mod_event,
148	.constructor =	ng_gif_constructor,
149	.rcvmsg =	ng_gif_rcvmsg,
150	.shutdown =	ng_gif_shutdown,
151	.newhook =	ng_gif_newhook,
152	.connect =	ng_gif_connect,
153	.rcvdata =	ng_gif_rcvdata,
154	.disconnect =	ng_gif_disconnect,
155	.cmdlist =	ng_gif_cmdlist,
156};
157MODULE_DEPEND(ng_gif, if_gif, 1,1,1);
158NETGRAPH_INIT(gif, &ng_gif_typestruct);
159
160/******************************************************************
161		       GIF FUNCTION HOOKS
162******************************************************************/
163
164/*
165 * Handle a packet that has come in on an interface. We get to
166 * look at it here before any upper layer protocols do.
167 */
168static void
169ng_gif_input(struct ifnet *ifp, struct mbuf **mp, int af)
170{
171	const node_p node = IFP2NG(ifp);
172	const priv_p priv = NG_NODE_PRIVATE(node);
173
174	/* If "lower" hook not connected, let packet continue */
175	if (priv->lower == NULL || priv->lowerOrphan)
176		return;
177	ng_gif_input2(node, mp, af);
178}
179
180/*
181 * Handle a packet that has come in on an interface, and which
182 * does not match any of our known protocols (an ``orphan'').
183 */
184static void
185ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af)
186{
187	const node_p node = IFP2NG(ifp);
188	const priv_p priv = NG_NODE_PRIVATE(node);
189
190	/* If "orphan" hook not connected, let packet continue */
191	if (priv->lower == NULL || !priv->lowerOrphan) {
192		m_freem(m);
193		return;
194	}
195	ng_gif_input2(node, &m, af);
196	if (m != NULL)
197		m_freem(m);
198}
199
200/*
201 * Handle a packet that has come in on a gif interface.
202 * Attach the address family to the mbuf for later use.
203 */
204static void
205ng_gif_input2(node_p node, struct mbuf **mp, int af)
206{
207	const priv_p priv = NG_NODE_PRIVATE(node);
208	int error;
209
210	/* Glue address family on */
211	if ((error = ng_gif_glue_af(mp, af)) != 0)
212		return;
213
214	/* Send out lower/orphan hook */
215	NG_SEND_DATA_ONLY(error, priv->lower, *mp);
216	*mp = NULL;
217}
218
219/*
220 * A new gif interface has been attached.
221 * Create a new node for it, etc.
222 */
223static void
224ng_gif_attach(struct ifnet *ifp)
225{
226	priv_p priv;
227	node_p node;
228
229	/* Create node */
230	KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
231	if (ng_make_node_common(&ng_gif_typestruct, &node) != 0) {
232		log(LOG_ERR, "%s: can't %s for %s\n",
233		    __func__, "create node", ifp->if_xname);
234		return;
235	}
236
237	/* Allocate private data */
238	priv = malloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
239	if (priv == NULL) {
240		log(LOG_ERR, "%s: can't %s for %s\n",
241		    __func__, "allocate memory", ifp->if_xname);
242		NG_NODE_UNREF(node);
243		return;
244	}
245	NG_NODE_SET_PRIVATE(node, priv);
246	priv->ifp = ifp;
247	IFP2NG_SET(ifp, node);
248
249	/* Try to give the node the same name as the interface */
250	if (ng_name_node(node, ifp->if_xname) != 0) {
251		log(LOG_WARNING, "%s: can't name node %s\n",
252		    __func__, ifp->if_xname);
253	}
254}
255
256/*
257 * An interface is being detached.
258 * REALLY Destroy its node.
259 */
260static void
261ng_gif_detach(struct ifnet *ifp)
262{
263	const node_p node = IFP2NG(ifp);
264	priv_p priv;
265
266	if (node == NULL)		/* no node (why not?), ignore */
267		return;
268	priv = NG_NODE_PRIVATE(node);
269	NG_NODE_REALLY_DIE(node);	/* Force real removal of node */
270	/*
271	 * We can't assume the ifnet is still around when we run shutdown
272	 * So zap it now. XXX We HOPE that anything running at this time
273	 * handles it (as it should in the non netgraph case).
274	 */
275	IFP2NG_SET(ifp, NULL);
276	priv->ifp = NULL;	/* XXX race if interrupted an output packet */
277	ng_rmnode_self(node);		/* remove all netgraph parts */
278}
279
280/*
281 * Optimization for gluing the address family onto
282 * the front of an incoming packet.
283 */
284static int
285ng_gif_glue_af(struct mbuf **mp, int af)
286{
287	struct mbuf *m = *mp;
288	int error = 0;
289	sa_family_t tmp_af;
290
291	tmp_af = (sa_family_t) af;
292
293	/*
294	 * XXX: should try to bring back some of the optimizations from
295	 * ng_ether.c
296	 */
297
298	/*
299	 * Doing anything more is likely to get more
300	 * expensive than it's worth..
301	 * it's probable that everything else is in one
302	 * big lump. The next node will do an m_pullup()
303	 * for exactly the amount of data it needs and
304	 * hopefully everything after that will not
305	 * need one. So let's just use M_PREPEND.
306	 */
307	M_PREPEND(m, sizeof (tmp_af), M_NOWAIT);
308	if (m == NULL) {
309		error = ENOBUFS;
310		goto done;
311	}
312
313#if 0
314copy:
315#endif
316	/* Copy header and return (possibly new) mbuf */
317	*mtod(m, sa_family_t *) = tmp_af;
318#if 0
319	bcopy((caddr_t)&tmp_af, mtod(m, sa_family_t *), sizeof(tmp_af));
320#endif
321done:
322	*mp = m;
323	return error;
324}
325
326/******************************************************************
327		    NETGRAPH NODE METHODS
328******************************************************************/
329
330/*
331 * It is not possible or allowable to create a node of this type.
332 * Nodes get created when the interface is attached (or, when
333 * this node type's KLD is loaded).
334 */
335static int
336ng_gif_constructor(node_p node)
337{
338	return (EINVAL);
339}
340
341/*
342 * Check for attaching a new hook.
343 */
344static	int
345ng_gif_newhook(node_p node, hook_p hook, const char *name)
346{
347	const priv_p priv = NG_NODE_PRIVATE(node);
348	u_char orphan = priv->lowerOrphan;
349	hook_p *hookptr;
350
351	/* Divert hook is an alias for lower */
352	if (strcmp(name, NG_GIF_HOOK_DIVERT) == 0)
353		name = NG_GIF_HOOK_LOWER;
354
355	/* Which hook? */
356	if (strcmp(name, NG_GIF_HOOK_LOWER) == 0) {
357		hookptr = &priv->lower;
358		orphan = 0;
359	} else if (strcmp(name, NG_GIF_HOOK_ORPHAN) == 0) {
360		hookptr = &priv->lower;
361		orphan = 1;
362	} else
363		return (EINVAL);
364
365	/* Check if already connected (shouldn't be, but doesn't hurt) */
366	if (*hookptr != NULL)
367		return (EISCONN);
368
369	/* OK */
370	*hookptr = hook;
371	priv->lowerOrphan = orphan;
372	return (0);
373}
374
375/*
376 * Hooks are attached, adjust to force queueing.
377 * We don't really care which hook it is.
378 * they should all be queuing for outgoing data.
379 */
380static	int
381ng_gif_connect(hook_p hook)
382{
383	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
384	return (0);
385}
386
387/*
388 * Receive an incoming control message.
389 */
390static int
391ng_gif_rcvmsg(node_p node, item_p item, hook_p lasthook)
392{
393	const priv_p priv = NG_NODE_PRIVATE(node);
394	struct ng_mesg *resp = NULL;
395	int error = 0;
396	struct ng_mesg *msg;
397
398	NGI_GET_MSG(item, msg);
399	switch (msg->header.typecookie) {
400	case NGM_GIF_COOKIE:
401		switch (msg->header.cmd) {
402		case NGM_GIF_GET_IFNAME:
403			NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
404			if (resp == NULL) {
405				error = ENOMEM;
406				break;
407			}
408			strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ);
409			break;
410		case NGM_GIF_GET_IFINDEX:
411			NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
412			if (resp == NULL) {
413				error = ENOMEM;
414				break;
415			}
416			*((u_int32_t *)resp->data) = priv->ifp->if_index;
417			break;
418		default:
419			error = EINVAL;
420			break;
421		}
422		break;
423	default:
424		error = EINVAL;
425		break;
426	}
427	NG_RESPOND_MSG(error, node, item, resp);
428	NG_FREE_MSG(msg);
429	return (error);
430}
431
432/*
433 * Receive data on a hook.
434 */
435static int
436ng_gif_rcvdata(hook_p hook, item_p item)
437{
438	const node_p node = NG_HOOK_NODE(hook);
439	const priv_p priv = NG_NODE_PRIVATE(node);
440	struct mbuf *m;
441
442	NGI_GET_M(item, m);
443	NG_FREE_ITEM(item);
444
445	if (hook == priv->lower)
446		return ng_gif_rcv_lower(node, m);
447	panic("%s: weird hook", __func__);
448}
449
450/*
451 * Handle an mbuf received on the "lower" hook.
452 */
453static int
454ng_gif_rcv_lower(node_p node, struct mbuf *m)
455{
456	struct sockaddr	dst;
457	const priv_p priv = NG_NODE_PRIVATE(node);
458
459	bzero(&dst, sizeof(dst));
460
461	/* Make sure header is fully pulled up */
462	if (m->m_pkthdr.len < sizeof(sa_family_t)) {
463		NG_FREE_M(m);
464		return (EINVAL);
465	}
466	if (m->m_len < sizeof(sa_family_t)
467	    && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
468		return (ENOBUFS);
469	}
470
471	dst.sa_family = *mtod(m, sa_family_t *);
472	m_adj(m, sizeof(sa_family_t));
473
474	/* Send it on its way */
475	/*
476	 * XXX: gif_output only uses dst for the family and passes the
477	 * fourth argument (rt) to in{,6}_gif_output which ignore it.
478	 * If this changes ng_gif will probably break.
479	 */
480	return gif_output(priv->ifp, m, &dst, NULL);
481}
482
483/*
484 * Shutdown node. This resets the node but does not remove it
485 * unless the REALLY_DIE flag is set.
486 */
487static int
488ng_gif_shutdown(node_p node)
489{
490	const priv_p priv = NG_NODE_PRIVATE(node);
491
492	if (node->nd_flags & NGF_REALLY_DIE) {
493		/*
494		 * WE came here because the gif interface is being destroyed,
495		 * so stop being persistent.
496		 * Actually undo all the things we did on creation.
497		 * Assume the ifp has already been freed.
498		 */
499		NG_NODE_SET_PRIVATE(node, NULL);
500		free(priv, M_NETGRAPH);
501		NG_NODE_UNREF(node);	/* free node itself */
502		return (0);
503	}
504	NG_NODE_REVIVE(node);		/* Signal ng_rmnode we are persisant */
505	return (0);
506}
507
508/*
509 * Hook disconnection.
510 */
511static int
512ng_gif_disconnect(hook_p hook)
513{
514	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
515
516	if (hook == priv->lower) {
517		priv->lower = NULL;
518		priv->lowerOrphan = 0;
519	} else
520		panic("%s: weird hook", __func__);
521	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
522	    && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
523		ng_rmnode_self(NG_HOOK_NODE(hook));	/* reset node */
524
525	return (0);
526}
527
528/******************************************************************
529		    	INITIALIZATION
530******************************************************************/
531
532/*
533 * Handle loading and unloading for this node type.
534 */
535static int
536ng_gif_mod_event(module_t mod, int event, void *data)
537{
538	VNET_ITERATOR_DECL(vnet_iter);
539	struct ifnet *ifp;
540	int error = 0;
541
542	switch (event) {
543	case MOD_LOAD:
544
545		/* Register function hooks */
546		if (ng_gif_attach_p != NULL) {
547			error = EEXIST;
548			break;
549		}
550		ng_gif_attach_p = ng_gif_attach;
551		ng_gif_detach_p = ng_gif_detach;
552		ng_gif_input_p = ng_gif_input;
553		ng_gif_input_orphan_p = ng_gif_input_orphan;
554
555		/* Create nodes for any already-existing gif interfaces */
556		VNET_LIST_RLOCK();
557		IFNET_RLOCK();
558		VNET_FOREACH(vnet_iter) {
559			CURVNET_SET_QUIET(vnet_iter); /* XXX revisit quiet */
560			CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
561				if (ifp->if_type == IFT_GIF)
562					ng_gif_attach(ifp);
563			}
564			CURVNET_RESTORE();
565		}
566		IFNET_RUNLOCK();
567		VNET_LIST_RUNLOCK();
568		break;
569
570	case MOD_UNLOAD:
571
572		/*
573		 * Note that the base code won't try to unload us until
574		 * all nodes have been removed, and that can't happen
575		 * until all gif interfaces are destroyed. In any
576		 * case, we know there are no nodes left if the action
577		 * is MOD_UNLOAD, so there's no need to detach any nodes.
578		 *
579		 * XXX: what about manual unloads?!?
580		 */
581
582		/* Unregister function hooks */
583		ng_gif_attach_p = NULL;
584		ng_gif_detach_p = NULL;
585		ng_gif_input_p = NULL;
586		ng_gif_input_orphan_p = NULL;
587		break;
588
589	default:
590		error = EOPNOTSUPP;
591		break;
592	}
593	return (error);
594}
595