FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_gif.c
1 /*
2 * ng_gif.c
3 *
4 * Copyright 2001 The Aerospace Corporation. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions, and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions, and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of The Aerospace Corporation may not be used to endorse or
16 * promote products derived from this software.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AEROSPACE CORPORATION BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 *
31 * Copyright (c) 1996-2000 Whistle Communications, Inc.
32 * All rights reserved.
33 *
34 * Subject to the following obligations and disclaimer of warranty, use and
35 * redistribution of this software, in source or object code forms, with or
36 * without modifications are expressly permitted by Whistle Communications;
37 * provided, however, that:
38 * 1. Any and all reproductions of the source or object code must include the
39 * copyright notice above and the following disclaimer of warranties; and
40 * 2. No rights are granted, in any manner or form, to use Whistle
41 * Communications, Inc. trademarks, including the mark "WHISTLE
42 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
43 * such appears in the above copyright notice or in the software.
44 *
45 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
46 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
47 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
48 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
49 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
50 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
51 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
52 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
53 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
54 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
55 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
56 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
57 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
58 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
61 * OF SUCH DAMAGE.
62 *
63 * $FreeBSD: releng/5.2/sys/netgraph/ng_gif.c 121816 2003-10-31 18:32:15Z brooks $
64 */
65
66 /*
67 * ng_gif(4) netgraph node type
68 */
69
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/kernel.h>
73 #include <sys/malloc.h>
74 #include <sys/mbuf.h>
75 #include <sys/errno.h>
76 #include <sys/syslog.h>
77 #include <sys/socket.h>
78
79 #include <net/if.h>
80 #include <net/route.h>
81 #include <net/if_types.h>
82 #include <net/if_var.h>
83 #include <net/if_gif.h>
84
85 #include <netgraph/ng_message.h>
86 #include <netgraph/netgraph.h>
87 #include <netgraph/ng_parse.h>
88 #include <netgraph/ng_gif.h>
89
90 #define IFP2NG(ifp) ((struct ng_node *)((struct gif_softc *)(ifp))->gif_netgraph)
91
92 /* Per-node private data */
93 struct private {
94 struct ifnet *ifp; /* associated interface */
95 hook_p lower; /* lower OR orphan hook connection */
96 u_char lowerOrphan; /* whether lower is lower or orphan */
97 };
98 typedef struct private *priv_p;
99
100 /* Functional hooks called from if_gif.c */
101 static void ng_gif_input(struct ifnet *ifp, struct mbuf **mp, int af);
102 static void ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af);
103 static void ng_gif_attach(struct ifnet *ifp);
104 static void ng_gif_detach(struct ifnet *ifp);
105
106 /* Other functions */
107 static void ng_gif_input2(node_p node, struct mbuf **mp, int af);
108 static int ng_gif_glue_af(struct mbuf **mp, int af);
109 static int ng_gif_rcv_lower(node_p node, struct mbuf *m, meta_p meta);
110
111 /* Netgraph node methods */
112 static ng_constructor_t ng_gif_constructor;
113 static ng_rcvmsg_t ng_gif_rcvmsg;
114 static ng_shutdown_t ng_gif_shutdown;
115 static ng_newhook_t ng_gif_newhook;
116 static ng_connect_t ng_gif_connect;
117 static ng_rcvdata_t ng_gif_rcvdata;
118 static ng_disconnect_t ng_gif_disconnect;
119 static int ng_gif_mod_event(module_t mod, int event, void *data);
120
121 /* List of commands and how to convert arguments to/from ASCII */
122 static const struct ng_cmdlist ng_gif_cmdlist[] = {
123 {
124 NGM_GIF_COOKIE,
125 NGM_GIF_GET_IFNAME,
126 "getifname",
127 NULL,
128 &ng_parse_string_type
129 },
130 {
131 NGM_GIF_COOKIE,
132 NGM_GIF_GET_IFINDEX,
133 "getifindex",
134 NULL,
135 &ng_parse_int32_type
136 },
137 { 0 }
138 };
139
140 static struct ng_type ng_gif_typestruct = {
141 NG_ABI_VERSION,
142 NG_GIF_NODE_TYPE,
143 ng_gif_mod_event,
144 ng_gif_constructor,
145 ng_gif_rcvmsg,
146 ng_gif_shutdown,
147 ng_gif_newhook,
148 NULL,
149 ng_gif_connect,
150 ng_gif_rcvdata,
151 ng_gif_disconnect,
152 ng_gif_cmdlist,
153 };
154 MODULE_VERSION(ng_gif, 1);
155 MODULE_DEPEND(ng_gif, if_gif, 1,1,1);
156 NETGRAPH_INIT(gif, &ng_gif_typestruct);
157
158 /******************************************************************
159 GIF FUNCTION HOOKS
160 ******************************************************************/
161
162 /*
163 * Handle a packet that has come in on an interface. We get to
164 * look at it here before any upper layer protocols do.
165 *
166 * NOTE: this function will get called at splimp()
167 */
168 static void
169 ng_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 *
184 * NOTE: this function will get called at splimp()
185 */
186 static void
187 ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af)
188 {
189 const node_p node = IFP2NG(ifp);
190 const priv_p priv = NG_NODE_PRIVATE(node);
191
192 /* If "orphan" hook not connected, let packet continue */
193 if (priv->lower == NULL || !priv->lowerOrphan) {
194 m_freem(m);
195 return;
196 }
197 ng_gif_input2(node, &m, af);
198 if (m != NULL)
199 m_freem(m);
200 }
201
202 /*
203 * Handle a packet that has come in on a gif interface.
204 * Attach the address family to the mbuf for later use.
205 *
206 * NOTE: this function will get called at splimp()
207 */
208 static void
209 ng_gif_input2(node_p node, struct mbuf **mp, int af)
210 {
211 const priv_p priv = NG_NODE_PRIVATE(node);
212 int error;
213
214 /* Glue address family on */
215 if ((error = ng_gif_glue_af(mp, af)) != 0)
216 return;
217
218 /* Send out lower/orphan hook */
219 NG_SEND_DATA_ONLY(error, priv->lower, *mp);
220 *mp = NULL;
221 }
222
223 /*
224 * A new gif interface has been attached.
225 * Create a new node for it, etc.
226 */
227 static void
228 ng_gif_attach(struct ifnet *ifp)
229 {
230 priv_p priv;
231 node_p node;
232
233 /* Create node */
234 KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
235 if (ng_make_node_common(&ng_gif_typestruct, &node) != 0) {
236 log(LOG_ERR, "%s: can't %s for %s\n",
237 __func__, "create node", ifp->if_xname);
238 return;
239 }
240
241 /* Allocate private data */
242 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
243 if (priv == NULL) {
244 log(LOG_ERR, "%s: can't %s for %s\n",
245 __func__, "allocate memory", ifp->if_xname);
246 NG_NODE_UNREF(node);
247 return;
248 }
249 NG_NODE_SET_PRIVATE(node, priv);
250 priv->ifp = ifp;
251 IFP2NG(ifp) = node;
252
253 /* Try to give the node the same name as the interface */
254 if (ng_name_node(node, ifp->if_xname) != 0) {
255 log(LOG_WARNING, "%s: can't name node %s\n",
256 __func__, ifp->if_xname);
257 }
258 }
259
260 /*
261 * An interface is being detached.
262 * REALLY Destroy its node.
263 */
264 static void
265 ng_gif_detach(struct ifnet *ifp)
266 {
267 const node_p node = IFP2NG(ifp);
268 const priv_p priv = NG_NODE_PRIVATE(node);
269
270 if (node == NULL) /* no node (why not?), ignore */
271 return;
272 NG_NODE_REALLY_DIE(node); /* Force real removal of node */
273 /*
274 * We can't assume the ifnet is still around when we run shutdown
275 * So zap it now. XXX We HOPE that anything running at this time
276 * handles it (as it should in the non netgraph case).
277 */
278 IFP2NG(ifp) = NULL;
279 priv->ifp = NULL; /* XXX race if interrupted an output packet */
280 ng_rmnode_self(node); /* remove all netgraph parts */
281 }
282
283 /*
284 * Optimization for gluing the address family onto
285 * the front of an incoming packet.
286 */
287 static int
288 ng_gif_glue_af(struct mbuf **mp, int af)
289 {
290 struct mbuf *m = *mp;
291 int error = 0;
292 sa_family_t tmp_af;
293
294 tmp_af = (sa_family_t) af;
295
296 /*
297 * XXX: should try to bring back some of the optimizations from
298 * ng_ether.c
299 */
300
301 /*
302 * Doing anything more is likely to get more
303 * expensive than it's worth..
304 * it's probable that everything else is in one
305 * big lump. The next node will do an m_pullup()
306 * for exactly the amount of data it needs and
307 * hopefully everything after that will not
308 * need one. So let's just use M_PREPEND.
309 */
310 M_PREPEND(m, sizeof (tmp_af), M_DONTWAIT);
311 if (m == NULL) {
312 error = ENOBUFS;
313 goto done;
314 }
315
316 #if 0
317 copy:
318 #endif
319 /* Copy header and return (possibly new) mbuf */
320 *mtod(m, sa_family_t *) = tmp_af;
321 #if 0
322 bcopy((caddr_t)&tmp_af, mtod(m, sa_family_t *), sizeof(tmp_af));
323 #endif
324 done:
325 *mp = m;
326 return error;
327 }
328
329 /******************************************************************
330 NETGRAPH NODE METHODS
331 ******************************************************************/
332
333 /*
334 * It is not possible or allowable to create a node of this type.
335 * Nodes get created when the interface is attached (or, when
336 * this node type's KLD is loaded).
337 */
338 static int
339 ng_gif_constructor(node_p node)
340 {
341 return (EINVAL);
342 }
343
344 /*
345 * Check for attaching a new hook.
346 */
347 static int
348 ng_gif_newhook(node_p node, hook_p hook, const char *name)
349 {
350 const priv_p priv = NG_NODE_PRIVATE(node);
351 u_char orphan = priv->lowerOrphan;
352 hook_p *hookptr;
353
354 /* Divert hook is an alias for lower */
355 if (strcmp(name, NG_GIF_HOOK_DIVERT) == 0)
356 name = NG_GIF_HOOK_LOWER;
357
358 /* Which hook? */
359 if (strcmp(name, NG_GIF_HOOK_LOWER) == 0) {
360 hookptr = &priv->lower;
361 orphan = 0;
362 } else if (strcmp(name, NG_GIF_HOOK_ORPHAN) == 0) {
363 hookptr = &priv->lower;
364 orphan = 1;
365 } else
366 return (EINVAL);
367
368 /* Check if already connected (shouldn't be, but doesn't hurt) */
369 if (*hookptr != NULL)
370 return (EISCONN);
371
372 /* OK */
373 *hookptr = hook;
374 priv->lowerOrphan = orphan;
375 return (0);
376 }
377
378 /*
379 * Hooks are attached, adjust to force queueing.
380 * We don't really care which hook it is.
381 * they should all be queuing for outgoing data.
382 */
383 static int
384 ng_gif_connect(hook_p hook)
385 {
386 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
387 return (0);
388 }
389
390 /*
391 * Receive an incoming control message.
392 */
393 static int
394 ng_gif_rcvmsg(node_p node, item_p item, hook_p lasthook)
395 {
396 const priv_p priv = NG_NODE_PRIVATE(node);
397 struct ng_mesg *resp = NULL;
398 int error = 0;
399 struct ng_mesg *msg;
400
401 NGI_GET_MSG(item, msg);
402 switch (msg->header.typecookie) {
403 case NGM_GIF_COOKIE:
404 switch (msg->header.cmd) {
405 case NGM_GIF_GET_IFNAME:
406 NG_MKRESPONSE(resp, msg, IFNAMSIZ + 1, M_NOWAIT);
407 if (resp == NULL) {
408 error = ENOMEM;
409 break;
410 }
411 strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ + 1);
412 break;
413 case NGM_GIF_GET_IFINDEX:
414 NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
415 if (resp == NULL) {
416 error = ENOMEM;
417 break;
418 }
419 *((u_int32_t *)resp->data) = priv->ifp->if_index;
420 break;
421 default:
422 error = EINVAL;
423 break;
424 }
425 break;
426 default:
427 error = EINVAL;
428 break;
429 }
430 NG_RESPOND_MSG(error, node, item, resp);
431 NG_FREE_MSG(msg);
432 return (error);
433 }
434
435 /*
436 * Receive data on a hook.
437 */
438 static int
439 ng_gif_rcvdata(hook_p hook, item_p item)
440 {
441 const node_p node = NG_HOOK_NODE(hook);
442 const priv_p priv = NG_NODE_PRIVATE(node);
443 struct mbuf *m;
444 meta_p meta;
445
446 NGI_GET_M(item, m);
447 NGI_GET_META(item, meta);
448 NG_FREE_ITEM(item);
449 if (hook == priv->lower)
450 return ng_gif_rcv_lower(node, m, meta);
451 panic("%s: weird hook", __func__);
452 }
453
454 /*
455 * Handle an mbuf received on the "lower" hook.
456 */
457 static int
458 ng_gif_rcv_lower(node_p node, struct mbuf *m, meta_p meta)
459 {
460 struct sockaddr dst;
461 const priv_p priv = NG_NODE_PRIVATE(node);
462
463 bzero(&dst, sizeof(dst));
464
465 /* We don't process metadata. */
466 NG_FREE_META(meta);
467
468 /* Make sure header is fully pulled up */
469 if (m->m_pkthdr.len < sizeof(sa_family_t)) {
470 NG_FREE_M(m);
471 return (EINVAL);
472 }
473 if (m->m_len < sizeof(sa_family_t)
474 && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
475 return (ENOBUFS);
476 }
477
478 dst.sa_family = *mtod(m, sa_family_t *);
479 m_adj(m, sizeof(sa_family_t));
480
481 /* Send it on its way */
482 /*
483 * XXX: gif_output only uses dst for the family and passes the
484 * fourth argument (rt) to in{,6}_gif_output which ignore it.
485 * If this changes ng_gif will probably break.
486 */
487 return gif_output(priv->ifp, m, &dst, NULL);
488 }
489
490 /*
491 * Shutdown node. This resets the node but does not remove it
492 * unless the REALLY_DIE flag is set.
493 */
494 static int
495 ng_gif_shutdown(node_p node)
496 {
497 const priv_p priv = NG_NODE_PRIVATE(node);
498
499 if (node->nd_flags & NG_REALLY_DIE) {
500 /*
501 * WE came here because the gif interface is being destroyed,
502 * so stop being persistant.
503 * Actually undo all the things we did on creation.
504 * Assume the ifp has already been freed.
505 */
506 NG_NODE_SET_PRIVATE(node, NULL);
507 FREE(priv, M_NETGRAPH);
508 NG_NODE_UNREF(node); /* free node itself */
509 return (0);
510 }
511 node->nd_flags &= ~NG_INVALID; /* Signal ng_rmnode we are persisant */
512 return (0);
513 }
514
515 /*
516 * Hook disconnection.
517 */
518 static int
519 ng_gif_disconnect(hook_p hook)
520 {
521 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
522
523 if (hook == priv->lower) {
524 priv->lower = NULL;
525 priv->lowerOrphan = 0;
526 } else
527 panic("%s: weird hook", __func__);
528 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
529 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
530 ng_rmnode_self(NG_HOOK_NODE(hook)); /* reset node */
531
532 return (0);
533 }
534
535 /******************************************************************
536 INITIALIZATION
537 ******************************************************************/
538
539 /*
540 * Handle loading and unloading for this node type.
541 */
542 static int
543 ng_gif_mod_event(module_t mod, int event, void *data)
544 {
545 struct ifnet *ifp;
546 int error = 0;
547 int s;
548
549 s = splnet();
550 switch (event) {
551 case MOD_LOAD:
552
553 /* Register function hooks */
554 if (ng_gif_attach_p != NULL) {
555 error = EEXIST;
556 break;
557 }
558 ng_gif_attach_p = ng_gif_attach;
559 ng_gif_detach_p = ng_gif_detach;
560 ng_gif_input_p = ng_gif_input;
561 ng_gif_input_orphan_p = ng_gif_input_orphan;
562
563 /* Create nodes for any already-existing gif interfaces */
564 IFNET_RLOCK();
565 TAILQ_FOREACH(ifp, &ifnet, if_link) {
566 if (ifp->if_type == IFT_GIF)
567 ng_gif_attach(ifp);
568 }
569 IFNET_RUNLOCK();
570 break;
571
572 case MOD_UNLOAD:
573
574 /*
575 * Note that the base code won't try to unload us until
576 * all nodes have been removed, and that can't happen
577 * until all gif interfaces are destroyed. In any
578 * case, we know there are no nodes left if the action
579 * is MOD_UNLOAD, so there's no need to detach any nodes.
580 *
581 * XXX: what about manual unloads?!?
582 */
583
584 /* Unregister function hooks */
585 ng_gif_attach_p = NULL;
586 ng_gif_detach_p = NULL;
587 ng_gif_input_p = NULL;
588 ng_gif_input_orphan_p = NULL;
589 break;
590
591 default:
592 error = EOPNOTSUPP;
593 break;
594 }
595 splx(s);
596 return (error);
597 }
598
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