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/5.1/sys/netgraph/ng_gif.c 111119 2003-02-19 05:47:46Z imp $
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 char name[IFNAMSIZ + 1];
231 priv_p priv;
232 node_p node;
233
234 /* Create node */
235 KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
236 snprintf(name, sizeof(name), "%s%d", ifp->if_name, ifp->if_unit);
237 if (ng_make_node_common(&ng_gif_typestruct, &node) != 0) {
238 log(LOG_ERR, "%s: can't %s for %s\n",
239 __func__, "create node", name);
240 return;
241 }
242
243 /* Allocate private data */
244 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
245 if (priv == NULL) {
246 log(LOG_ERR, "%s: can't %s for %s\n",
247 __func__, "allocate memory", name);
248 NG_NODE_UNREF(node);
249 return;
250 }
251 NG_NODE_SET_PRIVATE(node, priv);
252 priv->ifp = ifp;
253 IFP2NG(ifp) = node;
254
255 /* Try to give the node the same name as the interface */
256 if (ng_name_node(node, name) != 0) {
257 log(LOG_WARNING, "%s: can't name node %s\n",
258 __func__, name);
259 }
260 }
261
262 /*
263 * An interface is being detached.
264 * REALLY Destroy its node.
265 */
266 static void
267 ng_gif_detach(struct ifnet *ifp)
268 {
269 const node_p node = IFP2NG(ifp);
270 const priv_p priv = NG_NODE_PRIVATE(node);
271
272 if (node == NULL) /* no node (why not?), ignore */
273 return;
274 NG_NODE_REALLY_DIE(node); /* Force real removal of node */
275 /*
276 * We can't assume the ifnet is still around when we run shutdown
277 * So zap it now. XXX We HOPE that anything running at this time
278 * handles it (as it should in the non netgraph case).
279 */
280 IFP2NG(ifp) = NULL;
281 priv->ifp = NULL; /* XXX race if interrupted an output packet */
282 ng_rmnode_self(node); /* remove all netgraph parts */
283 }
284
285 /*
286 * Optimization for gluing the address family onto
287 * the front of an incoming packet.
288 */
289 static int
290 ng_gif_glue_af(struct mbuf **mp, int af)
291 {
292 struct mbuf *m = *mp;
293 int error = 0;
294 sa_family_t tmp_af;
295
296 tmp_af = (sa_family_t) af;
297
298 /*
299 * XXX: should try to bring back some of the optimizations from
300 * ng_ether.c
301 */
302
303 /*
304 * Doing anything more is likely to get more
305 * expensive than it's worth..
306 * it's probable that everything else is in one
307 * big lump. The next node will do an m_pullup()
308 * for exactly the amount of data it needs and
309 * hopefully everything after that will not
310 * need one. So let's just use M_PREPEND.
311 */
312 M_PREPEND(m, sizeof (tmp_af), M_DONTWAIT);
313 if (m == NULL) {
314 error = ENOBUFS;
315 goto done;
316 }
317
318 #if 0
319 copy:
320 #endif
321 /* Copy header and return (possibly new) mbuf */
322 *mtod(m, sa_family_t *) = tmp_af;
323 #if 0
324 bcopy((caddr_t)&tmp_af, mtod(m, sa_family_t *), sizeof(tmp_af));
325 #endif
326 done:
327 *mp = m;
328 return error;
329 }
330
331 /******************************************************************
332 NETGRAPH NODE METHODS
333 ******************************************************************/
334
335 /*
336 * It is not possible or allowable to create a node of this type.
337 * Nodes get created when the interface is attached (or, when
338 * this node type's KLD is loaded).
339 */
340 static int
341 ng_gif_constructor(node_p node)
342 {
343 return (EINVAL);
344 }
345
346 /*
347 * Check for attaching a new hook.
348 */
349 static int
350 ng_gif_newhook(node_p node, hook_p hook, const char *name)
351 {
352 const priv_p priv = NG_NODE_PRIVATE(node);
353 u_char orphan = priv->lowerOrphan;
354 hook_p *hookptr;
355
356 /* Divert hook is an alias for lower */
357 if (strcmp(name, NG_GIF_HOOK_DIVERT) == 0)
358 name = NG_GIF_HOOK_LOWER;
359
360 /* Which hook? */
361 if (strcmp(name, NG_GIF_HOOK_LOWER) == 0) {
362 hookptr = &priv->lower;
363 orphan = 0;
364 } else if (strcmp(name, NG_GIF_HOOK_ORPHAN) == 0) {
365 hookptr = &priv->lower;
366 orphan = 1;
367 } else
368 return (EINVAL);
369
370 /* Check if already connected (shouldn't be, but doesn't hurt) */
371 if (*hookptr != NULL)
372 return (EISCONN);
373
374 /* OK */
375 *hookptr = hook;
376 priv->lowerOrphan = orphan;
377 return (0);
378 }
379
380 /*
381 * Hooks are attached, adjust to force queueing.
382 * We don't really care which hook it is.
383 * they should all be queuing for outgoing data.
384 */
385 static int
386 ng_gif_connect(hook_p hook)
387 {
388 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
389 return (0);
390 }
391
392 /*
393 * Receive an incoming control message.
394 */
395 static int
396 ng_gif_rcvmsg(node_p node, item_p item, hook_p lasthook)
397 {
398 const priv_p priv = NG_NODE_PRIVATE(node);
399 struct ng_mesg *resp = NULL;
400 int error = 0;
401 struct ng_mesg *msg;
402
403 NGI_GET_MSG(item, msg);
404 switch (msg->header.typecookie) {
405 case NGM_GIF_COOKIE:
406 switch (msg->header.cmd) {
407 case NGM_GIF_GET_IFNAME:
408 NG_MKRESPONSE(resp, msg, IFNAMSIZ + 1, M_NOWAIT);
409 if (resp == NULL) {
410 error = ENOMEM;
411 break;
412 }
413 snprintf(resp->data, IFNAMSIZ + 1,
414 "%s%d", priv->ifp->if_name, priv->ifp->if_unit);
415 break;
416 case NGM_GIF_GET_IFINDEX:
417 NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
418 if (resp == NULL) {
419 error = ENOMEM;
420 break;
421 }
422 *((u_int32_t *)resp->data) = priv->ifp->if_index;
423 break;
424 default:
425 error = EINVAL;
426 break;
427 }
428 break;
429 default:
430 error = EINVAL;
431 break;
432 }
433 NG_RESPOND_MSG(error, node, item, resp);
434 NG_FREE_MSG(msg);
435 return (error);
436 }
437
438 /*
439 * Receive data on a hook.
440 */
441 static int
442 ng_gif_rcvdata(hook_p hook, item_p item)
443 {
444 const node_p node = NG_HOOK_NODE(hook);
445 const priv_p priv = NG_NODE_PRIVATE(node);
446 struct mbuf *m;
447 meta_p meta;
448
449 NGI_GET_M(item, m);
450 NGI_GET_META(item, meta);
451 NG_FREE_ITEM(item);
452 if (hook == priv->lower)
453 return ng_gif_rcv_lower(node, m, meta);
454 panic("%s: weird hook", __func__);
455 }
456
457 /*
458 * Handle an mbuf received on the "lower" hook.
459 */
460 static int
461 ng_gif_rcv_lower(node_p node, struct mbuf *m, meta_p meta)
462 {
463 struct sockaddr dst;
464 const priv_p priv = NG_NODE_PRIVATE(node);
465
466 bzero(&dst, sizeof(dst));
467
468 /* We don't process metadata. */
469 NG_FREE_META(meta);
470
471 /* Make sure header is fully pulled up */
472 if (m->m_pkthdr.len < sizeof(sa_family_t)) {
473 NG_FREE_M(m);
474 return (EINVAL);
475 }
476 if (m->m_len < sizeof(sa_family_t)
477 && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
478 return (ENOBUFS);
479 }
480
481 dst.sa_family = *mtod(m, sa_family_t *);
482 m_adj(m, sizeof(sa_family_t));
483
484 /* Send it on its way */
485 /*
486 * XXX: gif_output only uses dst for the family and passes the
487 * fourth argument (rt) to in{,6}_gif_output which ignore it.
488 * If this changes ng_gif will probably break.
489 */
490 return gif_output(priv->ifp, m, &dst, NULL);
491 }
492
493 /*
494 * Shutdown node. This resets the node but does not remove it
495 * unless the REALLY_DIE flag is set.
496 */
497 static int
498 ng_gif_shutdown(node_p node)
499 {
500 const priv_p priv = NG_NODE_PRIVATE(node);
501
502 if (node->nd_flags & NG_REALLY_DIE) {
503 /*
504 * WE came here because the gif interface is being destroyed,
505 * so stop being persistant.
506 * Actually undo all the things we did on creation.
507 * Assume the ifp has already been freed.
508 */
509 NG_NODE_SET_PRIVATE(node, NULL);
510 FREE(priv, M_NETGRAPH);
511 NG_NODE_UNREF(node); /* free node itself */
512 return (0);
513 }
514 node->nd_flags &= ~NG_INVALID; /* Signal ng_rmnode we are persisant */
515 return (0);
516 }
517
518 /*
519 * Hook disconnection.
520 */
521 static int
522 ng_gif_disconnect(hook_p hook)
523 {
524 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
525
526 if (hook == priv->lower) {
527 priv->lower = NULL;
528 priv->lowerOrphan = 0;
529 } else
530 panic("%s: weird hook", __func__);
531 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
532 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
533 ng_rmnode_self(NG_HOOK_NODE(hook)); /* reset node */
534
535 return (0);
536 }
537
538 /******************************************************************
539 INITIALIZATION
540 ******************************************************************/
541
542 /*
543 * Handle loading and unloading for this node type.
544 */
545 static int
546 ng_gif_mod_event(module_t mod, int event, void *data)
547 {
548 struct ifnet *ifp;
549 int error = 0;
550 int s;
551
552 s = splnet();
553 switch (event) {
554 case MOD_LOAD:
555
556 /* Register function hooks */
557 if (ng_gif_attach_p != NULL) {
558 error = EEXIST;
559 break;
560 }
561 ng_gif_attach_p = ng_gif_attach;
562 ng_gif_detach_p = ng_gif_detach;
563 ng_gif_input_p = ng_gif_input;
564 ng_gif_input_orphan_p = ng_gif_input_orphan;
565
566 /* Create nodes for any already-existing gif interfaces */
567 IFNET_RLOCK();
568 TAILQ_FOREACH(ifp, &ifnet, if_link) {
569 if (ifp->if_type == IFT_GIF)
570 ng_gif_attach(ifp);
571 }
572 IFNET_RUNLOCK();
573 break;
574
575 case MOD_UNLOAD:
576
577 /*
578 * Note that the base code won't try to unload us until
579 * all nodes have been removed, and that can't happen
580 * until all gif interfaces are destroyed. In any
581 * case, we know there are no nodes left if the action
582 * is MOD_UNLOAD, so there's no need to detach any nodes.
583 *
584 * XXX: what about manual unloads?!?
585 */
586
587 /* Unregister function hooks */
588 ng_gif_attach_p = NULL;
589 ng_gif_detach_p = NULL;
590 ng_gif_input_p = NULL;
591 ng_gif_input_orphan_p = NULL;
592 break;
593
594 default:
595 error = EOPNOTSUPP;
596 break;
597 }
598 splx(s);
599 return (error);
600 }
601
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