1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
5 * Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Netgraph "device" node
28 *
29 * This node presents a /dev/ngd%d device that interfaces to an other
30 * netgraph node.
31 *
32 */
33
34 #if 0
35 #define DBG do { printf("ng_device: %s\n", __func__); } while (0)
36 #else
37 #define DBG do {} while (0)
38 #endif
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/conf.h>
43 #include <sys/epoch.h>
44 #include <sys/fcntl.h>
45 #include <sys/filio.h>
46 #include <sys/ioccom.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/poll.h>
51 #include <sys/proc.h>
52 #include <sys/queue.h>
53 #include <sys/socket.h>
54 #include <sys/syslog.h>
55 #include <sys/uio.h>
56
57 #include <net/ethernet.h>
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63
64 #include <netgraph/ng_message.h>
65 #include <netgraph/netgraph.h>
66 #include <netgraph/ng_device.h>
67 #include <netgraph/ng_parse.h>
68
69 #define ERROUT(x) do { error = (x); goto done; } while (0)
70
71 /* Netgraph methods */
72 static int ng_device_mod_event(module_t, int, void *);
73 static ng_constructor_t ng_device_constructor;
74 static ng_rcvmsg_t ng_device_rcvmsg;
75 static ng_shutdown_t ng_device_shutdown;
76 static ng_newhook_t ng_device_newhook;
77 static ng_rcvdata_t ng_device_rcvdata;
78 static ng_disconnect_t ng_device_disconnect;
79
80 /* List of commands and how to convert arguments to/from ASCII. */
81 static const struct ng_cmdlist ng_device_cmds[] = {
82 {
83 NGM_DEVICE_COOKIE,
84 NGM_DEVICE_GET_DEVNAME,
85 "getdevname",
86 NULL,
87 &ng_parse_string_type
88 },
89 {
90 NGM_DEVICE_COOKIE,
91 NGM_DEVICE_ETHERALIGN,
92 "etheralign",
93 NULL,
94 NULL
95 },
96 { 0 }
97 };
98
99 /* Netgraph type */
100 static struct ng_type ngd_typestruct = {
101 .version = NG_ABI_VERSION,
102 .name = NG_DEVICE_NODE_TYPE,
103 .mod_event = ng_device_mod_event,
104 .constructor = ng_device_constructor,
105 .rcvmsg = ng_device_rcvmsg,
106 .shutdown = ng_device_shutdown,
107 .newhook = ng_device_newhook,
108 .rcvdata = ng_device_rcvdata,
109 .disconnect = ng_device_disconnect,
110 .cmdlist = ng_device_cmds,
111 };
112 NETGRAPH_INIT(device, &ngd_typestruct);
113
114 /* per node data */
115 struct ngd_private {
116 struct ifqueue readq;
117 struct ng_node *node;
118 struct ng_hook *hook;
119 struct cdev *ngddev;
120 struct mtx ngd_mtx;
121 int unit;
122 int ether_align;
123 uint16_t flags;
124 #define NGDF_OPEN 0x0001
125 #define NGDF_RWAIT 0x0002
126 };
127 typedef struct ngd_private *priv_p;
128
129 /* unit number allocator entity */
130 static struct unrhdr *ngd_unit;
131
132 /* Maximum number of NGD devices */
133 #define MAX_NGD 999
134
135 static d_close_t ngdclose;
136 static d_open_t ngdopen;
137 static d_read_t ngdread;
138 static d_write_t ngdwrite;
139 static d_ioctl_t ngdioctl;
140 static d_poll_t ngdpoll;
141
142 static struct cdevsw ngd_cdevsw = {
143 .d_version = D_VERSION,
144 .d_open = ngdopen,
145 .d_close = ngdclose,
146 .d_read = ngdread,
147 .d_write = ngdwrite,
148 .d_ioctl = ngdioctl,
149 .d_poll = ngdpoll,
150 .d_name = NG_DEVICE_DEVNAME,
151 };
152
153 /*
154 *****************************************************************************
155 * Netgraph methods
156 *****************************************************************************
157 */
158
159 /*
160 * Handle loading and unloading for this node type.
161 */
162 static int
ng_device_mod_event(module_t mod,int event,void * data)163 ng_device_mod_event(module_t mod, int event, void *data)
164 {
165 int error = 0;
166
167 switch (event) {
168 case MOD_LOAD:
169 ngd_unit = new_unrhdr(0, MAX_NGD, NULL);
170 break;
171 case MOD_UNLOAD:
172 delete_unrhdr(ngd_unit);
173 break;
174 default:
175 error = EOPNOTSUPP;
176 break;
177 }
178 return (error);
179 }
180
181 /*
182 * create new node
183 */
184 static int
ng_device_constructor(node_p node)185 ng_device_constructor(node_p node)
186 {
187 priv_p priv;
188
189 DBG;
190
191 priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
192
193 /* Allocate unit number */
194 priv->unit = alloc_unr(ngd_unit);
195
196 /* Initialize mutexes and queue */
197 mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
198 mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
199 IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
200
201 /* Link everything together */
202 NG_NODE_SET_PRIVATE(node, priv);
203 priv->node = node;
204
205 priv->ngddev = make_dev(&ngd_cdevsw, priv->unit, UID_ROOT,
206 GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
207 if (priv->ngddev == NULL) {
208 printf("%s(): make_dev() failed\n", __func__);
209 mtx_destroy(&priv->ngd_mtx);
210 mtx_destroy(&priv->readq.ifq_mtx);
211 free_unr(ngd_unit, priv->unit);
212 free(priv, M_NETGRAPH);
213 return (EINVAL);
214 }
215 /* XXX: race here? */
216 priv->ngddev->si_drv1 = priv;
217
218 /* Give this node the same name as the device (if possible). */
219 if (ng_name_node(node, devtoname(priv->ngddev)) != 0)
220 log(LOG_WARNING, "%s: can't acquire netgraph name\n",
221 devtoname(priv->ngddev));
222
223 return (0);
224 }
225
226 /*
227 * Process control message.
228 */
229
230 static int
ng_device_rcvmsg(node_p node,item_p item,hook_p lasthook)231 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
232 {
233 const priv_p priv = NG_NODE_PRIVATE(node);
234 struct ng_mesg *msg;
235 struct ng_mesg *resp = NULL;
236 const char *dn;
237 int error = 0;
238
239 NGI_GET_MSG(item, msg);
240
241 if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
242 switch (msg->header.cmd) {
243 case NGM_DEVICE_GET_DEVNAME:
244 /* XXX: Fix when MAX_NGD us bigger */
245 NG_MKRESPONSE(resp, msg,
246 strlen(NG_DEVICE_DEVNAME) + 4, M_NOWAIT);
247
248 if (resp == NULL)
249 ERROUT(ENOMEM);
250
251 dn = devtoname(priv->ngddev);
252 strlcpy((char *)resp->data, dn, strlen(dn) + 1);
253 break;
254
255 case NGM_DEVICE_ETHERALIGN:
256 /* Use ETHER_ALIGN on arches that require it. */
257 #ifndef __NO_STRICT_ALIGNMENT
258 priv->ether_align = ETHER_ALIGN;
259 #endif
260 break;
261
262 default:
263 error = EINVAL;
264 break;
265 }
266 } else
267 error = EINVAL;
268
269 done:
270 NG_RESPOND_MSG(error, node, item, resp);
271 NG_FREE_MSG(msg);
272 return (error);
273 }
274
275 /*
276 * Accept incoming hook. We support only one hook per node.
277 */
278 static int
ng_device_newhook(node_p node,hook_p hook,const char * name)279 ng_device_newhook(node_p node, hook_p hook, const char *name)
280 {
281 priv_p priv = NG_NODE_PRIVATE(node);
282
283 DBG;
284
285 /* We have only one hook per node */
286 if (priv->hook != NULL)
287 return (EISCONN);
288
289 priv->hook = hook;
290
291 return (0);
292 }
293
294 /*
295 * Receive data from hook, write it to device.
296 */
297 static int
ng_device_rcvdata(hook_p hook,item_p item)298 ng_device_rcvdata(hook_p hook, item_p item)
299 {
300 priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
301 struct mbuf *m;
302
303 DBG;
304
305 NGI_GET_M(item, m);
306 NG_FREE_ITEM(item);
307
308 IF_LOCK(&priv->readq);
309 if (_IF_QFULL(&priv->readq)) {
310 IF_UNLOCK(&priv->readq);
311 NG_FREE_M(m);
312 return (ENOBUFS);
313 }
314
315 _IF_ENQUEUE(&priv->readq, m);
316 IF_UNLOCK(&priv->readq);
317 mtx_lock(&priv->ngd_mtx);
318 if (priv->flags & NGDF_RWAIT) {
319 priv->flags &= ~NGDF_RWAIT;
320 wakeup(priv);
321 }
322 mtx_unlock(&priv->ngd_mtx);
323
324 return (0);
325 }
326
327 /*
328 * Removal of the hook destroys the node.
329 */
330 static int
ng_device_disconnect(hook_p hook)331 ng_device_disconnect(hook_p hook)
332 {
333 priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
334
335 DBG;
336
337 destroy_dev(priv->ngddev);
338 mtx_destroy(&priv->ngd_mtx);
339
340 IF_DRAIN(&priv->readq);
341 mtx_destroy(&(priv)->readq.ifq_mtx);
342
343 free_unr(ngd_unit, priv->unit);
344
345 free(priv, M_NETGRAPH);
346
347 ng_rmnode_self(NG_HOOK_NODE(hook));
348
349 return (0);
350 }
351
352 /*
353 * Node shutdown. Everything is already done in disconnect method.
354 */
355 static int
ng_device_shutdown(node_p node)356 ng_device_shutdown(node_p node)
357 {
358 NG_NODE_UNREF(node);
359 return (0);
360 }
361
362 /*
363 *****************************************************************************
364 * Device methods
365 *****************************************************************************
366 */
367
368 /*
369 * the device is opened
370 */
371 static int
ngdopen(struct cdev * dev,int flag,int mode,struct thread * td)372 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
373 {
374 priv_p priv = (priv_p)dev->si_drv1;
375
376 DBG;
377
378 mtx_lock(&priv->ngd_mtx);
379 priv->flags |= NGDF_OPEN;
380 mtx_unlock(&priv->ngd_mtx);
381
382 return (0);
383 }
384
385 /*
386 * the device is closed
387 */
388 static int
ngdclose(struct cdev * dev,int flag,int mode,struct thread * td)389 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
390 {
391 priv_p priv = (priv_p)dev->si_drv1;
392
393 DBG;
394 mtx_lock(&priv->ngd_mtx);
395 priv->flags &= ~NGDF_OPEN;
396 mtx_unlock(&priv->ngd_mtx);
397
398 return (0);
399 }
400
401 /*
402 * Process IOCTLs
403 *
404 * At this stage we only return success on FIONBIO to allow setting the device
405 * as non-blocking.
406 *
407 */
408 static int
ngdioctl(struct cdev * dev,u_long cmd,caddr_t data,int flag,struct thread * td)409 ngdioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag,
410 struct thread *td)
411 {
412 int error;
413
414 switch (cmd) {
415 case FIONBIO:
416 error = 0;
417 break;
418 case FIOASYNC:
419 if (*(int *)data != 0)
420 error = EINVAL;
421 else
422 error = 0;
423 break;
424 default:
425 error = ENOTTY;
426 }
427
428 return (error);
429 }
430
431 #if 0 /*
432 * The ioctl is transformed into netgraph control message.
433 * We do not process them, yet.
434 */
435 /*
436 * process ioctl
437 *
438 * they are translated into netgraph messages and passed on
439 *
440 */
441 static int
442 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag,
443 struct thread *td)
444 {
445 struct ngd_softc *sc = &ngd_softc;
446 struct ngd_connection *connection = NULL;
447 struct ngd_connection *tmp;
448 int error = 0;
449 struct ng_mesg *msg;
450 struct ngd_param_s *datap;
451
452 DBG;
453
454 NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
455 M_NOWAIT);
456 if (msg == NULL) {
457 printf("%s(): msg == NULL\n", __func__);
458 goto nomsg;
459 }
460
461 /* pass the ioctl data into the ->data area */
462 datap = (struct ngd_param_s *)msg->data;
463 datap->p = addr;
464
465 NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
466 if (error)
467 printf("%s(): NG_SEND_MSG_HOOK error: %d\n", __func__, error);
468
469 nomsg:
470
471 return (0);
472 }
473 #endif /* if 0 */
474
475 /*
476 * This function is called when a read(2) is done to our device.
477 * We process one mbuf from queue.
478 */
479 static int
ngdread(struct cdev * dev,struct uio * uio,int flag)480 ngdread(struct cdev *dev, struct uio *uio, int flag)
481 {
482 priv_p priv = (priv_p)dev->si_drv1;
483 struct mbuf *m;
484 int len, error = 0;
485
486 DBG;
487
488 /* get an mbuf */
489 do {
490 IF_DEQUEUE(&priv->readq, m);
491 if (m == NULL) {
492 if (flag & O_NONBLOCK)
493 return (EWOULDBLOCK);
494 mtx_lock(&priv->ngd_mtx);
495 priv->flags |= NGDF_RWAIT;
496 if ((error = msleep(priv, &priv->ngd_mtx,
497 PDROP | PCATCH | PZERO,
498 "ngdread", 0)) != 0)
499 return (error);
500 }
501 } while (m == NULL);
502
503 while (m && uio->uio_resid > 0 && error == 0) {
504 len = MIN(uio->uio_resid, m->m_len);
505 if (len != 0)
506 error = uiomove(mtod(m, void *), len, uio);
507 m = m_free(m);
508 }
509
510 if (m)
511 m_freem(m);
512
513 return (error);
514 }
515
516 /*
517 * This function is called when our device is written to.
518 * We read the data from userland into mbuf chain and pass it to the remote
519 * hook.
520 */
521 static int
ngdwrite(struct cdev * dev,struct uio * uio,int flag)522 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
523 {
524 struct epoch_tracker et;
525 priv_p priv = (priv_p)dev->si_drv1;
526 struct mbuf *m;
527 int error = 0;
528
529 DBG;
530
531 if (uio->uio_resid == 0)
532 return (0);
533
534 if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
535 return (EIO);
536
537 m = m_uiotombuf(uio, M_NOWAIT, 0, priv->ether_align, M_PKTHDR);
538 if (m == NULL)
539 return (ENOBUFS);
540
541 NET_EPOCH_ENTER(et);
542 NG_SEND_DATA_ONLY(error, priv->hook, m);
543 NET_EPOCH_EXIT(et);
544
545 return (error);
546 }
547
548 /*
549 * we are being polled/selected
550 * check if there is data available for read
551 */
552 static int
ngdpoll(struct cdev * dev,int events,struct thread * td)553 ngdpoll(struct cdev *dev, int events, struct thread *td)
554 {
555 priv_p priv = (priv_p)dev->si_drv1;
556 int revents = 0;
557
558 if (events & (POLLIN | POLLRDNORM) &&
559 !IFQ_IS_EMPTY(&priv->readq))
560 revents |= events & (POLLIN | POLLRDNORM);
561
562 return (revents);
563 }
564