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