1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002 Mark Santcroos <[email protected]>
5 * Copyright (c) 2004-2005 Gleb Smirnoff <[email protected]>
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 * $FreeBSD$
33 *
34 */
35
36 #if 0
37 #define DBG do { printf("ng_device: %s\n", __func__ ); } while (0)
38 #else
39 #define DBG do {} while (0)
40 #endif
41
42 #include <sys/param.h>
43 #include <sys/conf.h>
44 #include <sys/ioccom.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/poll.h>
49 #include <sys/proc.h>
50 #include <sys/epoch.h>
51 #include <sys/queue.h>
52 #include <sys/socket.h>
53 #include <sys/systm.h>
54 #include <sys/uio.h>
55 #include <sys/vnode.h>
56
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
67 #define ERROUT(x) do { error = (x); goto done; } while (0)
68
69 /* Netgraph methods */
70 static int ng_device_mod_event(module_t, int, void *);
71 static ng_constructor_t ng_device_constructor;
72 static ng_rcvmsg_t ng_device_rcvmsg;
73 static ng_shutdown_t ng_device_shutdown;
74 static ng_newhook_t ng_device_newhook;
75 static ng_rcvdata_t ng_device_rcvdata;
76 static ng_disconnect_t ng_device_disconnect;
77
78 /* Netgraph type */
79 static struct ng_type ngd_typestruct = {
80 .version = NG_ABI_VERSION,
81 .name = NG_DEVICE_NODE_TYPE,
82 .mod_event = ng_device_mod_event,
83 .constructor = ng_device_constructor,
84 .rcvmsg = ng_device_rcvmsg,
85 .shutdown = ng_device_shutdown,
86 .newhook = ng_device_newhook,
87 .rcvdata = ng_device_rcvdata,
88 .disconnect = ng_device_disconnect,
89 };
90 NETGRAPH_INIT(device, &ngd_typestruct);
91
92 /* per node data */
93 struct ngd_private {
94 struct ifqueue readq;
95 struct ng_node *node;
96 struct ng_hook *hook;
97 struct cdev *ngddev;
98 struct mtx ngd_mtx;
99 int unit;
100 uint16_t flags;
101 #define NGDF_OPEN 0x0001
102 #define NGDF_RWAIT 0x0002
103 };
104 typedef struct ngd_private *priv_p;
105
106 /* unit number allocator entity */
107 static struct unrhdr *ngd_unit;
108
109 /* Maximum number of NGD devices */
110 #define MAX_NGD 999
111
112 static d_close_t ngdclose;
113 static d_open_t ngdopen;
114 static d_read_t ngdread;
115 static d_write_t ngdwrite;
116 #if 0
117 static d_ioctl_t ngdioctl;
118 #endif
119 static d_poll_t ngdpoll;
120
121 static struct cdevsw ngd_cdevsw = {
122 .d_version = D_VERSION,
123 .d_open = ngdopen,
124 .d_close = ngdclose,
125 .d_read = ngdread,
126 .d_write = ngdwrite,
127 #if 0
128 .d_ioctl = ngdioctl,
129 #endif
130 .d_poll = ngdpoll,
131 .d_name = NG_DEVICE_DEVNAME,
132 };
133
134 /******************************************************************************
135 * Netgraph methods
136 ******************************************************************************/
137
138 /*
139 * Handle loading and unloading for this node type.
140 */
141 static int
ng_device_mod_event(module_t mod,int event,void * data)142 ng_device_mod_event(module_t mod, int event, void *data)
143 {
144 int error = 0;
145
146 switch (event) {
147 case MOD_LOAD:
148 ngd_unit = new_unrhdr(0, MAX_NGD, NULL);
149 break;
150 case MOD_UNLOAD:
151 delete_unrhdr(ngd_unit);
152 break;
153 default:
154 error = EOPNOTSUPP;
155 break;
156 }
157 return (error);
158 }
159
160 /*
161 * create new node
162 */
163 static int
ng_device_constructor(node_p node)164 ng_device_constructor(node_p node)
165 {
166 priv_p priv;
167
168 DBG;
169
170 priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
171
172 /* Allocate unit number */
173 priv->unit = alloc_unr(ngd_unit);
174
175 /* Initialize mutexes and queue */
176 mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
177 mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
178 IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
179
180 /* Link everything together */
181 NG_NODE_SET_PRIVATE(node, priv);
182 priv->node = node;
183
184 priv->ngddev = make_dev(&ngd_cdevsw, priv->unit, UID_ROOT,
185 GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
186 if(priv->ngddev == NULL) {
187 printf("%s(): make_dev() failed\n",__func__);
188 mtx_destroy(&priv->ngd_mtx);
189 mtx_destroy(&priv->readq.ifq_mtx);
190 free_unr(ngd_unit, priv->unit);
191 free(priv, M_NETGRAPH);
192 return(EINVAL);
193 }
194 /* XXX: race here? */
195 priv->ngddev->si_drv1 = priv;
196
197 return(0);
198 }
199
200 /*
201 * Process control message.
202 */
203
204 static int
ng_device_rcvmsg(node_p node,item_p item,hook_p lasthook)205 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
206 {
207 const priv_p priv = NG_NODE_PRIVATE(node);
208 struct ng_mesg *msg;
209 struct ng_mesg *resp = NULL;
210 const char *dn;
211 int error = 0;
212
213 NGI_GET_MSG(item, msg);
214
215 if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
216 switch (msg->header.cmd) {
217 case NGM_DEVICE_GET_DEVNAME:
218 /* XXX: Fix when MAX_NGD us bigger */
219 NG_MKRESPONSE(resp, msg,
220 strlen(NG_DEVICE_DEVNAME) + 4, M_NOWAIT);
221
222 if (resp == NULL)
223 ERROUT(ENOMEM);
224
225 dn = devtoname(priv->ngddev);
226 strlcpy((char *)resp->data, dn, strlen(dn) + 1);
227 break;
228
229 default:
230 error = EINVAL;
231 break;
232 }
233 } else
234 error = EINVAL;
235
236 done:
237 NG_RESPOND_MSG(error, node, item, resp);
238 NG_FREE_MSG(msg);
239 return (error);
240 }
241
242 /*
243 * Accept incoming hook. We support only one hook per node.
244 */
245 static int
ng_device_newhook(node_p node,hook_p hook,const char * name)246 ng_device_newhook(node_p node, hook_p hook, const char *name)
247 {
248 priv_p priv = NG_NODE_PRIVATE(node);
249
250 DBG;
251
252 /* We have only one hook per node */
253 if (priv->hook != NULL)
254 return (EISCONN);
255
256 priv->hook = hook;
257
258 return(0);
259 }
260
261 /*
262 * Receive data from hook, write it to device.
263 */
264 static int
ng_device_rcvdata(hook_p hook,item_p item)265 ng_device_rcvdata(hook_p hook, item_p item)
266 {
267 priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
268 struct mbuf *m;
269
270 DBG;
271
272 NGI_GET_M(item, m);
273 NG_FREE_ITEM(item);
274
275 IF_LOCK(&priv->readq);
276 if (_IF_QFULL(&priv->readq)) {
277 IF_UNLOCK(&priv->readq);
278 NG_FREE_M(m);
279 return (ENOBUFS);
280 }
281
282 _IF_ENQUEUE(&priv->readq, m);
283 IF_UNLOCK(&priv->readq);
284 mtx_lock(&priv->ngd_mtx);
285 if (priv->flags & NGDF_RWAIT) {
286 priv->flags &= ~NGDF_RWAIT;
287 wakeup(priv);
288 }
289 mtx_unlock(&priv->ngd_mtx);
290
291 return(0);
292 }
293
294 /*
295 * Removal of the hook destroys the node.
296 */
297 static int
ng_device_disconnect(hook_p hook)298 ng_device_disconnect(hook_p hook)
299 {
300 priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
301
302 DBG;
303
304 destroy_dev(priv->ngddev);
305 mtx_destroy(&priv->ngd_mtx);
306
307 IF_DRAIN(&priv->readq);
308 mtx_destroy(&(priv)->readq.ifq_mtx);
309
310 free_unr(ngd_unit, priv->unit);
311
312 free(priv, M_NETGRAPH);
313
314 ng_rmnode_self(NG_HOOK_NODE(hook));
315
316 return(0);
317 }
318
319 /*
320 * Node shutdown. Everything is already done in disconnect method.
321 */
322 static int
ng_device_shutdown(node_p node)323 ng_device_shutdown(node_p node)
324 {
325 NG_NODE_UNREF(node);
326 return (0);
327 }
328
329 /******************************************************************************
330 * Device methods
331 ******************************************************************************/
332
333 /*
334 * the device is opened
335 */
336 static int
ngdopen(struct cdev * dev,int flag,int mode,struct thread * td)337 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
338 {
339 priv_p priv = (priv_p )dev->si_drv1;
340
341 DBG;
342
343 mtx_lock(&priv->ngd_mtx);
344 priv->flags |= NGDF_OPEN;
345 mtx_unlock(&priv->ngd_mtx);
346
347 return(0);
348 }
349
350 /*
351 * the device is closed
352 */
353 static int
ngdclose(struct cdev * dev,int flag,int mode,struct thread * td)354 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
355 {
356 priv_p priv = (priv_p )dev->si_drv1;
357
358 DBG;
359 mtx_lock(&priv->ngd_mtx);
360 priv->flags &= ~NGDF_OPEN;
361 mtx_unlock(&priv->ngd_mtx);
362
363 return(0);
364 }
365
366 #if 0 /*
367 * The ioctl is transformed into netgraph control message.
368 * We do not process them, yet.
369 */
370 /*
371 * process ioctl
372 *
373 * they are translated into netgraph messages and passed on
374 *
375 */
376 static int
377 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
378 {
379 struct ngd_softc *sc = &ngd_softc;
380 struct ngd_connection * connection = NULL;
381 struct ngd_connection * tmp;
382 int error = 0;
383 struct ng_mesg *msg;
384 struct ngd_param_s * datap;
385
386 DBG;
387
388 NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
389 M_NOWAIT);
390 if (msg == NULL) {
391 printf("%s(): msg == NULL\n",__func__);
392 goto nomsg;
393 }
394
395 /* pass the ioctl data into the ->data area */
396 datap = (struct ngd_param_s *)msg->data;
397 datap->p = addr;
398
399 NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
400 if(error)
401 printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
402
403 nomsg:
404
405 return(0);
406 }
407 #endif /* if 0 */
408
409 /*
410 * This function is called when a read(2) is done to our device.
411 * We process one mbuf from queue.
412 */
413 static int
ngdread(struct cdev * dev,struct uio * uio,int flag)414 ngdread(struct cdev *dev, struct uio *uio, int flag)
415 {
416 priv_p priv = (priv_p )dev->si_drv1;
417 struct mbuf *m;
418 int len, error = 0;
419
420 DBG;
421
422 /* get an mbuf */
423 do {
424 IF_DEQUEUE(&priv->readq, m);
425 if (m == NULL) {
426 if (flag & IO_NDELAY)
427 return (EWOULDBLOCK);
428 mtx_lock(&priv->ngd_mtx);
429 priv->flags |= NGDF_RWAIT;
430 if ((error = msleep(priv, &priv->ngd_mtx,
431 PDROP | PCATCH | (PZERO + 1),
432 "ngdread", 0)) != 0)
433 return (error);
434 }
435 } while (m == NULL);
436
437 while (m && uio->uio_resid > 0 && error == 0) {
438 len = MIN(uio->uio_resid, m->m_len);
439 if (len != 0)
440 error = uiomove(mtod(m, void *), len, uio);
441 m = m_free(m);
442 }
443
444 if (m)
445 m_freem(m);
446
447 return (error);
448 }
449
450 /*
451 * This function is called when our device is written to.
452 * We read the data from userland into mbuf chain and pass it to the remote hook.
453 *
454 */
455 static int
ngdwrite(struct cdev * dev,struct uio * uio,int flag)456 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
457 {
458 struct epoch_tracker et;
459 priv_p priv = (priv_p )dev->si_drv1;
460 struct mbuf *m;
461 int error = 0;
462
463 DBG;
464
465 if (uio->uio_resid == 0)
466 return (0);
467
468 if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
469 return (EIO);
470
471 if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL)
472 return (ENOBUFS);
473
474 NET_EPOCH_ENTER(et);
475 NG_SEND_DATA_ONLY(error, priv->hook, m);
476 NET_EPOCH_EXIT(et);
477
478 return (error);
479 }
480
481 /*
482 * we are being polled/selected
483 * check if there is data available for read
484 */
485 static int
ngdpoll(struct cdev * dev,int events,struct thread * td)486 ngdpoll(struct cdev *dev, int events, struct thread *td)
487 {
488 priv_p priv = (priv_p )dev->si_drv1;
489 int revents = 0;
490
491 if (events & (POLLIN | POLLRDNORM) &&
492 !IFQ_IS_EMPTY(&priv->readq))
493 revents |= events & (POLLIN | POLLRDNORM);
494
495 return (revents);
496 }
497