xref: /freebsd/sys/netgraph/ng_device.c (revision 56b61ca2) 
1 /*-
2  * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
3  * Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  * Netgraph "device" node
26  *
27  * This node presents a /dev/ngd%d device that interfaces to an other
28  * netgraph node.
29  *
30  * $FreeBSD$
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/queue.h>
48 #include <sys/socket.h>
49 #include <sys/systm.h>
50 #include <sys/uio.h>
51 #include <sys/vnode.h>
52 
53 #include <net/if.h>
54 #include <net/if_var.h>
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 
59 #include <netgraph/ng_message.h>
60 #include <netgraph/netgraph.h>
61 #include <netgraph/ng_device.h>
62 
63 #define	ERROUT(x) do { error = (x); goto done; } while (0)
64 
65 /* Netgraph methods */
66 static int		ng_device_mod_event(module_t, int, void *);
67 static ng_constructor_t	ng_device_constructor;
68 static ng_rcvmsg_t	ng_device_rcvmsg;
69 static ng_shutdown_t	ng_device_shutdown;
70 static ng_newhook_t	ng_device_newhook;
71 static ng_rcvdata_t	ng_device_rcvdata;
72 static ng_disconnect_t	ng_device_disconnect;
73 
74 /* Netgraph type */
75 static struct ng_type ngd_typestruct = {
76 	.version =	NG_ABI_VERSION,
77 	.name =		NG_DEVICE_NODE_TYPE,
78 	.mod_event =	ng_device_mod_event,
79 	.constructor =	ng_device_constructor,
80 	.rcvmsg	=	ng_device_rcvmsg,
81 	.shutdown = 	ng_device_shutdown,
82 	.newhook =	ng_device_newhook,
83 	.rcvdata =	ng_device_rcvdata,
84 	.disconnect =	ng_device_disconnect,
85 };
86 NETGRAPH_INIT(device, &ngd_typestruct);
87 
88 /* per node data */
89 struct ngd_private {
90 	struct	ifqueue	readq;
91 	struct	ng_node	*node;
92 	struct	ng_hook	*hook;
93 	struct	cdev	*ngddev;
94 	struct	mtx	ngd_mtx;
95 	int 		unit;
96 	uint16_t	flags;
97 #define	NGDF_OPEN	0x0001
98 #define	NGDF_RWAIT	0x0002
99 };
100 typedef struct ngd_private *priv_p;
101 
102 /* unit number allocator entity */
103 static struct unrhdr *ngd_unit;
104 
105 /* Maximum number of NGD devices */
106 #define MAX_NGD	999
107 
108 static d_close_t ngdclose;
109 static d_open_t ngdopen;
110 static d_read_t ngdread;
111 static d_write_t ngdwrite;
112 #if 0
113 static d_ioctl_t ngdioctl;
114 #endif
115 static d_poll_t ngdpoll;
116 
117 static struct cdevsw ngd_cdevsw = {
118 	.d_version =	D_VERSION,
119 	.d_open =	ngdopen,
120 	.d_close =	ngdclose,
121 	.d_read =	ngdread,
122 	.d_write =	ngdwrite,
123 #if 0
124 	.d_ioctl =	ngdioctl,
125 #endif
126 	.d_poll =	ngdpoll,
127 	.d_name =	NG_DEVICE_DEVNAME,
128 };
129 
130 /******************************************************************************
131  *  Netgraph methods
132  ******************************************************************************/
133 
134 /*
135  * Handle loading and unloading for this node type.
136  */
137 static int
138 ng_device_mod_event(module_t mod, int event, void *data)
139 {
140 	int error = 0;
141 
142 	switch (event) {
143 	case MOD_LOAD:
144 		ngd_unit = new_unrhdr(0, MAX_NGD, NULL);
145 		break;
146 	case MOD_UNLOAD:
147 		delete_unrhdr(ngd_unit);
148 		break;
149 	default:
150 		error = EOPNOTSUPP;
151 		break;
152 	}
153 	return (error);
154 }
155 
156 /*
157  * create new node
158  */
159 static int
160 ng_device_constructor(node_p node)
161 {
162 	priv_p	priv;
163 
164 	DBG;
165 
166 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
167 
168 	/* Allocate unit number */
169 	priv->unit = alloc_unr(ngd_unit);
170 
171 	/* Initialize mutexes and queue */
172 	mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
173 	mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
174 	IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
175 
176 	/* Link everything together */
177 	NG_NODE_SET_PRIVATE(node, priv);
178 	priv->node = node;
179 
180 	priv->ngddev = make_dev(&ngd_cdevsw, priv->unit, UID_ROOT,
181 	    GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
182 	if(priv->ngddev == NULL) {
183 		printf("%s(): make_dev() failed\n",__func__);
184 		mtx_destroy(&priv->ngd_mtx);
185 		mtx_destroy(&priv->readq.ifq_mtx);
186 		free_unr(ngd_unit, priv->unit);
187 		free(priv, M_NETGRAPH);
188 		return(EINVAL);
189 	}
190 	/* XXX: race here? */
191 	priv->ngddev->si_drv1 = priv;
192 
193 	return(0);
194 }
195 
196 /*
197  * Process control message.
198  */
199 
200 static int
201 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
202 {
203 	const priv_p priv = NG_NODE_PRIVATE(node);
204 	struct ng_mesg *msg;
205 	struct ng_mesg *resp = NULL;
206 	const char *dn;
207 	int error = 0;
208 
209 	NGI_GET_MSG(item, msg);
210 
211 	if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
212 		switch (msg->header.cmd) {
213 		case NGM_DEVICE_GET_DEVNAME:
214 			/* XXX: Fix when MAX_NGD us bigger */
215 			NG_MKRESPONSE(resp, msg,
216 			    strlen(NG_DEVICE_DEVNAME) + 4, M_NOWAIT);
217 
218 			if (resp == NULL)
219 				ERROUT(ENOMEM);
220 
221 			dn = devtoname(priv->ngddev);
222 			strlcpy((char *)resp->data, dn, strlen(dn) + 1);
223 			break;
224 
225 		default:
226 			error = EINVAL;
227 			break;
228 		}
229 	} else
230 		error = EINVAL;
231 
232 done:
233 	NG_RESPOND_MSG(error, node, item, resp);
234 	NG_FREE_MSG(msg);
235 	return (error);
236 }
237 
238 /*
239  * Accept incoming hook. We support only one hook per node.
240  */
241 static int
242 ng_device_newhook(node_p node, hook_p hook, const char *name)
243 {
244 	priv_p priv = NG_NODE_PRIVATE(node);
245 
246 	DBG;
247 
248 	/* We have only one hook per node */
249 	if (priv->hook != NULL)
250 		return (EISCONN);
251 
252 	priv->hook = hook;
253 
254 	return(0);
255 }
256 
257 /*
258  * Receive data from hook, write it to device.
259  */
260 static int
261 ng_device_rcvdata(hook_p hook, item_p item)
262 {
263 	priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
264 	struct mbuf *m;
265 
266 	DBG;
267 
268 	NGI_GET_M(item, m);
269 	NG_FREE_ITEM(item);
270 
271 	IF_LOCK(&priv->readq);
272 	if (_IF_QFULL(&priv->readq)) {
273 		IF_UNLOCK(&priv->readq);
274 		NG_FREE_M(m);
275 		return (ENOBUFS);
276 	}
277 
278 	_IF_ENQUEUE(&priv->readq, m);
279 	IF_UNLOCK(&priv->readq);
280 	mtx_lock(&priv->ngd_mtx);
281 	if (priv->flags & NGDF_RWAIT) {
282 		priv->flags &= ~NGDF_RWAIT;
283 		wakeup(priv);
284 	}
285 	mtx_unlock(&priv->ngd_mtx);
286 
287 	return(0);
288 }
289 
290 /*
291  * Removal of the hook destroys the node.
292  */
293 static int
294 ng_device_disconnect(hook_p hook)
295 {
296 	priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
297 
298 	DBG;
299 
300 	destroy_dev(priv->ngddev);
301 	mtx_destroy(&priv->ngd_mtx);
302 
303 	IF_DRAIN(&priv->readq);
304 	mtx_destroy(&(priv)->readq.ifq_mtx);
305 
306 	free_unr(ngd_unit, priv->unit);
307 
308 	free(priv, M_NETGRAPH);
309 
310 	ng_rmnode_self(NG_HOOK_NODE(hook));
311 
312 	return(0);
313 }
314 
315 /*
316  * Node shutdown. Everything is already done in disconnect method.
317  */
318 static int
319 ng_device_shutdown(node_p node)
320 {
321 	NG_NODE_UNREF(node);
322 	return (0);
323 }
324 
325 /******************************************************************************
326  *  Device methods
327  ******************************************************************************/
328 
329 /*
330  * the device is opened
331  */
332 static int
333 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
334 {
335 	priv_p	priv = (priv_p )dev->si_drv1;
336 
337 	DBG;
338 
339 	mtx_lock(&priv->ngd_mtx);
340 	priv->flags |= NGDF_OPEN;
341 	mtx_unlock(&priv->ngd_mtx);
342 
343 	return(0);
344 }
345 
346 /*
347  * the device is closed
348  */
349 static int
350 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
351 {
352 	priv_p	priv = (priv_p )dev->si_drv1;
353 
354 	DBG;
355 	mtx_lock(&priv->ngd_mtx);
356 	priv->flags &= ~NGDF_OPEN;
357 	mtx_unlock(&priv->ngd_mtx);
358 
359 	return(0);
360 }
361 
362 #if 0	/*
363 	 * The ioctl is transformed into netgraph control message.
364 	 * We do not process them, yet.
365 	 */
366 /*
367  * process ioctl
368  *
369  * they are translated into netgraph messages and passed on
370  *
371  */
372 static int
373 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
374 {
375 	struct ngd_softc *sc = &ngd_softc;
376 	struct ngd_connection * connection = NULL;
377 	struct ngd_connection * tmp;
378 	int error = 0;
379 	struct ng_mesg *msg;
380 	struct ngd_param_s * datap;
381 
382 	DBG;
383 
384 	NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
385 			M_NOWAIT);
386 	if (msg == NULL) {
387 		printf("%s(): msg == NULL\n",__func__);
388 		goto nomsg;
389 	}
390 
391 	/* pass the ioctl data into the ->data area */
392 	datap = (struct ngd_param_s *)msg->data;
393 	datap->p = addr;
394 
395 	NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
396 	if(error)
397 		printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
398 
399 nomsg:
400 
401 	return(0);
402 }
403 #endif /* if 0 */
404 
405 /*
406  * This function is called when a read(2) is done to our device.
407  * We process one mbuf from queue.
408  */
409 static int
410 ngdread(struct cdev *dev, struct uio *uio, int flag)
411 {
412 	priv_p	priv = (priv_p )dev->si_drv1;
413 	struct mbuf *m;
414 	int len, error = 0;
415 
416 	DBG;
417 
418 	/* get an mbuf */
419 	do {
420 		IF_DEQUEUE(&priv->readq, m);
421 		if (m == NULL) {
422 			if (flag & IO_NDELAY)
423 				return (EWOULDBLOCK);
424 			mtx_lock(&priv->ngd_mtx);
425 			priv->flags |= NGDF_RWAIT;
426 			if ((error = msleep(priv, &priv->ngd_mtx,
427 			    PDROP | PCATCH | (PZERO + 1),
428 			    "ngdread", 0)) != 0)
429 				return (error);
430 		}
431 	} while (m == NULL);
432 
433 	while (m && uio->uio_resid > 0 && error == 0) {
434 		len = MIN(uio->uio_resid, m->m_len);
435 		if (len != 0)
436 			error = uiomove(mtod(m, void *), len, uio);
437 		m = m_free(m);
438 	}
439 
440 	if (m)
441 		m_freem(m);
442 
443 	return (error);
444 }
445 
446 
447 /*
448  * This function is called when our device is written to.
449  * We read the data from userland into mbuf chain and pass it to the remote hook.
450  *
451  */
452 static int
453 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
454 {
455 	priv_p	priv = (priv_p )dev->si_drv1;
456 	struct mbuf *m;
457 	int error = 0;
458 
459 	DBG;
460 
461 	if (uio->uio_resid == 0)
462 		return (0);
463 
464 	if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
465 		return (EIO);
466 
467 	if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL)
468 		return (ENOBUFS);
469 
470 	NG_SEND_DATA_ONLY(error, priv->hook, m);
471 
472 	return (error);
473 }
474 
475 /*
476  * we are being polled/selected
477  * check if there is data available for read
478  */
479 static int
480 ngdpoll(struct cdev *dev, int events, struct thread *td)
481 {
482 	priv_p	priv = (priv_p )dev->si_drv1;
483 	int revents = 0;
484 
485 	if (events & (POLLIN | POLLRDNORM) &&
486 	    !IFQ_IS_EMPTY(&priv->readq))
487 		revents |= events & (POLLIN | POLLRDNORM);
488 
489 	return (revents);
490 }
491