xref: /dragonfly/sys/netgraph7/ng_device.c (revision ab709bfb) 
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: src/sys/netgraph/ng_device.c,v 1.22 2006/11/02 17:37:21 andre Exp $
31  * $DragonFly: src/sys/netgraph7/ng_device.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
32  *
33  */
34 
35 #if 0
36 #define	DBG do { printf("ng_device: %s\n", __func__ ); } while (0)
37 #else
38 #define	DBG do {} while (0)
39 #endif
40 
41 #include <sys/param.h>
42 #include <sys/conf.h>
43 #include <sys/ioccom.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/poll.h>
48 #include <sys/queue.h>
49 #include <sys/socket.h>
50 #include <sys/systm.h>
51 #include <sys/uio.h>
52 #include <sys/vnode.h>
53 
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/ip.h>
59 
60 #include "ng_message.h"
61 #include "netgraph.h"
62 #include "ng_device.h"
63 
64 #define	ERROUT(x) do { error = (x); goto done; } while (0)
65 
66 /* Netgraph methods */
67 static int		ng_device_mod_event(module_t, int, void *);
68 static ng_constructor_t	ng_device_constructor;
69 static ng_rcvmsg_t	ng_device_rcvmsg;
70 static ng_shutdown_t	ng_device_shutdown;
71 static ng_newhook_t	ng_device_newhook;
72 static ng_rcvdata_t	ng_device_rcvdata;
73 static ng_disconnect_t	ng_device_disconnect;
74 
75 /* Netgraph type */
76 static struct ng_type ngd_typestruct = {
77 	.version =	NG_ABI_VERSION,
78 	.name =		NG_DEVICE_NODE_TYPE,
79 	.mod_event =	ng_device_mod_event,
80 	.constructor =	ng_device_constructor,
81 	.rcvmsg	=	ng_device_rcvmsg,
82 	.shutdown = 	ng_device_shutdown,
83 	.newhook =	ng_device_newhook,
84 	.rcvdata =	ng_device_rcvdata,
85 	.disconnect =	ng_device_disconnect,
86 };
87 NETGRAPH_INIT(device, &ngd_typestruct);
88 
89 /* per node data */
90 struct ngd_private {
91 	struct	ifqueue	readq;
92 	struct	ng_node	*node;
93 	struct	ng_hook	*hook;
94 	struct	cdev	*ngddev;
95 	struct	mtx	ngd_mtx;
96 	int 		unit;
97 	uint16_t	flags;
98 #define	NGDF_OPEN	0x0001
99 #define	NGDF_RWAIT	0x0002
100 };
101 typedef struct ngd_private *priv_p;
102 
103 /* unit number allocator entity */
104 static struct unrhdr *ngd_unit;
105 
106 /* Maximum number of NGD devices */
107 #define MAX_NGD	999
108 
109 static d_close_t ngdclose;
110 static d_open_t ngdopen;
111 static d_read_t ngdread;
112 static d_write_t ngdwrite;
113 #if 0
114 static d_ioctl_t ngdioctl;
115 #endif
116 static d_poll_t ngdpoll;
117 
118 static struct cdevsw ngd_cdevsw = {
119 	.d_version =	D_VERSION,
120 	.d_open =	ngdopen,
121 	.d_close =	ngdclose,
122 	.d_read =	ngdread,
123 	.d_write =	ngdwrite,
124 #if 0
125 	.d_ioctl =	ngdioctl,
126 #endif
127 	.d_poll =	ngdpoll,
128 	.d_name =	NG_DEVICE_DEVNAME,
129 };
130 
131 /******************************************************************************
132  *  Netgraph methods
133  ******************************************************************************/
134 
135 /*
136  * Handle loading and unloading for this node type.
137  */
138 static int
139 ng_device_mod_event(module_t mod, int event, void *data)
140 {
141 	int error = 0;
142 
143 	switch (event) {
144 	case MOD_LOAD:
145 		ngd_unit = new_unrhdr(0, MAX_NGD, NULL);
146 		break;
147 	case MOD_UNLOAD:
148 		delete_unrhdr(ngd_unit);
149 		break;
150 	default:
151 		error = EOPNOTSUPP;
152 		break;
153 	}
154 	return (error);
155 }
156 
157 /*
158  * create new node
159  */
160 static int
161 ng_device_constructor(node_p node)
162 {
163 	priv_p	priv;
164 
165 	DBG;
166 
167 	MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
168 	if (priv == NULL)
169 		return (ENOMEM);
170 
171 	/* Allocate unit number */
172 	priv->unit = alloc_unr(ngd_unit);
173 
174 	/* Initialize mutexes and queue */
175 	mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
176 	mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
177 	IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
178 
179 	/* Link everything together */
180 	NG_NODE_SET_PRIVATE(node, priv);
181 	priv->node = node;
182 
183 	priv->ngddev = make_dev(&ngd_cdevsw, unit2minor(priv->unit), UID_ROOT,
184 	    GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
185 	if(priv->ngddev == NULL) {
186 		printf("%s(): make_dev() failed\n",__func__);
187 		mtx_destroy(&priv->ngd_mtx);
188 		mtx_destroy(&priv->readq.ifq_mtx);
189 		free_unr(ngd_unit, priv->unit);
190 		FREE(priv, M_NETGRAPH);
191 		return(EINVAL);
192 	}
193 	/* XXX: race here? */
194 	priv->ngddev->si_drv1 = priv;
195 
196 	return(0);
197 }
198 
199 /*
200  * Process control message.
201  */
202 
203 static int
204 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
205 {
206 	const priv_p priv = NG_NODE_PRIVATE(node);
207 	struct ng_mesg *msg;
208 	struct ng_mesg *resp = NULL;
209 	int error = 0;
210 
211 	NGI_GET_MSG(item, msg);
212 
213 	if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
214 		switch (msg->header.cmd) {
215 		case NGM_DEVICE_GET_DEVNAME:
216 			/* XXX: Fix when MAX_NGD us bigger */
217 			NG_MKRESPONSE(resp, msg,
218 			    strlen(NG_DEVICE_DEVNAME) + 4, M_WAITOK);
219 
220 			if (resp == NULL)
221 				ERROUT(ENOMEM);
222 
223 			strlcpy((char *)resp->data, priv->ngddev->si_name,
224 			    strlen(priv->ngddev->si_name) + 1);
225 			break;
226 
227 		default:
228 			error = EINVAL;
229 			break;
230 		}
231 	} else
232 		error = EINVAL;
233 
234 done:
235 	NG_RESPOND_MSG(error, node, item, resp);
236 	NG_FREE_MSG(msg);
237 	return (error);
238 }
239 
240 /*
241  * Accept incoming hook. We support only one hook per node.
242  */
243 static int
244 ng_device_newhook(node_p node, hook_p hook, const char *name)
245 {
246 	priv_p priv = NG_NODE_PRIVATE(node);
247 
248 	DBG;
249 
250 	/* We have only one hook per node */
251 	if (priv->hook != NULL)
252 		return (EISCONN);
253 
254 	priv->hook = hook;
255 
256 	return(0);
257 }
258 
259 /*
260  * Receive data from hook, write it to device.
261  */
262 static int
263 ng_device_rcvdata(hook_p hook, item_p item)
264 {
265 	priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
266 	struct mbuf *m;
267 
268 	DBG;
269 
270 	NGI_GET_M(item, m);
271 	NG_FREE_ITEM(item);
272 
273 	IF_LOCK(&priv->readq);
274 	if (_IF_QFULL(&priv->readq)) {
275 		_IF_DROP(&priv->readq);
276 		IF_UNLOCK(&priv->readq);
277 		NG_FREE_M(m);
278 		return (ENOBUFS);
279 	}
280 
281 	_IF_ENQUEUE(&priv->readq, m);
282 	IF_UNLOCK(&priv->readq);
283 	mtx_lock(&priv->ngd_mtx);
284 	if (priv->flags & NGDF_RWAIT) {
285 		priv->flags &= ~NGDF_RWAIT;
286 		wakeup(priv);
287 	}
288 	mtx_unlock(&priv->ngd_mtx);
289 
290 	return(0);
291 }
292 
293 /*
294  * Removal of the hook destroys the node.
295  */
296 static int
297 ng_device_disconnect(hook_p hook)
298 {
299 	priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
300 
301 	DBG;
302 
303 	destroy_dev(priv->ngddev);
304 	mtx_destroy(&priv->ngd_mtx);
305 
306 	IF_DRAIN(&priv->readq);
307 	mtx_destroy(&(priv)->readq.ifq_mtx);
308 
309 	free_unr(ngd_unit, priv->unit);
310 
311 	FREE(priv, M_NETGRAPH);
312 
313 	ng_rmnode_self(NG_HOOK_NODE(hook));
314 
315 	return(0);
316 }
317 
318 /*
319  * Node shutdown. Everything is already done in disconnect method.
320  */
321 static int
322 ng_device_shutdown(node_p node)
323 {
324 	NG_NODE_UNREF(node);
325 	return (0);
326 }
327 
328 /******************************************************************************
329  *  Device methods
330  ******************************************************************************/
331 
332 /*
333  * the device is opened
334  */
335 static int
336 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
337 {
338 	priv_p	priv = (priv_p )dev->si_drv1;
339 
340 	DBG;
341 
342 	mtx_lock(&priv->ngd_mtx);
343 	priv->flags |= NGDF_OPEN;
344 	mtx_unlock(&priv->ngd_mtx);
345 
346 	return(0);
347 }
348 
349 /*
350  * the device is closed
351  */
352 static int
353 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
354 {
355 	priv_p	priv = (priv_p )dev->si_drv1;
356 
357 	DBG;
358 	mtx_lock(&priv->ngd_mtx);
359 	priv->flags &= ~NGDF_OPEN;
360 	mtx_unlock(&priv->ngd_mtx);
361 
362 	return(0);
363 }
364 
365 #if 0	/*
366 	 * The ioctl is transformed into netgraph control message.
367 	 * We do not process them, yet.
368 	 */
369 /*
370  * process ioctl
371  *
372  * they are translated into netgraph messages and passed on
373  *
374  */
375 static int
376 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
377 {
378 	struct ngd_softc *sc = &ngd_softc;
379 	struct ngd_connection * connection = NULL;
380 	struct ngd_connection * tmp;
381 	int error = 0;
382 	struct ng_mesg *msg;
383 	struct ngd_param_s * datap;
384 
385 	DBG;
386 
387 	NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
388 			M_WAITOK);
389 	if (msg == NULL) {
390 		printf("%s(): msg == NULL\n",__func__);
391 		goto nomsg;
392 	}
393 
394 	/* pass the ioctl data into the ->data area */
395 	datap = (struct ngd_param_s *)msg->data;
396 	datap->p = addr;
397 
398 	NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
399 	if(error)
400 		printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
401 
402 nomsg:
403 
404 	return(0);
405 }
406 #endif /* if 0 */
407 
408 /*
409  * This function is called when a read(2) is done to our device.
410  * We process one mbuf from queue.
411  */
412 static int
413 ngdread(struct cdev *dev, struct uio *uio, int flag)
414 {
415 	priv_p	priv = (priv_p )dev->si_drv1;
416 	struct mbuf *m;
417 	int len, error = 0;
418 
419 	DBG;
420 
421 	/* get an mbuf */
422 	do {
423 		IF_DEQUEUE(&priv->readq, m);
424 		if (m == NULL) {
425 			if (flag & IO_NDELAY)
426 				return (EWOULDBLOCK);
427 			mtx_lock(&priv->ngd_mtx);
428 			priv->flags |= NGDF_RWAIT;
429 			if ((error = msleep(priv, &priv->ngd_mtx,
430 			    PDROP | PCATCH | (PZERO + 1),
431 			    "ngdread", 0)) != 0)
432 				return (error);
433 		}
434 	} while (m == NULL);
435 
436 	while (m && uio->uio_resid > 0 && error == 0) {
437 		len = MIN(uio->uio_resid, m->m_len);
438 		if (len != 0)
439 			error = uiomove(mtod(m, void *), len, uio);
440 		m = m_free(m);
441 	}
442 
443 	if (m)
444 		m_freem(m);
445 
446 	return (error);
447 }
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
456 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
457 {
458 	priv_p	priv = (priv_p )dev->si_drv1;
459 	struct mbuf *m;
460 	int error = 0;
461 
462 	DBG;
463 
464 	if (uio->uio_resid == 0)
465 		return (0);
466 
467 	if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
468 		return (EIO);
469 
470 	if ((m = m_uiotombuf(uio, MB_DONTWAIT, 0, 0, M_PKTHDR)) == NULL)
471 		return (ENOBUFS);
472 
473 	NG_SEND_DATA_ONLY(error, priv->hook, m);
474 
475 	return (error);
476 }
477 
478 /*
479  * we are being polled/selected
480  * check if there is data available for read
481  */
482 static int
483 ngdpoll(struct cdev *dev, int events, struct thread *td)
484 {
485 	priv_p	priv = (priv_p )dev->si_drv1;
486 	int revents = 0;
487 
488 	if (events & (POLLIN | POLLRDNORM) &&
489 	    !IFQ_IS_EMPTY(&priv->readq))
490 		revents |= events & (POLLIN | POLLRDNORM);
491 
492 	return (revents);
493 }
494