Change the kernel dev_t, representing a pointer to a specinfo structure,
[dragonfly.git] / sys / netgraph / tty / ng_tty.c
CommitLineData
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1
2/*
3 * ng_tty.c
4 *
5 * Copyright (c) 1996-1999 Whistle Communications, Inc.
6 * All rights reserved.
7 *
8 * Subject to the following obligations and disclaimer of warranty, use and
9 * redistribution of this software, in source or object code forms, with or
10 * without modifications are expressly permitted by Whistle Communications;
11 * provided, however, that:
12 * 1. Any and all reproductions of the source or object code must include the
13 * copyright notice above and the following disclaimer of warranties; and
14 * 2. No rights are granted, in any manner or form, to use Whistle
15 * Communications, Inc. trademarks, including the mark "WHISTLE
16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17 * such appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35 * OF SUCH DAMAGE.
36 *
37 * Author: Archie Cobbs <archie@freebsd.org>
38 *
39 * $FreeBSD: src/sys/netgraph/ng_tty.c,v 1.7.2.3 2002/02/13 00:43:12 dillon Exp $
b13267a5 40 * $DragonFly: src/sys/netgraph/tty/ng_tty.c,v 1.13 2006/09/10 01:26:40 dillon Exp $
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41 * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $
42 */
43
44/*
45 * This file implements a terminal line discipline that is also a
46 * netgraph node. Installing this line discipline on a terminal device
47 * instantiates a new netgraph node of this type, which allows access
48 * to the device via the "hook" hook of the node.
49 *
50 * Once the line discipline is installed, you can find out the name
51 * of the corresponding netgraph node via a NGIOCGINFO ioctl().
52 *
53 * Incoming characters are delievered to the hook one at a time, each
54 * in its own mbuf. You may optionally define a ``hotchar,'' which causes
55 * incoming characters to be buffered up until either the hotchar is
56 * seen or the mbuf is full (MHLEN bytes). Then all buffered characters
57 * are immediately delivered.
58 *
59 * NOTE: This node operates at spltty().
60 */
61
62#include <sys/param.h>
63#include <sys/systm.h>
64#include <sys/kernel.h>
65#include <sys/conf.h>
66#include <sys/proc.h>
67#include <sys/mbuf.h>
68#include <sys/malloc.h>
69#include <sys/fcntl.h>
70#include <sys/tty.h>
71#include <sys/ttycom.h>
72#include <sys/syslog.h>
73#include <sys/errno.h>
74#include <sys/ioccom.h>
41e90fed 75#include <sys/thread2.h>
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76
77#include <netgraph/ng_message.h>
78#include <netgraph/netgraph.h>
1f2de5d4 79#include "ng_tty.h"
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80
81#ifdef __i386__ /* fiddle with the spl locking */
82#include <machine/ipl.h>
83#include <i386/isa/intr_machdep.h>
84#endif
85
86/* Misc defs */
87#define MAX_MBUFQ 3 /* Max number of queued mbufs */
88#define NGT_HIWATER 400 /* High water mark on output */
89
90/* Per-node private info */
91struct ngt_sc {
92 struct tty *tp; /* Terminal device */
93 node_p node; /* Netgraph node */
94 hook_p hook; /* Netgraph hook */
95 struct mbuf *m; /* Incoming data buffer */
96 struct mbuf *qhead, **qtail; /* Queue of outgoing mbuf's */
97 short qlen; /* Length of queue */
98 short hotchar; /* Hotchar, or -1 if none */
99 u_int flags; /* Flags */
5aed2989 100 struct callout ctimeout; /* See man timeout(9) */
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101};
102typedef struct ngt_sc *sc_p;
103
104/* Flags */
105#define FLG_TIMEOUT 0x0001 /* A timeout is pending */
106#define FLG_DEBUG 0x0002
107
108/* Debugging */
109#ifdef INVARIANTS
110#define QUEUECHECK(sc) \
111 do { \
112 struct mbuf **mp; \
113 int k; \
114 \
115 for (k = 0, mp = &sc->qhead; \
116 k <= MAX_MBUFQ && *mp; \
117 k++, mp = &(*mp)->m_nextpkt); \
118 if (k != sc->qlen || k > MAX_MBUFQ || *mp || mp != sc->qtail) \
5e2195bf 119 panic("%s: queue", __func__); \
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120 } while (0)
121#else
122#define QUEUECHECK(sc) do {} while (0)
123#endif
124
125/* Line discipline methods */
b13267a5 126static int ngt_open(cdev_t dev, struct tty *tp);
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127static int ngt_close(struct tty *tp, int flag);
128static int ngt_read(struct tty *tp, struct uio *uio, int flag);
129static int ngt_write(struct tty *tp, struct uio *uio, int flag);
130static int ngt_tioctl(struct tty *tp,
fef8985e 131 u_long cmd, caddr_t data, int flag, struct ucred *cred);
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132static int ngt_input(int c, struct tty *tp);
133static int ngt_start(struct tty *tp);
134
135/* Netgraph methods */
136static ng_constructor_t ngt_constructor;
137static ng_rcvmsg_t ngt_rcvmsg;
138static ng_shutdown_t ngt_shutdown;
139static ng_newhook_t ngt_newhook;
140static ng_rcvdata_t ngt_rcvdata;
141static ng_disconnect_t ngt_disconnect;
142static int ngt_mod_event(module_t mod, int event, void *data);
143
144/* Other stuff */
145static void ngt_timeout(void *arg);
146
147#define ERROUT(x) do { error = (x); goto done; } while (0)
148
149/* Line discipline descriptor */
150static struct linesw ngt_disc = {
151 ngt_open,
152 ngt_close,
153 ngt_read,
154 ngt_write,
155 ngt_tioctl,
156 ngt_input,
157 ngt_start,
158 ttymodem,
159 NG_TTY_DFL_HOTCHAR /* XXX can't change this in serial driver */
160};
161
162/* Netgraph node type descriptor */
163static struct ng_type typestruct = {
164 NG_VERSION,
165 NG_TTY_NODE_TYPE,
166 ngt_mod_event,
167 ngt_constructor,
168 ngt_rcvmsg,
169 ngt_shutdown,
170 ngt_newhook,
171 NULL,
172 NULL,
173 ngt_rcvdata,
174 ngt_rcvdata,
175 ngt_disconnect,
176 NULL
177};
178NETGRAPH_INIT(tty, &typestruct);
179
180static int ngt_unit;
181static int ngt_nodeop_ok; /* OK to create/remove node */
182static int ngt_ldisc;
183
184/******************************************************************
185 LINE DISCIPLINE METHODS
186******************************************************************/
187
188/*
189 * Set our line discipline on the tty.
190 * Called from device open routine or ttioctl() at >= splsofttty()
191 */
192static int
b13267a5 193ngt_open(cdev_t dev, struct tty *tp)
984263bc 194{
dadab5e9 195 struct thread *td = curthread; /* XXX */
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196 char name[sizeof(NG_TTY_NODE_TYPE) + 8];
197 sc_p sc;
41e90fed 198 int error;
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199
200 /* Super-user only */
dadab5e9 201 if ((error = suser(td)))
984263bc 202 return (error);
41e90fed 203 crit_enter();
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204
205 /* Already installed? */
206 if (tp->t_line == NETGRAPHDISC) {
207 sc = (sc_p) tp->t_sc;
208 if (sc != NULL && sc->tp == tp)
209 goto done;
210 }
211
212 /* Initialize private struct */
213 MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK);
214 if (sc == NULL) {
215 error = ENOMEM;
216 goto done;
217 }
218 bzero(sc, sizeof(*sc));
219 sc->tp = tp;
220 sc->hotchar = NG_TTY_DFL_HOTCHAR;
221 sc->qtail = &sc->qhead;
222 QUEUECHECK(sc);
5aed2989 223 callout_init(&sc->ctimeout);
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224
225 /* Setup netgraph node */
226 ngt_nodeop_ok = 1;
227 error = ng_make_node_common(&typestruct, &sc->node);
228 ngt_nodeop_ok = 0;
229 if (error) {
230 FREE(sc, M_NETGRAPH);
231 goto done;
232 }
233 snprintf(name, sizeof(name), "%s%d", typestruct.name, ngt_unit++);
234
235 /* Set back pointers */
236 sc->node->private = sc;
237 tp->t_sc = (caddr_t) sc;
238
239 /* Assign node its name */
240 if ((error = ng_name_node(sc->node, name))) {
241 log(LOG_ERR, "%s: node name exists?\n", name);
242 ngt_nodeop_ok = 1;
243 ng_rmnode(sc->node);
244 ngt_nodeop_ok = 0;
245 goto done;
246 }
247
248 /*
249 * Pre-allocate cblocks to the an appropriate amount.
250 * I'm not sure what is appropriate.
251 */
252 ttyflush(tp, FREAD | FWRITE);
253 clist_alloc_cblocks(&tp->t_canq, 0, 0);
254 clist_alloc_cblocks(&tp->t_rawq, 0, 0);
255 clist_alloc_cblocks(&tp->t_outq,
256 MLEN + NGT_HIWATER, MLEN + NGT_HIWATER);
257
258done:
259 /* Done */
41e90fed 260 crit_exit();
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261 return (error);
262}
263
264/*
265 * Line specific close routine, called from device close routine
266 * and from ttioctl at >= splsofttty(). This causes the node to
267 * be destroyed as well.
268 */
269static int
270ngt_close(struct tty *tp, int flag)
271{
272 const sc_p sc = (sc_p) tp->t_sc;
984263bc 273
41e90fed 274 crit_enter();
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275 ttyflush(tp, FREAD | FWRITE);
276 clist_free_cblocks(&tp->t_outq);
277 tp->t_line = 0;
278 if (sc != NULL) {
279 if (sc->flags & FLG_TIMEOUT) {
5aed2989 280 callout_stop(&sc->ctimeout);
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281 sc->flags &= ~FLG_TIMEOUT;
282 }
283 ngt_nodeop_ok = 1;
284 ng_rmnode(sc->node);
285 ngt_nodeop_ok = 0;
286 tp->t_sc = NULL;
287 }
41e90fed 288 crit_exit();
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289 return (0);
290}
291
292/*
293 * Once the device has been turned into a node, we don't allow reading.
294 */
295static int
296ngt_read(struct tty *tp, struct uio *uio, int flag)
297{
298 return (EIO);
299}
300
301/*
302 * Once the device has been turned into a node, we don't allow writing.
303 */
304static int
305ngt_write(struct tty *tp, struct uio *uio, int flag)
306{
307 return (EIO);
308}
309
310/*
311 * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
312 */
313static int
fef8985e 314ngt_tioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct ucred *cred)
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315{
316 const sc_p sc = (sc_p) tp->t_sc;
41e90fed 317 int error = 0;
984263bc 318
41e90fed 319 crit_enter();
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320 switch (cmd) {
321 case NGIOCGINFO:
322 {
323 struct nodeinfo *const ni = (struct nodeinfo *) data;
324 const node_p node = sc->node;
325
326 bzero(ni, sizeof(*ni));
327 if (node->name)
328 strncpy(ni->name, node->name, sizeof(ni->name) - 1);
329 strncpy(ni->type, node->type->name, sizeof(ni->type) - 1);
330 ni->id = (u_int32_t) node;
331 ni->hooks = node->numhooks;
332 break;
333 }
334 default:
335 ERROUT(ENOIOCTL);
336 }
337done:
41e90fed 338 crit_exit();
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339 return (error);
340}
341
342/*
343 * Receive data coming from the device. We get one character at
344 * a time, which is kindof silly.
345 * Only guaranteed to be at splsofttty() or spltty().
346 */
347static int
348ngt_input(int c, struct tty *tp)
349{
350 const sc_p sc = (sc_p) tp->t_sc;
351 const node_p node = sc->node;
352 struct mbuf *m;
41e90fed 353 int error = 0;
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354
355 if (!sc || tp != sc->tp)
356 return (0);
41e90fed 357 crit_enter();
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358 if (!sc->hook)
359 ERROUT(0);
360
361 /* Check for error conditions */
362 if ((tp->t_state & TS_CONNECTED) == 0) {
363 if (sc->flags & FLG_DEBUG)
364 log(LOG_DEBUG, "%s: no carrier\n", node->name);
365 ERROUT(0);
366 }
367 if (c & TTY_ERRORMASK) {
368 /* framing error or overrun on this char */
369 if (sc->flags & FLG_DEBUG)
370 log(LOG_DEBUG, "%s: line error %x\n",
371 node->name, c & TTY_ERRORMASK);
372 ERROUT(0);
373 }
374 c &= TTY_CHARMASK;
375
376 /* Get a new header mbuf if we need one */
377 if (!(m = sc->m)) {
74f1caca 378 MGETHDR(m, MB_DONTWAIT, MT_DATA);
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379 if (!m) {
380 if (sc->flags & FLG_DEBUG)
381 log(LOG_ERR,
382 "%s: can't get mbuf\n", node->name);
383 ERROUT(ENOBUFS);
384 }
385 m->m_len = m->m_pkthdr.len = 0;
386 m->m_pkthdr.rcvif = NULL;
387 sc->m = m;
388 }
389
390 /* Add char to mbuf */
391 *mtod(m, u_char *) = c;
392 m->m_data++;
393 m->m_len++;
394 m->m_pkthdr.len++;
395
396 /* Ship off mbuf if it's time */
397 if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) {
398 m->m_data = m->m_pktdat;
399 error = ng_queue_data(sc->hook, m, NULL);
400 sc->m = NULL;
401 }
402done:
41e90fed 403 crit_exit();
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404 return (error);
405}
406
407/*
408 * This is called when the device driver is ready for more output.
409 * Called from tty system at splsofttty() or spltty().
410 * Also call from ngt_rcv_data() when a new mbuf is available for output.
411 */
412static int
413ngt_start(struct tty *tp)
414{
415 const sc_p sc = (sc_p) tp->t_sc;
984263bc 416
41e90fed 417 crit_enter();
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418 while (tp->t_outq.c_cc < NGT_HIWATER) { /* XXX 2.2 specific ? */
419 struct mbuf *m = sc->qhead;
420
421 /* Remove first mbuf from queue */
422 if (!m)
423 break;
424 if ((sc->qhead = m->m_nextpkt) == NULL)
425 sc->qtail = &sc->qhead;
426 sc->qlen--;
427 QUEUECHECK(sc);
428
429 /* Send as much of it as possible */
430 while (m) {
431 int sent;
432
433 sent = m->m_len
434 - b_to_q(mtod(m, u_char *), m->m_len, &tp->t_outq);
435 m->m_data += sent;
436 m->m_len -= sent;
437 if (m->m_len > 0)
438 break; /* device can't take no more */
439 m = m_free(m);
440 }
441
442 /* Put remainder of mbuf chain (if any) back on queue */
443 if (m) {
444 m->m_nextpkt = sc->qhead;
445 sc->qhead = m;
446 if (sc->qtail == &sc->qhead)
447 sc->qtail = &m->m_nextpkt;
448 sc->qlen++;
449 QUEUECHECK(sc);
450 break;
451 }
452 }
453
454 /* Call output process whether or not there is any output. We are
455 * being called in lieu of ttstart and must do what it would. */
456 if (tp->t_oproc != NULL)
457 (*tp->t_oproc) (tp);
458
459 /* This timeout is needed for operation on a pseudo-tty, because the
460 * pty code doesn't call pppstart after it has drained the t_outq. */
461 if (sc->qhead && (sc->flags & FLG_TIMEOUT) == 0) {
5aed2989 462 callout_reset(&sc->ctimeout, 1, ngt_timeout, sc);
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463 sc->flags |= FLG_TIMEOUT;
464 }
41e90fed 465 crit_exit();
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466 return (0);
467}
468
469/*
470 * We still have data to output to the device, so try sending more.
471 */
472static void
473ngt_timeout(void *arg)
474{
475 const sc_p sc = (sc_p) arg;
984263bc 476
41e90fed 477 crit_enter();
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478 sc->flags &= ~FLG_TIMEOUT;
479 ngt_start(sc->tp);
41e90fed 480 crit_exit();
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481}
482
483/******************************************************************
484 NETGRAPH NODE METHODS
485******************************************************************/
486
487/*
488 * Initialize a new node of this type.
489 *
490 * We only allow nodes to be created as a result of setting
491 * the line discipline on a tty, so always return an error if not.
492 */
493static int
494ngt_constructor(node_p *nodep)
495{
496 if (!ngt_nodeop_ok)
497 return (EOPNOTSUPP);
498 return (ng_make_node_common(&typestruct, nodep));
499}
500
501/*
502 * Add a new hook. There can only be one.
503 */
504static int
505ngt_newhook(node_p node, hook_p hook, const char *name)
506{
507 const sc_p sc = node->private;
41e90fed 508 int error = 0;
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509
510 if (strcmp(name, NG_TTY_HOOK))
511 return (EINVAL);
41e90fed 512 crit_enter();
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513 if (sc->hook)
514 ERROUT(EISCONN);
515 sc->hook = hook;
516done:
41e90fed 517 crit_exit();
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518 return (error);
519}
520
521/*
522 * Disconnect the hook
523 */
524static int
525ngt_disconnect(hook_p hook)
526{
527 const sc_p sc = hook->node->private;
984263bc 528
41e90fed 529 crit_enter();
984263bc 530 if (hook != sc->hook)
5e2195bf 531 panic(__func__);
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532 sc->hook = NULL;
533 m_freem(sc->m);
534 sc->m = NULL;
41e90fed 535 crit_exit();
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536 return (0);
537}
538
539/*
540 * Remove this node. The does the netgraph portion of the shutdown.
541 * This should only be called indirectly from ngt_close().
542 */
543static int
544ngt_shutdown(node_p node)
545{
546 const sc_p sc = node->private;
547
548 if (!ngt_nodeop_ok)
549 return (EOPNOTSUPP);
550 ng_unname(node);
551 ng_cutlinks(node);
552 node->private = NULL;
553 ng_unref(sc->node);
554 m_freem(sc->qhead);
555 m_freem(sc->m);
556 bzero(sc, sizeof(*sc));
557 FREE(sc, M_NETGRAPH);
558 return (0);
559}
560
561/*
562 * Receive incoming data from netgraph system. Put it on our
563 * output queue and start output if necessary.
564 */
565static int
566ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
567{
568 const sc_p sc = hook->node->private;
41e90fed 569 int error = 0;
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570
571 if (hook != sc->hook)
5e2195bf 572 panic(__func__);
984263bc 573 NG_FREE_META(meta);
41e90fed 574 crit_enter();
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575 if (sc->qlen >= MAX_MBUFQ)
576 ERROUT(ENOBUFS);
577 m->m_nextpkt = NULL;
578 *sc->qtail = m;
579 sc->qtail = &m->m_nextpkt;
580 sc->qlen++;
581 QUEUECHECK(sc);
582 m = NULL;
583 if (sc->qlen == 1)
584 ngt_start(sc->tp);
585done:
41e90fed 586 crit_exit();
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587 if (m)
588 m_freem(m);
589 return (error);
590}
591
592/*
593 * Receive control message
594 */
595static int
596ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
597 struct ng_mesg **rptr)
598{
599 const sc_p sc = (sc_p) node->private;
600 struct ng_mesg *resp = NULL;
601 int error = 0;
602
603 switch (msg->header.typecookie) {
604 case NGM_TTY_COOKIE:
605 switch (msg->header.cmd) {
606 case NGM_TTY_SET_HOTCHAR:
607 {
608 int hotchar;
609
610 if (msg->header.arglen != sizeof(int))
611 ERROUT(EINVAL);
612 hotchar = *((int *) msg->data);
613 if (hotchar != (u_char) hotchar && hotchar != -1)
614 ERROUT(EINVAL);
615 sc->hotchar = hotchar; /* race condition is OK */
616 break;
617 }
618 case NGM_TTY_GET_HOTCHAR:
619 NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT);
620 if (!resp)
621 ERROUT(ENOMEM);
622 /* Race condition here is OK */
623 *((int *) resp->data) = sc->hotchar;
624 break;
625 default:
626 ERROUT(EINVAL);
627 }
628 break;
629 default:
630 ERROUT(EINVAL);
631 }
632 if (rptr)
633 *rptr = resp;
634 else if (resp)
635 FREE(resp, M_NETGRAPH);
636
637done:
638 FREE(msg, M_NETGRAPH);
639 return (error);
640}
641
642/******************************************************************
643 INITIALIZATION
644******************************************************************/
645
646/*
647 * Handle loading and unloading for this node type
648 */
649static int
650ngt_mod_event(module_t mod, int event, void *data)
651{
652 /* struct ng_type *const type = data;*/
41e90fed 653 int error = 0;
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654
655 switch (event) {
656 case MOD_LOAD:
984263bc 657 /* Register line discipline */
41e90fed 658 crit_enter();
984263bc 659 if ((ngt_ldisc = ldisc_register(NETGRAPHDISC, &ngt_disc)) < 0) {
41e90fed 660 crit_exit();
984263bc 661 log(LOG_ERR, "%s: can't register line discipline",
5e2195bf 662 __func__);
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663 return (EIO);
664 }
41e90fed 665 crit_exit();
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666 break;
667
668 case MOD_UNLOAD:
669
670 /* Unregister line discipline */
41e90fed 671 crit_enter();
984263bc 672 ldisc_deregister(ngt_ldisc);
41e90fed 673 crit_exit();
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674 break;
675
676 default:
677 error = EOPNOTSUPP;
678 break;
679 }
680 return (error);
681}
682