vrevoke/single-user - fix more revoke issues.
[dragonfly.git] / sys / dev / misc / nmdm / nmdm.c
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *      The Regents of the University of California.  All rights reserved.
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by the University of
16  *      California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: src/sys/dev/nmdm/nmdm.c,v 1.5.2.1 2001/08/11 00:54:14 mp Exp $
34  * $DragonFly: src/sys/dev/misc/nmdm/nmdm.c,v 1.16 2008/01/05 14:02:37 swildner Exp $
35  */
36
37 /*
38  * Pseudo-nulmodem Driver
39  */
40 #include "opt_compat.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
44 #include <sys/ioctl_compat.h>
45 #endif
46 #include <sys/proc.h>
47 #include <sys/priv.h>
48 #include <sys/thread2.h>
49 #include <sys/tty.h>
50 #include <sys/conf.h>
51 #include <sys/fcntl.h>
52 #include <sys/poll.h>
53 #include <sys/kernel.h>
54 #include <sys/vnode.h>
55 #include <sys/signalvar.h>
56 #include <sys/malloc.h>
57
58 MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
59
60 static void nmdmstart (struct tty *tp);
61 static void nmdmstop (struct tty *tp, int rw);
62 static void wakeup_other (struct tty *tp, int flag);
63 static void nmdminit (int n);
64
65 static  d_open_t        nmdmopen;
66 static  d_close_t       nmdmclose;
67 static  d_read_t        nmdmread;
68 static  d_write_t       nmdmwrite;
69 static  d_ioctl_t       nmdmioctl;
70
71 #define CDEV_MAJOR      18
72 static struct dev_ops nmdm_ops = {
73         { "pts", CDEV_MAJOR, D_TTY },
74         .d_open =       nmdmopen,
75         .d_close =      nmdmclose,
76         .d_read =       nmdmread,
77         .d_write =      nmdmwrite,
78         .d_ioctl =      nmdmioctl,
79         .d_poll =       ttypoll,
80         .d_revoke =     ttyrevoke
81 };
82
83 #define BUFSIZ 100              /* Chunk size iomoved to/from user */
84
85 struct softpart {
86         struct tty nm_tty;
87         cdev_t  dev;
88         int     modemsignals;   /* bits defined in sys/ttycom.h */
89         int     gotbreak;
90 };
91
92 struct  nm_softc {
93         int     pt_flags;
94         struct softpart part1, part2;
95         struct  prison *pt_prison;
96 };
97
98 #define PF_STOPPED      0x10            /* user told stopped */
99
100 static void
101 nmdm_crossover(struct nm_softc *pti,
102                 struct softpart *ourpart,
103                 struct softpart *otherpart);
104
105 #define GETPARTS(tp, ourpart, otherpart) \
106 do {    \
107         struct nm_softc *pti = tp->t_dev->si_drv1; \
108         if (tp == &pti->part1.nm_tty) { \
109                 ourpart = &pti->part1; \
110                 otherpart = &pti->part2; \
111         } else { \
112                 ourpart = &pti->part2; \
113                 otherpart = &pti->part1; \
114         }  \
115 } while (0)
116
117 /*
118  * This function creates and initializes a pair of ttys.
119  */
120 static void
121 nmdminit(int n)
122 {
123         cdev_t dev1, dev2;
124         struct nm_softc *pt;
125
126         /*
127          * Simplified unit number, use low 8 bits of minor number
128          * (remember, the minor number mask is 0xffff00ff).
129          */
130         if (n & ~0x7f)
131                 return;
132
133         pt = kmalloc(sizeof(*pt), M_NLMDM, M_WAITOK | M_ZERO);
134         dev_ops_add(&nmdm_ops, ~1, n << 1);
135         pt->part1.dev = dev1 = make_dev(&nmdm_ops, n << 1,
136             0, 0, 0666, "nmdm%dA", n);
137         pt->part2.dev = dev2 = make_dev(&nmdm_ops, (n << 1) + 1,
138             0, 0, 0666, "nmdm%dB", n);
139
140         dev1->si_drv1 = dev2->si_drv1 = pt;
141         dev1->si_tty = &pt->part1.nm_tty;
142         dev2->si_tty = &pt->part2.nm_tty;
143         ttyregister(&pt->part1.nm_tty);
144         ttyregister(&pt->part2.nm_tty);
145         pt->part1.nm_tty.t_oproc = nmdmstart;
146         pt->part2.nm_tty.t_oproc = nmdmstart;
147         pt->part1.nm_tty.t_stop = nmdmstop;
148         pt->part2.nm_tty.t_dev = dev1;
149         pt->part1.nm_tty.t_dev = dev2;
150         pt->part2.nm_tty.t_stop = nmdmstop;
151 }
152
153 /*ARGSUSED*/
154 static  int
155 nmdmopen(struct dev_open_args *ap)
156 {
157         cdev_t dev = ap->a_head.a_dev;
158         struct tty *tp, *tp2;
159         int error;
160         int minr;
161 #if 0
162         cdev_t nextdev;
163 #endif
164         struct nm_softc *pti;
165         int is_b;
166         int     pair;
167         struct  softpart *ourpart, *otherpart;
168
169         minr = lminor(dev);
170         pair = minr >> 1;
171         is_b = minr & 1;
172         
173 #if 0
174         /*
175          * XXX: Gross hack for DEVFS:
176          * If we openned this device, ensure we have the
177          * next one too, so people can open it.
178          */
179         if (pair < 127) {
180                 nextdev = makedev(major(dev), (pair+pair) + 1);
181                 if (!nextdev->si_drv1) {
182                         nmdminit(pair + 1);
183                 }
184         }
185 #endif
186         if (!dev->si_drv1)
187                 nmdminit(pair);
188
189         if (!dev->si_drv1)
190                 return(ENXIO);  
191
192         pti = dev->si_drv1;
193         if (is_b) 
194                 tp = &pti->part2.nm_tty;
195         else 
196                 tp = &pti->part1.nm_tty;
197         GETPARTS(tp, ourpart, otherpart);
198         tp2 = &otherpart->nm_tty;
199         ourpart->modemsignals |= TIOCM_LE;
200
201         if ((tp->t_state & TS_ISOPEN) == 0) {
202                 ttychars(tp);           /* Set up default chars */
203                 tp->t_iflag = TTYDEF_IFLAG;
204                 tp->t_oflag = TTYDEF_OFLAG;
205                 tp->t_lflag = TTYDEF_LFLAG;
206                 tp->t_cflag = TTYDEF_CFLAG;
207                 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
208         } else if (tp->t_state & TS_XCLUDE && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
209                 return (EBUSY);
210         } else if (pti->pt_prison != ap->a_cred->cr_prison) {
211                 return (EBUSY);
212         }
213
214         /*
215          * If the other side is open we have carrier
216          */
217         if (tp2->t_state & TS_ISOPEN) {
218                 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
219         }
220
221         /*
222          * And the other side gets carrier as we are now open.
223          */
224         (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
225
226         /* External processing makes no sense here */
227         tp->t_lflag &= ~EXTPROC;
228
229         /* 
230          * Wait here if we don't have carrier.
231          */
232 #if 0
233         while ((tp->t_state & TS_CARR_ON) == 0) {
234                 if (flag & FNONBLOCK)
235                         break;
236                 error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "nmdopn", 0);
237                 if (error)
238                         return (error);
239         }
240 #endif
241
242         /*
243          * Give the line disciplin a chance to set this end up.
244          */
245         error = (*linesw[tp->t_line].l_open)(dev, tp);
246
247         /*
248          * Wake up the other side.
249          * Theoretically not needed.
250          */
251         ourpart->modemsignals |= TIOCM_DTR;
252         nmdm_crossover(pti, ourpart, otherpart);
253         if (error == 0)
254                 wakeup_other(tp, FREAD|FWRITE); /* XXX */
255         return (error);
256 }
257
258 static int
259 nmdmclose(struct dev_close_args *ap)
260 {
261         cdev_t dev = ap->a_head.a_dev;
262         struct tty *tp, *tp2;
263         int err;
264         struct softpart *ourpart, *otherpart;
265
266         /*
267          * let the other end know that the game is up
268          */
269         tp = dev->si_tty;
270         GETPARTS(tp, ourpart, otherpart);
271         tp2 = &otherpart->nm_tty;
272         (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
273
274         /*
275          * XXX MDMBUF makes no sense for nmdms but would inhibit the above
276          * l_modem().  CLOCAL makes sense but isn't supported.   Special
277          * l_modem()s that ignore carrier drop make no sense for nmdms but
278          * may be in use because other parts of the line discipline make
279          * sense for nmdms.  Recover by doing everything that a normal
280          * ttymodem() would have done except for sending a SIGHUP.
281          */
282         if (tp2->t_state & TS_ISOPEN) {
283                 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
284                 tp2->t_state |= TS_ZOMBIE;
285                 ttyflush(tp2, FREAD | FWRITE);
286         }
287
288         err = (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
289         ourpart->modemsignals &= ~TIOCM_DTR;
290         nmdm_crossover(dev->si_drv1, ourpart, otherpart);
291         nmdmstop(tp, FREAD|FWRITE);
292         (void) ttyclose(tp);
293         return (err);
294 }
295
296 static int
297 nmdmread(struct dev_read_args *ap)
298 {
299         cdev_t dev = ap->a_head.a_dev;
300         int error = 0;
301         struct tty *tp, *tp2;
302         struct softpart *ourpart, *otherpart;
303
304         tp = dev->si_tty;
305         GETPARTS(tp, ourpart, otherpart);
306         tp2 = &otherpart->nm_tty;
307
308 #if 0
309         if (tp2->t_state & TS_ISOPEN) {
310                 error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, flag);
311                 wakeup_other(tp, FWRITE);
312         } else {
313                 if (flag & IO_NDELAY) {
314                         return (EWOULDBLOCK);
315                 }
316                 error = tsleep(TSA_PTC_READ(tp), PCATCH, "nmdout", 0);
317                 }
318         }
319 #else
320         if ((error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag)) == 0)
321                 wakeup_other(tp, FWRITE);
322 #endif
323         return (error);
324 }
325
326 /*
327  * Write to pseudo-tty.
328  * Wakeups of controlling tty will happen
329  * indirectly, when tty driver calls nmdmstart.
330  */
331 static  int
332 nmdmwrite(struct dev_write_args *ap)
333 {
334         cdev_t dev = ap->a_head.a_dev;
335         struct uio *uio = ap->a_uio;
336         u_char *cp = 0;
337         int cc = 0;
338         u_char locbuf[BUFSIZ];
339         int cnt = 0;
340         int error = 0;
341         struct tty *tp1, *tp;
342         struct softpart *ourpart, *otherpart;
343
344         tp1 = dev->si_tty;
345         /*
346          * Get the other tty struct.
347          * basically we are writing into the INPUT side of the other device.
348          */
349         GETPARTS(tp1, ourpart, otherpart);
350         tp = &otherpart->nm_tty;
351
352 again:
353         if ((tp->t_state & TS_ISOPEN) == 0) 
354                 return (EIO);
355         while (uio->uio_resid > 0 || cc > 0) {
356                 /*
357                  * Fill up the buffer if it's empty
358                  */
359                 if (cc == 0) {
360                         cc = min(uio->uio_resid, BUFSIZ);
361                         cp = locbuf;
362                         error = uiomove((caddr_t)cp, cc, uio);
363                         if (error)
364                                 return (error);
365                         /* check again for safety */
366                         if ((tp->t_state & TS_ISOPEN) == 0) {
367                                 /* adjust for data copied in but not written */
368                                 uio->uio_resid += cc;
369                                 return (EIO);
370                         }
371                 }
372                 while (cc > 0) {
373                         if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
374                         && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
375                                 /*
376                                  * Come here to wait for space in outq,
377                                  * or space in rawq, or an empty canq.
378                                  */
379                                 wakeup(TSA_HUP_OR_INPUT(tp));
380                                 if ((tp->t_state & TS_CONNECTED) == 0) {
381                                         /*
382                                          * Data piled up because not connected.
383                                          * Adjust for data copied in but
384                                          * not written.
385                                          */
386                                         uio->uio_resid += cc;
387                                         return (EIO);
388                                 }
389                                 if (ap->a_ioflag & IO_NDELAY) {
390                                         /*
391                                          * Don't wait if asked not to.
392                                          * Adjust for data copied in but
393                                          * not written.
394                                          */
395                                         uio->uio_resid += cc;
396                                         if (cnt == 0)
397                                                 return (EWOULDBLOCK);
398                                         return (0);
399                                 }
400                                 error = tsleep(TSA_PTC_WRITE(tp),
401                                                 PCATCH, "nmdout", 0);
402                                 if (error) {
403                                         /*
404                                          * Tsleep returned (signal?).
405                                          * Go find out what the user wants.
406                                          * adjust for data copied in but
407                                          * not written
408                                          */
409                                         uio->uio_resid += cc;
410                                         return (error);
411                                 }
412                                 goto again;
413                         }
414                         (*linesw[tp->t_line].l_rint)(*cp++, tp);
415                         cnt++;
416                         cc--;
417                 }
418                 cc = 0;
419         }
420         return (0);
421 }
422
423 /*
424  * Start output on pseudo-tty.
425  * Wake up process selecting or sleeping for input from controlling tty.
426  */
427 static void
428 nmdmstart(struct tty *tp)
429 {
430         struct nm_softc *pti = tp->t_dev->si_drv1;
431
432         if (tp->t_state & TS_TTSTOP)
433                 return;
434         pti->pt_flags &= ~PF_STOPPED;
435         wakeup_other(tp, FREAD);
436 }
437
438 /* Wakes up the OTHER tty;*/
439 static void
440 wakeup_other(struct tty *tp, int flag)
441 {
442         struct softpart *ourpart, *otherpart;
443
444         GETPARTS(tp, ourpart, otherpart);
445         if (flag & FREAD) {
446                 selwakeup(&otherpart->nm_tty.t_rsel);
447                 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
448         }
449         if (flag & FWRITE) {
450                 selwakeup(&otherpart->nm_tty.t_wsel);
451                 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
452         }
453 }
454
455 static  void
456 nmdmstop(struct tty *tp, int flush)
457 {
458         struct nm_softc *pti = tp->t_dev->si_drv1;
459         int flag;
460
461         /* note: FLUSHREAD and FLUSHWRITE already ok */
462         if (flush == 0) {
463                 flush = TIOCPKT_STOP;
464                 pti->pt_flags |= PF_STOPPED;
465         } else
466                 pti->pt_flags &= ~PF_STOPPED;
467         /* change of perspective */
468         flag = 0;
469         if (flush & FREAD)
470                 flag |= FWRITE;
471         if (flush & FWRITE)
472                 flag |= FREAD;
473         wakeup_other(tp, flag);
474 }
475
476 /*ARGSUSED*/
477 static  int
478 nmdmioctl(struct dev_ioctl_args *ap)
479 {
480         cdev_t dev = ap->a_head.a_dev;
481         struct tty *tp = dev->si_tty;
482         struct nm_softc *pti = dev->si_drv1;
483         int error;
484         struct tty *tp2;
485         struct softpart *ourpart, *otherpart;
486
487         crit_enter();
488         GETPARTS(tp, ourpart, otherpart);
489         tp2 = &otherpart->nm_tty;
490
491         error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
492                                               ap->a_fflag, ap->a_cred);
493         if (error == ENOIOCTL)
494                  error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
495         if (error == ENOIOCTL) {
496                 switch (ap->a_cmd) {
497                 case TIOCSBRK:
498                         otherpart->gotbreak = 1;
499                         break;
500                 case TIOCCBRK:
501                         break;
502                 case TIOCSDTR:
503                         ourpart->modemsignals |= TIOCM_DTR;
504                         break;
505                 case TIOCCDTR:
506                         ourpart->modemsignals &= TIOCM_DTR;
507                         break;
508                 case TIOCMSET:
509                         ourpart->modemsignals = *(int *)ap->a_data;
510                         otherpart->modemsignals = *(int *)ap->a_data;
511                         break;
512                 case TIOCMBIS:
513                         ourpart->modemsignals |= *(int *)ap->a_data;
514                         break;
515                 case TIOCMBIC:
516                         ourpart->modemsignals &= ~(*(int *)ap->a_data);
517                         otherpart->modemsignals &= ~(*(int *)ap->a_data);
518                         break;
519                 case TIOCMGET:
520                         *(int *)ap->a_data = ourpart->modemsignals;
521                         break;
522                 case TIOCMSDTRWAIT:
523                         break;
524                 case TIOCMGDTRWAIT:
525                         *(int *)ap->a_data = 0;
526                         break;
527                 case TIOCTIMESTAMP:
528                 case TIOCDCDTIMESTAMP:
529                 default:
530                         crit_exit();
531                         error = ENOTTY;
532                         return (error);
533                 }
534                 error = 0;
535                 nmdm_crossover(pti, ourpart, otherpart);
536         }
537         crit_exit();
538         return (error);
539 }
540
541 static void
542 nmdm_crossover(struct nm_softc *pti,
543                 struct softpart *ourpart,
544                 struct softpart *otherpart)
545 {
546         otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
547         if (ourpart->modemsignals & TIOCM_RTS)
548                 otherpart->modemsignals |= TIOCM_CTS;
549         if (ourpart->modemsignals & TIOCM_DTR)
550                 otherpart->modemsignals |= TIOCM_CAR;
551 }
552
553
554
555 static void nmdm_drvinit (void *unused);
556
557 static void
558 nmdm_drvinit(void *unused)
559 {
560         /* XXX: Gross hack for DEVFS */
561         nmdminit(0);
562 }
563
564 SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)