1 /* 2 * Copyright (c) 1982, 1986, 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)tty_pty.c 7.21 (Berkeley) 05/30/91 8 */ 9 10 /* 11 * Pseudo-teletype Driver 12 * (Actually two drivers, requiring two entries in 'cdevsw') 13 */ 14 #include "pty.h" 15 16 #if NPTY > 0 17 #include "param.h" 18 #include "systm.h" 19 #include "ioctl.h" 20 #include "tty.h" 21 #include "conf.h" 22 #include "file.h" 23 #include "proc.h" 24 #include "uio.h" 25 #include "kernel.h" 26 #include "vnode.h" 27 28 #if NPTY == 1 29 #undef NPTY 30 #define NPTY 32 /* crude XXX */ 31 #endif 32 33 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 34 35 /* 36 * pts == /dev/tty[pqrs]? 37 * ptc == /dev/pty[pqrs]? 38 */ 39 struct tty pt_tty[NPTY]; 40 struct pt_ioctl { 41 int pt_flags; 42 struct proc *pt_selr, *pt_selw; 43 u_char pt_send; 44 u_char pt_ucntl; 45 } pt_ioctl[NPTY]; 46 int npty = NPTY; /* for pstat -t */ 47 48 #define PF_RCOLL 0x01 49 #define PF_WCOLL 0x02 50 #define PF_PKT 0x08 /* packet mode */ 51 #define PF_STOPPED 0x10 /* user told stopped */ 52 #define PF_REMOTE 0x20 /* remote and flow controlled input */ 53 #define PF_NOSTOP 0x40 54 #define PF_UCNTL 0x80 /* user control mode */ 55 56 /*ARGSUSED*/ 57 ptsopen(dev, flag, devtype, p) 58 dev_t dev; 59 struct proc *p; 60 { 61 register struct tty *tp; 62 int error; 63 64 #ifdef lint 65 npty = npty; 66 #endif 67 if (minor(dev) >= NPTY) 68 return (ENXIO); 69 tp = &pt_tty[minor(dev)]; 70 if ((tp->t_state & TS_ISOPEN) == 0) { 71 tp->t_state |= TS_WOPEN; 72 ttychars(tp); /* Set up default chars */ 73 tp->t_iflag = TTYDEF_IFLAG; 74 tp->t_oflag = TTYDEF_OFLAG; 75 tp->t_lflag = TTYDEF_LFLAG; 76 tp->t_cflag = TTYDEF_CFLAG; 77 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED; 78 ttsetwater(tp); /* would be done in xxparam() */ 79 } else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0) 80 return (EBUSY); 81 if (tp->t_oproc) /* Ctrlr still around. */ 82 tp->t_state |= TS_CARR_ON; 83 while ((tp->t_state & TS_CARR_ON) == 0) { 84 tp->t_state |= TS_WOPEN; 85 if (flag&FNONBLOCK) 86 break; 87 if (error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH, 88 ttopen, 0)) 89 return (error); 90 } 91 error = (*linesw[tp->t_line].l_open)(dev, tp, flag); 92 ptcwakeup(tp, FREAD|FWRITE); 93 return (error); 94 } 95 96 ptsclose(dev, flag, mode, p) 97 dev_t dev; 98 int flag, mode; 99 struct proc *p; 100 { 101 register struct tty *tp; 102 103 tp = &pt_tty[minor(dev)]; 104 (*linesw[tp->t_line].l_close)(tp, flag); 105 ttyclose(tp); 106 ptcwakeup(tp, FREAD|FWRITE); 107 } 108 109 ptsread(dev, uio, flag) 110 dev_t dev; 111 struct uio *uio; 112 { 113 struct proc *p = curproc; 114 register struct tty *tp = &pt_tty[minor(dev)]; 115 register struct pt_ioctl *pti = &pt_ioctl[minor(dev)]; 116 int error = 0; 117 118 again: 119 if (pti->pt_flags & PF_REMOTE) { 120 while (isbackground(p, tp)) { 121 if ((p->p_sigignore & sigmask(SIGTTIN)) || 122 (p->p_sigmask & sigmask(SIGTTIN)) || 123 p->p_pgrp->pg_jobc == 0 || 124 p->p_flag&SPPWAIT) 125 return (EIO); 126 pgsignal(p->p_pgrp, SIGTTIN, 1); 127 if (error = ttysleep(tp, (caddr_t)&lbolt, 128 TTIPRI | PCATCH, ttybg, 0)) 129 return (error); 130 } 131 if (tp->t_canq.c_cc == 0) { 132 if (flag & IO_NDELAY) 133 return (EWOULDBLOCK); 134 if (error = ttysleep(tp, (caddr_t)&tp->t_canq, 135 TTIPRI | PCATCH, ttyin, 0)) 136 return (error); 137 goto again; 138 } 139 while (tp->t_canq.c_cc > 1 && uio->uio_resid > 0) 140 if (ureadc(getc(&tp->t_canq), uio) < 0) { 141 error = EFAULT; 142 break; 143 } 144 if (tp->t_canq.c_cc == 1) 145 (void) getc(&tp->t_canq); 146 if (tp->t_canq.c_cc) 147 return (error); 148 } else 149 if (tp->t_oproc) 150 error = (*linesw[tp->t_line].l_read)(tp, uio, flag); 151 ptcwakeup(tp, FWRITE); 152 return (error); 153 } 154 155 /* 156 * Write to pseudo-tty. 157 * Wakeups of controlling tty will happen 158 * indirectly, when tty driver calls ptsstart. 159 */ 160 ptswrite(dev, uio, flag) 161 dev_t dev; 162 struct uio *uio; 163 { 164 register struct tty *tp; 165 166 tp = &pt_tty[minor(dev)]; 167 if (tp->t_oproc == 0) 168 return (EIO); 169 return ((*linesw[tp->t_line].l_write)(tp, uio, flag)); 170 } 171 172 /* 173 * Start output on pseudo-tty. 174 * Wake up process selecting or sleeping for input from controlling tty. 175 */ 176 ptsstart(tp) 177 struct tty *tp; 178 { 179 register struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)]; 180 181 if (tp->t_state & TS_TTSTOP) 182 return; 183 if (pti->pt_flags & PF_STOPPED) { 184 pti->pt_flags &= ~PF_STOPPED; 185 pti->pt_send = TIOCPKT_START; 186 } 187 ptcwakeup(tp, FREAD); 188 } 189 190 ptcwakeup(tp, flag) 191 struct tty *tp; 192 { 193 struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)]; 194 195 if (flag & FREAD) { 196 if (pti->pt_selr) { 197 selwakeup(pti->pt_selr, pti->pt_flags & PF_RCOLL); 198 pti->pt_selr = 0; 199 pti->pt_flags &= ~PF_RCOLL; 200 } 201 wakeup((caddr_t)&tp->t_outq.c_cf); 202 } 203 if (flag & FWRITE) { 204 if (pti->pt_selw) { 205 selwakeup(pti->pt_selw, pti->pt_flags & PF_WCOLL); 206 pti->pt_selw = 0; 207 pti->pt_flags &= ~PF_WCOLL; 208 } 209 wakeup((caddr_t)&tp->t_rawq.c_cf); 210 } 211 } 212 213 /*ARGSUSED*/ 214 #ifdef __STDC__ 215 ptcopen(dev_t dev, int flag, int devtype, struct proc *p) 216 #else 217 ptcopen(dev, flag, devtype, p) 218 dev_t dev; 219 int flag, devtype; 220 struct proc *p; 221 #endif 222 { 223 register struct tty *tp; 224 struct pt_ioctl *pti; 225 226 if (minor(dev) >= NPTY) 227 return (ENXIO); 228 tp = &pt_tty[minor(dev)]; 229 if (tp->t_oproc) 230 return (EIO); 231 tp->t_oproc = ptsstart; 232 (void)(*linesw[tp->t_line].l_modem)(tp, 1); 233 tp->t_lflag &= ~EXTPROC; 234 pti = &pt_ioctl[minor(dev)]; 235 pti->pt_flags = 0; 236 pti->pt_send = 0; 237 pti->pt_ucntl = 0; 238 return (0); 239 } 240 241 ptcclose(dev) 242 dev_t dev; 243 { 244 register struct tty *tp; 245 246 tp = &pt_tty[minor(dev)]; 247 (void)(*linesw[tp->t_line].l_modem)(tp, 0); 248 tp->t_state &= ~TS_CARR_ON; 249 tp->t_oproc = 0; /* mark closed */ 250 tp->t_session = 0; 251 } 252 253 ptcread(dev, uio, flag) 254 dev_t dev; 255 struct uio *uio; 256 { 257 register struct tty *tp = &pt_tty[minor(dev)]; 258 struct pt_ioctl *pti = &pt_ioctl[minor(dev)]; 259 char buf[BUFSIZ]; 260 int error = 0, cc; 261 262 /* 263 * We want to block until the slave 264 * is open, and there's something to read; 265 * but if we lost the slave or we're NBIO, 266 * then return the appropriate error instead. 267 */ 268 for (;;) { 269 if (tp->t_state&TS_ISOPEN) { 270 if (pti->pt_flags&PF_PKT && pti->pt_send) { 271 error = ureadc((int)pti->pt_send, uio); 272 if (error) 273 return (error); 274 if (pti->pt_send & TIOCPKT_IOCTL) { 275 cc = MIN(uio->uio_resid, 276 sizeof(tp->t_termios)); 277 uiomove(&tp->t_termios, cc, uio); 278 } 279 pti->pt_send = 0; 280 return (0); 281 } 282 if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) { 283 error = ureadc((int)pti->pt_ucntl, uio); 284 if (error) 285 return (error); 286 pti->pt_ucntl = 0; 287 return (0); 288 } 289 if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0) 290 break; 291 } 292 if ((tp->t_state&TS_CARR_ON) == 0) 293 return (0); /* EOF */ 294 if (flag & IO_NDELAY) 295 return (EWOULDBLOCK); 296 if (error = tsleep((caddr_t)&tp->t_outq.c_cf, TTIPRI | PCATCH, 297 ttyin, 0)) 298 return (error); 299 } 300 if (pti->pt_flags & (PF_PKT|PF_UCNTL)) 301 error = ureadc(0, uio); 302 while (uio->uio_resid > 0 && error == 0) { 303 cc = q_to_b(&tp->t_outq, buf, MIN(uio->uio_resid, BUFSIZ)); 304 if (cc <= 0) 305 break; 306 error = uiomove(buf, cc, uio); 307 } 308 if (tp->t_outq.c_cc <= tp->t_lowat) { 309 if (tp->t_state&TS_ASLEEP) { 310 tp->t_state &= ~TS_ASLEEP; 311 wakeup((caddr_t)&tp->t_outq); 312 } 313 if (tp->t_wsel) { 314 selwakeup(tp->t_wsel, tp->t_state & TS_WCOLL); 315 tp->t_wsel = 0; 316 tp->t_state &= ~TS_WCOLL; 317 } 318 } 319 return (error); 320 } 321 322 ptsstop(tp, flush) 323 register struct tty *tp; 324 int flush; 325 { 326 struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)]; 327 int flag; 328 329 /* note: FLUSHREAD and FLUSHWRITE already ok */ 330 if (flush == 0) { 331 flush = TIOCPKT_STOP; 332 pti->pt_flags |= PF_STOPPED; 333 } else 334 pti->pt_flags &= ~PF_STOPPED; 335 pti->pt_send |= flush; 336 /* change of perspective */ 337 flag = 0; 338 if (flush & FREAD) 339 flag |= FWRITE; 340 if (flush & FWRITE) 341 flag |= FREAD; 342 ptcwakeup(tp, flag); 343 } 344 345 ptcselect(dev, rw, p) 346 dev_t dev; 347 int rw; 348 struct proc *p; 349 { 350 register struct tty *tp = &pt_tty[minor(dev)]; 351 struct pt_ioctl *pti = &pt_ioctl[minor(dev)]; 352 struct proc *prev; 353 int s; 354 355 if ((tp->t_state&TS_CARR_ON) == 0) 356 return (1); 357 switch (rw) { 358 359 case FREAD: 360 /* 361 * Need to block timeouts (ttrstart). 362 */ 363 s = spltty(); 364 if ((tp->t_state&TS_ISOPEN) && 365 tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0) { 366 splx(s); 367 return (1); 368 } 369 splx(s); 370 /* FALLTHROUGH */ 371 372 case 0: /* exceptional */ 373 if ((tp->t_state&TS_ISOPEN) && 374 (pti->pt_flags&PF_PKT && pti->pt_send || 375 pti->pt_flags&PF_UCNTL && pti->pt_ucntl)) 376 return (1); 377 if ((prev = pti->pt_selr) && prev->p_wchan == (caddr_t)&selwait) 378 pti->pt_flags |= PF_RCOLL; 379 else 380 pti->pt_selr = p; 381 break; 382 383 384 case FWRITE: 385 if (tp->t_state&TS_ISOPEN) { 386 if (pti->pt_flags & PF_REMOTE) { 387 if (tp->t_canq.c_cc == 0) 388 return (1); 389 } else { 390 if (tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) 391 return (1); 392 if (tp->t_canq.c_cc == 0 && (tp->t_iflag&ICANON)) 393 return (1); 394 } 395 } 396 if ((prev = pti->pt_selw) && prev->p_wchan == (caddr_t)&selwait) 397 pti->pt_flags |= PF_WCOLL; 398 else 399 pti->pt_selw = p; 400 break; 401 402 } 403 return (0); 404 } 405 406 ptcwrite(dev, uio, flag) 407 dev_t dev; 408 register struct uio *uio; 409 { 410 register struct tty *tp = &pt_tty[minor(dev)]; 411 register u_char *cp; 412 register int cc = 0; 413 u_char locbuf[BUFSIZ]; 414 int cnt = 0; 415 struct pt_ioctl *pti = &pt_ioctl[minor(dev)]; 416 int error = 0; 417 418 again: 419 if ((tp->t_state&TS_ISOPEN) == 0) 420 goto block; 421 if (pti->pt_flags & PF_REMOTE) { 422 if (tp->t_canq.c_cc) 423 goto block; 424 while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG - 1) { 425 if (cc == 0) { 426 cc = min(uio->uio_resid, BUFSIZ); 427 cc = min(cc, TTYHOG - 1 - tp->t_canq.c_cc); 428 cp = locbuf; 429 error = uiomove((caddr_t)cp, cc, uio); 430 if (error) 431 return (error); 432 /* check again for safety */ 433 if ((tp->t_state&TS_ISOPEN) == 0) 434 return (EIO); 435 } 436 if (cc) 437 (void) b_to_q((char *)cp, cc, &tp->t_canq); 438 cc = 0; 439 } 440 (void) putc(0, &tp->t_canq); 441 ttwakeup(tp); 442 wakeup((caddr_t)&tp->t_canq); 443 return (0); 444 } 445 while (uio->uio_resid > 0) { 446 if (cc == 0) { 447 cc = min(uio->uio_resid, BUFSIZ); 448 cp = locbuf; 449 error = uiomove((caddr_t)cp, cc, uio); 450 if (error) 451 return (error); 452 /* check again for safety */ 453 if ((tp->t_state&TS_ISOPEN) == 0) 454 return (EIO); 455 } 456 while (cc > 0) { 457 if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 && 458 (tp->t_canq.c_cc > 0 || !(tp->t_iflag&ICANON))) { 459 wakeup((caddr_t)&tp->t_rawq); 460 goto block; 461 } 462 (*linesw[tp->t_line].l_rint)(*cp++, tp); 463 cnt++; 464 cc--; 465 } 466 cc = 0; 467 } 468 return (0); 469 block: 470 /* 471 * Come here to wait for slave to open, for space 472 * in outq, or space in rawq. 473 */ 474 if ((tp->t_state&TS_CARR_ON) == 0) 475 return (EIO); 476 if (flag & IO_NDELAY) { 477 /* adjust for data copied in but not written */ 478 uio->uio_resid += cc; 479 if (cnt == 0) 480 return (EWOULDBLOCK); 481 return (0); 482 } 483 if (error = tsleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI | PCATCH, 484 ttyout, 0)) { 485 /* adjust for data copied in but not written */ 486 uio->uio_resid += cc; 487 return (error); 488 } 489 goto again; 490 } 491 492 /*ARGSUSED*/ 493 ptyioctl(dev, cmd, data, flag) 494 caddr_t data; 495 dev_t dev; 496 { 497 register struct tty *tp = &pt_tty[minor(dev)]; 498 register struct pt_ioctl *pti = &pt_ioctl[minor(dev)]; 499 register u_char *cc = tp->t_cc; 500 int stop, error; 501 extern ttyinput(); 502 503 /* 504 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG. 505 * ttywflush(tp) will hang if there are characters in the outq. 506 */ 507 if (cmd == TIOCEXT) { 508 /* 509 * When the EXTPROC bit is being toggled, we need 510 * to send an TIOCPKT_IOCTL if the packet driver 511 * is turned on. 512 */ 513 if (*(int *)data) { 514 if (pti->pt_flags & PF_PKT) { 515 pti->pt_send |= TIOCPKT_IOCTL; 516 ptcwakeup(tp); 517 } 518 tp->t_lflag |= EXTPROC; 519 } else { 520 if ((tp->t_state & EXTPROC) && 521 (pti->pt_flags & PF_PKT)) { 522 pti->pt_send |= TIOCPKT_IOCTL; 523 ptcwakeup(tp); 524 } 525 tp->t_lflag &= ~EXTPROC; 526 } 527 return(0); 528 } else 529 if (cdevsw[major(dev)].d_open == ptcopen) 530 switch (cmd) { 531 532 case TIOCGPGRP: 533 /* 534 * We aviod calling ttioctl on the controller since, 535 * in that case, tp must be the controlling terminal. 536 */ 537 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0; 538 return (0); 539 540 case TIOCPKT: 541 if (*(int *)data) { 542 if (pti->pt_flags & PF_UCNTL) 543 return (EINVAL); 544 pti->pt_flags |= PF_PKT; 545 } else 546 pti->pt_flags &= ~PF_PKT; 547 return (0); 548 549 case TIOCUCNTL: 550 if (*(int *)data) { 551 if (pti->pt_flags & PF_PKT) 552 return (EINVAL); 553 pti->pt_flags |= PF_UCNTL; 554 } else 555 pti->pt_flags &= ~PF_UCNTL; 556 return (0); 557 558 case TIOCREMOTE: 559 if (*(int *)data) 560 pti->pt_flags |= PF_REMOTE; 561 else 562 pti->pt_flags &= ~PF_REMOTE; 563 ttyflush(tp, FREAD|FWRITE); 564 return (0); 565 566 case TIOCSETP: 567 case TIOCSETN: 568 case TIOCSETD: 569 case TIOCSETA: 570 case TIOCSETAW: 571 case TIOCSETAF: 572 while (getc(&tp->t_outq) >= 0) 573 ; 574 break; 575 576 case TIOCSIG: 577 if (*(unsigned int *)data >= NSIG) 578 return(EINVAL); 579 if ((tp->t_lflag&NOFLSH) == 0) 580 ttyflush(tp, FREAD|FWRITE); 581 pgsignal(tp->t_pgrp, *(unsigned int *)data, 1); 582 if ((*(unsigned int *)data == SIGINFO) && 583 ((tp->t_lflag&NOKERNINFO) == 0)) 584 ttyinfo(tp); 585 return(0); 586 } 587 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag); 588 if (error < 0) 589 error = ttioctl(tp, cmd, data, flag); 590 /* 591 * Since we use the tty queues internally, 592 * pty's can't be switched to disciplines which overwrite 593 * the queues. We can't tell anything about the discipline 594 * from here... 595 */ 596 if (linesw[tp->t_line].l_rint != ttyinput) { 597 (*linesw[tp->t_line].l_close)(tp, flag); 598 tp->t_line = TTYDISC; 599 (void)(*linesw[tp->t_line].l_open)(dev, tp, flag); 600 error = ENOTTY; 601 } 602 if (error < 0) { 603 if (pti->pt_flags & PF_UCNTL && 604 (cmd & ~0xff) == UIOCCMD(0)) { 605 if (cmd & 0xff) { 606 pti->pt_ucntl = (u_char)cmd; 607 ptcwakeup(tp, FREAD); 608 } 609 return (0); 610 } 611 error = ENOTTY; 612 } 613 /* 614 * If external processing and packet mode send ioctl packet. 615 */ 616 if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) { 617 switch(cmd) { 618 case TIOCSETA: 619 case TIOCSETAW: 620 case TIOCSETAF: 621 case TIOCSETP: 622 case TIOCSETN: 623 #ifdef COMPAT_43 624 case TIOCSETC: 625 case TIOCSLTC: 626 case TIOCLBIS: 627 case TIOCLBIC: 628 case TIOCLSET: 629 #endif 630 pti->pt_send |= TIOCPKT_IOCTL; 631 default: 632 break; 633 } 634 } 635 stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s')) 636 && CCEQ(cc[VSTART], CTRL('q')); 637 if (pti->pt_flags & PF_NOSTOP) { 638 if (stop) { 639 pti->pt_send &= ~TIOCPKT_NOSTOP; 640 pti->pt_send |= TIOCPKT_DOSTOP; 641 pti->pt_flags &= ~PF_NOSTOP; 642 ptcwakeup(tp, FREAD); 643 } 644 } else { 645 if (!stop) { 646 pti->pt_send &= ~TIOCPKT_DOSTOP; 647 pti->pt_send |= TIOCPKT_NOSTOP; 648 pti->pt_flags |= PF_NOSTOP; 649 ptcwakeup(tp, FREAD); 650 } 651 } 652 return (error); 653 } 654 #endif 655