Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/tty_pts.c
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1 /* 2 * Copyright (c) 2003 Networks Associates Technology, Inc. 3 * Copyright (c) 2006 Robert N. M. Watson 4 * Copyright (c) 2006 Olivier Houchard 5 * All rights reserved. 6 * 7 * This software was developed for the FreeBSD Project in part by Network 8 * Associates Laboratories, the Security Research Division of Network 9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 10 * as part of the DARPA CHATS research program. 11 * 12 * Copyright (c) 1982, 1986, 1989, 1993 13 * The Regents of the University of California. All rights reserved. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * @(#)tty_pty.c 8.4 (Berkeley) 2/20/95 40 */ 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD: releng/7.3/sys/kern/tty_pts.c 181763 2008-08-15 19:22:33Z jhb $"); 44 45 /* 46 * Pseudo-teletype Driver 47 * (Actually two drivers, requiring two entries in 'cdevsw') 48 * 49 * XXX: This driver is currently disabled in FreeBSD 7.x due to reference 50 * count issues that prevent allocated but unused pty/pts devices from being 51 * garbage collected. 52 */ 53 #include "opt_compat.h" 54 #include "opt_tty.h" 55 #include <sys/param.h> 56 #include <sys/systm.h> 57 #include <sys/lock.h> 58 #include <sys/mutex.h> 59 #include <sys/sx.h> 60 #if defined(COMPAT_43TTY) 61 #include <sys/ioctl_compat.h> 62 #endif 63 #include <sys/priv.h> 64 #include <sys/proc.h> 65 #include <sys/queue.h> 66 #include <sys/tty.h> 67 #include <sys/fcntl.h> 68 #include <sys/poll.h> 69 #include <sys/kernel.h> 70 #include <sys/vnode.h> 71 #include <sys/signalvar.h> 72 #include <sys/malloc.h> 73 #include <sys/conf.h> 74 #include <sys/sysctl.h> 75 #include <sys/filio.h> 76 77 static MALLOC_DEFINE(M_PTY, "ptys", "pty data structures"); 78 79 static void ptsstart(struct tty *tp); 80 static void ptsstop(struct tty *tp, int rw); 81 static void ptcwakeup(struct tty *tp, int flag); 82 83 static d_open_t ptsopen; 84 static d_close_t ptsclose; 85 static d_read_t ptsread; 86 static d_write_t ptswrite; 87 static d_ioctl_t ptsioctl; 88 static d_ioctl_t ptcioctl; 89 static d_open_t ptcopen; 90 static d_close_t ptcclose; 91 static d_read_t ptcread; 92 static d_write_t ptcwrite; 93 static d_poll_t ptcpoll; 94 95 static struct cdevsw pts_cdevsw = { 96 .d_version = D_VERSION, 97 .d_open = ptsopen, 98 .d_close = ptsclose, 99 .d_read = ptsread, 100 .d_write = ptswrite, 101 .d_ioctl = ptsioctl, 102 .d_poll = ttypoll, 103 .d_name = "pts", 104 .d_flags = D_TTY | D_NEEDGIANT, 105 .d_kqfilter = ttykqfilter, 106 }; 107 108 static struct cdevsw ptc_cdevsw = { 109 .d_version = D_VERSION, 110 .d_open = ptcopen, 111 .d_close = ptcclose, 112 .d_read = ptcread, 113 .d_write = ptcwrite, 114 .d_ioctl = ptcioctl, 115 .d_poll = ptcpoll, 116 .d_name = "ptc", 117 .d_flags = D_TTY | D_NEEDGIANT, 118 .d_kqfilter = ttykqfilter, 119 }; 120 121 #define BUFSIZ 100 /* Chunk size iomoved to/from user */ 122 123 #define TSA_PTC_READ(tp) ((void *)&(tp)->t_outq.c_cf) 124 #define TSA_PTC_WRITE(tp) ((void *)&(tp)->t_rawq.c_cl) 125 #define TSA_PTS_READ(tp) ((void *)&(tp)->t_canq) 126 127 #define NUM_TO_MINOR(c) ((c & 0xff) | ((c & ~0xff) << 16)) 128 /*- 129 * Once a tty is allocated, it cannot (currently) be freed. As such, 130 * we keep a global list of ptys that have been used so we can recycle 131 * them. Another list is provided for released pts, which are 132 * not currently allocated, permitting reuse. pt_flags holds state 133 * associated with a particular session, so isn't overloaded for this. 134 * When a pty descriptor is unused, its number is set to -1 giving 135 * more consistent and traditional allocation orders to pty numbers. 136 * 137 * Locking: (p) indicates that the field is locked by the global pt_mtx. 138 * (c) indicates the value is constant after allocation. Other fields 139 * await tty locking generally, and are protected by Giant. 140 */ 141 struct pt_desc { 142 int pt_num; /* (c) pty number */ 143 LIST_ENTRY(pt_desc) pt_list; /* (p) global pty list */ 144 145 int pt_flags; 146 struct selinfo pt_selr, pt_selw; 147 u_char pt_send; 148 u_char pt_ucntl; 149 struct tty *pt_tty; 150 struct cdev *pt_devs, *pt_devc; 151 int pt_pts_open, pt_ptc_open; 152 struct prison *pt_prison; 153 }; 154 155 static struct mtx pt_mtx; 156 static LIST_HEAD(,pt_desc) pt_list; 157 static LIST_HEAD(,pt_desc) pt_free_list; 158 159 #define PF_PKT 0x008 /* packet mode */ 160 #define PF_STOPPED 0x010 /* user told stopped */ 161 #define PF_NOSTOP 0x040 162 #define PF_UCNTL 0x080 /* user control mode */ 163 164 static unsigned int next_avail_nb; 165 166 static int use_pts = 0; 167 168 static unsigned int max_pts = 1000; 169 170 static unsigned int nb_allocated; 171 172 TUNABLE_INT("kern.pts.enable", &use_pts); 173 174 SYSCTL_NODE(_kern, OID_AUTO, pts, CTLFLAG_RD, 0, "pts"); 175 176 SYSCTL_INT(_kern_pts, OID_AUTO, enable, CTLFLAG_RW, &use_pts, 0, 177 "enable pts"); 178 179 SYSCTL_INT(_kern_pts, OID_AUTO, max, CTLFLAG_RW, &max_pts, 0, "max pts"); 180 181 /* 182 * If there's a free pty descriptor in the pty descriptor list, retrieve it. 183 * Otherwise, allocate a new one, initialize it, and hook it up. If there's 184 * not a tty number, reject. 185 */ 186 static struct pt_desc * 187 pty_new(void) 188 { 189 struct pt_desc *pt; 190 int nb; 191 192 mtx_lock(&pt_mtx); 193 if (nb_allocated >= max_pts || nb_allocated == 0xffffff) { 194 mtx_unlock(&pt_mtx); 195 return (NULL); 196 } 197 nb_allocated++; 198 pt = LIST_FIRST(&pt_free_list); 199 if (pt) { 200 LIST_REMOVE(pt, pt_list); 201 } else { 202 nb = next_avail_nb++; 203 mtx_unlock(&pt_mtx); 204 pt = malloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO); 205 pt->pt_tty = ttyalloc(); 206 mtx_lock(&pt_mtx); 207 pt->pt_num = nb; 208 } 209 LIST_INSERT_HEAD(&pt_list, pt, pt_list); 210 mtx_unlock(&pt_mtx); 211 return (pt); 212 } 213 214 /* 215 * Release a pty descriptor back to the pool for reuse. The pty number 216 * remains allocated. 217 */ 218 static void 219 pty_release(void *v) 220 { 221 struct pt_desc *pt = (struct pt_desc *)v; 222 223 mtx_lock(&pt_mtx); 224 KASSERT(pt->pt_ptc_open == 0 && pt->pt_pts_open == 0, 225 ("pty_release: pts/%d freed while open\n", pt->pt_num)); 226 KASSERT(pt->pt_devs == NULL && pt->pt_devc == NULL, 227 ("pty_release: pts/%d freed whith non-null struct cdev\n", pt->pt_num)); 228 nb_allocated--; 229 LIST_REMOVE(pt, pt_list); 230 LIST_INSERT_HEAD(&pt_free_list, pt, pt_list); 231 mtx_unlock(&pt_mtx); 232 } 233 234 /* 235 * Given a pty descriptor, if both endpoints are closed, release all 236 * resources and destroy the device nodes to flush file system level 237 * state for the tty (owner, avoid races, etc). 238 */ 239 static void 240 pty_maybecleanup(struct pt_desc *pt) 241 { 242 struct cdev *pt_devs, *pt_devc; 243 244 if (pt->pt_ptc_open || pt->pt_pts_open) 245 return; 246 247 if (pt->pt_tty->t_refcnt > 1) 248 return; 249 250 if (bootverbose) 251 printf("destroying pty %d\n", pt->pt_num); 252 253 pt_devs = pt->pt_devs; 254 pt_devc = pt->pt_devc; 255 pt->pt_devs = pt->pt_devc = NULL; 256 pt->pt_tty->t_dev = NULL; 257 pt_devc->si_drv1 = NULL; 258 ttyrel(pt->pt_tty); 259 pt->pt_tty = NULL; 260 destroy_dev_sched(pt_devs); 261 destroy_dev_sched_cb(pt_devc, pty_release, pt); 262 } 263 264 /*ARGSUSED*/ 265 static int 266 ptsopen(struct cdev *dev, int flag, int devtype, struct thread *td) 267 { 268 struct tty *tp; 269 int error; 270 struct pt_desc *pt; 271 272 pt = dev->si_drv1; 273 tp = dev->si_tty; 274 if ((tp->t_state & TS_ISOPEN) == 0) 275 ttyinitmode(tp, 1, 0); 276 else if (tp->t_state & TS_XCLUDE && priv_check(td, 277 PRIV_TTY_EXCLUSIVE)) { 278 return (EBUSY); 279 } else if (pt->pt_prison != td->td_ucred->cr_prison && 280 priv_check(td, PRIV_TTY_PRISON)) { 281 return (EBUSY); 282 } 283 if (tp->t_oproc) /* Ctrlr still around. */ 284 ttyld_modem(tp, 1); 285 while ((tp->t_state & TS_CARR_ON) == 0) { 286 if (flag & FNONBLOCK) 287 break; 288 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH, 289 "ptsopn", 0); 290 if (error) 291 return (error); 292 } 293 error = ttyld_open(tp, dev); 294 if (error == 0) { 295 ptcwakeup(tp, FREAD|FWRITE); 296 pt->pt_pts_open = 1; 297 } 298 return (error); 299 } 300 301 static int 302 ptsclose(struct cdev *dev, int flag, int mode, struct thread *td) 303 { 304 struct pt_desc *pt = dev->si_drv1; 305 struct tty *tp; 306 int err; 307 308 tp = dev->si_tty; 309 err = ttyld_close(tp, flag); 310 ptsstop(tp, FREAD|FWRITE); 311 (void) tty_close(tp); 312 pt->pt_pts_open = 0; 313 pty_maybecleanup(pt); 314 return (err); 315 } 316 317 static int 318 ptsread(struct cdev *dev, struct uio *uio, int flag) 319 { 320 struct tty *tp = dev->si_tty; 321 int error = 0; 322 323 if (tp->t_oproc) 324 error = ttyld_read(tp, uio, flag); 325 ptcwakeup(tp, FWRITE); 326 return (error); 327 } 328 329 /* 330 * Write to pseudo-tty. 331 * Wakeups of controlling tty will happen 332 * indirectly, when tty driver calls ptsstart. 333 */ 334 static int 335 ptswrite(struct cdev *dev, struct uio *uio, int flag) 336 { 337 struct tty *tp; 338 339 tp = dev->si_tty; 340 if (tp->t_oproc == 0) 341 return (EIO); 342 return (ttyld_write(tp, uio, flag)); 343 } 344 345 /* 346 * Start output on pseudo-tty. 347 * Wake up process selecting or sleeping for input from controlling tty. 348 */ 349 static void 350 ptsstart(struct tty *tp) 351 { 352 struct pt_desc *pt = tp->t_dev->si_drv1; 353 354 if (tp->t_state & TS_TTSTOP) 355 return; 356 if (pt->pt_flags & PF_STOPPED) { 357 pt->pt_flags &= ~PF_STOPPED; 358 pt->pt_send = TIOCPKT_START; 359 } 360 ptcwakeup(tp, FREAD); 361 } 362 363 static void 364 ptcwakeup(struct tty *tp, int flag) 365 { 366 struct pt_desc *pt = tp->t_dev->si_drv1; 367 368 if (flag & FREAD) { 369 selwakeup(&pt->pt_selr); 370 wakeup(TSA_PTC_READ(tp)); 371 } 372 if (flag & FWRITE) { 373 selwakeup(&pt->pt_selw); 374 wakeup(TSA_PTC_WRITE(tp)); 375 } 376 } 377 378 /* 379 * ptcopen implementes exclusive access to the master/control device 380 * as well as creating the slave device based on the credential of the 381 * process opening the master. By creating the slave here, we avoid 382 * a race to access the master in terms of having a process with access 383 * to an incorrectly owned slave, but it does create the possibility 384 * that a racing process can cause a ptmx user to get EIO if it gets 385 * there first. Consumers of ptmx must look for EIO and retry if it 386 * happens. VFS locking may actually prevent this from occurring due 387 * to the lookup into devfs holding the vnode lock through open, but 388 * it's better to be careful. 389 */ 390 static int 391 ptcopen(struct cdev *dev, int flag, int devtype, struct thread *td) 392 { 393 struct pt_desc *pt; 394 struct tty *tp; 395 struct cdev *devs; 396 397 pt = dev->si_drv1; 398 if (pt == NULL) 399 return (EIO); 400 /* 401 * In case we have destroyed the struct tty at the last connect time, 402 * we need to recreate it. 403 */ 404 if (pt->pt_tty == NULL) { 405 tp = ttyalloc(); 406 mtx_lock(&pt_mtx); 407 if (pt->pt_tty == NULL) { 408 pt->pt_tty = tp; 409 dev->si_tty = pt->pt_tty; 410 mtx_unlock(&pt_mtx); 411 } else { 412 mtx_unlock(&pt_mtx); 413 ttyrel(tp); 414 } 415 } 416 tp = dev->si_tty; 417 if (tp->t_oproc) 418 return (EIO); 419 420 /* 421 * XXX: Might want to make the ownership/permissions here more 422 * configurable. 423 */ 424 if (pt->pt_devs) 425 devs = pt->pt_devs; 426 else 427 pt->pt_devs = devs = make_dev_cred(&pts_cdevsw, 428 NUM_TO_MINOR(pt->pt_num), 429 td->td_ucred, UID_ROOT, GID_WHEEL, 0666, "pts/%d", 430 pt->pt_num); 431 devs->si_drv1 = pt; 432 devs->si_tty = pt->pt_tty; 433 pt->pt_tty->t_dev = devs; 434 435 tp->t_timeout = -1; 436 tp->t_oproc = ptsstart; 437 tp->t_stop = ptsstop; 438 ttyld_modem(tp, 1); 439 tp->t_lflag &= ~EXTPROC; 440 pt = dev->si_drv1; 441 pt->pt_prison = td->td_ucred->cr_prison; 442 pt->pt_flags = 0; 443 pt->pt_send = 0; 444 pt->pt_ucntl = 0; 445 pt->pt_ptc_open = 1; 446 return (0); 447 } 448 449 static int 450 ptcclose(struct cdev *dev, int flags, int fmt, struct thread *td) 451 { 452 struct pt_desc *pt = dev->si_drv1; 453 struct tty *tp; 454 455 tp = dev->si_tty; 456 ttyld_modem(tp, 0); 457 458 /* 459 * XXX MDMBUF makes no sense for ptys but would inhibit the above 460 * l_modem(). CLOCAL makes sense but isn't supported. Special 461 * l_modem()s that ignore carrier drop make no sense for ptys but 462 * may be in use because other parts of the line discipline make 463 * sense for ptys. Recover by doing everything that a normal 464 * ttymodem() would have done except for sending a SIGHUP. 465 */ 466 if (tp->t_state & TS_ISOPEN) { 467 tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED); 468 tp->t_state |= TS_ZOMBIE; 469 ttyflush(tp, FREAD | FWRITE); 470 } 471 472 tp->t_oproc = 0; /* mark closed */ 473 pt->pt_ptc_open = 0; 474 pty_maybecleanup(pt); 475 return (0); 476 } 477 478 static int 479 ptcread(struct cdev *dev, struct uio *uio, int flag) 480 { 481 struct tty *tp = dev->si_tty; 482 struct pt_desc *pt = dev->si_drv1; 483 char buf[BUFSIZ]; 484 int error = 0, cc; 485 486 /* 487 * We want to block until the slave 488 * is open, and there's something to read; 489 * but if we lost the slave or we're NBIO, 490 * then return the appropriate error instead. 491 */ 492 for (;;) { 493 if (tp->t_state&TS_ISOPEN) { 494 if (pt->pt_flags&PF_PKT && pt->pt_send) { 495 error = ureadc((int)pt->pt_send, uio); 496 if (error) 497 return (error); 498 if (pt->pt_send & TIOCPKT_IOCTL) { 499 cc = min(uio->uio_resid, 500 sizeof(tp->t_termios)); 501 uiomove(&tp->t_termios, cc, uio); 502 } 503 pt->pt_send = 0; 504 return (0); 505 } 506 if (pt->pt_flags&PF_UCNTL && pt->pt_ucntl) { 507 error = ureadc((int)pt->pt_ucntl, uio); 508 if (error) 509 return (error); 510 pt->pt_ucntl = 0; 511 return (0); 512 } 513 if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0) 514 break; 515 } 516 if ((tp->t_state & TS_CONNECTED) == 0) 517 return (0); /* EOF */ 518 if (flag & O_NONBLOCK) 519 return (EWOULDBLOCK); 520 error = tsleep(TSA_PTC_READ(tp), TTIPRI | PCATCH, "ptcin", 0); 521 if (error) 522 return (error); 523 } 524 if (pt->pt_flags & (PF_PKT|PF_UCNTL)) 525 error = ureadc(0, uio); 526 while (uio->uio_resid > 0 && error == 0) { 527 cc = q_to_b(&tp->t_outq, buf, min(uio->uio_resid, BUFSIZ)); 528 if (cc <= 0) 529 break; 530 error = uiomove(buf, cc, uio); 531 } 532 ttwwakeup(tp); 533 return (error); 534 } 535 536 static void 537 ptsstop(struct tty *tp, int flush) 538 { 539 struct pt_desc *pt = tp->t_dev->si_drv1; 540 int flag; 541 542 /* note: FLUSHREAD and FLUSHWRITE already ok */ 543 if (flush == 0) { 544 flush = TIOCPKT_STOP; 545 pt->pt_flags |= PF_STOPPED; 546 } else 547 pt->pt_flags &= ~PF_STOPPED; 548 pt->pt_send |= flush; 549 /* change of perspective */ 550 flag = 0; 551 if (flush & FREAD) 552 flag |= FWRITE; 553 if (flush & FWRITE) 554 flag |= FREAD; 555 ptcwakeup(tp, flag); 556 } 557 558 static int 559 ptcpoll(struct cdev *dev, int events, struct thread *td) 560 { 561 struct tty *tp = dev->si_tty; 562 struct pt_desc *pt = dev->si_drv1; 563 int revents = 0; 564 int s; 565 566 if ((tp->t_state & TS_CONNECTED) == 0) 567 return (events & 568 (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM)); 569 570 /* 571 * Need to block timeouts (ttrstart). 572 */ 573 s = spltty(); 574 575 if (events & (POLLIN | POLLRDNORM)) 576 if ((tp->t_state & TS_ISOPEN) && 577 ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) || 578 ((pt->pt_flags & PF_PKT) && pt->pt_send) || 579 ((pt->pt_flags & PF_UCNTL) && pt->pt_ucntl))) 580 revents |= events & (POLLIN | POLLRDNORM); 581 582 if (events & (POLLOUT | POLLWRNORM)) 583 if (tp->t_state & TS_ISOPEN && 584 (((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) || 585 (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON))))) 586 revents |= events & (POLLOUT | POLLWRNORM); 587 588 if (events & POLLHUP) 589 if ((tp->t_state & TS_CARR_ON) == 0) 590 revents |= POLLHUP; 591 592 if (revents == 0) { 593 if (events & (POLLIN | POLLRDNORM)) 594 selrecord(td, &pt->pt_selr); 595 596 if (events & (POLLOUT | POLLWRNORM)) 597 selrecord(td, &pt->pt_selw); 598 } 599 splx(s); 600 601 return (revents); 602 } 603 604 static int 605 ptcwrite(struct cdev *dev, struct uio *uio, int flag) 606 { 607 struct tty *tp = dev->si_tty; 608 u_char *cp = 0; 609 int cc = 0; 610 u_char locbuf[BUFSIZ]; 611 int cnt = 0; 612 int error = 0; 613 614 again: 615 if ((tp->t_state&TS_ISOPEN) == 0) 616 goto block; 617 while (uio->uio_resid > 0 || cc > 0) { 618 if (cc == 0) { 619 cc = min(uio->uio_resid, BUFSIZ); 620 cp = locbuf; 621 error = uiomove(cp, cc, uio); 622 if (error) 623 return (error); 624 /* check again for safety */ 625 if ((tp->t_state & TS_ISOPEN) == 0) { 626 /* adjust for data copied in but not written */ 627 uio->uio_resid += cc; 628 return (EIO); 629 } 630 } 631 while (cc > 0) { 632 if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 && 633 (tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) { 634 wakeup(TSA_HUP_OR_INPUT(tp)); 635 goto block; 636 } 637 ttyld_rint(tp, *cp++); 638 cnt++; 639 cc--; 640 } 641 cc = 0; 642 } 643 return (0); 644 block: 645 /* 646 * Come here to wait for slave to open, for space 647 * in outq, or space in rawq, or an empty canq. 648 */ 649 if ((tp->t_state & TS_CONNECTED) == 0) { 650 /* adjust for data copied in but not written */ 651 uio->uio_resid += cc; 652 return (EIO); 653 } 654 if (flag & IO_NDELAY) { 655 /* adjust for data copied in but not written */ 656 uio->uio_resid += cc; 657 if (cnt == 0) 658 return (EWOULDBLOCK); 659 return (0); 660 } 661 error = tsleep(TSA_PTC_WRITE(tp), TTOPRI | PCATCH, "ptcout", 0); 662 if (error) { 663 /* adjust for data copied in but not written */ 664 uio->uio_resid += cc; 665 return (error); 666 } 667 goto again; 668 } 669 670 static int 671 ptcioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) 672 { 673 struct tty *tp = dev->si_tty; 674 struct pt_desc *pt = dev->si_drv1; 675 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ 676 defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 677 int ival; 678 #endif 679 680 switch (cmd) { 681 682 case TIOCGPGRP: 683 /* 684 * We avoid calling ttioctl on the controller since, 685 * in that case, tp must be the controlling terminal. 686 */ 687 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0; 688 return (0); 689 690 case TIOCPKT: 691 if (*(int *)data) { 692 if (pt->pt_flags & PF_UCNTL) 693 return (EINVAL); 694 pt->pt_flags |= PF_PKT; 695 } else 696 pt->pt_flags &= ~PF_PKT; 697 return (0); 698 699 case TIOCUCNTL: 700 if (*(int *)data) { 701 if (pt->pt_flags & PF_PKT) 702 return (EINVAL); 703 pt->pt_flags |= PF_UCNTL; 704 } else 705 pt->pt_flags &= ~PF_UCNTL; 706 return (0); 707 case TIOCGPTN: 708 *(unsigned int *)data = pt->pt_num; 709 return (0); 710 } 711 712 /* 713 * The rest of the ioctls shouldn't be called until 714 * the slave is open. 715 */ 716 if ((tp->t_state & TS_ISOPEN) == 0) { 717 if (cmd == TIOCGETA) { 718 /* 719 * TIOCGETA is used by isatty() to make sure it's 720 * a tty. Linux openpty() calls isatty() very early, 721 * before the slave is opened, so don't actually 722 * fill the struct termios, but just let isatty() 723 * know it's a tty. 724 */ 725 return (0); 726 } 727 if (cmd != FIONBIO && cmd != FIOASYNC) 728 return (EAGAIN); 729 } 730 731 switch (cmd) { 732 #ifdef COMPAT_43TTY 733 case TIOCSETP: 734 case TIOCSETN: 735 #endif 736 case TIOCSETD: 737 case TIOCSETA: 738 case TIOCSETAW: 739 case TIOCSETAF: 740 /* 741 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG. 742 * ttywflush(tp) will hang if there are characters in 743 * the outq. 744 */ 745 ndflush(&tp->t_outq, tp->t_outq.c_cc); 746 break; 747 748 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ 749 defined(COMPAT_FREEBSD4) || defined(COMPAT_43) 750 case _IO('t', 95): 751 ival = IOCPARM_IVAL(data); 752 data = (caddr_t)&ival; 753 /* FALLTHROUGH */ 754 #endif 755 case TIOCSIG: 756 if (*(unsigned int *)data >= NSIG || 757 *(unsigned int *)data == 0) 758 return(EINVAL); 759 if ((tp->t_lflag&NOFLSH) == 0) 760 ttyflush(tp, FREAD|FWRITE); 761 if (tp->t_pgrp != NULL) { 762 PGRP_LOCK(tp->t_pgrp); 763 pgsignal(tp->t_pgrp, *(unsigned int *)data, 1); 764 PGRP_UNLOCK(tp->t_pgrp); 765 } 766 if ((*(unsigned int *)data == SIGINFO) && 767 ((tp->t_lflag&NOKERNINFO) == 0)) 768 ttyinfo(tp); 769 return(0); 770 } 771 return (ptsioctl(dev, cmd, data, flag, td)); 772 } 773 /*ARGSUSED*/ 774 static int 775 ptsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) 776 { 777 struct tty *tp = dev->si_tty; 778 struct pt_desc *pt = dev->si_drv1; 779 u_char *cc = tp->t_cc; 780 int stop, error; 781 782 if (cmd == TIOCEXT) { 783 /* 784 * When the EXTPROC bit is being toggled, we need 785 * to send an TIOCPKT_IOCTL if the packet driver 786 * is turned on. 787 */ 788 if (*(int *)data) { 789 if (pt->pt_flags & PF_PKT) { 790 pt->pt_send |= TIOCPKT_IOCTL; 791 ptcwakeup(tp, FREAD); 792 } 793 tp->t_lflag |= EXTPROC; 794 } else { 795 if ((tp->t_lflag & EXTPROC) && 796 (pt->pt_flags & PF_PKT)) { 797 pt->pt_send |= TIOCPKT_IOCTL; 798 ptcwakeup(tp, FREAD); 799 } 800 tp->t_lflag &= ~EXTPROC; 801 } 802 return(0); 803 } 804 error = ttioctl(tp, cmd, data, flag); 805 if (error == ENOTTY) { 806 if (pt->pt_flags & PF_UCNTL && 807 (cmd & ~0xff) == UIOCCMD(0)) { 808 if (cmd & 0xff) { 809 pt->pt_ucntl = (u_char)cmd; 810 ptcwakeup(tp, FREAD); 811 } 812 return (0); 813 } 814 error = ENOTTY; 815 } 816 /* 817 * If external processing and packet mode send ioctl packet. 818 */ 819 if ((tp->t_lflag&EXTPROC) && (pt->pt_flags & PF_PKT)) { 820 switch(cmd) { 821 case TIOCSETA: 822 case TIOCSETAW: 823 case TIOCSETAF: 824 #ifdef COMPAT_43TTY 825 case TIOCSETP: 826 case TIOCSETN: 827 case TIOCSETC: 828 case TIOCSLTC: 829 case TIOCLBIS: 830 case TIOCLBIC: 831 case TIOCLSET: 832 #endif 833 pt->pt_send |= TIOCPKT_IOCTL; 834 ptcwakeup(tp, FREAD); 835 break; 836 default: 837 break; 838 } 839 } 840 stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s')) 841 && CCEQ(cc[VSTART], CTRL('q')); 842 if (pt->pt_flags & PF_NOSTOP) { 843 if (stop) { 844 pt->pt_send &= ~TIOCPKT_NOSTOP; 845 pt->pt_send |= TIOCPKT_DOSTOP; 846 pt->pt_flags &= ~PF_NOSTOP; 847 ptcwakeup(tp, FREAD); 848 } 849 } else { 850 if (!stop) { 851 pt->pt_send &= ~TIOCPKT_DOSTOP; 852 pt->pt_send |= TIOCPKT_NOSTOP; 853 pt->pt_flags |= PF_NOSTOP; 854 ptcwakeup(tp, FREAD); 855 } 856 } 857 return (error); 858 } 859 860 /* 861 * Match lookups on /dev/ptmx, find the next free pty (if any), set up 862 * the pty descriptor, register it, and return a reference to the master. 863 * 864 * pts == /dev/pts/xxx (oldstyle: ttyp...) 865 * ptc == /dev/pty/xxx (oldstyle: ptyp...) 866 */ 867 static void 868 pty_clone(void *arg, struct ucred *cred, char *name, int namelen, 869 struct cdev **dev) 870 { 871 struct pt_desc *pt; 872 struct cdev *devc; 873 874 if (!use_pts) 875 return; 876 877 if (*dev != NULL) 878 return; 879 880 if (strcmp(name, "ptmx") != 0) 881 return; 882 883 mtx_lock(&Giant); 884 pt = pty_new(); 885 if (pt == NULL) { 886 mtx_unlock(&Giant); 887 return; 888 } 889 890 /* 891 * XXX: Lack of locking here considered worrying. We expose the 892 * pts/pty device nodes before they are fully initialized, although 893 * Giant likely protects us (unless make_dev blocks...?). 894 * 895 * XXX: If a process performs a lookup on /dev/ptmx but never an 896 * open, we won't GC the device node. We should have a callout 897 * sometime later that GC's device instances that were never 898 * opened, or some way to tell devfs that "this had better be for 899 * an open() or we won't create a device". 900 */ 901 pt->pt_devc = devc = make_dev_credf(MAKEDEV_REF, &ptc_cdevsw, 902 NUM_TO_MINOR(pt->pt_num), cred, UID_ROOT, GID_WHEEL, 0666, 903 "pty/%d", pt->pt_num); 904 905 devc->si_drv1 = pt; 906 devc->si_tty = pt->pt_tty; 907 *dev = devc; 908 mtx_unlock(&Giant); 909 910 if (bootverbose) 911 printf("pty_clone: allocated pty %d to uid %d\n", pt->pt_num, 912 cred->cr_ruid); 913 914 return; 915 } 916 917 static void 918 pty_drvinit(void *unused) 919 { 920 921 mtx_init(&pt_mtx, "pt_mtx", NULL, MTX_DEF); 922 LIST_INIT(&pt_list); 923 LIST_INIT(&pt_free_list); 924 EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000); 925 } 926 927 SYSINIT(ptydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,pty_drvinit,NULL);
Cache object: 86590e3d16bd67e6cc6014c735380714
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