1 /* 2 * Copyright (C) 1991, 1992 Linus Torvalds 3 * 4 * Added support for a Unix98-style ptmx device. 5 * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 6 * 7 * When reading this code see also fs/devpts. In particular note that the 8 * driver_data field is used by the devpts side as a binding to the devpts 9 * inode. 10 */ 11 12 #include <linux/module.h> 13 14 #include <linux/errno.h> 15 #include <linux/interrupt.h> 16 #include <linux/tty.h> 17 #include <linux/tty_flip.h> 18 #include <linux/fcntl.h> 19 #include <linux/sched.h> 20 #include <linux/string.h> 21 #include <linux/major.h> 22 #include <linux/mm.h> 23 #include <linux/init.h> 24 #include <linux/sysctl.h> 25 #include <linux/device.h> 26 #include <linux/uaccess.h> 27 #include <linux/bitops.h> 28 #include <linux/devpts_fs.h> 29 #include <linux/slab.h> 30 31 #include <asm/system.h> 32 33 #ifdef CONFIG_UNIX98_PTYS 34 static struct tty_driver *ptm_driver; 35 static struct tty_driver *pts_driver; 36 #endif 37 38 static void pty_close(struct tty_struct *tty, struct file *filp) 39 { 40 BUG_ON(!tty); 41 if (tty->driver->subtype == PTY_TYPE_MASTER) 42 WARN_ON(tty->count > 1); 43 else { 44 if (tty->count > 2) 45 return; 46 } 47 wake_up_interruptible(&tty->read_wait); 48 wake_up_interruptible(&tty->write_wait); 49 tty->packet = 0; 50 if (!tty->link) 51 return; 52 tty->link->packet = 0; 53 set_bit(TTY_OTHER_CLOSED, &tty->link->flags); 54 wake_up_interruptible(&tty->link->read_wait); 55 wake_up_interruptible(&tty->link->write_wait); 56 if (tty->driver->subtype == PTY_TYPE_MASTER) { 57 set_bit(TTY_OTHER_CLOSED, &tty->flags); 58 #ifdef CONFIG_UNIX98_PTYS 59 if (tty->driver == ptm_driver) 60 devpts_pty_kill(tty->link); 61 #endif 62 tty_unlock(); 63 tty_vhangup(tty->link); 64 tty_lock(); 65 } 66 } 67 68 /* 69 * The unthrottle routine is called by the line discipline to signal 70 * that it can receive more characters. For PTY's, the TTY_THROTTLED 71 * flag is always set, to force the line discipline to always call the 72 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE 73 * characters in the queue. This is necessary since each time this 74 * happens, we need to wake up any sleeping processes that could be 75 * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() 76 * for the pty buffer to be drained. 77 */ 78 static void pty_unthrottle(struct tty_struct *tty) 79 { 80 tty_wakeup(tty->link); 81 set_bit(TTY_THROTTLED, &tty->flags); 82 } 83 84 /** 85 * pty_space - report space left for writing 86 * @to: tty we are writing into 87 * 88 * The tty buffers allow 64K but we sneak a peak and clip at 8K this 89 * allows a lot of overspill room for echo and other fun messes to 90 * be handled properly 91 */ 92 93 static int pty_space(struct tty_struct *to) 94 { 95 int n = 8192 - to->buf.memory_used; 96 if (n < 0) 97 return 0; 98 return n; 99 } 100 101 /** 102 * pty_write - write to a pty 103 * @tty: the tty we write from 104 * @buf: kernel buffer of data 105 * @count: bytes to write 106 * 107 * Our "hardware" write method. Data is coming from the ldisc which 108 * may be in a non sleeping state. We simply throw this at the other 109 * end of the link as if we were an IRQ handler receiving stuff for 110 * the other side of the pty/tty pair. 111 */ 112 113 static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) 114 { 115 struct tty_struct *to = tty->link; 116 117 if (tty->stopped) 118 return 0; 119 120 if (c > 0) { 121 /* Stuff the data into the input queue of the other end */ 122 c = tty_insert_flip_string(to, buf, c); 123 /* And shovel */ 124 if (c) { 125 tty_flip_buffer_push(to); 126 tty_wakeup(tty); 127 } 128 } 129 return c; 130 } 131 132 /** 133 * pty_write_room - write space 134 * @tty: tty we are writing from 135 * 136 * Report how many bytes the ldisc can send into the queue for 137 * the other device. 138 */ 139 140 static int pty_write_room(struct tty_struct *tty) 141 { 142 if (tty->stopped) 143 return 0; 144 return pty_space(tty->link); 145 } 146 147 /** 148 * pty_chars_in_buffer - characters currently in our tx queue 149 * @tty: our tty 150 * 151 * Report how much we have in the transmit queue. As everything is 152 * instantly at the other end this is easy to implement. 153 */ 154 155 static int pty_chars_in_buffer(struct tty_struct *tty) 156 { 157 return 0; 158 } 159 160 /* Set the lock flag on a pty */ 161 static int pty_set_lock(struct tty_struct *tty, int __user *arg) 162 { 163 int val; 164 if (get_user(val, arg)) 165 return -EFAULT; 166 if (val) 167 set_bit(TTY_PTY_LOCK, &tty->flags); 168 else 169 clear_bit(TTY_PTY_LOCK, &tty->flags); 170 return 0; 171 } 172 173 /* Send a signal to the slave */ 174 static int pty_signal(struct tty_struct *tty, int sig) 175 { 176 unsigned long flags; 177 struct pid *pgrp; 178 179 if (tty->link) { 180 spin_lock_irqsave(&tty->link->ctrl_lock, flags); 181 pgrp = get_pid(tty->link->pgrp); 182 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); 183 184 kill_pgrp(pgrp, sig, 1); 185 put_pid(pgrp); 186 } 187 return 0; 188 } 189 190 static void pty_flush_buffer(struct tty_struct *tty) 191 { 192 struct tty_struct *to = tty->link; 193 unsigned long flags; 194 195 if (!to) 196 return; 197 /* tty_buffer_flush(to); FIXME */ 198 if (to->packet) { 199 spin_lock_irqsave(&tty->ctrl_lock, flags); 200 tty->ctrl_status |= TIOCPKT_FLUSHWRITE; 201 wake_up_interruptible(&to->read_wait); 202 spin_unlock_irqrestore(&tty->ctrl_lock, flags); 203 } 204 } 205 206 static int pty_open(struct tty_struct *tty, struct file *filp) 207 { 208 int retval = -ENODEV; 209 210 if (!tty || !tty->link) 211 goto out; 212 213 retval = -EIO; 214 if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) 215 goto out; 216 if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) 217 goto out; 218 if (tty->link->count != 1) 219 goto out; 220 221 clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); 222 set_bit(TTY_THROTTLED, &tty->flags); 223 retval = 0; 224 out: 225 return retval; 226 } 227 228 static void pty_set_termios(struct tty_struct *tty, 229 struct ktermios *old_termios) 230 { 231 tty->termios->c_cflag &= ~(CSIZE | PARENB); 232 tty->termios->c_cflag |= (CS8 | CREAD); 233 } 234 235 /** 236 * pty_do_resize - resize event 237 * @tty: tty being resized 238 * @ws: window size being set. 239 * 240 * Update the termios variables and send the necessary signals to 241 * peform a terminal resize correctly 242 */ 243 244 int pty_resize(struct tty_struct *tty, struct winsize *ws) 245 { 246 struct pid *pgrp, *rpgrp; 247 unsigned long flags; 248 struct tty_struct *pty = tty->link; 249 250 /* For a PTY we need to lock the tty side */ 251 mutex_lock(&tty->termios_mutex); 252 if (!memcmp(ws, &tty->winsize, sizeof(*ws))) 253 goto done; 254 255 /* Get the PID values and reference them so we can 256 avoid holding the tty ctrl lock while sending signals. 257 We need to lock these individually however. */ 258 259 spin_lock_irqsave(&tty->ctrl_lock, flags); 260 pgrp = get_pid(tty->pgrp); 261 spin_unlock_irqrestore(&tty->ctrl_lock, flags); 262 263 spin_lock_irqsave(&pty->ctrl_lock, flags); 264 rpgrp = get_pid(pty->pgrp); 265 spin_unlock_irqrestore(&pty->ctrl_lock, flags); 266 267 if (pgrp) 268 kill_pgrp(pgrp, SIGWINCH, 1); 269 if (rpgrp != pgrp && rpgrp) 270 kill_pgrp(rpgrp, SIGWINCH, 1); 271 272 put_pid(pgrp); 273 put_pid(rpgrp); 274 275 tty->winsize = *ws; 276 pty->winsize = *ws; /* Never used so will go away soon */ 277 done: 278 mutex_unlock(&tty->termios_mutex); 279 return 0; 280 } 281 282 /* Traditional BSD devices */ 283 #ifdef CONFIG_LEGACY_PTYS 284 285 static int pty_install(struct tty_driver *driver, struct tty_struct *tty) 286 { 287 struct tty_struct *o_tty; 288 int idx = tty->index; 289 int retval; 290 291 o_tty = alloc_tty_struct(); 292 if (!o_tty) 293 return -ENOMEM; 294 if (!try_module_get(driver->other->owner)) { 295 /* This cannot in fact currently happen */ 296 retval = -ENOMEM; 297 goto err_free_tty; 298 } 299 initialize_tty_struct(o_tty, driver->other, idx); 300 301 /* We always use new tty termios data so we can do this 302 the easy way .. */ 303 retval = tty_init_termios(tty); 304 if (retval) 305 goto err_deinit_tty; 306 307 retval = tty_init_termios(o_tty); 308 if (retval) 309 goto err_free_termios; 310 311 /* 312 * Everything allocated ... set up the o_tty structure. 313 */ 314 driver->other->ttys[idx] = o_tty; 315 tty_driver_kref_get(driver->other); 316 if (driver->subtype == PTY_TYPE_MASTER) 317 o_tty->count++; 318 /* Establish the links in both directions */ 319 tty->link = o_tty; 320 o_tty->link = tty; 321 322 tty_driver_kref_get(driver); 323 tty->count++; 324 driver->ttys[idx] = tty; 325 return 0; 326 err_free_termios: 327 tty_free_termios(tty); 328 err_deinit_tty: 329 deinitialize_tty_struct(o_tty); 330 module_put(o_tty->driver->owner); 331 err_free_tty: 332 free_tty_struct(o_tty); 333 return retval; 334 } 335 336 static int pty_bsd_ioctl(struct tty_struct *tty, 337 unsigned int cmd, unsigned long arg) 338 { 339 switch (cmd) { 340 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ 341 return pty_set_lock(tty, (int __user *) arg); 342 case TIOCSIG: /* Send signal to other side of pty */ 343 return pty_signal(tty, (int) arg); 344 } 345 return -ENOIOCTLCMD; 346 } 347 348 static int legacy_count = CONFIG_LEGACY_PTY_COUNT; 349 module_param(legacy_count, int, 0); 350 351 /* 352 * The master side of a pty can do TIOCSPTLCK and thus 353 * has pty_bsd_ioctl. 354 */ 355 static const struct tty_operations master_pty_ops_bsd = { 356 .install = pty_install, 357 .open = pty_open, 358 .close = pty_close, 359 .write = pty_write, 360 .write_room = pty_write_room, 361 .flush_buffer = pty_flush_buffer, 362 .chars_in_buffer = pty_chars_in_buffer, 363 .unthrottle = pty_unthrottle, 364 .set_termios = pty_set_termios, 365 .ioctl = pty_bsd_ioctl, 366 .resize = pty_resize 367 }; 368 369 static const struct tty_operations slave_pty_ops_bsd = { 370 .install = pty_install, 371 .open = pty_open, 372 .close = pty_close, 373 .write = pty_write, 374 .write_room = pty_write_room, 375 .flush_buffer = pty_flush_buffer, 376 .chars_in_buffer = pty_chars_in_buffer, 377 .unthrottle = pty_unthrottle, 378 .set_termios = pty_set_termios, 379 .resize = pty_resize 380 }; 381 382 static void __init legacy_pty_init(void) 383 { 384 struct tty_driver *pty_driver, *pty_slave_driver; 385 386 if (legacy_count <= 0) 387 return; 388 389 pty_driver = alloc_tty_driver(legacy_count); 390 if (!pty_driver) 391 panic("Couldn't allocate pty driver"); 392 393 pty_slave_driver = alloc_tty_driver(legacy_count); 394 if (!pty_slave_driver) 395 panic("Couldn't allocate pty slave driver"); 396 397 pty_driver->owner = THIS_MODULE; 398 pty_driver->driver_name = "pty_master"; 399 pty_driver->name = "pty"; 400 pty_driver->major = PTY_MASTER_MAJOR; 401 pty_driver->minor_start = 0; 402 pty_driver->type = TTY_DRIVER_TYPE_PTY; 403 pty_driver->subtype = PTY_TYPE_MASTER; 404 pty_driver->init_termios = tty_std_termios; 405 pty_driver->init_termios.c_iflag = 0; 406 pty_driver->init_termios.c_oflag = 0; 407 pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 408 pty_driver->init_termios.c_lflag = 0; 409 pty_driver->init_termios.c_ispeed = 38400; 410 pty_driver->init_termios.c_ospeed = 38400; 411 pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; 412 pty_driver->other = pty_slave_driver; 413 tty_set_operations(pty_driver, &master_pty_ops_bsd); 414 415 pty_slave_driver->owner = THIS_MODULE; 416 pty_slave_driver->driver_name = "pty_slave"; 417 pty_slave_driver->name = "ttyp"; 418 pty_slave_driver->major = PTY_SLAVE_MAJOR; 419 pty_slave_driver->minor_start = 0; 420 pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; 421 pty_slave_driver->subtype = PTY_TYPE_SLAVE; 422 pty_slave_driver->init_termios = tty_std_termios; 423 pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 424 pty_slave_driver->init_termios.c_ispeed = 38400; 425 pty_slave_driver->init_termios.c_ospeed = 38400; 426 pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | 427 TTY_DRIVER_REAL_RAW; 428 pty_slave_driver->other = pty_driver; 429 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); 430 431 if (tty_register_driver(pty_driver)) 432 panic("Couldn't register pty driver"); 433 if (tty_register_driver(pty_slave_driver)) 434 panic("Couldn't register pty slave driver"); 435 } 436 #else 437 static inline void legacy_pty_init(void) { } 438 #endif 439 440 /* Unix98 devices */ 441 #ifdef CONFIG_UNIX98_PTYS 442 /* 443 * sysctl support for setting limits on the number of Unix98 ptys allocated. 444 * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. 445 */ 446 int pty_limit = NR_UNIX98_PTY_DEFAULT; 447 static int pty_limit_min; 448 static int pty_limit_max = NR_UNIX98_PTY_MAX; 449 static int pty_count; 450 451 static struct cdev ptmx_cdev; 452 453 static struct ctl_table pty_table[] = { 454 { 455 .procname = "max", 456 .maxlen = sizeof(int), 457 .mode = 0644, 458 .data = &pty_limit, 459 .proc_handler = proc_dointvec_minmax, 460 .extra1 = &pty_limit_min, 461 .extra2 = &pty_limit_max, 462 }, { 463 .procname = "nr", 464 .maxlen = sizeof(int), 465 .mode = 0444, 466 .data = &pty_count, 467 .proc_handler = proc_dointvec, 468 }, 469 {} 470 }; 471 472 static struct ctl_table pty_kern_table[] = { 473 { 474 .procname = "pty", 475 .mode = 0555, 476 .child = pty_table, 477 }, 478 {} 479 }; 480 481 static struct ctl_table pty_root_table[] = { 482 { 483 .procname = "kernel", 484 .mode = 0555, 485 .child = pty_kern_table, 486 }, 487 {} 488 }; 489 490 491 static int pty_unix98_ioctl(struct tty_struct *tty, 492 unsigned int cmd, unsigned long arg) 493 { 494 switch (cmd) { 495 case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ 496 return pty_set_lock(tty, (int __user *)arg); 497 case TIOCGPTN: /* Get PT Number */ 498 return put_user(tty->index, (unsigned int __user *)arg); 499 case TIOCSIG: /* Send signal to other side of pty */ 500 return pty_signal(tty, (int) arg); 501 } 502 503 return -ENOIOCTLCMD; 504 } 505 506 /** 507 * ptm_unix98_lookup - find a pty master 508 * @driver: ptm driver 509 * @idx: tty index 510 * 511 * Look up a pty master device. Called under the tty_mutex for now. 512 * This provides our locking. 513 */ 514 515 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, 516 struct inode *ptm_inode, int idx) 517 { 518 struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); 519 if (tty) 520 tty = tty->link; 521 return tty; 522 } 523 524 /** 525 * pts_unix98_lookup - find a pty slave 526 * @driver: pts driver 527 * @idx: tty index 528 * 529 * Look up a pty master device. Called under the tty_mutex for now. 530 * This provides our locking. 531 */ 532 533 static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, 534 struct inode *pts_inode, int idx) 535 { 536 struct tty_struct *tty = devpts_get_tty(pts_inode, idx); 537 /* Master must be open before slave */ 538 if (!tty) 539 return ERR_PTR(-EIO); 540 return tty; 541 } 542 543 static void pty_unix98_shutdown(struct tty_struct *tty) 544 { 545 tty_driver_remove_tty(tty->driver, tty); 546 /* We have our own method as we don't use the tty index */ 547 kfree(tty->termios); 548 } 549 550 /* We have no need to install and remove our tty objects as devpts does all 551 the work for us */ 552 553 static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) 554 { 555 struct tty_struct *o_tty; 556 int idx = tty->index; 557 558 o_tty = alloc_tty_struct(); 559 if (!o_tty) 560 return -ENOMEM; 561 if (!try_module_get(driver->other->owner)) { 562 /* This cannot in fact currently happen */ 563 goto err_free_tty; 564 } 565 initialize_tty_struct(o_tty, driver->other, idx); 566 567 tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); 568 if (tty->termios == NULL) 569 goto err_free_mem; 570 *tty->termios = driver->init_termios; 571 tty->termios_locked = tty->termios + 1; 572 573 o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); 574 if (o_tty->termios == NULL) 575 goto err_free_mem; 576 *o_tty->termios = driver->other->init_termios; 577 o_tty->termios_locked = o_tty->termios + 1; 578 579 tty_driver_kref_get(driver->other); 580 if (driver->subtype == PTY_TYPE_MASTER) 581 o_tty->count++; 582 /* Establish the links in both directions */ 583 tty->link = o_tty; 584 o_tty->link = tty; 585 /* 586 * All structures have been allocated, so now we install them. 587 * Failures after this point use release_tty to clean up, so 588 * there's no need to null out the local pointers. 589 */ 590 tty_driver_kref_get(driver); 591 tty->count++; 592 pty_count++; 593 return 0; 594 err_free_mem: 595 deinitialize_tty_struct(o_tty); 596 kfree(o_tty->termios); 597 kfree(tty->termios); 598 module_put(o_tty->driver->owner); 599 err_free_tty: 600 free_tty_struct(o_tty); 601 return -ENOMEM; 602 } 603 604 static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) 605 { 606 pty_count--; 607 } 608 609 static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) 610 { 611 } 612 613 static const struct tty_operations ptm_unix98_ops = { 614 .lookup = ptm_unix98_lookup, 615 .install = pty_unix98_install, 616 .remove = ptm_unix98_remove, 617 .open = pty_open, 618 .close = pty_close, 619 .write = pty_write, 620 .write_room = pty_write_room, 621 .flush_buffer = pty_flush_buffer, 622 .chars_in_buffer = pty_chars_in_buffer, 623 .unthrottle = pty_unthrottle, 624 .set_termios = pty_set_termios, 625 .ioctl = pty_unix98_ioctl, 626 .shutdown = pty_unix98_shutdown, 627 .resize = pty_resize 628 }; 629 630 static const struct tty_operations pty_unix98_ops = { 631 .lookup = pts_unix98_lookup, 632 .install = pty_unix98_install, 633 .remove = pts_unix98_remove, 634 .open = pty_open, 635 .close = pty_close, 636 .write = pty_write, 637 .write_room = pty_write_room, 638 .flush_buffer = pty_flush_buffer, 639 .chars_in_buffer = pty_chars_in_buffer, 640 .unthrottle = pty_unthrottle, 641 .set_termios = pty_set_termios, 642 .shutdown = pty_unix98_shutdown 643 }; 644 645 /** 646 * ptmx_open - open a unix 98 pty master 647 * @inode: inode of device file 648 * @filp: file pointer to tty 649 * 650 * Allocate a unix98 pty master device from the ptmx driver. 651 * 652 * Locking: tty_mutex protects the init_dev work. tty->count should 653 * protect the rest. 654 * allocated_ptys_lock handles the list of free pty numbers 655 */ 656 657 static int ptmx_open(struct inode *inode, struct file *filp) 658 { 659 struct tty_struct *tty; 660 int retval; 661 int index; 662 663 nonseekable_open(inode, filp); 664 665 retval = tty_alloc_file(filp); 666 if (retval) 667 return retval; 668 669 /* find a device that is not in use. */ 670 tty_lock(); 671 index = devpts_new_index(inode); 672 tty_unlock(); 673 if (index < 0) { 674 retval = index; 675 goto err_file; 676 } 677 678 mutex_lock(&tty_mutex); 679 tty_lock(); 680 tty = tty_init_dev(ptm_driver, index, 1); 681 mutex_unlock(&tty_mutex); 682 683 if (IS_ERR(tty)) { 684 retval = PTR_ERR(tty); 685 goto out; 686 } 687 688 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ 689 690 tty_add_file(tty, filp); 691 692 retval = devpts_pty_new(inode, tty->link); 693 if (retval) 694 goto err_release; 695 696 retval = ptm_driver->ops->open(tty, filp); 697 if (retval) 698 goto err_release; 699 700 tty_unlock(); 701 return 0; 702 err_release: 703 tty_unlock(); 704 tty_release(inode, filp); 705 return retval; 706 out: 707 devpts_kill_index(inode, index); 708 tty_unlock(); 709 err_file: 710 tty_free_file(filp); 711 return retval; 712 } 713 714 static struct file_operations ptmx_fops; 715 716 static void __init unix98_pty_init(void) 717 { 718 ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); 719 if (!ptm_driver) 720 panic("Couldn't allocate Unix98 ptm driver"); 721 pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); 722 if (!pts_driver) 723 panic("Couldn't allocate Unix98 pts driver"); 724 725 ptm_driver->owner = THIS_MODULE; 726 ptm_driver->driver_name = "pty_master"; 727 ptm_driver->name = "ptm"; 728 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; 729 ptm_driver->minor_start = 0; 730 ptm_driver->type = TTY_DRIVER_TYPE_PTY; 731 ptm_driver->subtype = PTY_TYPE_MASTER; 732 ptm_driver->init_termios = tty_std_termios; 733 ptm_driver->init_termios.c_iflag = 0; 734 ptm_driver->init_termios.c_oflag = 0; 735 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 736 ptm_driver->init_termios.c_lflag = 0; 737 ptm_driver->init_termios.c_ispeed = 38400; 738 ptm_driver->init_termios.c_ospeed = 38400; 739 ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | 740 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; 741 ptm_driver->other = pts_driver; 742 tty_set_operations(ptm_driver, &ptm_unix98_ops); 743 744 pts_driver->owner = THIS_MODULE; 745 pts_driver->driver_name = "pty_slave"; 746 pts_driver->name = "pts"; 747 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; 748 pts_driver->minor_start = 0; 749 pts_driver->type = TTY_DRIVER_TYPE_PTY; 750 pts_driver->subtype = PTY_TYPE_SLAVE; 751 pts_driver->init_termios = tty_std_termios; 752 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; 753 pts_driver->init_termios.c_ispeed = 38400; 754 pts_driver->init_termios.c_ospeed = 38400; 755 pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | 756 TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; 757 pts_driver->other = ptm_driver; 758 tty_set_operations(pts_driver, &pty_unix98_ops); 759 760 if (tty_register_driver(ptm_driver)) 761 panic("Couldn't register Unix98 ptm driver"); 762 if (tty_register_driver(pts_driver)) 763 panic("Couldn't register Unix98 pts driver"); 764 765 register_sysctl_table(pty_root_table); 766 767 /* Now create the /dev/ptmx special device */ 768 tty_default_fops(&ptmx_fops); 769 ptmx_fops.open = ptmx_open; 770 771 cdev_init(&ptmx_cdev, &ptmx_fops); 772 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || 773 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) 774 panic("Couldn't register /dev/ptmx driver\n"); 775 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); 776 } 777 778 #else 779 static inline void unix98_pty_init(void) { } 780 #endif 781 782 static int __init pty_init(void) 783 { 784 legacy_pty_init(); 785 unix98_pty_init(); 786 return 0; 787 } 788 module_init(pty_init); 789