1/* 2 * Copyright (c) 1988, 1990, 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 34#include "telnet_locl.h" 35 36RCSID("$Id: sys_bsd.c 10941 2002-04-18 16:18:43Z joda $"); 37 38/* 39 * The following routines try to encapsulate what is system dependent 40 * (at least between 4.x and dos) which is used in telnet.c. 41 */ 42 43int 44 tout, /* Output file descriptor */ 45 tin, /* Input file descriptor */ 46 net; 47 48struct termios old_tc = { 0 }; 49extern struct termios new_tc; 50 51# ifndef TCSANOW 52# ifdef TCSETS 53# define TCSANOW TCSETS 54# define TCSADRAIN TCSETSW 55# define tcgetattr(f, t) ioctl(f, TCGETS, (char *)t) 56# else 57# ifdef TCSETA 58# define TCSANOW TCSETA 59# define TCSADRAIN TCSETAW 60# define tcgetattr(f, t) ioctl(f, TCGETA, (char *)t) 61# else 62# define TCSANOW TIOCSETA 63# define TCSADRAIN TIOCSETAW 64# define tcgetattr(f, t) ioctl(f, TIOCGETA, (char *)t) 65# endif 66# endif 67# define tcsetattr(f, a, t) ioctl(f, a, (char *)t) 68# define cfgetospeed(ptr) ((ptr)->c_cflag&CBAUD) 69# ifdef CIBAUD 70# define cfgetispeed(ptr) (((ptr)->c_cflag&CIBAUD) >> IBSHIFT) 71# else 72# define cfgetispeed(ptr) cfgetospeed(ptr) 73# endif 74# endif /* TCSANOW */ 75 76static fd_set ibits, obits, xbits; 77 78 79void 80init_sys(void) 81{ 82 tout = fileno(stdout); 83 tin = fileno(stdin); 84 FD_ZERO(&ibits); 85 FD_ZERO(&obits); 86 FD_ZERO(&xbits); 87 88 errno = 0; 89} 90 91 92int 93TerminalWrite(char *buf, int n) 94{ 95 return write(tout, buf, n); 96} 97 98int 99TerminalRead(unsigned char *buf, int n) 100{ 101 return read(tin, buf, n); 102} 103 104/* 105 * 106 */ 107 108int 109TerminalAutoFlush(void) 110{ 111#if defined(LNOFLSH) 112 int flush; 113 114 ioctl(0, TIOCLGET, (char *)&flush); 115 return !(flush&LNOFLSH); /* if LNOFLSH, no autoflush */ 116#else /* LNOFLSH */ 117 return 1; 118#endif /* LNOFLSH */ 119} 120 121/* 122 * TerminalSpecialChars() 123 * 124 * Look at an input character to see if it is a special character 125 * and decide what to do. 126 * 127 * Output: 128 * 129 * 0 Don't add this character. 130 * 1 Do add this character 131 */ 132 133int 134TerminalSpecialChars(int c) 135{ 136 if (c == termIntChar) { 137 intp(); 138 return 0; 139 } else if (c == termQuitChar) { 140#ifdef KLUDGELINEMODE 141 if (kludgelinemode) 142 sendbrk(); 143 else 144#endif 145 sendabort(); 146 return 0; 147 } else if (c == termEofChar) { 148 if (my_want_state_is_will(TELOPT_LINEMODE)) { 149 sendeof(); 150 return 0; 151 } 152 return 1; 153 } else if (c == termSuspChar) { 154 sendsusp(); 155 return(0); 156 } else if (c == termFlushChar) { 157 xmitAO(); /* Transmit Abort Output */ 158 return 0; 159 } else if (!MODE_LOCAL_CHARS(globalmode)) { 160 if (c == termKillChar) { 161 xmitEL(); 162 return 0; 163 } else if (c == termEraseChar) { 164 xmitEC(); /* Transmit Erase Character */ 165 return 0; 166 } 167 } 168 return 1; 169} 170 171 172/* 173 * Flush output to the terminal 174 */ 175 176void 177TerminalFlushOutput(void) 178{ 179#ifdef TIOCFLUSH 180 ioctl(fileno(stdout), TIOCFLUSH, (char *) 0); 181#else 182 ioctl(fileno(stdout), TCFLSH, (char *) 0); 183#endif 184} 185 186void 187TerminalSaveState(void) 188{ 189 tcgetattr(0, &old_tc); 190 191 new_tc = old_tc; 192 193#ifndef VDISCARD 194 termFlushChar = CONTROL('O'); 195#endif 196#ifndef VWERASE 197 termWerasChar = CONTROL('W'); 198#endif 199#ifndef VREPRINT 200 termRprntChar = CONTROL('R'); 201#endif 202#ifndef VLNEXT 203 termLiteralNextChar = CONTROL('V'); 204#endif 205#ifndef VSTART 206 termStartChar = CONTROL('Q'); 207#endif 208#ifndef VSTOP 209 termStopChar = CONTROL('S'); 210#endif 211#ifndef VSTATUS 212 termAytChar = CONTROL('T'); 213#endif 214} 215 216cc_t* 217tcval(int func) 218{ 219 switch(func) { 220 case SLC_IP: return(&termIntChar); 221 case SLC_ABORT: return(&termQuitChar); 222 case SLC_EOF: return(&termEofChar); 223 case SLC_EC: return(&termEraseChar); 224 case SLC_EL: return(&termKillChar); 225 case SLC_XON: return(&termStartChar); 226 case SLC_XOFF: return(&termStopChar); 227 case SLC_FORW1: return(&termForw1Char); 228 case SLC_FORW2: return(&termForw2Char); 229# ifdef VDISCARD 230 case SLC_AO: return(&termFlushChar); 231# endif 232# ifdef VSUSP 233 case SLC_SUSP: return(&termSuspChar); 234# endif 235# ifdef VWERASE 236 case SLC_EW: return(&termWerasChar); 237# endif 238# ifdef VREPRINT 239 case SLC_RP: return(&termRprntChar); 240# endif 241# ifdef VLNEXT 242 case SLC_LNEXT: return(&termLiteralNextChar); 243# endif 244# ifdef VSTATUS 245 case SLC_AYT: return(&termAytChar); 246# endif 247 248 case SLC_SYNCH: 249 case SLC_BRK: 250 case SLC_EOR: 251 default: 252 return((cc_t *)0); 253 } 254} 255 256void 257TerminalDefaultChars(void) 258{ 259 memmove(new_tc.c_cc, old_tc.c_cc, sizeof(old_tc.c_cc)); 260# ifndef VDISCARD 261 termFlushChar = CONTROL('O'); 262# endif 263# ifndef VWERASE 264 termWerasChar = CONTROL('W'); 265# endif 266# ifndef VREPRINT 267 termRprntChar = CONTROL('R'); 268# endif 269# ifndef VLNEXT 270 termLiteralNextChar = CONTROL('V'); 271# endif 272# ifndef VSTART 273 termStartChar = CONTROL('Q'); 274# endif 275# ifndef VSTOP 276 termStopChar = CONTROL('S'); 277# endif 278# ifndef VSTATUS 279 termAytChar = CONTROL('T'); 280# endif 281} 282 283#ifdef notdef 284void 285TerminalRestoreState() 286{ 287} 288#endif 289 290/* 291 * TerminalNewMode - set up terminal to a specific mode. 292 * MODE_ECHO: do local terminal echo 293 * MODE_FLOW: do local flow control 294 * MODE_TRAPSIG: do local mapping to TELNET IAC sequences 295 * MODE_EDIT: do local line editing 296 * 297 * Command mode: 298 * MODE_ECHO|MODE_EDIT|MODE_FLOW|MODE_TRAPSIG 299 * local echo 300 * local editing 301 * local xon/xoff 302 * local signal mapping 303 * 304 * Linemode: 305 * local/no editing 306 * Both Linemode and Single Character mode: 307 * local/remote echo 308 * local/no xon/xoff 309 * local/no signal mapping 310 */ 311 312 313#ifdef SIGTSTP 314static RETSIGTYPE susp(int); 315#endif /* SIGTSTP */ 316#ifdef SIGINFO 317static RETSIGTYPE ayt(int); 318#endif 319 320void 321TerminalNewMode(int f) 322{ 323 static int prevmode = 0; 324 struct termios tmp_tc; 325 int onoff; 326 int old; 327 cc_t esc; 328 329 globalmode = f&~MODE_FORCE; 330 if (prevmode == f) 331 return; 332 333 /* 334 * Write any outstanding data before switching modes 335 * ttyflush() returns 0 only when there is no more data 336 * left to write out, it returns -1 if it couldn't do 337 * anything at all, otherwise it returns 1 + the number 338 * of characters left to write. 339 */ 340 old = ttyflush(SYNCHing|flushout); 341 if (old < 0 || old > 1) { 342 tcgetattr(tin, &tmp_tc); 343 do { 344 /* 345 * Wait for data to drain, then flush again. 346 */ 347 tcsetattr(tin, TCSADRAIN, &tmp_tc); 348 old = ttyflush(SYNCHing|flushout); 349 } while (old < 0 || old > 1); 350 } 351 352 old = prevmode; 353 prevmode = f&~MODE_FORCE; 354 tmp_tc = new_tc; 355 356 if (f&MODE_ECHO) { 357 tmp_tc.c_lflag |= ECHO; 358 tmp_tc.c_oflag |= ONLCR; 359 if (crlf) 360 tmp_tc.c_iflag |= ICRNL; 361 } else { 362 tmp_tc.c_lflag &= ~ECHO; 363 tmp_tc.c_oflag &= ~ONLCR; 364# ifdef notdef 365 if (crlf) 366 tmp_tc.c_iflag &= ~ICRNL; 367# endif 368 } 369 370 if ((f&MODE_FLOW) == 0) { 371 tmp_tc.c_iflag &= ~(IXOFF|IXON); /* Leave the IXANY bit alone */ 372 } else { 373 if (restartany < 0) { 374 tmp_tc.c_iflag |= IXOFF|IXON; /* Leave the IXANY bit alone */ 375 } else if (restartany > 0) { 376 tmp_tc.c_iflag |= IXOFF|IXON|IXANY; 377 } else { 378 tmp_tc.c_iflag |= IXOFF|IXON; 379 tmp_tc.c_iflag &= ~IXANY; 380 } 381 } 382 383 if ((f&MODE_TRAPSIG) == 0) { 384 tmp_tc.c_lflag &= ~ISIG; 385 localchars = 0; 386 } else { 387 tmp_tc.c_lflag |= ISIG; 388 localchars = 1; 389 } 390 391 if (f&MODE_EDIT) { 392 tmp_tc.c_lflag |= ICANON; 393 } else { 394 tmp_tc.c_lflag &= ~ICANON; 395 tmp_tc.c_iflag &= ~ICRNL; 396 tmp_tc.c_cc[VMIN] = 1; 397 tmp_tc.c_cc[VTIME] = 0; 398 } 399 400 if ((f&(MODE_EDIT|MODE_TRAPSIG)) == 0) { 401# ifdef VLNEXT 402 tmp_tc.c_cc[VLNEXT] = (cc_t)(_POSIX_VDISABLE); 403# endif 404 } 405 406 if (f&MODE_SOFT_TAB) { 407# ifdef OXTABS 408 tmp_tc.c_oflag |= OXTABS; 409# endif 410# ifdef TABDLY 411 tmp_tc.c_oflag &= ~TABDLY; 412 tmp_tc.c_oflag |= TAB3; 413# endif 414 } else { 415# ifdef OXTABS 416 tmp_tc.c_oflag &= ~OXTABS; 417# endif 418# ifdef TABDLY 419 tmp_tc.c_oflag &= ~TABDLY; 420# endif 421 } 422 423 if (f&MODE_LIT_ECHO) { 424# ifdef ECHOCTL 425 tmp_tc.c_lflag &= ~ECHOCTL; 426# endif 427 } else { 428# ifdef ECHOCTL 429 tmp_tc.c_lflag |= ECHOCTL; 430# endif 431 } 432 433 if (f == -1) { 434 onoff = 0; 435 } else { 436 if (f & MODE_INBIN) 437 tmp_tc.c_iflag &= ~ISTRIP; 438 else 439 tmp_tc.c_iflag |= ISTRIP; 440 if ((f & MODE_OUTBIN) || (f & MODE_OUT8)) { 441 tmp_tc.c_cflag &= ~(CSIZE|PARENB); 442 tmp_tc.c_cflag |= CS8; 443 if(f & MODE_OUTBIN) 444 tmp_tc.c_oflag &= ~OPOST; 445 else 446 tmp_tc.c_oflag |= OPOST; 447 } else { 448 tmp_tc.c_cflag &= ~(CSIZE|PARENB); 449 tmp_tc.c_cflag |= old_tc.c_cflag & (CSIZE|PARENB); 450 tmp_tc.c_oflag |= OPOST; 451 } 452 onoff = 1; 453 } 454 455 if (f != -1) { 456 457#ifdef SIGTSTP 458 signal(SIGTSTP, susp); 459#endif /* SIGTSTP */ 460#ifdef SIGINFO 461 signal(SIGINFO, ayt); 462#endif 463#ifdef NOKERNINFO 464 tmp_tc.c_lflag |= NOKERNINFO; 465#endif 466 /* 467 * We don't want to process ^Y here. It's just another 468 * character that we'll pass on to the back end. It has 469 * to process it because it will be processed when the 470 * user attempts to read it, not when we send it. 471 */ 472# ifdef VDSUSP 473 tmp_tc.c_cc[VDSUSP] = (cc_t)(_POSIX_VDISABLE); 474# endif 475 /* 476 * If the VEOL character is already set, then use VEOL2, 477 * otherwise use VEOL. 478 */ 479 esc = (rlogin != _POSIX_VDISABLE) ? rlogin : escape; 480 if ((tmp_tc.c_cc[VEOL] != esc) 481# ifdef VEOL2 482 && (tmp_tc.c_cc[VEOL2] != esc) 483# endif 484 ) { 485 if (tmp_tc.c_cc[VEOL] == (cc_t)(_POSIX_VDISABLE)) 486 tmp_tc.c_cc[VEOL] = esc; 487# ifdef VEOL2 488 else if (tmp_tc.c_cc[VEOL2] == (cc_t)(_POSIX_VDISABLE)) 489 tmp_tc.c_cc[VEOL2] = esc; 490# endif 491 } 492 } else { 493 sigset_t sm; 494 495#ifdef SIGINFO 496 signal(SIGINFO, ayt_status); 497#endif 498#ifdef SIGTSTP 499 signal(SIGTSTP, SIG_DFL); 500 sigemptyset(&sm); 501 sigaddset(&sm, SIGTSTP); 502 sigprocmask(SIG_UNBLOCK, &sm, NULL); 503#endif /* SIGTSTP */ 504 tmp_tc = old_tc; 505 } 506 if (tcsetattr(tin, TCSADRAIN, &tmp_tc) < 0) 507 tcsetattr(tin, TCSANOW, &tmp_tc); 508 509 ioctl(tin, FIONBIO, (char *)&onoff); 510 ioctl(tout, FIONBIO, (char *)&onoff); 511 512} 513 514/* 515 * Try to guess whether speeds are "encoded" (4.2BSD) or just numeric (4.4BSD). 516 */ 517#if B4800 != 4800 518#define DECODE_BAUD 519#endif 520 521#ifdef DECODE_BAUD 522#ifndef B7200 523#define B7200 B4800 524#endif 525 526#ifndef B14400 527#define B14400 B9600 528#endif 529 530#ifndef B19200 531# define B19200 B14400 532#endif 533 534#ifndef B28800 535#define B28800 B19200 536#endif 537 538#ifndef B38400 539# define B38400 B28800 540#endif 541 542#ifndef B57600 543#define B57600 B38400 544#endif 545 546#ifndef B76800 547#define B76800 B57600 548#endif 549 550#ifndef B115200 551#define B115200 B76800 552#endif 553 554#ifndef B230400 555#define B230400 B115200 556#endif 557 558 559/* 560 * This code assumes that the values B0, B50, B75... 561 * are in ascending order. They do not have to be 562 * contiguous. 563 */ 564struct termspeeds { 565 long speed; 566 long value; 567} termspeeds[] = { 568 { 0, B0 }, { 50, B50 }, { 75, B75 }, 569 { 110, B110 }, { 134, B134 }, { 150, B150 }, 570 { 200, B200 }, { 300, B300 }, { 600, B600 }, 571 { 1200, B1200 }, { 1800, B1800 }, { 2400, B2400 }, 572 { 4800, B4800 }, { 7200, B7200 }, { 9600, B9600 }, 573 { 14400, B14400 }, { 19200, B19200 }, { 28800, B28800 }, 574 { 38400, B38400 }, { 57600, B57600 }, { 115200, B115200 }, 575 { 230400, B230400 }, { -1, B230400 } 576}; 577#endif /* DECODE_BAUD */ 578 579void 580TerminalSpeeds(long *input_speed, long *output_speed) 581{ 582#ifdef DECODE_BAUD 583 struct termspeeds *tp; 584#endif /* DECODE_BAUD */ 585 long in, out; 586 587 out = cfgetospeed(&old_tc); 588 in = cfgetispeed(&old_tc); 589 if (in == 0) 590 in = out; 591 592#ifdef DECODE_BAUD 593 tp = termspeeds; 594 while ((tp->speed != -1) && (tp->value < in)) 595 tp++; 596 *input_speed = tp->speed; 597 598 tp = termspeeds; 599 while ((tp->speed != -1) && (tp->value < out)) 600 tp++; 601 *output_speed = tp->speed; 602#else /* DECODE_BAUD */ 603 *input_speed = in; 604 *output_speed = out; 605#endif /* DECODE_BAUD */ 606} 607 608int 609TerminalWindowSize(long *rows, long *cols) 610{ 611 struct winsize ws; 612 613 if (get_window_size (STDIN_FILENO, &ws) == 0) { 614 *rows = ws.ws_row; 615 *cols = ws.ws_col; 616 return 1; 617 } else 618 return 0; 619} 620 621int 622NetClose(int fd) 623{ 624 return close(fd); 625} 626 627 628void 629NetNonblockingIO(int fd, int onoff) 630{ 631 ioctl(fd, FIONBIO, (char *)&onoff); 632} 633 634 635/* 636 * Various signal handling routines. 637 */ 638 639static RETSIGTYPE deadpeer(int), 640 intr(int), intr2(int), susp(int), sendwin(int); 641#ifdef SIGINFO 642static RETSIGTYPE ayt(int); 643#endif 644 645 646 /* ARGSUSED */ 647static RETSIGTYPE 648deadpeer(int sig) 649{ 650 setcommandmode(); 651 longjmp(peerdied, -1); 652} 653 654int intr_happened = 0; 655int intr_waiting = 0; 656 657 /* ARGSUSED */ 658static RETSIGTYPE 659intr(int sig) 660{ 661 if (intr_waiting) { 662 intr_happened = 1; 663 return; 664 } 665 if (localchars) { 666 intp(); 667 return; 668 } 669 setcommandmode(); 670 longjmp(toplevel, -1); 671} 672 673 /* ARGSUSED */ 674static RETSIGTYPE 675intr2(int sig) 676{ 677 if (localchars) { 678#ifdef KLUDGELINEMODE 679 if (kludgelinemode) 680 sendbrk(); 681 else 682#endif 683 sendabort(); 684 return; 685 } 686} 687 688#ifdef SIGTSTP 689 /* ARGSUSED */ 690static RETSIGTYPE 691susp(int sig) 692{ 693 if ((rlogin != _POSIX_VDISABLE) && rlogin_susp()) 694 return; 695 if (localchars) 696 sendsusp(); 697} 698#endif 699 700#ifdef SIGWINCH 701 /* ARGSUSED */ 702static RETSIGTYPE 703sendwin(int sig) 704{ 705 if (connected) { 706 sendnaws(); 707 } 708} 709#endif 710 711#ifdef SIGINFO 712 /* ARGSUSED */ 713static RETSIGTYPE 714ayt(int sig) 715{ 716 if (connected) 717 sendayt(); 718 else 719 ayt_status(sig); 720} 721#endif 722 723 724void 725sys_telnet_init(void) 726{ 727 signal(SIGINT, intr); 728 signal(SIGQUIT, intr2); 729 signal(SIGPIPE, deadpeer); 730#ifdef SIGWINCH 731 signal(SIGWINCH, sendwin); 732#endif 733#ifdef SIGTSTP 734 signal(SIGTSTP, susp); 735#endif 736#ifdef SIGINFO 737 signal(SIGINFO, ayt); 738#endif 739 740 setconnmode(0); 741 742 NetNonblockingIO(net, 1); 743 744 745#if defined(SO_OOBINLINE) 746 if (SetSockOpt(net, SOL_SOCKET, SO_OOBINLINE, 1) == -1) 747 perror("setsockopt (SO_OOBINLINE) (ignored)"); 748#endif /* defined(SO_OOBINLINE) */ 749} 750 751/* 752 * Process rings - 753 * 754 * This routine tries to fill up/empty our various rings. 755 * 756 * The parameter specifies whether this is a poll operation, 757 * or a block-until-something-happens operation. 758 * 759 * The return value is 1 if something happened, 0 if not. 760 */ 761 762int 763process_rings(int netin, 764 int netout, 765 int netex, 766 int ttyin, 767 int ttyout, 768 int poll) /* If 0, then block until something to do */ 769{ 770 int c; 771 /* One wants to be a bit careful about setting returnValue 772 * to one, since a one implies we did some useful work, 773 * and therefore probably won't be called to block next 774 * time (TN3270 mode only). 775 */ 776 int returnValue = 0; 777 static struct timeval TimeValue = { 0 }; 778 779 if (net >= FD_SETSIZE 780 || tout >= FD_SETSIZE 781 || tin >= FD_SETSIZE) 782 errx (1, "fd too large"); 783 784 if (netout) { 785 FD_SET(net, &obits); 786 } 787 if (ttyout) { 788 FD_SET(tout, &obits); 789 } 790 if (ttyin) { 791 FD_SET(tin, &ibits); 792 } 793 if (netin) { 794 FD_SET(net, &ibits); 795 } 796#if !defined(SO_OOBINLINE) 797 if (netex) { 798 FD_SET(net, &xbits); 799 } 800#endif 801 if ((c = select(FD_SETSIZE, &ibits, &obits, &xbits, 802 (poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) { 803 if (c == -1) { 804 /* 805 * we can get EINTR if we are in line mode, 806 * and the user does an escape (TSTP), or 807 * some other signal generator. 808 */ 809 if (errno == EINTR) { 810 return 0; 811 } 812 /* I don't like this, does it ever happen? */ 813 printf("sleep(5) from telnet, after select\r\n"); 814 sleep(5); 815 } 816 return 0; 817 } 818 819 /* 820 * Any urgent data? 821 */ 822 if (FD_ISSET(net, &xbits)) { 823 FD_CLR(net, &xbits); 824 SYNCHing = 1; 825 ttyflush(1); /* flush already enqueued data */ 826 } 827 828 /* 829 * Something to read from the network... 830 */ 831 if (FD_ISSET(net, &ibits)) { 832 int canread; 833 834 FD_CLR(net, &ibits); 835 canread = ring_empty_consecutive(&netiring); 836#if !defined(SO_OOBINLINE) 837 /* 838 * In 4.2 (and some early 4.3) systems, the 839 * OOB indication and data handling in the kernel 840 * is such that if two separate TCP Urgent requests 841 * come in, one byte of TCP data will be overlaid. 842 * This is fatal for Telnet, but we try to live 843 * with it. 844 * 845 * In addition, in 4.2 (and...), a special protocol 846 * is needed to pick up the TCP Urgent data in 847 * the correct sequence. 848 * 849 * What we do is: if we think we are in urgent 850 * mode, we look to see if we are "at the mark". 851 * If we are, we do an OOB receive. If we run 852 * this twice, we will do the OOB receive twice, 853 * but the second will fail, since the second 854 * time we were "at the mark", but there wasn't 855 * any data there (the kernel doesn't reset 856 * "at the mark" until we do a normal read). 857 * Once we've read the OOB data, we go ahead 858 * and do normal reads. 859 * 860 * There is also another problem, which is that 861 * since the OOB byte we read doesn't put us 862 * out of OOB state, and since that byte is most 863 * likely the TELNET DM (data mark), we would 864 * stay in the TELNET SYNCH (SYNCHing) state. 865 * So, clocks to the rescue. If we've "just" 866 * received a DM, then we test for the 867 * presence of OOB data when the receive OOB 868 * fails (and AFTER we did the normal mode read 869 * to clear "at the mark"). 870 */ 871 if (SYNCHing) { 872 int atmark; 873 static int bogus_oob = 0, first = 1; 874 875 ioctl(net, SIOCATMARK, (char *)&atmark); 876 if (atmark) { 877 c = recv(net, netiring.supply, canread, MSG_OOB); 878 if ((c == -1) && (errno == EINVAL)) { 879 c = recv(net, netiring.supply, canread, 0); 880 if (clocks.didnetreceive < clocks.gotDM) { 881 SYNCHing = stilloob(); 882 } 883 } else if (first && c > 0) { 884 /* 885 * Bogosity check. Systems based on 4.2BSD 886 * do not return an error if you do a second 887 * recv(MSG_OOB). So, we do one. If it 888 * succeeds and returns exactly the same 889 * data, then assume that we are running 890 * on a broken system and set the bogus_oob 891 * flag. (If the data was different, then 892 * we probably got some valid new data, so 893 * increment the count...) 894 */ 895 int i; 896 i = recv(net, netiring.supply + c, canread - c, MSG_OOB); 897 if (i == c && 898 memcmp(netiring.supply, netiring.supply + c, i) == 0) { 899 bogus_oob = 1; 900 first = 0; 901 } else if (i < 0) { 902 bogus_oob = 0; 903 first = 0; 904 } else 905 c += i; 906 } 907 if (bogus_oob && c > 0) { 908 int i; 909 /* 910 * Bogosity. We have to do the read 911 * to clear the atmark to get out of 912 * an infinate loop. 913 */ 914 i = read(net, netiring.supply + c, canread - c); 915 if (i > 0) 916 c += i; 917 } 918 } else { 919 c = recv(net, netiring.supply, canread, 0); 920 } 921 } else { 922 c = recv(net, netiring.supply, canread, 0); 923 } 924 settimer(didnetreceive); 925#else /* !defined(SO_OOBINLINE) */ 926 c = recv(net, (char *)netiring.supply, canread, 0); 927#endif /* !defined(SO_OOBINLINE) */ 928 if (c < 0 && errno == EWOULDBLOCK) { 929 c = 0; 930 } else if (c <= 0) { 931 return -1; 932 } 933 if (netdata) { 934 Dump('<', netiring.supply, c); 935 } 936 if (c) 937 ring_supplied(&netiring, c); 938 returnValue = 1; 939 } 940 941 /* 942 * Something to read from the tty... 943 */ 944 if (FD_ISSET(tin, &ibits)) { 945 FD_CLR(tin, &ibits); 946 c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring)); 947 if (c < 0 && errno == EIO) 948 c = 0; 949 if (c < 0 && errno == EWOULDBLOCK) { 950 c = 0; 951 } else { 952 /* EOF detection for line mode!!!! */ 953 if ((c == 0) && MODE_LOCAL_CHARS(globalmode) && isatty(tin)) { 954 /* must be an EOF... */ 955 *ttyiring.supply = termEofChar; 956 c = 1; 957 } 958 if (c <= 0) { 959 return -1; 960 } 961 if (termdata) { 962 Dump('<', ttyiring.supply, c); 963 } 964 ring_supplied(&ttyiring, c); 965 } 966 returnValue = 1; /* did something useful */ 967 } 968 969 if (FD_ISSET(net, &obits)) { 970 FD_CLR(net, &obits); 971 returnValue |= netflush(); 972 } 973 if (FD_ISSET(tout, &obits)) { 974 FD_CLR(tout, &obits); 975 returnValue |= (ttyflush(SYNCHing|flushout) > 0); 976 } 977 978 return returnValue; 979} 980