state.c revision 1.8
1 /* 2 * Copyright (c) 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 34 #ifndef lint 35 /* from: static char sccsid[] = "@(#)state.c 8.5 (Berkeley) 5/30/95"; */ 36 static char rcsid[] = "$NetBSD: state.c,v 1.8 1996/02/24 01:22:19 jtk Exp $"; 37 #endif /* not lint */ 38 39 #include "telnetd.h" 40 #if defined(AUTHENTICATION) 41 #include <libtelnet/auth.h> 42 #endif 43 44 unsigned char doopt[] = { IAC, DO, '%', 'c', 0 }; 45 unsigned char dont[] = { IAC, DONT, '%', 'c', 0 }; 46 unsigned char will[] = { IAC, WILL, '%', 'c', 0 }; 47 unsigned char wont[] = { IAC, WONT, '%', 'c', 0 }; 48 int not42 = 1; 49 50 /* 51 * Buffer for sub-options, and macros 52 * for suboptions buffer manipulations 53 */ 54 unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer; 55 56 #define SB_CLEAR() subpointer = subbuffer 57 #define SB_TERM() { subend = subpointer; SB_CLEAR(); } 58 #define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \ 59 *subpointer++ = (c); \ 60 } 61 #define SB_GET() ((*subpointer++)&0xff) 62 #define SB_EOF() (subpointer >= subend) 63 #define SB_LEN() (subend - subpointer) 64 65 #ifdef ENV_HACK 66 unsigned char *subsave; 67 #define SB_SAVE() subsave = subpointer; 68 #define SB_RESTORE() subpointer = subsave; 69 #endif 70 71 72 /* 73 * State for recv fsm 74 */ 75 #define TS_DATA 0 /* base state */ 76 #define TS_IAC 1 /* look for double IAC's */ 77 #define TS_CR 2 /* CR-LF ->'s CR */ 78 #define TS_SB 3 /* throw away begin's... */ 79 #define TS_SE 4 /* ...end's (suboption negotiation) */ 80 #define TS_WILL 5 /* will option negotiation */ 81 #define TS_WONT 6 /* wont " */ 82 #define TS_DO 7 /* do " */ 83 #define TS_DONT 8 /* dont " */ 84 85 void 86 telrcv() 87 { 88 register int c; 89 static int state = TS_DATA; 90 #if defined(CRAY2) && defined(UNICOS5) 91 char *opfrontp = pfrontp; 92 #endif 93 94 while (ncc > 0) { 95 if ((&ptyobuf[BUFSIZ] - pfrontp) < 2) 96 break; 97 c = *netip++ & 0377, ncc--; 98 switch (state) { 99 100 case TS_CR: 101 state = TS_DATA; 102 /* Strip off \n or \0 after a \r */ 103 if ((c == 0) || (c == '\n')) { 104 break; 105 } 106 /* FALL THROUGH */ 107 108 case TS_DATA: 109 if (c == IAC) { 110 state = TS_IAC; 111 break; 112 } 113 /* 114 * We now map \r\n ==> \r for pragmatic reasons. 115 * Many client implementations send \r\n when 116 * the user hits the CarriageReturn key. 117 * 118 * We USED to map \r\n ==> \n, since \r\n says 119 * that we want to be in column 1 of the next 120 * printable line, and \n is the standard 121 * unix way of saying that (\r is only good 122 * if CRMOD is set, which it normally is). 123 */ 124 if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) { 125 int nc = *netip; 126 #ifdef LINEMODE 127 /* 128 * If we are operating in linemode, 129 * convert to local end-of-line. 130 */ 131 if (linemode && (ncc > 0) && (('\n' == nc) || 132 ((0 == nc) && tty_iscrnl())) ) { 133 netip++; ncc--; 134 c = '\n'; 135 } else 136 #endif 137 { 138 state = TS_CR; 139 } 140 } 141 *pfrontp++ = c; 142 break; 143 144 case TS_IAC: 145 gotiac: switch (c) { 146 147 /* 148 * Send the process on the pty side an 149 * interrupt. Do this with a NULL or 150 * interrupt char; depending on the tty mode. 151 */ 152 case IP: 153 DIAG(TD_OPTIONS, 154 printoption("td: recv IAC", c)); 155 interrupt(); 156 break; 157 158 case BREAK: 159 DIAG(TD_OPTIONS, 160 printoption("td: recv IAC", c)); 161 sendbrk(); 162 break; 163 164 /* 165 * Are You There? 166 */ 167 case AYT: 168 DIAG(TD_OPTIONS, 169 printoption("td: recv IAC", c)); 170 recv_ayt(); 171 break; 172 173 /* 174 * Abort Output 175 */ 176 case AO: 177 { 178 DIAG(TD_OPTIONS, 179 printoption("td: recv IAC", c)); 180 ptyflush(); /* half-hearted */ 181 init_termbuf(); 182 183 if (slctab[SLC_AO].sptr && 184 *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) { 185 *pfrontp++ = 186 (unsigned char)*slctab[SLC_AO].sptr; 187 } 188 189 netclear(); /* clear buffer back */ 190 *nfrontp++ = IAC; 191 *nfrontp++ = DM; 192 neturg = nfrontp-1; /* off by one XXX */ 193 DIAG(TD_OPTIONS, 194 printoption("td: send IAC", DM)); 195 break; 196 } 197 198 /* 199 * Erase Character and 200 * Erase Line 201 */ 202 case EC: 203 case EL: 204 { 205 cc_t ch; 206 207 DIAG(TD_OPTIONS, 208 printoption("td: recv IAC", c)); 209 ptyflush(); /* half-hearted */ 210 init_termbuf(); 211 if (c == EC) 212 ch = *slctab[SLC_EC].sptr; 213 else 214 ch = *slctab[SLC_EL].sptr; 215 if (ch != (cc_t)(_POSIX_VDISABLE)) 216 *pfrontp++ = (unsigned char)ch; 217 break; 218 } 219 220 /* 221 * Check for urgent data... 222 */ 223 case DM: 224 DIAG(TD_OPTIONS, 225 printoption("td: recv IAC", c)); 226 SYNCHing = stilloob(net); 227 settimer(gotDM); 228 break; 229 230 231 /* 232 * Begin option subnegotiation... 233 */ 234 case SB: 235 state = TS_SB; 236 SB_CLEAR(); 237 continue; 238 239 case WILL: 240 state = TS_WILL; 241 continue; 242 243 case WONT: 244 state = TS_WONT; 245 continue; 246 247 case DO: 248 state = TS_DO; 249 continue; 250 251 case DONT: 252 state = TS_DONT; 253 continue; 254 case EOR: 255 if (his_state_is_will(TELOPT_EOR)) 256 doeof(); 257 break; 258 259 /* 260 * Handle RFC 10xx Telnet linemode option additions 261 * to command stream (EOF, SUSP, ABORT). 262 */ 263 case xEOF: 264 doeof(); 265 break; 266 267 case SUSP: 268 sendsusp(); 269 break; 270 271 case ABORT: 272 sendbrk(); 273 break; 274 275 case IAC: 276 *pfrontp++ = c; 277 break; 278 } 279 state = TS_DATA; 280 break; 281 282 case TS_SB: 283 if (c == IAC) { 284 state = TS_SE; 285 } else { 286 SB_ACCUM(c); 287 } 288 break; 289 290 case TS_SE: 291 if (c != SE) { 292 if (c != IAC) { 293 /* 294 * bad form of suboption negotiation. 295 * handle it in such a way as to avoid 296 * damage to local state. Parse 297 * suboption buffer found so far, 298 * then treat remaining stream as 299 * another command sequence. 300 */ 301 302 /* for DIAGNOSTICS */ 303 SB_ACCUM(IAC); 304 SB_ACCUM(c); 305 subpointer -= 2; 306 307 SB_TERM(); 308 suboption(); 309 state = TS_IAC; 310 goto gotiac; 311 } 312 SB_ACCUM(c); 313 state = TS_SB; 314 } else { 315 /* for DIAGNOSTICS */ 316 SB_ACCUM(IAC); 317 SB_ACCUM(SE); 318 subpointer -= 2; 319 320 SB_TERM(); 321 suboption(); /* handle sub-option */ 322 state = TS_DATA; 323 } 324 break; 325 326 case TS_WILL: 327 willoption(c); 328 state = TS_DATA; 329 continue; 330 331 case TS_WONT: 332 wontoption(c); 333 state = TS_DATA; 334 continue; 335 336 case TS_DO: 337 dooption(c); 338 state = TS_DATA; 339 continue; 340 341 case TS_DONT: 342 dontoption(c); 343 state = TS_DATA; 344 continue; 345 346 default: 347 syslog(LOG_ERR, "telnetd: panic state=%d\n", state); 348 printf("telnetd: panic state=%d\n", state); 349 exit(1); 350 } 351 } 352 #if defined(CRAY2) && defined(UNICOS5) 353 if (!linemode) { 354 char xptyobuf[BUFSIZ+NETSLOP]; 355 char xbuf2[BUFSIZ]; 356 register char *cp; 357 int n = pfrontp - opfrontp, oc; 358 memmove(xptyobuf, opfrontp, n); 359 pfrontp = opfrontp; 360 pfrontp += term_input(xptyobuf, pfrontp, n, BUFSIZ+NETSLOP, 361 xbuf2, &oc, BUFSIZ); 362 for (cp = xbuf2; oc > 0; --oc) 363 if ((*nfrontp++ = *cp++) == IAC) 364 *nfrontp++ = IAC; 365 } 366 #endif /* defined(CRAY2) && defined(UNICOS5) */ 367 } /* end of telrcv */ 368 369 /* 370 * The will/wont/do/dont state machines are based on Dave Borman's 371 * Telnet option processing state machine. 372 * 373 * These correspond to the following states: 374 * my_state = the last negotiated state 375 * want_state = what I want the state to go to 376 * want_resp = how many requests I have sent 377 * All state defaults are negative, and resp defaults to 0. 378 * 379 * When initiating a request to change state to new_state: 380 * 381 * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) { 382 * do nothing; 383 * } else { 384 * want_state = new_state; 385 * send new_state; 386 * want_resp++; 387 * } 388 * 389 * When receiving new_state: 390 * 391 * if (want_resp) { 392 * want_resp--; 393 * if (want_resp && (new_state == my_state)) 394 * want_resp--; 395 * } 396 * if ((want_resp == 0) && (new_state != want_state)) { 397 * if (ok_to_switch_to new_state) 398 * want_state = new_state; 399 * else 400 * want_resp++; 401 * send want_state; 402 * } 403 * my_state = new_state; 404 * 405 * Note that new_state is implied in these functions by the function itself. 406 * will and do imply positive new_state, wont and dont imply negative. 407 * 408 * Finally, there is one catch. If we send a negative response to a 409 * positive request, my_state will be the positive while want_state will 410 * remain negative. my_state will revert to negative when the negative 411 * acknowlegment arrives from the peer. Thus, my_state generally tells 412 * us not only the last negotiated state, but also tells us what the peer 413 * wants to be doing as well. It is important to understand this difference 414 * as we may wish to be processing data streams based on our desired state 415 * (want_state) or based on what the peer thinks the state is (my_state). 416 * 417 * This all works fine because if the peer sends a positive request, the data 418 * that we receive prior to negative acknowlegment will probably be affected 419 * by the positive state, and we can process it as such (if we can; if we 420 * can't then it really doesn't matter). If it is that important, then the 421 * peer probably should be buffering until this option state negotiation 422 * is complete. 423 * 424 */ 425 void 426 send_do(option, init) 427 int option, init; 428 { 429 if (init) { 430 if ((do_dont_resp[option] == 0 && his_state_is_will(option)) || 431 his_want_state_is_will(option)) 432 return; 433 /* 434 * Special case for TELOPT_TM: We send a DO, but pretend 435 * that we sent a DONT, so that we can send more DOs if 436 * we want to. 437 */ 438 if (option == TELOPT_TM) 439 set_his_want_state_wont(option); 440 else 441 set_his_want_state_will(option); 442 do_dont_resp[option]++; 443 } 444 (void) sprintf(nfrontp, (char *)doopt, option); 445 nfrontp += sizeof (dont) - 2; 446 447 DIAG(TD_OPTIONS, printoption("td: send do", option)); 448 } 449 450 #ifdef AUTHENTICATION 451 extern void auth_request(); 452 #endif 453 #ifdef LINEMODE 454 extern void doclientstat(); 455 #endif 456 457 void 458 willoption(option) 459 int option; 460 { 461 int changeok = 0; 462 void (*func)() = 0; 463 464 /* 465 * process input from peer. 466 */ 467 468 DIAG(TD_OPTIONS, printoption("td: recv will", option)); 469 470 if (do_dont_resp[option]) { 471 do_dont_resp[option]--; 472 if (do_dont_resp[option] && his_state_is_will(option)) 473 do_dont_resp[option]--; 474 } 475 if (do_dont_resp[option] == 0) { 476 if (his_want_state_is_wont(option)) { 477 switch (option) { 478 479 case TELOPT_BINARY: 480 init_termbuf(); 481 tty_binaryin(1); 482 set_termbuf(); 483 changeok++; 484 break; 485 486 case TELOPT_ECHO: 487 /* 488 * See comments below for more info. 489 */ 490 not42 = 0; /* looks like a 4.2 system */ 491 break; 492 493 case TELOPT_TM: 494 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 495 /* 496 * This telnetd implementation does not really 497 * support timing marks, it just uses them to 498 * support the kludge linemode stuff. If we 499 * receive a will or wont TM in response to our 500 * do TM request that may have been sent to 501 * determine kludge linemode support, process 502 * it, otherwise TM should get a negative 503 * response back. 504 */ 505 /* 506 * Handle the linemode kludge stuff. 507 * If we are not currently supporting any 508 * linemode at all, then we assume that this 509 * is the client telling us to use kludge 510 * linemode in response to our query. Set the 511 * linemode type that is to be supported, note 512 * that the client wishes to use linemode, and 513 * eat the will TM as though it never arrived. 514 */ 515 if (lmodetype < KLUDGE_LINEMODE) { 516 lmodetype = KLUDGE_LINEMODE; 517 clientstat(TELOPT_LINEMODE, WILL, 0); 518 send_wont(TELOPT_SGA, 1); 519 } else if (lmodetype == NO_AUTOKLUDGE) { 520 lmodetype = KLUDGE_OK; 521 } 522 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 523 /* 524 * We never respond to a WILL TM, and 525 * we leave the state WONT. 526 */ 527 return; 528 529 case TELOPT_LFLOW: 530 /* 531 * If we are going to support flow control 532 * option, then don't worry peer that we can't 533 * change the flow control characters. 534 */ 535 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 536 slctab[SLC_XON].defset.flag |= SLC_DEFAULT; 537 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 538 slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT; 539 case TELOPT_TTYPE: 540 case TELOPT_SGA: 541 case TELOPT_NAWS: 542 case TELOPT_TSPEED: 543 case TELOPT_XDISPLOC: 544 case TELOPT_NEW_ENVIRON: 545 case TELOPT_OLD_ENVIRON: 546 changeok++; 547 break; 548 549 #ifdef LINEMODE 550 case TELOPT_LINEMODE: 551 # ifdef KLUDGELINEMODE 552 /* 553 * Note client's desire to use linemode. 554 */ 555 lmodetype = REAL_LINEMODE; 556 # endif /* KLUDGELINEMODE */ 557 func = doclientstat; 558 changeok++; 559 break; 560 #endif /* LINEMODE */ 561 562 #ifdef AUTHENTICATION 563 case TELOPT_AUTHENTICATION: 564 func = auth_request; 565 changeok++; 566 break; 567 #endif 568 569 570 default: 571 break; 572 } 573 if (changeok) { 574 set_his_want_state_will(option); 575 send_do(option, 0); 576 } else { 577 do_dont_resp[option]++; 578 send_dont(option, 0); 579 } 580 } else { 581 /* 582 * Option processing that should happen when 583 * we receive conformation of a change in 584 * state that we had requested. 585 */ 586 switch (option) { 587 case TELOPT_ECHO: 588 not42 = 0; /* looks like a 4.2 system */ 589 /* 590 * Egads, he responded "WILL ECHO". Turn 591 * it off right now! 592 */ 593 send_dont(option, 1); 594 /* 595 * "WILL ECHO". Kludge upon kludge! 596 * A 4.2 client is now echoing user input at 597 * the tty. This is probably undesireable and 598 * it should be stopped. The client will 599 * respond WONT TM to the DO TM that we send to 600 * check for kludge linemode. When the WONT TM 601 * arrives, linemode will be turned off and a 602 * change propogated to the pty. This change 603 * will cause us to process the new pty state 604 * in localstat(), which will notice that 605 * linemode is off and send a WILL ECHO 606 * so that we are properly in character mode and 607 * all is well. 608 */ 609 break; 610 #ifdef LINEMODE 611 case TELOPT_LINEMODE: 612 # ifdef KLUDGELINEMODE 613 /* 614 * Note client's desire to use linemode. 615 */ 616 lmodetype = REAL_LINEMODE; 617 # endif /* KLUDGELINEMODE */ 618 func = doclientstat; 619 break; 620 #endif /* LINEMODE */ 621 622 #ifdef AUTHENTICATION 623 case TELOPT_AUTHENTICATION: 624 func = auth_request; 625 break; 626 #endif 627 628 case TELOPT_LFLOW: 629 func = flowstat; 630 break; 631 } 632 } 633 } 634 set_his_state_will(option); 635 if (func) 636 (*func)(); 637 } /* end of willoption */ 638 639 void 640 send_dont(option, init) 641 int option, init; 642 { 643 if (init) { 644 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) || 645 his_want_state_is_wont(option)) 646 return; 647 set_his_want_state_wont(option); 648 do_dont_resp[option]++; 649 } 650 (void) sprintf(nfrontp, (char *)dont, option); 651 nfrontp += sizeof (doopt) - 2; 652 653 DIAG(TD_OPTIONS, printoption("td: send dont", option)); 654 } 655 656 void 657 wontoption(option) 658 int option; 659 { 660 /* 661 * Process client input. 662 */ 663 664 DIAG(TD_OPTIONS, printoption("td: recv wont", option)); 665 666 if (do_dont_resp[option]) { 667 do_dont_resp[option]--; 668 if (do_dont_resp[option] && his_state_is_wont(option)) 669 do_dont_resp[option]--; 670 } 671 if (do_dont_resp[option] == 0) { 672 if (his_want_state_is_will(option)) { 673 /* it is always ok to change to negative state */ 674 switch (option) { 675 case TELOPT_ECHO: 676 not42 = 1; /* doesn't seem to be a 4.2 system */ 677 break; 678 679 case TELOPT_BINARY: 680 init_termbuf(); 681 tty_binaryin(0); 682 set_termbuf(); 683 break; 684 685 #ifdef LINEMODE 686 case TELOPT_LINEMODE: 687 # ifdef KLUDGELINEMODE 688 /* 689 * If real linemode is supported, then client is 690 * asking to turn linemode off. 691 */ 692 if (lmodetype != REAL_LINEMODE) 693 break; 694 # endif /* KLUDGELINEMODE */ 695 clientstat(TELOPT_LINEMODE, WONT, 0); 696 break; 697 #endif /* LINEMODE */ 698 699 case TELOPT_TM: 700 /* 701 * If we get a WONT TM, and had sent a DO TM, 702 * don't respond with a DONT TM, just leave it 703 * as is. Short circut the state machine to 704 * achive this. 705 */ 706 set_his_want_state_wont(TELOPT_TM); 707 return; 708 709 case TELOPT_LFLOW: 710 /* 711 * If we are not going to support flow control 712 * option, then let peer know that we can't 713 * change the flow control characters. 714 */ 715 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 716 slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE; 717 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 718 slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE; 719 break; 720 721 #if defined(AUTHENTICATION) 722 case TELOPT_AUTHENTICATION: 723 auth_finished(0, AUTH_REJECT); 724 break; 725 #endif 726 727 /* 728 * For options that we might spin waiting for 729 * sub-negotiation, if the client turns off the 730 * option rather than responding to the request, 731 * we have to treat it here as if we got a response 732 * to the sub-negotiation, (by updating the timers) 733 * so that we'll break out of the loop. 734 */ 735 case TELOPT_TTYPE: 736 settimer(ttypesubopt); 737 break; 738 739 case TELOPT_TSPEED: 740 settimer(tspeedsubopt); 741 break; 742 743 case TELOPT_XDISPLOC: 744 settimer(xdisplocsubopt); 745 break; 746 747 case TELOPT_OLD_ENVIRON: 748 settimer(oenvironsubopt); 749 break; 750 751 case TELOPT_NEW_ENVIRON: 752 settimer(environsubopt); 753 break; 754 755 default: 756 break; 757 } 758 set_his_want_state_wont(option); 759 if (his_state_is_will(option)) 760 send_dont(option, 0); 761 } else { 762 switch (option) { 763 case TELOPT_TM: 764 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 765 if (lmodetype < NO_AUTOKLUDGE) { 766 lmodetype = NO_LINEMODE; 767 clientstat(TELOPT_LINEMODE, WONT, 0); 768 send_will(TELOPT_SGA, 1); 769 send_will(TELOPT_ECHO, 1); 770 } 771 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 772 break; 773 774 #if defined(AUTHENTICATION) 775 case TELOPT_AUTHENTICATION: 776 auth_finished(0, AUTH_REJECT); 777 break; 778 #endif 779 default: 780 break; 781 } 782 } 783 } 784 set_his_state_wont(option); 785 786 } /* end of wontoption */ 787 788 void 789 send_will(option, init) 790 int option, init; 791 { 792 if (init) { 793 if ((will_wont_resp[option] == 0 && my_state_is_will(option))|| 794 my_want_state_is_will(option)) 795 return; 796 set_my_want_state_will(option); 797 will_wont_resp[option]++; 798 } 799 (void) sprintf(nfrontp, (char *)will, option); 800 nfrontp += sizeof (doopt) - 2; 801 802 DIAG(TD_OPTIONS, printoption("td: send will", option)); 803 } 804 805 #if !defined(LINEMODE) || !defined(KLUDGELINEMODE) 806 /* 807 * When we get a DONT SGA, we will try once to turn it 808 * back on. If the other side responds DONT SGA, we 809 * leave it at that. This is so that when we talk to 810 * clients that understand KLUDGELINEMODE but not LINEMODE, 811 * we'll keep them in char-at-a-time mode. 812 */ 813 int turn_on_sga = 0; 814 #endif 815 816 void 817 dooption(option) 818 int option; 819 { 820 int changeok = 0; 821 822 /* 823 * Process client input. 824 */ 825 826 DIAG(TD_OPTIONS, printoption("td: recv do", option)); 827 828 if (will_wont_resp[option]) { 829 will_wont_resp[option]--; 830 if (will_wont_resp[option] && my_state_is_will(option)) 831 will_wont_resp[option]--; 832 } 833 if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) { 834 switch (option) { 835 case TELOPT_ECHO: 836 #ifdef LINEMODE 837 # ifdef KLUDGELINEMODE 838 if (lmodetype == NO_LINEMODE) 839 # else 840 if (his_state_is_wont(TELOPT_LINEMODE)) 841 # endif 842 #endif 843 { 844 init_termbuf(); 845 tty_setecho(1); 846 set_termbuf(); 847 } 848 changeok++; 849 break; 850 851 case TELOPT_BINARY: 852 init_termbuf(); 853 tty_binaryout(1); 854 set_termbuf(); 855 changeok++; 856 break; 857 858 case TELOPT_SGA: 859 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 860 /* 861 * If kludge linemode is in use, then we must 862 * process an incoming do SGA for linemode 863 * purposes. 864 */ 865 if (lmodetype == KLUDGE_LINEMODE) { 866 /* 867 * Receipt of "do SGA" in kludge 868 * linemode is the peer asking us to 869 * turn off linemode. Make note of 870 * the request. 871 */ 872 clientstat(TELOPT_LINEMODE, WONT, 0); 873 /* 874 * If linemode did not get turned off 875 * then don't tell peer that we did. 876 * Breaking here forces a wont SGA to 877 * be returned. 878 */ 879 if (linemode) 880 break; 881 } 882 #else 883 turn_on_sga = 0; 884 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 885 changeok++; 886 break; 887 888 case TELOPT_STATUS: 889 changeok++; 890 break; 891 892 case TELOPT_TM: 893 /* 894 * Special case for TM. We send a WILL, but 895 * pretend we sent a WONT. 896 */ 897 send_will(option, 0); 898 set_my_want_state_wont(option); 899 set_my_state_wont(option); 900 return; 901 902 case TELOPT_LOGOUT: 903 /* 904 * When we get a LOGOUT option, respond 905 * with a WILL LOGOUT, make sure that 906 * it gets written out to the network, 907 * and then just go away... 908 */ 909 set_my_want_state_will(TELOPT_LOGOUT); 910 send_will(TELOPT_LOGOUT, 0); 911 set_my_state_will(TELOPT_LOGOUT); 912 (void)netflush(); 913 cleanup(0); 914 /* NOT REACHED */ 915 break; 916 917 case TELOPT_LINEMODE: 918 case TELOPT_TTYPE: 919 case TELOPT_NAWS: 920 case TELOPT_TSPEED: 921 case TELOPT_LFLOW: 922 case TELOPT_XDISPLOC: 923 #ifdef TELOPT_ENVIRON 924 case TELOPT_NEW_ENVIRON: 925 #endif 926 case TELOPT_OLD_ENVIRON: 927 default: 928 break; 929 } 930 if (changeok) { 931 set_my_want_state_will(option); 932 send_will(option, 0); 933 } else { 934 will_wont_resp[option]++; 935 send_wont(option, 0); 936 } 937 } 938 set_my_state_will(option); 939 940 } /* end of dooption */ 941 942 void 943 send_wont(option, init) 944 int option, init; 945 { 946 if (init) { 947 if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) || 948 my_want_state_is_wont(option)) 949 return; 950 set_my_want_state_wont(option); 951 will_wont_resp[option]++; 952 } 953 (void) sprintf(nfrontp, (char *)wont, option); 954 nfrontp += sizeof (wont) - 2; 955 956 DIAG(TD_OPTIONS, printoption("td: send wont", option)); 957 } 958 959 void 960 dontoption(option) 961 int option; 962 { 963 /* 964 * Process client input. 965 */ 966 967 968 DIAG(TD_OPTIONS, printoption("td: recv dont", option)); 969 970 if (will_wont_resp[option]) { 971 will_wont_resp[option]--; 972 if (will_wont_resp[option] && my_state_is_wont(option)) 973 will_wont_resp[option]--; 974 } 975 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) { 976 switch (option) { 977 case TELOPT_BINARY: 978 init_termbuf(); 979 tty_binaryout(0); 980 set_termbuf(); 981 break; 982 983 case TELOPT_ECHO: /* we should stop echoing */ 984 #ifdef LINEMODE 985 # ifdef KLUDGELINEMODE 986 if ((lmodetype != REAL_LINEMODE) && 987 (lmodetype != KLUDGE_LINEMODE)) 988 # else 989 if (his_state_is_wont(TELOPT_LINEMODE)) 990 # endif 991 #endif 992 { 993 init_termbuf(); 994 tty_setecho(0); 995 set_termbuf(); 996 } 997 break; 998 999 case TELOPT_SGA: 1000 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 1001 /* 1002 * If kludge linemode is in use, then we 1003 * must process an incoming do SGA for 1004 * linemode purposes. 1005 */ 1006 if ((lmodetype == KLUDGE_LINEMODE) || 1007 (lmodetype == KLUDGE_OK)) { 1008 /* 1009 * The client is asking us to turn 1010 * linemode on. 1011 */ 1012 lmodetype = KLUDGE_LINEMODE; 1013 clientstat(TELOPT_LINEMODE, WILL, 0); 1014 /* 1015 * If we did not turn line mode on, 1016 * then what do we say? Will SGA? 1017 * This violates design of telnet. 1018 * Gross. Very Gross. 1019 */ 1020 } 1021 break; 1022 #else 1023 set_my_want_state_wont(option); 1024 if (my_state_is_will(option)) 1025 send_wont(option, 0); 1026 set_my_state_wont(option); 1027 if (turn_on_sga ^= 1) 1028 send_will(option, 1); 1029 return; 1030 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 1031 1032 default: 1033 break; 1034 } 1035 1036 set_my_want_state_wont(option); 1037 if (my_state_is_will(option)) 1038 send_wont(option, 0); 1039 } 1040 set_my_state_wont(option); 1041 1042 } /* end of dontoption */ 1043 1044 #ifdef ENV_HACK 1045 int env_ovar = -1; 1046 int env_ovalue = -1; 1047 #else /* ENV_HACK */ 1048 # define env_ovar OLD_ENV_VAR 1049 # define env_ovalue OLD_ENV_VALUE 1050 #endif /* ENV_HACK */ 1051 1052 /* envvarok(char*) */ 1053 /* check that variable is safe to pass to login or shell */ 1054 static int 1055 envvarok(varp) 1056 char *varp; 1057 { 1058 return (strncmp(varp, "LD_", strlen("LD_")) && 1059 strncmp(varp, "_RLD_", strlen("_RLD_")) && 1060 strcmp(varp, "LIBPATH") && 1061 strcmp(varp, "IFS")); 1062 } 1063 1064 /* 1065 * suboption() 1066 * 1067 * Look at the sub-option buffer, and try to be helpful to the other 1068 * side. 1069 * 1070 * Currently we recognize: 1071 * 1072 * Terminal type is 1073 * Linemode 1074 * Window size 1075 * Terminal speed 1076 */ 1077 void 1078 suboption() 1079 { 1080 register int subchar; 1081 1082 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);}); 1083 1084 subchar = SB_GET(); 1085 switch (subchar) { 1086 case TELOPT_TSPEED: { 1087 register int xspeed, rspeed; 1088 1089 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */ 1090 break; 1091 1092 settimer(tspeedsubopt); 1093 1094 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1095 return; 1096 1097 xspeed = atoi((char *)subpointer); 1098 1099 while (SB_GET() != ',' && !SB_EOF()); 1100 if (SB_EOF()) 1101 return; 1102 1103 rspeed = atoi((char *)subpointer); 1104 clientstat(TELOPT_TSPEED, xspeed, rspeed); 1105 1106 break; 1107 1108 } /* end of case TELOPT_TSPEED */ 1109 1110 case TELOPT_TTYPE: { /* Yaaaay! */ 1111 static char terminalname[41]; 1112 1113 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */ 1114 break; 1115 settimer(ttypesubopt); 1116 1117 if (SB_EOF() || SB_GET() != TELQUAL_IS) { 1118 return; /* ??? XXX but, this is the most robust */ 1119 } 1120 1121 terminaltype = terminalname; 1122 1123 while ((terminaltype < (terminalname + sizeof terminalname-1)) && 1124 !SB_EOF()) { 1125 register int c; 1126 1127 c = SB_GET(); 1128 if (isupper(c)) { 1129 c = tolower(c); 1130 } 1131 *terminaltype++ = c; /* accumulate name */ 1132 } 1133 *terminaltype = 0; 1134 terminaltype = terminalname; 1135 break; 1136 } /* end of case TELOPT_TTYPE */ 1137 1138 case TELOPT_NAWS: { 1139 register int xwinsize, ywinsize; 1140 1141 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */ 1142 break; 1143 1144 if (SB_EOF()) 1145 return; 1146 xwinsize = SB_GET() << 8; 1147 if (SB_EOF()) 1148 return; 1149 xwinsize |= SB_GET(); 1150 if (SB_EOF()) 1151 return; 1152 ywinsize = SB_GET() << 8; 1153 if (SB_EOF()) 1154 return; 1155 ywinsize |= SB_GET(); 1156 clientstat(TELOPT_NAWS, xwinsize, ywinsize); 1157 1158 break; 1159 1160 } /* end of case TELOPT_NAWS */ 1161 1162 #ifdef LINEMODE 1163 case TELOPT_LINEMODE: { 1164 register int request; 1165 1166 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */ 1167 break; 1168 /* 1169 * Process linemode suboptions. 1170 */ 1171 if (SB_EOF()) 1172 break; /* garbage was sent */ 1173 request = SB_GET(); /* get will/wont */ 1174 1175 if (SB_EOF()) 1176 break; /* another garbage check */ 1177 1178 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */ 1179 /* 1180 * Process suboption buffer of slc's 1181 */ 1182 start_slc(1); 1183 do_opt_slc(subpointer, subend - subpointer); 1184 (void) end_slc(0); 1185 break; 1186 } else if (request == LM_MODE) { 1187 if (SB_EOF()) 1188 return; 1189 useeditmode = SB_GET(); /* get mode flag */ 1190 clientstat(LM_MODE, 0, 0); 1191 break; 1192 } 1193 1194 if (SB_EOF()) 1195 break; 1196 switch (SB_GET()) { /* what suboption? */ 1197 case LM_FORWARDMASK: 1198 /* 1199 * According to spec, only server can send request for 1200 * forwardmask, and client can only return a positive response. 1201 * So don't worry about it. 1202 */ 1203 1204 default: 1205 break; 1206 } 1207 break; 1208 } /* end of case TELOPT_LINEMODE */ 1209 #endif 1210 case TELOPT_STATUS: { 1211 int mode; 1212 1213 if (SB_EOF()) 1214 break; 1215 mode = SB_GET(); 1216 switch (mode) { 1217 case TELQUAL_SEND: 1218 if (my_state_is_will(TELOPT_STATUS)) 1219 send_status(); 1220 break; 1221 1222 case TELQUAL_IS: 1223 break; 1224 1225 default: 1226 break; 1227 } 1228 break; 1229 } /* end of case TELOPT_STATUS */ 1230 1231 case TELOPT_XDISPLOC: { 1232 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1233 return; 1234 settimer(xdisplocsubopt); 1235 subpointer[SB_LEN()] = '\0'; 1236 (void)setenv("DISPLAY", (char *)subpointer, 1); 1237 break; 1238 } /* end of case TELOPT_XDISPLOC */ 1239 1240 #ifdef TELOPT_NEW_ENVIRON 1241 case TELOPT_NEW_ENVIRON: 1242 #endif 1243 case TELOPT_OLD_ENVIRON: { 1244 register int c; 1245 register char *cp, *varp, *valp; 1246 1247 if (SB_EOF()) 1248 return; 1249 c = SB_GET(); 1250 if (c == TELQUAL_IS) { 1251 if (subchar == TELOPT_OLD_ENVIRON) 1252 settimer(oenvironsubopt); 1253 else 1254 settimer(environsubopt); 1255 } else if (c != TELQUAL_INFO) { 1256 return; 1257 } 1258 1259 #ifdef TELOPT_NEW_ENVIRON 1260 if (subchar == TELOPT_NEW_ENVIRON) { 1261 while (!SB_EOF()) { 1262 c = SB_GET(); 1263 if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR)) 1264 break; 1265 } 1266 } else 1267 #endif 1268 { 1269 #ifdef ENV_HACK 1270 /* 1271 * We only want to do this if we haven't already decided 1272 * whether or not the other side has its VALUE and VAR 1273 * reversed. 1274 */ 1275 if (env_ovar < 0) { 1276 register int last = -1; /* invalid value */ 1277 int empty = 0; 1278 int got_var = 0, got_value = 0, got_uservar = 0; 1279 1280 /* 1281 * The other side might have its VALUE and VAR values 1282 * reversed. To be interoperable, we need to determine 1283 * which way it is. If the first recognized character 1284 * is a VAR or VALUE, then that will tell us what 1285 * type of client it is. If the fist recognized 1286 * character is a USERVAR, then we continue scanning 1287 * the suboption looking for two consecutive 1288 * VAR or VALUE fields. We should not get two 1289 * consecutive VALUE fields, so finding two 1290 * consecutive VALUE or VAR fields will tell us 1291 * what the client is. 1292 */ 1293 SB_SAVE(); 1294 while (!SB_EOF()) { 1295 c = SB_GET(); 1296 switch(c) { 1297 case OLD_ENV_VAR: 1298 if (last < 0 || last == OLD_ENV_VAR 1299 || (empty && (last == OLD_ENV_VALUE))) 1300 goto env_ovar_ok; 1301 got_var++; 1302 last = OLD_ENV_VAR; 1303 break; 1304 case OLD_ENV_VALUE: 1305 if (last < 0 || last == OLD_ENV_VALUE 1306 || (empty && (last == OLD_ENV_VAR))) 1307 goto env_ovar_wrong; 1308 got_value++; 1309 last = OLD_ENV_VALUE; 1310 break; 1311 case ENV_USERVAR: 1312 /* count strings of USERVAR as one */ 1313 if (last != ENV_USERVAR) 1314 got_uservar++; 1315 if (empty) { 1316 if (last == OLD_ENV_VALUE) 1317 goto env_ovar_ok; 1318 if (last == OLD_ENV_VAR) 1319 goto env_ovar_wrong; 1320 } 1321 last = ENV_USERVAR; 1322 break; 1323 case ENV_ESC: 1324 if (!SB_EOF()) 1325 c = SB_GET(); 1326 /* FALL THROUGH */ 1327 default: 1328 empty = 0; 1329 continue; 1330 } 1331 empty = 1; 1332 } 1333 if (empty) { 1334 if (last == OLD_ENV_VALUE) 1335 goto env_ovar_ok; 1336 if (last == OLD_ENV_VAR) 1337 goto env_ovar_wrong; 1338 } 1339 /* 1340 * Ok, the first thing was a USERVAR, and there 1341 * are not two consecutive VAR or VALUE commands, 1342 * and none of the VAR or VALUE commands are empty. 1343 * If the client has sent us a well-formed option, 1344 * then the number of VALUEs received should always 1345 * be less than or equal to the number of VARs and 1346 * USERVARs received. 1347 * 1348 * If we got exactly as many VALUEs as VARs and 1349 * USERVARs, the client has the same definitions. 1350 * 1351 * If we got exactly as many VARs as VALUEs and 1352 * USERVARS, the client has reversed definitions. 1353 */ 1354 if (got_uservar + got_var == got_value) { 1355 env_ovar_ok: 1356 env_ovar = OLD_ENV_VAR; 1357 env_ovalue = OLD_ENV_VALUE; 1358 } else if (got_uservar + got_value == got_var) { 1359 env_ovar_wrong: 1360 env_ovar = OLD_ENV_VALUE; 1361 env_ovalue = OLD_ENV_VAR; 1362 DIAG(TD_OPTIONS, {sprintf(nfrontp, 1363 "ENVIRON VALUE and VAR are reversed!\r\n"); 1364 nfrontp += strlen(nfrontp);}); 1365 1366 } 1367 } 1368 SB_RESTORE(); 1369 #endif 1370 1371 while (!SB_EOF()) { 1372 c = SB_GET(); 1373 if ((c == env_ovar) || (c == ENV_USERVAR)) 1374 break; 1375 } 1376 } 1377 1378 if (SB_EOF()) 1379 return; 1380 1381 cp = varp = (char *)subpointer; 1382 valp = 0; 1383 1384 while (!SB_EOF()) { 1385 c = SB_GET(); 1386 if (subchar == TELOPT_OLD_ENVIRON) { 1387 if (c == env_ovar) 1388 c = NEW_ENV_VAR; 1389 else if (c == env_ovalue) 1390 c = NEW_ENV_VALUE; 1391 } 1392 switch (c) { 1393 1394 case NEW_ENV_VALUE: 1395 *cp = '\0'; 1396 cp = valp = (char *)subpointer; 1397 break; 1398 1399 case NEW_ENV_VAR: 1400 case ENV_USERVAR: 1401 *cp = '\0'; 1402 if (envvarok(varp)) { 1403 if (valp) 1404 (void)setenv(varp, valp, 1); 1405 else 1406 unsetenv(varp); 1407 } 1408 cp = varp = (char *)subpointer; 1409 valp = 0; 1410 break; 1411 1412 case ENV_ESC: 1413 if (SB_EOF()) 1414 break; 1415 c = SB_GET(); 1416 /* FALL THROUGH */ 1417 default: 1418 *cp++ = c; 1419 break; 1420 } 1421 } 1422 *cp = '\0'; 1423 if (envvarok(varp)) { 1424 if (valp) 1425 (void)setenv(varp, valp, 1); 1426 else 1427 unsetenv(varp); 1428 } 1429 break; 1430 } /* end of case TELOPT_NEW_ENVIRON */ 1431 #if defined(AUTHENTICATION) 1432 case TELOPT_AUTHENTICATION: 1433 if (SB_EOF()) 1434 break; 1435 switch(SB_GET()) { 1436 case TELQUAL_SEND: 1437 case TELQUAL_REPLY: 1438 /* 1439 * These are sent by us and cannot be sent by 1440 * the client. 1441 */ 1442 break; 1443 case TELQUAL_IS: 1444 auth_is(subpointer, SB_LEN()); 1445 break; 1446 case TELQUAL_NAME: 1447 auth_name(subpointer, SB_LEN()); 1448 break; 1449 } 1450 break; 1451 #endif 1452 1453 default: 1454 break; 1455 } /* end of switch */ 1456 1457 } /* end of suboption */ 1458 1459 void 1460 doclientstat() 1461 { 1462 clientstat(TELOPT_LINEMODE, WILL, 0); 1463 } 1464 1465 #define ADD(c) *ncp++ = c 1466 #define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; } 1467 void 1468 send_status() 1469 { 1470 unsigned char statusbuf[256]; 1471 register unsigned char *ncp; 1472 register unsigned char i; 1473 1474 ncp = statusbuf; 1475 1476 netflush(); /* get rid of anything waiting to go out */ 1477 1478 ADD(IAC); 1479 ADD(SB); 1480 ADD(TELOPT_STATUS); 1481 ADD(TELQUAL_IS); 1482 1483 /* 1484 * We check the want_state rather than the current state, 1485 * because if we received a DO/WILL for an option that we 1486 * don't support, and the other side didn't send a DONT/WONT 1487 * in response to our WONT/DONT, then the "state" will be 1488 * WILL/DO, and the "want_state" will be WONT/DONT. We 1489 * need to go by the latter. 1490 */ 1491 for (i = 0; i < (unsigned char)NTELOPTS; i++) { 1492 if (my_want_state_is_will(i)) { 1493 ADD(WILL); 1494 ADD_DATA(i); 1495 } 1496 if (his_want_state_is_will(i)) { 1497 ADD(DO); 1498 ADD_DATA(i); 1499 } 1500 } 1501 1502 if (his_want_state_is_will(TELOPT_LFLOW)) { 1503 ADD(SB); 1504 ADD(TELOPT_LFLOW); 1505 if (flowmode) { 1506 ADD(LFLOW_ON); 1507 } else { 1508 ADD(LFLOW_OFF); 1509 } 1510 ADD(SE); 1511 1512 if (restartany >= 0) { 1513 ADD(SB); 1514 ADD(TELOPT_LFLOW); 1515 if (restartany) { 1516 ADD(LFLOW_RESTART_ANY); 1517 } else { 1518 ADD(LFLOW_RESTART_XON); 1519 } 1520 ADD(SE); 1521 } 1522 } 1523 1524 #ifdef LINEMODE 1525 if (his_want_state_is_will(TELOPT_LINEMODE)) { 1526 unsigned char *cp, *cpe; 1527 int len; 1528 1529 ADD(SB); 1530 ADD(TELOPT_LINEMODE); 1531 ADD(LM_MODE); 1532 ADD_DATA(editmode); 1533 ADD(SE); 1534 1535 ADD(SB); 1536 ADD(TELOPT_LINEMODE); 1537 ADD(LM_SLC); 1538 start_slc(0); 1539 send_slc(); 1540 len = end_slc(&cp); 1541 for (cpe = cp + len; cp < cpe; cp++) 1542 ADD_DATA(*cp); 1543 ADD(SE); 1544 } 1545 #endif /* LINEMODE */ 1546 1547 ADD(IAC); 1548 ADD(SE); 1549 1550 writenet(statusbuf, ncp - statusbuf); 1551 netflush(); /* Send it on its way */ 1552 1553 DIAG(TD_OPTIONS, 1554 {printsub('>', statusbuf, ncp - statusbuf); netflush();}); 1555 } 1556
Indexes created Fri Sep 26 20:09:58 GMT 2025