1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)state.c 8.4 (Berkeley) 02/20/95"; 10 #endif /* not lint */ 11 12 #include "telnetd.h" 13 #if defined(AUTHENTICATION) 14 #include <libtelnet/auth.h> 15 #endif 16 17 unsigned char doopt[] = { IAC, DO, '%', 'c', 0 }; 18 unsigned char dont[] = { IAC, DONT, '%', 'c', 0 }; 19 unsigned char will[] = { IAC, WILL, '%', 'c', 0 }; 20 unsigned char wont[] = { IAC, WONT, '%', 'c', 0 }; 21 int not42 = 1; 22 23 /* 24 * Buffer for sub-options, and macros 25 * for suboptions buffer manipulations 26 */ 27 unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer; 28 29 #define SB_CLEAR() subpointer = subbuffer 30 #define SB_TERM() { subend = subpointer; SB_CLEAR(); } 31 #define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \ 32 *subpointer++ = (c); \ 33 } 34 #define SB_GET() ((*subpointer++)&0xff) 35 #define SB_EOF() (subpointer >= subend) 36 #define SB_LEN() (subend - subpointer) 37 38 #ifdef ENV_HACK 39 unsigned char *subsave; 40 #define SB_SAVE() subsave = subpointer; 41 #define SB_RESTORE() subpointer = subsave; 42 #endif 43 44 45 /* 46 * State for recv fsm 47 */ 48 #define TS_DATA 0 /* base state */ 49 #define TS_IAC 1 /* look for double IAC's */ 50 #define TS_CR 2 /* CR-LF ->'s CR */ 51 #define TS_SB 3 /* throw away begin's... */ 52 #define TS_SE 4 /* ...end's (suboption negotiation) */ 53 #define TS_WILL 5 /* will option negotiation */ 54 #define TS_WONT 6 /* wont " */ 55 #define TS_DO 7 /* do " */ 56 #define TS_DONT 8 /* dont " */ 57 58 void 59 telrcv() 60 { 61 register int c; 62 static int state = TS_DATA; 63 #if defined(CRAY2) && defined(UNICOS5) 64 char *opfrontp = pfrontp; 65 #endif 66 67 while (ncc > 0) { 68 if ((&ptyobuf[BUFSIZ] - pfrontp) < 2) 69 break; 70 c = *netip++ & 0377, ncc--; 71 #ifdef ENCRYPTION 72 if (decrypt_input) 73 c = (*decrypt_input)(c); 74 #endif /* ENCRYPTION */ 75 switch (state) { 76 77 case TS_CR: 78 state = TS_DATA; 79 /* Strip off \n or \0 after a \r */ 80 if ((c == 0) || (c == '\n')) { 81 break; 82 } 83 /* FALL THROUGH */ 84 85 case TS_DATA: 86 if (c == IAC) { 87 state = TS_IAC; 88 break; 89 } 90 /* 91 * We now map \r\n ==> \r for pragmatic reasons. 92 * Many client implementations send \r\n when 93 * the user hits the CarriageReturn key. 94 * 95 * We USED to map \r\n ==> \n, since \r\n says 96 * that we want to be in column 1 of the next 97 * printable line, and \n is the standard 98 * unix way of saying that (\r is only good 99 * if CRMOD is set, which it normally is). 100 */ 101 if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) { 102 int nc = *netip; 103 #ifdef ENCRYPTION 104 if (decrypt_input) 105 nc = (*decrypt_input)(nc & 0xff); 106 #endif /* ENCRYPTION */ 107 #ifdef LINEMODE 108 /* 109 * If we are operating in linemode, 110 * convert to local end-of-line. 111 */ 112 if (linemode && (ncc > 0) && (('\n' == nc) || 113 ((0 == nc) && tty_iscrnl())) ) { 114 netip++; ncc--; 115 c = '\n'; 116 } else 117 #endif 118 { 119 #ifdef ENCRYPTION 120 if (decrypt_input) 121 (void)(*decrypt_input)(-1); 122 #endif /* ENCRYPTION */ 123 state = TS_CR; 124 } 125 } 126 *pfrontp++ = c; 127 break; 128 129 case TS_IAC: 130 gotiac: switch (c) { 131 132 /* 133 * Send the process on the pty side an 134 * interrupt. Do this with a NULL or 135 * interrupt char; depending on the tty mode. 136 */ 137 case IP: 138 DIAG(TD_OPTIONS, 139 printoption("td: recv IAC", c)); 140 interrupt(); 141 break; 142 143 case BREAK: 144 DIAG(TD_OPTIONS, 145 printoption("td: recv IAC", c)); 146 sendbrk(); 147 break; 148 149 /* 150 * Are You There? 151 */ 152 case AYT: 153 DIAG(TD_OPTIONS, 154 printoption("td: recv IAC", c)); 155 recv_ayt(); 156 break; 157 158 /* 159 * Abort Output 160 */ 161 case AO: 162 { 163 DIAG(TD_OPTIONS, 164 printoption("td: recv IAC", c)); 165 ptyflush(); /* half-hearted */ 166 init_termbuf(); 167 168 if (slctab[SLC_AO].sptr && 169 *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) { 170 *pfrontp++ = 171 (unsigned char)*slctab[SLC_AO].sptr; 172 } 173 174 netclear(); /* clear buffer back */ 175 *nfrontp++ = IAC; 176 *nfrontp++ = DM; 177 neturg = nfrontp-1; /* off by one XXX */ 178 DIAG(TD_OPTIONS, 179 printoption("td: send IAC", DM)); 180 break; 181 } 182 183 /* 184 * Erase Character and 185 * Erase Line 186 */ 187 case EC: 188 case EL: 189 { 190 cc_t ch; 191 192 DIAG(TD_OPTIONS, 193 printoption("td: recv IAC", c)); 194 ptyflush(); /* half-hearted */ 195 init_termbuf(); 196 if (c == EC) 197 ch = *slctab[SLC_EC].sptr; 198 else 199 ch = *slctab[SLC_EL].sptr; 200 if (ch != (cc_t)(_POSIX_VDISABLE)) 201 *pfrontp++ = (unsigned char)ch; 202 break; 203 } 204 205 /* 206 * Check for urgent data... 207 */ 208 case DM: 209 DIAG(TD_OPTIONS, 210 printoption("td: recv IAC", c)); 211 SYNCHing = stilloob(net); 212 settimer(gotDM); 213 break; 214 215 216 /* 217 * Begin option subnegotiation... 218 */ 219 case SB: 220 state = TS_SB; 221 SB_CLEAR(); 222 continue; 223 224 case WILL: 225 state = TS_WILL; 226 continue; 227 228 case WONT: 229 state = TS_WONT; 230 continue; 231 232 case DO: 233 state = TS_DO; 234 continue; 235 236 case DONT: 237 state = TS_DONT; 238 continue; 239 case EOR: 240 if (his_state_is_will(TELOPT_EOR)) 241 doeof(); 242 break; 243 244 /* 245 * Handle RFC 10xx Telnet linemode option additions 246 * to command stream (EOF, SUSP, ABORT). 247 */ 248 case xEOF: 249 doeof(); 250 break; 251 252 case SUSP: 253 sendsusp(); 254 break; 255 256 case ABORT: 257 sendbrk(); 258 break; 259 260 case IAC: 261 *pfrontp++ = c; 262 break; 263 } 264 state = TS_DATA; 265 break; 266 267 case TS_SB: 268 if (c == IAC) { 269 state = TS_SE; 270 } else { 271 SB_ACCUM(c); 272 } 273 break; 274 275 case TS_SE: 276 if (c != SE) { 277 if (c != IAC) { 278 /* 279 * bad form of suboption negotiation. 280 * handle it in such a way as to avoid 281 * damage to local state. Parse 282 * suboption buffer found so far, 283 * then treat remaining stream as 284 * another command sequence. 285 */ 286 287 /* for DIAGNOSTICS */ 288 SB_ACCUM(IAC); 289 SB_ACCUM(c); 290 subpointer -= 2; 291 292 SB_TERM(); 293 suboption(); 294 state = TS_IAC; 295 goto gotiac; 296 } 297 SB_ACCUM(c); 298 state = TS_SB; 299 } else { 300 /* for DIAGNOSTICS */ 301 SB_ACCUM(IAC); 302 SB_ACCUM(SE); 303 subpointer -= 2; 304 305 SB_TERM(); 306 suboption(); /* handle sub-option */ 307 state = TS_DATA; 308 } 309 break; 310 311 case TS_WILL: 312 willoption(c); 313 state = TS_DATA; 314 continue; 315 316 case TS_WONT: 317 wontoption(c); 318 state = TS_DATA; 319 continue; 320 321 case TS_DO: 322 dooption(c); 323 state = TS_DATA; 324 continue; 325 326 case TS_DONT: 327 dontoption(c); 328 state = TS_DATA; 329 continue; 330 331 default: 332 syslog(LOG_ERR, "telnetd: panic state=%d\n", state); 333 printf("telnetd: panic state=%d\n", state); 334 exit(1); 335 } 336 } 337 #if defined(CRAY2) && defined(UNICOS5) 338 if (!linemode) { 339 char xptyobuf[BUFSIZ+NETSLOP]; 340 char xbuf2[BUFSIZ]; 341 register char *cp; 342 int n = pfrontp - opfrontp, oc; 343 bcopy(opfrontp, xptyobuf, n); 344 pfrontp = opfrontp; 345 pfrontp += term_input(xptyobuf, pfrontp, n, BUFSIZ+NETSLOP, 346 xbuf2, &oc, BUFSIZ); 347 for (cp = xbuf2; oc > 0; --oc) 348 if ((*nfrontp++ = *cp++) == IAC) 349 *nfrontp++ = IAC; 350 } 351 #endif /* defined(CRAY2) && defined(UNICOS5) */ 352 } /* end of telrcv */ 353 354 /* 355 * The will/wont/do/dont state machines are based on Dave Borman's 356 * Telnet option processing state machine. 357 * 358 * These correspond to the following states: 359 * my_state = the last negotiated state 360 * want_state = what I want the state to go to 361 * want_resp = how many requests I have sent 362 * All state defaults are negative, and resp defaults to 0. 363 * 364 * When initiating a request to change state to new_state: 365 * 366 * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) { 367 * do nothing; 368 * } else { 369 * want_state = new_state; 370 * send new_state; 371 * want_resp++; 372 * } 373 * 374 * When receiving new_state: 375 * 376 * if (want_resp) { 377 * want_resp--; 378 * if (want_resp && (new_state == my_state)) 379 * want_resp--; 380 * } 381 * if ((want_resp == 0) && (new_state != want_state)) { 382 * if (ok_to_switch_to new_state) 383 * want_state = new_state; 384 * else 385 * want_resp++; 386 * send want_state; 387 * } 388 * my_state = new_state; 389 * 390 * Note that new_state is implied in these functions by the function itself. 391 * will and do imply positive new_state, wont and dont imply negative. 392 * 393 * Finally, there is one catch. If we send a negative response to a 394 * positive request, my_state will be the positive while want_state will 395 * remain negative. my_state will revert to negative when the negative 396 * acknowlegment arrives from the peer. Thus, my_state generally tells 397 * us not only the last negotiated state, but also tells us what the peer 398 * wants to be doing as well. It is important to understand this difference 399 * as we may wish to be processing data streams based on our desired state 400 * (want_state) or based on what the peer thinks the state is (my_state). 401 * 402 * This all works fine because if the peer sends a positive request, the data 403 * that we receive prior to negative acknowlegment will probably be affected 404 * by the positive state, and we can process it as such (if we can; if we 405 * can't then it really doesn't matter). If it is that important, then the 406 * peer probably should be buffering until this option state negotiation 407 * is complete. 408 * 409 */ 410 void 411 send_do(option, init) 412 int option, init; 413 { 414 if (init) { 415 if ((do_dont_resp[option] == 0 && his_state_is_will(option)) || 416 his_want_state_is_will(option)) 417 return; 418 /* 419 * Special case for TELOPT_TM: We send a DO, but pretend 420 * that we sent a DONT, so that we can send more DOs if 421 * we want to. 422 */ 423 if (option == TELOPT_TM) 424 set_his_want_state_wont(option); 425 else 426 set_his_want_state_will(option); 427 do_dont_resp[option]++; 428 } 429 (void) sprintf(nfrontp, (char *)doopt, option); 430 nfrontp += sizeof (dont) - 2; 431 432 DIAG(TD_OPTIONS, printoption("td: send do", option)); 433 } 434 435 #ifdef AUTHENTICATION 436 extern void auth_request(); 437 #endif 438 #ifdef LINEMODE 439 extern void doclientstat(); 440 #endif 441 #ifdef ENCRYPTION 442 extern void encrypt_send_support(); 443 #endif /* ENCRYPTION */ 444 445 void 446 willoption(option) 447 int option; 448 { 449 int changeok = 0; 450 void (*func)() = 0; 451 452 /* 453 * process input from peer. 454 */ 455 456 DIAG(TD_OPTIONS, printoption("td: recv will", option)); 457 458 if (do_dont_resp[option]) { 459 do_dont_resp[option]--; 460 if (do_dont_resp[option] && his_state_is_will(option)) 461 do_dont_resp[option]--; 462 } 463 if (do_dont_resp[option] == 0) { 464 if (his_want_state_is_wont(option)) { 465 switch (option) { 466 467 case TELOPT_BINARY: 468 init_termbuf(); 469 tty_binaryin(1); 470 set_termbuf(); 471 changeok++; 472 break; 473 474 case TELOPT_ECHO: 475 /* 476 * See comments below for more info. 477 */ 478 not42 = 0; /* looks like a 4.2 system */ 479 break; 480 481 case TELOPT_TM: 482 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 483 /* 484 * This telnetd implementation does not really 485 * support timing marks, it just uses them to 486 * support the kludge linemode stuff. If we 487 * receive a will or wont TM in response to our 488 * do TM request that may have been sent to 489 * determine kludge linemode support, process 490 * it, otherwise TM should get a negative 491 * response back. 492 */ 493 /* 494 * Handle the linemode kludge stuff. 495 * If we are not currently supporting any 496 * linemode at all, then we assume that this 497 * is the client telling us to use kludge 498 * linemode in response to our query. Set the 499 * linemode type that is to be supported, note 500 * that the client wishes to use linemode, and 501 * eat the will TM as though it never arrived. 502 */ 503 if (lmodetype < KLUDGE_LINEMODE) { 504 lmodetype = KLUDGE_LINEMODE; 505 clientstat(TELOPT_LINEMODE, WILL, 0); 506 send_wont(TELOPT_SGA, 1); 507 } else if (lmodetype == NO_AUTOKLUDGE) { 508 lmodetype = KLUDGE_OK; 509 } 510 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 511 /* 512 * We never respond to a WILL TM, and 513 * we leave the state WONT. 514 */ 515 return; 516 517 case TELOPT_LFLOW: 518 /* 519 * If we are going to support flow control 520 * option, then don't worry peer that we can't 521 * change the flow control characters. 522 */ 523 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 524 slctab[SLC_XON].defset.flag |= SLC_DEFAULT; 525 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 526 slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT; 527 case TELOPT_TTYPE: 528 case TELOPT_SGA: 529 case TELOPT_NAWS: 530 case TELOPT_TSPEED: 531 case TELOPT_XDISPLOC: 532 case TELOPT_NEW_ENVIRON: 533 case TELOPT_OLD_ENVIRON: 534 changeok++; 535 break; 536 537 #ifdef LINEMODE 538 case TELOPT_LINEMODE: 539 # ifdef KLUDGELINEMODE 540 /* 541 * Note client's desire to use linemode. 542 */ 543 lmodetype = REAL_LINEMODE; 544 # endif /* KLUDGELINEMODE */ 545 func = doclientstat; 546 changeok++; 547 break; 548 #endif /* LINEMODE */ 549 550 #ifdef AUTHENTICATION 551 case TELOPT_AUTHENTICATION: 552 func = auth_request; 553 changeok++; 554 break; 555 #endif 556 557 #ifdef ENCRYPTION 558 case TELOPT_ENCRYPT: 559 func = encrypt_send_support; 560 changeok++; 561 break; 562 #endif /* ENCRYPTION */ 563 564 default: 565 break; 566 } 567 if (changeok) { 568 set_his_want_state_will(option); 569 send_do(option, 0); 570 } else { 571 do_dont_resp[option]++; 572 send_dont(option, 0); 573 } 574 } else { 575 /* 576 * Option processing that should happen when 577 * we receive conformation of a change in 578 * state that we had requested. 579 */ 580 switch (option) { 581 case TELOPT_ECHO: 582 not42 = 0; /* looks like a 4.2 system */ 583 /* 584 * Egads, he responded "WILL ECHO". Turn 585 * it off right now! 586 */ 587 send_dont(option, 1); 588 /* 589 * "WILL ECHO". Kludge upon kludge! 590 * A 4.2 client is now echoing user input at 591 * the tty. This is probably undesireable and 592 * it should be stopped. The client will 593 * respond WONT TM to the DO TM that we send to 594 * check for kludge linemode. When the WONT TM 595 * arrives, linemode will be turned off and a 596 * change propogated to the pty. This change 597 * will cause us to process the new pty state 598 * in localstat(), which will notice that 599 * linemode is off and send a WILL ECHO 600 * so that we are properly in character mode and 601 * all is well. 602 */ 603 break; 604 #ifdef LINEMODE 605 case TELOPT_LINEMODE: 606 # ifdef KLUDGELINEMODE 607 /* 608 * Note client's desire to use linemode. 609 */ 610 lmodetype = REAL_LINEMODE; 611 # endif /* KLUDGELINEMODE */ 612 func = doclientstat; 613 break; 614 #endif /* LINEMODE */ 615 616 #ifdef AUTHENTICATION 617 case TELOPT_AUTHENTICATION: 618 func = auth_request; 619 break; 620 #endif 621 622 #ifdef ENCRYPTION 623 case TELOPT_ENCRYPT: 624 func = encrypt_send_support; 625 break; 626 #endif /* ENCRYPTION */ 627 case TELOPT_LFLOW: 628 func = flowstat; 629 break; 630 } 631 } 632 } 633 set_his_state_will(option); 634 if (func) 635 (*func)(); 636 } /* end of willoption */ 637 638 void 639 send_dont(option, init) 640 int option, init; 641 { 642 if (init) { 643 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) || 644 his_want_state_is_wont(option)) 645 return; 646 set_his_want_state_wont(option); 647 do_dont_resp[option]++; 648 } 649 (void) sprintf(nfrontp, (char *)dont, option); 650 nfrontp += sizeof (doopt) - 2; 651 652 DIAG(TD_OPTIONS, printoption("td: send dont", option)); 653 } 654 655 void 656 wontoption(option) 657 int option; 658 { 659 /* 660 * Process client input. 661 */ 662 663 DIAG(TD_OPTIONS, printoption("td: recv wont", option)); 664 665 if (do_dont_resp[option]) { 666 do_dont_resp[option]--; 667 if (do_dont_resp[option] && his_state_is_wont(option)) 668 do_dont_resp[option]--; 669 } 670 if (do_dont_resp[option] == 0) { 671 if (his_want_state_is_will(option)) { 672 /* it is always ok to change to negative state */ 673 switch (option) { 674 case TELOPT_ECHO: 675 not42 = 1; /* doesn't seem to be a 4.2 system */ 676 break; 677 678 case TELOPT_BINARY: 679 init_termbuf(); 680 tty_binaryin(0); 681 set_termbuf(); 682 break; 683 684 #ifdef LINEMODE 685 case TELOPT_LINEMODE: 686 # ifdef KLUDGELINEMODE 687 /* 688 * If real linemode is supported, then client is 689 * asking to turn linemode off. 690 */ 691 if (lmodetype != REAL_LINEMODE) 692 break; 693 # endif /* KLUDGELINEMODE */ 694 clientstat(TELOPT_LINEMODE, WONT, 0); 695 break; 696 #endif /* LINEMODE */ 697 698 case TELOPT_TM: 699 /* 700 * If we get a WONT TM, and had sent a DO TM, 701 * don't respond with a DONT TM, just leave it 702 * as is. Short circut the state machine to 703 * achive this. 704 */ 705 set_his_want_state_wont(TELOPT_TM); 706 return; 707 708 case TELOPT_LFLOW: 709 /* 710 * If we are not going to support flow control 711 * option, then let peer know that we can't 712 * change the flow control characters. 713 */ 714 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 715 slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE; 716 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 717 slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE; 718 break; 719 720 #if defined(AUTHENTICATION) 721 case TELOPT_AUTHENTICATION: 722 auth_finished(0, AUTH_REJECT); 723 break; 724 #endif 725 726 /* 727 * For options that we might spin waiting for 728 * sub-negotiation, if the client turns off the 729 * option rather than responding to the request, 730 * we have to treat it here as if we got a response 731 * to the sub-negotiation, (by updating the timers) 732 * so that we'll break out of the loop. 733 */ 734 case TELOPT_TTYPE: 735 settimer(ttypesubopt); 736 break; 737 738 case TELOPT_TSPEED: 739 settimer(tspeedsubopt); 740 break; 741 742 case TELOPT_XDISPLOC: 743 settimer(xdisplocsubopt); 744 break; 745 746 case TELOPT_OLD_ENVIRON: 747 settimer(oenvironsubopt); 748 break; 749 750 case TELOPT_NEW_ENVIRON: 751 settimer(environsubopt); 752 break; 753 754 default: 755 break; 756 } 757 set_his_want_state_wont(option); 758 if (his_state_is_will(option)) 759 send_dont(option, 0); 760 } else { 761 switch (option) { 762 case TELOPT_TM: 763 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 764 if (lmodetype < NO_AUTOKLUDGE) { 765 lmodetype = NO_LINEMODE; 766 clientstat(TELOPT_LINEMODE, WONT, 0); 767 send_will(TELOPT_SGA, 1); 768 send_will(TELOPT_ECHO, 1); 769 } 770 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 771 break; 772 773 #if defined(AUTHENTICATION) 774 case TELOPT_AUTHENTICATION: 775 auth_finished(0, AUTH_REJECT); 776 break; 777 #endif 778 default: 779 break; 780 } 781 } 782 } 783 set_his_state_wont(option); 784 785 } /* end of wontoption */ 786 787 void 788 send_will(option, init) 789 int option, init; 790 { 791 if (init) { 792 if ((will_wont_resp[option] == 0 && my_state_is_will(option))|| 793 my_want_state_is_will(option)) 794 return; 795 set_my_want_state_will(option); 796 will_wont_resp[option]++; 797 } 798 (void) sprintf(nfrontp, (char *)will, option); 799 nfrontp += sizeof (doopt) - 2; 800 801 DIAG(TD_OPTIONS, printoption("td: send will", option)); 802 } 803 804 #if !defined(LINEMODE) || !defined(KLUDGELINEMODE) 805 /* 806 * When we get a DONT SGA, we will try once to turn it 807 * back on. If the other side responds DONT SGA, we 808 * leave it at that. This is so that when we talk to 809 * clients that understand KLUDGELINEMODE but not LINEMODE, 810 * we'll keep them in char-at-a-time mode. 811 */ 812 int turn_on_sga = 0; 813 #endif 814 815 void 816 dooption(option) 817 int option; 818 { 819 int changeok = 0; 820 821 /* 822 * Process client input. 823 */ 824 825 DIAG(TD_OPTIONS, printoption("td: recv do", option)); 826 827 if (will_wont_resp[option]) { 828 will_wont_resp[option]--; 829 if (will_wont_resp[option] && my_state_is_will(option)) 830 will_wont_resp[option]--; 831 } 832 if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) { 833 switch (option) { 834 case TELOPT_ECHO: 835 #ifdef LINEMODE 836 # ifdef KLUDGELINEMODE 837 if (lmodetype == NO_LINEMODE) 838 # else 839 if (his_state_is_wont(TELOPT_LINEMODE)) 840 # endif 841 #endif 842 { 843 init_termbuf(); 844 tty_setecho(1); 845 set_termbuf(); 846 } 847 changeok++; 848 break; 849 850 case TELOPT_BINARY: 851 init_termbuf(); 852 tty_binaryout(1); 853 set_termbuf(); 854 changeok++; 855 break; 856 857 case TELOPT_SGA: 858 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 859 /* 860 * If kludge linemode is in use, then we must 861 * process an incoming do SGA for linemode 862 * purposes. 863 */ 864 if (lmodetype == KLUDGE_LINEMODE) { 865 /* 866 * Receipt of "do SGA" in kludge 867 * linemode is the peer asking us to 868 * turn off linemode. Make note of 869 * the request. 870 */ 871 clientstat(TELOPT_LINEMODE, WONT, 0); 872 /* 873 * If linemode did not get turned off 874 * then don't tell peer that we did. 875 * Breaking here forces a wont SGA to 876 * be returned. 877 */ 878 if (linemode) 879 break; 880 } 881 #else 882 turn_on_sga = 0; 883 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 884 changeok++; 885 break; 886 887 case TELOPT_STATUS: 888 changeok++; 889 break; 890 891 case TELOPT_TM: 892 /* 893 * Special case for TM. We send a WILL, but 894 * pretend we sent a WONT. 895 */ 896 send_will(option, 0); 897 set_my_want_state_wont(option); 898 set_my_state_wont(option); 899 return; 900 901 case TELOPT_LOGOUT: 902 /* 903 * When we get a LOGOUT option, respond 904 * with a WILL LOGOUT, make sure that 905 * it gets written out to the network, 906 * and then just go away... 907 */ 908 set_my_want_state_will(TELOPT_LOGOUT); 909 send_will(TELOPT_LOGOUT, 0); 910 set_my_state_will(TELOPT_LOGOUT); 911 (void)netflush(); 912 cleanup(0); 913 /* NOT REACHED */ 914 break; 915 916 #ifdef ENCRYPTION 917 case TELOPT_ENCRYPT: 918 changeok++; 919 break; 920 #endif /* ENCRYPTION */ 921 case TELOPT_LINEMODE: 922 case TELOPT_TTYPE: 923 case TELOPT_NAWS: 924 case TELOPT_TSPEED: 925 case TELOPT_LFLOW: 926 case TELOPT_XDISPLOC: 927 #ifdef TELOPT_ENVIRON 928 case TELOPT_NEW_ENVIRON: 929 #endif 930 case TELOPT_OLD_ENVIRON: 931 default: 932 break; 933 } 934 if (changeok) { 935 set_my_want_state_will(option); 936 send_will(option, 0); 937 } else { 938 will_wont_resp[option]++; 939 send_wont(option, 0); 940 } 941 } 942 set_my_state_will(option); 943 944 } /* end of dooption */ 945 946 void 947 send_wont(option, init) 948 int option, init; 949 { 950 if (init) { 951 if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) || 952 my_want_state_is_wont(option)) 953 return; 954 set_my_want_state_wont(option); 955 will_wont_resp[option]++; 956 } 957 (void) sprintf(nfrontp, (char *)wont, option); 958 nfrontp += sizeof (wont) - 2; 959 960 DIAG(TD_OPTIONS, printoption("td: send wont", option)); 961 } 962 963 void 964 dontoption(option) 965 int option; 966 { 967 /* 968 * Process client input. 969 */ 970 971 972 DIAG(TD_OPTIONS, printoption("td: recv dont", option)); 973 974 if (will_wont_resp[option]) { 975 will_wont_resp[option]--; 976 if (will_wont_resp[option] && my_state_is_wont(option)) 977 will_wont_resp[option]--; 978 } 979 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) { 980 switch (option) { 981 case TELOPT_BINARY: 982 init_termbuf(); 983 tty_binaryout(0); 984 set_termbuf(); 985 break; 986 987 case TELOPT_ECHO: /* we should stop echoing */ 988 #ifdef LINEMODE 989 # ifdef KLUDGELINEMODE 990 if ((lmodetype != REAL_LINEMODE) && 991 (lmodetype != KLUDGE_LINEMODE)) 992 # else 993 if (his_state_is_wont(TELOPT_LINEMODE)) 994 # endif 995 #endif 996 { 997 init_termbuf(); 998 tty_setecho(0); 999 set_termbuf(); 1000 } 1001 break; 1002 1003 case TELOPT_SGA: 1004 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 1005 /* 1006 * If kludge linemode is in use, then we 1007 * must process an incoming do SGA for 1008 * linemode purposes. 1009 */ 1010 if ((lmodetype == KLUDGE_LINEMODE) || 1011 (lmodetype == KLUDGE_OK)) { 1012 /* 1013 * The client is asking us to turn 1014 * linemode on. 1015 */ 1016 lmodetype = KLUDGE_LINEMODE; 1017 clientstat(TELOPT_LINEMODE, WILL, 0); 1018 /* 1019 * If we did not turn line mode on, 1020 * then what do we say? Will SGA? 1021 * This violates design of telnet. 1022 * Gross. Very Gross. 1023 */ 1024 } 1025 break; 1026 #else 1027 set_my_want_state_wont(option); 1028 if (my_state_is_will(option)) 1029 send_wont(option, 0); 1030 set_my_state_wont(option); 1031 if (turn_on_sga ^= 1) 1032 send_will(option, 1); 1033 return; 1034 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 1035 1036 default: 1037 break; 1038 } 1039 1040 set_my_want_state_wont(option); 1041 if (my_state_is_will(option)) 1042 send_wont(option, 0); 1043 } 1044 set_my_state_wont(option); 1045 1046 } /* end of dontoption */ 1047 1048 #ifdef ENV_HACK 1049 int env_ovar = -1; 1050 int env_ovalue = -1; 1051 #else /* ENV_HACK */ 1052 # define env_ovar OLD_ENV_VAR 1053 # define env_ovalue OLD_ENV_VALUE 1054 #endif /* ENV_HACK */ 1055 1056 /* 1057 * suboption() 1058 * 1059 * Look at the sub-option buffer, and try to be helpful to the other 1060 * side. 1061 * 1062 * Currently we recognize: 1063 * 1064 * Terminal type is 1065 * Linemode 1066 * Window size 1067 * Terminal speed 1068 */ 1069 void 1070 suboption() 1071 { 1072 register int subchar; 1073 1074 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);}); 1075 1076 subchar = SB_GET(); 1077 switch (subchar) { 1078 case TELOPT_TSPEED: { 1079 register int xspeed, rspeed; 1080 1081 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */ 1082 break; 1083 1084 settimer(tspeedsubopt); 1085 1086 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1087 return; 1088 1089 xspeed = atoi((char *)subpointer); 1090 1091 while (SB_GET() != ',' && !SB_EOF()); 1092 if (SB_EOF()) 1093 return; 1094 1095 rspeed = atoi((char *)subpointer); 1096 clientstat(TELOPT_TSPEED, xspeed, rspeed); 1097 1098 break; 1099 1100 } /* end of case TELOPT_TSPEED */ 1101 1102 case TELOPT_TTYPE: { /* Yaaaay! */ 1103 static char terminalname[41]; 1104 1105 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */ 1106 break; 1107 settimer(ttypesubopt); 1108 1109 if (SB_EOF() || SB_GET() != TELQUAL_IS) { 1110 return; /* ??? XXX but, this is the most robust */ 1111 } 1112 1113 terminaltype = terminalname; 1114 1115 while ((terminaltype < (terminalname + sizeof terminalname-1)) && 1116 !SB_EOF()) { 1117 register int c; 1118 1119 c = SB_GET(); 1120 if (isupper(c)) { 1121 c = tolower(c); 1122 } 1123 *terminaltype++ = c; /* accumulate name */ 1124 } 1125 *terminaltype = 0; 1126 terminaltype = terminalname; 1127 break; 1128 } /* end of case TELOPT_TTYPE */ 1129 1130 case TELOPT_NAWS: { 1131 register int xwinsize, ywinsize; 1132 1133 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */ 1134 break; 1135 1136 if (SB_EOF()) 1137 return; 1138 xwinsize = SB_GET() << 8; 1139 if (SB_EOF()) 1140 return; 1141 xwinsize |= SB_GET(); 1142 if (SB_EOF()) 1143 return; 1144 ywinsize = SB_GET() << 8; 1145 if (SB_EOF()) 1146 return; 1147 ywinsize |= SB_GET(); 1148 clientstat(TELOPT_NAWS, xwinsize, ywinsize); 1149 1150 break; 1151 1152 } /* end of case TELOPT_NAWS */ 1153 1154 #ifdef LINEMODE 1155 case TELOPT_LINEMODE: { 1156 register int request; 1157 1158 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */ 1159 break; 1160 /* 1161 * Process linemode suboptions. 1162 */ 1163 if (SB_EOF()) 1164 break; /* garbage was sent */ 1165 request = SB_GET(); /* get will/wont */ 1166 1167 if (SB_EOF()) 1168 break; /* another garbage check */ 1169 1170 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */ 1171 /* 1172 * Process suboption buffer of slc's 1173 */ 1174 start_slc(1); 1175 do_opt_slc(subpointer, subend - subpointer); 1176 (void) end_slc(0); 1177 break; 1178 } else if (request == LM_MODE) { 1179 if (SB_EOF()) 1180 return; 1181 useeditmode = SB_GET(); /* get mode flag */ 1182 clientstat(LM_MODE, 0, 0); 1183 break; 1184 } 1185 1186 if (SB_EOF()) 1187 break; 1188 switch (SB_GET()) { /* what suboption? */ 1189 case LM_FORWARDMASK: 1190 /* 1191 * According to spec, only server can send request for 1192 * forwardmask, and client can only return a positive response. 1193 * So don't worry about it. 1194 */ 1195 1196 default: 1197 break; 1198 } 1199 break; 1200 } /* end of case TELOPT_LINEMODE */ 1201 #endif 1202 case TELOPT_STATUS: { 1203 int mode; 1204 1205 if (SB_EOF()) 1206 break; 1207 mode = SB_GET(); 1208 switch (mode) { 1209 case TELQUAL_SEND: 1210 if (my_state_is_will(TELOPT_STATUS)) 1211 send_status(); 1212 break; 1213 1214 case TELQUAL_IS: 1215 break; 1216 1217 default: 1218 break; 1219 } 1220 break; 1221 } /* end of case TELOPT_STATUS */ 1222 1223 case TELOPT_XDISPLOC: { 1224 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1225 return; 1226 settimer(xdisplocsubopt); 1227 subpointer[SB_LEN()] = '\0'; 1228 (void)setenv("DISPLAY", (char *)subpointer, 1); 1229 break; 1230 } /* end of case TELOPT_XDISPLOC */ 1231 1232 #ifdef TELOPT_NEW_ENVIRON 1233 case TELOPT_NEW_ENVIRON: 1234 #endif 1235 case TELOPT_OLD_ENVIRON: { 1236 register int c; 1237 register char *cp, *varp, *valp; 1238 1239 if (SB_EOF()) 1240 return; 1241 c = SB_GET(); 1242 if (c == TELQUAL_IS) { 1243 if (subchar == TELOPT_OLD_ENVIRON) 1244 settimer(oenvironsubopt); 1245 else 1246 settimer(environsubopt); 1247 } else if (c != TELQUAL_INFO) { 1248 return; 1249 } 1250 1251 #ifdef TELOPT_NEW_ENVIRON 1252 if (subchar == TELOPT_NEW_ENVIRON) { 1253 while (!SB_EOF()) { 1254 c = SB_GET(); 1255 if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR)) 1256 break; 1257 } 1258 } else 1259 #endif 1260 { 1261 #ifdef ENV_HACK 1262 /* 1263 * We only want to do this if we haven't already decided 1264 * whether or not the other side has its VALUE and VAR 1265 * reversed. 1266 */ 1267 if (env_ovar < 0) { 1268 register int last = -1; /* invalid value */ 1269 int empty = 0; 1270 int got_var = 0, got_value = 0, got_uservar = 0; 1271 1272 /* 1273 * The other side might have its VALUE and VAR values 1274 * reversed. To be interoperable, we need to determine 1275 * which way it is. If the first recognized character 1276 * is a VAR or VALUE, then that will tell us what 1277 * type of client it is. If the fist recognized 1278 * character is a USERVAR, then we continue scanning 1279 * the suboption looking for two consecutive 1280 * VAR or VALUE fields. We should not get two 1281 * consecutive VALUE fields, so finding two 1282 * consecutive VALUE or VAR fields will tell us 1283 * what the client is. 1284 */ 1285 SB_SAVE(); 1286 while (!SB_EOF()) { 1287 c = SB_GET(); 1288 switch(c) { 1289 case OLD_ENV_VAR: 1290 if (last < 0 || last == OLD_ENV_VAR 1291 || (empty && (last == OLD_ENV_VALUE))) 1292 goto env_ovar_ok; 1293 got_var++; 1294 last = OLD_ENV_VAR; 1295 break; 1296 case OLD_ENV_VALUE: 1297 if (last < 0 || last == OLD_ENV_VALUE 1298 || (empty && (last == OLD_ENV_VAR))) 1299 goto env_ovar_wrong; 1300 got_value++; 1301 last = OLD_ENV_VALUE; 1302 break; 1303 case ENV_USERVAR: 1304 /* count strings of USERVAR as one */ 1305 if (last != ENV_USERVAR) 1306 got_uservar++; 1307 if (empty) { 1308 if (last == OLD_ENV_VALUE) 1309 goto env_ovar_ok; 1310 if (last == OLD_ENV_VAR) 1311 goto env_ovar_wrong; 1312 } 1313 last = ENV_USERVAR; 1314 break; 1315 case ENV_ESC: 1316 if (!SB_EOF()) 1317 c = SB_GET(); 1318 /* FALL THROUGH */ 1319 default: 1320 empty = 0; 1321 continue; 1322 } 1323 empty = 1; 1324 } 1325 if (empty) { 1326 if (last == OLD_ENV_VALUE) 1327 goto env_ovar_ok; 1328 if (last == OLD_ENV_VAR) 1329 goto env_ovar_wrong; 1330 } 1331 /* 1332 * Ok, the first thing was a USERVAR, and there 1333 * are not two consecutive VAR or VALUE commands, 1334 * and none of the VAR or VALUE commands are empty. 1335 * If the client has sent us a well-formed option, 1336 * then the number of VALUEs received should always 1337 * be less than or equal to the number of VARs and 1338 * USERVARs received. 1339 * 1340 * If we got exactly as many VALUEs as VARs and 1341 * USERVARs, the client has the same definitions. 1342 * 1343 * If we got exactly as many VARs as VALUEs and 1344 * USERVARS, the client has reversed definitions. 1345 */ 1346 if (got_uservar + got_var == got_value) { 1347 env_ovar_ok: 1348 env_ovar = OLD_ENV_VAR; 1349 env_ovalue = OLD_ENV_VALUE; 1350 } else if (got_uservar + got_value == got_var) { 1351 env_ovar_wrong: 1352 env_ovar = OLD_ENV_VALUE; 1353 env_ovalue = OLD_ENV_VAR; 1354 DIAG(TD_OPTIONS, {sprintf(nfrontp, 1355 "ENVIRON VALUE and VAR are reversed!\r\n"); 1356 nfrontp += strlen(nfrontp);}); 1357 1358 } 1359 } 1360 SB_RESTORE(); 1361 #endif 1362 1363 while (!SB_EOF()) { 1364 c = SB_GET(); 1365 if ((c == env_ovar) || (c == ENV_USERVAR)) 1366 break; 1367 } 1368 } 1369 1370 if (SB_EOF()) 1371 return; 1372 1373 cp = varp = (char *)subpointer; 1374 valp = 0; 1375 1376 while (!SB_EOF()) { 1377 c = SB_GET(); 1378 if (subchar == TELOPT_OLD_ENVIRON) { 1379 if (c == env_ovar) 1380 c = NEW_ENV_VAR; 1381 else if (c == env_ovalue) 1382 c = NEW_ENV_VALUE; 1383 } 1384 switch (c) { 1385 1386 case NEW_ENV_VALUE: 1387 *cp = '\0'; 1388 cp = valp = (char *)subpointer; 1389 break; 1390 1391 case NEW_ENV_VAR: 1392 case ENV_USERVAR: 1393 *cp = '\0'; 1394 if (valp) 1395 (void)setenv(varp, valp, 1); 1396 else 1397 unsetenv(varp); 1398 cp = varp = (char *)subpointer; 1399 valp = 0; 1400 break; 1401 1402 case ENV_ESC: 1403 if (SB_EOF()) 1404 break; 1405 c = SB_GET(); 1406 /* FALL THROUGH */ 1407 default: 1408 *cp++ = c; 1409 break; 1410 } 1411 } 1412 *cp = '\0'; 1413 if (valp) 1414 (void)setenv(varp, valp, 1); 1415 else 1416 unsetenv(varp); 1417 break; 1418 } /* end of case TELOPT_NEW_ENVIRON */ 1419 #if defined(AUTHENTICATION) 1420 case TELOPT_AUTHENTICATION: 1421 if (SB_EOF()) 1422 break; 1423 switch(SB_GET()) { 1424 case TELQUAL_SEND: 1425 case TELQUAL_REPLY: 1426 /* 1427 * These are sent by us and cannot be sent by 1428 * the client. 1429 */ 1430 break; 1431 case TELQUAL_IS: 1432 auth_is(subpointer, SB_LEN()); 1433 break; 1434 case TELQUAL_NAME: 1435 auth_name(subpointer, SB_LEN()); 1436 break; 1437 } 1438 break; 1439 #endif 1440 #ifdef ENCRYPTION 1441 case TELOPT_ENCRYPT: 1442 if (SB_EOF()) 1443 break; 1444 switch(SB_GET()) { 1445 case ENCRYPT_SUPPORT: 1446 encrypt_support(subpointer, SB_LEN()); 1447 break; 1448 case ENCRYPT_IS: 1449 encrypt_is(subpointer, SB_LEN()); 1450 break; 1451 case ENCRYPT_REPLY: 1452 encrypt_reply(subpointer, SB_LEN()); 1453 break; 1454 case ENCRYPT_START: 1455 encrypt_start(subpointer, SB_LEN()); 1456 break; 1457 case ENCRYPT_END: 1458 encrypt_end(); 1459 break; 1460 case ENCRYPT_REQSTART: 1461 encrypt_request_start(subpointer, SB_LEN()); 1462 break; 1463 case ENCRYPT_REQEND: 1464 /* 1465 * We can always send an REQEND so that we cannot 1466 * get stuck encrypting. We should only get this 1467 * if we have been able to get in the correct mode 1468 * anyhow. 1469 */ 1470 encrypt_request_end(); 1471 break; 1472 case ENCRYPT_ENC_KEYID: 1473 encrypt_enc_keyid(subpointer, SB_LEN()); 1474 break; 1475 case ENCRYPT_DEC_KEYID: 1476 encrypt_dec_keyid(subpointer, SB_LEN()); 1477 break; 1478 default: 1479 break; 1480 } 1481 break; 1482 #endif /* ENCRYPTION */ 1483 1484 default: 1485 break; 1486 } /* end of switch */ 1487 1488 } /* end of suboption */ 1489 1490 void 1491 doclientstat() 1492 { 1493 clientstat(TELOPT_LINEMODE, WILL, 0); 1494 } 1495 1496 #define ADD(c) *ncp++ = c 1497 #define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; } 1498 void 1499 send_status() 1500 { 1501 unsigned char statusbuf[256]; 1502 register unsigned char *ncp; 1503 register unsigned char i; 1504 1505 ncp = statusbuf; 1506 1507 netflush(); /* get rid of anything waiting to go out */ 1508 1509 ADD(IAC); 1510 ADD(SB); 1511 ADD(TELOPT_STATUS); 1512 ADD(TELQUAL_IS); 1513 1514 /* 1515 * We check the want_state rather than the current state, 1516 * because if we received a DO/WILL for an option that we 1517 * don't support, and the other side didn't send a DONT/WONT 1518 * in response to our WONT/DONT, then the "state" will be 1519 * WILL/DO, and the "want_state" will be WONT/DONT. We 1520 * need to go by the latter. 1521 */ 1522 for (i = 0; i < (unsigned char)NTELOPTS; i++) { 1523 if (my_want_state_is_will(i)) { 1524 ADD(WILL); 1525 ADD_DATA(i); 1526 } 1527 if (his_want_state_is_will(i)) { 1528 ADD(DO); 1529 ADD_DATA(i); 1530 } 1531 } 1532 1533 if (his_want_state_is_will(TELOPT_LFLOW)) { 1534 ADD(SB); 1535 ADD(TELOPT_LFLOW); 1536 if (flowmode) { 1537 ADD(LFLOW_ON); 1538 } else { 1539 ADD(LFLOW_OFF); 1540 } 1541 ADD(SE); 1542 1543 if (restartany >= 0) { 1544 ADD(SB); 1545 ADD(TELOPT_LFLOW); 1546 if (restartany) { 1547 ADD(LFLOW_RESTART_ANY); 1548 } else { 1549 ADD(LFLOW_RESTART_XON); 1550 } 1551 ADD(SE); 1552 } 1553 } 1554 1555 #ifdef LINEMODE 1556 if (his_want_state_is_will(TELOPT_LINEMODE)) { 1557 unsigned char *cp, *cpe; 1558 int len; 1559 1560 ADD(SB); 1561 ADD(TELOPT_LINEMODE); 1562 ADD(LM_MODE); 1563 ADD_DATA(editmode); 1564 ADD(SE); 1565 1566 ADD(SB); 1567 ADD(TELOPT_LINEMODE); 1568 ADD(LM_SLC); 1569 start_slc(0); 1570 send_slc(); 1571 len = end_slc(&cp); 1572 for (cpe = cp + len; cp < cpe; cp++) 1573 ADD_DATA(*cp); 1574 ADD(SE); 1575 } 1576 #endif /* LINEMODE */ 1577 1578 ADD(IAC); 1579 ADD(SE); 1580 1581 writenet(statusbuf, ncp - statusbuf); 1582 netflush(); /* Send it on its way */ 1583 1584 DIAG(TD_OPTIONS, 1585 {printsub('>', statusbuf, ncp - statusbuf); netflush();}); 1586 } 1587