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 8.1 (Berkeley) 06/04/93"; 10 #endif /* not lint */ 11 12 #include "telnetd.h" 13 #if defined(AUTHENTICATION) 14 #include <libtelnet/auth.h> 15 #endif 16 17 char doopt[] = { IAC, DO, '%', 'c', 0 }; 18 char dont[] = { IAC, DONT, '%', 'c', 0 }; 19 char will[] = { IAC, WILL, '%', 'c', 0 }; 20 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, 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_ENVIRON: 533 changeok++; 534 break; 535 536 #ifdef LINEMODE 537 case TELOPT_LINEMODE: 538 # ifdef KLUDGELINEMODE 539 /* 540 * Note client's desire to use linemode. 541 */ 542 lmodetype = REAL_LINEMODE; 543 # endif /* KLUDGELINEMODE */ 544 func = doclientstat; 545 changeok++; 546 break; 547 #endif /* LINEMODE */ 548 549 #ifdef AUTHENTICATION 550 case TELOPT_AUTHENTICATION: 551 func = auth_request; 552 changeok++; 553 break; 554 #endif 555 556 #ifdef ENCRYPTION 557 case TELOPT_ENCRYPT: 558 func = encrypt_send_support; 559 changeok++; 560 break; 561 #endif /* ENCRYPTION */ 562 563 default: 564 break; 565 } 566 if (changeok) { 567 set_his_want_state_will(option); 568 send_do(option, 0); 569 } else { 570 do_dont_resp[option]++; 571 send_dont(option, 0); 572 } 573 } else { 574 /* 575 * Option processing that should happen when 576 * we receive conformation of a change in 577 * state that we had requested. 578 */ 579 switch (option) { 580 case TELOPT_ECHO: 581 not42 = 0; /* looks like a 4.2 system */ 582 /* 583 * Egads, he responded "WILL ECHO". Turn 584 * it off right now! 585 */ 586 send_dont(option, 1); 587 /* 588 * "WILL ECHO". Kludge upon kludge! 589 * A 4.2 client is now echoing user input at 590 * the tty. This is probably undesireable and 591 * it should be stopped. The client will 592 * respond WONT TM to the DO TM that we send to 593 * check for kludge linemode. When the WONT TM 594 * arrives, linemode will be turned off and a 595 * change propogated to the pty. This change 596 * will cause us to process the new pty state 597 * in localstat(), which will notice that 598 * linemode is off and send a WILL ECHO 599 * so that we are properly in character mode and 600 * all is well. 601 */ 602 break; 603 #ifdef LINEMODE 604 case TELOPT_LINEMODE: 605 # ifdef KLUDGELINEMODE 606 /* 607 * Note client's desire to use linemode. 608 */ 609 lmodetype = REAL_LINEMODE; 610 # endif /* KLUDGELINEMODE */ 611 func = doclientstat; 612 break; 613 #endif /* LINEMODE */ 614 615 #ifdef AUTHENTICATION 616 case TELOPT_AUTHENTICATION: 617 func = auth_request; 618 break; 619 #endif 620 621 #ifdef ENCRYPTION 622 case TELOPT_ENCRYPT: 623 func = encrypt_send_support; 624 break; 625 #endif /* ENCRYPTION */ 626 case TELOPT_LFLOW: 627 func = flowstat; 628 break; 629 } 630 } 631 } 632 set_his_state_will(option); 633 if (func) 634 (*func)(); 635 } /* end of willoption */ 636 637 void 638 send_dont(option, init) 639 int option, init; 640 { 641 if (init) { 642 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) || 643 his_want_state_is_wont(option)) 644 return; 645 set_his_want_state_wont(option); 646 do_dont_resp[option]++; 647 } 648 (void) sprintf(nfrontp, dont, option); 649 nfrontp += sizeof (doopt) - 2; 650 651 DIAG(TD_OPTIONS, printoption("td: send dont", option)); 652 } 653 654 void 655 wontoption(option) 656 int option; 657 { 658 /* 659 * Process client input. 660 */ 661 662 DIAG(TD_OPTIONS, printoption("td: recv wont", option)); 663 664 if (do_dont_resp[option]) { 665 do_dont_resp[option]--; 666 if (do_dont_resp[option] && his_state_is_wont(option)) 667 do_dont_resp[option]--; 668 } 669 if (do_dont_resp[option] == 0) { 670 if (his_want_state_is_will(option)) { 671 /* it is always ok to change to negative state */ 672 switch (option) { 673 case TELOPT_ECHO: 674 not42 = 1; /* doesn't seem to be a 4.2 system */ 675 break; 676 677 case TELOPT_BINARY: 678 init_termbuf(); 679 tty_binaryin(0); 680 set_termbuf(); 681 break; 682 683 #ifdef LINEMODE 684 case TELOPT_LINEMODE: 685 # ifdef KLUDGELINEMODE 686 /* 687 * If real linemode is supported, then client is 688 * asking to turn linemode off. 689 */ 690 if (lmodetype != REAL_LINEMODE) 691 break; 692 lmodetype = KLUDGE_LINEMODE; 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_ENVIRON: 747 settimer(environsubopt); 748 break; 749 750 default: 751 break; 752 } 753 set_his_want_state_wont(option); 754 if (his_state_is_will(option)) 755 send_dont(option, 0); 756 } else { 757 switch (option) { 758 case TELOPT_TM: 759 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 760 if (lmodetype < NO_AUTOKLUDGE) { 761 lmodetype = NO_LINEMODE; 762 clientstat(TELOPT_LINEMODE, WONT, 0); 763 send_will(TELOPT_SGA, 1); 764 send_will(TELOPT_ECHO, 1); 765 } 766 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 767 break; 768 769 #if defined(AUTHENTICATION) 770 case TELOPT_AUTHENTICATION: 771 auth_finished(0, AUTH_REJECT); 772 break; 773 #endif 774 default: 775 break; 776 } 777 } 778 } 779 set_his_state_wont(option); 780 781 } /* end of wontoption */ 782 783 void 784 send_will(option, init) 785 int option, init; 786 { 787 if (init) { 788 if ((will_wont_resp[option] == 0 && my_state_is_will(option))|| 789 my_want_state_is_will(option)) 790 return; 791 set_my_want_state_will(option); 792 will_wont_resp[option]++; 793 } 794 (void) sprintf(nfrontp, will, option); 795 nfrontp += sizeof (doopt) - 2; 796 797 DIAG(TD_OPTIONS, printoption("td: send will", option)); 798 } 799 800 #if !defined(LINEMODE) || !defined(KLUDGELINEMODE) 801 /* 802 * When we get a DONT SGA, we will try once to turn it 803 * back on. If the other side responds DONT SGA, we 804 * leave it at that. This is so that when we talk to 805 * clients that understand KLUDGELINEMODE but not LINEMODE, 806 * we'll keep them in char-at-a-time mode. 807 */ 808 int turn_on_sga = 0; 809 #endif 810 811 void 812 dooption(option) 813 int option; 814 { 815 int changeok = 0; 816 817 /* 818 * Process client input. 819 */ 820 821 DIAG(TD_OPTIONS, printoption("td: recv do", option)); 822 823 if (will_wont_resp[option]) { 824 will_wont_resp[option]--; 825 if (will_wont_resp[option] && my_state_is_will(option)) 826 will_wont_resp[option]--; 827 } 828 if ((will_wont_resp[option] == 0) && (my_want_state_is_wont(option))) { 829 switch (option) { 830 case TELOPT_ECHO: 831 #ifdef LINEMODE 832 # ifdef KLUDGELINEMODE 833 if (lmodetype == NO_LINEMODE) 834 # else 835 if (his_state_is_wont(TELOPT_LINEMODE)) 836 # endif 837 #endif 838 { 839 init_termbuf(); 840 tty_setecho(1); 841 set_termbuf(); 842 } 843 changeok++; 844 break; 845 846 case TELOPT_BINARY: 847 init_termbuf(); 848 tty_binaryout(1); 849 set_termbuf(); 850 changeok++; 851 break; 852 853 case TELOPT_SGA: 854 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 855 /* 856 * If kludge linemode is in use, then we must 857 * process an incoming do SGA for linemode 858 * purposes. 859 */ 860 if (lmodetype == KLUDGE_LINEMODE) { 861 /* 862 * Receipt of "do SGA" in kludge 863 * linemode is the peer asking us to 864 * turn off linemode. Make note of 865 * the request. 866 */ 867 clientstat(TELOPT_LINEMODE, WONT, 0); 868 /* 869 * If linemode did not get turned off 870 * then don't tell peer that we did. 871 * Breaking here forces a wont SGA to 872 * be returned. 873 */ 874 if (linemode) 875 break; 876 } 877 #else 878 turn_on_sga = 0; 879 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 880 changeok++; 881 break; 882 883 case TELOPT_STATUS: 884 changeok++; 885 break; 886 887 case TELOPT_TM: 888 /* 889 * Special case for TM. We send a WILL, but 890 * pretend we sent a WONT. 891 */ 892 send_will(option, 0); 893 set_my_want_state_wont(option); 894 set_my_state_wont(option); 895 return; 896 897 case TELOPT_LOGOUT: 898 /* 899 * When we get a LOGOUT option, respond 900 * with a WILL LOGOUT, make sure that 901 * it gets written out to the network, 902 * and then just go away... 903 */ 904 set_my_want_state_will(TELOPT_LOGOUT); 905 send_will(TELOPT_LOGOUT, 0); 906 set_my_state_will(TELOPT_LOGOUT); 907 (void)netflush(); 908 cleanup(0); 909 /* NOT REACHED */ 910 break; 911 912 #ifdef ENCRYPTION 913 case TELOPT_ENCRYPT: 914 changeok++; 915 break; 916 #endif /* ENCRYPTION */ 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 case TELOPT_ENVIRON: 924 default: 925 break; 926 } 927 if (changeok) { 928 set_my_want_state_will(option); 929 send_will(option, 0); 930 } else { 931 will_wont_resp[option]++; 932 send_wont(option, 0); 933 } 934 } 935 set_my_state_will(option); 936 937 } /* end of dooption */ 938 939 void 940 send_wont(option, init) 941 int option, init; 942 { 943 if (init) { 944 if ((will_wont_resp[option] == 0 && my_state_is_wont(option)) || 945 my_want_state_is_wont(option)) 946 return; 947 set_my_want_state_wont(option); 948 will_wont_resp[option]++; 949 } 950 (void) sprintf(nfrontp, wont, option); 951 nfrontp += sizeof (wont) - 2; 952 953 DIAG(TD_OPTIONS, printoption("td: send wont", option)); 954 } 955 956 void 957 dontoption(option) 958 int option; 959 { 960 /* 961 * Process client input. 962 */ 963 964 965 DIAG(TD_OPTIONS, printoption("td: recv dont", option)); 966 967 if (will_wont_resp[option]) { 968 will_wont_resp[option]--; 969 if (will_wont_resp[option] && my_state_is_wont(option)) 970 will_wont_resp[option]--; 971 } 972 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) { 973 switch (option) { 974 case TELOPT_BINARY: 975 init_termbuf(); 976 tty_binaryout(0); 977 set_termbuf(); 978 break; 979 980 case TELOPT_ECHO: /* we should stop echoing */ 981 #ifdef LINEMODE 982 # ifdef KLUDGELINEMODE 983 if ((lmodetype != REAL_LINEMODE) && 984 (lmodetype != KLUDGE_LINEMODE)) 985 # else 986 if (his_state_is_wont(TELOPT_LINEMODE)) 987 # endif 988 #endif 989 { 990 init_termbuf(); 991 tty_setecho(0); 992 set_termbuf(); 993 } 994 break; 995 996 case TELOPT_SGA: 997 #if defined(LINEMODE) && defined(KLUDGELINEMODE) 998 /* 999 * If kludge linemode is in use, then we 1000 * must process an incoming do SGA for 1001 * linemode purposes. 1002 */ 1003 if ((lmodetype == KLUDGE_LINEMODE) || 1004 (lmodetype == KLUDGE_OK)) { 1005 /* 1006 * The client is asking us to turn 1007 * linemode on. 1008 */ 1009 lmodetype = KLUDGE_LINEMODE; 1010 clientstat(TELOPT_LINEMODE, WILL, 0); 1011 /* 1012 * If we did not turn line mode on, 1013 * then what do we say? Will SGA? 1014 * This violates design of telnet. 1015 * Gross. Very Gross. 1016 */ 1017 } 1018 break; 1019 #else 1020 set_my_want_state_wont(option); 1021 if (my_state_is_will(option)) 1022 send_wont(option, 0); 1023 set_my_state_wont(option); 1024 if (turn_on_sga ^= 1) 1025 send_will(option, 1); 1026 return; 1027 #endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 1028 1029 default: 1030 break; 1031 } 1032 1033 set_my_want_state_wont(option); 1034 if (my_state_is_will(option)) 1035 send_wont(option, 0); 1036 } 1037 set_my_state_wont(option); 1038 1039 } /* end of dontoption */ 1040 1041 #ifdef ENV_HACK 1042 int env_var = -1; 1043 int env_value = -1; 1044 #else /* ENV_HACK */ 1045 # define env_var ENV_VAR 1046 # define env_value ENV_VALUE 1047 #endif /* ENV_HACK */ 1048 1049 /* 1050 * suboption() 1051 * 1052 * Look at the sub-option buffer, and try to be helpful to the other 1053 * side. 1054 * 1055 * Currently we recognize: 1056 * 1057 * Terminal type is 1058 * Linemode 1059 * Window size 1060 * Terminal speed 1061 */ 1062 void 1063 suboption() 1064 { 1065 register int subchar; 1066 1067 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);}); 1068 1069 subchar = SB_GET(); 1070 switch (subchar) { 1071 case TELOPT_TSPEED: { 1072 register int xspeed, rspeed; 1073 1074 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */ 1075 break; 1076 1077 settimer(tspeedsubopt); 1078 1079 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1080 return; 1081 1082 xspeed = atoi((char *)subpointer); 1083 1084 while (SB_GET() != ',' && !SB_EOF()); 1085 if (SB_EOF()) 1086 return; 1087 1088 rspeed = atoi((char *)subpointer); 1089 clientstat(TELOPT_TSPEED, xspeed, rspeed); 1090 1091 break; 1092 1093 } /* end of case TELOPT_TSPEED */ 1094 1095 case TELOPT_TTYPE: { /* Yaaaay! */ 1096 static char terminalname[41]; 1097 1098 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */ 1099 break; 1100 settimer(ttypesubopt); 1101 1102 if (SB_EOF() || SB_GET() != TELQUAL_IS) { 1103 return; /* ??? XXX but, this is the most robust */ 1104 } 1105 1106 terminaltype = terminalname; 1107 1108 while ((terminaltype < (terminalname + sizeof terminalname-1)) && 1109 !SB_EOF()) { 1110 register int c; 1111 1112 c = SB_GET(); 1113 if (isupper(c)) { 1114 c = tolower(c); 1115 } 1116 *terminaltype++ = c; /* accumulate name */ 1117 } 1118 *terminaltype = 0; 1119 terminaltype = terminalname; 1120 break; 1121 } /* end of case TELOPT_TTYPE */ 1122 1123 case TELOPT_NAWS: { 1124 register int xwinsize, ywinsize; 1125 1126 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */ 1127 break; 1128 1129 if (SB_EOF()) 1130 return; 1131 xwinsize = SB_GET() << 8; 1132 if (SB_EOF()) 1133 return; 1134 xwinsize |= SB_GET(); 1135 if (SB_EOF()) 1136 return; 1137 ywinsize = SB_GET() << 8; 1138 if (SB_EOF()) 1139 return; 1140 ywinsize |= SB_GET(); 1141 clientstat(TELOPT_NAWS, xwinsize, ywinsize); 1142 1143 break; 1144 1145 } /* end of case TELOPT_NAWS */ 1146 1147 #ifdef LINEMODE 1148 case TELOPT_LINEMODE: { 1149 register int request; 1150 1151 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */ 1152 break; 1153 /* 1154 * Process linemode suboptions. 1155 */ 1156 if (SB_EOF()) 1157 break; /* garbage was sent */ 1158 request = SB_GET(); /* get will/wont */ 1159 1160 if (SB_EOF()) 1161 break; /* another garbage check */ 1162 1163 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */ 1164 /* 1165 * Process suboption buffer of slc's 1166 */ 1167 start_slc(1); 1168 do_opt_slc(subpointer, subend - subpointer); 1169 (void) end_slc(0); 1170 break; 1171 } else if (request == LM_MODE) { 1172 if (SB_EOF()) 1173 return; 1174 useeditmode = SB_GET(); /* get mode flag */ 1175 clientstat(LM_MODE, 0, 0); 1176 break; 1177 } 1178 1179 if (SB_EOF()) 1180 break; 1181 switch (SB_GET()) { /* what suboption? */ 1182 case LM_FORWARDMASK: 1183 /* 1184 * According to spec, only server can send request for 1185 * forwardmask, and client can only return a positive response. 1186 * So don't worry about it. 1187 */ 1188 1189 default: 1190 break; 1191 } 1192 break; 1193 } /* end of case TELOPT_LINEMODE */ 1194 #endif 1195 case TELOPT_STATUS: { 1196 int mode; 1197 1198 if (SB_EOF()) 1199 break; 1200 mode = SB_GET(); 1201 switch (mode) { 1202 case TELQUAL_SEND: 1203 if (my_state_is_will(TELOPT_STATUS)) 1204 send_status(); 1205 break; 1206 1207 case TELQUAL_IS: 1208 break; 1209 1210 default: 1211 break; 1212 } 1213 break; 1214 } /* end of case TELOPT_STATUS */ 1215 1216 case TELOPT_XDISPLOC: { 1217 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1218 return; 1219 settimer(xdisplocsubopt); 1220 subpointer[SB_LEN()] = '\0'; 1221 (void)setenv("DISPLAY", (char *)subpointer, 1); 1222 break; 1223 } /* end of case TELOPT_XDISPLOC */ 1224 1225 case TELOPT_ENVIRON: { 1226 register int c; 1227 register char *cp, *varp, *valp; 1228 1229 if (SB_EOF()) 1230 return; 1231 c = SB_GET(); 1232 if (c == TELQUAL_IS) 1233 settimer(environsubopt); 1234 else if (c != TELQUAL_INFO) 1235 return; 1236 1237 #ifdef ENV_HACK 1238 /* 1239 * We only want to do this if we haven't already decided 1240 * whether or not the other side has its VALUE and VAR 1241 * reversed. 1242 */ 1243 if (env_var < 0) { 1244 register int last = -1; /* invalid value */ 1245 int empty = 0; 1246 int got_var = 0, got_value = 0, got_uservar = 0; 1247 1248 /* 1249 * The other side might have its VALUE and VAR values 1250 * reversed. To be interoperable, we need to determine 1251 * which way it is. If the first recognized character 1252 * is a VAR or VALUE, then that will tell us what 1253 * type of client it is. If the fist recognized 1254 * character is a USERVAR, then we continue scanning 1255 * the suboption looking for two consecutive 1256 * VAR or VALUE fields. We should not get two 1257 * consecutive VALUE fields, so finding two 1258 * consecutive VALUE or VAR fields will tell us 1259 * what the client is. 1260 */ 1261 SB_SAVE(); 1262 while (!SB_EOF()) { 1263 c = SB_GET(); 1264 switch(c) { 1265 case ENV_VAR: 1266 if (last < 0 || last == ENV_VAR 1267 || (empty && (last == ENV_VALUE))) 1268 goto env_var_ok; 1269 got_var++; 1270 last = ENV_VAR; 1271 break; 1272 case ENV_VALUE: 1273 if (last < 0 || last == ENV_VALUE 1274 || (empty && (last == ENV_VAR))) 1275 goto env_var_wrong; 1276 got_value++; 1277 last = ENV_VALUE; 1278 break; 1279 case ENV_USERVAR: 1280 /* count strings of USERVAR as one */ 1281 if (last != ENV_USERVAR) 1282 got_uservar++; 1283 if (empty) { 1284 if (last == ENV_VALUE) 1285 goto env_var_ok; 1286 if (last == ENV_VAR) 1287 goto env_var_wrong; 1288 } 1289 last = ENV_USERVAR; 1290 break; 1291 case ENV_ESC: 1292 if (!SB_EOF()) 1293 c = SB_GET(); 1294 /* FALL THROUGH */ 1295 default: 1296 empty = 0; 1297 continue; 1298 } 1299 empty = 1; 1300 } 1301 if (empty) { 1302 if (last == ENV_VALUE) 1303 goto env_var_ok; 1304 if (last == ENV_VAR) 1305 goto env_var_wrong; 1306 } 1307 /* 1308 * Ok, the first thing was a USERVAR, and there 1309 * are not two consecutive VAR or VALUE commands, 1310 * and none of the VAR or VALUE commands are empty. 1311 * If the client has sent us a well-formed option, 1312 * then the number of VALUEs received should always 1313 * be less than or equal to the number of VARs and 1314 * USERVARs received. 1315 * 1316 * If we got exactly as many VALUEs as VARs and 1317 * USERVARs, the client has the same definitions. 1318 * 1319 * If we got exactly as many VARs as VALUEs and 1320 * USERVARS, the client has reversed definitions. 1321 */ 1322 if (got_uservar + got_var == got_value) { 1323 env_var_ok: 1324 env_var = ENV_VAR; 1325 env_value = ENV_VALUE; 1326 } else if (got_uservar + got_value == got_var) { 1327 env_var_wrong: 1328 env_var = ENV_VALUE; 1329 env_value = ENV_VAR; 1330 DIAG(TD_OPTIONS, {sprintf(nfrontp, 1331 "ENVIRON VALUE and VAR are reversed!\r\n"); 1332 nfrontp += strlen(nfrontp);}); 1333 1334 } 1335 } 1336 SB_RESTORE(); 1337 #endif 1338 1339 while (!SB_EOF()) { 1340 c = SB_GET(); 1341 if ((c == env_var) || (c == ENV_USERVAR)) 1342 break; 1343 } 1344 1345 if (SB_EOF()) 1346 return; 1347 1348 cp = varp = (char *)subpointer; 1349 valp = 0; 1350 1351 while (!SB_EOF()) { 1352 c = SB_GET(); 1353 #ifdef ENV_HACK 1354 if (c == env_var) 1355 c = ENV_VAR; 1356 else if (c == env_value) 1357 c = ENV_VALUE; 1358 #endif 1359 switch (c) { 1360 1361 case ENV_VALUE: 1362 *cp = '\0'; 1363 cp = valp = (char *)subpointer; 1364 break; 1365 1366 case ENV_VAR: 1367 case ENV_USERVAR: 1368 *cp = '\0'; 1369 if (valp) 1370 (void)setenv(varp, valp, 1); 1371 else 1372 unsetenv(varp); 1373 cp = varp = (char *)subpointer; 1374 valp = 0; 1375 break; 1376 1377 case ENV_ESC: 1378 if (SB_EOF()) 1379 break; 1380 c = SB_GET(); 1381 /* FALL THROUGH */ 1382 default: 1383 *cp++ = c; 1384 break; 1385 } 1386 } 1387 *cp = '\0'; 1388 if (valp) 1389 (void)setenv(varp, valp, 1); 1390 else 1391 unsetenv(varp); 1392 break; 1393 } /* end of case TELOPT_ENVIRON */ 1394 #if defined(AUTHENTICATION) 1395 case TELOPT_AUTHENTICATION: 1396 if (SB_EOF()) 1397 break; 1398 switch(SB_GET()) { 1399 case TELQUAL_SEND: 1400 case TELQUAL_REPLY: 1401 /* 1402 * These are sent by us and cannot be sent by 1403 * the client. 1404 */ 1405 break; 1406 case TELQUAL_IS: 1407 auth_is(subpointer, SB_LEN()); 1408 break; 1409 case TELQUAL_NAME: 1410 auth_name(subpointer, SB_LEN()); 1411 break; 1412 } 1413 break; 1414 #endif 1415 #ifdef ENCRYPTION 1416 case TELOPT_ENCRYPT: 1417 if (SB_EOF()) 1418 break; 1419 switch(SB_GET()) { 1420 case ENCRYPT_SUPPORT: 1421 encrypt_support(subpointer, SB_LEN()); 1422 break; 1423 case ENCRYPT_IS: 1424 encrypt_is(subpointer, SB_LEN()); 1425 break; 1426 case ENCRYPT_REPLY: 1427 encrypt_reply(subpointer, SB_LEN()); 1428 break; 1429 case ENCRYPT_START: 1430 encrypt_start(subpointer, SB_LEN()); 1431 break; 1432 case ENCRYPT_END: 1433 encrypt_end(); 1434 break; 1435 case ENCRYPT_REQSTART: 1436 encrypt_request_start(subpointer, SB_LEN()); 1437 break; 1438 case ENCRYPT_REQEND: 1439 /* 1440 * We can always send an REQEND so that we cannot 1441 * get stuck encrypting. We should only get this 1442 * if we have been able to get in the correct mode 1443 * anyhow. 1444 */ 1445 encrypt_request_end(); 1446 break; 1447 case ENCRYPT_ENC_KEYID: 1448 encrypt_enc_keyid(subpointer, SB_LEN()); 1449 break; 1450 case ENCRYPT_DEC_KEYID: 1451 encrypt_dec_keyid(subpointer, SB_LEN()); 1452 break; 1453 default: 1454 break; 1455 } 1456 break; 1457 #endif /* ENCRYPTION */ 1458 1459 default: 1460 break; 1461 } /* end of switch */ 1462 1463 } /* end of suboption */ 1464 1465 void 1466 doclientstat() 1467 { 1468 clientstat(TELOPT_LINEMODE, WILL, 0); 1469 } 1470 1471 #define ADD(c) *ncp++ = c; 1472 #define ADD_DATA(c) { *ncp++ = c; if (c == SE) *ncp++ = c; } 1473 void 1474 send_status() 1475 { 1476 unsigned char statusbuf[256]; 1477 register unsigned char *ncp; 1478 register unsigned char i; 1479 1480 ncp = statusbuf; 1481 1482 netflush(); /* get rid of anything waiting to go out */ 1483 1484 ADD(IAC); 1485 ADD(SB); 1486 ADD(TELOPT_STATUS); 1487 ADD(TELQUAL_IS); 1488 1489 /* 1490 * We check the want_state rather than the current state, 1491 * because if we received a DO/WILL for an option that we 1492 * don't support, and the other side didn't send a DONT/WONT 1493 * in response to our WONT/DONT, then the "state" will be 1494 * WILL/DO, and the "want_state" will be WONT/DONT. We 1495 * need to go by the latter. 1496 */ 1497 for (i = 0; i < NTELOPTS; i++) { 1498 if (my_want_state_is_will(i)) { 1499 ADD(WILL); 1500 ADD_DATA(i); 1501 if (i == IAC) 1502 ADD(IAC); 1503 } 1504 if (his_want_state_is_will(i)) { 1505 ADD(DO); 1506 ADD_DATA(i); 1507 if (i == IAC) 1508 ADD(IAC); 1509 } 1510 } 1511 1512 if (his_want_state_is_will(TELOPT_LFLOW)) { 1513 ADD(SB); 1514 ADD(TELOPT_LFLOW); 1515 if (flowmode) { 1516 ADD(LFLOW_ON); 1517 } else { 1518 ADD(LFLOW_OFF); 1519 } 1520 ADD(SE); 1521 1522 if (restartany >= 0) { 1523 ADD(SB) 1524 ADD(TELOPT_LFLOW); 1525 if (restartany) { 1526 ADD(LFLOW_RESTART_ANY); 1527 } else { 1528 ADD(LFLOW_RESTART_XON); 1529 } 1530 ADD(SE) 1531 ADD(SB); 1532 } 1533 } 1534 1535 #ifdef LINEMODE 1536 if (his_want_state_is_will(TELOPT_LINEMODE)) { 1537 unsigned char *cp, *cpe; 1538 int len; 1539 1540 ADD(SB); 1541 ADD(TELOPT_LINEMODE); 1542 ADD(LM_MODE); 1543 ADD_DATA(editmode); 1544 if (editmode == IAC) 1545 ADD(IAC); 1546 ADD(SE); 1547 1548 ADD(SB); 1549 ADD(TELOPT_LINEMODE); 1550 ADD(LM_SLC); 1551 start_slc(0); 1552 send_slc(); 1553 len = end_slc(&cp); 1554 for (cpe = cp + len; cp < cpe; cp++) 1555 ADD_DATA(*cp); 1556 ADD(SE); 1557 } 1558 #endif /* LINEMODE */ 1559 1560 ADD(IAC); 1561 ADD(SE); 1562 1563 writenet(statusbuf, ncp - statusbuf); 1564 netflush(); /* Send it on its way */ 1565 1566 DIAG(TD_OPTIONS, 1567 {printsub('>', statusbuf, ncp - statusbuf); netflush();}); 1568 } 1569