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#if 0 35#ifndef lint 36static const char sccsid[] = "@(#)state.c 8.5 (Berkeley) 5/30/95"; 37#endif 38#endif 39#include <sys/cdefs.h> 40__FBSDID("$FreeBSD: releng/10.3/contrib/telnet/telnetd/state.c 241021 2012-09-28 07:51:30Z kevlo $"); 41 42#include <stdarg.h> 43#include "telnetd.h" 44#ifdef AUTHENTICATION 45#include <libtelnet/auth.h> 46#endif 47#ifdef ENCRYPTION 48#include <libtelnet/encrypt.h> 49#endif 50 51unsigned char doopt[] = { IAC, DO, '%', 'c', 0 }; 52unsigned char dont[] = { IAC, DONT, '%', 'c', 0 }; 53unsigned char will[] = { IAC, WILL, '%', 'c', 0 }; 54unsigned char wont[] = { IAC, WONT, '%', 'c', 0 }; 55int not42 = 1; 56 57/* 58 * Buffer for sub-options, and macros 59 * for suboptions buffer manipulations 60 */ 61unsigned char subbuffer[512], *subpointer= subbuffer, *subend= subbuffer; 62 63#define SB_CLEAR() subpointer = subbuffer 64#define SB_TERM() { subend = subpointer; SB_CLEAR(); } 65#define SB_ACCUM(c) if (subpointer < (subbuffer+sizeof subbuffer)) { \ 66 *subpointer++ = (c); \ 67 } 68#define SB_GET() ((*subpointer++)&0xff) 69#define SB_EOF() (subpointer >= subend) 70#define SB_LEN() (subend - subpointer) 71 72#ifdef ENV_HACK 73unsigned char *subsave; 74#define SB_SAVE() subsave = subpointer; 75#define SB_RESTORE() subpointer = subsave; 76#endif 77 78 79/* 80 * State for recv fsm 81 */ 82#define TS_DATA 0 /* base state */ 83#define TS_IAC 1 /* look for double IAC's */ 84#define TS_CR 2 /* CR-LF ->'s CR */ 85#define TS_SB 3 /* throw away begin's... */ 86#define TS_SE 4 /* ...end's (suboption negotiation) */ 87#define TS_WILL 5 /* will option negotiation */ 88#define TS_WONT 6 /* wont " */ 89#define TS_DO 7 /* do " */ 90#define TS_DONT 8 /* dont " */ 91 92static void doclientstat(void); 93 94void 95telrcv(void) 96{ 97 int c; 98 static int state = TS_DATA; 99 100 while (ncc > 0) { 101 if ((&ptyobuf[BUFSIZ] - pfrontp) < 2) 102 break; 103 c = *netip++ & 0377, ncc--; 104#ifdef ENCRYPTION 105 if (decrypt_input) 106 c = (*decrypt_input)(c); 107#endif /* ENCRYPTION */ 108 switch (state) { 109 110 case TS_CR: 111 state = TS_DATA; 112 /* Strip off \n or \0 after a \r */ 113 if ((c == 0) || (c == '\n')) { 114 break; 115 } 116 /* FALLTHROUGH */ 117 118 case TS_DATA: 119 if (c == IAC) { 120 state = TS_IAC; 121 break; 122 } 123 /* 124 * We now map \r\n ==> \r for pragmatic reasons. 125 * Many client implementations send \r\n when 126 * the user hits the CarriageReturn key. 127 * 128 * We USED to map \r\n ==> \n, since \r\n says 129 * that we want to be in column 1 of the next 130 * printable line, and \n is the standard 131 * unix way of saying that (\r is only good 132 * if CRMOD is set, which it normally is). 133 */ 134 if ((c == '\r') && his_state_is_wont(TELOPT_BINARY)) { 135 int nc = *netip; 136#ifdef ENCRYPTION 137 if (decrypt_input) 138 nc = (*decrypt_input)(nc & 0xff); 139#endif /* ENCRYPTION */ 140#ifdef LINEMODE 141 /* 142 * If we are operating in linemode, 143 * convert to local end-of-line. 144 */ 145 if (linemode && (ncc > 0) && (('\n' == nc) || 146 ((0 == nc) && tty_iscrnl())) ) { 147 netip++; ncc--; 148 c = '\n'; 149 } else 150#endif 151 { 152#ifdef ENCRYPTION 153 if (decrypt_input) 154 (void)(*decrypt_input)(-1); 155#endif /* ENCRYPTION */ 156 state = TS_CR; 157 } 158 } 159 *pfrontp++ = c; 160 break; 161 162 case TS_IAC: 163gotiac: switch (c) { 164 165 /* 166 * Send the process on the pty side an 167 * interrupt. Do this with a NULL or 168 * interrupt char; depending on the tty mode. 169 */ 170 case IP: 171 DIAG(TD_OPTIONS, 172 printoption("td: recv IAC", c)); 173 interrupt(); 174 break; 175 176 case BREAK: 177 DIAG(TD_OPTIONS, 178 printoption("td: recv IAC", c)); 179 sendbrk(); 180 break; 181 182 /* 183 * Are You There? 184 */ 185 case AYT: 186 DIAG(TD_OPTIONS, 187 printoption("td: recv IAC", c)); 188 recv_ayt(); 189 break; 190 191 /* 192 * Abort Output 193 */ 194 case AO: 195 { 196 DIAG(TD_OPTIONS, 197 printoption("td: recv IAC", c)); 198 ptyflush(); /* half-hearted */ 199 init_termbuf(); 200 201 if (slctab[SLC_AO].sptr && 202 *slctab[SLC_AO].sptr != (cc_t)(_POSIX_VDISABLE)) { 203 *pfrontp++ = 204 (unsigned char)*slctab[SLC_AO].sptr; 205 } 206 207 netclear(); /* clear buffer back */ 208 output_data("%c%c", IAC, DM); 209 neturg = nfrontp-1; /* off by one XXX */ 210 DIAG(TD_OPTIONS, 211 printoption("td: send IAC", DM)); 212 break; 213 } 214 215 /* 216 * Erase Character and 217 * Erase Line 218 */ 219 case EC: 220 case EL: 221 { 222 cc_t ch; 223 224 DIAG(TD_OPTIONS, 225 printoption("td: recv IAC", c)); 226 ptyflush(); /* half-hearted */ 227 init_termbuf(); 228 if (c == EC) 229 ch = *slctab[SLC_EC].sptr; 230 else 231 ch = *slctab[SLC_EL].sptr; 232 if (ch != (cc_t)(_POSIX_VDISABLE)) 233 *pfrontp++ = (unsigned char)ch; 234 break; 235 } 236 237 /* 238 * Check for urgent data... 239 */ 240 case DM: 241 DIAG(TD_OPTIONS, 242 printoption("td: recv IAC", c)); 243 SYNCHing = stilloob(net); 244 settimer(gotDM); 245 break; 246 247 248 /* 249 * Begin option subnegotiation... 250 */ 251 case SB: 252 state = TS_SB; 253 SB_CLEAR(); 254 continue; 255 256 case WILL: 257 state = TS_WILL; 258 continue; 259 260 case WONT: 261 state = TS_WONT; 262 continue; 263 264 case DO: 265 state = TS_DO; 266 continue; 267 268 case DONT: 269 state = TS_DONT; 270 continue; 271 case EOR: 272 if (his_state_is_will(TELOPT_EOR)) 273 doeof(); 274 break; 275 276 /* 277 * Handle RFC 10xx Telnet linemode option additions 278 * to command stream (EOF, SUSP, ABORT). 279 */ 280 case xEOF: 281 doeof(); 282 break; 283 284 case SUSP: 285 sendsusp(); 286 break; 287 288 case ABORT: 289 sendbrk(); 290 break; 291 292 case IAC: 293 *pfrontp++ = c; 294 break; 295 } 296 state = TS_DATA; 297 break; 298 299 case TS_SB: 300 if (c == IAC) { 301 state = TS_SE; 302 } else { 303 SB_ACCUM(c); 304 } 305 break; 306 307 case TS_SE: 308 if (c != SE) { 309 if (c != IAC) { 310 /* 311 * bad form of suboption negotiation. 312 * handle it in such a way as to avoid 313 * damage to local state. Parse 314 * suboption buffer found so far, 315 * then treat remaining stream as 316 * another command sequence. 317 */ 318 319 /* for DIAGNOSTICS */ 320 SB_ACCUM(IAC); 321 SB_ACCUM(c); 322 subpointer -= 2; 323 324 SB_TERM(); 325 suboption(); 326 state = TS_IAC; 327 goto gotiac; 328 } 329 SB_ACCUM(c); 330 state = TS_SB; 331 } else { 332 /* for DIAGNOSTICS */ 333 SB_ACCUM(IAC); 334 SB_ACCUM(SE); 335 subpointer -= 2; 336 337 SB_TERM(); 338 suboption(); /* handle sub-option */ 339 state = TS_DATA; 340 } 341 break; 342 343 case TS_WILL: 344 willoption(c); 345 state = TS_DATA; 346 continue; 347 348 case TS_WONT: 349 wontoption(c); 350 state = TS_DATA; 351 continue; 352 353 case TS_DO: 354 dooption(c); 355 state = TS_DATA; 356 continue; 357 358 case TS_DONT: 359 dontoption(c); 360 state = TS_DATA; 361 continue; 362 363 default: 364 syslog(LOG_ERR, "panic state=%d", state); 365 printf("telnetd: panic state=%d\n", state); 366 exit(1); 367 } 368 } 369} /* end of telrcv */ 370 371/* 372 * The will/wont/do/dont state machines are based on Dave Borman's 373 * Telnet option processing state machine. 374 * 375 * These correspond to the following states: 376 * my_state = the last negotiated state 377 * want_state = what I want the state to go to 378 * want_resp = how many requests I have sent 379 * All state defaults are negative, and resp defaults to 0. 380 * 381 * When initiating a request to change state to new_state: 382 * 383 * if ((want_resp == 0 && new_state == my_state) || want_state == new_state) { 384 * do nothing; 385 * } else { 386 * want_state = new_state; 387 * send new_state; 388 * want_resp++; 389 * } 390 * 391 * When receiving new_state: 392 * 393 * if (want_resp) { 394 * want_resp--; 395 * if (want_resp && (new_state == my_state)) 396 * want_resp--; 397 * } 398 * if ((want_resp == 0) && (new_state != want_state)) { 399 * if (ok_to_switch_to new_state) 400 * want_state = new_state; 401 * else 402 * want_resp++; 403 * send want_state; 404 * } 405 * my_state = new_state; 406 * 407 * Note that new_state is implied in these functions by the function itself. 408 * will and do imply positive new_state, wont and dont imply negative. 409 * 410 * Finally, there is one catch. If we send a negative response to a 411 * positive request, my_state will be the positive while want_state will 412 * remain negative. my_state will revert to negative when the negative 413 * acknowlegment arrives from the peer. Thus, my_state generally tells 414 * us not only the last negotiated state, but also tells us what the peer 415 * wants to be doing as well. It is important to understand this difference 416 * as we may wish to be processing data streams based on our desired state 417 * (want_state) or based on what the peer thinks the state is (my_state). 418 * 419 * This all works fine because if the peer sends a positive request, the data 420 * that we receive prior to negative acknowlegment will probably be affected 421 * by the positive state, and we can process it as such (if we can; if we 422 * can't then it really doesn't matter). If it is that important, then the 423 * peer probably should be buffering until this option state negotiation 424 * is complete. 425 * 426 */ 427void 428send_do(int option, int init) 429{ 430 if (init) { 431 if ((do_dont_resp[option] == 0 && his_state_is_will(option)) || 432 his_want_state_is_will(option)) 433 return; 434 /* 435 * Special case for TELOPT_TM: We send a DO, but pretend 436 * that we sent a DONT, so that we can send more DOs if 437 * we want to. 438 */ 439 if (option == TELOPT_TM) 440 set_his_want_state_wont(option); 441 else 442 set_his_want_state_will(option); 443 do_dont_resp[option]++; 444 } 445 output_data((const char *)doopt, option); 446 447 DIAG(TD_OPTIONS, printoption("td: send do", option)); 448} 449 450void 451willoption(int option) 452{ 453 int changeok = 0; 454 void (*func)(void) = 0; 455 456 /* 457 * process input from peer. 458 */ 459 460 DIAG(TD_OPTIONS, printoption("td: recv will", option)); 461 462 if (do_dont_resp[option]) { 463 do_dont_resp[option]--; 464 if (do_dont_resp[option] && his_state_is_will(option)) 465 do_dont_resp[option]--; 466 } 467 if (do_dont_resp[option] == 0) { 468 if (his_want_state_is_wont(option)) { 469 switch (option) { 470 471 case TELOPT_BINARY: 472 init_termbuf(); 473 tty_binaryin(1); 474 set_termbuf(); 475 changeok++; 476 break; 477 478 case TELOPT_ECHO: 479 /* 480 * See comments below for more info. 481 */ 482 not42 = 0; /* looks like a 4.2 system */ 483 break; 484 485 case TELOPT_TM: 486#if defined(LINEMODE) && defined(KLUDGELINEMODE) 487 /* 488 * This telnetd implementation does not really 489 * support timing marks, it just uses them to 490 * support the kludge linemode stuff. If we 491 * receive a will or wont TM in response to our 492 * do TM request that may have been sent to 493 * determine kludge linemode support, process 494 * it, otherwise TM should get a negative 495 * response back. 496 */ 497 /* 498 * Handle the linemode kludge stuff. 499 * If we are not currently supporting any 500 * linemode at all, then we assume that this 501 * is the client telling us to use kludge 502 * linemode in response to our query. Set the 503 * linemode type that is to be supported, note 504 * that the client wishes to use linemode, and 505 * eat the will TM as though it never arrived. 506 */ 507 if (lmodetype < KLUDGE_LINEMODE) { 508 lmodetype = KLUDGE_LINEMODE; 509 clientstat(TELOPT_LINEMODE, WILL, 0); 510 send_wont(TELOPT_SGA, 1); 511 } else if (lmodetype == NO_AUTOKLUDGE) { 512 lmodetype = KLUDGE_OK; 513 } 514#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 515 /* 516 * We never respond to a WILL TM, and 517 * we leave the state WONT. 518 */ 519 return; 520 521 case TELOPT_LFLOW: 522 /* 523 * If we are going to support flow control 524 * option, then don't worry peer that we can't 525 * change the flow control characters. 526 */ 527 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 528 slctab[SLC_XON].defset.flag |= SLC_DEFAULT; 529 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 530 slctab[SLC_XOFF].defset.flag |= SLC_DEFAULT; 531 case TELOPT_TTYPE: 532 case TELOPT_SGA: 533 case TELOPT_NAWS: 534 case TELOPT_TSPEED: 535 case TELOPT_XDISPLOC: 536 case TELOPT_NEW_ENVIRON: 537 case TELOPT_OLD_ENVIRON: 538 changeok++; 539 break; 540 541#ifdef LINEMODE 542 case TELOPT_LINEMODE: 543# ifdef KLUDGELINEMODE 544 /* 545 * Note client's desire to use linemode. 546 */ 547 lmodetype = REAL_LINEMODE; 548# endif /* KLUDGELINEMODE */ 549 func = doclientstat; 550 changeok++; 551 break; 552#endif /* LINEMODE */ 553 554#ifdef AUTHENTICATION 555 case TELOPT_AUTHENTICATION: 556 if (auth_level >= 0) { 557 func = auth_request; 558 changeok++; 559 } 560 break; 561#endif 562 563#ifdef ENCRYPTION 564 case TELOPT_ENCRYPT: 565 func = encrypt_send_support; 566 changeok++; 567 break; 568#endif /* ENCRYPTION */ 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#ifdef ENCRYPTION 629 case TELOPT_ENCRYPT: 630 func = encrypt_send_support; 631 break; 632#endif /* ENCRYPTION */ 633 case TELOPT_LFLOW: 634 func = flowstat; 635 break; 636 } 637 } 638 } 639 set_his_state_will(option); 640 if (func) 641 (*func)(); 642} /* end of willoption */ 643 644void 645send_dont(int option, int init) 646{ 647 if (init) { 648 if ((do_dont_resp[option] == 0 && his_state_is_wont(option)) || 649 his_want_state_is_wont(option)) 650 return; 651 set_his_want_state_wont(option); 652 do_dont_resp[option]++; 653 } 654 output_data((const char *)dont, option); 655 656 DIAG(TD_OPTIONS, printoption("td: send dont", option)); 657} 658 659void 660wontoption(int option) 661{ 662 /* 663 * Process client input. 664 */ 665 666 DIAG(TD_OPTIONS, printoption("td: recv wont", option)); 667 668 if (do_dont_resp[option]) { 669 do_dont_resp[option]--; 670 if (do_dont_resp[option] && his_state_is_wont(option)) 671 do_dont_resp[option]--; 672 } 673 if (do_dont_resp[option] == 0) { 674 if (his_want_state_is_will(option)) { 675 /* it is always ok to change to negative state */ 676 switch (option) { 677 case TELOPT_ECHO: 678 not42 = 1; /* doesn't seem to be a 4.2 system */ 679 break; 680 681 case TELOPT_BINARY: 682 init_termbuf(); 683 tty_binaryin(0); 684 set_termbuf(); 685 break; 686 687#ifdef LINEMODE 688 case TELOPT_LINEMODE: 689# ifdef KLUDGELINEMODE 690 /* 691 * If real linemode is supported, then client is 692 * asking to turn linemode off. 693 */ 694 if (lmodetype != REAL_LINEMODE) 695 break; 696 lmodetype = KLUDGE_LINEMODE; 697# endif /* KLUDGELINEMODE */ 698 clientstat(TELOPT_LINEMODE, WONT, 0); 699 break; 700#endif /* LINEMODE */ 701 702 case TELOPT_TM: 703 /* 704 * If we get a WONT TM, and had sent a DO TM, 705 * don't respond with a DONT TM, just leave it 706 * as is. Short circut the state machine to 707 * achive this. 708 */ 709 set_his_want_state_wont(TELOPT_TM); 710 return; 711 712 case TELOPT_LFLOW: 713 /* 714 * If we are not going to support flow control 715 * option, then let peer know that we can't 716 * change the flow control characters. 717 */ 718 slctab[SLC_XON].defset.flag &= ~SLC_LEVELBITS; 719 slctab[SLC_XON].defset.flag |= SLC_CANTCHANGE; 720 slctab[SLC_XOFF].defset.flag &= ~SLC_LEVELBITS; 721 slctab[SLC_XOFF].defset.flag |= SLC_CANTCHANGE; 722 break; 723 724#ifdef AUTHENTICATION 725 case TELOPT_AUTHENTICATION: 726 auth_finished(0, AUTH_REJECT); 727 break; 728#endif 729 730 /* 731 * For options that we might spin waiting for 732 * sub-negotiation, if the client turns off the 733 * option rather than responding to the request, 734 * we have to treat it here as if we got a response 735 * to the sub-negotiation, (by updating the timers) 736 * so that we'll break out of the loop. 737 */ 738 case TELOPT_TTYPE: 739 settimer(ttypesubopt); 740 break; 741 742 case TELOPT_TSPEED: 743 settimer(tspeedsubopt); 744 break; 745 746 case TELOPT_XDISPLOC: 747 settimer(xdisplocsubopt); 748 break; 749 750 case TELOPT_OLD_ENVIRON: 751 settimer(oenvironsubopt); 752 break; 753 754 case TELOPT_NEW_ENVIRON: 755 settimer(environsubopt); 756 break; 757 758 default: 759 break; 760 } 761 set_his_want_state_wont(option); 762 if (his_state_is_will(option)) 763 send_dont(option, 0); 764 } else { 765 switch (option) { 766 case TELOPT_TM: 767#if defined(LINEMODE) && defined(KLUDGELINEMODE) 768 if (lmodetype < NO_AUTOKLUDGE) { 769 lmodetype = NO_LINEMODE; 770 clientstat(TELOPT_LINEMODE, WONT, 0); 771 send_will(TELOPT_SGA, 1); 772 send_will(TELOPT_ECHO, 1); 773 } 774#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 775 break; 776 777#ifdef AUTHENTICATION 778 case TELOPT_AUTHENTICATION: 779 auth_finished(0, AUTH_REJECT); 780 break; 781#endif 782 default: 783 break; 784 } 785 } 786 } 787 set_his_state_wont(option); 788 789} /* end of wontoption */ 790 791void 792send_will(int option, int init) 793{ 794 if (init) { 795 if ((will_wont_resp[option] == 0 && my_state_is_will(option))|| 796 my_want_state_is_will(option)) 797 return; 798 set_my_want_state_will(option); 799 will_wont_resp[option]++; 800 } 801 output_data((const char *)will, option); 802 803 DIAG(TD_OPTIONS, printoption("td: send will", option)); 804} 805 806#if !defined(LINEMODE) || !defined(KLUDGELINEMODE) 807/* 808 * When we get a DONT SGA, we will try once to turn it 809 * back on. If the other side responds DONT SGA, we 810 * leave it at that. This is so that when we talk to 811 * clients that understand KLUDGELINEMODE but not LINEMODE, 812 * we'll keep them in char-at-a-time mode. 813 */ 814int turn_on_sga = 0; 815#endif 816 817void 818dooption(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#ifdef ENCRYPTION 918 case TELOPT_ENCRYPT: 919 changeok++; 920 break; 921#endif /* ENCRYPTION */ 922 case TELOPT_LINEMODE: 923 case TELOPT_TTYPE: 924 case TELOPT_NAWS: 925 case TELOPT_TSPEED: 926 case TELOPT_LFLOW: 927 case TELOPT_XDISPLOC: 928#ifdef TELOPT_ENVIRON 929 case TELOPT_NEW_ENVIRON: 930#endif 931 case TELOPT_OLD_ENVIRON: 932 default: 933 break; 934 } 935 if (changeok) { 936 set_my_want_state_will(option); 937 send_will(option, 0); 938 } else { 939 will_wont_resp[option]++; 940 send_wont(option, 0); 941 } 942 } 943 set_my_state_will(option); 944 945} /* end of dooption */ 946 947void 948send_wont(int option, int 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 output_data((const char *)wont, option); 958 959 DIAG(TD_OPTIONS, printoption("td: send wont", option)); 960} 961 962void 963dontoption(int option) 964{ 965 /* 966 * Process client input. 967 */ 968 969 970 DIAG(TD_OPTIONS, printoption("td: recv dont", option)); 971 972 if (will_wont_resp[option]) { 973 will_wont_resp[option]--; 974 if (will_wont_resp[option] && my_state_is_wont(option)) 975 will_wont_resp[option]--; 976 } 977 if ((will_wont_resp[option] == 0) && (my_want_state_is_will(option))) { 978 switch (option) { 979 case TELOPT_BINARY: 980 init_termbuf(); 981 tty_binaryout(0); 982 set_termbuf(); 983 break; 984 985 case TELOPT_ECHO: /* we should stop echoing */ 986#ifdef LINEMODE 987# ifdef KLUDGELINEMODE 988 if ((lmodetype != REAL_LINEMODE) && 989 (lmodetype != KLUDGE_LINEMODE)) 990# else 991 if (his_state_is_wont(TELOPT_LINEMODE)) 992# endif 993#endif 994 { 995 init_termbuf(); 996 tty_setecho(0); 997 set_termbuf(); 998 } 999 break; 1000 1001 case TELOPT_SGA: 1002#if defined(LINEMODE) && defined(KLUDGELINEMODE) 1003 /* 1004 * If kludge linemode is in use, then we 1005 * must process an incoming do SGA for 1006 * linemode purposes. 1007 */ 1008 if ((lmodetype == KLUDGE_LINEMODE) || 1009 (lmodetype == KLUDGE_OK)) { 1010 /* 1011 * The client is asking us to turn 1012 * linemode on. 1013 */ 1014 lmodetype = KLUDGE_LINEMODE; 1015 clientstat(TELOPT_LINEMODE, WILL, 0); 1016 /* 1017 * If we did not turn line mode on, 1018 * then what do we say? Will SGA? 1019 * This violates design of telnet. 1020 * Gross. Very Gross. 1021 */ 1022 } 1023 break; 1024#else 1025 set_my_want_state_wont(option); 1026 if (my_state_is_will(option)) 1027 send_wont(option, 0); 1028 set_my_state_wont(option); 1029 if (turn_on_sga ^= 1) 1030 send_will(option, 1); 1031 return; 1032#endif /* defined(LINEMODE) && defined(KLUDGELINEMODE) */ 1033 1034 default: 1035 break; 1036 } 1037 1038 set_my_want_state_wont(option); 1039 if (my_state_is_will(option)) 1040 send_wont(option, 0); 1041 } 1042 set_my_state_wont(option); 1043 1044} /* end of dontoption */ 1045 1046#ifdef ENV_HACK 1047int env_ovar = -1; 1048int env_ovalue = -1; 1049#else /* ENV_HACK */ 1050# define env_ovar OLD_ENV_VAR 1051# define env_ovalue OLD_ENV_VALUE 1052#endif /* ENV_HACK */ 1053 1054/* 1055 * suboption() 1056 * 1057 * Look at the sub-option buffer, and try to be helpful to the other 1058 * side. 1059 * 1060 * Currently we recognize: 1061 * 1062 * Terminal type is 1063 * Linemode 1064 * Window size 1065 * Terminal speed 1066 */ 1067void 1068suboption(void) 1069{ 1070 int subchar; 1071 1072 DIAG(TD_OPTIONS, {netflush(); printsub('<', subpointer, SB_LEN()+2);}); 1073 1074 subchar = SB_GET(); 1075 switch (subchar) { 1076 case TELOPT_TSPEED: { 1077 int xspeed, rspeed; 1078 1079 if (his_state_is_wont(TELOPT_TSPEED)) /* Ignore if option disabled */ 1080 break; 1081 1082 settimer(tspeedsubopt); 1083 1084 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1085 return; 1086 1087 xspeed = atoi((char *)subpointer); 1088 1089 while (SB_GET() != ',' && !SB_EOF()); 1090 if (SB_EOF()) 1091 return; 1092 1093 rspeed = atoi((char *)subpointer); 1094 clientstat(TELOPT_TSPEED, xspeed, rspeed); 1095 1096 break; 1097 1098 } /* end of case TELOPT_TSPEED */ 1099 1100 case TELOPT_TTYPE: { /* Yaaaay! */ 1101 static char terminalname[41]; 1102 1103 if (his_state_is_wont(TELOPT_TTYPE)) /* Ignore if option disabled */ 1104 break; 1105 settimer(ttypesubopt); 1106 1107 if (SB_EOF() || SB_GET() != TELQUAL_IS) { 1108 return; /* ??? XXX but, this is the most robust */ 1109 } 1110 1111 terminaltype = terminalname; 1112 1113 while ((terminaltype < (terminalname + sizeof terminalname-1)) && 1114 !SB_EOF()) { 1115 int c; 1116 1117 c = SB_GET(); 1118 if (isupper(c)) { 1119 c = tolower(c); 1120 } 1121 *terminaltype++ = c; /* accumulate name */ 1122 } 1123 *terminaltype = 0; 1124 terminaltype = terminalname; 1125 break; 1126 } /* end of case TELOPT_TTYPE */ 1127 1128 case TELOPT_NAWS: { 1129 int xwinsize, ywinsize; 1130 1131 if (his_state_is_wont(TELOPT_NAWS)) /* Ignore if option disabled */ 1132 break; 1133 1134 if (SB_EOF()) 1135 return; 1136 xwinsize = SB_GET() << 8; 1137 if (SB_EOF()) 1138 return; 1139 xwinsize |= SB_GET(); 1140 if (SB_EOF()) 1141 return; 1142 ywinsize = SB_GET() << 8; 1143 if (SB_EOF()) 1144 return; 1145 ywinsize |= SB_GET(); 1146 clientstat(TELOPT_NAWS, xwinsize, ywinsize); 1147 1148 break; 1149 1150 } /* end of case TELOPT_NAWS */ 1151 1152#ifdef LINEMODE 1153 case TELOPT_LINEMODE: { 1154 int request; 1155 1156 if (his_state_is_wont(TELOPT_LINEMODE)) /* Ignore if option disabled */ 1157 break; 1158 /* 1159 * Process linemode suboptions. 1160 */ 1161 if (SB_EOF()) 1162 break; /* garbage was sent */ 1163 request = SB_GET(); /* get will/wont */ 1164 1165 if (SB_EOF()) 1166 break; /* another garbage check */ 1167 1168 if (request == LM_SLC) { /* SLC is not preceeded by WILL or WONT */ 1169 /* 1170 * Process suboption buffer of slc's 1171 */ 1172 start_slc(1); 1173 do_opt_slc(subpointer, subend - subpointer); 1174 (void) end_slc(0); 1175 break; 1176 } else if (request == LM_MODE) { 1177 if (SB_EOF()) 1178 return; 1179 useeditmode = SB_GET(); /* get mode flag */ 1180 clientstat(LM_MODE, 0, 0); 1181 break; 1182 } 1183 1184 if (SB_EOF()) 1185 break; 1186 switch (SB_GET()) { /* what suboption? */ 1187 case LM_FORWARDMASK: 1188 /* 1189 * According to spec, only server can send request for 1190 * forwardmask, and client can only return a positive response. 1191 * So don't worry about it. 1192 */ 1193 1194 default: 1195 break; 1196 } 1197 break; 1198 } /* end of case TELOPT_LINEMODE */ 1199#endif 1200 case TELOPT_STATUS: { 1201 int mode; 1202 1203 if (SB_EOF()) 1204 break; 1205 mode = SB_GET(); 1206 switch (mode) { 1207 case TELQUAL_SEND: 1208 if (my_state_is_will(TELOPT_STATUS)) 1209 send_status(); 1210 break; 1211 1212 case TELQUAL_IS: 1213 break; 1214 1215 default: 1216 break; 1217 } 1218 break; 1219 } /* end of case TELOPT_STATUS */ 1220 1221 case TELOPT_XDISPLOC: { 1222 if (SB_EOF() || SB_GET() != TELQUAL_IS) 1223 return; 1224 settimer(xdisplocsubopt); 1225 subpointer[SB_LEN()] = '\0'; 1226 (void)setenv("DISPLAY", (char *)subpointer, 1); 1227 break; 1228 } /* end of case TELOPT_XDISPLOC */ 1229 1230#ifdef TELOPT_NEW_ENVIRON 1231 case TELOPT_NEW_ENVIRON: 1232#endif 1233 case TELOPT_OLD_ENVIRON: { 1234 int c; 1235 char *cp, *varp, *valp; 1236 1237 if (SB_EOF()) 1238 return; 1239 c = SB_GET(); 1240 if (c == TELQUAL_IS) { 1241 if (subchar == TELOPT_OLD_ENVIRON) 1242 settimer(oenvironsubopt); 1243 else 1244 settimer(environsubopt); 1245 } else if (c != TELQUAL_INFO) { 1246 return; 1247 } 1248 1249#ifdef TELOPT_NEW_ENVIRON 1250 if (subchar == TELOPT_NEW_ENVIRON) { 1251 while (!SB_EOF()) { 1252 c = SB_GET(); 1253 if ((c == NEW_ENV_VAR) || (c == ENV_USERVAR)) 1254 break; 1255 } 1256 } else 1257#endif 1258 { 1259#ifdef ENV_HACK 1260 /* 1261 * We only want to do this if we haven't already decided 1262 * whether or not the other side has its VALUE and VAR 1263 * reversed. 1264 */ 1265 if (env_ovar < 0) { 1266 int last = -1; /* invalid value */ 1267 int empty = 0; 1268 int got_var = 0, got_value = 0, got_uservar = 0; 1269 1270 /* 1271 * The other side might have its VALUE and VAR values 1272 * reversed. To be interoperable, we need to determine 1273 * which way it is. If the first recognized character 1274 * is a VAR or VALUE, then that will tell us what 1275 * type of client it is. If the fist recognized 1276 * character is a USERVAR, then we continue scanning 1277 * the suboption looking for two consecutive 1278 * VAR or VALUE fields. We should not get two 1279 * consecutive VALUE fields, so finding two 1280 * consecutive VALUE or VAR fields will tell us 1281 * what the client is. 1282 */ 1283 SB_SAVE(); 1284 while (!SB_EOF()) { 1285 c = SB_GET(); 1286 switch(c) { 1287 case OLD_ENV_VAR: 1288 if (last < 0 || last == OLD_ENV_VAR 1289 || (empty && (last == OLD_ENV_VALUE))) 1290 goto env_ovar_ok; 1291 got_var++; 1292 last = OLD_ENV_VAR; 1293 break; 1294 case OLD_ENV_VALUE: 1295 if (last < 0 || last == OLD_ENV_VALUE 1296 || (empty && (last == OLD_ENV_VAR))) 1297 goto env_ovar_wrong; 1298 got_value++; 1299 last = OLD_ENV_VALUE; 1300 break; 1301 case ENV_USERVAR: 1302 /* count strings of USERVAR as one */ 1303 if (last != ENV_USERVAR) 1304 got_uservar++; 1305 if (empty) { 1306 if (last == OLD_ENV_VALUE) 1307 goto env_ovar_ok; 1308 if (last == OLD_ENV_VAR) 1309 goto env_ovar_wrong; 1310 } 1311 last = ENV_USERVAR; 1312 break; 1313 case ENV_ESC: 1314 if (!SB_EOF()) 1315 c = SB_GET(); 1316 /* FALLTHROUGH */ 1317 default: 1318 empty = 0; 1319 continue; 1320 } 1321 empty = 1; 1322 } 1323 if (empty) { 1324 if (last == OLD_ENV_VALUE) 1325 goto env_ovar_ok; 1326 if (last == OLD_ENV_VAR) 1327 goto env_ovar_wrong; 1328 } 1329 /* 1330 * Ok, the first thing was a USERVAR, and there 1331 * are not two consecutive VAR or VALUE commands, 1332 * and none of the VAR or VALUE commands are empty. 1333 * If the client has sent us a well-formed option, 1334 * then the number of VALUEs received should always 1335 * be less than or equal to the number of VARs and 1336 * USERVARs received. 1337 * 1338 * If we got exactly as many VALUEs as VARs and 1339 * USERVARs, the client has the same definitions. 1340 * 1341 * If we got exactly as many VARs as VALUEs and 1342 * USERVARS, the client has reversed definitions. 1343 */ 1344 if (got_uservar + got_var == got_value) { 1345 env_ovar_ok: 1346 env_ovar = OLD_ENV_VAR; 1347 env_ovalue = OLD_ENV_VALUE; 1348 } else if (got_uservar + got_value == got_var) { 1349 env_ovar_wrong: 1350 env_ovar = OLD_ENV_VALUE; 1351 env_ovalue = OLD_ENV_VAR; 1352 DIAG(TD_OPTIONS, 1353 output_data("ENVIRON VALUE and VAR are reversed!\r\n")); 1354 1355 } 1356 } 1357 SB_RESTORE(); 1358#endif 1359 1360 while (!SB_EOF()) { 1361 c = SB_GET(); 1362 if ((c == env_ovar) || (c == ENV_USERVAR)) 1363 break; 1364 } 1365 } 1366 1367 if (SB_EOF()) 1368 return; 1369 1370 cp = varp = (char *)subpointer; 1371 valp = 0; 1372 1373 while (!SB_EOF()) { 1374 c = SB_GET(); 1375 if (subchar == TELOPT_OLD_ENVIRON) { 1376 if (c == env_ovar) 1377 c = NEW_ENV_VAR; 1378 else if (c == env_ovalue) 1379 c = NEW_ENV_VALUE; 1380 } 1381 switch (c) { 1382 1383 case NEW_ENV_VALUE: 1384 *cp = '\0'; 1385 cp = valp = (char *)subpointer; 1386 break; 1387 1388 case NEW_ENV_VAR: 1389 case ENV_USERVAR: 1390 *cp = '\0'; 1391 if (valp) 1392 (void)setenv(varp, valp, 1); 1393 else 1394 unsetenv(varp); 1395 cp = varp = (char *)subpointer; 1396 valp = 0; 1397 break; 1398 1399 case ENV_ESC: 1400 if (SB_EOF()) 1401 break; 1402 c = SB_GET(); 1403 /* FALLTHROUGH */ 1404 default: 1405 *cp++ = c; 1406 break; 1407 } 1408 } 1409 *cp = '\0'; 1410 if (valp) 1411 (void)setenv(varp, valp, 1); 1412 else 1413 unsetenv(varp); 1414 break; 1415 } /* end of case TELOPT_NEW_ENVIRON */ 1416#ifdef AUTHENTICATION 1417 case TELOPT_AUTHENTICATION: 1418 if (SB_EOF()) 1419 break; 1420 switch(SB_GET()) { 1421 case TELQUAL_SEND: 1422 case TELQUAL_REPLY: 1423 /* 1424 * These are sent by us and cannot be sent by 1425 * the client. 1426 */ 1427 break; 1428 case TELQUAL_IS: 1429 auth_is(subpointer, SB_LEN()); 1430 break; 1431 case TELQUAL_NAME: 1432 auth_name(subpointer, SB_LEN()); 1433 break; 1434 } 1435 break; 1436#endif 1437#ifdef ENCRYPTION 1438 case TELOPT_ENCRYPT: 1439 if (SB_EOF()) 1440 break; 1441 switch(SB_GET()) { 1442 case ENCRYPT_SUPPORT: 1443 encrypt_support(subpointer, SB_LEN()); 1444 break; 1445 case ENCRYPT_IS: 1446 encrypt_is(subpointer, SB_LEN()); 1447 break; 1448 case ENCRYPT_REPLY: 1449 encrypt_reply(subpointer, SB_LEN()); 1450 break; 1451 case ENCRYPT_START: 1452 encrypt_start(subpointer, SB_LEN()); 1453 break; 1454 case ENCRYPT_END: 1455 encrypt_end(); 1456 break; 1457 case ENCRYPT_REQSTART: 1458 encrypt_request_start(subpointer, SB_LEN()); 1459 break; 1460 case ENCRYPT_REQEND: 1461 /* 1462 * We can always send an REQEND so that we cannot 1463 * get stuck encrypting. We should only get this 1464 * if we have been able to get in the correct mode 1465 * anyhow. 1466 */ 1467 encrypt_request_end(); 1468 break; 1469 case ENCRYPT_ENC_KEYID: 1470 encrypt_enc_keyid(subpointer, SB_LEN()); 1471 break; 1472 case ENCRYPT_DEC_KEYID: 1473 encrypt_dec_keyid(subpointer, SB_LEN()); 1474 break; 1475 default: 1476 break; 1477 } 1478 break; 1479#endif /* ENCRYPTION */ 1480 1481 default: 1482 break; 1483 } /* end of switch */ 1484 1485} /* end of suboption */ 1486 1487static void 1488doclientstat(void) 1489{ 1490 clientstat(TELOPT_LINEMODE, WILL, 0); 1491} 1492 1493#define ADD(c) *ncp++ = c 1494#define ADD_DATA(c) { *ncp++ = c; if (c == SE || c == IAC) *ncp++ = c; } 1495void 1496send_status(void) 1497{ 1498 unsigned char statusbuf[256]; 1499 unsigned char *ncp; 1500 unsigned char i; 1501 1502 ncp = statusbuf; 1503 1504 netflush(); /* get rid of anything waiting to go out */ 1505 1506 ADD(IAC); 1507 ADD(SB); 1508 ADD(TELOPT_STATUS); 1509 ADD(TELQUAL_IS); 1510 1511 /* 1512 * We check the want_state rather than the current state, 1513 * because if we received a DO/WILL for an option that we 1514 * don't support, and the other side didn't send a DONT/WONT 1515 * in response to our WONT/DONT, then the "state" will be 1516 * WILL/DO, and the "want_state" will be WONT/DONT. We 1517 * need to go by the latter. 1518 */ 1519 for (i = 0; i < (unsigned char)NTELOPTS; i++) { 1520 if (my_want_state_is_will(i)) { 1521 ADD(WILL); 1522 ADD_DATA(i); 1523 if (i == IAC) 1524 ADD(IAC); 1525 } 1526 if (his_want_state_is_will(i)) { 1527 ADD(DO); 1528 ADD_DATA(i); 1529 if (i == IAC) 1530 ADD(IAC); 1531 } 1532 } 1533 1534 if (his_want_state_is_will(TELOPT_LFLOW)) { 1535 ADD(SB); 1536 ADD(TELOPT_LFLOW); 1537 if (flowmode) { 1538 ADD(LFLOW_ON); 1539 } else { 1540 ADD(LFLOW_OFF); 1541 } 1542 ADD(SE); 1543 1544 if (restartany >= 0) { 1545 ADD(SB); 1546 ADD(TELOPT_LFLOW); 1547 if (restartany) { 1548 ADD(LFLOW_RESTART_ANY); 1549 } else { 1550 ADD(LFLOW_RESTART_XON); 1551 } 1552 ADD(SE); 1553 } 1554 } 1555 1556#ifdef LINEMODE 1557 if (his_want_state_is_will(TELOPT_LINEMODE)) { 1558 unsigned char *cp, *cpe; 1559 int len; 1560 1561 ADD(SB); 1562 ADD(TELOPT_LINEMODE); 1563 ADD(LM_MODE); 1564 ADD_DATA(editmode); 1565 ADD(SE); 1566 1567 ADD(SB); 1568 ADD(TELOPT_LINEMODE); 1569 ADD(LM_SLC); 1570 start_slc(0); 1571 send_slc(); 1572 len = end_slc(&cp); 1573 for (cpe = cp + len; cp < cpe; cp++) 1574 ADD_DATA(*cp); 1575 ADD(SE); 1576 } 1577#endif /* LINEMODE */ 1578 1579 ADD(IAC); 1580 ADD(SE); 1581 1582 output_datalen(statusbuf, ncp - statusbuf); 1583 netflush(); /* Send it on its way */ 1584 1585 DIAG(TD_OPTIONS, 1586 {printsub('>', statusbuf, ncp - statusbuf); netflush();}); 1587} 1588 1589/* 1590 * This function appends data to nfrontp and advances nfrontp. 1591 * Returns the number of characters written altogether (the 1592 * buffer may have been flushed in the process). 1593 */ 1594 1595int 1596output_data(const char *format, ...) 1597{ 1598 va_list args; 1599 int len; 1600 char *buf; 1601 1602 va_start(args, format); 1603 if ((len = vasprintf(&buf, format, args)) == -1) { 1604 va_end(args); 1605 return -1; 1606 } 1607 output_datalen(buf, len); 1608 va_end(args); 1609 free(buf); 1610 return (len); 1611} 1612 1613void 1614output_datalen(const char *buf, int len) 1615{ 1616 int remaining, copied; 1617 1618 remaining = BUFSIZ - (nfrontp - netobuf); 1619 while (len > 0) { 1620 /* Free up enough space if the room is too low*/ 1621 if ((len > BUFSIZ ? BUFSIZ : len) > remaining) { 1622 netflush(); 1623 remaining = BUFSIZ - (nfrontp - netobuf); 1624 } 1625 1626 /* Copy out as much as will fit */ 1627 copied = remaining > len ? len : remaining; 1628 memmove(nfrontp, buf, copied); 1629 nfrontp += copied; 1630 len -= copied; 1631 remaining -= copied; 1632 buf += copied; 1633 } 1634 return; 1635} 1636