Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 | /* vi: set sw=4 ts=4: */ /* * telnet implementation for busybox * * Author: Tomi Ollila <too@iki.fi> * Copyright (C) 1994-2000 by Tomi Ollila * * Created: Thu Apr 7 13:29:41 1994 too * Last modified: Fri Jun 9 14:34:24 2000 too * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * HISTORY * Revision 3.1 1994/04/17 11:31:54 too * initial revision * Modified 2000/06/13 for inclusion into BusyBox by Erik Andersen <andersen@codepoet.org> * Modified 2001/05/07 to add ability to pass TTYPE to remote host by Jim McQuillan * <jam@ltsp.org> * Modified 2004/02/11 to add ability to pass the USER variable to remote host * by Fernando Silveira <swrh@gmx.net> * */ #include <termios.h> #include <unistd.h> #include <errno.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> #include <signal.h> #include <arpa/telnet.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include "busybox.h" #if 0 static const int DOTRACE = 1; #endif #ifdef DOTRACE #include <arpa/inet.h> /* for inet_ntoa()... */ #define TRACE(x, y) do { if (x) printf y; } while (0) #else #define TRACE(x, y) #endif #if 0 #define USE_POLL #include <sys/poll.h> #else #include <sys/time.h> #endif #define DATABUFSIZE 128 #define IACBUFSIZE 128 static const int CHM_TRY = 0; static const int CHM_ON = 1; static const int CHM_OFF = 2; static const int UF_ECHO = 0x01; static const int UF_SGA = 0x02; enum { TS_0 = 1, TS_IAC = 2, TS_OPT = 3, TS_SUB1 = 4, TS_SUB2 = 5, }; #define WriteCS(fd, str) write(fd, str, sizeof str -1) typedef unsigned char byte; /* use globals to reduce size ??? */ /* test this hypothesis later */ static struct Globalvars { int netfd; /* console fd:s are 0 and 1 (and 2) */ /* same buffer used both for network and console read/write */ char buf[DATABUFSIZE]; /* allocating so static size is smaller */ byte telstate; /* telnet negotiation state from network input */ byte telwish; /* DO, DONT, WILL, WONT */ byte charmode; byte telflags; byte gotsig; /* buffer to handle telnet negotiations */ char iacbuf[IACBUFSIZE]; short iaclen; /* could even use byte */ struct termios termios_def; struct termios termios_raw; } G; #define xUSE_GLOBALVAR_PTR /* xUSE... -> don't use :D (makes smaller code) */ #ifdef USE_GLOBALVAR_PTR struct Globalvars * Gptr; #define G (*Gptr) #endif static inline void iacflush(void) { write(G.netfd, G.iacbuf, G.iaclen); G.iaclen = 0; } /* Function prototypes */ static void rawmode(void); static void cookmode(void); static void do_linemode(void); static void will_charmode(void); static void telopt(byte c); static int subneg(byte c); /* Some globals */ static int one = 1; #ifdef CONFIG_FEATURE_TELNET_TTYPE static char *ttype; #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN static char *autologin; #endif #ifdef CONFIG_FEATURE_AUTOWIDTH static int win_width, win_height; #endif static void doexit(int ev) { cookmode(); exit(ev); } static void conescape(void) { char b; if (G.gotsig) /* came from line mode... go raw */ rawmode(); WriteCS(1, "\r\nConsole escape. Commands are:\r\n\n" " l go to line mode\r\n" " c go to character mode\r\n" " z suspend telnet\r\n" " e exit telnet\r\n"); if (read(0, &b, 1) <= 0) doexit(1); switch (b) { case 'l': if (!G.gotsig) { do_linemode(); goto rrturn; } break; case 'c': if (G.gotsig) { will_charmode(); goto rrturn; } break; case 'z': cookmode(); kill(0, SIGTSTP); rawmode(); break; case 'e': doexit(0); } WriteCS(1, "continuing...\r\n"); if (G.gotsig) cookmode(); rrturn: G.gotsig = 0; } static void handlenetoutput(int len) { /* here we could do smart tricks how to handle 0xFF:s in output * stream like writing twice every sequence of FF:s (thus doing * many write()s. But I think interactive telnet application does * not need to be 100% 8-bit clean, so changing every 0xff:s to * 0x7f:s * * 2002-mar-21, Przemyslaw Czerpak (druzus@polbox.com) * I don't agree. * first - I cannot use programs like sz/rz * second - the 0x0D is sent as one character and if the next * char is 0x0A then it's eaten by a server side. * third - whay doy you have to make 'many write()s'? * I don't understand. * So I implemented it. It's realy useful for me. I hope that * others people will find it interesting to. */ int i, j; byte * p = G.buf; byte outbuf[4*DATABUFSIZE]; for (i = len, j = 0; i > 0; i--, p++) { if (*p == 0x1d) { conescape(); return; } outbuf[j++] = *p; if (*p == 0xff) outbuf[j++] = 0xff; else if (*p == 0x0d) outbuf[j++] = 0x00; } if (j > 0 ) write(G.netfd, outbuf, j); } static void handlenetinput(int len) { int i; int cstart = 0; for (i = 0; i < len; i++) { byte c = G.buf[i]; if (G.telstate == 0) /* most of the time state == 0 */ { if (c == IAC) { cstart = i; G.telstate = TS_IAC; } } else switch (G.telstate) { case TS_0: if (c == IAC) G.telstate = TS_IAC; else G.buf[cstart++] = c; break; case TS_IAC: if (c == IAC) /* IAC IAC -> 0xFF */ { G.buf[cstart++] = c; G.telstate = TS_0; break; } /* else */ switch (c) { case SB: G.telstate = TS_SUB1; break; case DO: case DONT: case WILL: case WONT: G.telwish = c; G.telstate = TS_OPT; break; default: G.telstate = TS_0; /* DATA MARK must be added later */ } break; case TS_OPT: /* WILL, WONT, DO, DONT */ telopt(c); G.telstate = TS_0; break; case TS_SUB1: /* Subnegotiation */ case TS_SUB2: /* Subnegotiation */ if (subneg(c)) G.telstate = TS_0; break; } } if (G.telstate) { if (G.iaclen) iacflush(); if (G.telstate == TS_0) G.telstate = 0; len = cstart; } if (len) write(1, G.buf, len); } /* ******************************* */ static inline void putiac(int c) { G.iacbuf[G.iaclen++] = c; } static void putiac2(byte wwdd, byte c) { if (G.iaclen + 3 > IACBUFSIZE) iacflush(); putiac(IAC); putiac(wwdd); putiac(c); } #if 0 static void putiac1(byte c) { if (G.iaclen + 2 > IACBUFSIZE) iacflush(); putiac(IAC); putiac(c); } #endif #ifdef CONFIG_FEATURE_TELNET_TTYPE static void putiac_subopt(byte c, char *str) { int len = strlen(str) + 6; // ( 2 + 1 + 1 + strlen + 2 ) if (G.iaclen + len > IACBUFSIZE) iacflush(); putiac(IAC); putiac(SB); putiac(c); putiac(0); while(*str) putiac(*str++); putiac(IAC); putiac(SE); } #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN static void putiac_subopt_autologin(void) { int len = strlen(autologin) + 6; // (2 + 1 + 1 + strlen + 2) char *user = "USER"; if (G.iaclen + len > IACBUFSIZE) iacflush(); putiac(IAC); putiac(SB); putiac(TELOPT_NEW_ENVIRON); putiac(TELQUAL_IS); putiac(NEW_ENV_VAR); while(*user) putiac(*user++); putiac(NEW_ENV_VALUE); while(*autologin) putiac(*autologin++); putiac(IAC); putiac(SE); } #endif #ifdef CONFIG_FEATURE_AUTOWIDTH static void putiac_naws(byte c, int x, int y) { if (G.iaclen + 9 > IACBUFSIZE) iacflush(); putiac(IAC); putiac(SB); putiac(c); putiac((x >> 8) & 0xff); putiac(x & 0xff); putiac((y >> 8) & 0xff); putiac(y & 0xff); putiac(IAC); putiac(SE); } #endif /* void putiacstring (subneg strings) */ /* ******************************* */ static char const escapecharis[] = "\r\nEscape character is "; static void setConMode(void) { if (G.telflags & UF_ECHO) { if (G.charmode == CHM_TRY) { G.charmode = CHM_ON; printf("\r\nEntering character mode%s'^]'.\r\n", escapecharis); rawmode(); } } else { if (G.charmode != CHM_OFF) { G.charmode = CHM_OFF; printf("\r\nEntering line mode%s'^C'.\r\n", escapecharis); cookmode(); } } } /* ******************************* */ static void will_charmode(void) { G.charmode = CHM_TRY; G.telflags |= (UF_ECHO | UF_SGA); setConMode(); putiac2(DO, TELOPT_ECHO); putiac2(DO, TELOPT_SGA); iacflush(); } static void do_linemode(void) { G.charmode = CHM_TRY; G.telflags &= ~(UF_ECHO | UF_SGA); setConMode(); putiac2(DONT, TELOPT_ECHO); putiac2(DONT, TELOPT_SGA); iacflush(); } /* ******************************* */ static inline void to_notsup(char c) { if (G.telwish == WILL) putiac2(DONT, c); else if (G.telwish == DO) putiac2(WONT, c); } static inline void to_echo(void) { /* if server requests ECHO, don't agree */ if (G.telwish == DO) { putiac2(WONT, TELOPT_ECHO); return; } else if (G.telwish == DONT) return; if (G.telflags & UF_ECHO) { if (G.telwish == WILL) return; } else if (G.telwish == WONT) return; if (G.charmode != CHM_OFF) G.telflags ^= UF_ECHO; if (G.telflags & UF_ECHO) putiac2(DO, TELOPT_ECHO); else putiac2(DONT, TELOPT_ECHO); setConMode(); WriteCS(1, "\r\n"); /* sudden modec */ } static inline void to_sga(void) { /* daemon always sends will/wont, client do/dont */ if (G.telflags & UF_SGA) { if (G.telwish == WILL) return; } else if (G.telwish == WONT) return; if ((G.telflags ^= UF_SGA) & UF_SGA) /* toggle */ putiac2(DO, TELOPT_SGA); else putiac2(DONT, TELOPT_SGA); return; } #ifdef CONFIG_FEATURE_TELNET_TTYPE static inline void to_ttype(void) { /* Tell server we will (or won't) do TTYPE */ if(ttype) putiac2(WILL, TELOPT_TTYPE); else putiac2(WONT, TELOPT_TTYPE); return; } #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN static inline void to_new_environ(void) { /* Tell server we will (or will not) do AUTOLOGIN */ if (autologin) putiac2(WILL, TELOPT_NEW_ENVIRON); else putiac2(WONT, TELOPT_NEW_ENVIRON); return; } #endif #ifdef CONFIG_FEATURE_AUTOWIDTH static inline void to_naws(void) { /* Tell server we will do NAWS */ putiac2(WILL, TELOPT_NAWS); return; } #endif static void telopt(byte c) { switch (c) { case TELOPT_ECHO: to_echo(); break; case TELOPT_SGA: to_sga(); break; #ifdef CONFIG_FEATURE_TELNET_TTYPE case TELOPT_TTYPE: to_ttype();break; #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN case TELOPT_NEW_ENVIRON: to_new_environ(); break; #endif #ifdef CONFIG_FEATURE_AUTOWIDTH case TELOPT_NAWS: to_naws(); putiac_naws(c, win_width, win_height); break; #endif default: to_notsup(c); break; } } /* ******************************* */ /* subnegotiation -- ignore all (except TTYPE,NAWS) */ static int subneg(byte c) { switch (G.telstate) { case TS_SUB1: if (c == IAC) G.telstate = TS_SUB2; #ifdef CONFIG_FEATURE_TELNET_TTYPE else if (c == TELOPT_TTYPE) putiac_subopt(TELOPT_TTYPE,ttype); #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN else if (c == TELOPT_NEW_ENVIRON) putiac_subopt_autologin(); #endif break; case TS_SUB2: if (c == SE) return TRUE; G.telstate = TS_SUB1; /* break; */ } return FALSE; } /* ******************************* */ static void fgotsig(int sig) { G.gotsig = sig; } static void rawmode(void) { tcsetattr(0, TCSADRAIN, &G.termios_raw); } static void cookmode(void) { tcsetattr(0, TCSADRAIN, &G.termios_def); } extern int telnet_main(int argc, char** argv) { int len; struct sockaddr_in s_in; #ifdef USE_POLL struct pollfd ufds[2]; #else fd_set readfds; int maxfd; #endif #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN int opt; #endif #ifdef CONFIG_FEATURE_AUTOWIDTH get_terminal_width_height(0, &win_width, &win_height); #endif #ifdef CONFIG_FEATURE_TELNET_TTYPE ttype = getenv("TERM"); #endif memset(&G, 0, sizeof G); if (tcgetattr(0, &G.termios_def) < 0) exit(1); G.termios_raw = G.termios_def; cfmakeraw(&G.termios_raw); if (argc < 2) bb_show_usage(); #ifdef CONFIG_FEATURE_TELNET_AUTOLOGIN autologin = NULL; while ((opt = getopt(argc, argv, "al:")) != EOF) { switch (opt) { case 'l': autologin = bb_xstrdup(optarg); break; case 'a': autologin = getenv("USER"); break; case '?': bb_show_usage(); break; } } if (optind < argc) { bb_lookup_host(&s_in, argv[optind++]); s_in.sin_port = bb_lookup_port((optind < argc) ? argv[optind++] : "telnet", "tcp", 23); if (optind < argc) bb_show_usage(); } else bb_show_usage(); #else bb_lookup_host(&s_in, argv[1]); s_in.sin_port = bb_lookup_port((argc == 3) ? argv[2] : "telnet", "tcp", 23); #endif G.netfd = xconnect(&s_in); setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof one); signal(SIGINT, fgotsig); #ifdef USE_POLL ufds[0].fd = 0; ufds[1].fd = G.netfd; ufds[0].events = ufds[1].events = POLLIN; #else FD_ZERO(&readfds); FD_SET(0, &readfds); FD_SET(G.netfd, &readfds); maxfd = G.netfd + 1; #endif while (1) { #ifndef USE_POLL fd_set rfds = readfds; switch (select(maxfd, &rfds, NULL, NULL, NULL)) #else switch (poll(ufds, 2, -1)) #endif { case 0: /* timeout */ case -1: /* error, ignore and/or log something, bay go to loop */ if (G.gotsig) conescape(); else sleep(1); break; default: #ifdef USE_POLL if (ufds[0].revents) /* well, should check POLLIN, but ... */ #else if (FD_ISSET(0, &rfds)) #endif { len = read(0, G.buf, DATABUFSIZE); if (len <= 0) doexit(0); TRACE(0, ("Read con: %d\n", len)); handlenetoutput(len); } #ifdef USE_POLL if (ufds[1].revents) /* well, should check POLLIN, but ... */ #else if (FD_ISSET(G.netfd, &rfds)) #endif { len = read(G.netfd, G.buf, DATABUFSIZE); if (len <= 0) { WriteCS(1, "Connection closed by foreign host.\r\n"); doexit(1); } TRACE(0, ("Read netfd (%d): %d\n", G.netfd, len)); handlenetinput(len); } } } } /* Local Variables: c-file-style: "linux" c-basic-offset: 4 tab-width: 4 End: */ |