usr.bin/rlogin/rlogin.c

   1 /*
   2  * Copyright (c) 1983, 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 2002 Networks Associates Technology, Inc.
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed for the FreeBSD Project by
   8  * ThinkSec AS and NAI Labs, the Security Research Division of Network
   9  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
  10  * ("CBOSS"), as part of the DARPA CHATS research program.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *      This product includes software developed by the University of
  23  *      California, Berkeley and its contributors.
  24  * 4. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  *
  40  * @(#) Copyright (c) 1983, 1990, 1993 The Regents of the University of California.  All rights reserved.
  41  * @(#)rlogin.c 8.1 (Berkeley) 6/6/93
  42  * $FreeBSD: src/usr.bin/rlogin/rlogin.c,v 1.30 2002/04/28 11:16:43 markm Exp $
  43  * $DragonFly: src/usr.bin/rlogin/rlogin.c,v 1.7 2005/02/15 01:24:49 cpressey Exp $
  44  */
  45
  46 /*
  47  * rlogin - remote login
  48  */
  49 #include <sys/param.h>
  50 #include <sys/socket.h>
  51 #include <sys/time.h>
  52 #include <sys/resource.h>
  53 #include <sys/wait.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58 #include <netinet/tcp.h>
  59
  60 #include <err.h>
  61 #include <errno.h>
  62 #include <fcntl.h>
  63 #include <libutil.h>
  64 #include <netdb.h>
  65 #include <paths.h>
  66 #include <pwd.h>
  67 #include <setjmp.h>
  68 #include <sgtty.h>
  69 #include <signal.h>
  70 #include <stdio.h>
  71 #include <stdlib.h>
  72 #include <string.h>
  73 #include <unistd.h>
  74
  75 #ifdef KERBEROS
  76 #include <openssl/des.h>
  77 #include <krb.h>
  78
  79 #include "krb.h"
  80
  81 CREDENTIALS cred;
  82 Key_schedule schedule;
  83 int use_kerberos = 1, doencrypt;
  84 char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
  85 #endif
  86
  87 #ifndef TIOCPKT_WINDOW
  88 #define TIOCPKT_WINDOW  0x80
  89 #endif
  90
  91 /* concession to Sun */
  92 #ifndef SIGUSR1
  93 #define SIGUSR1 30
  94 #endif
  95
  96 int eight, litout, rem;
  97 int family = PF_UNSPEC;
  98
  99 int noescape;
 100 u_char escapechar = '~';
 101
 102 const char *speeds[] = {
 103         "0", "50", "75", "110", "134", "150", "200", "300", "600", "1200",
 104         "1800", "2400", "4800", "9600", "19200", "38400", "57600", "115200"
 105 #define MAX_SPEED_LENGTH        (sizeof("115200") - 1)
 106 };
 107
 108 #define get_window_size(fd, wp) ioctl(fd, TIOCGWINSZ, wp)
 109 struct  winsize winsize;
 110
 111 void            catch_child(int);
 112 void            copytochild(int);
 113 void            doit(long) __dead2;
 114 void            done(int) __dead2;
 115 void            echo(char);
 116 u_int           getescape(char *);
 117 void            lostpeer(int);
 118 void            mode(int);
 119 void            msg(const char *);
 120 void            oob(int);
 121 int             reader(int);
 122 void            sendwindow(void);
 123 void            setsignal(int);
 124 void            sigwinch(int);
 125 void            stop(char);
 126 void            usage(void) __dead2;
 127 void            writer(void);
 128 void            writeroob(int);
 129
 130 int
 131 main(int argc, char *argv[])
 132 {
 133         struct passwd *pw;
 134         struct servent *sp;
 135         struct sgttyb ttyb;
 136         long omask;
 137         int argoff, ch, dflag, Dflag, one, uid;
 138         char *host, *localname, *p, *user, term[1024];
 139 #ifdef KERBEROS
 140         char *k;
 141 #endif
 142         struct sockaddr_storage ss;
 143         int sslen;
 144
 145         argoff = dflag = Dflag = 0;
 146         one = 1;
 147         host = localname = user = NULL;
 148
 149         if ((p = strrchr(argv[0], '/')))
 150                 ++p;
 151         else
 152                 p = argv[0];
 153
 154         if (strcmp(p, "rlogin"))
 155                 host = p;
 156
 157         /* handle "rlogin host flags" */
 158         if (!host && argc > 2 && argv[1][0] != '-') {
 159                 host = argv[1];
 160                 argoff = 1;
 161         }
 162
 163 #ifdef KERBEROS
 164 #define OPTIONS "468DEKLde:i:k:l:x"
 165 #else
 166 #define OPTIONS "468DEKLde:i:l:"
 167 #endif
 168         while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != -1)
 169                 switch(ch) {
 170                 case '4':
 171                         family = PF_INET;
 172                         break;
 173
 174                 case '6':
 175                         family = PF_INET6;
 176                         break;
 177
 178                 case '8':
 179                         eight = 1;
 180                         break;
 181                 case 'D':
 182                         Dflag = 1;
 183                         break;
 184                 case 'E':
 185                         noescape = 1;
 186                         break;
 187                 case 'K':
 188 #ifdef KERBEROS
 189                         use_kerberos = 0;
 190 #endif
 191                         break;
 192                 case 'L':
 193                         litout = 1;
 194                         break;
 195                 case 'd':
 196                         dflag = 1;
 197                         break;
 198                 case 'e':
 199                         noescape = 0;
 200                         escapechar = getescape(optarg);
 201                         break;
 202                 case 'i':
 203                         if (getuid() != 0)
 204                                 errx(1, "-i user: permission denied");
 205                         localname = optarg;
 206                         break;
 207 #ifdef KERBEROS
 208                 case 'k':
 209                         dest_realm = dst_realm_buf;
 210                         (void)strncpy(dest_realm, optarg, REALM_SZ);
 211                         break;
 212 #endif
 213                 case 'l':
 214                         user = optarg;
 215                         break;
 216 #ifdef CRYPT
 217 #ifdef KERBEROS
 218                 case 'x':
 219                         doencrypt = 1;
 220                         break;
 221 #endif
 222 #endif
 223                 case '?':
 224                 default:
 225                         usage();
 226                 }
 227         optind += argoff;
 228
 229         /* if haven't gotten a host yet, do so */
 230         if (!host && !(host = argv[optind++]))
 231                 usage();
 232
 233         if (argv[optind])
 234                 usage();
 235
 236         if (!(pw = getpwuid(uid = getuid())))
 237                 errx(1, "unknown user id");
 238         if (!user)
 239                 user = pw->pw_name;
 240         if (!localname)
 241                 localname = pw->pw_name;
 242
 243         sp = NULL;
 244 #ifdef KERBEROS
 245         k = auth_getval("auth_list");
 246         if (k && !strstr(k, "kerberos"))
 247             use_kerberos = 0;
 248         if (use_kerberos) {
 249                 sp = getservbyname((doencrypt ? "eklogin" : "klogin"), "tcp");
 250                 if (sp == NULL) {
 251                         use_kerberos = 0;
 252                         warn("can't get entry for %s/tcp service",
 253                             doencrypt ? "eklogin" : "klogin");
 254                 }
 255         }
 256 #endif
 257         if (sp == NULL)
 258                 sp = getservbyname("login", "tcp");
 259         if (sp == NULL)
 260                 errx(1, "login/tcp: unknown service");
 261
 262 #define MAX_TERM_LENGTH (sizeof(term) - 1 - MAX_SPEED_LENGTH - 1)
 263
 264         (void)strncpy(term, (p = getenv("TERM")) ? p : "network",
 265                       MAX_TERM_LENGTH);
 266         term[MAX_TERM_LENGTH] = '\0';
 267         if (ioctl(0, TIOCGETP, &ttyb) == 0) {
 268                 (void)strcat(term, "/");
 269                 (void)strcat(term, speeds[(int)ttyb.sg_ospeed]);
 270         }
 271
 272         (void)get_window_size(0, &winsize);
 273
 274         (void)signal(SIGPIPE, lostpeer);
 275         /* will use SIGUSR1 for window size hack, so hold it off */
 276         omask = sigblock(sigmask(SIGURG) | sigmask(SIGUSR1));
 277         /*
 278          * We set SIGURG and SIGUSR1 below so that an
 279          * incoming signal will be held pending rather than being
 280          * discarded. Note that these routines will be ready to get
 281          * a signal by the time that they are unblocked below.
 282          */
 283         (void)signal(SIGURG, copytochild);
 284         (void)signal(SIGUSR1, writeroob);
 285
 286 #ifdef KERBEROS
 287         if (use_kerberos) {
 288                 setuid(getuid());
 289                 rem = KSUCCESS;
 290                 errno = 0;
 291                 if (dest_realm == NULL)
 292                         dest_realm = krb_realmofhost(host);
 293
 294 #ifdef CRYPT
 295                 if (doencrypt) {
 296                         rem = krcmd_mutual(&host, sp->s_port, user, term, 0,
 297                             dest_realm, &cred, schedule);
 298                         des_set_key(&cred.session, schedule);
 299                 } else
 300 #endif /* CRYPT */
 301                         rem = krcmd(&host, sp->s_port, user, term, 0,
 302                             dest_realm);
 303                 if (rem < 0) {
 304                         int i;
 305                         char **newargv;
 306
 307                         sp = getservbyname("login", "tcp");
 308                         if (sp == NULL)
 309                                 errx(1, "unknown service login/tcp");
 310                         if (errno == ECONNREFUSED)
 311                                 warn("remote host doesn't support Kerberos");
 312                         if (errno == ENOENT)
 313                                 warn("can't provide Kerberos auth data");
 314                         newargv = malloc((argc + 2) * sizeof(*newargv));
 315                         if (newargv == NULL)
 316                                 err(1, "malloc");
 317                         newargv[0] = argv[0];
 318                         newargv[1] = "-K";
 319                         for(i = 1; i < argc; ++i)
 320                         newargv[i + 1] = argv[i];
 321                         newargv[argc + 1] = NULL;
 322                         execv(_PATH_RLOGIN, newargv);
 323                 }
 324         } else {
 325 #ifdef CRYPT
 326                 if (doencrypt)
 327                         errx(1, "the -x flag requires Kerberos authentication");
 328 #endif /* CRYPT */
 329                 rem = rcmd_af(&host, sp->s_port, localname, user, term, 0,
 330                               family);
 331         }
 332 #else
 333         rem = rcmd_af(&host, sp->s_port, localname, user, term, 0, family);
 334 #endif /* KERBEROS */
 335
 336         if (rem < 0)
 337                 exit(1);
 338
 339         if (dflag &&
 340             setsockopt(rem, SOL_SOCKET, SO_DEBUG, &one, sizeof(one)) < 0)
 341                 warn("setsockopt");
 342         if (Dflag &&
 343             setsockopt(rem, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)) < 0)
 344                 warn("setsockopt NODELAY (ignored)");
 345
 346         sslen = sizeof(ss);
 347         one = IPTOS_LOWDELAY;
 348         if (getsockname(rem, (struct sockaddr *)&ss, &sslen) == 0 &&
 349             ss.ss_family == AF_INET) {
 350                 if (setsockopt(rem, IPPROTO_IP, IP_TOS, (char *)&one,
 351                                sizeof(int)) < 0)
 352                         warn("setsockopt TOS (ignored)");
 353         } else
 354                 if (ss.ss_family == AF_INET)
 355                         warn("setsockopt getsockname failed");
 356
 357         (void)setuid(uid);
 358         doit(omask);
 359         /*NOTREACHED*/
 360 }
 361
 362 int child, defflags, deflflags, tabflag;
 363 char deferase, defkill;
 364 struct tchars deftc;
 365 struct ltchars defltc;
 366 struct tchars notc = { -1, -1, -1, -1, -1, -1 };
 367 struct ltchars noltc = { -1, -1, -1, -1, -1, -1 };
 368
 369 void
 370 doit(long omask)
 371 {
 372         struct sgttyb sb;
 373
 374         (void)ioctl(0, TIOCGETP, (char *)&sb);
 375         defflags = sb.sg_flags;
 376         tabflag = defflags & TBDELAY;
 377         defflags &= ECHO | CRMOD;
 378         deferase = sb.sg_erase;
 379         defkill = sb.sg_kill;
 380         (void)ioctl(0, TIOCLGET, &deflflags);
 381         (void)ioctl(0, TIOCGETC, &deftc);
 382         notc.t_startc = deftc.t_startc;
 383         notc.t_stopc = deftc.t_stopc;
 384         (void)ioctl(0, TIOCGLTC, &defltc);
 385         (void)signal(SIGINT, SIG_IGN);
 386         setsignal(SIGHUP);
 387         setsignal(SIGQUIT);
 388         child = fork();
 389         if (child == -1) {
 390                 warn("fork");
 391                 done(1);
 392         }
 393         if (child == 0) {
 394                 mode(1);
 395                 if (reader(omask) == 0) {
 396                         msg("connection closed.");
 397                         exit(0);
 398                 }
 399                 sleep(1);
 400                 msg("\007connection closed.");
 401                 exit(1);
 402         }
 403
 404         /*
 405          * We may still own the socket, and may have a pending SIGURG (or might
 406          * receive one soon) that we really want to send to the reader.  When
 407          * one of these comes in, the trap copytochild simply copies such
 408          * signals to the child. We can now unblock SIGURG and SIGUSR1
 409          * that were set above.
 410          */
 411         (void)sigsetmask(omask);
 412         (void)signal(SIGCHLD, catch_child);
 413         writer();
 414         msg("closed connection.");
 415         done(0);
 416 }
 417
 418 /* trap a signal, unless it is being ignored. */
 419 void
 420 setsignal(int sig)
 421 {
 422         int omask = sigblock(sigmask(sig));
 423
 424         if (signal(sig, exit) == SIG_IGN)
 425                 (void)signal(sig, SIG_IGN);
 426         (void)sigsetmask(omask);
 427 }
 428
 429 void
 430 done(int status)
 431 {
 432         int w, wstatus;
 433
 434         mode(0);
 435         if (child > 0) {
 436                 /* make sure catch_child does not snap it up */
 437                 (void)signal(SIGCHLD, SIG_DFL);
 438                 if (kill(child, SIGKILL) >= 0)
 439                         while ((w = wait(&wstatus)) > 0 && w != child);
 440         }
 441         exit(status);
 442 }
 443
 444 int dosigwinch;
 445
 446 /*
 447  * This is called when the reader process gets the out-of-band (urgent)
 448  * request to turn on the window-changing protocol.
 449  */
 450 void
 451 writeroob(int signo __unused)
 452 {
 453         if (dosigwinch == 0) {
 454                 sendwindow();
 455                 (void)signal(SIGWINCH, sigwinch);
 456         }
 457         dosigwinch = 1;
 458 }
 459
 460 void
 461 catch_child(int signo __unused)
 462 {
 463         union wait status;
 464         int pid;
 465
 466         for (;;) {
 467                 pid = wait3((int *)&status, WNOHANG|WUNTRACED, NULL);
 468                 if (pid == 0)
 469                         return;
 470                 /* if the child (reader) dies, just quit */
 471                 if (pid < 0 || (pid == child && !WIFSTOPPED(status)))
 472                         done((int)(status.w_termsig | status.w_retcode));
 473         }
 474         /* NOTREACHED */
 475 }
 476
 477 /*
 478  * writer: write to remote: 0 -> line.
 479  * ~.                           terminate
 480  * ~^Z                          suspend rlogin process.
 481  * ~<delayed-suspend char>      suspend rlogin process, but leave reader alone.
 482  */
 483 void
 484 writer(void)
 485 {
 486         int bol, local, n;
 487         char c;
 488
 489         bol = 1;                        /* beginning of line */
 490         local = 0;
 491         for (;;) {
 492                 n = read(STDIN_FILENO, &c, 1);
 493                 if (n <= 0) {
 494                         if (n < 0 && errno == EINTR)
 495                                 continue;
 496                         break;
 497                 }
 498                 /*
 499                  * If we're at the beginning of the line and recognize a
 500                  * command character, then we echo locally.  Otherwise,
 501                  * characters are echo'd remotely.  If the command character
 502                  * is doubled, this acts as a force and local echo is
 503                  * suppressed.
 504                  */
 505                 if (bol) {
 506                         bol = 0;
 507                         if (!noescape && c == escapechar) {
 508                                 local = 1;
 509                                 continue;
 510                         }
 511                 } else if (local) {
 512                         local = 0;
 513                         if (c == '.' || c == deftc.t_eofc) {
 514                                 echo(c);
 515                                 break;
 516                         }
 517                         if (c == defltc.t_suspc || c == defltc.t_dsuspc) {
 518                                 bol = 1;
 519                                 echo(c);
 520                                 stop(c);
 521                                 continue;
 522                         }
 523                         if (c != escapechar)
 524 #ifdef CRYPT
 525 #ifdef KERBEROS
 526                                 if (doencrypt)
 527                                         (void)des_enc_write(rem,
 528                                             (char *)&escapechar, 1,
 529                                                 schedule, &cred.session);
 530                                 else
 531 #endif
 532 #endif
 533                                         (void)write(rem, &escapechar, 1);
 534                 }
 535
 536 #ifdef CRYPT
 537 #ifdef KERBEROS
 538                 if (doencrypt) {
 539                         if (des_enc_write(rem, &c, 1, schedule, &cred.session) == 0) {
 540                                 msg("line gone");
 541                                 break;
 542                         }
 543                 } else
 544 #endif
 545 #endif
 546                         if (write(rem, &c, 1) == 0) {
 547                                 msg("line gone");
 548                                 break;
 549                         }
 550                 bol = c == defkill || c == deftc.t_eofc ||
 551                     c == deftc.t_intrc || c == defltc.t_suspc ||
 552                     c == '\r' || c == '\n';
 553         }
 554 }
 555
 556 void
 557 echo(char c)
 558 {
 559         char *p;
 560         char buf[8];
 561
 562         p = buf;
 563         c &= 0177;
 564         *p++ = escapechar;
 565         if (c < ' ') {
 566                 *p++ = '^';
 567                 *p++ = c + '@';
 568         } else if (c == 0177) {
 569                 *p++ = '^';
 570                 *p++ = '?';
 571         } else
 572                 *p++ = c;
 573         *p++ = '\r';
 574         *p++ = '\n';
 575         (void)write(STDOUT_FILENO, buf, p - buf);
 576 }
 577
 578 void
 579 stop(char cmdc)
 580 {
 581         mode(0);
 582         (void)signal(SIGCHLD, SIG_IGN);
 583         (void)kill(cmdc == defltc.t_suspc ? 0 : getpid(), SIGTSTP);
 584         (void)signal(SIGCHLD, catch_child);
 585         mode(1);
 586         sigwinch(0);                    /* check for size changes */
 587 }
 588
 589 void
 590 sigwinch(int signo __unused)
 591 {
 592         struct winsize ws;
 593
 594         if (dosigwinch && get_window_size(0, &ws) == 0 &&
 595             bcmp(&ws, &winsize, sizeof(ws))) {
 596                 winsize = ws;
 597                 sendwindow();
 598         }
 599 }
 600
 601 /*
 602  * Send the window size to the server via the magic escape
 603  */
 604 void
 605 sendwindow(void)
 606 {
 607         struct winsize *wp;
 608         char obuf[4 + sizeof (struct winsize)];
 609
 610         wp = (struct winsize *)(obuf+4);
 611         obuf[0] = 0377;
 612         obuf[1] = 0377;
 613         obuf[2] = 's';
 614         obuf[3] = 's';
 615         wp->ws_row = htons(winsize.ws_row);
 616         wp->ws_col = htons(winsize.ws_col);
 617         wp->ws_xpixel = htons(winsize.ws_xpixel);
 618         wp->ws_ypixel = htons(winsize.ws_ypixel);
 619
 620 #ifdef CRYPT
 621 #ifdef KERBEROS
 622         if(doencrypt)
 623                 (void)des_enc_write(rem, obuf, sizeof(obuf),
 624                         schedule, &cred.session);
 625         else
 626 #endif
 627 #endif
 628                 (void)write(rem, obuf, sizeof(obuf));
 629 }
 630
 631 /*
 632  * reader: read from remote: line -> 1
 633  */
 634 #define READING 1
 635 #define WRITING 2
 636
 637 jmp_buf rcvtop;
 638 int ppid, rcvcnt, rcvstate;
 639 char rcvbuf[8 * 1024];
 640
 641 void
 642 oob(int signo __unused)
 643 {
 644         struct sgttyb sb;
 645         int atmark, n, out, rcvd;
 646         char waste[BUFSIZ], mark;
 647
 648         out = O_RDWR;
 649         rcvd = 0;
 650         while (recv(rem, &mark, 1, MSG_OOB) < 0) {
 651                 switch (errno) {
 652                 case EWOULDBLOCK:
 653                         /*
 654                          * Urgent data not here yet.  It may not be possible
 655                          * to send it yet if we are blocked for output and
 656                          * our input buffer is full.
 657                          */
 658                         if (rcvcnt < (int)sizeof(rcvbuf)) {
 659                                 n = read(rem, rcvbuf + rcvcnt,
 660                                     sizeof(rcvbuf) - rcvcnt);
 661                                 if (n <= 0)
 662                                         return;
 663                                 rcvd += n;
 664                         } else {
 665                                 n = read(rem, waste, sizeof(waste));
 666                                 if (n <= 0)
 667                                         return;
 668                         }
 669                         continue;
 670                 default:
 671                         return;
 672                 }
 673         }
 674         if (mark & TIOCPKT_WINDOW) {
 675                 /* Let server know about window size changes */
 676                 (void)kill(ppid, SIGUSR1);
 677         }
 678         if (!eight && (mark & TIOCPKT_NOSTOP)) {
 679                 (void)ioctl(0, TIOCGETP, (char *)&sb);
 680                 sb.sg_flags &= ~CBREAK;
 681                 sb.sg_flags |= RAW;
 682                 (void)ioctl(0, TIOCSETN, (char *)&sb);
 683                 notc.t_stopc = -1;
 684                 notc.t_startc = -1;
 685                 (void)ioctl(0, TIOCSETC, (char *)&notc);
 686         }
 687         if (!eight && (mark & TIOCPKT_DOSTOP)) {
 688                 (void)ioctl(0, TIOCGETP, (char *)&sb);
 689                 sb.sg_flags &= ~RAW;
 690                 sb.sg_flags |= CBREAK;
 691                 (void)ioctl(0, TIOCSETN, (char *)&sb);
 692                 notc.t_stopc = deftc.t_stopc;
 693                 notc.t_startc = deftc.t_startc;
 694                 (void)ioctl(0, TIOCSETC, (char *)&notc);
 695         }
 696         if (mark & TIOCPKT_FLUSHWRITE) {
 697                 (void)ioctl(1, TIOCFLUSH, (char *)&out);
 698                 for (;;) {
 699                         if (ioctl(rem, SIOCATMARK, &atmark) < 0) {
 700                                 warn("ioctl");
 701                                 break;
 702                         }
 703                         if (atmark)
 704                                 break;
 705                         n = read(rem, waste, sizeof (waste));
 706                         if (n <= 0)
 707                                 break;
 708                 }
 709                 /*
 710                  * Don't want any pending data to be output, so clear the recv
 711                  * buffer.  If we were hanging on a write when interrupted,
 712                  * don't want it to restart.  If we were reading, restart
 713                  * anyway.
 714                  */
 715                 rcvcnt = 0;
 716                 longjmp(rcvtop, 1);
 717         }
 718
 719         /* oob does not do FLUSHREAD (alas!) */
 720
 721         /*
 722          * If we filled the receive buffer while a read was pending, longjmp
 723          * to the top to restart appropriately.  Don't abort a pending write,
 724          * however, or we won't know how much was written.
 725          */
 726         if (rcvd && rcvstate == READING)
 727                 longjmp(rcvtop, 1);
 728 }
 729
 730 /* reader: read from remote: line -> 1 */
 731 int
 732 reader(int omask)
 733 {
 734         int pid, n, remaining;
 735         char *bufp;
 736
 737 #if BSD >= 43 || defined(SUNOS4)
 738         pid = getpid();         /* modern systems use positives for pid */
 739 #else
 740         pid = -getpid();        /* old broken systems use negatives */
 741 #endif
 742         (void)signal(SIGTTOU, SIG_IGN);
 743         (void)signal(SIGURG, oob);
 744         (void)signal(SIGUSR1, oob); /* When propogating SIGURG from parent */
 745         ppid = getppid();
 746         (void)fcntl(rem, F_SETOWN, pid);
 747         (void)setjmp(rcvtop);
 748         (void)sigsetmask(omask);
 749         bufp = rcvbuf;
 750         for (;;) {
 751                 while ((remaining = rcvcnt - (bufp - rcvbuf)) > 0) {
 752                         rcvstate = WRITING;
 753                         n = write(STDOUT_FILENO, bufp, remaining);
 754                         if (n < 0) {
 755                                 if (errno != EINTR)
 756                                         return (-1);
 757                                 continue;
 758                         }
 759                         bufp += n;
 760                 }
 761                 bufp = rcvbuf;
 762                 rcvcnt = 0;
 763                 rcvstate = READING;
 764
 765 #ifdef CRYPT
 766 #ifdef KERBEROS
 767                 if (doencrypt)
 768                         rcvcnt = des_enc_read(rem, rcvbuf, sizeof(rcvbuf),
 769                                 schedule, &cred.session);
 770                 else
 771 #endif
 772 #endif
 773                         rcvcnt = read(rem, rcvbuf, sizeof (rcvbuf));
 774                 if (rcvcnt == 0)
 775                         return (0);
 776                 if (rcvcnt < 0) {
 777                         if (errno == EINTR)
 778                                 continue;
 779                         warn("read");
 780                         return (-1);
 781                 }
 782         }
 783 }
 784
 785 void
 786 mode(int f)
 787 {
 788         struct ltchars *ltc;
 789         struct sgttyb sb;
 790         struct tchars *tc;
 791         int lflags;
 792
 793         (void)ioctl(0, TIOCGETP, (char *)&sb);
 794         (void)ioctl(0, TIOCLGET, (char *)&lflags);
 795         switch(f) {
 796         case 0:
 797                 sb.sg_flags &= ~(CBREAK|RAW|TBDELAY);
 798                 sb.sg_flags |= defflags|tabflag;
 799                 tc = &deftc;
 800                 ltc = &defltc;
 801                 sb.sg_kill = defkill;
 802                 sb.sg_erase = deferase;
 803                 lflags = deflflags;
 804                 break;
 805         case 1:
 806                 sb.sg_flags |= (eight ? RAW : CBREAK);
 807                 sb.sg_flags &= ~defflags;
 808                 /* preserve tab delays, but turn off XTABS */
 809                 if ((sb.sg_flags & TBDELAY) == XTABS)
 810                         sb.sg_flags &= ~TBDELAY;
 811                 tc = &notc;
 812                 ltc = &noltc;
 813                 sb.sg_kill = sb.sg_erase = -1;
 814                 if (litout)
 815                         lflags |= LLITOUT;
 816                 break;
 817         default:
 818                 return;
 819         }
 820         (void)ioctl(0, TIOCSLTC, (char *)ltc);
 821         (void)ioctl(0, TIOCSETC, (char *)tc);
 822         (void)ioctl(0, TIOCSETN, (char *)&sb);
 823         (void)ioctl(0, TIOCLSET, (char *)&lflags);
 824 }
 825
 826 void
 827 lostpeer(int signo __unused)
 828 {
 829         (void)signal(SIGPIPE, SIG_IGN);
 830         msg("\007connection closed.");
 831         done(1);
 832 }
 833
 834 /* copy SIGURGs to the child process via SIGUSR1. */
 835 void
 836 copytochild(int signo __unused)
 837 {
 838         (void)kill(child, SIGUSR1);
 839 }
 840
 841 void
 842 msg(const char *str)
 843 {
 844         (void)fprintf(stderr, "rlogin: %s\r\n", str);
 845 }
 846
 847 void
 848 usage(void)
 849 {
 850         (void)fprintf(stderr,
 851         "usage: rlogin [-46%s]%s[-e char] [-i localname] [-l username] host\n",
 852 #ifdef KERBEROS
 853 #ifdef CRYPT
 854             "8DEKLdx", " [-k realm] ");
 855 #else
 856             "8DEKLd", " [-k realm] ");
 857 #endif
 858 #else
 859             "8DEKLd", " ");
 860 #endif
 861         exit(1);
 862 }
 863
 864 u_int
 865 getescape(char *p)
 866 {
 867         long val;
 868         int len;
 869
 870         if ((len = strlen(p)) == 1)     /* use any single char, including '\' */
 871                 return ((u_int)*p);
 872                                         /* otherwise, \nnn */
 873         if (*p == '\\' && len >= 2 && len <= 4) {
 874                 val = strtol(++p, NULL, 8);
 875                 for (;;) {
 876                         if (!*++p)
 877                                 return ((u_int)val);
 878                         if (*p < '0' || *p > '8')
 879                                 break;
 880                 }
 881         }
 882         msg("illegal option value -- e");
 883         usage();
 884         /* NOTREACHED */
 885 }