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