slirp/misc.c

   1 /*
   2  * Copyright (c) 1995 Danny Gasparovski.
   3  *
   4  * Please read the file COPYRIGHT for the
   5  * terms and conditions of the copyright.
   6  */
   7
   8 #define WANT_SYS_IOCTL_H
   9 #include <slirp.h>
  10
  11 u_int curtime, time_fasttimo, last_slowtimo;
  12
  13 #if 0
  14 int x_port = -1;
  15 int x_display = 0;
  16 int x_screen = 0;
  17
  18 int
  19 show_x(buff, inso)
  20         char *buff;
  21         struct socket *inso;
  22 {
  23         if (x_port < 0) {
  24                 lprint("X Redir: X not being redirected.\r\n");
  25         } else {
  26                 lprint("X Redir: In sh/bash/zsh/etc. type: DISPLAY=%s:%d.%d; export DISPLAY\r\n",
  27                       inet_ntoa(our_addr), x_port, x_screen);
  28                 lprint("X Redir: In csh/tcsh/etc. type:    setenv DISPLAY %s:%d.%d\r\n",
  29                       inet_ntoa(our_addr), x_port, x_screen);
  30                 if (x_display)
  31                    lprint("X Redir: Redirecting to display %d\r\n", x_display);
  32         }
  33
  34         return CFG_OK;
  35 }
  36
  37
  38 /*
  39  * XXX Allow more than one X redirection?
  40  */
  41 void
  42 redir_x(inaddr, start_port, display, screen)
  43         u_int32_t inaddr;
  44         int start_port;
  45         int display;
  46         int screen;
  47 {
  48         int i;
  49
  50         if (x_port >= 0) {
  51                 lprint("X Redir: X already being redirected.\r\n");
  52                 show_x(0, 0);
  53         } else {
  54                 for (i = 6001 + (start_port-1); i <= 6100; i++) {
  55                         if (solisten(htons(i), inaddr, htons(6000 + display), 0)) {
  56                                 /* Success */
  57                                 x_port = i - 6000;
  58                                 x_display = display;
  59                                 x_screen = screen;
  60                                 show_x(0, 0);
  61                                 return;
  62                         }
  63                 }
  64                 lprint("X Redir: Error: Couldn't redirect a port for X. Weird.\r\n");
  65         }
  66 }
  67 #endif
  68
  69 #ifndef HAVE_INET_ATON
  70 int
  71 inet_aton(cp, ia)
  72         const char *cp;
  73         struct in_addr *ia;
  74 {
  75         u_int32_t addr = inet_addr(cp);
  76         if (addr == 0xffffffff)
  77                 return 0;
  78         ia->s_addr = addr;
  79         return 1;
  80 }
  81 #endif
  82
  83 /*
  84  * Get our IP address and put it in our_addr
  85  */
  86 void
  87 getouraddr()
  88 {
  89         char buff[256];
  90         struct hostent *he = NULL;
  91
  92         if (gethostname(buff,256) == 0)
  93             he = gethostbyname(buff);
  94         if (he)
  95             our_addr = *(struct in_addr *)he->h_addr;
  96         if (our_addr.s_addr == 0)
  97             our_addr.s_addr = loopback_addr.s_addr;
  98 }
  99
 100 #if SIZEOF_CHAR_P == 8
 101
 102 struct quehead_32 {
 103         u_int32_t qh_link;
 104         u_int32_t qh_rlink;
 105 };
 106
 107 inline void
 108 insque_32(a, b)
 109         void *a;
 110         void *b;
 111 {
 112         register struct quehead_32 *element = (struct quehead_32 *) a;
 113         register struct quehead_32 *head = (struct quehead_32 *) b;
 114         element->qh_link = head->qh_link;
 115         head->qh_link = (u_int32_t)element;
 116         element->qh_rlink = (u_int32_t)head;
 117         ((struct quehead_32 *)(element->qh_link))->qh_rlink
 118         = (u_int32_t)element;
 119 }
 120
 121 inline void
 122 remque_32(a)
 123         void *a;
 124 {
 125         register struct quehead_32 *element = (struct quehead_32 *) a;
 126         ((struct quehead_32 *)(element->qh_link))->qh_rlink = element->qh_rlink;
 127         ((struct quehead_32 *)(element->qh_rlink))->qh_link = element->qh_link;
 128         element->qh_rlink = 0;
 129 }
 130
 131 #endif /* SIZEOF_CHAR_P == 8 */
 132
 133 struct quehead {
 134         struct quehead *qh_link;
 135         struct quehead *qh_rlink;
 136 };
 137
 138 inline void
 139 insque(a, b)
 140         void *a, *b;
 141 {
 142         register struct quehead *element = (struct quehead *) a;
 143         register struct quehead *head = (struct quehead *) b;
 144         element->qh_link = head->qh_link;
 145         head->qh_link = (struct quehead *)element;
 146         element->qh_rlink = (struct quehead *)head;
 147         ((struct quehead *)(element->qh_link))->qh_rlink
 148         = (struct quehead *)element;
 149 }
 150
 151 inline void
 152 remque(a)
 153      void *a;
 154 {
 155   register struct quehead *element = (struct quehead *) a;
 156   ((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
 157   ((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
 158   element->qh_rlink = NULL;
 159   /*  element->qh_link = NULL;  TCP FIN1 crashes if you do this.  Why ? */
 160 }
 161
 162 /* #endif */
 163
 164
 165 int
 166 add_exec(ex_ptr, do_pty, exec, addr, port)
 167         struct ex_list **ex_ptr;
 168         int do_pty;
 169         char *exec;
 170         int addr;
 171         int port;
 172 {
 173         struct ex_list *tmp_ptr;
 174
 175         /* First, check if the port is "bound" */
 176         for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
 177                 if (port == tmp_ptr->ex_fport && addr == tmp_ptr->ex_addr)
 178                    return -1;
 179         }
 180
 181         tmp_ptr = *ex_ptr;
 182         *ex_ptr = (struct ex_list *)malloc(sizeof(struct ex_list));
 183         (*ex_ptr)->ex_fport = port;
 184         (*ex_ptr)->ex_addr = addr;
 185         (*ex_ptr)->ex_pty = do_pty;
 186         (*ex_ptr)->ex_exec = strdup(exec);
 187         (*ex_ptr)->ex_next = tmp_ptr;
 188         return 0;
 189 }
 190
 191 #ifndef HAVE_STRERROR
 192
 193 /*
 194  * For systems with no strerror
 195  */
 196
 197 extern int sys_nerr;
 198 extern char *sys_errlist[];
 199
 200 char *
 201 strerror(error)
 202         int error;
 203 {
 204         if (error < sys_nerr)
 205            return sys_errlist[error];
 206         else
 207            return "Unknown error.";
 208 }
 209
 210 #endif
 211
 212
 213 #ifdef _WIN32
 214
 215 int
 216 fork_exec(struct socket *so, const char *ex, int do_pty)
 217 {
 218     /* not implemented */
 219     return 0;
 220 }
 221
 222 #else
 223
 224 #ifndef CONFIG_QEMU
 225 int
 226 slirp_openpty(amaster, aslave)
 227      int *amaster, *aslave;
 228 {
 229         register int master, slave;
 230
 231 #ifdef HAVE_GRANTPT
 232         char *ptr;
 233
 234         if ((master = open("/dev/ptmx", O_RDWR)) < 0 ||
 235             grantpt(master) < 0 ||
 236             unlockpt(master) < 0 ||
 237             (ptr = ptsname(master)) == NULL)  {
 238                 close(master);
 239                 return -1;
 240         }
 241
 242         if ((slave = open(ptr, O_RDWR)) < 0 ||
 243             ioctl(slave, I_PUSH, "ptem") < 0 ||
 244             ioctl(slave, I_PUSH, "ldterm") < 0 ||
 245             ioctl(slave, I_PUSH, "ttcompat") < 0) {
 246                 close(master);
 247                 close(slave);
 248                 return -1;
 249         }
 250
 251         *amaster = master;
 252         *aslave = slave;
 253         return 0;
 254
 255 #else
 256
 257         static char line[] = "/dev/ptyXX";
 258         register const char *cp1, *cp2;
 259
 260         for (cp1 = "pqrsPQRS"; *cp1; cp1++) {
 261                 line[8] = *cp1;
 262                 for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) {
 263                         line[9] = *cp2;
 264                         if ((master = open(line, O_RDWR, 0)) == -1) {
 265                                 if (errno == ENOENT)
 266                                    return (-1);    /* out of ptys */
 267                         } else {
 268                                 line[5] = 't';
 269                                 /* These will fail */
 270                                 (void) chown(line, getuid(), 0);
 271                                 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
 272 #ifdef HAVE_REVOKE
 273                                 (void) revoke(line);
 274 #endif
 275                                 if ((slave = open(line, O_RDWR, 0)) != -1) {
 276                                         *amaster = master;
 277                                         *aslave = slave;
 278                                         return 0;
 279                                 }
 280                                 (void) close(master);
 281                                 line[5] = 'p';
 282                         }
 283                 }
 284         }
 285         errno = ENOENT; /* out of ptys */
 286         return (-1);
 287 #endif
 288 }
 289 #endif
 290
 291 /*
 292  * XXX This is ugly
 293  * We create and bind a socket, then fork off to another
 294  * process, which connects to this socket, after which we
 295  * exec the wanted program.  If something (strange) happens,
 296  * the accept() call could block us forever.
 297  *
 298  * do_pty = 0   Fork/exec inetd style
 299  * do_pty = 1   Fork/exec using slirp.telnetd
 300  * do_ptr = 2   Fork/exec using pty
 301  */
 302 int
 303 fork_exec(struct socket *so, const char *ex, int do_pty)
 304 {
 305         int s;
 306         struct sockaddr_in addr;
 307         socklen_t addrlen = sizeof(addr);
 308         int opt;
 309         int master = -1;
 310         char *argv[256];
 311 #if 0
 312         char buff[256];
 313 #endif
 314         /* don't want to clobber the original */
 315         char *bptr;
 316         const char *curarg;
 317         int c, i, ret;
 318
 319         DEBUG_CALL("fork_exec");
 320         DEBUG_ARG("so = %lx", (long)so);
 321         DEBUG_ARG("ex = %lx", (long)ex);
 322         DEBUG_ARG("do_pty = %lx", (long)do_pty);
 323
 324         if (do_pty == 2) {
 325 #if 0
 326                 if (slirp_openpty(&master, &s) == -1) {
 327                         lprint("Error: openpty failed: %s\n", strerror(errno));
 328                         return 0;
 329                 }
 330 #else
 331                 return 0;
 332 #endif
 333         } else {
 334                 addr.sin_family = AF_INET;
 335                 addr.sin_port = 0;
 336                 addr.sin_addr.s_addr = INADDR_ANY;
 337
 338                 if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
 339                     bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
 340                     listen(s, 1) < 0) {
 341                         lprint("Error: inet socket: %s\n", strerror(errno));
 342                         closesocket(s);
 343
 344                         return 0;
 345                 }
 346         }
 347
 348         switch(fork()) {
 349          case -1:
 350                 lprint("Error: fork failed: %s\n", strerror(errno));
 351                 close(s);
 352                 if (do_pty == 2)
 353                    close(master);
 354                 return 0;
 355
 356          case 0:
 357                 /* Set the DISPLAY */
 358                 if (do_pty == 2) {
 359                         (void) close(master);
 360 #ifdef TIOCSCTTY /* XXXXX */
 361                         (void) setsid();
 362                         ioctl(s, TIOCSCTTY, (char *)NULL);
 363 #endif
 364                 } else {
 365                         getsockname(s, (struct sockaddr *)&addr, &addrlen);
 366                         close(s);
 367                         /*
 368                          * Connect to the socket
 369                          * XXX If any of these fail, we're in trouble!
 370                          */
 371                         s = socket(AF_INET, SOCK_STREAM, 0);
 372                         addr.sin_addr = loopback_addr;
 373                         do {
 374                             ret = connect(s, (struct sockaddr *)&addr, addrlen);
 375                         } while (ret < 0 && errno == EINTR);
 376                 }
 377
 378 #if 0
 379                 if (x_port >= 0) {
 380 #ifdef HAVE_SETENV
 381                         sprintf(buff, "%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
 382                         setenv("DISPLAY", buff, 1);
 383 #else
 384                         sprintf(buff, "DISPLAY=%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
 385                         putenv(buff);
 386 #endif
 387                 }
 388 #endif
 389                 dup2(s, 0);
 390                 dup2(s, 1);
 391                 dup2(s, 2);
 392                 for (s = getdtablesize() - 1; s >= 3; s--)
 393                    close(s);
 394
 395                 i = 0;
 396                 bptr = strdup(ex); /* No need to free() this */
 397                 if (do_pty == 1) {
 398                         /* Setup "slirp.telnetd -x" */
 399                         argv[i++] = "slirp.telnetd";
 400                         argv[i++] = "-x";
 401                         argv[i++] = bptr;
 402                 } else
 403                    do {
 404                         /* Change the string into argv[] */
 405                         curarg = bptr;
 406                         while (*bptr != ' ' && *bptr != (char)0)
 407                            bptr++;
 408                         c = *bptr;
 409                         *bptr++ = (char)0;
 410                         argv[i++] = strdup(curarg);
 411                    } while (c);
 412
 413                 argv[i] = 0;
 414                 execvp(argv[0], argv);
 415
 416                 /* Ooops, failed, let's tell the user why */
 417                   {
 418                           char buff[256];
 419
 420                           sprintf(buff, "Error: execvp of %s failed: %s\n",
 421                                   argv[0], strerror(errno));
 422                           write(2, buff, strlen(buff)+1);
 423                   }
 424                 close(0); close(1); close(2); /* XXX */
 425                 exit(1);
 426
 427          default:
 428                 if (do_pty == 2) {
 429                         close(s);
 430                         so->s = master;
 431                 } else {
 432                         /*
 433                          * XXX this could block us...
 434                          * XXX Should set a timer here, and if accept() doesn't
 435                          * return after X seconds, declare it a failure
 436                          * The only reason this will block forever is if socket()
 437                          * of connect() fail in the child process
 438                          */
 439                         do {
 440                             so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
 441                         } while (so->s < 0 && errno == EINTR);
 442                         closesocket(s);
 443                         opt = 1;
 444                         setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
 445                         opt = 1;
 446                         setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
 447                 }
 448                 fd_nonblock(so->s);
 449
 450                 /* Append the telnet options now */
 451                 if (so->so_m != 0 && do_pty == 1)  {
 452                         sbappend(so, so->so_m);
 453                         so->so_m = 0;
 454                 }
 455
 456                 return 1;
 457         }
 458 }
 459 #endif
 460
 461 #ifndef HAVE_STRDUP
 462 char *
 463 strdup(str)
 464         const char *str;
 465 {
 466         char *bptr;
 467
 468         bptr = (char *)malloc(strlen(str)+1);
 469         strcpy(bptr, str);
 470
 471         return bptr;
 472 }
 473 #endif
 474
 475 #if 0
 476 void
 477 snooze_hup(num)
 478         int num;
 479 {
 480         int s, ret;
 481 #ifndef NO_UNIX_SOCKETS
 482         struct sockaddr_un sock_un;
 483 #endif
 484         struct sockaddr_in sock_in;
 485         char buff[256];
 486
 487         ret = -1;
 488         if (slirp_socket_passwd) {
 489                 s = socket(AF_INET, SOCK_STREAM, 0);
 490                 if (s < 0)
 491                    slirp_exit(1);
 492                 sock_in.sin_family = AF_INET;
 493                 sock_in.sin_addr.s_addr = slirp_socket_addr;
 494                 sock_in.sin_port = htons(slirp_socket_port);
 495                 if (connect(s, (struct sockaddr *)&sock_in, sizeof(sock_in)) != 0)
 496                    slirp_exit(1); /* just exit...*/
 497                 sprintf(buff, "kill %s:%d", slirp_socket_passwd, slirp_socket_unit);
 498                 write(s, buff, strlen(buff)+1);
 499         }
 500 #ifndef NO_UNIX_SOCKETS
 501           else {
 502                 s = socket(AF_UNIX, SOCK_STREAM, 0);
 503                 if (s < 0)
 504                    slirp_exit(1);
 505                 sock_un.sun_family = AF_UNIX;
 506                 strcpy(sock_un.sun_path, socket_path);
 507                 if (connect(s, (struct sockaddr *)&sock_un,
 508                               sizeof(sock_un.sun_family) + sizeof(sock_un.sun_path)) != 0)
 509                    slirp_exit(1);
 510                 sprintf(buff, "kill none:%d", slirp_socket_unit);
 511                 write(s, buff, strlen(buff)+1);
 512         }
 513 #endif
 514         slirp_exit(0);
 515 }
 516
 517
 518 void
 519 snooze()
 520 {
 521         sigset_t s;
 522         int i;
 523
 524         /* Don't need our data anymore */
 525         /* XXX This makes SunOS barf */
 526 /*      brk(0); */
 527
 528         /* Close all fd's */
 529         for (i = 255; i >= 0; i--)
 530            close(i);
 531
 532         signal(SIGQUIT, slirp_exit);
 533         signal(SIGHUP, snooze_hup);
 534         sigemptyset(&s);
 535
 536         /* Wait for any signal */
 537         sigsuspend(&s);
 538
 539         /* Just in case ... */
 540         exit(255);
 541 }
 542
 543 void
 544 relay(s)
 545         int s;
 546 {
 547         char buf[8192];
 548         int n;
 549         fd_set readfds;
 550         struct ttys *ttyp;
 551
 552         /* Don't need our data anymore */
 553         /* XXX This makes SunOS barf */
 554 /*      brk(0); */
 555
 556         signal(SIGQUIT, slirp_exit);
 557         signal(SIGHUP, slirp_exit);
 558         signal(SIGINT, slirp_exit);
 559         signal(SIGTERM, slirp_exit);
 560
 561         /* Fudge to get term_raw and term_restore to work */
 562         if (NULL == (ttyp = tty_attach (0, slirp_tty))) {
 563          lprint ("Error: tty_attach failed in misc.c:relay()\r\n");
 564          slirp_exit (1);
 565     }
 566         ttyp->fd = 0;
 567         ttyp->flags |= TTY_CTTY;
 568         term_raw(ttyp);
 569
 570         while (1) {
 571                 FD_ZERO(&readfds);
 572
 573                 FD_SET(0, &readfds);
 574                 FD_SET(s, &readfds);
 575
 576                 n = select(s+1, &readfds, (fd_set *)0, (fd_set *)0, (struct timeval *)0);
 577
 578                 if (n <= 0)
 579                    slirp_exit(0);
 580
 581                 if (FD_ISSET(0, &readfds)) {
 582                         n = read(0, buf, 8192);
 583                         if (n <= 0)
 584                            slirp_exit(0);
 585                         n = writen(s, buf, n);
 586                         if (n <= 0)
 587                            slirp_exit(0);
 588                 }
 589
 590                 if (FD_ISSET(s, &readfds)) {
 591                         n = read(s, buf, 8192);
 592                         if (n <= 0)
 593                            slirp_exit(0);
 594                         n = writen(0, buf, n);
 595                         if (n <= 0)
 596                            slirp_exit(0);
 597                 }
 598         }
 599
 600         /* Just in case.... */
 601         exit(1);
 602 }
 603 #endif
 604
 605 #ifdef CONFIG_QEMU
 606 extern void term_vprintf(const char *fmt, va_list ap);
 607
 608 void lprint(const char *format, ...)
 609 {
 610     va_list args;
 611
 612     va_start(args, format);
 613     term_vprintf(format, args);
 614     va_end(args);
 615 }
 616 #else
 617 int (*lprint_print) _P((void *, const char *, va_list));
 618 char *lprint_ptr, *lprint_ptr2, **lprint_arg;
 619
 620 void
 621 #ifdef __STDC__
 622 lprint(const char *format, ...)
 623 #else
 624 lprint(va_alist) va_dcl
 625 #endif
 626 {
 627         va_list args;
 628
 629 #ifdef __STDC__
 630         va_start(args, format);
 631 #else
 632         char *format;
 633         va_start(args);
 634         format = va_arg(args, char *);
 635 #endif
 636 #if 0
 637         /* If we're printing to an sbuf, make sure there's enough room */
 638         /* XXX +100? */
 639         if (lprint_sb) {
 640                 if ((lprint_ptr - lprint_sb->sb_wptr) >=
 641                     (lprint_sb->sb_datalen - (strlen(format) + 100))) {
 642                         int deltaw = lprint_sb->sb_wptr - lprint_sb->sb_data;
 643                         int deltar = lprint_sb->sb_rptr - lprint_sb->sb_data;
 644                         int deltap = lprint_ptr -         lprint_sb->sb_data;
 645
 646                         lprint_sb->sb_data = (char *)realloc(lprint_sb->sb_data,
 647                                                              lprint_sb->sb_datalen + TCP_SNDSPACE);
 648
 649                         /* Adjust all values */
 650                         lprint_sb->sb_wptr = lprint_sb->sb_data + deltaw;
 651                         lprint_sb->sb_rptr = lprint_sb->sb_data + deltar;
 652                         lprint_ptr =         lprint_sb->sb_data + deltap;
 653
 654                         lprint_sb->sb_datalen += TCP_SNDSPACE;
 655                 }
 656         }
 657 #endif
 658         if (lprint_print)
 659            lprint_ptr += (*lprint_print)(*lprint_arg, format, args);
 660
 661         /* Check if they want output to be logged to file as well */
 662         if (lfd) {
 663                 /*
 664                  * Remove \r's
 665                  * otherwise you'll get ^M all over the file
 666                  */
 667                 int len = strlen(format);
 668                 char *bptr1, *bptr2;
 669
 670                 bptr1 = bptr2 = strdup(format);
 671
 672                 while (len--) {
 673                         if (*bptr1 == '\r')
 674                            memcpy(bptr1, bptr1+1, len+1);
 675                         else
 676                            bptr1++;
 677                 }
 678                 vfprintf(lfd, bptr2, args);
 679                 free(bptr2);
 680         }
 681         va_end(args);
 682 }
 683
 684 void
 685 add_emu(buff)
 686         char *buff;
 687 {
 688         u_int lport, fport;
 689         u_int8_t tos = 0, emu = 0;
 690         char buff1[256], buff2[256], buff4[128];
 691         char *buff3 = buff4;
 692         struct emu_t *emup;
 693         struct socket *so;
 694
 695         if (sscanf(buff, "%256s %256s", buff2, buff1) != 2) {
 696                 lprint("Error: Bad arguments\r\n");
 697                 return;
 698         }
 699
 700         if (sscanf(buff1, "%d:%d", &lport, &fport) != 2) {
 701                 lport = 0;
 702                 if (sscanf(buff1, "%d", &fport) != 1) {
 703                         lprint("Error: Bad first argument\r\n");
 704                         return;
 705                 }
 706         }
 707
 708         if (sscanf(buff2, "%128[^:]:%128s", buff1, buff3) != 2) {
 709                 buff3 = 0;
 710                 if (sscanf(buff2, "%256s", buff1) != 1) {
 711                         lprint("Error: Bad second argument\r\n");
 712                         return;
 713                 }
 714         }
 715
 716         if (buff3) {
 717                 if (strcmp(buff3, "lowdelay") == 0)
 718                    tos = IPTOS_LOWDELAY;
 719                 else if (strcmp(buff3, "throughput") == 0)
 720                    tos = IPTOS_THROUGHPUT;
 721                 else {
 722                         lprint("Error: Expecting \"lowdelay\"/\"throughput\"\r\n");
 723                         return;
 724                 }
 725         }
 726
 727         if (strcmp(buff1, "ftp") == 0)
 728            emu = EMU_FTP;
 729         else if (strcmp(buff1, "irc") == 0)
 730            emu = EMU_IRC;
 731         else if (strcmp(buff1, "none") == 0)
 732            emu = EMU_NONE; /* ie: no emulation */
 733         else {
 734                 lprint("Error: Unknown service\r\n");
 735                 return;
 736         }
 737
 738         /* First, check that it isn't already emulated */
 739         for (emup = tcpemu; emup; emup = emup->next) {
 740                 if (emup->lport == lport && emup->fport == fport) {
 741                         lprint("Error: port already emulated\r\n");
 742                         return;
 743                 }
 744         }
 745
 746         /* link it */
 747         emup = (struct emu_t *)malloc(sizeof (struct emu_t));
 748         emup->lport = (u_int16_t)lport;
 749         emup->fport = (u_int16_t)fport;
 750         emup->tos = tos;
 751         emup->emu = emu;
 752         emup->next = tcpemu;
 753         tcpemu = emup;
 754
 755         /* And finally, mark all current sessions, if any, as being emulated */
 756         for (so = tcb.so_next; so != &tcb; so = so->so_next) {
 757                 if ((lport && lport == ntohs(so->so_lport)) ||
 758                     (fport && fport == ntohs(so->so_fport))) {
 759                         if (emu)
 760                            so->so_emu = emu;
 761                         if (tos)
 762                            so->so_iptos = tos;
 763                 }
 764         }
 765
 766         lprint("Adding emulation for %s to port %d/%d\r\n", buff1, emup->lport, emup->fport);
 767 }
 768 #endif
 769
 770 #ifdef BAD_SPRINTF
 771
 772 #undef vsprintf
 773 #undef sprintf
 774
 775 /*
 776  * Some BSD-derived systems have a sprintf which returns char *
 777  */
 778
 779 int
 780 vsprintf_len(string, format, args)
 781         char *string;
 782         const char *format;
 783         va_list args;
 784 {
 785         vsprintf(string, format, args);
 786         return strlen(string);
 787 }
 788
 789 int
 790 #ifdef __STDC__
 791 sprintf_len(char *string, const char *format, ...)
 792 #else
 793 sprintf_len(va_alist) va_dcl
 794 #endif
 795 {
 796         va_list args;
 797 #ifdef __STDC__
 798         va_start(args, format);
 799 #else
 800         char *string;
 801         char *format;
 802         va_start(args);
 803         string = va_arg(args, char *);
 804         format = va_arg(args, char *);
 805 #endif
 806         vsprintf(string, format, args);
 807         return strlen(string);
 808 }
 809
 810 #endif
 811
 812 void
 813 u_sleep(usec)
 814         int usec;
 815 {
 816         struct timeval t;
 817         fd_set fdset;
 818
 819         FD_ZERO(&fdset);
 820
 821         t.tv_sec = 0;
 822         t.tv_usec = usec * 1000;
 823
 824         select(0, &fdset, &fdset, &fdset, &t);
 825 }
 826
 827 /*
 828  * Set fd blocking and non-blocking
 829  */
 830
 831 void
 832 fd_nonblock(fd)
 833         int fd;
 834 {
 835 #ifdef FIONBIO
 836         int opt = 1;
 837
 838         ioctlsocket(fd, FIONBIO, &opt);
 839 #else
 840         int opt;
 841
 842         opt = fcntl(fd, F_GETFL, 0);
 843         opt |= O_NONBLOCK;
 844         fcntl(fd, F_SETFL, opt);
 845 #endif
 846 }
 847
 848 void
 849 fd_block(fd)
 850         int fd;
 851 {
 852 #ifdef FIONBIO
 853         int opt = 0;
 854
 855         ioctlsocket(fd, FIONBIO, &opt);
 856 #else
 857         int opt;
 858
 859         opt = fcntl(fd, F_GETFL, 0);
 860         opt &= ~O_NONBLOCK;
 861         fcntl(fd, F_SETFL, opt);
 862 #endif
 863 }
 864
 865
 866 #if 0
 867 /*
 868  * invoke RSH
 869  */
 870 int
 871 rsh_exec(so,ns, user, host, args)
 872         struct socket *so;
 873         struct socket *ns;
 874         char *user;
 875         char *host;
 876         char *args;
 877 {
 878         int fd[2];
 879         int fd0[2];
 880         int s;
 881         char buff[256];
 882
 883         DEBUG_CALL("rsh_exec");
 884         DEBUG_ARG("so = %lx", (long)so);
 885
 886         if (pipe(fd)<0) {
 887           lprint("Error: pipe failed: %s\n", strerror(errno));
 888           return 0;
 889         }
 890 /* #ifdef HAVE_SOCKETPAIR */
 891 #if 1
 892         if (socketpair(PF_UNIX,SOCK_STREAM,0, fd0) == -1) {
 893           close(fd[0]);
 894           close(fd[1]);
 895           lprint("Error: openpty failed: %s\n", strerror(errno));
 896           return 0;
 897         }
 898 #else
 899         if (slirp_openpty(&fd0[0], &fd0[1]) == -1) {
 900           close(fd[0]);
 901           close(fd[1]);
 902           lprint("Error: openpty failed: %s\n", strerror(errno));
 903           return 0;
 904         }
 905 #endif
 906
 907         switch(fork()) {
 908          case -1:
 909            lprint("Error: fork failed: %s\n", strerror(errno));
 910            close(fd[0]);
 911            close(fd[1]);
 912            close(fd0[0]);
 913            close(fd0[1]);
 914            return 0;
 915
 916          case 0:
 917            close(fd[0]);
 918            close(fd0[0]);
 919
 920                 /* Set the DISPLAY */
 921            if (x_port >= 0) {
 922 #ifdef HAVE_SETENV
 923              sprintf(buff, "%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
 924              setenv("DISPLAY", buff, 1);
 925 #else
 926              sprintf(buff, "DISPLAY=%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
 927              putenv(buff);
 928 #endif
 929            }
 930
 931            dup2(fd0[1], 0);
 932            dup2(fd0[1], 1);
 933            dup2(fd[1], 2);
 934            for (s = 3; s <= 255; s++)
 935              close(s);
 936
 937            execlp("rsh","rsh","-l", user, host, args, NULL);
 938
 939            /* Ooops, failed, let's tell the user why */
 940
 941            sprintf(buff, "Error: execlp of %s failed: %s\n",
 942                    "rsh", strerror(errno));
 943            write(2, buff, strlen(buff)+1);
 944            close(0); close(1); close(2); /* XXX */
 945            exit(1);
 946
 947         default:
 948           close(fd[1]);
 949           close(fd0[1]);
 950           ns->s=fd[0];
 951           so->s=fd0[0];
 952
 953           return 1;
 954         }
 955 }
 956 #endif