usr.bin/tip/hunt.c

   1 /*      $NetBSD: hunt.c,v 1.15 2006/04/30 23:34:50 christos Exp $       */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)hunt.c      8.1 (Berkeley) 6/6/93";
  36 #endif
  37 __RCSID("$NetBSD: hunt.c,v 1.15 2006/04/30 23:34:50 christos Exp $");
  38 #endif /* not lint */
  39
  40 #include "tip.h"
  41
  42 static  jmp_buf deadline;
  43 static  int deadfl;
  44
  45 void    dead(int);
  46
  47 void
  48 /*ARGSUSED*/
  49 dead(int dummy __unused)
  50 {
  51         deadfl = 1;
  52         longjmp(deadline, 1);
  53 }
  54
  55 int
  56 hunt(char *name)
  57 {
  58         char *cp;
  59         sig_t f;
  60
  61         f = signal(SIGALRM, dead);
  62         while ((cp = getremote(name)) != NULL) {
  63                 deadfl = 0;
  64                 /*
  65                  * Straight through call units, such as the BIZCOMP,
  66                  * VADIC and the DF, must indicate they're hardwired in
  67                  *  order to get an open file descriptor placed in FD.
  68                  * Otherwise, as for a DN-11, the open will have to
  69                  *  be done in the "open" routine.
  70                  */
  71                 if (!HW)
  72                         break;
  73                 if (setjmp(deadline) == 0) {
  74                         (void)alarm(10);
  75                         FD = open(cp, (O_RDWR | (DC ? O_NONBLOCK : 0)));
  76                 }
  77                 (void)alarm(0);
  78                 if (FD < 0) {
  79                         warn(cp);
  80                         deadfl = 1;
  81                 } else if (!deadfl) {
  82                         struct termios cntrl;
  83
  84                         if (flock(FD, (LOCK_EX|LOCK_NB)) != 0) {
  85                                 (void)close(FD);
  86                                 FD = -1;
  87                                 continue;
  88                         }
  89
  90                         (void)tcgetattr(FD, &cntrl);
  91                         if (!DC)
  92                                 cntrl.c_cflag |= HUPCL;
  93                         (void)tcsetattr(FD, TCSAFLUSH, &cntrl);
  94                         (void)ioctl(FD, TIOCEXCL, 0);
  95                         (void)signal(SIGALRM, SIG_DFL);
  96                         return (cp != NULL);
  97                 }
  98         }
  99         (void)signal(SIGALRM, f);
 100         return (deadfl ? -1 : cp != NULL);
 101 }