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      1 /*	$NetBSD: hunt.c,v 1.18 2011/09/06 18:33:01 joerg 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 1.18 2011/09/06 18:33:01 joerg Exp $");
     38 #endif /* not lint */
     39 
     40 #include "tip.h"
     41 
     42 static	jmp_buf deadline;
     43 static	int deadfl;
     44 
     45 __dead static void	dead(int);
     46 
     47 static 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("%s", 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 }
    102