usr.bin/rsh/getport.c

   1 /*      $NetBSD: getport.c,v 1.1 2004/10/16 02:03:54 christos Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Christos Zoulas.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __RCSID("$NetBSD: getport.c,v 1.1 2004/10/16 02:03:54 christos Exp $");
  34
  35 #include <stdlib.h>
  36 #include <err.h>
  37 #include <netdb.h>
  38 #include <limits.h>
  39 #include <errno.h>
  40 #include <netinet/in.h>
  41
  42 #include "getport.h"
  43
  44 struct servent *
  45 getport(const char *service, const char *protocol)
  46 {
  47         long port;
  48         char *ep;
  49         struct servent *sp = getservbyname(service, protocol);
  50         if (sp != NULL)
  51                 return sp;
  52
  53         if ((sp = calloc(1, sizeof(*sp))) == NULL)
  54                 err(1, "malloc");
  55         sp->s_name = __UNCONST(service);
  56         sp->s_proto = __UNCONST(protocol);
  57         port = strtol(service, &ep, 0);
  58         if ((service[0] != '\0' && *ep != '\0') ||
  59             (errno == ERANGE &&
  60             (port == LONG_MAX || port == LONG_MIN)) ||
  61             (port <= 0 || port >= IPPORT_ANONMAX))
  62                 errx(1,"port must be between 1 and %d",
  63                     IPPORT_ANONMAX);
  64         sp->s_port = htons((uint16_t)port);
  65         return sp;
  66 }