1 /* $OpenBSD: rresvport.c,v 1.9 2005/11/10 10:00:17 espie Exp $ */ 2 /* 3 * Copyright (c) 1995, 1996, 1998 Theo de Raadt. All rights reserved. 4 * Copyright (c) 1983, 1993, 1994 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/param.h> 33 #include <sys/socket.h> 34 #include <sys/stat.h> 35 36 #include <netinet/in.h> 37 #include <arpa/inet.h> 38 39 #include <signal.h> 40 #include <fcntl.h> 41 #include <netdb.h> 42 #include <unistd.h> 43 #include <pwd.h> 44 #include <errno.h> 45 #include <stdio.h> 46 #include <ctype.h> 47 #include <string.h> 48 #include <syslog.h> 49 #include <stdlib.h> 50 #include <netgroup.h> 51 52 int 53 rresvport(int *alport) 54 { 55 return rresvport_af(alport, AF_INET); 56 } 57 58 59 int 60 rresvport_af(int *alport, int af) 61 { 62 struct sockaddr_storage ss; 63 struct sockaddr *sa; 64 u_int16_t *portp; 65 int s; 66 67 bzero(&ss, sizeof ss); 68 sa = (struct sockaddr *)&ss; 69 70 switch (af) { 71 case AF_INET: 72 sa->sa_len = sizeof(struct sockaddr_in); 73 portp = &((struct sockaddr_in *)sa)->sin_port; 74 break; 75 case AF_INET6: 76 sa->sa_len = sizeof(struct sockaddr_in6); 77 portp = &((struct sockaddr_in6 *)sa)->sin6_port; 78 break; 79 default: 80 errno = EPFNOSUPPORT; 81 return (-1); 82 } 83 sa->sa_family = af; 84 85 s = socket(af, SOCK_STREAM, 0); 86 if (s < 0) 87 return (-1); 88 89 *portp = htons(*alport); 90 if (*alport < IPPORT_RESERVED - 1) { 91 if (bind(s, sa, sa->sa_len) >= 0) 92 return (s); 93 if (errno != EADDRINUSE) { 94 (void)close(s); 95 return (-1); 96 } 97 } 98 99 *portp = 0; 100 sa->sa_family = af; 101 if (bindresvport_sa(s, sa) == -1) { 102 (void)close(s); 103 return (-1); 104 } 105 *alport = ntohs(*portp); 106 return (s); 107 } 108