1 /* This file has be substantially modified from the original OpenBSD source */ 2 3 /* $OpenBSD: bindresvport.c,v 1.15 2003/05/20 22:42:35 deraadt Exp $ */ 4 5 /* 6 * Copyright 1996, Jason Downs. All rights reserved. 7 * Copyright 1998, Theo de Raadt. All rights reserved. 8 * Copyright 2000, Damien Miller. All rights reserved. 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include "includes.h" 32 33 #ifndef HAVE_BINDRESVPORT_SA 34 35 #include "includes.h" 36 37 #define STARTPORT 600 38 #define ENDPORT (IPPORT_RESERVED - 1) 39 #define NPORTS (ENDPORT - STARTPORT + 1) 40 41 /* 42 * Bind a socket to a privileged IP port 43 */ 44 int 45 bindresvport_sa(sd, sa) 46 int sd; 47 struct sockaddr *sa; 48 { 49 int error, af; 50 struct sockaddr_storage myaddr; 51 struct sockaddr_in *sin; 52 struct sockaddr_in6 *sin6; 53 u_int16_t *portp; 54 u_int16_t port; 55 socklen_t salen; 56 int i; 57 58 if (sa == NULL) { 59 memset(&myaddr, 0, sizeof(myaddr)); 60 sa = (struct sockaddr *)&myaddr; 61 62 if (getsockname(sd, sa, &salen) == -1) 63 return -1; /* errno is correctly set */ 64 65 af = sa->sa_family; 66 memset(&myaddr, 0, salen); 67 } else 68 af = sa->sa_family; 69 70 if (af == AF_INET) { 71 sin = (struct sockaddr_in *)sa; 72 salen = sizeof(struct sockaddr_in); 73 portp = &sin->sin_port; 74 } else if (af == AF_INET6) { 75 sin6 = (struct sockaddr_in6 *)sa; 76 salen = sizeof(struct sockaddr_in6); 77 portp = &sin6->sin6_port; 78 } else { 79 errno = EPFNOSUPPORT; 80 return (-1); 81 } 82 sa->sa_family = af; 83 84 port = ntohs(*portp); 85 if (port == 0) 86 port = (arc4random() % NPORTS) + STARTPORT; 87 88 /* Avoid warning */ 89 error = -1; 90 91 for(i = 0; i < NPORTS; i++) { 92 *portp = htons(port); 93 94 error = bind(sd, sa, salen); 95 96 /* Terminate on success */ 97 if (error == 0) 98 break; 99 100 /* Terminate on errors, except "address already in use" */ 101 if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL))) 102 break; 103 104 port++; 105 if (port > ENDPORT) 106 port = STARTPORT; 107 } 108 109 return (error); 110 } 111 112 #endif /* HAVE_BINDRESVPORT_SA */ 113