1 /* This file has be substantially modified from the original OpenBSD source */ 2 3 /* $OpenBSD: bindresvport.c,v 1.17 2005/12/21 01:40:22 millert 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 /* OPENBSD ORIGINAL: lib/libc/rpc/bindresvport.c */ 32 33 #include "includes.h" 34 35 #ifndef HAVE_BINDRESVPORT_SA 36 #include <sys/types.h> 37 #include <sys/socket.h> 38 39 #include <netinet/in.h> 40 #include <arpa/inet.h> 41 42 #include <errno.h> 43 #include <stdlib.h> 44 #include <string.h> 45 46 #define STARTPORT 600 47 #define ENDPORT (IPPORT_RESERVED - 1) 48 #define NPORTS (ENDPORT - STARTPORT + 1) 49 50 /* 51 * Bind a socket to a privileged IP port 52 */ 53 int 54 bindresvport_sa(int sd, struct sockaddr *sa) 55 { 56 int error, af; 57 struct sockaddr_storage myaddr; 58 struct sockaddr_in *in; 59 struct sockaddr_in6 *in6; 60 u_int16_t *portp; 61 u_int16_t port; 62 socklen_t salen; 63 int i; 64 65 if (sa == NULL) { 66 memset(&myaddr, 0, sizeof(myaddr)); 67 sa = (struct sockaddr *)&myaddr; 68 salen = sizeof(myaddr); 69 70 if (getsockname(sd, sa, &salen) == -1) 71 return -1; /* errno is correctly set */ 72 73 af = sa->sa_family; 74 memset(&myaddr, 0, salen); 75 } else 76 af = sa->sa_family; 77 78 if (af == AF_INET) { 79 in = (struct sockaddr_in *)sa; 80 salen = sizeof(struct sockaddr_in); 81 portp = &in->sin_port; 82 } else if (af == AF_INET6) { 83 in6 = (struct sockaddr_in6 *)sa; 84 salen = sizeof(struct sockaddr_in6); 85 portp = &in6->sin6_port; 86 } else { 87 errno = EPFNOSUPPORT; 88 return (-1); 89 } 90 sa->sa_family = af; 91 92 port = ntohs(*portp); 93 if (port == 0) 94 port = arc4random_uniform(NPORTS) + STARTPORT; 95 96 /* Avoid warning */ 97 error = -1; 98 99 for(i = 0; i < NPORTS; i++) { 100 *portp = htons(port); 101 102 error = bind(sd, sa, salen); 103 104 /* Terminate on success */ 105 if (error == 0) 106 break; 107 108 /* Terminate on errors, except "address already in use" */ 109 if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL))) 110 break; 111 112 port++; 113 if (port > ENDPORT) 114 port = STARTPORT; 115 } 116 117 return (error); 118 } 119 120 #endif /* HAVE_BINDRESVPORT_SA */ 121