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 <string.h> 44 45 #define STARTPORT 600 46 #define ENDPORT (IPPORT_RESERVED - 1) 47 #define NPORTS (ENDPORT - STARTPORT + 1) 48 49 /* 50 * Bind a socket to a privileged IP port 51 */ 52 int 53 bindresvport_sa(int sd, struct sockaddr *sa) 54 { 55 int error, af; 56 struct sockaddr_storage myaddr; 57 struct sockaddr_in *in; 58 struct sockaddr_in6 *in6; 59 u_int16_t *portp; 60 u_int16_t port; 61 socklen_t salen; 62 int i; 63 64 if (sa == NULL) { 65 memset(&myaddr, 0, sizeof(myaddr)); 66 sa = (struct sockaddr *)&myaddr; 67 salen = sizeof(myaddr); 68 69 if (getsockname(sd, sa, &salen) == -1) 70 return -1; /* errno is correctly set */ 71 72 af = sa->sa_family; 73 memset(&myaddr, 0, salen); 74 } else 75 af = sa->sa_family; 76 77 if (af == AF_INET) { 78 in = (struct sockaddr_in *)sa; 79 salen = sizeof(struct sockaddr_in); 80 portp = &in->sin_port; 81 } else if (af == AF_INET6) { 82 in6 = (struct sockaddr_in6 *)sa; 83 salen = sizeof(struct sockaddr_in6); 84 portp = &in6->sin6_port; 85 } else { 86 errno = EPFNOSUPPORT; 87 return (-1); 88 } 89 sa->sa_family = af; 90 91 port = ntohs(*portp); 92 if (port == 0) 93 port = arc4random_uniform(NPORTS) + STARTPORT; 94 95 /* Avoid warning */ 96 error = -1; 97 98 for(i = 0; i < NPORTS; i++) { 99 *portp = htons(port); 100 101 error = bind(sd, sa, salen); 102 103 /* Terminate on success */ 104 if (error == 0) 105 break; 106 107 /* Terminate on errors, except "address already in use" */ 108 if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL))) 109 break; 110 111 port++; 112 if (port > ENDPORT) 113 port = STARTPORT; 114 } 115 116 return (error); 117 } 118 119 #endif /* HAVE_BINDRESVPORT_SA */ 120