openssh/openbsd-compat/bindresvport.c

113 lines
3.1 KiB
C

/* This file has be substantially modified from the original OpenBSD source */
/* $OpenBSD: bindresvport.c,v 1.16 2005/04/01 07:44:03 otto Exp $ */
/*
* Copyright 1996, Jason Downs. All rights reserved.
* Copyright 1998, Theo de Raadt. All rights reserved.
* Copyright 2000, Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* OPENBSD ORIGINAL: lib/libc/rpc/bindresvport.c */
#include "includes.h"
#ifndef HAVE_BINDRESVPORT_SA
#include "includes.h"
#define STARTPORT 600
#define ENDPORT (IPPORT_RESERVED - 1)
#define NPORTS (ENDPORT - STARTPORT + 1)
/*
* Bind a socket to a privileged IP port
*/
int
bindresvport_sa(int sd, struct sockaddr *sa)
{
int error, af;
struct sockaddr_storage myaddr;
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
u_int16_t *portp;
u_int16_t port;
socklen_t salen;
int i;
if (sa == NULL) {
memset(&myaddr, 0, sizeof(myaddr));
sa = (struct sockaddr *)&myaddr;
if (getsockname(sd, sa, &salen) == -1)
return -1; /* errno is correctly set */
af = sa->sa_family;
memset(&myaddr, 0, salen);
} else
af = sa->sa_family;
if (af == AF_INET) {
sin = (struct sockaddr_in *)sa;
salen = sizeof(struct sockaddr_in);
portp = &sin->sin_port;
} else if (af == AF_INET6) {
sin6 = (struct sockaddr_in6 *)sa;
salen = sizeof(struct sockaddr_in6);
portp = &sin6->sin6_port;
} else {
errno = EPFNOSUPPORT;
return (-1);
}
sa->sa_family = af;
port = ntohs(*portp);
if (port == 0)
port = (arc4random() % NPORTS) + STARTPORT;
/* Avoid warning */
error = -1;
for(i = 0; i < NPORTS; i++) {
*portp = htons(port);
error = bind(sd, sa, salen);
/* Terminate on success */
if (error == 0)
break;
/* Terminate on errors, except "address already in use" */
if ((error < 0) && !((errno == EADDRINUSE) || (errno == EINVAL)))
break;
port++;
if (port > ENDPORT)
port = STARTPORT;
}
return (error);
}
#endif /* HAVE_BINDRESVPORT_SA */