This patch imports the unmodified current version of NetBSD libc. The NetBSD includes are in /nbsd_include, while the libc code itself is split between lib/nbsd_libc and common/lib/libc.
185 lines
5.3 KiB
Groff
185 lines
5.3 KiB
Groff
.\" $NetBSD: bind.2,v 1.27 2010/05/31 12:16:20 njoly Exp $
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.\"
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.\" Copyright (c) 1983, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)bind.2 8.1 (Berkeley) 6/4/93
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.\"
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.Dd August 30, 2005
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.Dt BIND 2
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.Os
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.Sh NAME
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.Nm bind
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.Nd bind a name to a socket
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In sys/socket.h
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.Ft int
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.Fn bind "int s" "const struct sockaddr *name" "socklen_t namelen"
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.Sh DESCRIPTION
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.Fn bind
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assigns a name to an unnamed socket.
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When a socket is created
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with
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.Xr socket 2
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it exists in a name space (address family)
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but has no name assigned.
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.Fn bind
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requests that
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.Fa name
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be assigned to the socket.
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.Fa namelen
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indicates the amount of space pointed to by
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.Fa name ,
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in bytes.
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.Sh NOTES
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Binding a name in the
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.Ux
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domain creates a socket in the file
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system that must be deleted by the caller when it is no longer
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needed (using
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.Xr unlink 2 ) .
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.Pp
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The rules used in name binding vary between communication domains.
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Consult the manual entries in section 4 for detailed information.
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.Sh RETURN VALUES
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If the bind is successful, a 0 value is returned.
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A return value of \-1 indicates an error, which is
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further specified in the global
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.Va errno .
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.Sh ERRORS
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The
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.Fn bind
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call will fail if:
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.Bl -tag -width Er
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.It Bq Er EBADF
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.Fa s
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is not a valid descriptor.
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.It Bq Er ENOTSOCK
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.Fa s
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is not a socket.
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.It Bq Er EADDRNOTAVAIL
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The specified address is not available from the local machine.
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.It Bq Er EADDRINUSE
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The specified address is already in use.
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.It Bq Er EINVAL
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The socket is already bound to an address.
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.It Bq Er EINVAL
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The family of the socket and that requested in
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.Fa name-\*[Gt]sa_family
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are not equivalent.
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.It Bq Er EACCES
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The requested address is protected, and the current user
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has inadequate permission to access it.
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.It Bq Er EFAULT
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The
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.Fa name
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parameter is not in a valid part of the user
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address space.
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.El
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.Pp
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The following errors are specific to binding names in the
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.Ux
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domain.
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.Bl -tag -width Er
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.It Bq Er ENOTDIR
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A component of the path prefix is not a directory.
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.It Bq Er ENAMETOOLONG
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A component of a pathname exceeded
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.Brq Dv NAME_MAX
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characters, or an entire path name exceeded
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.Brq Dv PATH_MAX
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characters.
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.It Bq Er ENOENT
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A prefix component of the path name does not exist.
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.It Bq Er ELOOP
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Too many symbolic links were encountered in translating the pathname.
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.It Bq Er EIO
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An I/O error occurred while making the directory entry or allocating the inode.
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.It Bq Er EROFS
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The name would reside on a read-only file system.
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.It Bq Er EISDIR
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An empty pathname was specified.
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.El
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.Sh SEE ALSO
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.Xr connect 2 ,
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.Xr getsockname 2 ,
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.Xr listen 2 ,
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.Xr socket 2
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.Sh HISTORY
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The
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.Fn bind
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function call appeared in
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.Bx 4.2 .
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.Sh SECURITY CONSIDERATIONS
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.Fn bind
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was changed in
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.Nx 1.4
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to prevent the binding of a socket to the same port as an existing
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socket when all of the following is true:
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.Bl -bullet -compact -offset indent
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.It
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either of the existing or new addresses is
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.Li INADDR_ANY ,
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.It
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the uid of the new socket is not root, and
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the uids of the creators of the sockets are different,
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.It
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the address is not a multicast address, and
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.It
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both sockets are not bound to
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.Li INADDR_ANY
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with
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.Li SO_REUSEPORT
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set.
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.El
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.Pp
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This prevents an attack where a user could bind to a port with
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the host's IP address (after setting
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.Li SO_REUSEADDR )
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and
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.Sq steal
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packets destined for a server that bound to the
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same port with
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.Li INADDR_ANY .
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.Pp
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.Fn bind
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was changed in
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.Nx 4.0
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to honor the user's umask when binding sockets in the local domain.
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This was done to match the behavior of other operating systems,
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including
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.Fx ,
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.Ox ,
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and
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Linux, and to improve compatibility with some third-party software.
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Please note that this behavior
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.Em is not portable .
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If you must bind a local socket in a portable and secure way, you need
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to make a directory with tight permissions and then create the socket
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inside it.
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