BIND (2)

SYNOPSIS

#include <sys/types.h> #include <sys/socket.h> int bind(int sockfd , struct sockaddr * my_addr , socklen_t addrlen );

DESCRIPTION

bind gives the socket sockfd the local address my_addr . my_addr is addrlen bytes long. Traditionally, this is called \(lqassigning a name to a socket.\(rq When a socket is created with socket (2), it exists in a name space (address family) but has no name assigned.

It is normally necessary to assign a local address using bind before a SOCK_STREAM socket may receive connections (see accept (2)).

NOTES

The rules used in name binding vary between address families. Consult the manual entries in Section 7 for detailed information. For AF_INET see ip (7), for AF_UNIX see unix (7), for AF_APPLETALK see ddp (7), for AF_PACKET see packet (7), for AF_X25 see x25 (7) and for AF_NETLINK see netlink (7).

RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

ERRORS

EBADF

sockfd is not a valid descriptor.

EINVAL

The socket is already bound to an address. This may change in the future: see linux/unix/sock.c for details.

EACCES

The address is protected, and the user is not the super-user.

ENOTSOCK

Argument is a descriptor for a file, not a socket.

The following errors are specific to UNIX domain ( AF_UNIX ) sockets:

EINVAL

The addrlen is wrong, or the socket was not in the AF_UNIX family.

EROFS

The socket inode would reside on a read-only file system.

EFAULT

my_addr points outside the user's accessible address space.

ENAMETOOLONG

my_addr is too long.

ENOENT

The file does not exist.

ENOMEM

Insufficient kernel memory was available.

ENOTDIR

A component of the path prefix is not a directory.

EACCES

Search permission is denied on a component of the path prefix.

ELOOP

Too many symbolic links were encountered in resolving my_addr .

BUGS

The transparent proxy options are not described.

CONFORMING TO

SVr4, 4.4BSD (the bind function first appeared in BSD 4.2). SVr4 documents additional EADDRNOTAVAIL , EADDRINUSE , and ENOSR general error conditions, and additional EIO , EISDIR and EROFS Unix-domain error conditions.

NOTE

The third argument of bind is in reality an int (and this is what BSD 4.* and libc4 and libc5 have). Some POSIX confusion resulted in the present socklen_t. The draft standard has not been adopted yet, but glibc2 already follows it and also has socklen_t. See also accept (2).

SEE ALSO

- accept (2) - - connect (2) - - listen (2) - - socket (2) - - getsockname (2) - - ip (7) - - socket (7) - man2/unimplemented 2