Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

getsockname(2) [netbsd man page]

GETSOCKNAME(2)						      BSD System Calls Manual						    GETSOCKNAME(2)

NAME
getsockname -- get socket name LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <sys/socket.h> int getsockname(int s, struct sockaddr * restrict name, socklen_t * restrict namelen); DESCRIPTION
getsockname() returns the locally bound address information for a specified socket. Common uses of this function are as follows: o When bind(2) is called with a port number of 0 (indicating the kernel should pick an ephemeral port) getsockname() is used to retrieve the kernel-assigned port number. o When a process calls bind(2) on a wildcard IP address, getsockname() is used to retrieve the local IP address for the connection. o When a function wishes to know the address family of a socket, getsockname() can be used. getsockname() takes three parameters: s, Contains the file descriptor for the socket to be looked up. name points to a sockaddr structure which will hold the resulting address information. Normal use requires one to use a structure specific to the protocol family in use, such as sockaddr_in (IPv4) or sockaddr_in6 (IPv6), cast to a (struct sockaddr *). For greater portability (such as newer protocol families) the new structure sockaddr_storage exists. sockaddr_storage is large enough to hold any of the other sockaddr_* variants. On return, it should be cast to the correct sockaddr type, according to the current protocol fam- ily. namelen indicates the amount of space pointed to by name, in bytes. Upon return, namelen is set to the actual size of the returned address information. If the address of the destination socket for a given socket connection is needed, the getpeername(2) function should be used instead. If name does not point to enough space to hold the entire socket address, the result will be truncated to namelen bytes. RETURN VALUES
On success, getsockname() returns a 0, and namelen is set to the actual size of the socket address returned in name. Otherwise, errno is set, and a value of -1 is returned. ERRORS
The call succeeds unless: [EBADF] The argument s is not a valid descriptor. [ENOTSOCK] The argument s is a file, not a socket. [EINVAL] The socket has been shut down. [ENOBUFS] Insufficient resources were available in the system to perform the operation. [EFAULT] The name parameter points to memory not in a valid part of the process address space. SEE ALSO
bind(2), socket(2) HISTORY
The getsockname() function call appeared in 4.2BSD. BUGS
Names bound to sockets in the UNIX domain are inaccessible; getsockname() returns a zero length name. BSD
August 11, 2002 BSD

Check Out this Related Man Page

getpeername(3XNET)				   X/Open Networking Services Library Functions 				getpeername(3XNET)

NAME
getpeername - get the name of the peer socket SYNOPSIS
cc [ flag ... ] file ... -lxnet [ library ... ] #include <sys/socket.h> int getpeername(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len); DESCRIPTION
The getpeername() function retrieves the peer address of the specified socket, stores this address in the sockaddr structure pointed to by the address argument, and stores the length of this address in the object pointed to by the address_len argument. If the actual length of the address is greater than the length of the supplied sockaddr structure, the stored address will be truncated. If the protocol permits connections by unbound clients, and the peer is not bound, then the value stored in the object pointed to by address is unspecified. RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error. ERRORS
The getpeername() function will fail if: EBADF The socket argument is not a valid file descriptor. EFAULT The address or address_len parameter can not be accessed or written. EINVAL The socket has been shut down. ENOTCONN The socket is not connected or otherwise has not had the peer prespecified. ENOTSOCK The socket argument does not refer to a socket. EOPNOTSUPP The operation is not supported for the socket protocol. The getpeername() function may fail if: ENOBUFS Insufficient resources were available in the system to complete the call. ENOSR There were insufficient STREAMS resources available for the operation to complete. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
accept(3XNET), bind(3XNET), getsockname(3XNET), socket(3XNET), attributes(5), standards(5) SunOS 5.10 10 Jun 2002 getpeername(3XNET)
Man Page