GETSOCKNAME(2) | System Calls Manual | GETSOCKNAME(2) |
getsockname
— get
socket name
#include
<sys/socket.h>
int
getsockname
(int
s, struct sockaddr
*name, socklen_t
*namelen);
getsockname
()
returns the locally bound address information for a specified socket.
Common uses of this function are as follows:
getsockname
()
is used to retrieve the kernel-assigned port number.getsockname
() is used to
retrieve the local IP address for the connection.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 family.
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.
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.
If getsockname
() fails,
errno is set to one of the following:
accept(2), bind(2), getpeername(2), socket(2), getpeereid(3)
The getsockname
() function conforms to
IEEE Std 1003.1-2008 (“POSIX.1”).
The getsockname
() function call appeared
in 4.2BSD.
September 10, 2015 | OpenBSD-6.8 |