getpeername

Name

getpeername - gets name of connected peer socket

Library

libc.lib

Synopsis

#include <sys/types.h>

#include <sys/socket.h>

int getpeername (int s, struct sockaddr * restrict name, socklen_t * restrict namelen);

Return values

The getpeername() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

Detailed description

The getpeername system call returns the name of the peer connected to socket s. The namelen argument should be initialized to indicate the amount of space pointed to by name. On return it contains the actual size of the name returned (in bytes). The name is truncated if the buffer provided is too small.

Examples

#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
void GetSockName()
{
   int sock_fd;
   int newsock_fd;
   struct sockaddr_in addr;
   struct sockaddr_in ss;
   struct sockaddr_in new_socket;
   unsigned int len;
   unsigned int addr_len;
    
   sock_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
       
   addr.sin_family = AF_INET;
   addr.sin_addr.s_addr = htonl(INADDR_ANY);
   addr.sin_port = htons(5000);
   bind(sock_fd,(struct sockaddr*)&addr,sizeof(addr));
   listen(sock_fd,1);
   newsock_fd = accept(sock_fd,(struct sockaddr*)&new_socket,&addr_len); // Code blocks here
  
   // Assuming client has connected to the server. 
   len = sizeof(ss);
   getpeername(sock_fd,(struct sockaddr*)&ss,&len);
   close(newsock_fd);
   close(sock_fd);
 }

Errors

The call succeeds unless:

[`EBADF`]
	The argument s is not a valid descriptor.
[`ECONNRESET`]
	The connection has been reset by the peer.
[`ENOTSOCK`]
	The argument s is a file, not a socket.
[`ENOTCONN`]
	The socket is not connected.
[`ENOBUFS`]
	Insufficient resources were available in the system to perform the operation.
[`EFAULT`]
	The name argument points to memory not in a valid part of the process address space.
[`EINVAL`]
	The namelen argument is invalid.