lwIP - A Minimal TCP/IP implementation - Wikia

17 BSD SOCKET LIBRARY 17.3 Connection setup
int
connect(int s, struct sockaddr *name, int namelen)
{
struct netconn *conn;
struct ip_addr *remote_addr;
unsigned short remote_port;
remote_addr = (struct ip_addr *)name->sin_addr;
remote_port = name->sin_port;
conn = sockets[s];
netconn_connect(conn, remote_addr, remote_port);
}
return 0;
17.3.3 The listen() call
The listen() call is the equivalent of the lwIP API function netconn listen() and can only be
used for TCP connections. The only difference is that the BSD socket API allows the application
to specify the size of the queue of pending connections (the backlog). This is not possible with
lwIP and the backlog parameter is ignored.
int
listen(int s, int backlog)
{
netconn_listen(sockets[s]);
return 0;
}
17.3.4 The accept() call
The accept() call is used to wait for incoming connections on a TCP socket that previously has
been set into LISTEN state by a call to listen(). The call to accept() blocks until a connection
has been established with a remote host. The arguments to listen are result parameters that are
set by the call to accept(). These are filled with the address of the remote host.
When the new connection has been established, the lwIP function netconn accept() will
return the connection handle for the new connection. After the IP address and port number of
the remote host has been filled in, a new socket identifier is allocated and returned.
int
accept(int s, struct sockaddr *addr, int *addrlen)
{
struct netconn *conn, *newconn;
struct ip_addr *addr;
unsigned short port;
int i;
conn = sockets[s];
newconn = netconn_accept(conn);
/* get the IP address and port of the remote host */
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