Users Guide: Network Microcontroller Supplement User Manual

High-Speed Microcontroller User’s
Guide: Network Microcontroller
Supplement
198
listen
Description: int listen(
int s, /* socket on which to listen for connections */
int backlog); /* maximum queue length for pending connections */
The listen function listens for connections on the specified socket. It creates a queue of length backlog; backlog is the max-
imum number of pending new incoming connections (max.16). This function returns a success/failure code. To move an
incoming connection request from the queue to an established state, accept must be called. It is generally required to use
bind to assign a local name to a socket before invoking listen.
accept
Description: int accept(
int s, /* socket on which to accept a pending connection */
struct sockaddr *addr, /* addr
ess for new socket connection */
int addrlen); /* length of addr structure */
The accept function accepts a TCP connection on the specified socket. This function moves the first pending new incoming
connection r
equest fr
om the listen queue into the established state. It assigns a new local socket (connection endpoint) to the
connection and returns its socket handle. Accept blocks if there are no pending new incoming connection requests. The sock-
et s must first be created by the socket call, bound to an address-using bind, and a listen queue must be created for it using
listen. If addr is not NULL, the remote address is filled in.
recv
Description: int recv(
int s, /* socket fr
om which to receive data */
void *buf, /* pointer to receive data buffer */
int len, /* maximum number of bytes to receive */
int flags); /* currently ignored */
The recv function reads data from a connection-oriented (TCP) socket. This function reads up to len bytes from the socket s,
which must be in a connected state, into the buffer buf. It r
eturns the number of bytes read. The flags parameter is ignored. If
there
is no data on the socket, recv blocks infinitely unless a socket timeout is set using setsockopt.
INPUT PARAMETER#–DESCRIPTION OUTPUT DESCRIPTION
s
*buf
len
flags
Param0[0]–socket handle #
Param1[0:2]–pointer to TCP data
Param2[0:1]–max bytes to read
Param3–currently ignored
ACC
R1:R0
Return value (= 0 for success)
Number of bytes read
INPUT PARAMETER#–DESCRIPTION OUTPUT DESCRIPTION
s
*addr
addrlen
Param0[0]–socket handle #
Param1[0:2]–pointer to addr
Param2[0]–size of addr structure
ACC
R0
Return value (= 0 for success)
New socket handle #
INPUT PARAMETER#–DESCRIPTION OUTPUT DESCRIPTION
s
backlog
Param0[0]–socket handle #
Param1[0]–max queue backlog
ACC Return value (= 0 for success)
Maxim Integrated