Berkeley sockets emulation

Collaboration diagram for Berkeley sockets emulation:

Data Structures
struct	sockaddr
struct	in_addr
struct	sockaddr_in

Macros
#define	AF_INET   2
#define	SOCK_STREAM   1
#define	SOCK_DGRAM   2
#define	IPPROTO_TCP   6
#define	IPPROTO_UDP   17
#define	SOL_SOCKET   1
#define	SO_RCVTIMEO   20
#define	SO_SNDTIMEO   21
#define	TCP_NODELAY   1
#define	FIONBIO   0x5421
#define	HTONS(hostshort)   UIP_HTONS(hostshort)

Typedefs
typedef uint16_t	sa_family_t
typedef uint32_t	socklen_t

Functions
static uint16_t	htons (uint16_t hostshort)
int	socket (int domain, int type, int protocol)
int	bind (int sockfd, const struct sockaddr *addr, socklen_t addrlen)
int	listen (int sockfd, int backlog)
int	accept (int sockfd, struct sockaddr *addr, socklen_t *addrlen)
int	connect (int sockfd, const struct sockaddr *addr, socklen_t addrlen)
int	closesocket (int sockfd)
ssize_t	recv (int sockfd, void *buf, size_t len, int flags)
int	poll_recv (int sockfd, uint32_t timeout)
ssize_t	send (int sockfd, const void *buf, size_t len, int flags)
int	poll_send (int sockfd, uint32_t timeout)
int	select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout)
int	ioctlsocket (int sockfd, int request, const void *opt)
int	setsockopt (int sockfd, int level, int request, const void *opt, socklen_t length)

Detailed Description

Macro Definition Documentation

#define AF_INET   2

INET address family

Definition at line 89 of file rtos.h.

#define SOCK_STREAM   1

Stream socket type

Definition at line 90 of file rtos.h.

#define SOCK_DGRAM   2

Datagram socket type

Definition at line 91 of file rtos.h.

#define IPPROTO_TCP   6

TCP protocol

Definition at line 92 of file rtos.h.

#define IPPROTO_UDP   17

UDP protocol

Definition at line 93 of file rtos.h.

#define SOL_SOCKET   1

setsockopt() socket options

Definition at line 94 of file rtos.h.

#define SO_RCVTIMEO   20

recv() timeout

Definition at line 95 of file rtos.h.

#define SO_SNDTIMEO   21

send() timeout

Definition at line 96 of file rtos.h.

#define TCP_NODELAY   1

Disable Nagle's algorithm

Definition at line 97 of file rtos.h.

#define FIONBIO   0x5421

Async. socket IOCTL

Definition at line 98 of file rtos.h.

#define HTONS

(

hostshort

)

UIP_HTONS(hostshort)

Host to network order

Parameters

hostshort

Host-order short value

Returns

Network-order short value

Definition at line 810 of file rtos.h.

Typedef Documentation

typedef uint16_t sa_family_t

Socket address family type

Definition at line 773 of file rtos.h.

typedef uint32_t socklen_t

Socket address length type

Definition at line 774 of file rtos.h.

Function Documentation

static uint16_t htons ( uint16_t  hostshort )

inlinestatic

Host to network order

Parameters

hostshort

Host-order short value

Returns

Network-order short value

Definition at line 818 of file rtos.h.

References accept(), backlog, bind(), closesocket(), connect(), ioctlsocket(), listen(), poll_recv(), poll_send(), recv(), select(), send(), setsockopt(), socket(), and UIP_HTONS.

int socket	(	int	domain,
		int	type,
		int	protocol
	)

Creates an endpoint for communication and returns a descriptor for the socket.

Parameters

domain	The protocol family of the created socket.
type	SOCK_STREAM or SOCK_DGRAM
protocol	The actual transport protocol to use. 0 or IPPROTO_xxx

Returns

-1 if an error occurred. Otherwise, it returns an integer representing the newly assigned descriptor.

Referenced by htons().

int bind	(	int	sockfd,
		const struct sockaddr *	addr,
		socklen_t	addrlen
	)

Assigns a socket to an address.

Parameters

sockfd	A descriptor representing the socket to perform the bind on.
addr	A pointer to a sockaddr structure representing the address to bind to.
addrlen	The size of the sockaddr structure, pointed by addr.

Returns

0 on success or -1 if an error occurs.

Referenced by htons().

int listen	(	int	sockfd,
		int	backlog
	)

Prepares a socket for incoming connections.

Parameters

sockfd	A socket descriptor.
backlog	The number of pending connections that can be queued up at any one time (ignored by the current implementation).

Returns

0 on success or -1 if an error occurs.

Referenced by htons().

int accept	(	int	sockfd,
		struct sockaddr *	addr,
		socklen_t *	addrlen
	)

Creates a new socket for an incoming connection.

Parameters

sockfd	A descriptor representing the listening socket.
addr	A pointer to a sockaddr structure to receive the client's address information.
addrlen	A pointer to a variable, containing size of the sockaddr structure. Updated by the call.

Referenced by htons().

int connect	(	int	sockfd,
		const struct sockaddr *	addr,
		socklen_t	addrlen
	)

Establishes a communication link towards a remote host.

Parameters

sockfd	A local socket descriptor
addr	A pointer to a sockaddr structure representing the address of the remote host.
addrlen	The size of the sockaddr structure, pointed by addr.

Returns

0 on success or -1 if an error occurs.

Referenced by htons().

int closesocket

(

int

sockfd

)

Closes a socket desctiptor.

Parameters

sockfd

A socket descriptor

Returns

0 on success or -1 if an error occurs.

Referenced by htons().

ssize_t recv	(	int	sockfd,
		void *	buf,
		size_t	len,
		int	flags
	)

Receives data from a socket

Parameters

sockfd	A socket descriptor.
buf	The buffer to be filled by data
len	Length of the buffer.
flags	Ignored in the current implementation

Returns

Amount of bytes received or -1 if an error occurs.

Referenced by htons().

int poll_recv	(	int	sockfd,
		uint32_t	timeout
	)

Waits for a socket becomes available for data reading

If this function returns 0 for a socket, then a consequent recv() call will not block and will not return EWOULDBLOCK.

Parameters

sockfd	A socket descriptor.
timeout	Timeout in system ticks.

Returns

0 if the socket becomes available, or -1 if not.

Referenced by htons().

ssize_t send	(	int	sockfd,
		const void *	buf,
		size_t	len,
		int	flags
	)

Sends data into a socket

Parameters

sockfd	A socket descriptor.
buf	The buffer to be sent
len	Length of the buffer.
flags	Ignored in the current implementation

Returns

Amount of bytes sent or -1 if an error occurs.

Referenced by htons(), and uip_process().

int poll_send	(	int	sockfd,
		uint32_t	timeout
	)

Waits for a socket becomes available for data sending

If thiss function returns 0 for a socket, then a consequent send() call will not block and will not return EWOULDBLOCK.

Parameters

sockfd	A socket descriptor.
timeout	Timeout in system ticks.

Returns

0 if the socket becomes available, or -1 if not.

Referenced by htons().

int select	(	int	nfds,
		fd_set *	readfds,
		fd_set *	writefds,
		fd_set *	exceptfds,
		struct timeval *	timeout
	)

Synchronous I/O multiplexing

Parameters

nfds	The highest-numbered socket descriptor plus 1.
readfds	set of sockets, watched for read, updated on return.
writefds	set of sockets, watched for write, updated on return.
exceptfds	set of sockets, watched for exception, updated on return.
timeout	timeout. Infinite if NULL.

Returns

the total number of bits set in the readfds, writefds, exceptfds.

Referenced by htons().

int ioctlsocket	(	int	sockfd,
		int	request,
		const void *	opt
	)

Controls socket options (IOCTL ones).

Parameters

sockfd	A socket descriptor.
request	IOCTL request (so far FIONBIO is the only supported)
opt	The option value

Returns

0

int opt = 1;
ioctlsocket(fd, FIONBIO, &opt);

Referenced by htons().

int setsockopt	(	int	sockfd,
		int	level,
		int	request,
		const void *	opt,
		socklen_t	length
	)

Controls socket options (setsockopt ones).

Parameters

sockfd	A socket descriptor.
level	Option level (SOL_SOCKET, IPPROTO_TCP)
request	The option name (SO_RCVTIMEO, SO_SNDTIMEO, TCP_NODELAY)
opt	The option value
length	Length of the option

Returns

0

struct timeval tv;
tv.tv_sec = 30;
setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
setsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));

int flag = 1;
setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(flag));

Referenced by htons().