net_sockets.h File Reference

Network sockets abstraction layer to integrate Mbed TLS into a BSD-style sockets API. More...

#include "config.h"
#include "ssl.h"
#include <stddef.h>
#include <stdint.h>

Include dependency graph for net_sockets.h:

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Classes
struct	mbedtls_net_context

Macros
#define	MBEDTLS_ERR_NET_SOCKET_FAILED   -0x0042
#define	MBEDTLS_ERR_NET_CONNECT_FAILED   -0x0044
#define	MBEDTLS_ERR_NET_BIND_FAILED   -0x0046
#define	MBEDTLS_ERR_NET_LISTEN_FAILED   -0x0048
#define	MBEDTLS_ERR_NET_ACCEPT_FAILED   -0x004A
#define	MBEDTLS_ERR_NET_RECV_FAILED   -0x004C
#define	MBEDTLS_ERR_NET_SEND_FAILED   -0x004E
#define	MBEDTLS_ERR_NET_CONN_RESET   -0x0050
#define	MBEDTLS_ERR_NET_UNKNOWN_HOST   -0x0052
#define	MBEDTLS_ERR_NET_BUFFER_TOO_SMALL   -0x0043
#define	MBEDTLS_ERR_NET_INVALID_CONTEXT   -0x0045
#define	MBEDTLS_ERR_NET_POLL_FAILED   -0x0047
#define	MBEDTLS_ERR_NET_BAD_INPUT_DATA   -0x0049
#define	MBEDTLS_NET_LISTEN_BACKLOG   10
#define	MBEDTLS_NET_PROTO_TCP   0
#define	MBEDTLS_NET_PROTO_UDP   1
#define	MBEDTLS_NET_POLL_READ   1
#define	MBEDTLS_NET_POLL_WRITE   2

Typedefs
typedef struct mbedtls_net_context	mbedtls_net_context

Functions
void	mbedtls_net_init (mbedtls_net_context *ctx)
	Initialize a context Just makes the context ready to be used or freed safely. More...
int	mbedtls_net_connect (mbedtls_net_context *ctx, const char *host, const char *port, int proto)
	Initiate a connection with host:port in the given protocol. More...
int	mbedtls_net_bind (mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto)
	Create a receiving socket on bind_ip:port in the chosen protocol. If bind_ip == NULL, all interfaces are bound. More...
int	mbedtls_net_accept (mbedtls_net_context *bind_ctx, mbedtls_net_context *client_ctx, void *client_ip, size_t buf_size, size_t *ip_len)
	Accept a connection from a remote client. More...
int	mbedtls_net_poll (mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout)
	Check and wait for the context to be ready for read/write. More...
int	mbedtls_net_set_block (mbedtls_net_context *ctx)
	Set the socket blocking. More...
int	mbedtls_net_set_nonblock (mbedtls_net_context *ctx)
	Set the socket non-blocking. More...
void	mbedtls_net_usleep (unsigned long usec)
	Portable usleep helper. More...
int	mbedtls_net_recv (void *ctx, unsigned char *buf, size_t len)
	Read at most 'len' characters. If no error occurs, the actual amount read is returned. More...
int	mbedtls_net_send (void *ctx, const unsigned char *buf, size_t len)
	Write at most 'len' characters. If no error occurs, the actual amount read is returned. More...
int	mbedtls_net_recv_timeout (void *ctx, unsigned char *buf, size_t len, uint32_t timeout)
	Read at most 'len' characters, blocking for at most 'timeout' seconds. If no error occurs, the actual amount read is returned. More...
void	mbedtls_net_free (mbedtls_net_context *ctx)
	Gracefully shutdown the connection and free associated data. More...

Detailed Description

Network sockets abstraction layer to integrate Mbed TLS into a BSD-style sockets API.

The network sockets module provides an example integration of the Mbed TLS library into a BSD sockets implementation. The module is intended to be an example of how Mbed TLS can be integrated into a networking stack, as well as to be Mbed TLS's network integration for its supported platforms.

The module is intended only to be used with the Mbed TLS library and is not intended to be used by third party application software directly.

The supported platforms are as follows:

• Microsoft Windows and Windows CE
• POSIX/Unix platforms including Linux, OS X

Macro Definition Documentation

MBEDTLS_ERR_NET_ACCEPT_FAILED

#define MBEDTLS_ERR_NET_ACCEPT_FAILED   -0x004A

Could not accept the incoming connection.

MBEDTLS_ERR_NET_BAD_INPUT_DATA

#define MBEDTLS_ERR_NET_BAD_INPUT_DATA   -0x0049

Input invalid.

MBEDTLS_ERR_NET_BIND_FAILED

#define MBEDTLS_ERR_NET_BIND_FAILED   -0x0046

Binding of the socket failed.

MBEDTLS_ERR_NET_BUFFER_TOO_SMALL

#define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL   -0x0043

Buffer is too small to hold the data.

MBEDTLS_ERR_NET_CONN_RESET

#define MBEDTLS_ERR_NET_CONN_RESET   -0x0050

Connection was reset by peer.

MBEDTLS_ERR_NET_CONNECT_FAILED

#define MBEDTLS_ERR_NET_CONNECT_FAILED   -0x0044

The connection to the given server / port failed.

MBEDTLS_ERR_NET_INVALID_CONTEXT

#define MBEDTLS_ERR_NET_INVALID_CONTEXT   -0x0045

The context is invalid, eg because it was free()ed.

MBEDTLS_ERR_NET_LISTEN_FAILED

#define MBEDTLS_ERR_NET_LISTEN_FAILED   -0x0048

Could not listen on the socket.

MBEDTLS_ERR_NET_POLL_FAILED

#define MBEDTLS_ERR_NET_POLL_FAILED   -0x0047

Polling the net context failed.

MBEDTLS_ERR_NET_RECV_FAILED

#define MBEDTLS_ERR_NET_RECV_FAILED   -0x004C

Reading information from the socket failed.

MBEDTLS_ERR_NET_SEND_FAILED

#define MBEDTLS_ERR_NET_SEND_FAILED   -0x004E

Sending information through the socket failed.

MBEDTLS_ERR_NET_SOCKET_FAILED

#define MBEDTLS_ERR_NET_SOCKET_FAILED   -0x0042

Failed to open a socket.

MBEDTLS_ERR_NET_UNKNOWN_HOST

#define MBEDTLS_ERR_NET_UNKNOWN_HOST   -0x0052

Failed to get an IP address for the given hostname.

MBEDTLS_NET_LISTEN_BACKLOG

#define MBEDTLS_NET_LISTEN_BACKLOG   10

The backlog that listen() should use.

MBEDTLS_NET_POLL_READ

#define MBEDTLS_NET_POLL_READ   1

Used in mbedtls_net_poll to check for pending data

MBEDTLS_NET_POLL_WRITE

#define MBEDTLS_NET_POLL_WRITE   2

Used in mbedtls_net_poll to check if write possible

MBEDTLS_NET_PROTO_TCP

#define MBEDTLS_NET_PROTO_TCP   0

The TCP transport protocol

MBEDTLS_NET_PROTO_UDP

#define MBEDTLS_NET_PROTO_UDP   1

The UDP transport protocol

Typedef Documentation

mbedtls_net_context

typedef struct mbedtls_net_context mbedtls_net_context

Wrapper type for sockets.

Currently backed by just a file descriptor, but might be more in the future (eg two file descriptors for combined IPv4 + IPv6 support, or additional structures for hand-made UDP demultiplexing).

Function Documentation

mbedtls_net_accept()

int mbedtls_net_accept	(	mbedtls_net_context *	bind_ctx,
		mbedtls_net_context *	client_ctx,
		void *	client_ip,
		size_t	buf_size,
		size_t *	ip_len
	)

Accept a connection from a remote client.

Parameters

bind_ctx	Relevant socket
client_ctx	Will contain the connected client socket
client_ip	Will contain the client IP address, can be NULL
buf_size	Size of the client_ip buffer
ip_len	Will receive the size of the client IP written, can be NULL if client_ip is null

Returns

0 if successful, or MBEDTLS_ERR_NET_ACCEPT_FAILED, or MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to non-blocking and accept() would block.

mbedtls_net_bind()

int mbedtls_net_bind	(	mbedtls_net_context *	ctx,
		const char *	bind_ip,
		const char *	port,
		int	proto
	)

Create a receiving socket on bind_ip:port in the chosen protocol. If bind_ip == NULL, all interfaces are bound.

Parameters

ctx	Socket to use
bind_ip	IP to bind to, can be NULL
port	Port number to use
proto	Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP

Returns

0 if successful, or one of: MBEDTLS_ERR_NET_SOCKET_FAILED, MBEDTLS_ERR_NET_BIND_FAILED, MBEDTLS_ERR_NET_LISTEN_FAILED

Note

Regardless of the protocol, opens the sockets and binds it. In addition, make the socket listening if protocol is TCP.

mbedtls_net_connect()

int mbedtls_net_connect	(	mbedtls_net_context *	ctx,
		const char *	host,
		const char *	port,
		int	proto
	)

Initiate a connection with host:port in the given protocol.

Parameters

ctx	Socket to use
host	Host to connect to
port	Port to connect to
proto	Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP

Returns

0 if successful, or one of: MBEDTLS_ERR_NET_SOCKET_FAILED, MBEDTLS_ERR_NET_UNKNOWN_HOST, MBEDTLS_ERR_NET_CONNECT_FAILED

Note

Sets the socket in connected mode even with UDP.

mbedtls_net_free()

void mbedtls_net_free

(

mbedtls_net_context *

ctx

)

Gracefully shutdown the connection and free associated data.

Parameters

ctx	The context to free

mbedtls_net_init()

void mbedtls_net_init

(

mbedtls_net_context *

ctx

)

Initialize a context Just makes the context ready to be used or freed safely.

Parameters

ctx	Context to initialize

mbedtls_net_poll()

int mbedtls_net_poll	(	mbedtls_net_context *	ctx,
		uint32_t	rw,
		uint32_t	timeout
	)

Check and wait for the context to be ready for read/write.

Parameters

ctx	Socket to check
rw	Bitflag composed of MBEDTLS_NET_POLL_READ and MBEDTLS_NET_POLL_WRITE specifying the events to wait for: If MBEDTLS_NET_POLL_READ is set, the function will return as soon as the net context is available for reading. If MBEDTLS_NET_POLL_WRITE is set, the function will return as soon as the net context is available for writing.
timeout	Maximal amount of time to wait before returning, in milliseconds. If timeout is zero, the function returns immediately. If timeout is -1u, the function blocks potentially indefinitely.

Returns

Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE on success or timeout, or a negative return code otherwise.

mbedtls_net_recv()

int mbedtls_net_recv	(	void *	ctx,
		unsigned char *	buf,
		size_t	len
	)

Read at most 'len' characters. If no error occurs, the actual amount read is returned.

Parameters

ctx	Socket
buf	The buffer to write to
len	Maximum length of the buffer

Returns

the number of bytes received, or a non-zero error code; with a non-blocking socket, MBEDTLS_ERR_SSL_WANT_READ indicates read() would block.

mbedtls_net_recv_timeout()

int mbedtls_net_recv_timeout	(	void *	ctx,
		unsigned char *	buf,
		size_t	len,
		uint32_t	timeout
	)

Read at most 'len' characters, blocking for at most 'timeout' seconds. If no error occurs, the actual amount read is returned.

Parameters

ctx	Socket
buf	The buffer to write to
len	Maximum length of the buffer
timeout	Maximum number of milliseconds to wait for data 0 means no timeout (wait forever)

Returns

the number of bytes received, or a non-zero error code: MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out, MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal.

Note

This function will block (until data becomes available or timeout is reached) even if the socket is set to non-blocking. Handling timeouts with non-blocking reads requires a different strategy.

mbedtls_net_send()

int mbedtls_net_send	(	void *	ctx,
		const unsigned char *	buf,
		size_t	len
	)

Write at most 'len' characters. If no error occurs, the actual amount read is returned.

Parameters

ctx	Socket
buf	The buffer to read from
len	The length of the buffer

Returns

the number of bytes sent, or a non-zero error code; with a non-blocking socket, MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block.

mbedtls_net_set_block()

int mbedtls_net_set_block

(

mbedtls_net_context *

ctx

)

Set the socket blocking.

Parameters

ctx	Socket to set

Returns

0 if successful, or a non-zero error code

mbedtls_net_set_nonblock()

int mbedtls_net_set_nonblock

(

mbedtls_net_context *

ctx

)

Set the socket non-blocking.

Parameters

ctx	Socket to set

Returns

0 if successful, or a non-zero error code

mbedtls_net_usleep()

void mbedtls_net_usleep

(

unsigned long

usec

)

Portable usleep helper.

Parameters

usec	Amount of microseconds to sleep

Note

Real amount of time slept will not be less than select()'s timeout granularity (typically, 10ms).