mbed TLS v3.1.0
Data Structures | Macros | Typedefs | Functions
net_sockets.h File Reference

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

#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include "mbedtls/ssl.h"
#include <stddef.h>
#include <stdint.h>
Include dependency graph for net_sockets.h:

Go to the source code of this file.

Data Structures

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_close (mbedtls_net_context *ctx)
 Closes down the connection and free associated data. 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:

Definition in file net_sockets.h.

Macro Definition Documentation

#define MBEDTLS_ERR_NET_ACCEPT_FAILED   -0x004A

Could not accept the incoming connection.

Definition at line 58 of file net_sockets.h.

#define MBEDTLS_ERR_NET_BAD_INPUT_DATA   -0x0049

Input invalid.

Definition at line 74 of file net_sockets.h.

#define MBEDTLS_ERR_NET_BIND_FAILED   -0x0046

Binding of the socket failed.

Definition at line 54 of file net_sockets.h.

#define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL   -0x0043

Buffer is too small to hold the data.

Definition at line 68 of file net_sockets.h.

#define MBEDTLS_ERR_NET_CONN_RESET   -0x0050

Connection was reset by peer.

Definition at line 64 of file net_sockets.h.

#define MBEDTLS_ERR_NET_CONNECT_FAILED   -0x0044

The connection to the given server / port failed.

Definition at line 52 of file net_sockets.h.

#define MBEDTLS_ERR_NET_INVALID_CONTEXT   -0x0045

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

Definition at line 70 of file net_sockets.h.

#define MBEDTLS_ERR_NET_LISTEN_FAILED   -0x0048

Could not listen on the socket.

Definition at line 56 of file net_sockets.h.

#define MBEDTLS_ERR_NET_POLL_FAILED   -0x0047

Polling the net context failed.

Definition at line 72 of file net_sockets.h.

#define MBEDTLS_ERR_NET_RECV_FAILED   -0x004C

Reading information from the socket failed.

Definition at line 60 of file net_sockets.h.

#define MBEDTLS_ERR_NET_SEND_FAILED   -0x004E

Sending information through the socket failed.

Definition at line 62 of file net_sockets.h.

#define MBEDTLS_ERR_NET_SOCKET_FAILED   -0x0042

Failed to open a socket.

Definition at line 50 of file net_sockets.h.

#define MBEDTLS_ERR_NET_UNKNOWN_HOST   -0x0052

Failed to get an IP address for the given hostname.

Definition at line 66 of file net_sockets.h.

#define MBEDTLS_NET_LISTEN_BACKLOG   10

The backlog that listen() should use.

Definition at line 76 of file net_sockets.h.

#define MBEDTLS_NET_POLL_READ   1

Used in mbedtls_net_poll to check for pending data

Definition at line 81 of file net_sockets.h.

#define MBEDTLS_NET_POLL_WRITE   2

Used in mbedtls_net_poll to check if write possible

Definition at line 82 of file net_sockets.h.

#define MBEDTLS_NET_PROTO_TCP   0

The TCP transport protocol

Definition at line 78 of file net_sockets.h.

#define MBEDTLS_NET_PROTO_UDP   1

The UDP transport protocol

Definition at line 79 of file net_sockets.h.

Typedef Documentation

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

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_ctxRelevant socket
client_ctxWill contain the connected client socket
client_ipWill contain the client IP address, can be NULL
buf_sizeSize of the client_ip buffer
ip_lenWill receive the size of the client IP written, can be NULL if client_ip is null
Returns
0 if successful, or MBEDTLS_ERR_NET_SOCKET_FAILED, MBEDTLS_ERR_NET_BIND_FAILED, 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.
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
ctxSocket to use
bind_ipIP to bind to, can be NULL
portPort number to use
protoProtocol: 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_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.
void mbedtls_net_close ( mbedtls_net_context ctx)

Closes down the connection and free associated data.

Parameters
ctxThe context to close
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
ctxSocket to use
hostHost to connect to
portPort to connect to
protoProtocol: 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.
void mbedtls_net_free ( mbedtls_net_context ctx)

Gracefully shutdown the connection and free associated data.

Parameters
ctxThe context to free
void mbedtls_net_init ( mbedtls_net_context ctx)

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

Parameters
ctxContext to initialize
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.

Note
The current implementation of this function uses select() and returns an error if the file descriptor is FD_SETSIZE or greater.
Parameters
ctxSocket to check
rwBitflag 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.
timeoutMaximal 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.
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
ctxSocket
bufThe buffer to write to
lenMaximum 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.
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.

Note
The current implementation of this function uses select() and returns an error if the file descriptor is FD_SETSIZE or greater.
Parameters
ctxSocket
bufThe buffer to write to
lenMaximum length of the buffer
timeoutMaximum number of milliseconds to wait for data 0 means no timeout (wait forever)
Returns
The number of bytes received if successful. MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out. MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. Another negative error code (MBEDTLS_ERR_NET_xxx) for other failures.
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.
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
ctxSocket
bufThe buffer to read from
lenThe 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.
int mbedtls_net_set_block ( mbedtls_net_context ctx)

Set the socket blocking.

Parameters
ctxSocket to set
Returns
0 if successful, or a non-zero error code
int mbedtls_net_set_nonblock ( mbedtls_net_context ctx)

Set the socket non-blocking.

Parameters
ctxSocket to set
Returns
0 if successful, or a non-zero error code
void mbedtls_net_usleep ( unsigned long  usec)

Portable usleep helper.

Parameters
usecAmount of microseconds to sleep
Note
Real amount of time slept will not be less than select()'s timeout granularity (typically, 10ms).