mbed TLS v2.16.0: net_sockets.h File Reference

mbed TLS v2.16.0

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 "config.h"`
`#include "ssl.h"`
`#include <stddef.h>`
`#include <stdint.h>`
Include dependency graph for net_sockets.h:
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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_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

Definition in file net_sockets.h.

## Macro Definition Documentation

## ◆ MBEDTLS_ERR_NET_ACCEPT_FAILED

#define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A

Could not accept the incoming connection.

Definition at line 58 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_BAD_INPUT_DATA

#define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049

Input invalid.

Definition at line 66 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_BIND_FAILED

#define MBEDTLS_ERR_NET_BIND_FAILED -0x0046

Binding of the socket failed.

Definition at line 56 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_BUFFER_TOO_SMALL

#define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043

Buffer is too small to hold the data.

Definition at line 63 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_CONN_RESET

#define MBEDTLS_ERR_NET_CONN_RESET -0x0050

Connection was reset by peer.

Definition at line 61 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_CONNECT_FAILED

#define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044

The connection to the given server / port failed.

Definition at line 55 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_INVALID_CONTEXT

#define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045

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

Definition at line 64 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_LISTEN_FAILED

#define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048

Could not listen on the socket.

Definition at line 57 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_POLL_FAILED

#define MBEDTLS_ERR_NET_POLL_FAILED -0x0047

Polling the net context failed.

Definition at line 65 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_RECV_FAILED

#define MBEDTLS_ERR_NET_RECV_FAILED -0x004C

Reading information from the socket failed.

Definition at line 59 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_SEND_FAILED

#define MBEDTLS_ERR_NET_SEND_FAILED -0x004E

Sending information through the socket failed.

Definition at line 60 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_SOCKET_FAILED

#define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042

Failed to open a socket.

Definition at line 54 of file net_sockets.h.

## ◆ MBEDTLS_ERR_NET_UNKNOWN_HOST

#define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052

Failed to get an IP address for the given hostname.

Definition at line 62 of file net_sockets.h.

## ◆ MBEDTLS_NET_LISTEN_BACKLOG

#define MBEDTLS_NET_LISTEN_BACKLOG 10

The backlog that listen() should use.

Definition at line 68 of file net_sockets.h.

## ◆ MBEDTLS_NET_POLL_READ

#define MBEDTLS_NET_POLL_READ 1

Used in `mbedtls_net_poll` to check for pending data

Definition at line 73 of file net_sockets.h.

## ◆ MBEDTLS_NET_POLL_WRITE

#define MBEDTLS_NET_POLL_WRITE 2

Used in `mbedtls_net_poll` to check if write possible

Definition at line 74 of file net_sockets.h.

## ◆ MBEDTLS_NET_PROTO_TCP

#define MBEDTLS_NET_PROTO_TCP 0

The TCP transport protocol

Definition at line 70 of file net_sockets.h.

## ◆ MBEDTLS_NET_PROTO_UDP

#define MBEDTLS_NET_PROTO_UDP 1

The UDP transport protocol

Definition at line 71 of file net_sockets.h.

## 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).