hdlc.c File Reference

#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include <stdio.h>
#include "spandsp/telephony.h"
#include "spandsp/async.h"
#include "spandsp/crc.h"
#include "spandsp/bit_operations.h"
#include "spandsp/hdlc.h"
#include "spandsp/private/hdlc.h"

Functions

void hdlc_rx_put_bit (hdlc_rx_state_t *s, int new_bit)
void hdlc_rx_put_byte (hdlc_rx_state_t *s, int new_byte)
void hdlc_rx_put (hdlc_rx_state_t *s, const uint8_t buf[], int len)
void hdlc_rx_set_max_frame_len (hdlc_rx_state_t *s, size_t max_len)
 Set the maximum frame length for an HDLC receiver context.
void hdlc_rx_set_octet_counting_report_interval (hdlc_rx_state_t *s, int interval)
 Set the octet counting report interval.
hdlc_rx_state_thdlc_rx_init (hdlc_rx_state_t *s, int crc32, int report_bad_frames, int framing_ok_threshold, hdlc_frame_handler_t handler, void *user_data)
 Initialise an HDLC receiver context.
void hdlc_rx_set_frame_handler (hdlc_rx_state_t *s, hdlc_frame_handler_t handler, void *user_data)
 Change the put_bit function associated with an HDLC receiver context.
void hdlc_rx_set_status_handler (hdlc_rx_state_t *s, modem_rx_status_func_t handler, void *user_data)
 Change the status report function associated with an HDLC receiver context.
int hdlc_rx_release (hdlc_rx_state_t *s)
 Release an HDLC receiver context.
int hdlc_rx_free (hdlc_rx_state_t *s)
 Free an HDLC receiver context.
int hdlc_rx_get_stats (hdlc_rx_state_t *s, hdlc_rx_stats_t *t)
 Get the current receive statistics.
int hdlc_tx_frame (hdlc_tx_state_t *s, const uint8_t *frame, size_t len)
 Transmit a frame.
int hdlc_tx_flags (hdlc_tx_state_t *s, int len)
 Transmit a specified quantity of flag octets, typically as a preamble.
int hdlc_tx_abort (hdlc_tx_state_t *s)
 Send an abort.
int hdlc_tx_corrupt_frame (hdlc_tx_state_t *s)
 Corrupt the frame currently being transmitted, by giving it the wrong CRC.
int hdlc_tx_get_byte (hdlc_tx_state_t *s)
int hdlc_tx_get_bit (hdlc_tx_state_t *s)
int hdlc_tx_get (hdlc_tx_state_t *s, uint8_t buf[], size_t max_len)
void hdlc_tx_set_max_frame_len (hdlc_tx_state_t *s, size_t max_len)
 Set the maximum frame length for an HDLC transmitter context.
hdlc_tx_state_thdlc_tx_init (hdlc_tx_state_t *s, int crc32, int inter_frame_flags, int progressive, hdlc_underflow_handler_t handler, void *user_data)
 Initialise an HDLC transmitter context.
int hdlc_tx_release (hdlc_tx_state_t *s)
int hdlc_tx_free (hdlc_tx_state_t *s)

Detailed Description


Function Documentation

int hdlc_rx_free ( hdlc_rx_state_t s  ) 

Free an HDLC receiver context.

Free an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
Returns:
0 for OK

int hdlc_rx_get_stats ( hdlc_rx_state_t s,
hdlc_rx_stats_t t 
)

Get the current receive statistics.

Parameters:
s A pointer to an HDLC receiver context.
t A pointer to the buffer for the statistics.
Returns:
0 for OK, else -1.

hdlc_rx_state_t* hdlc_rx_init ( hdlc_rx_state_t s,
int  crc32,
int  report_bad_frames,
int  framing_ok_threshold,
hdlc_frame_handler_t  handler,
void *  user_data 
)

Initialise an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
crc32 TRUE to use ITU CRC32. FALSE to use ITU CRC16.
report_bad_frames TRUE to request the reporting of bad frames.
framing_ok_threshold The number of back-to-back flags needed to start the framing OK condition. This may be used where a series of flag octets is used as a preamble, such as in the T.30 protocol.
handler The function to be called when a good HDLC frame is received.
user_data An opaque parameter for the callback routine.
Returns:
A pointer to the HDLC receiver context.

int hdlc_rx_release ( hdlc_rx_state_t s  ) 

Release an HDLC receiver context.

Release an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
Returns:
0 for OK

void hdlc_rx_set_frame_handler ( hdlc_rx_state_t s,
hdlc_frame_handler_t  handler,
void *  user_data 
)

Change the put_bit function associated with an HDLC receiver context.

Change the put_bit function associated with an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
handler The function to be called when a good HDLC frame is received.
user_data An opaque parameter for the callback routine.

void hdlc_rx_set_max_frame_len ( hdlc_rx_state_t s,
size_t  max_len 
)

Set the maximum frame length for an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
max_len The maximum permitted length of a frame.

void hdlc_rx_set_octet_counting_report_interval ( hdlc_rx_state_t s,
int  interval 
)

Set the octet counting report interval.

Parameters:
s A pointer to an HDLC receiver context.
interval The interval, in octets.

void hdlc_rx_set_status_handler ( hdlc_rx_state_t s,
modem_rx_status_func_t  handler,
void *  user_data 
)

Change the status report function associated with an HDLC receiver context.

Change the status report function associated with an HDLC receiver context.

Parameters:
s A pointer to an HDLC receiver context.
handler The callback routine used to report status changes.
user_data An opaque parameter for the callback routine.

int hdlc_tx_abort ( hdlc_tx_state_t s  ) 

Send an abort.

Parameters:
s A pointer to an HDLC transmitter context.
Returns:
0 if the frame was aborted, else -1.

int hdlc_tx_corrupt_frame ( hdlc_tx_state_t s  ) 

Corrupt the frame currently being transmitted, by giving it the wrong CRC.

Parameters:
s A pointer to an HDLC transmitter context.
Returns:
0 if the frame was corrupted, else -1.

int hdlc_tx_flags ( hdlc_tx_state_t s,
int  len 
)

Transmit a specified quantity of flag octets, typically as a preamble.

Parameters:
s A pointer to an HDLC transmitter context.
len The length of the required period of flags, in flag octets. If len is zero this requests that HDLC transmission be terminated when the buffers have fully drained.
Returns:
0 if the flags were accepted for transmission, else -1.

int hdlc_tx_frame ( hdlc_tx_state_t s,
const uint8_t *  frame,
size_t  len 
)

Transmit a frame.

Parameters:
s A pointer to an HDLC transmitter context.
frame A pointer to the frame to be transmitted.
len The length of the frame to be transmitted.
Returns:
0 if the frame was accepted for transmission, else -1.

hdlc_tx_state_t* hdlc_tx_init ( hdlc_tx_state_t s,
int  crc32,
int  inter_frame_flags,
int  progressive,
hdlc_underflow_handler_t  handler,
void *  user_data 
)

Initialise an HDLC transmitter context.

Parameters:
s A pointer to an HDLC transmitter context.
crc32 TRUE to use ITU CRC32. FALSE to use ITU CRC16.
inter_frame_flags The minimum flag octets to insert between frames (usually one).
progressive TRUE if frame creation works in progressive mode.
handler The callback function called when the HDLC transmitter underflows.
user_data An opaque parameter for the callback routine.
Returns:
A pointer to the HDLC transmitter context.

void hdlc_tx_set_max_frame_len ( hdlc_tx_state_t s,
size_t  max_len 
)

Set the maximum frame length for an HDLC transmitter context.

Parameters:
s A pointer to an HDLC transmitter context.
max_len The maximum length.


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