ESP8266 part of the f105-motor-demo project (see f105-motor-demo_stm32)
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f105-motor-demo_esp/sbmp/sbmp_session.c

416 lines
10 KiB

#include "esp8266.h"
#include "sbmp_config.h"
#include "sbmp_logging.h"
#include "sbmp_session.h"
// protos
static void handle_hsk_datagram(SBMP_Endpoint *ep, SBMP_Datagram *dg);
// lsb, msb for uint16_t
#define U16_LSB(x) ((x) & 0xFF)
#define U16_MSB(x) ((x >> 8) & 0xFF)
// length of the payload sent with a handshake packet.
#define HSK_PAYLOAD_LEN 3
// Datagram header length - 2 B sesn, 1 B type
#define DATAGRA_HEADER_LEN 3
/** Rx handler that is assigned to the framing layer */
static void FLASH_FN ep_rx_handler(uint8_t *buf, uint16_t len, void *token)
{
// endpoint pointer is stored in the user token
SBMP_Endpoint *ep = (SBMP_Endpoint *)token;
if (NULL != sbmp_dg_parse(&ep->static_dg, buf, len)) {
// payload parsed OK
// check if handshake datagram, else call user callback.
handle_hsk_datagram(ep, &ep->static_dg);
}
}
/**
* @brief Initialize the endpoint.
*
* @param ep : Endpoint var pointer, or NULL to allocate one.
* @param buffer : Rx buffer. NULL to allocate one.
* @param buffer_size : Rx buffer length
* @return the endpoint struct pointer (allocated if ep was NULL)
*/
SBMP_Endpoint FLASH_FN *sbmp_ep_init(
SBMP_Endpoint *ep,
uint8_t *buffer,
uint16_t buffer_size,
void (*dg_rx_handler)(SBMP_Datagram *dg),
void (*tx_func)(uint8_t byte))
{
if (ep == NULL) {
// request to allocate it
#if SBMP_MALLOC
ep = malloc(sizeof(SBMP_Endpoint));
#else
return NULL; // fail
#endif
}
// set up the framing layer
sbmp_frm_init(&ep->frm, buffer, buffer_size, ep_rx_handler, tx_func);
// set token, so callback knows what EP it's for.
sbmp_frm_set_user_token(&ep->frm, (void *) ep);
ep->rx_handler = dg_rx_handler;
ep->buffer_size = buffer_size; // sent to the peer
#if SBMP_HAS_CRC32
ep->peer_pref_cksum = SBMP_CKSUM_CRC32;
ep->pref_cksum = SBMP_CKSUM_CRC32;
#else
ep->peer_pref_cksum = SBMP_CKSUM_XOR;
ep->pref_cksum = SBMP_CKSUM_XOR;
#endif
// reset state information
sbmp_ep_reset(ep);
return ep;
}
/**
* @brief Reset an endpoint and it's Framing Layer
*
* This discards all state information.
*
* @param ep : Endpoint
*/
void FLASH_FN sbmp_ep_reset(SBMP_Endpoint *ep)
{
ep->next_session = 0;
ep->origin = 0;
// init the handshake status
ep->hsk_session = 0;
ep->hsk_state = SBMP_HSK_NOT_STARTED;
ep->peer_buffer_size = 0xFFFF; // max possible buffer
sbmp_frm_reset(&ep->frm);
}
// --- Customizing settings ---
/** Set session number (good to randomize before first message) */
void FLASH_FN sbmp_ep_seed_session(SBMP_Endpoint *ep, uint16_t sesn)
{
ep->next_session = sesn & 0x7FFF;
}
/** Set the origin bit (bypass handshake) */
void FLASH_FN sbmp_ep_set_origin(SBMP_Endpoint *endp, bool bit)
{
endp->origin = bit;
}
/** Set the preferred checksum. */
void FLASH_FN sbmp_ep_set_preferred_cksum(SBMP_Endpoint *endp, SBMP_CksumType cksum_type)
{
if (cksum_type == SBMP_CKSUM_CRC32 && !SBMP_HAS_CRC32) {
sbmp_error("CRC32 not avail, using XOR instead.");
cksum_type = SBMP_CKSUM_XOR;
}
endp->pref_cksum = cksum_type;
}
/** Enable or disable RX in the FrmInst backing this Endpoint */
void FLASH_FN sbmp_ep_enable_rx(SBMP_Endpoint *ep, bool enable_rx)
{
sbmp_frm_enable_rx(&ep->frm, enable_rx);
}
/** Enable or disable TX in the FrmInst backing this Endpoint */
void FLASH_FN sbmp_ep_enable_tx(SBMP_Endpoint *ep, bool enable_tx)
{
sbmp_frm_enable_tx(&ep->frm, enable_tx);
}
/** Enable or disable Rx & TX in the FrmInst backing this Endpoint */
void FLASH_FN sbmp_ep_enable(SBMP_Endpoint *ep, bool enable)
{
sbmp_frm_enable(&ep->frm, enable);
}
// ---
/** Get a new session number */
static uint16_t FLASH_FN next_session(SBMP_Endpoint *ep)
{
uint16_t sesn = ep->next_session;
if (++ep->next_session == 0x8000) {
// overflow into the origin bit
ep->next_session = 0; // start from zero
}
return sesn | (uint16_t)(ep->origin << 15); // add the origin bit
}
// --- Header/body send funcs ---
/** Start a message as a reply */
bool FLASH_FN sbmp_ep_start_response(SBMP_Endpoint *ep, SBMP_DgType type, uint16_t length, uint16_t sesn)
{
uint16_t peer_accepts = ep->peer_buffer_size - DATAGRA_HEADER_LEN;
if (length > peer_accepts) {
sbmp_error("Msg too long (%d B), peer accepts max %d B.", length, peer_accepts);
return false;
}
return sbmp_dg_start(&ep->frm, ep->peer_pref_cksum, sesn, type, length);
}
/** Start a message in a new session */
bool FLASH_FN sbmp_ep_start_session(SBMP_Endpoint *ep, SBMP_DgType type, uint16_t length, uint16_t *sesn_ptr)
{
uint16_t sn = next_session(ep);
bool suc = sbmp_ep_start_response(ep, type, length, sn);
if (suc) {
if (sesn_ptr != NULL) *sesn_ptr = sn;
}
return suc;
}
/** Send one byte in the current message */
bool FLASH_FN sbmp_ep_send_byte(SBMP_Endpoint *ep, uint8_t byte)
{
return sbmp_frm_send_byte(&ep->frm, byte);
}
/** Send a data buffer (or a part) in the current message */
uint16_t FLASH_FN sbmp_ep_send_buffer(SBMP_Endpoint *ep, const uint8_t *buffer, uint16_t length)
{
return sbmp_frm_send_buffer(&ep->frm, buffer, length);
}
/** Rx, pass to framing layer */
SBMP_RxStatus FLASH_FN sbmp_ep_receive(SBMP_Endpoint *ep, uint8_t byte)
{
return sbmp_frm_receive(&ep->frm, byte);
}
// --- All-in-one send funcs ---
/** Send a message in a session. */
bool FLASH_FN sbmp_ep_send_response(
SBMP_Endpoint *ep,
SBMP_DgType type,
const uint8_t *buffer,
uint16_t length,
uint16_t sesn,
uint16_t *sent_bytes_ptr)
{
bool suc = sbmp_ep_start_response(ep, type, length, sesn);
if (suc) {
uint16_t sent = sbmp_ep_send_buffer(ep, buffer, length);
if (sent_bytes_ptr != NULL) *sent_bytes_ptr = sent;
}
return suc;
}
/** Send message in a new session */
bool FLASH_FN sbmp_ep_send_message(
SBMP_Endpoint *ep,
SBMP_DgType type,
const uint8_t *buffer,
uint16_t length,
uint16_t *sesn_ptr,
uint16_t *sent_bytes_ptr)
{
// This juggling with session nr is because it wouldn't work
// without actual hardware delay otherwise.
uint16_t sn = next_session(ep);;
uint16_t old_sesn = 0;
if (sesn_ptr != NULL) {
old_sesn = *sesn_ptr;
*sesn_ptr = sn;
}
bool suc = sbmp_ep_send_response(ep, type, buffer, length, sn, sent_bytes_ptr);
if (!suc) {
if (sesn_ptr != NULL) {
*sesn_ptr = old_sesn; // restore
}
}
return suc;
}
// --- Handshake ---
/**
* Prepare a buffer to send to peer during handshake
*
* The buffer is long HSK_PAYLOAD_LEN bytes
*/
static void FLASH_FN populate_hsk_buf(SBMP_Endpoint *ep, uint8_t* buf)
{
// [ pref_crc 1B | buf_size 2B ]
buf[0] = ep->pref_cksum;
buf[1] = U16_LSB(ep->buffer_size);
buf[2] = U16_MSB(ep->buffer_size);
}
/** Parse peer info from received handhsake dg payload */
static void FLASH_FN parse_peer_hsk_buf(SBMP_Endpoint *ep, const uint8_t* buf)
{
ep->peer_pref_cksum = buf[0];
ep->peer_buffer_size = (uint16_t)(buf[1] | (buf[2] << 8));
sbmp_info("HSK success, peer buf %d, pref cksum %d",
ep->peer_buffer_size,
ep->peer_pref_cksum);
// check if checksum available
if (ep->peer_pref_cksum == SBMP_CKSUM_CRC32 && !SBMP_HAS_CRC32) {
sbmp_error("CRC32 not avail, using XOR as peer's pref cksum.");
ep->peer_pref_cksum = SBMP_CKSUM_XOR;
}
}
/**
* @brief Start a handshake (origin bit arbitration)
* @param ep : Endpoint state
*/
bool FLASH_FN sbmp_ep_start_handshake(SBMP_Endpoint *ep)
{
if (ep->hsk_state == SBMP_HSK_AWAIT_REPLY) {
// busy now
sbmp_error("Can't start HSK, in progress already.");
return false;
}
ep->hsk_state = 0;
uint8_t buf[HSK_PAYLOAD_LEN];
populate_hsk_buf(ep, buf);
ep->hsk_state = SBMP_HSK_AWAIT_REPLY;
bool suc = sbmp_ep_send_message(ep, SBMP_DG_HSK_START, buf, 3, &ep->hsk_session, NULL);
if (!suc) {
ep->hsk_state = SBMP_HSK_NOT_STARTED;
}
return suc;
}
/** Get hsk state */
SBMP_HandshakeStatus FLASH_FN sbmp_ep_handshake_status(SBMP_Endpoint *ep)
{
return ep->hsk_state;
}
/**
* @brief Process handshake datagrams & update handshake state accordingly.
*
* Non-handshake datagrams are passed on to the user Rx callback.
*
* @param ep : endpoint
* @param dg : datagram
*/
static void FLASH_FN handle_hsk_datagram(SBMP_Endpoint *ep, SBMP_Datagram *dg)
{
bool hsk_start = (dg->type == SBMP_DG_HSK_START);
bool hsk_accept = (dg->type == SBMP_DG_HSK_ACCEPT);
bool hsk_conflict = (dg->type == SBMP_DG_HSK_CONFLICT);
if (hsk_start || hsk_accept || hsk_conflict) {
// prepare payload to send in response
uint8_t our_info_pld[HSK_PAYLOAD_LEN];
populate_hsk_buf(ep, our_info_pld);
//printf("hsk_state = %d, hsk_ses %d, dg_ses %d\n",ep->hsk_state, ep->hsk_session, dg->session);
if (hsk_start) {
// peer requests origin
sbmp_info("Rx HSK request");
if (ep->hsk_state == SBMP_HSK_AWAIT_REPLY) {
// conflict occured - we're already waiting for a reply.
sbmp_ep_send_response(ep, SBMP_DG_HSK_CONFLICT, our_info_pld, HSK_PAYLOAD_LEN, dg->session, NULL);
ep->hsk_state = SBMP_HSK_CONFLICT;
sbmp_error("HSK conflict");
} else {
// we're idle, accept the request.
bool peer_origin = (dg->session & 0x8000) >> 15;
sbmp_ep_set_origin(ep, !peer_origin);
// read peer's info
if (dg->length >= HSK_PAYLOAD_LEN) {
parse_peer_hsk_buf(ep, dg->payload);
}
ep->hsk_state = SBMP_HSK_SUCCESS;
// Send Accept response
sbmp_ep_send_response(ep, SBMP_DG_HSK_ACCEPT, our_info_pld, HSK_PAYLOAD_LEN, dg->session, NULL);
}
} else if (hsk_accept) {
// peer accepted our request
sbmp_info("Rx HSK accept");
if (ep->hsk_state != SBMP_HSK_AWAIT_REPLY || ep->hsk_session != dg->session) {
// but we didn't send any request
sbmp_error("Rx unexpected HSK accept, ignoring.");
} else {
// OK, we were waiting for this reply
// read peer's info
if (dg->length >= HSK_PAYLOAD_LEN) {
parse_peer_hsk_buf(ep, dg->payload);
}
ep->hsk_state = SBMP_HSK_SUCCESS;
}
} else if (hsk_conflict) {
// peer rejected our request due to conflict
sbmp_info("Rx HSK conflict");
if (ep->hsk_state != SBMP_HSK_AWAIT_REPLY || ep->hsk_session != dg->session) {
// but we didn't send any request
sbmp_error("Rx unexpected HSK conflict, ignoring.");
} else {
// Acknowledge the conflict
// reset everything
sbmp_frm_reset(&ep->frm);
ep->hsk_state = SBMP_HSK_CONFLICT;
}
}
} else {
// Not a HSK message
ep->rx_handler(dg);
}
}