btstack/src/hci_transport_h4.c

/*
 * Copyright (C) 2009 by Matthias Ringwald
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

/*
 *  hci_h4_transport.c
 *
 *  HCI Transport API implementation for basic H4 protocol
 *
 *  Created by Matthias Ringwald on 4/29/09.
 */
#include <termios.h>  /* POSIX terminal control definitions */
#include <fcntl.h>    /* File control definitions */
#include <unistd.h>   /* UNIX standard function definitions */
#include <stdio.h>
#include <string.h>

#include "hci.h"
#include "hci_transport.h"
#include "hci_dump.h"

typedef enum {
    H4_W4_PACKET_TYPE,
    H4_W4_EVENT_HEADER,
    H4_W4_EVENT_PAYLOAD,
    H4_W4_ACL_HEADER,
    H4_W4_ACL_PAYLOAD
} H4_STATE;

typedef struct hci_transport_h4 {
    hci_transport_t transport;
    data_source_t *ds;
} hci_transport_h4_t;

// single instance
static hci_transport_h4_t * hci_transport_h4 = NULL;

static int  h4_process(struct data_source *ds);
static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 
static      hci_uart_config_t *hci_uart_config;

static  void (*packet_handler)(uint8_t packet_type, uint8_t *packet, uint16_t size) = dummy_handler;

// packet reader state machine
static  H4_STATE h4_state;
static int bytes_to_read;
static int read_pos;
// static uint8_t hci_event_buffer[255+2]; // maximal payload + 2 bytes header
static uint8_t hci_packet[HCI_ACL_3DH5_SIZE]; // bigger than largest packet

#ifdef TEST_LONG_INVALID_REMOTE_NAME
// test event with remote name of 255 bytes length
const uint8_t remoteNameEvent[] = { 0x07, 0xFF, 0x00, 0xC4, 0xC6, 0x65, 0x5A, 0x12, 0x00, 0x4D, 0x69,
      0x63, 0x72, 0x6F, 0x73, 0x6F, 0x66, 0x74, 0xAE, 0x20, 0x57, 0x69, 0x72, 0x65, 0x6C, 0x65,
      0x73, 0x73, 0x20, 0x4E, 0x6F, 0x74, 0x65, 0x62, 0x6F, 0x6F, 0x6B, 0x20, 0x50, 0x72, 0x65,
      0x73, 0x65, 0x6E, 0x74, 0x65, 0x72, 0x20, 0x4D, 0x6F, 0x75, 0x73, 0x65, 0x20, 0x38, 0x30,
      0x30, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
const int remoteNameEventSize = sizeof(remoteNameEvent);
#endif


// prototypes
static int    h4_open(void *transport_config){
    hci_uart_config = (hci_uart_config_t*) transport_config;
    struct termios toptions;
    int fd = open(hci_uart_config->device_name, O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1)  {
        perror("init_serialport: Unable to open port ");
        perror(hci_uart_config->device_name);
        return -1;
    }
    
    if (tcgetattr(fd, &toptions) < 0) {
        perror("init_serialport: Couldn't get term attributes");
        return -1;
    }
    speed_t brate = hci_uart_config->baudrate; // let you override switch below if needed
    switch(hci_uart_config->baudrate) {
        case 57600:  brate=B57600;  break;
        case 115200: brate=B115200; break;
#ifdef B230400
        case 230400: brate=B230400; break;
#endif
#ifdef B460800
        case 460800: brate=B460800; break;
#endif
#ifdef B921600
        case 921600: brate=B921600; break;
#endif
    }
    cfsetispeed(&toptions, brate);
    cfsetospeed(&toptions, brate);
    
    // 8N1
    toptions.c_cflag &= ~PARENB;
    toptions.c_cflag &= ~CSTOPB;
    toptions.c_cflag &= ~CSIZE;
    toptions.c_cflag |= CS8;

    if (hci_uart_config->flowcontrol) {
        // with flow control
        toptions.c_cflag |= CRTSCTS;
    } else {
        // no flow control
        toptions.c_cflag &= ~CRTSCTS;
    }
    
    toptions.c_cflag |= CREAD | CLOCAL;  // turn on READ & ignore ctrl lines
    toptions.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
    
    toptions.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
    toptions.c_oflag &= ~OPOST; // make raw
    
    // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
    toptions.c_cc[VMIN]  = 1;
    toptions.c_cc[VTIME] = 0;
    
    if( tcsetattr(fd, TCSANOW, &toptions) < 0) {
        perror("init_serialport: Couldn't set term attributes");
        return -1;
    }
    
    // set up data_source
    hci_transport_h4->ds = malloc(sizeof(data_source_t));
    if (!hci_transport_h4) return -1;
    hci_transport_h4->ds->fd = fd;
    hci_transport_h4->ds->process = h4_process;
    run_loop_add_data_source(hci_transport_h4->ds);
    
    // init state machine
    bytes_to_read = 1;
    h4_state = H4_W4_PACKET_TYPE;
    read_pos = 0;

    return 0;
}

static int    h4_close(){
    // first remove run loop handler
	run_loop_remove_data_source(hci_transport_h4->ds);
    
    // close device 
    close(hci_transport_h4->ds->fd);
    free(hci_transport_h4->ds);
    
    // free struct
    hci_transport_h4->ds = NULL;
    return 0;
}

static int h4_send_packet(uint8_t packet_type, uint8_t * packet, int size){
    if (hci_transport_h4->ds == NULL) return -1;
    if (hci_transport_h4->ds->fd == 0) return -1;
    hci_dump_packet( (uint8_t) packet_type, 0, packet, size);
    write(hci_transport_h4->ds->fd, &packet_type, 1);
    char *data = (char*) packet;
    while (size > 0) {
        int bytes_written = write(hci_transport_h4->ds->fd, data, size);
        if (bytes_written < 0) {
            return bytes_written;
        }
        data += bytes_written;
        size -= bytes_written;
    }
    return 0;
}

static void   h4_register_packet_handler(void (*handler)(uint8_t packet_type, uint8_t *packet, uint16_t size)){
    packet_handler = handler;
}

static int    h4_process(struct data_source *ds) {
    if (hci_transport_h4->ds->fd == 0) return -1;

    // read up to bytes_to_read data in
    int bytes_read = read(hci_transport_h4->ds->fd, &hci_packet[read_pos], bytes_to_read);
    if (bytes_read < 0) {
        return bytes_read;
    }
    bytes_to_read -= bytes_read;
    read_pos      += bytes_read;
    if (bytes_to_read > 0) {
        return 0;
    }
    
    // act
    switch (h4_state) {
            
        case H4_W4_PACKET_TYPE:
            if (hci_packet[0] == HCI_EVENT_PACKET){
                read_pos = 0;
                bytes_to_read = HCI_EVENT_PKT_HDR;
                h4_state = H4_W4_EVENT_HEADER;
            } else if (hci_packet[0] == HCI_ACL_DATA_PACKET){
                read_pos = 0;
                bytes_to_read = HCI_ACL_DATA_PKT_HDR;
                h4_state = H4_W4_ACL_HEADER;
            } else {
                fprintf(stderr, "h4_process: invalid packet type 0x%02x\n", hci_packet[0]);
                read_pos = 0;
                bytes_to_read = 1;
            }
            break;
            
        case H4_W4_EVENT_HEADER:
            bytes_to_read = hci_packet[1];
            h4_state = H4_W4_EVENT_PAYLOAD;
            break;
            
        case H4_W4_EVENT_PAYLOAD:
            
#ifdef TEST_LONG_INVALID_REMOTE_NAME
            if (hci_packet[0] == HCI_EVENT_REMOTE_NAME_REQUEST_COMPLETE){
                hci_packet[1] = remoteNameEvent[1];
                memcpy( &hci_packet[9], &remoteNameEvent[9], remoteNameEventSize);
                read_pos = remoteNameEventSize;
            }
#endif            
			hci_dump_packet( HCI_EVENT_PACKET, 1, hci_packet, read_pos);
            packet_handler(HCI_EVENT_PACKET, hci_packet, read_pos);
            h4_state = H4_W4_PACKET_TYPE;
            read_pos = 0;
            bytes_to_read = 1;
            break;
            
        case H4_W4_ACL_HEADER:
            bytes_to_read = READ_BT_16( hci_packet, 2);
            h4_state = H4_W4_ACL_PAYLOAD;
            break;
            
        case H4_W4_ACL_PAYLOAD:
            hci_dump_packet( HCI_ACL_DATA_PACKET, 1, hci_packet, read_pos);
            packet_handler(HCI_ACL_DATA_PACKET, hci_packet, read_pos);
            h4_state = H4_W4_PACKET_TYPE;
            read_pos = 0;
            bytes_to_read = 1;
            break;
    }
    return 0;
}

static const char * h4_get_transport_name(){
    return "H4";
}

static void dummy_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){
}

// get h4 singleton
hci_transport_t * hci_transport_h4_instance() {
    if (hci_transport_h4 == NULL) {
        hci_transport_h4 = malloc( sizeof(hci_transport_h4_t));
        hci_transport_h4->ds                                      = NULL;
        hci_transport_h4->transport.open                          = h4_open;
        hci_transport_h4->transport.close                         = h4_close;
        hci_transport_h4->transport.send_packet                   = h4_send_packet;
        hci_transport_h4->transport.register_packet_handler       = h4_register_packet_handler;
        hci_transport_h4->transport.get_transport_name            = h4_get_transport_name;
    }
    return (hci_transport_t *) hci_transport_h4;
}