btstack/example/embedded/panu_demo.c

/* -*- Mode: C; indent-tabs-mode: nil; c-basic-offset: 4; tab-width: 4 -*-  */
/*
 * panu_demo.c
 * Copyright (C) 2014 Ole Reinhardt <ole.reinhardt@kernelconcepts.de>
 *
 */

#include "btstack-config.h"

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <linux/in.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#include <net/if_arp.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>


#include <btstack/hci_cmds.h>
#include <btstack/run_loop.h>
#include <btstack/sdp_util.h>

#include "hci.h"
#include "btstack_memory.h"
#include "hci_dump.h"
#include "l2cap.h"
#include "sdp_parser.h"
#include "sdp_client.h"
#include "sdp_query_util.h"
#include "pan.h"

static int record_id = -1;
static uint16_t bnep_protocol_id    = 0x000f;
static uint16_t bnep_l2cap_psm      = 0;
static uint32_t bnep_remote_uuid    = 0;
static uint16_t bnep_version        = 0;
static uint16_t bnep_cid            = 0;

static uint8_t   attribute_value[1000];
static const unsigned int attribute_value_buffer_size = sizeof(attribute_value);

//static bd_addr_t remote = {0x04,0x0C,0xCE,0xE4,0x85,0xD3};
static bd_addr_t remote = {0xE0,0x06,0xE6,0xBB,0x95,0x79};

static int  tap_fd = -1;
static char tap_dev_name[16] = "bnep%d";
static uint8_t network_buffer[BNEP_MTU_MIN];
static size_t  network_buffer_len = 0;

static data_source_t tap_dev_ds;
/*************** TUN / TAP interface routines *********************
 *                                                                * 
 * https://www.kernel.org/doc/Documentation/networking/tuntap.txt *
 *                                                                *
 ******************************************************************/

int tap_alloc(char *dev, bd_addr_t bd_addr)
{
    struct ifreq ifr;
    int fd_dev;
    int fd_socket;
    int err;

    if( (fd_dev = open("/dev/net/tun", O_RDWR)) < 0 ) {
        fprintf(stderr, "TAP: Error opening /dev/net/tun: %s\n", strerror(errno));
        return -1;
    }

    memset(&ifr, 0, sizeof(ifr));

    /* Flags: IFF_TUN   - TUN device (no Ethernet headers) 
     *        IFF_TAP   - TAP device  
     *
     *        IFF_NO_PI - Do not provide packet information  
     */ 
    ifr.ifr_flags = IFF_TAP | IFF_NO_PI; 
    if( *dev ) {
        strncpy(ifr.ifr_name, dev, IFNAMSIZ);
    }

    if( (err = ioctl(fd_dev, TUNSETIFF, (void *) &ifr)) < 0 ) {
        fprintf(stderr, "TAP: Error setting device name: %s\n", strerror(errno));
        close(fd_dev);
        return -1;
    }  
    strcpy(dev, ifr.ifr_name);

    fd_socket = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
	if (fd_socket < 0) {
        close(fd_dev);
		fprintf(stderr, "TAP: Error opening netlink socket: %s\n", strerror(errno));
		return -1;
	}

    /* Configure the MAC address of the newly created bnep(x) device to the local bd_address */
    memset (&ifr, 0, sizeof(struct ifreq));
    strcpy(ifr.ifr_name, dev);
    memcpy(ifr.ifr_hwaddr.sa_data, bd_addr, sizeof(bd_addr_t));
    ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;

	if (ioctl(fd_socket, SIOCSIFHWADDR, &ifr) == -1) {
        close(fd_dev);
        close(fd_socket);
        fprintf(stderr, "TAP: Error setting hw addr: %s\n", strerror(errno));
        exit(1);
		return -1;
	}

    /* Bring the interface up */
	if (ioctl(fd_socket, SIOCGIFFLAGS, &ifr) == -1) {
        close(fd_dev);
        close(fd_socket);
		fprintf(stderr, "TAP: Error reading interface flags: %s\n", strerror(errno));
		return -1;
	}

	if ((ifr.ifr_flags & IFF_UP) == 0) {
		ifr.ifr_flags |= IFF_UP;

		if (ioctl(fd_socket, SIOCSIFFLAGS, &ifr) == -1) {
            close(fd_dev);
            close(fd_socket);
            fprintf(stderr, "TAP: Error set IFF_UP: %s\n", strerror(errno));
            return -1;
		}
	}

	close(fd_socket);
    
    return fd_dev;
}

int process_tap_dev_data(struct data_source *ds) 
{
    ssize_t len;
    len = read(ds->fd, network_buffer, sizeof(network_buffer));
    if (len > 0) {
        network_buffer_len = len;
    } else {
        fprintf(stderr, "TAP: Error while reading: %s\n", strerror(errno));
    }

    if (bnep_can_send_packet_now(bnep_cid)) {
        bnep_send(bnep_cid, network_buffer, network_buffer_len);
        network_buffer_len = 0;
    } else {
        /* park the current network packet */
        run_loop_remove_data_source(&tap_dev_ds);
    }
    
    return 0;
}

/*************** PANU client routines *********************/

char * get_string_from_data_element(uint8_t * element){
    de_size_t de_size = de_get_size_type(element);
    int pos     = de_get_header_size(element);
    int len = 0;
    switch (de_size){
        case DE_SIZE_VAR_8:
            len = element[1];
            break;
        case DE_SIZE_VAR_16:
            len = READ_NET_16(element, 1);
            break;
        default:
            break;
    }
    char * str = (char*)malloc(len+1);
    memcpy(str, &element[pos], len);
    str[len] ='\0';
    return str; 
}


/* SDP parser callback */
static void handle_sdp_client_query_result(sdp_query_event_t *event)
{
    sdp_query_attribute_value_event_t *value_event;
    sdp_query_complete_event_t        *complete_event;
    des_iterator_t des_list_it;
    des_iterator_t prot_it;
    char *str;

    switch (event->type){
        case SDP_QUERY_ATTRIBUTE_VALUE:
            value_event = (sdp_query_attribute_value_event_t*) event;
            
            /* Handle new SDP record */
            if (value_event->record_id != record_id) {
                record_id = value_event->record_id;
                printf("SDP Record: Nr: %d\n", record_id);
            }

            if (value_event->attribute_length <= attribute_value_buffer_size) {
                attribute_value[value_event->data_offset] = value_event->data;
                
                if ((uint16_t)(value_event->data_offset+1) == value_event->attribute_length) {

                    switch(value_event->attribute_id) {
                        case SDP_ServiceClassIDList:
                            if (de_get_element_type(attribute_value) != DE_DES) break;
                            for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {
                                uint8_t * element = des_iterator_get_element(&des_list_it);
                                if (de_get_element_type(element) != DE_UUID) continue;
                                uint32_t uuid = de_get_uuid32(element);
                                switch (uuid){
                                    case BNEP_UUID_PANU:
                                    case BNEP_UUID_NAP:
                                    case BNEP_UUID_GN:
                                        printf("SDP Attribute 0x%04x: BNEP PAN protocol UUID: %04x\n", value_event->attribute_id, uuid);
                                        bnep_remote_uuid = uuid;
                                        break;
                                    default:
                                        break;
                                }
                            }
                            break;
                        case 0x0100:
                        case 0x0101:
                            str = get_string_from_data_element(attribute_value);
                            printf("SDP Attribute: 0x%04x: %s\n", value_event->attribute_id, str);
                            free(str);
                            break;
                        case 0x0004: {
                                printf("SDP Attribute: 0x%04x\n", value_event->attribute_id);

                                for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) {                                    
                                    uint8_t       *des_element;
                                    uint8_t       *element;
                                    uint32_t       uuid;

                                    if (des_iterator_get_type(&des_list_it) != DE_DES) continue;

                                    des_element = des_iterator_get_element(&des_list_it);
                                    des_iterator_init(&prot_it, des_element);
                                    element = des_iterator_get_element(&prot_it);
                                    
                                    if (de_get_element_type(element) != DE_UUID) continue;
                                    
                                    uuid = de_get_uuid32(element);
                                    switch (uuid){
                                        case 0x0100:
                                            if (!des_iterator_has_more(&prot_it)) continue;
                                            des_iterator_next(&prot_it);
                                            de_element_get_uint16(des_iterator_get_element(&prot_it), &bnep_l2cap_psm);
                                            break;
                                        case 0x000f:
                                            if (!des_iterator_has_more(&prot_it)) continue;
                                            des_iterator_next(&prot_it);
                                            de_element_get_uint16(des_iterator_get_element(&prot_it), &bnep_version);
                                            break;
                                        default:
                                            break;
                                    }
                                }
                                printf("l2cap_psm 0x%04x, bnep_version 0x%04x\n", bnep_l2cap_psm, bnep_version);

                                /* Create BNEP connection */
                                bnep_connect(NULL, &remote, bnep_l2cap_psm, bnep_remote_uuid);
                            }
                            break;
                        default:
                            break;
                    }
                }
            } else {
                fprintf(stderr, "SDP attribute value buffer size exceeded: available %d, required %d\n", attribute_value_buffer_size, value_event->attribute_length);
            }
            break;
            
        case SDP_QUERY_COMPLETE:
            complete_event = (sdp_query_complete_event_t*) event;
            fprintf(stderr, "General query done with status %d.\n", complete_event->status);

            break;
    }
}

static void packet_handler (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)
{
    int       rc;
    uint8_t   event;
    bd_addr_t event_addr;
    uint16_t  uuid_source;
    uint16_t  uuid_dest;
    uint16_t  mtu;    
  
    switch (packet_type) {
		case HCI_EVENT_PACKET:
            event = packet[0];
            switch (event) {            
                case BTSTACK_EVENT_STATE:
                    /* BT Stack activated, get started */ 
                    if (packet[2] == HCI_STATE_WORKING) {
                        /* Send a general query for BNEP Protocol ID */
                        printf("Start SDP BNEP query.\n");
                        sdp_general_query_for_uuid(remote, bnep_protocol_id);
                    }
                    break;

                case HCI_EVENT_COMMAND_COMPLETE:
					if (COMMAND_COMPLETE_EVENT(packet, hci_read_bd_addr)){
                        bt_flip_addr(event_addr, &packet[6]);
                        printf("BD-ADDR: %s\n", bd_addr_to_str(event_addr));
                        break;
                    }
                    break;

                case HCI_EVENT_PIN_CODE_REQUEST:
					// inform about pin code request
                    printf("Pin code request - using '0000'\n");
                    bt_flip_addr(event_addr, &packet[2]);
					hci_send_cmd(&hci_pin_code_request_reply, &event_addr, 4, "0000");
					break;

                case HCI_EVENT_USER_CONFIRMATION_REQUEST:
                    // inform about user confirmation request
                    printf("SSP User Confirmation Request with numeric value '%06u'\n", READ_BT_32(packet, 8));
                    printf("SSP User Confirmation Auto accept\n");
                    break;

                case BNEP_EVENT_INCOMING_CONNECTION:
					// data: event(8), len(8), bnep source uuid (16), bnep destination uuid (16), remote_address (48)
                    uuid_source = READ_BT_16(packet, 2);
                    uuid_dest   = READ_BT_16(packet, 4);
                    mtu         = READ_BT_16(packet, 6);
                    bnep_cid    = channel;
                    memcpy(&event_addr, &packet[8], sizeof(bd_addr_t));
					printf("BNEP connection from %s source UUID 0x%04x dest UUID: 0x%04x, max frame size: %u\n", bd_addr_to_str(event_addr), uuid_source, uuid_dest, mtu);
                    /* Create the tap interface */
                    tap_fd = tap_alloc(tap_dev_name, *hci_local_bd_addr());
                    if (tap_fd < 0) {
                        printf("Creating BNEP tap device failed: %s\n", strerror(errno));
                    } else {
                        printf("BNEP device \"%s\" allocated.\n", tap_dev_name);
                        /* Create and register a new runloop data source */
                        tap_dev_ds.fd = tap_fd;
                        tap_dev_ds.process = process_tap_dev_data;
                        run_loop_add_data_source(&tap_dev_ds);
                    }
					break;
					
				case BNEP_EVENT_OPEN_CHANNEL_COMPLETE:
                    if (packet[2]) {
                        printf("BNEP channel open failed, status %02x\n", packet[2]);
                    } else {
                        // data: event(8), len(8), status (8), bnep source uuid (16), bnep destination uuid (16), remote_address (48)
                        uuid_source = READ_BT_16(packet, 3);
                        uuid_dest   = READ_BT_16(packet, 5);
                        mtu         = READ_BT_16(packet, 7);
                        bnep_cid    = channel;
                        //bt_flip_addr(event_addr, &packet[9]); 
                        memcpy(&event_addr, &packet[9], sizeof(bd_addr_t));
                        printf("BNEP connection open succeeded to %s source UUID 0x%04x dest UUID: 0x%04x, max frame size %u\n", bd_addr_to_str(event_addr), uuid_source, uuid_dest, mtu);
                        /* Create the tap interface */
                        tap_fd = tap_alloc(tap_dev_name, *hci_local_bd_addr());
                        if (tap_fd < 0) {
                            printf("Creating BNEP tap device failed: %s\n", strerror(errno));
                        } else {
                            printf("BNEP device \"%s\" allocated.\n", tap_dev_name);
                            /* Create and register a new runloop data source */
                            tap_dev_ds.fd = tap_fd;
                            tap_dev_ds.process = process_tap_dev_data;
                            run_loop_add_data_source(&tap_dev_ds);
                        }
                    }
					break;
                    
                case BNEP_EVENT_CHANNEL_TIMEOUT:
                    printf("BNEP channel timeout! Channel will be closed\n");
                    break;
                    
                case BNEP_EVENT_CHANNEL_CLOSED:
                    printf("BNEP channel closed\n");
                    run_loop_remove_data_source(&tap_dev_ds);
                    if (tap_fd > 0) {
                        close(tap_fd);
                        tap_fd = -1;
                    }
                    break;

                case BNEP_EVENT_READY_TO_SEND:
                    /* Check for parked network packets and send it out now */
                    if (network_buffer_len > 0) {
                        bnep_send(bnep_cid, network_buffer, network_buffer_len);
                        network_buffer_len = 0;
                        /* Re-add the tap device data source */
                        run_loop_add_data_source(&tap_dev_ds);
                    }
                    
                    break;
                    
                default:
                    break;
            }
            break;
        case BNEP_DATA_PACKET:
            /* Write out the ethernet frame to the tap device */
            if (tap_fd > 0) {
                rc = write(tap_fd, packet, size);
                if (rc < 0) {
                    fprintf(stderr, "TAP: Could not write to TAP device: %s\n", strerror(errno));
                } else 
                if (rc != size) {
                    fprintf(stderr, "TAP: Package written only partially %d of %d bytes\n", rc, size);
                }
            }
            break;            
            
        default:
            break;
    }
}

int btstack_main(int argc, const char * argv[]);
int btstack_main(int argc, const char * argv[]){

    printf("Client HCI init done\n");
    
    /* Initialize L2CAP */
    l2cap_init();
    l2cap_register_packet_handler(packet_handler);

    /* Initialise BNEP */
    bnep_init();
    bnep_register_packet_handler(packet_handler);
    bnep_register_service(NULL, BNEP_UUID_PANU, 1691);  /* Minimum L2CAP MTU for bnep is 1691 bytes */

    /* Turn on the device */
    hci_power_control(HCI_POWER_ON);

    /* Initialise SDP */
    sdp_parser_init();
    sdp_parser_register_callback(handle_sdp_client_query_result);

    /* Start mainloop */
    run_loop_execute(); 
    return 0;
}