Bluetooth Server

l2cap-server.c

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/l2cap.h>
#include <bluetooth/sdp.h>
#include <bluetooth/sdp_lib.h>

sdp_session_t *register_service();

int main(int argc, char **argv)
{
    register_service();
    struct sockaddr_l2 loc_addr = { 0 }, rem_addr = { 0 };
    char buf[1024] = { 0 };
    int s, client, bytes_read;
    socklen_t opt = sizeof(rem_addr);

    // allocate socket
    s = socket(AF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);

    // bind socket to port 0x1001 of the first available 
    // bluetooth adapter
    loc_addr.l2_family = AF_BLUETOOTH;
    loc_addr.l2_bdaddr = *BDADDR_ANY;
    loc_addr.l2_psm = htobs(0x1001);

    bind(s, (struct sockaddr *)&loc_addr, sizeof(loc_addr));

    // put socket into listening mode
    listen(s, 1);

    // accept one connection
    client = accept(s, (struct sockaddr *)&rem_addr, &opt);

    ba2str( &rem_addr.l2_bdaddr, buf );
    fprintf(stderr, "accepted connection from %s\n", buf);

    memset(buf, 0, sizeof(buf));

    // read data from the client
    bytes_read = read(client, buf, sizeof(buf));
    if( bytes_read > 0 ) {
        printf("received [%s]\n", buf);
    }

    // close connection
    close(client);
    close(s);
}

sdp_session_t *register_service()
{
    uint32_t service_uuid_int[] = { 0, 0, 0, 0x110B };
    uint8_t rfcomm_channel = 11;
    uint16_t l2cap_psm = 0x1001;
    const char *service_name = "Bluetooth Router";
    const char *service_dsc = "An experimental plumbing router";
    const char *service_prov = "Bitchin Tech Incorporated";

    uuid_t root_uuid, l2cap_uuid, rfcomm_uuid, svc_uuid, svc_class_uuid;

    sdp_list_t *l2cap_list = 0, 
               *rfcomm_list = 0,
               *root_list = 0,
               *proto_list = 0, 
               *access_proto_list = 0,
               *svc_class_list = 0,
               *profile_list = 0;
    sdp_data_t *channel = 0, *psm = 0;

    sdp_record_t *record = sdp_record_alloc();

    sdp_profile_desc_t profile;

    // set the general service ID
    sdp_uuid128_create( &svc_uuid, &service_uuid_int );
    sdp_set_service_id( record, svc_uuid );

    // make the service record publicly browsable
    sdp_uuid16_create(&root_uuid, PUBLIC_BROWSE_GROUP);
    root_list = sdp_list_append( 0, &root_uuid );
    sdp_set_browse_groups( record, root_list );

    // set l2cap information
    sdp_uuid16_create(&l2cap_uuid, L2CAP_UUID);
    psm = sdp_data_alloc(SDP_UINT16, &l2cap_psm);
    l2cap_list = sdp_list_append( 0, &l2cap_uuid );
    sdp_list_append( l2cap_list, psm );
    proto_list = sdp_list_append( 0, l2cap_list );

    // set rfcomm information
    sdp_uuid16_create(&rfcomm_uuid, RFCOMM_UUID);
    channel = sdp_data_alloc(SDP_UINT8, &rfcomm_channel);
    rfcomm_list = sdp_list_append( 0, &rfcomm_uuid );
    sdp_list_append( rfcomm_list, channel );
    sdp_list_append( proto_list, rfcomm_list );

    // attach profile information
    sdp_uuid16_create(&profile.uuid, AUDIO_SINK_PROFILE_ID);
    profile.version = 0x0100;
    profile_list = sdp_list_append(0, &profile);
    sdp_set_profile_descs(record, profile_list);

    // attach service class information
    sdp_uuid16_create(&svc_class_uuid, AUDIO_SINK_SVCLASS_ID);
    svc_class_list = sdp_list_append(0, &svc_class_uuid);
    sdp_set_service_classes(record, svc_class_list);

    // attach protocol information to service record
    access_proto_list = sdp_list_append( 0, proto_list );
    sdp_set_access_protos( record, access_proto_list );

    // set the name, provider, and description
    sdp_set_info_attr(record, service_name, service_prov, service_dsc);
    int err = 0;
    sdp_session_t *session = 0;

    // connect to the local SDP server, register the service record, and 
    // disconnect
    session = sdp_connect( BDADDR_ANY, BDADDR_LOCAL, SDP_RETRY_IF_BUSY );
    err = sdp_record_register(session, record, 0);

    // cleanup
    sdp_data_free( channel );
    sdp_list_free( l2cap_list, 0 );
    sdp_list_free( rfcomm_list, 0 );
    sdp_list_free( root_list, 0 );
    sdp_list_free( access_proto_list, 0 );

    return session;
}