[Bluez-devel] BlueZ, testing socket

From: Meenakshi Seeballack <hidden>
Date: 2007-03-31 10:43:28

Hi all,
This code below connects to the server socket and selects the protocol to be
used (L2CAP), opens the socket for that protocol, creates a bluetooth
address object and sets its port to the PSM and binds the socket to this
address, tells the sockets to listen for incoming connections, creates a
blank socket and pass it to the listening socket through accept (When this
call completes the socket passed in a parameter is now fully connected and
can be used to send and receive data)

QUESTION: How do I test this socket works? I want to send a messge like
"Hello World". Please help...anyone

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <malloc.h>
#include <syslog.h>
#include <signal.h>
#include <getopt.h>
#include <sys/poll.h>
#include <sys/ioctl.h>
#include <sys/socket.h>

#include <linux/input.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/l2cap.h>
#include <bluetooth/sdp.h>
#include <bluetooth/hidp.h>

/*
 * l2cap_listen(l2cap_channel)
 *
 * Searches all sockets listening to the L2CAP protocol,
 * Checks for a socket waiting for an incoming connection
 * request.
 * Ensures that there is not already a connection
 * with the source address of the requesting Bluetooth device.
 *
 *    Use this channel as a listening post. This will
 *    result in calls to:
 *
 *        proto->newconn(upper, laddr, raddr)
 *
 *    for incoming connections matching the psm and local
 *    address of the channel
 *
 *    The upper layer should create and return a new channel.
 *
 *    This channel cannot be used for anything else subsequent to this call
 */
static int l2cap_listen(const bdaddr_t *bdaddr, unsigned short psm, int lm,
int backlog)
{
    struct sockaddr_l2 addr;
    struct l2cap_options opts;
    int sk;

    // create socket
    if ((sk = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP)) < 0)
        return -1;

    /* open connection to remote device */
    memset(&addr, 0, sizeof(addr));
    addr.l2_family = AF_BLUETOOTH;
    bacpy(&addr.l2_bdaddr, bdaddr); /* update source address of socket */
    addr.l2_psm = htobs(psm);

    // associate local address with socket
    if (bind(sk, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
        perror("ERROR: Could not bind socket");
        close(sk);
        return -1;
    }

    setsockopt(sk, SOL_L2CAP, L2CAP_LM, &lm, sizeof(lm));

    memset(&opts, 0, sizeof(opts));
    opts.imtu = HIDP_DEFAULT_MTU;
    opts.omtu = HIDP_DEFAULT_MTU;
    opts.flush_to = 0xffff;

    setsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &opts, sizeof(opts));

    if (listen(sk, backlog) < 0) {
        close(sk);
        return -1;
    }

    return sk;
}

/*
 * l2cap_connect_req()
 * Establishes connection with specific socket
 * Request to establish connection from remote
 * communication partner.
 * Such a socket has to have been previously created
 * by an application with the command listen.
 */
static int l2cap_connect(bdaddr_t *src, bdaddr_t *dst, unsigned short psm)
{
    struct sockaddr_l2 addr;
    struct l2cap_options opts;
    int sk;

    // socket allocation
    if ((sk = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP)) < 0)
        perror("ERROR: Could not create socket");
        return -1;

    memset(&addr, 0, sizeof(addr));
    addr.l2_family  = AF_BLUETOOTH;
    bacpy(&addr.l2_bdaddr, src); /*update source address of socket */

    if (bind(sk, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
        close(sk);
        return -1;
    }

    memset(&opts, 0, sizeof(opts));
    opts.imtu = HIDP_DEFAULT_MTU;
    opts.omtu = HIDP_DEFAULT_MTU;
    opts.flush_to = 0xffff;

    setsockopt(sk, SOL_L2CAP, L2CAP_OPTIONS, &opts, sizeof(opts));

    memset(&addr, 0, sizeof(addr));
    addr.l2_family  = AF_BLUETOOTH;
    bacpy(&addr.l2_bdaddr, dst);
    addr.l2_psm = htobs(psm);

    if (connect(sk, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
        close(sk);
        return -1;
    }

    return sk;
}

/*
 * l2cap_accept()
 * Permits incoming connection
 * Function switches from BT_LISTEN to BT_CONNECTED
 */
static int l2cap_accept(int sk, bdaddr_t *bdaddr)
{
    struct sockaddr_l2 addr;
    socklen_t addrlen;
    int nsk;

    memset(&addr, 0, sizeof(addr));
    addrlen = sizeof(addr);

    // accept one connection
    if ((nsk = accept(sk, (struct sockaddr *) &addr, &addrlen)) < 0)
        return -1;

    if (bdaddr)
        bacpy(bdaddr, &addr.l2_bdaddr);

    return nsk;
}

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