/*
 * sender.c
 *
 * Usage: sender <receiver-hostname>
 *
 * Function: Example code to send a buffer of characters to a receiver 
 *           through a Fore ATM switch.  
 *
 * Notes:
 * 
 * The ATM interface name for the receiver must be on the command line.
 * 
 * The receiver must be started before the sender is started.
 *
 * The RSAP in this file must agree with the RSAP in receiver.c.
 *
 */


#include <stdio.h>
#include <sys/file.h>
#include <sys/fcntl.h>

#include <fore_atm/fore_atm_user.h>

#define ATM_DEVICE "qaa0"
/* qaa[0-3], fa0 - logical devices mapping to same ATM adapter card */
#define RSAP 4096
#define PBW 2000   /* peak bandwidth in kbits/sec */
#define MBW 2000   /* mean bandwidth in kbits/sec */
#define BURST 2    /* burst size in kbits */ 

#define min(a,b) (a > b ? b : a)

main(argc, argv)
    int argc;
    char **argv;
{
    int fd, qlen, mtu, i;
    Atm_info info;
    Atm_endpoint rcvr;
    Atm_qos qos;
    Atm_qos_sel qos_selected;
    Atm_sap asap;

    Aal_type aal = aal_type_5;  
    /* fore_xdr.h: defines aal_null, aal_type_[1-5] */
    /* XXX Are aal_type_[1,2] really supported? */

    Atm_dataflow dataflow = simplex;
    /* fore_atm_user.h: defines simplex, duplex, multicast */

    char *device_name;
    char *tbuf;


    if (argc != 2) {
        fprintf(stderr, "Usage: %s receiver-hostname\n",argv[0]);
        exit(1);
    }

    /* Open ATM device and get file descriptor */
    device_name = malloc(strlen("/dev/") + strlen(ATM_DEVICE) + 1);
    sprintf(device_name, "/dev/%s", ATM_DEVICE);

    printf("Opening device %s.\n",device_name);
    if ((fd = atm_open(device_name, O_RDWR, &info)) < 0) {
        perror("atm_open");
        exit(1);
    }
    printf("Device opened.\n");

    /* Bind ASAP to file descriptor */
    asap = 0;  
    /* fore_xdr.h: Atm_sap defined as u_int */
    /* atm_bind: asap = 0 causes device driver to select asap */
    /* sender asap does not need to be known anywhere else */
   
    qlen = 0;
    /* atm_bind: 0 means will not accept any connection request */

    printf("Binding ASAP to file descriptor.\n");
    if (atm_bind(fd, asap, &asap, qlen) < 0) {
        atm_error("atm_bind");
        exit(1);
    }
    printf("Binding done.  ASAP assigned %d\n",asap);

    /* Get receiver's NSAP */
    printf("Getting receiver's NSAP.\n");
    if (atm_gethostbyname(argv[1], &rcvr.nsap) < 0) {
        fprintf(stderr, "atm_gethostbyname failed\n");
        exit(1);
    }
    printf("Got NSAP %d for receiver\n",rcvr.nsap);

    /* Set up qos parameters and request connection to receiver */
    rcvr.asap = RSAP;
    qos.peak_bandwidth.target = PBW;
    qos.peak_bandwidth.minimum = PBW;
    qos.mean_bandwidth.target = MBW;
    qos.mean_bandwidth.minimum = MBW;
    qos.mean_burst.target = BURST;  
    qos.mean_burst.minimum = BURST;

    printf("Connecting to destination.\n");
    if (atm_connect(fd, &rcvr, &qos, &qos_selected, aal, dataflow) < 0) {
        atm_error("atm_connect");
        exit(1);
    }
    mtu = min(info.mtu, 4092);    /* will break if mtu larger than 4092 */
    printf("Connection made.\n");
    printf("Selected qos: peak %d, mean %d, burst %d, mtu %d\n",
	    qos_selected.peak_bandwidth, qos_selected.mean_bandwidth,
	    qos_selected.mean_burst, mtu);

    /* Finally, let's write to the destination */
    tbuf = malloc(mtu);
    for (i = 0; i < mtu; i++) tbuf[i] = i;
    printf("Sending to receiver.\n");
    if (atm_send(fd, tbuf, mtu) < 0) {
        atm_error("atm_send");
        exit(1);
    }
    printf("Data sent.\n");
    
}