new copyright notice

[unix-history] / usr / src / usr.sbin / timed / timed / acksend.c

/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)acksend.c   2.7 (Berkeley) %G%";
#endif /* not lint */

#include "globals.h"
#include <protocols/timed.h>

#define RECEIVED        0
#define LOST            1
#define SECFORACK       1       /* seconds */
#define USECFORACK      0       /* microseconds */
#define MAXCOUNT        5

struct tsp *answer;

/*
* Acksend implements reliable datagram transmission by using sequence 
* numbers and retransmission when necessary.
* `name' is the name of the destination
* `addr' is the address to send to
* If `name' is ANYADDR, this routine implements reliable broadcast.
*/

struct tsp *acksend(message, addr, name, ack, net)
struct tsp *message;
struct sockaddr_in *addr;
char *name;
int ack;
struct netinfo *net;
{
       int count;
       int flag;
       extern u_short sequence;
       struct timeval tout;
       struct tsp *readmsg();

       count = 0;

       message->tsp_vers = TSPVERSION;
       message->tsp_seq = sequence;
       if (trace) {
               fprintf(fd, "acksend: ");
               if (name == ANYADDR)
                       fprintf(fd, "broadcast: ");
               else
                       fprintf(fd, "%s: ", name);
               print(message, addr);
       }
       bytenetorder(message);
       do {
               if (sendto(sock, (char *)message, sizeof(struct tsp), 0, addr,
                   sizeof(struct sockaddr_in)) < 0) {
                       syslog(LOG_ERR, "acksend: sendto: %m");
                       exit(1);
               }
               tout.tv_sec = SECFORACK;
               tout.tv_usec = USECFORACK;
               answer  = readmsg(ack, name, &tout, net);
               if (answer != NULL) {
                       if (answer->tsp_seq != sequence) {
                               if (trace)
                                       fprintf(fd, "acksend: seq # %d != %d\n",
                                           answer->tsp_seq, sequence);
                               continue;
                       }
                       flag = RECEIVED;
               } else {
                       flag = LOST;
                       if (++count == MAXCOUNT) {
                               break;
                       }
               }
       } while (flag != RECEIVED);
       sequence++;
       return(answer);
}