timed.tproj/timed.tproj/acksend.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*-
  25  * Copyright (c) 1985, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgement:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  */
  56
  57 #ifndef lint
  58 static char sccsid[] = "@(#)acksend.c   8.1 (Berkeley) 6/6/93";
  59 #endif /* not lint */
  60
  61 #ifdef sgi
  62 #ident "$Revision: 1.1.1.1 $"
  63 #endif
  64
  65 #include "globals.h"
  66
  67 struct tsp *answer;
  68
  69 extern u_short sequence;
  70
  71 void
  72 xmit(type, seq, addr)
  73         int type;
  74         u_int seq;
  75         struct sockaddr_in *addr;
  76 {
  77         static struct tsp msg;
  78
  79         msg.tsp_type = type;
  80         msg.tsp_seq = seq;
  81         msg.tsp_vers = TSPVERSION;
  82         (void)strcpy(msg.tsp_name, hostname);
  83         bytenetorder(&msg);
  84         if (sendto(sock, (char *)&msg, sizeof(struct tsp), 0,
  85                    (struct sockaddr*)addr, sizeof(struct sockaddr)) < 0) {
  86                 trace_sendto_err(addr->sin_addr);
  87         }
  88 }
  89
  90
  91 /*
  92  * Acksend implements reliable datagram transmission by using sequence
  93  * numbers and retransmission when necessary.
  94  * If `name' is ANYADDR, this routine implements reliable broadcast.
  95  *
  96  * Because this function calls readmsg(), none of its args may be in
  97  *      a message provided by readmsg().
  98  */
  99 struct tsp *
 100 acksend(message, addr, name, ack, net, bad)
 101         struct tsp *message;                    /* this message */
 102         struct sockaddr_in *addr;               /* to here */
 103         char *name;
 104         int ack;                                /* look for this ack */
 105         struct netinfo *net;                    /* receive from this network */
 106         int bad;                                /* 1=losing patience */
 107 {
 108         struct timeval twait;
 109         int count;
 110         long msec;
 111
 112         message->tsp_vers = TSPVERSION;
 113         message->tsp_seq = sequence;
 114         if (trace) {
 115                 fprintf(fd, "acksend: to %s: ",
 116                         (name == ANYADDR ? "broadcast" : name));
 117                 print(message, addr);
 118         }
 119         bytenetorder(message);
 120
 121         msec = 200;
 122         count = bad ? 1 : 5;    /* 5 packets in 6.4 seconds */
 123         answer = 0;
 124         do {
 125                 if (!answer) {
 126                         /* do not go crazy transmitting just because the
 127                          * other guy cannot keep our sequence numbers
 128                          * straight.
 129                          */
 130                         if (sendto(sock, (char *)message, sizeof(struct tsp),
 131                                    0, (struct sockaddr*)addr,
 132                                    sizeof(struct sockaddr)) < 0) {
 133                                 trace_sendto_err(addr->sin_addr);
 134                                 break;
 135                         }
 136                 }
 137
 138                 mstotvround(&twait, msec);
 139                 answer  = readmsg(ack, name, &twait, net);
 140                 if (answer != 0) {
 141                         if (answer->tsp_seq != sequence) {
 142                                 if (trace)
 143                                         fprintf(fd,"acksend: seq # %u!=%u\n",
 144                                                 answer->tsp_seq, sequence);
 145                                 continue;
 146                         }
 147                         break;
 148                 }
 149
 150                 msec *= 2;
 151         } while (--count > 0);
 152         sequence++;
 153
 154         return(answer);
 155 }