1/*- 2 * Copyright (c) 1985, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#ifndef lint 31#if 0 32static char sccsid[] = "@(#)acksend.c 8.1 (Berkeley) 6/6/93"; 33#endif 34static const char rcsid[] = 35 "$FreeBSD$"; 36#endif /* not lint */ 37 38#include "globals.h" 39 40struct tsp *answer; 41 42extern u_short sequence; 43 44void 45xmit(int type, u_int seq, struct sockaddr_in *addr) 46{ 47 static struct tsp msg; 48 49 msg.tsp_type = type; 50 msg.tsp_seq = seq; 51 msg.tsp_vers = TSPVERSION; 52 (void)strcpy(msg.tsp_name, hostname); 53 bytenetorder(&msg); 54 if (sendto(sock, (char *)&msg, sizeof(struct tsp), 0, 55 (struct sockaddr*)addr, sizeof(struct sockaddr)) < 0) { 56 trace_sendto_err(addr->sin_addr); 57 } 58} 59 60 61/* 62 * Acksend implements reliable datagram transmission by using sequence 63 * numbers and retransmission when necessary. 64 * If `name' is ANYADDR, this routine implements reliable broadcast. 65 * 66 * Because this function calls readmsg(), none of its args may be in 67 * a message provided by readmsg(). 68 * message this message 69 * addr to here 70 * ack look for this ack 71 * net receive from this network 72 * bad 1=losing patience 73 */ 74struct tsp * 75acksend(struct tsp *message, struct sockaddr_in *addr, char *name, 76 int ack, struct netinfo *net, int bad) 77{ 78 struct timeval twait; 79 int count; 80 long msec; 81 82 message->tsp_vers = TSPVERSION; 83 message->tsp_seq = sequence; 84 if (trace) { 85 fprintf(fd, "acksend: to %s: ", 86 (name == ANYADDR ? "broadcast" : name)); 87 print(message, addr); 88 } 89 bytenetorder(message); 90 91 msec = 200; 92 count = bad ? 1 : 5; /* 5 packets in 6.4 seconds */ 93 answer = NULL; 94 do { 95 if (!answer) { 96 /* do not go crazy transmitting just because the 97 * other guy cannot keep our sequence numbers 98 * straight. 99 */ 100 if (sendto(sock, (char *)message, sizeof(struct tsp), 101 0, (struct sockaddr*)addr, 102 sizeof(struct sockaddr)) < 0) { 103 trace_sendto_err(addr->sin_addr); 104 break; 105 } 106 } 107 108 mstotvround(&twait, msec); 109 answer = readmsg(ack, name, &twait, net); 110 if (answer != NULL) { 111 if (answer->tsp_seq != sequence) { 112 if (trace) 113 fprintf(fd,"acksend: seq # %u!=%u\n", 114 answer->tsp_seq, sequence); 115 continue; 116 } 117 break; 118 } 119 120 msec *= 2; 121 } while (--count > 0); 122 sequence++; 123 124 return(answer); 125} 126