2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1985, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 static char sccsid[] = "@(#)acksend.c 8.1 (Berkeley) 6/6/93";
36 static const char rcsid[] =
44 extern u_short sequence;
47 xmit(int type, u_int seq, struct sockaddr_in *addr)
49 static struct tsp msg;
53 msg.tsp_vers = TSPVERSION;
54 (void)strcpy(msg.tsp_name, hostname);
56 if (sendto(sock, (char *)&msg, sizeof(struct tsp), 0,
57 (struct sockaddr*)addr, sizeof(struct sockaddr)) < 0) {
58 trace_sendto_err(addr->sin_addr);
64 * Acksend implements reliable datagram transmission by using sequence
65 * numbers and retransmission when necessary.
66 * If `name' is ANYADDR, this routine implements reliable broadcast.
68 * Because this function calls readmsg(), none of its args may be in
69 * a message provided by readmsg().
70 * message this message
72 * ack look for this ack
73 * net receive from this network
74 * bad 1=losing patience
77 acksend(struct tsp *message, struct sockaddr_in *addr, char *name,
78 int ack, struct netinfo *net, int bad)
84 message->tsp_vers = TSPVERSION;
85 message->tsp_seq = sequence;
87 fprintf(fd, "acksend: to %s: ",
88 (name == ANYADDR ? "broadcast" : name));
91 bytenetorder(message);
94 count = bad ? 1 : 5; /* 5 packets in 6.4 seconds */
98 /* do not go crazy transmitting just because the
99 * other guy cannot keep our sequence numbers
102 if (sendto(sock, (char *)message, sizeof(struct tsp),
103 0, (struct sockaddr*)addr,
104 sizeof(struct sockaddr)) < 0) {
105 trace_sendto_err(addr->sin_addr);
110 mstotvround(&twait, msec);
111 answer = readmsg(ack, name, &twait, net);
112 if (answer != NULL) {
113 if (answer->tsp_seq != sequence) {
115 fprintf(fd,"acksend: seq # %u!=%u\n",
116 answer->tsp_seq, sequence);
123 } while (--count > 0);