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