1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/*-
* Copyright (c) 2015 George V. Neville-Neil
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sysexits.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#define PORT 6969 /* Default port */
#define LISTEN 5 /* Default backlog */
#define RECV_LIMIT 64 /* When do we move listen to 0? */
void usage(void);
void usage()
{
err(EX_USAGE, "listen [-p port] [-l limit]\n");
}
int main(int argc, char **argv)
{
int ch, srv_sock, cli_sock, recvd = 0;
int port = PORT;
int limit = LISTEN;
struct sockaddr_in localaddr;
while ((ch = getopt(argc, argv, "p:l:")) != -1) {
switch (ch) {
case 'p':
port = atoi(optarg);
break;
case 'l':
limit = atoi(optarg);
break;
case 'h':
default:
usage();
}
}
bzero(&localaddr, sizeof(localaddr));
localaddr.sin_len = sizeof(localaddr);
localaddr.sin_family = AF_INET;
localaddr.sin_port = htons(port);
localaddr.sin_addr.s_addr = INADDR_ANY;
srv_sock = socket(AF_INET, SOCK_STREAM, 0);
if (bind(srv_sock, (struct sockaddr *)&localaddr,
sizeof(struct sockaddr_in)) < 0)
err(EX_OSERR, "Could not bind to INADDR_ANY:%d", port);
if (listen(srv_sock, limit) < 0)
err(EX_OSERR, "Failed to listen with depth of %d\n", limit);
while (((cli_sock = accept(srv_sock, NULL, NULL)) >= 0)
&& (recvd < RECV_LIMIT)) {
close(cli_sock);
recvd++;
}
listen(srv_sock, 0);
while (((cli_sock = accept(srv_sock, NULL, NULL)) >= 0)
&& (recvd <= (RECV_LIMIT + limit + 1))) {
close(cli_sock);
recvd++;
}
if (accept(srv_sock, NULL, NULL) >= 0)
printf ("Late connection at %d\n", recvd);
else
printf("recvd %d\n", recvd);
}
|
