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
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* NetCosm - a MUD server
* Copyright (C) 2015 Franklin Wei
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "netcosm.h"
#define PORT 1234
#define BACKLOG 16
void __attribute__((noreturn)) error(const char *fmt, ...)
{
char buf[128];
memset(buf, 0, sizeof(buf));
va_list ap;
va_start(ap, fmt);
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
perror(buf);
exit(EXIT_FAILURE);
}
int num_clients = 0;
void sigchld_handler(int s)
{
(void) s;
printf("Client disconnect.\n");
// waitpid() might overwrite errno, so we save and restore it:
int saved_errno = errno;
while(waitpid(-1, NULL, WNOHANG) > 0);
errno = saved_errno;
--num_clients;
}
int port;
void handle_client(int fd, struct sockaddr_in *addr, int num_clients)
{
client_main(fd, addr, num_clients);
}
int server_socket;
void serv_cleanup(void)
{
printf("Shutdown server.\n");
if(shutdown(server_socket, SHUT_RDWR) > 0)
error("shutdown");
close(server_socket);
}
void sigint_handler(int sig)
{
(void) sig;
serv_cleanup();
}
int main(int argc, char *argv[])
{
if(argc != 2)
port = PORT;
else
port = strtol(argv[1], NULL, 0);
srand(time(0));
int sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock<0)
error("socket");
int tmp = 1;
if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &tmp, sizeof tmp) < 0)
error("setsockopt");
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if(bind(sock, (struct sockaddr*) &addr, sizeof addr) < 0)
error("bind");
if(listen(sock, BACKLOG) < 0)
error("listen");
server_socket = sock;
struct sigaction sa;
sa.sa_handler = sigchld_handler; // reap all dead processes
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
if (sigaction(SIGCHLD, &sa, NULL) == -1) {
perror("sigaction");
exit(1);
}
signal(SIGINT, sigint_handler);
if(access(USERFILE, F_OK) < 0)
first_run_setup();
printf("Listening on port %d\n", port);
while(1)
{
struct sockaddr_in client;
socklen_t client_len = sizeof(client);
int new_sock = accept(sock, (struct sockaddr*) &client, &client_len);
if(new_sock < 0)
error("accept");
++num_clients;
pid_t pid = fork();
if(pid < 0)
error("fork");
if(!pid)
{
close(sock);
server_socket = new_sock;
handle_client(new_sock, &client, num_clients);
exit(0);
}
else
close(new_sock);
}
}
|
