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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
|
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <poll.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include "types.h"
clientstate_t clientStates[MAX_CLIENTS];
void init_clients(void) {
int i;
for (i = 0; i < MAX_CLIENTS; i++) {
/* -1 means client slot is free */
clientStates[i].fd = -1;
clientStates[i].state = STATE_NEW;
memset(&clientStates[i].buffer, 0, BUF_SIZE);
}
}
int find_free_client(void) {
int i = 0;
for (i = 0; i < MAX_CLIENTS; i++)
if (clientStates[i].fd == -1)
return i;
return -1;
}
int find_slot_by_fd(int fd)
{
int i;
for (i = 0; i < MAX_CLIENTS; i++) {
if (clientStates[i].fd == fd)
return i;
}
return -1;
}
void handle_client(int fd)
{
char buf[4096] = {0};
proto_hdr_t *hdr = (proto_hdr_t*)buf;
int *data;
int reallen;
hdr->type = htonl(PROTO_HELLO);
reallen = sizeof(int);
hdr->len = htons(reallen);
data = (int *)&hdr[1];
*data = htonl(1);
printf("hdr_ptr: %p data_ptr: %p\n", hdr, data);
write(fd, hdr, sizeof(proto_hdr_t) + reallen);
}
int main(void)
{
int err;
int listen_fd, conn_fd, nfds, freeSlot;
struct sockaddr_in serverInfo = {0};
struct sockaddr_in clientInfo = {0};
socklen_t csize;
int opt = 1;
struct pollfd fds[MAX_CLIENTS + 1];
memset(fds, 9, sizeof(fds));
serverInfo.sin_family = AF_INET;
serverInfo.sin_addr.s_addr = 0; /* bind to all IPs */
serverInfo.sin_port = htons(SERVER_PORT);
init_clients();
listen_fd = socket(AF_INET, SOCK_STREAM, 0);
if (listen_fd < 0) {
perror("socket");
exit(1);
}
err = bind(listen_fd,
(struct sockaddr *)&serverInfo,
sizeof(serverInfo));
if (err < 0) {
perror("bind");
close(listen_fd);
exit(1);
}
err = listen(listen_fd, 0);
if (err < 0) {
perror("listen");
close(listen_fd);
exit(1);
}
if (setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
perror("setsockopt");
close(listen_fd);
exit(1);
}
printf("Server listening to port: %d\n", SERVER_PORT);
csize = sizeof(clientInfo);
fds[0].fd = listen_fd;
fds[0].events = POLLIN;
nfds = 1;
while (1) {
int i, j;
int nevents;
/* fds is initialized with MAX_CLIENTS + 1 */
for (i = 0, j = 1; i < MAX_CLIENTS; i++, j++) {
if (clientStates[i].fd != -1) {
/* Add open fd to the poll */
fds[j].fd = clientStates[i].fd;
fds[j].events = POLLIN;
printf("FD %d added to poll\n", clientStates[i].fd);
}
}
nevents = poll(fds, nfds, -1);
if (nevents == -1) {
perror("poll");
exit(1);
}
/* if listen_fd is ready, accept it */
if (fds[0].revents & POLLIN) {
conn_fd = accept(listen_fd,
(struct sockaddr*)&clientInfo,
&csize);
if (conn_fd < 0) {
perror("accept");
continue;
}
printf("New connection from: %s:%d\n",
inet_ntoa(clientInfo.sin_addr),
ntohs(clientInfo.sin_port));
freeSlot = find_free_client();
if (freeSlot < 0) {
printf("Server full - closing connection\n");
close(conn_fd);
} else {
clientStates[freeSlot].fd = conn_fd;
clientStates[freeSlot].state = STATE_CONNECTED;
nfds++;
printf("Adding fd %d to slot %d\n",
conn_fd, freeSlot);
}
nevents--;
}
printf("NFDS: %d\n", nfds);
for (i = 1; i <= nfds && nevents > 0; i++) {
int fd, slot;
ssize_t bytes_read;
if (fds[i].revents & POLLIN) {
nevents--;
fd = fds[i].fd;
slot = find_slot_by_fd(fd);
bytes_read = read(fd,
&clientStates[slot].buffer,
sizeof(clientStates[slot].buffer));
if (bytes_read <= 0) {
close(fd);
printf("Connection error\n");
if (slot == -1) {
printf("Trying to close an invalid fd\n");
} else {
clientStates[slot].fd = -1;
clientStates[slot].state = STATE_DISCONNECTED;
printf("Client disconnected or error\n");
nfds--;
}
} else {
printf("Data received: %s\n", clientStates[slot].buffer);
}
}
}
}
return 0;
}
|
