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#include <netinet/in.h>
#include <poll.h>
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
struct client {
char nickname[32];
int has_nickname;
};
// returns a socket file descriptor.
// if connection could not be established, -1 gets returned
int establish_connection(struct sockaddr_in addr) {
int sfd = socket(AF_INET, SOCK_STREAM, 0);
if (sfd == -1) {
return -1;
}
int opt = -1;
setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
int bind_addr = bind(sfd, (struct sockaddr *)&addr, sizeof(addr));
if (bind_addr == -1) {
close(sfd);
return -1;
}
int listen_addr = listen(sfd, 100);
if (listen_addr == -1) {
close(sfd);
return -1;
}
return sfd;
}
// handles new telnet connections.
// returns 0 on success and -1 on failure.
int handle_new_connection(int sfd, struct pollfd *fds, nfds_t *nfds,
struct client *clients) {
int conn = accept(sfd, NULL, NULL);
if (conn == -1)
return -1;
fds[*nfds].fd = conn;
fds[*nfds].events = POLLIN;
clients[*nfds].has_nickname = 0;
char *message = "Enter your nickname:\n";
write(fds[*nfds].fd, message, strlen(message));
(*nfds)++;
return 0;
}
// process message to all the connected clients.
// returns 0 on success and -1 on failure.
// TODO: add struct client *clients
int process_message(struct pollfd *fds, nfds_t *nfds, struct client *clients) {
for (nfds_t i = 1; i < *nfds; i++) {
/* if client has something to say */
if (fds[i].revents & POLLIN) {
char buffer[1024]; /* create a new empty buffer */
ssize_t message =
read(fds[i].fd, buffer,
sizeof(buffer)); /* read the message which the client sent */
if (message == 0) {
/* close the connection if client disappeared or disconnected */
close(fds[i].fd);
fds[i] = fds[*nfds - 1]; /* move back last slot */
(*nfds)--; /* size down the current array */
i--;
} else if (message == -1) {
/* if message of the client returns an error */
close(fds[i].fd);
fds[i] = fds[*nfds - 1]; /* move back last slot */
(*nfds)--; /* size down the current array */
i--;
return -1;
} else {
if (clients[i].has_nickname == 0) {
}
/* send every message bytes to the other clients */
for (nfds_t j = 1; j < *nfds; j++) {
if (j != i) {
write(fds[j].fd, buffer, message);
}
}
}
}
}
return 0;
}
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