/* receive any incoming data, send any pending data */
static void process_data(struct telnet_session_s *t, int wait_flag)
{
fd_set readfds;
fd_set writefds;
fd_set exceptfds;
struct timeval tv_zero;
struct timeval *tv;
/* set up our select() variables */
FD_ZERO(&readfds);
FD_ZERO(&writefds);
FD_ZERO(&exceptfds);
if (wait_flag) {
tv = NULL;
} else {
tv_zero.tv_sec = 0;
tv_zero.tv_usec = 0;
tv = &tv_zero;
}
/* only check for input if we can accept input */
if ((t->in_errno == 0) && (t->in_eof == 0) && (max_input_read(t) > 0)) {
FD_SET(t->in_fd, &readfds);
FD_SET(t->in_fd, &exceptfds);
}
/* only check for output if we have pending output */
if ((t->out_errno == 0) && (t->out_eof == 0) && (t->out_buflen > 0)) {
FD_SET(t->out_fd, &writefds);
FD_SET(t->out_fd, &exceptfds);
}
/* see if there's anything to do */
if (select(FD_SETSIZE, &readfds, &writefds, &exceptfds, tv) > 0) {
if (FD_ISSET(t->in_fd, &exceptfds)) {
t->in_eof = 1;
} else if (FD_ISSET(t->in_fd, &readfds)) {
read_incoming_data(t);
}
if (FD_ISSET(t->out_fd, &exceptfds)) {
t->out_eof = 1;
} else if (FD_ISSET(t->out_fd, &writefds)) {
write_outgoing_data(t);
}
}
}
int
handle_connections(int portnum)
{
int listenfd;
int acceptfd;
pid_t childpid;
listenfd = create_listener(portnum);
if (listenfd < 0) {
fprintf(stderr, "Warning: Exiting main network event loop\n");
return -1;
}
while (1) {
fprintf(stderr, "Notice: Waiting for a connection...\n");
acceptfd = wait_for_connection(listenfd);
if (acceptfd < 0) {
fprintf(stderr, "Warning: Exiting main network event loop\n");
return -1;
}
childpid = fork();
if (childpid > 0) {
close(acceptfd);
fprintf(stderr, "Notice: Child process id=%d forked to handle incoming connection\n", childpid);
}
else if (childpid == 0) {
close(listenfd);
fprintf(stderr, "Notice: Processing request in child process\n");
read_incoming_data(acceptfd);
exit(0);
}
else {
perror("fork");
fprintf(stderr, "Error: Unable to create child process to handle new connection\n");
}
}
} /* handle_connections() */