- * The Waker.
- *
- * With console, block and network devices, we can have lots of input which we
- * need to process. We could try to tell the kernel what file descriptors to
- * watch, but handing a file descriptor mask through to the kernel is fairly
- * icky.
- *
- * Instead, we fork off a process which watches the file descriptors and writes
- * the LHREQ_BREAK command to the /dev/lguest file descriptor to tell the Host
- * stop running the Guest. This causes the Launcher to return from the
- * /dev/lguest read with -EAGAIN, where it will write to /dev/lguest to reset
- * the LHREQ_BREAK and wake us up again.
- *
- * This, of course, is merely a different *kind* of icky.
- */
-static void wake_parent(int pipefd, int lguest_fd)
-{
- /* Add the pipe from the Launcher to the fdset in the device_list, so
- * we watch it, too. */
- add_device_fd(pipefd);
-
- for (;;) {
- fd_set rfds = devices.infds;
- unsigned long args[] = { LHREQ_BREAK, 1 };
-
- /* Wait until input is ready from one of the devices. */
- select(devices.max_infd+1, &rfds, NULL, NULL, NULL);
- /* Is it a message from the Launcher? */
- if (FD_ISSET(pipefd, &rfds)) {
- int fd;
- /* If read() returns 0, it means the Launcher has
- * exited. We silently follow. */
- if (read(pipefd, &fd, sizeof(fd)) == 0)
- exit(0);
- /* Otherwise it's telling us to change what file
- * descriptors we're to listen to. Positive means
- * listen to a new one, negative means stop
- * listening. */
- if (fd >= 0)
- FD_SET(fd, &devices.infds);
- else
- FD_CLR(-fd - 1, &devices.infds);
- } else /* Send LHREQ_BREAK command. */
- write(lguest_fd, args, sizeof(args));
- }
-}
-
-/* This routine just sets up a pipe to the Waker process. */
-static int setup_waker(int lguest_fd)
-{
- int pipefd[2], child;
-
- /* We create a pipe to talk to the Waker, and also so it knows when the
- * Launcher dies (and closes pipe). */
- pipe(pipefd);
- child = fork();
- if (child == -1)
- err(1, "forking");
-
- if (child == 0) {
- /* We are the Waker: close the "writing" end of our copy of the
- * pipe and start waiting for input. */
- close(pipefd[1]);
- wake_parent(pipefd[0], lguest_fd);
- }
- /* Close the reading end of our copy of the pipe. */
- close(pipefd[0]);
-
- /* Here is the fd used to talk to the waker. */
- return pipefd[1];
-}
-
-/*