From 9a88f7da453eadc72d8f333700dbd80777feecd1 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@tele2.at>
Date: Sun, 25 Feb 2018 14:33:19 +0100
Subject: Initial commit

Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
---
 initd/main.c | 238 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 238 insertions(+)
 create mode 100644 initd/main.c

(limited to 'initd/main.c')

diff --git a/initd/main.c b/initd/main.c
new file mode 100644
index 0000000..211188e
--- /dev/null
+++ b/initd/main.c
@@ -0,0 +1,238 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <poll.h>
+
+#include <sys/signalfd.h>
+
+#include "init.h"
+
+static service_list_t cfg;
+
+static int target = TGT_BOOT;		/* runlevel we are targetting */
+static int runlevel = -1;		/* runlevel we are currently on */
+
+static void handle_exited(service_t *svc)
+{
+	switch (svc->type) {
+	case SVC_RESPAWN:
+		if (target == TGT_REBOOT || target == TGT_SHUTDOWN) {
+			delsrv(svc);
+			break;
+		}
+
+		svc->pid = runlst(svc->exec, svc->num_exec, svc->ctty);
+		if (svc->pid == -1) {
+			print_status(svc->desc, STATUS_FAIL, false);
+			delsrv(svc);
+		}
+
+		svclist_add(svc);
+		break;
+	case SVC_ONCE:
+		print_status(svc->desc,
+			     svc->status == EXIT_SUCCESS ?
+			     STATUS_OK : STATUS_FAIL, false);
+		/* fall-through */
+	default:
+		delsrv(svc);
+		break;
+	}
+}
+
+static void handle_signal(int sigfd)
+{
+	struct signalfd_siginfo info;
+	service_t *svc;
+	int status;
+	pid_t pid;
+
+	if (read(sigfd, &info, sizeof(info)) != sizeof(info)) {
+		perror("read on signal fd");
+		return;
+	}
+
+	switch (info.ssi_signo) {
+	case SIGCHLD:
+		for (;;) {
+			pid = waitpid(-1, &status, WNOHANG);
+			if (pid <= 0)
+				break;
+
+			status = WIFEXITED(status) ? WEXITSTATUS(status) :
+						     EXIT_FAILURE;
+
+			svc = svclist_remove(pid);
+
+			if (svc != NULL)
+				handle_exited(svc);
+		}
+		break;
+	case SIGINT:
+		/* TODO: ctrl-alt-del */
+		break;
+	}
+}
+
+static void start_runlevel(int level)
+{
+	service_t *svc;
+	int status;
+
+	while (cfg.targets[level] != NULL) {
+		svc = cfg.targets[level];
+		cfg.targets[level] = svc->next;
+
+		if (!svc->num_exec) {
+			print_status(svc->desc, STATUS_OK, false);
+			delsrv(svc);
+			continue;
+		}
+
+		if (svc->type == SVC_WAIT) {
+			print_status(svc->desc, STATUS_WAIT, false);
+
+			status = runlst_wait(svc->exec, svc->num_exec,
+					     svc->ctty);
+
+			print_status(svc->desc,
+				     status == EXIT_SUCCESS ?
+				     STATUS_OK : STATUS_FAIL,
+				     true);
+			delsrv(svc);
+		} else {
+			svc->pid = runlst(svc->exec, svc->num_exec, svc->ctty);
+			if (svc->pid == -1) {
+				print_status(svc->desc, STATUS_FAIL, false);
+				delsrv(svc);
+				continue;
+			}
+
+			svclist_add(svc);
+		}
+	}
+}
+
+static int read_msg(int fd, ti_msg_t *msg)
+{
+	ssize_t ret;
+retry:
+	ret = read(fd, msg, sizeof(*msg));
+
+	if (ret < 0) {
+		if (errno == EINTR)
+			goto retry;
+		perror("read on telinit socket");
+		return -1;
+	}
+
+	if ((size_t)ret < sizeof(*msg)) {
+		fputs("short read on telinit socket", stderr);
+		return -1;
+	}
+
+	return 0;
+}
+
+static void handle_tellinit(int ti_sock)
+{
+	ti_msg_t msg;
+	int fd;
+
+	fd = accept(ti_sock, NULL, NULL);
+	if (fd == -1)
+		return;
+
+	if (read_msg(fd, &msg)) {
+		close(fd);
+		return;
+	}
+
+	switch (msg.type) {
+	case TI_SHUTDOWN:
+		target = TGT_SHUTDOWN;
+		break;
+	case TI_REBOOT:
+		target = TGT_REBOOT;
+		break;
+	}
+
+	close(fd);
+}
+
+int main(void)
+{
+	int ti_sock, sfd, ret;
+	struct pollfd pfd[2];
+	sigset_t mask;
+
+	if (getpid() != 1) {
+		fputs("init does not have pid 1, terminating!\n", stderr);
+		return EXIT_FAILURE;
+	}
+
+	if (reboot(LINUX_REBOOT_CMD_CAD_OFF))
+		perror("cannot disable CTRL+ALT+DEL");
+
+	if (srvscan(SVCDIR, &cfg)) {
+		fputs("Error reading service list from " SVCDIR "\n"
+			"Trying to continue anyway\n", stderr);
+	}
+
+	sigfillset(&mask);
+	if (sigprocmask(SIG_SETMASK, &mask, NULL) == -1) {
+		perror("sigprocmask");
+		return EXIT_FAILURE;
+	}
+
+	sfd = signalfd(-1, &mask, SFD_CLOEXEC);
+	if (sfd == -1) {
+		perror("signalfd");
+		return EXIT_FAILURE;
+	}
+
+	ti_sock = mksock();
+	if (ti_sock == -1)
+		return EXIT_FAILURE;
+
+	if (setup_tty())
+		return EXIT_FAILURE;
+
+	memset(pfd, 0, sizeof(pfd));
+	pfd[0].fd = sfd;
+	pfd[1].fd = ti_sock;
+	pfd[0].events = pfd[1].events = POLLIN;
+
+	for (;;) {
+		if (!svclist_have_singleshot()) {
+			if (target != runlevel) {
+				start_runlevel(target);
+				runlevel = target;
+				continue;
+			}
+
+			if (runlevel == TGT_SHUTDOWN)
+				do_shutdown(RB_POWER_OFF);
+
+			if (runlevel == TGT_REBOOT)
+				do_shutdown(RB_AUTOBOOT);
+		}
+
+		ret = poll(pfd, sizeof(pfd) / sizeof(pfd[0]), -1);
+
+		if (ret > 0) {
+			if (pfd[0].revents & POLLIN)
+				handle_signal(sfd);
+
+			if (pfd[1].revents & POLLIN)
+				handle_tellinit(ti_sock);
+		}
+	}
+
+	return EXIT_SUCCESS;
+}
-- 
cgit v1.2.3