xref: /kvmtool/guest/init.c (revision 69071bcef7f4ff6542efadc5ac07cf10e1424494)
1 /*
2  * This is a simple init for shared rootfs guests. This part should be limited
3  * to doing mounts and running stage 2 of the init process.
4  */
5 #include <sys/mount.h>
6 #include <string.h>
7 #include <unistd.h>
8 #include <stdio.h>
9 #include <errno.h>
10 #include <linux/reboot.h>
11 
12 static int run_process(char *filename)
13 {
14 	char *new_argv[] = { filename, NULL };
15 	char *new_env[] = { "TERM=linux", "DISPLAY=192.168.33.1:0", NULL };
16 
17 	return execve(filename, new_argv, new_env);
18 }
19 
20 static int run_process_sandbox(char *filename)
21 {
22 	char *new_argv[] = { filename, "/virt/sandbox.sh", NULL };
23 	char *new_env[] = { "TERM=linux", NULL };
24 
25 	return execve(filename, new_argv, new_env);
26 }
27 
28 static void do_mounts(void)
29 {
30 	mount("hostfs", "/host", "9p", MS_RDONLY, "trans=virtio,version=9p2000.L");
31 	mount("", "/sys", "sysfs", 0, NULL);
32 	mount("proc", "/proc", "proc", 0, NULL);
33 	mount("devtmpfs", "/dev", "devtmpfs", 0, NULL);
34 	mkdir("/dev/pts", 0755);
35 	mount("devpts", "/dev/pts", "devpts", 0, NULL);
36 }
37 
38 int main(int argc, char *argv[])
39 {
40 	pid_t child;
41 	int status;
42 
43 	puts("Mounting...");
44 
45 	do_mounts();
46 
47 	/* get session leader */
48 	setsid();
49 
50 	/* set controlling terminal */
51 	ioctl(0, TIOCSCTTY, 1);
52 
53 	child = fork();
54 	if (child < 0) {
55 		printf("Fatal: fork() failed with %d\n", child);
56 		return 0;
57 	} else if (child == 0) {
58 		if (access("/virt/sandbox.sh", R_OK) == 0)
59 			run_process_sandbox("/bin/sh");
60 		else
61 			run_process("/bin/sh");
62 	} else {
63 		waitpid(child, &status, 0);
64 	}
65 
66 	reboot(LINUX_REBOOT_CMD_RESTART);
67 
68 	printf("Init failed: %s\n", strerror(errno));
69 
70 	return 0;
71 }
72