#include <sys/file.h>

#include <sys/fpath.h>

#include <sys/creds.h>

#include <sys/proc.h>

#include <sys/mount.h>

#include <config.h>

#include <util.h>

#include <main.h>

ERRTAG("init");

static void check_pid_one(void)

{

if(sys_getpid() != 1)

fail("not running as pid 1", NULL, 0);

}

static int open_something(void)

{

int fd;

if((fd = sys_open("/dev/null", O_RDWR)) >= 0)

return fd;

if((fd = sys_open("/", O_PATH)) >= 0)

return fd;

return -ENOENT;

}

static int dup_to_std_012(int fd)

{

if((fd < 1) && (sys_dup2(fd, STDOUT) < 0))

return -1;

if((fd < 2) && (sys_dup2(fd, STDERR) < 0))

return -1;

if(fd > 2 && (sys_close(fd) < 0))

return -1;

return 0;

}

static void setup_std_fds(void)

{

int fd, ret;

if(sys_fcntl(STDERR, F_GETFD) >= 0)

return;

if((fd = open_something()) < 0)

_exit(0xFE);

if((ret = dup_to_std_012(fd)) < 0)

_exit(0xFD);

}

static void mount(char* dir, char* fstype, int flags)

{

int ret;

struct stat st;

if((ret = sys_stat(dir, &st)) < 0)

return;

if((st.mode & S_IFMT) != S_IFDIR)

return;

if((ret = sys_mount("none", dir, fstype, flags, NULL)) >= 0)

return;

if(ret == -EBUSY)

return;

fail("mount", dir, ret);

}

static void mount_basic_filesystems(void)

{

mount("/sys", "sysfs", MS_NOSUID | MS_NOEXEC | MS_NODEV);

mount("/run", "tmpfs", MS_NOSUID | MS_NOEXEC | MS_NODEV);

mount("/proc", "proc", MS_NOSUID | MS_NOEXEC | MS_NODEV);

mount("/dev", "devtmpfs", MS_NOSUID | MS_NOEXEC);

}

static noreturn void invoke_next_stage(int argc, char** argv)

{

char* path = BASE_ETC "/boot/sysinit";

char* base = basename(path);

char** envp = argv + argc + 1;

argv[0] = base;

int ret = sys_execve(path, argv, envp);

fail(NULL, path, ret);

}

int main(int argc, char** argv)

{

check_pid_one();

setup_std_fds();

mount_basic_filesystems();

invoke_next_stage(argc, argv);

}