1 files changed, 331 insertions, 0 deletions
diff --git a/usr/kinit/kinit.c b/usr/kinit/kinit.c
new file mode 100644
index 0000000..28d2953
--- /dev/null
+++ b/usr/kinit/kinit.c
@@ -0,0 +1,331 @@
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <alloca.h>
+#include <limits.h>
+#include <ctype.h>
+#include <termios.h>
+
+#include "kinit.h"
+#include "ipconfig.h"
+#include "run-init.h"
+#include "resume.h"
+
+const char *progname = "kinit";
+int mnt_procfs;
+int mnt_sysfs;
+
+#ifdef DEBUG
+void dump_args(int argc, char *argv[])
+{
+	int i;
+
+	printf("  argc == %d\n", argc);
+
+	for (i = 0; i < argc; i++)
+		printf("  argv[%d]: \"%s\"\n", i, argv[i]);
+
+	if (argv[argc] != NULL)
+		printf("  argv[%d]: \"%s\" (SHOULD BE NULL)\n",
+			argc, argv[argc]);
+}
+#endif /* DEBUG */
+
+
+static int do_ipconfig(int argc, char *argv[])
+{
+	int i, a = 0;
+	char **args = alloca((argc + 3) * sizeof(char *));
+
+	if (!args)
+		return -1;
+
+	args[a++] = (char *)"IP-Config";
+	args[a++] = (char *)"-i";
+	args[a++] = (char *)"Linux kinit";
+
+	dprintf("Running ipconfig\n");
+
+	for (i = 1; i < argc; i++) {
+		if (strncmp(argv[i], "ip=", 3) == 0 ||
+		    strncmp(argv[i], "nfsaddrs=", 9) == 0) {
+			args[a++] = argv[i];
+		}
+	}
+
+	if (a > 1) {
+		args[a] = NULL;
+		dump_args(a, args);
+		return ipconfig_main(a, args);
+	}
+
+	return 0;
+}
+
+static int split_cmdline(int cmdcmax, char *cmdv[], char *argv0,
+			 char *cmdlines[], char *args[])
+{
+	int was_space;
+	char c, *p;
+	int vmax = cmdcmax;
+	int v = 1;
+	int space;
+
+	if (cmdv)
+		cmdv[0] = argv0;
+
+	/* First, add the parsable command lines */
+
+	while (*cmdlines) {
+		p = *cmdlines++;
+		was_space = 1;
+		while (v < vmax) {
+			c = *p;
+			space = isspace(c);
+			if ((space || !c) && !was_space) {
+				if (cmdv)
+					*p = '\0';
+				v++;
+			} else if (was_space) {
+				if (cmdv)
+					cmdv[v] = p;
+			}
+
+			if (!c)
+				break;
+
+			was_space = space;
+			p++;
+		}
+	}
+
+	/* Second, add the explicit command line arguments */
+
+	while (*args && v < vmax) {
+		if (cmdv)
+			cmdv[v] = *args;
+		v++;
+		args++;
+	}
+
+	if (cmdv)
+		cmdv[v] = NULL;
+
+	return v;
+}
+
+static int mount_sys_fs(const char *check, const char *fsname,
+			const char *fstype)
+{
+	struct stat st;
+
+	if (stat(check, &st) == 0)
+		return 0;
+
+	mkdir(fsname, 0555);
+
+	if (mount("none", fsname, fstype, 0, NULL) == -1) {
+		fprintf(stderr, "%s: could not mount %s as %s\n",
+			progname, fsname, fstype);
+		return -1;
+	}
+
+	return 1;
+}
+
+static void check_path(const char *path)
+{
+	struct stat st;
+
+	if (stat(path, &st) == -1) {
+		if (errno != ENOENT) {
+			perror("stat");
+			exit(1);
+		}
+		if (mkdir(path, 0755) == -1) {
+			perror("mkdir");
+			exit(1);
+		}
+	} else if (!S_ISDIR(st.st_mode)) {
+		fprintf(stderr, "%s: '%s' not a directory\n", progname, path);
+		exit(1);
+	}
+}
+
+static const char *find_init(const char *root, const char *user)
+{
+	const char *init_paths[] = {
+		"/sbin/init", "/bin/init", "/etc/init", "/bin/sh", NULL
+	};
+	const char **p;
+	const char *path;
+
+	if (chdir(root)) {
+		perror("chdir");
+		exit(1);
+	}
+
+	if (user)
+		dprintf("Checking for init: %s\n", user);
+
+	if (user && user[0] == '/' && !access(user+1, X_OK)) {
+		path = user;
+	} else {
+		for (p = init_paths; *p; p++) {
+			dprintf("Checking for init: %s\n", *p);
+			if (!access(*p+1, X_OK))
+				break;
+		}
+		path = *p;
+	}
+	chdir("/");
+	return path;
+}
+
+/* This is the argc and argv we pass to init */
+const char *init_path;
+int init_argc;
+char **init_argv;
+
+extern ssize_t readfile(const char *, char **);
+
+int main(int argc, char *argv[])
+{
+	char **cmdv, **args;
+	char *cmdlines[3];
+	int i;
+	const char *errmsg;
+	int ret = 0;
+	int cmdc;
+	int fd;
+	struct timeval now;
+
+	gettimeofday(&now, NULL);
+	srand48(now.tv_usec ^ (now.tv_sec << 24));
+
+	/* Default parameters for anything init-like we execute */
+	init_argc = argc;
+	init_argv = alloca((argc+1)*sizeof(char *));
+	memcpy(init_argv, argv, (argc+1)*sizeof(char *));
+
+	if ((fd = open("/dev/console", O_RDWR)) != -1) {
+		dup2(fd, STDIN_FILENO);
+		dup2(fd, STDOUT_FILENO);
+		dup2(fd, STDERR_FILENO);
+
+		if (fd > STDERR_FILENO)
+			close(fd);
+	}
+
+	mnt_procfs = mount_sys_fs("/proc/cmdline", "/proc", "proc") >= 0;
+	if (!mnt_procfs) {
+		ret = 1;
+		goto bail;
+	}
+
+	mnt_sysfs = mount_sys_fs("/sys/bus", "/sys", "sysfs") >= 0;
+	if (!mnt_sysfs) {
+		ret = 1;
+		goto bail;
+	}
+
+	/* Construct the effective kernel command line.  The
+	   effective kernel command line consists of /arch.cmd, if
+	   it exists, /proc/cmdline, plus any arguments after an --
+	   argument on the proper command line, in that order. */
+
+	ret = readfile("/arch.cmd", &cmdlines[0]);
+	if (ret < 0)
+		cmdlines[0] = "";
+
+	ret = readfile("/proc/cmdline", &cmdlines[1]);
+	if (ret < 0) {
+		fprintf(stderr, "%s: cannot read /proc/cmdline\n", progname);
+		ret = 1;
+		goto bail;
+	}
+
+	cmdlines[2] = NULL;
+
+	/* Find an -- argument, and if so append to the command line */
+	for (i = 1; i < argc; i++) {
+		if (!strcmp(argv[i], "--")) {
+			i++;
+			break;
+		}
+	}
+	args = &argv[i];	/* Points either to first argument past -- or
+				   to the final NULL */
+
+	/* Count the number of arguments */
+	cmdc = split_cmdline(INT_MAX, NULL, argv[0], cmdlines, args);
+
+	/* Actually generate the cmdline array */
+	cmdv = (char **)alloca((cmdc+1)*sizeof(char *));
+	if (split_cmdline(cmdc, cmdv, argv[0], cmdlines, args) != cmdc) {
+		ret = 1;
+		goto bail;
+	}
+
+	/* Debugging... */
+	dump_args(cmdc, cmdv);
+
+	/* Resume from suspend-to-disk, if appropriate */
+	/* If successful, does not return */
+	do_resume(cmdc, cmdv);
+
+	/* Initialize networking, if applicable */
+	do_ipconfig(cmdc, cmdv);
+
+	check_path("/root");
+	do_mounts(cmdc, cmdv);
+
+	if (mnt_procfs) {
+		umount2("/proc", 0);
+		mnt_procfs = 0;
+	}
+
+	if (mnt_sysfs) {
+		umount2("/sys", 0);
+		mnt_sysfs = 0;
+	}
+
+	init_path = find_init("/root", get_arg(cmdc, cmdv, "init="));
+	if (!init_path) {
+		fprintf(stderr, "%s: init not found!\n", progname);
+		ret = 2;
+		goto bail;
+	}
+
+	init_argv[0] = strrchr(init_path, '/') + 1;
+
+	errmsg = run_init("/root", "/dev/console",
+			  get_arg(cmdc, cmdv, "drop_capabilities="), false,
+			  false, init_path, init_argv);
+
+	/* If run_init returned, something went bad */
+	fprintf(stderr, "%s: %s: %s\n", progname, errmsg, strerror(errno));
+	ret = 2;
+	goto bail;
+
+bail:
+	if (mnt_procfs)
+		umount2("/proc", 0);
+
+	if (mnt_sysfs)
+		umount2("/sys", 0);
+
+	/*
+	 * If we get here, something bad probably happened, and the kernel
+	 * will most likely panic.  Drain console output so the user can
+	 * figure out what happened.
+	 */
+	tcdrain(2);
+	tcdrain(1);
+
+	return ret;
+}