/* ----------------------------------------------------------------------- *

 *   

 *  mount_bind.c      - module to mount a local filesystem if possible;

 *			otherwise create a symlink.

 *

 *   Copyright 2000 Transmeta Corporation - All Rights Reserved

 *

 *   This program is free software; you can redistribute it and/or modify

 *   it under the terms of the GNU General Public License as published by

 *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,

 *   USA; either version 2 of the License, or (at your option) any later

 *   version; incorporated herein by reference.

 *

 * ----------------------------------------------------------------------- */

#include <stdio.h>

#include <malloc.h>

#include <string.h>

#include <stdlib.h>

#include <sys/param.h>

#include <sys/types.h>

#include <sys/stat.h>

#define MODULE_MOUNT

#include "automount.h"

#define MODPREFIX "mount(bind): "

int mount_version = AUTOFS_MOUNT_VERSION;	/* Required by protocol */

static int bind_works = 0;

int mount_init(void **context)

{

	char tmp1[] = "/tmp/autoXXXXXX", *t1_dir;

	char tmp2[] = "/tmp/autoXXXXXX", *t2_dir;

	int err;

	struct stat st1, st2;

	t1_dir = mkdtemp(tmp1);

	t2_dir = mkdtemp(tmp2);

	if (t1_dir == NULL || t2_dir == NULL) {

		if (t1_dir)

			rmdir(t1_dir);

		if (t2_dir)

			rmdir(t2_dir);

		return 0;

	}

	if (lstat(t1_dir, &st1) == -1)

		goto out;

	err = spawn_mount(LOGOPT_NONE, "-n", "--bind", t1_dir, t2_dir, NULL);

	if (err == 0 &&

	    lstat(t2_dir, &st2) == 0 &&

	    st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino) {

		bind_works = 1;

	}

	if (spawn_umount(LOGOPT_NONE, "-n", t2_dir, NULL) != 0)

		debug(LOGOPT_ANY, MODPREFIX "umount failed for %s", t2_dir);

out:

	rmdir(t1_dir);

	rmdir(t2_dir);

	return 0;

}

int mount_reinit(void **context)

{

	return 0;

}

int mount_mount(struct autofs_point *ap, const char *root, const char *name, int name_len,

		const char *what, const char *fstype, const char *options, void *context)

{

	char fullpath[PATH_MAX];

	char buf[MAX_ERR_BUF];

	int err;

	int i, len;

	int symlnk = (*name != '/' && (ap->flags & MOUNT_FLAG_SYMLINK));

	if (ap->flags & MOUNT_FLAG_REMOUNT)

		return 0;

	/* Extract "symlink" pseudo-option which forces local filesystems

	 * to be symlinked instead of bound.

	 */

	if (*name != '/' && !symlnk && options) {

		const char *comma;

		int o_len = strlen(options) + 1;

		for (comma = options; *comma != '\0';) {

			const char *cp;

			const char *end;

			while (*comma == ',')

				comma++;

			/* Skip leading white space */

			while (*comma == ' ' || *comma == '\t')

				comma++;

			cp = comma;

			while (*comma != '\0' && *comma != ',')

				comma++;

			/* Skip trailing white space */

			end = comma - 1;

			while (*comma == ' ' || *comma == '\t')

				end--;

			o_len = end - cp + 1;

			if (_strncmp("symlink", cp, o_len) == 0)

				symlnk = 1;

		}

	}

	/* Root offset of multi-mount */

	len = strlen(root);

	if (root[len - 1] == '/') {

		len = snprintf(fullpath, len, "%s", root);

	} else if (*name == '/') {

		/*

		 * Direct or offset mount, name is absolute path so

		 * don't use root (but with move mount changes root

		 * is now the same as name).

		 */

		len = sprintf(fullpath, "%s", root);

	} else {

		len = sprintf(fullpath, "%s/%s", root, name);

	}

	fullpath[len] = '\0';

	i = len;

	while (--i > 0 && fullpath[i] == '/')

		fullpath[i] = '\0';

	if (options == NULL || *options == '\0')

		options = "defaults";

	if (!strcmp(what, fullpath)) {

		debug(ap->logopt, MODPREFIX

		     "cannot mount or symlink %s to itself", fullpath);

		return 1;

	}

	if (!symlnk && bind_works) {

		int status, existed = 1;

		debug(ap->logopt, MODPREFIX "calling mkdir_path %s", fullpath);

		status = mkdir_path(fullpath, mp_mode);

		if (status && errno != EEXIST) {

			char *estr = strerror_r(errno, buf, MAX_ERR_BUF);

			error(ap->logopt,

			      MODPREFIX "mkdir_path %s failed: %s",

			      fullpath, estr);

			return 1;

		}

		if (!status)

			existed = 0;

		debug(ap->logopt, MODPREFIX

		      "calling mount --bind -o %s %s %s",

		      options, what, fullpath);

		err = spawn_bind_mount(ap->logopt, "-o",

				       options, what, fullpath, NULL);

		if (err) {

			if (ap->type != LKP_INDIRECT)

				return 1;

			if (!existed &&

			   (!(ap->flags & MOUNT_FLAG_GHOST) && name_len))

				rmdir_path(ap, fullpath, ap->dev);

			return err;

		} else {

			debug(ap->logopt,

			      MODPREFIX "mounted %s type %s on %s",

			      what, fstype, fullpath);

			return 0;

		}

	} else {

		char *cp;

		char basepath[PATH_MAX];

		int status;

		struct stat st;

		strcpy(basepath, fullpath);

		cp = strrchr(basepath, '/');

		if (cp != NULL && cp != basepath)

			*cp = '\0';

		if ((status = stat(fullpath, &st)) == 0) {

			if (S_ISDIR(st.st_mode))

				rmdir(fullpath);

		} else {

			debug(ap->logopt,

			      MODPREFIX "calling mkdir_path %s", basepath);

			if (mkdir_path(basepath, mp_mode) && errno != EEXIST) {

				char *estr;

				estr = strerror_r(errno, buf, MAX_ERR_BUF);

				error(ap->logopt,

				      MODPREFIX "mkdir_path %s failed: %s",

				      basepath, estr);

				return 1;

			}

		}

		if (symlink(what, fullpath) && errno != EEXIST) {

			error(ap->logopt,

			      MODPREFIX

			      "failed to create symlink %s -> %s",

			      fullpath, what);

			if ((ap->flags & MOUNT_FLAG_GHOST) && !status) {

				if (mkdir_path(fullpath, mp_mode) && errno != EEXIST) {

					char *estr = strerror_r(errno, buf, MAX_ERR_BUF);

					error(ap->logopt,

					      MODPREFIX "mkdir_path %s failed: %s",

					      fullpath, estr);

				}

			} else {

				if (ap->type == LKP_INDIRECT)

					rmdir_path(ap, fullpath, ap->dev);

			}

			return 1;

		} else {

			debug(ap->logopt,

			      MODPREFIX "symlinked %s -> %s", fullpath, what);

			return 0;

		}

	}

}

int mount_done(void *context)

{

	return 0;

}