/*
 *
 *	Generic IO operations on quotafiles
 *
 *	Jan Kara <jack@suse.cz> - sponsored by SuSE CR
 */

#include "config.h"

#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <endian.h>

#include "pot.h"
#include "bylabel.h"
#include "common.h"
#include "quotasys.h"
#include "quotaio.h"

#include "dqblk_v1.h"
#include "dqblk_v2.h"
#include "dqblk_rpc.h"
#include "dqblk_xfs.h"

/* Header in all newer quotafiles */
struct disk_dqheader {
	u_int32_t dqh_magic;
	u_int32_t dqh_version;
} __attribute__ ((packed));

/*
 *	Detect quota format and initialize quota IO
 */
struct quota_handle *init_io(struct mount_entry *mnt, int type, int fmt, int flags)
{
	char *qfname = NULL;
	int fd = -1, kernfmt;
	struct quota_handle *h = smalloc(sizeof(struct quota_handle));
	int nameflag;

	if (!me_hasquota(mnt, type))
		goto out_handle;
	if (stat(mnt->me_devname, &h->qh_stat) < 0)
		memset(&h->qh_stat, 0, sizeof(struct stat));
	h->qh_io_flags = 0;
	if (flags & IOI_READONLY)
		h->qh_io_flags |= IOFL_RO;
	if (flags & IOI_NFS_MIXED_PATHS)
		h->qh_io_flags |= IOFL_NFS_MIXED_PATHS;
	h->qh_type = type;
	sstrncpy(h->qh_quotadev, mnt->me_devname, sizeof(h->qh_quotadev));
	sstrncpy(h->qh_fstype, mnt->me_type, MAX_FSTYPE_LEN);
	sstrncpy(h->qh_dir, mnt->me_dir, PATH_MAX);
	if (nfs_fstype(mnt->me_type)) {	/* NFS filesystem? */
		if (fmt != -1 && fmt != QF_RPC) {	/* User wanted some other format? */
			errstr(_("Only RPC quota format is allowed on NFS filesystem.\n"));
			goto out_handle;
		}
#ifdef RPC
		h->qh_fd = -1;
		h->qh_fmt = QF_RPC;
		h->qh_ops = &quotafile_ops_rpc;
		memset(&h->qh_info, 0, sizeof(h->qh_info));
		h->qh_ops->init_io(h);
		return h;
#else
		errstr(_("RPC quota format not compiled.\n"));
		goto out_handle;
#endif
	} else if (fmt == QF_RPC) {
		errstr(_("RPC quota format specified for non-NFS filesystem.\n"));
		goto out_handle;
	}

	if (!strcmp(mnt->me_type, MNTTYPE_XFS) ||	/* XFS filesystem? */
	    !strcmp(mnt->me_type, MNTTYPE_GFS2) ||	/* XFS filesystem? */
	    !strcmp(mnt->me_type, MNTTYPE_EXFS)) {	/* EXFS filesystem? */
		if (fmt != -1 && fmt != QF_XFS) {	/* User wanted some other format? */
			errstr(_("Only XFS quota format is allowed on XFS filesystem.\n"));
			goto out_handle;
		}
		h->qh_fd = -1;
		h->qh_fmt = QF_XFS;
		h->qh_ops = &quotafile_ops_xfs;
		memset(&h->qh_info, 0, sizeof(h->qh_info));
		h->qh_ops->init_io(h);
		return h;
	}
	else if (fmt == QF_XFS) {
		errstr(_("XFS quota allowed only on XFS filesystem.\n"));
		goto out_handle;
	}
	if (kern_qfmt_supp(fmt)) {	/* Quota compiled and desired format available? */
		/* Quota turned on? */
		kernfmt = kern_quota_on(mnt, type, fmt);
		if (kernfmt >= 0) {
			h->qh_io_flags |= IOFL_QUOTAON;
			fmt = kernfmt;	/* Default is kernel used format */
		}
	}

	if (meta_qf_fstype(mnt->me_type) || mnt->me_qfmt[type] == QF_META) {
		if (!QIO_ENABLED(h)) {
			errstr(_("Quota not supported by the filesystem.\n"));
			goto out_handle;
		}
		h->qh_fd = -1;
		h->qh_fmt = fmt;
		goto set_ops;
	}

	nameflag = (!QIO_ENABLED(h) || flags & IOI_INITSCAN) ? NF_FORMAT : 0;
	if (fmt == -1) {
		/* Let's try any VFSv0 quota format... */
		if (get_qf_name(mnt, type, QF_VFSV0, nameflag, &qfname) >= 0)
			fmt = QF_VFSV0;
		/* And then VFSv1 quota format... */
		else if (get_qf_name(mnt, type, QF_VFSV1, nameflag, &qfname) >= 0)
			fmt = QF_VFSV1;
		/* And then old quota format... */
		else if (get_qf_name(mnt, type, QF_VFSOLD, nameflag, &qfname) >= 0)
			fmt = QF_VFSOLD;
		else {	/* Don't know... */
			errstr(_("Cannot find any quota file to work on.\n"));
			goto out_handle;
		}
	} else {
		if (get_qf_name(mnt, type, fmt, nameflag, &qfname) < 0) {
			errstr(_("Quota file not found or has wrong format.\n"));
			goto out_handle;
		}
	}
	if (!QIO_ENABLED(h) || flags & IOI_INITSCAN) {	/* Need to open file? */
		if (QIO_ENABLED(h)) {	/* Kernel uses same file? */
			unsigned int cmd =
				(kernel_iface == IFACE_GENERIC) ? Q_SYNC : Q_6_5_SYNC;
			if (quotactl(QCMD(cmd, h->qh_type), h->qh_quotadev,
				     0, NULL) < 0) {
				die(4, _("Cannot sync quotas on device %s: %s\n"),
				    h->qh_quotadev, strerror(errno));
			}
		}
		/* We still need to open file for operations like 'repquota' */
		if ((fd = open(qfname, QIO_RO(h) ? O_RDONLY : O_RDWR)) < 0) {
			errstr(_("Cannot open quotafile %s: %s\n"),
				qfname, strerror(errno));
			goto out_handle;
		}
		flock(fd, QIO_RO(h) ? LOCK_SH : LOCK_EX);
		/* Init handle */
		h->qh_fd = fd;
		h->qh_fmt = fmt;
	} else {
		h->qh_fd = -1;
		h->qh_fmt = fmt;
	}
	free(qfname);	/* We don't need it anymore */
	qfname = NULL;

set_ops:
	if (fmt == QF_VFSOLD)
		h->qh_ops = &quotafile_ops_1;
	else if (is_tree_qfmt(fmt))
		h->qh_ops = &quotafile_ops_2;
	else if (fmt == QF_META)
		h->qh_ops = &quotafile_ops_meta;
	memset(&h->qh_info, 0, sizeof(h->qh_info));

	if (h->qh_ops->init_io && h->qh_ops->init_io(h) < 0) {
		errstr(_("Cannot initialize quota on %s: %s\n"), h->qh_quotadev, strerror(errno));
		goto out_lock;
	}
	return h;
out_lock:
	if (fd != -1)
		flock(fd, LOCK_UN);
out_handle:
	if (qfname)
		free(qfname);
	free(h);
	return NULL;
}

/*
 *	Create new quotafile of specified format on given filesystem
 */
struct quota_handle *new_io(struct mount_entry *mnt, int type, int fmt)
{
	char *qfname;
	int fd;
	struct quota_handle *h;
	char namebuf[PATH_MAX];

	if (fmt == -1)
		fmt = QF_VFSV0;
	else if (fmt == QF_RPC || fmt == QF_XFS) {
		errstr(_("Creation of %s quota format is not supported.\n"),
			fmt2name(fmt));
		return NULL;
	}
	/*
	 * For filesystems which never have quotas in quota files or for
 	 * filesystems which have quotas already stored in system files we
	 * refuse to create anything.
	 */
 	if (meta_qf_fstype(mnt->me_type) || mnt->me_qfmt[type] == QF_META) {
		errstr(_("Quota on %s is stored in system files and must"
			 " be manipulated by fs tools.\n"), mnt->me_dir);
		return NULL;
	}
	if (get_qf_name(mnt, type, fmt, 0, &qfname) < 0)
		return NULL;
	sstrncpy(namebuf, qfname, PATH_MAX);
	sstrncat(namebuf, ".new", PATH_MAX);
	free(qfname);
	if ((fd = open(namebuf, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR)) < 0) {
		errstr(_("Cannot create new quotafile %s: %s\n"),
			namebuf, strerror(errno));
		return NULL;
	}
	h = smalloc(sizeof(struct quota_handle));

	h->qh_fd = fd;
	h->qh_io_flags = 0;
	sstrncpy(h->qh_quotadev, mnt->me_devname, sizeof(h->qh_quotadev));
	sstrncpy(h->qh_fstype, mnt->me_type, MAX_FSTYPE_LEN);
	sstrncpy(h->qh_dir, mnt->me_dir, PATH_MAX);
	h->qh_type = type;
	h->qh_fmt = fmt;
	memset(&h->qh_info, 0, sizeof(h->qh_info));
	if (fmt == QF_VFSOLD)
		h->qh_ops = &quotafile_ops_1;
	else
		h->qh_ops = &quotafile_ops_2;

	flock(fd, LOCK_EX);
	if (h->qh_ops->new_io && h->qh_ops->new_io(h) < 0) {
		flock(fd, LOCK_UN);
		free(h);
		goto out_fd;
	}
	return h;
out_fd:
	close(fd);
	return NULL;
}

/*
 *	Close quotafile and release handle
 */
int end_io(struct quota_handle *h)
{
	if (h->qh_io_flags & IOFL_INFODIRTY) {
		if (h->qh_ops->write_info && h->qh_ops->write_info(h) < 0)
			return -1;
		h->qh_io_flags &= ~IOFL_INFODIRTY;
	}
	if (h->qh_ops->end_io && h->qh_ops->end_io(h) < 0)
		return -1;
	if (h->qh_fd != -1) {
		flock(h->qh_fd, LOCK_UN);
		close(h->qh_fd);
	}
	free(h);
	return 0;
}

/*
 *	Create empty quota structure
 */
struct dquot *get_empty_dquot(void)
{
	struct dquot *dquot = smalloc(sizeof(struct dquot));

	memset(dquot, 0, sizeof(*dquot));
	dquot->dq_id = -1;
	return dquot;
}

/*
 *	Check whether values in current dquot can be stored on disk
 */
int check_dquot_range(struct dquot *dquot)
{
	struct util_dqinfo *info = &dquot->dq_h->qh_info;

	if (dquot->dq_dqb.dqb_bhardlimit > info->dqi_max_b_limit ||
	    dquot->dq_dqb.dqb_bsoftlimit > info->dqi_max_b_limit ||
	    dquot->dq_dqb.dqb_ihardlimit > info->dqi_max_i_limit ||
	    dquot->dq_dqb.dqb_isoftlimit > info->dqi_max_i_limit) {
		errstr(_("Trying to set quota limits out of range "
				 "supported by quota format on %s.\n"), dquot->dq_h->qh_quotadev);
		return -1;
	}
	if (dquot->dq_dqb.dqb_curinodes > info->dqi_max_i_usage ||
	    dquot->dq_dqb.dqb_curspace > info->dqi_max_b_usage) {
		errstr(_("Trying to set quota usage out of range "
			 "supported by quota format on %s.\n"), dquot->dq_h->qh_quotadev);
		return -1;
	}
	return 0;
}