/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if 0
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1990, 1993, 1994\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)df.c	8.9 (Berkeley) 5/8/95";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <getopt.h>
#include <libutil.h>
#include <locale.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <libxo/xo.h>

#define UNITS_SI	1
#define UNITS_2		2

/* Maximum widths of various fields. */
struct maxwidths {
	int	mntfrom;
	int	fstype;
	int	total;
	int	used;
	int	avail;
	int	iused;
	int	ifree;
};

static void	  addstat(struct statfs *, struct statfs *);
static char	 *getmntpt(const char *);
static const char **makevfslist(char *fslist, int *skip);
static int	  checkvfsname(const char *vfsname, const char **vfslist, int skip);
static int	  checkvfsselected(char *);
static int	  int64width(int64_t);
static char	 *makenetvfslist(void);
static void	  prthuman(const struct statfs *, int64_t);
static void	  prthumanval(const char *, int64_t);
static intmax_t	  fsbtoblk(int64_t, uint64_t, u_long);
static void	  prtstat(struct statfs *, struct maxwidths *);
static size_t	  regetmntinfo(struct statfs **, long);
static void	  update_maxwidths(struct maxwidths *, const struct statfs *);
static void	  usage(void);

static __inline int
imax(int a, int b)
{
	return (a > b ? a : b);
}

static int	  aflag = 0, cflag, hflag, iflag, kflag, lflag = 0, nflag, Tflag;
static int	  thousands;
static int	  skipvfs_l, skipvfs_t;
static const char **vfslist_l, **vfslist_t;

static const struct option long_options[] =
{
	{ "si", no_argument, NULL, 'H' },
	{ NULL, no_argument, NULL, 0 },
};

int
main(int argc, char *argv[])
{
	struct stat stbuf;
	struct statfs statfsbuf, totalbuf;
	struct maxwidths maxwidths;
	struct statfs *mntbuf;
	char *mntpt;
	int i, mntsize;
	int ch, rv;

	(void)setlocale(LC_ALL, "");
	memset(&maxwidths, 0, sizeof(maxwidths));
	memset(&totalbuf, 0, sizeof(totalbuf));
	totalbuf.f_bsize = DEV_BSIZE;
	strlcpy(totalbuf.f_mntfromname, "total", MNAMELEN);

	argc = xo_parse_args(argc, argv);
	if (argc < 0)
		exit(1);

	while ((ch = getopt_long(argc, argv, "+abcgHhiklmnPt:T,", long_options,
	    NULL)) != -1)
		switch (ch) {
		case 'a':
			aflag = 1;
			break;
		case 'b':
				/* FALLTHROUGH */
		case 'P':
			/*
			 * POSIX specifically discusses the behavior of
			 * both -k and -P. It states that the blocksize should
			 * be set to 1024. Thus, if this occurs, simply break
			 * rather than clobbering the old blocksize.
			 */
			if (kflag)
				break;
			setenv("BLOCKSIZE", "512", 1);
			hflag = 0;
			break;
		case 'c':
			cflag = 1;
			break;
		case 'g':
			setenv("BLOCKSIZE", "1g", 1);
			hflag = 0;
			break;
		case 'H':
			hflag = UNITS_SI;
			break;
		case 'h':
			hflag = UNITS_2;
			break;
		case 'i':
			iflag = 1;
			break;
		case 'k':
			kflag++;
			setenv("BLOCKSIZE", "1024", 1);
			hflag = 0;
			break;
		case 'l':
			/* Ignore duplicate -l */
			if (lflag)
				break;
			vfslist_l = makevfslist(makenetvfslist(), &skipvfs_l);
			lflag = 1;
			break;
		case 'm':
			setenv("BLOCKSIZE", "1m", 1);
			hflag = 0;
			break;
		case 'n':
			nflag = 1;
			break;
		case 't':
			if (vfslist_t != NULL)
				xo_errx(1, "only one -t option may be specified");
			vfslist_t = makevfslist(optarg, &skipvfs_t);
			break;
		case 'T':
			Tflag = 1;
			break;
		case ',':
			thousands = 1;
			break;
		case '?':
		default:
			usage();
		}
	argc -= optind;
	argv += optind;

	rv = EXIT_SUCCESS;
	if (!*argv) {
		/* everything (modulo -t) */
		mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
		mntsize = regetmntinfo(&mntbuf, mntsize);
	} else {
		/* just the filesystems specified on the command line */
		mntbuf = malloc(argc * sizeof(*mntbuf));
		if (mntbuf == NULL)
			xo_err(1, "malloc()");
		mntsize = 0;
		/* continued in for loop below */
	}

	xo_open_container("storage-system-information");
	xo_open_list("filesystem");

	/* iterate through specified filesystems */
	for (; *argv; argv++) {
		if (stat(*argv, &stbuf) < 0) {
			if ((mntpt = getmntpt(*argv)) == NULL) {
				xo_warn("%s", *argv);
				rv = EXIT_FAILURE;
				continue;
			}
		} else if (S_ISCHR(stbuf.st_mode)) {
			mntpt = getmntpt(*argv);
			if (mntpt == NULL) {
				xo_warnx("%s: not mounted", *argv);
				rv = EXIT_FAILURE;
				continue;
			}
		} else {
			mntpt = *argv;
		}

		/*
		 * Statfs does not take a `wait' flag, so we cannot
		 * implement nflag here.
		 */
		if (statfs(mntpt, &statfsbuf) < 0) {
			xo_warn("%s", mntpt);
			rv = EXIT_FAILURE;
			continue;
		}

		/*
		 * Check to make sure the arguments we've been given are
		 * satisfied.  Return an error if we have been asked to
		 * list a mount point that does not match the other args
		 * we've been given (-l, -t, etc.).
		 */
		if (checkvfsselected(statfsbuf.f_fstypename) != 0) {
			rv = EXIT_FAILURE;
			continue;
		}

		/* the user asked for it, so ignore the ignore flag */
		statfsbuf.f_flags &= ~MNT_IGNORE;

		/* add to list */
		mntbuf[mntsize++] = statfsbuf;
	}

	memset(&maxwidths, 0, sizeof(maxwidths));
	for (i = 0; i < mntsize; i++) {
		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0) {
			update_maxwidths(&maxwidths, &mntbuf[i]);
			if (cflag)
				addstat(&totalbuf, &mntbuf[i]);
		}
	}
	for (i = 0; i < mntsize; i++)
		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0)
			prtstat(&mntbuf[i], &maxwidths);

	xo_close_list("filesystem");

	if (cflag)
		prtstat(&totalbuf, &maxwidths);

	xo_close_container("storage-system-information");
	if (xo_finish() < 0)
		rv = EXIT_FAILURE;
	exit(rv);
}

static char *
getmntpt(const char *name)
{
	size_t mntsize, i;
	struct statfs *mntbuf;

	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
	for (i = 0; i < mntsize; i++) {
		if (!strcmp(mntbuf[i].f_mntfromname, name))
			return (mntbuf[i].f_mntonname);
	}
	return (NULL);
}

static const char **
makevfslist(char *fslist, int *skip)
{
	const char **av;
	int i;
	char *nextcp;

	if (fslist == NULL)
		return (NULL);
	*skip = 0;
	if (fslist[0] == 'n' && fslist[1] == 'o') {
		fslist += 2;
		*skip = 1;
	}
	for (i = 0, nextcp = fslist; *nextcp; nextcp++)
		if (*nextcp == ',')
			i++;
	if ((av = malloc((size_t)(i + 2) * sizeof(char *))) == NULL) {
		xo_warnx("malloc failed");
		return (NULL);
	}
	nextcp = fslist;
	i = 0;
	av[i++] = nextcp;
	while ((nextcp = strchr(nextcp, ',')) != NULL) {
		*nextcp++ = '\0';
		av[i++] = nextcp;
	}
	av[i++] = NULL;
	return (av);
}

static int
checkvfsname(const char *vfsname, const char **vfslist, int skip)
{

	if (vfslist == NULL)
		return (0);
	while (*vfslist != NULL) {
		if (strcmp(vfsname, *vfslist) == 0)
			return (skip);
		++vfslist;
	}
	return (!skip);
}

/*
 * Without -l and -t option, all file system types are enabled.
 * The -l option selects the local file systems, if present.
 * A -t option modifies the selection by adding or removing further
 * file system types, based on the argument that is passed.
 */
static int
checkvfsselected(char *fstypename)
{
	int result;

	if (vfslist_t) {
		/* if -t option used then select passed types */
		result = checkvfsname(fstypename, vfslist_t, skipvfs_t);
		if (vfslist_l) {
			/* if -l option then adjust selection */
			if (checkvfsname(fstypename, vfslist_l, skipvfs_l) == skipvfs_t)
				result = skipvfs_t;
		}
	} else {
		/* no -t option then -l decides */
		result = checkvfsname(fstypename, vfslist_l, skipvfs_l);
	}
	return (result);
}

/*
 * Make a pass over the file system info in ``mntbuf'' filtering out
 * file system types not in vfslist_{l,t} and possibly re-stating to get
 * current (not cached) info.  Returns the new count of valid statfs bufs.
 */
static size_t
regetmntinfo(struct statfs **mntbufp, long mntsize)
{
	int error, i, j;
	struct statfs *mntbuf;

	if (vfslist_l == NULL && vfslist_t == NULL)
		return (nflag ? mntsize : getmntinfo(mntbufp, MNT_WAIT));

	mntbuf = *mntbufp;
	for (j = 0, i = 0; i < mntsize; i++) {
		if (checkvfsselected(mntbuf[i].f_fstypename) != 0)
			continue;
		/*
		 * XXX statfs(2) can fail for various reasons. It may be
		 * possible that the user does not have access to the
		 * pathname, if this happens, we will fall back on
		 * "stale" filesystem statistics.
		 */
		error = statfs(mntbuf[i].f_mntonname, &mntbuf[j]);
		if (nflag || error < 0)
			if (i != j) {
				if (error < 0)
					xo_warnx("%s stats possibly stale",
					    mntbuf[i].f_mntonname);
				mntbuf[j] = mntbuf[i];
			}
		j++;
	}
	return (j);
}

static void
prthuman(const struct statfs *sfsp, int64_t used)
{

	prthumanval("  {:blocks/%6s}", sfsp->f_blocks * sfsp->f_bsize);
	prthumanval("  {:used/%6s}", used * sfsp->f_bsize);
	prthumanval("  {:available/%6s}", sfsp->f_bavail * sfsp->f_bsize);
}

static void
prthumanval(const char *fmt, int64_t bytes)
{
	char buf[6];
	int flags;

	flags = HN_B | HN_NOSPACE | HN_DECIMAL;
	if (hflag == UNITS_SI)
		flags |= HN_DIVISOR_1000;

	humanize_number(buf, sizeof(buf) - (bytes < 0 ? 0 : 1),
	    bytes, "", HN_AUTOSCALE, flags);

	xo_attr("value", "%lld", (long long) bytes);
	xo_emit(fmt, buf);
}

/*
 * Print an inode count in "human-readable" format.
 */
static void
prthumanvalinode(const char *fmt, int64_t bytes)
{
	char buf[6];
	int flags;

	flags = HN_NOSPACE | HN_DECIMAL | HN_DIVISOR_1000;

	humanize_number(buf, sizeof(buf) - (bytes < 0 ? 0 : 1),
	    bytes, "", HN_AUTOSCALE, flags);

	xo_attr("value", "%lld", (long long) bytes);
	xo_emit(fmt, buf);
}

/*
 * Convert statfs returned file system size into BLOCKSIZE units.
 */
static intmax_t
fsbtoblk(int64_t num, uint64_t fsbs, u_long bs)
{
	return (num * (intmax_t) fsbs / (int64_t) bs);
}

/*
 * Print out status about a file system.
 */
static void
prtstat(struct statfs *sfsp, struct maxwidths *mwp)
{
	static long blocksize;
	static int headerlen, timesthrough = 0;
	static const char *header;
	int64_t used, availblks, inodes;
	const char *format;

	if (++timesthrough == 1) {
		mwp->mntfrom = imax(mwp->mntfrom, (int)strlen("Filesystem"));
		mwp->fstype = imax(mwp->fstype, (int)strlen("Type"));
		if (thousands) {		/* make space for commas */
		    mwp->total += (mwp->total - 1) / 3;
		    mwp->used  += (mwp->used - 1) / 3;
		    mwp->avail += (mwp->avail - 1) / 3;
		    mwp->iused += (mwp->iused - 1) / 3;
		    mwp->ifree += (mwp->ifree - 1) / 3;
		}
		if (hflag) {
			header = "   Size";
			mwp->total = mwp->used = mwp->avail =
			    (int)strlen(header);
		} else {
			header = getbsize(&headerlen, &blocksize);
			mwp->total = imax(mwp->total, headerlen);
		}
		mwp->used = imax(mwp->used, (int)strlen("Used"));
		mwp->avail = imax(mwp->avail, (int)strlen("Avail"));

		xo_emit("{T:/%-*s}", mwp->mntfrom, "Filesystem");
		if (Tflag)
			xo_emit("  {T:/%-*s}", mwp->fstype, "Type");
		xo_emit(" {T:/%*s} {T:/%*s} {T:/%*s} {T:Capacity}",
			mwp->total, header,
			mwp->used, "Used", mwp->avail, "Avail");
		if (iflag) {
			mwp->iused = imax(hflag ? 0 : mwp->iused,
			    (int)strlen("  iused"));
			mwp->ifree = imax(hflag ? 0 : mwp->ifree,
			    (int)strlen("ifree"));
			xo_emit(" {T:/%*s} {T:/%*s} {T:\%iused}",
			    mwp->iused - 2, "iused", mwp->ifree, "ifree");
		}
		xo_emit("  {T:Mounted on}\n");
	}

	xo_open_instance("filesystem");
	/* Check for 0 block size.  Can this happen? */
	if (sfsp->f_bsize == 0) {
		xo_warnx ("File system %s does not have a block size, assuming 512.",
		    sfsp->f_mntonname);
		sfsp->f_bsize = 512;
	}
	xo_emit("{tk:name/%-*s}", mwp->mntfrom, sfsp->f_mntfromname);
	if (Tflag)
		xo_emit("  {:type/%-*s}", mwp->fstype, sfsp->f_fstypename);
	used = sfsp->f_blocks - sfsp->f_bfree;
	availblks = sfsp->f_bavail + used;
	if (hflag) {
		prthuman(sfsp, used);
	} else {
		if (thousands)
		    format = " {t:total-blocks/%*j'd} {t:used-blocks/%*j'd} "
			"{t:available-blocks/%*j'd}";
		else
		    format = " {t:total-blocks/%*jd} {t:used-blocks/%*jd} "
			"{t:available-blocks/%*jd}";
		xo_emit(format,
		    mwp->total, fsbtoblk(sfsp->f_blocks,
		    sfsp->f_bsize, blocksize),
		    mwp->used, fsbtoblk(used, sfsp->f_bsize, blocksize),
		    mwp->avail, fsbtoblk(sfsp->f_bavail,
		    sfsp->f_bsize, blocksize));
	}
	xo_emit(" {:used-percent/%5.0f}{U:%%}",
	    availblks == 0 ? 100.0 : (double)used / (double)availblks * 100.0);
	if (iflag) {
		inodes = sfsp->f_files;
		used = inodes - sfsp->f_ffree;
		if (hflag) {
			xo_emit("  ");
			prthumanvalinode(" {:inodes-used/%5s}", used);
			prthumanvalinode(" {:inodes-free/%5s}", sfsp->f_ffree);
		} else {
			if (thousands)
			    format = " {:inodes-used/%*j'd} {:inodes-free/%*j'd}";
			else
			    format = " {:inodes-used/%*jd} {:inodes-free/%*jd}";
			xo_emit(format, mwp->iused, (intmax_t)used,
			    mwp->ifree, (intmax_t)sfsp->f_ffree);
		}
		if (inodes == 0)
			xo_emit(" {:inodes-used-percent/    -}{U:} ");
		else {
			xo_emit(" {:inodes-used-percent/%4.0f}{U:%%} ",
				(double)used / (double)inodes * 100.0);
		}
	} else
		xo_emit("  ");
	if (strncmp(sfsp->f_mntfromname, "total", MNAMELEN) != 0)
		xo_emit("  {:mounted-on}", sfsp->f_mntonname);
	xo_emit("\n");
	xo_close_instance("filesystem");
}

static void
addstat(struct statfs *totalfsp, struct statfs *statfsp)
{
	uint64_t bsize;

	bsize = statfsp->f_bsize / totalfsp->f_bsize;
	totalfsp->f_blocks += statfsp->f_blocks * bsize;
	totalfsp->f_bfree += statfsp->f_bfree * bsize;
	totalfsp->f_bavail += statfsp->f_bavail * bsize;
	totalfsp->f_files += statfsp->f_files;
	totalfsp->f_ffree += statfsp->f_ffree;
}

/*
 * Update the maximum field-width information in `mwp' based on
 * the file system specified by `sfsp'.
 */
static void
update_maxwidths(struct maxwidths *mwp, const struct statfs *sfsp)
{
	static long blocksize = 0;
	int dummy;

	if (blocksize == 0)
		getbsize(&dummy, &blocksize);

	mwp->mntfrom = imax(mwp->mntfrom, (int)strlen(sfsp->f_mntfromname));
	mwp->fstype = imax(mwp->fstype, (int)strlen(sfsp->f_fstypename));
	mwp->total = imax(mwp->total, int64width(
	    fsbtoblk((int64_t)sfsp->f_blocks, sfsp->f_bsize, blocksize)));
	mwp->used = imax(mwp->used,
	    int64width(fsbtoblk((int64_t)sfsp->f_blocks -
	    (int64_t)sfsp->f_bfree, sfsp->f_bsize, blocksize)));
	mwp->avail = imax(mwp->avail, int64width(fsbtoblk(sfsp->f_bavail,
	    sfsp->f_bsize, blocksize)));
	mwp->iused = imax(mwp->iused, int64width((int64_t)sfsp->f_files -
	    sfsp->f_ffree));
	mwp->ifree = imax(mwp->ifree, int64width(sfsp->f_ffree));
}

/* Return the width in characters of the specified value. */
static int
int64width(int64_t val)
{
	int len;

	len = 0;
	/* Negative or zero values require one extra digit. */
	if (val <= 0) {
		val = -val;
		len++;
	}
	while (val > 0) {
		len++;
		val /= 10;
	}

	return (len);
}

static void
usage(void)
{

	xo_error(
"usage: df [-b | -g | -H | -h | -k | -m | -P] [-acilnT] [-t type] [-,]\n"
"          [file | filesystem ...]\n");
	exit(EX_USAGE);
}

static char *
makenetvfslist(void)
{
	char *str, *strptr, **listptr;
	struct xvfsconf *xvfsp, *keep_xvfsp;
	size_t buflen;
	int cnt, i, maxvfsconf;

	if (sysctlbyname("vfs.conflist", NULL, &buflen, NULL, 0) < 0) {
		xo_warn("sysctl(vfs.conflist)");
		return (NULL);
	}
	xvfsp = malloc(buflen);
	if (xvfsp == NULL) {
		xo_warnx("malloc failed");
		return (NULL);
	}
	keep_xvfsp = xvfsp;
	if (sysctlbyname("vfs.conflist", xvfsp, &buflen, NULL, 0) < 0) {
		xo_warn("sysctl(vfs.conflist)");
		free(keep_xvfsp);
		return (NULL);
	}
	maxvfsconf = buflen / sizeof(struct xvfsconf);

	if ((listptr = malloc(sizeof(char*) * maxvfsconf)) == NULL) {
		xo_warnx("malloc failed");
		free(keep_xvfsp);
		return (NULL);
	}

	for (cnt = 0, i = 0; i < maxvfsconf; i++) {
		if (xvfsp->vfc_flags & VFCF_NETWORK) {
			listptr[cnt++] = strdup(xvfsp->vfc_name);
			if (listptr[cnt-1] == NULL) {
				xo_warnx("malloc failed");
				free(listptr);
				free(keep_xvfsp);
				return (NULL);
			}
		}
		xvfsp++;
	}

	if (cnt == 0 ||
	    (str = malloc(sizeof(char) * (32 * cnt + cnt + 2))) == NULL) {
		if (cnt > 0)
			xo_warnx("malloc failed");
		free(listptr);
		free(keep_xvfsp);
		return (NULL);
	}

	*str = 'n'; *(str + 1) = 'o';
	for (i = 0, strptr = str + 2; i < cnt; i++, strptr++) {
		strlcpy(strptr, listptr[i], 32);
		strptr += strlen(listptr[i]);
		*strptr = ',';
		free(listptr[i]);
	}
	*(--strptr) = '\0';

	free(keep_xvfsp);
	free(listptr);
	return (str);
}