/*
 * Copyright (c) 2013 SUSE.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Started by Jan Kara <jack@suse.cz>
 *
 * DESCRIPTION
 *     Check that fanotify work for a file
 */
#define _GNU_SOURCE
#include "config.h"

#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <sys/syscall.h>
#include "test.h"
#include "lapi/syscalls.h"
#include "fanotify.h"
#include "safe_macros.h"

char *TCID = "fanotify01";
int TST_TOTAL = 12;

#if defined(HAVE_SYS_FANOTIFY_H)
#include <sys/fanotify.h>

#define EVENT_MAX 1024
/* size of the event structure, not counting name */
#define EVENT_SIZE  (sizeof (struct fanotify_event_metadata))
/* reasonable guess as to size of 1024 events */
#define EVENT_BUF_LEN        (EVENT_MAX * EVENT_SIZE)

static void setup(void);
static void cleanup(void);

#define BUF_SIZE 256
static char fname[BUF_SIZE];
static char buf[BUF_SIZE];
static int fd, fd_notify;

static unsigned long long event_set[EVENT_MAX];

static char event_buf[EVENT_BUF_LEN];

int main(int ac, char **av)
{
	int lc;

	tst_parse_opts(ac, av, NULL, NULL);

	setup();

	for (lc = 0; TEST_LOOPING(lc); lc++) {
		int ret, len, i = 0, test_num = 0;

		tst_count = 0;

		if (fanotify_mark(fd_notify, FAN_MARK_ADD, FAN_ACCESS | FAN_MODIFY |
				    FAN_CLOSE | FAN_OPEN, AT_FDCWD, fname) < 0) {
			tst_brkm(TBROK | TERRNO, cleanup,
			    "fanotify_mark (%d, FAN_MARK_ADD, FAN_ACCESS | "
			    "FAN_MODIFY | FAN_CLOSE | FAN_OPEN, AT_FDCWD, %s) "
			    "failed", fd_notify, fname);
		}

		/*
		 * generate sequence of events
		 */
		fd = SAFE_OPEN(cleanup, fname, O_RDONLY);
		event_set[tst_count] = FAN_OPEN;
		tst_count++;

		SAFE_READ(cleanup, 0, fd, buf, BUF_SIZE);
		event_set[tst_count] = FAN_ACCESS;
		tst_count++;

		SAFE_CLOSE(cleanup, fd);
		event_set[tst_count] = FAN_CLOSE_NOWRITE;
		tst_count++;

		/*
		 * Get list of events so far. We get events here to avoid
		 * merging of following events with the previous ones.
		 */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf, EVENT_BUF_LEN);
		len = ret;

		fd = SAFE_OPEN(cleanup, fname, O_RDWR | O_CREAT, 0700);
		event_set[tst_count] = FAN_OPEN;
		tst_count++;

		SAFE_WRITE(cleanup, 1, fd, fname, strlen(fname));
		event_set[tst_count] = FAN_MODIFY;
		tst_count++;

		SAFE_CLOSE(cleanup, fd);
		event_set[tst_count] = FAN_CLOSE_WRITE;
		tst_count++;

		/*
		 * get another list of events
		 */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf + len,
				EVENT_BUF_LEN - len);
		len += ret;

		/*
		 * Ignore mask testing
		 */

		/* Ignore access events */
		if (fanotify_mark(fd_notify,
				    FAN_MARK_ADD | FAN_MARK_IGNORED_MASK,
				    FAN_ACCESS, AT_FDCWD, fname) < 0) {
			tst_brkm(TBROK | TERRNO, cleanup,
			     "fanotify_mark (%d, FAN_MARK_ADD | "
			     "FAN_MARK_IGNORED_MASK, FAN_ACCESS, "
			     "AT_FDCWD, %s) failed", fd_notify, fname);
		}

		fd = SAFE_OPEN(cleanup, fname, O_RDWR);
		event_set[tst_count] = FAN_OPEN;
		tst_count++;

		/* This event should be ignored */
		SAFE_READ(cleanup, 0, fd, buf, BUF_SIZE);

		/*
		 * get another list of events to verify the last one got ignored
		 */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf + len,
				EVENT_BUF_LEN - len);
		len += ret;

		lseek(fd, 0, SEEK_SET);
		/* Generate modify event to clear ignore mask */
		SAFE_WRITE(cleanup, 1, fd, fname, 1);
		event_set[tst_count] = FAN_MODIFY;
		tst_count++;

		/*
		 * This event shouldn't be ignored because previous modification
		 * should have removed the ignore mask
		 */
		SAFE_READ(cleanup, 0, fd, buf, BUF_SIZE);
		event_set[tst_count] = FAN_ACCESS;
		tst_count++;

		SAFE_CLOSE(cleanup, fd);
		event_set[tst_count] = FAN_CLOSE_WRITE;
		tst_count++;

		/* Read events to verify previous access was properly generated */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf + len,
				EVENT_BUF_LEN - len);
		len += ret;

		/*
		 * Now ignore open & close events regardless of file
		 * modifications
		 */
		if (fanotify_mark(fd_notify,
				    FAN_MARK_ADD | FAN_MARK_IGNORED_MASK | FAN_MARK_IGNORED_SURV_MODIFY,
				    FAN_OPEN | FAN_CLOSE, AT_FDCWD, fname) < 0) {
			tst_brkm(TBROK | TERRNO, cleanup,
			     "fanotify_mark (%d, FAN_MARK_ADD | "
			     "FAN_MARK_IGNORED_MASK | "
			     "FAN_MARK_IGNORED_SURV_MODIFY, FAN_OPEN | "
			     "FAN_CLOSE, AT_FDCWD, %s) failed", fd_notify,
			     fname);
		}

		/* This event should be ignored */
		fd = SAFE_OPEN(cleanup, fname, O_RDWR);

		SAFE_WRITE(cleanup, 1, fd, fname, 1);
		event_set[tst_count] = FAN_MODIFY;
		tst_count++;

		/* This event should be still ignored */
		SAFE_CLOSE(cleanup, fd);

		/* This event should still be ignored */
		fd = SAFE_OPEN(cleanup, fname, O_RDWR);

		/* Read events to verify open & close were ignored */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf + len,
				EVENT_BUF_LEN - len);
		len += ret;

		/* Now remove open and close from ignored mask */
		if (fanotify_mark(fd_notify,
				    FAN_MARK_REMOVE | FAN_MARK_IGNORED_MASK,
				    FAN_OPEN | FAN_CLOSE, AT_FDCWD, fname) < 0) {
			tst_brkm(TBROK | TERRNO, cleanup,
			     "fanotify_mark (%d, FAN_MARK_REMOVE | "
			     "FAN_MARK_IGNORED_MASK, FAN_OPEN | "
			     "FAN_CLOSE, AT_FDCWD, %s) failed", fd_notify,
			     fname);
		}

		SAFE_CLOSE(cleanup, fd);
		event_set[tst_count] = FAN_CLOSE_WRITE;
		tst_count++;

		/* Read events to verify close was generated */
		ret = SAFE_READ(cleanup, 0, fd_notify, event_buf + len,
				EVENT_BUF_LEN - len);
		len += ret;

		if (TST_TOTAL != tst_count) {
			tst_brkm(TBROK, cleanup,
				 "TST_TOTAL (%d) and tst_count (%d) are not "
				 "equal", TST_TOTAL, tst_count);
		}
		tst_count = 0;

		/*
		 * check events
		 */
		while (i < len) {
			struct fanotify_event_metadata *event;

			event = (struct fanotify_event_metadata *)&event_buf[i];
			if (test_num >= TST_TOTAL) {
				tst_resm(TFAIL,
					 "get unnecessary event: mask=%llx "
					 "pid=%u fd=%u",
					 (unsigned long long)event->mask,
					 (unsigned)event->pid, event->fd);
			} else if (!(event->mask & event_set[test_num])) {
				tst_resm(TFAIL,
					 "get event: mask=%llx (expected %llx) "
					 "pid=%u fd=%u",
					 (unsigned long long)event->mask,
					 event_set[test_num],
					 (unsigned)event->pid, event->fd);
			} else if (event->pid != getpid()) {
				tst_resm(TFAIL,
					 "get event: mask=%llx pid=%u "
					 "(expected %u) fd=%u",
					 (unsigned long long)event->mask,
					 (unsigned)event->pid,
					 (unsigned)getpid(),
					 event->fd);
			} else {
				if (event->fd == -2)
					goto pass;
				ret = read(event->fd, buf, BUF_SIZE);
				if (ret != strlen(fname)) {
					tst_resm(TFAIL,
						 "cannot read from returned fd "
						 "of event: mask=%llx pid=%u "
						 "fd=%u ret=%d (errno=%d)",
						 (unsigned long long)event->mask,
						 (unsigned)event->pid,
						 event->fd, ret, errno);
				} else if (memcmp(buf, fname, strlen(fname))) {
					tst_resm(TFAIL,
						 "wrong data read from returned fd "
						 "of event: mask=%llx pid=%u "
						 "fd=%u",
						 (unsigned long long)event->mask,
						 (unsigned)event->pid,
						 event->fd);
				} else {
pass:
					tst_resm(TPASS,
					    "get event: mask=%llx pid=%u fd=%u",
					    (unsigned long long)event->mask,
					    (unsigned)event->pid, event->fd);
				}
			}
			/*
			 * We have verified the data now so close fd and
			 * invalidate it so that we don't check it again
			 * unnecessarily
			 */
			close(event->fd);
			event->fd = -2;
			event->mask &= ~event_set[test_num];
			/* No events left in current mask? Go for next event */
			if (event->mask == 0) {
				i += event->event_len;
			}
			test_num++;
		}
		for (; test_num < TST_TOTAL; test_num++) {
			tst_resm(TFAIL, "didn't get event: mask=%llx",
				 event_set[test_num]);

		}
		/* Remove mark to clear FAN_MARK_IGNORED_SURV_MODIFY */
		if (fanotify_mark(fd_notify, FAN_MARK_REMOVE, FAN_ACCESS | FAN_MODIFY |
				    FAN_CLOSE | FAN_OPEN, AT_FDCWD, fname) < 0) {
			tst_brkm(TBROK | TERRNO, cleanup,
			    "fanotify_mark (%d, FAN_MARK_REMOVE, FAN_ACCESS | "
			    "FAN_MODIFY | FAN_CLOSE | FAN_OPEN, AT_FDCWD, %s) "
			    "failed", fd_notify, fname);
		}

	}

	cleanup();
	tst_exit();
}

static void setup(void)
{
	tst_sig(NOFORK, DEF_HANDLER, cleanup);

	TEST_PAUSE;

	tst_tmpdir();

	sprintf(fname, "tfile_%d", getpid());
	fd = SAFE_OPEN(cleanup, fname, O_RDWR | O_CREAT, 0700);
	SAFE_WRITE(cleanup, 1, fd, fname, 1);

	/* close the file we have open */
	SAFE_CLOSE(cleanup, fd);

	if ((fd_notify = fanotify_init(FAN_CLASS_NOTIF, O_RDONLY)) < 0) {
		if (errno == ENOSYS) {
			tst_brkm(TCONF, cleanup,
				 "fanotify is not configured in this kernel.");
		} else {
			tst_brkm(TBROK | TERRNO, cleanup,
				 "fanotify_init failed");
		}
	}
}

static void cleanup(void)
{
	if (fd_notify > 0 && close(fd_notify))
		tst_resm(TWARN | TERRNO, "close(%d) failed", fd_notify);

	tst_rmdir();
}

#else

int main(void)
{
	tst_brkm(TCONF, NULL, "system doesn't have required fanotify support");
}

#endif
