GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.bin/rdistd/filesys.c Lines: 0 125 0.0 %
Date: 2017-11-07 Branches: 0 96 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: filesys.c,v 1.19 2015/01/21 04:08:37 guenther Exp $	*/
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/*
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 * Copyright (c) 1983 Regents of the University of California.
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <sys/types.h>
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#include <sys/mount.h>
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#include <errno.h>
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#include <string.h>
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#include <unistd.h>
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#include "server.h"
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/*
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 * This file contains functions dealing with getting info
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 * about mounted filesystems.
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 */
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jmp_buf env;
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/*
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 * Given a pathname, find the fullest component that exists.
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 * If statbuf is not NULL, set it to point at our stat buffer.
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 */
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char *
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find_file(char *pathname, struct stat *statbuf, int *isvalid)
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{
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	static char last_pathname[PATH_MAX];
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	static char file[PATH_MAX + 3];
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	static struct stat filestat;
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	char *p;
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	/*
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	 * Mark the statbuf as invalid to start with.
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	 */
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	*isvalid = 0;
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	/*
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	 * If this is the same pathname as the last time, and
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	 * the file buffer is valid and we're doing the same stat()
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	 * or lstat(), then set statbuf to the last filestat and
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	 * return the last file we found.
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	 */
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	if (strcmp(pathname, last_pathname) == 0 && file[0]) {
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		if (statbuf)
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			statbuf = &filestat;
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		if (strcmp(pathname, file) == 0)
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			*isvalid = 1;
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		return(file);
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	}
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	if (strlen(pathname) > sizeof(file) + 3) {
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		error("%s: Name to large for buffer.", pathname);
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	        return(NULL);
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	}
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	/*
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	 * Save for next time
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	 */
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	(void) strlcpy(last_pathname, pathname, sizeof(last_pathname));
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	if (*pathname == '/')
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	        (void) strlcpy(file, pathname, sizeof(file));
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	else {
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		/*
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		 * Ensure we have a directory (".") in our path
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		 * so we have something to stat in case the file
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		 * does not exist.
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		 */
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	        (void) strlcpy(file, "./", sizeof(file));
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		(void) strlcat(file, pathname, sizeof(file));
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	}
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	while (lstat(file, &filestat) != 0) {
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		/*
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		 * Trim the last part of the pathname to try next level up
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		 */
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		if (errno == ENOENT) {
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			/*
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			 * Trim file name to get directory name.
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			 * Normally we want to change /dir1/dir2/file
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			 * into "/dir1/dir2/."
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			 */
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			if ((p = strrchr(file, '/')) != NULL) {
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				if (strcmp(p, "/.") == 0) {
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					*p = CNULL;
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				} else {
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					*++p = '.';
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					*++p = CNULL;
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				}
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			} else {
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				/*
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				 * Couldn't find anything, so give up.
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				 */
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				debugmsg(DM_MISC, "Cannot find dir of `%s'",
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					 pathname);
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				return(NULL);
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			}
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			continue;
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		} else {
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			error("%s: lstat failed: %s", pathname, SYSERR);
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			return(NULL);
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		}
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	}
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	if (statbuf)
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		bcopy(&filestat, statbuf, sizeof(filestat));
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	/*
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	 * Trim the "/." that we added.
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	 */
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	p = &file[strlen(file) - 1];
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	if (*p == '.')
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		*p-- = CNULL;
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	for ( ; p && *p && *p == '/' && p != file; --p)
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		*p = CNULL;
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	/*
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	 * If this file is a symlink we really want the parent directory
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	 * name in case the symlink points to another filesystem.
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	 */
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	if (S_ISLNK(filestat.st_mode))
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		if ((p = strrchr(file, '/')) && *p+1) {
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			/* Is this / (root)? */
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			if (p == file)
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				file[1] = CNULL;
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			else
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				*p = CNULL;
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		}
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	if (strcmp(pathname, file) == 0)
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		*isvalid = 1;
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	return(*file ? file : NULL);
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}
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/*
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 * Find the device that "filest" is on in the "mntinfo" linked list.
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 */
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mntent_t *
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findmnt(struct stat *filest, struct mntinfo *mntinfo)
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{
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	struct mntinfo *mi;
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	for (mi = mntinfo; mi; mi = mi->mi_nxt) {
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		if (mi->mi_mnt->me_flags & MEFLAG_IGNORE)
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			continue;
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		if (filest->st_dev == mi->mi_dev)
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			return(mi->mi_mnt);
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	}
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	return(NULL);
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}
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/*
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 * Is "mnt" a duplicate of any of the mntinfo->mi_mnt elements?
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 */
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int
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isdupmnt(mntent_t *mnt, struct mntinfo *mntinfo)
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{
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	struct mntinfo *m;
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	for (m = mntinfo; m; m = m->mi_nxt)
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		if (strcmp(m->mi_mnt->me_path, mnt->me_path) == 0)
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			return(1);
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	return(0);
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}
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/*
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 * Alarm clock
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 */
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void
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wakeup(int dummy)
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{
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	debugmsg(DM_CALL, "wakeup() in filesys.c called");
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	longjmp(env, 1);
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}
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/*
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 * Make a linked list of mntinfo structures.
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 * Use "mi" as the base of the list if it's non NULL.
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 */
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struct mntinfo *
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makemntinfo(struct mntinfo *mi)
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{
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	static struct mntinfo *mntinfo;
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	struct mntinfo *newmi, *m;
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	struct stat mntstat;
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	mntent_t *mnt;
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	int timeo = 310;
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	if (!setmountent()) {
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		message(MT_NERROR, "setmntent failed: %s", SYSERR);
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		return(NULL);
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	}
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	(void) signal(SIGALRM, wakeup);
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	(void) alarm(timeo);
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	if (setjmp(env)) {
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		message(MT_NERROR, "Timeout getting mount info");
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		return(NULL);
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	}
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	mntinfo = mi;
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	while ((mnt = getmountent()) != NULL) {
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		debugmsg(DM_MISC, "mountent = '%s'", mnt->me_path);
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		/*
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		 * Make sure we don't already have it for some reason
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		 */
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		if (isdupmnt(mnt, mntinfo))
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			continue;
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		/*
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		 * Get stat info
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		 */
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		if (stat(mnt->me_path, &mntstat) != 0) {
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			message(MT_WARNING, "%s: Cannot stat filesystem: %s",
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				mnt->me_path, SYSERR);
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			continue;
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		}
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		/*
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		 * Create new entry
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		 */
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		newmi = xcalloc(1, sizeof(*newmi));
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		newmi->mi_mnt = newmountent(mnt);
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		newmi->mi_dev = mntstat.st_dev;
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		/*
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		 * Add entry to list
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		 */
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		if (mntinfo) {
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			for (m = mntinfo; m->mi_nxt; m = m->mi_nxt)
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				continue;
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			m->mi_nxt = newmi;
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		} else
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			mntinfo = newmi;
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	}
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	alarm(0);
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	endmountent();
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	return(mntinfo);
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}
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/*
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 * Given a name like /usr/src/etc/foo.c returns the mntent
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 * structure for the file system it lives in.
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 *
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 * If "statbuf" is not NULL it is used as the stat buffer too avoid
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 * stat()'ing the file again back in server.c.
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 */
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mntent_t *
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getmntpt(char *pathname, struct stat *statbuf, int *isvalid)
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{
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	static struct mntinfo *mntinfo = NULL;
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	static struct stat filestat;
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	struct stat *pstat;
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	struct mntinfo *tmpmi;
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	mntent_t *mnt;
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	/*
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	 * Use the supplied stat buffer if not NULL or our own.
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	 */
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	if (statbuf)
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		pstat = statbuf;
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	else
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		pstat = &filestat;
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	if (!find_file(pathname, pstat, isvalid))
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	        return(NULL);
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	/*
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	 * Make mntinfo if it doesn't exist.
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	 */
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	if (!mntinfo)
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		mntinfo = makemntinfo(NULL);
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	/*
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	 * Find the mnt that pathname is on.
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	 */
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	if ((mnt = findmnt(pstat, mntinfo)) != NULL)
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		return(mnt);
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	/*
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	 * We failed to find correct mnt, so maybe it's a newly
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	 * mounted filesystem.  We rebuild mntinfo and try again.
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	 */
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	if ((tmpmi = makemntinfo(mntinfo)) != NULL) {
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		mntinfo = tmpmi;
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		if ((mnt = findmnt(pstat, mntinfo)) != NULL)
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			return(mnt);
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	}
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	error("%s: Could not find mount point", pathname);
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	return(NULL);
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}
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/*
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 * Is "path" NFS mounted?  Return 1 if it is, 0 if not, or -1 on error.
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 */
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int
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is_nfs_mounted(char *path, struct stat *statbuf, int *isvalid)
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{
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	mntent_t *mnt;
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	if ((mnt = getmntpt(path, statbuf, isvalid)) == NULL)
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		return(-1);
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	if (mnt->me_flags & MEFLAG_NFS)
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		return(1);
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	return(0);
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}
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/*
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 * Is "path" on a read-only mounted filesystem?
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 * Return 1 if it is, 0 if not, or -1 on error.
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 */
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int
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is_ro_mounted(char *path, struct stat *statbuf, int *isvalid)
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{
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	mntent_t *mnt;
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	if ((mnt = getmntpt(path, statbuf, isvalid)) == NULL)
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		return(-1);
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	if (mnt->me_flags & MEFLAG_READONLY)
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		return(1);
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	return(0);
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}
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/*
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 * Is "path" a symlink?
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 * Return 1 if it is, 0 if not, or -1 on error.
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 */
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int
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is_symlinked(char *path, struct stat *statbuf, int *isvalid)
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{
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	static struct stat stb;
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	if (!(*isvalid)) {
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		if (lstat(path, &stb) != 0)
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			return(-1);
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		statbuf = &stb;
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	}
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	if (S_ISLNK(statbuf->st_mode))
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		return(1);
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	return(0);
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}
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/*
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 * Get filesystem information for "file".  Set freespace
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 * to the amount of free (available) space and number of free
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 * files (inodes) on the filesystem "file" resides on.
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 * Returns 0 on success or -1 on failure.
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 * Filesystem values < 0 indicate unsupported or unavailable
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 * information.
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 */
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int
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getfilesysinfo(char *file, int64_t *freespace, int64_t *freefiles)
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{
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	struct statfs statfsbuf;
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	char *mntpt;
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	int64_t val;
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	int t, r;
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	/*
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	 * Get the mount point of the file.
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	 */
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	mntpt = find_file(file, NULL, &t);
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	if (!mntpt) {
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		debugmsg(DM_MISC, "unknown mount point for `%s'", file);
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		return(-1);
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	}
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	r = statfs(mntpt, &statfsbuf);
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	if (r < 0) {
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		error("%s: Cannot statfs filesystem: %s.", mntpt, SYSERR);
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		return(-1);
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	}
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417
	/*
418
	 * If values are < 0, then assume the value is unsupported
419
	 * or unavailable for that filesystem type.
420
	 */
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	val = -1;
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	if (statfsbuf.f_bavail >= 0)
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		val = (statfsbuf.f_bavail * (statfsbuf.f_bsize / 512)) / 2;
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	*freespace = val;
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	val = -1;
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	if (statfsbuf.f_favail >= 0)
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		val = statfsbuf.f_favail;
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	*freefiles = val;
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	return(0);
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}