Potential buffer overflow in restore.

[dump.git] / restore / utilities.c

/*
 *	Ported to Linux's Second Extended File System as part of the
 *	dump and restore backup suit
 *	Remy Card <card@Linux.EU.Org>, 1994-1997
 *	Stelian Pop <pop@cybercable.fr>, 1999-2000
 */

/*
 * Copyright (c) 1983, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static const char rcsid[] =
	"$Id: utilities.c,v 1.8 2000/02/08 12:22:43 stelian Exp $";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>

#ifdef	__linux__
#include <sys/time.h>
#include <linux/ext2_fs.h>
#include <bsdcompat.h>
#else	/* __linux__ */
#include <ufs/ufs/dinode.h>
#include <ufs/ufs/dir.h>
#endif	/* __linux__ */

#include <errno.h>
#include <compaterr.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#ifdef	__linux__
#include <ext2fs/ext2fs.h>
#endif

#include "restore.h"
#include "extern.h"

/*
 * Insure that all the components of a pathname exist.
 */
void
pathcheck(char *name)
{
	register char *cp;
	struct entry *ep;
	char *start;

	start = strchr(name, '/');
	if (start == 0)
		return;
	for (cp = start; *cp != '\0'; cp++) {
		if (*cp != '/')
			continue;
		*cp = '\0';
		ep = lookupname(name);
		if (ep == NULL) {
			/* Safe; we know the pathname exists in the dump. */
			ep = addentry(name, pathsearch(name)->d_ino, NODE);
			newnode(ep);
		}
		ep->e_flags |= NEW|KEEP;
		*cp = '/';
	}
}

/*
 * Change a name to a unique temporary name.
 */
void
mktempname(struct entry *ep)
{
	char oldname[MAXPATHLEN];

	if (ep->e_flags & TMPNAME)
		badentry(ep, "mktempname: called with TMPNAME");
	ep->e_flags |= TMPNAME;
	(void) strcpy(oldname, myname(ep));
	freename(ep->e_name);
	ep->e_name = savename(gentempname(ep));
	ep->e_namlen = strlen(ep->e_name);
	renameit(oldname, myname(ep));
}

/*
 * Generate a temporary name for an entry.
 */
char *
gentempname(struct entry *ep)
{
	static char name[MAXPATHLEN];
	struct entry *np;
	long i = 0;

	for (np = lookupino(ep->e_ino);
	    np != NULL && np != ep; np = np->e_links)
		i++;
	if (np == NULL)
		badentry(ep, "not on ino list");
	(void) snprintf(name, sizeof(name), "%s%ld%lu", TMPHDR, i, (unsigned long)ep->e_ino);
	return (name);
}

/*
 * Rename a file or directory.
 */
void
renameit(char *from, char *to)
{
	if (!Nflag && rename(from, to) < 0) {
		warn("cannot rename %s to %s", from, to);
		return;
	}
	Vprintf(stdout, "rename %s to %s\n", from, to);
}

/*
 * Create a new node (directory).
 */
void
newnode(struct entry *np)
{
	char *cp;
	if (np->e_type != NODE)
		badentry(np, "newnode: not a node");
	cp = myname(np);
	if (command == 'C') return;

	if (!Nflag && mkdir(cp, 0777) < 0 && !uflag) {
		np->e_flags |= EXISTED;
		warn("%s", cp);
		return;
	}
	Vprintf(stdout, "Make node %s\n", cp);
}

/*
 * Remove an old node (directory).
 */
void
removenode(struct entry *ep)
{
	char *cp;

	if (ep->e_type != NODE)
		badentry(ep, "removenode: not a node");
	if (ep->e_entries != NULL)
		badentry(ep, "removenode: non-empty directory");
	ep->e_flags |= REMOVED;
	ep->e_flags &= ~TMPNAME;
	cp = myname(ep);
	if (!Nflag && rmdir(cp) < 0) {
		warn("%s", cp);
		return;
	}
	Vprintf(stdout, "Remove node %s\n", cp);
}

/*
 * Remove a leaf.
 */
void
removeleaf(struct entry *ep)
{
	char *cp;

	if (command == 'C') return;

	if (ep->e_type != LEAF)
		badentry(ep, "removeleaf: not a leaf");
	ep->e_flags |= REMOVED;
	ep->e_flags &= ~TMPNAME;
	cp = myname(ep);
	if (!Nflag && unlink(cp) < 0) {
		warn("%s", cp);
		return;
	}
	Vprintf(stdout, "Remove leaf %s\n", cp);
}

/*
 * Create a link.
 */
int
linkit(char *existing, char *new, int type)
{

	/* if we want to unlink first, do it now so *link() won't fail */
	if (uflag && !Nflag)
		(void)unlink(new);

	if (type == SYMLINK) {
		if (!Nflag && symlink(existing, new) < 0) {
			warn("cannot create symbolic link %s->%s",
			    new, existing);
			return (FAIL);
		}
	} else if (type == HARDLINK) {
		int ret;

		if (!Nflag && (ret = link(existing, new)) < 0) {

#ifndef __linux__
			struct stat s;

			/*
			 * Most likely, the schg flag is set.  Clear the
			 * flags and try again.
			 */
			if (stat(existing, &s) == 0 && s.st_flags != 0 &&
			    chflags(existing, 0) == 0) {
				ret = link(existing, new);
				chflags(existing, s.st_flags);
			}
#else
			unsigned long s;

			/*
			 * Most likely, the immutable or append-only attribute
			 * is set. Clear the attributes and try again.
			 */
			if (fgetflags (existing, &s) != -1 &&
			    fsetflags (existing, 0) != -1) {
			    	ret = link(existing, new);
				fsetflags(existing, s);
			}
#endif
			if (ret < 0) {
				warn("warning: cannot create hard link %s->%s",
				    new, existing);
				return (FAIL);
			}
		}
	} else {
		panic("linkit: unknown type %d\n", type);
		return (FAIL);
	}
	Vprintf(stdout, "Create %s link %s->%s\n",
		type == SYMLINK ? "symbolic" : "hard", new, existing);
	return (GOOD);
}

#ifndef	__linux__
/*
 * Create a whiteout.
 */
int
addwhiteout(char *name)
{

	if (!Nflag && mknod(name, S_IFWHT, 0) < 0) {
		warn("cannot create whiteout %s", name);
		return (FAIL);
	}
	Vprintf(stdout, "Create whiteout %s\n", name);
	return (GOOD);
}

/*
 * Delete a whiteout.
 */
void
delwhiteout(struct entry *ep)
{
	char *name;

	if (ep->e_type != LEAF)
		badentry(ep, "delwhiteout: not a leaf");
	ep->e_flags |= REMOVED;
	ep->e_flags &= ~TMPNAME;
	name = myname(ep);
	if (!Nflag && undelete(name) < 0) {
		warn("cannot delete whiteout %s", name);
		return;
	}
	Vprintf(stdout, "Delete whiteout %s\n", name);
}
#endif

/*
 * find lowest number file (above "start") that needs to be extracted
 */
ino_t
lowerbnd(ino_t start)
{
	register struct entry *ep;

	for ( ; start < maxino; start++) {
		ep = lookupino(start);
		if (ep == NULL || ep->e_type == NODE)
			continue;
		if (ep->e_flags & (NEW|EXTRACT))
			return (start);
	}
	return (start);
}

/*
 * find highest number file (below "start") that needs to be extracted
 */
ino_t
upperbnd(ino_t start)
{
	register struct entry *ep;

	for ( ; start > ROOTINO; start--) {
		ep = lookupino(start);
		if (ep == NULL || ep->e_type == NODE)
			continue;
		if (ep->e_flags & (NEW|EXTRACT))
			return (start);
	}
	return (start);
}

/*
 * report on a badly formed entry
 */
void
badentry(struct entry *ep, const char *msg)
{

	fprintf(stderr, "bad entry: %s\n", msg);
	fprintf(stderr, "name: %s\n", myname(ep));
	fprintf(stderr, "parent name %s\n", myname(ep->e_parent));
	if (ep->e_sibling != NULL)
		fprintf(stderr, "sibling name: %s\n", myname(ep->e_sibling));
	if (ep->e_entries != NULL)
		fprintf(stderr, "next entry name: %s\n", myname(ep->e_entries));
	if (ep->e_links != NULL)
		fprintf(stderr, "next link name: %s\n", myname(ep->e_links));
	if (ep->e_next != NULL)
		fprintf(stderr,
		    "next hashchain name: %s\n", myname(ep->e_next));
	fprintf(stderr, "entry type: %s\n",
		ep->e_type == NODE ? "NODE" : "LEAF");
	fprintf(stderr, "inode number: %lu\n", (unsigned long)ep->e_ino);
	panic("flags: %s\n", flagvalues(ep));
}

/*
 * Construct a string indicating the active flag bits of an entry.
 */
char *
flagvalues(struct entry *ep)
{
	static char flagbuf[BUFSIZ];

	(void) strcpy(flagbuf, "|NIL");
	flagbuf[0] = '\0';
	if (ep->e_flags & REMOVED)
		(void) strcat(flagbuf, "|REMOVED");
	if (ep->e_flags & TMPNAME)
		(void) strcat(flagbuf, "|TMPNAME");
	if (ep->e_flags & EXTRACT)
		(void) strcat(flagbuf, "|EXTRACT");
	if (ep->e_flags & NEW)
		(void) strcat(flagbuf, "|NEW");
	if (ep->e_flags & KEEP)
		(void) strcat(flagbuf, "|KEEP");
	if (ep->e_flags & EXISTED)
		(void) strcat(flagbuf, "|EXISTED");
	return (&flagbuf[1]);
}

/*
 * Check to see if a name is on a dump tape.
 */
ino_t
dirlookup(const char *name)
{
	struct direct *dp;
	ino_t ino;

	ino = ((dp = pathsearch(name)) == NULL) ? 0 : dp->d_ino;

	if (ino == 0 || TSTINO(ino, dumpmap) == 0)
		fprintf(stderr, "%s is not on the tape\n", name);
	return (ino);
}

/*
 * Elicit a reply.
 */
int
reply(const char *question)
{
	char c;

	do	{
		fprintf(stderr, "%s? [yn] ", question);
		(void) fflush(stderr);
		c = getc(terminal);
		while (c != '\n' && getc(terminal) != '\n')
			if (feof(terminal))
				return (FAIL);
	} while (c != 'y' && c != 'n');
	if (c == 'y')
		return (GOOD);
	return (FAIL);
}

/*
 * handle unexpected inconsistencies
 */
#ifdef __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#ifdef __STDC__
panic(const char *fmt, ...)
#else
panic(fmt, va_alist)
	char *fmt;
	va_dcl
#endif
{
	va_list ap;
#ifdef __STDC__
	va_start(ap, fmt);
#else
	va_start(ap);
#endif

	vfprintf(stderr, fmt, ap);
	if (yflag)
		return;
	if (reply("abort") == GOOD) {
		if (reply("dump core") == GOOD)
			abort();
		exit(1);
	}
}