safecalls.h

/*
 * Copyright (c) 2007 Apple Inc. All rights reserved.
 *
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 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
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 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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/*
 * FILE: safecalls.h
 * AUTH: Soren Spies (sspies)
 * DATE: 16 June 2006 (Copyright Apple Computer, Inc)
 * DESC: picky syscalls (constrained to one volume)
 *
 * CAVEAT: fchdir is used heavily ... until we have openat(2) and/or
 * per-thread chdir, this code is not safe to use on multiple threads.
 * we attempt to restore CWD within each call, but failure is not returned
 *
 */

#include <sys/types.h>

// secure versions of common syscalls (only if args on vol specified by fd)

// O_EXCL added if O_CREAT specified
int sopen(int fdvol, const char *path, int flags, mode_t mode);
// WARNING: child will point to basename() [static] data
// additionally, caller must close non-(-1) olddir if requested (cf. restoredir)
int schdir(int fdvol, const char *path, int *olddir);
int schdirparent(int fdvol, const char *path, int *olddir, char childname[PATH_MAX]);
int restoredir(int savedir);        // check errors if you want them

// these are trivially implemented with the above
int smkdir(int fdvol, const char *path, mode_t mode);
int srmdir(int fdvol, const char *path);
int sunlink(int fdvol, const char *path);
// srename only renames within a directory; uses basename(newname)
int srename(int fdvol, const char *oldpath, const char *newname);

// uses FTS to recurse downwards, calling sunlink and srmdir as appropriate
int sdeepunlink(int fdvol, char *path);     // fts_open won't take const char*
// overwrite a file with zeros; attempt to ftruncate; no unlink; ENOENT okay
int szerofile(int fdvol, const char *path);
// 'mkdir -p' (recursively applies mode)
int sdeepmkdir(int fdvol, const char *path, mode_t mode);
// creates intermediate directories for you; only copies one file
int scopyitem(int srcvolfd, const char *src, int dstvolfd, const char *dst);

#ifndef STRICT_SAFETY
#define STRICT_SAFETY 1
#endif
#if STRICT_SAFETY

// #define open()               // #error use sopen (need a chicken)
#define chdir()                 // #error use schdir

#define mkdir()                 // #error use smkdir
#define rmdir()                 // #error use srmdir
#define unlink()                // #error use sunlink
#define rename()                // #error srename

#define copyfile()              // #error use scopyfile

#endif // STRICT_SAFETY