/[magellan-source]/trunk/mkinitrd-magellan/busybox/libbb/copy_file.c

Diff of /trunk/mkinitrd-magellan/busybox/libbb/copy_file.c

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-revision 983 by niro,
Fri Apr 24 18:33:46 2009 UTC
+revision 984 by niro,
Sun May 30 11:32:42 2010 UTC
 Line 6
   * SELinux support by Yuichi Nakamura <ynakam@hitachisoft.jp>
   *
   * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
-  *
   */
  #include "libbb.h"
+ // FEATURE_NON_POSIX_CP:
+ //
  // POSIX: if exists and -i, ask (w/o -i assume yes).
  // Then open w/o EXCL (yes, not unlink!).
  // If open still fails and -f, try unlink, then try open again.
  // Result: a mess:
- // If dest is a softlink, we overwrite softlink's destination!
+ // If dest is a (sym)link, we overwrite link destination!
  // (or fail, if it points to dir/nonexistent location/etc).
  // This is strange, but POSIX-correct.
  // coreutils cp has --remove-destination to override this...
- //
- // NB: we have special code which still allows for "cp file /dev/node"
- // to work POSIX-ly (the only realistic case where it makes sense)
- #define DO_POSIX_CP 0  /* 1 - POSIX behavior, 0 - safe behavior */
+ /* Called if open of destination, link creation etc fails.
+  * errno must be set to relevant value ("why we cannot create dest?")
- // errno must be set to relevant value ("why we cannot create dest?")
+  * to give reasonable error message */
- // for POSIX mode to give reasonable error message
  static int ask_and_unlink(const char *dest, int flags)
  {
  	int e = errno;
- #if DO_POSIX_CP
+ #if !ENABLE_FEATURE_NON_POSIX_CP
  	if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) {
- 		// Either it exists, or the *path* doesnt exist
+ 		/* Either it exists, or the *path* doesnt exist */
- 		bb_perror_msg("cannot create '%s'", dest);
+ 		bb_perror_msg("can't create '%s'", dest);
  		return -1;
  	}
  #endif
- 	// If !DO_POSIX_CP, act as if -f is always in effect - we don't want
+ 	// else: act as if -f is always in effect.
- 	// "cannot create" msg, we want unlink to be done (silently unless -i).
+ 	// We don't want "can't create" msg, we want unlink to be done
+ 	// (silently unless -i). Why? POSIX cp usually succeeds with
+ 	// O_TRUNC open of existing file, and user is left ignorantly happy.
+ 	// With above block unconditionally enabled, non-POSIX cp
+ 	// will complain a lot more than POSIX one.
- 	// TODO: maybe we should do it only if ctty is present?
+ 	/* TODO: maybe we should do it only if ctty is present? */
  	if (flags & FILEUTILS_INTERACTIVE) {
  		// We would not do POSIX insanity. -i asks,
  		// then _unlinks_ the offender. Presto.
-Line 48 
 static int ask_and_unlink(const char *de
+Line 49 
 static int ask_and_unlink(const char *de
  		// Or else we will end up having 3 open()s!
  		fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest);
  		if (!bb_ask_confirmation())
- 			return 0; // not allowed to overwrite
+ 			return 0; /* not allowed to overwrite */
  	}
  	if (unlink(dest) < 0) {
  #if ENABLE_FEATURE_VERBOSE_CP_MESSAGE
  		if (e == errno && e == ENOENT) {
  			/* e == ENOTDIR is similar: path has non-dir component,
  			 * but in this case we don't even reach copy_file() */
- 			bb_error_msg("cannot create '%s': Path does not exist", dest);
+ 			bb_error_msg("can't create '%s': Path does not exist", dest);
- 			return -1; // error
+ 			return -1; /* error */
  		}
  #endif
- 		errno = e;
+ 		errno = e; /* do not use errno from unlink */
- 		bb_perror_msg("cannot create '%s'", dest);
+ 		bb_perror_msg("can't create '%s'", dest);
- 		return -1; // error
+ 		return -1; /* error */
  	}
- 	return 1; // ok (to try again)
+ 	return 1; /* ok (to try again) */
  }
  /* Return:
-Line 82 
 int FAST_FUNC copy_file(const char *sour
+Line 83 
 int FAST_FUNC copy_file(const char *sour
  	signed char ovr;
  /* Inverse of cp -d ("cp without -d") */
- #define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
+ #define FLAGS_DEREF (flags & (FILEUTILS_DEREFERENCE + FILEUTILS_DEREFERENCE_L0))
  	if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
- 		// This may be a dangling symlink.
+ 		/* This may be a dangling symlink.
- 		// Making [sym]links to dangling symlinks works, so...
+ 		 * Making [sym]links to dangling symlinks works, so... */
  		if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK))
  			goto make_links;
- 		bb_perror_msg("cannot stat '%s'", source);
+ 		bb_perror_msg("can't stat '%s'", source);
  		return -1;
  	}
  	if (lstat(dest, &dest_stat) < 0) {
  		if (errno != ENOENT) {
- 			bb_perror_msg("cannot stat '%s'", dest);
+ 			bb_perror_msg("can't stat '%s'", dest);
  			return -1;
  		}
  	} else {
-Line 113 
 int FAST_FUNC copy_file(const char *sour
+Line 114 
 int FAST_FUNC copy_file(const char *sour
  		security_context_t con;
  		if (lgetfilecon(source, &con) >= 0) {
  			if (setfscreatecon(con) < 0) {
- 				bb_perror_msg("cannot set setfscreatecon %s", con);
+ 				bb_perror_msg("can't set setfscreatecon %s", con);
  				freecon(con);
  				return -1;
  			}
  		} else if (errno == ENOTSUP || errno == ENODATA) {
  			setfscreatecon_or_die(NULL);
  		} else {
- 			bb_perror_msg("cannot lgetfilecon %s", source);
+ 			bb_perror_msg("can't lgetfilecon %s", source);
  			return -1;
  		}
  	}
-Line 165 
 int FAST_FUNC copy_file(const char *sour
+Line 166 
 int FAST_FUNC copy_file(const char *sour
  			mode |= S_IRWXU;
  			if (mkdir(dest, mode) < 0) {
  				umask(saved_umask);
- 				bb_perror_msg("cannot create directory '%s'", dest);
+ 				bb_perror_msg("can't create directory '%s'", dest);
  				return -1;
  			}
  			umask(saved_umask);
  			/* need stat info for add_to_ino_dev_hashtable */
  			if (lstat(dest, &dest_stat) < 0) {
- 				bb_perror_msg("cannot stat '%s'", dest);
+ 				bb_perror_msg("can't stat '%s'", dest);
  				return -1;
  			}
  		}
-Line 193 
 int FAST_FUNC copy_file(const char *sour
+Line 194 
 int FAST_FUNC copy_file(const char *sour
  			if (new_source == NULL)
  				continue;
  			new_dest = concat_path_file(dest, d->d_name);
- 			if (copy_file(new_source, new_dest, flags) < 0)
+ 			if (copy_file(new_source, new_dest, flags & ~FILEUTILS_DEREFERENCE_L0) < 0)
  				retval = -1;
  			free(new_source);
  			free(new_dest);
-Line 203 
 int FAST_FUNC copy_file(const char *sour
+Line 204 
 int FAST_FUNC copy_file(const char *sour
  		if (!dest_exists
  		 && chmod(dest, source_stat.st_mode & ~saved_umask) < 0
  		) {
- 			bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
+ 			bb_perror_msg("can't preserve %s of '%s'", "permissions", dest);
  			/* retval = -1; - WRONG! copy *WAS* made */
  		}
  		goto preserve_mode_ugid_time;
-Line 212 
 int FAST_FUNC copy_file(const char *sour
+Line 213 
 int FAST_FUNC copy_file(const char *sour
  	if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
  		int (*lf)(const char *oldpath, const char *newpath);
   make_links:
- 		// Hmm... maybe
+ 		/* Hmm... maybe
- 		// if (DEREF && MAKE_SOFTLINK) source = realpath(source) ?
+ 		 * if (DEREF && MAKE_SOFTLINK) source = realpath(source) ?
- 		// (but realpath returns NULL on dangling symlinks...)
+ 		 * (but realpath returns NULL on dangling symlinks...) */
  		lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link;
  		if (lf(source, dest) < 0) {
  			ovr = ask_and_unlink(dest, flags);
  			if (ovr <= 0)
  				return ovr;
  			if (lf(source, dest) < 0) {
- 				bb_perror_msg("cannot create link '%s'", dest);
+ 				bb_perror_msg("can't create link '%s'", dest);
  				return -1;
  			}
  		}
  		/* _Not_ jumping to preserve_mode_ugid_time:
- 		 * hard/softlinks don't have those */
+ 		 * (sym)links don't have those */
  		return 0;
  	}
-Line 256 
 int FAST_FUNC copy_file(const char *sour
+Line 257 
 int FAST_FUNC copy_file(const char *sour
  					if (ovr <= 0)
  						return ovr;
  					if (link(link_target, dest) < 0) {
- 						bb_perror_msg("cannot create link '%s'", dest);
+ 						bb_perror_msg("can't create link '%s'", dest);
  						return -1;
  					}
  				}
-Line 274 
 int FAST_FUNC copy_file(const char *sour
+Line 275 
 int FAST_FUNC copy_file(const char *sour
  		if (!S_ISREG(source_stat.st_mode))
  			new_mode = 0666;
- 		/* POSIX way is a security problem versus symlink attacks,
+ 		// POSIX way is a security problem versus (sym)link attacks
- 		 * we do it only for non-symlinks, and only for non-recursive,
+ 		if (!ENABLE_FEATURE_NON_POSIX_CP) {
- 		 * non-interactive cp. NB: it is still racy
- 		 * for "cp file /home/bad_user/file" case
- 		 * (user can rm file and create a link to /etc/passwd) */
- 		if (DO_POSIX_CP
- 		 || (dest_exists
- 		     && !(flags & (FILEUTILS_RECUR|FILEUTILS_INTERACTIVE))
- 		     && !S_ISLNK(dest_stat.st_mode))
- 		) {
  			dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode);
- 		} else  /* safe way: */
+ 		} else { /* safe way: */
  			dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode);
+ 		}
  		if (dst_fd == -1) {
  			ovr = ask_and_unlink(dest, flags);
  			if (ovr <= 0) {
-Line 324 
 int FAST_FUNC copy_file(const char *sour
+Line 318 
 int FAST_FUNC copy_file(const char *sour
  			retval = -1;
  		/* Ok, writing side I can understand... */
  		if (close(dst_fd) < 0) {
- 			bb_perror_msg("cannot close '%s'", dest);
+ 			bb_perror_msg("can't close '%s'", dest);
  			retval = -1;
  		}
  		/* ...but read size is already checked by bb_copyfd_eof */
-Line 351 
 int FAST_FUNC copy_file(const char *sour
+Line 345 
 int FAST_FUNC copy_file(const char *sour
  			int r = symlink(lpath, dest);
  			free(lpath);
  			if (r < 0) {
- 				bb_perror_msg("cannot create symlink '%s'", dest);
+ 				bb_perror_msg("can't create symlink '%s'", dest);
  				return -1;
  			}
  			if (flags & FILEUTILS_PRESERVE_STATUS)
  				if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
- 					bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
+ 					bb_perror_msg("can't preserve %s of '%s'", "ownership", dest);
  		}
  		/* _Not_ jumping to preserve_mode_ugid_time:
  		 * symlinks don't have those */
-Line 366 
 int FAST_FUNC copy_file(const char *sour
+Line 360 
 int FAST_FUNC copy_file(const char *sour
  	 || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
  	) {
  		if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
- 			bb_perror_msg("cannot create '%s'", dest);
+ 			bb_perror_msg("can't create '%s'", dest);
  			return -1;
  		}
  	} else {
-Line 380 
 int FAST_FUNC copy_file(const char *sour
+Line 374 
 int FAST_FUNC copy_file(const char *sour
  	/* Cannot happen: */
  	/* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
  	) {
- 		struct utimbuf times;
+ 		struct timeval times[2];
- 		times.actime = source_stat.st_atime;
+ 		times[1].tv_sec = times[0].tv_sec = source_stat.st_mtime;
- 		times.modtime = source_stat.st_mtime;
+ 		times[1].tv_usec = times[0].tv_usec = 0;
  		/* BTW, utimes sets usec-precision time - just FYI */
- 		if (utime(dest, &times) < 0)
+ 		if (utimes(dest, times) < 0)
- 			bb_perror_msg("cannot preserve %s of '%s'", "times", dest);
+ 			bb_perror_msg("can't preserve %s of '%s'", "times", dest);
  		if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {
  			source_stat.st_mode &= ~(S_ISUID | S_ISGID);
- 			bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
+ 			bb_perror_msg("can't preserve %s of '%s'", "ownership", dest);
  		}
  		if (chmod(dest, source_stat.st_mode) < 0)
- 			bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
+ 			bb_perror_msg("can't preserve %s of '%s'", "permissions", dest);
  	}
  	return retval;

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