busybox/coreutils/cp.c

/* vi: set sw=4 ts=4: */
/*
 * Mini cp implementation for busybox
 *
 * Copyright (C) 2000 by Matt Kraai <kraai@alumni.carnegiemellon.edu>
 * SELinux support by Yuichi Nakamura <ynakam@hitachisoft.jp>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Size reduction.
 */
//config:config CP
//config:	bool "cp (10 kb)"
//config:	default y
//config:	help
//config:	cp is used to copy files and directories.
//config:
//config:config FEATURE_CP_LONG_OPTIONS
//config:	bool "Enable long options"
//config:	default y
//config:	depends on CP && LONG_OPTS
//config:	help
//config:	Enable long options.
//config:	Also add support for --parents option.
//config:
//config:config FEATURE_CP_REFLINK
//config:	bool "Enable --reflink[=auto]"
//config:	default y
//config:	depends on FEATURE_CP_LONG_OPTIONS

//applet:IF_CP(APPLET_NOEXEC(cp, cp, BB_DIR_BIN, BB_SUID_DROP, cp))
/* NOEXEC despite cases when it can be a "runner" (cp -r LARGE_DIR NEW_DIR) */

//kbuild:lib-$(CONFIG_CP) += cp.o

/* http://www.opengroup.org/onlinepubs/007904975/utilities/cp.html */

//usage:#define cp_trivial_usage
//usage:       "[OPTIONS] SOURCE... DEST"
//usage:#define cp_full_usage "\n\n"
//usage:       "Copy SOURCE(s) to DEST\n"
//usage:     "\n	-a	Same as -dpR"
//usage:	IF_SELINUX(
//usage:     "\n	-c	Preserve security context"
//usage:	)
//usage:     "\n	-R,-r	Recurse"
//usage:     "\n	-d,-P	Preserve symlinks (default if -R)"
//usage:     "\n	-L	Follow all symlinks"
//usage:     "\n	-H	Follow symlinks on command line"
//usage:     "\n	-p	Preserve file attributes if possible"
//usage:     "\n	-f	Overwrite"
//usage:     "\n	-i	Prompt before overwrite"
//usage:     "\n	-l,-s	Create (sym)links"
//usage:     "\n	-T	Treat DEST as a normal file"
//usage:     "\n	-u	Copy only newer files"

#include "libbb.h"
#include "libcoreutils/coreutils.h"

/* This is a NOEXEC applet. Be very careful! */

int cp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cp_main(int argc, char **argv)
{
	struct stat source_stat;
	struct stat dest_stat;
	const char *last;
	const char *dest;
	int s_flags;
	int d_flags;
	int flags;
	int status;
	enum {
		FILEUTILS_CP_OPTNUM = sizeof(FILEUTILS_CP_OPTSTR)-1,
#if ENABLE_FEATURE_CP_LONG_OPTIONS
		/*OPT_rmdest  = FILEUTILS_RMDEST = 1 << FILEUTILS_CP_OPTNUM */
		OPT_parents = 1 << (FILEUTILS_CP_OPTNUM+1),
		OPT_reflink = 1 << (FILEUTILS_CP_OPTNUM+2),
#endif
	};

#if ENABLE_FEATURE_CP_LONG_OPTIONS
# if ENABLE_FEATURE_CP_REFLINK
	char *reflink = NULL;
# endif
	flags = getopt32long(argv, "^"
		FILEUTILS_CP_OPTSTR
		"\0"
		// Need at least two arguments
		// Soft- and hardlinking doesn't mix
		// -P and -d are the same (-P is POSIX, -d is GNU)
		// -r and -R are the same
		// -R (and therefore -r) turns on -d (coreutils does this)
		// -a = -pdR
		"-2:l--s:s--l:Pd:rRd:Rd:apdR",
		"archive\0"        No_argument "a"
		"force\0"          No_argument "f"
		"interactive\0"    No_argument "i"
		"link\0"           No_argument "l"
		"dereference\0"    No_argument "L"
		"no-dereference\0" No_argument "P"
		"recursive\0"      No_argument "R"
		"symbolic-link\0"  No_argument "s"
		"no-target-directory\0" No_argument "T"
		"verbose\0"        No_argument "v"
		"update\0"         No_argument "u"
		"remove-destination\0" No_argument "\xff"
		"parents\0"        No_argument "\xfe"
# if ENABLE_FEATURE_CP_REFLINK
		"reflink\0"        Optional_argument "\xfd"
		, &reflink
# endif
	);
# if ENABLE_FEATURE_CP_REFLINK
	BUILD_BUG_ON((int)OPT_reflink != (int)FILEUTILS_REFLINK);
	if (flags & FILEUTILS_REFLINK) {
		if (!reflink)
			flags |= FILEUTILS_REFLINK_ALWAYS;
		else if (strcmp(reflink, "always") == 0)
			flags |= FILEUTILS_REFLINK_ALWAYS;
		else if (strcmp(reflink, "auto") != 0)
			bb_show_usage();
	}
# endif
#else
	flags = getopt32(argv, "^"
		FILEUTILS_CP_OPTSTR
		"\0"
		"-2:l--s:s--l:Pd:rRd:Rd:apdR"
	);
#endif
	/* Options of cp from GNU coreutils 6.10:
	 * -a, --archive
	 * -f, --force
	 * -i, --interactive
	 * -l, --link
	 * -L, --dereference
	 * -P, --no-dereference
	 * -R, -r, --recursive
	 * -s, --symbolic-link
	 * -v, --verbose
	 * -H	follow command-line symbolic links in SOURCE
	 * -d	same as --no-dereference --preserve=links
	 * -p	same as --preserve=mode,ownership,timestamps
	 * -c	same as --preserve=context
	 * -u, --update
	 *	copy only when the SOURCE file is newer than the destination
	 *	file or when the destination file is missing
	 * --remove-destination
	 *	remove each existing destination file before attempting to open
	 * --parents
	 *	use full source file name under DIRECTORY
	 * -T, --no-target-directory
	 *	treat DEST as a normal file
	 * NOT SUPPORTED IN BBOX:
	 * --backup[=CONTROL]
	 *	make a backup of each existing destination file
	 * -b	like --backup but does not accept an argument
	 * --copy-contents
	 *	copy contents of special files when recursive
	 * --preserve[=ATTR_LIST]
	 *	preserve attributes (default: mode,ownership,timestamps),
	 *	if possible additional attributes: security context,links,all
	 * --no-preserve=ATTR_LIST
	 * --sparse=WHEN
	 *	control creation of sparse files
	 * --strip-trailing-slashes
	 *	remove any trailing slashes from each SOURCE argument
	 * -S, --suffix=SUFFIX
	 *	override the usual backup suffix
	 * -t, --target-directory=DIRECTORY
	 *	copy all SOURCE arguments into DIRECTORY
	 * -x, --one-file-system
	 *	stay on this file system
	 * -Z, --context=CONTEXT
	 *	(SELinux) set SELinux security context of copy to CONTEXT
	 */
	argc -= optind;
	argv += optind;
	/* Reverse this bit. If there is -d, bit is not set: */
	flags ^= FILEUTILS_DEREFERENCE;
	/* coreutils 6.9 compat:
	 * by default, "cp" derefs symlinks (creates regular dest files),
	 * but "cp -R" does not. We switch off deref if -r or -R (see above).
	 * However, "cp -RL" must still deref symlinks: */
	if (flags & FILEUTILS_DEREF_SOFTLINK) /* -L */
		flags |= FILEUTILS_DEREFERENCE;

#if ENABLE_SELINUX
	if (flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) {
		selinux_or_die();
	}
#endif

	status = EXIT_SUCCESS;
	last = argv[argc - 1];
	/* If there are only two arguments and...  */
	if (argc == 2) {
		s_flags = cp_mv_stat2(*argv, &source_stat,
				(flags & FILEUTILS_DEREFERENCE) ? stat : lstat);
		if (s_flags < 0)
			return EXIT_FAILURE;
		d_flags = cp_mv_stat(last, &dest_stat);
		if (d_flags < 0)
			return EXIT_FAILURE;

		if (flags & FILEUTILS_NO_TARGET_DIR) { /* -T */
			if (!(s_flags & 2) && (d_flags & 2))
				/* cp -T NOTDIR DIR */
				bb_error_msg_and_die("'%s' is a directory", last);
		}

#if ENABLE_FEATURE_CP_LONG_OPTIONS
		//bb_error_msg("flags:%x FILEUTILS_RMDEST:%x OPT_parents:%x",
		//	flags, FILEUTILS_RMDEST, OPT_parents);
		if (flags & OPT_parents) {
			if (!(d_flags & 2)) {
				bb_error_msg_and_die("with --parents, the destination must be a directory");
			}
		}
		if (flags & FILEUTILS_RMDEST) {
			flags |= FILEUTILS_FORCE;
		}
#endif

		/* ...if neither is a directory...  */
		if (!((s_flags | d_flags) & 2)
		    /* ...or: recursing, the 1st is a directory, and the 2nd doesn't exist... */
		 || ((flags & FILEUTILS_RECUR) && (s_flags & 2) && !d_flags)
		 || (flags & FILEUTILS_NO_TARGET_DIR)
		) {
			/* Do a simple copy */
			dest = last;
			goto DO_COPY; /* NB: argc==2 -> *++argv==last */
		}
	} else if (flags & FILEUTILS_NO_TARGET_DIR) {
		bb_error_msg_and_die("too many arguments");
	}

	while (1) {
#if ENABLE_FEATURE_CP_LONG_OPTIONS
		if (flags & OPT_parents) {
			char *dest_dup;
			char *dest_dir;
			dest = concat_path_file(last, *argv);
			dest_dup = xstrdup(dest);
			dest_dir = dirname(dest_dup);
			if (bb_make_directory(dest_dir, -1, FILEUTILS_RECUR)) {
				return EXIT_FAILURE;
			}
			free(dest_dup);
			goto DO_COPY;
		}
#endif
		dest = concat_path_file(last, bb_get_last_path_component_strip(*argv));
 DO_COPY:
		if (copy_file(*argv, dest, flags) < 0) {
			status = EXIT_FAILURE;
		}
		if (*++argv == last) {
			/* possibly leaking dest... */
			break;
		}
		/* don't move up: dest may be == last and not malloced! */
		free((void*)dest);
	}

	/* Exit. We are NOEXEC, not NOFORK. We do exit at the end of main() */
	return status;
}