Exemplo n.º 1
0
/* Write out a tar header for the specified file/directory/whatever */
static int writeTarHeader(struct TarBallInfo *tbInfo,
		const char *header_name, const char *fileName, struct stat *statbuf)
{
	struct tar_header_t header;

	memset(&header, 0, sizeof(header));

	strncpy(header.name, header_name, sizeof(header.name));

	/* POSIX says to mask mode with 07777. */
	PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
	PUT_OCTAL(header.uid, statbuf->st_uid);
	PUT_OCTAL(header.gid, statbuf->st_gid);
	memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
	/* users report that files with negative st_mtime cause trouble, so: */
	PUT_OCTAL(header.mtime, statbuf->st_mtime >= 0 ? statbuf->st_mtime : 0);

	/* Enter the user and group names */
	safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
	safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));

	if (tbInfo->hlInfo) {
		/* This is a hard link */
		header.typeflag = LNKTYPE;
		strncpy(header.linkname, tbInfo->hlInfo->name,
				sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
		/* Write out long linkname if needed */
		if (header.linkname[sizeof(header.linkname)-1])
			writeLongname(tbInfo->tarFd, GNULONGLINK,
					tbInfo->hlInfo->name, 0);
#endif
	} else if (S_ISLNK(statbuf->st_mode)) {
		char *lpath = xmalloc_readlink_or_warn(fileName);
		if (!lpath)
			return FALSE;
		header.typeflag = SYMTYPE;
		strncpy(header.linkname, lpath, sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
		/* Write out long linkname if needed */
		if (header.linkname[sizeof(header.linkname)-1])
			writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
#else
		/* If it is larger than 100 bytes, bail out */
		if (header.linkname[sizeof(header.linkname)-1]) {
			free(lpath);
			bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
			return FALSE;
		}
#endif
		free(lpath);
	} else if (S_ISDIR(statbuf->st_mode)) {
		header.typeflag = DIRTYPE;
		/* Append '/' only if there is a space for it */
		if (!header.name[sizeof(header.name)-1])
			header.name[strlen(header.name)] = '/';
	} else if (S_ISCHR(statbuf->st_mode)) {
		header.typeflag = CHRTYPE;
		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
	} else if (S_ISBLK(statbuf->st_mode)) {
		header.typeflag = BLKTYPE;
		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
	} else if (S_ISFIFO(statbuf->st_mode)) {
		header.typeflag = FIFOTYPE;
	} else if (S_ISREG(statbuf->st_mode)) {
		/* header.size field is 12 bytes long */
		/* Does octal-encoded size fit? */
		uoff_t filesize = statbuf->st_size;
		if (sizeof(filesize) <= 4
		 || filesize <= (uoff_t)0777777777777LL
		) {
			PUT_OCTAL(header.size, filesize);
		}
		/* Does base256-encoded size fit?
		 * It always does unless off_t is wider than 64 bits.
		 */
		else if (ENABLE_FEATURE_TAR_GNU_EXTENSIONS
#if ULLONG_MAX > 0xffffffffffffffffLL /* 2^64-1 */
		 && (filesize <= 0x3fffffffffffffffffffffffLL)
#endif
		) {
	                /* GNU tar uses "base-256 encoding" for very large numbers.
	                 * Encoding is binary, with highest bit always set as a marker
	                 * and sign in next-highest bit:
	                 * 80 00 .. 00 - zero
	                 * bf ff .. ff - largest positive number
	                 * ff ff .. ff - minus 1
	                 * c0 00 .. 00 - smallest negative number
			 */
			char *p8 = header.size + sizeof(header.size);
			do {
				*--p8 = (uint8_t)filesize;
				filesize >>= 8;
			} while (p8 != header.size);
			*p8 |= 0x80;
		} else {
Exemplo n.º 2
0
static int writeTarHeader(struct TarBallInfo *tbInfo,
		const char *header_name, const char *fileName, struct stat *statbuf)
{
	struct TarHeader header;

	if (sizeof(header) != 512)
		BUG_tar_header_size();

	memset(&header, 0, sizeof(struct TarHeader));

	strncpy(header.name, header_name, sizeof(header.name));

	/* POSIX says to mask mode with 07777. */
	PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
	PUT_OCTAL(header.uid, statbuf->st_uid);
	PUT_OCTAL(header.gid, statbuf->st_gid);
	memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
	PUT_OCTAL(header.mtime, statbuf->st_mtime);

	/* Enter the user and group names */
	safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
	safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));

	if (tbInfo->hlInfo) {
		/* This is a hard link */
		header.typeflag = LNKTYPE;
		strncpy(header.linkname, tbInfo->hlInfo->name,
				sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
		/* Write out long linkname if needed */
		if (header.linkname[sizeof(header.linkname)-1])
			writeLongname(tbInfo->tarFd, GNULONGLINK,
					tbInfo->hlInfo->name, 0);
#endif
	} else if (S_ISLNK(statbuf->st_mode)) {
		char *lpath = xmalloc_readlink_or_warn(fileName);
		if (!lpath)
			return FALSE;
		header.typeflag = SYMTYPE;
		strncpy(header.linkname, lpath, sizeof(header.linkname));
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
		/* Write out long linkname if needed */
		if (header.linkname[sizeof(header.linkname)-1])
			writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
#else
		/* If it is larger than 100 bytes, bail out */
		if (header.linkname[sizeof(header.linkname)-1]) {
			free(lpath);
			bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
			return FALSE;
		}
#endif
		free(lpath);
	} else if (S_ISDIR(statbuf->st_mode)) {
		header.typeflag = DIRTYPE;
		/* Append '/' only if there is a space for it */
		if (!header.name[sizeof(header.name)-1])
			header.name[strlen(header.name)] = '/';
	} else if (S_ISCHR(statbuf->st_mode)) {
		header.typeflag = CHRTYPE;
		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
	} else if (S_ISBLK(statbuf->st_mode)) {
		header.typeflag = BLKTYPE;
		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
	} else if (S_ISFIFO(statbuf->st_mode)) {
		header.typeflag = FIFOTYPE;
	} else if (S_ISREG(statbuf->st_mode)) {
		if (sizeof(statbuf->st_size) > 4
		 && statbuf->st_size > (off_t)0777777777777LL
		) {
			bb_error_msg_and_die("cannot store file '%s' "
				"of size %"OFF_FMT"d, aborting",
				fileName, statbuf->st_size);
		}
		header.typeflag = REGTYPE;
		PUT_OCTAL(header.size, statbuf->st_size);
	} else {
		bb_error_msg("%s: unknown file type", fileName);
		return FALSE;
	}

#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
	/* Write out long name if needed */
	/* (we, like GNU tar, output long linkname *before* long name) */
	if (header.name[sizeof(header.name)-1])
		writeLongname(tbInfo->tarFd, GNULONGNAME,
				header_name, S_ISDIR(statbuf->st_mode));
#endif

	/* Now write the header out to disk */
	chksum_and_xwrite(tbInfo->tarFd, &header);

	/* Now do the verbose thing (or not) */
	if (tbInfo->verboseFlag) {
		FILE *vbFd = stdout;

		/* If archive goes to stdout, verbose goes to stderr */
		if (tbInfo->tarFd == STDOUT_FILENO)
			vbFd = stderr;
		/* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
		/* We don't have such excesses here: for us "v" == "vv" */
		/* '/' is probably a GNUism */
		fprintf(vbFd, "%s%s\n", header_name,
				S_ISDIR(statbuf->st_mode) ? "/" : "");
	}

	return TRUE;
}