tar.c

手机嵌入式Linux下可用的busybox源码

				return( FALSE);
			}
		} else {
			actualWriteSz=writeSize;
		}

		size -= actualWriteSz;
	}

	/* Now we are done writing the file out, so try 
	 * and fix up the permissions and whatnot */
	if (extractFlag==TRUE && tostdoutFlag==FALSE) {
		close(outFd);
		fixUpPermissions(header);
	}
	return( TRUE);
}

static int
tarExtractDirectory(TarInfo *header, int extractFlag, int tostdoutFlag)
{
	if (extractFlag==FALSE || tostdoutFlag==TRUE)
		return( TRUE);

	if (make_directory(header->name, header->mode, FILEUTILS_RECUR) < 0)
		return( FALSE);

	fixUpPermissions(header);
	return( TRUE);
}

static int
tarExtractHardLink(TarInfo *header, int extractFlag, int tostdoutFlag)
{
	if (extractFlag==FALSE || tostdoutFlag==TRUE)
		return( TRUE);

	if (link(header->linkname, header->name) < 0) {
		perror_msg("%s: Cannot create hard link to '%s'", header->name,
				header->linkname); 
		return( FALSE);
	}

	/* Now set permissions etc. for the new directory */
	fixUpPermissions(header);
	return( TRUE);
}

static int
tarExtractSymLink(TarInfo *header, int extractFlag, int tostdoutFlag)
{
	if (extractFlag==FALSE || tostdoutFlag==TRUE)
		return( TRUE);

#ifdef	S_ISLNK
	if (symlink(header->linkname, header->name) < 0) {
		perror_msg("%s: Cannot create symlink to '%s'", header->name,
				header->linkname); 
		return( FALSE);
	}
	/* Try to change ownership of the symlink.
	 * If libs doesn't support that, don't bother.
	 * Changing the pointed-to-file is the Wrong Thing(tm).
	 */
#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
	lchown(header->name, header->uid, header->gid);
#endif

	/* Do not change permissions or date on symlink,
	 * since it changes the pointed to file instead.  duh. */
#else
	error_msg("%s: Cannot create symlink to '%s': %s", 
			header->name, header->linkname, 
			"symlinks not supported"); 
#endif
	return( TRUE);
}

static int
tarExtractSpecial(TarInfo *header, int extractFlag, int tostdoutFlag)
{
	if (extractFlag==FALSE || tostdoutFlag==TRUE)
		return( TRUE);

	if (S_ISCHR(header->mode) || S_ISBLK(header->mode) || S_ISSOCK(header->mode)) {
		if (mknod(header->name, header->mode, makedev(header->devmajor, header->devminor)) < 0) {
			perror_msg("%s: Cannot mknod", header->name); 
			return( FALSE);
		}
	} else if (S_ISFIFO(header->mode)) {
		if (mkfifo(header->name, header->mode) < 0) {
			perror_msg("%s: Cannot mkfifo", header->name); 
			return( FALSE);
		}
	}

	/* Now set permissions etc. for the new directory */
	fixUpPermissions(header);
	return( TRUE);
}

/* Parse the tar header and fill in the nice struct with the details */
static int
readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
{
	int i;
	long chksum, sum=0;
	unsigned char *s = (unsigned char *)rawHeader;

	header->name  = rawHeader->name;
	/* Check for and relativify any absolute paths */
	if ( *(header->name) == '/' ) {
		static int alreadyWarned=FALSE;

		while (*(header->name) == '/')
			header->name++;

		if (alreadyWarned == FALSE) {
			error_msg("Removing leading '/' from member names");
			alreadyWarned = TRUE;
		}
	}

	header->mode  = strtol(rawHeader->mode, NULL, 8);
	header->uid   = strtol(rawHeader->uid, NULL, 8);
	header->gid   = strtol(rawHeader->gid, NULL, 8);
	header->size  = strtol(rawHeader->size, NULL, 8);
	header->mtime = strtol(rawHeader->mtime, NULL, 8);
	chksum = strtol(rawHeader->chksum, NULL, 8);
	header->type  = rawHeader->typeflag;
	header->linkname  = rawHeader->linkname;
	header->devmajor  = strtol(rawHeader->devmajor, NULL, 8);
	header->devminor  = strtol(rawHeader->devminor, NULL, 8);

	/* Check the checksum */
	for (i = sizeof(*rawHeader); i-- != 0;) {
		sum += *s++;
	}
	/* Remove the effects of the checksum field (replace 
	 * with blanks for the purposes of the checksum) */
	s = rawHeader->chksum;
	for (i = sizeof(rawHeader->chksum) ; i-- != 0;) {
		sum -= *s++;
	}
	sum += ' ' * sizeof(rawHeader->chksum);
	if (sum == chksum )
		return ( TRUE);
	return( FALSE);
}

#if defined BB_FEATURE_TAR_EXCLUDE
static int exclude_file(char **excluded_files, const char *file)
{
	int i;

	if (excluded_files == NULL)
		return 0;

	for (i = 0; excluded_files[i] != NULL; i++) {
		if (excluded_files[i][0] == '/') {
			if (fnmatch(excluded_files[i], file,
						FNM_PATHNAME | FNM_LEADING_DIR) == 0)
				return 1;
		} else {
			const char *p;

			for (p = file; p[0] != '\0'; p++) {
				if ((p == file || p[-1] == '/') && p[0] != '/' &&
						fnmatch(excluded_files[i], p,
							FNM_PATHNAME | FNM_LEADING_DIR) == 0)
					return 1;
			}
		}
	}

	return 0;
}
#endif

static int extract_file(char **extract_files, const char *file)
{
	int i;

	if (extract_files == NULL)
		return 1;

	for (i = 0; extract_files[i] != NULL; i++) {
		if (fnmatch(extract_files[i], file, FNM_LEADING_DIR) == 0)
			return 1;
	}

	return 0;
}

/*
 * Read a tar file and extract or list the specified files within it.
 * If the list is empty than all files are extracted or listed.
 */
static int readTarFile(int tarFd, int extractFlag, int listFlag, 
		int tostdoutFlag, int verboseFlag, char** extractList,
		char** excludeList)
{
	int status;
	int errorFlag=FALSE;
	int skipNextHeaderFlag=FALSE;
	TarHeader rawHeader;
	TarInfo header;

	/* Read the tar file, and iterate over it one file at a time */
	while ( (status = full_read(tarFd, (char*)&rawHeader, TAR_BLOCK_SIZE)) == TAR_BLOCK_SIZE ) {

		/* Try to read the header */
		if ( readTarHeader(&rawHeader, &header) == FALSE ) {
			if ( *(header.name) == '\0' ) {
				goto endgame;
			} else {
				errorFlag=TRUE;
				error_msg("Bad tar header, skipping");
				continue;
			}
		}
		if ( *(header.name) == '\0' )
			continue;
		header.tarFd = tarFd;

		/* Skip funky extra GNU headers that precede long files */
		if ( (header.type == GNULONGNAME) || (header.type == GNULONGLINK) ) {
			skipNextHeaderFlag=TRUE;
			if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
				errorFlag = TRUE;
			continue;
		}
		if ( skipNextHeaderFlag == TRUE ) { 
			skipNextHeaderFlag=FALSE;
			error_msg(name_longer_than_foo, NAME_SIZE); 
			if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
				errorFlag = TRUE;
			continue;
		}

#if defined BB_FEATURE_TAR_EXCLUDE
		if (exclude_file(excludeList, header.name)) {
			/* There are not the droids you're looking for, move along */
			/* If it is a regular file, pretend to extract it with
			 * the extractFlag set to FALSE, so the junk in the tarball
			 * is properly skipped over */
			if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
				if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
					errorFlag = TRUE;
			}
			continue;
		}
#endif

		if (!extract_file(extractList, header.name)) {
			/* There are not the droids you're looking for, move along */
			/* If it is a regular file, pretend to extract it with
			 * the extractFlag set to FALSE, so the junk in the tarball
			 * is properly skipped over */
			if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
				if (tarExtractRegularFile(&header, FALSE, FALSE) == FALSE)
					errorFlag = TRUE;
			}
			continue;
		}

		if (listFlag == TRUE) {
			/* Special treatment if the list (-t) flag is on */
			if (verboseFlag == TRUE) {
				int len, len1;
				char buf[35];
				struct tm *tm = localtime (&(header.mtime));

				len=printf("%s ", mode_string(header.mode));
				my_getpwuid(buf, header.uid);
				if (! *buf)
					len+=printf("%d", header.uid);
				else
					len+=printf("%s", buf);
				my_getgrgid(buf, header.gid);
				if (! *buf)
					len+=printf("/%-d ", header.gid);
				else
					len+=printf("/%-s ", buf);

				if (header.type==CHRTYPE || header.type==BLKTYPE) {
					len1=snprintf(buf, sizeof(buf), "%ld,%-ld ", 
							header.devmajor, header.devminor);
				} else {
					len1=snprintf(buf, sizeof(buf), "%lu ", (long)header.size);
				}
				/* Jump through some hoops to make the columns match up */
				for(;(len+len1)<31;len++)
					printf(" ");
				printf(buf);

				/* Use ISO 8610 time format */
				if (tm) { 
					printf ("%04d-%02d-%02d %02d:%02d:%02d ", 
							tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
							tm->tm_hour, tm->tm_min, tm->tm_sec);
				}
			}
			printf("%s", header.name);
			if (verboseFlag == TRUE) {
				if (header.type==LNKTYPE)	/* If this is a link, say so */
					printf(" link to %s", header.linkname);
				else if (header.type==SYMTYPE)
					printf(" -> %s", header.linkname);
			}
			printf("\n");
		}

		/* List contents if we are supposed to do that */
		if (verboseFlag == TRUE && extractFlag == TRUE) {
			/* Now the normal listing */
			FILE *vbFd = stdout;
			if (tostdoutFlag == TRUE)	// If the archive goes to stdout, verbose to stderr
				vbFd = stderr;
			fprintf(vbFd, "%s\n", header.name);
		}
			
		/* Remove files if we would overwrite them */
		if (extractFlag == TRUE && tostdoutFlag == FALSE)
			unlink(header.name);

		/* If we got here, we can be certain we have a legitimate 
		 * header to work with.  So work with it.  */
		switch ( header.type ) {
			case REGTYPE:
			case REGTYPE0:
				/* If the name ends in a '/' then assume it is
				 * supposed to be a directory, and fall through */
				if (!last_char_is(header.name,'/')) {
					if (tarExtractRegularFile(&header, extractFlag, tostdoutFlag)==FALSE)
						errorFlag=TRUE;
					break;
				}
			case DIRTYPE:
				if (tarExtractDirectory( &header, extractFlag, tostdoutFlag)==FALSE)
					errorFlag=TRUE;
				break;
			case LNKTYPE:
				if (tarExtractHardLink( &header, extractFlag, tostdoutFlag)==FALSE)
					errorFlag=TRUE;
				break;
			case SYMTYPE:
				if (tarExtractSymLink( &header, extractFlag, tostdoutFlag)==FALSE)
					errorFlag=TRUE;
				break;
			case CHRTYPE:
			case BLKTYPE:
			case FIFOTYPE:
				if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE)
					errorFlag=TRUE;
				break;
#if 0
			/* Handled earlier */
			case GNULONGNAME:
			case GNULONGLINK:
				skipNextHeaderFlag=TRUE;
				break;
#endif
			default:
				error_msg("Unknown file type '%c' in tar file", header.type);
				close( tarFd);
				return( FALSE);
		}
	}
	close(tarFd);
	if (status > 0) {
		/* Bummer - we read a partial header */
		perror_msg("Error reading tar file");
		return ( FALSE);
	}
	else if (errorFlag==TRUE) {
		error_msg( "Error exit delayed from previous errors");
		return( FALSE);
	} else 
		return( status);

	/* Stuff to do when we are done */
endgame:
	close( tarFd);
	if ( *(header.name) == '\0' ) {