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Diffstat (limited to 'src/VBox/Runtime/common/zip/tar.h')
| -rw-r--r-- | src/VBox/Runtime/common/zip/tar.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/zip/tar.h b/src/VBox/Runtime/common/zip/tar.h new file mode 100644 index 00000000..b247b777 --- /dev/null +++ b/src/VBox/Runtime/common/zip/tar.h @@ -0,0 +1,146 @@ +/* $Id: tar.h $ */ +/** @file + * IPRT - TAR Virtual Filesystem. + */ + +/* + * Copyright (C) 2010-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + +#ifndef IPRT_INCLUDED_SRC_common_zip_tar_h +#define IPRT_INCLUDED_SRC_common_zip_tar_h +#ifndef RT_WITHOUT_PRAGMA_ONCE +# pragma once +#endif + +#include <iprt/assert.h> +#include <iprt/formats/tar.h> + +/** + * Tar header union. + */ +typedef union RTZIPTARHDR +{ + /** Byte view. */ + char ab[512]; + /** The standard header. */ + RTZIPTARHDRANCIENT Ancient; + /** The standard header. */ + RTZIPTARHDRPOSIX Posix; + /** The GNU header. */ + RTZIPTARHDRGNU Gnu; + /** The bits common to both GNU and the standard header. */ + RTZIPTARHDRCOMMON Common; + /** GNU sparse header. */ + RTZIPTARHDRGNUSPARSE GnuSparse; +} RTZIPTARHDR; +AssertCompileSize(RTZIPTARHDR, 512); +/** Pointer to a tar file header. */ +typedef RTZIPTARHDR *PRTZIPTARHDR; +/** Pointer to a const tar file header. */ +typedef RTZIPTARHDR const *PCRTZIPTARHDR; + + +/** + * Tar header type. + */ +typedef enum RTZIPTARTYPE +{ + /** Invalid type value. */ + RTZIPTARTYPE_INVALID = 0, + /** Posix header. */ + RTZIPTARTYPE_POSIX, + /** The old GNU header, has layout conflicting with posix. */ + RTZIPTARTYPE_GNU, + /** Ancient tar header which does not use anything beyond the magic. */ + RTZIPTARTYPE_ANCIENT, + /** End of the valid type values (this is not valid). */ + RTZIPTARTYPE_END, + /** The usual type blow up. */ + RTZIPTARTYPE_32BIT_HACK = 0x7fffffff +} RTZIPTARTYPE; +typedef RTZIPTARTYPE *PRTZIPTARTYPE; + + +/** + * Calculates the TAR header checksums and detects if it's all zeros. + * + * @returns true if all zeros, false if not. + * @param pHdr The header to checksum. + * @param pi32Unsigned Where to store the checksum calculated using + * unsigned chars. This is the one POSIX specifies. + * @param pi32Signed Where to store the checksum calculated using + * signed chars. + * + * @remarks The reason why we calculate the checksum as both signed and unsigned + * has to do with various the char C type being signed on some hosts + * and unsigned on others. + */ +DECLINLINE(bool) rtZipTarCalcChkSum(PCRTZIPTARHDR pHdr, int32_t *pi32Unsigned, int32_t *pi32Signed) +{ + int32_t i32Unsigned = 0; + int32_t i32Signed = 0; + + /* + * Sum up the entire header. + */ + const char *pch = (const char *)pHdr; + const char *pchEnd = pch + sizeof(*pHdr); + do + { + i32Unsigned += *(unsigned char *)pch; + i32Signed += *(signed char *)pch; + } while (++pch != pchEnd); + + /* + * Check if it's all zeros and replace the chksum field with spaces. + */ + bool const fZeroHdr = i32Unsigned == 0; + + pch = pHdr->Common.chksum; + pchEnd = pch + sizeof(pHdr->Common.chksum); + do + { + i32Unsigned -= *(unsigned char *)pch; + i32Signed -= *(signed char *)pch; + } while (++pch != pchEnd); + + i32Unsigned += (unsigned char)' ' * sizeof(pHdr->Common.chksum); + i32Signed += (signed char)' ' * sizeof(pHdr->Common.chksum); + + *pi32Unsigned = i32Unsigned; + if (pi32Signed) + *pi32Signed = i32Signed; + return fZeroHdr; +} + + +#endif /* !IPRT_INCLUDED_SRC_common_zip_tar_h */ + |