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author | kientzle <kientzle@FreeBSD.org> | 2004-02-09 23:22:54 +0000 |
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committer | kientzle <kientzle@FreeBSD.org> | 2004-02-09 23:22:54 +0000 |
commit | af9413b539628b0758b4af66ffbb879fba49cc6d (patch) | |
tree | 20e1d80fd0a1d288a08af1696ee258bcd08f41d0 /lib/libarchive/archive_private.h | |
parent | 6b6e533f7e91602d4ccb3353351eb9f816c2daf2 (diff) | |
download | FreeBSD-src-af9413b539628b0758b4af66ffbb879fba49cc6d.zip FreeBSD-src-af9413b539628b0758b4af66ffbb879fba49cc6d.tar.gz |
Initial import of libarchive.
What it is:
A library for reading and writing various streaming archive
formats, especially tar and cpio. Being a library, it should
be easy to incorporate into pkg_* tools, sysinstall, and any
other place that needs to read or write such archives.
Features:
* Full automatic detection of both compression and archive format.
* Extensible internal architecture to make it easy to add new formats.
* Support for "pax interchange format," a new POSIX-standard tar format
that eliminates essentially all of the restrictions of historic formats.
* BSD license
Thanks to: jkh for pushing me to start this work, gordon for
encouraging me to commit it, bde for answering endless style
questions, and many others for feedback and encouragement.
Status: Pretty good overall, though there are still a few rough edges and
the library could always use more testing. Feedback eagerly solicited.
Diffstat (limited to 'lib/libarchive/archive_private.h')
-rw-r--r-- | lib/libarchive/archive_private.h | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/lib/libarchive/archive_private.h b/lib/libarchive/archive_private.h new file mode 100644 index 0000000..58c093b --- /dev/null +++ b/lib/libarchive/archive_private.h @@ -0,0 +1,267 @@ +/*- + * Copyright (c) 2003-2004 Tim Kientzle + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer + * in this position and unchanged. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#ifndef ARCHIVE_PRIVATE_H_INCLUDED +#define ARCHIVE_PRIVATE_H_INCLUDED + +#include <stdint.h> + +#include "archive.h" +#include "archive_string.h" + +#define ARCHIVE_WRITE_MAGIC (0xb0c5c0deU) +#define ARCHIVE_READ_MAGIC (0xdeb0c5U) + +/* + * This is used by archive_extract to keep track of non-writable + * directories so that they can be initially restored writable, then + * fixed up at end. This also handles mtime/atime fixups. + */ +struct archive_extract_dir_entry { + struct archive_extract_dir_entry *next; + mode_t mode; + int64_t mtime; + int64_t atime; + unsigned long mtime_nanos; + unsigned long atime_nanos; + /* Note: ctime cannot be restored, so don't bother */ + char *name; +}; + +struct archive { + /* + * The magic/state values are used to sanity-check the + * client's usage. If an API function is called at a + * rediculous time, or the client passes us an invalid + * pointer, these values allow me to catch that. + */ + unsigned magic; + unsigned state; + + struct archive_entry *entry; + + /* + * Space to store per-entry strings. Most header strings are + * copied here from the format-specific header, in order to + * gaurantee null-termination. Maybe these should go into + * per-format storage? + */ + struct archive_string entry_name; + struct archive_string entry_linkname; + struct archive_string entry_uname; + struct archive_string entry_gname; + + /* Utility: Pointer to a block of nulls. */ + const char *nulls; + size_t null_length; + + /* + * Used to limit reads of entry data. Eventually, each reader + * will be able to register it's own read_data routine and these + * will move into the per-format data for the formats that use them. + */ + uint64_t entry_bytes_remaining; + uint64_t entry_padding; /* Skip this much after entry data. */ + + uid_t user_uid; /* UID of current user. */ + + /* Callbacks to open/read/write/close archive stream. */ + archive_open_callback *client_opener; + archive_read_callback *client_reader; + archive_write_callback *client_writer; + archive_close_callback *client_closer; + void *client_data; + + /* + * Blocking information. Note that bytes_in_last_block is + * misleadingly named; I should find a better name. These + * control the final output from all compressors, including + * compression_none. + */ + int bytes_per_block; + int bytes_in_last_block; + + /* + * These control whether data within a gzip/bzip2 compressed + * stream gets padded or not. If pad_uncompressed is set, + * the data will be padded to a full block before being + * compressed. The pad_uncompressed_byte determines the value + * that will be used for padding. Note that these have no + * effect on compression "none." + */ + int pad_uncompressed; + int pad_uncompressed_byte; /* TODO: Support this. */ + + /* + * PAX extended header data. When reading, + * name/linkname/uname/gname fields may point into here. This + * should be moved into per-format data storage. + */ + struct archive_string pax_header; + + /* + * GNU header fields. These should be moved into format-specific + * storage. + */ + struct archive_string gnu_name; + struct archive_string gnu_linkname; + int gnu_header_recursion_depth; + + /* Position in UNCOMPRESSED data stream. */ + intmax_t file_position; + /* File offset of beginning of most recently-read header. */ + intmax_t header_position; + + /* + * Detection functions for decompression: bid functions are + * given a block of data from the beginning of the stream and + * can bid on whether or not they support the data stream. + * General guideline: bid the number of bits that you actually + * test, e.g., 16 if you test a 2-byte magic value. The + * highest bidder will have their init function invoked, which + * can set up pointers to specific handlers. + * + * On write, the client just invokes an archive_write_set function + * which sets up the data here directly. + */ + int compression_code; /* Currently active compression. */ + const char *compression_name; + struct { + int (*bid)(const void *buff, size_t); + int (*init)(struct archive *, const void *buff, size_t); + } decompressors[4]; + /* Read/write data stream (with compression). */ + void *compression_data; /* Data for (de)compressor. */ + int (*compression_init)(struct archive *); /* Initialize. */ + int (*compression_finish)(struct archive *); + ssize_t (*compression_write)(struct archive *, const void *, size_t); + /* + * Read uses a peek/consume I/O model: the decompression code + * returns a pointer to the requested block and advances the + * file position only when requested by a consume call. This + * reduces copying and also simplifies look-ahead for format + * detection. + */ + ssize_t (*compression_read_ahead)(struct archive *, + const void **, size_t request); + ssize_t (*compression_read_consume)(struct archive *, size_t); + + /* + * Format detection is mostly the same as compression + * detection, with two significant differences: The bidders + * use the read_ahead calls above to examine the stream rather + * than having the supervisor hand them a block of data to + * examine, and the auction is repeated for every header. + * Winning bidders should set the archive_format and + * archive_format_name appropriately. Bid routines should + * check archive_format and decline to bid if the format of + * the last header was incompatible. + * + * Again, write support is considerably simpler because there's + * no need for an auction. + */ + int archive_format; + const char *archive_format_name; + + struct archive_format_descriptor { + int (*bid)(struct archive *); + int (*read_header)(struct archive *, struct archive_entry *); + int (*cleanup)(struct archive *); + void *format_data; /* Format-specific data for readers. */ + } formats[4]; + struct archive_format_descriptor *format; /* Active format. */ + + /* + * Storage for format-specific data. Note that there can be + * multiple format readers active at one time, so we need to + * allow for multiple format readers to have their data + * available. The pformat_data slot here is the solution: on + * read, it's set up in the bid phase and is gauranteed to + * always point to a void* variable that the format can use. + */ + void **pformat_data; /* Pointer to current format_data. */ + void *format_data; /* Used by writers. */ + + /* + * Pointers to format-specific functions. On read, these are + * initialized in the bid process. On write, they're initialized by + * archive_write_set_format_XXX() calls. + */ + int (*format_init)(struct archive *); /* Only used on write. */ + int (*format_finish)(struct archive *); + int (*format_finish_entry)(struct archive *); + int (*format_write_header)(struct archive *, + struct archive_entry *); + int (*format_write_data)(struct archive *, + const void *buff, size_t); + + /* + * Various information needed by archive_extract. + */ + struct archive_string extract_mkdirpath; + struct archive_extract_dir_entry *archive_extract_dir_list; + void (*cleanup_archive_extract)(struct archive *); + + int archive_error_number; + const char *error; + struct archive_string error_string; +}; + + +/* Utility function to format a USTAR header into a buffer. */ +int +__archive_write_format_header_ustar(struct archive *, char buff[512], + struct archive_entry *); + +#define ARCHIVE_STATE_ANY 0xFFFFU +#define ARCHIVE_STATE_NEW 1U +#define ARCHIVE_STATE_HEADER 2U +#define ARCHIVE_STATE_DATA 4U +#define ARCHIVE_STATE_EOF 8U +#define ARCHIVE_STATE_CLOSED 0x10U +#define ARCHIVE_STATE_FATAL 0x8000U + +/* Check magic value and state; exit if it isn't valid. */ +void +__archive_check_magic(struct archive *, unsigned magic, + unsigned state, const char *func); + +#define archive_check_magic(a,m,s) \ + __archive_check_magic((a), (m), (s), __func__) + +int __archive_read_register_format(struct archive *a, + void *format_data, + int (*bid)(struct archive *), + int (*read_header)(struct archive *, struct archive_entry *), + int (*cleanup)(struct archive *)); + +int __archive_read_register_compression(struct archive *a, + int (*bid)(const void *, size_t), + int (*init)(struct archive *, const void *, size_t)); + +#endif |