1145683Sharti/*-
2145683Sharti * Copyright (c) 2003-2007 Tim Kientzle
3145683Sharti * All rights reserved.
4145683Sharti *
5145683Sharti * Redistribution and use in source and binary forms, with or without
6145683Sharti * modification, are permitted provided that the following conditions
7145683Sharti * are met:
8145683Sharti * 1. Redistributions of source code must retain the above copyright
9145683Sharti *    notice, this list of conditions and the following disclaimer.
10145683Sharti * 2. Redistributions in binary form must reproduce the above copyright
11145683Sharti *    notice, this list of conditions and the following disclaimer in the
12145683Sharti *    documentation and/or other materials provided with the distribution.
13145683Sharti *
14145683Sharti * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15145683Sharti * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16145683Sharti * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17145683Sharti * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18145683Sharti * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19145683Sharti * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20145683Sharti * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21145683Sharti * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22145683Sharti * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23145683Sharti * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24145683Sharti *
25145683Sharti * $FreeBSD$
26145683Sharti */
27145683Sharti
28145683Sharti#ifndef __LIBARCHIVE_BUILD
29145683Sharti#error This header is only to be used internally to libarchive.
30145683Sharti#endif
31145683Sharti
32145683Sharti#ifndef ARCHIVE_READ_PRIVATE_H_INCLUDED
33145683Sharti#define	ARCHIVE_READ_PRIVATE_H_INCLUDED
34145683Sharti
35145683Sharti#include "archive.h"
36145683Sharti#include "archive_string.h"
37#include "archive_private.h"
38
39struct archive_read;
40struct archive_read_filter_bidder;
41struct archive_read_filter;
42
43/*
44 * How bidding works for filters:
45 *   * The bid manager initializes the client-provided reader as the
46 *     first filter.
47 *   * It invokes the bidder for each registered filter with the
48 *     current head filter.
49 *   * The bidders can use archive_read_filter_ahead() to peek ahead
50 *     at the incoming data to compose their bids.
51 *   * The bid manager creates a new filter structure for the winning
52 *     bidder and gives the winning bidder a chance to initialize it.
53 *   * The new filter becomes the new top filter and we repeat the
54 *     process.
55 * This ends only when no bidder provides a non-zero bid.  Then
56 * we perform a similar dance with the registered format handlers.
57 */
58struct archive_read_filter_bidder {
59	/* Configuration data for the bidder. */
60	void *data;
61	/* Name of the filter */
62	const char *name;
63	/* Taste the upstream filter to see if we handle this. */
64	int (*bid)(struct archive_read_filter_bidder *,
65	    struct archive_read_filter *);
66	/* Initialize a newly-created filter. */
67	int (*init)(struct archive_read_filter *);
68	/* Set an option for the filter bidder. */
69	int (*options)(struct archive_read_filter_bidder *,
70	    const char *key, const char *value);
71	/* Release the bidder's configuration data. */
72	int (*free)(struct archive_read_filter_bidder *);
73};
74
75/*
76 * This structure is allocated within the archive_read core
77 * and initialized by archive_read and the init() method of the
78 * corresponding bidder above.
79 */
80struct archive_read_filter {
81	int64_t position;
82	/* Essentially all filters will need these values, so
83	 * just declare them here. */
84	struct archive_read_filter_bidder *bidder; /* My bidder. */
85	struct archive_read_filter *upstream; /* Who I read from. */
86	struct archive_read *archive; /* Associated archive. */
87	/* Open a block for reading */
88	int (*open)(struct archive_read_filter *self);
89	/* Return next block. */
90	ssize_t (*read)(struct archive_read_filter *, const void **);
91	/* Skip forward this many bytes. */
92	int64_t (*skip)(struct archive_read_filter *self, int64_t request);
93	/* Seek to an absolute location. */
94	int64_t (*seek)(struct archive_read_filter *self, int64_t offset, int whence);
95	/* Close (just this filter) and free(self). */
96	int (*close)(struct archive_read_filter *self);
97	/* Function that handles switching from reading one block to the next/prev */
98	int (*sswitch)(struct archive_read_filter *self, unsigned int iindex);
99	/* My private data. */
100	void *data;
101
102	const char	*name;
103	int		 code;
104
105	/* Used by reblocking logic. */
106	char		*buffer;
107	size_t		 buffer_size;
108	char		*next;		/* Current read location. */
109	size_t		 avail;		/* Bytes in my buffer. */
110	const void	*client_buff;	/* Client buffer information. */
111	size_t		 client_total;
112	const char	*client_next;
113	size_t		 client_avail;
114	char		 end_of_file;
115	char		 closed;
116	char		 fatal;
117};
118
119/*
120 * The client looks a lot like a filter, so we just wrap it here.
121 *
122 * TODO: Make archive_read_filter and archive_read_client identical so
123 * that users of the library can easily register their own
124 * transformation filters.  This will probably break the API/ABI and
125 * so should be deferred at least until libarchive 3.0.
126 */
127struct archive_read_data_node {
128	int64_t begin_position;
129	int64_t total_size;
130	void *data;
131};
132struct archive_read_client {
133	archive_open_callback	*opener;
134	archive_read_callback	*reader;
135	archive_skip_callback	*skipper;
136	archive_seek_callback	*seeker;
137	archive_close_callback	*closer;
138	archive_switch_callback *switcher;
139	unsigned int nodes;
140	unsigned int cursor;
141	int64_t position;
142	struct archive_read_data_node *dataset;
143};
144
145struct archive_read {
146	struct archive	archive;
147
148	struct archive_entry	*entry;
149
150	/* Dev/ino of the archive being read/written. */
151	int		  skip_file_set;
152	int64_t		  skip_file_dev;
153	int64_t		  skip_file_ino;
154
155	/*
156	 * Used by archive_read_data() to track blocks and copy
157	 * data to client buffers, filling gaps with zero bytes.
158	 */
159	const char	 *read_data_block;
160	int64_t		  read_data_offset;
161	int64_t		  read_data_output_offset;
162	size_t		  read_data_remaining;
163
164	/*
165	 * Used by formats/filters to determine the amount of data
166	 * requested from a call to archive_read_data(). This is only
167	 * useful when the format/filter has seek support.
168	 */
169	char		  read_data_is_posix_read;
170	size_t		  read_data_requested;
171
172	/* Callbacks to open/read/write/close client archive streams. */
173	struct archive_read_client client;
174
175	/* Registered filter bidders. */
176	struct archive_read_filter_bidder bidders[14];
177
178	/* Last filter in chain */
179	struct archive_read_filter *filter;
180
181	/* Whether to bypass filter bidding process */
182	int bypass_filter_bidding;
183
184	/* File offset of beginning of most recently-read header. */
185	int64_t		  header_position;
186
187	/* Nodes and offsets of compressed data block */
188	unsigned int data_start_node;
189	unsigned int data_end_node;
190
191	/*
192	 * Format detection is mostly the same as compression
193	 * detection, with one significant difference: The bidders
194	 * use the read_ahead calls above to examine the stream rather
195	 * than having the supervisor hand them a block of data to
196	 * examine.
197	 */
198
199	struct archive_format_descriptor {
200		void	 *data;
201		const char *name;
202		int	(*bid)(struct archive_read *, int best_bid);
203		int	(*options)(struct archive_read *, const char *key,
204		    const char *value);
205		int	(*read_header)(struct archive_read *, struct archive_entry *);
206		int	(*read_data)(struct archive_read *, const void **, size_t *, int64_t *);
207		int	(*read_data_skip)(struct archive_read *);
208		int64_t	(*seek_data)(struct archive_read *, int64_t, int);
209		int	(*cleanup)(struct archive_read *);
210	}	formats[16];
211	struct archive_format_descriptor	*format; /* Active format. */
212
213	/*
214	 * Various information needed by archive_extract.
215	 */
216	struct extract		 *extract;
217	int			(*cleanup_archive_extract)(struct archive_read *);
218};
219
220int	__archive_read_register_format(struct archive_read *a,
221	    void *format_data,
222	    const char *name,
223	    int (*bid)(struct archive_read *, int),
224	    int (*options)(struct archive_read *, const char *, const char *),
225	    int (*read_header)(struct archive_read *, struct archive_entry *),
226	    int (*read_data)(struct archive_read *, const void **, size_t *, int64_t *),
227	    int (*read_data_skip)(struct archive_read *),
228	    int64_t (*seek_data)(struct archive_read *, int64_t, int),
229	    int (*cleanup)(struct archive_read *));
230
231int __archive_read_get_bidder(struct archive_read *a,
232    struct archive_read_filter_bidder **bidder);
233
234const void *__archive_read_ahead(struct archive_read *, size_t, ssize_t *);
235const void *__archive_read_filter_ahead(struct archive_read_filter *,
236    size_t, ssize_t *);
237int64_t	__archive_read_seek(struct archive_read*, int64_t, int);
238int64_t	__archive_read_filter_seek(struct archive_read_filter *, int64_t, int);
239int64_t	__archive_read_consume(struct archive_read *, int64_t);
240int64_t	__archive_read_filter_consume(struct archive_read_filter *, int64_t);
241int __archive_read_program(struct archive_read_filter *, const char *);
242void __archive_read_free_filters(struct archive_read *);
243int  __archive_read_close_filters(struct archive_read *);
244#endif
245