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      1 /*-
      2  * Copyright (c) 2003-2007 Tim Kientzle
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
     15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
     18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef ARCHIVE_READ_PRIVATE_H_INCLUDED
     27 #define ARCHIVE_READ_PRIVATE_H_INCLUDED
     28 
     29 #ifndef __LIBARCHIVE_BUILD
     30 #ifndef __LIBARCHIVE_TEST
     31 #error This header is only to be used internally to libarchive.
     32 #endif
     33 #endif
     34 
     35 #include "archive.h"
     36 #include "archive_string.h"
     37 #include "archive_private.h"
     38 
     39 struct archive_read;
     40 struct archive_read_filter_bidder;
     41 struct archive_read_filter;
     42 
     43 struct archive_read_filter_bidder_vtable {
     44 	/* Taste the upstream filter to see if we handle this. */
     45 	int (*bid)(struct archive_read_filter_bidder *,
     46 	    struct archive_read_filter *);
     47 	/* Initialize a newly-created filter. */
     48 	int (*init)(struct archive_read_filter *);
     49 	/* Release the bidder's configuration data. */
     50 	void (*free)(struct archive_read_filter_bidder *);
     51 };
     52 
     53 /*
     54  * How bidding works for filters:
     55  *   * The bid manager initializes the client-provided reader as the
     56  *     first filter.
     57  *   * It invokes the bidder for each registered filter with the
     58  *     current head filter.
     59  *   * The bidders can use archive_read_filter_ahead() to peek ahead
     60  *     at the incoming data to compose their bids.
     61  *   * The bid manager creates a new filter structure for the winning
     62  *     bidder and gives the winning bidder a chance to initialize it.
     63  *   * The new filter becomes the new top filter and we repeat the
     64  *     process.
     65  * This ends only when no bidder provides a non-zero bid.  Then
     66  * we perform a similar dance with the registered format handlers.
     67  */
     68 struct archive_read_filter_bidder {
     69 	/* Configuration data for the bidder. */
     70 	void *data;
     71 	/* Name of the filter */
     72 	const char *name;
     73 	const struct archive_read_filter_bidder_vtable *vtable;
     74 };
     75 
     76 struct archive_read_filter_vtable {
     77 	/* Return next block. */
     78 	ssize_t (*read)(struct archive_read_filter *, const void **);
     79 	/* Close (just this filter) and free(self). */
     80 	int (*close)(struct archive_read_filter *self);
     81 	/* Read any header metadata if available. */
     82 	int (*read_header)(struct archive_read_filter *self, struct archive_entry *entry);
     83 };
     84 
     85 /*
     86  * This structure is allocated within the archive_read core
     87  * and initialized by archive_read and the init() method of the
     88  * corresponding bidder above.
     89  */
     90 struct archive_read_filter {
     91 	int64_t position;
     92 	/* Essentially all filters will need these values, so
     93 	 * just declare them here. */
     94 	struct archive_read_filter_bidder *bidder; /* My bidder. */
     95 	struct archive_read_filter *upstream; /* Who I read from. */
     96 	struct archive_read *archive; /* Associated archive. */
     97 	const struct archive_read_filter_vtable *vtable;
     98 	/* My private data. */
     99 	void *data;
    100 
    101 	const char	*name;
    102 	int		 code;
    103 	int		 can_skip;
    104 	int		 can_seek;
    105 
    106 	/* Used by reblocking logic. */
    107 	char		*buffer;
    108 	size_t		 buffer_size;
    109 	char		*next;		/* Current read location. */
    110 	size_t		 avail;		/* Bytes in my buffer. */
    111 	const void	*client_buff;	/* Client buffer information. */
    112 	size_t		 client_total;
    113 	const char	*client_next;
    114 	size_t		 client_avail;
    115 	char		 end_of_file;
    116 	char		 closed;
    117 	char		 fatal;
    118 };
    119 
    120 /*
    121  * The client looks a lot like a filter, so we just wrap it here.
    122  *
    123  * TODO: Make archive_read_filter and archive_read_client identical so
    124  * that users of the library can easily register their own
    125  * transformation filters.  This will probably break the API/ABI and
    126  * so should be deferred at least until libarchive 3.0.
    127  */
    128 struct archive_read_data_node {
    129 	int64_t begin_position;
    130 	int64_t total_size;
    131 	void *data;
    132 };
    133 struct archive_read_client {
    134 	archive_open_callback	*opener;
    135 	archive_read_callback	*reader;
    136 	archive_skip_callback	*skipper;
    137 	archive_seek_callback	*seeker;
    138 	archive_close_callback	*closer;
    139 	archive_switch_callback *switcher;
    140 	unsigned int nodes;
    141 	unsigned int cursor;
    142 	int64_t position;
    143 	struct archive_read_data_node *dataset;
    144 };
    145 struct archive_read_passphrase {
    146 	char	*passphrase;
    147 	struct archive_read_passphrase *next;
    148 };
    149 
    150 struct archive_read_extract {
    151 	struct archive *ad; /* archive_write_disk object */
    152 
    153 	/* Progress function invoked during extract. */
    154 	void			(*extract_progress)(void *);
    155 	void			 *extract_progress_user_data;
    156 };
    157 
    158 struct archive_read {
    159 	struct archive	archive;
    160 
    161 	struct archive_entry	*entry;
    162 
    163 	/* Dev/ino of the archive being read/written. */
    164 	int		  skip_file_set;
    165 	int64_t		  skip_file_dev;
    166 	int64_t		  skip_file_ino;
    167 
    168 	/* Callbacks to open/read/write/close client archive streams. */
    169 	struct archive_read_client client;
    170 
    171 	/* Registered filter bidders. */
    172 	struct archive_read_filter_bidder bidders[16];
    173 
    174 	/* Last filter in chain */
    175 	struct archive_read_filter *filter;
    176 
    177 	/* Whether to bypass filter bidding process */
    178 	int bypass_filter_bidding;
    179 
    180 	/* File offset of beginning of most recently-read header. */
    181 	int64_t		  header_position;
    182 
    183 	/* Nodes and offsets of compressed data block */
    184 	unsigned int data_start_node;
    185 	unsigned int data_end_node;
    186 
    187 	/*
    188 	 * Format detection is mostly the same as compression
    189 	 * detection, with one significant difference: The bidders
    190 	 * use the read_ahead calls above to examine the stream rather
    191 	 * than having the supervisor hand them a block of data to
    192 	 * examine.
    193 	 */
    194 
    195 	struct archive_format_descriptor {
    196 		void	 *data;
    197 		const char *name;
    198 		int	(*bid)(struct archive_read *, int best_bid);
    199 		int	(*options)(struct archive_read *, const char *key,
    200 		    const char *value);
    201 		int	(*read_header)(struct archive_read *, struct archive_entry *);
    202 		int	(*read_data)(struct archive_read *, const void **, size_t *, int64_t *);
    203 		int	(*read_data_skip)(struct archive_read *);
    204 		int64_t	(*seek_data)(struct archive_read *, int64_t, int);
    205 		int	(*cleanup)(struct archive_read *);
    206 		int	(*format_capabilties)(struct archive_read *);
    207 		int	(*has_encrypted_entries)(struct archive_read *);
    208 	}	formats[16];
    209 	struct archive_format_descriptor	*format; /* Active format. */
    210 
    211 	/*
    212 	 * Various information needed by archive_extract.
    213 	 */
    214 	struct archive_read_extract		*extract;
    215 	int			(*cleanup_archive_extract)(struct archive_read *);
    216 
    217 	/*
    218 	 * Decryption passphrase.
    219 	 */
    220 	struct {
    221 		struct archive_read_passphrase *first;
    222 		struct archive_read_passphrase **last;
    223 		int candidate;
    224 		archive_passphrase_callback *callback;
    225 		void *client_data;
    226 	}		passphrases;
    227 };
    228 
    229 int	__archive_read_register_format(struct archive_read *a,
    230 		void *format_data,
    231 		const char *name,
    232 		int (*bid)(struct archive_read *, int),
    233 		int (*options)(struct archive_read *, const char *, const char *),
    234 		int (*read_header)(struct archive_read *, struct archive_entry *),
    235 		int (*read_data)(struct archive_read *, const void **, size_t *, int64_t *),
    236 		int (*read_data_skip)(struct archive_read *),
    237 		int64_t (*seek_data)(struct archive_read *, int64_t, int),
    238 		int (*cleanup)(struct archive_read *),
    239 		int (*format_capabilities)(struct archive_read *),
    240 		int (*has_encrypted_entries)(struct archive_read *));
    241 
    242 int __archive_read_register_bidder(struct archive_read *a,
    243 		void *bidder_data,
    244 		const char *name,
    245 		const struct archive_read_filter_bidder_vtable *vtable);
    246 
    247 const void *__archive_read_ahead(struct archive_read *, size_t, ssize_t *);
    248 const void *__archive_read_filter_ahead(struct archive_read_filter *,
    249     size_t, ssize_t *);
    250 int64_t	__archive_read_seek(struct archive_read*, int64_t, int);
    251 int64_t	__archive_read_filter_seek(struct archive_read_filter *, int64_t, int);
    252 int64_t	__archive_read_consume(struct archive_read *, int64_t);
    253 int64_t	__archive_read_filter_consume(struct archive_read_filter *, int64_t);
    254 int __archive_read_header(struct archive_read *, struct archive_entry *);
    255 int __archive_read_program(struct archive_read_filter *, const char *);
    256 void __archive_read_free_filters(struct archive_read *);
    257 struct archive_read_extract *__archive_read_get_extract(struct archive_read *);
    258 
    259 
    260 /*
    261  * Get a decryption passphrase.
    262  */
    263 void __archive_read_reset_passphrase(struct archive_read *a);
    264 const char * __archive_read_next_passphrase(struct archive_read *a);
    265 #endif
    266