lib/zip_source_window.c - third_party/libzip - Git at Google

 /*
   zip_source_window.c -- return part of lower source
   Copyright (C) 2012-2017 Dieter Baron and Thomas Klausner

   This file is part of libzip, a library to manipulate ZIP archives.
   The authors can be contacted at <libzip@nih.at>

   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.
   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.
   3. The names of the authors may not be used to endorse or promote
      products derived from this software without specific prior
      written permission.

   THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.
 */


 #include <stdlib.h>
 #include <string.h>

 #include "zipint.h"

 struct window {
     zip_uint64_t start; /* where in file we start reading */
     zip_uint64_t end;   /* where in file we stop reading */

     /* if not NULL, read file data for this file */
     zip_t *source_archive;
     zip_uint64_t source_index;

     zip_uint64_t offset; /* offset in src for next read */

     zip_stat_t stat;
     zip_int8_t compression_flags;
     zip_error_t error;
     zip_int64_t supports;
     bool needs_seek;
 };

 static zip_int64_t window_read(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t);


 zip_source_t *
 zip_source_window(zip_t *za, zip_source_t *src, zip_uint64_t start, zip_uint64_t len) {
     return _zip_source_window_new(src, start, len, NULL, 0, NULL, 0, &za->error);
 }


 zip_source_t *
 _zip_source_window_new(zip_source_t *src, zip_uint64_t start, zip_uint64_t length, zip_stat_t *st, zip_int8_t compression_flags, zip_t *source_archive, zip_uint64_t source_index, zip_error_t *error) {
     struct window *ctx;

     if (src == NULL || start + length < start || (source_archive == NULL && source_index != 0)) {
 	zip_error_set(error, ZIP_ER_INVAL, 0);
 	return NULL;
     }

     if ((ctx = (struct window *)malloc(sizeof(*ctx))) == NULL) {
 	zip_error_set(error, ZIP_ER_MEMORY, 0);
 	return NULL;
     }

     ctx->start = start;
     ctx->end = start + length;
     zip_stat_init(&ctx->stat);
     ctx->compression_flags = compression_flags;
     ctx->source_archive = source_archive;
     ctx->source_index = source_index;
     zip_error_init(&ctx->error);
     ctx->supports = (zip_source_supports(src) & ZIP_SOURCE_SUPPORTS_SEEKABLE) | (zip_source_make_command_bitmap(ZIP_SOURCE_GET_COMPRESSION_FLAGS, ZIP_SOURCE_SUPPORTS, ZIP_SOURCE_TELL, -1));
     ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;

     if (st) {
 	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
 	    free(ctx);
 	    return NULL;
 	}
     }

     return zip_source_layered_create(src, window_read, ctx, error);
 }


 int
 _zip_source_set_source_archive(zip_source_t *src, zip_t *za) {
     src->source_archive = za;
     return _zip_register_source(za, src);
 }


 /* called by zip_discard to avoid operating on file from closed archive */
 void
 _zip_source_invalidate(zip_source_t *src) {
     src->source_closed = 1;

     if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
 	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
     }
 }


 static zip_int64_t
 window_read(zip_source_t *src, void *_ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
     struct window *ctx;
     zip_int64_t ret;
     zip_uint64_t n, i;
     char b[8192];

     ctx = (struct window *)_ctx;

     switch (cmd) {
     case ZIP_SOURCE_CLOSE:
 	return 0;

     case ZIP_SOURCE_ERROR:
 	return zip_error_to_data(&ctx->error, data, len);

     case ZIP_SOURCE_FREE:
 	free(ctx);
 	return 0;

     case ZIP_SOURCE_OPEN:
 	if (ctx->source_archive) {
 	    zip_uint64_t offset;

 	    if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
 		return -1;
 	    }
 	    if (ctx->end + offset < ctx->end) {
 		/* zip archive data claims end of data past zip64 limits */
 		zip_error_set(&ctx->error, ZIP_ER_INCONS, 0);
 		return -1;
 	    }
 	    ctx->start += offset;
 	    ctx->end += offset;
 	    ctx->source_archive = NULL;
 	}

 	if (!ctx->needs_seek) {
 	    for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
 		i = (ctx->start - n > sizeof(b) ? sizeof(b) : ctx->start - n);
 		if ((ret = zip_source_read(src, b, i)) < 0) {
 		    _zip_error_set_from_source(&ctx->error, src);
 		    return -1;
 		}
 		if (ret == 0) {
 		    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
 		    return -1;
 		}
 	    }
 	}
 	ctx->offset = ctx->start;
 	return 0;

     case ZIP_SOURCE_READ:
 	if (len > ctx->end - ctx->offset)
 	    len = ctx->end - ctx->offset;

 	if (len == 0)
 	    return 0;

 	if (ctx->needs_seek) {
 	    if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
 		_zip_error_set_from_source(&ctx->error, src);
 		return -1;
 	    }
 	}

 	if ((ret = zip_source_read(src, data, len)) < 0) {
 	    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
 	    return -1;
 	}

 	ctx->offset += (zip_uint64_t)ret;

 	if (ret == 0) {
 	    if (ctx->offset < ctx->end) {
 		zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
 		return -1;
 	    }
 	}
 	return ret;

     case ZIP_SOURCE_SEEK: {
 	zip_int64_t new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, ctx->end - ctx->start, data, len, &ctx->error);

 	if (new_offset < 0) {
 	    return -1;
 	}

 	ctx->offset = (zip_uint64_t)new_offset + ctx->start;
 	return 0;
     }

     case ZIP_SOURCE_STAT: {
 	zip_stat_t *st;

 	st = (zip_stat_t *)data;

 	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
 	    return -1;
 	}
 	return 0;
     }

     case ZIP_SOURCE_GET_COMPRESSION_FLAGS:
 	return ctx->compression_flags;

     case ZIP_SOURCE_SUPPORTS:
 	return ctx->supports;

     case ZIP_SOURCE_TELL:
 	return (zip_int64_t)(ctx->offset - ctx->start);

     default:
 	zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);
 	return -1;
     }
 }


 void
 _zip_deregister_source(zip_t *za, zip_source_t *src) {
     unsigned int i;

     for (i = 0; i < za->nopen_source; i++) {
 	if (za->open_source[i] == src) {
 	    za->open_source[i] = za->open_source[za->nopen_source - 1];
 	    za->nopen_source--;
 	    break;
 	}
     }
 }


 int
 _zip_register_source(zip_t *za, zip_source_t *src) {
     zip_source_t **open_source;

     if (za->nopen_source + 1 >= za->nopen_source_alloc) {
 	unsigned int n;
 	n = za->nopen_source_alloc + 10;
 	open_source = (zip_source_t **)realloc(za->open_source, n * sizeof(zip_source_t *));
 	if (open_source == NULL) {
 	    zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
 	    return -1;
 	}
 	za->nopen_source_alloc = n;
 	za->open_source = open_source;
     }

     za->open_source[za->nopen_source++] = src;

     return 0;
 }
	/*
	zip_source_window.c -- return part of lower source
	Copyright (C) 2012-2017 Dieter Baron and Thomas Klausner

	This file is part of libzip, a library to manipulate ZIP archives.
	The authors can be contacted at <libzip@nih.at>

	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.
	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.
	3. The names of the authors may not be used to endorse or promote
	products derived from this software without specific prior
	written permission.

	THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.
	*/


	#include <stdlib.h>
	#include <string.h>

	#include "zipint.h"

	struct window {
	zip_uint64_t start; /* where in file we start reading */
	zip_uint64_t end; /* where in file we stop reading */

	/* if not NULL, read file data for this file */
	zip_t *source_archive;
	zip_uint64_t source_index;

	zip_uint64_t offset; /* offset in src for next read */

	zip_stat_t stat;
	zip_int8_t compression_flags;
	zip_error_t error;
	zip_int64_t supports;
	bool needs_seek;
	};

	static zip_int64_t window_read(zip_source_t , void , void *, zip_uint64_t, zip_source_cmd_t);


	zip_source_t *
	zip_source_window(zip_t za, zip_source_t src, zip_uint64_t start, zip_uint64_t len) {
	return _zip_source_window_new(src, start, len, NULL, 0, NULL, 0, &za->error);
	}


	zip_source_t *
	_zip_source_window_new(zip_source_t src, zip_uint64_t start, zip_uint64_t length, zip_stat_t st, zip_int8_t compression_flags, zip_t source_archive, zip_uint64_t source_index, zip_error_t error) {
	struct window *ctx;

	if (src == NULL \|\| start + length < start \|\| (source_archive == NULL && source_index != 0)) {
	zip_error_set(error, ZIP_ER_INVAL, 0);
	return NULL;
	}

	if ((ctx = (struct window )malloc(sizeof(ctx))) == NULL) {
	zip_error_set(error, ZIP_ER_MEMORY, 0);
	return NULL;
	}

	ctx->start = start;
	ctx->end = start + length;
	zip_stat_init(&ctx->stat);
	ctx->compression_flags = compression_flags;
	ctx->source_archive = source_archive;
	ctx->source_index = source_index;
	zip_error_init(&ctx->error);
	ctx->supports = (zip_source_supports(src) & ZIP_SOURCE_SUPPORTS_SEEKABLE) \| (zip_source_make_command_bitmap(ZIP_SOURCE_GET_COMPRESSION_FLAGS, ZIP_SOURCE_SUPPORTS, ZIP_SOURCE_TELL, -1));
	ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;

	if (st) {
	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
	free(ctx);
	return NULL;
	}
	}

	return zip_source_layered_create(src, window_read, ctx, error);
	}


	int
	_zip_source_set_source_archive(zip_source_t src, zip_t za) {
	src->source_archive = za;
	return _zip_register_source(za, src);
	}


	/* called by zip_discard to avoid operating on file from closed archive */
	void
	_zip_source_invalidate(zip_source_t *src) {
	src->source_closed = 1;

	if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
	}
	}


	static zip_int64_t
	window_read(zip_source_t src, void _ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
	struct window *ctx;
	zip_int64_t ret;
	zip_uint64_t n, i;
	char b[8192];

	ctx = (struct window *)_ctx;

	switch (cmd) {
	case ZIP_SOURCE_CLOSE:
	return 0;

	case ZIP_SOURCE_ERROR:
	return zip_error_to_data(&ctx->error, data, len);

	case ZIP_SOURCE_FREE:
	free(ctx);
	return 0;

	case ZIP_SOURCE_OPEN:
	if (ctx->source_archive) {
	zip_uint64_t offset;

	if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
	return -1;
	}
	if (ctx->end + offset < ctx->end) {
	/* zip archive data claims end of data past zip64 limits */
	zip_error_set(&ctx->error, ZIP_ER_INCONS, 0);
	return -1;
	}
	ctx->start += offset;
	ctx->end += offset;
	ctx->source_archive = NULL;
	}

	if (!ctx->needs_seek) {
	for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
	i = (ctx->start - n > sizeof(b) ? sizeof(b) : ctx->start - n);
	if ((ret = zip_source_read(src, b, i)) < 0) {
	_zip_error_set_from_source(&ctx->error, src);
	return -1;
	}
	if (ret == 0) {
	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
	return -1;
	}
	}
	}
	ctx->offset = ctx->start;
	return 0;

	case ZIP_SOURCE_READ:
	if (len > ctx->end - ctx->offset)
	len = ctx->end - ctx->offset;

	if (len == 0)
	return 0;

	if (ctx->needs_seek) {
	if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
	_zip_error_set_from_source(&ctx->error, src);
	return -1;
	}
	}

	if ((ret = zip_source_read(src, data, len)) < 0) {
	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
	return -1;
	}

	ctx->offset += (zip_uint64_t)ret;

	if (ret == 0) {
	if (ctx->offset < ctx->end) {
	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
	return -1;
	}
	}
	return ret;

	case ZIP_SOURCE_SEEK: {
	zip_int64_t new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, ctx->end - ctx->start, data, len, &ctx->error);

	if (new_offset < 0) {
	return -1;
	}

	ctx->offset = (zip_uint64_t)new_offset + ctx->start;
	return 0;
	}

	case ZIP_SOURCE_STAT: {
	zip_stat_t *st;

	st = (zip_stat_t *)data;

	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
	return -1;
	}
	return 0;
	}

	case ZIP_SOURCE_GET_COMPRESSION_FLAGS:
	return ctx->compression_flags;

	case ZIP_SOURCE_SUPPORTS:
	return ctx->supports;

	case ZIP_SOURCE_TELL:
	return (zip_int64_t)(ctx->offset - ctx->start);

	default:
	zip_error_set(&ctx->error, ZIP_ER_OPNOTSUPP, 0);
	return -1;
	}
	}


	void
	_zip_deregister_source(zip_t za, zip_source_t src) {
	unsigned int i;

	for (i = 0; i < za->nopen_source; i++) {
	if (za->open_source[i] == src) {
	za->open_source[i] = za->open_source[za->nopen_source - 1];
	za->nopen_source--;
	break;
	}
	}
	}


	int
	_zip_register_source(zip_t za, zip_source_t src) {
	zip_source_t **open_source;

	if (za->nopen_source + 1 >= za->nopen_source_alloc) {
	unsigned int n;
	n = za->nopen_source_alloc + 10;
	open_source = (zip_source_t *)realloc(za->open_source, n sizeof(zip_source_t *));
	if (open_source == NULL) {
	zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
	return -1;
	}
	za->nopen_source_alloc = n;
	za->open_source = open_source;
	}

	za->open_source[za->nopen_source++] = src;

	return 0;
	}