blob: f4701a04b2ca599d1bc7f1ac040d80a53c64fdb4 [file] [log] [blame]
/*
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;
}