/src/libzip/lib/zip_source_window.c

Source
/*
  zip_source_window.c -- return part of lower source
  Copyright (C) 2012-2024 Dieter Baron and Thomas Klausner

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

  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 "zipint.h"

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

struct window {
    zip_uint64_t start; /* where in file we start reading */
    zip_uint64_t end;   /* where in file we stop reading */
    bool end_valid;     /* whether end is set, otherwise read until EOF */

    /* 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_uint64_t stat_invalid;
    zip_file_attributes_t attributes;
    zip_dostime_t dostime;
    bool dostime_valid;
    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_EXTERN zip_source_t *
zip_source_window_create(zip_source_t *src, zip_uint64_t start, zip_int64_t len, zip_error_t *error) {
    return _zip_source_window_new(src, start, len, NULL, 0, NULL, NULL, NULL, 0, false, error);
}


zip_source_t *
_zip_source_window_new(zip_source_t *src, zip_uint64_t start, zip_int64_t length, zip_stat_t *st, zip_uint64_t st_invalid, zip_file_attributes_t *attributes, zip_dostime_t *dostime, zip_t *source_archive, zip_uint64_t source_index, bool take_ownership, zip_error_t *error) {
    zip_source_t* window_source;
    struct window *ctx;

    if (src == NULL || length < -1 || (source_archive == NULL && source_index != 0)) {
        zip_error_set(error, ZIP_ER_INVAL, 0);
        return NULL;
    }
    
    if (length >= 0) {
        if (start + (zip_uint64_t)length < start) {
            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;
    if (length == -1) {
        ctx->end_valid = false;
    }
    else {
        ctx->end = start + (zip_uint64_t)length;
        ctx->end_valid = true;
    }
    zip_stat_init(&ctx->stat);
    ctx->stat_invalid = st_invalid;
    if (attributes != NULL) {
        (void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
    }
    else {
        zip_file_attributes_init(&ctx->attributes);
    }
    if (dostime != NULL) {
        ctx->dostime = *dostime;
        ctx->dostime_valid = true;
    }
    else {
        ctx->dostime_valid = false;
    }
    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_SUPPORTS_REOPEN)) | (zip_source_make_command_bitmap(ZIP_SOURCE_GET_FILE_ATTRIBUTES, ZIP_SOURCE_GET_DOS_TIME, ZIP_SOURCE_SUPPORTS, ZIP_SOURCE_TELL, ZIP_SOURCE_FREE, -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;
        }
    }
    
    window_source = zip_source_layered_create(src, window_read, ctx, error);
    if (window_source != NULL && !take_ownership) {
        zip_source_keep(src);
    }
    return window_source;
}


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;

    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, MAKE_DETAIL_WITH_INDEX(ZIP_ER_DETAIL_CDIR_ENTRY_INVALID, ctx->source_index));
                return -1;
            }
            ctx->start += offset;
            ctx->end += offset;
            ctx->source_archive = NULL;
        }

        if (!ctx->needs_seek) {
            DEFINE_BYTE_ARRAY(b, BUFSIZE);

            if (!byte_array_init(b, BUFSIZE)) {
                zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
                return -1;
            }

            for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
                i = (ctx->start - n > BUFSIZE ? BUFSIZE : ctx->start - n);
                if ((ret = zip_source_read(src, b, i)) < 0) {
                    zip_error_set_from_source(&ctx->error, src);
                    byte_array_fini(b);
                    return -1;
                }
                if (ret == 0) {
                    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
                    byte_array_fini(b);
                    return -1;
                }
            }

            byte_array_fini(b);
        }

        ctx->offset = ctx->start;
        return 0;

    case ZIP_SOURCE_READ:
        if (ctx->end_valid && 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->end_valid && 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;
        
        if (!ctx->end_valid) {
            zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
            
            if (args == NULL) {
                return -1;
            }
            if (args->whence == SEEK_END) {
                if (zip_source_seek(src, args->offset, args->whence) < 0) {
                    zip_error_set_from_source(&ctx->error, src);
                    return -1;
                }
                new_offset = zip_source_tell(src);
                if (new_offset < 0) {
                    zip_error_set_from_source(&ctx->error, src);
                    return -1;
                }
                if ((zip_uint64_t)new_offset < ctx->start) {
                    zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
                    (void)zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET);
                    return -1;
                }
                ctx->offset = (zip_uint64_t)new_offset;
                return 0;
            }
        }

        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;
        }

        if (!(ctx->stat.valid & ZIP_STAT_SIZE)) {
            if (ctx->end_valid) {
                st->valid |= ZIP_STAT_SIZE;
                st->size = ctx->end - ctx->start;
            }
            else if (st->valid & ZIP_STAT_SIZE) {
                st->size -= ctx->start;
            }
        }

        st->valid &= ~ctx->stat_invalid;

        return 0;
    }

    case ZIP_SOURCE_GET_FILE_ATTRIBUTES:
        if (len < sizeof(ctx->attributes)) {
            zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
            return -1;
        }

        (void)memcpy_s(data, sizeof(ctx->attributes), &ctx->attributes, sizeof(ctx->attributes));
        return sizeof(ctx->attributes);

    case ZIP_SOURCE_GET_DOS_TIME:
        if (len < sizeof(ctx->dostime)) {
            zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
            return -1;
        }
        if (ctx->dostime_valid) {
            (void)memcpy_s(data, sizeof(ctx->dostime), &ctx->dostime, sizeof(ctx->dostime));
            return sizeof(ctx->dostime);
        }
        else {
            return 0;
        }

    case ZIP_SOURCE_SUPPORTS:
        return ctx->supports;

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

    default:
        return zip_source_pass_to_lower_layer(src, data, len, cmd);
    }
}


void
_zip_deregister_source(zip_t *za, zip_source_t *src) {
    zip_uint64_t 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) {
    if (za->nopen_source + 1 >= za->nopen_source_alloc) {
        if (!ZIP_REALLOC(za->open_source, za->nopen_source_alloc, 10, &za->error)) {
            return -1;
        }
    }

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

    return 0;
}

Coverage Report

Created: 2025-11-16 07:22

Line	Count	Source
1		/*
2		zip_source_window.c -- return part of lower source
3		Copyright (C) 2012-2024 Dieter Baron and Thomas Klausner
4
5		This file is part of libzip, a library to manipulate ZIP archives.
6		The authors can be contacted at <info@libzip.org>
7
8		Redistribution and use in source and binary forms, with or without
9		modification, are permitted provided that the following conditions
10		are met:
11		1. Redistributions of source code must retain the above copyright
12		notice, this list of conditions and the following disclaimer.
13		2. Redistributions in binary form must reproduce the above copyright
14		notice, this list of conditions and the following disclaimer in
15		the documentation and/or other materials provided with the
16		distribution.
17		3. The names of the authors may not be used to endorse or promote
18		products derived from this software without specific prior
19		written permission.
20
21		THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
22		OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23		WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24		ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
25		DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26		DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27		GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28		INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
29		IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30		OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
31		IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32		*/
33
34		#include "zipint.h"
35
36		#include <stdlib.h>
37		#include <string.h>
38
39		struct window {
40		zip_uint64_t start; /* where in file we start reading */
41		zip_uint64_t end; /* where in file we stop reading */
42		bool end_valid; /* whether end is set, otherwise read until EOF */
43
44		/* if not NULL, read file data for this file */
45		zip_t *source_archive;
46		zip_uint64_t source_index;
47
48		zip_uint64_t offset; /* offset in src for next read */
49
50		zip_stat_t stat;
51		zip_uint64_t stat_invalid;
52		zip_file_attributes_t attributes;
53		zip_dostime_t dostime;
54		bool dostime_valid;
55		zip_error_t error;
56		zip_int64_t supports;
57		bool needs_seek;
58		};
59
60		static zip_int64_t window_read(zip_source_t , void , void *, zip_uint64_t, zip_source_cmd_t);
61
62
63		ZIP_EXTERN zip_source_t *
64	0	zip_source_window_create(zip_source_t src, zip_uint64_t start, zip_int64_t len, zip_error_t error) {
65	0	return _zip_source_window_new(src, start, len, NULL, 0, NULL, NULL, NULL, 0, false, error);
66	0	}
67
68
69		zip_source_t *
70	0	_zip_source_window_new(zip_source_t src, zip_uint64_t start, zip_int64_t length, zip_stat_t st, zip_uint64_t st_invalid, zip_file_attributes_t attributes, zip_dostime_t dostime, zip_t source_archive, zip_uint64_t source_index, bool take_ownership, zip_error_t error) {
71	0	zip_source_t* window_source;
72	0	struct window *ctx;
73
74	0	if (src == NULL \|\| length < -1 \|\| (source_archive == NULL && source_index != 0)) {
75	0	zip_error_set(error, ZIP_ER_INVAL, 0);
76	0	return NULL;
77	0	}
78
79	0	if (length >= 0) {
80	0	if (start + (zip_uint64_t)length < start) {
81	0	zip_error_set(error, ZIP_ER_INVAL, 0);
82	0	return NULL;
83	0	}
84	0	}
85
86	0	if ((ctx = (struct window )malloc(sizeof(ctx))) == NULL) {
87	0	zip_error_set(error, ZIP_ER_MEMORY, 0);
88	0	return NULL;
89	0	}
90
91	0	ctx->start = start;
92	0	if (length == -1) {
93	0	ctx->end_valid = false;
94	0	}
95	0	else {
96	0	ctx->end = start + (zip_uint64_t)length;
97	0	ctx->end_valid = true;
98	0	}
99	0	zip_stat_init(&ctx->stat);
100	0	ctx->stat_invalid = st_invalid;
101	0	if (attributes != NULL) {
102	0	(void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
103	0	}
104	0	else {
105	0	zip_file_attributes_init(&ctx->attributes);
106	0	}
107	0	if (dostime != NULL) {
108	0	ctx->dostime = *dostime;
109	0	ctx->dostime_valid = true;
110	0	}
111	0	else {
112	0	ctx->dostime_valid = false;
113	0	}
114	0	ctx->source_archive = source_archive;
115	0	ctx->source_index = source_index;
116	0	zip_error_init(&ctx->error);
117	0	ctx->supports = (zip_source_supports(src) & (ZIP_SOURCE_SUPPORTS_SEEKABLE \| ZIP_SOURCE_SUPPORTS_REOPEN)) \| (zip_source_make_command_bitmap(ZIP_SOURCE_GET_FILE_ATTRIBUTES, ZIP_SOURCE_GET_DOS_TIME, ZIP_SOURCE_SUPPORTS, ZIP_SOURCE_TELL, ZIP_SOURCE_FREE, -1));
118	0	ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;
119
120	0	if (st) {
121	0	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
122	0	free(ctx);
123	0	return NULL;
124	0	}
125	0	}
126
127	0	window_source = zip_source_layered_create(src, window_read, ctx, error);
128	0	if (window_source != NULL && !take_ownership) {
129	0	zip_source_keep(src);
130	0	}
131	0	return window_source;
132	0	}
133
134
135		int
136	0	_zip_source_set_source_archive(zip_source_t src, zip_t za) {
137	0	src->source_archive = za;
138	0	return _zip_register_source(za, src);
139	0	}
140
141
142		/* called by zip_discard to avoid operating on file from closed archive */
143		void
144	0	_zip_source_invalidate(zip_source_t *src) {
145	0	src->source_closed = 1;
146
147	0	if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
148	0	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
149	0	}
150	0	}
151
152
153		static zip_int64_t
154	0	window_read(zip_source_t src, void _ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
155	0	struct window *ctx;
156	0	zip_int64_t ret;
157	0	zip_uint64_t n, i;
158
159	0	ctx = (struct window *)_ctx;
160
161	0	switch (cmd) {
162	0	case ZIP_SOURCE_CLOSE:
163	0	return 0;
164
165	0	case ZIP_SOURCE_ERROR:
166	0	return zip_error_to_data(&ctx->error, data, len);
167
168	0	case ZIP_SOURCE_FREE:
169	0	free(ctx);
170	0	return 0;
171
172	0	case ZIP_SOURCE_OPEN:
173	0	if (ctx->source_archive) {
174	0	zip_uint64_t offset;
175
176	0	if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
177	0	return -1;
178	0	}
179	0	if (ctx->end + offset < ctx->end) {
180		/* zip archive data claims end of data past zip64 limits */
181	0	zip_error_set(&ctx->error, ZIP_ER_INCONS, MAKE_DETAIL_WITH_INDEX(ZIP_ER_DETAIL_CDIR_ENTRY_INVALID, ctx->source_index));
182	0	return -1;
183	0	}
184	0	ctx->start += offset;
185	0	ctx->end += offset;
186	0	ctx->source_archive = NULL;
187	0	}
188
189	0	if (!ctx->needs_seek) {
190	0	DEFINE_BYTE_ARRAY(b, BUFSIZE);
191
192	0	if (!byte_array_init(b, BUFSIZE)) {
193	0	zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
194	0	return -1;
195	0	}
196
197	0	for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
198	0	i = (ctx->start - n > BUFSIZE ? BUFSIZE : ctx->start - n);
199	0	if ((ret = zip_source_read(src, b, i)) < 0) {
200	0	zip_error_set_from_source(&ctx->error, src);
201	0	byte_array_fini(b);
202	0	return -1;
203	0	}
204	0	if (ret == 0) {
205	0	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
206	0	byte_array_fini(b);
207	0	return -1;
208	0	}
209	0	}
210
211	0	byte_array_fini(b);
212	0	}
213
214	0	ctx->offset = ctx->start;
215	0	return 0;
216
217	0	case ZIP_SOURCE_READ:
218	0	if (ctx->end_valid && len > ctx->end - ctx->offset) {
219	0	len = ctx->end - ctx->offset;
220	0	}
221
222	0	if (len == 0) {
223	0	return 0;
224	0	}
225
226	0	if (ctx->needs_seek) {
227	0	if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
228	0	zip_error_set_from_source(&ctx->error, src);
229	0	return -1;
230	0	}
231	0	}
232
233	0	if ((ret = zip_source_read(src, data, len)) < 0) {
234	0	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
235	0	return -1;
236	0	}
237
238	0	ctx->offset += (zip_uint64_t)ret;
239
240	0	if (ret == 0) {
241	0	if (ctx->end_valid && ctx->offset < ctx->end) {
242	0	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
243	0	return -1;
244	0	}
245	0	}
246	0	return ret;
247
248	0	case ZIP_SOURCE_SEEK: {
249	0	zip_int64_t new_offset;
250
251	0	if (!ctx->end_valid) {
252	0	zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
253
254	0	if (args == NULL) {
255	0	return -1;
256	0	}
257	0	if (args->whence == SEEK_END) {
258	0	if (zip_source_seek(src, args->offset, args->whence) < 0) {
259	0	zip_error_set_from_source(&ctx->error, src);
260	0	return -1;
261	0	}
262	0	new_offset = zip_source_tell(src);
263	0	if (new_offset < 0) {
264	0	zip_error_set_from_source(&ctx->error, src);
265	0	return -1;
266	0	}
267	0	if ((zip_uint64_t)new_offset < ctx->start) {
268	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
269	0	(void)zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET);
270	0	return -1;
271	0	}
272	0	ctx->offset = (zip_uint64_t)new_offset;
273	0	return 0;
274	0	}
275	0	}
276
277	0	new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, ctx->end - ctx->start, data, len, &ctx->error);
278
279	0	if (new_offset < 0) {
280	0	return -1;
281	0	}
282
283	0	ctx->offset = (zip_uint64_t)new_offset + ctx->start;
284	0	return 0;
285	0	}
286
287	0	case ZIP_SOURCE_STAT: {
288	0	zip_stat_t *st;
289
290	0	st = (zip_stat_t *)data;
291
292	0	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
293	0	return -1;
294	0	}
295
296	0	if (!(ctx->stat.valid & ZIP_STAT_SIZE)) {
297	0	if (ctx->end_valid) {
298	0	st->valid \|= ZIP_STAT_SIZE;
299	0	st->size = ctx->end - ctx->start;
300	0	}
301	0	else if (st->valid & ZIP_STAT_SIZE) {
302	0	st->size -= ctx->start;
303	0	}
304	0	}
305
306	0	st->valid &= ~ctx->stat_invalid;
307
308	0	return 0;
309	0	}
310
311	0	case ZIP_SOURCE_GET_FILE_ATTRIBUTES:
312	0	if (len < sizeof(ctx->attributes)) {
313	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
314	0	return -1;
315	0	}
316
317	0	(void)memcpy_s(data, sizeof(ctx->attributes), &ctx->attributes, sizeof(ctx->attributes));
318	0	return sizeof(ctx->attributes);
319
320	0	case ZIP_SOURCE_GET_DOS_TIME:
321	0	if (len < sizeof(ctx->dostime)) {
322	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
323	0	return -1;
324	0	}
325	0	if (ctx->dostime_valid) {
326	0	(void)memcpy_s(data, sizeof(ctx->dostime), &ctx->dostime, sizeof(ctx->dostime));
327	0	return sizeof(ctx->dostime);
328	0	}
329	0	else {
330	0	return 0;
331	0	}
332
333	0	case ZIP_SOURCE_SUPPORTS:
334	0	return ctx->supports;
335
336	0	case ZIP_SOURCE_TELL:
337	0	return (zip_int64_t)(ctx->offset - ctx->start);
338
339	0	default:
340	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
341	0	}
342	0	}
343
344
345		void
346	0	_zip_deregister_source(zip_t za, zip_source_t src) {
347	0	zip_uint64_t i;
348
349	0	for (i = 0; i < za->nopen_source; i++) {
350	0	if (za->open_source[i] == src) {
351	0	za->open_source[i] = za->open_source[za->nopen_source - 1];
352	0	za->nopen_source--;
353	0	break;
354	0	}
355	0	}
356	0	}
357
358
359		int
360	0	_zip_register_source(zip_t za, zip_source_t src) {
361	0	if (za->nopen_source + 1 >= za->nopen_source_alloc) {
362	0	if (!ZIP_REALLOC(za->open_source, za->nopen_source_alloc, 10, &za->error)) {
363	0	return -1;
364	0	}
365	0	}
366
367	0	za->open_source[za->nopen_source++] = src;
368
369	0	return 0;
370	0	}