/src/libzip/lib/zip_source_window.c

Source
/*
  zip_source_window.c -- return part of lower source
  Copyright (C) 2012-2025 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));
    if (ctx->end_valid) {
        ctx->supports |= ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_AT_EOF);
    }
    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) {
        free(ctx);
        return NULL;
    }
    if (!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_AT_EOF:
        if (ctx->end_valid) {
            return ctx->offset == ctx->end;
        }
        else {
            return zip_source_pass_to_lower_layer(src, data, len, 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_valid) {
                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->end += offset;
            }
            ctx->start += 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_from_source(&ctx->error, src);
            return -1;
        }

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

        ctx->offset += (zip_uint64_t)ret;
        return ret;

    case ZIP_SOURCE_SEEK: {
        zip_uint64_t length;
        zip_int64_t new_offset;
        zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);

        /*
          If we don't know the length and seek from the end, we seek in the lower source to get the new offset.
        */
        if (!ctx->end_valid && args->whence == SEEK_END) {
            zip_int64_t lower_offset;

            if (zip_source_seek(src, args->offset, args->whence) < 0) {
                zip_error_set_from_source(&ctx->error, src);
                return -1;
            }
            if ((lower_offset = zip_source_tell(src)) < 0) {
                zip_error_set_from_source(&ctx->error, src);
                return -1;
            }
            if ((zip_uint64_t)lower_offset < ctx->start) {
                zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
                return -1;
            }
            ctx->offset = (zip_uint64_t)lower_offset;
            return 0;
        }

        /* 
          If we don't know the length, we disable the end check in zip_source_seek_compute_offset by passing in the largest possible value and seek in the lower source to validate the new offset.
        */
        length = ctx->end_valid ? (ctx->end - ctx->start) : ZIP_INT64_MAX;
        new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, length, data, len, &ctx->error);

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

        if (new_offset + ctx->start < ctx->start) {
            zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
            return -1;
        }
        new_offset += ctx->start;

        if (!ctx->end_valid) {
            if (zip_source_seek(src, new_offset, SEEK_SET) < 0) {
                zip_error_set_from_source(&ctx->error, src);
                return -1;
            }
        }
        ctx->offset = (zip_uint64_t)new_offset;
        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: 2026-08-25 06:40

Line	Count	Source
1		/*
2		zip_source_window.c -- return part of lower source
3		Copyright (C) 2012-2025 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	0	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) {
64	0	return _zip_source_window_new(src, start, len, NULL, 0, NULL, NULL, NULL, 0, false, error);
65	0	}
66
67
68	11.4k	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) {
69	11.4k	zip_source_t *window_source;
70	11.4k	struct window *ctx;
71
72	11.4k	if (src == NULL \|\| length < -1 \|\| (source_archive == NULL && source_index != 0)) {
73	0	zip_error_set(error, ZIP_ER_INVAL, 0);
74	0	return NULL;
75	0	}
76
77	11.4k	if (length >= 0) {
78	11.4k	if (start + (zip_uint64_t)length < start) {
79	0	zip_error_set(error, ZIP_ER_INVAL, 0);
80	0	return NULL;
81	0	}
82	11.4k	}
83
84	11.4k	if ((ctx = (struct window )malloc(sizeof(ctx))) == NULL) {
85	0	zip_error_set(error, ZIP_ER_MEMORY, 0);
86	0	return NULL;
87	0	}
88
89	11.4k	ctx->start = start;
90	11.4k	if (length == -1) {
91	0	ctx->end_valid = false;
92	0	}
93	11.4k	else {
94	11.4k	ctx->end = start + (zip_uint64_t)length;
95	11.4k	ctx->end_valid = true;
96	11.4k	}
97	11.4k	zip_stat_init(&ctx->stat);
98	11.4k	ctx->stat_invalid = st_invalid;
99	11.4k	if (attributes != NULL) {
100	11.3k	(void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
101	11.3k	}
102	31	else {
103	31	zip_file_attributes_init(&ctx->attributes);
104	31	}
105	11.4k	if (dostime != NULL) {
106	11.3k	ctx->dostime = *dostime;
107	11.3k	ctx->dostime_valid = true;
108	11.3k	}
109	31	else {
110	31	ctx->dostime_valid = false;
111	31	}
112	11.4k	ctx->source_archive = source_archive;
113	11.4k	ctx->source_index = source_index;
114	11.4k	zip_error_init(&ctx->error);
115	11.4k	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));
116	11.4k	if (ctx->end_valid) {
117	11.4k	ctx->supports \|= ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_AT_EOF);
118	11.4k	}
119	11.4k	ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;
120
121	11.4k	if (st) {
122	11.4k	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
123	0	free(ctx);
124	0	return NULL;
125	0	}
126	11.4k	}
127
128	11.4k	window_source = zip_source_layered_create(src, window_read, ctx, error);
129	11.4k	if (window_source == NULL) {
130	0	free(ctx);
131	0	return NULL;
132	0	}
133	11.4k	if (!take_ownership) {
134	11.2k	zip_source_keep(src);
135	11.2k	}
136	11.4k	return window_source;
137	11.4k	}
138
139
140	11.3k	int _zip_source_set_source_archive(zip_source_t src, zip_t za) {
141	11.3k	src->source_archive = za;
142	11.3k	return _zip_register_source(za, src);
143	11.3k	}
144
145
146		/* called by zip_discard to avoid operating on file from closed archive */
147	0	void _zip_source_invalidate(zip_source_t *src) {
148	0	src->source_closed = 1;
149
150	0	if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
151	0	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
152	0	}
153	0	}
154
155
156	93.0k	static zip_int64_t window_read(zip_source_t src, void _ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
157	93.0k	struct window *ctx;
158	93.0k	zip_int64_t ret;
159	93.0k	zip_uint64_t n, i;
160
161	93.0k	ctx = (struct window *)_ctx;
162
163	93.0k	switch (cmd) {
164	1.67k	case ZIP_SOURCE_AT_EOF:
165	1.67k	if (ctx->end_valid) {
166	1.67k	return ctx->offset == ctx->end;
167	1.67k	}
168	0	else {
169	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
170	0	}
171
172	9.82k	case ZIP_SOURCE_CLOSE:
173	9.82k	return 0;
174
175	3.36k	case ZIP_SOURCE_ERROR:
176	3.36k	return zip_error_to_data(&ctx->error, data, len);
177
178	11.4k	case ZIP_SOURCE_FREE:
179	11.4k	free(ctx);
180	11.4k	return 0;
181
182	10.9k	case ZIP_SOURCE_OPEN:
183	10.9k	if (ctx->source_archive) {
184	10.8k	zip_uint64_t offset;
185
186	10.8k	if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
187	1.15k	return -1;
188	1.15k	}
189	9.69k	if (ctx->end_valid) {
190	9.69k	if (ctx->end + offset < ctx->end) {
191		/* zip archive data claims end of data past zip64 limits */
192	0	zip_error_set(&ctx->error, ZIP_ER_INCONS, MAKE_DETAIL_WITH_INDEX(ZIP_ER_DETAIL_CDIR_ENTRY_INVALID, ctx->source_index));
193	0	return -1;
194	0	}
195	9.69k	ctx->end += offset;
196	9.69k	}
197	9.69k	ctx->start += offset;
198	9.69k	ctx->source_archive = NULL;
199	9.69k	}
200
201	9.82k	if (!ctx->needs_seek) {
202	0	DEFINE_BYTE_ARRAY(b, BUFSIZE);
203
204	0	if (!byte_array_init(b, BUFSIZE)) {
205	0	zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
206	0	return -1;
207	0	}
208
209	0	for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
210	0	i = (ctx->start - n > BUFSIZE ? BUFSIZE : ctx->start - n);
211	0	if ((ret = zip_source_read(src, b, i)) < 0) {
212	0	zip_error_set_from_source(&ctx->error, src);
213	0	byte_array_fini(b);
214	0	return -1;
215	0	}
216	0	if (ret == 0) {
217	0	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
218	0	byte_array_fini(b);
219	0	return -1;
220	0	}
221	0	}
222
223	0	byte_array_fini(b);
224	0	}
225
226	9.82k	ctx->offset = ctx->start;
227	9.82k	return 0;
228
229	21.2k	case ZIP_SOURCE_READ:
230	21.2k	if (ctx->end_valid && len > ctx->end - ctx->offset) {
231	12.6k	len = ctx->end - ctx->offset;
232	12.6k	}
233
234	21.2k	if (len == 0) {
235	6.00k	return 0;
236	6.00k	}
237
238	15.2k	if (ctx->needs_seek) {
239	15.2k	if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
240	255	zip_error_set_from_source(&ctx->error, src);
241	255	return -1;
242	255	}
243	15.2k	}
244
245	15.0k	if ((ret = zip_source_read(src, data, len)) < 0) {
246	0	zip_error_set_from_source(&ctx->error, src);
247	0	return -1;
248	0	}
249
250	15.0k	if (ret == 0) {
251	1.95k	if (ctx->end_valid && ctx->offset < ctx->end) {
252	1.95k	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
253	1.95k	return -1;
254	1.95k	}
255	1.95k	}
256
257	13.0k	ctx->offset += (zip_uint64_t)ret;
258	13.0k	return ret;
259
260	0	case ZIP_SOURCE_SEEK: {
261	0	zip_uint64_t length;
262	0	zip_int64_t new_offset;
263	0	zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
264
265		/*
266		If we don't know the length and seek from the end, we seek in the lower source to get the new offset.
267		*/
268	0	if (!ctx->end_valid && args->whence == SEEK_END) {
269	0	zip_int64_t lower_offset;
270
271	0	if (zip_source_seek(src, args->offset, args->whence) < 0) {
272	0	zip_error_set_from_source(&ctx->error, src);
273	0	return -1;
274	0	}
275	0	if ((lower_offset = zip_source_tell(src)) < 0) {
276	0	zip_error_set_from_source(&ctx->error, src);
277	0	return -1;
278	0	}
279	0	if ((zip_uint64_t)lower_offset < ctx->start) {
280	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
281	0	return -1;
282	0	}
283	0	ctx->offset = (zip_uint64_t)lower_offset;
284	0	return 0;
285	0	}
286
287		/*
288		If we don't know the length, we disable the end check in zip_source_seek_compute_offset by passing in the largest possible value and seek in the lower source to validate the new offset.
289		*/
290	0	length = ctx->end_valid ? (ctx->end - ctx->start) : ZIP_INT64_MAX;
291	0	new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, length, data, len, &ctx->error);
292
293	0	if (new_offset < 0) {
294	0	return -1;
295	0	}
296
297	0	if (new_offset + ctx->start < ctx->start) {
298	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
299	0	return -1;
300	0	}
301	0	new_offset += ctx->start;
302
303	0	if (!ctx->end_valid) {
304	0	if (zip_source_seek(src, new_offset, SEEK_SET) < 0) {
305	0	zip_error_set_from_source(&ctx->error, src);
306	0	return -1;
307	0	}
308	0	}
309	0	ctx->offset = (zip_uint64_t)new_offset;
310	0	return 0;
311	0	}
312
313	15.3k	case ZIP_SOURCE_STAT: {
314	15.3k	zip_stat_t *st;
315
316	15.3k	st = (zip_stat_t *)data;
317
318	15.3k	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
319	0	return -1;
320	0	}
321
322	15.3k	if (!(ctx->stat.valid & ZIP_STAT_SIZE)) {
323	0	if (ctx->end_valid) {
324	0	st->valid \|= ZIP_STAT_SIZE;
325	0	st->size = ctx->end - ctx->start;
326	0	}
327	0	else if (st->valid & ZIP_STAT_SIZE) {
328	0	st->size -= ctx->start;
329	0	}
330	0	}
331
332	15.3k	st->valid &= ~ctx->stat_invalid;
333
334	15.3k	return 0;
335	15.3k	}
336
337	7.81k	case ZIP_SOURCE_GET_FILE_ATTRIBUTES:
338	7.81k	if (len < sizeof(ctx->attributes)) {
339	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
340	0	return -1;
341	0	}
342
343	7.81k	(void)memcpy_s(data, sizeof(ctx->attributes), &ctx->attributes, sizeof(ctx->attributes));
344	7.81k	return sizeof(ctx->attributes);
345
346	0	case ZIP_SOURCE_GET_DOS_TIME:
347	0	if (len < sizeof(ctx->dostime)) {
348	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
349	0	return -1;
350	0	}
351	0	if (ctx->dostime_valid) {
352	0	(void)memcpy_s(data, sizeof(ctx->dostime), &ctx->dostime, sizeof(ctx->dostime));
353	0	return sizeof(ctx->dostime);
354	0	}
355	0	else {
356	0	return 0;
357	0	}
358
359	11.4k	case ZIP_SOURCE_SUPPORTS:
360	11.4k	return ctx->supports;
361
362	0	case ZIP_SOURCE_TELL:
363	0	return (zip_int64_t)(ctx->offset - ctx->start);
364
365	0	default:
366	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
367	93.0k	}
368	93.0k	}
369
370
371	11.3k	void _zip_deregister_source(zip_t za, zip_source_t src) {
372	11.3k	zip_uint64_t i;
373
374	11.3k	for (i = 0; i < za->nopen_source; i++) {
375	11.3k	if (za->open_source[i] == src) {
376	11.3k	za->open_source[i] = za->open_source[za->nopen_source - 1];
377	11.3k	za->nopen_source--;
378	11.3k	break;
379	11.3k	}
380	11.3k	}
381	11.3k	}
382
383
384	11.3k	int _zip_register_source(zip_t za, zip_source_t src) {
385	11.3k	if (za->nopen_source + 1 >= za->nopen_source_alloc) {
386	4.62k	if (!ZIP_REALLOC(za->open_source, za->nopen_source_alloc, 10, &za->error)) {
387	0	return -1;
388	0	}
389	4.62k	}
390
391	11.3k	za->open_source[za->nopen_source++] = src;
392
393	11.3k	return 0;
394	11.3k	}