/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: 2026-08-11 07:29

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	10.0k	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	10.0k	zip_source_t *window_source;
70	10.0k	struct window *ctx;
71
72	10.0k	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	10.0k	if (length >= 0) {
78	10.0k	if (start + (zip_uint64_t)length < start) {
79	0	zip_error_set(error, ZIP_ER_INVAL, 0);
80	0	return NULL;
81	0	}
82	10.0k	}
83
84	10.0k	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	10.0k	ctx->start = start;
90	10.0k	if (length == -1) {
91	0	ctx->end_valid = false;
92	0	}
93	10.0k	else {
94	10.0k	ctx->end = start + (zip_uint64_t)length;
95	10.0k	ctx->end_valid = true;
96	10.0k	}
97	10.0k	zip_stat_init(&ctx->stat);
98	10.0k	ctx->stat_invalid = st_invalid;
99	10.0k	if (attributes != NULL) {
100	9.99k	(void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
101	9.99k	}
102	8	else {
103	8	zip_file_attributes_init(&ctx->attributes);
104	8	}
105	10.0k	if (dostime != NULL) {
106	9.99k	ctx->dostime = *dostime;
107	9.99k	ctx->dostime_valid = true;
108	9.99k	}
109	8	else {
110	8	ctx->dostime_valid = false;
111	8	}
112	10.0k	ctx->source_archive = source_archive;
113	10.0k	ctx->source_index = source_index;
114	10.0k	zip_error_init(&ctx->error);
115	10.0k	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	10.0k	if (ctx->end_valid) {
117	10.0k	ctx->supports \|= ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_AT_EOF);
118	10.0k	}
119	10.0k	ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;
120
121	10.0k	if (st) {
122	10.0k	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
123	0	free(ctx);
124	0	return NULL;
125	0	}
126	10.0k	}
127
128	10.0k	window_source = zip_source_layered_create(src, window_read, ctx, error);
129	10.0k	if (window_source == NULL) {
130	0	free(ctx);
131	0	return NULL;
132	0	}
133	10.0k	if (!take_ownership) {
134	9.94k	zip_source_keep(src);
135	9.94k	}
136	10.0k	return window_source;
137	10.0k	}
138
139
140	9.99k	int _zip_source_set_source_archive(zip_source_t src, zip_t za) {
141	9.99k	src->source_archive = za;
142	9.99k	return _zip_register_source(za, src);
143	9.99k	}
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	79.7k	static zip_int64_t window_read(zip_source_t src, void _ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
157	79.7k	struct window *ctx;
158	79.7k	zip_int64_t ret;
159	79.7k	zip_uint64_t n, i;
160
161	79.7k	ctx = (struct window *)_ctx;
162
163	79.7k	switch (cmd) {
164	1.84k	case ZIP_SOURCE_AT_EOF:
165	1.84k	if (ctx->end_valid) {
166	1.84k	return ctx->offset == ctx->end;
167	1.84k	}
168	0	else {
169	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
170	0	}
171
172	8.88k	case ZIP_SOURCE_CLOSE:
173	8.88k	return 0;
174
175	2.07k	case ZIP_SOURCE_ERROR:
176	2.07k	return zip_error_to_data(&ctx->error, data, len);
177
178	10.0k	case ZIP_SOURCE_FREE:
179	10.0k	free(ctx);
180	10.0k	return 0;
181
182	9.73k	case ZIP_SOURCE_OPEN:
183	9.73k	if (ctx->source_archive) {
184	9.67k	zip_uint64_t offset;
185
186	9.67k	if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
187	846	return -1;
188	846	}
189	8.82k	if (ctx->end_valid) {
190	8.82k	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	8.82k	ctx->end += offset;
196	8.82k	}
197	8.82k	ctx->start += offset;
198	8.82k	ctx->source_archive = NULL;
199	8.82k	}
200
201	8.88k	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	8.88k	ctx->offset = ctx->start;
227	8.88k	return 0;
228
229	15.8k	case ZIP_SOURCE_READ:
230	15.8k	if (ctx->end_valid && len > ctx->end - ctx->offset) {
231	12.4k	len = ctx->end - ctx->offset;
232	12.4k	}
233
234	15.8k	if (len == 0) {
235	5.95k	return 0;
236	5.95k	}
237
238	9.94k	if (ctx->needs_seek) {
239	9.94k	if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
240	123	zip_error_set_from_source(&ctx->error, src);
241	123	return -1;
242	123	}
243	9.94k	}
244
245	9.82k	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	9.82k	if (ret == 0) {
251	1.10k	if (ctx->end_valid && ctx->offset < ctx->end) {
252	1.10k	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
253	1.10k	return -1;
254	1.10k	}
255	1.10k	}
256
257	8.71k	ctx->offset += (zip_uint64_t)ret;
258	8.71k	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	14.5k	case ZIP_SOURCE_STAT: {
314	14.5k	zip_stat_t *st;
315
316	14.5k	st = (zip_stat_t *)data;
317
318	14.5k	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
319	0	return -1;
320	0	}
321
322	14.5k	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	14.5k	st->valid &= ~ctx->stat_invalid;
333
334	14.5k	return 0;
335	14.5k	}
336
337	6.74k	case ZIP_SOURCE_GET_FILE_ATTRIBUTES:
338	6.74k	if (len < sizeof(ctx->attributes)) {
339	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
340	0	return -1;
341	0	}
342
343	6.74k	(void)memcpy_s(data, sizeof(ctx->attributes), &ctx->attributes, sizeof(ctx->attributes));
344	6.74k	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	10.0k	case ZIP_SOURCE_SUPPORTS:
360	10.0k	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	79.7k	}
368	79.7k	}
369
370
371	9.99k	void _zip_deregister_source(zip_t za, zip_source_t src) {
372	9.99k	zip_uint64_t i;
373
374	9.99k	for (i = 0; i < za->nopen_source; i++) {
375	9.99k	if (za->open_source[i] == src) {
376	9.99k	za->open_source[i] = za->open_source[za->nopen_source - 1];
377	9.99k	za->nopen_source--;
378	9.99k	break;
379	9.99k	}
380	9.99k	}
381	9.99k	}
382
383
384	9.99k	int _zip_register_source(zip_t za, zip_source_t src) {
385	9.99k	if (za->nopen_source + 1 >= za->nopen_source_alloc) {
386	3.68k	if (!ZIP_REALLOC(za->open_source, za->nopen_source_alloc, 10, &za->error)) {
387	0	return -1;
388	0	}
389	3.68k	}
390
391	9.99k	za->open_source[za->nopen_source++] = src;
392
393	9.99k	return 0;
394	9.99k	}