/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;
};

typedef struct window window_t;

static window_t *window_new(void);
static void window_free(window_t *ctx);

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;
    zip_stat_t lower_st;

    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;
        }
    }

    zip_stat_init(&lower_st);
    (void)zip_source_stat(src, &lower_st);

    if (lower_st.valid & ZIP_STAT_SIZE) {
        if (start > lower_st.size || (length > 0 && start + (zip_uint64_t)length > lower_st.size)) {
            zip_error_set(error, ZIP_ER_INVAL, 0);
            return NULL;
        }
    }

    if ((ctx = window_new()) == 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;
    }
    ctx->stat_invalid = st_invalid;
    if (attributes != NULL) {
        (void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
    }
    if (dostime != NULL) {
        ctx->dostime = *dostime;
        ctx->dostime_valid = true;
    }
    ctx->source_archive = source_archive;
    ctx->source_index = source_index;
    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) {
            window_free(ctx);
            return NULL;
        }
    }

    window_source = zip_source_layered_create(src, window_read, ctx, error);
    if (window_source == NULL) {
        window_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) {
    if (ZIP_SOURCE_IS_OPEN_READING(src)) {
        (void)zip_source_close(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:
        window_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);
                if (zip_error_code_zip(&ctx->error) == ZIP_ER_INVAL) {
                    /* We validated ctx->offset in ZIP_SEEK. */
                    zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
                }
                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) {
                if (st->size < ctx->start) {
                    st->valid &= ~ZIP_STAT_SIZE;
                }
                else {
                    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;
}

static window_t *window_new(void) {
    window_t *ctx;

    if ((ctx = (window_t *)malloc(sizeof(window_t))) == NULL) {
        return NULL;
    }

    ctx->start = 0;
    ctx->end = 0;
    ctx->end_valid = false;
    ctx->source_archive = NULL;
    ctx->source_index = 0;
    ctx->offset = 0;
    zip_stat_init(&ctx->stat);
    ctx->stat_invalid = 0;
    zip_file_attributes_init(&ctx->attributes);
    ctx->dostime_valid = false;
    zip_error_init(&ctx->error);
    ctx->supports = 0;
    ctx->needs_seek = false;

    return ctx;
}

static void window_free(window_t *ctx) {
    if (ctx == NULL) {
        return;
    }

    zip_error_fini(&ctx->error);
    free(ctx);
}

Coverage Report

Created: 2026-10-14 06:52

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		typedef struct window window_t;
61
62		static window_t *window_new(void);
63		static void window_free(window_t *ctx);
64
65		static zip_int64_t window_read(zip_source_t , void , void *, zip_uint64_t, zip_source_cmd_t);
66
67
68	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) {
69	0	return _zip_source_window_new(src, start, len, NULL, 0, NULL, NULL, NULL, 0, false, error);
70	0	}
71
72
73	10.4k	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) {
74	10.4k	zip_source_t *window_source;
75	10.4k	struct window *ctx;
76	10.4k	zip_stat_t lower_st;
77
78	10.4k	if (src == NULL \|\| length < -1 \|\| (source_archive == NULL && source_index != 0)) {
79	0	zip_error_set(error, ZIP_ER_INVAL, 0);
80	0	return NULL;
81	0	}
82
83	10.4k	if (length > 0) {
84	10.3k	if (start + (zip_uint64_t)length < start) {
85	0	zip_error_set(error, ZIP_ER_INVAL, 0);
86	0	return NULL;
87	0	}
88	10.3k	}
89
90	10.4k	zip_stat_init(&lower_st);
91	10.4k	(void)zip_source_stat(src, &lower_st);
92
93	10.4k	if (lower_st.valid & ZIP_STAT_SIZE) {
94	10.4k	if (start > lower_st.size \|\| (length > 0 && start + (zip_uint64_t)length > lower_st.size)) {
95	553	zip_error_set(error, ZIP_ER_INVAL, 0);
96	553	return NULL;
97	553	}
98	10.4k	}
99
100	9.88k	if ((ctx = window_new()) == NULL) {
101	0	zip_error_set(error, ZIP_ER_MEMORY, 0);
102	0	return NULL;
103	0	}
104
105	9.88k	ctx->start = start;
106	9.88k	if (length == -1) {
107	0	ctx->end_valid = false;
108	0	}
109	9.88k	else {
110	9.88k	ctx->end = start + (zip_uint64_t)length;
111	9.88k	ctx->end_valid = true;
112	9.88k	}
113	9.88k	ctx->stat_invalid = st_invalid;
114	9.88k	if (attributes != NULL) {
115	9.82k	(void)memcpy_s(&ctx->attributes, sizeof(ctx->attributes), attributes, sizeof(ctx->attributes));
116	9.82k	}
117	9.88k	if (dostime != NULL) {
118	9.82k	ctx->dostime = *dostime;
119	9.82k	ctx->dostime_valid = true;
120	9.82k	}
121	9.88k	ctx->source_archive = source_archive;
122	9.88k	ctx->source_index = source_index;
123	9.88k	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));
124	9.88k	if (ctx->end_valid) {
125	9.88k	ctx->supports \|= ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_AT_EOF);
126	9.88k	}
127	9.88k	ctx->needs_seek = (ctx->supports & ZIP_SOURCE_MAKE_COMMAND_BITMASK(ZIP_SOURCE_SEEK)) ? true : false;
128
129	9.88k	if (st) {
130	9.88k	if (_zip_stat_merge(&ctx->stat, st, error) < 0) {
131	0	window_free(ctx);
132	0	return NULL;
133	0	}
134	9.88k	}
135
136	9.88k	window_source = zip_source_layered_create(src, window_read, ctx, error);
137	9.88k	if (window_source == NULL) {
138	0	window_free(ctx);
139	0	return NULL;
140	0	}
141	9.88k	if (!take_ownership) {
142	9.82k	zip_source_keep(src);
143	9.82k	}
144	9.88k	return window_source;
145	9.88k	}
146
147
148	9.82k	int _zip_source_set_source_archive(zip_source_t src, zip_t za) {
149	9.82k	src->source_archive = za;
150	9.82k	return _zip_register_source(za, src);
151	9.82k	}
152
153
154		/* called by zip_discard to avoid operating on file from closed archive */
155	0	void _zip_source_invalidate(zip_source_t *src) {
156	0	if (ZIP_SOURCE_IS_OPEN_READING(src)) {
157	0	(void)zip_source_close(src);
158	0	}
159
160	0	src->source_closed = 1;
161
162	0	if (zip_error_code_zip(&src->error) == ZIP_ER_OK) {
163	0	zip_error_set(&src->error, ZIP_ER_ZIPCLOSED, 0);
164	0	}
165	0	}
166
167
168	77.3k	static zip_int64_t window_read(zip_source_t src, void _ctx, void *data, zip_uint64_t len, zip_source_cmd_t cmd) {
169	77.3k	struct window *ctx;
170	77.3k	zip_int64_t ret;
171	77.3k	zip_uint64_t n, i;
172
173	77.3k	ctx = (struct window *)_ctx;
174
175	77.3k	switch (cmd) {
176	1.31k	case ZIP_SOURCE_AT_EOF:
177	1.31k	if (ctx->end_valid) {
178	1.31k	return ctx->offset == ctx->end;
179	1.31k	}
180	0	else {
181	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
182	0	}
183
184	8.45k	case ZIP_SOURCE_CLOSE:
185	8.45k	return 0;
186
187	1.38k	case ZIP_SOURCE_ERROR:
188	1.38k	return zip_error_to_data(&ctx->error, data, len);
189
190	9.88k	case ZIP_SOURCE_FREE:
191	9.88k	window_free(ctx);
192	9.88k	return 0;
193
194	9.35k	case ZIP_SOURCE_OPEN:
195	9.35k	if (ctx->source_archive) {
196	9.25k	zip_uint64_t offset;
197
198	9.25k	if ((offset = _zip_file_get_offset(ctx->source_archive, ctx->source_index, &ctx->error)) == 0) {
199	904	return -1;
200	904	}
201	8.34k	if (ctx->end_valid) {
202	8.34k	if (ctx->end + offset < ctx->end) {
203		/* zip archive data claims end of data past zip64 limits */
204	0	zip_error_set(&ctx->error, ZIP_ER_INCONS, MAKE_DETAIL_WITH_INDEX(ZIP_ER_DETAIL_CDIR_ENTRY_INVALID, ctx->source_index));
205	0	return -1;
206	0	}
207	8.34k	ctx->end += offset;
208	8.34k	}
209	8.34k	ctx->start += offset;
210	8.34k	ctx->source_archive = NULL;
211	8.34k	}
212
213	8.45k	if (!ctx->needs_seek) {
214	0	DEFINE_BYTE_ARRAY(b, BUFSIZE);
215
216	0	if (!byte_array_init(b, BUFSIZE)) {
217	0	zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
218	0	return -1;
219	0	}
220
221	0	for (n = 0; n < ctx->start; n += (zip_uint64_t)ret) {
222	0	i = (ctx->start - n > BUFSIZE ? BUFSIZE : ctx->start - n);
223	0	if ((ret = zip_source_read(src, b, i)) < 0) {
224	0	zip_error_set_from_source(&ctx->error, src);
225	0	byte_array_fini(b);
226	0	return -1;
227	0	}
228	0	if (ret == 0) {
229	0	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
230	0	byte_array_fini(b);
231	0	return -1;
232	0	}
233	0	}
234
235	0	byte_array_fini(b);
236	0	}
237
238	8.45k	ctx->offset = ctx->start;
239	8.45k	return 0;
240
241	15.4k	case ZIP_SOURCE_READ:
242	15.4k	if (ctx->end_valid && len > ctx->end - ctx->offset) {
243	14.1k	len = ctx->end - ctx->offset;
244	14.1k	}
245
246	15.4k	if (len == 0) {
247	6.76k	return 0;
248	6.76k	}
249
250	8.67k	if (ctx->needs_seek) {
251	8.67k	if (zip_source_seek(src, (zip_int64_t)ctx->offset, SEEK_SET) < 0) {
252	191	zip_error_set_from_source(&ctx->error, src);
253	191	if (zip_error_code_zip(&ctx->error) == ZIP_ER_INVAL) {
254		/* We validated ctx->offset in ZIP_SEEK. */
255	191	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
256	191	}
257	191	return -1;
258	191	}
259	8.67k	}
260
261	8.48k	if ((ret = zip_source_read(src, data, len)) < 0) {
262	0	zip_error_set_from_source(&ctx->error, src);
263	0	return -1;
264	0	}
265
266	8.48k	if (ret == 0) {
267	285	if (ctx->end_valid && ctx->offset < ctx->end) {
268	285	zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
269	285	return -1;
270	285	}
271	285	}
272
273	8.19k	ctx->offset += (zip_uint64_t)ret;
274	8.19k	return ret;
275
276	0	case ZIP_SOURCE_SEEK: {
277	0	zip_uint64_t length;
278	0	zip_int64_t new_offset;
279	0	zip_source_args_seek_t *args = ZIP_SOURCE_GET_ARGS(zip_source_args_seek_t, data, len, &ctx->error);
280
281		/*
282		If we don't know the length and seek from the end, we seek in the lower source to get the new offset.
283		*/
284	0	if (!ctx->end_valid && args->whence == SEEK_END) {
285	0	zip_int64_t lower_offset;
286
287	0	if (zip_source_seek(src, args->offset, args->whence) < 0) {
288	0	zip_error_set_from_source(&ctx->error, src);
289	0	return -1;
290	0	}
291	0	if ((lower_offset = zip_source_tell(src)) < 0) {
292	0	zip_error_set_from_source(&ctx->error, src);
293	0	return -1;
294	0	}
295	0	if ((zip_uint64_t)lower_offset < ctx->start) {
296	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
297	0	return -1;
298	0	}
299	0	ctx->offset = (zip_uint64_t)lower_offset;
300	0	return 0;
301	0	}
302
303		/*
304		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.
305		*/
306	0	length = ctx->end_valid ? (ctx->end - ctx->start) : ZIP_INT64_MAX;
307	0	new_offset = zip_source_seek_compute_offset(ctx->offset - ctx->start, length, data, len, &ctx->error);
308
309	0	if (new_offset < 0) {
310	0	return -1;
311	0	}
312
313	0	if (new_offset + ctx->start < ctx->start) {
314	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
315	0	return -1;
316	0	}
317	0	new_offset += ctx->start;
318
319	0	if (!ctx->end_valid) {
320	0	if (zip_source_seek(src, new_offset, SEEK_SET) < 0) {
321	0	zip_error_set_from_source(&ctx->error, src);
322	0	return -1;
323	0	}
324	0	}
325	0	ctx->offset = (zip_uint64_t)new_offset;
326	0	return 0;
327	0	}
328
329	14.9k	case ZIP_SOURCE_STAT: {
330	14.9k	zip_stat_t *st;
331
332	14.9k	st = (zip_stat_t *)data;
333
334	14.9k	if (_zip_stat_merge(st, &ctx->stat, &ctx->error) < 0) {
335	0	return -1;
336	0	}
337
338	14.9k	if (!(ctx->stat.valid & ZIP_STAT_SIZE)) {
339	0	if (ctx->end_valid) {
340	0	st->valid \|= ZIP_STAT_SIZE;
341	0	st->size = ctx->end - ctx->start;
342	0	}
343	0	else if (st->valid & ZIP_STAT_SIZE) {
344	0	if (st->size < ctx->start) {
345	0	st->valid &= ~ZIP_STAT_SIZE;
346	0	}
347	0	else {
348	0	st->size -= ctx->start;
349	0	}
350	0	}
351	0	}
352
353	14.9k	st->valid &= ~ctx->stat_invalid;
354
355	14.9k	return 0;
356	14.9k	}
357
358	6.71k	case ZIP_SOURCE_GET_FILE_ATTRIBUTES:
359	6.71k	if (len < sizeof(ctx->attributes)) {
360	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
361	0	return -1;
362	0	}
363
364	6.71k	(void)memcpy_s(data, sizeof(ctx->attributes), &ctx->attributes, sizeof(ctx->attributes));
365	6.71k	return sizeof(ctx->attributes);
366
367	0	case ZIP_SOURCE_GET_DOS_TIME:
368	0	if (len < sizeof(ctx->dostime)) {
369	0	zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
370	0	return -1;
371	0	}
372	0	if (ctx->dostime_valid) {
373	0	(void)memcpy_s(data, sizeof(ctx->dostime), &ctx->dostime, sizeof(ctx->dostime));
374	0	return sizeof(ctx->dostime);
375	0	}
376	0	else {
377	0	return 0;
378	0	}
379
380	9.88k	case ZIP_SOURCE_SUPPORTS:
381	9.88k	return ctx->supports;
382
383	0	case ZIP_SOURCE_TELL:
384	0	return (zip_int64_t)(ctx->offset - ctx->start);
385
386	0	default:
387	0	return zip_source_pass_to_lower_layer(src, data, len, cmd);
388	77.3k	}
389	77.3k	}
390
391
392	9.82k	void _zip_deregister_source(zip_t za, zip_source_t src) {
393	9.82k	zip_uint64_t i;
394
395	9.82k	for (i = 0; i < za->nopen_source; i++) {
396	9.82k	if (za->open_source[i] == src) {
397	9.82k	za->open_source[i] = za->open_source[za->nopen_source - 1];
398	9.82k	za->nopen_source--;
399	9.82k	break;
400	9.82k	}
401	9.82k	}
402	9.82k	}
403
404
405	9.82k	int _zip_register_source(zip_t za, zip_source_t src) {
406	9.82k	if (za->nopen_source + 1 >= za->nopen_source_alloc) {
407	3.70k	if (!ZIP_REALLOC(za->open_source, za->nopen_source_alloc, 10, &za->error)) {
408	0	return -1;
409	0	}
410	3.70k	}
411
412	9.82k	za->open_source[za->nopen_source++] = src;
413
414	9.82k	return 0;
415	9.82k	}
416
417	9.88k	static window_t *window_new(void) {
418	9.88k	window_t *ctx;
419
420	9.88k	if ((ctx = (window_t *)malloc(sizeof(window_t))) == NULL) {
421	0	return NULL;
422	0	}
423
424	9.88k	ctx->start = 0;
425	9.88k	ctx->end = 0;
426	9.88k	ctx->end_valid = false;
427	9.88k	ctx->source_archive = NULL;
428	9.88k	ctx->source_index = 0;
429	9.88k	ctx->offset = 0;
430	9.88k	zip_stat_init(&ctx->stat);
431	9.88k	ctx->stat_invalid = 0;
432	9.88k	zip_file_attributes_init(&ctx->attributes);
433	9.88k	ctx->dostime_valid = false;
434	9.88k	zip_error_init(&ctx->error);
435	9.88k	ctx->supports = 0;
436	9.88k	ctx->needs_seek = false;
437
438	9.88k	return ctx;
439	9.88k	}
440
441	9.88k	static void window_free(window_t *ctx) {
442	9.88k	if (ctx == NULL) {
443	0	return;
444	0	}
445
446	9.88k	zip_error_fini(&ctx->error);
447	9.88k	free(ctx);
448	9.88k	}