1 /*
2 zip_source_zip.c -- create data source from zip file
3 Copyright (C) 1999-2009 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 <libzip@nih.at>
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
35
36 #include <stdlib.h>
37 #include <string.h>
38
39 #include "zipint.h"
40
41 struct read_zip {
42 struct zip_file *zf;
43 struct zip_stat st;
44 zip_uint64_t off;
45 zip_int64_t len;
46 };
47
48 static zip_int64_t read_zip(void *st, void *data, zip_uint64_t len,
49 enum zip_source_cmd cmd);
50
51
52
53 ZIP_EXTERN(struct zip_source *)
zip_source_zip(struct zip * za,struct zip * srcza,zip_uint64_t srcidx,int flags,zip_uint64_t start,zip_int64_t len)54 zip_source_zip(struct zip *za, struct zip *srcza, zip_uint64_t srcidx,
55 int flags, zip_uint64_t start, zip_int64_t len)
56 {
57 struct zip_error error;
58 struct zip_source *zs;
59 struct read_zip *p;
60
61 /* XXX: ZIP_FL_RECOMPRESS */
62
63 if (za == NULL)
64 return NULL;
65
66 if (srcza == NULL || len < -1 || srcidx < 0 || srcidx >= srcza->nentry) {
67 _zip_error_set(&za->error, ZIP_ER_INVAL, 0);
68 return NULL;
69 }
70
71 if ((flags & ZIP_FL_UNCHANGED) == 0
72 && ZIP_ENTRY_DATA_CHANGED(srcza->entry+srcidx)) {
73 _zip_error_set(&za->error, ZIP_ER_CHANGED, 0);
74 return NULL;
75 }
76
77 if (len == 0)
78 len = -1;
79
80 if (start == 0 && len == -1 && (flags & ZIP_FL_RECOMPRESS) == 0)
81 flags |= ZIP_FL_COMPRESSED;
82 else
83 flags &= ~ZIP_FL_COMPRESSED;
84
85 if ((p=(struct read_zip *)malloc(sizeof(*p))) == NULL) {
86 _zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
87 return NULL;
88 }
89
90 _zip_error_copy(&error, &srcza->error);
91
92 if (zip_stat_index(srcza, srcidx, flags, &p->st) < 0
93 || (p->zf=zip_fopen_index(srcza, srcidx, flags)) == NULL) {
94 free(p);
95 _zip_error_copy(&za->error, &srcza->error);
96 _zip_error_copy(&srcza->error, &error);
97
98 return NULL;
99 }
100 p->off = start;
101 p->len = len;
102
103 if ((flags & ZIP_FL_COMPRESSED) == 0) {
104 p->st.size = p->st.comp_size = len;
105 p->st.comp_method = ZIP_CM_STORE;
106 p->st.crc = 0;
107 }
108
109 if ((zs=zip_source_function(za, read_zip, p)) == NULL) {
110 free(p);
111 return NULL;
112 }
113
114 return zs;
115 }
116
117
118
119 static zip_int64_t
read_zip(void * state,void * data,zip_uint64_t len,enum zip_source_cmd cmd)120 read_zip(void *state, void *data, zip_uint64_t len, enum zip_source_cmd cmd)
121 {
122 struct read_zip *z;
123 char b[8192], *buf;
124 int i;
125 zip_uint64_t n;
126
127 z = (struct read_zip *)state;
128 buf = (char *)data;
129
130 switch (cmd) {
131 case ZIP_SOURCE_OPEN:
132 for (n=0; n<z->off; n+= i) {
133 i = (z->off-n > sizeof(b) ? sizeof(b) : z->off-n);
134 if ((i=zip_fread(z->zf, b, i)) < 0) {
135 zip_fclose(z->zf);
136 z->zf = NULL;
137 return -1;
138 }
139 }
140 return 0;
141
142 case ZIP_SOURCE_READ:
143 if (z->len != -1)
144 n = len > z->len ? z->len : len;
145 else
146 n = len;
147
148
149 if ((i=zip_fread(z->zf, buf, n)) < 0)
150 return -1;
151
152 if (z->len != -1)
153 z->len -= i;
154
155 return i;
156
157 case ZIP_SOURCE_CLOSE:
158 return 0;
159
160 case ZIP_SOURCE_STAT:
161 if (len < sizeof(z->st))
162 return -1;
163 len = sizeof(z->st);
164
165 memcpy(data, &z->st, len);
166 return len;
167
168 case ZIP_SOURCE_ERROR:
169 {
170 int *e;
171
172 if (len < sizeof(int)*2)
173 return -1;
174
175 e = (int *)data;
176 zip_file_error_get(z->zf, e, e+1);
177 }
178 return sizeof(int)*2;
179
180 case ZIP_SOURCE_FREE:
181 zip_fclose(z->zf);
182 free(z);
183 return 0;
184
185 default:
186 ;
187 }
188
189 return -1;
190 }
191
