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a29fd7dd | 1 | /* |
503b54c9 MS |
2 | * Example code for encoding and decoding large amounts of data in a PPD file. |
3 | * This would typically be used in a driver to save configuration/state | |
4 | * information that could be used by an application. | |
a29fd7dd | 5 | * |
503b54c9 | 6 | * Copyright 2012 by Apple Inc. |
a29fd7dd | 7 | * |
e3101897 | 8 | * Licensed under Apache License v2.0. See the file "LICENSE" for more information. |
a29fd7dd MS |
9 | */ |
10 | ||
11 | /* | |
12 | * Include necessary headers... | |
13 | */ | |
14 | ||
15 | #include "ppdx.h" | |
16 | #include <stdio.h> | |
17 | #include <stdlib.h> | |
18 | #include <string.h> | |
19 | #include <zlib.h> /* For compression of the data */ | |
20 | ||
21 | ||
22 | /* | |
23 | * Constants... | |
24 | */ | |
25 | ||
26 | #define PPDX_MAX_VALUE (PPD_MAX_LINE - PPD_MAX_NAME - 4) | |
27 | /* Max value length with delimiters + nul */ | |
28 | #define PPDX_MAX_CHUNK (PPDX_MAX_VALUE * 3 / 4) | |
29 | /* Max length of each chunk when Base64-encoded */ | |
30 | ||
31 | ||
32 | /* | |
33 | * 'ppdxReadData()' - Read encoded data from a ppd_file_t *. | |
34 | * | |
35 | * Reads chunked data in the PPD file "ppd" using the prefix "name". Returns | |
36 | * an allocated pointer to the data (which is nul-terminated for convenience) | |
37 | * along with the length of the data in the variable pointed to by "datasize", | |
38 | * which can be NULL to indicate the caller doesn't need the length. | |
39 | * | |
40 | * Returns NULL if no data is present in the PPD with the prefix. | |
41 | */ | |
42 | ||
43 | void * /* O - Data or NULL */ | |
44 | ppdxReadData(ppd_file_t *ppd, /* I - PPD file */ | |
45 | const char *name, /* I - Keyword prefix */ | |
46 | size_t *datasize) /* O - Size of data or NULL for don't care */ | |
47 | { | |
48 | char keyword[PPD_MAX_NAME], /* Keyword name */ | |
49 | decoded[PPDX_MAX_CHUNK + 1]; | |
50 | /* Decoded string */ | |
51 | unsigned chunk = 0; /* Current chunk number */ | |
52 | int len; /* Length of current chunk */ | |
53 | ppd_attr_t *attr; /* Keyword/value from PPD file */ | |
54 | Bytef *data; /* Pointer to data */ | |
55 | size_t alloc_size; /* Allocated size of data buffer */ | |
56 | z_stream decomp; /* Decompressor stream */ | |
57 | int error; /* Error/status from inflate() */ | |
58 | ||
59 | ||
60 | /* | |
61 | * Range check input... | |
62 | */ | |
63 | ||
64 | if (datasize) | |
65 | *datasize = 0; | |
66 | ||
67 | if (!ppd || !name) | |
68 | return (NULL); | |
69 | ||
70 | /* | |
71 | * First see if there are any instances of the named keyword in the PPD... | |
72 | */ | |
73 | ||
74 | snprintf(keyword, sizeof(keyword), "%s%04x", name, chunk); | |
75 | if ((attr = ppdFindAttr(ppd, keyword, NULL)) == NULL) | |
76 | return (NULL); | |
77 | ||
78 | /* | |
79 | * Allocate some memory and start decoding... | |
80 | */ | |
81 | ||
82 | data = malloc(257); | |
83 | alloc_size = 256; | |
84 | ||
85 | memset(&decomp, 0, sizeof(decomp)); | |
86 | decomp.next_out = data; | |
87 | decomp.avail_out = 256; | |
88 | ||
89 | inflateInit(&decomp); | |
90 | ||
91 | do | |
92 | { | |
93 | /* | |
94 | * Grab the data from the current attribute and decode it... | |
95 | */ | |
96 | ||
97 | len = sizeof(decoded); | |
98 | if (!httpDecode64_2(decoded, &len, attr->value) || len == 0) | |
99 | break; | |
100 | ||
101 | // printf("chunk %04x has length %d\n", chunk, len); | |
102 | ||
103 | /* | |
104 | * Decompress this chunk... | |
105 | */ | |
106 | ||
107 | decomp.next_in = decoded; | |
108 | decomp.avail_in = len; | |
109 | ||
110 | do | |
111 | { | |
112 | Bytef *temp; /* Temporary pointer */ | |
113 | size_t temp_size; /* Temporary allocation size */ | |
114 | ||
115 | // printf("Before inflate: avail_in=%d, avail_out=%d\n", decomp.avail_in, | |
116 | // decomp.avail_out); | |
117 | ||
118 | if ((error = inflate(&decomp, Z_NO_FLUSH)) < Z_OK) | |
119 | { | |
120 | fprintf(stderr, "ERROR: inflate returned %d (%s)\n", error, decomp.msg); | |
121 | break; | |
122 | } | |
123 | ||
124 | // printf("After inflate: avail_in=%d, avail_out=%d, error=%d\n", | |
125 | // decomp.avail_in, decomp.avail_out, error); | |
126 | ||
127 | if (decomp.avail_out == 0) | |
128 | { | |
129 | if (alloc_size < 2048) | |
130 | temp_size = alloc_size * 2; | |
131 | else if (alloc_size < PPDX_MAX_DATA) | |
132 | temp_size = alloc_size + 2048; | |
133 | else | |
134 | break; | |
135 | ||
136 | if ((temp = realloc(data, temp_size + 1)) == NULL) | |
137 | { | |
138 | free(data); | |
139 | return (NULL); | |
140 | } | |
141 | ||
142 | decomp.next_out = temp + (decomp.next_out - data); | |
143 | decomp.avail_out = temp_size - alloc_size; | |
144 | data = temp; | |
145 | alloc_size = temp_size; | |
146 | } | |
147 | } | |
148 | while (decomp.avail_in > 0); | |
149 | ||
150 | chunk ++; | |
151 | snprintf(keyword, sizeof(keyword), "%s%04x", name, chunk); | |
152 | } | |
153 | while ((attr = ppdFindAttr(ppd, keyword, NULL)) != NULL); | |
154 | ||
155 | inflateEnd(&decomp); | |
156 | ||
157 | /* | |
158 | * Nul-terminate the data (usually a string)... | |
159 | */ | |
160 | ||
161 | *(decomp.next_out) = '\0'; | |
162 | ||
163 | if (datasize) | |
164 | *datasize = decomp.next_out - data; | |
165 | ||
166 | return (data); | |
167 | } | |
168 | ||
169 | ||
170 | /* | |
171 | * 'ppdxWriteData()' - Writes encoded data to stderr using PPD: messages. | |
172 | * | |
173 | * Writes chunked data to the PPD file using PPD: messages sent to stderr for | |
174 | * cupsd. "name" must be a valid PPD keyword string whose length is less than | |
175 | * 37 characters to allow for chunk numbering. "data" provides a pointer to the | |
176 | * data to be written, and "datasize" provides the length. | |
177 | */ | |
178 | ||
179 | extern void | |
180 | ppdxWriteData(const char *name, /* I - Base name of keyword */ | |
181 | const void *data, /* I - Data to write */ | |
182 | size_t datasize) /* I - Number of bytes in data */ | |
183 | { | |
184 | char buffer[PPDX_MAX_CHUNK], /* Chunk buffer */ | |
185 | encoded[PPDX_MAX_VALUE + 1], | |
186 | /* Encoded data */ | |
187 | pair[PPD_MAX_LINE], /* name=value pair */ | |
188 | line[PPDX_MAX_STATUS], /* Line buffer */ | |
189 | *lineptr, /* Current position in line buffer */ | |
190 | *lineend; /* End of line buffer */ | |
191 | unsigned chunk = 0; /* Current chunk number */ | |
192 | int len; /* Length of current chunk */ | |
193 | z_stream comp; /* Compressor stream */ | |
194 | int error; /* Error/status from deflate() */ | |
195 | ||
196 | ||
197 | /* | |
198 | * Range check input... | |
199 | */ | |
200 | ||
201 | if (!name || (!data && datasize > 0) || datasize > PPDX_MAX_DATA) | |
202 | return; | |
203 | ||
204 | strlcpy(line, "PPD:", sizeof(line)); | |
205 | lineptr = line + 4; | |
206 | lineend = line + sizeof(line) - 2; | |
207 | ||
208 | if (datasize > 0) | |
209 | { | |
210 | /* | |
211 | * Compress and encode output... | |
212 | */ | |
213 | ||
214 | memset(&comp, 0, sizeof(comp)); | |
215 | comp.next_in = (Bytef *)data; | |
216 | comp.avail_in = datasize; | |
217 | ||
218 | deflateInit(&comp, 9); | |
219 | ||
220 | do | |
221 | { | |
222 | /* | |
223 | * Compress a chunk... | |
224 | */ | |
225 | ||
226 | comp.next_out = buffer; | |
227 | comp.avail_out = sizeof(buffer); | |
228 | ||
229 | if ((error = deflate(&comp, Z_FINISH)) < Z_OK) | |
230 | { | |
231 | fprintf(stderr, "ERROR: deflate returned %d (%s)\n", error, comp.msg); | |
232 | break; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Write a chunk... | |
237 | */ | |
238 | ||
239 | len = sizeof(buffer) - comp.avail_out; | |
240 | httpEncode64_2(encoded, sizeof(encoded), buffer, len); | |
241 | ||
242 | len = (int)snprintf(pair, sizeof(pair), " %s%04x=%s", name, chunk, | |
243 | encoded); | |
244 | #ifdef DEBUG | |
245 | fprintf(stderr, "DEBUG: *%s%04x: \"%s\"\n", name, chunk, encoded); | |
246 | #endif /* DEBUG */ | |
247 | ||
248 | if ((lineptr + len) >= lineend) | |
249 | { | |
250 | *lineptr++ = '\n'; | |
251 | *lineptr = '\0'; | |
252 | ||
253 | fputs(line, stderr); | |
254 | lineptr = line + 4; | |
255 | } | |
256 | ||
257 | strlcpy(lineptr, pair, lineend - lineptr); | |
258 | lineptr += len; | |
259 | ||
260 | /* | |
261 | * Setup for the next one... | |
262 | */ | |
263 | ||
264 | chunk ++; | |
265 | } | |
266 | while (comp.avail_out == 0); | |
267 | } | |
268 | ||
269 | deflateEnd(&comp); | |
270 | ||
271 | /* | |
272 | * Write a trailing empty chunk to signal EOD... | |
273 | */ | |
274 | ||
275 | len = (int)snprintf(pair, sizeof(pair), " %s%04x=\"\"", name, chunk); | |
276 | #ifdef DEBUG | |
277 | fprintf(stderr, "DEBUG: *%s%04x: \"\"\n", name, chunk); | |
278 | #endif /* DEBUG */ | |
279 | ||
280 | if ((lineptr + len) >= lineend) | |
281 | { | |
282 | *lineptr++ = '\n'; | |
283 | *lineptr = '\0'; | |
284 | ||
285 | fputs(line, stderr); | |
286 | lineptr = line + 4; | |
287 | } | |
288 | ||
289 | strlcpy(lineptr, pair, lineend - lineptr); | |
290 | lineptr += len; | |
291 | ||
292 | *lineptr++ = '\n'; | |
293 | *lineptr = '\0'; | |
294 | ||
295 | fputs(line, stderr); | |
296 | } |