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/*
* Example code for encoding and decoding large amounts of data in a PPD file.
* This would typically be used in a driver to save configuration/state
* information that could be used by an application.
*
* Copyright 2012 by Apple Inc.
*
* Licensed under Apache License v2.0. See the file "LICENSE" for more information.
*/
/*
* Include necessary headers...
*/
#include "ppdx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h> /* For compression of the data */
/*
* Constants...
*/
#define PPDX_MAX_VALUE (PPD_MAX_LINE - PPD_MAX_NAME - 4)
/* Max value length with delimiters + nul */
#define PPDX_MAX_CHUNK (PPDX_MAX_VALUE * 3 / 4)
/* Max length of each chunk when Base64-encoded */
/*
* 'ppdxReadData()' - Read encoded data from a ppd_file_t *.
*
* Reads chunked data in the PPD file "ppd" using the prefix "name". Returns
* an allocated pointer to the data (which is nul-terminated for convenience)
* along with the length of the data in the variable pointed to by "datasize",
* which can be NULL to indicate the caller doesn't need the length.
*
* Returns NULL if no data is present in the PPD with the prefix.
*/
void * /* O - Data or NULL */
ppdxReadData(ppd_file_t *ppd, /* I - PPD file */
const char *name, /* I - Keyword prefix */
size_t *datasize) /* O - Size of data or NULL for don't care */
{
char keyword[PPD_MAX_NAME], /* Keyword name */
decoded[PPDX_MAX_CHUNK + 1];
/* Decoded string */
unsigned chunk = 0; /* Current chunk number */
int len; /* Length of current chunk */
ppd_attr_t *attr; /* Keyword/value from PPD file */
Bytef *data; /* Pointer to data */
size_t alloc_size; /* Allocated size of data buffer */
z_stream decomp; /* Decompressor stream */
int error; /* Error/status from inflate() */
/*
* Range check input...
*/
if (datasize)
*datasize = 0;
if (!ppd || !name)
return (NULL);
/*
* First see if there are any instances of the named keyword in the PPD...
*/
snprintf(keyword, sizeof(keyword), "%s%04x", name, chunk);
if ((attr = ppdFindAttr(ppd, keyword, NULL)) == NULL)
return (NULL);
/*
* Allocate some memory and start decoding...
*/
data = malloc(257);
alloc_size = 256;
memset(&decomp, 0, sizeof(decomp));
decomp.next_out = data;
decomp.avail_out = 256;
inflateInit(&decomp);
do
{
/*
* Grab the data from the current attribute and decode it...
*/
len = sizeof(decoded);
if (!httpDecode64_2(decoded, &len, attr->value) || len == 0)
break;
// printf("chunk %04x has length %d\n", chunk, len);
/*
* Decompress this chunk...
*/
decomp.next_in = decoded;
decomp.avail_in = len;
do
{
Bytef *temp; /* Temporary pointer */
size_t temp_size; /* Temporary allocation size */
// printf("Before inflate: avail_in=%d, avail_out=%d\n", decomp.avail_in,
// decomp.avail_out);
if ((error = inflate(&decomp, Z_NO_FLUSH)) < Z_OK)
{
fprintf(stderr, "ERROR: inflate returned %d (%s)\n", error, decomp.msg);
break;
}
// printf("After inflate: avail_in=%d, avail_out=%d, error=%d\n",
// decomp.avail_in, decomp.avail_out, error);
if (decomp.avail_out == 0)
{
if (alloc_size < 2048)
temp_size = alloc_size * 2;
else if (alloc_size < PPDX_MAX_DATA)
temp_size = alloc_size + 2048;
else
break;
if ((temp = realloc(data, temp_size + 1)) == NULL)
{
free(data);
return (NULL);
}
decomp.next_out = temp + (decomp.next_out - data);
decomp.avail_out = temp_size - alloc_size;
data = temp;
alloc_size = temp_size;
}
}
while (decomp.avail_in > 0);
chunk ++;
snprintf(keyword, sizeof(keyword), "%s%04x", name, chunk);
}
while ((attr = ppdFindAttr(ppd, keyword, NULL)) != NULL);
inflateEnd(&decomp);
/*
* Nul-terminate the data (usually a string)...
*/
*(decomp.next_out) = '\0';
if (datasize)
*datasize = decomp.next_out - data;
return (data);
}
/*
* 'ppdxWriteData()' - Writes encoded data to stderr using PPD: messages.
*
* Writes chunked data to the PPD file using PPD: messages sent to stderr for
* cupsd. "name" must be a valid PPD keyword string whose length is less than
* 37 characters to allow for chunk numbering. "data" provides a pointer to the
* data to be written, and "datasize" provides the length.
*/
extern void
ppdxWriteData(const char *name, /* I - Base name of keyword */
const void *data, /* I - Data to write */
size_t datasize) /* I - Number of bytes in data */
{
char buffer[PPDX_MAX_CHUNK], /* Chunk buffer */
encoded[PPDX_MAX_VALUE + 1],
/* Encoded data */
pair[PPD_MAX_LINE], /* name=value pair */
line[PPDX_MAX_STATUS], /* Line buffer */
*lineptr, /* Current position in line buffer */
*lineend; /* End of line buffer */
unsigned chunk = 0; /* Current chunk number */
int len; /* Length of current chunk */
z_stream comp; /* Compressor stream */
int error; /* Error/status from deflate() */
/*
* Range check input...
*/
if (!name || (!data && datasize > 0) || datasize > PPDX_MAX_DATA)
return;
strlcpy(line, "PPD:", sizeof(line));
lineptr = line + 4;
lineend = line + sizeof(line) - 2;
if (datasize > 0)
{
/*
* Compress and encode output...
*/
memset(&comp, 0, sizeof(comp));
comp.next_in = (Bytef *)data;
comp.avail_in = datasize;
deflateInit(&comp, 9);
do
{
/*
* Compress a chunk...
*/
comp.next_out = buffer;
comp.avail_out = sizeof(buffer);
if ((error = deflate(&comp, Z_FINISH)) < Z_OK)
{
fprintf(stderr, "ERROR: deflate returned %d (%s)\n", error, comp.msg);
break;
}
/*
* Write a chunk...
*/
len = sizeof(buffer) - comp.avail_out;
httpEncode64_2(encoded, sizeof(encoded), buffer, len);
len = (int)snprintf(pair, sizeof(pair), " %s%04x=%s", name, chunk,
encoded);
#ifdef DEBUG
fprintf(stderr, "DEBUG: *%s%04x: \"%s\"\n", name, chunk, encoded);
#endif /* DEBUG */
if ((lineptr + len) >= lineend)
{
*lineptr++ = '\n';
*lineptr = '\0';
fputs(line, stderr);
lineptr = line + 4;
}
strlcpy(lineptr, pair, lineend - lineptr);
lineptr += len;
/*
* Setup for the next one...
*/
chunk ++;
}
while (comp.avail_out == 0);
}
deflateEnd(&comp);
/*
* Write a trailing empty chunk to signal EOD...
*/
len = (int)snprintf(pair, sizeof(pair), " %s%04x=\"\"", name, chunk);
#ifdef DEBUG
fprintf(stderr, "DEBUG: *%s%04x: \"\"\n", name, chunk);
#endif /* DEBUG */
if ((lineptr + len) >= lineend)
{
*lineptr++ = '\n';
*lineptr = '\0';
fputs(line, stderr);
lineptr = line + 4;
}
strlcpy(lineptr, pair, lineend - lineptr);
lineptr += len;
*lineptr++ = '\n';
*lineptr = '\0';
fputs(line, stderr);
}