/* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*/
#include <apr_strings.h>
#include <zlib.h>
/* This conditional isn't defined anywhere yet. */
#ifdef HAVE_ZUTIL_H
#include <zutil.h>
#endif
#include "serf.h"
#include "serf_bucket_util.h"
/* magic header */
static char deflate_magic[2] = { '\037', '\213' };
#define DEFLATE_MAGIC_SIZE 10
#define DEFLATE_VERIFY_SIZE 8
#define DEFLATE_BUFFER_SIZE 8096
static const int DEFLATE_WINDOW_SIZE = -15;
static const int DEFLATE_MEMLEVEL = 9;
typedef struct {
serf_bucket_t *stream;
serf_bucket_t *inflate_stream;
int format; /* Are we 'deflate' or 'gzip'? */
enum {
STATE_READING_HEADER, /* reading the gzip header */
STATE_HEADER, /* read the gzip header */
STATE_INIT, /* init'ing zlib functions */
STATE_INFLATE, /* inflating the content now */
STATE_READING_VERIFY, /* reading the final gzip CRC */
STATE_VERIFY, /* verifying the final gzip CRC */
STATE_FINISH, /* clean up after reading body */
STATE_DONE, /* body is done; we'll return EOF here */
} state;
z_stream zstream;
char hdr_buffer[DEFLATE_MAGIC_SIZE];
unsigned char buffer[DEFLATE_BUFFER_SIZE];
unsigned long crc;
int windowSize;
int memLevel;
int bufferSize;
/* How much of the chunk, or the terminator, do we have left to read? */
apr_size_t stream_left;
/* How much are we supposed to read? */
apr_size_t stream_size;
int stream_status; /* What was the last status we read? */
} deflate_context_t;
/* Inputs a string and returns a long. */
static unsigned long getLong(unsigned char *string)
{
return ((unsigned long)string[0])
| (((unsigned long)string[1]) << 8)
| (((unsigned long)string[2]) << 16)
| (((unsigned long)string[3]) << 24);
}
serf_bucket_t *serf_bucket_deflate_create(
serf_bucket_t *stream,
serf_bucket_alloc_t *allocator,
int format)
{
deflate_context_t *ctx;
ctx = serf_bucket_mem_alloc(allocator, sizeof(*ctx));
ctx->stream = stream;
ctx->stream_status = APR_SUCCESS;
ctx->inflate_stream = serf_bucket_aggregate_create(allocator);
ctx->format = format;
ctx->crc = 0;
/* zstream must be NULL'd out. */
memset(&ctx->zstream, 0, sizeof(ctx->zstream));
switch (ctx->format) {
case SERF_DEFLATE_GZIP:
ctx->state = STATE_READING_HEADER;
break;
case SERF_DEFLATE_DEFLATE:
/* deflate doesn't have a header. */
ctx->state = STATE_INIT;
break;
default:
/* Not reachable */
return NULL;
}
/* Initial size of gzip header. */
ctx->stream_left = ctx->stream_size = DEFLATE_MAGIC_SIZE;
ctx->windowSize = DEFLATE_WINDOW_SIZE;
ctx->memLevel = DEFLATE_MEMLEVEL;
ctx->bufferSize = DEFLATE_BUFFER_SIZE;
return serf_bucket_create(&serf_bucket_type_deflate, allocator, ctx);
}
static void serf_deflate_destroy_and_data(serf_bucket_t *bucket)
{
deflate_context_t *ctx = bucket->data;
if (ctx->state > STATE_INIT &&
ctx->state <= STATE_FINISH)
inflateEnd(&ctx->zstream);
/* We may have appended inflate_stream into the stream bucket.
* If so, avoid free'ing it twice.
*/
if (ctx->inflate_stream) {
serf_bucket_destroy(ctx->inflate_stream);
}
serf_bucket_destroy(ctx->stream);
serf_default_destroy_and_data(bucket);
}
static apr_status_t serf_deflate_read(serf_bucket_t *bucket,
apr_size_t requested,
const char **data, apr_size_t *len)
{
deflate_context_t *ctx = bucket->data;
apr_status_t status;
const char *private_data;
apr_size_t private_len;
int zRC;
while (1) {
switch (ctx->state) {
case STATE_READING_HEADER:
case STATE_READING_VERIFY:
status = serf_bucket_read(ctx->stream, ctx->stream_left,
&private_data, &private_len);
if (SERF_BUCKET_READ_ERROR(status)) {
return status;
}
memcpy(ctx->hdr_buffer + (ctx->stream_size - ctx->stream_left),
private_data, private_len);
ctx->stream_left -= private_len;
if (ctx->stream_left == 0) {
ctx->state++;
if (APR_STATUS_IS_EAGAIN(status)) {
*len = 0;
return status;
}
}
else if (status) {
*len = 0;
return status;
}
break;
case STATE_HEADER:
if (ctx->hdr_buffer[0] != deflate_magic[0] ||
ctx->hdr_buffer[1] != deflate_magic[1]) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
if (ctx->hdr_buffer[3] != 0) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
ctx->state++;
break;
case STATE_VERIFY:
{
unsigned long compCRC, compLen, actualLen;
/* Do the checksum computation. */
compCRC = getLong((unsigned char*)ctx->hdr_buffer);
if (ctx->crc != compCRC) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
compLen = getLong((unsigned char*)ctx->hdr_buffer + 4);
/* The length in the trailer is module 2^32, so do the same for
the actual length. */
actualLen = ctx->zstream.total_out;
actualLen &= 0xFFFFFFFF;
if (actualLen != compLen) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
ctx->state++;
break;
}
case STATE_INIT:
zRC = inflateInit2(&ctx->zstream, ctx->windowSize);
if (zRC != Z_OK) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
ctx->zstream.next_out = ctx->buffer;
ctx->zstream.avail_out = ctx->bufferSize;
ctx->state++;
break;
case STATE_FINISH:
inflateEnd(&ctx->zstream);
serf_bucket_aggregate_prepend(ctx->stream, ctx->inflate_stream);
ctx->inflate_stream = 0;
ctx->state++;
break;
case STATE_INFLATE:
/* Do we have anything already uncompressed to read? */
status = serf_bucket_read(ctx->inflate_stream, requested, data,
len);
if (SERF_BUCKET_READ_ERROR(status)) {
return status;
}
/* Hide EOF. */
if (APR_STATUS_IS_EOF(status)) {
status = ctx->stream_status;
if (APR_STATUS_IS_EOF(status)) {
/* We've read all of the data from our stream, but we
* need to continue to iterate until we flush
* out the zlib buffer.
*/
status = APR_SUCCESS;
}
}
if (*len != 0) {
return status;
}
/* We tried; but we have nothing buffered. Fetch more. */
/* It is possible that we maxed out avail_out before
* exhausting avail_in; therefore, continue using the
* previous buffer. Otherwise, fetch more data from
* our stream bucket.
*/
if (ctx->zstream.avail_in == 0) {
/* When we empty our inflated stream, we'll return this
* status - this allow us to eventually pass up EAGAINs.
*/
ctx->stream_status = serf_bucket_read(ctx->stream,
ctx->bufferSize,
&private_data,
&private_len);
if (SERF_BUCKET_READ_ERROR(ctx->stream_status)) {
return ctx->stream_status;
}
if (!private_len && APR_STATUS_IS_EAGAIN(ctx->stream_status)) {
*len = 0;
status = ctx->stream_status;
ctx->stream_status = APR_SUCCESS;
return status;
}
ctx->zstream.next_in = (unsigned char*)private_data;
ctx->zstream.avail_in = private_len;
}
while (1) {
zRC = inflate(&ctx->zstream, Z_NO_FLUSH);
/* We're full or zlib requires more space. Either case, clear
out our buffer, reset, and return. */
if (zRC == Z_BUF_ERROR || ctx->zstream.avail_out == 0) {
serf_bucket_t *tmp;
ctx->zstream.next_out = ctx->buffer;
private_len = ctx->bufferSize - ctx->zstream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer,
private_len);
/* FIXME: There probably needs to be a free func. */
tmp = SERF_BUCKET_SIMPLE_STRING_LEN((char *)ctx->buffer,
private_len,
bucket->allocator);
serf_bucket_aggregate_append(ctx->inflate_stream, tmp);
ctx->zstream.avail_out = ctx->bufferSize;
break;
}
if (zRC == Z_STREAM_END) {
serf_bucket_t *tmp;
private_len = ctx->bufferSize - ctx->zstream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer,
private_len);
/* FIXME: There probably needs to be a free func. */
tmp = SERF_BUCKET_SIMPLE_STRING_LEN((char *)ctx->buffer,
private_len,
bucket->allocator);
serf_bucket_aggregate_append(ctx->inflate_stream, tmp);
ctx->zstream.avail_out = ctx->bufferSize;
/* Push back the remaining data to be read. */
tmp = serf_bucket_aggregate_create(bucket->allocator);
serf_bucket_aggregate_prepend(tmp, ctx->stream);
ctx->stream = tmp;
/* We now need to take the remaining avail_in and
* throw it in ctx->stream so our next read picks it up.
*/
tmp = SERF_BUCKET_SIMPLE_STRING_LEN(
(const char*)ctx->zstream.next_in,
ctx->zstream.avail_in,
bucket->allocator);
serf_bucket_aggregate_prepend(ctx->stream, tmp);
switch (ctx->format) {
case SERF_DEFLATE_GZIP:
ctx->stream_left = ctx->stream_size =
DEFLATE_VERIFY_SIZE;
ctx->state++;
break;
case SERF_DEFLATE_DEFLATE:
/* Deflate does not have a verify footer. */
ctx->state = STATE_FINISH;
break;
default:
/* Not reachable */
return APR_EGENERAL;
}
break;
}
/* Any other error? */
if (zRC != Z_OK) {
return SERF_ERROR_DECOMPRESSION_FAILED;
}
/* As long as zRC == Z_OK, just keep looping. */
}
/* Okay, we've inflated. Try to read. */
status = serf_bucket_read(ctx->inflate_stream, requested, data,
len);
/* Hide EOF. */
if (APR_STATUS_IS_EOF(status)) {
status = ctx->stream_status;
/* If the inflation wasn't finished, return APR_SUCCESS. */
if (zRC != Z_STREAM_END)
return APR_SUCCESS;
/* If our stream is finished too and all data was inflated,
* return SUCCESS so we'll iterate one more time.
*/
if (APR_STATUS_IS_EOF(status)) {
/* No more data to read from the stream, and everything
inflated. If all data was received correctly, state
should have been advanced to STATE_READING_VERIFY or
STATE_FINISH. If not, then the data was incomplete
and we have an error. */
if (ctx->state != STATE_INFLATE)
return APR_SUCCESS;
else
return SERF_ERROR_DECOMPRESSION_FAILED;
}
}
return status;
case STATE_DONE:
/* We're done inflating. Use our finished buffer. */
return serf_bucket_read(ctx->stream, requested, data, len);
default:
/* Not reachable */
return APR_EGENERAL;
}
}
/* NOTREACHED */
}
/* ### need to implement */
#define serf_deflate_readline NULL
#define serf_deflate_peek NULL
const serf_bucket_type_t serf_bucket_type_deflate = {
"DEFLATE",
serf_deflate_read,
serf_deflate_readline,
serf_default_read_iovec,
serf_default_read_for_sendfile,
serf_default_read_bucket,
serf_deflate_peek,
serf_deflate_destroy_and_data,
};