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DEFINITIONS
This source file includes following definitions.
- check_gzip
- putLong
- getLong
- create_deflate_server_config
- deflate_set_window_size
- deflate_set_buffer_size
- deflate_set_note
- deflate_set_memlevel
- deflate_set_compressionlevel
- flush_libz_buffer
- deflate_ctx_cleanup
- deflate_check_etag
- deflate_out_filter
- deflate_in_filter
- inflate_out_filter
- register_hooks
/* 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.
*/
/*
* mod_deflate.c: Perform deflate content-encoding on the fly
*
* Written by Ian Holsman, Justin Erenkrantz, and Nick Kew
*/
/*
* Portions of this software are based upon zlib code by Jean-loup Gailly
* (zlib functions gz_open and gzwrite, check_header)
*/
/* zlib flags */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define RESERVED 0xE0 /* bits 5..7: reserved */
#include "httpd.h"
#include "http_config.h"
#include "http_log.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "apr_general.h"
#include "util_filter.h"
#include "apr_buckets.h"
#include "http_request.h"
#define APR_WANT_STRFUNC
#include "apr_want.h"
#include "zlib.h"
static const char deflateFilterName[] = "DEFLATE";
module AP_MODULE_DECLARE_DATA deflate_module;
typedef struct deflate_filter_config_t
{
int windowSize;
int memlevel;
int compressionlevel;
apr_size_t bufferSize;
char *note_ratio_name;
char *note_input_name;
char *note_output_name;
} deflate_filter_config;
/* RFC 1952 Section 2.3 defines the gzip header:
*
* +---+---+---+---+---+---+---+---+---+---+
* |ID1|ID2|CM |FLG| MTIME |XFL|OS |
* +---+---+---+---+---+---+---+---+---+---+
*/
static const char gzip_header[10] =
{ '\037', '\213', Z_DEFLATED, 0,
0, 0, 0, 0, /* mtime */
0, 0x03 /* Unix OS_CODE */
};
/* magic header */
static const char deflate_magic[2] = { '\037', '\213' };
/* windowsize is negative to suppress Zlib header */
#define DEFAULT_COMPRESSION Z_DEFAULT_COMPRESSION
#define DEFAULT_WINDOWSIZE -15
#define DEFAULT_MEMLEVEL 9
#define DEFAULT_BUFFERSIZE 8096
/* Check whether a request is gzipped, so we can un-gzip it.
* If a request has multiple encodings, we need the gzip
* to be the outermost non-identity encoding.
*/
static int check_gzip(request_rec *r, apr_table_t *hdrs1, apr_table_t *hdrs2)
{
int found = 0;
apr_table_t *hdrs = hdrs1;
const char *encoding = apr_table_get(hdrs, "Content-Encoding");
if (!encoding && (hdrs2 != NULL)) {
/* the output filter has two tables and a content_encoding to check */
encoding = apr_table_get(hdrs2, "Content-Encoding");
hdrs = hdrs2;
if (!encoding) {
encoding = r->content_encoding;
hdrs = NULL;
}
}
if (encoding && *encoding) {
/* check the usual/simple case first */
if (!strcasecmp(encoding, "gzip")
|| !strcasecmp(encoding, "x-gzip")) {
found = 1;
if (hdrs) {
apr_table_unset(hdrs, "Content-Encoding");
}
else {
r->content_encoding = NULL;
}
}
else if (ap_strchr_c(encoding, ',') != NULL) {
/* If the outermost encoding isn't gzip, there's nowt
* we can do. So only check the last non-identity token
*/
char *new_encoding = apr_pstrdup(r->pool, encoding);
char *ptr;
for(;;) {
char *token = ap_strrchr(new_encoding, ',');
if (!token) { /* gzip:identity or other:identity */
if (!strcasecmp(new_encoding, "gzip")
|| !strcasecmp(new_encoding, "x-gzip")) {
found = 1;
if (hdrs) {
apr_table_unset(hdrs, "Content-Encoding");
}
else {
r->content_encoding = NULL;
}
}
break; /* seen all tokens */
}
for (ptr=token+1; apr_isspace(*ptr); ++ptr);
if (!strcasecmp(ptr, "gzip")
|| !strcasecmp(ptr, "x-gzip")) {
*token = '\0';
if (hdrs) {
apr_table_setn(hdrs, "Content-Encoding", new_encoding);
}
else {
r->content_encoding = new_encoding;
}
found = 1;
}
else if (!ptr[0] || !strcasecmp(ptr, "identity")) {
*token = '\0';
continue; /* strip the token and find the next one */
}
break; /* found a non-identity token */
}
}
}
return found;
}
/* Outputs a long in LSB order to the given file
* only the bottom 4 bits are required for the deflate file format.
*/
static void putLong(unsigned char *string, unsigned long x)
{
string[0] = (unsigned char)(x & 0xff);
string[1] = (unsigned char)((x & 0xff00) >> 8);
string[2] = (unsigned char)((x & 0xff0000) >> 16);
string[3] = (unsigned char)((x & 0xff000000) >> 24);
}
/* 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);
}
static void *create_deflate_server_config(apr_pool_t *p, server_rec *s)
{
deflate_filter_config *c = apr_pcalloc(p, sizeof *c);
c->memlevel = DEFAULT_MEMLEVEL;
c->windowSize = DEFAULT_WINDOWSIZE;
c->bufferSize = DEFAULT_BUFFERSIZE;
c->compressionlevel = DEFAULT_COMPRESSION;
return c;
}
static const char *deflate_set_window_size(cmd_parms *cmd, void *dummy,
const char *arg)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
int i;
i = atoi(arg);
if (i < 1 || i > 15)
return "DeflateWindowSize must be between 1 and 15";
c->windowSize = i * -1;
return NULL;
}
static const char *deflate_set_buffer_size(cmd_parms *cmd, void *dummy,
const char *arg)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
int n = atoi(arg);
if (n <= 0) {
return "DeflateBufferSize should be positive";
}
c->bufferSize = (apr_size_t)n;
return NULL;
}
static const char *deflate_set_note(cmd_parms *cmd, void *dummy,
const char *arg1, const char *arg2)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
if (arg2 == NULL) {
c->note_ratio_name = apr_pstrdup(cmd->pool, arg1);
}
else if (!strcasecmp(arg1, "ratio")) {
c->note_ratio_name = apr_pstrdup(cmd->pool, arg2);
}
else if (!strcasecmp(arg1, "input")) {
c->note_input_name = apr_pstrdup(cmd->pool, arg2);
}
else if (!strcasecmp(arg1, "output")) {
c->note_output_name = apr_pstrdup(cmd->pool, arg2);
}
else {
return apr_psprintf(cmd->pool, "Unknown note type %s", arg1);
}
return NULL;
}
static const char *deflate_set_memlevel(cmd_parms *cmd, void *dummy,
const char *arg)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
int i;
i = atoi(arg);
if (i < 1 || i > 9)
return "DeflateMemLevel must be between 1 and 9";
c->memlevel = i;
return NULL;
}
static const char *deflate_set_compressionlevel(cmd_parms *cmd, void *dummy,
const char *arg)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
int i;
i = atoi(arg);
if (i < 1 || i > 9)
return "Compression Level must be between 1 and 9";
c->compressionlevel = i;
return NULL;
}
typedef struct deflate_ctx_t
{
z_stream stream;
unsigned char *buffer;
unsigned long crc;
apr_bucket_brigade *bb, *proc_bb;
int (*libz_end_func)(z_streamp);
unsigned char *validation_buffer;
apr_size_t validation_buffer_length;
int inflate_init;
} deflate_ctx;
/* Number of validation bytes (CRC and length) after the compressed data */
#define VALIDATION_SIZE 8
/* Do not update ctx->crc, see comment in flush_libz_buffer */
#define NO_UPDATE_CRC 0
/* Do update ctx->crc, see comment in flush_libz_buffer */
#define UPDATE_CRC 1
static int flush_libz_buffer(deflate_ctx *ctx, deflate_filter_config *c,
struct apr_bucket_alloc_t *bucket_alloc,
int (*libz_func)(z_streamp, int), int flush,
int crc)
{
int zRC = Z_OK;
int done = 0;
unsigned int deflate_len;
apr_bucket *b;
for (;;) {
deflate_len = c->bufferSize - ctx->stream.avail_out;
if (deflate_len != 0) {
/*
* Do we need to update ctx->crc? Usually this is the case for
* inflate action where we need to do a crc on the output, whereas
* in the deflate case we need to do a crc on the input
*/
if (crc) {
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer,
deflate_len);
}
b = apr_bucket_heap_create((char *)ctx->buffer,
deflate_len, NULL,
bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->bb, b);
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
}
if (done)
break;
zRC = libz_func(&ctx->stream, flush);
/*
* We can ignore Z_BUF_ERROR because:
* When we call libz_func we can assume that
*
* - avail_in is zero (due to the surrounding code that calls
* flush_libz_buffer)
* - avail_out is non zero due to our actions some lines above
*
* So the only reason for Z_BUF_ERROR is that the internal libz
* buffers are now empty and thus we called libz_func one time
* too often. This does not hurt. It simply says that we are done.
*/
if (zRC == Z_BUF_ERROR) {
zRC = Z_OK;
break;
}
done = (ctx->stream.avail_out != 0 || zRC == Z_STREAM_END);
if (zRC != Z_OK && zRC != Z_STREAM_END)
break;
}
return zRC;
}
static apr_status_t deflate_ctx_cleanup(void *data)
{
deflate_ctx *ctx = (deflate_ctx *)data;
if (ctx)
ctx->libz_end_func(&ctx->stream);
return APR_SUCCESS;
}
/* PR 39727: we're screwing up our clients if we leave a strong ETag
* header while transforming content. Henrik Nordstrom suggests
* appending ";gzip".
*
* Pending a more thorough review of our Etag handling, let's just
* implement his suggestion. It fixes the bug, or at least turns it
* from a showstopper to an inefficiency. And it breaks nothing that
* wasn't already broken.
*/
static void deflate_check_etag(request_rec *r, const char *transform)
{
const char *etag = apr_table_get(r->headers_out, "ETag");
if (etag && (((etag[0] != 'W') && (etag[0] !='w')) || (etag[1] != '/'))) {
apr_table_set(r->headers_out, "ETag",
apr_pstrcat(r->pool, etag, "-", transform, NULL));
}
}
static apr_status_t deflate_out_filter(ap_filter_t *f,
apr_bucket_brigade *bb)
{
apr_bucket *e;
request_rec *r = f->r;
deflate_ctx *ctx = f->ctx;
int zRC;
deflate_filter_config *c;
/* Do nothing if asked to filter nothing. */
if (APR_BRIGADE_EMPTY(bb)) {
return ap_pass_brigade(f->next, bb);
}
c = ap_get_module_config(r->server->module_config,
&deflate_module);
/* If we don't have a context, we need to ensure that it is okay to send
* the deflated content. If we have a context, that means we've done
* this before and we liked it.
* This could be not so nice if we always fail. But, if we succeed,
* we're in better shape.
*/
if (!ctx) {
char *token;
const char *encoding;
/* only work on main request/no subrequests */
if (r->main != NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* some browsers might have problems, so set no-gzip
* (with browsermatch) for them
*/
if (apr_table_get(r->subprocess_env, "no-gzip")) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* We can't operate on Content-Ranges */
if (apr_table_get(r->headers_out, "Content-Range") != NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* Some browsers might have problems with content types
* other than text/html, so set gzip-only-text/html
* (with browsermatch) for them
*/
if (r->content_type == NULL
|| strncmp(r->content_type, "text/html", 9)) {
const char *env_value = apr_table_get(r->subprocess_env,
"gzip-only-text/html");
if ( env_value && (strcmp(env_value,"1") == 0) ) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
}
/* Let's see what our current Content-Encoding is.
* If it's already encoded, don't compress again.
* (We could, but let's not.)
*/
encoding = apr_table_get(r->headers_out, "Content-Encoding");
if (encoding) {
const char *err_enc;
err_enc = apr_table_get(r->err_headers_out, "Content-Encoding");
if (err_enc) {
encoding = apr_pstrcat(r->pool, encoding, ",", err_enc, NULL);
}
}
else {
encoding = apr_table_get(r->err_headers_out, "Content-Encoding");
}
if (r->content_encoding) {
encoding = encoding ? apr_pstrcat(r->pool, encoding, ",",
r->content_encoding, NULL)
: r->content_encoding;
}
if (encoding) {
const char *tmp = encoding;
token = ap_get_token(r->pool, &tmp, 0);
while (token && *token) {
/* stolen from mod_negotiation: */
if (strcmp(token, "identity") && strcmp(token, "7bit") &&
strcmp(token, "8bit") && strcmp(token, "binary")) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* Otherwise, skip token */
if (*tmp) {
++tmp;
}
token = (*tmp) ? ap_get_token(r->pool, &tmp, 0) : NULL;
}
}
/* Even if we don't accept this request based on it not having
* the Accept-Encoding, we need to note that we were looking
* for this header and downstream proxies should be aware of that.
*/
apr_table_mergen(r->headers_out, "Vary", "Accept-Encoding");
/* force-gzip will just force it out regardless if the browser
* can actually do anything with it.
*/
if (!apr_table_get(r->subprocess_env, "force-gzip")) {
const char *accepts;
/* if they don't have the line, then they can't play */
accepts = apr_table_get(r->headers_in, "Accept-Encoding");
if (accepts == NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
token = ap_get_token(r->pool, &accepts, 0);
while (token && token[0] && strcasecmp(token, "gzip")) {
/* skip parameters, XXX: ;q=foo evaluation? */
while (*accepts == ';') {
++accepts;
token = ap_get_token(r->pool, &accepts, 1);
}
/* retrieve next token */
if (*accepts == ',') {
++accepts;
}
token = (*accepts) ? ap_get_token(r->pool, &accepts, 0) : NULL;
}
/* No acceptable token found. */
if (token == NULL || token[0] == '\0') {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
}
/* For a 304 or 204 response there is no entity included in
* the response and hence nothing to deflate. */
if (r->status == HTTP_NOT_MODIFIED || r->status == HTTP_NO_CONTENT) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* We're cool with filtering this. */
ctx = f->ctx = apr_pcalloc(r->pool, sizeof(*ctx));
ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc);
ctx->buffer = apr_palloc(r->pool, c->bufferSize);
ctx->libz_end_func = deflateEnd;
zRC = deflateInit2(&ctx->stream, c->compressionlevel, Z_DEFLATED,
c->windowSize, c->memlevel,
Z_DEFAULT_STRATEGY);
if (zRC != Z_OK) {
deflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"unable to init Zlib: "
"deflateInit2 returned %d: URL %s",
zRC, r->uri);
/*
* Remove ourselves as it does not make sense to return:
* We are not able to init libz and pass data down the chain
* uncompressed.
*/
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/*
* Register a cleanup function to ensure that we cleanup the internal
* libz resources.
*/
apr_pool_cleanup_register(r->pool, ctx, deflate_ctx_cleanup,
apr_pool_cleanup_null);
/* add immortal gzip header */
e = apr_bucket_immortal_create(gzip_header, sizeof gzip_header,
f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
/* If the entire Content-Encoding is "identity", we can replace it. */
if (!encoding || !strcasecmp(encoding, "identity")) {
apr_table_setn(r->headers_out, "Content-Encoding", "gzip");
}
else {
apr_table_mergen(r->headers_out, "Content-Encoding", "gzip");
}
apr_table_unset(r->headers_out, "Content-Length");
apr_table_unset(r->headers_out, "Content-MD5");
deflate_check_etag(r, "gzip");
/* initialize deflate output buffer */
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
}
while (!APR_BRIGADE_EMPTY(bb))
{
const char *data;
apr_bucket *b;
apr_size_t len;
e = APR_BRIGADE_FIRST(bb);
if (APR_BUCKET_IS_EOS(e)) {
char *buf;
ctx->stream.avail_in = 0; /* should be zero already anyway */
/* flush the remaining data from the zlib buffers */
flush_libz_buffer(ctx, c, f->c->bucket_alloc, deflate, Z_FINISH,
NO_UPDATE_CRC);
buf = apr_palloc(r->pool, VALIDATION_SIZE);
putLong((unsigned char *)&buf[0], ctx->crc);
putLong((unsigned char *)&buf[4], ctx->stream.total_in);
b = apr_bucket_pool_create(buf, VALIDATION_SIZE, r->pool,
f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->bb, b);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"Zlib: Compressed %ld to %ld : URL %s",
ctx->stream.total_in, ctx->stream.total_out, r->uri);
/* leave notes for logging */
if (c->note_input_name) {
apr_table_setn(r->notes, c->note_input_name,
(ctx->stream.total_in > 0)
? apr_off_t_toa(r->pool,
ctx->stream.total_in)
: "-");
}
if (c->note_output_name) {
apr_table_setn(r->notes, c->note_output_name,
(ctx->stream.total_in > 0)
? apr_off_t_toa(r->pool,
ctx->stream.total_out)
: "-");
}
if (c->note_ratio_name) {
apr_table_setn(r->notes, c->note_ratio_name,
(ctx->stream.total_in > 0)
? apr_itoa(r->pool,
(int)(ctx->stream.total_out
* 100
/ ctx->stream.total_in))
: "-");
}
deflateEnd(&ctx->stream);
/* No need for cleanup any longer */
apr_pool_cleanup_kill(r->pool, ctx, deflate_ctx_cleanup);
/* Remove EOS from the old list, and insert into the new. */
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
/* Okay, we've seen the EOS.
* Time to pass it along down the chain.
*/
return ap_pass_brigade(f->next, ctx->bb);
}
if (APR_BUCKET_IS_FLUSH(e)) {
apr_status_t rv;
/* flush the remaining data from the zlib buffers */
zRC = flush_libz_buffer(ctx, c, f->c->bucket_alloc, deflate,
Z_SYNC_FLUSH, NO_UPDATE_CRC);
if (zRC != Z_OK) {
return APR_EGENERAL;
}
/* Remove flush bucket from old brigade anf insert into the new. */
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
rv = ap_pass_brigade(f->next, ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
continue;
}
if (APR_BUCKET_IS_METADATA(e)) {
/*
* Remove meta data bucket from old brigade and insert into the
* new.
*/
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
continue;
}
/* read */
apr_bucket_read(e, &data, &len, APR_BLOCK_READ);
/* This crc32 function is from zlib. */
ctx->crc = crc32(ctx->crc, (const Bytef *)data, len);
/* write */
ctx->stream.next_in = (unsigned char *)data; /* We just lost const-ness,
* but we'll just have to
* trust zlib */
ctx->stream.avail_in = len;
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
apr_status_t rv;
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
b = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->bb, b);
ctx->stream.avail_out = c->bufferSize;
/* Send what we have right now to the next filter. */
rv = ap_pass_brigade(f->next, ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
}
zRC = deflate(&(ctx->stream), Z_NO_FLUSH);
if (zRC != Z_OK) {
return APR_EGENERAL;
}
}
apr_bucket_delete(e);
}
apr_brigade_cleanup(bb);
return APR_SUCCESS;
}
/* This is the deflate input filter (inflates). */
static apr_status_t deflate_in_filter(ap_filter_t *f,
apr_bucket_brigade *bb,
ap_input_mode_t mode,
apr_read_type_e block,
apr_off_t readbytes)
{
apr_bucket *bkt;
request_rec *r = f->r;
deflate_ctx *ctx = f->ctx;
int zRC;
apr_status_t rv;
deflate_filter_config *c;
/* just get out of the way of things we don't want. */
if (mode != AP_MODE_READBYTES) {
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
c = ap_get_module_config(r->server->module_config, &deflate_module);
if (!ctx) {
char deflate_hdr[10];
apr_size_t len;
/* only work on main request/no subrequests */
if (!ap_is_initial_req(r)) {
ap_remove_input_filter(f);
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
/* We can't operate on Content-Ranges */
if (apr_table_get(r->headers_in, "Content-Range") != NULL) {
ap_remove_input_filter(f);
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
/* Check whether request body is gzipped.
*
* If it is, we're transforming the contents, invalidating
* some request headers including Content-Encoding.
*
* If not, we just remove ourself.
*/
if (check_gzip(r, r->headers_in, NULL) == 0) {
ap_remove_input_filter(f);
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
f->ctx = ctx = apr_pcalloc(f->r->pool, sizeof(*ctx));
ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc);
ctx->proc_bb = apr_brigade_create(r->pool, f->c->bucket_alloc);
ctx->buffer = apr_palloc(r->pool, c->bufferSize);
rv = ap_get_brigade(f->next, ctx->bb, AP_MODE_READBYTES, block, 10);
if (rv != APR_SUCCESS) {
return rv;
}
apr_table_unset(r->headers_in, "Content-Length");
apr_table_unset(r->headers_in, "Content-MD5");
len = 10;
rv = apr_brigade_flatten(ctx->bb, deflate_hdr, &len);
if (rv != APR_SUCCESS) {
return rv;
}
/* We didn't get the magic bytes. */
if (len != 10 ||
deflate_hdr[0] != deflate_magic[0] ||
deflate_hdr[1] != deflate_magic[1]) {
return APR_EGENERAL;
}
/* We can't handle flags for now. */
if (deflate_hdr[3] != 0) {
return APR_EGENERAL;
}
zRC = inflateInit2(&ctx->stream, c->windowSize);
if (zRC != Z_OK) {
f->ctx = NULL;
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"unable to init Zlib: "
"inflateInit2 returned %d: URL %s",
zRC, r->uri);
ap_remove_input_filter(f);
return ap_get_brigade(f->next, bb, mode, block, readbytes);
}
/* initialize deflate output buffer */
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
apr_brigade_cleanup(ctx->bb);
}
if (APR_BRIGADE_EMPTY(ctx->proc_bb)) {
rv = ap_get_brigade(f->next, ctx->bb, mode, block, readbytes);
if (rv != APR_SUCCESS) {
/* What about APR_EAGAIN errors? */
inflateEnd(&ctx->stream);
return rv;
}
for (bkt = APR_BRIGADE_FIRST(ctx->bb);
bkt != APR_BRIGADE_SENTINEL(ctx->bb);
bkt = APR_BUCKET_NEXT(bkt))
{
const char *data;
apr_size_t len;
/* If we actually see the EOS, that means we screwed up! */
if (APR_BUCKET_IS_EOS(bkt)) {
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
if (APR_BUCKET_IS_FLUSH(bkt)) {
apr_bucket *tmp_heap;
zRC = inflate(&(ctx->stream), Z_SYNC_FLUSH);
if (zRC != Z_OK) {
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap);
ctx->stream.avail_out = c->bufferSize;
/* Move everything to the returning brigade. */
APR_BUCKET_REMOVE(bkt);
APR_BRIGADE_CONCAT(bb, ctx->bb);
break;
}
/* read */
apr_bucket_read(bkt, &data, &len, APR_BLOCK_READ);
/* pass through zlib inflate. */
ctx->stream.next_in = (unsigned char *)data;
ctx->stream.avail_in = len;
zRC = Z_OK;
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
apr_bucket *tmp_heap;
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap);
ctx->stream.avail_out = c->bufferSize;
}
zRC = inflate(&ctx->stream, Z_NO_FLUSH);
if (zRC == Z_STREAM_END) {
break;
}
if (zRC != Z_OK) {
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
}
if (zRC == Z_STREAM_END) {
apr_bucket *tmp_heap, *eos;
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"Zlib: Inflated %ld to %ld : URL %s",
ctx->stream.total_in, ctx->stream.total_out,
r->uri);
len = c->bufferSize - ctx->stream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap);
ctx->stream.avail_out = c->bufferSize;
/* Is the remaining 8 bytes already in the avail stream? */
if (ctx->stream.avail_in >= 8) {
unsigned long compCRC, compLen;
compCRC = getLong(ctx->stream.next_in);
if (ctx->crc != compCRC) {
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
ctx->stream.next_in += 4;
compLen = getLong(ctx->stream.next_in);
if (ctx->stream.total_out != compLen) {
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
}
else {
/* FIXME: We need to grab the 8 verification bytes
* from the wire! */
inflateEnd(&ctx->stream);
return APR_EGENERAL;
}
inflateEnd(&ctx->stream);
eos = apr_bucket_eos_create(f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, eos);
break;
}
}
apr_brigade_cleanup(ctx->bb);
}
/* If we are about to return nothing for a 'blocking' read and we have
* some data in our zlib buffer, flush it out so we can return something.
*/
if (block == APR_BLOCK_READ &&
APR_BRIGADE_EMPTY(ctx->proc_bb) &&
ctx->stream.avail_out < c->bufferSize) {
apr_bucket *tmp_heap;
apr_size_t len;
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, tmp_heap);
ctx->stream.avail_out = c->bufferSize;
}
if (!APR_BRIGADE_EMPTY(ctx->proc_bb)) {
apr_bucket_brigade *newbb;
/* May return APR_INCOMPLETE which is fine by us. */
apr_brigade_partition(ctx->proc_bb, readbytes, &bkt);
newbb = apr_brigade_split(ctx->proc_bb, bkt);
APR_BRIGADE_CONCAT(bb, ctx->proc_bb);
APR_BRIGADE_CONCAT(ctx->proc_bb, newbb);
}
return APR_SUCCESS;
}
/* Filter to inflate for a content-transforming proxy. */
static apr_status_t inflate_out_filter(ap_filter_t *f,
apr_bucket_brigade *bb)
{
int zlib_method;
int zlib_flags;
apr_bucket *e;
request_rec *r = f->r;
deflate_ctx *ctx = f->ctx;
int zRC;
apr_status_t rv;
deflate_filter_config *c;
/* Do nothing if asked to filter nothing. */
if (APR_BRIGADE_EMPTY(bb)) {
return ap_pass_brigade(f->next, bb);
}
c = ap_get_module_config(r->server->module_config, &deflate_module);
if (!ctx) {
/* only work on main request/no subrequests */
if (!ap_is_initial_req(r)) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* We can't operate on Content-Ranges */
if (apr_table_get(r->headers_out, "Content-Range") != NULL) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/*
* Let's see what our current Content-Encoding is.
* Only inflate if gzipped.
*/
if (check_gzip(r, r->headers_out, r->err_headers_out) == 0) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* No need to inflate HEAD or 204/304 */
if (APR_BUCKET_IS_EOS(APR_BRIGADE_FIRST(bb))) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
f->ctx = ctx = apr_pcalloc(f->r->pool, sizeof(*ctx));
ctx->bb = apr_brigade_create(r->pool, f->c->bucket_alloc);
ctx->buffer = apr_palloc(r->pool, c->bufferSize);
ctx->libz_end_func = inflateEnd;
ctx->validation_buffer = NULL;
ctx->validation_buffer_length = 0;
zRC = inflateInit2(&ctx->stream, c->windowSize);
if (zRC != Z_OK) {
f->ctx = NULL;
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"unable to init Zlib: "
"inflateInit2 returned %d: URL %s",
zRC, r->uri);
/*
* Remove ourselves as it does not make sense to return:
* We are not able to init libz and pass data down the chain
* compressed.
*/
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/*
* Register a cleanup function to ensure that we cleanup the internal
* libz resources.
*/
apr_pool_cleanup_register(r->pool, ctx, deflate_ctx_cleanup,
apr_pool_cleanup_null);
/* these are unlikely to be set anyway, but ... */
apr_table_unset(r->headers_out, "Content-Length");
apr_table_unset(r->headers_out, "Content-MD5");
deflate_check_etag(r, "gunzip");
/* initialize inflate output buffer */
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
ctx->inflate_init = 0;
}
while (!APR_BRIGADE_EMPTY(bb))
{
const char *data;
apr_bucket *b;
apr_size_t len;
e = APR_BRIGADE_FIRST(bb);
if (APR_BUCKET_IS_EOS(e)) {
/*
* We are really done now. Ensure that we never return here, even
* if a second EOS bucket falls down the chain. Thus remove
* ourselves.
*/
ap_remove_output_filter(f);
/* should be zero already anyway */
ctx->stream.avail_in = 0;
/*
* Flush the remaining data from the zlib buffers. It is correct
* to use Z_SYNC_FLUSH in this case and not Z_FINISH as in the
* deflate case. In the inflate case Z_FINISH requires to have a
* large enough output buffer to put ALL data in otherwise it
* fails, whereas in the deflate case you can empty a filled output
* buffer and call it again until no more output can be created.
*/
flush_libz_buffer(ctx, c, f->c->bucket_alloc, inflate, Z_SYNC_FLUSH,
UPDATE_CRC);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"Zlib: Inflated %ld to %ld : URL %s",
ctx->stream.total_in, ctx->stream.total_out, r->uri);
if (ctx->validation_buffer_length == VALIDATION_SIZE) {
unsigned long compCRC, compLen;
compCRC = getLong(ctx->validation_buffer);
if (ctx->crc != compCRC) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"Zlib: Checksum of inflated stream invalid");
return APR_EGENERAL;
}
ctx->validation_buffer += VALIDATION_SIZE / 2;
compLen = getLong(ctx->validation_buffer);
if (ctx->stream.total_out != compLen) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"Zlib: Length of inflated stream invalid");
return APR_EGENERAL;
}
}
else {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"Zlib: Validation bytes not present");
return APR_EGENERAL;
}
inflateEnd(&ctx->stream);
/* No need for cleanup any longer */
apr_pool_cleanup_kill(r->pool, ctx, deflate_ctx_cleanup);
/* Remove EOS from the old list, and insert into the new. */
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
/*
* Okay, we've seen the EOS.
* Time to pass it along down the chain.
*/
return ap_pass_brigade(f->next, ctx->bb);
}
if (APR_BUCKET_IS_FLUSH(e)) {
apr_status_t rv;
/* flush the remaining data from the zlib buffers */
zRC = flush_libz_buffer(ctx, c, f->c->bucket_alloc, inflate,
Z_SYNC_FLUSH, UPDATE_CRC);
if (zRC != Z_OK) {
return APR_EGENERAL;
}
/* Remove flush bucket from old brigade anf insert into the new. */
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
rv = ap_pass_brigade(f->next, ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
continue;
}
if (APR_BUCKET_IS_METADATA(e)) {
/*
* Remove meta data bucket from old brigade and insert into the
* new.
*/
APR_BUCKET_REMOVE(e);
APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
continue;
}
/* read */
apr_bucket_read(e, &data, &len, APR_BLOCK_READ);
/* first bucket contains zlib header */
if (!ctx->inflate_init++) {
if (len < 10) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"Insufficient data for inflate");
return APR_EGENERAL;
}
else {
zlib_method = data[2];
zlib_flags = data[3];
if (zlib_method != Z_DEFLATED) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"inflate: data not deflated!");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
if (data[0] != deflate_magic[0] ||
data[1] != deflate_magic[1] ||
(zlib_flags & RESERVED) != 0) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"inflate: bad header");
return APR_EGENERAL ;
}
data += 10 ;
len -= 10 ;
}
if (zlib_flags & EXTRA_FIELD) {
unsigned int bytes = (unsigned int)(data[0]);
bytes += ((unsigned int)(data[1])) << 8;
bytes += 2;
if (len < bytes) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
"inflate: extra field too big (not "
"supported)");
return APR_EGENERAL;
}
data += bytes;
len -= bytes;
}
if (zlib_flags & ORIG_NAME) {
while (len-- && *data++);
}
if (zlib_flags & COMMENT) {
while (len-- && *data++);
}
if (zlib_flags & HEAD_CRC) {
len -= 2;
data += 2;
}
}
/* pass through zlib inflate. */
ctx->stream.next_in = (unsigned char *)data;
ctx->stream.avail_in = len;
if (ctx->validation_buffer) {
if (ctx->validation_buffer_length < VALIDATION_SIZE) {
apr_size_t copy_size;
copy_size = VALIDATION_SIZE - ctx->validation_buffer_length;
if (copy_size > ctx->stream.avail_in)
copy_size = ctx->stream.avail_in;
memcpy(ctx->validation_buffer + ctx->validation_buffer_length,
ctx->stream.next_in, copy_size);
/* Saved copy_size bytes */
ctx->stream.avail_in -= copy_size;
ctx->validation_buffer_length += copy_size;
}
if (ctx->stream.avail_in) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"Zlib: %d bytes of garbage at the end of "
"compressed stream.", ctx->stream.avail_in);
/*
* There is nothing worth consuming for zlib left, because it is
* either garbage data or the data has been copied to the
* validation buffer (processing validation data is no business
* for zlib). So set ctx->stream.avail_in to zero to indicate
* this to the following while loop.
*/
ctx->stream.avail_in = 0;
}
}
zRC = Z_OK;
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
b = apr_bucket_heap_create((char *)ctx->buffer, len,
NULL, f->c->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(ctx->bb, b);
ctx->stream.avail_out = c->bufferSize;
/* Send what we have right now to the next filter. */
rv = ap_pass_brigade(f->next, ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
}
zRC = inflate(&ctx->stream, Z_NO_FLUSH);
if (zRC == Z_STREAM_END) {
/*
* We have inflated all data. Now try to capture the
* validation bytes. We may not have them all available
* right now, but capture what is there.
*/
ctx->validation_buffer = apr_pcalloc(f->r->pool,
VALIDATION_SIZE);
if (ctx->stream.avail_in > VALIDATION_SIZE) {
ctx->validation_buffer_length = VALIDATION_SIZE;
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
"Zlib: %d bytes of garbage at the end of "
"compressed stream.",
ctx->stream.avail_in - VALIDATION_SIZE);
} else if (ctx->stream.avail_in > 0) {
ctx->validation_buffer_length = ctx->stream.avail_in;
}
if (ctx->validation_buffer_length)
memcpy(ctx->validation_buffer, ctx->stream.next_in,
ctx->validation_buffer_length);
break;
}
if (zRC != Z_OK) {
return APR_EGENERAL;
}
}
apr_bucket_delete(e);
}
apr_brigade_cleanup(bb);
return APR_SUCCESS;
}
#define PROTO_FLAGS AP_FILTER_PROTO_CHANGE|AP_FILTER_PROTO_CHANGE_LENGTH
static void register_hooks(apr_pool_t *p)
{
ap_register_output_filter(deflateFilterName, deflate_out_filter, NULL,
AP_FTYPE_CONTENT_SET);
ap_register_output_filter("INFLATE", inflate_out_filter, NULL,
AP_FTYPE_RESOURCE-1);
ap_register_input_filter(deflateFilterName, deflate_in_filter, NULL,
AP_FTYPE_CONTENT_SET);
}
static const command_rec deflate_filter_cmds[] = {
AP_INIT_TAKE12("DeflateFilterNote", deflate_set_note, NULL, RSRC_CONF,
"Set a note to report on compression ratio"),
AP_INIT_TAKE1("DeflateWindowSize", deflate_set_window_size, NULL,
RSRC_CONF, "Set the Deflate window size (1-15)"),
AP_INIT_TAKE1("DeflateBufferSize", deflate_set_buffer_size, NULL, RSRC_CONF,
"Set the Deflate Buffer Size"),
AP_INIT_TAKE1("DeflateMemLevel", deflate_set_memlevel, NULL, RSRC_CONF,
"Set the Deflate Memory Level (1-9)"),
AP_INIT_TAKE1("DeflateCompressionLevel", deflate_set_compressionlevel, NULL, RSRC_CONF,
"Set the Deflate Compression Level (1-9)"),
{NULL}
};
module AP_MODULE_DECLARE_DATA deflate_module = {
STANDARD20_MODULE_STUFF,
NULL, /* dir config creater */
NULL, /* dir merger --- default is to override */
create_deflate_server_config, /* server config */
NULL, /* merge server config */
deflate_filter_cmds, /* command table */
register_hooks /* register hooks */
};