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apache / httpd / 19d98a5802beedc00415c8ef0ab512fee0ec98b3 / . / modules / filters / mod_deflate.c
blob: 3ee78c7d0b08ead66add96d9d7fafcd2e9a2512e [file] [log] [blame]
/* 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 "http_core.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 "mod_ssl.h"
#include "zlib.h"
static const char deflateFilterName[] = "DEFLATE";
module AP_MODULE_DECLARE_DATA deflate_module;
#define AP_DEFLATE_ETAG_ADDSUFFIX 0
#define AP_DEFLATE_ETAG_NOCHANGE 1
#define AP_DEFLATE_ETAG_REMOVE 2
#define AP_INFLATE_RATIO_LIMIT 200
#define AP_INFLATE_RATIO_BURST 3
typedef struct deflate_filter_config_t
{
int windowSize;
int memlevel;
int compressionlevel;
int bufferSize;
const char *note_ratio_name;
const char *note_input_name;
const char *note_output_name;
int etag_opt;
} deflate_filter_config;
typedef struct deflate_dirconf_t {
apr_off_t inflate_limit;
int ratio_limit,
ratio_burst;
} deflate_dirconf_t;
/* 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
static APR_OPTIONAL_FN_TYPE(ssl_var_lookup) *mod_deflate_ssl_var = NULL;
/* 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 (!ap_cstr_casecmp(encoding, "gzip")
|| !ap_cstr_casecmp(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 nothing
* 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 (!ap_cstr_casecmp(new_encoding, "gzip")
|| !ap_cstr_casecmp(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 (!ap_cstr_casecmp(ptr, "gzip")
|| !ap_cstr_casecmp(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] || !ap_cstr_casecmp(ptr, "identity")) {
*token = '\0';
continue; /* strip the token and find the next one */
}
break; /* found a non-identity token */
}
}
}
/*
* If we have dealt with the headers above but content_encoding was set
* before sync it with the new value in the hdrs table as
* r->content_encoding takes precedence later on in the http_header_filter
* and hence would destroy what we have just set in the hdrs table.
*/
if (hdrs && r->content_encoding) {
r->content_encoding = apr_table_get(hdrs, "Content-Encoding");
}
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;
c->etag_opt = AP_DEFLATE_ETAG_ADDSUFFIX;
return c;
}
static void *create_deflate_dirconf(apr_pool_t *p, char *dummy)
{
deflate_dirconf_t *dc = apr_pcalloc(p, sizeof(*dc));
dc->ratio_limit = AP_INFLATE_RATIO_LIMIT;
dc->ratio_burst = AP_INFLATE_RATIO_BURST;
return dc;
}
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 = 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 = arg1;
}
else if (!strcasecmp(arg1, "ratio")) {
c->note_ratio_name = arg2;
}
else if (!strcasecmp(arg1, "input")) {
c->note_input_name = arg2;
}
else if (!strcasecmp(arg1, "output")) {
c->note_output_name = 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_etag(cmd_parms *cmd, void *dummy,
const char *arg)
{
deflate_filter_config *c = ap_get_module_config(cmd->server->module_config,
&deflate_module);
if (!strcasecmp(arg, "NoChange")) {
c->etag_opt = AP_DEFLATE_ETAG_NOCHANGE;
}
else if (!strcasecmp(arg, "AddSuffix")) {
c->etag_opt = AP_DEFLATE_ETAG_ADDSUFFIX;
}
else if (!strcasecmp(arg, "Remove")) {
c->etag_opt = AP_DEFLATE_ETAG_REMOVE;
}
else {
return "DeflateAlterETAG accepts only 'NoChange', 'AddSuffix', and 'Remove'";
}
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;
}
static const char *deflate_set_inflate_limit(cmd_parms *cmd, void *dirconf,
const char *arg)
{
deflate_dirconf_t *dc = (deflate_dirconf_t*) dirconf;
char *errp;
if (APR_SUCCESS != apr_strtoff(&dc->inflate_limit, arg, &errp, 10)) {
return "DeflateInflateLimitRequestBody is not parsable.";
}
if (*errp || dc->inflate_limit < 0) {
return "DeflateInflateLimitRequestBody requires a non-negative integer.";
}
return NULL;
}
static const char *deflate_set_inflate_ratio_limit(cmd_parms *cmd,
void *dirconf,
const char *arg)
{
deflate_dirconf_t *dc = (deflate_dirconf_t*) dirconf;
int i;
i = atoi(arg);
if (i <= 0)
return "DeflateInflateRatioLimit must be positive";
dc->ratio_limit = i;
return NULL;
}
static const char *deflate_set_inflate_ratio_burst(cmd_parms *cmd,
void *dirconf,
const char *arg)
{
deflate_dirconf_t *dc = (deflate_dirconf_t*) dirconf;
int i;
i = atoi(arg);
if (i <= 0)
return "DeflateInflateRatioBurst must be positive";
dc->ratio_burst = 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;
char header[10]; /* sizeof(gzip_header) */
apr_size_t header_len;
int zlib_flags;
int ratio_hits;
apr_off_t inflate_total;
unsigned int consume_pos,
consume_len;
unsigned int filter_init:1;
unsigned int done:1;
} 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 void consume_buffer(deflate_ctx *ctx, deflate_filter_config *c,
int len, int crc, apr_bucket_brigade *bb)
{
apr_bucket *b;
/*
* 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, len);
}
b = apr_bucket_heap_create((char *)ctx->buffer, len, NULL,
bb->bucket_alloc);
APR_BRIGADE_INSERT_TAIL(bb, b);
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
}
static int flush_libz_buffer(deflate_ctx *ctx, deflate_filter_config *c,
int (*libz_func)(z_streamp, int), int flush,
int crc)
{
int zRC = Z_OK;
int done = 0;
int deflate_len;
for (;;) {
deflate_len = c->bufferSize - ctx->stream.avail_out;
if (deflate_len > 0) {
consume_buffer(ctx, c, deflate_len, crc, ctx->bb);
}
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;
}
/* ETag must be unique among the possible representations, so a change
* to content-encoding requires a corresponding change to the ETag.
* This routine appends -transform (e.g., -gzip) to the entity-tag
* value inside the double-quotes if an ETag has already been set
* and its value already contains double-quotes. PR 39727
*/
static void deflate_check_etag(request_rec *r, const char *transform, int etag_opt)
{
const char *etag = apr_table_get(r->headers_out, "ETag");
apr_size_t etaglen;
if (etag_opt == AP_DEFLATE_ETAG_REMOVE) {
apr_table_unset(r->headers_out, "ETag");
return;
}
if ((etag && ((etaglen = strlen(etag)) > 2))) {
if (etag[etaglen - 1] == '"') {
apr_size_t transformlen = strlen(transform);
char *newtag = apr_palloc(r->pool, etaglen + transformlen + 2);
char *d = newtag;
char *e = d + etaglen - 1;
const char *s = etag;
for (; d < e; ++d, ++s) {
*d = *s; /* copy etag to newtag up to last quote */
}
*d++ = '-'; /* append dash to newtag */
s = transform;
e = d + transformlen;
for (; d < e; ++d, ++s) {
*d = *s; /* copy transform to newtag */
}
*d++ = '"'; /* append quote to newtag */
*d = '\0'; /* null terminate newtag */
apr_table_setn(r->headers_out, "ETag", newtag);
}
}
}
/* Check whether the (inflate) ratio exceeds the configured limit/burst. */
static int check_ratio(request_rec *r, deflate_ctx *ctx,
const deflate_dirconf_t *dc)
{
if (ctx->stream.total_in) {
int ratio = ctx->stream.total_out / ctx->stream.total_in;
if (ratio < dc->ratio_limit) {
ctx->ratio_hits = 0;
}
else if (++ctx->ratio_hits > dc->ratio_burst) {
return 0;
}
}
return 1;
}
static int have_ssl_compression(request_rec *r)
{
const char *comp;
if (mod_deflate_ssl_var == NULL)
return 0;
comp = mod_deflate_ssl_var(r->pool, r->server, r->connection, r,
"SSL_COMPRESS_METHOD");
if (comp == NULL || *comp == '\0' || strcmp(comp, "NULL") == 0)
return 0;
return 1;
}
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;
apr_status_t rv;
apr_size_t len = 0, blen;
const char *data;
deflate_filter_config *c;
/* Do nothing if asked to filter nothing. */
if (APR_BRIGADE_EMPTY(bb)) {
return APR_SUCCESS;
}
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;
if (have_ssl_compression(r)) {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Compression enabled at SSL level; not compressing "
"at HTTP level.");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* We have checked above that bb is not empty */
e = APR_BRIGADE_LAST(bb);
if (APR_BUCKET_IS_EOS(e)) {
/*
* If we already know the size of the response, we can skip
* compression on responses smaller than the compression overhead.
* However, if we compress, we must initialize deflate_out before
* calling ap_pass_brigade() for the first time. Otherwise the
* headers will be sent to the client without
* "Content-Encoding: gzip".
*/
e = APR_BRIGADE_FIRST(bb);
while (1) {
apr_status_t rc;
if (APR_BUCKET_IS_EOS(e)) {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Not compressing very small response of %"
APR_SIZE_T_FMT " bytes", len);
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
if (APR_BUCKET_IS_METADATA(e)) {
e = APR_BUCKET_NEXT(e);
continue;
}
rc = apr_bucket_read(e, &data, &blen, APR_BLOCK_READ);
if (rc != APR_SUCCESS)
return rc;
len += blen;
/* 50 is for Content-Encoding and Vary headers and ETag suffix */
if (len > sizeof(gzip_header) + VALIDATION_SIZE + 50)
break;
e = APR_BUCKET_NEXT(e);
}
}
ctx = f->ctx = apr_pcalloc(r->pool, sizeof(*ctx));
/*
* Only work on main request, not subrequests,
* that are not a 204 response with no content
* and are not tagged with the no-gzip env variable
* and not a partial response to a Range request.
*/
if ((r->main != NULL) || (r->status == HTTP_NO_CONTENT) ||
apr_table_get(r->subprocess_env, "no-gzip") ||
apr_table_get(r->headers_out, "Content-Range")
) {
if (APLOG_R_IS_LEVEL(r, APLOG_TRACE1)) {
const char *reason =
(r->main != NULL) ? "subrequest" :
(r->status == HTTP_NO_CONTENT) ? "no content" :
apr_table_get(r->subprocess_env, "no-gzip") ? "no-gzip" :
"content-range";
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Not compressing (%s)", reason);
}
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_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Not compressing, (gzip-only-text/html)");
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_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Not compressing (content-encoding already "
" set: %s)", token);
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] && ap_cstr_casecmp(token, "gzip")) {
/* skip parameters, XXX: ;q=foo evaluation? */
while (*accepts == ';') {
++accepts;
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_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Not compressing (no Accept-Encoding: gzip)");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
}
else {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Forcing compression (force-gzip set)");
}
/* At this point we have decided to filter the content. Let's try to
* to initialize zlib (except for 304 responses, where we will only
* send out the headers).
*/
if (r->status != HTTP_NOT_MODIFIED) {
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, APLOGNO(01383)
"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);
/* Set the filter init flag so subsequent invocations know we are
* active.
*/
ctx->filter_init = 1;
}
/*
* Zlib initialization worked, so we can now change the important
* content metadata before sending the response out.
*/
/* If the entire Content-Encoding is "identity", we can replace it. */
if (!encoding || !ap_cstr_casecmp(encoding, "identity")) {
apr_table_setn(r->headers_out, "Content-Encoding", "gzip");
}
else {
apr_table_mergen(r->headers_out, "Content-Encoding", "gzip");
}
/* Fix r->content_encoding if it was set before */
if (r->content_encoding) {
r->content_encoding = apr_table_get(r->headers_out,
"Content-Encoding");
}
apr_table_unset(r->headers_out, "Content-Length");
apr_table_unset(r->headers_out, "Content-MD5");
if (c->etag_opt != AP_DEFLATE_ETAG_NOCHANGE) {
deflate_check_etag(r, "gzip", c->etag_opt);
}
/* For a 304 response, only change the headers */
if (r->status == HTTP_NOT_MODIFIED) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/* 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);
/* initialize deflate output buffer */
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
} else if (!ctx->filter_init) {
/* Hmm. We've run through the filter init before as we have a ctx,
* but we never initialized. We probably have a dangling ref. Bail.
*/
return ap_pass_brigade(f->next, bb);
}
while (!APR_BRIGADE_EMPTY(bb))
{
apr_bucket *b;
/*
* Optimization: If we are a HEAD request and bytes_sent is not zero
* it means that we have passed the content-length filter once and
* have more data to sent. This means that the content-length filter
* could not determine our content-length for the response to the
* HEAD request anyway (the associated GET request would deliver the
* body in chunked encoding) and we can stop compressing.
*/
if (r->header_only && r->bytes_sent) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
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, 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, APLOGNO(01384)
"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.
*/
rv = ap_pass_brigade(f->next, ctx->bb);
apr_brigade_cleanup(ctx->bb);
return rv;
}
if (APR_BUCKET_IS_FLUSH(e)) {
/* flush the remaining data from the zlib buffers */
zRC = flush_libz_buffer(ctx, c, deflate, Z_SYNC_FLUSH,
NO_UPDATE_CRC);
if (zRC != Z_OK) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01385)
"Zlib error %d flushing zlib output buffer (%s)",
zRC, ctx->stream.msg);
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);
apr_brigade_cleanup(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);
if (!len) {
apr_bucket_delete(e);
continue;
}
if (len > APR_INT32_MAX) {
apr_bucket_split(e, APR_INT32_MAX);
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 = (int)len;
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
consume_buffer(ctx, c, c->bufferSize, NO_UPDATE_CRC, ctx->bb);
/* Send what we have right now to the next filter. */
rv = ap_pass_brigade(f->next, ctx->bb);
apr_brigade_cleanup(ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
}
zRC = deflate(&(ctx->stream), Z_NO_FLUSH);
if (zRC != Z_OK) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01386)
"Zlib error %d deflating data (%s)", zRC,
ctx->stream.msg);
return APR_EGENERAL;
}
}
apr_bucket_delete(e);
}
return APR_SUCCESS;
}
static apr_status_t consume_zlib_flags(deflate_ctx *ctx,
const char **data, apr_size_t *len)
{
if ((ctx->zlib_flags & EXTRA_FIELD)) {
/* Consume 2 bytes length prefixed data. */
if (ctx->consume_pos == 0) {
if (!*len) {
return APR_INCOMPLETE;
}
ctx->consume_len = (unsigned int)**data;
ctx->consume_pos++;
++*data;
--*len;
}
if (ctx->consume_pos == 1) {
if (!*len) {
return APR_INCOMPLETE;
}
ctx->consume_len += ((unsigned int)**data) << 8;
ctx->consume_pos++;
++*data;
--*len;
}
if (*len < ctx->consume_len) {
ctx->consume_len -= *len;
*len = 0;
return APR_INCOMPLETE;
}
*data += ctx->consume_len;
*len -= ctx->consume_len;
ctx->consume_len = ctx->consume_pos = 0;
ctx->zlib_flags &= ~EXTRA_FIELD;
}
if ((ctx->zlib_flags & ORIG_NAME)) {
/* Consume nul terminated string. */
while (*len && **data) {
++*data;
--*len;
}
if (!*len) {
return APR_INCOMPLETE;
}
/* .. and nul. */
++*data;
--*len;
ctx->zlib_flags &= ~ORIG_NAME;
}
if ((ctx->zlib_flags & COMMENT)) {
/* Consume nul terminated string. */
while (*len && **data) {
++*data;
--*len;
}
if (!*len) {
return APR_INCOMPLETE;
}
/* .. and nul. */
++*data;
--*len;
ctx->zlib_flags &= ~COMMENT;
}
if ((ctx->zlib_flags & HEAD_CRC)) {
/* Consume CRC16 (2 octets). */
if (ctx->consume_pos == 0) {
if (!*len) {
return APR_INCOMPLETE;
}
ctx->consume_pos++;
++*data;
--*len;
}
if (!*len) {
return APR_INCOMPLETE;
}
++*data;
--*len;
ctx->consume_pos = 0;
ctx->zlib_flags &= ~HEAD_CRC;
}
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;
deflate_dirconf_t *dc;
apr_off_t inflate_limit;
/* 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);
dc = ap_get_module_config(r->per_dir_config, &deflate_module);
if (!ctx || ctx->header_len < sizeof(ctx->header)) {
apr_size_t len;
if (!ctx) {
/* 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);
}
do {
apr_brigade_cleanup(ctx->bb);
len = sizeof(ctx->header) - ctx->header_len;
rv = ap_get_brigade(f->next, ctx->bb, AP_MODE_READBYTES, block,
len);
/* ap_get_brigade may return success with an empty brigade for
* a non-blocking read which would block (an empty brigade for
* a blocking read is an issue which is simply forwarded here).
*/
if (rv != APR_SUCCESS || APR_BRIGADE_EMPTY(ctx->bb)) {
return rv;
}
/* zero length body? step aside */
bkt = APR_BRIGADE_FIRST(ctx->bb);
if (APR_BUCKET_IS_EOS(bkt)) {
if (ctx->header_len) {
/* If the header was (partially) read it's an error, this
* is not a gzip Content-Encoding, as claimed.
*/
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02619)
"Encountered premature end-of-stream while "
"reading inflate header");
return APR_EGENERAL;
}
APR_BUCKET_REMOVE(bkt);
APR_BRIGADE_INSERT_TAIL(bb, bkt);
ap_remove_input_filter(f);
return APR_SUCCESS;
}
rv = apr_brigade_flatten(ctx->bb,
ctx->header + ctx->header_len, &len);
if (rv != APR_SUCCESS) {
return rv;
}
if (len && !ctx->header_len) {
apr_table_unset(r->headers_in, "Content-Length");
apr_table_unset(r->headers_in, "Content-MD5");
}
ctx->header_len += len;
} while (ctx->header_len < sizeof(ctx->header));
/* We didn't get the magic bytes. */
if (ctx->header[0] != deflate_magic[0] ||
ctx->header[1] != deflate_magic[1]) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01387)
"Zlib: Invalid header");
return APR_EGENERAL;
}
ctx->zlib_flags = ctx->header[3];
if ((ctx->zlib_flags & RESERVED)) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01388)
"Zlib: Invalid flags %02x", ctx->zlib_flags);
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, APLOGNO(01389)
"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);
}
inflate_limit = dc->inflate_limit;
if (inflate_limit == 0) {
/* The core is checking the deflated body, we'll check the inflated */
inflate_limit = ap_get_limit_req_body(f->r);
}
if (APR_BRIGADE_EMPTY(ctx->proc_bb)) {
rv = ap_get_brigade(f->next, ctx->bb, mode, block, readbytes);
/* Don't terminate on EAGAIN (or success with an empty brigade in
* non-blocking mode), just return focus.
*/
if (block == APR_NONBLOCK_READ
&& (APR_STATUS_IS_EAGAIN(rv)
|| (rv == APR_SUCCESS && APR_BRIGADE_EMPTY(ctx->bb)))) {
return rv;
}
if (rv != APR_SUCCESS) {
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 (APR_BUCKET_IS_EOS(bkt)) {
if (!ctx->done) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02481)
"Encountered premature end-of-stream while inflating");
return APR_EGENERAL;
}
/* Move everything to the returning brigade. */
APR_BUCKET_REMOVE(bkt);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, bkt);
break;
}
if (APR_BUCKET_IS_FLUSH(bkt)) {
apr_bucket *tmp_b;
ctx->inflate_total += ctx->stream.avail_out;
zRC = inflate(&(ctx->stream), Z_SYNC_FLUSH);
ctx->inflate_total -= ctx->stream.avail_out;
if (zRC != Z_OK) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01391)
"Zlib error %d inflating data (%s)", zRC,
ctx->stream.msg);
return APR_EGENERAL;
}
if (inflate_limit && ctx->inflate_total > inflate_limit) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02647)
"Inflated content length of %" APR_OFF_T_FMT
" is larger than the configured limit"
" of %" APR_OFF_T_FMT,
ctx->inflate_total, inflate_limit);
return APR_ENOSPC;
}
if (!check_ratio(r, ctx, dc)) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02805)
"Inflated content ratio is larger than the "
"configured limit %i by %i time(s)",
dc->ratio_limit, dc->ratio_burst);
return APR_EINVAL;
}
consume_buffer(ctx, c, c->bufferSize - ctx->stream.avail_out,
UPDATE_CRC, ctx->proc_bb);
/* Flush everything so far in the returning brigade, but continue
* reading should EOS/more follow (don't lose them).
*/
tmp_b = APR_BUCKET_PREV(bkt);
APR_BUCKET_REMOVE(bkt);
APR_BRIGADE_INSERT_TAIL(ctx->proc_bb, bkt);
bkt = tmp_b;
continue;
}
/* sanity check - data after completed compressed body and before eos? */
if (ctx->done) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02482)
"Encountered extra data after compressed data");
return APR_EGENERAL;
}
/* read */
apr_bucket_read(bkt, &data, &len, APR_BLOCK_READ);
if (!len) {
continue;
}
if (len > APR_INT32_MAX) {
apr_bucket_split(bkt, APR_INT32_MAX);
apr_bucket_read(bkt, &data, &len, APR_BLOCK_READ);
}
if (ctx->zlib_flags) {
rv = consume_zlib_flags(ctx, &data, &len);
if (rv == APR_SUCCESS) {
ctx->zlib_flags = 0;
}
if (!len) {
continue;
}
}
/* pass through zlib inflate. */
ctx->stream.next_in = (unsigned char *)data;
ctx->stream.avail_in = (int)len;
zRC = Z_OK;
if (!ctx->validation_buffer) {
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
consume_buffer(ctx, c, c->bufferSize, UPDATE_CRC,
ctx->proc_bb);
}
ctx->inflate_total += ctx->stream.avail_out;
zRC = inflate(&ctx->stream, Z_NO_FLUSH);
ctx->inflate_total -= ctx->stream.avail_out;
if (zRC != Z_OK && zRC != Z_STREAM_END) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01392)
"Zlib error %d inflating data (%s)", zRC,
ctx->stream.msg);
return APR_EGENERAL;
}
if (inflate_limit && ctx->inflate_total > inflate_limit) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02648)
"Inflated content length of %" APR_OFF_T_FMT
" is larger than the configured limit"
" of %" APR_OFF_T_FMT,
ctx->inflate_total, inflate_limit);
return APR_ENOSPC;
}
if (!check_ratio(r, ctx, dc)) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02649)
"Inflated content ratio is larger than the "
"configured limit %i by %i time(s)",
dc->ratio_limit, dc->ratio_burst);
return APR_EINVAL;
}
if (zRC == Z_STREAM_END) {
ctx->validation_buffer = apr_pcalloc(r->pool,
VALIDATION_SIZE);
ctx->validation_buffer_length = 0;
break;
}
}
}
if (ctx->validation_buffer) {
apr_size_t avail, valid;
unsigned char *buf = ctx->validation_buffer;
avail = ctx->stream.avail_in;
valid = (apr_size_t)VALIDATION_SIZE -
ctx->validation_buffer_length;
/*
* 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.
*/
if (avail < valid) {
memcpy(buf + ctx->validation_buffer_length,
ctx->stream.next_in, avail);
ctx->validation_buffer_length += avail;
continue;
}
memcpy(buf + ctx->validation_buffer_length,
ctx->stream.next_in, valid);
ctx->validation_buffer_length += valid;
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01393)
"Zlib: Inflated %ld to %ld : URL %s",
ctx->stream.total_in, ctx->stream.total_out,
r->uri);
consume_buffer(ctx, c, c->bufferSize - ctx->stream.avail_out,
UPDATE_CRC, ctx->proc_bb);
{
unsigned long compCRC, compLen;
compCRC = getLong(buf);
if (ctx->crc != compCRC) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01394)
"Zlib: CRC error inflating data");
return APR_EGENERAL;
}
compLen = getLong(buf + VALIDATION_SIZE / 2);
/* gzip stores original size only as 4 byte value */
if ((ctx->stream.total_out & 0xFFFFFFFF) != compLen) {
inflateEnd(&ctx->stream);
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01395)
"Zlib: Length %ld of inflated data does "
"not match expected value %ld",
ctx->stream.total_out, compLen);
return APR_EGENERAL;
}
}
inflateEnd(&ctx->stream);
ctx->done = 1;
/* Did we have trailing data behind the closing 8 bytes? */
if (avail > valid) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02485)
"Encountered extra data after compressed data");
return APR_EGENERAL;
}
}
}
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) {
consume_buffer(ctx, c, c->bufferSize - ctx->stream.avail_out,
UPDATE_CRC, ctx->proc_bb);
}
if (!APR_BRIGADE_EMPTY(ctx->proc_bb)) {
if (apr_brigade_partition(ctx->proc_bb, readbytes, &bkt) == APR_INCOMPLETE) {
APR_BRIGADE_CONCAT(bb, ctx->proc_bb);
}
else {
APR_BRIGADE_CONCAT(bb, ctx->proc_bb);
apr_brigade_split_ex(bb, bkt, ctx->proc_bb);
}
if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(bb))) {
ap_remove_input_filter(f);
}
}
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)
{
apr_bucket *e;
request_rec *r = f->r;
deflate_ctx *ctx = f->ctx;
int zRC;
apr_status_t rv;
deflate_filter_config *c;
deflate_dirconf_t *dc;
/* Do nothing if asked to filter nothing. */
if (APR_BRIGADE_EMPTY(bb)) {
return APR_SUCCESS;
}
c = ap_get_module_config(r->server->module_config, &deflate_module);
dc = ap_get_module_config(r->per_dir_config, &deflate_module);
if (!ctx) {
/*
* Only work on main request, not subrequests,
* that are not a 204 response with no content
* and not a partial response to a Range request,
* and only when Content-Encoding ends in gzip.
*/
if (!ap_is_initial_req(r) || (r->status == HTTP_NO_CONTENT) ||
(apr_table_get(r->headers_out, "Content-Range") != NULL) ||
(check_gzip(r, r->headers_out, r->err_headers_out) == 0)
) {
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
/*
* At this point we have decided to filter the content, so change
* important content metadata before sending any response out.
* Content-Encoding was already reset by the check_gzip() call.
*/
apr_table_unset(r->headers_out, "Content-Length");
apr_table_unset(r->headers_out, "Content-MD5");
if (c->etag_opt != AP_DEFLATE_ETAG_NOCHANGE) {
deflate_check_etag(r, "gunzip", c->etag_opt);
}
/* For a 304 response, only change the headers */
if (r->status == HTTP_NOT_MODIFIED) {
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, APLOGNO(01397)
"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);
/* initialize inflate output buffer */
ctx->stream.next_out = ctx->buffer;
ctx->stream.avail_out = c->bufferSize;
}
while (!APR_BRIGADE_EMPTY(bb))
{
const char *data;
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, inflate, Z_SYNC_FLUSH, UPDATE_CRC);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01398)
"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, APLOGNO(01399)
"Zlib: Checksum of inflated stream invalid");
return APR_EGENERAL;
}
ctx->validation_buffer += VALIDATION_SIZE / 2;
compLen = getLong(ctx->validation_buffer);
/* gzip stores original size only as 4 byte value */
if ((ctx->stream.total_out & 0xFFFFFFFF) != compLen) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01400)
"Zlib: Length of inflated stream invalid");
return APR_EGENERAL;
}
}
else {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01401)
"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.
*/
rv = ap_pass_brigade(f->next, ctx->bb);
apr_brigade_cleanup(ctx->bb);
return rv;
}
if (APR_BUCKET_IS_FLUSH(e)) {
/* flush the remaining data from the zlib buffers */
zRC = flush_libz_buffer(ctx, c, inflate, Z_SYNC_FLUSH, UPDATE_CRC);
if (zRC == Z_STREAM_END) {
if (ctx->validation_buffer == NULL) {
ctx->validation_buffer = apr_pcalloc(f->r->pool,
VALIDATION_SIZE);
}
}
else if (zRC != Z_OK) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01402)
"Zlib error %d flushing inflate buffer (%s)",
zRC, ctx->stream.msg);
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);
apr_brigade_cleanup(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);
if (!len) {
apr_bucket_delete(e);
continue;
}
if (len > APR_INT32_MAX) {
apr_bucket_split(e, APR_INT32_MAX);
apr_bucket_read(e, &data, &len, APR_BLOCK_READ);
}
/* first bucket contains zlib header */
if (ctx->header_len < sizeof(ctx->header)) {
apr_size_t rem;
rem = sizeof(ctx->header) - ctx->header_len;
if (len < rem) {
memcpy(ctx->header + ctx->header_len, data, len);
ctx->header_len += len;
apr_bucket_delete(e);
continue;
}
memcpy(ctx->header + ctx->header_len, data, rem);
ctx->header_len += rem;
{
int zlib_method;
zlib_method = ctx->header[2];
if (zlib_method != Z_DEFLATED) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01404)
"inflate: data not deflated!");
ap_remove_output_filter(f);
return ap_pass_brigade(f->next, bb);
}
if (ctx->header[0] != deflate_magic[0] ||
ctx->header[1] != deflate_magic[1]) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01405)
"inflate: bad header");
return APR_EGENERAL ;
}
ctx->zlib_flags = ctx->header[3];
if ((ctx->zlib_flags & RESERVED)) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02620)
"inflate: bad flags %02x",
ctx->zlib_flags);
return APR_EGENERAL;
}
}
if (len == rem) {
apr_bucket_delete(e);
continue;
}
data += rem;
len -= rem;
}
if (ctx->zlib_flags) {
rv = consume_zlib_flags(ctx, &data, &len);
if (rv == APR_SUCCESS) {
ctx->zlib_flags = 0;
}
if (!len) {
apr_bucket_delete(e);
continue;
}
}
/* 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, APLOGNO(01407)
"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;
}
}
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
consume_buffer(ctx, c, c->bufferSize, UPDATE_CRC, ctx->bb);
/* Send what we have right now to the next filter. */
rv = ap_pass_brigade(f->next, ctx->bb);
apr_brigade_cleanup(ctx->bb);
if (rv != APR_SUCCESS) {
return rv;
}
}
zRC = inflate(&ctx->stream, Z_NO_FLUSH);
if (zRC != Z_OK && zRC != Z_STREAM_END) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01409)
"Zlib error %d inflating data (%s)", zRC,
ctx->stream.msg);
return APR_EGENERAL;
}
/* Don't check length limits on inflate_out */
if (!check_ratio(r, ctx, dc)) {
ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(02650)
"Inflated content ratio is larger than the "
"configured limit %i by %i time(s)",
dc->ratio_limit, dc->ratio_burst);
return APR_EINVAL;
}
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, APLOGNO(01408)
"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;
}
}
apr_bucket_delete(e);
}
return APR_SUCCESS;
}
static int mod_deflate_post_config(apr_pool_t *pconf, apr_pool_t *plog,
apr_pool_t *ptemp, server_rec *s)
{
mod_deflate_ssl_var = APR_RETRIEVE_OPTIONAL_FN(ssl_var_lookup);
return OK;
}
#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);
ap_hook_post_config(mod_deflate_post_config, NULL, NULL, APR_HOOK_MIDDLE);
}
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)"),
AP_INIT_TAKE1("DeflateAlterEtag", deflate_set_etag, NULL, RSRC_CONF,
"Set how mod_deflate should modify ETAG response headers: 'AddSuffix' (default), 'NoChange' (2.2.x behavior), 'Remove'"),
AP_INIT_TAKE1("DeflateInflateLimitRequestBody", deflate_set_inflate_limit, NULL, OR_ALL,
"Set a limit on size of inflated input"),
AP_INIT_TAKE1("DeflateInflateRatioLimit", deflate_set_inflate_ratio_limit, NULL, OR_ALL,
"Set the inflate ratio limit above which inflation is "
"aborted (default: " APR_STRINGIFY(AP_INFLATE_RATIO_LIMIT) ")"),
AP_INIT_TAKE1("DeflateInflateRatioBurst", deflate_set_inflate_ratio_burst, NULL, OR_ALL,
"Set the maximum number of following inflate ratios above limit "
"(default: " APR_STRINGIFY(AP_INFLATE_RATIO_BURST) ")"),
{NULL}
};
/* zlib can be built with #define deflate z_deflate */
#ifdef deflate
#undef deflate
#endif
AP_DECLARE_MODULE(deflate) = {
STANDARD20_MODULE_STUFF,
create_deflate_dirconf, /* 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 */
};