diff --git a/modules/filters/mod_deflate.c b/modules/filters/mod_deflate.c
index 79f6f8d..6c415c8 100644
--- a/modules/filters/mod_deflate.c
+++ b/modules/filters/mod_deflate.c
@@ -37,6 +37,7 @@
#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"
@@ -52,6 +53,9 @@
static const char deflateFilterName[] = "DEFLATE";
module AP_MODULE_DECLARE_DATA deflate_module;
+#define AP_INFLATE_RATIO_LIMIT 200
+#define AP_INFLATE_RATIO_BURST 3
+
typedef struct deflate_filter_config_t
{
int windowSize;
@@ -63,6 +67,12 @@ typedef struct deflate_filter_config_t
char *note_output_name;
} 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:
*
* +---+---+---+---+---+---+---+---+---+---+
@@ -204,6 +214,14 @@ static void *create_deflate_server_config(apr_pool_t *p, server_rec *s)
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)
{
@@ -295,6 +313,55 @@ static const char *deflate_set_compressionlevel(cmd_parms *cmd, void *dummy,
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;
@@ -304,6 +371,8 @@ typedef struct deflate_ctx_t
int (*libz_end_func)(z_streamp);
unsigned char *validation_buffer;
apr_size_t validation_buffer_length;
+ int ratio_hits;
+ apr_off_t inflate_total;
unsigned int inflate_init:1;
unsigned int filter_init:1;
unsigned int done:1;
@@ -422,6 +491,22 @@ static void deflate_check_etag(request_rec *r, const char *transform)
}
}
+/* 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;
@@ -897,6 +982,8 @@ static apr_status_t deflate_in_filter(ap_filter_t *f,
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) {
@@ -904,6 +991,7 @@ static apr_status_t deflate_in_filter(ap_filter_t *f,
}
c = ap_get_module_config(r->server->module_config, &deflate_module);
+ dc = ap_get_module_config(r->per_dir_config, &deflate_module);
if (!ctx) {
char deflate_hdr[10];
@@ -994,6 +1082,12 @@ static apr_status_t deflate_in_filter(ap_filter_t *f,
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);
@@ -1038,6 +1132,17 @@ static apr_status_t deflate_in_filter(ap_filter_t *f,
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
+
+ ctx->inflate_total += len;
+ 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;
+ }
ctx->crc = crc32(ctx->crc, (const Bytef *)ctx->buffer, len);
tmp_heap = apr_bucket_heap_create((char *)ctx->buffer, len,
@@ -1073,6 +1178,26 @@ static apr_status_t deflate_in_filter(ap_filter_t *f,
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
+ ctx->inflate_total += len;
+ 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;
+ }
+
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);
@@ -1193,6 +1318,7 @@ static apr_status_t inflate_out_filter(ap_filter_t *f,
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)) {
@@ -1200,6 +1326,7 @@ static apr_status_t inflate_out_filter(ap_filter_t *f,
}
c = ap_get_module_config(r->server->module_config, &deflate_module);
+ dc = ap_get_module_config(r->per_dir_config, &deflate_module);
if (!ctx) {
@@ -1462,6 +1589,14 @@ static apr_status_t inflate_out_filter(ap_filter_t *f,
while (ctx->stream.avail_in != 0) {
if (ctx->stream.avail_out == 0) {
+ 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;
+ }
+
ctx->stream.next_out = ctx->buffer;
len = c->bufferSize - ctx->stream.avail_out;
@@ -1548,12 +1683,20 @@ static const command_rec deflate_filter_cmds[] = {
"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("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}
};
AP_DECLARE_MODULE(deflate) = {
STANDARD20_MODULE_STUFF,
- NULL, /* dir config creater */
+ create_deflate_dirconf, /* dir config creater */
NULL, /* dir merger --- default is to override */
create_deflate_server_config, /* server config */
NULL, /* merge server config */