add MaxRanges directive institute a default limit of 200 (post-merge …

…where

applicable) Ranges before returning the complete resource.

(minor mmn bump for core_dir_config addition)



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1162584 13f79535-47bb-0310-9956-ffa450edef68

CHANGES

@@ -1,6 +1,10 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.3.15
 
+  *) core: Add MaxRanges directive to control the number of ranges permitted
+     before returning the entire resource, with a default limit of 200. 
+     [Eric Covener]
+
   *) mod_cache: Ensure that CacheDisable can correctly appear within
      a LocationMatch. [Graham Leggett]
 

include/ap_mmn.h

@@ -348,14 +348,15 @@
  * 20110724.1 (2.3.15-dev) add NOT_IN_HTACCESS
  * 20110724.2 (2.3.15-dev) retries and retry_delay in util_ldap_state_t
  * 20110724.3 (2.3.15-dev) add util_varbuf.h / ap_varbuf API
+ * 20110724.4 (2.3.15-dev) add max_ranges to core_dir_config
  */
 
 #define MODULE_MAGIC_COOKIE 0x41503234UL /* "AP24" */
 
 #ifndef MODULE_MAGIC_NUMBER_MAJOR
 #define MODULE_MAGIC_NUMBER_MAJOR 20110724
 #endif
-#define MODULE_MAGIC_NUMBER_MINOR 3                    /* 0...n */
+#define MODULE_MAGIC_NUMBER_MINOR 4                    /* 0...n */
 
 /**
  * Determine if the server's current MODULE_MAGIC_NUMBER is at least a

include/http_core.h

@@ -605,6 +605,9 @@ typedef struct {
     /** Table of directives allowed per AllowOverrideList */
     apr_table_t *override_list;
 
+    /** Number of Ranges before returning HTTP_OK, 0/unlimited -1/unset. **/
+    int max_ranges;
+
 } core_dir_config;
 
 /* macro to implement off by default behaviour */

modules/http/byterange_filter.c

@@ -59,6 +59,10 @@
 #include <unistd.h>
 #endif
 
+#ifndef DEFAULT_MAX_RANGES
+#define DEFAULT_MAX_RANGES 200
+#endif
+
 APLOG_USE_MODULE(http);
 
 static int ap_set_byterange(request_rec *r, apr_off_t clength,
@@ -255,6 +259,11 @@ typedef struct indexes_t {
     apr_off_t end;
 } indexes_t;
 
+static int get_max_ranges(request_rec *r) { 
+    core_dir_config *core_conf = ap_get_core_module_config(r->per_dir_config);
+    return core_conf->max_ranges == -1 ? DEFAULT_MAX_RANGES : core_conf->max_ranges;
+}
+
 AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
                                                          apr_bucket_brigade *bb)
 {
@@ -274,6 +283,8 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
     apr_array_header_t *indexes;
     indexes_t *idx;
     int i;
+    int original_status;
+    int max_ranges = get_max_ranges(r);
 
     /*
      * Iterate through the brigade until reaching EOS or a bucket with
@@ -297,10 +308,12 @@ AP_CORE_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f,
         return ap_pass_brigade(f->next, bb);
     }
 
+    original_status = r->status;
     num_ranges = ap_set_byterange(r, clength, &indexes);
 
     /* We have nothing to do, get out of the way. */
-    if (num_ranges == 0) {
+    if (num_ranges == 0 || (max_ranges > 0 && num_ranges > max_ranges)) {
+        r->status = original_status;
         ap_remove_output_filter(f);
         return ap_pass_brigade(f->next, bb);
     }

server/core.c

@@ -178,6 +178,8 @@ static void *create_core_dir_config(apr_pool_t *a, char *dir)
     conf->enable_sendfile = ENABLE_SENDFILE_UNSET;
     conf->allow_encoded_slashes = 0;
     conf->decode_encoded_slashes = 0;
+
+    conf->max_ranges = -1;
 
     return (void *)conf;
 }
@@ -397,6 +399,8 @@ static void *merge_core_dir_configs(apr_pool_t *a, void *basev, void *newv)
         }
     }
 
+    conf->max_ranges = new->max_ranges != -1 ? new->max_ranges : base->max_ranges;
+
     return (void*)conf;
 }
 
@@ -3260,6 +3264,16 @@ static const char *set_limit_xml_req_body(cmd_parms *cmd, void *conf_,
     return NULL;
 }
 
+static const char *set_max_ranges(cmd_parms *cmd, void *conf_, const char *arg)
+{
+    core_dir_config *conf = conf_;
+
+    conf->max_ranges = atoi(arg);
+    if (conf->max_ranges < 0)
+        return "MaxRanges requires a non-negative integer (0 = unlimited)";
+
+    return NULL;
+}
 AP_DECLARE(size_t) ap_get_limit_xml_body(const request_rec *r)
 {
     core_dir_config *conf;
@@ -3876,6 +3890,9 @@ AP_INIT_TAKE1("LimitXMLRequestBody", set_limit_xml_req_body, NULL, OR_ALL,
 AP_INIT_RAW_ARGS("Mutex", ap_set_mutex, NULL, RSRC_CONF,
                  "mutex (or \"default\") and mechanism"),
 
+AP_INIT_TAKE1("MaxRanges", set_max_ranges, NULL, RSRC_CONF|ACCESS_CONF,
+              "Maximum number of Ranges in a request before returning the entire "
+              "resource, or 0 for unlimited"),
 /* System Resource Controls */
 #ifdef RLIMIT_CPU
 AP_INIT_TAKE12("RLimitCPU", set_limit_cpu,