Merging r4036, r4055, r4056, r4057, r4058, r4059, r4060, r4061, r4062, r4063, r4064: Ranges related fixes: The "max_ranges" directive. "max_ranges 0" disables ranges support at all, "max_ranges 1" allows the single range, etc. By default number of ranges is unlimited, to be precise, 2^31-1. If client requests more ranges than "max_ranges" permits, nginx disables ranges and returns just the source response. If total size of all ranges is greater than source response size, then nginx disables ranges and returns just the source response. This fix should not affect well-behaving applications but will defeat DoS attempts exploiting malicious byte ranges. Now unsatisfiable ranges are processed according to RFC 2616.

--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -363,6 +363,7 @@ struct ngx_http_core_loc_conf_s {
     ngx_uint_t    satisfy;                 /* satisfy */
     ngx_uint_t    lingering_close;         /* lingering_close */
     ngx_uint_t    if_modified_since;       /* if_modified_since */
+    ngx_uint_t    max_ranges;              /* max_ranges */
     ngx_uint_t    client_body_in_file_only; /* client_body_in_file_only */
 
     ngx_flag_t    client_body_in_single_buffer;