feature: allow use of ngx.exit() in the context of body_filter_by_lua

README.markdown

@@ -5460,7 +5460,7 @@ ngx.exit
 
 **syntax:** *ngx.exit(status)*
 
-**context:** *rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, ngx.timer.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**
+**context:** *rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, ngx.timer.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua**
 
 When `status >= 200` (i.e., `ngx.HTTP_OK` and above), it will interrupt the execution of the current request and return status code to Nginx.
 
@@ -5505,7 +5505,7 @@ Note that while this method accepts all [HTTP status constants](#http-status-con
 
 Also note that this method call terminates the processing of the current request and that it is recommended that a coding style that combines this method call with the `return` statement, i.e., `return ngx.exit(...)` be used to reinforce the fact that the request processing is being terminated.
 
-When being used in the contexts of [header_filter_by_lua*](#header_filter_by_lua), [balancer_by_lua*](#balancer_by_lua_block), and
+When being used in the contexts of [header_filter_by_lua*](#header_filter_by_lua), [body_filter_by_lua*](#body_filter_by_lua_block), [balancer_by_lua*](#balancer_by_lua_block), and
 [ssl_session_store_by_lua*](#ssl_session_store_by_lua_block), `ngx.exit()` is
 an asynchronous operation and will return immediately. This behavior may change in future and it is recommended that users always use `return` in combination as suggested above.
 

doc/HttpLuaModule.wiki

@@ -4579,7 +4579,7 @@ Since <code>v0.8.3</code> this function returns <code>1</code> on success, or re
 
 '''syntax:''' ''ngx.exit(status)''
 
-'''context:''' ''rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, ngx.timer.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''
+'''context:''' ''rewrite_by_lua*, access_by_lua*, content_by_lua*, header_filter_by_lua*, body_filter_by_lua*, ngx.timer.*, balancer_by_lua*, ssl_certificate_by_lua*, ssl_session_fetch_by_lua*, ssl_session_store_by_lua*''
 
 When <code>status >= 200</code> (i.e., <code>ngx.HTTP_OK</code> and above), it will interrupt the execution of the current request and return status code to Nginx.
 
@@ -4621,7 +4621,7 @@ Note that while this method accepts all [[#HTTP status constants|HTTP status con
 
 Also note that this method call terminates the processing of the current request and that it is recommended that a coding style that combines this method call with the <code>return</code> statement, i.e., <code>return ngx.exit(...)</code> be used to reinforce the fact that the request processing is being terminated.
 
-When being used in the contexts of [[#header_filter_by_lua|header_filter_by_lua*]], [[#balancer_by_lua_block|balancer_by_lua*]], and
+When being used in the contexts of [[#header_filter_by_lua|header_filter_by_lua*]], [[#body_filter_by_lua_block|body_filter_by_lua*]], [[#balancer_by_lua_block|balancer_by_lua*]], and
 [[#ssl_session_store_by_lua_block|ssl_session_store_by_lua*]], <code>ngx.exit()</code> is
 an asynchronous operation and will return immediately. This behavior may change in future and it is recommended that users always use <code>return</code> in combination as suggested above.
 

src/ngx_http_lua_bodyfilterby.c

@@ -82,12 +82,15 @@ ngx_int_t
 ngx_http_lua_body_filter_by_chunk(lua_State *L, ngx_http_request_t *r,
     ngx_chain_t *in)
 {
-    ngx_int_t        rc;
-    u_char          *err_msg;
-    size_t           len;
+    ngx_int_t                    rc;
+    u_char                      *err_msg;
+    size_t                       len;
 #if (NGX_PCRE)
-    ngx_pool_t      *old_pool;
+    ngx_pool_t                  *old_pool;
 #endif
+    ngx_http_lua_ctx_t          *ctx;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
 
     dd("initialize nginx context in Lua VM, code chunk at stack top  sp = 1");
     ngx_http_lua_body_filter_by_lua_env(L, r, in);
@@ -110,6 +113,8 @@ ngx_http_lua_body_filter_by_chunk(lua_State *L, ngx_http_request_t *r,
     ngx_http_lua_pcre_malloc_done(old_pool);
 #endif
 
+    dd("rc == %d", (int) rc);
+
     if (rc != 0) {
 
         /*  error occurred */
@@ -136,7 +141,10 @@ ngx_http_lua_body_filter_by_chunk(lua_State *L, ngx_http_request_t *r,
 
     lua_settop(L, 0);
 
-    if (rc == NGX_ERROR || rc >= NGX_HTTP_SPECIAL_RESPONSE) {
+    if (ctx->body_filter_aborted
+        || rc == NGX_ERROR
+        || rc >= NGX_HTTP_SPECIAL_RESPONSE)
+    {
         return NGX_ERROR;
     }
 
@@ -166,15 +174,9 @@ ngx_http_lua_body_filter_inline(ngx_http_request_t *r, ngx_chain_t *in)
         return NGX_ERROR;
     }
 
-    rc = ngx_http_lua_body_filter_by_chunk(L, r, in);
-
-    dd("body filter by chunk returns %d", (int) rc);
-
-    if (rc != NGX_OK) {
-        return NGX_ERROR;
-    }
+    dd("calling body filter by chunk");
 
-    return NGX_OK;
+    return ngx_http_lua_body_filter_by_chunk(L, r, in);
 }
 
 
@@ -216,13 +218,7 @@ ngx_http_lua_body_filter_file(ngx_http_request_t *r, ngx_chain_t *in)
     /*  make sure we have a valid code chunk */
     ngx_http_lua_assert(lua_isfunction(L, -1));
 
-    rc = ngx_http_lua_body_filter_by_chunk(L, r, in);
-
-    if (rc != NGX_OK) {
-        return NGX_ERROR;
-    }
-
-    return NGX_OK;
+    return ngx_http_lua_body_filter_by_chunk(L, r, in);
 }
 
 
@@ -262,6 +258,12 @@ ngx_http_lua_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
         }
     }
 
+    if (ctx->body_filter_aborted) {
+        /* maybe there is a bug in the output body filter caller, other
+         * outputs will be intercepted here */
+        return NGX_ERROR;
+    }
+
     if (ctx->seen_last_in_filter) {
         for (/* void */; in; in = in->next) {
             dd("mark the buf as consumed: %d", (int) ngx_buf_size(in->buf));

src/ngx_http_lua_common.h

@@ -559,6 +559,8 @@ typedef struct ngx_http_lua_ctx_s {
 
     unsigned         exited:1;
 
+    unsigned         body_filter_aborted:1;
+
     unsigned         eof:1;             /*  1: last_buf has been sent;
                                             0: last_buf not sent yet */
 

src/ngx_http_lua_control.c

@@ -365,6 +365,7 @@ ngx_http_lua_ffi_exit(ngx_http_request_t *r, int status, u_char *err,
                                        | NGX_HTTP_LUA_CONTEXT_CONTENT
                                        | NGX_HTTP_LUA_CONTEXT_TIMER
                                        | NGX_HTTP_LUA_CONTEXT_HEADER_FILTER
+                                       | NGX_HTTP_LUA_CONTEXT_BODY_FILTER
                                        | NGX_HTTP_LUA_CONTEXT_BALANCER
                                        | NGX_HTTP_LUA_CONTEXT_SSL_CERT
                                        | NGX_HTTP_LUA_CONTEXT_SSL_SESS_STORE
@@ -375,6 +376,19 @@ ngx_http_lua_ffi_exit(ngx_http_request_t *r, int status, u_char *err,
         return NGX_ERROR;
     }
 
+    if (ctx->context & NGX_HTTP_LUA_CONTEXT_BODY_FILTER) {
+
+        if (status != NGX_ERROR && status != NGX_HTTP_CLOSE) {
+            *errlen = ngx_snprintf(err, *errlen, "attempt to exit with the "
+                                   "code not 444 or ngx.ERROR")
+                      - err;
+            return NGX_ERROR;
+        }
+
+        ctx->body_filter_aborted = 1;
+        return NGX_DONE;
+    }
+
     if (ctx->context & (NGX_HTTP_LUA_CONTEXT_SSL_CERT
                         | NGX_HTTP_LUA_CONTEXT_SSL_SESS_STORE
                         | NGX_HTTP_LUA_CONTEXT_SSL_SESS_FETCH))

t/082-body-filter.t

@@ -10,7 +10,7 @@ log_level('debug');
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 3 + 11);
+plan tests => repeat_each() * (blocks() * 3 + 8);
 
 #no_diff();
 no_long_string();
@@ -838,3 +838,46 @@ GET /lua
 --- ignore_response
 --- error_log
 API disabled in the context of body_filter_by_lua*
+
+
+
+=== TEST 27: exit 444
+--- config
+    location = /t {
+        content_by_lua_block {
+            ngx.say("111")
+            ngx.say("222")
+            ngx.say("333")
+        }
+
+        body_filter_by_lua_block {
+            ngx.exit(444)
+        }
+    }
+--- request
+    GET /t
+--- ignore_response
+--- no_error_log
+[error]
+[alert]
+
+
+
+=== TEST 28: exit OK
+--- config
+    location = /t {
+        content_by_lua_block {
+            ngx.say("111")
+            ngx.say("222")
+            ngx.say("333")
+        }
+
+        body_filter_by_lua_block {
+            ngx.exit(200)
+        }
+    }
+--- request
+    GET /t
+--- ignore_response
+--- error_log
+attempt to exit with the code not 444 or ngx.ERROR