feature: allow use of ngx.exit() in the context of header_filter_by_lua*. but in this context ngx.exit() returns immediately.

Author: agentzh

src/ngx_http_lua_control.c

@@ -303,7 +303,8 @@ ngx_http_lua_ngx_exit(lua_State *L)
     ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                                | NGX_HTTP_LUA_CONTEXT_ACCESS
                                | NGX_HTTP_LUA_CONTEXT_CONTENT
-                               | NGX_HTTP_LUA_CONTEXT_TIMER);
+                               | NGX_HTTP_LUA_CONTEXT_TIMER
+                               | NGX_HTTP_LUA_CONTEXT_HEADER_FILTER);
 
     rc = (ngx_int_t) luaL_checkinteger(L, 1);
 
@@ -331,12 +332,18 @@ ngx_http_lua_ngx_exit(lua_State *L)
         rc = NGX_HTTP_OK;
     }
 
+    dd("setting exit code: %d", (int) rc);
+
     ctx->exit_code = rc;
     ctx->exited = 1;
 
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "lua exit with code %i", ctx->exit_code);
 
+    if (ctx->context & NGX_HTTP_LUA_CONTEXT_HEADER_FILTER) {
+        return 0;
+    }
+
     dd("calling yield");
     return lua_yield(L, 0);
 }
@@ -415,7 +422,8 @@ ngx_http_lua_ffi_exit(ngx_http_request_t *r, int status, u_char *err,
     if (ngx_http_lua_ffi_check_context(ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                                        | NGX_HTTP_LUA_CONTEXT_ACCESS
                                        | NGX_HTTP_LUA_CONTEXT_CONTENT
-                                       | NGX_HTTP_LUA_CONTEXT_TIMER,
+                                       | NGX_HTTP_LUA_CONTEXT_TIMER
+                                       | NGX_HTTP_LUA_CONTEXT_HEADER_FILTER,
                                        err, errlen)
         != NGX_OK)
     {
@@ -456,6 +464,10 @@ ngx_http_lua_ffi_exit(ngx_http_request_t *r, int status, u_char *err,
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "lua exit with code %i", ctx->exit_code);
 
+    if (ctx->context & NGX_HTTP_LUA_CONTEXT_HEADER_FILTER) {
+        return NGX_DONE;
+    }
+
     return NGX_OK;
 }
 #endif  /* NGX_HTTP_LUA_NO_FFI_API */

src/ngx_http_lua_headerfilterby.c

@@ -84,12 +84,19 @@ ngx_http_lua_header_filter_by_lua_env(lua_State *L, ngx_http_request_t *r)
 ngx_int_t
 ngx_http_lua_header_filter_by_chunk(lua_State *L, ngx_http_request_t *r)
 {
+    int              old_exit_code = 0;
     ngx_int_t        rc;
     u_char          *err_msg;
     size_t           len;
 #if (NGX_PCRE)
     ngx_pool_t      *old_pool;
 #endif
+    ngx_http_lua_ctx_t          *ctx;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx->exited) {
+        old_exit_code = ctx->exit_code;
+    }
 
     /*  initialize nginx context in Lua VM, code chunk at stack top    sp = 1 */
     ngx_http_lua_header_filter_by_lua_env(L, r);
@@ -112,6 +119,8 @@ ngx_http_lua_header_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 occured when running loaded code */
         err_msg = (u_char *) lua_tolstring(L, -1, &len);
@@ -129,6 +138,25 @@ ngx_http_lua_header_filter_by_chunk(lua_State *L, ngx_http_request_t *r)
         return NGX_ERROR;
     }
 
+    dd("exited: %d, exit code: %d, old exit code: %d",
+       (int) ctx->exited, (int) ctx->exit_code, (int) old_exit_code);
+
+    if (ctx->exited && ctx->exit_code != old_exit_code) {
+        if (ctx->exit_code == NGX_ERROR) {
+            return NGX_ERROR;
+        }
+
+        dd("finalize request with %d", (int) ctx->exit_code);
+
+        rc = ngx_http_filter_finalize_request(r, &ngx_http_lua_module,
+                                              ctx->exit_code);
+        if (rc == NGX_ERROR || rc == NGX_AGAIN) {
+            return rc;
+        }
+
+        return NGX_DECLINED;
+    }
+
     /*  clear Lua stack */
     lua_settop(L, 0);
 
@@ -156,15 +184,9 @@ ngx_http_lua_header_filter_inline(ngx_http_request_t *r)
         return NGX_ERROR;
     }
 
-    rc = ngx_http_lua_header_filter_by_chunk(L, r);
-
-    dd("header filter by chunk returns %d", (int) rc);
+    dd("calling header filter by chunk");
 
-    if (rc != NGX_OK) {
-        return NGX_ERROR;
-    }
-
-    return NGX_OK;
+    return ngx_http_lua_header_filter_by_chunk(L, r);
 }
 
 
@@ -205,13 +227,7 @@ ngx_http_lua_header_filter_file(ngx_http_request_t *r)
     /*  make sure we have a valid code chunk */
     assert(lua_isfunction(L, -1));
 
-    rc = ngx_http_lua_header_filter_by_chunk(L, r);
-
-    if (rc != NGX_OK) {
-        return NGX_ERROR;
-    }
-
-    return NGX_OK;
+    return ngx_http_lua_header_filter_by_chunk(L, r);
 }
 
 
@@ -268,9 +284,12 @@ ngx_http_lua_header_filter(ngx_http_request_t *r)
 
     ctx->context = old_context;
 
-    if (rc != NGX_OK) {
-        dd("calling header filter handler rc %d", (int)rc);
-        return NGX_ERROR;
+    if (rc == NGX_DECLINED) {
+        return NGX_OK;
+    }
+
+    if (rc == NGX_AGAIN || rc == NGX_ERROR) {
+        return rc;
     }
 
     return ngx_http_next_header_filter(r);

t/005-exit.t

@@ -11,7 +11,7 @@ repeat_each(2);
 #log_level('warn');
 #worker_connections(1024);
 
-plan tests => repeat_each() * (blocks() * 3 + 1);
+plan tests => repeat_each() * (blocks() * 3 + 2);
 
 $ENV{TEST_NGINX_MEMCACHED_PORT} ||= 11211;
 $ENV{TEST_NGINX_MYSQL_PORT} ||= 3306;
@@ -637,3 +637,91 @@ lua sending HTTP 1.0 response headers
 [error]
 [alert]
 
+
+
+=== TEST 21: exit 403 in header filter
+--- config
+    location = /t {
+        content_by_lua "ngx.say('hi');";
+        header_filter_by_lua '
+            return ngx.exit(403)
+        ';
+    }
+--- request
+GET /t
+--- error_code: 403
+--- response_body_like: 403 Forbidden
+--- no_error_log
+[error]
+
+
+
+=== TEST 22: exit 201 in header filter
+--- config
+    lingering_close always;
+    location = /t {
+        content_by_lua "ngx.say('hi');";
+        header_filter_by_lua '
+            return ngx.exit(201)
+        ';
+    }
+--- request
+GET /t
+--- error_code: 201
+--- response_body
+--- no_error_log
+[error]
+
+
+
+=== TEST 23: exit both in header filter and content handler
+--- config
+    location = /t {
+        content_by_lua "ngx.status = 201 ngx.say('hi') ngx.exit(201)";
+        header_filter_by_lua '
+            return ngx.exit(201)
+        ';
+    }
+--- request
+GET /t
+--- error_code: 201
+--- stap2
+/*
+F(ngx_http_send_header) {
+    printf("=== %d\n", $r->headers_out->status)
+    print_ubacktrace()
+}
+*/
+F(ngx_http_lua_header_filter_inline) {
+    printf("=== %d\n", $r->headers_out->status)
+    print_ubacktrace()
+}
+F(ngx_http_lua_header_filter_by_chunk).return {
+    if ($return == -1) {
+        printf("====== header filter by chunk\n")
+        print_ubacktrace()
+    }
+}
+--- stap_out
+--- response_body
+--- no_error_log
+[error]
+[alert]
+
+
+
+=== TEST 24: exit 444 in header filter
+--- config
+    location = /t {
+        content_by_lua "ngx.say('hello world');";
+        header_filter_by_lua '
+            return ngx.exit(444)
+        ';
+    }
+--- request
+GET /t
+--- error_code: 444
+--- response_body
+--- no_error_log
+[error]
+

t/041-header-filter.t

@@ -11,7 +11,7 @@ log_level('debug');
 
 repeat_each(2);
 
-plan tests => repeat_each() * 92;
+plan tests => repeat_each() * 91;
 
 #no_diff();
 #no_long_string();
@@ -589,20 +589,6 @@ API disabled in the context of header_filter_by_lua*
 
 
 
-=== TEST 30: no ngx.exit
---- config
-    location /lua {
-        header_filter_by_lua 'ngx.exit(0)';
-        echo ok;
-    }
---- request
-GET /lua
---- ignore_response
---- error_log
-API disabled in the context of header_filter_by_lua*
-
-
-
 === TEST 31: no ngx.redirect
 --- config
     location /lua {