fix: off one memory write access (#20)

Author: spacewander

src/http/ngx_http_wasm_api.c

@@ -93,7 +93,8 @@ proxy_get_property(int32_t path_data, int32_t path_size,
       return PROXY_RESULT_INVALID_MEMORY_ACCESS;
     }
 
-    if (ngx_strncmp(p, "plugin_root_id", sizeof("plugin_root_id") - 1) == 0) {
+    if (path_size == 14 && ngx_strncmp(p, "plugin_root_id", 14) == 0) {
+        /* assemblyscript SDK assumes plugin_root_id is always given */
         ngx_str_t       *name;
 
         name = ngx_http_wasm_get_plugin_name();

src/http/ngx_http_wasm_module.c

@@ -199,7 +199,7 @@ ngx_http_wasm_load_plugin(const char *name, size_t name_len,
     hw_plugin->name.data = (u_char *) (hw_plugin + 1);
     ngx_memcpy(hw_plugin->name.data, name, name_len);
 
-    hw_plugin->state = (ngx_http_wasm_state_t *) (hw_plugin->name.data + name_len + 1);
+    hw_plugin->state = (ngx_http_wasm_state_t *) (hw_plugin->name.data + name_len);
     hw_plugin->state->plugin_name = &hw_plugin->name;
 
     ngx_queue_init(&hw_plugin->occupied);