增加参数检查

- 使用nobody之前检查是否是root用户
 - 限制参数和环境变量数量

.gitignore

@@ -6,3 +6,4 @@ runner
 CMakeLists.txt
 main
 demo
+.DS_Store

judger.c

@@ -1,3 +1,5 @@
+#include <unistd.h>
+#include <sys/types.h>
 #include <python2.7/Python.h>
 #include "runner.h"
 
@@ -53,6 +55,10 @@ static PyObject *judger_run(PyObject *self, PyObject *args, PyObject *kwargs) {
             }
             config.args[count] = PyString_AsString(next);
             count++;
+            if(count > 95) {
+                PyErr_SetString(PyExc_ValueError, "max number of args is 95");
+                return NULL;
+            }
         }
     }
     config.args[count] = NULL;
@@ -75,6 +81,10 @@ static PyObject *judger_run(PyObject *self, PyObject *args, PyObject *kwargs) {
             }
             config.env[count] = PyString_AsString(next);
             count++;
+            if(count > 95) {
+                PyErr_SetString(PyExc_ValueError, "max number of env is 95");
+                return NULL;
+            }
         }
     }
     config.env[count] = NULL;
@@ -101,6 +111,11 @@ static PyObject *judger_run(PyObject *self, PyObject *args, PyObject *kwargs) {
         config.use_nobody = 1;
     }
 
+    if(config.use_nobody && getuid() != 0) {
+        PyErr_SetString(PyExc_ValueError, "root use is required when using nobody");
+        return NULL;
+    }
+
     run(&config, &result);
     return Py_BuildValue("{s:i, s:l, s:i, s:i, s:i, s:i}",
                          "cpu_time", result.cpu_time, "memory", result.memory, "real_time", result.real_time, "signal",