implement getenv and putenv in go (#1086)

* implement getenv and putenv in go

* fix typo

* apply formatting

* return a bool

* prevent ENV= from crashing

* optimization

* optimization

* split env workflows and use go_strings

* clean up unused code

* update tests

* remove useless sprintf

* see if this fixes the asan issues

* clean up comments

* check that VAR= works correctly and use actual php to validate the behavior

* move all unpinning to the end of the request

* handle the case where php is not installed

* fix copy-paste

* optimization

* use strings.cut

* fix lint

* override how env is filled

* reuse fullenv

* use corect function

Author: withinboredom

frankenphp.c

@@ -150,6 +150,25 @@ static void frankenphp_worker_request_shutdown() {
   SG(rfc1867_uploaded_files) = NULL;
 }
 
+PHPAPI void get_full_env(zval *track_vars_array) {
+  struct go_getfullenv_return full_env = go_getfullenv(thread_index);
+
+  for (int i = 0; i < full_env.r1; i++) {
+    go_string key = full_env.r0[i * 2];
+    go_string val = full_env.r0[i * 2 + 1];
+
+    // create PHP strings for key and value
+    zend_string *key_str = zend_string_init(key.data, key.len, 0);
+    zend_string *val_str = zend_string_init(val.data, val.len, 0);
+
+    // add to the associative array
+    add_assoc_str(track_vars_array, ZSTR_VAL(key_str), val_str);
+
+    // release the key string
+    zend_string_release(key_str);
+  }
+}
+
 /* Adapted from php_request_startup() */
 static int frankenphp_worker_request_startup() {
   int retval = SUCCESS;
@@ -242,6 +261,60 @@ PHP_FUNCTION(frankenphp_finish_request) { /* {{{ */
   RETURN_TRUE;
 } /* }}} */
 
+/* {{{ Call go's putenv to prevent race conditions */
+PHP_FUNCTION(frankenphp_putenv) {
+  char *setting;
+  size_t setting_len;
+
+  ZEND_PARSE_PARAMETERS_START(1, 1)
+  Z_PARAM_STRING(setting, setting_len)
+  ZEND_PARSE_PARAMETERS_END();
+
+  // Cast str_len to int (ensure it fits in an int)
+  if (setting_len > INT_MAX) {
+    php_error(E_WARNING, "String length exceeds maximum integer value");
+    RETURN_FALSE;
+  }
+
+  if (go_putenv(setting, (int)setting_len)) {
+    RETURN_TRUE;
+  } else {
+    RETURN_FALSE;
+  }
+} /* }}} */
+
+/* {{{ Call go's getenv to prevent race conditions */
+PHP_FUNCTION(frankenphp_getenv) {
+  char *name = NULL;
+  size_t name_len = 0;
+  bool local_only = 0;
+
+  ZEND_PARSE_PARAMETERS_START(0, 2)
+  Z_PARAM_OPTIONAL
+  Z_PARAM_STRING_OR_NULL(name, name_len)
+  Z_PARAM_BOOL(local_only)
+  ZEND_PARSE_PARAMETERS_END();
+
+  if (!name) {
+    array_init(return_value);
+    get_full_env(return_value);
+
+    return;
+  }
+
+  go_string gname = {name_len, name};
+
+  struct go_getenv_return result = go_getenv(thread_index, &gname);
+
+  if (result.r0) {
+    // Return the single environment variable as a string
+    RETVAL_STRINGL(result.r1->data, result.r1->len);
+  } else {
+    // Environment variable does not exist
+    RETVAL_FALSE;
+  }
+} /* }}} */
+
 /* {{{ Fetch all HTTP request headers */
 PHP_FUNCTION(frankenphp_request_headers) {
   if (zend_parse_parameters_none() == FAILURE) {
@@ -260,8 +333,6 @@ PHP_FUNCTION(frankenphp_request_headers) {
 
     add_assoc_stringl_ex(return_value, key.data, key.len, val.data, val.len);
   }
-
-  go_apache_request_cleanup(thread_index);
 }
 /* }}} */
 
@@ -408,15 +479,39 @@ PHP_FUNCTION(headers_send) {
   RETURN_LONG(sapi_send_headers());
 }
 
+PHP_MINIT_FUNCTION(frankenphp) {
+  zend_function *func;
+
+  // Override putenv
+  func = zend_hash_str_find_ptr(CG(function_table), "putenv",
+                                sizeof("putenv") - 1);
+  if (func != NULL && func->type == ZEND_INTERNAL_FUNCTION) {
+    ((zend_internal_function *)func)->handler = ZEND_FN(frankenphp_putenv);
+  } else {
+    php_error(E_WARNING, "Failed to find built-in putenv function");
+  }
+
+  // Override getenv
+  func = zend_hash_str_find_ptr(CG(function_table), "getenv",
+                                sizeof("getenv") - 1);
+  if (func != NULL && func->type == ZEND_INTERNAL_FUNCTION) {
+    ((zend_internal_function *)func)->handler = ZEND_FN(frankenphp_getenv);
+  } else {
+    php_error(E_WARNING, "Failed to find built-in getenv function");
+  }
+
+  return SUCCESS;
+}
+
 static zend_module_entry frankenphp_module = {
     STANDARD_MODULE_HEADER,
     "frankenphp",
-    ext_functions, /* function table */
-    NULL,          /* initialization */
-    NULL,          /* shutdown */
-    NULL,          /* request initialization */
-    NULL,          /* request shutdown */
-    NULL,          /* information */
+    ext_functions,         /* function table */
+    PHP_MINIT(frankenphp), /* initialization */
+    NULL,                  /* shutdown */
+    NULL,                  /* request initialization */
+    NULL,                  /* request shutdown */
+    NULL,                  /* information */
     TOSTRING(FRANKENPHP_VERSION),
     STANDARD_MODULE_PROPERTIES};
 
@@ -473,6 +568,8 @@ int frankenphp_update_server_context(
 }
 
 static int frankenphp_startup(sapi_module_struct *sapi_module) {
+  php_import_environment_variables = get_full_env;
+
   return php_module_startup(sapi_module, &frankenphp_module);
 }
 
@@ -662,14 +759,15 @@ static void frankenphp_register_variables(zval *track_vars_array) {
   /* https://www.php.net/manual/en/reserved.variables.server.php */
 
   /* In CGI mode, we consider the environment to be a part of the server
-   * variables
+   * variables.
    */
 
   frankenphp_server_context *ctx = SG(server_context);
 
   /* in non-worker mode we import the os environment regularly */
   if (!ctx->has_main_request) {
-    php_import_environment_variables(track_vars_array);
+    get_full_env(track_vars_array);
+    // php_import_environment_variables(track_vars_array);
     go_register_variables(thread_index, track_vars_array);
     return;
   }
@@ -678,7 +776,8 @@ static void frankenphp_register_variables(zval *track_vars_array) {
   if (os_environment == NULL) {
     os_environment = malloc(sizeof(zval));
     array_init(os_environment);
-    php_import_environment_variables(os_environment);
+    get_full_env(os_environment);
+    // php_import_environment_variables(os_environment);
   }
   zend_hash_copy(Z_ARR_P(track_vars_array), Z_ARR_P(os_environment),
                  (copy_ctor_func_t)zval_add_ref);

frankenphp.go

@@ -507,6 +507,76 @@ func ServeHTTP(responseWriter http.ResponseWriter, request *http.Request) error
 	return nil
 }
 
+//export go_putenv
+func go_putenv(str *C.char, length C.int) C.bool {
+	// Create a byte slice from C string with a specified length
+	s := C.GoBytes(unsafe.Pointer(str), length)
+
+	// Convert byte slice to string
+	envString := string(s)
+
+	// Check if '=' is present in the string
+	if key, val, found := strings.Cut(envString, "="); found {
+		if os.Setenv(key, val) != nil {
+			return false // Failure
+		}
+	} else {
+		// No '=', unset the environment variable
+		if os.Unsetenv(envString) != nil {
+			return false // Failure
+		}
+	}
+
+	return true // Success
+}
+
+//export go_getfullenv
+func go_getfullenv(threadIndex C.uintptr_t) (*C.go_string, C.size_t) {
+	thread := phpThreads[threadIndex]
+
+	env := os.Environ()
+	goStrings := make([]C.go_string, len(env)*2)
+
+	for i, envVar := range env {
+		key, val, _ := strings.Cut(envVar, "=")
+		k := unsafe.StringData(key)
+		v := unsafe.StringData(val)
+		thread.Pin(k)
+		thread.Pin(v)
+
+		goStrings[i*2] = C.go_string{C.size_t(len(key)), (*C.char)(unsafe.Pointer(k))}
+		goStrings[i*2+1] = C.go_string{C.size_t(len(val)), (*C.char)(unsafe.Pointer(v))}
+	}
+
+	value := unsafe.SliceData(goStrings)
+	thread.Pin(value)
+
+	return value, C.size_t(len(env))
+}
+
+//export go_getenv
+func go_getenv(threadIndex C.uintptr_t, name *C.go_string) (C.bool, *C.go_string) {
+	thread := phpThreads[threadIndex]
+
+	// Create a byte slice from C string with a specified length
+	envName := C.GoStringN(name.data, C.int(name.len))
+
+	// Get the environment variable value
+	envValue, exists := os.LookupEnv(envName)
+	if !exists {
+		// Environment variable does not exist
+		return false, nil // Return 0 to indicate failure
+	}
+
+	// Convert Go string to C string
+	val := unsafe.StringData(envValue)
+	thread.Pin(val)
+	value := &C.go_string{C.size_t(len(envValue)), (*C.char)(unsafe.Pointer(val))}
+	thread.Pin(value)
+
+	return true, value // Return 1 to indicate success
+}
+
 //export go_handle_request
 func go_handle_request(threadIndex C.uintptr_t) bool {
 	select {
@@ -524,6 +594,7 @@ func go_handle_request(threadIndex C.uintptr_t) bool {
 		defer func() {
 			maybeCloseContext(fc)
 			thread.mainRequest = nil
+			thread.Unpin()
 		}()
 
 		if err := updateServerContext(r, true, false); err != nil {
@@ -647,8 +718,6 @@ func go_register_variables(threadIndex C.uintptr_t, trackVarsArray *C.zval) {
 
 	C.frankenphp_register_bulk_variables(&knownVariables[0], dvsd, C.size_t(l), trackVarsArray)
 
-	thread.Unpin()
-
 	fc.env = nil
 }
 
@@ -691,11 +760,6 @@ func go_apache_request_headers(threadIndex C.uintptr_t, hasActiveRequest bool) (
 	return sd, C.size_t(len(r.Header))
 }
 
-//export go_apache_request_cleanup
-func go_apache_request_cleanup(threadIndex C.uintptr_t) {
-	phpThreads[threadIndex].Unpin()
-}
-
 func addHeader(fc *FrankenPHPContext, cString *C.char, length C.int) {
 	parts := strings.SplitN(C.GoStringN(cString, length), ": ", 2)
 	if len(parts) != 2 {

frankenphp_test.go

@@ -622,6 +622,33 @@ func TestFailingWorker(t *testing.T) {
 	}, &testOptions{workerScript: "failing-worker.php"})
 }
 
+func TestEnv(t *testing.T) {
+	testEnv(t, &testOptions{})
+}
+func TestEnvWorker(t *testing.T) {
+	testEnv(t, &testOptions{workerScript: "test-env.php"})
+}
+func testEnv(t *testing.T, opts *testOptions) {
+	runTest(t, func(handler func(http.ResponseWriter, *http.Request), _ *httptest.Server, i int) {
+		req := httptest.NewRequest("GET", fmt.Sprintf("http://example.com/test-env.php?var=%d", i), nil)
+		w := httptest.NewRecorder()
+		handler(w, req)
+
+		resp := w.Result()
+		body, _ := io.ReadAll(resp.Body)
+
+		// execute the script as regular php script
+		cmd := exec.Command("php", "testdata/test-env.php", strconv.Itoa(i))
+		stdoutStderr, err := cmd.CombinedOutput()
+		if err != nil {
+			// php is not installed or other issue, use the hardcoded output below:
+			stdoutStderr = []byte("Set MY_VAR successfully.\nMY_VAR = HelloWorld\nUnset MY_VAR successfully.\nMY_VAR is unset.\nMY_VAR set to empty successfully.\nMY_VAR = \nUnset NON_EXISTING_VAR successfully.\n")
+		}
+
+		assert.Equal(t, string(stdoutStderr), string(body))
+	}, opts)
+}
+
 func TestFileUpload_module(t *testing.T) { testFileUpload(t, &testOptions{}) }
 func TestFileUpload_worker(t *testing.T) {
 	testFileUpload(t, &testOptions{workerScript: "file-upload.php"})

testdata/test-env.php

@@ -0,0 +1,50 @@
+<?php
+
+require_once __DIR__.'/_executor.php';
+
+return function() {
+    $var = 'MY_VAR_' . ($_GET['var'] ?? '');
+    // Setting an environment variable
+    $result = putenv("$var=HelloWorld");
+    if ($result) {
+        echo "Set MY_VAR successfully.\n";
+        echo "MY_VAR = " . getenv($var) . "\n";
+    } else {
+        echo "Failed to set MY_VAR.\n";
+    }
+
+    // Unsetting the environment variable
+    $result = putenv($var);
+    if ($result) {
+        echo "Unset MY_VAR successfully.\n";
+        $value = getenv($var);
+        if ($value === false) {
+            echo "MY_VAR is unset.\n";
+        } else {
+            echo "MY_VAR = " . $value . "\n";
+        }
+    } else {
+        echo "Failed to unset MY_VAR.\n";
+    }
+
+    $result = putenv("$var=");
+    if ($result) {
+        echo "MY_VAR set to empty successfully.\n";
+        $value = getenv($var);
+        if ($value === false) {
+            echo "MY_VAR is unset.\n";
+        } else {
+            echo "MY_VAR = " . $value . "\n";
+        }
+    } else {
+        echo "Failed to set MY_VAR.\n";
+    }
+
+    // Attempt to unset a non-existing variable
+    $result = putenv('NON_EXISTING_VAR' . ($_GET['var'] ?? ''));
+    if ($result) {
+        echo "Unset NON_EXISTING_VAR successfully.\n";
+    } else {
+        echo "Failed to unset NON_EXISTING_VAR.\n";
+    }
+};

worker.go

@@ -310,4 +310,6 @@ func go_frankenphp_finish_request(threadIndex C.uintptr_t, isWorkerRequest bool)
 
 		c.Write(fields...)
 	}
+
+	thread.Unpin()
 }