Add whitelist support for php's wrappers

1 files changed, 70 insertions, 0 deletions

diff --git a/src/sp_wrapper.c b/src/sp_wrapper.c
new file mode 100644
index 0000000..d9cd296
--- /dev/null
+++ b/src/sp_wrapper.c
@@ -0,0 +1,70 @@
+#include "php_snuffleupagus.h"
+#include "sp_config.h"
+
+ZEND_DECLARE_MODULE_GLOBALS(snuffleupagus)
+
+static bool wrapper_is_whitelisted(const zend_string *zs) {
+  const sp_list_node *list = SNUFFLEUPAGUS_G(config).config_wrapper->whitelist;
+
+  if (!zs) {
+    return false;
+  }
+
+  while (list) {
+    if (zend_string_equals_ci(zs, (const zend_string*)list->data)) {
+      return true;
+    }
+    list = list->next;
+  }
+  return false;
+}
+
+void sp_disable_wrapper() {
+  HashTable *orig = php_stream_get_url_stream_wrappers_hash();
+  HashTable *orig_complete = pemalloc(sizeof(*orig_complete), 1);
+  zval *zv;
+  zend_string *zs;
+
+  // Copy the original hashtable into a temporary one, as I'm not sure about
+  // the behaviour of ZEND_HASH_FOREACH when element are removed from the
+  // hashtable used in the loop.
+  zend_hash_init(orig_complete, zend_hash_num_elements(orig), NULL, NULL, 1);
+  zend_hash_copy(orig_complete, orig, NULL);
+  zend_hash_clean(orig);
+
+  ZEND_HASH_FOREACH_STR_KEY_VAL(orig_complete, zs, zv) {
+    if (wrapper_is_whitelisted(zs)) {
+      zend_hash_add(orig, zs, zv);
+    }
+  }
+  ZEND_HASH_FOREACH_END();
+
+  zend_hash_destroy(orig_complete);
+  pefree(orig_complete, 1);
+  SNUFFLEUPAGUS_G(config).config_wrapper->num_wrapper = zend_hash_num_elements(orig);
+}
+
+PHP_FUNCTION(sp_stream_wrapper_register) {
+  void (*orig_handler)(INTERNAL_FUNCTION_PARAMETERS);
+  zend_string *protocol_name = NULL;
+
+  ZEND_PARSE_PARAMETERS_START_EX(ZEND_PARSE_PARAMS_QUIET, 2, EX_NUM_ARGS());
+  Z_PARAM_STR(protocol_name);
+  ZEND_PARSE_PARAMETERS_END_EX((void)0);
+
+  if (wrapper_is_whitelisted(protocol_name)) {
+    orig_handler = zend_hash_str_find_ptr(
+        SNUFFLEUPAGUS_G(sp_internal_functions_hook),
+        "stream_wrapper_register", sizeof("stream_wrapper_register") - 1);
+    orig_handler(INTERNAL_FUNCTION_PARAM_PASSTHRU);
+  }
+}
+
+int hook_stream_wrappers() {
+  TSRMLS_FETCH();
+
+  HOOK_FUNCTION("stream_wrapper_register", sp_internal_functions_hook,
+                PHP_FN(sp_stream_wrapper_register));
+
+  return SUCCESS;
+}