From c77a3b5adc0ace19da2c29788f756c9e9ca3251d Mon Sep 17 00:00:00 2001
From: Hitesh Ahuja <108540135+hahuja2@users.noreply.github.com>
Date: Thu, 15 Feb 2024 15:25:27 -0800
Subject: [PATCH] fix(agent): ensure package version retrieval does not error
 out (#833)

This PR does the following:

- For Drupal the `Drupal::VERSION` class constant is retrieved using
zend calls from C and does not require using `zend_eval_string`. The
retrieval is robust against the this constant not being defined.
- For Wordpress, the presence of the `wp_version` value in `$GLOBAL` is
verified before trying to retrieve the value.

---------

Co-authored-by: Michael Fulbright <mfulbright@newrelic.com>
Co-authored-by: Michal Nowacki <mnowacki@newrelic.com>
Co-authored-by: Michael Fulbright <89205663+mfulb@users.noreply.github.com>
---
 agent/fw_drupal8.c   | 40 +++++++++++++++++++++++++++++-----------
 agent/fw_wordpress.c | 25 +++++++++++++++++++------
 2 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/agent/fw_drupal8.c b/agent/fw_drupal8.c
index 52f550868..5456cf390 100644
--- a/agent/fw_drupal8.c
+++ b/agent/fw_drupal8.c
@@ -533,20 +533,38 @@ NR_PHP_WRAPPER(nr_drupal8_name_the_wt_via_symfony) {
 }
 NR_PHP_WRAPPER_END
 
+/*
+ * Drupal stores the version of the framework in the class constant
+ * Drupal::VERSION. This code first verifies the 'Drupal' class exists (note
+ * having to pass the lower case name of the class). If present then an attempt
+ * is made to retrieve the 'VERSION' class constant. Both of these checks rely
+ * on existing "nr_" routines that have been designed to be robust and will not
+ * cause an issue in user's application if either check were to fail.
+ */
 void nr_drupal_version() {
-  char* string = "Drupal::VERSION;";
-  zval retval;
-  int result
-      = zend_eval_string(string, &retval, "Retrieve Drupal Version");
-  
+  zval* zval_version = NULL;
+  zend_class_entry* class_entry = NULL;
+
+  class_entry = nr_php_find_class("drupal");
+  if (NULL == class_entry) {
+    nrl_verbosedebug(NRL_INSTRUMENT, "%s: 'Drupal' class not found", __func__);
+    return;
+  }
+
+  zval_version = nr_php_get_class_constant(class_entry, "VERSION");
+  if (NULL == zval_version) {
+    nrl_verbosedebug(NRL_INSTRUMENT, "%s: Drupal does not have VERSION",
+                     __func__);
+    return;
+  }
+
   // Add php package to transaction
-  if (result == SUCCESS) {
-    if (Z_TYPE(retval) == IS_STRING) {
-      char* version = Z_STRVAL(retval);
-      nr_txn_add_php_package(NRPRG(txn), "drupal/core", version);
-    }
-    zval_dtor(&retval);
+  if (nr_php_is_zval_valid_string(zval_version)) {
+    char* version = Z_STRVAL_P(zval_version);
+    nr_txn_add_php_package(NRPRG(txn), "drupal/core", version);
   }
+
+  nr_php_zval_free(&zval_version);
 }
 
 void nr_drupal8_enable(TSRMLS_D) {
diff --git a/agent/fw_wordpress.c b/agent/fw_wordpress.c
index 675360a49..32ce1fdc1 100644
--- a/agent/fw_wordpress.c
+++ b/agent/fw_wordpress.c
@@ -658,14 +658,27 @@ NR_PHP_WRAPPER_END
 #endif /* PHP 7.4+ */
 
 void nr_wordpress_version() {
-  char* string = "$GLOBALS['wp_version'];";
+  char* func_string
+      = ""
+        "(function() {"
+        "  try {"
+        "    if (array_key_exists('wp_version', $GLOBALS)) {"
+        "      return $GLOBALS['wp_version'];"
+        "    }"
+        "    else {"
+        "      return ' ';"
+        "    }"
+        "  } catch (Exception $e) {"
+        "      return ' ';"
+        "  }"
+        "})();";
+
   zval retval;
-  int result = zend_eval_string(string, &retval,
-                                "Retrieve Wordpress Version");
-  
+  int result
+      = zend_eval_string(func_string, &retval, "Get Wordpress Version");
   // Add php package to transaction
-  if (result == SUCCESS) {
-    if (Z_TYPE(retval) == IS_STRING) {
+  if (SUCCESS == result) {
+    if (nr_php_is_zval_valid_string(&retval)) {
       char* version = Z_STRVAL(retval);
       nr_txn_add_php_package(NRPRG(txn), "wordpress", version);
     }