1 files changed, 142 insertions, 0 deletions

diff --git a/src/sp_ini.c b/src/sp_ini.c
new file mode 100644
index 0000000..7fec297
--- /dev/null
+++ b/src/sp_ini.c
@@ -0,0 +1,142 @@
+#include "php_snuffleupagus.h"
+
+#define SP_INI_HAS_CHECKS_COND(entry) (entry->min || entry->max || entry->regexp)
+#define SP_INI_ACCESS_READONLY_COND(entry, cfg) (entry->access == SP_READONLY || (!entry->access && cfg->policy_readonly))
+
+#define sp_log_auto2(feature, is_simulation, drop, ...) \
+  sp_log_msgf(feature, ((is_simulation || !drop) ? SP_LOG_WARN : SP_LOG_ERROR), \
+            (is_simulation ? SP_TYPE_SIMULATION : (drop ? SP_TYPE_DROP : SP_TYPE_LOG)),   \
+            __VA_ARGS__)
+#define sp_log_ini_check_violation(...) if (simulation || cfg->policy_drop || (entry && entry->drop) || !cfg->policy_silent_fail) { \
+    sp_log_auto2("ini_protection", simulation, (cfg->policy_drop || (entry && entry->drop)), __VA_ARGS__); \
+  }
+
+
+static bool /* success */ sp_ini_check(zend_string *varname, zend_string *new_value, sp_ini_entry **sp_entry_p) {
+  if (!varname || ZSTR_LEN(varname) == 0) {
+    return false;
+  }
+
+  sp_config_ini *cfg = &(SPCFG(ini));
+  sp_ini_entry *entry = zend_hash_find_ptr(cfg->entries, varname);
+  if (sp_entry_p) {
+    *sp_entry_p = entry;
+  }
+  bool simulation = (cfg->simulation || (entry && entry->simulation));
+
+  if (!entry) {
+    if (cfg->policy_readonly) {
+      if (!cfg->policy_silent_ro) {
+        sp_log_ini_check_violation("INI setting is read-only");
+      }
+      return simulation;
+    }
+    return true;
+  }
+
+  // we have an entry.
+
+  if (SP_INI_ACCESS_READONLY_COND(entry, cfg)) {
+    if (!cfg->policy_silent_ro) {
+      sp_log_ini_check_violation("%s", (entry->msg ? ZSTR_VAL(entry->msg) : "INI setting is read-only"));
+    }
+    return simulation;
+  }
+
+  if (!new_value || ZSTR_LEN(new_value) == 0) {
+    if (entry->allow_null) {
+      return true; // allow NULL value and skip other tests
+    }
+    if (SP_INI_HAS_CHECKS_COND(entry)) {
+      sp_log_ini_check_violation("new INI value must not be NULL or empty");
+      return simulation;
+    }
+    return true; // no new_value, but no checks to perform
+  }
+
+  // we have a new_value.
+
+  if (entry->min || entry->max) {
+    zend_long lvalue = zend_atol(ZSTR_VAL(new_value), ZSTR_LEN(new_value));
+    if ((entry->min && zend_atol(ZSTR_VAL(entry->min), ZSTR_LEN(entry->min)) > lvalue) ||
+        (entry->max && zend_atol(ZSTR_VAL(entry->max), ZSTR_LEN(entry->max)) < lvalue)) {
+      sp_log_ini_check_violation("%s", (entry->msg ? ZSTR_VAL(entry->msg) : "INI value out of range"));
+      return simulation;
+    }
+  }
+
+  if (entry->regexp) {
+    if (!sp_is_regexp_matching_zstr(entry->regexp, new_value)) {
+      sp_log_ini_check_violation("%s", (entry->msg ? ZSTR_VAL(entry->msg) : "INI value does not match regex"));
+      return simulation;
+    }
+  }
+
+  return true;
+}
+
+static PHP_INI_MH(sp_ini_onmodify) {
+  zend_ini_entry *ini_entry = entry;
+  sp_ini_entry *sp_entry = NULL;
+
+  if (!sp_ini_check(ini_entry->name, new_value, &sp_entry)) {
+    return FAILURE;
+  }
+
+  if (sp_entry && sp_entry->orig_onmodify) {
+    return sp_entry->orig_onmodify(entry, new_value, mh_arg1, mh_arg2, mh_arg3, stage);
+  }
+
+  return SUCCESS;
+}
+
+void sp_hook_ini() {
+  sp_config_ini *cfg = &(SPCFG(ini));
+  sp_ini_entry *sp_entry;
+  zend_ini_entry *ini_entry;
+  ZEND_HASH_FOREACH_PTR(cfg->entries, sp_entry)
+    if ((ini_entry = zend_hash_find_ptr(EG(ini_directives), sp_entry->key)) == NULL) {
+      sp_log_warn("ini_protection", "Cannot hook INI var `%s`. Maybe a typo or the PHP extension providing this var is not loaded yet.", ZSTR_VAL(sp_entry->key));
+      continue;
+    }
+    if (SP_INI_ACCESS_READONLY_COND(sp_entry, cfg) && (cfg->policy_silent_ro || cfg->policy_silent_fail) && !sp_entry->drop && !(sp_entry->simulation || cfg->simulation)) {
+      ini_entry->modifiable = ini_entry->orig_modifiable = 0;
+    }
+    PHP_INI_MH((*orig_onmodify)) = ini_entry->on_modify;
+
+    if (SP_INI_HAS_CHECKS_COND(sp_entry) || SP_INI_ACCESS_READONLY_COND(sp_entry, cfg)) {
+      // only hook on_modify if there is any check to perform
+      sp_entry->orig_onmodify = ini_entry->on_modify;
+      ini_entry->on_modify = sp_ini_onmodify;
+    }
+
+    if (sp_entry->set) {
+      zend_string *duplicate = zend_string_copy(sp_entry->set);
+
+      if (!orig_onmodify || orig_onmodify(ini_entry, duplicate, ini_entry->mh_arg1, ini_entry->mh_arg2, ini_entry->mh_arg3, ZEND_INI_STAGE_STARTUP) == SUCCESS) {
+        ini_entry->value = duplicate;
+      } else {
+        zend_string_release(duplicate);
+        sp_log_warn("ini_protection", "Failed to set INI var `%s`.", ZSTR_VAL(sp_entry->key));
+        continue;
+      }
+    }
+  ZEND_HASH_FOREACH_END();
+}
+
+void sp_unhook_ini() {
+  sp_ini_entry *sp_entry;
+  zend_ini_entry *ini_entry;
+  ZEND_HASH_FOREACH_PTR(SPCFG(ini).entries, sp_entry)
+    if (!sp_entry->orig_onmodify) {
+      // not hooked or no original onmodify
+      continue;
+    }
+    if ((ini_entry = zend_hash_find_ptr(EG(ini_directives), sp_entry->key)) == NULL) {
+      // unusual. ini entry is missing.
+      continue;
+    }
+    ini_entry->on_modify = sp_entry->orig_onmodify;
+    sp_entry->orig_onmodify = NULL;
+  ZEND_HASH_FOREACH_END();
+}