From 50ef17f43df607fbf5e64c9418ea0fcc5d355ea4 Mon Sep 17 00:00:00 2001
From: Martin Conte Mac Donell <martin@lyft.com>
Date: Sat, 4 Feb 2017 00:58:26 -0800
Subject: [PATCH] Remove `readdir_r` in favor of `readdir`

`readdir_r` has been considered harmful for a while now and it's
deprecated by glibc since 2.24. I know `readdir_r` was historically the
thread-safe alternative but even if POSIX don't require `readdir` to be
thread-safe, it is thread-safe in any modern implementation such as
glibc.

Note that the docs says that the next POSIX spec will require `readdir`
to be thread-safe "officially".
---
 source/common/runtime/runtime_impl.cc | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/source/common/runtime/runtime_impl.cc b/source/common/runtime/runtime_impl.cc
index b31e648d5444d..bfa5cae5fb6d0 100644
--- a/source/common/runtime/runtime_impl.cc
+++ b/source/common/runtime/runtime_impl.cc
@@ -75,30 +75,29 @@ uint64_t SnapshotImpl::getInteger(const std::string& key, uint64_t default_value
 void SnapshotImpl::walkDirectory(const std::string& path, const std::string& prefix) {
   log_debug("walking directory: {}", path);
   Directory current_dir(path);
-  dirent entry;
-  dirent* result;
   while (true) {
-    int rc = readdir_r(current_dir.dir_, &entry, &result);
-    if (0 != rc) {
+    errno = 0;
+    dirent* entry = readdir(current_dir.dir_);
+    if (entry == nullptr && errno != 0) {
       throw EnvoyException(fmt::format("unable to iterate directory: {}", path));
     }
 
-    if (!result) {
+    if (entry == nullptr) {
       break;
     }
 
-    std::string full_path = path + "/" + entry.d_name;
+    std::string full_path = path + "/" + entry->d_name;
     std::string full_prefix;
     if (prefix.empty()) {
-      full_prefix = entry.d_name;
+      full_prefix = entry->d_name;
     } else {
-      full_prefix = prefix + "." + entry.d_name;
+      full_prefix = prefix + "." + entry->d_name;
     }
 
-    if (entry.d_type == DT_DIR && std::string(entry.d_name) != "." &&
-        std::string(entry.d_name) != "..") {
+    if (entry->d_type == DT_DIR && std::string(entry->d_name) != "." &&
+        std::string(entry->d_name) != "..") {
       walkDirectory(full_path, full_prefix);
-    } else if (entry.d_type == DT_REG) {
+    } else if (entry->d_type == DT_REG) {
       // Suck the file into a string. This is not very efficient but it should be good enough
       // for small files. Also, as noted elsewhere, none of this is non-blocking which could
       // theoretically lead to issues.