From 1b5da9c7c5423eed7a567a02e66c244705116724 Mon Sep 17 00:00:00 2001
From: networkException <git@nwex.de>
Date: Thu, 30 May 2024 02:07:04 +0200
Subject: [PATCH] Don't call `setgroups` unconditionally in mainrelay

This patch moves the call to `setgroups` from the beginning of the
`drop_priviliges` function to branch in which `setuid` is actually
called. This still fulfills the intention of
acbf7e15c9290e0891a6b6b5ce6e81bbaa77ce5a, initially introducting
the call to `setgroups`:

> Fix related to POS36-C and rpmlint error
> "missing-call-to-setgroups-before-setuid".

As per this intention is is not required to call `setgroups`
otherwise, reducing the more exotic (as in not part of POSIX and
considered priviliged by systemd) system calls coturn needs to make
at startup.
---
 src/apps/relay/mainrelay.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/apps/relay/mainrelay.c b/src/apps/relay/mainrelay.c
index cf370ec8a..56eaf82d0 100644
--- a/src/apps/relay/mainrelay.c
+++ b/src/apps/relay/mainrelay.c
@@ -2913,7 +2913,6 @@ static void drop_privileges(void) {
 #if defined(WINDOWS)
   // TODO: implement it!!!
 #else
-  setgroups(0, NULL);
   if (procgroupid_set) {
     if (getgid() != procgroupid) {
       if (setgid(procgroupid) != 0) {
@@ -2929,6 +2928,11 @@ static void drop_privileges(void) {
 
   if (procuserid_set) {
     if (procuserid != getuid()) {
+      if (setgroups(0, NULL) != 0) {
+        perror("setgroups: Unable drop supplementary groups");
+        exit(-1);
+      }
+
       if (setuid(procuserid) != 0) {
         perror("setuid: Unable to change user privileges");
         exit(-1);