From b299d7e36b3f1fa17b781a3da4e1a67e49aea388 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Sat, 24 Jul 2021 11:12:37 -0500
Subject: [PATCH] move setuid/setgid into separate functions in
 platform-dependent files

---
 cmd/yggdrasil/main.go         | 14 ++++++++++----
 cmd/yggdrasil/setids_other.go | 13 +++++++++++++
 cmd/yggdrasil/setids_posix.go | 13 +++++++++++++
 3 files changed, 36 insertions(+), 4 deletions(-)
 create mode 100644 cmd/yggdrasil/setids_other.go
 create mode 100644 cmd/yggdrasil/setids_posix.go

diff --git a/cmd/yggdrasil/main.go b/cmd/yggdrasil/main.go
index f994bbd7..f1ef29c4 100644
--- a/cmd/yggdrasil/main.go
+++ b/cmd/yggdrasil/main.go
@@ -376,12 +376,18 @@ func run(args yggArgs, ctx context.Context, done chan struct{}) {
 	// Lower permissions from root to something else, if the user wants to
 	if syscall.Getuid() == 0 {
 		if args.rungid > 0 {
-			fmt.Println("Dropping gid to ", args.rungid)
-			syscall.Setgid(args.rungid)
+			logger.Infoln("Setting gid to:", args.rungid)
+			if err := setgid(args.rungid); err != nil {
+				logger.Errorln("Failed to set gid:", err)
+				return
+			}
 		}
 		if args.runuid > 0 {
-			fmt.Println("Dropping uid to ", args.rungid)
-			syscall.Setuid(args.runuid)
+			logger.Infoln("Setting uid to:", args.runuid)
+			if err := setuid(args.runuid); err != nil {
+				logger.Errorln("Failed to set uid:", err)
+				return
+			}
 		}
 	}
 	logger.Infof("Your public key is %s", hex.EncodeToString(public[:]))
diff --git a/cmd/yggdrasil/setids_other.go b/cmd/yggdrasil/setids_other.go
new file mode 100644
index 00000000..dcf1020a
--- /dev/null
+++ b/cmd/yggdrasil/setids_other.go
@@ -0,0 +1,13 @@
+// +build !linux,!darwin,!freebsd,!openbsd
+
+package main
+
+import "errors"
+
+func setuid(uid int) error {
+	return errors.New("setting uid not supported on this platform")
+}
+
+func setgid(gid int) error {
+	return errors.New("setting gid not supported on this platform")
+}
diff --git a/cmd/yggdrasil/setids_posix.go b/cmd/yggdrasil/setids_posix.go
new file mode 100644
index 00000000..1e23568d
--- /dev/null
+++ b/cmd/yggdrasil/setids_posix.go
@@ -0,0 +1,13 @@
+// +build linux darwin freebsd openbsd
+
+package main
+
+import "syscall"
+
+func setuid(uid int) error {
+	return syscall.Setuid(uid)
+}
+
+func setgid(gid int) error {
+	return syscall.Setgid(gid)
+}