From 09f1553e4034acb531dc1fc7c693d3b8a8f60fce Mon Sep 17 00:00:00 2001
From: Alex X <alexey.khit@gmail.com>
Date: Wed, 11 Oct 2023 11:31:37 +0300
Subject: [PATCH] Fix SO_REUSEPORT for macOS #626

---
 pkg/mdns/syscall_darwin.go                | 24 +++++++++++++++++++++++
 pkg/mdns/{syscall.go => syscall_linux.go} |  6 +++---
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 pkg/mdns/syscall_darwin.go
 rename pkg/mdns/{syscall.go => syscall_linux.go} (86%)

diff --git a/pkg/mdns/syscall_darwin.go b/pkg/mdns/syscall_darwin.go
new file mode 100644
index 00000000..c1f1225b
--- /dev/null
+++ b/pkg/mdns/syscall_darwin.go
@@ -0,0 +1,24 @@
+package mdns
+
+import (
+	"syscall"
+)
+
+func SetsockoptInt(fd uintptr, level, opt int, value int) (err error) {
+	// change SO_REUSEADDR and REUSEPORT flags simultaneously for BSD-like OS
+	// https://github.com/AlexxIT/go2rtc/issues/626
+	// https://stackoverflow.com/questions/14388706/how-do-so-reuseaddr-and-so-reuseport-differ/14388707
+	if opt == syscall.SO_REUSEADDR {
+		if err = syscall.SetsockoptInt(int(fd), level, opt, value); err != nil {
+			return
+		}
+
+		opt = syscall.SO_REUSEPORT
+	}
+
+	return syscall.SetsockoptInt(int(fd), level, opt, value)
+}
+
+func SetsockoptIPMreq(fd uintptr, level, opt int, mreq *syscall.IPMreq) (err error) {
+	return syscall.SetsockoptIPMreq(int(fd), level, opt, mreq)
+}
diff --git a/pkg/mdns/syscall.go b/pkg/mdns/syscall_linux.go
similarity index 86%
rename from pkg/mdns/syscall.go
rename to pkg/mdns/syscall_linux.go
index f678b684..fc0caeb0 100644
--- a/pkg/mdns/syscall.go
+++ b/pkg/mdns/syscall_linux.go
@@ -1,8 +1,8 @@
-//go:build darwin || linux
-
 package mdns
 
-import "syscall"
+import (
+	"syscall"
+)
 
 func SetsockoptInt(fd uintptr, level, opt int, value int) (err error) {
 	return syscall.SetsockoptInt(int(fd), level, opt, value)