imap: fix build on macos

Fix the following build error on mac os:

 worker/imap/worker.go:368:29: undefined: syscall.TCP_KEEPCNT
 worker/imap/worker.go:376:29: undefined: syscall.TCP_KEEPINTVL

These symbols are not defined on darwin.

Fixes: 5dfeff75f368 ("imap: add tcp connection options")
Signed-off-by: Robin Jarry <robin@jarry.cc>

2 files changed, 28 insertions, 0 deletions

diff --git a/lib/keepalive_dummy.go b/lib/keepalive_dummy.go
new file mode 100644
index 00000000..205b577b
--- /dev/null
+++ b/lib/keepalive_dummy.go
@@ -0,0 +1,11 @@
+//+build !linux
+
+package lib
+
+func SetTcpKeepaliveProbes(fd, count int) error {
+	return nil
+}
+
+func SetTcpKeepaliveInterval(fd, interval int) error {
+	return nil
+}
diff --git a/lib/keepalive_linux.go b/lib/keepalive_linux.go
new file mode 100644
index 00000000..0dc32850
--- /dev/null
+++ b/lib/keepalive_linux.go
@@ -0,0 +1,17 @@
+//+build linux
+
+package lib
+
+import (
+	"syscall"
+)
+
+func SetTcpKeepaliveProbes(fd, count int) error {
+	return syscall.SetsockoptInt(
+		fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPCNT, count)
+}
+
+func SetTcpKeepaliveInterval(fd, interval int) error {
+	return syscall.SetsockoptInt(
+		fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, interval)
+}