From a78fb6d7476111bf464af25f0d208fed98989eca Mon Sep 17 00:00:00 2001
From: Juliusz Chroboczek <jch@irif.fr>
Date: Thu, 29 Jul 2021 14:26:41 +0200
Subject: [PATCH] Increase file descriptor limit at startup.

---
 galene.go           |  8 ++++++++
 go.mod              |  1 +
 go.sum              |  3 ++-
 limit/limit.go      |  7 +++++++
 limit/limit_unix.go | 44 ++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 limit/limit.go
 create mode 100644 limit/limit_unix.go

diff --git a/galene.go b/galene.go
index 8a25d85..b384d52 100644
--- a/galene.go
+++ b/galene.go
@@ -15,6 +15,7 @@ import (
 	"github.com/jech/galene/diskwriter"
 	"github.com/jech/galene/group"
 	"github.com/jech/galene/ice"
+	"github.com/jech/galene/limit"
 	"github.com/jech/galene/turnserver"
 	"github.com/jech/galene/webserver"
 )
@@ -104,6 +105,13 @@ func main() {
 		}()
 	}
 
+	n, err := limit.Nofile(0xFFFF)
+	if err != nil {
+		log.Printf("Couldn't set file descriptor limit: %v", err)
+	} else if n < 0xFFFF {
+		log.Printf("File descriptor limit is %v, please increase it!", n)
+	}
+
 	ice.ICEFilename = filepath.Join(dataDir, "ice-servers.json")
 
 	go group.ReadPublicGroups()
diff --git a/go.mod b/go.mod
index 56aebcb..ee1d1af 100644
--- a/go.mod
+++ b/go.mod
@@ -13,4 +13,5 @@ require (
 	github.com/pion/turn/v2 v2.0.5
 	github.com/pion/webrtc/v3 v3.0.31
 	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97
+	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
 )
diff --git a/go.sum b/go.sum
index 68dd18c..f0dd56d 100644
--- a/go.sum
+++ b/go.sum
@@ -122,8 +122,9 @@ golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210112080510-489259a85091/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c h1:F1jZWGFhYfh0Ci55sIpILtKKK8p3i2/krTr0H1rg74I=
+golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
diff --git a/limit/limit.go b/limit/limit.go
new file mode 100644
index 0000000..11fb867
--- /dev/null
+++ b/limit/limit.go
@@ -0,0 +1,7 @@
+// +build windows plan9
+
+package limit
+
+func Nofile(desired uint64) (uint64, error) {
+	return desired, nil
+}
diff --git a/limit/limit_unix.go b/limit/limit_unix.go
new file mode 100644
index 0000000..6365d54
--- /dev/null
+++ b/limit/limit_unix.go
@@ -0,0 +1,44 @@
+// +build !windows
+// +build !plan9
+
+package limit
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+func Nofile(desired uint64) (uint64, error) {
+	var old unix.Rlimit
+
+	err := unix.Getrlimit(unix.RLIMIT_NOFILE, &old)
+	if err != nil {
+		return 0, err
+	}
+
+	if old.Cur >= desired {
+		return old.Cur, nil
+	}
+
+	if old.Max < desired {
+		limit := unix.Rlimit{
+			Cur: desired,
+			Max: desired,
+		}
+		err := unix.Setrlimit(unix.RLIMIT_NOFILE, &limit)
+		if err == nil {
+			return limit.Cur, nil
+		}
+
+		desired = old.Max
+	}
+
+	limit := unix.Rlimit{
+		Cur: desired,
+		Max: old.Max,
+	}
+	err = unix.Setrlimit(unix.RLIMIT_NOFILE, &limit)
+	if err != nil {
+		return old.Cur, err
+	}
+	return limit.Cur, nil
+}