Clamp negative protocol ban durations

gumble/gumble/bans.go

@@ -16,6 +16,9 @@ type BanList []*Ban
 
 // Add creates a new ban list entry with the given parameters.
 func (b *BanList) Add(address net.IP, mask net.IPMask, reason string, duration time.Duration) *Ban {
+	if duration < 0 {
+		duration = 0
+	}
 	ban := &Ban{
 		Address:  address,
 		Mask:     mask,
@@ -66,6 +69,9 @@ func (b *Ban) SetReason(reason string) {
 
 // SetDuration changes the duration of the ban.
 func (b *Ban) SetDuration(duration time.Duration) {
+	if duration < 0 {
+		duration = 0
+	}
 	b.Duration = duration
 }
 

gumble/gumble/bans_regression_test.go

@@ -0,0 +1,21 @@
+package gumble
+
+import (
+	"net"
+	"testing"
+	"time"
+)
+
+// Regression: negative durations were converted to uint32 seconds for the
+// protocol, creating an unexpectedly huge ban rather than a safe duration.
+func TestBanDurationsNeverRemainNegative(t *testing.T) {
+	var bans BanList
+	ban := bans.Add(net.ParseIP("192.0.2.1"), net.CIDRMask(32, 32), "test", -time.Minute)
+	if ban.Duration != 0 {
+		t.Fatalf("Add duration = %v", ban.Duration)
+	}
+	ban.SetDuration(-time.Second)
+	if ban.Duration != 0 {
+		t.Fatalf("SetDuration = %v", ban.Duration)
+	}
+}