httpcaddyfile: Support explicitly turning off strict_sni_host (#4592)

caddyconfig/httpcaddyfile/serveroptions.go

@@ -157,11 +157,14 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (interface{}, error
 						serverOpts.ExperimentalHTTP3 = true
 
 					case "strict_sni_host":
-						if d.NextArg() {
+						if d.NextArg() && d.Val() != "insecure_off" && d.Val() != "on" {
-							return nil, d.ArgErr()
+							return nil, d.Errf("strict_sni_host only supports 'on' or 'insecure_off', got '%s'", d.Val())
 						}
-						trueBool := true
+						boolVal := true
-						serverOpts.StrictSNIHost = &trueBool
+						if d.Val() == "insecure_off" {
+							boolVal = false
+						}
+						serverOpts.StrictSNIHost = &boolVal
 
 					default:
 						return nil, d.Errf("unrecognized protocol option '%s'", d.Val())

caddytest/integration/caddyfile_adapt/global_server_options_multi.txt

@@ -3,6 +3,9 @@
 		timeouts {
 			idle 90s
 		}
+		protocol {
+			strict_sni_host insecure_off
+		}
 	}
 	servers :80 {
 		timeouts {
@@ -13,6 +16,9 @@
 		timeouts {
 			idle 30s
 		}
+		protocol {
+			strict_sni_host
+		}
 	}
 }
 
@@ -46,7 +52,8 @@ http://bar.com {
 							],
 							"terminal": true
 						}
-					]
+					],
+					"strict_sni_host": true
 				},
 				"srv1": {
 					"listen": [
@@ -70,7 +77,8 @@ http://bar.com {
 					"listen": [
 						":8080"
 					],
-					"idle_timeout": 90000000000
+					"idle_timeout": 90000000000,
+					"strict_sni_host": false
 				}
 			}
 		}