The header size and the idle time as settings (closes #70)

SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES (default 32K) and SWWAF_CLIENT_IDLE_TIMEOUT (default 120s) replace the two values the proxy fixed. The idle time is read like the other durations, and can be off. Go's server reads 4K past the header limit it is given before it refuses, so it is still given the setting less 4K. The header size must be more than 4K and cannot be off; any other value stops the start with a message that does not offer off. SPEC.md and README.md say so. README.md lists both settings, no longer calls them fixed, and names them as built. Model: opus-5-5
2026-10-06 05:05:31 +02:00
parent 50df9ee36e
commit 0f85c9ae07
9 changed files with 244 additions and 124 deletions
@@ -30,6 +30,13 @@ type Config struct {
 	// ClientRequestTimeout bounds reading the whole request from the
 	// client (SWWAF_CLIENT_REQUEST_TIMEOUT).
 	ClientRequestTimeout time.Duration
+	// ClientRequestHeaderMaxBytes is the largest request line and headers
+	// a client may send (SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES). It is
+	// never off, and always more than 4K.
+	ClientRequestHeaderMaxBytes int64
+	// ClientIdleTimeout bounds how long a kept-open client connection
+	// may wait for its next request (SWWAF_CLIENT_IDLE_TIMEOUT).
+	ClientIdleTimeout time.Duration
 	// ClientResponseTimeout bounds writing the whole response to the
 	// client (SWWAF_CLIENT_RESPONSE_TIMEOUT).
 	ClientResponseTimeout time.Duration
@@ -103,6 +110,7 @@ var (
 	errNotCountry = errors.New(
 		"is not a two-letter country code such as de or kp")
 	errOnBothLists = errors.New("is in SWWAF_DENIED_COUNTRIES too")
+	errNotOver4K   = errors.New("is not a size of more than 4K, such as 32K")
 )

 // FromEnvironment reads the settings with lookupEnv, normally
@@ -111,10 +119,13 @@ var (
 func FromEnvironment(lookupEnv func(string) (string, bool)) (*Config, error) {
 	env := &environment{lookupEnv: lookupEnv}
 	cfg := &Config{
-		ListenAddr:              env.address("SWWAF_LISTEN_ADDR", ":8080"),
-		UpstreamURL:             env.appURL("SWWAF_UPSTREAM_URL", "http://127.0.0.1:8081"),
-		TrustedProxies:          env.netblocks("SWWAF_TRUSTED_PROXIES", privateRanges),
-		ClientRequestTimeout:    env.duration("SWWAF_CLIENT_REQUEST_TIMEOUT", "60s"),
+		ListenAddr:           env.address("SWWAF_LISTEN_ADDR", ":8080"),
+		UpstreamURL:          env.appURL("SWWAF_UPSTREAM_URL", "http://127.0.0.1:8081"),
+		TrustedProxies:       env.netblocks("SWWAF_TRUSTED_PROXIES", privateRanges),
+		ClientRequestTimeout: env.duration("SWWAF_CLIENT_REQUEST_TIMEOUT", "60s"),
+		ClientRequestHeaderMaxBytes: env.headerSize(
+			"SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES", "32K"),
+		ClientIdleTimeout:       env.duration("SWWAF_CLIENT_IDLE_TIMEOUT", "120s"),
 		ClientResponseTimeout:   env.duration("SWWAF_CLIENT_RESPONSE_TIMEOUT", "30m"),
 		UpstreamRequestTimeout:  env.duration("SWWAF_UPSTREAM_REQUEST_TIMEOUT", "60s"),
 		UpstreamResponseTimeout: env.duration("SWWAF_UPSTREAM_RESPONSE_TIMEOUT", "30m"),
@@ -225,6 +236,15 @@ func (e *environment) size(name, defaultValue string) int64 {
 	return size
 }

+// headerSize reads the setting that is the largest request line and
+// headers.
+func (e *environment) headerSize(name, defaultValue string) int64 {
+	size, err := parseHeaderSize(e.value(name, defaultValue))
+	e.check(name, err)
+
+	return size
+}
+
 // count reads a setting that is a number of requests.
 func (e *environment) count(name, defaultValue string) int64 {
 	count, err := parseCount(e.value(name, defaultValue))
@@ -296,6 +316,19 @@ func parseSize(value string) (int64, error) {
 	return n * unit, nil
 }

+// parseHeaderSize reads the largest request line and headers: a size as
+// parseSize reads it, but more than 4K and never off. Go's server reads 4K
+// past the limit it is given before it refuses, so proxy.New gives it this
+// size less 4K, which must leave a limit.
+func parseHeaderSize(value string) (int64, error) {
+	size, err := parseSize(value)
+	if err != nil || size <= 4*kibibyte {
+		return 0, fmt.Errorf("%q %w", value, errNotOver4K)
+	}
+
+	return size, nil
+}
+
 // splitUnit splits a size into its number and the bytes its suffix
 // stands for.
 func splitUnit(value string) (string, int64) {
@@ -20,6 +20,8 @@ const (
 	upstreamURL             = "SWWAF_UPSTREAM_URL"
 	trustedProxies          = "SWWAF_TRUSTED_PROXIES"
 	clientRequestTimeout    = "SWWAF_CLIENT_REQUEST_TIMEOUT"
+	clientHeaderMaxBytes    = "SWWAF_CLIENT_REQUEST_HEADER_MAX_BYTES"
+	clientIdleTimeout       = "SWWAF_CLIENT_IDLE_TIMEOUT"
 	clientResponseTimeout   = "SWWAF_CLIENT_RESPONSE_TIMEOUT"
 	upstreamRequestTimeout  = "SWWAF_UPSTREAM_REQUEST_TIMEOUT"
 	upstreamResponseTimeout = "SWWAF_UPSTREAM_RESPONSE_TIMEOUT"
@@ -66,16 +68,18 @@ func TestDefaults(t *testing.T) {
 	cfg := fromEnvironment(t, environment{})

 	wantSettings(t, cfg, config.Config{
-		ListenAddr:              ":8080",
-		ClientRequestTimeout:    time.Minute,
-		ClientResponseTimeout:   30 * time.Minute,
-		UpstreamRequestTimeout:  time.Minute,
-		UpstreamResponseTimeout: 30 * time.Minute,
-		RequestMaxBytes:         100 << 20,
-		ResponseMaxBytes:        5 << 30,
-		RateLimitPerMinute:      1000,
-		RateLimitPerHour:        10000,
-		RateLimitPerDay:         50000,
+		ListenAddr:                  ":8080",
+		ClientRequestTimeout:        time.Minute,
+		ClientRequestHeaderMaxBytes: 32 << 10,
+		ClientIdleTimeout:           2 * time.Minute,
+		ClientResponseTimeout:       30 * time.Minute,
+		UpstreamRequestTimeout:      time.Minute,
+		UpstreamResponseTimeout:     30 * time.Minute,
+		RequestMaxBytes:             100 << 20,
+		ResponseMaxBytes:            5 << 30,
+		RateLimitPerMinute:          1000,
+		RateLimitPerHour:            10000,
+		RateLimitPerDay:             50000,
 	})

 	if cfg.UpstreamURL.String() != "http://127.0.0.1:8081" {
@@ -99,6 +103,8 @@ func TestValuesAsSet(t *testing.T) {
 		upstreamURL:             "https://app.internal:8443/",
 		trustedProxies:          " 192.0.2.1, 10.1.2.3/8 ,2001:db8::/32",
 		clientRequestTimeout:    "90s",
+		clientHeaderMaxBytes:    "8K",
+		clientIdleTimeout:       "5m",
 		clientResponseTimeout:   "7d",
 		upstreamRequestTimeout:  "1h30m",
 		upstreamResponseTimeout: off,
@@ -115,16 +121,18 @@ func TestValuesAsSet(t *testing.T) {
 	})

 	wantSettings(t, cfg, config.Config{
-		ListenAddr:              "127.0.0.1:9000",
-		ClientRequestTimeout:    90 * time.Second,
-		ClientResponseTimeout:   7 * 24 * time.Hour,
-		UpstreamRequestTimeout:  90 * time.Minute,
-		UpstreamResponseTimeout: 0,
-		RequestMaxBytes:         512 << 10,
-		ResponseMaxBytes:        1234,
-		RateLimitPerMinute:      60,
-		RateLimitPerHour:        600,
-		RateLimitPerDay:         6000,
+		ListenAddr:                  "127.0.0.1:9000",
+		ClientRequestTimeout:        90 * time.Second,
+		ClientRequestHeaderMaxBytes: 8 << 10,
+		ClientIdleTimeout:           5 * time.Minute,
+		ClientResponseTimeout:       7 * 24 * time.Hour,
+		UpstreamRequestTimeout:      90 * time.Minute,
+		UpstreamResponseTimeout:     0,
+		RequestMaxBytes:             512 << 10,
+		ResponseMaxBytes:            1234,
+		RateLimitPerMinute:          60,
+		RateLimitPerHour:            600,
+		RateLimitPerDay:             6000,
 	})

 	if cfg.UpstreamURL.String() != "https://app.internal:8443/" {
@@ -163,12 +171,42 @@ func TestSizesAndOff(t *testing.T) {
 		requestMaxBytes:      "3G",
 		responseMaxBytes:     off,
 		clientRequestTimeout: off,
+		clientIdleTimeout:    off,
 	})

 	if cfg.RequestMaxBytes != 3<<30 || cfg.ResponseMaxBytes != 0 ||
-		cfg.ClientRequestTimeout != 0 {
-		t.Errorf("3G, off and off read as %d, %d and %s",
-			cfg.RequestMaxBytes, cfg.ResponseMaxBytes, cfg.ClientRequestTimeout)
+		cfg.ClientRequestTimeout != 0 || cfg.ClientIdleTimeout != 0 {
+		t.Errorf("3G, off, off and off read as %d, %d, %s and %s",
+			cfg.RequestMaxBytes, cfg.ResponseMaxBytes, cfg.ClientRequestTimeout,
+			cfg.ClientIdleTimeout)
+	}
+}
+
+func TestRequestHeaderMaxBytesJustOver4K(t *testing.T) {
+	t.Parallel()
+
+	cfg := fromEnvironment(t, environment{clientHeaderMaxBytes: "4097"})
+	if cfg.ClientRequestHeaderMaxBytes != 4097 {
+		t.Errorf("4097 read as %d", cfg.ClientRequestHeaderMaxBytes)
+	}
+}
+
+func TestRequestHeaderMaxBytesRefusalNeverOffersOff(t *testing.T) {
+	t.Parallel()
+
+	for _, value := range []string{"32KB", "0", "4K", off} {
+		t.Run(value, func(t *testing.T) {
+			t.Parallel()
+
+			_, err := config.FromEnvironment(
+				environment{clientHeaderMaxBytes: value}.lookupEnv)
+
+			want := clientHeaderMaxBytes + `: "` + value +
+				`" is not a size of more than 4K, such as 32K`
+			if err == nil || err.Error() != want {
+				t.Errorf("error %v, want %s", err, want)
+			}
+		})
 	}
 }

@@ -222,6 +260,8 @@ func TestInvalidValueStopsTheStart(t *testing.T) {
 		{denyNets, "198.51.100.0/24,"},
 		{clientRequestTimeout, "60"},
 		{clientRequestTimeout, ""},
+		{clientIdleTimeout, "0s"},
+		{clientIdleTimeout, "2 minutes"},
 		{clientResponseTimeout, "1y"},
 		{upstreamRequestTimeout, "-1s"},
 		{upstreamResponseTimeout, "0s"},
@@ -289,6 +329,8 @@ func TestLogsEachSettingWithItsValue(t *testing.T) {
 		upstreamURL:             "http://127.0.0.1:8081",
 		trustedProxies:          "10.0.0.0/8,172.16.0.0/12,192.168.0.0/16",
 		clientRequestTimeout:    "45s",
+		clientHeaderMaxBytes:    "32K",
+		clientIdleTimeout:       "120s",
 		clientResponseTimeout:   "30m",
 		upstreamRequestTimeout:  "60s",
 		upstreamResponseTimeout: "30m",
@@ -314,6 +356,8 @@ func wantSettings(t *testing.T, got *config.Config, want config.Config) {

 	if got.ListenAddr != want.ListenAddr ||
 		got.ClientRequestTimeout != want.ClientRequestTimeout ||
+		got.ClientRequestHeaderMaxBytes != want.ClientRequestHeaderMaxBytes ||
+		got.ClientIdleTimeout != want.ClientIdleTimeout ||
 		got.ClientResponseTimeout != want.ClientResponseTimeout ||
 		got.UpstreamRequestTimeout != want.UpstreamRequestTimeout ||
 		got.UpstreamResponseTimeout != want.UpstreamResponseTimeout ||