Map uinput keysyms and typed text through the console's active keymap, and cover the keypad, lock and AltGr keysyms

client/vnc/server/input_uinput_keymap_linux_test.go

@@ -0,0 +1,62 @@
+//go:build linux
+
+package server
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// KDGKBENT values come in two encodings: a type byte with a Latin-1 character
+// below it, or a Unicode code point XOR 0xf000. Anything that is not a
+// character (function keys, modifiers, holes) must not map to one.
+func TestConsoleKeymapRune(t *testing.T) {
+	tests := []struct {
+		name   string
+		value  uint16
+		want   rune
+		wantOK bool
+	}{
+		{"latin a", 0x0061, 'a', true},
+		{"letter a (caps-lock aware)", 0x0b61, 'a', true},
+		{"unicode e-acute", 0x00e9 ^ 0xf000, 'é', true},
+		{"unicode euro", 0x20ac ^ 0xf000, '€', true},
+		{"unicode y-umlaut", 0x00ff ^ 0xf000, 'ÿ', true},
+		{"function key", 0x0100, 0, false},
+		{"braille type is not unicode", 0x0e01, 0, false},
+		{"hole", 0x0200, 0, false},
+		{"control char", 0x0009, 0, false},
+		{"delete", 0x007f, 0, false},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := consoleKeymapRune(tc.value)
+			assert.Equal(t, tc.wantOK, ok, "decodes to a character")
+			if tc.wantOK {
+				assert.Equal(t, tc.want, got, "decoded character")
+			}
+		})
+	}
+}
+
+// On a German console 'y' and 'z' swap places. The keysym table has to follow
+// the console, or every z typed remotely comes out as a y.
+func TestOverlayConsoleKeymap_FollowsLayout(t *testing.T) {
+	const keyY, keyZ = 21, 44
+	table := map[uint32]uint16{'y': keyY, 'z': keyZ, 0xff0d: keyEnter}
+	german := map[rune]consoleKey{'z': {code: keyY}, 'y': {code: keyZ}, 'Z': {code: keyY, shift: true}}
+
+	got := overlayConsoleKeymap(table, german)
+
+	assert.Equal(t, uint16(keyY), got['z'], "z is on the US y key on a German layout")
+	assert.Equal(t, uint16(keyZ), got['y'], "y is on the US z key on a German layout")
+	assert.Equal(t, uint16(keyY), got['Z'], "uppercase follows its key; the client sends Shift itself")
+	assert.Equal(t, uint16(keyEnter), got[0xff0d], "non-character keysyms are left alone")
+}
+
+// Without a console keymap the US table stands.
+func TestOverlayConsoleKeymap_NilKeepsTable(t *testing.T) {
+	table := map[uint32]uint16{'y': 21}
+	assert.Equal(t, uint16(21), overlayConsoleKeymap(table, nil)['y'])
+}