tunnel: support turning off automatic routing table

This supports the familiar "Table = off" syntax as on Linux, and then
interprets other valid values as simply "on".

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

2 files changed, 21 insertions, 3 deletions

diff --git a/ui/syntax/highlighter.go b/ui/syntax/highlighter.go
index d49cab32..a531854b 100644
--- a/ui/syntax/highlighter.go
+++ b/ui/syntax/highlighter.go
@@ -26,6 +26,7 @@ const (
 	highlightKeepalive
 	highlightComment
 	highlightDelimiter
+	highlightTable
 	highlightCmd
 	highlightError
 )
@@ -256,6 +257,10 @@ func (s stringSpan) isValidMTU() bool {
 	return s.isValidUint(false, 576, 65535)
 }
 
+func (s stringSpan) isValidTable() bool {
+	return s.isSame("off") || s.isSame("auto") || s.isSame("main") || s.isValidUint(false, 0, (1<<32)-1)
+}
+
 func (s stringSpan) isValidPersistentKeepAlive() bool {
 	if s.isSame("off") {
 		return true
@@ -360,6 +365,7 @@ const (
 	fieldAddress
 	fieldDNS
 	fieldMTU
+	fieldTable
 	fieldPreUp
 	fieldPostUp
 	fieldPreDown
@@ -395,6 +401,8 @@ func (s stringSpan) field() field {
 		return fieldDNS
 	case s.isCaselessSame("MTU"):
 		return fieldMTU
+	case s.isCaselessSame("Table"):
+		return fieldTable
 	case s.isCaselessSame("PublicKey"):
 		return fieldPublicKey
 	case s.isCaselessSame("PresharedKey"):
@@ -508,6 +516,8 @@ func (hsa *highlightSpanArray) highlightValue(parent stringSpan, s stringSpan, s
 		hsa.append(parent.s, s, validateHighlight(s.isValidKey(), highlightPresharedKey))
 	case fieldMTU:
 		hsa.append(parent.s, s, validateHighlight(s.isValidMTU(), highlightMTU))
+	case fieldTable:
+		hsa.append(parent.s, s, validateHighlight(s.isValidTable(), highlightTable))
 	case fieldPreUp, fieldPostUp, fieldPreDown, fieldPostDown:
 		hsa.append(parent.s, s, validateHighlight(s.isValidPrePostUpDown(), highlightCmd))
 	case fieldListenPort:
diff --git a/ui/syntax/syntaxedit.go b/ui/syntax/syntaxedit.go
index 26cd533f..42f6e7b7 100644
--- a/ui/syntax/syntaxedit.go
+++ b/ui/syntax/syntaxedit.go
@@ -100,6 +100,7 @@ var stylemap = map[highlight]spanStyle{
 	highlightHost:         spanStyle{color: win.RGB(0x0E, 0x0E, 0xFF)},
 	highlightPort:         spanStyle{color: win.RGB(0x81, 0x5F, 0x03)},
 	highlightMTU:          spanStyle{color: win.RGB(0x1C, 0x00, 0xCF)},
+	highlightTable:        spanStyle{color: win.RGB(0x1C, 0x00, 0xCF)},
 	highlightKeepalive:    spanStyle{color: win.RGB(0x1C, 0x00, 0xCF)},
 	highlightComment:      spanStyle{color: win.RGB(0x53, 0x65, 0x79), effects: win.CFE_ITALIC},
 	highlightDelimiter:    spanStyle{color: win.RGB(0x00, 0x00, 0x00)},
@@ -110,6 +111,8 @@ var stylemap = map[highlight]spanStyle{
 func (se *SyntaxEdit) evaluateUntunneledBlocking(cfg string, spans []highlightSpan) {
 	state := InevaluableBlockingUntunneledTraffic
 	var onAllowedIPs,
+		onTable,
+		tableOff,
 		seenPeer,
 		seen00v6,
 		seen00v4,
@@ -132,10 +135,13 @@ func (se *SyntaxEdit) evaluateUntunneledBlocking(cfg string, spans []highlightSp
 			} else {
 				goto done
 			}
-			break
 		case highlightField:
 			onAllowedIPs = strings.EqualFold(cfg[span.s:span.s+span.len], "AllowedIPs")
-			break
+			onTable = strings.EqualFold(cfg[span.s:span.s+span.len], "Table")
+		case highlightTable:
+			if onTable {
+				tableOff = cfg[span.s:span.s+span.len] == "off"
+			}
 		case highlightIP:
 			if !onAllowedIPs || !seenPeer {
 				break
@@ -166,9 +172,11 @@ func (se *SyntaxEdit) evaluateUntunneledBlocking(cfg string, spans []highlightSp
 					seen80001v6 = true
 				}
 			}
-			break
 		}
 	}
+	if tableOff {
+		return
+	}
 
 	if seen00v4 || seen00v6 {
 		state = BlockingUntunneledTraffic