wip: migrate to mono-repo. SPN has already been moved to spn/

service/network/state/tcp.go

@@ -0,0 +1,91 @@
+package state
+
+import (
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/safing/portbase/log"
+	"github.com/safing/portbase/utils"
+	"github.com/safing/portmaster/service/network/socket"
+)
+
+const (
+	minDurationBetweenTableUpdates = 10 * time.Millisecond
+)
+
+type tcpTable struct {
+	version int
+
+	connections []*socket.ConnectionInfo
+	listeners   []*socket.BindInfo
+	lock        sync.RWMutex
+
+	// lastUpdateAt stores the time when the tables where last updated as unix nanoseconds.
+	lastUpdateAt atomic.Int64
+
+	fetchLimiter *utils.CallLimiter
+	fetchTable   func() (connections []*socket.ConnectionInfo, listeners []*socket.BindInfo, err error)
+
+	dualStack *tcpTable
+}
+
+var (
+	tcp6Table = &tcpTable{
+		version:      6,
+		fetchLimiter: utils.NewCallLimiter(minDurationBetweenTableUpdates),
+		fetchTable:   getTCP6Table,
+	}
+
+	tcp4Table = &tcpTable{
+		version:      4,
+		fetchLimiter: utils.NewCallLimiter(minDurationBetweenTableUpdates),
+		fetchTable:   getTCP4Table,
+	}
+)
+
+// EnableTCPDualStack adds the TCP6 table to the TCP4 table as a dual-stack.
+// Must be called before any lookup operation.
+func EnableTCPDualStack() {
+	tcp4Table.dualStack = tcp6Table
+}
+
+func (table *tcpTable) getCurrentTables() (
+	connections []*socket.ConnectionInfo,
+	listeners []*socket.BindInfo,
+) {
+	table.lock.RLock()
+	defer table.lock.RUnlock()
+
+	return table.connections, table.listeners
+}
+
+func (table *tcpTable) updateTables() (
+	connections []*socket.ConnectionInfo,
+	listeners []*socket.BindInfo,
+) {
+	// Fetch tables.
+	table.fetchLimiter.Do(func() {
+		// Fetch new tables from system.
+		connections, listeners, err := table.fetchTable()
+		if err != nil {
+			log.Warningf("state: failed to get TCP%d socket table: %s", table.version, err)
+			return
+		}
+
+		// Pre-check for any listeners.
+		for _, bindInfo := range listeners {
+			bindInfo.ListensAny = bindInfo.Local.IP.Equal(net.IPv4zero) || bindInfo.Local.IP.Equal(net.IPv6zero)
+		}
+
+		// Apply new tables.
+		table.lock.Lock()
+		defer table.lock.Unlock()
+		table.connections = connections
+		table.listeners = listeners
+		table.lastUpdateAt.Store(time.Now().UnixNano())
+	})
+
+	return table.getCurrentTables()
+}