Added LastSeen and Active Members to Session Struct

c2/channel/channel.go

@@ -31,6 +31,8 @@ type Session struct {
 	RemoteAddr     string
 	ConnectionTime time.Time
 	conn           *net.Conn
+	Active         bool
+	LastSeen       time.Time
 }
 
 // HasSessions checks if a channel has any tracked sessions. This can be used to lookup if a C2
@@ -39,7 +41,13 @@ type Session struct {
 //	c, ok := c2.GetInstance(conf.C2Type)
 //	c.Channel().HasSessions()
 func (c *Channel) HasSessions() bool {
-	return len(c.Sessions) > 0
+	for _, sess := range c.Sessions {
+		if sess.Active {
+			return true
+		}
+	}
+
+	return false
 }
 
 // AddSession adds a remote connection for session tracking. If a network connection is being
@@ -65,19 +73,61 @@ func (c *Channel) AddSession(conn *net.Conn, addr string) bool {
 		ConnectionTime: time.Now(),
 		conn:           conn,
 		RemoteAddr:     addr,
+		LastSeen:       time.Now(),
+		Active:         true,
+	}
+
+	return true
+}
+
+// Updates the LastSeen value for provided connection to the provided time
+func (c *Channel) UpdateLastSeenByConn(conn net.Conn, timeStamp time.Time) bool {
+	id, ok := c.GetSessionIDByConn(conn)
+	if !ok {
+		return false
+	}
+
+	session, ok := c.Sessions[id]
+	if !ok {
+		output.PrintFrameworkError("Session ID does not exist")
+
+		return false
 	}
 
+	session.LastSeen = timeStamp
+	c.Sessions[id] = session
+
 	return true
 }
 
+// Returns the session ID that contains a given connection
+func (c *Channel) GetSessionIDByConn(conn net.Conn) (string, bool) {
+	if len(c.Sessions) == 0 {
+		output.PrintFrameworkDebug("No sessions exist")
+
+		return "", false
+	}
+
+	for id, session := range c.Sessions {
+		if *session.conn == conn {
+			return id, true
+		}
+	}
+
+	output.PrintFrameworkError("Conn does not exist in sessions")
+
+	return "", false
+}
+
+
 // RemoveSession removes a specific session ID and if a connection exists, closes it.
 func (c *Channel) RemoveSession(id string) bool {
 	if len(c.Sessions) == 0 {
 		output.PrintFrameworkDebug("No sessions exist")
 
 		return false
 	}
-	_, ok := c.Sessions[id]
+	session, ok := c.Sessions[id]
 	if !ok {
 		output.PrintFrameworkError("Session ID does not exist")
 
@@ -86,7 +136,8 @@ func (c *Channel) RemoveSession(id string) bool {
 	if c.Sessions[id].conn != nil {
 		(*c.Sessions[id].conn).Close()
 	}
-	delete(c.Sessions, id)
+	session.Active = false
+	c.Sessions[id] = session
 
 	return true
 }
@@ -98,11 +149,8 @@ func (c *Channel) RemoveSessions() bool {
 
 		return false
 	}
-	for k := range c.Sessions {
-		if c.Sessions[k].conn != nil {
-			(*c.Sessions[k].conn).Close()
-		}
-		delete(c.Sessions, k)
+	for id := range c.Sessions {
+		c.RemoveSession(id)
 	}
 
 	return true

c2/cli/basic.go

@@ -48,6 +48,13 @@ func backgroundResponse(ch *channel.Channel, wg *sync.WaitGroup, conn net.Conn,
 			// could have move data to write, but the user has already called exit
 			// below. I that that's tolerable for now.
 			responseCh <- string(responseBuffer[:bytesRead])
+			// Update "Last Seen"
+			ok := ch.UpdateLastSeenByConn(conn, time.Now())
+			if !ok {
+				output.PrintFrameworkError("Failed to update LastSeen value for connection")
+
+				return
+			}
 		}
 		time.Sleep(10 * time.Millisecond)
 	}