From 350555f843b255c499f1946ce8acb8e46a130d04 Mon Sep 17 00:00:00 2001
From: Daniel <dhaavi@users.noreply.github.com>
Date: Fri, 24 Apr 2020 09:59:36 +0200
Subject: [PATCH] Fix concurrent map read/write, maybe

---
 network/clean.go    | 11 +++++++----
 network/database.go |  6 ++++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/network/clean.go b/network/clean.go
index ec51b611..3b1bbac9 100644
--- a/network/clean.go
+++ b/network/clean.go
@@ -41,8 +41,14 @@ func cleanConnections() (activePIDs map[int]struct{}) {
 		now := time.Now().Unix()
 		deleteOlderThan := time.Now().Add(-deleteConnsAfterEndedThreshold).Unix()
 
-		// network connections
+		// lock both together because we cannot fully guarantee in which map a connection lands
+		// of course every connection should land in the correct map, but this increases resilience
 		connsLock.Lock()
+		defer connsLock.Unlock()
+		dnsConnsLock.Lock()
+		defer dnsConnsLock.Unlock()
+
+		// network connections
 		for key, conn := range conns {
 			conn.Lock()
 
@@ -67,10 +73,8 @@ func cleanConnections() (activePIDs map[int]struct{}) {
 
 			conn.Unlock()
 		}
-		connsLock.Unlock()
 
 		// dns requests
-		dnsConnsLock.Lock()
 		for _, conn := range dnsConns {
 			conn.Lock()
 
@@ -82,7 +86,6 @@ func cleanConnections() (activePIDs map[int]struct{}) {
 
 			conn.Unlock()
 		}
-		dnsConnsLock.Unlock()
 
 		return nil
 	})
diff --git a/network/database.go b/network/database.go
index 073dcbc0..ee42a5b1 100644
--- a/network/database.go
+++ b/network/database.go
@@ -77,9 +77,11 @@ func (s *StorageInterface) processQuery(q *query.Query, it *iterator.Iterator) {
 	if slashes <= 1 {
 		// processes
 		for _, proc := range process.All() {
+			proc.Lock()
 			if q.Matches(proc) {
 				it.Next <- proc
 			}
+			proc.Unlock()
 		}
 	}
 
@@ -87,9 +89,11 @@ func (s *StorageInterface) processQuery(q *query.Query, it *iterator.Iterator) {
 		// dns scopes only
 		dnsConnsLock.RLock()
 		for _, dnsConn := range dnsConns {
+			dnsConn.Lock()
 			if q.Matches(dnsConn) {
 				it.Next <- dnsConn
 			}
+			dnsConn.Unlock()
 		}
 		dnsConnsLock.RUnlock()
 	}
@@ -98,9 +102,11 @@ func (s *StorageInterface) processQuery(q *query.Query, it *iterator.Iterator) {
 		// connections
 		connsLock.RLock()
 		for _, conn := range conns {
+			conn.Lock()
 			if q.Matches(conn) {
 				it.Next <- conn
 			}
+			conn.Unlock()
 		}
 		connsLock.RUnlock()
 	}