net: use Sock in CConnman::ListenSocket

Change `CConnman::ListenSocket` to use a pointer to `Sock` instead of a
bare `SOCKET` and use `Sock::Accept()` instead of bare `accept()`. This
will help mocking / testing / fuzzing more code.

Author: vasild

src/net.cpp

@@ -1098,10 +1098,10 @@ bool CConnman::AttemptToEvictConnection()
 void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
-    SOCKET hSocket = accept(hListenSocket.socket, (struct sockaddr*)&sockaddr, &len);
+    auto sock = hListenSocket.sock->Accept((struct sockaddr*)&sockaddr, &len);
     CAddress addr;
 
-    if (hSocket == INVALID_SOCKET) {
+    if (!sock) {
         const int nErr = WSAGetLastError();
         if (nErr != WSAEWOULDBLOCK) {
             LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr));
@@ -1115,12 +1115,12 @@ void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
         addr = CAddress{MaybeFlipIPv6toCJDNS(addr), NODE_NONE};
     }
 
-    const CAddress addr_bind{MaybeFlipIPv6toCJDNS(GetBindAddress(hSocket)), NODE_NONE};
+    const CAddress addr_bind{MaybeFlipIPv6toCJDNS(GetBindAddress(sock->Get())), NODE_NONE};
 
     NetPermissionFlags permissionFlags = NetPermissionFlags::None;
     hListenSocket.AddSocketPermissionFlags(permissionFlags);
 
-    CreateNodeFromAcceptedSocket(hSocket, permissionFlags, addr_bind, addr);
+    CreateNodeFromAcceptedSocket(sock->Release(), permissionFlags, addr_bind, addr);
 }
 
 void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
@@ -1359,7 +1359,7 @@ bool CConnman::GenerateSelectSet(const std::vector<CNode*>& nodes,
                                  std::set<SOCKET>& error_set)
 {
     for (const ListenSocket& hListenSocket : vhListenSocket) {
-        recv_set.insert(hListenSocket.socket);
+        recv_set.insert(hListenSocket.sock->Get());
     }
 
     for (CNode* pnode : nodes) {
@@ -1640,7 +1640,7 @@ void CConnman::SocketHandlerListening(const std::set<SOCKET>& recv_set)
         if (interruptNet) {
             return;
         }
-        if (recv_set.count(listen_socket.socket) > 0) {
+        if (recv_set.count(listen_socket.sock->Get()) > 0) {
             AcceptConnection(listen_socket);
         }
     }
@@ -2391,7 +2391,7 @@ bool CConnman::BindListenPort(const CService& addrBind, bilingual_str& strError,
         return false;
     }
 
-    vhListenSocket.push_back(ListenSocket(sock->Release(), permissions));
+    vhListenSocket.emplace_back(std::move(sock), permissions);
     return true;
 }
 
@@ -2700,15 +2700,6 @@ void CConnman::StopNodes()
         DeleteNode(pnode);
     }
 
-    // Close listening sockets.
-    for (ListenSocket& hListenSocket : vhListenSocket) {
-        if (hListenSocket.socket != INVALID_SOCKET) {
-            if (!CloseSocket(hListenSocket.socket)) {
-                LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
-            }
-        }
-    }
-
     for (CNode* pnode : m_nodes_disconnected) {
         DeleteNode(pnode);
     }

src/net.h

@@ -26,6 +26,7 @@
 #include <threadinterrupt.h>
 #include <uint256.h>
 #include <util/check.h>
+#include <util/sock.h>
 
 #include <atomic>
 #include <condition_variable>
@@ -947,9 +948,13 @@ class CConnman
 private:
     struct ListenSocket {
     public:
-        SOCKET socket;
+        std::shared_ptr<Sock> sock;
         inline void AddSocketPermissionFlags(NetPermissionFlags& flags) const { NetPermissions::AddFlag(flags, m_permissions); }
-        ListenSocket(SOCKET socket_, NetPermissionFlags permissions_) : socket(socket_), m_permissions(permissions_) {}
+        ListenSocket(std::shared_ptr<Sock> sock_, NetPermissionFlags permissions_)
+            : sock{sock_}, m_permissions{permissions_}
+        {
+        }
+
     private:
         NetPermissionFlags m_permissions;
     };