fix: potential endless loop under extremely high load

If there are more connections waiting to be accepted than
MAX_INCOMING_CONNECTIONS existing accepted connections are overwritten.

Author: sudden6

other/bootstrap_daemon/docker/tox-bootstrapd.sha256

@@ -1 +1 @@
-5cf49ad258527f6a2734a9d1f863084f66189338f47ca9d0a49482b4217577fb  /usr/local/bin/tox-bootstrapd
+2f7cc0e1acb07697f55fce064328e8193e54bd20189370b0c56c3b2264bdfa24  /usr/local/bin/tox-bootstrapd

toxcore/TCP_server.c

@@ -1033,12 +1033,15 @@ TCP_Server *new_TCP_server(const Logger *logger, const Random *rng, const Networ
 non_null()
 static void do_TCP_accept_new(TCP_Server *tcp_server)
 {
-    for (uint32_t i = 0; i < tcp_server->num_listening_socks; ++i) {
-        Socket sock;
+    for (uint32_t sock_idx = 0; sock_idx < tcp_server->num_listening_socks; ++sock_idx) {
+
+        for (uint32_t connection_idx = 0; connection_idx < MAX_INCOMING_CONNECTIONS; ++connection_idx) {
+            const Socket sock = net_accept(tcp_server->ns, tcp_server->socks_listening[sock_idx]);
 
-        do {
-            sock = net_accept(tcp_server->ns, tcp_server->socks_listening[i]);
-        } while (accept_connection(tcp_server, sock) != -1);
+            if (accept_connection(tcp_server, sock) == -1) {
+                break;
+            }
+        }
     }
 }
 #endif