Package: stunnel4 Version: 3:5.74-2 Severity: normal I have a single configured tunnel, very simply
$ cat /etc/stunnel/jon-znc.conf [jon-znc] accept = 1234 connect = 127.0.0.1:1235 cert = <redacted> key = <redacted> If I try to start this using the systemd generator, it fails with "address already in use" # systemctl start [email protected] # systemctl status [email protected] … Aug 18 14:29:46 luv stunnel[1424926]: LOG5[ui]: Binding service [jon-znc] to :::1234: Address already in use (98) There is nothing bound to port 1234. Starting the service by hand works: $ sudo /usr/bin/stunnel4 /etc/stunnel/jon-znc.conf $ sudo lsof -ni:1234 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME stunnel4 1424947 root 9u IPv4 20106843 0t0 TCP *:1234 (LISTEN) The host is dual stack. If I configure the accept to my public IPv4 address, I get past that specific error, but inexplicably the server terminates shortly afterwards. Note: I'd rather not encode my public IPv4 in this file, but I can't see another way to say "bind on IPv4 only": Aug 18 15:00:06 luv systemd[1]: Started [email protected] - TLS tunnel for network daemons - per-config-file service. Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: stunnel 5.74 on aarch64-unknown-linux-gnu platform Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Compiled with OpenSSL 3.4.0 22 Oct 2024 Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Running with OpenSSL 3.5.1 1 Jul 2025 Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Update OpenSSL shared libraries or rebuild stunnel Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Threading:PTHREAD Sockets:POLL,IPv6,SYSTEMD TLS:ENGINE,OCSP,PSK,SNI Auth:LIBWRAP Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Reading configuration from file /etc/stunnel/jon-znc.conf Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: UTF-8 byte order mark not detected Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: FIPS mode disabled Aug 18 15:00:06 luv stunnel[1425647]: LOG5[ui]: Configuration successful Aug 18 15:00:06 luv stunnel[1425651]: LOG5[main]: Terminated Aug 18 15:00:06 luv systemd[1]: [email protected]: Deactivated successfully.
