Count unix sockets when counting client listeners

Users can't run an anonymous client and non-anonymous single
onion service at the same time. We need to know whether we have
any client ports or sockets open to do this check.

When determining whether a client port (SOCKS, Trans, NATD, DNS)
is set, count unix sockets when counting client listeners. This
has no user-visible behaviour change, because these options are
set once and never read in the current tor codebase.

Don't count sockets when setting ControlPort_set, that's what
ControlSocket is for. (This will be reviewed in #19665.)

Don't count sockets when counting server listeners, because the code
that uses these options expects to count externally-visible ports.
(And it would change the behaviour of Tor.)

1 files changed, 7 insertions, 3 deletions

diff --git a/src/or/or.h b/src/or/or.h
index 34089ad994..574f184a13 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -3604,9 +3604,13 @@ typedef struct {
 
   /** @name port booleans
    *
-   * Derived booleans: True iff there is a non-listener port on an AF_INET or
-   * AF_INET6 address of the given type configured in one of the _lines
-   * options above.
+   * Derived booleans: For server ports and ControlPort, true iff there is a
+   * non-listener port on an AF_INET or AF_INET6 address of the given type
+   * configured in one of the _lines options above.
+   * For client ports, also true if there is a unix socket configured.
+   * If you are checking for client ports, you may want to use:
+   *   SocksPort_set || TransPort_set || NATDPort_set || DNSPort_set
+   * rather than SocksPort_set.
    *
    * @{
    */