fwd: Broaden what we consider for DNS specific forwarding rules

passt/pasta has options to redirect DNS requests from the guest to a
different server address on the host side.  Currently, however, only UDP
packets to port 53 are considered "DNS requests".  This ignores DNS
requests over TCP - less common, but certainly possible.  It also ignores
encrypted DNS requests on port 853.

Extend the DNS forwarding logic to handle both of those cases.

Link: https://github.com/containers/podman/issues/23239
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/passt.1 b/passt.1
index abc13d5..81789cc 100644
--- a/passt.1
+++ b/passt.1
@@ -244,11 +244,11 @@ usage of DNS addresses altogether.
 
 .TP
 .BR \-\-dns-forward " " \fIaddr
-Map \fIaddr\fR (IPv4 or IPv6) as seen from guest or namespace to the first
-configured DNS resolver (with corresponding IP version). Mapping is limited to
-UDP traffic directed to port 53, and DNS answers are translated back with a
-reverse mapping.
-This option can be specified zero to two times (once for IPv4, once for IPv6).
+Map \fIaddr\fR (IPv4 or IPv6) as seen from guest or namespace to the
+first configured DNS resolver (with corresponding IP version). Maps
+only UDP and TCP traffic to port 53 or port 853.  Replies are
+translated back with a reverse mapping.  This option can be specified
+zero to two times (once for IPv4, once for IPv6).
 
 .TP
 .BR \-S ", " \-\-search " " \fIlist