From ff63ac922a4017de8a5d384b1c0be36433436ed8 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 3 Oct 2024 15:14:02 +1000 Subject: conf: Add --dns-host option to configure host side nameserver When redirecting DNS queries with the --dns-forward option, passt/pasta needs a host side nameserver to redirect the queries to. This is controlled by the c->ip[46].dns_host variables. This is set to the first first nameserver listed in the host's /etc/resolv.conf, and there isn't currently a way to override it from the command line. Prior to 0b25cac9 ("conf: Treat --dns addresses as guest visible addresses") it was possible to alter this with the -D/--dns option. However, doing so was confusing and had some nonsensical edge cases because -D generally takes guest side addresses, rather than host side addresses. Add a new --dns-host option to restore this functionality in a more sensible way. Link: https://bugs.passt.top/show_bug.cgi?id=102 Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- passt.1 | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'passt.1') diff --git a/passt.1 b/passt.1 index 5ac2962..ef33267 100644 --- a/passt.1 +++ b/passt.1 @@ -249,10 +249,19 @@ the host. .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). 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). +nameserver (with corresponding IP version) specified by the +\fB\-\-dns-host\fR option. 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 \-\-dns-host " " \fIaddr +Configure the host nameserver which guest or namespace queries to the +\fB\-\-dns-forward\fR address will be redirected to. This option can +be specified zero to two times (once for IPv4, once for IPv6). +By default, the first nameserver from the host's +\fI/etc/resolv.conf\fR. .TP .BR \-S ", " \-\-search " " \fIlist -- cgit v1.2.3