conf, netlink: Don't require a default route to start

There might be isolated testing environments where default routes and
global connectivity are not needed, a single interface has all
non-loopback addresses and routes, and still passt and pasta are
expected to work.

In this case, it's pretty obvious what our upstream interface should
be, so go ahead and select the only interface with at least one
route, disabling DHCP and implying --no-map-gw as the documentation
already states.

If there are multiple interfaces with routes, though, refuse to start,
because at that point it's really not clear what we should do.

Reported-by: Martin Pitt <mpitt@redhat.com>
Link: https://github.com/containers/podman/issues/21896
Signed-off-by: Stefano brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/conf.c b/conf.c
index ac9fb34..644752c 100644
--- a/conf.c
+++ b/conf.c
@@ -584,7 +584,7 @@ static unsigned int conf_ip4(unsigned int ifi,
 		ifi = nl_get_ext_if(nl_sock, AF_INET);
 
 	if (!ifi) {
-		info("No interface with a default route for IPv4: disabling IPv4");
+		info("No interface with a route for IPv4: disabling IPv4");
 		return 0;
 	}
 
@@ -656,7 +656,7 @@ static unsigned int conf_ip6(unsigned int ifi,
 		ifi = nl_get_ext_if(nl_sock, AF_INET6);
 
 	if (!ifi) {
-		info("No interface with a default route for IPv6: disabling IPv6");
+		info("No interface with a route for IPv6: disabling IPv6");
 		return 0;
 	}