conf: Warn if we can't advertise any nameserver via DHCP, NDP, or DHCPv6

We might have read from resolv.conf, or from the command line, a
resolver that's reachable via loopback address, but that doesn't mean
we can offer that via DHCP, NDP or DHCPv6: warn if there are no
resolvers we can offer for a given IP version.

Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Stefano Brivio 2024-03-12 19:13:46 +01:00
parent 43881636c2
commit 4d05ba2c58

17
conf.c
View file

@ -464,8 +464,21 @@ static void get_dns(struct ctx *c)
close(fd);
out:
if (!dns_set && !added)
warn("Couldn't get any nameserver address");
if (!dns_set) {
if (!added)
warn("Couldn't get any nameserver address");
if (c->no_dhcp_dns)
return;
if (c->ifi4 && !c->no_dhcp &&
IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns[0]))
warn("No IPv4 nameserver available for DHCP");
if (c->ifi6 && ((!c->no_ndp && !c->no_ra) || !c->no_dhcpv6) &&
IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns[0]))
warn("No IPv6 nameserver available for NDP/DHCPv6");
}
}
/**