From 4d05ba2c58cd6e314f07fbb569c1d05efb12ba46 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Tue, 12 Mar 2024 19:13:46 +0100 Subject: 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 Signed-off-by: Stefano Brivio Reviewed-by: David Gibson --- conf.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'conf.c') diff --git a/conf.c b/conf.c index 17c667a..ac9fb34 100644 --- a/conf.c +++ b/conf.c @@ -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"); + } } /** -- cgit v1.2.3