net: dhcpv6: Honor network interface for DNS servers (248cb3d2) · Commits · Wenxi XU / zephyr

subsys/net/lib/dhcpv6/Kconfig

+17 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,23 @@ config NET_DHCPV6_OPTION_DNS_ADDRESS
		option from the server, and if available, use obtained information
		to configure DNS resolver.

		config NET_DHCPV6_DNS_SERVER_VIA_INTERFACE
		bool "Make DNS servers specific to the network interface"
		depends on NET_DHCPV6_OPTION_DNS_ADDRESS
		default y
		help
		If this is set, then if the system has multiple network interfaces
		and each has DHCP enabled, then assign DNS servers received from that
		network interface, to that specific interface.
		If this option is not set, then any interface can be used for all
		the configured DNS server addresses when doing DNS queries.
		Example: We receive DNS server 2001:db8::1:53 DHCPv6 option from Wi-Fi
		interface and DNS server 2001:db8::2:53 from Ethernet interface.
		When this option is set, the DNS resolver will use DNS server
		2001:db8::1:53 when sending DNS query to the Wi-Fi interface and DNS
		server 2001:db8::2:53 when sending DNS query to the Ethernet
		interface.

		if NET_DHCPV6
		module = NET_DHCPV6
		module-dep = NET_LOG

+19 −1

Original line number	Diff line number	Diff line
		@@ -1412,7 +1412,25 @@ static int dhcpv6_handle_dns_server_option(struct net_pkt *pkt)
		}

		ctx = dns_resolve_get_default();

		if (IS_ENABLED(CONFIG_NET_DHCPV6_DNS_SERVER_VIA_INTERFACE)) {
		/* If we are using the interface to resolve DNS servers,
		* we need to save the interface index.
		*/
		int ifindex = net_if_get_by_iface(net_pkt_iface(pkt));
		int interfaces[MAX_DNS_SERVERS];

		for (uint8_t i = 0; i < server_count; i++) {
		interfaces[i] = ifindex;
		}

		status = dns_resolve_reconfigure_with_interfaces(ctx, NULL,
		dns_servers,
		interfaces);
		} else {
		status = dns_resolve_reconfigure(ctx, NULL, dns_servers);
		}

		if (status < 0) {
		NET_DBG("Failed to reconfigure DNS resolver from DHCPv6 "
		"option: %d", status);