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From: Patrick Geltinger <patlkli@patlkli.org>
To: connman@lists.linux.dev
Cc: Patrick Geltinger <patlkli@patlkli.org>
Subject: [PATCH] dns: filter invalid addresses for systemd-resolved
Date: Wed, 23 Aug 2023 19:46:13 +0200	[thread overview]
Message-ID: <20230823174613.706596-1-patlkli@patlkli.org> (raw)

systemd-resolved's SetLinkDNS method will refuse to apply any changes if
any of the specified DNS server addresses are invalid (zero address or
their own DNS stub).

To avoid a misconfigured DHCP server leaving the system without any DNS
configuration, filter the server list before calling SetLinkDNS.
---
 src/dns-systemd-resolved.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/dns-systemd-resolved.c b/src/dns-systemd-resolved.c
index 912ab3fe..413daf20 100644
--- a/src/dns-systemd-resolved.c
+++ b/src/dns-systemd-resolved.c
@@ -99,11 +99,16 @@ static void setlinkdns_append(DBusMessageIter *iter, void *user_data)
 
 		DBG("index: %d, server: %s", iface->index, server);
 
+		type = connman_inet_check_ipaddress(server);
+
+		if (__connman_inet_is_any_addr(server, type)) {
+			DBG("Ignoring invalid address: %s", server);
+			continue;
+		}
+
 		dbus_message_iter_open_container(&address_array,
 				DBUS_TYPE_STRUCT, NULL, &struct_array);
 
-		type = connman_inet_check_ipaddress(server);
-
 		if (type == AF_INET) {
 			result = inet_pton(type, server, ipv4_bytes);
 			if (result != 1) {
-- 
2.39.2


                 reply	other threads:[~2023-08-23 17:54 UTC|newest]

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