From dc907405494d6c490011daf32ac132006fe18faf Mon Sep 17 00:00:00 2001
From: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Date: Sat, 28 Mar 2020 10:34:01 +0100
Subject: [PATCH] nic_router: accept DHCP reply with missing option

The options are not always set, which throws exception. This leads to not
accepting the selected IP address.

Fixes #3716
---
 repos/os/src/server/nic_router/dhcp_client.cc | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/repos/os/src/server/nic_router/dhcp_client.cc b/repos/os/src/server/nic_router/dhcp_client.cc
index acd94b278..b8e662bcb 100644
--- a/repos/os/src/server/nic_router/dhcp_client.cc
+++ b/repos/os/src/server/nic_router/dhcp_client.cc
@@ -142,12 +142,19 @@ void Dhcp_client::handle_dhcp_reply(Dhcp_packet &dhcp)
 				}
 				_lease_time_sec = dhcp.option<Dhcp_packet::Ip_lease_time>().value();
 				_set_state(State::BOUND, _rerequest_timeout(1));
+
 				Ipv4_address dns_server;
+				Ipv4_address subnet_mask;
+				Ipv4_address router_ip;
+
 				try { dns_server = dhcp.option<Dhcp_packet::Dns_server_ipv4>().value(); }
 				catch (Dhcp_packet::Option_not_found) { }
-				_domain().ip_config(dhcp.yiaddr(),
-				                    dhcp.option<Dhcp_packet::Subnet_mask>().value(),
-				                    dhcp.option<Dhcp_packet::Router_ipv4>().value(),
+				try { subnet_mask = dhcp.option<Dhcp_packet::Subnet_mask>().value(); }
+				catch (Dhcp_packet::Option_not_found) { }
+				try { router_ip = dhcp.option<Dhcp_packet::Router_ipv4>().value(); }
+				catch (Net::Dhcp_packet::Option_not_found) { }
+
+				_domain().ip_config(dhcp.yiaddr(), subnet_mask, router_ip,
 				                    dns_server);
 				break;
 			}