From: Tom Gundersen Date: Mon, 27 Jan 2014 19:52:07 +0000 (+0100) Subject: networkd: dhcpv4 - add notion of 'CriticalConnection' X-Git-Tag: v209~286 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=eb27aeca247a4cf8816fffc4c0dbcab55ead3864 networkd: dhcpv4 - add notion of 'CriticalConnection' These connections are never torn down, even when the DHCP specifications say that they should be. This is useful/necessary when the rootfs (or another critical fs) is mounted over this network connection, and dataloss would result if the connection is lost. This option defaults to off, but our initrd generator (TBD) will enable it when applicable. --- diff --git a/man/systemd-networkd.service.xml b/man/systemd-networkd.service.xml index 3403a7a1a..3e6fddc71 100644 --- a/man/systemd-networkd.service.xml +++ b/man/systemd-networkd.service.xml @@ -293,6 +293,14 @@ will be used as the transient hostname. + + CriticalConnection + + When true the connection will never be torn down even if the DHCP lease + expires. This is contrary to the DHCP specification, but may be the best choice + if, say, the root filesystem relies on this connection. Defaults to false. + + diff --git a/src/network/networkd-gperf.gperf b/src/network/networkd-gperf.gperf index aff23bb55..de7280562 100644 --- a/src/network/networkd-gperf.gperf +++ b/src/network/networkd-gperf.gperf @@ -15,28 +15,29 @@ struct ConfigPerfItem; %struct-type %includes %% -Match.MACAddress, config_parse_hwaddr, 0, offsetof(Network, match_mac) -Match.Path, config_parse_string, 0, offsetof(Network, match_path) -Match.Driver, config_parse_string, 0, offsetof(Network, match_driver) -Match.Type, config_parse_string, 0, offsetof(Network, match_type) -Match.Name, config_parse_ifname, 0, offsetof(Network, match_name) -Network.Description, config_parse_string, 0, offsetof(Network, description) -Network.Bridge, config_parse_bridge, 0, offsetof(Network, bridge) -Network.Bond, config_parse_bond, 0, offsetof(Network, bond) -Network.VLAN, config_parse_vlan, 0, offsetof(Network, vlan) -Network.DHCP, config_parse_bool, 0, offsetof(Network, dhcp) -Network.Address, config_parse_address, 0, 0 -Network.Gateway, config_parse_gateway, 0, 0 -Network.DNS, config_parse_dns, 0, offsetof(Network, dns) -Address.Address, config_parse_address, 0, 0 -Address.Label, config_parse_label, 0, 0 -Route.Gateway, config_parse_gateway, 0, 0 -Route.Destination, config_parse_destination, 0, 0 -DHCPv4.UseDNS, config_parse_bool, 0, offsetof(Network, dhcp_dns) -DHCPv4.UseMTU, config_parse_bool, 0, offsetof(Network, dhcp_mtu) -DHCPv4.UseHostname, config_parse_bool, 0, offsetof(Network, dhcp_hostname) -DHCPv4.UseDomainName, config_parse_bool, 0, offsetof(Network, dhcp_domainname) -Netdev.Description, config_parse_string, 0, offsetof(Netdev, description) -Netdev.Name, config_parse_ifname, 0, offsetof(Netdev, name) -Netdev.Kind, config_parse_netdev_kind, 0, offsetof(Netdev, kind) -VLAN.Id, config_parse_int, 0, offsetof(Netdev, vlanid) +Match.MACAddress, config_parse_hwaddr, 0, offsetof(Network, match_mac) +Match.Path, config_parse_string, 0, offsetof(Network, match_path) +Match.Driver, config_parse_string, 0, offsetof(Network, match_driver) +Match.Type, config_parse_string, 0, offsetof(Network, match_type) +Match.Name, config_parse_ifname, 0, offsetof(Network, match_name) +Network.Description, config_parse_string, 0, offsetof(Network, description) +Network.Bridge, config_parse_bridge, 0, offsetof(Network, bridge) +Network.Bond, config_parse_bond, 0, offsetof(Network, bond) +Network.VLAN, config_parse_vlan, 0, offsetof(Network, vlan) +Network.DHCP, config_parse_bool, 0, offsetof(Network, dhcp) +Network.Address, config_parse_address, 0, 0 +Network.Gateway, config_parse_gateway, 0, 0 +Network.DNS, config_parse_dns, 0, offsetof(Network, dns) +Address.Address, config_parse_address, 0, 0 +Address.Label, config_parse_label, 0, 0 +Route.Gateway, config_parse_gateway, 0, 0 +Route.Destination, config_parse_destination, 0, 0 +DHCPv4.UseDNS, config_parse_bool, 0, offsetof(Network, dhcp_dns) +DHCPv4.UseMTU, config_parse_bool, 0, offsetof(Network, dhcp_mtu) +DHCPv4.UseHostname, config_parse_bool, 0, offsetof(Network, dhcp_hostname) +DHCPv4.UseDomainName, config_parse_bool, 0, offsetof(Network, dhcp_domainname) +DHCPv4.CriticalConnection, config_parse_bool, 0, offsetof(Network, dhcp_critical) +Netdev.Description, config_parse_string, 0, offsetof(Netdev, description) +Netdev.Name, config_parse_ifname, 0, offsetof(Netdev, name) +Netdev.Kind, config_parse_netdev_kind, 0, offsetof(Netdev, kind) +VLAN.Id, config_parse_int, 0, offsetof(Netdev, vlanid) diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c index d9622ac4b..9b5ebeda2 100644 --- a/src/network/networkd-link.c +++ b/src/network/networkd-link.c @@ -443,6 +443,12 @@ static void dhcp_handler(sd_dhcp_client *client, int event, void *userdata) { if (event == DHCP_EVENT_IP_CHANGE || event == DHCP_EVENT_EXPIRED || event == DHCP_EVENT_STOP) { + if (link->network->dhcp_critical) { + log_warning_link(link, "DHCPv4 connection considered system critical, " + "ignoring request to reconfigure it down."); + return; + } + if (link->dhcp_address) { address_drop(link->dhcp_address, link, address_drop_handler); diff --git a/src/network/networkd.h b/src/network/networkd.h index 22dcbd098..968edf6a7 100644 --- a/src/network/networkd.h +++ b/src/network/networkd.h @@ -103,6 +103,7 @@ struct Network { bool dhcp_mtu; bool dhcp_hostname; bool dhcp_domainname; + bool dhcp_critical; LIST_HEAD(Address, static_addresses); LIST_HEAD(Route, static_routes);