networkd: drop DHCPv4 config on stop, keep on restart, by default

This partially reverts 95355a2. It seems that other parts of link_stop_clients() should be skipped when restarting, but I don't know enough about those other clients to have an opinion if it is better to stop&start them on restart or not. Anyway, that can be done in later patches now that the support for restarts is there. Fixes #13625.
systemd · Oct 2, 2019 · 8006035 · 8006035
1 parent ab76be5
commit 8006035
Show file tree

Hide file tree

Showing 3 changed files with 10 additions and 8 deletions.
diff --git a/man/systemd.network.xml b/man/systemd.network.xml
@@ -876,8 +876,8 @@
  lease expires. This is contrary to the DHCP specification, but may be the best choice if,
  e.g., the root filesystem relies on this connection. The setting <literal>dhcp</literal>
  implies <literal>dhcp-on-stop</literal>, and <literal>yes</literal> implies
- <literal>dhcp</literal> and <literal>static</literal>. Defaults to
- <literal>dhcp-on-stop</literal>.</para>
+ <literal>dhcp</literal> and <literal>static</literal>. Defaults to <literal>no</literal>.
+ </para>
  </listitem>
  </varlistentry>
 

diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
@@ -770,8 +770,12 @@ int link_stop_clients(Link *link, bool may_keep_dhcp) {
 
  dhcp4_release_old_lease(link);
 
- if (link->dhcp_client && (!may_keep_dhcp || !link->network ||
- !FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP_ON_STOP))) {
+ bool keep_dhcp = may_keep_dhcp &&
+ link->network &&
+ (link->manager->restarting ||
+ FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP_ON_STOP));
+
+ if (link->dhcp_client && !keep_dhcp) {
  k = sd_dhcp_client_stop(link->dhcp_client);
  if (k < 0)
  r = log_link_warning_errno(link, k, "Could not stop DHCPv4 client: %m");

diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
@@ -268,13 +268,11 @@ int network_verify(Network *network) {
  /* CriticalConnection=yes also preserve foreign static configurations. */
  network->keep_configuration = KEEP_CONFIGURATION_YES;
  else
- /* For backward compatibility, we do not release DHCP addresses on manager stop. */
- network->keep_configuration = KEEP_CONFIGURATION_DHCP_ON_STOP;
+ network->keep_configuration = KEEP_CONFIGURATION_NO;
  }
 
  if (network->keep_configuration < 0)
- /* For backward compatibility, we do not release DHCP addresses on manager stop. */
- network->keep_configuration = KEEP_CONFIGURATION_DHCP_ON_STOP;
+ network->keep_configuration = KEEP_CONFIGURATION_NO;
 
  LIST_FOREACH_SAFE(addresses, address, address_next, network->static_addresses)
  if (address_section_verify(address) < 0)