From: Andrei Pavel <andrei@isc.org>
Date: Wed, 6 Jul 2022 19:33:37 +0000 (+0300)
Subject: [#2448] make NEXT_STEP_DROP in dhcpX_srv_configured lead to DHCPX_CONFIG_LOAD_FAIL
X-Git-Tag: Kea-2.2.0~74
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7879c8d56edf9ca3b0428bbb1cb84c5d5749d481;p=thirdparty%2Fkea.git

[#2448] make NEXT_STEP_DROP in dhcpX_srv_configured lead to DHCPX_CONFIG_LOAD_FAIL
---

diff --git a/src/bin/dhcp4/ctrl_dhcp4_srv.cc b/src/bin/dhcp4/ctrl_dhcp4_srv.cc
index 196b03a809..431c13026f 100644
--- a/src/bin/dhcp4/ctrl_dhcp4_srv.cc
+++ b/src/bin/dhcp4/ctrl_dhcp4_srv.cc
@@ -914,7 +914,6 @@ ControlledDhcpv4Srv::processConfig(isc::data::ConstElementPtr config) {
     try {
         Dhcp4to6Ipc::instance().open();
     } catch (const std::exception& ex) {
-        std::ostringstream err;
         err << "error starting DHCPv4-over-DHCPv6 IPC "
                " after server reconfiguration: " << ex.what();
         return (isc::config::createAnswer(1, err.str()));
@@ -1013,8 +1012,16 @@ ControlledDhcpv4Srv::processConfig(isc::data::ConstElementPtr config) {
         HooksManager::callCallouts(Hooks.hooks_index_dhcp4_srv_configured_,
                                    *callout_handle);
 
-        // Ignore status code as none of them would have an effect on further
-        // operation.
+        // If next step is DROP, report a configuration error.
+        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) {
+            string error;
+            try {
+                callout_handle->getArgument("error", error);
+            } catch (NoSuchArgument const& ex) {
+                error = "unknown error";
+            }
+            return (isc::config::createAnswer(CONTROL_RESULT_ERROR, error));
+        }
     }
 
     // Apply multi threading settings.
diff --git a/src/bin/dhcp4/dhcp4_hooks.dox b/src/bin/dhcp4/dhcp4_hooks.dox
index b88f76b986..47a490b347 100644
--- a/src/bin/dhcp4/dhcp4_hooks.dox
+++ b/src/bin/dhcp4/dhcp4_hooks.dox
@@ -63,8 +63,11 @@ to the end of this list.
    provides access to the DHCP service state of the server and allows for
    enabling and disabling the DHCP service from the hooks libraries.
 
- - <b>Next step status</b>: Status codes returned by the callouts installed on
-   this hook point are ignored.
+ - <b>Next step status</b>: If any callout sets the status to DROP, the server
+   will interrupt the reconfiguration process. The hook callout is expected to
+   have completed the cause of the interruption under the "error" handle argument
+   with a std::string which is then logged. Finally, this leads to the
+   termination of kea-dhcp4.
 
  @subsection dhcpv4HooksCb4Update cb4_updated
  - @b Arguments:
diff --git a/src/bin/dhcp6/ctrl_dhcp6_srv.cc b/src/bin/dhcp6/ctrl_dhcp6_srv.cc
index 40d27c971b..316937ebad 100644
--- a/src/bin/dhcp6/ctrl_dhcp6_srv.cc
+++ b/src/bin/dhcp6/ctrl_dhcp6_srv.cc
@@ -919,7 +919,6 @@ ControlledDhcpv6Srv::processConfig(isc::data::ConstElementPtr config) {
         }
 
     } catch (const std::exception& ex) {
-        std::ostringstream err;
         err << "unable to configure server identifier: " << ex.what();
         return (isc::config::createAnswer(1, err.str()));
     }
@@ -937,7 +936,6 @@ ControlledDhcpv6Srv::processConfig(isc::data::ConstElementPtr config) {
     try {
         Dhcp6to4Ipc::instance().open();
     } catch (const std::exception& ex) {
-        std::ostringstream err;
         err << "error starting DHCPv4-over-DHCPv6 IPC "
                " after server reconfiguration: " << ex.what();
         return (isc::config::createAnswer(1, err.str()));
@@ -1035,8 +1033,16 @@ ControlledDhcpv6Srv::processConfig(isc::data::ConstElementPtr config) {
         HooksManager::callCallouts(Hooks.hooks_index_dhcp6_srv_configured_,
                                    *callout_handle);
 
-        // Ignore status code as none of them would have an effect on further
-        // operation.
+        // If next step is DROP, report a configuration error.
+        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) {
+            string error;
+            try {
+                callout_handle->getArgument("error", error);
+            } catch (NoSuchArgument const& ex) {
+                error = "unknown error";
+            }
+            return (isc::config::createAnswer(CONTROL_RESULT_ERROR, error));
+        }
     }
 
     // Apply multi threading settings.
diff --git a/src/bin/dhcp6/dhcp6_hooks.dox b/src/bin/dhcp6/dhcp6_hooks.dox
index a7afd1ae7e..4c5af6ff8b 100644
--- a/src/bin/dhcp6/dhcp6_hooks.dox
+++ b/src/bin/dhcp6/dhcp6_hooks.dox
@@ -63,8 +63,12 @@ to the end of this list.
    provides access to the DHCP service state of the server and allows for
    enabling and disabling the DHCP service from the hooks libraries.
 
- - <b>Next step status</b>: Status codes returned by the callouts installed on
-   this hook point are ignored.
+
+ - <b>Next step status</b>: If any callout sets the status to DROP, the server
+   will interrupt the reconfiguration process. The hook callout is expected to
+   have completed the cause of the interruption under the "error" handle argument
+   with a std::string which is then logged. Finally, this leads to the
+   termination of kea-dhcp6.
 
  @subsection dhcpv6HooksCb6Update cb6_updated
  - @b Arguments: