[#3683] Some fixes and improvements

fxdupont · fxdupont · commit 39465743d249 · 2025-03-04T22:49:13.000+01:00
diff --git a/changelog_unreleased/3683-registering-ipv6-addrs b/changelog_unreleased/3683-registering-ipv6-addrs
@@ -0,0 +1,4 @@
+[func]		fdupont
+	Added experimental support for registering self-generated
+	IPv6 addresses using DHCPv6 (RFC 9686).
+	(Gitlab #3683)
diff --git a/src/bin/dhcp6/dhcp6_hooks.dox b/src/bin/dhcp6/dhcp6_hooks.dox
@@ -352,15 +352,16 @@ called before "subnet6_select".
   - name: @b response6, type: isc::dhcp::Pkt6Ptr, direction: <b>in</b>
   - name: @b address6, type: isc::asiolink::IOAddress, direction: <b>in</b>
   - name: @b old_lease6, type: isc::dhcp::Lease6Ptr, direction: <b>in</b>
-  - name: @b new_lease6, type: isc::dhcp::Lease6Ptr, direction: <b>in/out<b>
+  - name: @b new_lease6, type: isc::dhcp::Lease6Ptr, direction: <b>in<b>
 
  - @b Description: this callout is executed when an addr-reg-inform was
-   received and successfully processed. When the new_lease is cleared
-   this instructs the server to make stateless registration i.e. address
-   registration is used only for side effects and does not maintain state.
+   received and successfully processed before the lease operation which
+   maintains when not skipped the registration state.
 
- - <b>Next step status</b>: If any callout sets the status to SKIP or DROP,
-   the server will cancel current packet processing.
+ - <b>Next step status</b>: If any callout sets the status to SKIP, the
+   lease operation (add or update) will be skipped. If any callout sets the
+   status to DROP, the server will cancel current packet processing and
+   the query dropped.
 
 @subsection dhcpv6Leases6Committed leases6_committed
 
diff --git a/src/bin/dhcp6/dhcp6_messages.cc b/src/bin/dhcp6/dhcp6_messages.cc
@@ -65,6 +65,7 @@ extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION = "DHCP6_DYNAMIC_
 extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION_FAIL = "DHCP6_DYNAMIC_RECONFIGURATION_FAIL";
 extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION_SUCCESS = "DHCP6_DYNAMIC_RECONFIGURATION_SUCCESS";
 extern const isc::log::MessageID DHCP6_FLEX_ID = "DHCP6_FLEX_ID";
+extern const isc::log::MessageID DHCP6_HOOK_ADDR6_REGISTER_DROP = "DHCP6_HOOK_ADDR6_REGISTER_DROP";
 extern const isc::log::MessageID DHCP6_HOOK_ADDR6_REGISTER_SKIP = "DHCP6_HOOK_ADDR6_REGISTER_SKIP";
 extern const isc::log::MessageID DHCP6_HOOK_BUFFER_RCVD_DROP = "DHCP6_HOOK_BUFFER_RCVD_DROP";
 extern const isc::log::MessageID DHCP6_HOOK_BUFFER_RCVD_SKIP = "DHCP6_HOOK_BUFFER_RCVD_SKIP";
@@ -237,7 +238,8 @@ const char* values[] = {
     "DHCP6_DYNAMIC_RECONFIGURATION_FAIL", "dynamic server reconfiguration failed with file: %1",
     "DHCP6_DYNAMIC_RECONFIGURATION_SUCCESS", "dynamic server reconfiguration succeeded with file: %1",
     "DHCP6_FLEX_ID", "%1: flexible identifier generated for incoming packet: %2",
-    "DHCP6_HOOK_ADDR6_REGISTER_SKIP", "%1: ADDR-REG-INFORM for %2 is dropped, because a callout set the next step to SKIP",
+    "DHCP6_HOOK_ADDR6_REGISTER_DROP", "%1: ADDR-REG-INFORM for %2 is dropped, because a callout set the next step to DROP",
+    "DHCP6_HOOK_ADDR6_REGISTER_SKIP", "%1: lease %2 operation for %3 is skipped, because a callout set the next step to SKIP",
     "DHCP6_HOOK_BUFFER_RCVD_DROP", "received buffer from %1 to %2 over interface %3 was dropped because a callout set the drop flag",
     "DHCP6_HOOK_BUFFER_RCVD_SKIP", "received buffer from %1 to %2 over interface %3 is not parsed because a callout set the next step to SKIP",
     "DHCP6_HOOK_BUFFER_SEND_SKIP", "%1: prepared DHCPv6 response was dropped because a callout set the next step to SKIP",
diff --git a/src/bin/dhcp6/dhcp6_messages.h b/src/bin/dhcp6/dhcp6_messages.h
@@ -66,6 +66,7 @@ extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION;
 extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION_FAIL;
 extern const isc::log::MessageID DHCP6_DYNAMIC_RECONFIGURATION_SUCCESS;
 extern const isc::log::MessageID DHCP6_FLEX_ID;
+extern const isc::log::MessageID DHCP6_HOOK_ADDR6_REGISTER_DROP;
 extern const isc::log::MessageID DHCP6_HOOK_ADDR6_REGISTER_SKIP;
 extern const isc::log::MessageID DHCP6_HOOK_BUFFER_RCVD_DROP;
 extern const isc::log::MessageID DHCP6_HOOK_BUFFER_RCVD_SKIP;
diff --git a/src/bin/dhcp6/dhcp6_messages.mes b/src/bin/dhcp6/dhcp6_messages.mes
@@ -380,13 +380,20 @@ and the expression specified in its configuration generated (was evaluated to)
 an identifier for incoming packet. This debug message is mainly intended as a
 debugging assistance for flexible identifier.
 
-% DHCP6_HOOK_ADDR6_REGISTER_SKIP %1: ADDR-REG-INFORM for %2 is dropped, because a callout set the next step to SKIP
+% DHCP6_HOOK_ADDR6_REGISTER_DROP %1: ADDR-REG-INFORM for %2 is dropped, because a callout set the next step to DROP
 Logged at debug log level 40.
 This debug message is printed when a callout installed on the addr6_register
-hook point sets the next step to SKIP. For this particular hook point, the
+hook point sets the next step to DROP. For this particular hook point, the
 value setting instructs the server to cancel the address registration and
 drop the packet.
 
+% DHCP6_HOOK_ADDR6_REGISTER_SKIP %1: lease %2 operation for %3 is skipped, because a callout set the next step to SKIP
+Logged at debug log level 40.
+This debug message is printed when a callout installed on the addr6_register
+hook point sets the next step to SKIP. For this particular hook point, the
+value setting instructs the server to skip the lease add or update operation
+for the registered address so not maintaining the registration state.
+
 % DHCP6_HOOK_BUFFER_RCVD_DROP received buffer from %1 to %2 over interface %3 was dropped because a callout set the drop flag
 Logged at debug log level 15.
 This debug message is printed when a callout installed on buffer6_receive
diff --git a/src/bin/dhcp6/dhcp6_srv.cc b/src/bin/dhcp6/dhcp6_srv.cc
@@ -4611,6 +4611,7 @@ Dhcpv6Srv::processAddrRegInform(AllocEngine::ClientContext6& ctx) {
     appendRequestedVendorOptions(addr_reg_inf, addr_reg_rep, ctx, co_list);
 
     // Handle the "addr6_register" callout point.
+    bool skip = false;
     if (HooksManager::calloutsPresent(Hooks.hook_index_addr6_register_)) {
         CalloutHandlePtr callout_handle = getCalloutHandle(addr_reg_inf);
         ScopedCalloutHandleState callout_handle_state(callout_handle);
@@ -4636,25 +4637,27 @@ Dhcpv6Srv::processAddrRegInform(AllocEngine::ClientContext6& ctx) {
         HooksManager::callCallouts(Hooks.hook_index_addr6_register_, *callout_handle);
 
         // Callouts decided to skip the next processing step. This means
-        // cancel processing so drop.
-        if ((callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) ||
-            (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP)) {
+        // to not perform the lease operation.
+        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_SKIP) {
             LOG_DEBUG(hooks_logger, DBG_DHCP6_HOOKS,
                       DHCP6_HOOK_ADDR6_REGISTER_SKIP)
                 .arg(addr_reg_inf->getLabel())
+                .arg(old_lease ? "update" : "add")
+                .arg(addr);
+            skip = true;
+        } else
+        // Callouts decided to drop the next processing step. This means
+        // cancel processing so drop the query.
+        if (callout_handle->getStatus() == CalloutHandle::NEXT_STEP_DROP) {
+            LOG_DEBUG(hooks_logger, DBG_DHCP6_HOOKS,
+                      DHCP6_HOOK_ADDR6_REGISTER_DROP)
+                .arg(addr_reg_inf->getLabel())
                 .arg(addr);
             return (Pkt6Ptr());
         }
-
-        Lease6Ptr new_lease;
-        callout_handle->getArgument("new_lease6", new_lease);
-        if (!new_lease) {
-            // Stateless registration: skip lease code.
-            lease.reset();
-        }
     }
 
-    if (lease) {
+    if (!skip) {
         // Statefull registration.
         if (old_lease) {
             try {
@@ -4666,8 +4669,6 @@ Dhcpv6Srv::processAddrRegInform(AllocEngine::ClientContext6& ctx) {
                     .arg(ex.what());
                 return (Pkt6Ptr());
             }
-            // Save the old lease for the lease6_committed callout.
-            ctx.currentIA().old_leases_.push_back(old_lease);
             // Save the old lease for the DNS update.
             ctx.currentIA().changed_leases_.push_back(old_lease);
             // Update stats when the subnet changed.
@@ -4704,7 +4705,7 @@ Dhcpv6Srv::processAddrRegInform(AllocEngine::ClientContext6& ctx) {
             StatsMgr::instance().addValue("cumulative-registered-nas",
                                           static_cast<int64_t>(1));
         }
-        // Save the new lease for the lease6_committed callout.
+        // Save the new lease for the leases6_committed callout.
         ctx.new_leases_.push_back(lease);
     }
 
diff --git a/src/bin/dhcp6/tests/addr_reg_unittest.cc b/src/bin/dhcp6/tests/addr_reg_unittest.cc
