[master] Update DDNS code to remove PTR even if removing FWD had issues

Squashed commit of the following:

commit 70eb39525494f0c8ee6d1b1f1ae2cca391ab309e
Author: Shawn Routhier <sar@isc.org>
Date:   Mon Jun 27 13:46:37 2016 -0700

    [rt23954] Update DDNS code to remove PTR even if removing FWD had issues

diff --git a/RELNOTES b/RELNOTES
index 15d469f4a908a98737873198390ca36de0a6231e..3d05131271d2b474a3dc2816aaebdd32d30ddcc1 100644 (file)
--- a/RELNOTES
+++ b/RELNOTES
@@ -88,6 +88,10 @@ by Eric Young (eay@cryptsoft.com).
   a cut and paste error.
   [ISC-Bugs #42253]
 
+- Modify the DDNS code to clean up the PTR record even if there
+  are issues while cleaning up the A or AAAA records.
+  [ISC-Bugs #23954]
+
                        Changes since 4.3.4b1
 
 - None

diff --git a/server/ddns.c b/server/ddns.c
index d500a16955e73432fbf0cfa3eb31586a0118eaf7..d6d53bf4737b47b02614d2c994923cd1b1d24068 100644 (file)
--- a/server/ddns.c
+++ b/server/ddns.c
@@ -1347,6 +1347,12 @@ ddns_ptr_remove(dhcp_ddns_cb_t *ddns_cb,
                break;
        }
 
+       /* If we aren't suppossed to do the next step, set the result
+        * flag so ddns_fwd_srv_connector won't do much
+        */
+       if ((ddns_cb->flags & DDNS_EXECUTE_NEXT) == 0)
+               result = ISC_R_FAILURE;
+
        ddns_update_lease_ptr(NULL, NULL, ddns_cb, NULL, MDL);
        ddns_fwd_srv_connector(NULL, NULL, NULL, ddns_cb->next_op, result);
        ddns_cb_free(ddns_cb, MDL);
@@ -1587,23 +1593,42 @@ void
 ddns_fwd_srv_rem2(dhcp_ddns_cb_t *ddns_cb,
                  isc_result_t    eresult)
 {
-       if (eresult == ISC_R_SUCCESS) {
+
+       /*
+        * To get here we have already managed to remove the A/AAAA
+        * record and are trying to remove the DHCID/TXT record as well.
+        * On success (removed DHCID/TXT) or YXRRSET (DHCID/TXT still in
+        * use by something else) we clean up the lease.
+        * On some other error we don't clean up the lease and hope that
+        * if we try this again it will work.  An example would be if we
+        * got a timeout as the DNS server halted between the first and
+        * second steps.  The DNS server would still have the DHCID/TXT
+        * and we would like to remove that in the future.
+        *
+        * On success set the EXECUTE_NEXT flag which triggers any
+        * add that is next in the chain.
+        */
+       if ((eresult == ISC_R_SUCCESS) ||
+           (eresult == DNS_R_YXRRSET))  {
                ddns_update_lease_text(ddns_cb, NULL);
+               eresult = ISC_R_SUCCESS;
+       }
 
-               /* Do the next operation */
-               if ((ddns_cb->flags & DDNS_UPDATE_PTR) != 0) {
-                       /* if we have zone information get rid of it */
-                       if (ddns_cb->zone != NULL) {
-                               ddns_cb_forget_zone(ddns_cb);
-                       }
+       /* Do the next operation */
+       if ((ddns_cb->flags & DDNS_UPDATE_PTR) != 0) {
+               /* if we have zone information get rid of it */
+               if (ddns_cb->zone != NULL) {
+                       ddns_cb_forget_zone(ddns_cb);
+               }
 
-                       ddns_cb->state = DDNS_STATE_REM_PTR;
-                       ddns_cb->cur_func = ddns_ptr_remove;
-                       
-                       eresult = ddns_modify_ptr(ddns_cb, MDL);
-                       if (eresult == ISC_R_SUCCESS) {
-                               return;
-                       }
+               ddns_cb->state = DDNS_STATE_REM_PTR;
+               ddns_cb->cur_func = ddns_ptr_remove;
+               if (eresult == ISC_R_SUCCESS)
+                       ddns_cb->flags |= DDNS_EXECUTE_NEXT;
+
+               eresult = ddns_modify_ptr(ddns_cb, MDL);
+               if (eresult == ISC_R_SUCCESS) {
+                       return;
                }
        }
 
@@ -1654,7 +1679,20 @@ ddns_fwd_srv_rem1(dhcp_ddns_cb_t *ddns_cb,
                log_info("DDNS: no forward map to remove. %p", ddns_cb);
 #endif
 
-               /* Do the next operation */
+               /* Trigger the add operation */
+               eresult = ISC_R_SUCCESS;
+
+               /* Fall through */
+       default:
+
+               /* We do the remove operation in most cases
+                * but we don't want to continue with adding a forward
+                * record if the forward removal had issues so we
+                * check the eresult and set the EXECUTE_NEXT flag on
+                * success.
+                */
+
+               /* Do the remove operation */
                if ((ddns_cb->flags & DDNS_UPDATE_PTR) != 0) {
                        /* if we have zone information get rid of it */
                        if (ddns_cb->zone != NULL) {
@@ -1663,19 +1701,14 @@ ddns_fwd_srv_rem1(dhcp_ddns_cb_t *ddns_cb,
 
                        ddns_cb->state    = DDNS_STATE_REM_PTR;
                        ddns_cb->cur_func = ddns_ptr_remove;
-                       
+                       if (eresult == ISC_R_SUCCESS)
+                               ddns_cb->flags |= DDNS_EXECUTE_NEXT;
+
                        result = ddns_modify_ptr(ddns_cb, MDL);
                        if (result == ISC_R_SUCCESS) {
                                return;
                        }
                }
-               else {
-                       /* Trigger the add operation */
-                       eresult = ISC_R_SUCCESS;
-               }
-               break;
-                       
-       default:
                break;
        }
 
@@ -1956,6 +1989,7 @@ ddns_removals(struct lease    *lease,
        if ((ddns_cb->flags & DDNS_UPDATE_PTR) != 0) {
                ddns_cb->state      = DDNS_STATE_REM_PTR;
                ddns_cb->cur_func   = ddns_ptr_remove;
+               ddns_cb->flags      |= DDNS_EXECUTE_NEXT;
 
                /*
                 * if execute add isn't success remove the control block so