Fix leafref binary search accepting entries excluded by xpath predicates

lib/src/clixon_validate.c

@@ -283,6 +283,25 @@ leafref_opt_cache_new(yang_stmt *ys,
     return 0;
 }
 
+/*! Count children of xp with yang spec ys
+ *
+ * @param[in]  xp  XML parent
+ * @param[in]  ys  Yang spec of children to count
+ * @retval     n   Number of children
+ */
+static size_t
+leafref_opt_count(cxobj     *xp,
+                  yang_stmt *ys)
+{
+    cxobj  *x = NULL;
+    size_t  n = 0;
+
+    while ((x = xml_child_each(xp, x, CX_ELMNT)) != NULL)
+        if (xml_spec(x) == ys)
+            n++;
+    return n;
+}
+
 /*! Detect if binary search can be used
  *
  * If xlen is very large, this takes time
@@ -294,6 +313,7 @@ leafref_opt_cache_new(yang_stmt *ys,
  * IF yang of all elements is same YANG
  * AND that yang is LEAF-LIST AND is ordered-by system
  * OR that yang's parent is LIST AND is ordered-by system
+ * AND xvec contains all such siblings, ie not filtered by xpath predicates
  * THEN use binary search
  * @param[in]  xvec   Vector of matching XML values
  * @param[in]  xlen   Length of xvec
@@ -369,6 +389,15 @@ leafref_opt_search_detect(cxobj **xvec,
         }
     }
     if (i == xlen && x0 != NULL && xml_parent(x0) && xml_spec(x0)){
+        /* Binary search covers all siblings, but xvec may be a subset filtered by
+         * xpath predicates, eg ../iface[enabled='true']/name
+         */
+        if (is_list){
+            if (xpp == NULL || leafref_opt_count(xpp, y0p) != xlen)
+                return 0;
+        }
+        else if (leafref_opt_count(x0p, y0) != xlen)
+            return 0;
         *search = 1;
         *x0pp = x0;
     }

test/test_leafref.sh

@@ -99,7 +99,18 @@ module example{
         leaf template{
             type leafref{
                 path "/sender/name";
-                require-instance true;  
+                require-instance true;
+            }
+        }
+        leaf enabled{
+            type boolean;
+        }
+        /* leafref filtered by predicate: binary search must not match
+         * entries excluded by the predicate */
+        leaf active-template{
+            type leafref{
+                path "/sender[enabled='true']/name";
+                require-instance true;
             }
         }
     }
@@ -279,6 +290,24 @@ expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS>
 new "issue 669: discard-changes"
 expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><discard-changes/></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
 
+# Leafref path with predicate on the list: xvec is a subset of the list entries.
+# LEAFREF_OPTIMIZE binary search must not be used, it searches all entries and
+# would accept a reference to an entry excluded by the predicate.
+new "leafref predicate: add senders s1,s3 enabled, s2 disabled, s4 refers to disabled s2"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><sender xmlns=\"urn:example:clixon\"><name>s1</name><enabled>true</enabled></sender><sender xmlns=\"urn:example:clixon\"><name>s2</name><enabled>false</enabled></sender><sender xmlns=\"urn:example:clixon\"><name>s3</name><enabled>true</enabled></sender><sender xmlns=\"urn:example:clixon\"><name>s4</name><active-template>s2</active-template></sender></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "leafref predicate: validate expect failure (s2 is disabled)"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "<rpc-error>" ""
+
+new "leafref predicate: set s4 to refer to enabled s3"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><edit-config><target><candidate/></target><config><sender xmlns=\"urn:example:clixon\"><name>s4</name><active-template>s3</active-template></sender></config></edit-config></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "leafref predicate: validate expect OK (s3 is enabled)"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><validate><source><candidate/></source></validate></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
+new "leafref predicate: discard-changes"
+expecteof_netconf "$clixon_netconf -qf $cfg" 0 "$DEFAULTHELLO" "<rpc $DEFAULTNS><discard-changes/></rpc>" "" "<rpc-reply $DEFAULTNS><ok/></rpc-reply>"
+
 # Leafref to non-key leaf in a list: LEAFREF_OPTIMIZE binary search must not
 # be used when the target leaf is not the list key.  With two routers present
 # (key "vrf-id"), the target leaf "area-tag" is a non-key unique leaf.