ATTN: parse/bonds: handle same primary in multiple bonds (#451)

* ATTN: parse/bonds: handle same primary in multiple bonds

Error out if an interface is declared as primary of multiple bonds.
Besides being wrong it's causing a memory leak.

ATTN: as this makes the parser stricter, it probably should not be
included in backports/SRUs. Consider converting the error to a warning
and freeing the memory allocation to avoid the leak.

* parse/bond: identify bond assigned to primary

Look for the bond that already has the primary member assigned and
identify it in the error message.

src/parse.c

@@ -2313,6 +2313,11 @@ handle_bond_primary_member(NetplanParser* npp, yaml_node_t* node, const void* da
                               npp->current.netdef->id, npp->current.netdef->bond_params.primary_member);
 
         ref_ptr = ((char**) ((void*) component + GPOINTER_TO_UINT(data)));
+        if (*ref_ptr) {
+            NetplanNetDefinition* bond = _netplan_parser_find_bond_for_primary_member(npp, *ref_ptr);
+            return yaml_error(npp, node, error, "%s: interface '%s' is already a primary of %s",
+                              npp->current.netdef->id, *ref_ptr, bond->id);
+        }
         *ref_ptr = g_strdup(scalar(node));
         npp->current.netdef->bond_params.primary_member = g_strdup(scalar(node));
         mark_data_as_dirty(npp, ref_ptr);

src/util-internal.h

@@ -78,6 +78,9 @@ netplan_netdef_new(NetplanParser* npp, const char* id, NetplanDefType type, Netp
 const char *
 netplan_parser_get_filename(NetplanParser* npp);
 
+NetplanNetDefinition*
+_netplan_parser_find_bond_for_primary_member(const NetplanParser* npp, const char* primary);
+
 gboolean
 has_openvswitch(const NetplanOVSSettings* ovs, NetplanBackend backend, GHashTable *ovs_ports);
 

src/util.c

@@ -1184,3 +1184,23 @@ _is_valid_macaddress(const char* value)
 
     return regexec(&re, value, 0, NULL, 0) == 0;
 }
+
+/* Given a netdef ID, look for the netdef representing a bond device that has it as primary member */
+NetplanNetDefinition*
+_netplan_parser_find_bond_for_primary_member(const NetplanParser* npp, const char* primary)
+{
+    GList* iter = npp->ordered;
+    NetplanNetDefinition* netdef = NULL;
+
+    while (iter) {
+        netdef = iter->data;
+        if (netdef->type == NETPLAN_DEF_TYPE_BOND) {
+            if (!g_strcmp0(netdef->bond_params.primary_member, primary)) {
+                break;
+            }
+        }
+        iter = iter->next;
+    }
+
+    return netdef;
+}

tests/generator/test_bonds.py

@@ -968,6 +968,20 @@ def test_bond_multiple_assignments(self):
       interfaces: [eno1]''', expect_fail=True)
         self.assertIn("bond1: interface 'eno1' is already assigned to bond bond0", err)
 
+    def test_bond_primary_multiple_assignments(self):
+        err = self.generate('''network:
+  version: 2
+  ethernets:
+    eno1: {}
+  bonds:
+    bond0:
+      parameters:
+        primary: eno1
+    bond1:
+      parameters:
+        primary: eno1''', expect_fail=True)
+        self.assertIn("bond1: interface 'eno1' is already a primary of bond0", err)
+
     def test_bond_bridge_cross_assignments1(self):
         err = self.generate('''network:
   version: 2