[libvirt] [PATCH] nwfilter: fix adding std MAC and IP values to filter binding

[Nikolay Shirokovskiy]

Commit d1a7c08eb changed filter instantiation code to ignore MAC and IP
variables explicitly specified for filter binding. It just replaces
explicit values with values associated with the binding. Before the
commit virNWFilterCreateVarsFrom was used so that explicit value
take precedence. Let's bring old behavior back.

This is useful. For example if domain has two interfaces it makes
sense to list both mac adresses in MAC var of every interface
filterref. So that if guest make a bond of these interfaces
and start sending frames with one of the mac adresses from
both interfaces we can pass outgress traffic from both
interfaces too.

Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
---
 src/nwfilter/nwfilter_gentech_driver.c | 92 ++++++++++++----------------------
 1 file changed, 32 insertions(+), 60 deletions(-)

diff --git a/src/nwfilter/nwfilter_gentech_driver.c b/src/nwfilter/nwfilter_gentech_driver.c
index 655f088..6d68189 100644
--- a/src/nwfilter/nwfilter_gentech_driver.c
+++ b/src/nwfilter/nwfilter_gentech_driver.c
@@ -127,60 +127,6 @@ virNWFilterRuleInstFree(virNWFilterRuleInstPtr inst)
 
 
 /**
- * virNWFilterVarHashmapAddStdValues:
- * @tables: pointer to hash tabel to add values to
- * @macaddr: The string of the MAC address to add to the hash table,
- *    may be NULL
- * @ipaddr: The string of the IP address to add to the hash table;
- *    may be NULL
- *
- * Returns 0 in case of success, -1 in case an error happened with
- * error having been reported.
- *
- * Adds a couple of standard keys (MAC, IP) to the hash table.
- */
-static int
-virNWFilterVarHashmapAddStdValues(virHashTablePtr table,
-                                  const char *macaddr,
-                                  const virNWFilterVarValue *ipaddr)
-{
-    virNWFilterVarValue *val;
-
-    if (macaddr) {
-        val = virNWFilterVarValueCreateSimpleCopyValue(macaddr);
-        if (!val)
-            return -1;
-
-        if (virHashUpdateEntry(table,
-                               NWFILTER_STD_VAR_MAC,
-                               val) < 0) {
-            virNWFilterVarValueFree(val);
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           "%s", _("Could not add variable 'MAC' to hashmap"));
-            return -1;
-        }
-    }
-
-    if (ipaddr) {
-        val = virNWFilterVarValueCopy(ipaddr);
-        if (!val)
-            return -1;
-
-        if (virHashUpdateEntry(table,
-                               NWFILTER_STD_VAR_IP,
-                               val) < 0) {
-            virNWFilterVarValueFree(val);
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           "%s", _("Could not add variable 'IP' to hashmap"));
-            return -1;
-        }
-    }
-
-    return 0;
-}
-
-
-/**
  * Convert a virHashTable into a string of comma-separated
  * variable names.
  */
@@ -705,6 +651,28 @@ virNWFilterDoInstantiate(virNWFilterTechDriverPtr techdriver,
 }
 
 
+static int
+virNWFilterVarHashmapAddStdValue(virHashTablePtr table,
+                                 const char *var,
+                                 const char *value)
+{
+    virNWFilterVarValue *val;
+
+    if (virHashLookup(table, var))
+        return 0;
+
+    if (!(val = virNWFilterVarValueCreateSimpleCopyValue(value)))
+        return -1;
+
+    if (virHashAddEntry(table, var, val) < 0) {
+        virNWFilterVarValueFree(val);
+        return -1;
+    }
+
+    return 0;
+}
+
+
 /*
  * Call this function while holding the NWFilter filter update lock
  */
@@ -717,7 +685,7 @@ virNWFilterInstantiateFilterUpdate(virNWFilterDriverStatePtr driver,
                                    bool forceWithPendingReq,
                                    bool *foundNewFilter)
 {
-    int rc;
+    int rc = -1;
     const char *drvname = EBIPTABLES_DRIVER_ID;
     virNWFilterTechDriverPtr techdriver;
     virNWFilterObjPtr obj;
@@ -743,14 +711,18 @@ virNWFilterInstantiateFilterUpdate(virNWFilterDriverStatePtr driver,
         return -1;
 
     virMacAddrFormat(&binding->mac, vmmacaddr);
+    if (virNWFilterVarHashmapAddStdValue(binding->filterparams,
+                                         NWFILTER_STD_VAR_MAC,
+                                         vmmacaddr) < 0)
+        goto err_exit;
 
     ipaddr = virNWFilterIPAddrMapGetIPAddr(binding->portdevname);
-
-    if (virNWFilterVarHashmapAddStdValues(binding->filterparams,
-                                          vmmacaddr, ipaddr) < 0) {
-        rc = -1;
+    if (ipaddr &&
+        virNWFilterVarHashmapAddStdValue(binding->filterparams,
+                                         NWFILTER_STD_VAR_IP,
+                                         virNWFilterVarValueGetSimple(ipaddr)) < 0)
         goto err_exit;
-    }
+
 
     filter = virNWFilterObjGetDef(obj);
 
-- 
1.8.3.1