nwfilter: enable rejection of packets

This patch adds the possibility to not just drop packets, but to also have them rejected where iptables at least sends an ICMP msg back to the originator. On ebtables this again maps into dropping packets since rejecting is not supported.

I am adding 'since 0.8.9' to the docs assuming this will be the next version of libvirt.

docs/formatnwfilter.html.in

@@ -260,9 +260,11 @@
     </p>
     <ul>
      <li>
-        action -- mandatory; must either be <code>drop</code> or <code>accept</code> if
+        action -- mandatory; must either be <code>drop</code>,
-        the evaluation of the filtering rule is supposed to drop or accept
+        <code>reject</code><span class="since">(since 0.8.9)</span>,
-        a packet
+        or <code>accept</code> if
+        the evaluation of the filtering rule is supposed to drop,
+        reject (using ICMP message), or accept a packet
      </li>
      <li>
         direction -- mandatory; must either be <code>in</code>, <code>out</code> or

docs/schemas/nwfilter.rng

@@ -839,6 +839,7 @@
     <choice>
       <value>drop</value>
       <value>accept</value>
+      <value>reject</value>
     </choice>
   </define>
 

src/conf/nwfilter_conf.c

@@ -53,11 +53,13 @@
 
 VIR_ENUM_IMPL(virNWFilterRuleAction, VIR_NWFILTER_RULE_ACTION_LAST,
               "drop",
-              "accept");
+              "accept",
+              "reject");
 
 VIR_ENUM_IMPL(virNWFilterJumpTarget, VIR_NWFILTER_RULE_ACTION_LAST,
               "DROP",
-              "ACCEPT");
+              "ACCEPT",
+              "REJECT");
 
 VIR_ENUM_IMPL(virNWFilterRuleDirection, VIR_NWFILTER_RULE_DIRECTION_LAST,
               "in",

src/conf/nwfilter_conf.h

@@ -291,6 +291,7 @@ struct _udpliteHdrFilterDef {
 enum virNWFilterRuleActionType {
     VIR_NWFILTER_RULE_ACTION_DROP = 0,
     VIR_NWFILTER_RULE_ACTION_ACCEPT,
+    VIR_NWFILTER_RULE_ACTION_REJECT,
 
     VIR_NWFILTER_RULE_ACTION_LAST,
 };

src/nwfilter/nwfilter_ebiptables_driver.c

@@ -1516,7 +1516,7 @@ _iptablesCreateRuleInstance(int directionIn,
     if (rule->action == VIR_NWFILTER_RULE_ACTION_ACCEPT)
         target = accept_target;
     else {
-        target = "DROP";
+        target = virNWFilterJumpTargetTypeToString(rule->action);
         skipMatch = defMatch;
     }
 
@@ -1880,6 +1880,7 @@ ebtablesCreateRuleInstance(char chainPrefix,
          number[20];
     char chain[MAX_CHAINNAME_LENGTH];
     virBuffer buf = VIR_BUFFER_INITIALIZER;
+    const char *target;
 
     if (!ebtables_cmd_path) {
         virNWFilterReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -2295,10 +2296,20 @@ ebtablesCreateRuleInstance(char chainPrefix,
         return -1;
     }
 
+    switch (rule->action) {
+    case VIR_NWFILTER_RULE_ACTION_REJECT:
+        /* REJECT not supported */
+        target = virNWFilterJumpTargetTypeToString(
+                                     VIR_NWFILTER_RULE_ACTION_DROP);
+    break;
+    default:
+        target = virNWFilterJumpTargetTypeToString(rule->action);
+    }
+
     virBufferVSprintf(&buf,
                       " -j %s" CMD_DEF_POST CMD_SEPARATOR
                       CMD_EXEC,
-                      virNWFilterJumpTargetTypeToString(rule->action));
+                      target);
 
     if (virBufferError(&buf)) {
         virBufferFreeAndReset(&buf);