nwfilter: Add ARP src/dst IP mask for ebtables ARP

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=862887

Add a netmask for the source and destination IP address for the
ebtables --arp-ip-src and --arp-ip-dst options. Extend the XML
parser with support for XML attributes for these netmasks similar
to already supported netmasks. Extend the documentation.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

docs/formatnwfilter.html.in

@@ -989,11 +989,21 @@
          <td>IP_ADDR</td>
          <td>Source IP address in ARP/RARP packet</td>
        </tr>
+       <tr>
+         <td>arpsrcipmask <span class="since">(Since 1.2.3)</span></td>
+         <td>IP_MASK</td>
+         <td>Source IP mask</td>
+       </tr>
        <tr>
          <td>arpdstipaddr</td>
          <td>IP_ADDR</td>
          <td>Destination IP address in ARP/RARP packet</td>
        </tr>
+       <tr>
+         <td>arpdstipmask <span class="since">(Since 1.2.3)</span></td>
+         <td>IP_MASK</td>
+         <td>Destination IP mask</td>
+       </tr>
        <tr>
          <td>comment <span class="since">(Since 0.8.5)</span></td>
          <td>STRING</td>

src/conf/nwfilter_conf.c

@@ -173,7 +173,9 @@ static const char dstmacmask_str[]    = "dstmacmask";
 static const char arpsrcmacaddr_str[] = "arpsrcmacaddr";
 static const char arpdstmacaddr_str[] = "arpdstmacaddr";
 static const char arpsrcipaddr_str[]  = "arpsrcipaddr";
+static const char arpsrcipmask_str[]  = "arpsrcipmask";
 static const char arpdstipaddr_str[]  = "arpdstipaddr";
+static const char arpdstipmask_str[]  = "arpdstipmask";
 static const char srcipaddr_str[]     = "srcipaddr";
 static const char srcipmask_str[]     = "srcipmask";
 static const char dstipaddr_str[]     = "dstipaddr";
@@ -198,7 +200,9 @@ static const char ipsetflags_str[]    = "ipsetflags";
 #define ARPSRCMACADDR arpsrcmacaddr_str
 #define ARPDSTMACADDR arpdstmacaddr_str
 #define ARPSRCIPADDR  arpsrcipaddr_str
+#define ARPSRCIPMASK  arpsrcipmask_str
 #define ARPDSTIPADDR  arpdstipaddr_str
+#define ARPDSTIPMASK  arpdstipmask_str
 #define SRCIPADDR     srcipaddr_str
 #define SRCIPMASK     srcipmask_str
 #define DSTIPADDR     dstipaddr_str
@@ -1301,10 +1305,18 @@ static const virXMLAttr2Struct arpAttributes[] = {
         .name = ARPSRCIPADDR,
         .datatype = DATATYPE_IPADDR,
         .dataIdx = offsetof(virNWFilterRuleDef, p.arpHdrFilter.dataARPSrcIPAddr),
+    }, {
+        .name = ARPSRCIPMASK,
+        .datatype = DATATYPE_IPMASK,
+        .dataIdx = offsetof(virNWFilterRuleDef, p.arpHdrFilter.dataARPSrcIPMask),
     }, {
         .name = ARPDSTIPADDR,
         .datatype = DATATYPE_IPADDR,
         .dataIdx = offsetof(virNWFilterRuleDef, p.arpHdrFilter.dataARPDstIPAddr),
+    }, {
+        .name = ARPDSTIPMASK,
+        .datatype = DATATYPE_IPMASK,
+        .dataIdx = offsetof(virNWFilterRuleDef, p.arpHdrFilter.dataARPDstIPMask),
     }, {
         .name = "gratuitous",
         .datatype = DATATYPE_BOOLEAN,

src/conf/nwfilter_conf.h

@@ -209,8 +209,10 @@ struct _arpHdrFilterDef {
     nwItemDesc dataOpcode;
     nwItemDesc dataARPSrcMACAddr;
     nwItemDesc dataARPSrcIPAddr;
+    nwItemDesc dataARPSrcIPMask;
     nwItemDesc dataARPDstMACAddr;
     nwItemDesc dataARPDstIPAddr;
+    nwItemDesc dataARPDstIPMask;
     nwItemDesc dataGratuitousARP;
     nwItemDesc dataComment;
 };

src/nwfilter/nwfilter_ebiptables_driver.c

@@ -2052,6 +2052,7 @@ ebtablesCreateRuleInstance(char chainPrefix,
 {
     char macaddr[VIR_MAC_STRING_BUFLEN],
          ipaddr[INET_ADDRSTRLEN],
+         ipmask[INET_ADDRSTRLEN],
          ipv6addr[INET6_ADDRSTRLEN],
          number[MAX(INT_BUFSIZE_BOUND(uint32_t),
                     INT_BUFSIZE_BOUND(int))],
@@ -2059,6 +2060,7 @@ ebtablesCreateRuleInstance(char chainPrefix,
     char chain[MAX_CHAINNAME_LENGTH];
     virBuffer buf = VIR_BUFFER_INITIALIZER;
     const char *target;
+    bool hasMask = false;
 
     if (!ebtables_cmd_path) {
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -2262,11 +2264,20 @@ ebtablesCreateRuleInstance(char chainPrefix,
                               &rule->p.arpHdrFilter.dataARPSrcIPAddr) < 0)
                 goto err_exit;
 
+            if (HAS_ENTRY_ITEM(&rule->p.arpHdrFilter.dataARPSrcIPMask)) {
+                if (printDataType(vars,
+                                  ipmask, sizeof(ipmask),
+                                  &rule->p.arpHdrFilter.dataARPSrcIPMask) < 0)
+                    goto err_exit;
+                hasMask = true;
+            }
+
             virBufferAsprintf(&buf,
-                          " %s %s %s",
+                          " %s %s %s/%s",
                           reverse ? "--arp-ip-dst" : "--arp-ip-src",
                           ENTRY_GET_NEG_SIGN(&rule->p.arpHdrFilter.dataARPSrcIPAddr),
-                          ipaddr);
+                          ipaddr,
+                          hasMask ? ipmask : "32");
         }
 
         if (HAS_ENTRY_ITEM(&rule->p.arpHdrFilter.dataARPDstIPAddr)) {
@@ -2275,11 +2286,20 @@ ebtablesCreateRuleInstance(char chainPrefix,
                               &rule->p.arpHdrFilter.dataARPDstIPAddr) < 0)
                 goto err_exit;
 
+            if (HAS_ENTRY_ITEM(&rule->p.arpHdrFilter.dataARPDstIPMask)) {
+                if (printDataType(vars,
+                                  ipmask, sizeof(ipmask),
+                                  &rule->p.arpHdrFilter.dataARPDstIPMask) < 0)
+                    goto err_exit;
+                hasMask = true;
+            }
+
             virBufferAsprintf(&buf,
-                          " %s %s %s",
+                          " %s %s %s/%s",
                           reverse ? "--arp-ip-src" : "--arp-ip-dst",
                           ENTRY_GET_NEG_SIGN(&rule->p.arpHdrFilter.dataARPDstIPAddr),
-                          ipaddr);
+                          ipaddr,
+                          hasMask ? ipmask : "32");
         }
 
         if (HAS_ENTRY_ITEM(&rule->p.arpHdrFilter.dataARPSrcMACAddr)) {