nwfilter: Add support for ipset

This patch adds support for the recent ipset iptables extension
to libvirt's nwfilter subsystem. Ipset allows to maintain 'sets'
of IP addresses, ports and other packet parameters and allows for
faster lookup (in the order of O(1) vs. O(n)) and rule evaluation
to achieve higher throughput than what can be achieved with
individual iptables rules.

On the command line iptables supports ipset using

iptables ... -m set --match-set <ipset name> <flags> -j ...

where 'ipset name' is the name of a previously created ipset and
flags is a comma-separated list of up to 6 flags. Flags use 'src' and 'dst'
for selecting IP addresses, ports etc. from the source or
destination part of a packet. So a concrete example may look like this:

iptables -A INPUT -m set --match-set test src,src -j ACCEPT

Since ipset management is quite complex, the idea was to leave ipset 
management outside of libvirt but still allow users to reference an ipset.
The user would have to make sure the ipset is available once the VM is
started so that the iptables rule(s) referencing the ipset can be created.

Using XML to describe an ipset in an nwfilter rule would then look as
follows:

  <rule action='accept' direction='in'>
    <all ipset='test' ipsetflags='src,src'/>
  </rule>

The two parameters on the command line are also the two distinct XML attributes
'ipset' and 'ipsetflags'.

FYI: Here is the man page for ipset:

https://ipset.netfilter.org/ipset.man.html

Regards,
    Stefan

docs/formatnwfilter.html.in

@@ -528,6 +528,11 @@
      <li>IPV6_MASK: IPv6 mask in numbers format (FFFF:FFFF:FC00::) or CIDR mask (0-128)</li>
      <li>STRING: A string</li>
      <li>BOOLEAN: 'true', 'yes', '1' or 'false', 'no', '0'</li>
+     <li>IPSETFLAGS: The source and destination flags of the ipset described
+         by up to 6 'src' or 'dst' elements selecting features from either
+         the source or destination part of the packet header; example:
+         src,src,dst. The number of 'selectors' to provide here depends
+         on the type of ipset that is referenced.</li>
     </ul>
     <p>
      <br/><br/>
@@ -1169,6 +1174,16 @@
          <td>STRING</td>
          <td>TCP-only: format of mask/flags with mask and flags each being a comma separated list of SYN,ACK,URG,PSH,FIN,RST or NONE or ALL</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>
@@ -1269,6 +1284,16 @@
          <td>STRING</td>
          <td>comma separated list of NEW,ESTABLISHED,RELATED,INVALID or NONE</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>
@@ -1358,6 +1383,16 @@
          <td>STRING</td>
          <td>comma separated list of NEW,ESTABLISHED,RELATED,INVALID or NONE</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>
@@ -1459,6 +1494,16 @@
          <td>STRING</td>
          <td>TCP-only: format of mask/flags with mask and flags each being a comma separated list of SYN,ACK,URG,PSH,FIN,RST or NONE or ALL</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>
@@ -1545,6 +1590,16 @@
          <td>STRING</td>
          <td>comma separated list of NEW,ESTABLISHED,RELATED,INVALID or NONE</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>
@@ -1619,6 +1674,16 @@
          <td>STRING</td>
          <td>comma separated list of NEW,ESTABLISHED,RELATED,INVALID or NONE</td>
        </tr>
+       <tr>
+         <td>ipset <span class="since">(Since 0.9.13)</span></td>
+         <td>STRING</td>
+         <td>The name of an IPSet managed outside of libvirt</td>
+       </tr>
+       <tr>
+         <td>ipsetflags <span class="since">(Since 0.9.13)</span></td>
+         <td>IPSETFLAGS</td>
+         <td>flags for the IPSet; requires ipset attribute</td>
+       </tr>
       </table>
     <p>
       <br/><br/>

docs/schemas/nwfilter.rng

@@ -485,6 +485,14 @@
           <ref name="stateflags-type"/>
         </attribute>
       </optional>
+      <optional>
+        <attribute name="ipset">
+          <ref name="ipset-name-type"/>
+        </attribute>
+        <attribute name="ipsetflags">
+          <ref name="ipset-flags-type"/>
+        </attribute>
+      </optional>
     </interleave>
   </define>
 
@@ -1060,4 +1068,19 @@
       <param name="pattern">((SYN|ACK|URG|PSH|FIN|RST)(,(SYN|ACK|URG|PSH|FIN|RST))*|ALL|NONE)/((SYN|ACK|URG|PSH|FIN|RST)(,(SYN|ACK|URG|PSH|FIN|RST))*|ALL|NONE)</param>
     </data>
   </define>
+
+  <define name='ipset-name-type'>
+    <choice>
+      <ref name="variable-name-type"/>
+      <data type="string">
+        <param name="pattern">[a-zA-Z0-9_\.:\-\+ ]{1,31}</param>
+      </data>
+    </choice>
+  </define>
+
+  <define name='ipset-flags-type'>
+    <data type="string">
+      <param name="pattern">(src|dst)(,(src|dst)){0,5}</param>
+    </data>
+  </define>
 </grammar>

src/conf/nwfilter_conf.c

@@ -183,6 +183,8 @@ static const char dstportstart_str[] = "dstportstart";
 static const char dstportend_str[]   = "dstportend";
 static const char dscp_str[]         = "dscp";
 static const char state_str[]        = "state";
+static const char ipset_str[]        = "ipset";
+static const char ipsetflags_str[]   = "ipsetflags";
 
 #define SRCMACADDR    srcmacaddr_str
 #define SRCMACMASK    srcmacmask_str
@@ -206,6 +208,8 @@ static const char state_str[]        = "state";
 #define DSTPORTEND    dstportend_str
 #define DSCP          dscp_str
 #define STATE         state_str
+#define IPSET         ipset_str
+#define IPSETFLAGS    ipsetflags_str
 
 
 /**
@@ -980,6 +984,97 @@ tcpFlagsFormatter(virBufferPtr buf,
     return true;
 }
 
+static bool
+ipsetValidator(enum attrDatatype datatype ATTRIBUTE_UNUSED, union data *val,
+               virNWFilterRuleDefPtr nwf ATTRIBUTE_UNUSED,
+               nwItemDesc *item)
+{
+    const char *errmsg = NULL;
+
+    if (virStrcpy(item->u.ipset.setname, val->c,
+                  sizeof(item->u.ipset.setname)) == NULL) {
+        errmsg = _("ipset name is too long");
+        goto arg_err_exit;
+    }
+
+    if (item->u.ipset.setname[strspn(item->u.ipset.setname,
+                                     VALID_IPSETNAME)] != 0) {
+        errmsg = _("ipset name contains invalid characters");
+        goto arg_err_exit;
+    }
+
+    return true;
+
+arg_err_exit:
+    virNWFilterReportError(VIR_ERR_INVALID_ARG,
+                           "%s", errmsg);
+    return false;
+}
+
+static bool
+ipsetFormatter(virBufferPtr buf,
+               virNWFilterRuleDefPtr nwf ATTRIBUTE_UNUSED,
+               nwItemDesc *item)
+{
+    virBufferAdd(buf, item->u.ipset.setname, -1);
+
+    return true;
+}
+
+static bool
+ipsetFlagsValidator(enum attrDatatype datatype ATTRIBUTE_UNUSED, union data *val,
+                    virNWFilterRuleDefPtr nwf ATTRIBUTE_UNUSED, nwItemDesc *item)
+{
+    const char *errmsg = NULL;
+    size_t idx = 0;
+
+    item->u.ipset.numFlags = 0;
+    item->u.ipset.flags = 0;
+
+    errmsg = _("malformed ipset flags");
+
+    while (item->u.ipset.numFlags < 6) {
+        if (STRCASEEQLEN(&val->c[idx], "src", 3)) {
+            item->u.ipset.flags |= (1 << item->u.ipset.numFlags);
+        } else if (!STRCASEEQLEN(&val->c[idx], "dst", 3)) {
+            goto arg_err_exit;
+        }
+        item->u.ipset.numFlags++;
+        idx += 3;
+        if (val->c[idx] != ',')
+            break;
+        idx++;
+    }
+
+    if (val->c[idx] != '\0')
+        goto arg_err_exit;
+
+    return true;
+
+arg_err_exit:
+    virNWFilterReportError(VIR_ERR_INVALID_ARG,
+                           "%s", errmsg);
+    return false;
+}
+
+static bool
+ipsetFlagsFormatter(virBufferPtr buf,
+                    virNWFilterRuleDefPtr nwf ATTRIBUTE_UNUSED,
+                    nwItemDesc *item)
+{
+    uint8_t ctr;
+
+    for (ctr = 0; ctr < item->u.ipset.numFlags; ctr++) {
+        if (ctr != 0)
+            virBufferAddLit(buf, ",");
+        if ((item->u.ipset.flags & (1 << ctr)))
+            virBufferAddLit(buf, "src");
+        else
+            virBufferAddLit(buf, "dst");
+    }
+
+    return true;
+}
 
 #define COMMON_MAC_PROPS(STRUCT) \
     {\
@@ -1411,6 +1506,20 @@ static const virXMLAttr2Struct ipv6Attributes[] = {
         .dataIdx = offsetof(virNWFilterRuleDef, p.STRUCT.ipHdr.dataState),\
         .validator = stateValidator,\
         .formatter = stateFormatter,\
+    },\
+    {\
+        .name = IPSET,\
+        .datatype = DATATYPE_IPSETNAME,\
+        .dataIdx = offsetof(virNWFilterRuleDef, p.STRUCT.ipHdr.dataIPSet),\
+        .validator = ipsetValidator,\
+        .formatter = ipsetFormatter,\
+    },\
+    {\
+        .name = IPSETFLAGS,\
+        .datatype = DATATYPE_IPSETFLAGS,\
+        .dataIdx = offsetof(virNWFilterRuleDef, p.STRUCT.ipHdr.dataIPSetFlags),\
+        .validator = ipsetFlagsValidator,\
+        .formatter = ipsetFlagsFormatter,\
     }
 
 #define COMMON_PORT_PROPS(STRUCT) \
@@ -1853,6 +1962,8 @@ virNWFilterRuleDetailsParse(xmlNodePtr node,
                         break;
 
                         case DATATYPE_STRING:
+                        case DATATYPE_IPSETFLAGS:
+                        case DATATYPE_IPSETNAME:
                             if (!validator) {
                                 /* not supported */
                                 rc = -1;
@@ -1964,6 +2075,19 @@ err_exit:
     goto cleanup;
 }
 
+static void
+virNWFilterRuleDefFixupIPSet(ipHdrDataDefPtr ipHdr)
+{
+    if (HAS_ENTRY_ITEM(&ipHdr->dataIPSet) &&
+        !HAS_ENTRY_ITEM(&ipHdr->dataIPSetFlags)) {
+        ipHdr->dataIPSetFlags.flags = NWFILTER_ENTRY_ITEM_FLAG_EXISTS;
+        ipHdr->dataIPSetFlags.u.ipset.numFlags = 1;
+        ipHdr->dataIPSetFlags.u.ipset.flags = 1;
+    } else {
+        ipHdr->dataIPSet.flags = 0;
+        ipHdr->dataIPSetFlags.flags = 0;
+    }
+}
 
 static void
 virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
@@ -2017,6 +2141,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.ipHdrFilter.ipHdr.dataSrcIPAddr);
         COPY_NEG_SIGN(rule->p.ipHdrFilter.ipHdr.dataDstIPMask,
                       rule->p.ipHdrFilter.ipHdr.dataDstIPAddr);
+        virNWFilterRuleDefFixupIPSet(&rule->p.ipHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_IPV6:
@@ -2024,6 +2149,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.ipv6HdrFilter.ipHdr.dataSrcIPAddr);
         COPY_NEG_SIGN(rule->p.ipv6HdrFilter.ipHdr.dataDstIPMask,
                       rule->p.ipv6HdrFilter.ipHdr.dataDstIPAddr);
+        virNWFilterRuleDefFixupIPSet(&rule->p.ipv6HdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_ARP:
@@ -2047,6 +2173,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.tcpHdrFilter.portData.dataSrcPortStart);
         COPY_NEG_SIGN(rule->p.tcpHdrFilter.portData.dataDstPortEnd,
                       rule->p.tcpHdrFilter.portData.dataSrcPortStart);
+        virNWFilterRuleDefFixupIPSet(&rule->p.tcpHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_UDP:
@@ -2065,6 +2192,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.udpHdrFilter.portData.dataSrcPortStart);
         COPY_NEG_SIGN(rule->p.udpHdrFilter.portData.dataDstPortEnd,
                       rule->p.udpHdrFilter.portData.dataSrcPortStart);
+        virNWFilterRuleDefFixupIPSet(&rule->p.udpHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_UDPLITE:
@@ -2077,6 +2205,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.udpliteHdrFilter.ipHdr.dataSrcIPFrom);
         COPY_NEG_SIGN(rule->p.udpliteHdrFilter.ipHdr.dataDstIPTo,
                       rule->p.udpliteHdrFilter.ipHdr.dataDstIPFrom);
+        virNWFilterRuleDefFixupIPSet(&rule->p.udpliteHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_ESP:
@@ -2089,6 +2218,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.espHdrFilter.ipHdr.dataSrcIPFrom);
         COPY_NEG_SIGN(rule->p.espHdrFilter.ipHdr.dataDstIPTo,
                       rule->p.espHdrFilter.ipHdr.dataDstIPFrom);
+        virNWFilterRuleDefFixupIPSet(&rule->p.espHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_AH:
@@ -2101,6 +2231,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.ahHdrFilter.ipHdr.dataSrcIPFrom);
         COPY_NEG_SIGN(rule->p.ahHdrFilter.ipHdr.dataDstIPTo,
                       rule->p.ahHdrFilter.ipHdr.dataDstIPFrom);
+        virNWFilterRuleDefFixupIPSet(&rule->p.ahHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_SCTP:
@@ -2119,6 +2250,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.sctpHdrFilter.portData.dataSrcPortStart);
         COPY_NEG_SIGN(rule->p.sctpHdrFilter.portData.dataDstPortEnd,
                       rule->p.sctpHdrFilter.portData.dataSrcPortStart);
+        virNWFilterRuleDefFixupIPSet(&rule->p.sctpHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_ICMP:
@@ -2133,6 +2265,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.icmpHdrFilter.ipHdr.dataDstIPFrom);
         COPY_NEG_SIGN(rule->p.icmpHdrFilter.dataICMPCode,
                       rule->p.icmpHdrFilter.dataICMPType);
+        virNWFilterRuleDefFixupIPSet(&rule->p.icmpHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_ALL:
@@ -2156,6 +2289,7 @@ virNWFilterRuleDefFixup(virNWFilterRuleDefPtr rule)
                       rule->p.igmpHdrFilter.ipHdr.dataSrcIPFrom);
         COPY_NEG_SIGN(rule->p.igmpHdrFilter.ipHdr.dataDstIPTo,
                       rule->p.igmpHdrFilter.ipHdr.dataDstIPFrom);
+        virNWFilterRuleDefFixupIPSet(&rule->p.igmpHdrFilter.ipHdr);
     break;
 
     case VIR_NWFILTER_RULE_PROTOCOL_LAST:
@@ -3120,7 +3254,7 @@ virNWFilterRuleDefDetailsFormat(virBufferPtr buf,
 
             virBufferAsprintf(buf, " %s='",
                               att[i].name);
-            if (att[i].formatter) {
+            if (att[i].formatter && !(flags & NWFILTER_ENTRY_ITEM_FLAG_HAS_VAR)) {
                if (!att[i].formatter(buf, def, item)) {
                   virNWFilterReportError(VIR_ERR_INTERNAL_ERROR,
                                          _("formatter for %s %s reported error"),

src/conf/nwfilter_conf.h

@@ -79,6 +79,7 @@ enum virNWFilterEntryItemFlags {
 
 
 # define MAX_COMMENT_LENGTH  256
+# define MAX_IPSET_NAME_LENGTH 32 /* incl. terminating '\0' */
 
 # define HAS_ENTRY_ITEM(data) \
   (((data)->flags) & NWFILTER_ENTRY_ITEM_FLAG_EXISTS)
@@ -103,8 +104,10 @@ enum attrDatatype {
     DATATYPE_BOOLEAN          = (1 << 12),
     DATATYPE_UINT32           = (1 << 13),
     DATATYPE_UINT32_HEX       = (1 << 14),
+    DATATYPE_IPSETNAME        = (1 << 15),
+    DATATYPE_IPSETFLAGS       = (1 << 16),
 
-    DATATYPE_LAST             = (1 << 15),
+    DATATYPE_LAST             = (1 << 17),
 };
 
 # define NWFILTER_MAC_BGA "01:80:c2:00:00:00"
@@ -136,9 +139,16 @@ struct _nwItemDesc {
             uint8_t  mask;
             uint8_t  flags;
         } tcpFlags;
+        struct {
+            char setname[MAX_IPSET_NAME_LENGTH];
+            uint8_t numFlags;
+            uint8_t flags;
+        } ipset;
     } u;
 };
 
+# define VALID_IPSETNAME \
+  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.:-+ "
 
 typedef struct _ethHdrDataDef ethHdrDataDef;
 typedef ethHdrDataDef *ethHdrDataDefPtr;
@@ -232,6 +242,8 @@ struct _ipHdrDataDef {
     nwItemDesc dataState;
     nwItemDesc dataConnlimitAbove;
     nwItemDesc dataComment;
+    nwItemDesc dataIPSet;
+    nwItemDesc dataIPSetFlags;
 };
 
 

src/nwfilter/nwfilter_ebiptables_driver.c

@@ -256,10 +256,13 @@ static int
 _printDataType(virNWFilterVarCombIterPtr vars,
                char *buf, int bufsize,
                nwItemDescPtr item,
-               bool asHex)
+               bool asHex, bool directionIn)
 {
     int done;
     char *data;
+    uint8_t ctr;
+    virBuffer vb = VIR_BUFFER_INITIALIZER;
+    char *flags;
 
     if (printVar(vars, buf, bufsize, item, &done) < 0)
         return -1;
@@ -346,6 +349,48 @@ _printDataType(virNWFilterVarCombIterPtr vars,
         }
     break;
 
+    case DATATYPE_IPSETNAME:
+        if (virStrcpy(buf, item->u.ipset.setname, bufsize) == NULL) {
+            virNWFilterReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                                   _("Buffer to small for ipset name"));
+            return -1;
+        }
+    break;
+
+    case DATATYPE_IPSETFLAGS:
+        for (ctr = 0; ctr < item->u.ipset.numFlags; ctr++) {
+            if (ctr != 0)
+                virBufferAddLit(&vb, ",");
+            if ((item->u.ipset.flags & (1 << ctr))) {
+                if (directionIn)
+                    virBufferAddLit(&vb, "dst");
+                else
+                    virBufferAddLit(&vb, "src");
+            } else {
+                if (directionIn)
+                    virBufferAddLit(&vb, "src");
+                else
+                    virBufferAddLit(&vb, "dst");
+            }
+        }
+
+        if (virBufferError(&vb)) {
+            virReportOOMError();
+            virBufferFreeAndReset(&vb);
+            return -1;
+        }
+
+        flags = virBufferContentAndReset(&vb);
+
+        if (virStrcpy(buf, flags, bufsize) == NULL) {
+            virNWFilterReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                                   _("Buffer too small for IPSETFLAGS type"));
+            VIR_FREE(flags);
+            return -1;
+        }
+        VIR_FREE(flags);
+    break;
+
     default:
         virNWFilterReportError(VIR_ERR_INTERNAL_ERROR,
                                _("Unhandled datatype %x"), item->datatype);
@@ -362,16 +407,23 @@ printDataType(virNWFilterVarCombIterPtr vars,
               char *buf, int bufsize,
               nwItemDescPtr item)
 {
-    return _printDataType(vars, buf, bufsize, item, 0);
+    return _printDataType(vars, buf, bufsize, item, 0, 0);
 }
 
+static int
+printDataTypeDirection(virNWFilterVarCombIterPtr vars,
+                       char *buf, int bufsize,
+                       nwItemDescPtr item, bool directionIn)
+{
+    return _printDataType(vars, buf, bufsize, item, 0, directionIn);
+}
 
 static int
 printDataTypeAsHex(virNWFilterVarCombIterPtr vars,
                    char *buf, int bufsize,
                    nwItemDescPtr item)
 {
-    return _printDataType(vars, buf, bufsize, item, 1);
+    return _printDataType(vars, buf, bufsize, item, 1, 0);
 }
 
 
@@ -927,6 +979,7 @@ iptablesHandleIpHdr(virBufferPtr buf,
     char ipaddr[INET6_ADDRSTRLEN],
          number[MAX(INT_BUFSIZE_BOUND(uint32_t),
                     INT_BUFSIZE_BOUND(int))];
+    char str[MAX_IPSET_NAME_LENGTH];
     const char *src = "--source";
     const char *dst = "--destination";
     const char *srcrange = "--src-range";
@@ -938,6 +991,26 @@ iptablesHandleIpHdr(virBufferPtr buf,
         dstrange = "--src-range";
     }
 
+    if (HAS_ENTRY_ITEM(&ipHdr->dataIPSet) &&
+        HAS_ENTRY_ITEM(&ipHdr->dataIPSetFlags)) {
+
+        if (printDataType(vars,
+                          str, sizeof(str),
+                          &ipHdr->dataIPSet) < 0)
+            goto err_exit;
+
+        virBufferAsprintf(afterStateMatch,
+                          " -m set --match-set \"%s\" ",
+                          str);
+
+        if (printDataTypeDirection(vars,
+                                   str, sizeof(str),
+                                   &ipHdr->dataIPSetFlags, directionIn) < 0)
+            goto err_exit;
+
+        virBufferAdd(afterStateMatch, str, -1);
+    }
+
     if (HAS_ENTRY_ITEM(&ipHdr->dataSrcIPAddr)) {
 
         if (printDataType(vars,

tests/nwfilterxml2xmlin/ipset-test.xml

+<filter name='testcase' chain='root'>
+  <uuid>5c6d49af-b071-6127-b4ec-6f8ed4b55335</uuid>
+  <rule action='accept' direction='out'>
+     <all  ipset='test' ipsetflags='src,dst' />
+  </rule>
+  <rule action='accept' direction='in'>
+     <all  state='NONE' ipset='test' ipsetflags='src,dst' comment='in+NONE'/>
+  </rule>
+  <rule action='accept' direction='out'>
+     <all  state='NONE' ipset='test' ipsetflags='src,dst' comment='out+NONE'/>
+  </rule>
+  <rule action='accept' direction='in'>
+     <all  ipset='test' ipsetflags='SRC,DST,SRC' />
+  </rule>
+  <rule action='accept' direction='in'>
+     <all  ipset='test:_.-+' ipsetflags='SRC,dSt,SRC' />
+  </rule>
+  <rule action='accept' direction='in'>
+     <all  ipset='$IPSETNAME' ipsetflags='src,dst' />
+  </rule>
+  <rule action='accept' direction='inout'>
+     <all  ipset='$IPSETNAME' ipsetflags='src,dst' comment='inout'/>
+  </rule>
+</filter>

tests/nwfilterxml2xmlout/ipset-test.xml

+<filter name='testcase' chain='root'>
+  <uuid>5c6d49af-b071-6127-b4ec-6f8ed4b55335</uuid>
+  <rule action='accept' direction='out' priority='500'>
+    <all ipset='test' ipsetflags='src,dst'/>
+  </rule>
+  <rule action='accept' direction='in' priority='500'>
+    <all state='NONE' ipset='test' ipsetflags='src,dst' comment='in+NONE'/>
+  </rule>
+  <rule action='accept' direction='out' priority='500'>
+    <all state='NONE' ipset='test' ipsetflags='src,dst' comment='out+NONE'/>
+  </rule>
+  <rule action='accept' direction='in' priority='500'>
+    <all ipset='test' ipsetflags='src,dst,src'/>
+  </rule>
+  <rule action='accept' direction='in' priority='500'>
+    <all ipset='test:_.-+' ipsetflags='src,dst,src'/>
+  </rule>
+  <rule action='accept' direction='in' priority='500'>
+    <all ipset='$IPSETNAME' ipsetflags='src,dst'/>
+  </rule>
+  <rule action='accept' direction='inout' priority='500'>
+    <all ipset='$IPSETNAME' ipsetflags='src,dst' comment='inout'/>
+  </rule>
+</filter>

tests/nwfilterxml2xmltest.c

@@ -157,6 +157,8 @@ mymain(void)
     DO_TEST("iter-test2", false);
     DO_TEST("iter-test3", false);
 
+    DO_TEST("ipset-test", false);
+
     return ret==0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }