Update iptables.c to also support ip6tables.

All of the iptables functions eventually call down to a single
bottom-level function, and fortunately, ip6tables syntax (for all the
args that we use) is identical to iptables format (except the
addresses), so all we need to do is:

1) Get an address family down to the lowest level function in each
   case, either implied through an address, or explicitly when no
   address is in the parameter list, and

2) At the lowest level, just decide whether to call "iptables" or
   "ip6tables" based on the family.

The location of the ip6tables binary is determined at build time by
autoconf. If a particular target system happens to not have ip6tables
installed, any attempts to run it will generate an error, but that
won't happen unless someone tries to define an IPv6 address for a
network. This is identical behavior to IPv4 addresses and iptables.

configure.ac

@@ -312,6 +312,9 @@ AC_DEFINE_UNQUOTED([IP_PATH], "$IP_PATH", [path to ip binary])
 AC_PATH_PROG([IPTABLES_PATH], [iptables], /sbin/iptables, [/usr/sbin:$PATH])
 AC_DEFINE_UNQUOTED([IPTABLES_PATH], "$IPTABLES_PATH", [path to iptables binary])
 
+AC_PATH_PROG([IP6TABLES_PATH], [ip6tables], /sbin/ip6tables, [/usr/sbin:$PATH])
+AC_DEFINE_UNQUOTED([IP6TABLES_PATH], "$IP6TABLES_PATH", [path to ip6tables binary])
+
 AC_PATH_PROG([EBTABLES_PATH], [ebtables], /sbin/ebtables, [/usr/sbin:$PATH])
 AC_DEFINE_UNQUOTED([EBTABLES_PATH], "$EBTABLES_PATH", [path to ebtables binary])
 

src/network/bridge_driver.c

@@ -842,14 +842,16 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
 
     /* allow DHCP requests through to dnsmasq */
 
-    if (iptablesAddTcpInput(driver->iptables, network->def->bridge, 67) < 0) {
+    if (iptablesAddTcpInput(driver->iptables, AF_INET,
+                            network->def->bridge, 67) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow DHCP requests from '%s'"),
                            network->def->bridge);
         goto err1;
     }
 
-    if (iptablesAddUdpInput(driver->iptables, network->def->bridge, 67) < 0) {
+    if (iptablesAddUdpInput(driver->iptables, AF_INET,
+                            network->def->bridge, 67) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow DHCP requests from '%s'"),
                            network->def->bridge);
@@ -871,14 +873,16 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
     }
 
     /* allow DNS requests through to dnsmasq */
-    if (iptablesAddTcpInput(driver->iptables, network->def->bridge, 53) < 0) {
+    if (iptablesAddTcpInput(driver->iptables, AF_INET,
+                            network->def->bridge, 53) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow DNS requests from '%s'"),
                            network->def->bridge);
         goto err3;
     }
 
-    if (iptablesAddUdpInput(driver->iptables, network->def->bridge, 53) < 0) {
+    if (iptablesAddUdpInput(driver->iptables, AF_INET,
+                            network->def->bridge, 53) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow DNS requests from '%s'"),
                            network->def->bridge);
@@ -887,7 +891,8 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
 
     /* allow TFTP requests through to dnsmasq if necessary */
     if (ipv4def && ipv4def->tftproot &&
-        iptablesAddUdpInput(driver->iptables, network->def->bridge, 69) < 0) {
+        iptablesAddUdpInput(driver->iptables, AF_INET,
+                            network->def->bridge, 69) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow TFTP requests from '%s'"),
                            network->def->bridge);
@@ -896,14 +901,16 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
 
     /* Catch all rules to block forwarding to/from bridges */
 
-    if (iptablesAddForwardRejectOut(driver->iptables, network->def->bridge) < 0) {
+    if (iptablesAddForwardRejectOut(driver->iptables, AF_INET,
+                                    network->def->bridge) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to block outbound traffic from '%s'"),
                            network->def->bridge);
         goto err6;
     }
 
-    if (iptablesAddForwardRejectIn(driver->iptables, network->def->bridge) < 0) {
+    if (iptablesAddForwardRejectIn(driver->iptables, AF_INET,
+                                   network->def->bridge) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to block inbound traffic to '%s'"),
                            network->def->bridge);
@@ -911,7 +918,8 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
     }
 
     /* Allow traffic between guests on the same bridge */
-    if (iptablesAddForwardAllowCross(driver->iptables, network->def->bridge) < 0) {
+    if (iptablesAddForwardAllowCross(driver->iptables, AF_INET,
+                                     network->def->bridge) < 0) {
         networkReportError(VIR_ERR_SYSTEM_ERROR,
                            _("failed to add iptables rule to allow cross bridge traffic on '%s'"),
                            network->def->bridge);
@@ -922,21 +930,21 @@ networkAddGeneralIptablesRules(struct network_driver *driver,
 
     /* unwind in reverse order from the point of failure */
 err8:
-    iptablesRemoveForwardRejectIn(driver->iptables, network->def->bridge);
+    iptablesRemoveForwardRejectIn(driver->iptables, AF_INET, network->def->bridge);
 err7:
-    iptablesRemoveForwardRejectOut(driver->iptables, network->def->bridge);
+    iptablesRemoveForwardRejectOut(driver->iptables, AF_INET, network->def->bridge);
 err6:
     if (ipv4def && ipv4def->tftproot) {
-        iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 69);
+        iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 69);
     }
 err5:
-    iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 53);
+    iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 53);
 err4:
-    iptablesRemoveTcpInput(driver->iptables, network->def->bridge, 53);
+    iptablesRemoveTcpInput(driver->iptables, AF_INET, network->def->bridge, 53);
 err3:
-    iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 67);
+    iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 67);
 err2:
-    iptablesRemoveTcpInput(driver->iptables, network->def->bridge, 67);
+    iptablesRemoveTcpInput(driver->iptables, AF_INET, network->def->bridge, 67);
 err1:
     return -1;
 }
@@ -955,20 +963,20 @@ networkRemoveGeneralIptablesRules(struct network_driver *driver,
             break;
     }
 
-    iptablesRemoveForwardAllowCross(driver->iptables, network->def->bridge);
-    iptablesRemoveForwardRejectIn(driver->iptables, network->def->bridge);
-    iptablesRemoveForwardRejectOut(driver->iptables, network->def->bridge);
+    iptablesRemoveForwardAllowCross(driver->iptables, AF_INET, network->def->bridge);
+    iptablesRemoveForwardRejectIn(driver->iptables, AF_INET, network->def->bridge);
+    iptablesRemoveForwardRejectOut(driver->iptables, AF_INET, network->def->bridge);
     if (ipv4def && ipv4def->tftproot) {
-        iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 69);
+        iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 69);
     }
-    iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 53);
-    iptablesRemoveTcpInput(driver->iptables, network->def->bridge, 53);
+    iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 53);
+    iptablesRemoveTcpInput(driver->iptables, AF_INET, network->def->bridge, 53);
     if (ipv4def && (ipv4def->nranges || ipv4def->nhosts)) {
         iptablesRemoveOutputFixUdpChecksum(driver->iptables,
                                            network->def->bridge, 68);
     }
-    iptablesRemoveUdpInput(driver->iptables, network->def->bridge, 67);
-    iptablesRemoveTcpInput(driver->iptables, network->def->bridge, 67);
+    iptablesRemoveUdpInput(driver->iptables, AF_INET, network->def->bridge, 67);
+    iptablesRemoveTcpInput(driver->iptables, AF_INET, network->def->bridge, 67);
 }
 
 static int

src/util/iptables.c

@@ -99,14 +99,17 @@ iptRulesNew(const char *table,
 }
 
 static int ATTRIBUTE_SENTINEL
-iptablesAddRemoveRule(iptRules *rules, int action, const char *arg, ...)
+iptablesAddRemoveRule(iptRules *rules, int family, int action,
+                      const char *arg, ...)
 {
     va_list args;
     int ret;
     virCommandPtr cmd;
     const char *s;
 
-    cmd = virCommandNew(IPTABLES_PATH);
+    cmd = virCommandNew((family == AF_INET6)
+                        ? IP6TABLES_PATH : IPTABLES_PATH);
+
     virCommandAddArgList(cmd, "--table", rules->table,
                          action == ADD ? "--insert" : "--delete",
                          rules->chain, arg, NULL);
@@ -177,6 +180,7 @@ iptablesContextFree(iptablesContext *ctx)
 
 static int
 iptablesInput(iptablesContext *ctx,
+              int family,
               const char *iface,
               int port,
               int action,
@@ -188,6 +192,7 @@ iptablesInput(iptablesContext *ctx,
     portstr[sizeof(portstr) - 1] = '\0';
 
     return iptablesAddRemoveRule(ctx->input_filter,
+                                 family,
                                  action,
                                  "--in-interface", iface,
                                  "--protocol", tcp ? "tcp" : "udp",
@@ -210,10 +215,11 @@ iptablesInput(iptablesContext *ctx,
 
 int
 iptablesAddTcpInput(iptablesContext *ctx,
+                    int family,
                     const char *iface,
                     int port)
 {
-    return iptablesInput(ctx, iface, port, ADD, 1);
+    return iptablesInput(ctx, family, iface, port, ADD, 1);
 }
 
 /**
@@ -229,10 +235,11 @@ iptablesAddTcpInput(iptablesContext *ctx,
  */
 int
 iptablesRemoveTcpInput(iptablesContext *ctx,
+                       int family,
                        const char *iface,
                        int port)
 {
-    return iptablesInput(ctx, iface, port, REMOVE, 1);
+    return iptablesInput(ctx, family, iface, port, REMOVE, 1);
 }
 
 /**
@@ -249,10 +256,11 @@ iptablesRemoveTcpInput(iptablesContext *ctx,
 
 int
 iptablesAddUdpInput(iptablesContext *ctx,
+                    int family,
                     const char *iface,
                     int port)
 {
-    return iptablesInput(ctx, iface, port, ADD, 0);
+    return iptablesInput(ctx, family, iface, port, ADD, 0);
 }
 
 /**
@@ -268,10 +276,11 @@ iptablesAddUdpInput(iptablesContext *ctx,
  */
 int
 iptablesRemoveUdpInput(iptablesContext *ctx,
+                       int family,
                        const char *iface,
                        int port)
 {
-    return iptablesInput(ctx, iface, port, REMOVE, 0);
+    return iptablesInput(ctx, family, iface, port, REMOVE, 0);
 }
 
 
@@ -282,9 +291,10 @@ static char *iptablesFormatNetwork(virSocketAddr *netaddr,
     char *netstr;
     char *ret;
 
-    if (!VIR_SOCKET_IS_FAMILY(netaddr, AF_INET)) {
+    if (!(VIR_SOCKET_IS_FAMILY(netaddr, AF_INET) ||
+          VIR_SOCKET_IS_FAMILY(netaddr, AF_INET6))) {
         iptablesError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                      _("Only IPv4 addresses can be used with iptables"));
+                      _("Only IPv4 or IPv6 addresses can be used with iptables"));
         return NULL;
     }
 
@@ -327,6 +337,7 @@ iptablesForwardAllowOut(iptablesContext *ctx,
 
     if (physdev && physdev[0]) {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--source", networkstr,
                                     "--in-interface", iface,
@@ -335,6 +346,7 @@ iptablesForwardAllowOut(iptablesContext *ctx,
                                     NULL);
     } else {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--source", networkstr,
                                     "--in-interface", iface,
@@ -411,6 +423,7 @@ iptablesForwardAllowRelatedIn(iptablesContext *ctx,
 
     if (physdev && physdev[0]) {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--destination", networkstr,
                                     "--in-interface", physdev,
@@ -421,6 +434,7 @@ iptablesForwardAllowRelatedIn(iptablesContext *ctx,
                                     NULL);
     } else {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--destination", networkstr,
                                     "--out-interface", iface,
@@ -497,6 +511,7 @@ iptablesForwardAllowIn(iptablesContext *ctx,
 
     if (physdev && physdev[0]) {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--destination", networkstr,
                                     "--in-interface", physdev,
@@ -505,6 +520,7 @@ iptablesForwardAllowIn(iptablesContext *ctx,
                                     NULL);
     } else {
         ret = iptablesAddRemoveRule(ctx->forward_filter,
+                                    VIR_SOCKET_FAMILY(netaddr),
                                     action,
                                     "--destination", networkstr,
                                     "--out-interface", iface,
@@ -567,10 +583,12 @@ iptablesRemoveForwardAllowIn(iptablesContext *ctx,
  */
 static int
 iptablesForwardAllowCross(iptablesContext *ctx,
+                          int family,
                           const char *iface,
                           int action)
 {
     return iptablesAddRemoveRule(ctx->forward_filter,
+                                 family,
                                  action,
                                  "--in-interface", iface,
                                  "--out-interface", iface,
@@ -591,8 +609,10 @@ iptablesForwardAllowCross(iptablesContext *ctx,
  */
 int
 iptablesAddForwardAllowCross(iptablesContext *ctx,
-                             const char *iface) {
-    return iptablesForwardAllowCross(ctx, iface, ADD);
+                             int family,
+                             const char *iface)
+{
+    return iptablesForwardAllowCross(ctx, family, iface, ADD);
 }
 
 /**
@@ -608,8 +628,10 @@ iptablesAddForwardAllowCross(iptablesContext *ctx,
  */
 int
 iptablesRemoveForwardAllowCross(iptablesContext *ctx,
-                                const char *iface) {
-    return iptablesForwardAllowCross(ctx, iface, REMOVE);
+                                int family,
+                                const char *iface)
+{
+    return iptablesForwardAllowCross(ctx, family, iface, REMOVE);
 }
 
 
@@ -618,14 +640,16 @@ iptablesRemoveForwardAllowCross(iptablesContext *ctx,
  */
 static int
 iptablesForwardRejectOut(iptablesContext *ctx,
+                         int family,
                          const char *iface,
                          int action)
 {
     return iptablesAddRemoveRule(ctx->forward_filter,
-                                     action,
-                                     "--in-interface", iface,
-                                     "--jump", "REJECT",
-                                     NULL);
+                                 family,
+                                 action,
+                                 "--in-interface", iface,
+                                 "--jump", "REJECT",
+                                 NULL);
 }
 
 /**
@@ -640,9 +664,10 @@ iptablesForwardRejectOut(iptablesContext *ctx,
  */
 int
 iptablesAddForwardRejectOut(iptablesContext *ctx,
+                            int family,
                             const char *iface)
 {
-    return iptablesForwardRejectOut(ctx, iface, ADD);
+    return iptablesForwardRejectOut(ctx, family, iface, ADD);
 }
 
 /**
@@ -657,9 +682,10 @@ iptablesAddForwardRejectOut(iptablesContext *ctx,
  */
 int
 iptablesRemoveForwardRejectOut(iptablesContext *ctx,
+                               int family,
                                const char *iface)
 {
-    return iptablesForwardRejectOut(ctx, iface, REMOVE);
+    return iptablesForwardRejectOut(ctx, family, iface, REMOVE);
 }
 
 
@@ -670,10 +696,12 @@ iptablesRemoveForwardRejectOut(iptablesContext *ctx,
  */
 static int
 iptablesForwardRejectIn(iptablesContext *ctx,
+                        int family,
                         const char *iface,
                         int action)
 {
     return iptablesAddRemoveRule(ctx->forward_filter,
+                                 family,
                                  action,
                                  "--out-interface", iface,
                                  "--jump", "REJECT",
@@ -692,9 +720,10 @@ iptablesForwardRejectIn(iptablesContext *ctx,
  */
 int
 iptablesAddForwardRejectIn(iptablesContext *ctx,
+                           int family,
                            const char *iface)
 {
-    return iptablesForwardRejectIn(ctx, iface, ADD);
+    return iptablesForwardRejectIn(ctx, family, iface, ADD);
 }
 
 /**
@@ -709,9 +738,10 @@ iptablesAddForwardRejectIn(iptablesContext *ctx,
  */
 int
 iptablesRemoveForwardRejectIn(iptablesContext *ctx,
+                              int family,
                               const char *iface)
 {
-    return iptablesForwardRejectIn(ctx, iface, REMOVE);
+    return iptablesForwardRejectIn(ctx, family, iface, REMOVE);
 }
 
 
@@ -735,6 +765,7 @@ iptablesForwardMasquerade(iptablesContext *ctx,
     if (protocol && protocol[0]) {
         if (physdev && physdev[0]) {
             ret = iptablesAddRemoveRule(ctx->nat_postrouting,
+                                        VIR_SOCKET_FAMILY(netaddr),
                                         action,
                                         "--source", networkstr,
                                         "-p", protocol,
@@ -745,6 +776,7 @@ iptablesForwardMasquerade(iptablesContext *ctx,
                                         NULL);
         } else {
             ret = iptablesAddRemoveRule(ctx->nat_postrouting,
+                                        VIR_SOCKET_FAMILY(netaddr),
                                         action,
                                         "--source", networkstr,
                                         "-p", protocol,
@@ -756,6 +788,7 @@ iptablesForwardMasquerade(iptablesContext *ctx,
     } else {
         if (physdev && physdev[0]) {
             ret = iptablesAddRemoveRule(ctx->nat_postrouting,
+                                        VIR_SOCKET_FAMILY(netaddr),
                                         action,
                                         "--source", networkstr,
                                         "!", "--destination", networkstr,
@@ -764,6 +797,7 @@ iptablesForwardMasquerade(iptablesContext *ctx,
                                         NULL);
         } else {
             ret = iptablesAddRemoveRule(ctx->nat_postrouting,
+                                        VIR_SOCKET_FAMILY(netaddr),
                                         action,
                                         "--source", networkstr,
                                         "!", "--destination", networkstr,
@@ -834,6 +868,7 @@ iptablesOutputFixUdpChecksum(iptablesContext *ctx,
     portstr[sizeof(portstr) - 1] = '\0';
 
     return iptablesAddRemoveRule(ctx->mangle_postrouting,
+                                 AF_INET,
                                  action,
                                  "--out-interface", iface,
                                  "--protocol", "udp",

src/util/iptables.h

@@ -30,16 +30,20 @@ iptablesContext *iptablesContextNew              (void);
 void             iptablesContextFree             (iptablesContext *ctx);
 
 int              iptablesAddTcpInput             (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface,
                                                   int port);
 int              iptablesRemoveTcpInput          (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface,
                                                   int port);
 
 int              iptablesAddUdpInput             (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface,
                                                   int port);
 int              iptablesRemoveUdpInput          (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface,
                                                   int port);
 
@@ -77,18 +81,24 @@ int              iptablesRemoveForwardAllowIn    (iptablesContext *ctx,
                                                   const char *physdev);
 
 int              iptablesAddForwardAllowCross    (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 int              iptablesRemoveForwardAllowCross (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 
 int              iptablesAddForwardRejectOut     (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 int              iptablesRemoveForwardRejectOut  (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 
 int              iptablesAddForwardRejectIn      (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 int              iptablesRemoveForwardRejectIn   (iptablesContext *ctx,
+                                                  int family,
                                                   const char *iface);
 
 int              iptablesAddForwardMasquerade    (iptablesContext *ctx,