util: rename/move iptablesFormatNetwork to virSocketAddrFormatWithPrefix

This function formats an address + prefix as, e.g. 192.168.122.0/24,
which is useful in places other than iptables. Move it to
virsocketaddr.c and make it public so that others can use it. While
moving, the bit that masks off the host bits of the address is made
optional, so that the function is more generally useful.

Signed-off-by: Laine Stump <laine@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

src/libvirt_private.syms

@@ -3269,6 +3269,7 @@ virSocketAddrCheckNetmask;
 virSocketAddrEqual;
 virSocketAddrFormat;
 virSocketAddrFormatFull;
+virSocketAddrFormatWithPrefix;
 virSocketAddrGetIPPrefix;
 virSocketAddrGetNumNetmaskBits;
 virSocketAddrGetPath;

src/util/viriptables.c

@@ -353,37 +353,6 @@ iptablesRemoveUdpOutput(virFirewall *fw,
 }
 
 
-static char *iptablesFormatNetwork(virSocketAddr *netaddr,
-                                   unsigned int prefix)
-{
-    virSocketAddr network;
-    g_autofree char *netstr = NULL;
-    char *ret;
-
-    if (!(VIR_SOCKET_ADDR_IS_FAMILY(netaddr, AF_INET) ||
-          VIR_SOCKET_ADDR_IS_FAMILY(netaddr, AF_INET6))) {
-        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                       _("Only IPv4 or IPv6 addresses can be used with iptables"));
-        return NULL;
-    }
-
-    if (virSocketAddrMaskByPrefix(netaddr, prefix, &network) < 0) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("Failure to mask address"));
-        return NULL;
-    }
-
-    netstr = virSocketAddrFormat(&network);
-
-    if (!netstr)
-        return NULL;
-
-    ret = g_strdup_printf("%s/%d", netstr, prefix);
-
-    return ret;
-}
-
-
 /* Allow all traffic coming from the bridge, with a valid network address
  * to proceed to WAN
  */
@@ -399,7 +368,7 @@ iptablesForwardAllowOut(virFirewall *fw,
     virFirewallLayer layer = VIR_SOCKET_ADDR_FAMILY(netaddr) == AF_INET ?
         VIR_FIREWALL_LAYER_IPV4 : VIR_FIREWALL_LAYER_IPV6;
 
-    if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
+    if (!(networkstr = virSocketAddrFormatWithPrefix(netaddr, prefix, true)))
         return -1;
 
     if (physdev && physdev[0])
@@ -487,7 +456,7 @@ iptablesForwardAllowRelatedIn(virFirewall *fw,
         VIR_FIREWALL_LAYER_IPV4 : VIR_FIREWALL_LAYER_IPV6;
     g_autofree char *networkstr = NULL;
 
-    if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
+    if (!(networkstr = virSocketAddrFormatWithPrefix(netaddr, prefix, true)))
         return -1;
 
     if (physdev && physdev[0])
@@ -577,7 +546,7 @@ iptablesForwardAllowIn(virFirewall *fw,
         VIR_FIREWALL_LAYER_IPV4 : VIR_FIREWALL_LAYER_IPV6;
     g_autofree char *networkstr = NULL;
 
-    if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
+    if (!(networkstr = virSocketAddrFormatWithPrefix(netaddr, prefix, true)))
         return -1;
 
     if (physdev && physdev[0])
@@ -829,7 +798,7 @@ iptablesForwardMasquerade(virFirewall *fw,
     virFirewallLayer layer = af == AF_INET ?
         VIR_FIREWALL_LAYER_IPV4 : VIR_FIREWALL_LAYER_IPV6;
 
-    if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
+    if (!(networkstr = virSocketAddrFormatWithPrefix(netaddr, prefix, true)))
         return -1;
 
     if (VIR_SOCKET_ADDR_IS_FAMILY(&addr->start, af)) {
@@ -972,7 +941,7 @@ iptablesForwardDontMasquerade(virFirewall *fw,
     virFirewallLayer layer = VIR_SOCKET_ADDR_FAMILY(netaddr) == AF_INET ?
         VIR_FIREWALL_LAYER_IPV4 : VIR_FIREWALL_LAYER_IPV6;
 
-    if (!(networkstr = iptablesFormatNetwork(netaddr, prefix)))
+    if (!(networkstr = virSocketAddrFormatWithPrefix(netaddr, prefix, true)))
         return -1;
 
     if (physdev && physdev[0])

src/util/virsocketaddr.c

@@ -511,6 +511,50 @@ virSocketAddrFormatFull(const virSocketAddr *addr,
 }
 
 
+/*
+ * virSocketAddrFormatWithPrefix:
+ * @addr: an initialized virSocketAddr *
+ * @prefix: an IP network prefix (0-32 if IPv4, 0-128 if IPv6)
+ * @masked: true to mask off the host bits of the address
+ *
+ * Returns a string representation of the IP network described by
+ * @netaddr/@prefix. If @masked is true, the address is masked to
+ * remove the host bits according to prefix. So, for example, sending
+ * f(1.2.3.4, 24, true) would return "1.2.3.0/24", but f(1.2.3.4, 24,
+ * false) would return "1.2.3.4/24".
+ *
+ * returns false on failure (and logs an error message)
+ */
+char *
+virSocketAddrFormatWithPrefix(virSocketAddr *addr,
+                              unsigned int prefix,
+                              bool masked)
+{
+    virSocketAddr network;
+    g_autofree char *netstr = NULL;
+
+    if (!(VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET) ||
+          VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET6))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Only IPv4 or IPv6 addresses can be used with a prefix"));
+        return NULL;
+    }
+
+    if (masked && virSocketAddrMaskByPrefix(addr, prefix, &network) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Failure to mask address"));
+        return NULL;
+    }
+
+    netstr = virSocketAddrFormat(&network);
+
+    if (!netstr)
+        return NULL;
+
+    return g_strdup_printf("%s/%d", netstr, prefix);
+}
+
+
 /*
  * virSocketAddrSetPort:
  * @addr: an initialized virSocketAddr *

src/util/virsocketaddr.h

@@ -88,6 +88,9 @@ char *virSocketAddrFormat(const virSocketAddr *addr);
 char *virSocketAddrFormatFull(const virSocketAddr *addr,
                               bool withService,
                               const char *separator);
+char *virSocketAddrFormatWithPrefix(virSocketAddr *addr,
+                                    unsigned int prefix,
+                                    bool masked);
 
 char *virSocketAddrGetPath(virSocketAddr *addr);