libvirt previously only touched an interface's disable_ipv6 setting in
sysfs if it needed to be set to 1, assuming that 0 is the
default. Apparently that isn't always the case though (kernel 3.15.7-1
in Arch Linux reportedly defaults a new interface's disable_ipv6
setting to 1) so this patch explicitly sets it to 0 or 1 as
appropriate.
---
src/network/bridge_driver.c | 41 +
1 file changed, 21 insertions(+), 20 deletions(-)
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 6ccc6e2..965fdec 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -1824,33 +1824,34 @@ networkSetIPv6Sysctls(virNetworkObjPtr network)
{
char *field = NULL;
int ret = -1;
+bool enableIPv6 = !!virNetworkDefGetIpByIndex(network->def, AF_INET6, 0);
-if (!virNetworkDefGetIpByIndex(network->def, AF_INET6, 0)) {
-/* Only set disable_ipv6 if there are no ipv6 addresses defined for
- * the network.
- */
-if (virAsprintf(&field, SYSCTL_PATH "/net/ipv6/conf/%s/disable_ipv6",
-network->def->bridge) < 0)
-goto cleanup;
+/* set disable_ipv6 if there are no ipv6 addresses defined for the
+ * network. But also unset it if there *are* ipv6 addresses, as we
+ * can't be sure of its default value.
+ */
+if (virAsprintf(&field, SYSCTL_PATH "/net/ipv6/conf/%s/disable_ipv6",
+network->def->bridge) < 0)
+ goto cleanup;
-if (access(field, W_OK) < 0 && errno == ENOENT) {
+if (access(field, W_OK) < 0 && errno == ENOENT) {
+if (!enableIPv6)
VIR_DEBUG("ipv6 appears to already be disabled on %s",
network->def->bridge);
-ret = 0;
-goto cleanup;
-}
+ret = 0;
+goto cleanup;
+}
-if (virFileWriteStr(field, "1", 0) < 0) {
-virReportSystemError(errno,
- _("cannot write to %s to disable IPv6 on
bridge %s"),
- field, network->def->bridge);
-goto cleanup;
-}
-VIR_FREE(field);
+if (virFileWriteStr(field, enableIPv6 ? "0" : "1", 0) < 0) {
+virReportSystemError(errno,
+ _("cannot write to %s to enable/disable IPv6 "
+ "on bridge %s"), field, network->def->bridge);
+goto cleanup;
}
+VIR_FREE(field);
-/* The rest of the ipv6 sysctl tunables should always be set,
- * whether or not we're using ipv6 on this bridge.
+/* The rest of the ipv6 sysctl tunables should always be set the
+ * same, whether or not we're using ipv6 on this bridge.
*/
/* Prevent guests from hijacking the host network by sending out
--
1.9.3
--
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