[libvirt] [PATCH 10/25] util: new function virNetDevOpenvswitchInterfaceGetMaster()
From: Laine Stump <laine(a)laine.org>
This function retrieves the name of the OVS bridge that the given
netdev is attached to. This separate function is necessary because OVS
set the IFLA_MASTER attribute to "ovs-system" for all netdevs that are
attached to an OVS bridge, so the standard method of retrieving the
master can't be used.
Signed-off-by: Laine Stump <laine(a)laine.org>
ACKed-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/libvirt_private.syms | 1 +
src/util/virnetdevopenvswitch.c | 56 +++++++++++++++++++++++++++++++++++++++++
src/util/virnetdevopenvswitch.h | 6 +++++
3 files changed, 63 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index b87e813..ffe5dfd 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2389,6 +2389,7 @@ virNetDevMidonetUnbindPort;
virNetDevOpenvswitchAddPort;
virNetDevOpenvswitchGetMigrateData;
virNetDevOpenvswitchGetVhostuserIfname;
+virNetDevOpenvswitchInterfaceGetMaster;
virNetDevOpenvswitchInterfaceStats;
virNetDevOpenvswitchRemovePort;
virNetDevOpenvswitchSetMigrateData;
diff --git a/src/util/virnetdevopenvswitch.c b/src/util/virnetdevopenvswitch.c
index f86f698..d1c5cf4 100644
--- a/src/util/virnetdevopenvswitch.c
+++ b/src/util/virnetdevopenvswitch.c
@@ -404,6 +404,62 @@ virNetDevOpenvswitchInterfaceStats(const char *ifname,
return ret;
}
+
+/**
+ * virNetDeOpenvswitchGetMaster:
+ * @ifname: name of interface we're interested in
+ * @master: used to return a string containing the name of @ifname's
"master"
+ * (this is the bridge or bond device that this device is attached to)
+ *
+ * Returns 0 on success, -1 on failure (if @ifname has no master
+ * @master will be NULL, but return value will still be 0 (success)).
+ *
+ * NB: This function is needed because the IFLA_MASTER attribute of an
+ * interface in a netlink dump (see virNetDevGetMaster()) will always
+ * return "ovs-system" for any interface that is attached to an OVS
+ * switch. When that happens, virNetDevOpenvswitchInterfaceGetMaster()
+ * must be called to get the "real" master of the interface.
+ */
+int
+virNetDevOpenvswitchInterfaceGetMaster(const char *ifname, char **master)
+{
+ virCommandPtr cmd = NULL;
+ int ret = -1;
+ int exitstatus;
+
+ *master = NULL;
+
+ cmd = virCommandNew(OVSVSCTL);
+ virNetDevOpenvswitchAddTimeout(cmd);
+ virCommandAddArgList(cmd, "iface-to-br", ifname, NULL);
+ virCommandSetOutputBuffer(cmd, master);
+
+ if (virCommandRun(cmd, &exitstatus) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Unable to run command to get OVS master for "
+ "interface %s"), ifname);
+ goto cleanup;
+ }
+
+ /* non-0 exit code just means that the interface has no master in OVS */
+ if (exitstatus != 0)
+ VIR_FREE(*master);
+
+ if (*master) {
+ /* truncate at the first newline */
+ char *nl = strchr(*master, '\n');
+ if (nl)
+ *nl = '\0';
+ }
+
+ VIR_DEBUG("OVS master for %s is %s", ifname, *master ? *master :
"(none)");
+
+ ret = 0;
+ cleanup:
+ return ret;
+}
+
+
/**
* virNetDevOpenvswitchVhostuserGetIfname:
* @path: the path of the unix socket
diff --git a/src/util/virnetdevopenvswitch.h b/src/util/virnetdevopenvswitch.h
index 6f6e620..331e483 100644
--- a/src/util/virnetdevopenvswitch.h
+++ b/src/util/virnetdevopenvswitch.h
@@ -47,6 +47,9 @@ int virNetDevOpenvswitchAddPort(const char *brname,
int virNetDevOpenvswitchRemovePort(const char *brname, const char *ifname)
ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
+int virNetDevOpenvswitchInterfaceGetMaster(const char *ifname, char **master)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
+
int virNetDevOpenvswitchGetMigrateData(char **migrate, const char *ifname)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK;
@@ -57,6 +60,9 @@ int virNetDevOpenvswitchInterfaceStats(const char *ifname,
virDomainInterfaceStatsPtr stats)
ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
+int virNetDevOpenvswitchInterfaceGetMaster(const char *ifname, char **master)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
+
int virNetDevOpenvswitchGetVhostuserIfname(const char *path,
char **ifname)
ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK ATTRIBUTE_NOINLINE;
--
1.8.3.1