[libvirt] [PATCH 10/25] util: new function virNetDevOpenvswitchInterfaceGetMaster()

From: Laine Stump <laine(a)laine.org&gt; 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&gt; ACKed-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- 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