[libvirt] [PATCHv3 3/4] util: function to get local nl_pid used by netlink event service socket

This value will be needed to set the src_pid when sending netlink messages to lldpad. It is part of the solution to: https://bugzilla.redhat.com/show_bug.cgi?id=816465 Note that libnl's port generation algorithm guarantees that the nl_socket_get_local_port() will always be > 0, so it is okay to cast the uint32_t to int (thus allowing us to use -1 as an error sentinel). --- src/libvirt_private.syms | 1 + src/util/virnetlink.c | 18 ++++++++++++++++++ src/util/virnetlink.h | 5 +++++ 3 files changed, 24 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 9b20dd4..4ab1e65 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1331,6 +1331,7 @@ virNetlinkCommand; virNetlinkEventAddClient; virNetlinkEventRemoveClient; virNetlinkEventServiceIsRunning; +virNetlinkEventServiceLocalPid; virNetlinkEventServiceStop; virNetlinkEventServiceStart; virNetlinkShutdown; diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c index df0f57a..aeca2a7 100644 --- a/src/util/virnetlink.c +++ b/src/util/virnetlink.c @@ -379,6 +379,24 @@ virNetlinkEventServiceIsRunning(void) } /** + * virNetlinkEventServiceLocalPid: + * + * Returns the nl_pid value that was used to bind() the netlink socket + * used by the netlink event service, or -1 on error (netlink + * guarantees that this value will always be > 0). + */ +int virNetlinkEventServiceLocalPid(void) +{ + if (!(server && server->netlinknh)) { + netlinkError(VIR_ERR_INTERNAL_ERROR, "%s", + _("netlink event service not running")); + return -1; + } + return (int)nl_socket_get_local_port(server->netlinknh); +} + + +/** * virNetlinkEventServiceStart: * * start a monitor to receive netlink messages for libvirtd. diff --git a/src/util/virnetlink.h b/src/util/virnetlink.h index c57be82..bafe8ca 100644 --- a/src/util/virnetlink.h +++ b/src/util/virnetlink.h @@ -62,6 +62,11 @@ int virNetlinkEventServiceStart(void); bool virNetlinkEventServiceIsRunning(void); /** + * virNetlinkEventServiceLocalPid: returns nl_pid used to bind() netlink socket + */ +int virNetlinkEventServiceLocalPid(void); + +/** * virNetlinkEventAddClient: register a callback for handling of netlink messages */ int virNetlinkEventAddClient(virNetlinkEventHandleCallback handleCB, -- 1.7.10