package netlink import ( "fmt" "syscall" "time" "github.com/vishvananda/netlink/nl" "github.com/vishvananda/netns" ) // Empty handle used by the netlink package methods var pkgHandle = &Handle{} // Handle is an handle for the netlink requests on a // specific network namespace. All the requests on the // same netlink family share the same netlink socket, // which gets released when the handle is deleted. type Handle struct { sockets map[int]*nl.SocketHandle lookupByDump bool } // SupportsNetlinkFamily reports whether the passed netlink family is supported by this Handle func (h *Handle) SupportsNetlinkFamily(nlFamily int) bool { _, ok := h.sockets[nlFamily] return ok } // NewHandle returns a netlink handle on the current network namespace. // Caller may specify the netlink families the handle should support. // If no families are specified, all the families the netlink package // supports will be automatically added. func NewHandle(nlFamilies ...int) (*Handle, error) { return newHandle(netns.None(), netns.None(), nlFamilies...) } // SetSocketTimeout sets the send and receive timeout for each socket in the // netlink handle. Although the socket timeout has granularity of one // microsecond, the effective granularity is floored by the kernel timer tick, // which default value is four milliseconds. func (h *Handle) SetSocketTimeout(to time.Duration) error { if to < time.Microsecond { return fmt.Errorf("invalid timeout, minimul value is %s", time.Microsecond) } tv := syscall.NsecToTimeval(to.Nanoseconds()) for _, sh := range h.sockets { if err := sh.Socket.SetSendTimeout(&tv); err != nil { return err } if err := sh.Socket.SetReceiveTimeout(&tv); err != nil { return err } } return nil } // SetSocketReceiveBufferSize sets the receive buffer size for each // socket in the netlink handle. The maximum value is capped by // /proc/sys/net/core/rmem_max. func (h *Handle) SetSocketReceiveBufferSize(size int, force bool) error { opt := syscall.SO_RCVBUF if force { opt = syscall.SO_RCVBUFFORCE } for _, sh := range h.sockets { fd := sh.Socket.GetFd() err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, opt, size) if err != nil { return err } } return nil } // GetSocketReceiveBufferSize gets the receiver buffer size for each // socket in the netlink handle. The retrieved value should be the // double to the one set for SetSocketReceiveBufferSize. func (h *Handle) GetSocketReceiveBufferSize() ([]int, error) { results := make([]int, len(h.sockets)) i := 0 for _, sh := range h.sockets { fd := sh.Socket.GetFd() size, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_RCVBUF) if err != nil { return nil, err } results[i] = size i++ } return results, nil } // NewHandle returns a netlink handle on the network namespace // specified by ns. If ns=netns.None(), current network namespace // will be assumed func NewHandleAt(ns netns.NsHandle, nlFamilies ...int) (*Handle, error) { return newHandle(ns, netns.None(), nlFamilies...) } // NewHandleAtFrom works as NewHandle but allows client to specify the // new and the origin netns Handle. func NewHandleAtFrom(newNs, curNs netns.NsHandle) (*Handle, error) { return newHandle(newNs, curNs) } func newHandle(newNs, curNs netns.NsHandle, nlFamilies ...int) (*Handle, error) { h := &Handle{sockets: map[int]*nl.SocketHandle{}} fams := nl.SupportedNlFamilies if len(nlFamilies) != 0 { fams = nlFamilies } for _, f := range fams { s, err := nl.GetNetlinkSocketAt(newNs, curNs, f) if err != nil { return nil, err } h.sockets[f] = &nl.SocketHandle{Socket: s} } return h, nil } // Delete releases the resources allocated to this handle func (h *Handle) Delete() { for _, sh := range h.sockets { sh.Close() } h.sockets = nil } func (h *Handle) newNetlinkRequest(proto, flags int) *nl.NetlinkRequest { // Do this so that package API still use nl package variable nextSeqNr if h.sockets == nil { return nl.NewNetlinkRequest(proto, flags) } return &nl.NetlinkRequest{ NlMsghdr: syscall.NlMsghdr{ Len: uint32(syscall.SizeofNlMsghdr), Type: uint16(proto), Flags: syscall.NLM_F_REQUEST | uint16(flags), }, Sockets: h.sockets, } }