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