netlink/handle_linux.go
Flavio Crisciani 6177f17de7 Add method to set netlink recv timeout
If the socket is closed the recv that are waiting for messages
are not woken up. The result especially for Subscribe socket is
most likely a go routine leak.
This commit introduces a method to set the timeout

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>
2017-10-20 10:09:56 -07:00

109 lines
3.1 KiB
Go

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
}
// 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,
}
}