Dmitrii Stepanov
e35ad63f2d
The use of network interfaces does not cover cases where it is necessary to use network interfaces to access different subnets. Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
56 lines
1.5 KiB
Go
56 lines
1.5 KiB
Go
package multinet
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import (
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"context"
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"errors"
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"fmt"
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"net"
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"sync/atomic"
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)
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// BalancerType reperents the algorithm which is used to pick source address.
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type BalancerType string
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const (
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// BalancerTypeNoop picks first address for which link is up.
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BalancerTypeNoop BalancerType = ""
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// BalancerTypeNoop implements simple round-robin between up links.
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// It is not fair in case some links are down.
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BalancerTypeRoundRobin BalancerType = "roundrobin"
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)
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var errNoSuitableNodeFound = errors.New("no suitale node found")
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type balancer interface {
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DialContext(ctx context.Context, s *Subnet, network, address string) (net.Conn, error)
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}
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type roundRobin struct {
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d *dialer
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i atomic.Uint32
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}
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func (r *roundRobin) DialContext(ctx context.Context, s *Subnet, network, address string) (net.Conn, error) {
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next := int(r.i.Add(1))
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for i := range s.SourceIPs {
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ii := s.SourceIPs[(i+next)%len(s.SourceIPs)]
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dd := r.d.dialer
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dd.LocalAddr = &net.TCPAddr{IP: net.IP(ii.AsSlice())}
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return r.d.dialContext(&dd, ctx, network, address)
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}
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return nil, fmt.Errorf("(*roundRobin).DialContext: %w", errNoSuitableNodeFound)
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}
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type firstEnabled struct {
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d *dialer
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}
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func (r *firstEnabled) DialContext(ctx context.Context, s *Subnet, network, address string) (net.Conn, error) {
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for i := range s.SourceIPs {
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ii := s.SourceIPs[i]
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dd := r.d.dialer
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dd.LocalAddr = &net.TCPAddr{IP: net.IP(ii.AsSlice())}
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return r.d.dialContext(&dd, ctx, network, address)
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}
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return nil, fmt.Errorf("(*firstEnabled).DialContext: %w", errNoSuitableNodeFound)
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}
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