72 lines
1.8 KiB
Go
72 lines
1.8 KiB
Go
package subnet
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import (
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"errors"
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"net/netip"
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"sync"
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)
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type Direction uint8
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const (
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EngineerToSite Direction = iota + 1
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SiteToEngineer
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)
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// SessionBinding contains the exact identities used by receive validation.
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type SessionBinding struct {
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SessionID uint64
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PeerOverlayIP netip.Addr
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EngineerOverlayIP netip.Addr
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RemoteCIDRs []netip.Prefix
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Direction Direction
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Active bool
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}
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// Registry is the listener's concurrency-safe Active Session lookup.
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type Registry struct {
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mu sync.RWMutex
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sessions map[uint64]SessionBinding
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}
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func NewRegistry() *Registry { return &Registry{sessions: make(map[uint64]SessionBinding)} }
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func (r *Registry) Upsert(binding SessionBinding) error {
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if err := validateBinding(binding); err != nil {
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return err
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}
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binding.RemoteCIDRs = append([]netip.Prefix(nil), binding.RemoteCIDRs...)
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r.mu.Lock()
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r.sessions[binding.SessionID] = binding
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r.mu.Unlock()
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return nil
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}
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func (r *Registry) Remove(sessionID uint64) {
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r.mu.Lock()
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delete(r.sessions, sessionID)
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r.mu.Unlock()
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}
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func (r *Registry) Lookup(sessionID uint64) (SessionBinding, bool) {
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r.mu.RLock()
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binding, found := r.sessions[sessionID]
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r.mu.RUnlock()
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return binding, found
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}
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func validateBinding(binding SessionBinding) error {
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if binding.SessionID == 0 || !binding.PeerOverlayIP.Is4() || !binding.EngineerOverlayIP.Is4() || len(binding.RemoteCIDRs) == 0 {
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return errors.New("Session binding requires nonzero ID, IPv4 peers, and Remote CIDRs")
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}
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if binding.Direction != EngineerToSite && binding.Direction != SiteToEngineer {
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return errors.New("Session binding direction is invalid")
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}
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for _, prefix := range binding.RemoteCIDRs {
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if !prefix.Addr().Is4() || prefix != prefix.Masked() || prefix.Bits() == 0 {
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return errors.New("Session Remote CIDRs must be canonical non-default IPv4 prefixes")
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}
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}
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return nil
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}
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