63 lines
1.3 KiB
Go
63 lines
1.3 KiB
Go
package service
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import (
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"github.com/pkg/errors"
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"google.golang.org/grpc/codes"
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"google.golang.org/grpc/status"
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)
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// TTL constants.
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const (
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// ZeroTTL is an upper bound of invalid TTL values.
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ZeroTTL = iota
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// NonForwardingTTL is a TTL value that does not imply a request forwarding.
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NonForwardingTTL
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// SingleForwardingTTL is a TTL value that imply potential forwarding with NonForwardingTTL.
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SingleForwardingTTL
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)
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// SetTTL is a TTL field setter.
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func (m *RequestMetaHeader) SetTTL(v uint32) {
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m.TTL = v
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}
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// IRNonForwarding condition that allows NonForwardingTTL only for IR.
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func IRNonForwarding(role NodeRole) TTLCondition {
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return func(ttl uint32) error {
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if ttl == NonForwardingTTL && role != InnerRingNode {
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return ErrInvalidTTL
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}
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return nil
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}
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}
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// ProcessRequestTTL validates and updates requests with TTL.
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func ProcessRequestTTL(req TTLContainer, cond ...TTLCondition) error {
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ttl := req.GetTTL()
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if ttl == ZeroTTL {
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return status.New(codes.InvalidArgument, ErrInvalidTTL.Error()).Err()
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}
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for i := range cond {
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if cond[i] == nil {
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continue
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}
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// check specific condition:
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if err := cond[i](ttl); err != nil {
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if st, ok := status.FromError(errors.Cause(err)); ok {
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return st.Err()
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}
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return status.New(codes.InvalidArgument, err.Error()).Err()
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}
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}
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req.SetTTL(ttl - 1)
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return nil
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}
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