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gcp.go
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gcp.go
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package tlvparse
import (
"encoding/binary"
"github.com/pires/go-proxyproto"
)
const (
// PP2_TYPE_GCP indicates a Google Cloud Platform header
PP2_TYPE_GCP proxyproto.PP2Type = 0xE0
)
// ExtractPSCConnectionID returns the first PSC Connection ID in the TLV if it exists and is well-formed and
// a bool indicating one was found.
func ExtractPSCConnectionID(tlvs []proxyproto.TLV) (uint64, bool) {
for _, tlv := range tlvs {
if linkID, err := pscConnectionID(tlv); err == nil {
return linkID, true
}
}
return 0, false
}
// pscConnectionID returns the ID of a GCP PSC extension TLV or errors with ErrIncompatibleTLV or
// ErrMalformedTLV if it's the wrong TLV type or is malformed.
//
// Field Length (bytes) Description
// Type 1 PP2_TYPE_GCP (0xE0)
// Length 2 Length of value (always 0x0008)
// Value 8 The 8-byte PSC Connection ID (decode to uint64; big endian)
//
// For example proxyproto.TLV{Type:0xea, Length:8, Value:[]byte{0xff, 0xff, 0xff, 0xff, 0xc0, 0xa8, 0x64, 0x02}}
// will be decoded as 18446744072646845442.
//
// See https://cloud.google.com/vpc/docs/configure-private-service-connect-producer
func pscConnectionID(t proxyproto.TLV) (uint64, error) {
if !isPSCConnectionID(t) {
return 0, proxyproto.ErrIncompatibleTLV
}
linkID := binary.BigEndian.Uint64(t.Value)
return linkID, nil
}
func isPSCConnectionID(t proxyproto.TLV) bool {
return t.Type == PP2_TYPE_GCP && len(t.Value) == 8
}