types/netlogtype: add constants for maximum serialized sizes of ConnectionCounts (#6163)

There is a finite limit to the maximum message size that logtail can upload.
We need to make sure network logging messages remain under this size.
These constants allow us to compute the maximum number of ConnectionCounts
we can buffer before we must flush.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This commit is contained in:
Joe Tsai 2022-11-09 15:50:07 -08:00 committed by GitHub
parent 25e26c16ee
commit 4de643b714
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2 changed files with 82 additions and 14 deletions

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@ -18,17 +18,45 @@
// Message is the log message that captures network traffic.
type Message struct {
NodeID tailcfg.StableNodeID `json:"nodeId"` // e.g., "n123456CNTRL"
NodeID tailcfg.StableNodeID `json:"nodeId" cbor:"0,keyasint"` // e.g., "n123456CNTRL"
Start time.Time `json:"start"` // inclusive
End time.Time `json:"end"` // inclusive
Start time.Time `json:"start" cbor:"12,keyasint"` // inclusive
End time.Time `json:"end" cbor:"13,keyasint"` // inclusive
VirtualTraffic []ConnectionCounts `json:"virtualTraffic,omitempty"`
SubnetTraffic []ConnectionCounts `json:"subnetTraffic,omitempty"`
ExitTraffic []ConnectionCounts `json:"exitTraffic,omitempty"`
PhysicalTraffic []ConnectionCounts `json:"physicalTraffic,omitempty"`
VirtualTraffic []ConnectionCounts `json:"virtualTraffic,omitempty" cbor:"14,keyasint,omitempty"`
SubnetTraffic []ConnectionCounts `json:"subnetTraffic,omitempty" cbor:"15,keyasint,omitempty"`
ExitTraffic []ConnectionCounts `json:"exitTraffic,omitempty" cbor:"16,keyasint,omitempty"`
PhysicalTraffic []ConnectionCounts `json:"physicalTraffic,omitempty" cbor:"17,keyasint,omitempty"`
}
const (
maxJSONConnCounts = `{` + maxJSONConn + `,` + maxJSONCounts + `}`
maxJSONConn = `"proto":` + maxJSONProto + `,"src":` + maxJSONAddrPort + `,"dst":` + maxJSONAddrPort
maxJSONProto = `255`
maxJSONAddrPort = `"[ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff]:65535"`
maxJSONCounts = `"txPkts":` + maxJSONCount + `,"txBytes":` + maxJSONCount + `,"rxPkts":` + maxJSONCount + `,"rxBytes":` + maxJSONCount
maxJSONCount = `18446744073709551615`
// MaxConnectionCountsJSONSize is the maximum size of a ConnectionCounts
// when it is serialized as JSON, assuming no superfluous whitespace.
// It does not include the trailing comma that often appears when
// this object is nested within an array.
// It assumes that netip.Addr never has IPv6 zones.
MaxConnectionCountsJSONSize = len(maxJSONConnCounts)
maxCBORConnCounts = "\xbf" + maxCBORConn + maxCBORCounts + "\xff"
maxCBORConn = "\x00" + maxCBORProto + "\x01" + maxCBORAddrPort + "\x02" + maxCBORAddrPort
maxCBORProto = "\x18\xff"
maxCBORAddrPort = "\x52\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff"
maxCBORCounts = "\x0c" + maxCBORCount + "\x0d" + maxCBORCount + "\x0e" + maxCBORCount + "\x0f" + maxCBORCount
maxCBORCount = "\x1b\xff\xff\xff\xff\xff\xff\xff\xff"
// MaxConnectionCountsCBORSize is the maximum size of a ConnectionCounts
// when it is serialized as CBOR.
// It assumes that netip.Addr never has IPv6 zones.
MaxConnectionCountsCBORSize = len(maxCBORConnCounts)
)
// ConnectionCounts is a flattened struct of both a connection and counts.
type ConnectionCounts struct {
Connection
@ -37,19 +65,19 @@ type ConnectionCounts struct {
// Connection is a 5-tuple of proto, source and destination IP and port.
type Connection struct {
Proto ipproto.Proto `json:"proto,omitzero,omitempty"`
Src netip.AddrPort `json:"src,omitzero"`
Dst netip.AddrPort `json:"dst,omitzero"`
Proto ipproto.Proto `json:"proto,omitzero,omitempty" cbor:"0,keyasint,omitempty"`
Src netip.AddrPort `json:"src,omitzero,omitempty" cbor:"1,keyasint,omitempty"`
Dst netip.AddrPort `json:"dst,omitzero,omitempty" cbor:"2,keyasint,omitempty"`
}
func (c Connection) IsZero() bool { return c == Connection{} }
// Counts are statistics about a particular connection.
type Counts struct {
TxPackets uint64 `json:"txPkts,omitzero,omitempty"`
TxBytes uint64 `json:"txBytes,omitzero,omitempty"`
RxPackets uint64 `json:"rxPkts,omitzero,omitempty"`
RxBytes uint64 `json:"rxBytes,omitzero,omitempty"`
TxPackets uint64 `json:"txPkts,omitzero,omitempty" cbor:"12,keyasint,omitempty"`
TxBytes uint64 `json:"txBytes,omitzero,omitempty" cbor:"13,keyasint,omitempty"`
RxPackets uint64 `json:"rxPkts,omitzero,omitempty" cbor:"14,keyasint,omitempty"`
RxBytes uint64 `json:"rxBytes,omitzero,omitempty" cbor:"15,keyasint,omitempty"`
}
func (c Counts) IsZero() bool { return c == Counts{} }

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@ -0,0 +1,40 @@
// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package netlogtype
import (
"encoding/json"
"math"
"net/netip"
"testing"
"github.com/fxamacker/cbor/v2"
"github.com/google/go-cmp/cmp"
"tailscale.com/util/must"
)
func TestMaxSize(t *testing.T) {
maxAddr := netip.AddrFrom16([16]byte{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255})
maxAddrPort := netip.AddrPortFrom(maxAddr, math.MaxUint16)
cc := ConnectionCounts{
// NOTE: These composite literals are deliberately unkeyed so that
// added fields result in a build failure here.
// Newly added fields should result in an update to both
// MaxConnectionCountsJSONSize and MaxConnectionCountsCBORSize.
Connection{math.MaxUint8, maxAddrPort, maxAddrPort},
Counts{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64},
}
outJSON := must.Get(json.Marshal(cc))
if string(outJSON) != maxJSONConnCounts {
t.Errorf("JSON mismatch (-got +want):\n%s", cmp.Diff(string(outJSON), maxJSONConnCounts))
}
outCBOR := must.Get(cbor.Marshal(cc))
maxCBORConnCountsAlt := "\xa7" + maxCBORConnCounts[1:len(maxCBORConnCounts)-1] // may use a definite encoding of map
if string(outCBOR) != maxCBORConnCounts && string(outCBOR) != maxCBORConnCountsAlt {
t.Errorf("CBOR mismatch (-got +want):\n%s", cmp.Diff(string(outCBOR), maxCBORConnCounts))
}
}