control/controlclient: support incremental packet filter updates [capver 81]

Updates #10299

Change-Id: I87e4235c668a1db7de7ef1abc743f0beecb86d3d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2023-11-17 09:20:08 -08:00 committed by Brad Fitzpatrick
parent b8a2aedccd
commit fb829ea7f1
4 changed files with 156 additions and 4 deletions

View File

@ -16,6 +16,7 @@
"sync"
"time"
xmaps "golang.org/x/exp/maps"
"tailscale.com/control/controlknobs"
"tailscale.com/envknob"
"tailscale.com/tailcfg"
@ -27,6 +28,7 @@
"tailscale.com/types/views"
"tailscale.com/util/clientmetric"
"tailscale.com/util/cmpx"
"tailscale.com/util/mak"
"tailscale.com/wgengine/filter"
)
@ -75,7 +77,8 @@ type mapSession struct {
lastDNSConfig *tailcfg.DNSConfig
lastDERPMap *tailcfg.DERPMap
lastUserProfile map[tailcfg.UserID]tailcfg.UserProfile
lastPacketFilterRules views.Slice[tailcfg.FilterRule]
lastPacketFilterRules views.Slice[tailcfg.FilterRule] // concatenation of all namedPacketFilters
namedPacketFilters map[string]views.Slice[tailcfg.FilterRule]
lastParsedPacketFilter []filter.Match
lastSSHPolicy *tailcfg.SSHPolicy
collectServices bool
@ -259,10 +262,39 @@ func (ms *mapSession) updateStateFromResponse(resp *tailcfg.MapResponse) {
ms.lastDERPMap = dm
}
var packetFilterChanged bool
// Older way, one big blob:
if pf := resp.PacketFilter; pf != nil {
packetFilterChanged = true
mak.Set(&ms.namedPacketFilters, "base", views.SliceOf(pf))
}
// Newer way, named chunks:
if m := resp.PacketFilters; m != nil {
packetFilterChanged = true
if v, ok := m["*"]; ok && v == nil {
ms.namedPacketFilters = nil
}
for k, v := range m {
if k == "*" {
continue
}
if v != nil {
mak.Set(&ms.namedPacketFilters, k, views.SliceOf(v))
} else {
delete(ms.namedPacketFilters, k)
}
}
}
if packetFilterChanged {
keys := xmaps.Keys(ms.namedPacketFilters)
sort.Strings(keys)
var concat []tailcfg.FilterRule
for _, v := range keys {
concat = ms.namedPacketFilters[v].AppendTo(concat)
}
ms.lastPacketFilterRules = views.SliceOf(concat)
var err error
ms.lastPacketFilterRules = views.SliceOf(pf)
ms.lastParsedPacketFilter, err = filter.MatchesFromFilterRules(pf)
ms.lastParsedPacketFilter, err = filter.MatchesFromFilterRules(concat)
if err != nil {
ms.logf("parsePacketFilter: %v", err)
}

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@ -547,6 +547,98 @@ func TestNetmapForResponse(t *testing.T) {
t.Errorf("Node mismatch in 2nd netmap; got: %s", j)
}
})
t.Run("named_packetfilter", func(t *testing.T) {
pfA := []tailcfg.FilterRule{
{
SrcIPs: []string{"10.0.0.1"},
DstPorts: []tailcfg.NetPortRange{
{IP: "10.2.3.4", Ports: tailcfg.PortRange{First: 22, Last: 22}},
},
},
}
pfB := []tailcfg.FilterRule{
{
SrcIPs: []string{"10.0.0.2"},
DstPorts: []tailcfg.NetPortRange{
{IP: "10.2.3.4", Ports: tailcfg.PortRange{First: 22, Last: 22}},
},
},
}
ms := newTestMapSession(t, nil)
// Mix of old & new style (PacketFilter and PacketFilters).
nm1 := ms.netmapForResponse(&tailcfg.MapResponse{
Node: new(tailcfg.Node),
PacketFilter: pfA,
PacketFilters: map[string][]tailcfg.FilterRule{
"pf-b": pfB,
},
})
if got, want := len(nm1.PacketFilter), 2; got != want {
t.Fatalf("PacketFilter length = %v; want %v", got, want)
}
if got, want := first(nm1.PacketFilter[0].Srcs).String(), "10.0.0.1/32"; got != want {
t.Fatalf("PacketFilter[0].Srcs = %v; want %v", got, want)
}
if got, want := first(nm1.PacketFilter[1].Srcs).String(), "10.0.0.2/32"; got != want {
t.Fatalf("PacketFilter[0].Srcs = %v; want %v", got, want)
}
// No-op change. Remember the old stuff.
nm2 := ms.netmapForResponse(&tailcfg.MapResponse{
Node: new(tailcfg.Node),
PacketFilter: nil,
PacketFilters: nil,
})
if got, want := len(nm2.PacketFilter), 2; got != want {
t.Fatalf("PacketFilter length = %v; want %v", got, want)
}
if !reflect.DeepEqual(nm1.PacketFilter, nm2.PacketFilter) {
t.Error("packet filters differ")
}
// New style only, with clear.
nm3 := ms.netmapForResponse(&tailcfg.MapResponse{
Node: new(tailcfg.Node),
PacketFilter: nil,
PacketFilters: map[string][]tailcfg.FilterRule{
"*": nil,
"pf-b": pfB,
},
})
if got, want := len(nm3.PacketFilter), 1; got != want {
t.Fatalf("PacketFilter length = %v; want %v", got, want)
}
if got, want := first(nm3.PacketFilter[0].Srcs).String(), "10.0.0.2/32"; got != want {
t.Fatalf("PacketFilter[0].Srcs = %v; want %v", got, want)
}
// New style only, adding pfA back, not as the legacy "base" layer:.
nm4 := ms.netmapForResponse(&tailcfg.MapResponse{
Node: new(tailcfg.Node),
PacketFilter: nil,
PacketFilters: map[string][]tailcfg.FilterRule{
"pf-a": pfA,
},
})
if got, want := len(nm4.PacketFilter), 2; got != want {
t.Fatalf("PacketFilter length = %v; want %v", got, want)
}
if got, want := first(nm4.PacketFilter[0].Srcs).String(), "10.0.0.1/32"; got != want {
t.Fatalf("PacketFilter[0].Srcs = %v; want %v", got, want)
}
if got, want := first(nm4.PacketFilter[1].Srcs).String(), "10.0.0.2/32"; got != want {
t.Fatalf("PacketFilter[0].Srcs = %v; want %v", got, want)
}
})
}
func first[T any](s []T) T {
if len(s) == 0 {
var zero T
return zero
}
return s[0]
}
func TestDeltaDERPMap(t *testing.T) {

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@ -121,7 +121,8 @@
// - 78: 2023-10-05: can handle c2n Wake-on-LAN sending
// - 79: 2023-10-05: Client understands UrgentSecurityUpdate in ClientVersion
// - 80: 2023-11-16: can handle c2n GET /tls-cert-status
const CurrentCapabilityVersion CapabilityVersion = 80
// - 81: 2023-11-17: MapResponse.PacketFilters (incremental packet filter updates)
const CurrentCapabilityVersion CapabilityVersion = 81
type StableID string
@ -1797,8 +1798,34 @@ type MapResponse struct {
// Note that this package's type, due its use of a slice and omitempty, is
// unable to marshal a zero-length non-nil slice. The control server needs
// to marshal this type using a separate type. See MapResponse docs.
//
// See PacketFilters for the newer way to send PacketFilter updates.
PacketFilter []FilterRule `json:",omitempty"`
// PacketFilters encodes incremental packet filter updates to the client
// without having to send the entire packet filter on any changes as
// required by the older PacketFilter (singular) field above. The map keys
// are server-assigned arbitrary strings. The map values are the new rules
// for that key, or nil to delete it. The client then concatenates all the
// rules together to generate the final packet filter. Because the
// FilterRules can only match or not match, the ordering of filter rules
// doesn't matter. (That said, the client generates the file merged packet
// filter rules by concananting all the packet filter rules sorted by the
// map key name. But it does so for stability and testability, not
// correctness. If something needs to rely on that property, something has
// gone wrong.)
//
// If the server sends a non-nil PacketFilter (above), that is equivalent to
// a named packet filter with the key "base". It is valid for the server to
// send both PacketFilter and PacketFilters in the same MapResponse or
// alternate between them within a session. The PacketFilter is applied
// first (if set) and then the PacketFilters.
//
// As a special case, the map key "*" with a value of nil means to clear all
// prior named packet filters (including any implicit "base") before
// processing the other map entries.
PacketFilters map[string][]FilterRule `json:",omitempty"`
// UserProfiles are the user profiles of nodes in the network.
// As as of 1.1.541 (mapver 5), this contains new or updated
// user profiles only.

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@ -161,6 +161,7 @@ func mapResponseContainsNonPatchFields(res *tailcfg.MapResponse) bool {
res.Domain != "" ||
res.CollectServices != "" ||
res.PacketFilter != nil ||
res.PacketFilters != nil ||
res.UserProfiles != nil ||
res.Health != nil ||
res.SSHPolicy != nil ||