This depends on improved support from the control server, to send the
new subnet width (Bits) fields. If these are missing, we fall back to
assuming their value is /32.
Conversely, if the server sends Bits fields to an older client, it will
interpret them as /32 addresses. Since the only rules we allow are
"accept" rules, this will be narrower or equal to the intended rule, so
older clients will simply reject hosts on the wider subnet (fail
closed).
With this change, the internal filter.Matches format has diverged
from the wire format used by controlclient, so move the wire format
into tailcfg and convert it to filter.Matches in controlclient.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
This avoids a non-obvious data race, where the JSON decoder ends
up creating do-nothing writes into global variables.
==================
WARNING: DATA RACE
Write at 0x0000011e1860 by goroutine 201:
tailscale.com/wgengine/packet.(*IP).UnmarshalJSON()
/home/crawshaw/repo/corp/oss/wgengine/packet/packet.go:83 +0x2d9
encoding/json.(*decodeState).literalStore()
/home/crawshaw/go/go/src/encoding/json/decode.go:877 +0x445e
...
encoding/json.Unmarshal()
/home/crawshaw/go/go/src/encoding/json/decode.go:107 +0x1de
tailscale.com/control/controlclient.(*Direct).decodeMsg()
/home/crawshaw/repo/corp/oss/control/controlclient/direct.go:615 +0x1ab
tailscale.com/control/controlclient.(*Direct).PollNetMap()
/home/crawshaw/repo/corp/oss/control/controlclient/direct.go:525 +0x1053
tailscale.com/control/controlclient.(*Client).mapRoutine()
/home/crawshaw/repo/corp/oss/control/controlclient/auto.go:428 +0x3a6
Previous read at 0x0000011e1860 by goroutine 86:
tailscale.com/wgengine/filter.matchIPWithoutPorts()
/home/crawshaw/repo/corp/oss/wgengine/filter/match.go:108 +0x91
tailscale.com/wgengine/filter.(*Filter).runIn()
/home/crawshaw/repo/corp/oss/wgengine/filter/filter.go:147 +0x3c6
tailscale.com/wgengine/filter.(*Filter).RunIn()
/home/crawshaw/repo/corp/oss/wgengine/filter/filter.go:127 +0xb0
tailscale.com/wgengine.(*userspaceEngine).SetFilter.func1()
/home/crawshaw/repo/corp/oss/wgengine/userspace.go:390 +0xfc
github.com/tailscale/wireguard-go/device.(*Device).RoutineDecryption()
/home/crawshaw/repo/corp/wireguard-go/device/receive.go:295 +0xa1f
For #112
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
