net/tstun: use untyped consts, simplify DefaultMTU func

Updates #cleanup

Change-Id: Ic9ad1d6134818699f777c66a31024e846dfdc5d4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2023-09-23 11:48:20 -07:00 committed by Brad Fitzpatrick
parent 3b32d6c679
commit 241c983920

View File

@ -5,8 +5,8 @@
import "tailscale.com/envknob"
const (
maxMTU uint32 = 65536
defaultMTU uint32 = 1280
maxMTU = 65536
defaultMTU = 1280
)
// DefaultMTU returns either the constant default MTU of 1280, or the value set
@ -21,13 +21,8 @@ func DefaultMTU() uint32 {
// 1280 is the smallest MTU allowed for IPv6, which is a sensible
// "probably works everywhere" setting until we develop proper PMTU
// discovery.
tunMTU := defaultMTU
if mtu, ok := envknob.LookupUintSized("TS_DEBUG_MTU", 10, 32); ok {
mtu := uint32(mtu)
if mtu > maxMTU {
mtu = maxMTU
}
tunMTU = mtu
return min(uint32(mtu), maxMTU)
}
return tunMTU
return defaultMTU
}