FreeBSD handles subnet routes in netstack by default, but the router
still installed its pf NAT rules whenever SNATSubnetRoutes was set,
which is the default. Every FreeBSD node, subnet router or not, loaded
and enabled pf, inserted anchor references into the host's main
ruleset and loaded NAT rules that netstack never needed, since
netstack dials subnet destinations from the host's own addresses.
It also flipped the forwarding sysctls for any advertised route.
Only do either when the kernel path is opted into with
TS_DEBUG_NETSTACK_SUBNETS=false and routes are advertised.
TestSubnetRouterFreeBSDManyFlows ran in netstack mode since the default
changed, so it no longer exercised pf at all. Opt it into the kernel
path and assert the anchor holds NAT rules, and have
TestSubnetRouterFreeBSD assert the default mode leaves pf untouched.
Also drop the stale claim in handleSubnetsInNetstack that the pf NAT
rule never matches; that was the (self) pool bug, since fixed.
Updates #21450
Change-Id: Ibf91a676a026cebb29f64e39a64fe8e75488360b
Signed-off-by: Martin Minkus <martin.minkus@sonic.com>
Martin Minkus
27b2a7d1a1