This has the same meaning as omitting left/rightsubnet, i.e. replace it
by the IKE address. Supporting %dynamic allows configurations with multiple
dynamic selectors in a left/rightsubnet, each with potentially different
proto/port selectors.
If a transport/BEET SA has different selectors for different proto/ports,
installing just the proto/port of the first SA would break any additional
selector.
When we have a trap installed, but a CHILD_SA gets established for the same
config from the peer, we should reuse the same reqid. Otherwise we would have
two identical policies using different reqids, what we can't handle in our
kernel backend.
Previously we silently replaced an existing policy with a new one if the
reqid changed for the same selectors. This will break an old policy in the
favour of the new one (for example if two clients behind the same NAT use
transport mode).
With this change any new policy gets rejected if the reqid differs. This will
make sure we break no existing policy. For rekeying and acquires we still can
have overlapping policies (as we use the same reqid), but for unrelated
connections this is not true anymore (it wasn't actually before, we just
silently broke the existing policy).
When a connection has a single pool that queries recursively the DHCP backend,
we shouldn't return any attributes directly from DHCP when queried for that
pool.
If one selector has a wider IP range than the other, but the other has a
wider port/protocol selector than the first one, none is completely contained
in the other. The check for a match using is_contained_in() therefore would
fail. Using get_subset() can handle such cases, fixing configuration selection.
This new flag gives the kernel-interface a hint how it should priorize the
use of newly installed SAs during rekeying.
Consider the following rekey procedure in IKEv2:
Initiator --- Responder
I1 -------CREATE-------> R1
I2 <------CREATE--------
-------DELETE-------> R2
I3 <------DELETE--------
SAs are always handled as pairs, the following happens at the SA level:
* Initiator starts the exchange at I1
* Responder installs new SA pair at R1
* Initiator installs new SA pair at I2
* Responder removes old SA pair at R2
* Initiator removes old SA pair at I3
This makes sure SAs get installed/removed overlapping during rekeying. However,
to avoid any packet loss, it is crucial that the new outbound SA gets
activated at the correct position:
* as exchange initiator, in I2
* as exchange responder, in R2
This should guarantee that we don't use the new outbound SA before the peer
could install its corresponding inbound SA.
The new parameter allows the kernel backend to install the new SA with
appropriate priorities, i.e. it should:
* as exchange inititator, have the new outbound SA installed with higher
priority than the old SA
* as exchange responder, have the new outbound SA installed with lower
priority than the old SA
While we could split up the SA installation at the responder, this approach
has another advantage: it allows the kernel backend to switch SAs based on
other criteria, for example when receiving traffic on the new inbound SA.
RFC 5996 compatible implementations MAY send an INFORMATIONAL message
with an AUTHENTICATION_FAILED if the initiator failed to authenticate us.
Handle such a message like a DELETE for an IKE_SA.
Martin Willi