HONEYCOMB-139: ietf-acl translation layer. IP6 L3 ACL support

Other changes:
- documentation update
- eth + ip4 writer rafactoring + tests

Change-Id: I1ac6a4e99dd4f12c870cbd749af6b98018294dd4
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/acl/Readme.adoc b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/acl/Readme.adoc
new file mode 100644
index 000000000..e59f72abe
--- /dev/null
+++ b/v3po/v3po2vpp/src/main/java/io/fd/honeycomb/translate/v3po/interfaces/acl/Readme.adoc
@@ -0,0 +1,32 @@
+= VPP to IETF-ACL model translation
+
+Package provides VPP translation code for draft-ietf-netmod-acl-model-08.
+Access control lists are mapped to chains of classify tables, each with single classify session.
+
+== Available operations
+
+=== Configuration data
+Configuration data for the model is stored in Honeycomb. Corresponding classify tables and sessions
+are not created until control access list is assigned to an interface.
+
+Classify tables and sessions are removed from VPP when ACL assignment is deleted.
+
+ACLs can be shared among interfaces, but each time, new instance of classify table chain would be created in VPP.
+
+ACLs that are assigned to an interface have to be unassigned before update/removal.
+
+=== Operational state
+Operational read in terms of ietf-acl model is not supported (would require storing additional metadata in vpp).
+As a consequence, configuration data initialization based on operational state is not possible.
+
+To check how ietf-acl model was translated to classify tables/session, low-level vpp-classfier model can be used.
+
+== Restrictions
+
+VPP classfier works in form of offsets and masks of 16B units.
+The offset always starts at the beginning of L2 Ethernet header
+of input packet. Because IP header can have variable length,
+source/destination port matching (L4 features of ietf-acl model) is not possible.
+
+Current implementation also assumes constant Ethernet header size
+(802.1Q headers are not supported).
\ No newline at end of file