classifier-based ACL: refactor + add output ACL

For implementation of MACIP ACLs enhancement (VPP-1088), an outbound
classifier-based ACL would be needed. There was an existing incomplete
code for outbound ACLs, it looked almost exact copy of input ACLs, minus
the various enhancements, trying to sync that code seemed error-prone
and cumbersome to maintain in the longer run.

This change refactors the input+output ACLs processing into a unified
routine (thus any changes will have effect on both), and also adds
the API to set the output interface ACL, with the same format
and semantics as the existing input one (except working on output
ACL of course).

WARNING: IP outbound ACL in L3 mode clobbers the ip.* fields
in the vnet_buffer_opaque_t, since the code is using l2_classify.*
The net_buffer (p0)->ip.save_rewrite_length is rescued into
l2_classify.pad.l2_len, and used to rewind the header in case of
drop, so that ipX_drop prints something sensible.

Change-Id: I62f814f1e3650e504474a3a5359edb8a0a8836ed
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/vnet/classify/classify.api b/src/vnet/classify/classify.api
index c22d6104704..7320d5ffa90 100644
--- a/src/vnet/classify/classify.api
+++ b/src/vnet/classify/classify.api
@@ -384,6 +384,28 @@ autoreply define input_acl_set_interface
   u8 is_add;
 };
 
+/** \brief Set/unset output ACL interface
+    @param client_index - opaque cookie to identify the sender
+    @param context - sender context, to match reply w/ request
+    @param sw_if_index - interface to set/unset output ACL
+    @param ip4_table_index - ip4 classify table index (~0 for skip)
+    @param ip6_table_index - ip6 classify table index (~0 for skip)
+    @param l2_table_index  -  l2 classify table index (~0 for skip)
+    @param is_add - Set output ACL if non-zero, else unset
+    Note: User is recommeneded to use just one valid table_index per call.
+          (ip4_table_index, ip6_table_index, or l2_table_index)
+*/
+autoreply define output_acl_set_interface
+{
+  u32 client_index;
+  u32 context;
+  u32 sw_if_index;
+  u32 ip4_table_index;
+  u32 ip6_table_index;
+  u32 l2_table_index;
+  u8 is_add;
+};
+
 /*
  * Local Variables:
  * eval: (c-set-style "gnu")