acl-plugin: rework the optimization 7383, fortify acl-plugin memory behavior (VPP-910)

The further prolonged testing from testbed that reported VPP-910
has uncovered a couple of deeper issues with optimization from
7384, and the usage of subscripts rather than vec_elt_at_index()
allowed to hide a couple of further errors in the code.
Also, the current acl-plugin behavior of using the global
heap for its dynamic data is problematic - it makes
the troubleshooting much harder by potentially spreading
the problem around.

Based on this experience, this commits makes a few changes to fix
the issues seen, also improving the serviceability of the acl-plugin
code for the future:

- Use separate mheaps for any ACL-related control plane
operations and separate for the hash lookup datastructures,
to compartmentalize any memory-related issues for the ACL plugin.

- Ensure vec_elt_at_index() usage throughout the hash_lookup.c file.

- Use vectors rather than raw memory for storing the "ordinary" ACL rules.

- Rework the optimization from 7384 to use a separate tail pointer
rather than overloading the "prev" field.

- Make get_session_ptr() more conservative and adjust is_valid_session_ptr
accordingly

Change-Id: Ifda85193f361de5ed3782a4acd39622bd33c5830
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>
(cherry picked from commit bd9c5ffe39e9ce61db95d74d150e07d738f24da1)

1 files changed, 6 insertions, 0 deletions

diff --git a/src/plugins/acl/acl.h b/src/plugins/acl/acl.h
index b84ed7a42dc..14c6129c07f 100644
--- a/src/plugins/acl/acl.h
+++ b/src/plugins/acl/acl.h
@@ -122,12 +122,18 @@ typedef struct
 } ace_mask_type_entry_t;
 
 typedef struct {
+  /* mheap to hold all the ACL module related allocations, other than hash */
+  void *acl_mheap;
+
   /* API message ID base */
   u16 msg_id_base;
 
   acl_list_t *acls;	/* Pool of ACLs */
   hash_acl_info_t *hash_acl_infos; /* corresponding hash matching housekeeping info */
   clib_bihash_48_8_t acl_lookup_hash; /* ACL lookup hash table. */
+
+  /* mheap to hold all the miscellaneous allocations related to hash-based lookups */
+  void *hash_lookup_mheap;
   int acl_lookup_hash_initialized;
   applied_hash_ace_entry_t **input_hash_entry_vec_by_sw_if_index;
   applied_hash_ace_entry_t **output_hash_entry_vec_by_sw_if_index;