VPP-1027: DNS name resolver

This patch is a plausible first-cut, suitable for initial testing by
vcl (host stack client library).

Main features;
- recursive name resolution
- multiple ip4/ip6 name servers
- cache size limit enforcement
  - currently limited to 65K
- ttl / aging
- static mapping support
- show / clear / debug CLI commands

Binary APIs provided for the following:
- add/delete name servers
- enable/disable the name cache
- resolve a name

To Do list:
- Respond to ip4/ip6 client DNS requests (vs. binary API requests)
- Perf / scale tuning
  - map pending transaction ids to pool indices, so the cache
    can (greatly) exceed 65K entries
- Security improvements
  - Use unpredictable dns transaction IDs, related to previous item
  - Make sure that response-packet src ip addresses match the server
- Add binary APIs
  - deliver raw response data to clients
  - control recursive name resolution
- Documentation

Change-Id: I48c373d5c05d7108ccd814d4055caf8c75ca10b7
Signed-off-by: Dave Barach <dave@barachs.net>

1 files changed, 16 insertions, 1 deletions

diff --git a/src/vlibapi/api_shared.c b/src/vlibapi/api_shared.c
index 1bb50d43def..4d11b519cf2 100644
--- a/src/vlibapi/api_shared.c
+++ b/src/vlibapi/api_shared.c
@@ -665,7 +665,22 @@ vl_msg_api_config (vl_msg_api_msg_config_t * c)
 {
   api_main_t *am = &api_main;
 
-  ASSERT (c->id > 0);
+  /*
+   * This happens during the java core tests if the message
+   * dictionary is missing newly added xxx_reply_t messages.
+   * Should never happen, but since I shot myself in the foot once
+   * this way, I thought I'd make it easy to debug if I ever do
+   * it again... (;-)...
+   */
+  if (c->id == 0)
+    {
+      if (c->name)
+	clib_warning ("Trying to register %s with a NULL msg id!", c->name);
+      else
+	clib_warning ("Trying to register a NULL msg with a NULL msg id!");
+      clib_warning ("Did you forget to call setup_message_id_table?");
+      return;
+    }
 
 #define _(a) vec_validate (am->a, c->id);
   foreach_msg_api_vector;