Repair vlib API socket server

- Teach vpp_api_test to send/receive API messages over sockets
- Add memfd-based shared memory
- Add api messages to create memfd-based shared memory segments
- vpp_api_test supports both socket and shared memory segment connections
- vpp_api_test pivot from socket to shared memory API messaging
- add socket client support to libvlibclient.so
- dead client reaper sends ping messages, container-friendly
- dead client reaper falls back to kill (<pid>, 0) live checking
  if e.g. a python app goes silent for tens of seconds
- handle ping messages in python client support code
- teach show api ring about pairwise shared-memory segments
- fix ip probing of already resolved destinations (VPP-998)

We'll need this work to implement proper host-stack client isolation

Change-Id: Ic23b65f75c854d0393d9a2e9d6b122a9551be769
Signed-off-by: Dave Barach <dave@barachs.net>
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
Signed-off-by: Florin Coras <fcoras@cisco.com>

2 files changed, 38 insertions, 1 deletions

diff --git a/src/vpp-api/client/client.c b/src/vpp-api/client/client.c
index 8bdcda01c4d..668461aad6c 100644
--- a/src/vpp-api/client/client.c
+++ b/src/vpp-api/client/client.c
@@ -133,8 +133,11 @@ static void *
 vac_rx_thread_fn (void *arg)
 {
   unix_shared_memory_queue_t *q;
+  vl_api_memclnt_keepalive_t *mp;
+  vl_api_memclnt_keepalive_reply_t *rmp;
   vac_main_t *pm = &vac_main;
   api_main_t *am = &api_main;
+  vl_shmem_hdr_t *shmem_hdr;
   uword msg;
 
   q = am->vl_input_queue;
@@ -169,6 +172,17 @@ vac_rx_thread_fn (void *arg)
 	  vl_msg_api_free((void *) msg);
 	  break;
 
+        case VL_API_MEMCLNT_KEEPALIVE:
+          mp = (void *)msg;
+          rmp = vl_msg_api_alloc (sizeof (*rmp));
+          memset (rmp, 0, sizeof (*rmp));
+          rmp->_vl_msg_id = ntohs(VL_API_MEMCLNT_KEEPALIVE_REPLY);
+          rmp->context = mp->context;
+          shmem_hdr = am->shmem_hdr;
+          vl_msg_api_send_shmem(shmem_hdr->vl_input_queue, (u8 *)&rmp);
+          vl_msg_api_free((void *) msg);
+	  break;
+
 	default:
 	  vac_api_handler((void *)msg);
 	}
@@ -370,8 +384,12 @@ vac_read (char **p, int *l, u16 timeout)
   unix_shared_memory_queue_t *q;
   api_main_t *am = &api_main;
   vac_main_t *pm = &vac_main;
+  vl_api_memclnt_keepalive_t *mp;
+  vl_api_memclnt_keepalive_reply_t *rmp;
   uword msg;
   msgbuf_t *msgbuf;
+  int rv;
+  vl_shmem_hdr_t *shmem_hdr;
 
   if (!pm->connected_to_vlib) return -1;
 
@@ -384,7 +402,9 @@ vac_read (char **p, int *l, u16 timeout)
     set_timeout(timeout);
 
   q = am->vl_input_queue;
-  int rv = unix_shared_memory_queue_sub(q, (u8 *)&msg, 0);
+
+ again:
+  rv = unix_shared_memory_queue_sub(q, (u8 *)&msg, 0);
   if (rv == 0) {
     u16 msg_id = ntohs(*((u16 *)msg));
     switch (msg_id) {
@@ -397,6 +417,21 @@ vac_read (char **p, int *l, u16 timeout)
     case VL_API_MEMCLNT_READ_TIMEOUT:
       printf("Received read timeout %ds\n", timeout);
       goto error;
+    case VL_API_MEMCLNT_KEEPALIVE:
+      /* Handle an alive-check ping from vpp. */
+      mp = (void *)msg;
+      rmp = vl_msg_api_alloc (sizeof (*rmp));
+      memset (rmp, 0, sizeof (*rmp));
+      rmp->_vl_msg_id = ntohs(VL_API_MEMCLNT_KEEPALIVE_REPLY);
+      rmp->context = mp->context;
+      shmem_hdr = am->shmem_hdr;
+      vl_msg_api_send_shmem(shmem_hdr->vl_input_queue, (u8 *)&rmp);
+      vl_msg_api_free((void *) msg);
+      /* 
+       * Python code is blissfully unaware of these pings, so
+       * act as if it never happened...
+       */
+      goto again;
 
     default:
       msgbuf = (msgbuf_t *)(((u8 *)msg) - offsetof(msgbuf_t, data));
diff --git a/src/vpp-api/vapi/vapi.c b/src/vpp-api/vapi/vapi.c
index 3150d2b427e..25c0b3be1d3 100644
--- a/src/vpp-api/vapi/vapi.c
+++ b/src/vpp-api/vapi/vapi.c
@@ -26,6 +26,8 @@
 #include <vpp-api/vapi/vapi.h>
 #include <vpp-api/vapi/vapi_internal.h>
 #include <vppinfra/types.h>
+#include <vppinfra/pool.h>
+#include <vlib/vlib.h>
 #include <vlibapi/api_common.h>
 #include <vlibmemory/api_common.h>