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>

1 files changed, 137 insertions, 0 deletions

diff --git a/src/svm/memfd.c b/src/svm/memfd.c
new file mode 100644
index 00000000000..9fe487db788
--- /dev/null
+++ b/src/svm/memfd.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "memfd.h"
+
+int
+memfd_master_init (memfd_private_t * memfd, u32 master_index)
+{
+  int flags;
+  memfd_shared_header_t *sh;
+  u64 ticks = clib_cpu_time_now ();
+  u64 randomize_baseva;
+  void *oldheap;
+
+  if (memfd->memfd_size == 0)
+    return MEMFD_API_ERROR_NO_SIZE;
+
+  ASSERT (vec_c_string_is_terminated (memfd->name));
+  memfd->name = format (0, "memfd svm region %d", master_index);
+
+  memfd->fd = memfd_create ((char *) memfd->name, MFD_ALLOW_SEALING);
+  if (memfd->fd < 0)
+    {
+      clib_unix_warning ("create segment '%s'", memfd->name);
+      return MEMFD_API_ERROR_CREATE_FAILURE;
+    }
+
+  if ((ftruncate (memfd->fd, memfd->memfd_size)) == -1)
+    {
+      clib_unix_warning ("set memfd size");
+      return MEMFD_API_ERROR_SET_SIZE;
+    }
+
+  if ((fcntl (memfd->fd, F_ADD_SEALS, F_SEAL_SHRINK)) == -1)
+    clib_unix_warning ("fcntl (F_ADD_SEALS, F_SEAL_SHRINK)");
+
+  flags = MAP_SHARED;
+  if (memfd->requested_va)
+    flags |= MAP_FIXED;
+
+  randomize_baseva = (ticks & 15) * MMAP_PAGESIZE;
+
+  if (memfd->requested_va)
+    memfd->requested_va += randomize_baseva;
+
+  sh = memfd->sh =
+    (memfd_shared_header_t *) mmap ((void *) memfd->requested_va,
+				    memfd->memfd_size, PROT_READ | PROT_WRITE,
+				    flags, memfd->fd, 0);
+
+  if (memfd->sh == MAP_FAILED)
+    {
+      clib_unix_warning ("mmap");
+      close (memfd->fd);
+      return MEMFD_API_ERROR_MMAP;
+    }
+
+  memfd->my_pid = getpid ();
+  sh->master_pid = memfd->my_pid;
+  sh->memfd_size = memfd->memfd_size;
+  sh->heap = mheap_alloc_with_flags
+    (((u8 *) sh) + MMAP_PAGESIZE, memfd->memfd_size - MMAP_PAGESIZE,
+     MHEAP_FLAG_DISABLE_VM | MHEAP_FLAG_THREAD_SAFE);
+
+  sh->memfd_va = pointer_to_uword (sh);
+  sh->master_index = master_index;
+
+  oldheap = memfd_push_heap (sh);
+  sh->name = format (0, "%s%c", memfd->name, 0);
+  memfd_pop_heap (oldheap);
+
+  memfd->i_am_master = 1;
+
+  /* The application has to set set sh->ready... */
+  return 0;
+}
+
+/*
+ * Subtly different than svm_slave_init. The caller
+ * needs to acquire a usable file descriptor for the memfd segment
+ * e.g. via vppinfra/socket.c:default_socket_recvmsg
+ */
+
+int
+memfd_slave_init (memfd_private_t * memfd)
+{
+  memfd_shared_header_t *sh;
+
+  memfd->i_am_master = 0;
+
+  /* Map the segment once, to look at the shared header */
+  sh = (void *) mmap (0, MMAP_PAGESIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
+		      memfd->fd, 0);
+  if (sh == MAP_FAILED)
+    {
+      clib_unix_warning ("slave research mmap");
+      close (memfd->fd);
+      return MEMFD_API_ERROR_MMAP;
+    }
+
+  memfd->requested_va = (u64) sh->memfd_va;
+  memfd->memfd_size = sh->memfd_size;
+  munmap (sh, MMAP_PAGESIZE);
+
+  sh = memfd->sh =
+    (void *) mmap ((void *) memfd->requested_va, memfd->memfd_size,
+		   PROT_READ | PROT_WRITE,
+		   MAP_SHARED | MAP_FIXED, memfd->fd, 0);
+
+  if (sh == MAP_FAILED)
+    {
+      clib_unix_warning ("slave final mmap");
+      close (memfd->fd);
+      return MEMFD_API_ERROR_MMAP;
+    }
+  sh->slave_pid = getpid ();
+  return 0;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */