SCTP stack (RFC4960)

== CONTENT ==
* SCTP chunks definition as per RFC4960;
* Helper functions to set/get values to/from the corresponding chunks;
* Hooks to the session/application layers;
* Complete state-machine handling;
* Implementation for unexpected chunk received in a certain
state (state-machine error handling)
* Support for 1-single connection;
* Sample application to test receive/transmit data-path;
* Test to validate SCTP stack;

Change-Id: I1b55c455ab400be9513f4e094dadfc3181d2ebc9
Signed-off-by: Marco Varlese <marco.varlese@suse.com>

1 files changed, 472 insertions, 0 deletions

diff --git a/src/vnet/sctp/builtin_server.c b/src/vnet/sctp/builtin_server.c
new file mode 100644
index 00000000000..81267e78434
--- /dev/null
+++ b/src/vnet/sctp/builtin_server.c
@@ -0,0 +1,472 @@
+/*
+ * Copyright (c) 2018 SUSE LLC.
+ * 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 <vnet/vnet.h>
+#include <vlibmemory/api.h>
+#include <vnet/session/application.h>
+#include <vnet/session/application_interface.h>
+
+typedef struct
+{
+  /*
+   * Server app parameters
+   */
+  svm_queue_t **vpp_queue;
+  svm_queue_t *vl_input_queue;		/**< Sever's event queue */
+
+  u32 app_index;		/**< Server app index */
+  u32 my_client_index;		/**< API client handle */
+  u32 node_index;		/**< process node index for evnt scheduling */
+
+  /*
+   * Config params
+   */
+  u8 no_echo;			/**< Don't echo traffic */
+  u32 fifo_size;			/**< Fifo size */
+  u32 rcv_buffer_size;		/**< Rcv buffer size */
+  u32 prealloc_fifos;		/**< Preallocate fifos */
+  u32 private_segment_count;	/**< Number of private segments  */
+  u32 private_segment_size;	/**< Size of private segments  */
+  char *server_uri;		/**< Server URI */
+
+  /*
+   * Test state
+   */
+  u8 **rx_buf;			/**< Per-thread RX buffer */
+  u64 byte_index;
+  u32 **rx_retries;
+
+  vlib_main_t *vlib_main;
+} builtin_server_main_t;
+
+builtin_server_main_t builtin_server_main;
+
+int
+builtin_sctp_session_accept_callback (stream_session_t * s)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+
+  bsm->vpp_queue[s->thread_index] =
+    session_manager_get_vpp_event_queue (s->thread_index);
+  s->session_state = SESSION_STATE_READY;
+  bsm->byte_index = 0;
+  vec_validate (bsm->rx_retries[s->thread_index], s->session_index);
+  bsm->rx_retries[s->thread_index][s->session_index] = 0;
+  return 0;
+}
+
+void
+builtin_sctp_session_disconnect_callback (stream_session_t * s)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  vnet_disconnect_args_t _a, *a = &_a;
+
+  a->handle = session_handle (s);
+  a->app_index = bsm->app_index;
+  vnet_disconnect_session (a);
+}
+
+void
+builtin_sctp_session_reset_callback (stream_session_t * s)
+{
+  clib_warning ("Reset session %U", format_stream_session, s, 2);
+  stream_session_cleanup (s);
+}
+
+
+int
+builtin_sctp_session_connected_callback (u32 app_index, u32 api_context,
+					 stream_session_t * s, u8 is_fail)
+{
+  clib_warning ("called...");
+  return -1;
+}
+
+int
+builtin_sctp_add_segment_callback (u32 client_index,
+				   const u8 * seg_name, u32 seg_size)
+{
+  clib_warning ("called...");
+  return -1;
+}
+
+int
+builtin_sctp_redirect_connect_callback (u32 client_index, void *mp)
+{
+  clib_warning ("called...");
+  return -1;
+}
+
+void
+test_bytes_sctp (builtin_server_main_t * bsm, int actual_transfer)
+{
+  int i;
+  u32 my_thread_id = vlib_get_thread_index ();
+
+  for (i = 0; i < actual_transfer; i++)
+    {
+      if (bsm->rx_buf[my_thread_id][i] != ((bsm->byte_index + i) & 0xff))
+	{
+	  clib_warning ("at %lld expected %d got %d", bsm->byte_index + i,
+			(bsm->byte_index + i) & 0xff,
+			bsm->rx_buf[my_thread_id][i]);
+	}
+    }
+  bsm->byte_index += actual_transfer;
+}
+
+/*
+ * If no-echo, just read the data and be done with it
+ */
+int
+builtin_sctp_server_rx_callback_no_echo (stream_session_t * s)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  u32 my_thread_id = vlib_get_thread_index ();
+  int actual_transfer;
+  svm_fifo_t *rx_fifo;
+
+  rx_fifo = s->server_rx_fifo;
+
+  do
+    {
+      actual_transfer =
+	svm_fifo_dequeue_nowait (rx_fifo, bsm->rcv_buffer_size,
+				 bsm->rx_buf[my_thread_id]);
+    }
+  while (actual_transfer > 0);
+  return 0;
+}
+
+int
+builtin_sctp_server_rx_callback (stream_session_t * s)
+{
+  u32 n_written, max_dequeue, max_enqueue, max_transfer;
+  int actual_transfer;
+  svm_fifo_t *tx_fifo, *rx_fifo;
+  builtin_server_main_t *bsm = &builtin_server_main;
+  session_fifo_event_t evt;
+  u32 thread_index = vlib_get_thread_index ();
+
+  ASSERT (s->thread_index == thread_index);
+
+  rx_fifo = s->server_rx_fifo;
+  tx_fifo = s->server_tx_fifo;
+
+  ASSERT (rx_fifo->master_thread_index == thread_index);
+  ASSERT (tx_fifo->master_thread_index == thread_index);
+
+  max_dequeue = svm_fifo_max_dequeue (s->server_rx_fifo);
+  max_enqueue = svm_fifo_max_enqueue (s->server_tx_fifo);
+
+  if (PREDICT_FALSE (max_dequeue == 0))
+    return 0;
+
+  /* Number of bytes we're going to copy */
+  max_transfer = (max_dequeue < max_enqueue) ? max_dequeue : max_enqueue;
+
+  /* No space in tx fifo */
+  if (PREDICT_FALSE (max_transfer == 0))
+    {
+      /* XXX timeout for session that are stuck */
+
+    rx_event:
+      /* Program self-tap to retry */
+      if (svm_fifo_set_event (rx_fifo))
+	{
+	  svm_queue_t *q;
+	  evt.fifo = rx_fifo;
+	  evt.event_type = FIFO_EVENT_BUILTIN_RX;
+
+	  q = bsm->vpp_queue[thread_index];
+	  if (PREDICT_FALSE (q->cursize == q->maxsize))
+	    clib_warning ("out of event queue space");
+	  else if (svm_queue_add (q, (u8 *) & evt, 0))
+	    clib_warning ("failed to enqueue self-tap");
+
+	  if (bsm->rx_retries[thread_index][s->session_index] == 500000)
+	    {
+	      clib_warning ("session stuck: %U", format_stream_session, s, 2);
+	    }
+	  if (bsm->rx_retries[thread_index][s->session_index] < 500001)
+	    bsm->rx_retries[thread_index][s->session_index]++;
+	}
+
+      return 0;
+    }
+
+  _vec_len (bsm->rx_buf[thread_index]) = max_transfer;
+
+  actual_transfer = svm_fifo_dequeue_nowait (rx_fifo, max_transfer,
+					     bsm->rx_buf[thread_index]);
+  ASSERT (actual_transfer == max_transfer);
+
+//  test_bytes (bsm, actual_transfer);
+
+  /*
+   * Echo back
+   */
+
+  n_written = svm_fifo_enqueue_nowait (tx_fifo, actual_transfer,
+				       bsm->rx_buf[thread_index]);
+
+  if (n_written != max_transfer)
+    clib_warning ("short trout!");
+
+  if (svm_fifo_set_event (tx_fifo))
+    {
+      /* Fabricate TX event, send to vpp */
+      evt.fifo = tx_fifo;
+      evt.event_type = FIFO_EVENT_APP_TX;
+
+      if (svm_queue_add (bsm->vpp_queue[s->thread_index],
+			 (u8 *) & evt, 0 /* do wait for mutex */ ))
+	clib_warning ("failed to enqueue tx evt");
+    }
+
+  if (PREDICT_FALSE (n_written < max_dequeue))
+    goto rx_event;
+
+  return 0;
+}
+
+static session_cb_vft_t builtin_session_cb_vft = {
+  .session_accept_callback = builtin_sctp_session_accept_callback,
+  .session_disconnect_callback = builtin_sctp_session_disconnect_callback,
+  .session_connected_callback = builtin_sctp_session_connected_callback,
+  .add_segment_callback = builtin_sctp_add_segment_callback,
+  .redirect_connect_callback = builtin_sctp_redirect_connect_callback,
+  .builtin_server_rx_callback = builtin_sctp_server_rx_callback,
+  .session_reset_callback = builtin_sctp_session_reset_callback
+};
+
+/* Abuse VPP's input queue */
+static int
+create_api_loopback (vlib_main_t * vm)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  api_main_t *am = &api_main;
+  vl_shmem_hdr_t *shmem_hdr;
+
+  shmem_hdr = am->shmem_hdr;
+  bsm->vl_input_queue = shmem_hdr->vl_input_queue;
+  bsm->my_client_index =
+    vl_api_memclnt_create_internal ("sctp_test_server", bsm->vl_input_queue);
+  return 0;
+}
+
+static int
+server_attach (u8 * appns_id, u64 appns_flags, u64 appns_secret)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  u8 segment_name[128];
+  u64 options[APP_OPTIONS_N_OPTIONS];
+  vnet_app_attach_args_t _a, *a = &_a;
+  u32 segment_size = 512 << 20;
+
+  memset (a, 0, sizeof (*a));
+  memset (options, 0, sizeof (options));
+
+  if (bsm->no_echo)
+    builtin_session_cb_vft.builtin_server_rx_callback =
+      builtin_sctp_server_rx_callback_no_echo;
+  else
+    builtin_session_cb_vft.builtin_server_rx_callback =
+      builtin_sctp_server_rx_callback;
+
+  if (bsm->private_segment_size)
+    segment_size = bsm->private_segment_size;
+
+  a->api_client_index = bsm->my_client_index;
+  a->session_cb_vft = &builtin_session_cb_vft;
+  a->options = options;
+  a->options[APP_OPTIONS_SEGMENT_SIZE] = segment_size;
+  a->options[APP_OPTIONS_RX_FIFO_SIZE] = bsm->fifo_size;
+  a->options[APP_OPTIONS_TX_FIFO_SIZE] = bsm->fifo_size;
+  a->options[APP_OPTIONS_PRIVATE_SEGMENT_COUNT] = bsm->private_segment_count;
+  a->options[APP_OPTIONS_PREALLOC_FIFO_PAIRS] =
+    bsm->prealloc_fifos ? bsm->prealloc_fifos : 1;
+
+  a->options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
+  if (appns_id)
+    {
+      a->namespace_id = appns_id;
+      a->options[APP_OPTIONS_FLAGS] |= appns_flags;
+      a->options[APP_OPTIONS_NAMESPACE_SECRET] = appns_secret;
+    }
+  a->segment_name = segment_name;
+  a->segment_name_length = ARRAY_LEN (segment_name);
+
+  if (vnet_application_attach (a))
+    {
+      clib_warning ("failed to attach server");
+      return -1;
+    }
+  bsm->app_index = a->app_index;
+  return 0;
+}
+
+static int
+server_listen ()
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  vnet_bind_args_t _a, *a = &_a;
+  memset (a, 0, sizeof (*a));
+  a->app_index = bsm->app_index;
+  a->uri = bsm->server_uri;
+  return vnet_bind_uri (a);
+}
+
+static int
+server_create (vlib_main_t * vm, u8 * appns_id, u64 appns_flags,
+	       u64 appns_secret)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  u32 num_threads;
+  int i;
+
+  if (bsm->my_client_index == (u32) ~ 0)
+    {
+      if (create_api_loopback (vm))
+	{
+	  clib_warning ("failed to create api loopback");
+	  return -1;
+	}
+    }
+
+  num_threads = 1 /* main thread */  + vtm->n_threads;
+  vec_validate (builtin_server_main.vpp_queue, num_threads - 1);
+  vec_validate (bsm->rx_buf, num_threads - 1);
+  vec_validate (bsm->rx_retries, num_threads - 1);
+
+  for (i = 0; i < num_threads; i++)
+    vec_validate (bsm->rx_buf[i], bsm->rcv_buffer_size);
+
+  if (server_attach (appns_id, appns_flags, appns_secret))
+    {
+      clib_warning ("failed to attach server");
+      return -1;
+    }
+  if (server_listen ())
+    {
+      clib_warning ("failed to start listening");
+      return -1;
+    }
+  return 0;
+}
+
+static clib_error_t *
+server_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			  vlib_cli_command_t * cmd)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  u8 server_uri_set = 0, *appns_id = 0;
+  u64 tmp, appns_flags = 0, appns_secret = 0;
+  int rv;
+
+  bsm->no_echo = 0;
+  bsm->fifo_size = 64 << 10;
+  bsm->rcv_buffer_size = 128 << 10;
+  bsm->prealloc_fifos = 0;
+  bsm->private_segment_count = 0;
+  bsm->private_segment_size = 0;
+  vec_free (bsm->server_uri);
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "no-echo"))
+	bsm->no_echo = 1;
+      else if (unformat (input, "fifo-size %d", &bsm->fifo_size))
+	bsm->fifo_size <<= 10;
+      else if (unformat (input, "rcv-buf-size %d", &bsm->rcv_buffer_size))
+	;
+      else if (unformat (input, "prealloc-fifos %d", &bsm->prealloc_fifos))
+	;
+      else if (unformat (input, "private-segment-count %d",
+			 &bsm->private_segment_count))
+	;
+      else if (unformat (input, "private-segment-size %U",
+			 unformat_memory_size, &tmp))
+	{
+	  if (tmp >= 0x100000000ULL)
+	    return clib_error_return
+	      (0, "private segment size %lld (%llu) too large", tmp, tmp);
+	  bsm->private_segment_size = tmp;
+	}
+      else if (unformat (input, "uri %s", &bsm->server_uri))
+	server_uri_set = 1;
+      else if (unformat (input, "appns %_%v%_", &appns_id))
+	;
+      else if (unformat (input, "all-scope"))
+	appns_flags |= (APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE
+			| APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE);
+      else if (unformat (input, "local-scope"))
+	appns_flags |= APP_OPTIONS_FLAGS_USE_LOCAL_SCOPE;
+      else if (unformat (input, "global-scope"))
+	appns_flags |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
+      else if (unformat (input, "secret %lu", &appns_secret))
+	;
+      else
+	return clib_error_return (0, "unknown input `%U'",
+				  format_unformat_error, input);
+    }
+
+  vnet_session_enable_disable (vm, 1 /* turn on SCTP, etc. */ );
+
+  if (!server_uri_set)
+    bsm->server_uri = (char *) format (0, "sctp://0.0.0.0/1234%c", 0);
+
+  rv = server_create (vm, appns_id, appns_flags, appns_secret);
+  vec_free (appns_id);
+  switch (rv)
+    {
+    case 0:
+      break;
+    default:
+      return clib_error_return (0, "server_create returned %d", rv);
+    }
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (server_create_command, static) =
+{
+  .path = "test sctp server",
+  .short_help = "test sctp server [no echo][fifo-size <mbytes>] "
+      "[rcv-buf-size <bytes>][prealloc-fifos <count>]"
+      "[private-segment-count <count>][private-segment-size <bytes[m|g]>]"
+      "[uri <sctp://ip/port>]",
+  .function = server_create_command_fn,
+};
+/* *INDENT-ON* */
+
+clib_error_t *
+builtin_sctp_server_main_init (vlib_main_t * vm)
+{
+  builtin_server_main_t *bsm = &builtin_server_main;
+  bsm->my_client_index = ~0;
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (builtin_sctp_server_main_init);
+
+/*
+* fd.io coding-style-patch-verification: ON
+*
+* Local Variables:
+* eval: (c-set-style "gnu")
+* End:
+*/