tls: dtls initial implementation

Type: feature

Basic dtls transport protocol implementation that relies on openssl
wire protocol implementation. Retries/timeouts not yet supported.

To test using vcl test apps, first ensure all arp entries are properly
resolved and subsequently:

server: vcl_server -p dtls 1234
client: vcl_client -p dtls <server-ip> 1234 -U -N 2000000 -T 1460 -X

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I04b4516a8fe9ce85ba230bcdd891f33a900046ed

1 files changed, 225 insertions, 0 deletions

diff --git a/src/plugins/tlsopenssl/dtls_bio.c b/src/plugins/tlsopenssl/dtls_bio.c
new file mode 100644
index 00000000000..7cd2abd42e2
--- /dev/null
+++ b/src/plugins/tlsopenssl/dtls_bio.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2021 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 <openssl/bio.h>
+#include <openssl/err.h>
+
+#include <vnet/session/session.h>
+#include <vnet/session/application_interface.h>
+
+static inline session_t *
+bio_session (BIO *bio)
+{
+  return session_get_from_handle (pointer_to_uword (BIO_get_data (bio)));
+}
+
+static int
+bio_dtls_alloc (BIO *bio)
+{
+  BIO_set_init (bio, 0);
+  BIO_set_data (bio, 0);
+  BIO_set_flags (bio, 0);
+  BIO_set_shutdown (bio, 0);
+  return 1;
+}
+
+static int
+bio_dtls_free (BIO *bio)
+{
+  if (!bio)
+    return 0;
+
+  if (BIO_get_shutdown (bio))
+    {
+      if (BIO_get_init (bio))
+	session_close (bio_session (bio));
+      BIO_set_init (bio, 0);
+      BIO_set_flags (bio, 0);
+    }
+  return 1;
+}
+
+static int
+bio_dtls_read (BIO *b, char *out, int outl)
+{
+  app_session_transport_t at;
+  session_t *s;
+  int rv;
+
+  if (PREDICT_FALSE (!out))
+    return 0;
+
+  s = bio_session (b);
+  if (!s)
+    {
+      clib_warning ("no session");
+      errno = EBADFD;
+      return -1;
+    }
+
+  rv = app_recv_dgram_raw (s->rx_fifo, (u8 *) out, outl, &at,
+			   0 /* clear evt */, 0 /* peek */);
+
+  if (rv < 0)
+    {
+      BIO_set_retry_read (b);
+      errno = EAGAIN;
+      return -1;
+    }
+
+  if (svm_fifo_is_empty_cons (s->rx_fifo))
+    svm_fifo_unset_event (s->rx_fifo);
+
+  BIO_clear_retry_flags (b);
+
+  return rv;
+}
+
+static int
+bio_dtls_write (BIO *b, const char *in, int inl)
+{
+  app_session_transport_t at = { 0 };
+  svm_msg_q_t *mq;
+  session_t *s;
+  int rv;
+
+  if (PREDICT_FALSE (!in))
+    return 0;
+
+  s = bio_session (b);
+  if (!s)
+    {
+      clib_warning ("no session");
+      errno = EBADFD;
+      return -1;
+    }
+
+  mq = session_main_get_vpp_event_queue (s->thread_index);
+  rv = app_send_dgram_raw (s->tx_fifo, &at, mq, (u8 *) in, inl,
+			   SESSION_IO_EVT_TX, 1 /* do_evt */, 0 /* noblock */);
+
+  if (rv < 0)
+    {
+      BIO_set_retry_read (b);
+      errno = EAGAIN;
+      return -1;
+    }
+
+  BIO_clear_retry_flags (b);
+
+  return rv;
+}
+
+static int
+dtls_dgram_overhead (BIO *b)
+{
+  session_t *s = bio_session (b);
+  if (session_type_is_ip4 (s->session_type))
+    /* 20B ip 8B udp */
+    return 28;
+  else
+    /* 40B ip 8B udp */
+    return 48;
+}
+
+static u16
+dtls_dgram_mss (BIO *b)
+{
+  session_t *s = bio_session (b);
+  transport_send_params_t sp;
+
+  transport_connection_snd_params (session_get_transport (s), &sp);
+
+  return sp.snd_mss;
+}
+
+long
+bio_dtls_ctrl (BIO *b, int cmd, long larg, void *parg)
+{
+  long ret = 1;
+
+  switch (cmd)
+    {
+    case BIO_C_SET_FD:
+      os_panic ();
+      break;
+    case BIO_C_GET_FD:
+      os_panic ();
+      break;
+    case BIO_CTRL_GET_CLOSE:
+      ret = BIO_get_shutdown (b);
+      break;
+    case BIO_CTRL_SET_CLOSE:
+      BIO_set_shutdown (b, (int) larg);
+      break;
+    case BIO_CTRL_PENDING:
+    case BIO_CTRL_WPENDING:
+      ret = 0;
+      break;
+    case BIO_CTRL_DUP:
+    case BIO_CTRL_FLUSH:
+      ret = 1;
+      break;
+    case BIO_CTRL_DGRAM_QUERY_MTU:
+      ret = dtls_dgram_mss (b);
+      break;
+    case BIO_CTRL_DGRAM_SET_MTU:
+      ret = 0;
+      break;
+    case BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT:
+      ret = 0;
+      break;
+    case BIO_CTRL_DGRAM_GET_MTU_OVERHEAD:
+      ret = dtls_dgram_overhead (b);
+      break;
+    default:
+      ret = 0;
+      break;
+    }
+  return ret;
+}
+
+BIO *
+BIO_new_dtls (session_handle_t sh)
+{
+  static BIO_METHOD *dtls_bio_method;
+  BIO *b;
+
+  if (!dtls_bio_method)
+    {
+      dtls_bio_method = BIO_meth_new (BIO_TYPE_SOCKET, "dtls_bio");
+      BIO_meth_set_write (dtls_bio_method, bio_dtls_write);
+      BIO_meth_set_read (dtls_bio_method, bio_dtls_read);
+      BIO_meth_set_create (dtls_bio_method, bio_dtls_alloc);
+      BIO_meth_set_destroy (dtls_bio_method, bio_dtls_free);
+      BIO_meth_set_ctrl (dtls_bio_method, bio_dtls_ctrl);
+    }
+
+  b = BIO_new (dtls_bio_method);
+
+  /* Initialize the BIO */
+  BIO_set_data (b, uword_to_pointer (sh, void *));
+  BIO_set_init (b, 1);
+
+  return b;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */