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, 19 deletions

diff --git a/src/plugins/tlsopenssl/tls_openssl.c b/src/plugins/tlsopenssl/tls_openssl.c
index 789c64d88d3..00cd4621897 100644
--- a/src/plugins/tlsopenssl/tls_openssl.c
+++ b/src/plugins/tlsopenssl/tls_openssl.c
@@ -26,19 +26,19 @@
 #include <vnet/tls/tls.h>
 #include <ctype.h>
 #include <tlsopenssl/tls_openssl.h>
-#include <tlsopenssl/tls_bio.h>
+#include <tlsopenssl/tls_bios.h>
 
 #define MAX_CRYPTO_LEN 64
 
 openssl_main_t openssl_main;
+
 static u32
-openssl_ctx_alloc (void)
+openssl_ctx_alloc_w_thread (u32 thread_index)
 {
-  u8 thread_index = vlib_get_thread_index ();
-  openssl_main_t *tm = &openssl_main;
+  openssl_main_t *om = &openssl_main;
   openssl_ctx_t **ctx;
 
-  pool_get (tm->ctx_pool[thread_index], ctx);
+  pool_get (om->ctx_pool[thread_index], ctx);
   if (!(*ctx))
     *ctx = clib_mem_alloc (sizeof (openssl_ctx_t));
 
@@ -46,10 +46,16 @@ openssl_ctx_alloc (void)
   (*ctx)->ctx.c_thread_index = thread_index;
   (*ctx)->ctx.tls_ctx_engine = CRYPTO_ENGINE_OPENSSL;
   (*ctx)->ctx.app_session_handle = SESSION_INVALID_HANDLE;
-  (*ctx)->openssl_ctx_index = ctx - tm->ctx_pool[thread_index];
+  (*ctx)->openssl_ctx_index = ctx - om->ctx_pool[thread_index];
   return ((*ctx)->openssl_ctx_index);
 }
 
+static u32
+openssl_ctx_alloc (void)
+{
+  return openssl_ctx_alloc_w_thread (vlib_get_thread_index ());
+}
+
 static void
 openssl_ctx_free (tls_ctx_t * ctx)
 {
@@ -68,6 +74,40 @@ openssl_ctx_free (tls_ctx_t * ctx)
 		  oc->openssl_ctx_index);
 }
 
+static void *
+openssl_ctx_detach (tls_ctx_t *ctx)
+{
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx, *oc_copy;
+
+  oc_copy = clib_mem_alloc (sizeof (*oc_copy));
+  clib_memcpy (oc_copy, oc, sizeof (*oc));
+
+  return oc_copy;
+}
+
+static u32
+openssl_ctx_attach (u32 thread_index, void *ctx_ptr)
+{
+  openssl_main_t *om = &openssl_main;
+  session_handle_t sh;
+  openssl_ctx_t **oc;
+
+  pool_get (om->ctx_pool[thread_index], oc);
+  /* Free the old instance instead of looking for an empty spot */
+  if (*oc)
+    clib_mem_free (*oc);
+
+  *oc = ctx_ptr;
+  (*oc)->openssl_ctx_index = oc - om->ctx_pool[thread_index];
+  (*oc)->ctx.c_thread_index = thread_index;
+
+  sh = (*oc)->ctx.tls_session_handle;
+  BIO_set_data ((*oc)->rbio, uword_to_pointer (sh, void *));
+  BIO_set_data ((*oc)->wbio, uword_to_pointer (sh, void *));
+
+  return ((*oc)->openssl_ctx_index);
+}
+
 tls_ctx_t *
 openssl_ctx_get (u32 ctx_index)
 {
@@ -310,9 +350,9 @@ openssl_confirm_app_close (tls_ctx_t * ctx)
   session_transport_closed_notify (&ctx->connection);
 }
 
-static inline int
-openssl_ctx_write (tls_ctx_t * ctx, session_t * app_session,
-		   transport_send_params_t * sp)
+static int
+openssl_ctx_write_tls (tls_ctx_t *ctx, session_t *app_session,
+		       transport_send_params_t *sp)
 {
   openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
   u32 deq_max, space, enq_buf;
@@ -358,8 +398,77 @@ check_tls_fifo:
   return wrote;
 }
 
+static int
+openssl_ctx_write_dtls (tls_ctx_t *ctx, session_t *app_session,
+			transport_send_params_t *sp)
+{
+  openssl_main_t *om = &openssl_main;
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  session_dgram_pre_hdr_t hdr;
+  session_t *us;
+  int wrote, rv;
+  u32 read = 0, to_deq, dgram_sz;
+  u8 *buf;
+
+  us = session_get_from_handle (ctx->tls_session_handle);
+  to_deq = svm_fifo_max_dequeue_cons (app_session->tx_fifo);
+  buf = om->tx_bufs[ctx->c_thread_index];
+
+  while (to_deq > 0)
+    {
+      /* Peeking only pre-header dgram because the session is connected */
+      rv = svm_fifo_peek (app_session->tx_fifo, 0, sizeof (hdr), (u8 *) &hdr);
+      ASSERT (rv == sizeof (hdr) && hdr.data_length < vec_len (buf));
+      ASSERT (to_deq >= hdr.data_length + SESSION_CONN_HDR_LEN);
+
+      dgram_sz = hdr.data_length + SESSION_CONN_HDR_LEN;
+      if (svm_fifo_max_enqueue_prod (us->tx_fifo) < dgram_sz + TLSO_CTRL_BYTES)
+	{
+	  svm_fifo_add_want_deq_ntf (us->tx_fifo, SVM_FIFO_WANT_DEQ_NOTIF);
+	  transport_connection_deschedule (&ctx->connection);
+	  sp->flags |= TRANSPORT_SND_F_DESCHED;
+	  goto done;
+	}
+
+      rv = svm_fifo_peek (app_session->tx_fifo, SESSION_CONN_HDR_LEN,
+			  hdr.data_length, buf);
+      ASSERT (rv == hdr.data_length);
+      svm_fifo_dequeue_drop (app_session->tx_fifo, dgram_sz);
+
+      wrote = SSL_write (oc->ssl, buf, rv);
+      ASSERT (wrote > 0);
+
+      read += rv;
+      to_deq -= dgram_sz;
+    }
+
+done:
+
+  if (svm_fifo_needs_deq_ntf (app_session->tx_fifo, read))
+    session_dequeue_notify (app_session);
+
+  if (read)
+    tls_add_vpp_q_tx_evt (us);
+
+  if (PREDICT_FALSE (ctx->app_closed &&
+		     !svm_fifo_max_enqueue_prod (us->rx_fifo)))
+    openssl_confirm_app_close (ctx);
+
+  return read;
+}
+
+static inline int
+openssl_ctx_write (tls_ctx_t *ctx, session_t *app_session,
+		   transport_send_params_t *sp)
+{
+  if (ctx->tls_type == TRANSPORT_PROTO_TLS)
+    return openssl_ctx_write_tls (ctx, app_session, sp);
+  else
+    return openssl_ctx_write_dtls (ctx, app_session, sp);
+}
+
 static inline int
-openssl_ctx_read (tls_ctx_t * ctx, session_t * tls_session)
+openssl_ctx_read_tls (tls_ctx_t *ctx, session_t *tls_session)
 {
   openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
   session_t *app_session;
@@ -387,6 +496,76 @@ openssl_ctx_read (tls_ctx_t * ctx, session_t * tls_session)
   return wrote;
 }
 
+static inline int
+openssl_ctx_read_dtls (tls_ctx_t *ctx, session_t *us)
+{
+  openssl_main_t *om = &openssl_main;
+  openssl_ctx_t *oc = (openssl_ctx_t *) ctx;
+  session_dgram_hdr_t hdr;
+  session_t *app_session;
+  u32 wrote = 0;
+  int read, rv;
+  u8 *buf;
+
+  if (PREDICT_FALSE (SSL_in_init (oc->ssl)))
+    {
+      u32 us_index = us->session_index;
+      if (openssl_ctx_handshake_rx (ctx, us) < 0)
+	return 0;
+      /* Session pool might grow when allocating the app's session */
+      us = session_get (us_index, ctx->c_thread_index);
+    }
+
+  buf = om->rx_bufs[ctx->c_thread_index];
+  app_session = session_get_from_handle (ctx->app_session_handle);
+  svm_fifo_fill_chunk_list (app_session->rx_fifo);
+
+  while (svm_fifo_max_dequeue_cons (us->rx_fifo) > 0)
+    {
+      if (svm_fifo_max_enqueue_prod (app_session->rx_fifo) < DTLSO_MAX_DGRAM)
+	{
+	  tls_add_vpp_q_builtin_rx_evt (us);
+	  goto done;
+	}
+
+      read = SSL_read (oc->ssl, buf, vec_len (buf));
+      if (PREDICT_FALSE (read <= 0))
+	{
+	  if (read < 0)
+	    tls_add_vpp_q_builtin_rx_evt (us);
+	  goto done;
+	}
+      wrote += read;
+
+      hdr.data_length = read;
+      hdr.data_offset = 0;
+
+      svm_fifo_seg_t segs[2] = { { (u8 *) &hdr, sizeof (hdr) },
+				 { buf, read } };
+
+      rv = svm_fifo_enqueue_segments (app_session->rx_fifo, segs, 2,
+				      0 /* allow partial */);
+      ASSERT (rv > 0);
+    }
+
+done:
+
+  /* If handshake just completed, session may still be in accepting state */
+  if (app_session->session_state >= SESSION_STATE_READY)
+    tls_notify_app_enqueue (ctx, app_session);
+
+  return wrote;
+}
+
+static inline int
+openssl_ctx_read (tls_ctx_t *ctx, session_t *ts)
+{
+  if (ctx->tls_type == TRANSPORT_PROTO_TLS)
+    return openssl_ctx_read_tls (ctx, ts);
+  else
+    return openssl_ctx_read_dtls (ctx, ts);
+}
+
 static int
 openssl_ctx_init_client (tls_ctx_t * ctx)
 {
@@ -396,10 +575,11 @@ openssl_ctx_init_client (tls_ctx_t * ctx)
   const SSL_METHOD *method;
   int rv, err;
 
-  method = SSLv23_client_method ();
+  method = ctx->tls_type == TRANSPORT_PROTO_TLS ? SSLv23_client_method () :
+						  DTLS_client_method ();
   if (method == NULL)
     {
-      TLS_DBG (1, "SSLv23_method returned null");
+      TLS_DBG (1, "(D)TLS_method returned null");
       return -1;
     }
 
@@ -433,8 +613,16 @@ openssl_ctx_init_client (tls_ctx_t * ctx)
       return -1;
     }
 
-  oc->rbio = BIO_new_tls (ctx->tls_session_handle);
-  oc->wbio = BIO_new_tls (ctx->tls_session_handle);
+  if (ctx->tls_type == TRANSPORT_PROTO_TLS)
+    {
+      oc->rbio = BIO_new_tls (ctx->tls_session_handle);
+      oc->wbio = BIO_new_tls (ctx->tls_session_handle);
+    }
+  else
+    {
+      oc->rbio = BIO_new_dtls (ctx->tls_session_handle);
+      oc->wbio = BIO_new_dtls (ctx->tls_session_handle);
+    }
 
   SSL_set_bio (oc->ssl, oc->wbio, oc->rbio);
   SSL_set_connect_state (oc->ssl);
@@ -504,7 +692,8 @@ openssl_start_listen (tls_ctx_t * lctx)
       return -1;
     }
 
-  method = SSLv23_method ();
+  method = lctx->tls_type == TRANSPORT_PROTO_TLS ? SSLv23_server_method () :
+						   DTLS_server_method ();
   ssl_ctx = SSL_CTX_new (method);
   if (!ssl_ctx)
     {
@@ -604,8 +793,16 @@ openssl_ctx_init_server (tls_ctx_t * ctx)
       return -1;
     }
 
-  oc->rbio = BIO_new_tls (ctx->tls_session_handle);
-  oc->wbio = BIO_new_tls (ctx->tls_session_handle);
+  if (ctx->tls_type == TRANSPORT_PROTO_TLS)
+    {
+      oc->rbio = BIO_new_tls (ctx->tls_session_handle);
+      oc->wbio = BIO_new_tls (ctx->tls_session_handle);
+    }
+  else
+    {
+      oc->rbio = BIO_new_dtls (ctx->tls_session_handle);
+      oc->wbio = BIO_new_dtls (ctx->tls_session_handle);
+    }
 
   SSL_set_bio (oc->ssl, oc->wbio, oc->rbio);
   SSL_set_accept_state (oc->ssl);
@@ -682,7 +879,10 @@ openssl_app_close (tls_ctx_t * ctx)
 
 const static tls_engine_vft_t openssl_engine = {
   .ctx_alloc = openssl_ctx_alloc,
+  .ctx_alloc_w_thread = openssl_ctx_alloc_w_thread,
   .ctx_free = openssl_ctx_free,
+  .ctx_attach = openssl_ctx_attach,
+  .ctx_detach = openssl_ctx_detach,
   .ctx_get = openssl_ctx_get,
   .ctx_get_w_thread = openssl_ctx_get_w_thread,
   .ctx_init_server = openssl_ctx_init_server,
@@ -771,7 +971,7 @@ tls_openssl_init (vlib_main_t * vm)
   vlib_thread_main_t *vtm = vlib_get_thread_main ();
   openssl_main_t *om = &openssl_main;
   clib_error_t *error = 0;
-  u32 num_threads;
+  u32 num_threads, i;
 
   error = tls_openssl_api_init (vm);
   num_threads = 1 /* main thread */  + vtm->n_threads;
@@ -786,7 +986,13 @@ tls_openssl_init (vlib_main_t * vm)
     }
 
   vec_validate (om->ctx_pool, num_threads - 1);
-
+  vec_validate (om->rx_bufs, num_threads - 1);
+  vec_validate (om->tx_bufs, num_threads - 1);
+  for (i = 0; i < num_threads; i++)
+    {
+      vec_validate (om->rx_bufs[i], DTLSO_MAX_DGRAM);
+      vec_validate (om->tx_bufs[i], DTLSO_MAX_DGRAM);
+    }
   tls_register_engine (&openssl_engine, CRYPTO_ENGINE_OPENSSL);
 
   om->engine_init = 0;