session: add support for application namespacing
[vpp.git] / src / vnet / session / session.c
index fe19804..88b38f1 100644 (file)
  */
 
 #include <vnet/session/session.h>
+#include <vnet/session/session_debug.h>
+#include <vnet/session/application.h>
 #include <vlibmemory/api.h>
 #include <vnet/dpo/load_balance.h>
 #include <vnet/fib/ip4_fib.h>
-#include <vnet/session/application.h>
 #include <vnet/tcp/tcp.h>
-#include <vnet/session/session_debug.h>
-
-/**
- * Per-type vector of transport protocol virtual function tables
- */
-static transport_proto_vft_t *tp_vfts;
 
 session_manager_main_t session_manager_main;
-
-/*
- * Session lookup key; (src-ip, dst-ip, src-port, dst-port, session-type)
- * Value: (owner thread index << 32 | session_index);
- */
-void
-stream_session_table_add_for_tc (transport_connection_t * tc, u64 value)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  session_kv6_t kv6;
-
-  switch (tc->proto)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      make_v4_ss_kv_from_tc (&kv4, tc);
-      kv4.value = value;
-      clib_bihash_add_del_16_8 (&smm->v4_session_hash, &kv4, 1 /* is_add */ );
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      make_v6_ss_kv_from_tc (&kv6, tc);
-      kv6.value = value;
-      clib_bihash_add_del_48_8 (&smm->v6_session_hash, &kv6, 1 /* is_add */ );
-      break;
-    default:
-      clib_warning ("Session type not supported");
-      ASSERT (0);
-    }
-}
-
-void
-stream_session_table_add (session_manager_main_t * smm, stream_session_t * s,
-                         u64 value)
-{
-  transport_connection_t *tc;
-
-  tc = tp_vfts[s->session_type].get_connection (s->connection_index,
-                                               s->thread_index);
-  stream_session_table_add_for_tc (tc, value);
-}
-
-static void
-stream_session_half_open_table_add (session_type_t sst,
-                                   transport_connection_t * tc, u64 value)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  session_kv6_t kv6;
-
-  switch (sst)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      make_v4_ss_kv_from_tc (&kv4, tc);
-      kv4.value = value;
-      clib_bihash_add_del_16_8 (&smm->v4_half_open_hash, &kv4,
-                               1 /* is_add */ );
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      make_v6_ss_kv_from_tc (&kv6, tc);
-      kv6.value = value;
-      clib_bihash_add_del_48_8 (&smm->v6_half_open_hash, &kv6,
-                               1 /* is_add */ );
-      break;
-    default:
-      clib_warning ("Session type not supported");
-      ASSERT (0);
-    }
-}
-
-int
-stream_session_table_del_for_tc (transport_connection_t * tc)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  session_kv6_t kv6;
-  switch (tc->proto)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      make_v4_ss_kv_from_tc (&kv4, tc);
-      return clib_bihash_add_del_16_8 (&smm->v4_session_hash, &kv4,
-                                      0 /* is_add */ );
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      make_v6_ss_kv_from_tc (&kv6, tc);
-      return clib_bihash_add_del_48_8 (&smm->v6_session_hash, &kv6,
-                                      0 /* is_add */ );
-      break;
-    default:
-      clib_warning ("Session type not supported");
-      ASSERT (0);
-    }
-
-  return 0;
-}
-
-static int
-stream_session_table_del (session_manager_main_t * smm, stream_session_t * s)
-{
-  transport_connection_t *ts;
-
-  ts = tp_vfts[s->session_type].get_connection (s->connection_index,
-                                               s->thread_index);
-  return stream_session_table_del_for_tc (ts);
-}
-
-static void
-stream_session_half_open_table_del (session_manager_main_t * smm, u8 sst,
-                                   transport_connection_t * tc)
-{
-  session_kv4_t kv4;
-  session_kv6_t kv6;
-
-  switch (sst)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      make_v4_ss_kv_from_tc (&kv4, tc);
-      clib_bihash_add_del_16_8 (&smm->v4_half_open_hash, &kv4,
-                               0 /* is_add */ );
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      make_v6_ss_kv_from_tc (&kv6, tc);
-      clib_bihash_add_del_48_8 (&smm->v6_half_open_hash, &kv6,
-                               0 /* is_add */ );
-      break;
-    default:
-      clib_warning ("Session type not supported");
-      ASSERT (0);
-    }
-}
-
-stream_session_t *
-stream_session_lookup_listener4 (ip4_address_t * lcl, u16 lcl_port, u8 proto)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  int rv;
-
-  make_v4_listener_kv (&kv4, lcl, lcl_port, proto);
-  rv = clib_bihash_search_inline_16_8 (&smm->v4_session_hash, &kv4);
-  if (rv == 0)
-    return pool_elt_at_index (smm->listen_sessions[proto], (u32) kv4.value);
-
-  /* Zero out the lcl ip */
-  kv4.key[0] = 0;
-  rv = clib_bihash_search_inline_16_8 (&smm->v4_session_hash, &kv4);
-  if (rv == 0)
-    return pool_elt_at_index (smm->listen_sessions[proto], kv4.value);
-
-  return 0;
-}
-
-/** Looks up a session based on the 5-tuple passed as argument.
- *
- * First it tries to find an established session, if this fails, it tries
- * finding a listener session if this fails, it tries a lookup with a
- * wildcarded local source (listener bound to all interfaces)
- */
-stream_session_t *
-stream_session_lookup4 (ip4_address_t * lcl, ip4_address_t * rmt,
-                       u16 lcl_port, u16 rmt_port, u8 proto,
-                       u32 my_thread_index)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  int rv;
-
-  /* Lookup session amongst established ones */
-  make_v4_ss_kv (&kv4, lcl, rmt, lcl_port, rmt_port, proto);
-  rv = clib_bihash_search_inline_16_8 (&smm->v4_session_hash, &kv4);
-  if (rv == 0)
-    return stream_session_get_tsi (kv4.value, my_thread_index);
-
-  /* If nothing is found, check if any listener is available */
-  return stream_session_lookup_listener4 (lcl, lcl_port, proto);
-}
-
-stream_session_t *
-stream_session_lookup_listener6 (ip6_address_t * lcl, u16 lcl_port, u8 proto)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv6_t kv6;
-  int rv;
-
-  make_v6_listener_kv (&kv6, lcl, lcl_port, proto);
-  rv = clib_bihash_search_inline_48_8 (&smm->v6_session_hash, &kv6);
-  if (rv == 0)
-    return pool_elt_at_index (smm->listen_sessions[proto], kv6.value);
-
-  /* Zero out the lcl ip */
-  kv6.key[0] = kv6.key[1] = 0;
-  rv = clib_bihash_search_inline_48_8 (&smm->v6_session_hash, &kv6);
-  if (rv == 0)
-    return pool_elt_at_index (smm->listen_sessions[proto], kv6.value);
-
-  return 0;
-}
-
-/* Looks up a session based on the 5-tuple passed as argument.
- * First it tries to find an established session, if this fails, it tries
- * finding a listener session if this fails, it tries a lookup with a
- * wildcarded local source (listener bound to all interfaces) */
-stream_session_t *
-stream_session_lookup6 (ip6_address_t * lcl, ip6_address_t * rmt,
-                       u16 lcl_port, u16 rmt_port, u8 proto,
-                       u32 my_thread_index)
-{
-  session_manager_main_t *smm = vnet_get_session_manager_main ();
-  session_kv6_t kv6;
-  int rv;
-
-  make_v6_ss_kv (&kv6, lcl, rmt, lcl_port, rmt_port, proto);
-  rv = clib_bihash_search_inline_48_8 (&smm->v6_session_hash, &kv6);
-  if (rv == 0)
-    return stream_session_get_tsi (kv6.value, my_thread_index);
-
-  /* If nothing is found, check if any listener is available */
-  return stream_session_lookup_listener6 (lcl, lcl_port, proto);
-}
-
-stream_session_t *
-stream_session_lookup_listener (ip46_address_t * lcl, u16 lcl_port, u8 proto)
-{
-  switch (proto)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      return stream_session_lookup_listener4 (&lcl->ip4, lcl_port, proto);
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      return stream_session_lookup_listener6 (&lcl->ip6, lcl_port, proto);
-      break;
-    }
-  return 0;
-}
-
-static u64
-stream_session_half_open_lookup (session_manager_main_t * smm,
-                                ip46_address_t * lcl, ip46_address_t * rmt,
-                                u16 lcl_port, u16 rmt_port, u8 proto)
-{
-  session_kv4_t kv4;
-  session_kv6_t kv6;
-  int rv;
-
-  switch (proto)
-    {
-    case SESSION_TYPE_IP4_UDP:
-    case SESSION_TYPE_IP4_TCP:
-      make_v4_ss_kv (&kv4, &lcl->ip4, &rmt->ip4, lcl_port, rmt_port, proto);
-      rv = clib_bihash_search_inline_16_8 (&smm->v4_half_open_hash, &kv4);
-
-      if (rv == 0)
-       return kv4.value;
-
-      return (u64) ~ 0;
-      break;
-    case SESSION_TYPE_IP6_UDP:
-    case SESSION_TYPE_IP6_TCP:
-      make_v6_ss_kv (&kv6, &lcl->ip6, &rmt->ip6, lcl_port, rmt_port, proto);
-      rv = clib_bihash_search_inline_48_8 (&smm->v6_half_open_hash, &kv6);
-
-      if (rv == 0)
-       return kv6.value;
-
-      return (u64) ~ 0;
-      break;
-    }
-  return 0;
-}
-
-transport_connection_t *
-stream_session_lookup_transport4 (ip4_address_t * lcl, ip4_address_t * rmt,
-                                 u16 lcl_port, u16 rmt_port, u8 proto,
-                                 u32 my_thread_index)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  session_kv4_t kv4;
-  stream_session_t *s;
-  int rv;
-
-  /* Lookup session amongst established ones */
-  make_v4_ss_kv (&kv4, lcl, rmt, lcl_port, rmt_port, proto);
-  rv = clib_bihash_search_inline_16_8 (&smm->v4_session_hash, &kv4);
-  if (rv == 0)
-    {
-      s = stream_session_get_tsi (kv4.value, my_thread_index);
-
-      return tp_vfts[s->session_type].get_connection (s->connection_index,
-                                                     my_thread_index);
-    }
-
-  /* If nothing is found, check if any listener is available */
-  s = stream_session_lookup_listener4 (lcl, lcl_port, proto);
-  if (s)
-    return tp_vfts[s->session_type].get_listener (s->connection_index);
-
-  /* Finally, try half-open connections */
-  rv = clib_bihash_search_inline_16_8 (&smm->v4_half_open_hash, &kv4);
-  if (rv == 0)
-    return tp_vfts[proto].get_half_open (kv4.value & 0xFFFFFFFF);
-
-  return 0;
-}
-
-transport_connection_t *
-stream_session_lookup_transport6 (ip6_address_t * lcl, ip6_address_t * rmt,
-                                 u16 lcl_port, u16 rmt_port, u8 proto,
-                                 u32 my_thread_index)
-{
-  session_manager_main_t *smm = &session_manager_main;
-  stream_session_t *s;
-  session_kv6_t kv6;
-  int rv;
-
-  make_v6_ss_kv (&kv6, lcl, rmt, lcl_port, rmt_port, proto);
-  rv = clib_bihash_search_inline_48_8 (&smm->v6_session_hash, &kv6);
-  if (rv == 0)
-    {
-      s = stream_session_get_tsi (kv6.value, my_thread_index);
-
-      return tp_vfts[s->session_type].get_connection (s->connection_index,
-                                                     my_thread_index);
-    }
-
-  /* If nothing is found, check if any listener is available */
-  s = stream_session_lookup_listener6 (lcl, lcl_port, proto);
-  if (s)
-    return tp_vfts[s->session_type].get_listener (s->connection_index);
-
-  /* Finally, try half-open connections */
-  rv = clib_bihash_search_inline_48_8 (&smm->v6_half_open_hash, &kv6);
-  if (rv == 0)
-    return tp_vfts[proto].get_half_open (kv6.value & 0xFFFFFFFF);
-
-  return 0;
-}
+extern transport_proto_vft_t *tp_vfts;
 
 int
 stream_session_create_i (segment_manager_t * sm, transport_connection_t * tc,
-                        stream_session_t ** ret_s)
+                        u8 alloc_fifos, stream_session_t ** ret_s)
 {
   session_manager_main_t *smm = &session_manager_main;
   svm_fifo_t *server_rx_fifo = 0, *server_tx_fifo = 0;
@@ -390,30 +41,39 @@ stream_session_create_i (segment_manager_t * sm, transport_connection_t * tc,
   u32 thread_index = tc->thread_index;
   int rv;
 
-  if ((rv = segment_manager_alloc_session_fifos (sm, &server_rx_fifo,
-                                                &server_tx_fifo,
-                                                &fifo_segment_index)))
-    return rv;
+  ASSERT (thread_index == vlib_get_thread_index ());
 
   /* Create the session */
   pool_get_aligned (smm->sessions[thread_index], s, CLIB_CACHE_LINE_BYTES);
   memset (s, 0, sizeof (*s));
-
-  /* Initialize backpointers */
   pool_index = s - smm->sessions[thread_index];
-  server_rx_fifo->master_session_index = pool_index;
-  server_rx_fifo->master_thread_index = thread_index;
 
-  server_tx_fifo->master_session_index = pool_index;
-  server_tx_fifo->master_thread_index = thread_index;
+  /* Allocate fifos */
+  if (alloc_fifos)
+    {
+      if ((rv = segment_manager_alloc_session_fifos (sm, &server_rx_fifo,
+                                                    &server_tx_fifo,
+                                                    &fifo_segment_index)))
+       {
+         pool_put (smm->sessions[thread_index], s);
+         return rv;
+       }
+      /* Initialize backpointers */
+      server_rx_fifo->master_session_index = pool_index;
+      server_rx_fifo->master_thread_index = thread_index;
+
+      server_tx_fifo->master_session_index = pool_index;
+      server_tx_fifo->master_thread_index = thread_index;
 
-  s->server_rx_fifo = server_rx_fifo;
-  s->server_tx_fifo = server_tx_fifo;
+      s->server_rx_fifo = server_rx_fifo;
+      s->server_tx_fifo = server_tx_fifo;
+      s->svm_segment_index = fifo_segment_index;
+    }
 
   /* Initialize state machine, such as it is... */
-  s->session_type = tc->proto;
+  s->session_type = session_type_from_proto_and_ip (tc->transport_proto,
+                                                   tc->is_ip4);
   s->session_state = SESSION_STATE_CONNECTING;
-  s->svm_segment_index = fifo_segment_index;
   s->thread_index = thread_index;
   s->session_index = pool_index;
 
@@ -424,46 +84,112 @@ stream_session_create_i (segment_manager_t * sm, transport_connection_t * tc,
   tc->s_index = s->session_index;
 
   /* Add to the main lookup table */
-  value = (((u64) thread_index) << 32) | (u64) s->session_index;
-  stream_session_table_add_for_tc (tc, value);
+  value = stream_session_handle (s);
+  session_lookup_add_connection (tc, value);
 
   *ret_s = s;
 
   return 0;
 }
 
-/** Enqueue buffer chain tail */
+/**
+ * Discards bytes from buffer chain
+ *
+ * It discards n_bytes_to_drop starting at first buffer after chain_b
+ */
+always_inline void
+session_enqueue_discard_chain_bytes (vlib_main_t * vm, vlib_buffer_t * b,
+                                    vlib_buffer_t ** chain_b,
+                                    u32 n_bytes_to_drop)
+{
+  vlib_buffer_t *next = *chain_b;
+  u32 to_drop = n_bytes_to_drop;
+  ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+  while (to_drop && (next->flags & VLIB_BUFFER_NEXT_PRESENT))
+    {
+      next = vlib_get_buffer (vm, next->next_buffer);
+      if (next->current_length > to_drop)
+       {
+         vlib_buffer_advance (next, to_drop);
+         to_drop = 0;
+       }
+      else
+       {
+         to_drop -= next->current_length;
+         next->current_length = 0;
+       }
+    }
+  *chain_b = next;
+
+  if (to_drop == 0)
+    b->total_length_not_including_first_buffer -= n_bytes_to_drop;
+}
+
+/**
+ * Enqueue buffer chain tail
+ */
 always_inline int
 session_enqueue_chain_tail (stream_session_t * s, vlib_buffer_t * b,
                            u32 offset, u8 is_in_order)
 {
   vlib_buffer_t *chain_b;
-  u32 chain_bi = b->next_buffer;
+  u32 chain_bi, len, diff;
   vlib_main_t *vm = vlib_get_main ();
-  u8 *data, len;
-  u16 written = 0;
+  u8 *data;
+  u32 written = 0;
   int rv = 0;
 
+  if (is_in_order && offset)
+    {
+      diff = offset - b->current_length;
+      if (diff > b->total_length_not_including_first_buffer)
+       return 0;
+      chain_b = b;
+      session_enqueue_discard_chain_bytes (vm, b, &chain_b, diff);
+      chain_bi = vlib_get_buffer_index (vm, chain_b);
+    }
+  else
+    chain_bi = b->next_buffer;
+
   do
     {
       chain_b = vlib_get_buffer (vm, chain_bi);
       data = vlib_buffer_get_current (chain_b);
       len = chain_b->current_length;
+      if (!len)
+       continue;
       if (is_in_order)
        {
          rv = svm_fifo_enqueue_nowait (s->server_rx_fifo, len, data);
-         if (rv < len)
+         if (rv == len)
+           {
+             written += rv;
+           }
+         else if (rv < len)
            {
              return (rv > 0) ? (written + rv) : written;
            }
-         written += rv;
+         else if (rv > len)
+           {
+             written += rv;
+
+             /* written more than what was left in chain */
+             if (written > b->total_length_not_including_first_buffer)
+               return written;
+
+             /* drop the bytes that have already been delivered */
+             session_enqueue_discard_chain_bytes (vm, b, &chain_b, rv - len);
+           }
        }
       else
        {
          rv = svm_fifo_enqueue_with_offset (s->server_rx_fifo, offset, len,
                                             data);
          if (rv)
-           return -1;
+           {
+             clib_warning ("failed to enqueue multi-buffer seg");
+             return -1;
+           }
          offset += len;
        }
     }
@@ -495,22 +221,22 @@ stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
                             u32 offset, u8 queue_event, u8 is_in_order)
 {
   stream_session_t *s;
-  int enqueued = 0, rv;
+  int enqueued = 0, rv, in_order_off;
 
-  s = stream_session_get (tc->s_index, tc->thread_index);
+  s = session_get (tc->s_index, tc->thread_index);
 
   if (is_in_order)
     {
-      enqueued =
-       svm_fifo_enqueue_nowait (s->server_rx_fifo, b->current_length,
-                                vlib_buffer_get_current (b));
-      if (PREDICT_FALSE
-         ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && enqueued > 0))
+      enqueued = svm_fifo_enqueue_nowait (s->server_rx_fifo,
+                                         b->current_length,
+                                         vlib_buffer_get_current (b));
+      if (PREDICT_FALSE ((b->flags & VLIB_BUFFER_NEXT_PRESENT)
+                        && enqueued >= 0))
        {
-         rv = session_enqueue_chain_tail (s, b, 0, 1);
-         if (rv <= 0)
-           return enqueued;
-         enqueued += rv;
+         in_order_off = enqueued > b->current_length ? enqueued : 0;
+         rv = session_enqueue_chain_tail (s, b, in_order_off, 1);
+         if (rv > 0)
+           enqueued += rv;
        }
     }
   else
@@ -519,9 +245,10 @@ stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
                                         b->current_length,
                                         vlib_buffer_get_current (b));
       if (PREDICT_FALSE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && !rv))
-       rv = session_enqueue_chain_tail (s, b, offset + b->current_length, 0);
-      if (rv)
-       return -1;
+       session_enqueue_chain_tail (s, b, offset + b->current_length, 0);
+      /* if something was enqueued, report even this as success for ooo
+       * segment handling */
+      return rv;
     }
 
   if (queue_event)
@@ -540,10 +267,7 @@ stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
        }
     }
 
-  if (is_in_order)
-    return enqueued;
-
-  return 0;
+  return enqueued;
 }
 
 /** Check if we have space in rx fifo to push more bytes */
@@ -551,7 +275,7 @@ u8
 stream_session_no_space (transport_connection_t * tc, u32 thread_index,
                         u16 data_len)
 {
-  stream_session_t *s = stream_session_get (tc->s_index, thread_index);
+  stream_session_t *s = session_get (tc->s_index, thread_index);
 
   if (PREDICT_FALSE (s->session_state != SESSION_STATE_READY))
     return 1;
@@ -565,8 +289,8 @@ stream_session_no_space (transport_connection_t * tc, u32 thread_index,
 u32
 stream_session_tx_fifo_max_dequeue (transport_connection_t * tc)
 {
-  stream_session_t *s = stream_session_get (tc->s_index, tc->thread_index);
-  if (s->session_state != SESSION_STATE_READY)
+  stream_session_t *s = session_get (tc->s_index, tc->thread_index);
+  if (!s->server_tx_fifo)
     return 0;
   return svm_fifo_max_dequeue (s->server_tx_fifo);
 }
@@ -575,14 +299,14 @@ int
 stream_session_peek_bytes (transport_connection_t * tc, u8 * buffer,
                           u32 offset, u32 max_bytes)
 {
-  stream_session_t *s = stream_session_get (tc->s_index, tc->thread_index);
+  stream_session_t *s = session_get (tc->s_index, tc->thread_index);
   return svm_fifo_peek (s->server_tx_fifo, offset, max_bytes, buffer);
 }
 
 u32
 stream_session_dequeue_drop (transport_connection_t * tc, u32 max_bytes)
 {
-  stream_session_t *s = stream_session_get (tc->s_index, tc->thread_index);
+  stream_session_t *s = session_get (tc->s_index, tc->thread_index);
   return svm_fifo_dequeue_drop (s->server_tx_fifo, max_bytes);
 }
 
@@ -603,10 +327,22 @@ stream_session_enqueue_notify (stream_session_t * s, u8 block)
   static u32 serial_number;
 
   if (PREDICT_FALSE (s->session_state == SESSION_STATE_CLOSED))
-    return 0;
+    {
+      /* Session is closed so app will never clean up. Flush rx fifo */
+      u32 to_dequeue = svm_fifo_max_dequeue (s->server_rx_fifo);
+      if (to_dequeue)
+       svm_fifo_dequeue_drop (s->server_rx_fifo, to_dequeue);
+      return 0;
+    }
 
   /* Get session's server */
-  app = application_get (s->app_index);
+  app = application_get_if_valid (s->app_index);
+
+  if (PREDICT_FALSE (app == 0))
+    {
+      clib_warning ("invalid s->app_index = %d", s->app_index);
+      return 0;
+    }
 
   /* Built-in server? Hand event to the callback... */
   if (app->cb_fns.builtin_server_rx_callback)
@@ -667,8 +403,9 @@ session_manager_flush_enqueue_events (u32 thread_index)
       stream_session_t *s0;
 
       /* Get session */
-      s0 = stream_session_get (session_indices_to_enqueue[i], thread_index);
-      if (stream_session_enqueue_notify (s0, 0 /* don't block */ ))
+      s0 = stream_session_get_if_valid (session_indices_to_enqueue[i],
+                                       thread_index);
+      if (s0 == 0 || stream_session_enqueue_notify (s0, 0 /* don't block */ ))
        {
          errors++;
        }
@@ -695,42 +432,47 @@ stream_session_init_fifos_pointers (transport_connection_t * tc,
                                    u32 rx_pointer, u32 tx_pointer)
 {
   stream_session_t *s;
-  s = stream_session_get (tc->s_index, tc->thread_index);
+  s = session_get (tc->s_index, tc->thread_index);
   svm_fifo_init_pointers (s->server_rx_fifo, rx_pointer);
   svm_fifo_init_pointers (s->server_tx_fifo, tx_pointer);
 }
 
 int
-stream_session_connect_notify (transport_connection_t * tc, u8 sst,
-                              u8 is_fail)
+stream_session_connect_notify (transport_connection_t * tc, u8 is_fail)
 {
-  session_manager_main_t *smm = &session_manager_main;
   application_t *app;
   stream_session_t *new_s = 0;
   u64 handle;
-  u32 api_context = 0;
+  u32 opaque = 0;
   int error = 0;
 
-  handle = stream_session_half_open_lookup (smm, &tc->lcl_ip, &tc->rmt_ip,
-                                           tc->lcl_port, tc->rmt_port,
-                                           tc->proto);
+  handle = session_lookup_half_open_handle (tc);
   if (handle == HALF_OPEN_LOOKUP_INVALID_VALUE)
     {
-      clib_warning ("This can't be good!");
+      SESSION_DBG ("half-open was removed!");
       return -1;
     }
 
-  /* Get the app's index from the handle we stored when opening connection */
-  app = application_get (handle >> 32);
-  api_context = tc->s_index;
+  /* Cleanup half-open table */
+  session_lookup_del_half_open (tc);
+
+  /* Get the app's index from the handle we stored when opening connection
+   * and the opaque (api_context for external apps) from transport session
+   * index */
+  app = application_get_if_valid (handle >> 32);
+  if (!app)
+    return -1;
+
+  opaque = tc->s_index;
 
   if (!is_fail)
     {
       segment_manager_t *sm;
+      u8 alloc_fifos;
       sm = application_get_connect_segment_manager (app);
-
+      alloc_fifos = application_is_proxy (app);
       /* Create new session (svm segments are allocated if needed) */
-      if (stream_session_create_i (sm, tc, &new_s))
+      if (stream_session_create_i (sm, tc, alloc_fifos, &new_s))
        {
          is_fail = 1;
          error = -1;
@@ -739,12 +481,19 @@ stream_session_connect_notify (transport_connection_t * tc, u8 sst,
        new_s->app_index = app->index;
     }
 
-  /* Notify client */
-  app->cb_fns.session_connected_callback (app->index, api_context, new_s,
-                                         is_fail);
-
-  /* Cleanup session lookup */
-  stream_session_half_open_table_del (smm, sst, tc);
+  /* Notify client application */
+  if (app->cb_fns.session_connected_callback (app->index, opaque, new_s,
+                                             is_fail))
+    {
+      SESSION_DBG ("failed to notify app");
+      if (!is_fail)
+       stream_session_disconnect (new_s);
+    }
+  else
+    {
+      if (!is_fail)
+       new_s->session_state = SESSION_STATE_READY;
+    }
 
   return error;
 }
@@ -755,7 +504,7 @@ stream_session_accept_notify (transport_connection_t * tc)
   application_t *server;
   stream_session_t *s;
 
-  s = stream_session_get (tc->s_index, tc->thread_index);
+  s = session_get (tc->s_index, tc->thread_index);
   server = application_get (s->app_index);
   server->cb_fns.session_accept_callback (s);
 }
@@ -773,35 +522,40 @@ stream_session_disconnect_notify (transport_connection_t * tc)
   application_t *server;
   stream_session_t *s;
 
-  s = stream_session_get (tc->s_index, tc->thread_index);
+  s = session_get (tc->s_index, tc->thread_index);
   server = application_get (s->app_index);
   server->cb_fns.session_disconnect_callback (s);
 }
 
 /**
- * Cleans up session and associated app if needed.
+ * Cleans up session and lookup table.
  */
 void
 stream_session_delete (stream_session_t * s)
 {
   session_manager_main_t *smm = vnet_get_session_manager_main ();
+  int rv;
 
   /* Delete from the main lookup table. */
-  stream_session_table_del (smm, s);
+  if ((rv = session_lookup_del_session (s)))
+    clib_warning ("hash delete error, rv %d", rv);
 
   /* Cleanup fifo segments */
   segment_manager_dealloc_fifos (s->svm_segment_index, s->server_rx_fifo,
                                 s->server_tx_fifo);
 
   pool_put (smm->sessions[s->thread_index], s);
+  if (CLIB_DEBUG)
+    memset (s, 0xFA, sizeof (*s));
 }
 
 /**
  * Notification from transport that connection is being deleted
  *
- * This should be called only on previously fully established sessions. For
- * instance failed connects should call stream_session_connect_notify and
- * indicate that the connect has failed.
+ * This removes the session if it is still valid. It should be called only on
+ * previously fully established sessions. For instance failed connects should
+ * call stream_session_connect_notify and indicate that the connect has
+ * failed.
  */
 void
 stream_session_delete_notify (transport_connection_t * tc)
@@ -811,9 +565,7 @@ stream_session_delete_notify (transport_connection_t * tc)
   /* App might've been removed already */
   s = stream_session_get_if_valid (tc->s_index, tc->thread_index);
   if (!s)
-    {
-      return;
-    }
+    return;
   stream_session_delete (s);
 }
 
@@ -825,7 +577,7 @@ stream_session_reset_notify (transport_connection_t * tc)
 {
   stream_session_t *s;
   application_t *app;
-  s = stream_session_get (tc->s_index, tc->thread_index);
+  s = session_get (tc->s_index, tc->thread_index);
 
   app = application_get (s->app_index);
   app->cb_fns.session_reset_callback (s);
@@ -836,24 +588,27 @@ stream_session_reset_notify (transport_connection_t * tc)
  */
 int
 stream_session_accept (transport_connection_t * tc, u32 listener_index,
-                      u8 sst, u8 notify)
+                      u8 notify)
 {
   application_t *server;
   stream_session_t *s, *listener;
   segment_manager_t *sm;
-
+  session_type_t sst;
   int rv;
 
+  sst = session_type_from_proto_and_ip (tc->transport_proto, tc->is_ip4);
+
   /* Find the server */
   listener = listen_session_get (sst, listener_index);
   server = application_get (listener->app_index);
 
   sm = application_get_listen_segment_manager (server, listener);
-  if ((rv = stream_session_create_i (sm, tc, &s)))
+  if ((rv = stream_session_create_i (sm, tc, 1, &s)))
     return rv;
 
   s->app_index = server->index;
   s->listener_index = listener_index;
+  s->session_state = SESSION_STATE_ACCEPTING;
 
   /* Shoulder-tap the server */
   if (notify)
@@ -877,22 +632,23 @@ stream_session_accept (transport_connection_t * tc, u32 listener_index,
  * @param res Resulting transport connection .
  */
 int
-stream_session_open (u32 app_index, session_type_t st,
-                    transport_endpoint_t * tep,
+stream_session_open (u32 app_index, session_endpoint_t * rmt,
                     transport_connection_t ** res)
 {
   transport_connection_t *tc;
+  session_type_t sst;
   int rv;
   u64 handle;
 
-  rv = tp_vfts[st].open (&tep->ip, tep->port);
+  sst = session_type_from_proto_and_ip (rmt->transport_proto, rmt->is_ip4);
+  rv = tp_vfts[sst].open (session_endpoint_to_transport (rmt));
   if (rv < 0)
     {
       clib_warning ("Transport failed to open connection.");
-      return VNET_API_ERROR_SESSION_CONNECT_FAIL;
+      return VNET_API_ERROR_SESSION_CONNECT;
     }
 
-  tc = tp_vfts[st].get_half_open ((u32) rv);
+  tc = tp_vfts[sst].get_half_open ((u32) rv);
 
   /* Save app and tc index. The latter is needed to help establish the
    * connection while the former is needed when the connect notify comes
@@ -900,7 +656,7 @@ stream_session_open (u32 app_index, session_type_t st,
   handle = (((u64) app_index) << 32) | (u64) tc->c_index;
 
   /* Add to the half-open lookup table */
-  stream_session_half_open_table_add (st, tc, handle);
+  session_lookup_add_half_open (tc, handle);
 
   *res = tc;
 
@@ -916,13 +672,14 @@ stream_session_open (u32 app_index, session_type_t st,
  * @param tep Local endpoint to be listened on.
  */
 int
-stream_session_listen (stream_session_t * s, transport_endpoint_t * tep)
+stream_session_listen (stream_session_t * s, session_endpoint_t * tep)
 {
   transport_connection_t *tc;
   u32 tci;
 
   /* Transport bind/listen  */
-  tci = tp_vfts[s->session_type].bind (s->session_index, &tep->ip, tep->port);
+  tci = tp_vfts[s->session_type].bind (s->session_index,
+                                      session_endpoint_to_transport (tep));
 
   if (tci == (u32) ~ 0)
     return -1;
@@ -936,7 +693,7 @@ stream_session_listen (stream_session_t * s, transport_endpoint_t * tep)
     return -1;
 
   /* Add to the main lookup table */
-  stream_session_table_add_for_tc (tc, s->session_index);
+  session_lookup_add_connection (tc, s->session_index);
 
   return 0;
 }
@@ -964,7 +721,7 @@ stream_session_stop_listen (stream_session_t * s)
       return VNET_API_ERROR_ADDRESS_NOT_IN_USE;
     }
 
-  stream_session_table_del_for_tc (tc);
+  session_lookup_del_connection (tc);
   tp_vfts[s->session_type].unbind (s->connection_index);
   return 0;
 }
@@ -975,6 +732,7 @@ session_send_session_evt_to_thread (u64 session_handle,
                                    u32 thread_index)
 {
   static u16 serial_number = 0;
+  u32 tries = 0;
   session_fifo_event_t evt;
   unix_shared_memory_queue_t *q;
 
@@ -984,21 +742,14 @@ session_send_session_evt_to_thread (u64 session_handle,
   evt.event_id = serial_number++;
 
   q = session_manager_get_vpp_event_queue (thread_index);
-
-  /* Based on request block (or not) for lack of space */
-  if (PREDICT_TRUE (q->cursize < q->maxsize))
+  while (unix_shared_memory_queue_add (q, (u8 *) & evt, 1))
     {
-      if (unix_shared_memory_queue_add (q, (u8 *) & evt,
-                                       1 /* do wait for mutex */ ))
+      if (tries++ == 3)
        {
-         clib_warning ("failed to enqueue evt");
+         TCP_DBG ("failed to enqueue evt");
+         break;
        }
     }
-  else
-    {
-      clib_warning ("queue full");
-      return;
-    }
 }
 
 /**
@@ -1024,41 +775,18 @@ stream_session_disconnect (stream_session_t * s)
 void
 stream_session_cleanup (stream_session_t * s)
 {
-  session_manager_main_t *smm = &session_manager_main;
   int rv;
 
   s->session_state = SESSION_STATE_CLOSED;
 
   /* Delete from the main lookup table to avoid more enqueues */
-  rv = stream_session_table_del (smm, s);
+  rv = session_lookup_del_session (s);
   if (rv)
     clib_warning ("hash delete error, rv %d", rv);
 
   tp_vfts[s->session_type].cleanup (s->connection_index, s->thread_index);
 }
 
-void
-session_register_transport (u8 type, const transport_proto_vft_t * vft)
-{
-  session_manager_main_t *smm = vnet_get_session_manager_main ();
-
-  vec_validate (tp_vfts, type);
-  tp_vfts[type] = *vft;
-
-  /* If an offset function is provided, then peek instead of dequeue */
-  smm->session_tx_fns[type] =
-    (vft->tx_fifo_offset) ? session_tx_fifo_peek_and_snd :
-    session_tx_fifo_dequeue_and_snd;
-}
-
-transport_proto_vft_t *
-session_get_transport_vft (u8 type)
-{
-  if (type >= vec_len (tp_vfts))
-    return 0;
-  return &tp_vfts[type];
-}
-
 /**
  * Allocate vpp event queue (once) per worker thread
  */
@@ -1088,12 +816,54 @@ session_vpp_event_queue_allocate (session_manager_main_t * smm,
     }
 }
 
+session_type_t
+session_type_from_proto_and_ip (transport_proto_t proto, u8 is_ip4)
+{
+  if (proto == TRANSPORT_PROTO_TCP)
+    {
+      if (is_ip4)
+       return SESSION_TYPE_IP4_TCP;
+      else
+       return SESSION_TYPE_IP6_TCP;
+    }
+  else
+    {
+      if (is_ip4)
+       return SESSION_TYPE_IP4_UDP;
+      else
+       return SESSION_TYPE_IP6_UDP;
+    }
+
+  return SESSION_N_TYPES;
+}
+
+int
+listen_session_get_local_session_endpoint (stream_session_t * listener,
+                                          session_endpoint_t * sep)
+{
+  transport_connection_t *tc;
+  tc =
+    tp_vfts[listener->session_type].get_listener (listener->connection_index);
+  if (!tc)
+    {
+      clib_warning ("no transport");
+      return -1;
+    }
+
+  /* N.B. The ip should not be copied because this is the local endpoint */
+  sep->port = tc->lcl_port;
+  sep->transport_proto = tc->transport_proto;
+  sep->is_ip4 = tc->is_ip4;
+  return 0;
+}
+
 static clib_error_t *
 session_manager_main_enable (vlib_main_t * vm)
 {
   session_manager_main_t *smm = &session_manager_main;
   vlib_thread_main_t *vtm = vlib_get_thread_main ();
   u32 num_threads;
+  u32 preallocated_sessions_per_worker;
   int i;
 
   num_threads = 1 /* main thread */  + vtm->n_threads;
@@ -1130,30 +900,30 @@ session_manager_main_enable (vlib_main_t * vm)
   for (i = 0; i < vec_len (smm->vpp_event_queues); i++)
     session_vpp_event_queue_allocate (smm, i);
 
-  /* $$$$ preallocate hack config parameter */
-  for (i = 0; i < 200000; i++)
+  /* Preallocate sessions */
+  if (smm->preallocated_sessions)
     {
-      stream_session_t *ss;
-      pool_get_aligned (smm->sessions[0], ss, CLIB_CACHE_LINE_BYTES);
-      memset (ss, 0, sizeof (*ss));
-    }
-
-  for (i = 0; i < 200000; i++)
-    pool_put_index (smm->sessions[0], i);
+      if (num_threads == 1)
+       {
+         pool_init_fixed (smm->sessions[0], smm->preallocated_sessions);
+       }
+      else
+       {
+         int j;
+         preallocated_sessions_per_worker =
+           (1.1 * (f64) smm->preallocated_sessions /
+            (f64) (num_threads - 1));
 
-  clib_bihash_init_16_8 (&smm->v4_session_hash, "v4 session table",
-                        200000 /* $$$$ config parameter nbuckets */ ,
-                        (64 << 20) /*$$$ config parameter table size */ );
-  clib_bihash_init_48_8 (&smm->v6_session_hash, "v6 session table",
-                        200000 /* $$$$ config parameter nbuckets */ ,
-                        (64 << 20) /*$$$ config parameter table size */ );
+         for (j = 1; j < num_threads; j++)
+           {
+             pool_init_fixed (smm->sessions[j],
+                              preallocated_sessions_per_worker);
+           }
+       }
+    }
 
-  clib_bihash_init_16_8 (&smm->v4_half_open_hash, "v4 half-open table",
-                        200000 /* $$$$ config parameter nbuckets */ ,
-                        (64 << 20) /*$$$ config parameter table size */ );
-  clib_bihash_init_48_8 (&smm->v6_half_open_hash, "v6 half-open table",
-                        200000 /* $$$$ config parameter nbuckets */ ,
-                        (64 << 20) /*$$$ config parameter table size */ );
+  session_lookup_init ();
+  app_namespaces_init ();
 
   smm->is_enabled = 1;
 
@@ -1178,14 +948,14 @@ session_node_enable_disable (u8 is_en)
 clib_error_t *
 vnet_session_enable_disable (vlib_main_t * vm, u8 is_en)
 {
+  clib_error_t *error = 0;
   if (is_en)
     {
       if (session_manager_main.is_enabled)
        return 0;
 
       session_node_enable_disable (is_en);
-
-      return session_manager_main_enable (vm);
+      error = session_manager_main_enable (vm);
     }
   else
     {
@@ -1193,27 +963,25 @@ vnet_session_enable_disable (vlib_main_t * vm, u8 is_en)
       session_node_enable_disable (is_en);
     }
 
-  return 0;
+  return error;
 }
 
 clib_error_t *
 session_manager_main_init (vlib_main_t * vm)
 {
   session_manager_main_t *smm = &session_manager_main;
-
-  smm->vlib_main = vm;
-  smm->vnet_main = vnet_get_main ();
   smm->is_enabled = 0;
-
   return 0;
 }
 
-VLIB_INIT_FUNCTION (session_manager_main_init)
-     static clib_error_t *session_config_fn (vlib_main_t * vm,
-                                            unformat_input_t * input)
+VLIB_INIT_FUNCTION (session_manager_main_init);
+
+static clib_error_t *
+session_config_fn (vlib_main_t * vm, unformat_input_t * input)
 {
   session_manager_main_t *smm = &session_manager_main;
   u32 nitems;
+  uword tmp;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -1224,6 +992,53 @@ VLIB_INIT_FUNCTION (session_manager_main_init)
          else
            clib_warning ("event queue length %d too small, ignored", nitems);
        }
+      else if (unformat (input, "preallocated-sessions %d",
+                        &smm->preallocated_sessions))
+       ;
+      else if (unformat (input, "v4-session-table-buckets %d",
+                        &smm->configured_v4_session_table_buckets))
+       ;
+      else if (unformat (input, "v4-halfopen-table-buckets %d",
+                        &smm->configured_v4_halfopen_table_buckets))
+       ;
+      else if (unformat (input, "v6-session-table-buckets %d",
+                        &smm->configured_v6_session_table_buckets))
+       ;
+      else if (unformat (input, "v6-halfopen-table-buckets %d",
+                        &smm->configured_v6_halfopen_table_buckets))
+       ;
+      else if (unformat (input, "v4-session-table-memory %U",
+                        unformat_memory_size, &tmp))
+       {
+         if (tmp >= 0x100000000)
+           return clib_error_return (0, "memory size %llx (%lld) too large",
+                                     tmp, tmp);
+         smm->configured_v4_session_table_memory = tmp;
+       }
+      else if (unformat (input, "v4-halfopen-table-memory %U",
+                        unformat_memory_size, &tmp))
+       {
+         if (tmp >= 0x100000000)
+           return clib_error_return (0, "memory size %llx (%lld) too large",
+                                     tmp, tmp);
+         smm->configured_v4_halfopen_table_memory = tmp;
+       }
+      else if (unformat (input, "v6-session-table-memory %U",
+                        unformat_memory_size, &tmp))
+       {
+         if (tmp >= 0x100000000)
+           return clib_error_return (0, "memory size %llx (%lld) too large",
+                                     tmp, tmp);
+         smm->configured_v6_session_table_memory = tmp;
+       }
+      else if (unformat (input, "v6-halfopen-table-memory %U",
+                        unformat_memory_size, &tmp))
+       {
+         if (tmp >= 0x100000000)
+           return clib_error_return (0, "memory size %llx (%lld) too large",
+                                     tmp, tmp);
+         smm->configured_v6_halfopen_table_memory = tmp;
+       }
       else
        return clib_error_return (0, "unknown input `%U'",
                                  format_unformat_error, input);