session: add support for application namespacing

Applications are now provided the option to select the namespace they
are to be attached to and the scope of their attachement. Application
namespaces are meant to:
1) constrain the scope of communication through the network by
association with source interfaces and/or fib tables that provide the
source ips to be used and limit the scope of routing
2) provide a namespace local scope to session layer communication, as
opposed to the global scope provided by 1). That is, sessions can be
established without assistance from transport and network layers.
Albeit, zero/local-host ip addresses must still be provided in session
establishment messages due to existing application idiosyncrasies. This
mode of communication uses shared-memory fifos (cut-through sessions)
exclusively.

If applications request no namespace, they are assigned to the default
one, which at its turn uses the default fib. Applications can request
access to both local and global scopes for a namespace. If no scope is
specified, session layer defaults to the global one.

When a sw_if_index is provided for a namespace, zero-ip (INADDR_ANY)
binds are converted to binds to the requested interface.

Change-Id: Ia0f660bbf7eec7f89673f75b4821fc7c3d58e3d1
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 124 insertions, 0 deletions

diff --git a/src/vnet/session/session_table.c b/src/vnet/session/session_table.c
new file mode 100644
index 00000000000..04c0c816ab0
--- /dev/null
+++ b/src/vnet/session/session_table.c
@@ -0,0 +1,124 @@
+/*
+ * 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 <vnet/session/session_table.h>
+#include <vnet/session/session.h>
+
+/**
+ * Pool of session tables
+ */
+static session_table_t *lookup_tables;
+
+session_table_t *
+session_table_alloc (void)
+{
+  session_table_t *slt;
+  pool_get_aligned (lookup_tables, slt, CLIB_CACHE_LINE_BYTES);
+  memset (slt, 0, sizeof (*slt));
+  return slt;
+}
+
+u32
+session_table_index (session_table_t * slt)
+{
+  return (slt - lookup_tables);
+}
+
+session_table_t *
+session_table_get (u32 table_index)
+{
+  if (vec_len (lookup_tables) <= table_index)
+    return 0;
+  return vec_elt_at_index (lookup_tables, table_index);
+}
+
+#define foreach_hash_table_parameter            \
+  _(v4,session,buckets,20000)                   \
+  _(v4,session,memory,(64<<20))                 \
+  _(v6,session,buckets,20000)                   \
+  _(v6,session,memory,(64<<20))                 \
+  _(v4,halfopen,buckets,20000)                  \
+  _(v4,halfopen,memory,(64<<20))                \
+  _(v6,halfopen,buckets,20000)                  \
+  _(v6,halfopen,memory,(64<<20))
+
+/**
+ * Initialize session table hash tables
+ *
+ * If vpp configured with set of table parameters it uses them,
+ * otherwise it uses defaults above.
+ */
+void
+session_table_init (session_table_t * slt)
+{
+#define _(af,table,parm,value) 						\
+  u32 configured_##af##_##table##_table_##parm = value;
+  foreach_hash_table_parameter;
+#undef _
+
+#define _(af,table,parm,value)                                          \
+  if (session_manager_main.configured_##af##_##table##_table_##parm)    \
+    configured_##af##_##table##_table_##parm =                          \
+      session_manager_main.configured_##af##_##table##_table_##parm;
+  foreach_hash_table_parameter;
+#undef _
+
+  clib_bihash_init_16_8 (&slt->v4_session_hash, "v4 session table",
+			 configured_v4_session_table_buckets,
+			 configured_v4_session_table_memory);
+  clib_bihash_init_48_8 (&slt->v6_session_hash, "v6 session table",
+			 configured_v6_session_table_buckets,
+			 configured_v6_session_table_memory);
+  clib_bihash_init_16_8 (&slt->v4_half_open_hash, "v4 half-open table",
+			 configured_v4_halfopen_table_buckets,
+			 configured_v4_halfopen_table_memory);
+  clib_bihash_init_48_8 (&slt->v6_half_open_hash, "v6 half-open table",
+			 configured_v6_halfopen_table_buckets,
+			 configured_v6_halfopen_table_memory);
+}
+
+typedef struct _ip4_session_table_walk_ctx_t
+{
+  ip4_session_table_walk_fn_t fn;
+  void *ctx;
+} ip4_session_table_walk_ctx_t;
+
+void
+ip4_session_table_walk_cb (clib_bihash_kv_16_8_t * kvp, void *arg)
+{
+  ip4_session_table_walk_ctx_t *ctx = arg;
+  ctx->fn (kvp, ctx->ctx);
+}
+
+void
+ip4_session_table_walk (clib_bihash_16_8_t * hash,
+			ip4_session_table_walk_fn_t fn, void *arg)
+{
+  ip4_session_table_walk_ctx_t ctx = {
+    .fn = fn,
+    .ctx = arg,
+  };
+  clib_bihash_foreach_key_value_pair_16_8 (hash, ip4_session_table_walk_cb,
+					   &ctx);
+}
+
+/* *INDENT-ON* */
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */