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authorFlorin Coras <fcoras@cisco.com>2021-01-06 17:35:17 -0800
committerDave Wallace <dwallacelf@gmail.com>2021-05-25 21:18:54 +0000
commit6621abf49aec6d764e654316ff75274c75d4c1a1 (patch)
tree918ce456d904d3cf192e8f79ba6b8c6609f7129d /src/plugins/srtp
parent6bb77dec7074e6b7b27d6bc94238bcddda375a66 (diff)
srtp: basic implementation based on libsrtp2
Type: feature Signed-off-by: Florin Coras <fcoras@cisco.com> Change-Id: Ic5e99938a5f130e83de6d590d2f89252d055bceb
Diffstat (limited to 'src/plugins/srtp')
-rw-r--r--src/plugins/srtp/CMakeLists.txt41
-rw-r--r--src/plugins/srtp/FEATURE.yaml8
-rw-r--r--src/plugins/srtp/srtp.c994
-rw-r--r--src/plugins/srtp/srtp.h120
-rw-r--r--src/plugins/srtp/srtp_plugin.md72
5 files changed, 1235 insertions, 0 deletions
diff --git a/src/plugins/srtp/CMakeLists.txt b/src/plugins/srtp/CMakeLists.txt
new file mode 100644
index 00000000000..acbdf3177d8
--- /dev/null
+++ b/src/plugins/srtp/CMakeLists.txt
@@ -0,0 +1,41 @@
+# 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 (CheckFunctionExists)
+
+vpp_plugin_find_library(srtp SRTP_LIB libsrtp2.a)
+
+if (NOT SRTP_LIB)
+ message(WARNING "srtp plugin - srtp2 lib not found - plugin disabled")
+ return()
+endif()
+
+vpp_find_path(SRTP_INCLUDE_DIR NAMES srtp2/srtp.h)
+
+if (NOT SRTP_INCLUDE_DIR)
+ message(WARNING "srtp plugin - srtp.h not found - plugin disabled")
+ return()
+endif()
+
+include_directories (${SRTP_INCLUDE_DIR})
+
+set(CMAKE_REQUIRED_FLAGS "-fPIC -shared -pthread -Wno-unused-command-line-argument ${SRTP_LIB}")
+set(CMAKE_REQUIRED_INCLUDES "${SRTP_INCLUDE_DIR}")
+
+add_vpp_plugin(srtp
+ SOURCES
+ srtp.c
+
+ LINK_LIBRARIES
+ ${SRTP_LIB}
+)
diff --git a/src/plugins/srtp/FEATURE.yaml b/src/plugins/srtp/FEATURE.yaml
new file mode 100644
index 00000000000..dbbe7121962
--- /dev/null
+++ b/src/plugins/srtp/FEATURE.yaml
@@ -0,0 +1,8 @@
+---
+name: SRTP (Secure Real-time Transport Protocol)
+maintainer: Florin Coras <fcoras@cisco.com>
+features:
+ - SRTP transport protocol implementation
+description: "SRTP transport protocol implementation based on libsrtp2"
+state: experimental
+properties: [MULTITHREAD]
diff --git a/src/plugins/srtp/srtp.c b/src/plugins/srtp/srtp.c
new file mode 100644
index 00000000000..98bf9085da3
--- /dev/null
+++ b/src/plugins/srtp/srtp.c
@@ -0,0 +1,994 @@
+/*
+ * 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 <srtp/srtp.h>
+#include <vnet/session/application_interface.h>
+#include <vnet/session/session.h>
+
+static srtp_main_t srtp_main;
+
+static void srtp_disconnect (u32 ctx_handle, u32 thread_index);
+static void srtp_disconnect_transport (srtp_tc_t *ctx);
+
+static inline u32
+srtp_ctx_alloc_w_thread (u32 thread_index)
+{
+ srtp_tc_t *ctx;
+ pool_get_zero (srtp_main.ctx_pool[thread_index], ctx);
+ ctx->c_thread_index = thread_index;
+ ctx->srtp_ctx_handle = ctx - srtp_main.ctx_pool[thread_index];
+ ctx->app_session_handle = SESSION_INVALID_HANDLE;
+ return ctx->srtp_ctx_handle;
+}
+
+static inline srtp_tc_t *
+srtp_ctx_get_w_thread (u32 ctx_index, u32 thread_index)
+{
+ return pool_elt_at_index (srtp_main.ctx_pool[thread_index], ctx_index);
+}
+
+static void
+srtp_init_policy (srtp_tc_t *ctx, transport_endpt_cfg_srtp_t *cfg)
+{
+ transport_endpt_cfg_srtp_policy_t *sp_cfg;
+ srtp_policy_t *sp;
+ int i;
+
+ for (i = 0; i < 2; i++)
+ {
+ sp = &ctx->srtp_policy[i];
+ sp_cfg = &cfg->policies[i];
+
+ srtp_crypto_policy_set_rtp_default (&sp->rtp);
+ srtp_crypto_policy_set_rtcp_default (&sp->rtcp);
+ sp->ssrc.type = sp_cfg->ssrc_type;
+ sp->ssrc.value = sp_cfg->ssrc_value;
+ sp->key = clib_mem_alloc (sp_cfg->key_len);
+ clib_memcpy (sp->key, sp_cfg->key, sp_cfg->key_len);
+ sp->ekt = 0;
+ sp->next = i < 1 ? &ctx->srtp_policy[i + 1] : 0;
+ sp->window_size = sp_cfg->window_size;
+ sp->allow_repeat_tx = sp_cfg->allow_repeat_tx;
+ }
+}
+
+static void
+srtp_ctx_free_policy (srtp_tc_t *ctx)
+{
+ clib_mem_free (ctx->srtp_policy[0].key);
+ clib_mem_free (ctx->srtp_policy[1].key);
+}
+
+void
+srtp_ctx_free (srtp_tc_t *ctx)
+{
+ if (!ctx->is_migrated)
+ srtp_ctx_free_policy (ctx);
+ pool_put (srtp_main.ctx_pool[ctx->c_thread_index], ctx);
+}
+
+static inline u32
+srtp_ctx_attach (u32 thread_index, void *ctx_ptr)
+{
+ srtp_tc_t *ctx;
+
+ pool_get (srtp_main.ctx_pool[thread_index], ctx);
+ clib_memcpy (ctx, ctx_ptr, sizeof (*ctx));
+
+ ctx->c_thread_index = thread_index;
+ ctx->srtp_ctx_handle = ctx - srtp_main.ctx_pool[thread_index];
+ return 0;
+}
+
+static inline void *
+srtp_ctx_detach (srtp_tc_t *ctx)
+{
+ srtp_tc_t *sc;
+
+ sc = clib_mem_alloc (sizeof (*sc));
+ clib_memcpy (sc, ctx, sizeof (*sc));
+
+ return sc;
+}
+
+u32
+srtp_listener_ctx_alloc (void)
+{
+ srtp_main_t *sm = &srtp_main;
+ srtp_tc_t *ctx;
+
+ pool_get_zero (sm->listener_ctx_pool, ctx);
+ return ctx - sm->listener_ctx_pool;
+}
+
+void
+srtp_listener_ctx_free (srtp_tc_t *ctx)
+{
+ srtp_ctx_free_policy (ctx);
+ if (CLIB_DEBUG)
+ clib_memset (ctx, 0xfb, sizeof (*ctx));
+ pool_put (srtp_main.listener_ctx_pool, ctx);
+}
+
+srtp_tc_t *
+srtp_listener_ctx_get (u32 ctx_index)
+{
+ return pool_elt_at_index (srtp_main.listener_ctx_pool, ctx_index);
+}
+
+u32
+srtp_listener_ctx_index (srtp_tc_t *ctx)
+{
+ return (ctx - srtp_main.listener_ctx_pool);
+}
+
+static int
+srtp_ctx_init_client (srtp_tc_t *ctx)
+{
+ session_t *app_session;
+ app_worker_t *app_wrk;
+ session_error_t err;
+
+ if (srtp_create (&ctx->srtp_ctx, &ctx->srtp_policy[0]) != srtp_err_status_ok)
+ {
+ SRTP_DBG (0, "failed to init srtp ctx");
+ return -1;
+ }
+
+ app_wrk = app_worker_get (ctx->parent_app_wrk_index);
+ app_session = session_get (ctx->c_s_index, ctx->c_thread_index);
+ app_session->app_wrk_index = ctx->parent_app_wrk_index;
+ app_session->connection_index = ctx->srtp_ctx_handle;
+ app_session->session_type =
+ session_type_from_proto_and_ip (TRANSPORT_PROTO_SRTP, ctx->udp_is_ip4);
+
+ if ((err = app_worker_init_connected (app_wrk, app_session)))
+ goto failed;
+
+ app_session->session_state = SESSION_STATE_READY;
+ if (app_worker_connect_notify (app_wrk, app_session, SESSION_E_NONE,
+ ctx->parent_app_api_context))
+ {
+ SRTP_DBG (0, "failed to notify app");
+ app_session->session_state = SESSION_STATE_CONNECTING;
+ srtp_disconnect (ctx->srtp_ctx_handle, vlib_get_thread_index ());
+ return -1;
+ }
+
+ ctx->app_session_handle = session_handle (app_session);
+
+ return 0;
+
+failed:
+ /* Free app session pre-allocated when transport was established */
+ session_free (session_get (ctx->c_s_index, ctx->c_thread_index));
+ ctx->no_app_session = 1;
+ srtp_disconnect (ctx->srtp_ctx_handle, vlib_get_thread_index ());
+ return app_worker_connect_notify (app_wrk, 0, err,
+ ctx->parent_app_api_context);
+}
+
+static int
+srtp_ctx_init_server (srtp_tc_t *ctx)
+{
+ session_t *app_listener, *app_session;
+ app_worker_t *app_wrk;
+ srtp_tc_t *lctx;
+ int rv;
+
+ if (srtp_create (&ctx->srtp_ctx, ctx->srtp_policy) != srtp_err_status_ok)
+ return -1;
+
+ lctx = srtp_listener_ctx_get (ctx->listener_ctx_index);
+ app_listener = listen_session_get_from_handle (lctx->app_session_handle);
+
+ app_session = session_get (ctx->c_s_index, ctx->c_thread_index);
+ app_session->app_wrk_index = ctx->parent_app_wrk_index;
+ app_session->connection_index = ctx->srtp_ctx_handle;
+ app_session->session_type = app_listener->session_type;
+ app_session->listener_handle = listen_session_get_handle (app_listener);
+ app_session->session_state = SESSION_STATE_ACCEPTING;
+
+ if ((rv = app_worker_init_accepted (app_session)))
+ {
+ SRTP_DBG (1, "failed to allocate fifos");
+ session_free (app_session);
+ return rv;
+ }
+ ctx->app_session_handle = session_handle (app_session);
+ ctx->parent_app_wrk_index = app_session->app_wrk_index;
+ app_wrk = app_worker_get (app_session->app_wrk_index);
+ return app_worker_accept_notify (app_wrk, app_session);
+}
+
+static int
+srtp_ctx_deinit (srtp_tc_t *ctx)
+{
+ if (srtp_dealloc (ctx->srtp_ctx))
+ SRTP_DBG (0, "%u failed to cleanup srtp state", ctx->c_c_index);
+ return 0;
+}
+
+static inline int
+srtp_ctx_write (srtp_tc_t *ctx, session_t *app_session,
+ transport_send_params_t *sp)
+{
+ u32 n_wrote = 0, to_deq, dgram_sz;
+ session_dgram_pre_hdr_t hdr;
+ app_session_transport_t at;
+ svm_msg_q_t *mq;
+ session_t *us;
+ u8 buf[2000];
+ int rv, len;
+
+ sp->max_burst_size = sp->max_burst_size * TRANSPORT_PACER_MIN_MSS;
+
+ us = session_get_from_handle (ctx->srtp_session_handle);
+ to_deq = svm_fifo_max_dequeue_cons (app_session->tx_fifo);
+ mq = session_main_get_vpp_event_queue (us->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 + 1000)
+ {
+ 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);
+
+ len = rv;
+
+ rv = srtp_protect (ctx->srtp_ctx, buf, &len);
+ if (rv != srtp_err_status_ok)
+ {
+ SRTP_DBG (0, "failed to protect %u", rv);
+ return 0;
+ }
+
+ rv = app_send_dgram_raw (us->tx_fifo, &at, mq, (u8 *) buf, len,
+ SESSION_IO_EVT_TX, 1 /* do_evt */,
+ 0 /* noblock */);
+ ASSERT (rv == len);
+
+ n_wrote += rv;
+ to_deq -= dgram_sz;
+ }
+
+done:
+
+ if (svm_fifo_needs_deq_ntf (app_session->tx_fifo, n_wrote))
+ session_dequeue_notify (app_session);
+
+ if (n_wrote)
+ {
+ if (svm_fifo_set_event (us->tx_fifo))
+ session_send_io_evt_to_thread (us->tx_fifo, SESSION_IO_EVT_TX);
+ }
+
+ if (PREDICT_FALSE (ctx->app_closed &&
+ !svm_fifo_max_enqueue_prod (us->rx_fifo)))
+ {
+ srtp_disconnect_transport (ctx);
+ session_transport_closed_notify (&ctx->connection);
+ }
+
+ return n_wrote > 0 ? clib_max (n_wrote / TRANSPORT_PACER_MIN_MSS, 1) : 0;
+}
+
+int
+srtp_add_vpp_q_builtin_rx_evt (session_t *s)
+{
+ if (svm_fifo_set_event (s->rx_fifo))
+ session_send_io_evt_to_thread (s->rx_fifo, SESSION_IO_EVT_BUILTIN_RX);
+ return 0;
+}
+
+void
+srtp_notify_app_enqueue (srtp_tc_t *ctx, session_t *app_session)
+{
+ app_worker_t *app_wrk;
+ app_wrk = app_worker_get_if_valid (app_session->app_wrk_index);
+ if (PREDICT_TRUE (app_wrk != 0))
+ app_worker_lock_and_send_event (app_wrk, app_session, SESSION_IO_EVT_RX);
+}
+
+static inline int
+srtp_ctx_read (srtp_tc_t *ctx, session_t *us)
+{
+ app_session_transport_t at;
+ session_dgram_hdr_t hdr;
+ session_t *app_session;
+ u32 n_read = 0;
+ u8 buf[2000];
+ int rv, len;
+
+ 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) < 2000)
+ {
+ srtp_add_vpp_q_builtin_rx_evt (us);
+ goto done;
+ }
+
+ rv = app_recv_dgram_raw (us->rx_fifo, (u8 *) buf, 2000, &at,
+ 0 /* clear evt */, 0 /* peek */);
+ ASSERT (rv > 0);
+ len = rv;
+
+ rv = srtp_unprotect (ctx->srtp_ctx, buf, &len);
+
+ if (rv != srtp_err_status_ok)
+ {
+ SRTP_DBG (0, "failed to unprotect %d", rv);
+ return 0;
+ }
+ n_read += len;
+
+ hdr.data_length = len;
+ hdr.data_offset = 0;
+
+ svm_fifo_seg_t segs[2] = { { (u8 *) &hdr, sizeof (hdr) }, { buf, len } };
+
+ rv = svm_fifo_enqueue_segments (app_session->rx_fifo, segs, 2,
+ 0 /* allow partial */);
+ ASSERT (rv > 0);
+ }
+
+done:
+
+ srtp_notify_app_enqueue (ctx, app_session);
+
+ return n_read;
+}
+
+int
+srtp_add_segment_callback (u32 client_index, u64 segment_handle)
+{
+ /* No-op for builtin */
+ return 0;
+}
+
+int
+srtp_del_segment_callback (u32 client_index, u64 segment_handle)
+{
+ return 0;
+}
+
+void
+srtp_session_disconnect_callback (session_t *us)
+{
+ clib_warning ("udp %u disconnected?", us->session_index);
+}
+
+void
+srtp_session_reset_callback (session_t *us)
+{
+ clib_warning ("udp %u reset?", us->session_index);
+}
+
+static int
+srtp_session_connected_callback (u32 srtp_app_index, u32 ctx_handle,
+ session_t *us, session_error_t err)
+{
+ session_t *app_session;
+ session_type_t st;
+ srtp_tc_t *ctx;
+
+ ctx = srtp_ctx_get_w_thread (ctx_handle, 1 /* udp allocs on thread 1 */);
+
+ ctx->srtp_session_handle = session_handle (us);
+ ctx->c_flags |= TRANSPORT_CONNECTION_F_NO_LOOKUP;
+ us->opaque = ctx_handle;
+
+ /* Preallocate app session. Avoids allocating a session on srtp_session rx
+ * and potentially invalidating the session pool */
+ app_session = session_alloc (ctx->c_thread_index);
+ app_session->session_state = SESSION_STATE_CREATED;
+ ctx->c_s_index = app_session->session_index;
+
+ st = session_type_from_proto_and_ip (TRANSPORT_PROTO_SRTP, ctx->udp_is_ip4);
+ app_session->session_type = st;
+ app_session->connection_index = ctx->srtp_ctx_handle;
+
+ return srtp_ctx_init_client (ctx);
+}
+
+int
+srtp_session_accept_callback (session_t *us)
+{
+ session_t *srtp_listener, *app_session;
+ srtp_tc_t *lctx, *ctx;
+ u32 ctx_handle;
+
+ srtp_listener = listen_session_get_from_handle (us->listener_handle);
+ lctx = srtp_listener_ctx_get (srtp_listener->opaque);
+
+ ctx_handle = srtp_ctx_alloc_w_thread (us->thread_index);
+ ctx = srtp_ctx_get_w_thread (ctx_handle, us->thread_index);
+ clib_memcpy_fast (ctx, lctx, sizeof (*lctx));
+ ctx->c_thread_index = vlib_get_thread_index ();
+ ctx->srtp_ctx_handle = ctx_handle;
+ us->session_state = SESSION_STATE_READY;
+ us->opaque = ctx_handle;
+ ctx->srtp_session_handle = session_handle (us);
+ ctx->listener_ctx_index = srtp_listener->opaque;
+ ctx->c_flags |= TRANSPORT_CONNECTION_F_NO_LOOKUP;
+
+ ctx->srtp_policy[0].key = clib_mem_alloc (SRTP_MAX_KEYLEN);
+ clib_memcpy (ctx->srtp_policy[0].key, lctx->srtp_policy[0].key,
+ SRTP_MAX_KEYLEN);
+ ctx->srtp_policy[1].key = clib_mem_alloc (SRTP_MAX_KEYLEN);
+ clib_memcpy (ctx->srtp_policy[1].key, lctx->srtp_policy[1].key,
+ SRTP_MAX_KEYLEN);
+
+ app_session = session_alloc (ctx->c_thread_index);
+ app_session->session_state = SESSION_STATE_CREATED;
+ ctx->c_s_index = app_session->session_index;
+
+ SRTP_DBG (1, "Accept on listener %u new connection [%u]%x",
+ srtp_listener->opaque, vlib_get_thread_index (), ctx_handle);
+
+ return srtp_ctx_init_server (ctx);
+}
+
+int
+srtp_app_rx_callback (session_t *us)
+{
+ srtp_tc_t *ctx;
+
+ ctx = srtp_ctx_get_w_thread (us->opaque, us->thread_index);
+ srtp_ctx_read (ctx, us);
+ return 0;
+}
+
+int
+srtp_app_tx_callback (session_t *us)
+{
+ srtp_tc_t *ctx;
+
+ ctx = srtp_ctx_get_w_thread (us->opaque, us->thread_index);
+ transport_connection_reschedule (&ctx->connection);
+
+ return 0;
+}
+
+static void
+srtp_app_session_cleanup (session_t *s, session_cleanup_ntf_t ntf)
+{
+ srtp_tc_t *ctx;
+
+ if (ntf == SESSION_CLEANUP_TRANSPORT)
+ {
+ /* Allow cleanup of tcp session */
+ if (s->session_state == SESSION_STATE_TRANSPORT_DELETED)
+ session_close (s);
+ return;
+ }
+
+ ctx = srtp_ctx_get_w_thread (s->opaque, s->thread_index);
+ if (!ctx->no_app_session)
+ session_transport_delete_notify (&ctx->connection);
+ srtp_ctx_deinit (ctx);
+ srtp_ctx_free (ctx);
+}
+
+static void
+srtp_migrate_ctx_reply (void *arg)
+{
+ u32 ctx_index = pointer_to_uword (arg);
+ srtp_tc_t *ctx;
+
+ ctx = srtp_ctx_get_w_thread (ctx_index, vlib_get_thread_index ());
+ srtp_ctx_free (ctx);
+}
+
+static void
+srtp_migrate_ctx (void *arg)
+{
+ u32 ctx_handle, thread_index, old_thread_index, old_ctx_index;
+ srtp_tc_t *ctx = (srtp_tc_t *) arg;
+ session_t *us, *new_app_session;
+ void *rargs;
+
+ old_thread_index = ctx->c_thread_index;
+ old_ctx_index = ctx->c_c_index;
+ thread_index = session_thread_from_handle (ctx->srtp_session_handle);
+ ASSERT (thread_index == vlib_get_thread_index ());
+
+ ctx_handle = srtp_ctx_attach (thread_index, ctx);
+ ctx = srtp_ctx_get_w_thread (ctx_handle, thread_index);
+ ctx->srtp_ctx_handle = ctx_handle;
+ SRTP_DBG (1, "migrated ctx handle %u", ctx_handle);
+
+ us = session_get_from_handle (ctx->srtp_session_handle);
+ us->opaque = ctx_handle;
+ us->flags &= ~SESSION_F_IS_MIGRATING;
+ if (svm_fifo_max_dequeue (us->tx_fifo))
+ session_send_io_evt_to_thread (us->tx_fifo, SESSION_IO_EVT_TX);
+
+ /* Migrate app session as well */
+ session_dgram_connect_notify (&ctx->connection, old_thread_index,
+ &new_app_session);
+
+ /* Call back original thread and ask for cleanup */
+ rargs = uword_to_pointer ((uword) old_ctx_index, void *);
+ session_send_rpc_evt_to_thread (old_thread_index, srtp_migrate_ctx_reply,
+ rargs);
+}
+
+static void
+srtp_session_migrate_callback (session_t *us, session_handle_t new_sh)
+{
+ u32 new_thread = session_thread_from_handle (new_sh);
+ srtp_tc_t *ctx, *cloned_ctx;
+
+ ctx = srtp_ctx_get_w_thread (us->opaque, us->thread_index);
+ ctx->srtp_session_handle = new_sh;
+ cloned_ctx = srtp_ctx_detach (ctx);
+ SRTP_DBG (1, "ctx %u attached to udp %x session migrating",
+ cloned_ctx->c_c_index, new_sh);
+
+ session_send_rpc_evt_to_thread (new_thread, srtp_migrate_ctx,
+ (void *) cloned_ctx);
+
+ /* Can't free ctx now because app might be sending as srtp is not
+ * connection oriented, so it won't wait for a handshake */
+ ctx->is_migrated = 1;
+}
+
+static session_cb_vft_t srtp_app_cb_vft = {
+ .session_accept_callback = srtp_session_accept_callback,
+ .session_disconnect_callback = srtp_session_disconnect_callback,
+ .session_connected_callback = srtp_session_connected_callback,
+ .session_reset_callback = srtp_session_reset_callback,
+ .add_segment_callback = srtp_add_segment_callback,
+ .del_segment_callback = srtp_del_segment_callback,
+ .builtin_app_rx_callback = srtp_app_rx_callback,
+ .builtin_app_tx_callback = srtp_app_tx_callback,
+ .session_migrate_callback = srtp_session_migrate_callback,
+ .session_cleanup_callback = srtp_app_session_cleanup,
+};
+
+static clib_error_t *
+srtp_enable (vlib_main_t *vm, u8 is_en)
+{
+ u32 add_segment_size = 256 << 20, first_seg_size = 32 << 20;
+ vnet_app_detach_args_t _da, *da = &_da;
+ vnet_app_attach_args_t _a, *a = &_a;
+ u64 options[APP_OPTIONS_N_OPTIONS];
+ srtp_main_t *sm = &srtp_main;
+ u32 fifo_size = 128 << 12;
+
+ if (!is_en)
+ {
+ da->app_index = sm->app_index;
+ da->api_client_index = APP_INVALID_INDEX;
+ vnet_application_detach (da);
+ return 0;
+ }
+
+ srtp_init ();
+ vec_validate (sm->ctx_pool, vlib_num_workers ());
+
+ first_seg_size = sm->first_seg_size ? sm->first_seg_size : first_seg_size;
+ fifo_size = sm->fifo_size ? sm->fifo_size : fifo_size;
+
+ clib_memset (a, 0, sizeof (*a));
+ clib_memset (options, 0, sizeof (options));
+
+ a->session_cb_vft = &srtp_app_cb_vft;
+ a->api_client_index = APP_INVALID_INDEX;
+ a->options = options;
+ a->name = format (0, "srtp");
+ a->options[APP_OPTIONS_SEGMENT_SIZE] = first_seg_size;
+ a->options[APP_OPTIONS_ADD_SEGMENT_SIZE] = add_segment_size;
+ a->options[APP_OPTIONS_RX_FIFO_SIZE] = fifo_size;
+ a->options[APP_OPTIONS_TX_FIFO_SIZE] = fifo_size;
+ a->options[APP_OPTIONS_FLAGS] = APP_OPTIONS_FLAGS_IS_BUILTIN;
+ a->options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_USE_GLOBAL_SCOPE;
+ a->options[APP_OPTIONS_FLAGS] |= APP_OPTIONS_FLAGS_IS_TRANSPORT_APP;
+
+ if (vnet_application_attach (a))
+ return clib_error_return (0, "failed to attach srtp app");
+
+ sm->app_index = a->app_index;
+ vec_free (a->name);
+
+ return 0;
+}
+
+int
+srtp_connect (transport_endpoint_cfg_t *tep)
+{
+ vnet_connect_args_t _cargs = { {}, }, *cargs = &_cargs;
+ session_endpoint_cfg_t *sep;
+ srtp_main_t *sm = &srtp_main;
+ app_worker_t *app_wrk;
+ application_t *app;
+ srtp_tc_t *ctx;
+ u32 ctx_index;
+ int rv;
+
+ sep = (session_endpoint_cfg_t *) tep;
+ if (!sep->ext_cfg)
+ return SESSION_E_NOEXTCFG;
+
+ app_wrk = app_worker_get (sep->app_wrk_index);
+ app = application_get (app_wrk->app_index);
+
+ ctx_index = srtp_ctx_alloc_w_thread (1 /* because of udp */);
+ ctx = srtp_ctx_get_w_thread (ctx_index, 1);
+ ctx->parent_app_wrk_index = sep->app_wrk_index;
+ ctx->parent_app_api_context = sep->opaque;
+ ctx->udp_is_ip4 = sep->is_ip4;
+ ctx->srtp_ctx_handle = ctx_index;
+
+ srtp_init_policy (ctx, (transport_endpt_cfg_srtp_t *) sep->ext_cfg->data);
+
+ clib_memcpy_fast (&cargs->sep, sep, sizeof (session_endpoint_t));
+ cargs->sep.transport_proto = TRANSPORT_PROTO_UDP;
+ cargs->sep_ext.transport_flags = TRANSPORT_CFG_F_CONNECTED;
+ cargs->app_index = sm->app_index;
+ cargs->api_context = ctx_index;
+ cargs->sep_ext.ns_index = app->ns_index;
+ if ((rv = vnet_connect (cargs)))
+ return rv;
+
+ SRTP_DBG (1, "New connect request %u", ctx_index);
+ return 0;
+}
+
+static void
+srtp_disconnect_transport (srtp_tc_t *ctx)
+{
+ vnet_disconnect_args_t a = {
+ .handle = ctx->srtp_session_handle,
+ .app_index = srtp_main.app_index,
+ };
+
+ if (vnet_disconnect_session (&a))
+ SRTP_DBG (0, "disconnect returned");
+}
+
+static void
+srtp_disconnect (u32 ctx_handle, u32 thread_index)
+{
+ session_t *app_session;
+ srtp_tc_t *ctx;
+
+ SRTP_DBG (1, "App disconnecting %x", ctx_handle);
+
+ ctx = srtp_ctx_get_w_thread (ctx_handle, thread_index);
+
+ app_session = session_get_from_handle (ctx->app_session_handle);
+ if (!svm_fifo_max_dequeue_cons (app_session->tx_fifo))
+ {
+ /* Confirm close */
+ srtp_disconnect_transport (ctx);
+ session_transport_closed_notify (&ctx->connection);
+ }
+ else
+ {
+ /* Wait for all data to be written to udp */
+ ctx->app_closed = 1;
+ }
+}
+
+static u32
+srtp_start_listen (u32 app_listener_index, transport_endpoint_t *tep)
+{
+ vnet_listen_args_t _bargs, *args = &_bargs;
+ session_handle_t udp_al_handle;
+ srtp_main_t *sm = &srtp_main;
+ session_endpoint_cfg_t *sep;
+ session_t *srtp_listener;
+ session_t *app_listener;
+ app_worker_t *app_wrk;
+ application_t *app;
+ app_listener_t *al;
+ srtp_tc_t *lctx;
+ u32 lctx_index;
+
+ sep = (session_endpoint_cfg_t *) tep;
+ if (!sep->ext_cfg)
+ return SESSION_E_NOEXTCFG;
+
+ app_wrk = app_worker_get (sep->app_wrk_index);
+ app = application_get (app_wrk->app_index);
+
+ clib_memset (args, 0, sizeof (*args));
+ args->app_index = sm->app_index;
+ args->sep_ext = *sep;
+ args->sep_ext.ns_index = app->ns_index;
+ args->sep_ext.transport_proto = TRANSPORT_PROTO_UDP;
+ args->sep_ext.transport_flags = TRANSPORT_CFG_F_CONNECTED;
+ if (vnet_listen (args))
+ return -1;
+
+ lctx_index = srtp_listener_ctx_alloc ();
+ udp_al_handle = args->handle;
+ al = app_listener_get_w_handle (udp_al_handle);
+ srtp_listener = app_listener_get_session (al);
+ srtp_listener->opaque = lctx_index;
+
+ app_listener = listen_session_get (app_listener_index);
+
+ lctx = srtp_listener_ctx_get (lctx_index);
+ lctx->parent_app_wrk_index = sep->app_wrk_index;
+ lctx->srtp_session_handle = udp_al_handle;
+ lctx->app_session_handle = listen_session_get_handle (app_listener);
+ lctx->udp_is_ip4 = sep->is_ip4;
+
+ srtp_init_policy (lctx, (transport_endpt_cfg_srtp_t *) sep->ext_cfg->data);
+
+ SRTP_DBG (1, "Started listening %d", lctx_index);
+ return lctx_index;
+}
+
+u32
+srtp_stop_listen (u32 lctx_index)
+{
+ session_endpoint_t sep = SESSION_ENDPOINT_NULL;
+ transport_connection_t *lc;
+ srtp_tc_t *lctx;
+ session_t *ls;
+ int rv;
+
+ lctx = srtp_listener_ctx_get (lctx_index);
+
+ /* Cleanup listener from session lookup table */
+ ls = session_get_from_handle (lctx->srtp_session_handle);
+ lc = session_get_transport (ls);
+
+ sep.fib_index = lc->fib_index;
+ sep.port = lc->lcl_port;
+ sep.is_ip4 = lc->is_ip4;
+ sep.transport_proto = TRANSPORT_PROTO_SRTP;
+ clib_memcpy (&sep.ip, &lc->lcl_ip, sizeof (lc->lcl_ip));
+ session_lookup_del_session_endpoint2 (&sep);
+
+ vnet_unlisten_args_t a = {
+ .handle = lctx->srtp_session_handle,
+ .app_index = srtp_main.app_index,
+ .wrk_map_index = 0 /* default wrk */
+ };
+ if ((rv = vnet_unlisten (&a)))
+ SRTP_DBG (0, "unlisten returned %d", rv);
+
+ srtp_listener_ctx_free (lctx);
+ return 0;
+}
+
+transport_connection_t *
+srtp_connection_get (u32 ctx_index, u32 thread_index)
+{
+ srtp_tc_t *ctx;
+ ctx = srtp_ctx_get_w_thread (ctx_index, thread_index);
+ return &ctx->connection;
+}
+
+transport_connection_t *
+srtp_listener_get (u32 listener_index)
+{
+ srtp_tc_t *ctx;
+ ctx = srtp_listener_ctx_get (listener_index);
+ return &ctx->connection;
+}
+
+int
+srtp_custom_tx_callback (void *session, transport_send_params_t *sp)
+{
+ session_t *app_session = (session_t *) session;
+ srtp_tc_t *ctx;
+
+ if (PREDICT_FALSE (app_session->session_state >=
+ SESSION_STATE_TRANSPORT_CLOSED))
+ return 0;
+
+ sp->flags = 0;
+ ctx = srtp_ctx_get_w_thread (app_session->connection_index,
+ app_session->thread_index);
+ if (PREDICT_FALSE (ctx->is_migrated))
+ return 0;
+
+ return srtp_ctx_write (ctx, app_session, sp);
+}
+
+u8 *
+format_srtp_ctx (u8 *s, va_list *args)
+{
+ srtp_tc_t *ctx = va_arg (*args, srtp_tc_t *);
+ u32 udp_si, udp_ti;
+
+ session_parse_handle (ctx->srtp_session_handle, &udp_si, &udp_ti);
+ s = format (s, "[%d:%d][SRTP] app_wrk %u index %u udp %d:%d",
+ ctx->c_thread_index, ctx->c_s_index, ctx->parent_app_wrk_index,
+ ctx->srtp_ctx_handle, udp_ti, udp_si);
+
+ return s;
+}
+
+static u8 *
+format_srtp_listener_ctx (u8 *s, va_list *args)
+{
+ session_t *udp_listener;
+ app_listener_t *al;
+ srtp_tc_t *ctx;
+
+ ctx = va_arg (*args, srtp_tc_t *);
+
+ al = app_listener_get_w_handle (ctx->srtp_session_handle);
+ udp_listener = app_listener_get_session (al);
+ s = format (s, "[%d:%d][SRTP] app_wrk %u udp %d:%d", ctx->c_thread_index,
+ ctx->c_s_index, ctx->parent_app_wrk_index,
+ udp_listener->thread_index, udp_listener->session_index);
+
+ return s;
+}
+
+static u8 *
+format_srtp_ctx_state (u8 *s, va_list *args)
+{
+ srtp_tc_t *ctx;
+ session_t *us;
+
+ ctx = va_arg (*args, srtp_tc_t *);
+ us = session_get (ctx->c_s_index, ctx->c_thread_index);
+ if (us->session_state == SESSION_STATE_LISTENING)
+ s = format (s, "%s", "LISTEN");
+ else
+ {
+ if (us->session_state >= SESSION_STATE_TRANSPORT_CLOSED)
+ s = format (s, "%s", "CLOSED");
+ else if (us->session_state == SESSION_STATE_APP_CLOSED)
+ s = format (s, "%s", "APP-CLOSED");
+ else if (us->session_state >= SESSION_STATE_TRANSPORT_CLOSING)
+ s = format (s, "%s", "CLOSING");
+ else
+ s = format (s, "%s", "ESTABLISHED");
+ }
+
+ return s;
+}
+
+u8 *
+format_srtp_connection (u8 *s, va_list *args)
+{
+ u32 ctx_index = va_arg (*args, u32);
+ u32 thread_index = va_arg (*args, u32);
+ u32 verbose = va_arg (*args, u32);
+ srtp_tc_t *ctx;
+
+ ctx = srtp_ctx_get_w_thread (ctx_index, thread_index);
+ if (!ctx)
+ return s;
+
+ s = format (s, "%-" SESSION_CLI_ID_LEN "U", format_srtp_ctx, ctx);
+ if (verbose)
+ {
+ s =
+ format (s, "%-" SESSION_CLI_STATE_LEN "U", format_srtp_ctx_state, ctx);
+ if (verbose > 1)
+ s = format (s, "\n");
+ }
+ return s;
+}
+
+u8 *
+format_srtp_listener (u8 *s, va_list *args)
+{
+ u32 tc_index = va_arg (*args, u32);
+ u32 __clib_unused thread_index = va_arg (*args, u32);
+ u32 verbose = va_arg (*args, u32);
+ srtp_tc_t *ctx = srtp_listener_ctx_get (tc_index);
+
+ s = format (s, "%-" SESSION_CLI_ID_LEN "U", format_srtp_listener_ctx, ctx);
+ if (verbose)
+ s = format (s, "%-" SESSION_CLI_STATE_LEN "U", format_srtp_ctx_state, ctx);
+ return s;
+}
+
+u8 *
+format_srtp_half_open (u8 *s, va_list *args)
+{
+ return 0;
+}
+
+static void
+srtp_transport_endpoint_get (u32 ctx_handle, u32 thread_index,
+ transport_endpoint_t *tep, u8 is_lcl)
+{
+ srtp_tc_t *ctx = srtp_ctx_get_w_thread (ctx_handle, thread_index);
+ session_t *udp_session;
+
+ udp_session = session_get_from_handle (ctx->srtp_session_handle);
+ session_get_endpoint (udp_session, tep, is_lcl);
+}
+
+static void
+srtp_transport_listener_endpoint_get (u32 ctx_handle,
+ transport_endpoint_t *tep, u8 is_lcl)
+{
+ session_t *srtp_listener;
+ app_listener_t *al;
+ srtp_tc_t *ctx = srtp_listener_ctx_get (ctx_handle);
+
+ al = app_listener_get_w_handle (ctx->srtp_session_handle);
+ srtp_listener = app_listener_get_session (al);
+ session_get_endpoint (srtp_listener, tep, is_lcl);
+}
+
+static const transport_proto_vft_t srtp_proto = {
+ .enable = srtp_enable,
+ .connect = srtp_connect,
+ .close = srtp_disconnect,
+ .start_listen = srtp_start_listen,
+ .stop_listen = srtp_stop_listen,
+ .get_connection = srtp_connection_get,
+ .get_listener = srtp_listener_get,
+ .custom_tx = srtp_custom_tx_callback,
+ .format_connection = format_srtp_connection,
+ .format_half_open = format_srtp_half_open,
+ .format_listener = format_srtp_listener,
+ .get_transport_endpoint = srtp_transport_endpoint_get,
+ .get_transport_listener_endpoint = srtp_transport_listener_endpoint_get,
+ .transport_options = {
+ .name = "srtp",
+ .short_name = "R",
+ .tx_type = TRANSPORT_TX_INTERNAL,
+ .service_type = TRANSPORT_SERVICE_APP,
+ },
+};
+
+static clib_error_t *
+srtp_transport_init (vlib_main_t *vm)
+{
+ transport_register_protocol (TRANSPORT_PROTO_SRTP, &srtp_proto,
+ FIB_PROTOCOL_IP4, ~0);
+ transport_register_protocol (TRANSPORT_PROTO_SRTP, &srtp_proto,
+ FIB_PROTOCOL_IP6, ~0);
+ return 0;
+}
+
+VLIB_INIT_FUNCTION (srtp_transport_init);
+
+VLIB_PLUGIN_REGISTER () = {
+ .version = VPP_BUILD_VER,
+ .description = "Secure Real-time Transport Protocol (SRTP)",
+ /* .default_disabled = 1, */
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/srtp/srtp.h b/src/plugins/srtp/srtp.h
new file mode 100644
index 00000000000..16475b0bd2f
--- /dev/null
+++ b/src/plugins/srtp/srtp.h
@@ -0,0 +1,120 @@
+/*
+ * 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 <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+
+#include <vnet/session/application_interface.h>
+#include <vnet/session/application.h>
+
+#include <srtp2/srtp.h>
+
+#ifndef SRC_PLUGINS_SRTP_SRTP_H_
+#define SRC_PLUGINS_SRTP_SRTP_H_
+
+#define SRTP_DEBUG 0
+
+#if SRTP_DEBUG
+#define SRTP_DBG(_lvl, _fmt, _args...) \
+ if (_lvl <= SRTP_DEBUG) \
+ clib_warning (_fmt, ##_args)
+#else
+#define SRTP_DBG(_lvl, _fmt, _args...)
+#endif
+
+typedef struct srtp_cxt_id_
+{
+ union
+ {
+ session_handle_t app_session_handle;
+ u32 parent_app_api_ctx;
+ };
+ session_handle_t srtp_session_handle;
+ u32 parent_app_wrk_index;
+ u32 srtp_ctx;
+ u32 listener_ctx_index;
+ u8 udp_is_ip4;
+} srtp_ctx_id_t;
+
+STATIC_ASSERT (sizeof (srtp_ctx_id_t) <= TRANSPORT_CONN_ID_LEN,
+ "ctx id must be less than TRANSPORT_CONN_ID_LEN");
+
+#define SRTP_MAX_KEYLEN 46 /**< libsrtp AES 256 key len with salt */
+
+typedef struct transport_endpt_cfg_srtp_policy
+{
+ u32 ssrc_type;
+ u32 ssrc_value;
+ u32 window_size;
+ u8 allow_repeat_tx;
+ u8 key_len;
+ u8 key[SRTP_MAX_KEYLEN];
+} transport_endpt_cfg_srtp_policy_t;
+
+typedef struct transport_endpt_cfg_srtp
+{
+ transport_endpt_cfg_srtp_policy_t policies[2];
+} transport_endpt_cfg_srtp_t;
+
+typedef struct srtp_ctx_
+{
+ union
+ {
+ transport_connection_t connection;
+ srtp_ctx_id_t c_srtp_ctx_id;
+ };
+#define parent_app_wrk_index c_srtp_ctx_id.parent_app_wrk_index
+#define app_session_handle c_srtp_ctx_id.app_session_handle
+#define srtp_session_handle c_srtp_ctx_id.srtp_session_handle
+#define listener_ctx_index c_srtp_ctx_id.listener_ctx_index
+#define udp_is_ip4 c_srtp_ctx_id.udp_is_ip4
+#define srtp_ctx_engine c_srtp_ctx_id.srtp_engine_id
+#define srtp_ssl_ctx c_srtp_ctx_id.ssl_ctx
+#define srtp_ctx_handle c_c_index
+ /* Temporary storage for session open opaque. Overwritten once
+ * underlying tcp connection is established */
+#define parent_app_api_context c_srtp_ctx_id.parent_app_api_ctx
+
+ u8 is_passive_close;
+ u8 resume;
+ u8 app_closed;
+ u8 no_app_session;
+ u8 is_migrated;
+ srtp_t srtp_ctx;
+ srtp_policy_t srtp_policy[2];
+} srtp_tc_t;
+
+typedef struct srtp_main_
+{
+ srtp_tc_t **ctx_pool;
+ srtp_tc_t *listener_ctx_pool;
+ u32 app_index;
+ clib_rwlock_t half_open_rwlock;
+ /*
+ * Config
+ */
+ u64 first_seg_size;
+ u32 fifo_size;
+} srtp_main_t;
+
+#endif /* SRC_PLUGINS_SRTP_SRTP_H_ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/srtp/srtp_plugin.md b/src/plugins/srtp/srtp_plugin.md
new file mode 100644
index 00000000000..81185864dbe
--- /dev/null
+++ b/src/plugins/srtp/srtp_plugin.md
@@ -0,0 +1,72 @@
+# SRTP (Secure Real-time Transport Protocol) {#srtp_doc}
+
+libsrtp2 based SRTP transport protocol implementation.
+
+## Maturity level
+Experimental
+
+## Quickstart
+
+1. Install libsrtp2-dev. On debian based OS:
+
+```
+sudo apt get install libsrtp2-dev
+```
+
+2. Build vpp
+
+```
+make build
+```
+
+3. Test protocol using vcl test server and client. On server side, start vpp and server app:
+
+```
+export VT_PATH=$WS/build-root/build-vpp_debug-native/vpp/bin
+$VT_PATH/vcl_test_server 1234 -p srtp
+```
+
+On client side:
+
+```
+export VT_PATH=$WS/build-root/build-vpp_debug-native/vpp/bin
+$VT_PATH/vcl_test_client <server-ip> 1234 -U -X -S -N 10000 -T 128 -p srtp
+```
+
+## Custom libsrtp2 build
+
+1. Create `build/external/packages/srtp.mk` with following example contents:
+
+```
+srtp_version := 2.3.0
+srtp_tarball := srtp_$(srtp_version).tar.gz
+srtp_tarball_md5sum := da38ee5d9c31be212a12964c22d7f795
+srtp_tarball_strip_dirs := 1
+srtp_url := https://github.com/cisco/libsrtp/archive/v$(srtp_version).tar.gz
+
+define srtp_build_cmds
+ @cd $(srtp_build_dir) && \
+ $(CMAKE) -DCMAKE_INSTALL_PREFIX:PATH=$(srtp_install_dir) \
+ -DCMAKE_C_FLAGS='-fPIC -fvisibility=hidden' $(srtp_src_dir) > $(srtp_build_log)
+ @$(MAKE) $(MAKE_ARGS) -C $(srtp_build_dir) > $(srtp_build_log)
+endef
+
+define srtp_config_cmds
+ @true
+endef
+
+define srtp_install_cmds
+ @$(MAKE) $(MAKE_ARGS) -C $(srtp_build_dir) install > $(srtp_install_log)
+endef
+
+
+$(eval $(call package,srtp))
+```
+
+2. Include `srtp.mk` in `build/external/Makefile` and add to install target.
+
+3. Rebuild external dependencies:
+
+```
+make install-ext-deps
+```