eclipse-cyclonedds · eboasson · Jan 9, 2026 · Jan 13, 2026 · Jan 13, 2026 · Jan 13, 2026
diff --git a/docs/manual/config/config_file_reference.rst b/docs/manual/config/config_file_reference.rst
@@ -2795,8 +2795,8 @@ The default value is: ``none``
 
 ..
    generated from ddsi_config.h[6b6cd6f2af797765bc3753758bdd5f166f64b418] 
-   generated from ddsi_config.c[a48ec3d818f2ad852949a7832951709c3488dc10] 
-   generated from ddsi__cfgelems.h[32ba43b085108475f0fc5041d4593a9926c0f6f9] 
+   generated from ddsi_config.c[98a66b82efe4476934c17d3df879e70add3b65a2] 
+   generated from ddsi__cfgelems.h[7fe8f980955d7eab1f9515a474d5a51042698343] 
    generated from cfgunits.h[05f093223fce107d24dd157ebaafa351dc9df752] 
    generated from _confgen.h[bb9a0fc6ef1f7f7c46790ee00132e340e5fff36d] 
    generated from _confgen.c[0d833a6f2c98902f1249e63aed03a6164f0791d6] 

diff --git a/docs/manual/options.md b/docs/manual/options.md
@@ -1961,8 +1961,8 @@ The categorisation of tracing output is incomplete and hence most of the verbosi
 
 The default value is: `none`
 <!--- generated from ddsi_config.h[6b6cd6f2af797765bc3753758bdd5f166f64b418] -->
-<!--- generated from ddsi_config.c[a48ec3d818f2ad852949a7832951709c3488dc10] -->
-<!--- generated from ddsi__cfgelems.h[32ba43b085108475f0fc5041d4593a9926c0f6f9] -->
+<!--- generated from ddsi_config.c[98a66b82efe4476934c17d3df879e70add3b65a2] -->
+<!--- generated from ddsi__cfgelems.h[7fe8f980955d7eab1f9515a474d5a51042698343] -->
 <!--- generated from cfgunits.h[05f093223fce107d24dd157ebaafa351dc9df752] -->
 <!--- generated from _confgen.h[bb9a0fc6ef1f7f7c46790ee00132e340e5fff36d] -->
 <!--- generated from _confgen.c[0d833a6f2c98902f1249e63aed03a6164f0791d6] -->

diff --git a/etc/cyclonedds.rnc b/etc/cyclonedds.rnc
@@ -1360,8 +1360,8 @@ MIIEpAIBAAKCAQEA3HIh...AOBaaqSV37XBUJg==<br>
   maybe_memsize = xsd:token { pattern = "default|0|(\d+(\.\d*)?([Ee][\-+]?\d+)?|\.\d+([Ee][\-+]?\d+)?) *([kMG]i?)?B" }
 }
 # generated from ddsi_config.h[6b6cd6f2af797765bc3753758bdd5f166f64b418] 
-# generated from ddsi_config.c[a48ec3d818f2ad852949a7832951709c3488dc10] 
-# generated from ddsi__cfgelems.h[32ba43b085108475f0fc5041d4593a9926c0f6f9] 
+# generated from ddsi_config.c[98a66b82efe4476934c17d3df879e70add3b65a2] 
+# generated from ddsi__cfgelems.h[7fe8f980955d7eab1f9515a474d5a51042698343] 
 # generated from cfgunits.h[05f093223fce107d24dd157ebaafa351dc9df752] 
 # generated from _confgen.h[bb9a0fc6ef1f7f7c46790ee00132e340e5fff36d] 
 # generated from _confgen.c[0d833a6f2c98902f1249e63aed03a6164f0791d6] 

diff --git a/etc/cyclonedds.xsd b/etc/cyclonedds.xsd
@@ -2047,8 +2047,8 @@ MIIEpAIBAAKCAQEA3HIh...AOBaaqSV37XBUJg==&lt;br&gt;
   </xs:simpleType>
 </xs:schema>
 <!--- generated from ddsi_config.h[6b6cd6f2af797765bc3753758bdd5f166f64b418] -->
-<!--- generated from ddsi_config.c[a48ec3d818f2ad852949a7832951709c3488dc10] -->
-<!--- generated from ddsi__cfgelems.h[32ba43b085108475f0fc5041d4593a9926c0f6f9] -->
+<!--- generated from ddsi_config.c[98a66b82efe4476934c17d3df879e70add3b65a2] -->
+<!--- generated from ddsi__cfgelems.h[7fe8f980955d7eab1f9515a474d5a51042698343] -->
 <!--- generated from cfgunits.h[05f093223fce107d24dd157ebaafa351dc9df752] -->
 <!--- generated from _confgen.h[bb9a0fc6ef1f7f7c46790ee00132e340e5fff36d] -->
 <!--- generated from _confgen.c[0d833a6f2c98902f1249e63aed03a6164f0791d6] -->

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -49,6 +49,7 @@ option(ENABLE_TYPELIB "Enable Type Library support" ON)
 option(ENABLE_TYPE_DISCOVERY "Enable Type Discovery support" ON)
 option(ENABLE_TOPIC_DISCOVERY "Enable Topic Discovery support" ON)
 option(ENABLE_QOS_PROVIDER "Enable Qos Provider support" ON)
+option(ENABLE_TCP "Enable PoC support for DDS-over-TCP" OFF)
 if(ENABLE_TYPE_DISCOVERY)
   if(NOT ENABLE_TYPELIB)
     message(FATAL_ERROR "ENABLE_TYPE_DISCOVERY requires ENABLE_TYPELIB to be enabled")

diff --git a/src/core/ddsc/tests/CMakeLists.txt b/src/core/ddsc/tests/CMakeLists.txt
@@ -153,6 +153,11 @@ if(ENABLE_QOS_PROVIDER)
     "qos_provider.c")
 endif()
 
+if(ENABLE_TCP)
+  list(APPEND ddsc_test_sources
+    "tcp.c")
+endif()
+
 add_cunit_executable(cunit_ddsc ${ddsc_test_sources})
 
 if(MSVC)

diff --git a/src/core/ddsc/tests/tcp.c b/src/core/ddsc/tests/tcp.c
@@ -0,0 +1,246 @@
+// Copyright(c) 2025 ZettaScale Technology and others
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
+// v. 1.0 which is available at
+// http://www.eclipse.org/org/documents/edl-v10.php.
+//
+// SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+
+#include <stdio.h>
+#include <ctype.h>
+
+#include "dds/ddsi/ddsi_protocol.h"
+#include "dds/ddsi/ddsi_thread.h"
+#include "dds/ddsrt/time.h"
+#include "dds__guid.h"
+#include "ddsi__tran.h"
+#include "test_common.h"
+#include "dds/ddsi/ddsi_entity_index.h"
+#include "dds/ddsi/ddsi_proxy_participant.h"
+#include "dds/ddsi/ddsi_addrset.h"
+
+#include "dds/dds.h"
+#include "dds/ddsrt/io.h"
+#include "dds/ddsrt/heap.h"
+#include "ddsi__addrset.h"
+
+static ddsrt_atomic_uint32_t framing_errors;
+
+static void scan_for_framing_error (void *ptr, const dds_log_data_t *data)
+{
+  (void) ptr;
+  //tprintf ("[%"PRIu32"] %s", data->domid, data->message);
+  if (strstr (data->message, "framing error, dropping connection") != NULL)
+    ddsrt_atomic_or32 (&framing_errors, 1u << data->domid);
+}
+
+static void do_tcp (void (*action) (dds_entity_t rd, dds_entity_t wr, void *arg), void *arg)
+{
+  const char *config_fmt =
+    "<General>"
+    "  <Interfaces>"
+    "    <NetworkInterface address=\"127.0.0.1\"/>"
+    "  </Interfaces>"
+    "  <Transport>tcp</Transport>"
+    "</General>"
+    "<Discovery>"
+    "  <ExternalDomainId>0</ExternalDomainId>"
+    "  <Tag>${CYCLONEDDS_PID}</Tag>"
+    "  <Peers>"
+    "    %s"
+    "  </Peers>"
+    "</Discovery>"
+    "<TCP>"
+    "  <Port>%d</Port>"
+    "</TCP>"
+    "<Tracing><Category>trace,tcp</Category><OutputFile>stdout</OutputFile></Tracing>";
+
+  ddsrt_atomic_st32 (&framing_errors, 0);
+  dds_set_log_sink (scan_for_framing_error, NULL);
+  dds_set_trace_sink (scan_for_framing_error, NULL);
+
+  // Start up a new domain listening to an ephemeral TCP port
+  char *configs = NULL;
+  (void) ddsrt_asprintf (&configs, config_fmt, "", 0);
+  const dds_entity_t doms = dds_create_domain (0, configs);
+  ddsrt_free (configs);
+
+#ifdef DDS_HAS_TCP
+  CU_ASSERT_GT_FATAL (doms, 0);
+  struct ddsi_domaingv * const gvs = get_domaingv (doms);
+  CU_ASSERT_NEQ_FATAL (gvs, NULL);
+
+  // Create a second domain instance without a server socket and with the
+  // first domain's ephemeral port as the peer
+  char peerlocbuf[DDSI_LOCSTRLEN];
+  char *peerstr = NULL;
+  (void) ddsrt_asprintf (&peerstr, "<Peer address=\"%s\"/>", ddsi_locator_to_string (peerlocbuf, sizeof (peerlocbuf), &gvs->loc_meta_uc));
+  char *configc = NULL;
+  (void) ddsrt_asprintf (&configc, config_fmt, peerstr, -1);
+  const dds_entity_t domc = dds_create_domain (1, configc);
+  CU_ASSERT_GT_FATAL (domc, 0);
+  ddsrt_free (configc);
+  ddsrt_free (peerstr);
+
+  const dds_entity_t pp_pub = dds_create_participant (0, NULL, NULL);
+  CU_ASSERT_GT_FATAL (pp_pub, 0);
+  const dds_entity_t pp_sub = dds_create_participant (1, NULL, NULL);
+  CU_ASSERT_GT_FATAL (pp_sub, 0);
+  char topicname[100];
+  create_unique_topic_name ("tcp_basic", topicname, sizeof (topicname));
+  dds_qos_t *qos = dds_create_qos ();
+  dds_qset_reliability (qos, DDS_RELIABILITY_RELIABLE, DDS_INFINITY);
+  const dds_entity_t tp_pub = dds_create_topic (pp_pub, &Space_Type1_desc, topicname, qos, NULL);
+  const dds_entity_t tp_sub = dds_create_topic (pp_sub, &Space_Type1_desc, topicname, qos, NULL);
+  dds_delete_qos (qos);
+
+  const dds_entity_t wr = dds_create_writer (pp_pub, tp_pub, NULL, NULL);
+  const dds_entity_t rd = dds_create_reader (pp_sub, tp_sub, NULL, NULL);
+  sync_reader_writer (pp_sub, rd, pp_pub, wr);
+
+  action (rd, wr, arg);
+
+  dds_return_t rc;
+  rc = dds_delete (domc);
+  CU_ASSERT_EQ_FATAL (rc, 0);
+  rc = dds_delete (doms);
+  CU_ASSERT_EQ_FATAL (rc, 0);
+#else // DDS_HAS_TCP
+  (void) action;
+  (void) arg;
+  CU_ASSERT_LT_FATAL (doms, 0);
+#endif // DDS_HAS_TCP
+
+  dds_set_log_sink (scan_for_framing_error, NULL);
+  dds_set_trace_sink (scan_for_framing_error, NULL);
+}
+
+static void do_basic_write (dds_entity_t rd, dds_entity_t wr, void *varg)
+{
+  (void) varg;
+
+  dds_return_t rc;
+  rc = dds_write (wr, &(Space_Type1){345,678,101});
+  CU_ASSERT_EQ_FATAL (rc, 0);
+
+  const dds_entity_t ws = dds_create_waitset (dds_get_participant (rd));
+  CU_ASSERT_GT_FATAL (ws, 0);
+  rc = dds_set_status_mask (rd, DDS_DATA_AVAILABLE_STATUS);
+  CU_ASSERT_EQ_FATAL (rc, 0);
+  rc = dds_waitset_attach (ws, rd, 0);
+  CU_ASSERT_EQ_FATAL (rc, 0);
+  rc = dds_waitset_wait (ws, NULL, 0, DDS_MSECS (5000));
+  CU_ASSERT_EQ (rc, 1);
+
+  Space_Type1 sample;
+  void *rawsample = &sample;
+  dds_sample_info_t si;
+  rc = dds_take (rd, &rawsample, &si, 1, 1);
+  CU_ASSERT_EQ_FATAL (rc, 1);
+  CU_ASSERT_FATAL(si.valid_data);
+  CU_ASSERT_EQ_FATAL (sample.long_1, 345);
+  CU_ASSERT_EQ_FATAL (sample.long_2, 678);
+  CU_ASSERT_EQ_FATAL (sample.long_3, 101);
+}
+
+CU_Test (ddsc_tcp, basic)
+{
+  do_tcp (do_basic_write, NULL);
+}
+
+struct inject_arg {
+  ddsrt_iovec_t data;
+};
+
+static void do_inject (dds_entity_t rd, dds_entity_t wr, void *varg)
+{
+  const struct inject_arg *arg = varg;
+  struct ddsi_domaingv * const gvwr = get_domaingv (wr);
+
+  // Find reader's proxy participant in writer's domain
+  dds_guid_t rdguid;
+  dds_get_guid (rd, &rdguid);
+  ddsi_guid_t rdpp_guid = dds_guid_to_ddsi_guid (rdguid);
+  rdpp_guid.entityid.u = DDSI_ENTITYID_PARTICIPANT;
+  ddsi_thread_state_awake (ddsi_lookup_thread_state (), gvwr);
+  struct ddsi_proxy_participant *rdproxypp = ddsi_entidx_lookup_proxy_participant_guid (gvwr->entity_index, &rdpp_guid);
+  CU_ASSERT_NEQ_FATAL (rdproxypp, NULL);
+  ddsi_thread_state_asleep (ddsi_lookup_thread_state ());
+  // ... because we need the address
+  ddsi_xlocator_t xloc;
+  ddsi_addrset_any_uc (rdproxypp->as_default, &xloc);
+
+  // Make writer's domain mute so we can inject garbage in the TCP connection without
+  // interfering with RTPS messages being sent in the background
+  dds_domain_set_deafmute (wr, false, true, DDS_INFINITY);
+
+  DDSI_DECL_TRAN_WRITE_MSGFRAGS_PTR(mf, 1);
+  mf->niov = 1;
+  mf->iov[0] = arg->data;
+  ddsi_conn_write (xloc.conn, &xloc.c, mf, 0);
+
+  // logger should
+  dds_domainid_t rd_domain_id;
+  dds_return_t rc;
+  rc = dds_get_domainid (rd, &rd_domain_id);
+  CU_ASSERT_EQ_FATAL (rc, 0);
+  while (ddsrt_atomic_ld32 (&framing_errors) == 0)
+    dds_sleepfor (DDS_MSECS (10));
+  CU_ASSERT_EQ_FATAL (ddsrt_atomic_ld32 (&framing_errors), (1u << rd_domain_id));
+}
+
+CU_Test (ddsc_tcp, inject_wrong_smid)
+{
+  unsigned char msg[] = {
+    'R', 'T', 'P', 'S', /* version (don't care): */ 2,5,
+    /* vendor id (don't care, 1.16 = Cyclone */ 1,16,
+    /* GUID prefix (don't care) */ 1,16,3,4, 5,6,7,8, 9,10,11,12,
+    /* SMID_ADLINK_MSG_LEN, big-endian, 4 octets-to-next-header */ 130,0,0,4,
+    /* fake length */ 0x0,0x0,0x0,0x20
+  };
+  struct inject_arg arg = {
+    .data = {
+      .iov_len = 28,
+      .iov_base = msg
+    }
+  };
+  do_tcp (do_inject, &arg);
+}
+
+CU_Test (ddsc_tcp, inject_short_length)
+{
+  unsigned char msg[] = {
+    'R', 'T', 'P', 'S', /* version (don't care): */ 2,5,
+    /* vendor id (don't care, 1.16 = Cyclone */ 1,16,
+    /* GUID prefix (don't care) */ 1,16,3,4, 5,6,7,8, 9,10,11,12,
+    /* SMID_ADLINK_MSG_LEN, big-endian, 4 octets-to-next-header */ 129,0,0,4,
+    /* fake length */ 0x0,0x0,0x0,0x3
+  };
+  struct inject_arg arg = {
+    .data = {
+      .iov_len = 28,
+      .iov_base = msg
+    }
+  };
+  do_tcp (do_inject, &arg);
+}
+
+CU_Test (ddsc_tcp, inject_oversize_length)
+{
+  unsigned char msg[] = {
+    'R', 'T', 'P', 'S', /* version (don't care): */ 2,5,
+    /* vendor id (don't care, 1.16 = Cyclone */ 1,16,
+    /* GUID prefix (don't care) */ 1,16,3,4, 5,6,7,8, 9,10,11,12,
+    /* SMID_ADLINK_MSG_LEN, big-endian, 4 octets-to-next-header */ 129,0,0,4,
+    /* fake length */ 0x33,0x44,0x55,0x66
+  };
+  struct inject_arg arg = {
+    .data = {
+      .iov_len = 28,
+      .iov_base = msg
+    }
+  };
+  do_tcp (do_inject, &arg);
+}
diff --git a/src/core/ddsi/defconfig.c b/src/core/ddsi/defconfig.c
@@ -104,8 +104,8 @@ void ddsi_config_init_default (struct ddsi_config *cfg)
 #endif /* DDS_HAS_TCP_TLS */
 }
 /* generated from ddsi_config.h[6b6cd6f2af797765bc3753758bdd5f166f64b418] */
-/* generated from ddsi_config.c[a48ec3d818f2ad852949a7832951709c3488dc10] */
-/* generated from ddsi__cfgelems.h[32ba43b085108475f0fc5041d4593a9926c0f6f9] */
+/* generated from ddsi_config.c[98a66b82efe4476934c17d3df879e70add3b65a2] */
+/* generated from ddsi__cfgelems.h[7fe8f980955d7eab1f9515a474d5a51042698343] */
 /* generated from cfgunits.h[05f093223fce107d24dd157ebaafa351dc9df752] */
 /* generated from _confgen.h[bb9a0fc6ef1f7f7c46790ee00132e340e5fff36d] */
 /* generated from _confgen.c[0d833a6f2c98902f1249e63aed03a6164f0791d6] */

diff --git a/src/core/ddsi/src/ddsi__cfgelems.h b/src/core/ddsi/src/ddsi__cfgelems.h
@@ -306,13 +306,23 @@ static struct cfgelem general_cfgelems[] = {
     FUNCTIONS(0, uf_boolean_default, 0, pf_nop),
     DESCRIPTION("<p>Deprecated (use Transport instead)</p>"),
     VALUES("false","true","default")),
+#ifdef DDS_HAS_TCP
   ENUM("Transport", NULL, 1, "default",
     MEMBER(transport_selector),
     FUNCTIONS(0, uf_transport_selector, 0, pf_transport_selector),
     DESCRIPTION(
       "<p>This element allows selecting the transport to be used (udp, udp6, "
       "tcp, tcp6, raweth)</p>"),
     VALUES("default","udp","udp6","tcp","tcp6","raweth")),
+#else
+  ENUM("Transport", NULL, 1, "default",
+    MEMBER(transport_selector),
+    FUNCTIONS(0, uf_transport_selector, 0, pf_transport_selector),
+    DESCRIPTION(
+      "<p>This element allows selecting the transport to be used (udp, udp6, "
+      "raweth)</p>"),
+    VALUES("default","udp","udp6","raweth")),
+#endif
   BOOL("EnableMulticastLoopback", NULL, 1, "true",
     MEMBER(enableMulticastLoopback),
     FUNCTIONS(0, uf_boolean, 0, pf_boolean),
@@ -1712,6 +1722,7 @@ static struct cfgelem discovery_ports_cfgelems[] = {
   END_MARKER
 };
 
+#ifdef DDS_HAS_TCP
 static struct cfgelem tcp_cfgelems[] = {
   ENUM("Enable", NULL, 1, "default",
     MEMBER(compat_tcp_enable),
@@ -1764,6 +1775,7 @@ static struct cfgelem tcp_cfgelems[] = {
     )),
   END_MARKER
 };
+#endif
 
 #ifdef DDS_HAS_TCP_TLS
 static struct cfgelem ssl_cfgelems[] = {
@@ -2249,13 +2261,15 @@ static struct cfgelem domain_cfgelems[] = {
       "functionality is reserved. This includes renaming or moving "
       "options.</p>"
     )),
+#ifdef DDS_HAS_TCP
   GROUP("TCP", tcp_cfgelems, NULL, 1,
     NOMEMBER,
     NOFUNCTIONS,
     DESCRIPTION(
       "<p>The TCP element allows you to specify various parameters related to "
       "running DDSI over TCP.</p>"
     )),
+#endif
 #ifdef DDS_HAS_TCP_TLS
   GROUP("SSL", ssl_cfgelems, NULL, 1,
     NOMEMBER,
@@ -2294,7 +2308,9 @@ static struct cfgelem root_cfgelems[] = {
   MOVED("Discovery", "CycloneDDS/Domain/Discovery"),
   MOVED("Tracing", "CycloneDDS/Domain/Tracing"),
   MOVED("Internal|Unsupported", "CycloneDDS/Domain/Internal"),
+#if DDS_HAS_TCP
   MOVED("TCP", "CycloneDDS/Domain/TCP"),
+#endif
 #if DDS_HAS_SECURITY
   MOVED("DDSSecurity", "CycloneDDS/Domain/Security"),
 #endif

diff --git a/src/core/ddsi/src/ddsi__receive.h b/src/core/ddsi/src/ddsi__receive.h
@@ -57,7 +57,7 @@ int ddsi_user_dqueue_handler (const struct ddsi_rsample_info *sampleinfo, const
 int ddsi_add_gap (struct ddsi_xmsg *msg, struct ddsi_writer *wr, struct ddsi_proxy_reader *prd, ddsi_seqno_t start, ddsi_seqno_t base, uint32_t numbits, const uint32_t *bits);
 
 /** @component incoming_rtps */
-void ddsi_handle_rtps_message (struct ddsi_thread_state * const thrst, struct ddsi_domaingv *gv, struct ddsi_tran_conn * conn, const ddsi_guid_prefix_t *guidprefix, struct ddsi_rbufpool *rbpool, struct ddsi_rmsg *rmsg, size_t sz, unsigned char *msg, const struct ddsi_network_packet_info *pktinfo);
+void ddsi_handle_rtps_message (struct ddsi_thread_state * const thrst, struct ddsi_domaingv *gv, struct ddsi_tran_conn * conn, const ddsi_guid_prefix_t *guidprefix, struct ddsi_rbufpool *rbpool, struct ddsi_rmsg *rmsg, size_t sz, const struct ddsi_network_packet_info *pktinfo);
 
 #if defined (__cplusplus)
 }