module-avb: introducing unsolicited notification reply

src/modules/meson.build

@@ -740,6 +740,7 @@ if build_module_avb
       'module-avb/aecp-aem-cmds-resps/cmd-available.c',
       'module-avb/aecp-aem-cmds-resps/cmd-register-unsolicited-notifications.c',
       'module-avb/aecp-aem-cmds-resps/cmd-deregister-unsolicited-notifications.c',
+      'module-avb/aecp-aem-cmds-resps/reply-unsol-helpers.c',
       'module-avb/es-builder.c',
       'module-avb/avdecc.c',
       'module-avb/maap.c',

src/modules/module-avb/aecp-aem-cmds-resps/reply-unsol-helpers.c

@@ -0,0 +1,153 @@
+/* AVB support */
+/* SPDX-FileCopyrightText: Copyright © 2025 Kebag-Logic */
+/* SPDX-FileCopyrightText: Copyright © 2025 Alex Malki <alexandre.malki@kebag-logic.com> */
+/* SPDX-License-Identifier: MIT  */
+
+#include "../aecp-aem.h"
+#include "../aecp-aem-state.h"
+#include "../internal.h"
+
+#include "reply-unsol-helpers.h"
+
+#include <pipewire/log.h>
+
+#define AECP_UNSOL_BUFFER_SIZE 		(128U)
+#define AECP_AEM_MIN_PACKET_LENGTH 	(64U)
+
+static int reply_unsol_get_specific_info(struct aecp *aecp, struct descriptor *desc,
+	struct aecp_aem_unsol_notification_state **unsol_state, size_t *count)
+{
+	enum avb_mode mode = aecp->server->avb_mode;
+
+	switch (mode) {
+	case AVB_MODE_LEGACY:
+		pw_log_error("Not implemented\n");
+	break;
+	case AVB_MODE_MILAN_V12:
+		struct aecp_aem_entity_milan_state *entity_state;
+
+		entity_state = desc->ptr;
+		*unsol_state = entity_state->unsol_notif_state;
+		*count = AECP_AEM_MILAN_MAX_CONTROLLER;
+
+	return 0;
+	default:
+		pw_log_error("Invalid avb_mode %d\n", mode);
+	break;
+	}
+
+	return -1;
+}
+
+static int reply_unsol_send(struct aecp *aecp, uint64_t controller_id,
+		void *packet, size_t len, bool internal)
+{
+	size_t ctrler_index;
+	int rc = 0;
+	struct avb_ethernet_header *h;
+	struct avb_packet_aecp_aem *p;
+	struct aecp_aem_unsol_notification_state *unsol_state;
+	struct descriptor *desc;
+	size_t max_ctrler;
+
+	desc = server_find_descriptor(aecp->server, AVB_AEM_DESC_ENTITY, 0);
+	if (desc == NULL) {
+		pw_log_error("Could not find the ENTITY descriptor 0");
+		return -EINVAL;
+	}
+
+	rc = reply_unsol_get_specific_info(aecp, desc, &unsol_state, &max_ctrler);
+	if (rc) {
+		return -EINVAL;
+	}
+
+	h = (struct avb_ethernet_header*) packet;
+	p = SPA_PTROFF(h, sizeof(*h), void);
+
+	/* Loop through all the unsol entities. */
+	for (ctrler_index = 0; ctrler_index < max_ctrler; ctrler_index++)
+	{
+		if (!unsol_state[ctrler_index].is_registered) {
+			pw_log_debug("Not registered %zu", ctrler_index);
+			continue;
+		}
+
+		if ((controller_id == unsol_state[ctrler_index].ctrler_entity_id)
+			&& !internal) {
+			/* Do not send unsolicited if that the one triggering
+			 changes this is not a timeout. */
+			pw_log_debug("Do not send twice of %"PRIx64" %"PRIx64, 
+				controller_id,
+				unsol_state[ctrler_index].ctrler_entity_id);
+			continue;
+		}
+
+		p->aecp.controller_guid = 
+			htobe64(unsol_state[ctrler_index].ctrler_entity_id);
+
+		p->aecp.sequence_id = htons(unsol_state[ctrler_index].next_seq_id);
+
+		unsol_state[ctrler_index].next_seq_id++;
+		rc = avb_server_send_packet(aecp->server,
+				unsol_state[ctrler_index].ctrler_mac_addr,
+				AVB_TSN_ETH, packet, len);
+
+		if (rc) {
+			pw_log_error("while sending packet to %"PRIx64,
+				unsol_state[ctrler_index].ctrler_entity_id);
+			return rc;
+		}
+	}
+
+	return rc;
+}
+
+static void reply_unsol_notifications_prepare(struct aecp *aecp,
+		uint8_t *buf, void *packet, size_t len)
+{
+	struct avb_ethernet_header *h;
+	struct avb_packet_aecp_aem *p;
+	size_t ctrl_data_length;
+
+	/* Here the value of 12 is the delta between the target_entity_id and
+	   start of the AECP message specific data. */
+	ctrl_data_length = len - (sizeof(*h) + sizeof(*p)) + 
+		AVB_PACKET_CONTROL_DATA_OFFSET;
+
+	h = (struct avb_ethernet_header*) packet;
+	p = SPA_PTROFF(h, sizeof(*h), void);
+
+	p->aecp.hdr.subtype = AVB_SUBTYPE_AECP;
+	AVB_PACKET_AECP_SET_MESSAGE_TYPE(&p->aecp, AVB_AECP_MESSAGE_TYPE_AEM_RESPONSE);
+	AVB_PACKET_SET_VERSION(&p->aecp.hdr, 0);
+	AVB_PACKET_AECP_SET_STATUS(&p->aecp, AVB_AECP_AEM_STATUS_SUCCESS);
+	AVB_PACKET_SET_LENGTH(&p->aecp.hdr, ctrl_data_length);
+	p->u = 1;
+	p->aecp.target_guid = htobe64(aecp->server->entity_id);
+}
+
+/**
+ * @brief Sends unsolicited notifications. Does not sends information unless to
+ *  the controller id unless an internal change has happenned (timeout, action
+ *  etc)
+ *
+ */
+int reply_unsolicited_notifications(struct aecp *aecp,
+	struct aecp_aem_base_info *b_state, void *packet, size_t len,
+	 bool internal)
+{
+	uint8_t buf[AECP_UNSOL_BUFFER_SIZE];
+
+	if (len < AECP_AEM_MIN_PACKET_LENGTH) {
+		memset(buf, 0, AECP_AEM_MIN_PACKET_LENGTH);
+		memcpy(buf, packet, len);
+		len = AECP_AEM_MIN_PACKET_LENGTH;
+		packet = buf;
+	}
+
+	/** Retrieve the entity descriptor */
+	reply_unsol_notifications_prepare(aecp, buf, packet, len);
+
+    return reply_unsol_send(aecp, b_state->controller_entity_id, packet, len,
+							 internal);
+}

src/modules/module-avb/aecp-aem-cmds-resps/reply-unsol-helpers.h

@@ -0,0 +1,23 @@
+/* AVB support */
+/* SPDX-FileCopyrightText: Copyright © 2025 Kebag-Logic */
+/* SPDX-FileCopyrightText: Copyright © 2025 Alex Malki <alexandre.malki@kebag-logic.com> */
+/* SPDX-License-Identifier: MIT  */
+
+#ifndef __AVB_REPLY_UNSOL_HELPER_H__
+#define __AVB_REPLY_UNSOL_HELPER_H__
+
+#include <stdint.h>
+#include <pipewire/log.h>
+
+/**
+ * @brief Sends unsolicited notifications. Does not sends information unless to
+ *  the controller id unless an internal change has happenned (timeout, action
+ *  etc)
+ * @see Milan V1.2 Section 5.4.2.21
+ * @see IEEE 1722.1-2021 7.5.2 ( Unsolicited Notifications )
+ */
+int reply_unsolicited_notifications(struct aecp *aecp,
+	struct aecp_aem_base_info *b_state, void *packet, size_t len,
+	bool internal);
+
+#endif // __AVB_REPLY_UNSOL_HELPER_H__