Allow virtually unlimited BLE-MIDI SysEx messages

src/ba-transport.c

@@ -38,6 +38,7 @@
 #include "ba-rfcomm.h"
 #include "ba-transport-pcm.h"
 #include "ba-config.h"
+#include "ble-midi.h"
 #include "bluealsa-dbus.h"
 #include "bluez-iface.h"
 #include "bluez.h"
@@ -882,6 +883,7 @@ void ba_transport_unref(struct ba_transport *t) {
 	else if (t->profile & BA_TRANSPORT_PROFILE_MIDI) {
 		if (t->midi.seq_parser != NULL)
 			snd_midi_event_free(t->midi.seq_parser);
+		ble_midi_decode_free(&t->midi.ble_decoder);
 	}
 #endif
 

src/ble-midi.c

@@ -1,6 +1,6 @@
 /*
  * BlueALSA - ble-midi.c
- * Copyright (c) 2016-2024 Arkadiusz Bokowy
+ * Copyright (c) 2016-2025 Arkadiusz Bokowy
  *
  * This file is a part of bluez-alsa.
  *
@@ -63,13 +63,40 @@ static size_t ble_midi_message_len(uint8_t status) {
 	return 0;
 }
 
+/**
+ * Get SysEx buffer which can hold at least additional len bytes. */
+static uint8_t *ble_midi_get_sys_buffer(struct ble_midi_dec *bmd, size_t len) {
+
+	if (bmd->buffer_sys_len + len <= bmd->buffer_sys_size)
+		goto final;
+
+	uint8_t *tmp = bmd->buffer_sys;
+	size_t size = bmd->buffer_sys_size + MAX(len, 512);
+	if ((tmp = realloc(tmp, size * sizeof(*tmp))) == NULL) {
+		warn("Couldn't resize BLE-MIDI SysEx buffer: %s", strerror(errno));
+		goto final;
+	}
+
+	bmd->buffer_sys = tmp;
+	bmd->buffer_sys_size = size;
+
+final:
+	return bmd->buffer_sys;
+}
+
 /**
  * Initialize BLE-MIDI decoder. */
 void ble_midi_decode_init(struct ble_midi_dec *bmd) {
 	memset(bmd, 0, sizeof(*bmd));
 	gettimestamp(&bmd->ts0);
 }
 
+/**
+ * Free BLE-MIDI decoder resources. */
+void ble_midi_decode_free(struct ble_midi_dec *bmd) {
+	free(bmd->buffer_sys);
+}
+
 /**
  * Decode BLE-MIDI packet.
  *
@@ -99,8 +126,8 @@ int ble_midi_decode(struct ble_midi_dec *bmd, const uint8_t *data, size_t len) {
 	/* If the system exclusive message was not ended in the previous
 	 * packet we need to reconstruct fragmented message. */
 	if (bmd->status_sys) {
-		bm_buffer = bmd->buffer_sys;
-		bm_buffer_size = sizeof(bmd->buffer_sys);
+		bm_buffer = ble_midi_get_sys_buffer(bmd, len);
+		bm_buffer_size = bmd->buffer_sys_size;
 		bm_buffer_len = bmd->buffer_sys_len;
 		bm_status = 0xF0;
 	}
@@ -209,8 +236,8 @@ int ble_midi_decode(struct ble_midi_dec *bmd, const uint8_t *data, size_t len) {
 				/* System exclusive message needs to be stored in a dedicated buffer.
 				 * First of all, it can span multiple BLE-MIDI packets. Secondly, it
 				 * can be interleaved with MIDI real-time messages. */
-				bm_buffer = bmd->buffer_sys;
-				bm_buffer_size = sizeof(bmd->buffer_sys);
+				bm_buffer = ble_midi_get_sys_buffer(bmd, len);
+				bm_buffer_size = bmd->buffer_sys_size;
 				bm_buffer_len = bmd->buffer_sys_len;
 				bmd->status_sys = true;
 				break;

src/ble-midi.h

@@ -1,6 +1,6 @@
 /*
  * BlueALSA - ble-midi.h
- * Copyright (c) 2016-2024 Arkadiusz Bokowy
+ * Copyright (c) 2016-2025 Arkadiusz Bokowy
  *
  * This file is a part of bluez-alsa.
  *
@@ -33,7 +33,8 @@ struct ble_midi_dec {
 	uint8_t buffer_midi[8];
 	size_t buffer_midi_len;
 	/* storage for decoded system exclusive message */
-	uint8_t buffer_sys[256];
+	uint8_t *buffer_sys;
+	size_t buffer_sys_size;
 	size_t buffer_sys_len;
 
 	/* reconstructed timestamp value */
@@ -73,6 +74,7 @@ struct ble_midi_enc {
 };
 
 void ble_midi_decode_init(struct ble_midi_dec *bmd);
+void ble_midi_decode_free(struct ble_midi_dec *bmd);
 int ble_midi_decode(struct ble_midi_dec *bmd, const uint8_t *data, size_t len);
 
 void ble_midi_encode_init(struct ble_midi_enc *bme);

test/test-ba.c

@@ -49,6 +49,7 @@
 /* Keep persistent storage in the current directory. */
 #define TEST_BLUEALSA_STORAGE_DIR "storage-test-ba"
 
+void ble_midi_decode_free(struct ble_midi_dec *bmd) { (void)bmd; }
 int midi_transport_alsa_seq_create(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_alsa_seq_delete(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_start(struct ba_transport *t) { (void)t; return 0; }

test/test-ble-midi.c

@@ -1,6 +1,6 @@
 /*
  * test-ble-midi.c
- * Copyright (c) 2016-2024 Arkadiusz Bokowy
+ * Copyright (c) 2016-2025 Arkadiusz Bokowy
  *
  * This file is a part of bluez-alsa.
  *
@@ -185,6 +185,8 @@ CK_START_TEST(test_ble_midi_decode_single_system_exclusive) {
 	ck_assert_uint_eq(bmd.len, sizeof(midi));
 	ck_assert_mem_eq(bmd.buffer, midi, sizeof(midi));
 
+	ble_midi_decode_free(&bmd);
+
 } CK_END_TEST
 
 CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive) {
@@ -204,6 +206,8 @@ CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive) {
 	ck_assert_uint_eq(bmd.len, sizeof(midi));
 	ck_assert_mem_eq(bmd.buffer, midi, sizeof(midi));
 
+	ble_midi_decode_free(&bmd);
+
 } CK_END_TEST
 
 CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive_2) {
@@ -223,6 +227,8 @@ CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive_2) {
 	ck_assert_uint_eq(bmd.len, sizeof(midi));
 	ck_assert_mem_eq(bmd.buffer, midi, sizeof(midi));
 
+	ble_midi_decode_free(&bmd);
+
 } CK_END_TEST
 
 CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive_3) {
@@ -231,11 +237,12 @@ CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive_3) {
 	ble_midi_decode_init(&bmd);
 
 	const uint8_t data1[] = { 0x80, 0x81, 0xF0, 0x01, 0x02, 0x03 };
-	uint8_t data2[512] = { 0x80, 0x81, 0x77 };
-	memset(data2 + 3, 0x77, sizeof(data2) - 3);
+	uint8_t data2[2 + 512] = { 0x80, 0x81, /* ... */ };
+	memset(data2 + 2, 0x77, sizeof(data2) - 2);
 	const uint8_t data3[] = { 0x80, 0x81, 0xF7 };
-	uint8_t midi[sizeof(bmd.buffer_sys)] = { 0xF0, 0x01, 0x02, 0x03, 0x77 };
-	memset(midi + 5, 0x77, sizeof(midi) - 5);
+	uint8_t midi[1 + 3 + 512 + 1] = { 0xF0, 0x01, 0x02, 0x03, /* ... */ 0xF7 };
+	memset(midi + 4, 0x77, sizeof(midi) - 4);
+	midi[sizeof(midi) - 1] = 0xF7;
 
 	ck_assert_int_eq(ble_midi_decode(&bmd, data1, sizeof(data1)), 0);
 	ck_assert_int_eq(ble_midi_decode(&bmd, data2, sizeof(data2)), 0);
@@ -245,7 +252,8 @@ CK_START_TEST(test_ble_midi_decode_multiple_system_exclusive_3) {
 	ck_assert_uint_eq(timespec2ms(&bmd.ts), 1);
 	ck_assert_uint_eq(bmd.len, sizeof(midi));
 	ck_assert_mem_eq(bmd.buffer, midi, sizeof(midi));
-	ck_assert_uint_eq(errno, EMSGSIZE);
+
+	ble_midi_decode_free(&bmd);
 
 } CK_END_TEST
 
@@ -258,6 +266,8 @@ CK_START_TEST(test_ble_midi_decode_invalid_system_exclusive) {
 
 	ck_assert_int_eq(ble_midi_decode(&bmd, data, sizeof(data)), -1);
 
+	ble_midi_decode_free(&bmd);
+
 } CK_END_TEST
 
 CK_START_TEST(test_ble_midi_decode_single_running_status) {

test/test-io.c

@@ -148,6 +148,7 @@ bool bluez_a2dp_set_configuration(const char *current_dbus_sep_path,
 	return false; }
 int ofono_call_volume_update(struct ba_transport *t) {
 	debug("%s: %p", __func__, t); (void)t; return 0; }
+void ble_midi_decode_free(struct ble_midi_dec *bmd) { (void)bmd; }
 int midi_transport_alsa_seq_create(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_alsa_seq_delete(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_start(struct ba_transport *t) { (void)t; return 0; }

test/test-rfcomm.c

@@ -58,6 +58,7 @@ static void dbus_update_counters_wait(unsigned int *counter, unsigned int value)
 	pthread_mutex_unlock(&dbus_update_mtx);
 }
 
+void ble_midi_decode_free(struct ble_midi_dec *bmd) { (void)bmd; }
 int midi_transport_alsa_seq_create(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_alsa_seq_delete(struct ba_transport *t) { (void)t; return 0; }
 int midi_transport_start(struct ba_transport *t) { (void)t; return 0; }