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Merged
DedeHai merged 1 commit into from
May 1, 2026
Merged

16_x less restrictive DDP header acceptance & bugfix #5554

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2 changes: 1 addition & 1 deletion wled00/data/common.js
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Original file line number Diff line number Diff line change
Expand Up @@ -200,7 +200,7 @@ function sendDDP(ws, start, len, colors) {
let pkt = new Uint8Array(11 + dLen); // DDP header is 10 bytes, plus 1 byte for WLED websocket protocol indicator
pkt[0] = 0x02; // DDP protocol indicator for WLED websocket. Note: below DDP protocol bytes are offset by 1
pkt[1] = 0x40; // flags: 0x40 = no push, 0x41 = push (i.e. render), note: this is DDP protocol byte 0
pkt[2] = 0x00; // reserved
pkt[2] = 0x00; // upper nibble is reserved, lower nibble is sequence number, if set to 0 no sequence checking is done (if enabled)
pkt[3] = 0x0B; // RGB, 8bit per channel
pkt[4] = 0x01; // destination id (not used but 0x01 is default output)
pkt[5] = (off >> 24) & 255; // DDP protocol 4-7 is offset
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48 changes: 33 additions & 15 deletions wled00/e131.cpp
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Expand Up @@ -5,7 +5,7 @@
#define MAX_CHANNELS_PER_UNIVERSE 512

// forward declarations
static void handleDDPPacket(e131_packet_t* p);
static void handleDDPPacket(e131_packet_t* p, size_t packetLen);
static void handleArtnetPollReply(IPAddress ipAddress);
static void prepareArtnetPollReply(ArtPollReply *reply);
static void sendArtnetPollReply(ArtPollReply *reply, IPAddress ipAddress, uint16_t portAddress);
Expand All @@ -17,20 +17,31 @@ static void sendArtnetPollReply(ArtPollReply *reply, IPAddress ipAddress, uint16

//DDP protocol support, called by handleE131Packet
//handles RGB data only
static void handleDDPPacket(e131_packet_t* p) {
static void handleDDPPacket(e131_packet_t* p, size_t packetLen) {
static bool ddpSeenPush = false; // have we seen a push yet?
int lastPushSeq = e131LastSequenceNumber[0];

if (packetLen < DDP_HEADER_LEN) return; // too short to safely read any DDP header fields

// reject unsupported color data types (only RGB and RGBW are supported)
uint8_t maskedType = p->dataType & 0x3F; // mask out custom and reserved flags, only type bits are relevant
if (maskedType != DDP_TYPE_RGB24 && maskedType != DDP_TYPE_RGBW32) return;
//uint8_t maskedType = p->dataType & 0x3F; // mask out custom and reserved flags, only type bits are relevant
//if (maskedType != DDP_TYPE_RGB24 && maskedType != DDP_TYPE_RGBW32) return;

// note: for maximum compatibility we do not reject unknonw or malformed data types but simply default to RGB24 and check there is enough data available in the packet to do so
// also we assume 8bit per channel and currently do not support other bit depths

// reject control, status and config packets (not implemented)
if (p->destination == DDP_ID_CONTROL || p->destination == DDP_ID_STATUS || p->destination == DDP_ID_CONFIG) return;

// reject query and response packets (not implemented)
if (p->flags & (DDP_FLAGS_QUERY | DDP_FLAGS_REPLY)) return;

// reject status and config packets (not implemented)
if (p->destination == DDP_ID_STATUS || p->destination == DDP_ID_CONFIG) return;
bool push = p->flags & DDP_FLAGS_PUSH; // push flag means "render now"
if (!push && (p->flags & DDP_FLAGS_STORAGE)) return; // reject "from storage" flag but still let the push flag pass if set along with it

//reject late packets belonging to previous frame (assuming 4 packets max. before push)
//reject late packets belonging to previous frame (assuming 4 packets max. before push, if more are used and packets are very late, they are still accepted)
if (e131SkipOutOfSequence && lastPushSeq) {
int sn = p->sequenceNum & 0xF;
int sn = p->sequenceNum & 0xF; // sequence number is 4 bits, 1-15, 0 means unused
if (sn) {
if (lastPushSeq > 5) {
if (sn > (lastPushSeq -5) && sn < lastPushSeq) return;
Expand All @@ -40,7 +51,8 @@ static void handleDDPPacket(e131_packet_t* p) {
}
}

unsigned ddpChannelsPerLed = ((p->dataType & 0b00111000)>>3 == 0b011) ? 4 : 3; // data type 0x1B (formerly 0x1A) is RGBW (type 3, 8 bit/channel)
unsigned ddpChannelsPerLed = 3; // default to RGB
if ((p->dataType & 0b00111000)>>3 == 0b011) ddpChannelsPerLed = 4; // RGBW data type (see DDP protocol definition)

uint32_t start = htonl(p->channelOffset) / ddpChannelsPerLed;
start += DMXAddress / ddpChannelsPerLed;
Expand All @@ -50,8 +62,14 @@ static void handleDDPPacket(e131_packet_t* p) {
unsigned c = 0;
if (p->flags & DDP_FLAGS_TIME) c = 4; //packet has timecode flag, we do not support it, but data starts 4 bytes later

// ensure the received packet is at least as long as the header claims
if (packetLen < DDP_HEADER_LEN + c + dataLen) {
DEBUG_PRINTLN(F("DDP packet incomplete"));
return;
}

unsigned numLeds = stop - start; // stop >= start is guaranteed
unsigned maxDataIndex = c + numLeds * ddpChannelsPerLed; // validate bounds before accessing data array
unsigned maxDataIndex = numLeds * ddpChannelsPerLed; // validate bounds before accessing data array
if (maxDataIndex > dataLen) {
DEBUG_PRINTLN(F("DDP packet data bounds exceeded, rejecting."));
return;
Expand All @@ -66,7 +84,6 @@ static void handleDDPPacket(e131_packet_t* p) {
}
}

bool push = p->flags & DDP_FLAGS_PUSH;
ddpSeenPush |= push;
if (!ddpSeenPush || push) { // if we've never seen a push, or this is one, render display
e131NewData = true;
Expand All @@ -76,14 +93,15 @@ static void handleDDPPacket(e131_packet_t* p) {
}

//E1.31 and Art-Net protocol support
void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol){
void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol, size_t packetLen){

int uni = 0, dmxChannels = 0;
uint8_t* e131_data = nullptr;
int seq = 0, mde = REALTIME_MODE_E131;

if (protocol == P_ARTNET)
{
if (packetLen < 10) return; // need at least art_opcode (offset 8, 2 bytes)
if (p->art_opcode == ARTNET_OPCODE_OPPOLL) {
handleArtnetPollReply(clientIP);
return;
Expand All @@ -96,9 +114,9 @@ void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol){
} else if (protocol == P_E131) {
// Ignore PREVIEW data (E1.31: 6.2.6)
if ((p->options & 0x80) != 0) return;
dmxChannels = htons(p->property_value_count) - 1;
dmxChannels = htons(p->property_value_count) - 1; // on malformed packets, this can become negative, checked below
// DMX level data is zero start code. Ignore everything else. (E1.11: 8.5)
if (dmxChannels == 0 || p->property_values[0] != 0) return;
if (dmxChannels <= 0 || p->property_values[0] != 0) return;
uni = htons(p->universe);
e131_data = p->property_values;
seq = p->sequence_number;
Expand All @@ -110,7 +128,7 @@ void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol){
}
} else { //DDP
realtimeIP = clientIP;
handleDDPPacket(p);
handleDDPPacket(p, packetLen);
return;
}

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2 changes: 1 addition & 1 deletion wled00/fcn_declare.h
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Expand Up @@ -100,7 +100,7 @@ void initDMXInput();
void handleDMXInput();

//e131.cpp
void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol);
void handleE131Packet(e131_packet_t* p, IPAddress clientIP, byte protocol, size_t packetLen);
void handleDMXData(uint16_t uni, uint16_t dmxChannels, uint8_t* e131_data, uint8_t mde, uint8_t previousUniverses);
// void handleArtnetPollReply(IPAddress ipAddress); // local function, only used in e131.cpp
// void prepareArtnetPollReply(ArtPollReply* reply); // local function, only used in e131.cpp
Expand Down
19 changes: 11 additions & 8 deletions wled00/src/dependencies/e131/ESPAsyncE131.cpp
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Expand Up @@ -21,10 +21,10 @@
#include "../network/Network.h"
#include <string.h>

// E1.17 ACN Packet Identifier
// E1.17 ACN Packet Identifier "ASC-E1.17"
const byte ESPAsyncE131::ACN_ID[12] = { 0x41, 0x53, 0x43, 0x2d, 0x45, 0x31, 0x2e, 0x31, 0x37, 0x00, 0x00, 0x00 };

// Art-Net Packet Identifier
// Art-Net Packet Identifier "Art-Net"
const byte ESPAsyncE131::ART_ID[8] = { 0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00 };

// Constructor
Expand Down Expand Up @@ -100,13 +100,16 @@ bool ESPAsyncE131::initMulticast(uint16_t port, uint16_t universe, uint8_t n) {
void ESPAsyncE131::parsePacket(AsyncUDPPacket _packet) {
bool error = false;
uint8_t protocol = P_E131;
const size_t pktLen = _packet.length();

e131_packet_t *sbuff = reinterpret_cast<e131_packet_t *>(_packet.data());

//E1.31 packet identifier ("ACS-E1.17")
if (memcmp(sbuff->acn_id, ESPAsyncE131::ACN_ID, sizeof(sbuff->acn_id)))
protocol = P_ARTNET;


// E1.31 packet identifier (ACN_ID = "ASC-E1.17"), need at least 16 bytes to safely read acn_id (offset 4, length 12).
if (pktLen >= 16) {
if (memcmp(sbuff->acn_id, ESPAsyncE131::ACN_ID, sizeof(sbuff->acn_id)))
protocol = P_ARTNET;
}

if (protocol == P_ARTNET) {
if (memcmp(sbuff->art_id, ESPAsyncE131::ART_ID, sizeof(sbuff->art_id)))
error = true; //not "Art-Net"
Expand All @@ -129,6 +132,6 @@ void ESPAsyncE131::parsePacket(AsyncUDPPacket _packet) {
}

if (!error) {
_callback(sbuff, _packet.remoteIP(), protocol);
_callback(sbuff, _packet.remoteIP(), protocol, pktLen);
}
}
19 changes: 12 additions & 7 deletions wled00/src/dependencies/e131/ESPAsyncE131.h
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Expand Up @@ -55,19 +55,24 @@ typedef struct ip_addr ip4_addr_t;
#define DDP_FLAGS_VER 0xc0 // version mask
#define DDP_FLAGS_VER1 0x40 // version=1
#define DDP_FLAGS_PUSH 0x01
#define DDP_FLAGS_QUERY 0x02
#define DDP_FLAGS_REPLY 0x04
#define DDP_FLAGS_STORAGE 0x08
#define DDP_FLAGS_QUERY 0x02 // unsupported - used by XLights for auto-discovery
#define DDP_FLAGS_REPLY 0x04 // unsupported - response packet from another display
#define DDP_FLAGS_STORAGE 0x08 // unsupported - show data from a storage unit instead of from packet data field. Data field defines storage unit (by name, number, URL or whatever mechanism wanted).
#define DDP_FLAGS_TIME 0x10

#define DDP_CHANNELS_PER_PACKET 1440 // 480 leds

#define DDP_TYPE_RGB24 0x0B // 00 001 011 (RGB , 8 bits per channel, 3 channels)
#define DDP_TYPE_RGBW32 0x1B // 00 011 011 (RGBW, 8 bits per channel, 4 channels)
#define DDP_TYPE_LEGACY 0x01 // 00 000 001 legacy RGB 8bit definition
#define DDP_TYPE_UNDEF 0x00 // type and bit depth undefined

#define DDP_ID_DISPLAY 1
#define DDP_ID_CONFIG 250
#define DDP_ID_STATUS 251
// DDP Source or Destination ID (header byte 3)
#define DDP_ID_DISPLAY 1 // default output device
#define DDP_ID_CONTROL 246 // JSON control (not implemented)
#define DDP_ID_CONFIG 250 // JSON config (not implemented)
#define DDP_ID_STATUS 251 // JSON status (not implemented)
#define DDP_ID_ALL 255 // all devices

#define ARTNET_OPCODE_OPDMX 0x5000
#define ARTNET_OPCODE_OPPOLL 0x2000
Expand Down Expand Up @@ -212,7 +217,7 @@ typedef union {
} ArtPollReply;

// new packet callback
typedef void (*e131_packet_callback_function) (e131_packet_t* p, IPAddress clientIP, byte protocol);
typedef void (*e131_packet_callback_function) (e131_packet_t* p, IPAddress clientIP, byte protocol, size_t packetLen);

class ESPAsyncE131 {
private:
Expand Down
1 change: 1 addition & 0 deletions wled00/udp.cpp
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Expand Up @@ -804,6 +804,7 @@ uint8_t realtimeBroadcast(uint8_t type, IPAddress client, uint16_t length, const

// write the header
/*0*/ddpUdp.write(flags);
// TODO: sequence number should be 1-15 as 0 means "unused", it has no bad consequences other than out of sequence packet may be accepted
/*1*/ddpUdp.write(sequenceNumber++ & 0x0F); // sequence may be unnecessary unless we are sending twice (as requested in Sync settings)
/*2*/ddpUdp.write(isRGBW ? DDP_TYPE_RGBW32 : DDP_TYPE_RGB24);
/*3*/ddpUdp.write(DDP_ID_DISPLAY);
Expand Down
12 changes: 3 additions & 9 deletions wled00/ws.cpp
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Expand Up @@ -87,19 +87,13 @@ void wsEvent(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventTyp
if (!data || len < offset+1) return; // catch invalid / single-byte payload
switch (data[0]) {
case BINARY_PROTOCOL_E131:
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_E131);
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_E131, len - offset);
break;
case BINARY_PROTOCOL_ARTNET:
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_ARTNET);
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_ARTNET, len - offset);
break;
case BINARY_PROTOCOL_DDP:
if (len < 10 + offset) return; // DDP header is 10 bytes (+1 protocol byte)
size_t ddpDataLen = (data[8+offset] << 8) | data[9+offset]; // data length in bytes from DDP header
uint8_t flags = data[0+offset];
if ((flags & DDP_FLAGS_TIME) ) ddpDataLen += 4; // timecode flag adds 4 bytes to data length
if (len < (10 + offset + ddpDataLen)) return; // not enough data, prevent out of bounds read
// could be a valid DDP packet, forward to handler
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_DDP);
handleE131Packet((e131_packet_t*)&data[offset], client->remoteIP(), P_DDP, len - offset);
}
}
} else {
Expand Down
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