From f6e6fdaa051e8d34f74bc88c77a96bd23d9993ac Mon Sep 17 00:00:00 2001 From: Scott Powell Date: Sun, 17 May 2026 22:10:13 +1000 Subject: [PATCH 1/4] * support for sending 5-byte ACKs --- src/Mesh.cpp | 19 +++++------- src/Mesh.h | 6 ++-- src/helpers/BaseChatMesh.cpp | 18 ++++++----- src/helpers/BaseChatMesh.h | 2 +- src/helpers/SimpleMeshTables.h | 55 +++++----------------------------- 5 files changed, 31 insertions(+), 69 deletions(-) diff --git a/src/Mesh.cpp b/src/Mesh.cpp index 57fee14036..7252974a92 100644 --- a/src/Mesh.cpp +++ b/src/Mesh.cpp @@ -361,13 +361,10 @@ DispatcherAction Mesh::forwardMultipartDirect(Packet* pkt) { void Mesh::routeDirectRecvAcks(Packet* packet, uint32_t delay_millis) { if (!packet->isMarkedDoNotRetransmit()) { - uint32_t crc; - memcpy(&crc, packet->payload, 4); - uint8_t extra = getExtraAckTransmitCount(); while (extra > 0) { delay_millis += getDirectRetransmitDelay(packet) + 300; - auto a1 = createMultiAck(crc, extra); + auto a1 = createMultiAck(packet->payload, packet->payload_len, extra); if (a1) { a1->path_len = Packet::copyPath(a1->path, packet->path, packet->path_len); a1->header &= ~PH_ROUTE_MASK; @@ -377,7 +374,7 @@ void Mesh::routeDirectRecvAcks(Packet* packet, uint32_t delay_millis) { extra--; } - auto a2 = createAck(crc); + auto a2 = createAck(packet->payload, packet->payload_len); if (a2) { a2->path_len = Packet::copyPath(a2->path, packet->path, packet->path_len); a2->header &= ~PH_ROUTE_MASK; @@ -543,7 +540,7 @@ Packet* Mesh::createGroupDatagram(uint8_t type, const GroupChannel& channel, con return packet; } -Packet* Mesh::createAck(uint32_t ack_crc) { +Packet* Mesh::createAck(const uint8_t* ack, uint8_t len) { Packet* packet = obtainNewPacket(); if (packet == NULL) { MESH_DEBUG_PRINTLN("%s Mesh::createAck(): error, packet pool empty", getLogDateTime()); @@ -551,13 +548,13 @@ Packet* Mesh::createAck(uint32_t ack_crc) { } packet->header = (PAYLOAD_TYPE_ACK << PH_TYPE_SHIFT); // ROUTE_TYPE_* set later - memcpy(packet->payload, &ack_crc, 4); - packet->payload_len = 4; + memcpy(packet->payload, ack, len); + packet->payload_len = len; return packet; } -Packet* Mesh::createMultiAck(uint32_t ack_crc, uint8_t remaining) { +Packet* Mesh::createMultiAck(const uint8_t* ack, uint8_t len, uint8_t remaining) { Packet* packet = obtainNewPacket(); if (packet == NULL) { MESH_DEBUG_PRINTLN("%s Mesh::createMultiAck(): error, packet pool empty", getLogDateTime()); @@ -566,8 +563,8 @@ Packet* Mesh::createMultiAck(uint32_t ack_crc, uint8_t remaining) { packet->header = (PAYLOAD_TYPE_MULTIPART << PH_TYPE_SHIFT); // ROUTE_TYPE_* set later packet->payload[0] = (remaining << 4) | PAYLOAD_TYPE_ACK; - memcpy(&packet->payload[1], &ack_crc, 4); - packet->payload_len = 5; + memcpy(&packet->payload[1], ack, len); + packet->payload_len = 1 + len; return packet; } diff --git a/src/Mesh.h b/src/Mesh.h index f9f8786320..d53d6d25fa 100644 --- a/src/Mesh.h +++ b/src/Mesh.h @@ -185,8 +185,10 @@ class Mesh : public Dispatcher { Packet* createDatagram(uint8_t type, const Identity& dest, const uint8_t* secret, const uint8_t* data, size_t len); Packet* createAnonDatagram(uint8_t type, const LocalIdentity& sender, const Identity& dest, const uint8_t* secret, const uint8_t* data, size_t data_len); Packet* createGroupDatagram(uint8_t type, const GroupChannel& channel, const uint8_t* data, size_t data_len); - Packet* createAck(uint32_t ack_crc); - Packet* createMultiAck(uint32_t ack_crc, uint8_t remaining); + Packet* createAck(const uint8_t* ack, uint8_t len); + Packet* createAck(uint32_t ack_crc) { return createAck((uint8_t *) &ack_crc, 4); } + Packet* createMultiAck(const uint8_t* ack, uint8_t len, uint8_t remaining); + Packet* createMultiAck(uint32_t ack_crc, uint8_t remaining) { return createMultiAck((uint8_t *)&ack_crc, 4, remaining); } Packet* createPathReturn(const uint8_t* dest_hash, const uint8_t* secret, const uint8_t* path, uint8_t path_len, uint8_t extra_type, const uint8_t*extra, size_t extra_len); Packet* createPathReturn(const Identity& dest, const uint8_t* secret, const uint8_t* path, uint8_t path_len, uint8_t extra_type, const uint8_t*extra, size_t extra_len); Packet* createRawData(const uint8_t* data, size_t len); diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp index 7ddc461d29..5cfa0a0425 100644 --- a/src/helpers/BaseChatMesh.cpp +++ b/src/helpers/BaseChatMesh.cpp @@ -38,9 +38,9 @@ mesh::Packet* BaseChatMesh::createSelfAdvert(const char* name, double lat, doubl return createAdvert(self_id, app_data, app_data_len); } -void BaseChatMesh::sendAckTo(const ContactInfo& dest, uint32_t ack_hash) { +void BaseChatMesh::sendAckTo(const ContactInfo& dest, const uint8_t* ack_hash, uint8_t ack_len) { if (dest.out_path_len == OUT_PATH_UNKNOWN) { - mesh::Packet* ack = createAck(ack_hash); + mesh::Packet* ack = createAck(ack_hash, ack_len); if (ack) sendFloodScoped(dest, ack, TXT_ACK_DELAY); } else { uint32_t d = TXT_ACK_DELAY; @@ -50,7 +50,7 @@ void BaseChatMesh::sendAckTo(const ContactInfo& dest, uint32_t ack_hash) { d += 300; } - mesh::Packet* a2 = createAck(ack_hash); + mesh::Packet* a2 = createAck(ack_hash, ack_len); if (a2) sendDirect(a2, dest.out_path, dest.out_path_len, d); } } @@ -218,16 +218,18 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender from.lastmod = getRTCClock()->getCurrentTime(); // update last heard time onMessageRecv(from, packet, timestamp, (const char *) &data[5]); // let UI know - uint32_t ack_hash; // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it - mesh::Utils::sha256((uint8_t *) &ack_hash, 4, data, 5 + strlen((char *)&data[5]), from.id.pub_key, PUB_KEY_SIZE); + uint8_t ack_hash[5]; // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it + mesh::Utils::sha256(ack_hash, 4, data, 5 + strlen((char *)&data[5]), from.id.pub_key, PUB_KEY_SIZE); + // NEW: append (potential) extended attempt byte (to make packethash unique) + ack_hash[4] = data[len - 1]; if (packet->isRouteFlood()) { // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the ACK mesh::Packet* path = createPathReturn(from.id, secret, packet->path, packet->path_len, - PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 4); + PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 5); if (path) sendFloodScoped(from, path, TXT_ACK_DELAY); } else { - sendAckTo(from, ack_hash); + sendAckTo(from, ack_hash, 5); } } else if (flags == TXT_TYPE_CLI_DATA) { onCommandDataRecv(from, packet, timestamp, (const char *) &data[5]); // let UI know @@ -254,7 +256,7 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 4); if (path) sendFloodScoped(from, path, TXT_ACK_DELAY); } else { - sendAckTo(from, ack_hash); + sendAckTo(from, (uint8_t *) &ack_hash); } } else { MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported message type: %u", (uint32_t) flags); diff --git a/src/helpers/BaseChatMesh.h b/src/helpers/BaseChatMesh.h index b39e736388..88af3c7ad5 100644 --- a/src/helpers/BaseChatMesh.h +++ b/src/helpers/BaseChatMesh.h @@ -72,7 +72,7 @@ class BaseChatMesh : public mesh::Mesh { ConnectionInfo connections[MAX_CONNECTIONS]; mesh::Packet* composeMsgPacket(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char *text, uint32_t& expected_ack); - void sendAckTo(const ContactInfo& dest, uint32_t ack_hash); + void sendAckTo(const ContactInfo& dest, const uint8_t* ack_hash, uint8_t ack_len=4); protected: BaseChatMesh(mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::PacketManager& mgr, mesh::MeshTables& tables) diff --git a/src/helpers/SimpleMeshTables.h b/src/helpers/SimpleMeshTables.h index 2f8af52af1..0b79cfb422 100644 --- a/src/helpers/SimpleMeshTables.h +++ b/src/helpers/SimpleMeshTables.h @@ -6,22 +6,17 @@ #include #endif -#define MAX_PACKET_HASHES 128 -#define MAX_PACKET_ACKS 64 +#define MAX_PACKET_HASHES (128+32) class SimpleMeshTables : public mesh::MeshTables { uint8_t _hashes[MAX_PACKET_HASHES*MAX_HASH_SIZE]; int _next_idx; - uint32_t _acks[MAX_PACKET_ACKS]; - int _next_ack_idx; uint32_t _direct_dups, _flood_dups; public: SimpleMeshTables() { memset(_hashes, 0, sizeof(_hashes)); _next_idx = 0; - memset(_acks, 0, sizeof(_acks)); - _next_ack_idx = 0; _direct_dups = _flood_dups = 0; } @@ -29,37 +24,14 @@ class SimpleMeshTables : public mesh::MeshTables { void restoreFrom(File f) { f.read(_hashes, sizeof(_hashes)); f.read((uint8_t *) &_next_idx, sizeof(_next_idx)); - f.read((uint8_t *) &_acks[0], sizeof(_acks)); - f.read((uint8_t *) &_next_ack_idx, sizeof(_next_ack_idx)); } void saveTo(File f) { f.write(_hashes, sizeof(_hashes)); f.write((const uint8_t *) &_next_idx, sizeof(_next_idx)); - f.write((const uint8_t *) &_acks[0], sizeof(_acks)); - f.write((const uint8_t *) &_next_ack_idx, sizeof(_next_ack_idx)); } #endif bool hasSeen(const mesh::Packet* packet) override { - if (packet->getPayloadType() == PAYLOAD_TYPE_ACK) { - uint32_t ack; - memcpy(&ack, packet->payload, 4); - for (int i = 0; i < MAX_PACKET_ACKS; i++) { - if (ack == _acks[i]) { - if (packet->isRouteDirect()) { - _direct_dups++; // keep some stats - } else { - _flood_dups++; - } - return true; - } - } - - _acks[_next_ack_idx] = ack; - _next_ack_idx = (_next_ack_idx + 1) % MAX_PACKET_ACKS; // cyclic table - return false; - } - uint8_t hash[MAX_HASH_SIZE]; packet->calculatePacketHash(hash); @@ -81,25 +53,14 @@ class SimpleMeshTables : public mesh::MeshTables { } void clear(const mesh::Packet* packet) override { - if (packet->getPayloadType() == PAYLOAD_TYPE_ACK) { - uint32_t ack; - memcpy(&ack, packet->payload, 4); - for (int i = 0; i < MAX_PACKET_ACKS; i++) { - if (ack == _acks[i]) { - _acks[i] = 0; - break; - } - } - } else { - uint8_t hash[MAX_HASH_SIZE]; - packet->calculatePacketHash(hash); + uint8_t hash[MAX_HASH_SIZE]; + packet->calculatePacketHash(hash); - uint8_t* sp = _hashes; - for (int i = 0; i < MAX_PACKET_HASHES; i++, sp += MAX_HASH_SIZE) { - if (memcmp(hash, sp, MAX_HASH_SIZE) == 0) { - memset(sp, 0, MAX_HASH_SIZE); - break; - } + uint8_t* sp = _hashes; + for (int i = 0; i < MAX_PACKET_HASHES; i++, sp += MAX_HASH_SIZE) { + if (memcmp(hash, sp, MAX_HASH_SIZE) == 0) { + memset(sp, 0, MAX_HASH_SIZE); + break; } } } From 2eb747d504f29cdc050e185bddec9824789e162a Mon Sep 17 00:00:00 2001 From: Scott Powell Date: Sun, 17 May 2026 22:38:42 +1000 Subject: [PATCH 2/4] * fix --- src/helpers/BaseChatMesh.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp index 5cfa0a0425..789f904100 100644 --- a/src/helpers/BaseChatMesh.cpp +++ b/src/helpers/BaseChatMesh.cpp @@ -45,7 +45,7 @@ void BaseChatMesh::sendAckTo(const ContactInfo& dest, const uint8_t* ack_hash, u } else { uint32_t d = TXT_ACK_DELAY; if (getExtraAckTransmitCount() > 0) { - mesh::Packet* a1 = createMultiAck(ack_hash, 1); + mesh::Packet* a1 = createMultiAck(ack_hash, ack_len, 1); if (a1) sendDirect(a1, dest.out_path, dest.out_path_len, d); d += 300; } From 717142abd69be48c8c0b4ae4dd6f7f8aec7a4a7a Mon Sep 17 00:00:00 2001 From: Scott Powell Date: Tue, 19 May 2026 17:06:42 +1000 Subject: [PATCH 3/4] * bug fix --- src/helpers/BaseChatMesh.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp index 789f904100..7b6b23944d 100644 --- a/src/helpers/BaseChatMesh.cpp +++ b/src/helpers/BaseChatMesh.cpp @@ -218,10 +218,11 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender from.lastmod = getRTCClock()->getCurrentTime(); // update last heard time onMessageRecv(from, packet, timestamp, (const char *) &data[5]); // let UI know + int text_len = strlen((char *)&data[5]); uint8_t ack_hash[5]; // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it - mesh::Utils::sha256(ack_hash, 4, data, 5 + strlen((char *)&data[5]), from.id.pub_key, PUB_KEY_SIZE); + mesh::Utils::sha256(ack_hash, 4, data, 5 + text_len, from.id.pub_key, PUB_KEY_SIZE); // NEW: append (potential) extended attempt byte (to make packethash unique) - ack_hash[4] = data[len - 1]; + ack_hash[4] = data[5 + text_len + 1]; if (packet->isRouteFlood()) { // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the ACK From a130a95a0db05a43b2d93797eb15ec4e4bbe6816 Mon Sep 17 00:00:00 2001 From: Scott Powell Date: Thu, 21 May 2026 00:00:03 +1000 Subject: [PATCH 4/4] * added 6th byte to ACK, with RNG --- src/helpers/BaseChatMesh.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp index 7b6b23944d..e2b116b456 100644 --- a/src/helpers/BaseChatMesh.cpp +++ b/src/helpers/BaseChatMesh.cpp @@ -219,18 +219,19 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender onMessageRecv(from, packet, timestamp, (const char *) &data[5]); // let UI know int text_len = strlen((char *)&data[5]); - uint8_t ack_hash[5]; // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it + uint8_t ack_hash[6]; // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it mesh::Utils::sha256(ack_hash, 4, data, 5 + text_len, from.id.pub_key, PUB_KEY_SIZE); // NEW: append (potential) extended attempt byte (to make packethash unique) ack_hash[4] = data[5 + text_len + 1]; + getRNG()->random(&ack_hash[5], 1); // make 6th byte random if (packet->isRouteFlood()) { // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the ACK mesh::Packet* path = createPathReturn(from.id, secret, packet->path, packet->path_len, - PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 5); + PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 6); if (path) sendFloodScoped(from, path, TXT_ACK_DELAY); } else { - sendAckTo(from, ack_hash, 5); + sendAckTo(from, ack_hash, 6); } } else if (flags == TXT_TYPE_CLI_DATA) { onCommandDataRecv(from, packet, timestamp, (const char *) &data[5]); // let UI know