* room refactor: extracted MyMesh class

examples/simple_room_server/MyMesh.cpp

@@ -0,0 +1,809 @@
+#include "MyMesh.h"
+
+#define REPLY_DELAY_MILLIS          1500
+#define PUSH_NOTIFY_DELAY_MILLIS    2000
+#define SYNC_PUSH_INTERVAL          1200
+
+#define PUSH_ACK_TIMEOUT_FLOOD      12000
+#define PUSH_TIMEOUT_BASE           4000
+#define PUSH_ACK_TIMEOUT_FACTOR     2000
+
+#define POST_SYNC_DELAY_SECS        6
+
+#define CLIENT_KEEP_ALIVE_SECS      0 // Now Disabled (was 128)
+
+#define REQ_TYPE_GET_STATUS         0x01 // same as _GET_STATS
+#define REQ_TYPE_KEEP_ALIVE         0x02
+#define REQ_TYPE_GET_TELEMETRY_DATA 0x03
+
+#define RESP_SERVER_LOGIN_OK        0 // response to ANON_REQ
+
+struct ServerStats {
+  uint16_t batt_milli_volts;
+  uint16_t curr_tx_queue_len;
+  int16_t noise_floor;
+  int16_t last_rssi;
+  uint32_t n_packets_recv;
+  uint32_t n_packets_sent;
+  uint32_t total_air_time_secs;
+  uint32_t total_up_time_secs;
+  uint32_t n_sent_flood, n_sent_direct;
+  uint32_t n_recv_flood, n_recv_direct;
+  uint16_t err_events; // was 'n_full_events'
+  int16_t last_snr;    // x 4
+  uint16_t n_direct_dups, n_flood_dups;
+  uint16_t n_posted, n_post_push;
+};
+
+ClientInfo *MyMesh::putClient(const mesh::Identity &id) {
+  for (int i = 0; i < num_clients; i++) {
+    if (id.matches(known_clients[i].id)) return &known_clients[i]; // already known
+  }
+  ClientInfo *newClient;
+  if (num_clients < MAX_CLIENTS) {
+    newClient = &known_clients[num_clients++];
+  } else { // table is currently full
+    // evict least active client
+    uint32_t oldest_timestamp = 0xFFFFFFFF;
+    newClient = &known_clients[0];
+    for (int i = 0; i < num_clients; i++) {
+      auto c = &known_clients[i];
+      if (c->last_activity < oldest_timestamp) {
+        oldest_timestamp = c->last_activity;
+        newClient = c;
+      }
+    }
+  }
+  newClient->id = id;
+  newClient->out_path_len = -1; // initially out_path is unknown
+  newClient->last_timestamp = 0;
+  return newClient;
+}
+
+void MyMesh::evict(ClientInfo *client) {
+  client->last_activity = 0; // this slot will now be re-used (will be oldest)
+  memset(client->id.pub_key, 0, sizeof(client->id.pub_key));
+  memset(client->secret, 0, sizeof(client->secret));
+  client->pending_ack = 0;
+}
+
+void MyMesh::addPost(ClientInfo *client, const char *postData) {
+  // TODO: suggested postData format: <title>/<descrption>
+  posts[next_post_idx].author = client->id; // add to cyclic queue
+  StrHelper::strncpy(posts[next_post_idx].text, postData, MAX_POST_TEXT_LEN);
+
+  posts[next_post_idx].post_timestamp = getRTCClock()->getCurrentTimeUnique();
+  next_post_idx = (next_post_idx + 1) % MAX_UNSYNCED_POSTS;
+
+  next_push = futureMillis(PUSH_NOTIFY_DELAY_MILLIS);
+  _num_posted++; // stats
+}
+
+void MyMesh::pushPostToClient(ClientInfo *client, PostInfo &post) {
+  int len = 0;
+  memcpy(&reply_data[len], &post.post_timestamp, 4);
+  len += 4; // this is a PAST timestamp... but should be accepted by client
+
+  uint8_t attempt;
+  getRNG()->random(&attempt, 1); // need this for re-tries, so packet hash (and ACK) will be different
+  reply_data[len++] = (TXT_TYPE_SIGNED_PLAIN << 2) | (attempt & 3); // 'signed' plain text
+
+  // encode prefix of post.author.pub_key
+  memcpy(&reply_data[len], post.author.pub_key, 4);
+  len += 4; // just first 4 bytes
+
+  int text_len = strlen(post.text);
+  memcpy(&reply_data[len], post.text, text_len);
+  len += text_len;
+
+  // calc expected ACK reply
+  mesh::Utils::sha256((uint8_t *)&client->pending_ack, 4, reply_data, len, client->id.pub_key, PUB_KEY_SIZE);
+  client->push_post_timestamp = post.post_timestamp;
+
+  auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, client->secret, reply_data, len);
+  if (reply) {
+    if (client->out_path_len < 0) {
+      sendFlood(reply);
+      client->ack_timeout = futureMillis(PUSH_ACK_TIMEOUT_FLOOD);
+    } else {
+      sendDirect(reply, client->out_path, client->out_path_len);
+      client->ack_timeout =
+          futureMillis(PUSH_TIMEOUT_BASE + PUSH_ACK_TIMEOUT_FACTOR * (client->out_path_len + 1));
+    }
+    _num_post_pushes++; // stats
+  } else {
+    client->pending_ack = 0;
+    MESH_DEBUG_PRINTLN("Unable to push post to client");
+  }
+}
+
+uint8_t MyMesh::getUnsyncedCount(ClientInfo *client) {
+  uint8_t count = 0;
+  for (int k = 0; k < MAX_UNSYNCED_POSTS; k++) {
+    if (posts[k].post_timestamp > client->sync_since // is new post for this Client?
+        && !posts[k].author.matches(client->id)) {   // don't push posts to the author
+      count++;
+    }
+  }
+  return count;
+}
+
+bool MyMesh::processAck(const uint8_t *data) {
+  for (int i = 0; i < num_clients; i++) {
+    auto client = &known_clients[i];
+    if (client->pending_ack && memcmp(data, &client->pending_ack, 4) == 0) { // got an ACK from Client!
+      client->pending_ack = 0; // clear this, so next push can happen
+      client->push_failures = 0;
+      client->sync_since = client->push_post_timestamp; // advance Client's SINCE timestamp, to sync next post
+      return true;
+    }
+  }
+  return false;
+}
+
+mesh::Packet *MyMesh::createSelfAdvert() {
+  uint8_t app_data[MAX_ADVERT_DATA_SIZE];
+  uint8_t app_data_len;
+  {
+    AdvertDataBuilder builder(ADV_TYPE_ROOM, _prefs.node_name, _prefs.node_lat, _prefs.node_lon);
+    app_data_len = builder.encodeTo(app_data);
+  }
+
+  return createAdvert(self_id, app_data, app_data_len);
+}
+
+File MyMesh::openAppend(const char *fname) {
+#if defined(NRF52_PLATFORM)
+  return _fs->open(fname, FILE_O_WRITE);
+#elif defined(RP2040_PLATFORM)
+  return _fs->open(fname, "a");
+#else
+  return _fs->open(fname, "a", true);
+#endif
+}
+
+int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t *payload,
+                          size_t payload_len) {
+  // uint32_t now = getRTCClock()->getCurrentTimeUnique();
+  // memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
+  memcpy(reply_data, &sender_timestamp, 4); // reflect sender_timestamp back in response packet (kind of like a 'tag')
+
+  switch (payload[0]) {
+  case REQ_TYPE_GET_STATUS: {
+    ServerStats stats;
+    stats.batt_milli_volts = board.getBattMilliVolts();
+    stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
+    stats.noise_floor = (int16_t)_radio->getNoiseFloor();
+    stats.last_rssi = (int16_t)radio_driver.getLastRSSI();
+    stats.n_packets_recv = radio_driver.getPacketsRecv();
+    stats.n_packets_sent = radio_driver.getPacketsSent();
+    stats.total_air_time_secs = getTotalAirTime() / 1000;
+    stats.total_up_time_secs = _ms->getMillis() / 1000;
+    stats.n_sent_flood = getNumSentFlood();
+    stats.n_sent_direct = getNumSentDirect();
+    stats.n_recv_flood = getNumRecvFlood();
+    stats.n_recv_direct = getNumRecvDirect();
+    stats.err_events = _err_flags;
+    stats.last_snr = (int16_t)(radio_driver.getLastSNR() * 4);
+    stats.n_direct_dups = ((SimpleMeshTables *)getTables())->getNumDirectDups();
+    stats.n_flood_dups = ((SimpleMeshTables *)getTables())->getNumFloodDups();
+    stats.n_posted = _num_posted;
+    stats.n_post_push = _num_post_pushes;
+
+    memcpy(&reply_data[4], &stats, sizeof(stats));
+    return 4 + sizeof(stats);
+  }
+
+  case REQ_TYPE_GET_TELEMETRY_DATA: {
+    uint8_t perm_mask = ~(payload[1]); // NEW: first reserved byte (of 4), is now inverse mask to apply to permissions
+
+    telemetry.reset();
+    telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
+    // query other sensors -- target specific
+    sensors.querySensors((sender->permission == RoomPermission::ADMIN ? 0xFF : 0x00) & perm_mask, telemetry);
+
+    uint8_t tlen = telemetry.getSize();
+    memcpy(&reply_data[4], telemetry.getBuffer(), tlen);
+    return 4 + tlen; // reply_len
+  }
+  }
+  return 0; // unknown command
+}
+
+void MyMesh::logRxRaw(float snr, float rssi, const uint8_t raw[], int len) {
+#if MESH_PACKET_LOGGING
+  Serial.print(getLogDateTime());
+  Serial.print(" RAW: ");
+  mesh::Utils::printHex(Serial, raw, len);
+  Serial.println();
+#endif
+}
+
+void MyMesh::logRx(mesh::Packet *pkt, int len, float score) {
+  if (_logging) {
+    File f = openAppend(PACKET_LOG_FILE);
+    if (f) {
+      f.print(getLogDateTime());
+      f.printf(": RX, len=%d (type=%d, route=%s, payload_len=%d) SNR=%d RSSI=%d score=%d", len,
+               pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len,
+               (int)_radio->getLastSNR(), (int)_radio->getLastRSSI(), (int)(score * 1000));
+
+      if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH || pkt->getPayloadType() == PAYLOAD_TYPE_REQ ||
+          pkt->getPayloadType() == PAYLOAD_TYPE_RESPONSE || pkt->getPayloadType() == PAYLOAD_TYPE_TXT_MSG) {
+        f.printf(" [%02X -> %02X]\n", (uint32_t)pkt->payload[1], (uint32_t)pkt->payload[0]);
+      } else {
+        f.printf("\n");
+      }
+      f.close();
+    }
+  }
+}
+void MyMesh::logTx(mesh::Packet *pkt, int len) {
+  if (_logging) {
+    File f = openAppend(PACKET_LOG_FILE);
+    if (f) {
+      f.print(getLogDateTime());
+      f.printf(": TX, len=%d (type=%d, route=%s, payload_len=%d)", len, pkt->getPayloadType(),
+               pkt->isRouteDirect() ? "D" : "F", pkt->payload_len);
+
+      if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH || pkt->getPayloadType() == PAYLOAD_TYPE_REQ ||
+          pkt->getPayloadType() == PAYLOAD_TYPE_RESPONSE || pkt->getPayloadType() == PAYLOAD_TYPE_TXT_MSG) {
+        f.printf(" [%02X -> %02X]\n", (uint32_t)pkt->payload[1], (uint32_t)pkt->payload[0]);
+      } else {
+        f.printf("\n");
+      }
+      f.close();
+    }
+  }
+}
+void MyMesh::logTxFail(mesh::Packet *pkt, int len) {
+  if (_logging) {
+    File f = openAppend(PACKET_LOG_FILE);
+    if (f) {
+      f.print(getLogDateTime());
+      f.printf(": TX FAIL!, len=%d (type=%d, route=%s, payload_len=%d)\n", len, pkt->getPayloadType(),
+               pkt->isRouteDirect() ? "D" : "F", pkt->payload_len);
+      f.close();
+    }
+  }
+}
+
+int MyMesh::calcRxDelay(float score, uint32_t air_time) const {
+  if (_prefs.rx_delay_base <= 0.0f) return 0;
+  return (int)((pow(_prefs.rx_delay_base, 0.85f - score) - 1.0) * air_time);
+}
+
+const char *MyMesh::getLogDateTime() {
+  static char tmp[32];
+  uint32_t now = getRTCClock()->getCurrentTime();
+  DateTime dt = DateTime(now);
+  sprintf(tmp, "%02d:%02d:%02d - %d/%d/%d U", dt.hour(), dt.minute(), dt.second(), dt.day(), dt.month(),
+          dt.year());
+  return tmp;
+}
+
+uint32_t MyMesh::getRetransmitDelay(const mesh::Packet *packet) {
+  uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.tx_delay_factor);
+  return getRNG()->nextInt(0, 6) * t;
+}
+uint32_t MyMesh::getDirectRetransmitDelay(const mesh::Packet *packet) {
+  uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
+  return getRNG()->nextInt(0, 6) * t;
+}
+
+bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
+  if (_prefs.disable_fwd) return false;
+  if (packet->isRouteFlood() && packet->path_len >= _prefs.flood_max) return false;
+  return true;
+}
+
+void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const mesh::Identity &sender,
+                            uint8_t *data, size_t len) {
+  if (packet->getPayloadType() == PAYLOAD_TYPE_ANON_REQ) { // received an initial request by a possible admin
+                                                           // client (unknown at this stage)
+    uint32_t sender_timestamp, sender_sync_since;
+    memcpy(&sender_timestamp, data, 4);
+    memcpy(&sender_sync_since, &data[4], 4); // sender's "sync messags SINCE x" timestamp
+
+    RoomPermission perm;
+    data[len] = 0;                                        // ensure null terminator
+    if (strcmp((char *)&data[8], _prefs.password) == 0) { // check for valid admin password
+      perm = RoomPermission::ADMIN;
+    } else {
+      if (strcmp((char *)&data[8], _prefs.guest_password) == 0) { // check the room/public password
+        perm = RoomPermission::GUEST;
+      } else if (_prefs.allow_read_only) {
+        perm = RoomPermission::READ_ONLY;
+      } else {
+        MESH_DEBUG_PRINTLN("Incorrect room password");
+        return; // no response. Client will timeout
+      }
+    }
+
+    auto client = putClient(sender); // add to known clients (if not already known)
+    if (sender_timestamp <= client->last_timestamp) {
+      MESH_DEBUG_PRINTLN("possible replay attack!");
+      return;
+    }
+
+    MESH_DEBUG_PRINTLN("Login success!");
+    client->permission = perm;
+    client->last_timestamp = sender_timestamp;
+    client->sync_since = sender_sync_since;
+    client->pending_ack = 0;
+    client->push_failures = 0;
+    memcpy(client->secret, secret, PUB_KEY_SIZE);
+
+    uint32_t now = getRTCClock()->getCurrentTime();
+    client->last_activity = now;
+
+    now = getRTCClock()->getCurrentTimeUnique();
+    memcpy(reply_data, &now, 4); // response packets always prefixed with timestamp
+    // TODO: maybe reply with count of messages waiting to be synced for THIS client?
+    reply_data[4] = RESP_SERVER_LOGIN_OK;
+    reply_data[5] = (CLIENT_KEEP_ALIVE_SECS >> 4); // NEW: recommended keep-alive interval (secs / 16)
+    reply_data[6] = (perm == RoomPermission::ADMIN ? 1 : (perm == RoomPermission::GUEST ? 0 : 2));
+    reply_data[7] = getUnsyncedCount(client); // NEW
+    memcpy(&reply_data[8], "OK", 2);          // REVISIT: not really needed
+
+    next_push = futureMillis(PUSH_NOTIFY_DELAY_MILLIS); // delay next push, give RESPONSE packet time to arrive first
+
+    if (packet->isRouteFlood()) {
+      // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
+      mesh::Packet *path = createPathReturn(sender, client->secret, packet->path, packet->path_len,
+                                            PAYLOAD_TYPE_RESPONSE, reply_data, 8 + 2);
+      if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
+    } else {
+      mesh::Packet *reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, client->secret, reply_data, 8 + 2);
+      if (reply) {
+        if (client->out_path_len >= 0) { // we have an out_path, so send DIRECT
+          sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
+        } else {
+          sendFlood(reply, SERVER_RESPONSE_DELAY);
+        }
+      }
+    }
+  }
+}
+
+int MyMesh::searchPeersByHash(const uint8_t *hash) {
+  int n = 0;
+  for (int i = 0; i < num_clients; i++) {
+    if (known_clients[i].id.isHashMatch(hash)) {
+      matching_peer_indexes[n++] = i; // store the INDEXES of matching contacts (for subsequent 'peer' methods)
+    }
+  }
+  return n;
+}
+
+void MyMesh::getPeerSharedSecret(uint8_t *dest_secret, int peer_idx) {
+  int i = matching_peer_indexes[peer_idx];
+  if (i >= 0 && i < num_clients) {
+    // lookup pre-calculated shared_secret
+    memcpy(dest_secret, known_clients[i].secret, PUB_KEY_SIZE);
+  } else {
+    MESH_DEBUG_PRINTLN("getPeerSharedSecret: Invalid peer idx: %d", i);
+  }
+}
+
+void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx, const uint8_t *secret,
+                            uint8_t *data, size_t len) {
+  int i = matching_peer_indexes[sender_idx];
+  if (i < 0 || i >= num_clients) { // get from our known_clients table (sender SHOULD already be known in this context)
+    MESH_DEBUG_PRINTLN("onPeerDataRecv: invalid peer idx: %d", i);
+    return;
+  }
+  auto client = &known_clients[i];
+  if (type == PAYLOAD_TYPE_TXT_MSG && len > 5) { // a CLI command or new Post
+    uint32_t sender_timestamp;
+    memcpy(&sender_timestamp, data, 4); // timestamp (by sender's RTC clock - which could be wrong)
+    uint flags = (data[4] >> 2);        // message attempt number, and other flags
+
+    if (!(flags == TXT_TYPE_PLAIN || flags == TXT_TYPE_CLI_DATA)) {
+      MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported command flags received: flags=%02x", (uint32_t)flags);
+    } else if (sender_timestamp >= client->last_timestamp) { // prevent replay attacks, but send Acks for retries
+      bool is_retry = (sender_timestamp == client->last_timestamp);
+      client->last_timestamp = sender_timestamp;
+
+      uint32_t now = getRTCClock()->getCurrentTimeUnique();
+      client->last_activity = now;
+      client->push_failures = 0; // reset so push can resume (if prev failed)
+
+      // len can be > original length, but 'text' will be padded with zeroes
+      data[len] = 0; // need to make a C string again, with null terminator
+
+      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]), client->id.pub_key,
+                          PUB_KEY_SIZE);
+
+      uint8_t temp[166];
+      bool send_ack;
+      if (flags == TXT_TYPE_CLI_DATA) {
+        if (client->permission == RoomPermission::ADMIN) {
+          if (is_retry) {
+            temp[5] = 0; // no reply
+          } else {
+            handleCommand(sender_timestamp, (char *)&data[5], (char *)&temp[5]);
+            temp[4] = (TXT_TYPE_CLI_DATA << 2); // attempt and flags,  (NOTE: legacy was: TXT_TYPE_PLAIN)
+          }
+          send_ack = false;
+        } else {
+          temp[5] = 0;      // no reply
+          send_ack = false; // and no ACK...  user shoudn't be sending these
+        }
+      } else { // TXT_TYPE_PLAIN
+        if (client->permission == RoomPermission::READ_ONLY) {
+          temp[5] = 0;      // no reply
+          send_ack = false; // no ACK
+        } else {
+          if (!is_retry) {
+            addPost(client, (const char *)&data[5]);
+          }
+          temp[5] = 0; // no reply (ACK is enough)
+          send_ack = true;
+        }
+      }
+
+      uint32_t delay_millis;
+      if (send_ack) {
+        if (client->out_path_len < 0) {
+          mesh::Packet *ack = createAck(ack_hash);
+          if (ack) sendFlood(ack, TXT_ACK_DELAY);
+          delay_millis = TXT_ACK_DELAY + REPLY_DELAY_MILLIS;
+        } else {
+          uint32_t d = TXT_ACK_DELAY;
+          if (getExtraAckTransmitCount() > 0) {
+            mesh::Packet *a1 = createMultiAck(ack_hash, 1);
+            if (a1) sendDirect(a1, client->out_path, client->out_path_len, d);
+            d += 300;
+          }
+
+          mesh::Packet *a2 = createAck(ack_hash);
+          if (a2) sendDirect(a2, client->out_path, client->out_path_len, d);
+          delay_millis = d + REPLY_DELAY_MILLIS;
+        }
+      } else {
+        delay_millis = 0;
+      }
+
+      int text_len = strlen((char *)&temp[5]);
+      if (text_len > 0) {
+        if (now == sender_timestamp) {
+          // WORKAROUND: the two timestamps need to be different, in the CLI view
+          now++;
+        }
+        memcpy(temp, &now, 4); // mostly an extra blob to help make packet_hash unique
+
+        // calc expected ACK reply
+        // mesh::Utils::sha256((uint8_t *)&expected_ack_crc, 4, temp, 5 + text_len, self_id.pub_key,
+        // PUB_KEY_SIZE);
+
+        auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, secret, temp, 5 + text_len);
+        if (reply) {
+          if (client->out_path_len < 0) {
+            sendFlood(reply, delay_millis + SERVER_RESPONSE_DELAY);
+          } else {
+            sendDirect(reply, client->out_path, client->out_path_len, delay_millis + SERVER_RESPONSE_DELAY);
+          }
+        }
+      }
+    } else {
+      MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
+    }
+  } else if (type == PAYLOAD_TYPE_REQ && len >= 5) {
+    uint32_t sender_timestamp;
+    memcpy(&sender_timestamp, data, 4); // timestamp (by sender's RTC clock - which could be wrong)
+    if (sender_timestamp < client->last_timestamp) { // prevent replay attacks
+      MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
+    } else {
+      client->last_timestamp = sender_timestamp;
+
+      uint32_t now = getRTCClock()->getCurrentTime();
+      client->last_activity = now; // <-- THIS will keep client connection alive
+      client->push_failures = 0;   // reset so push can resume (if prev failed)
+
+      if (data[4] == REQ_TYPE_KEEP_ALIVE && packet->isRouteDirect()) { // request type
+        uint32_t forceSince = 0;
+        if (len >= 9) {                     // optional - last post_timestamp client received
+          memcpy(&forceSince, &data[5], 4); // NOTE: this may be 0, if part of decrypted PADDING!
+        } else {
+          memcpy(&data[5], &forceSince, 4); // make sure there are zeroes in payload (for ack_hash calc below)
+        }
+        if (forceSince > 0) {
+          client->sync_since = forceSince; // force-update the 'sync since'
+        }
+
+        client->pending_ack = 0;
+
+        // TODO: Throttle KEEP_ALIVE requests!
+        // if client sends too quickly, evict()
+
+        // RULE: only send keep_alive response DIRECT!
+        if (client->out_path_len >= 0) {
+          uint32_t ack_hash; // calc ACK to prove to sender that we got request
+          mesh::Utils::sha256((uint8_t *)&ack_hash, 4, data, 9, client->id.pub_key, PUB_KEY_SIZE);
+
+          auto reply = createAck(ack_hash);
+          if (reply) {
+            reply->payload[reply->payload_len++] = getUnsyncedCount(client); // NEW: add unsynced counter to end of ACK packet
+            sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
+          }
+        }
+      } else {
+        int reply_len = handleRequest(client, sender_timestamp, &data[4], len - 4);
+        if (reply_len > 0) { // valid command
+          if (packet->isRouteFlood()) {
+            // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
+            mesh::Packet *path = createPathReturn(client->id, secret, packet->path, packet->path_len,
+                                                  PAYLOAD_TYPE_RESPONSE, reply_data, reply_len);
+            if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
+          } else {
+            mesh::Packet *reply = createDatagram(PAYLOAD_TYPE_RESPONSE, client->id, secret, reply_data, reply_len);
+            if (reply) {
+              if (client->out_path_len >= 0) { // we have an out_path, so send DIRECT
+                sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
+              } else {
+                sendFlood(reply, SERVER_RESPONSE_DELAY);
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+
+bool MyMesh::onPeerPathRecv(mesh::Packet *packet, int sender_idx, const uint8_t *secret, uint8_t *path,
+                            uint8_t path_len, uint8_t extra_type, uint8_t *extra, uint8_t extra_len) {
+  // TODO: prevent replay attacks
+  int i = matching_peer_indexes[sender_idx];
+
+  if (i >= 0 && i < num_clients) { // get from our known_clients table (sender SHOULD already be known in this context)
+    MESH_DEBUG_PRINTLN("PATH to client, path_len=%d", (uint32_t)path_len);
+    auto client = &known_clients[i];
+    memcpy(client->out_path, path, client->out_path_len = path_len); // store a copy of path, for sendDirect()
+  } else {
+    MESH_DEBUG_PRINTLN("onPeerPathRecv: invalid peer idx: %d", i);
+  }
+
+  if (extra_type == PAYLOAD_TYPE_ACK && extra_len >= 4) {
+    // also got an encoded ACK!
+    processAck(extra);
+  }
+
+  // NOTE: no reciprocal path send!!
+  return false;
+}
+
+void MyMesh::onAckRecv(mesh::Packet *packet, uint32_t ack_crc) {
+  if (processAck((uint8_t *)&ack_crc)) {
+    packet->markDoNotRetransmit(); // ACK was for this node, so don't retransmit
+  }
+}
+
+MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondClock &ms, mesh::RNG &rng,
+               mesh::RTCClock &rtc, mesh::MeshTables &tables)
+    : mesh::Mesh(radio, ms, rng, rtc, *new StaticPoolPacketManager(32), tables),
+      _cli(board, rtc, &_prefs, this), telemetry(MAX_PACKET_PAYLOAD - 4) {
+  next_local_advert = next_flood_advert = 0;
+  _logging = false;
+  set_radio_at = revert_radio_at = 0;
+
+  // defaults
+  memset(&_prefs, 0, sizeof(_prefs));
+  _prefs.airtime_factor = 1.0;   // one half
+  _prefs.rx_delay_base = 0.0f;   // off by default, was 10.0
+  _prefs.tx_delay_factor = 0.5f; // was 0.25f;
+  StrHelper::strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name));
+  _prefs.node_lat = ADVERT_LAT;
+  _prefs.node_lon = ADVERT_LON;
+  StrHelper::strncpy(_prefs.password, ADMIN_PASSWORD, sizeof(_prefs.password));
+  _prefs.freq = LORA_FREQ;
+  _prefs.sf = LORA_SF;
+  _prefs.bw = LORA_BW;
+  _prefs.cr = LORA_CR;
+  _prefs.tx_power_dbm = LORA_TX_POWER;
+  _prefs.disable_fwd = 1;
+  _prefs.advert_interval = 1;        // default to 2 minutes for NEW installs
+  _prefs.flood_advert_interval = 12; // 12 hours
+  _prefs.flood_max = 64;
+  _prefs.interference_threshold = 0; // disabled
+#ifdef ROOM_PASSWORD
+  StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
+#endif
+
+  num_clients = 0;
+  next_post_idx = 0;
+  next_client_idx = 0;
+  next_push = 0;
+  memset(posts, 0, sizeof(posts));
+  _num_posted = _num_post_pushes = 0;
+}
+
+void MyMesh::begin(FILESYSTEM *fs) {
+  mesh::Mesh::begin();
+  _fs = fs;
+  // load persisted prefs
+  _cli.loadPrefs(_fs);
+
+  radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
+  radio_set_tx_power(_prefs.tx_power_dbm);
+
+  updateAdvertTimer();
+  updateFloodAdvertTimer();
+}
+
+void MyMesh::applyTempRadioParams(float freq, float bw, uint8_t sf, uint8_t cr, int timeout_mins) {
+  set_radio_at = futureMillis(2000); // give CLI reply some time to be sent back, before applying temp radio params
+  pending_freq = freq;
+  pending_bw = bw;
+  pending_sf = sf;
+  pending_cr = cr;
+
+  revert_radio_at = futureMillis(2000 + timeout_mins * 60 * 1000); // schedule when to revert radio params
+}
+
+bool MyMesh::formatFileSystem() {
+#if defined(NRF52_PLATFORM)
+  return InternalFS.format();
+#elif defined(RP2040_PLATFORM)
+  return LittleFS.format();
+#elif defined(ESP32)
+  return SPIFFS.format();
+#else
+#error "need to implement file system erase"
+  return false;
+#endif
+}
+
+void MyMesh::sendSelfAdvertisement(int delay_millis) {
+  mesh::Packet *pkt = createSelfAdvert();
+  if (pkt) {
+    sendFlood(pkt, delay_millis);
+  } else {
+    MESH_DEBUG_PRINTLN("ERROR: unable to create advertisement packet!");
+  }
+}
+
+void MyMesh::updateAdvertTimer() {
+  if (_prefs.advert_interval > 0) { // schedule local advert timer
+    next_local_advert = futureMillis((uint32_t)_prefs.advert_interval * 2 * 60 * 1000);
+  } else {
+    next_local_advert = 0; // stop the timer
+  }
+}
+void MyMesh::updateFloodAdvertTimer() {
+  if (_prefs.flood_advert_interval > 0) { // schedule flood advert timer
+    next_flood_advert = futureMillis(((uint32_t)_prefs.flood_advert_interval) * 60 * 60 * 1000);
+  } else {
+    next_flood_advert = 0; // stop the timer
+  }
+}
+
+void MyMesh::dumpLogFile() {
+#if defined(RP2040_PLATFORM)
+  File f = _fs->open(PACKET_LOG_FILE, "r");
+#else
+  File f = _fs->open(PACKET_LOG_FILE);
+#endif
+  if (f) {
+    while (f.available()) {
+      int c = f.read();
+      if (c < 0) break;
+      Serial.print((char)c);
+    }
+    f.close();
+  }
+}
+
+void MyMesh::setTxPower(uint8_t power_dbm) {
+  radio_set_tx_power(power_dbm);
+}
+
+void MyMesh::saveIdentity(const mesh::LocalIdentity &new_id) {
+  self_id = new_id;
+#if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
+  IdentityStore store(*_fs, "");
+#elif defined(ESP32)
+  IdentityStore store(*_fs, "/identity");
+#elif defined(RP2040_PLATFORM)
+  IdentityStore store(*_fs, "/identity");
+#else
+#error "need to define saveIdentity()"
+#endif
+  store.save("_main", self_id);
+}
+
+void MyMesh::clearStats() {
+  radio_driver.resetStats();
+  resetStats();
+  ((SimpleMeshTables *)getTables())->resetStats();
+}
+
+void MyMesh::handleCommand(uint32_t sender_timestamp, char *command, char *reply) {
+  while (*command == ' ')
+    command++; // skip leading spaces
+
+  if (strlen(command) > 4 && command[2] == '|') { // optional prefix (for companion radio CLI)
+    memcpy(reply, command, 3);                    // reflect the prefix back
+    reply += 3;
+    command += 3;
+  }
+
+  _cli.handleCommand(sender_timestamp, command, reply); // common CLI commands
+}
+
+void MyMesh::loop() {
+  mesh::Mesh::loop();
+
+  if (millisHasNowPassed(next_push) && num_clients > 0) {
+    // check for ACK timeouts
+    for (int i = 0; i < num_clients; i++) {
+      auto c = &known_clients[i];
+      if (c->pending_ack && millisHasNowPassed(c->ack_timeout)) {
+        c->push_failures++;
+        c->pending_ack = 0; // reset  (TODO: keep prev expected_ack's in a list, incase they arrive LATER, after we retry)
+        MESH_DEBUG_PRINTLN("pending ACK timed out: push_failures: %d", (uint32_t)c->push_failures);
+      }
+    }
+    // check next Round-Robin client, and sync next new post
+    auto client = &known_clients[next_client_idx];
+    bool did_push = false;
+    if (client->pending_ack == 0 && client->last_activity != 0 &&
+        client->push_failures < 3) { // not already waiting for ACK, AND not evicted, AND retries not max
+      MESH_DEBUG_PRINTLN("loop - checking for client %02X", (uint32_t)client->id.pub_key[0]);
+      uint32_t now = getRTCClock()->getCurrentTime();
+      for (int k = 0, idx = next_post_idx; k < MAX_UNSYNCED_POSTS; k++) {
+        auto p = &posts[idx];
+        if (now >= p->post_timestamp + POST_SYNC_DELAY_SECS &&
+            p->post_timestamp > client->sync_since // is new post for this Client?
+            && !p->author.matches(client->id)) {   // don't push posts to the author
+          // push this post to Client, then wait for ACK
+          pushPostToClient(client, *p);
+          did_push = true;
+          MESH_DEBUG_PRINTLN("loop - pushed to client %02X: %s", (uint32_t)client->id.pub_key[0], p->text);
+          break;
+        }
+        idx = (idx + 1) % MAX_UNSYNCED_POSTS; // wrap to start of cyclic queue
+      }
+    } else {
+      MESH_DEBUG_PRINTLN("loop - skipping busy (or evicted) client %02X", (uint32_t)client->id.pub_key[0]);
+    }
+    next_client_idx = (next_client_idx + 1) % num_clients; // round robin polling for each client
+
+    if (did_push) {
+      next_push = futureMillis(SYNC_PUSH_INTERVAL);
+    } else {
+      // were no unsynced posts for curr client, so proccess next client much quicker! (in next loop())
+      next_push = futureMillis(SYNC_PUSH_INTERVAL / 8);
+    }
+  }
+
+  if (next_flood_advert && millisHasNowPassed(next_flood_advert)) {
+    mesh::Packet *pkt = createSelfAdvert();
+    if (pkt) sendFlood(pkt);
+
+    updateFloodAdvertTimer(); // schedule next flood advert
+    updateAdvertTimer();      // also schedule local advert (so they don't overlap)
+  } else if (next_local_advert && millisHasNowPassed(next_local_advert)) {
+    mesh::Packet *pkt = createSelfAdvert();
+    if (pkt) sendZeroHop(pkt);
+
+    updateAdvertTimer(); // schedule next local advert
+  }
+
+  if (set_radio_at && millisHasNowPassed(set_radio_at)) { // apply pending (temporary) radio params
+    set_radio_at = 0;                                     // clear timer
+    radio_set_params(pending_freq, pending_bw, pending_sf, pending_cr);
+    MESH_DEBUG_PRINTLN("Temp radio params");
+  }
+
+  if (revert_radio_at && millisHasNowPassed(revert_radio_at)) { // revert radio params to orig
+    revert_radio_at = 0;                                        // clear timer
+    radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
+    MESH_DEBUG_PRINTLN("Radio params restored");
+  }
+
+  // TODO: periodically check for OLD/inactive entries in known_clients[], and evict
+}

examples/simple_room_server/MyMesh.h

@@ -0,0 +1,220 @@
+#pragma once
+
+#include <Arduino.h>   // needed for PlatformIO
+#include <Mesh.h>
+
+#if defined(NRF52_PLATFORM)
+  #include <InternalFileSystem.h>
+#elif defined(RP2040_PLATFORM)
+  #include <LittleFS.h>
+#elif defined(ESP32)
+  #include <SPIFFS.h>
+#endif
+
+#include <helpers/ArduinoHelpers.h>
+#include <helpers/StaticPoolPacketManager.h>
+#include <helpers/SimpleMeshTables.h>
+#include <helpers/IdentityStore.h>
+#include <helpers/AdvertDataHelpers.h>
+#include <helpers/TxtDataHelpers.h>
+#include <helpers/CommonCLI.h>
+#include <RTClib.h>
+#include <target.h>
+
+/* ------------------------------ Config -------------------------------- */
+
+#ifndef FIRMWARE_BUILD_DATE
+  #define FIRMWARE_BUILD_DATE   "1 Sep 2025"
+#endif
+
+#ifndef FIRMWARE_VERSION
+  #define FIRMWARE_VERSION   "v1.8.1"
+#endif
+
+#ifndef LORA_FREQ
+  #define LORA_FREQ   915.0
+#endif
+#ifndef LORA_BW
+  #define LORA_BW     250
+#endif
+#ifndef LORA_SF
+  #define LORA_SF     10
+#endif
+#ifndef LORA_CR
+  #define LORA_CR      5
+#endif
+#ifndef LORA_TX_POWER
+  #define LORA_TX_POWER  20
+#endif
+
+#ifndef ADVERT_NAME
+  #define  ADVERT_NAME   "Test BBS"
+#endif
+#ifndef ADVERT_LAT
+  #define  ADVERT_LAT  0.0
+#endif
+#ifndef ADVERT_LON
+  #define  ADVERT_LON  0.0
+#endif
+
+#ifndef ADMIN_PASSWORD
+  #define  ADMIN_PASSWORD  "password"
+#endif
+
+#ifndef MAX_CLIENTS
+ #define MAX_CLIENTS           32
+#endif
+
+#ifndef MAX_UNSYNCED_POSTS
+  #define MAX_UNSYNCED_POSTS    32
+#endif
+
+#ifndef SERVER_RESPONSE_DELAY
+  #define SERVER_RESPONSE_DELAY   300
+#endif
+
+#ifndef TXT_ACK_DELAY
+  #define TXT_ACK_DELAY     200
+#endif
+
+#define FIRMWARE_ROLE "room_server"
+
+#define PACKET_LOG_FILE  "/packet_log"
+
+enum RoomPermission {
+  ADMIN,
+  GUEST,
+  READ_ONLY
+};
+
+struct ClientInfo {
+  mesh::Identity id;
+  uint32_t last_timestamp;  // by THEIR clock
+  uint32_t last_activity;   // by OUR clock
+  uint32_t sync_since;  // sync messages SINCE this timestamp (by OUR clock)
+  uint32_t pending_ack;
+  uint32_t push_post_timestamp;
+  unsigned long ack_timeout;
+  RoomPermission  permission;
+  uint8_t  push_failures;
+  uint8_t  secret[PUB_KEY_SIZE];
+  int      out_path_len;
+  uint8_t  out_path[MAX_PATH_SIZE];
+};
+
+#define MAX_POST_TEXT_LEN    (160-9)
+
+struct PostInfo {
+  mesh::Identity author;
+  uint32_t post_timestamp;   // by OUR clock
+  char text[MAX_POST_TEXT_LEN+1];
+};
+
+class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
+  FILESYSTEM* _fs;
+  unsigned long next_local_advert, next_flood_advert;
+  bool _logging;
+  NodePrefs _prefs;
+  CommonCLI _cli;
+  uint8_t reply_data[MAX_PACKET_PAYLOAD];
+  int num_clients;
+  ClientInfo known_clients[MAX_CLIENTS];
+  unsigned long next_push;
+  uint16_t _num_posted, _num_post_pushes;
+  int next_client_idx;  // for round-robin polling
+  int next_post_idx;
+  PostInfo posts[MAX_UNSYNCED_POSTS];   // cyclic queue
+  CayenneLPP telemetry;
+  unsigned long set_radio_at, revert_radio_at;
+  float pending_freq;
+  float pending_bw;
+  uint8_t pending_sf;
+  uint8_t pending_cr;
+  int  matching_peer_indexes[MAX_CLIENTS];
+
+  ClientInfo* putClient(const mesh::Identity& id);
+  void  evict(ClientInfo* client);
+  void addPost(ClientInfo* client, const char* postData);
+  void pushPostToClient(ClientInfo* client, PostInfo& post);
+  uint8_t getUnsyncedCount(ClientInfo* client);
+  bool processAck(const uint8_t *data);
+  mesh::Packet* createSelfAdvert();
+  File openAppend(const char* fname);
+  int handleRequest(ClientInfo* sender, uint32_t sender_timestamp, uint8_t* payload, size_t payload_len);
+
+protected:
+  float getAirtimeBudgetFactor() const override {
+    return _prefs.airtime_factor;
+  }
+
+  void logRxRaw(float snr, float rssi, const uint8_t raw[], int len) override;
+  void logRx(mesh::Packet* pkt, int len, float score) override;
+  void logTx(mesh::Packet* pkt, int len) override;
+  void logTxFail(mesh::Packet* pkt, int len) override;
+
+  int calcRxDelay(float score, uint32_t air_time) const override;
+  const char* getLogDateTime() override;
+  uint32_t getRetransmitDelay(const mesh::Packet* packet) override;
+  uint32_t getDirectRetransmitDelay(const mesh::Packet* packet) override;
+
+  int getInterferenceThreshold() const override {
+    return _prefs.interference_threshold;
+  }
+  int getAGCResetInterval() const override {
+    return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
+  }
+  uint8_t getExtraAckTransmitCount() const override {
+    return _prefs.multi_acks;
+  }
+
+  bool allowPacketForward(const mesh::Packet* packet) override;
+  void onAnonDataRecv(mesh::Packet* packet, const uint8_t* secret, const mesh::Identity& sender, uint8_t* data, size_t len) override;
+  int searchPeersByHash(const uint8_t* hash) override ;
+  void getPeerSharedSecret(uint8_t* dest_secret, int peer_idx) override;
+  void onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_idx, const uint8_t* secret, uint8_t* data, size_t len) override;
+  bool onPeerPathRecv(mesh::Packet* packet, int sender_idx, const uint8_t* secret, uint8_t* path, uint8_t path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) override;
+  void onAckRecv(mesh::Packet* packet, uint32_t ack_crc) override;
+
+public:
+  MyMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::MeshTables& tables);
+
+  void begin(FILESYSTEM* fs);
+
+  const char* getFirmwareVer() override { return FIRMWARE_VERSION; }
+  const char* getBuildDate() override { return FIRMWARE_BUILD_DATE; }
+  const char* getRole() override { return FIRMWARE_ROLE; }
+  const char* getNodeName() { return _prefs.node_name; }
+  NodePrefs* getNodePrefs() {
+    return &_prefs;
+  }
+
+  void savePrefs() override {
+    _cli.savePrefs(_fs);
+  }
+
+  void applyTempRadioParams(float freq, float bw, uint8_t sf, uint8_t cr, int timeout_mins) override;
+  bool formatFileSystem() override;
+  void sendSelfAdvertisement(int delay_millis) override;
+  void updateAdvertTimer() override;
+  void updateFloodAdvertTimer() override;
+
+  void setLoggingOn(bool enable) override { _logging = enable; }
+
+  void eraseLogFile() override {
+    _fs->remove(PACKET_LOG_FILE);
+  }
+
+  void dumpLogFile() override;
+  void setTxPower(uint8_t power_dbm) override;
+
+  void formatNeighborsReply(char *reply) override {
+    strcpy(reply, "not supported");
+  }
+
+  mesh::LocalIdentity& getSelfId() override { return self_id; }
+
+  void saveIdentity(const mesh::LocalIdentity& new_id) override;
+  void clearStats() override;
+  void handleCommand(uint32_t sender_timestamp, char* command, char* reply);
+  void loop();
+};

examples/simple_room_server/main.cpp

@@ -1,979 +1,13 @@
 #include <Arduino.h>   // needed for PlatformIO
 #include <Mesh.h>
 
-#if defined(NRF52_PLATFORM)
-  #include <InternalFileSystem.h>
-#elif defined(RP2040_PLATFORM)
-  #include <LittleFS.h>
-#elif defined(ESP32)
-  #include <SPIFFS.h>
-#endif
-
-#include <helpers/ArduinoHelpers.h>
-#include <helpers/StaticPoolPacketManager.h>
-#include <helpers/SimpleMeshTables.h>
-#include <helpers/IdentityStore.h>
-#include <helpers/AdvertDataHelpers.h>
-#include <helpers/TxtDataHelpers.h>
-#include <helpers/CommonCLI.h>
-#include <RTClib.h>
-#include <target.h>
-
-/* ------------------------------ Config -------------------------------- */
-
-#ifndef FIRMWARE_BUILD_DATE
-  #define FIRMWARE_BUILD_DATE   "1 Sep 2025"
-#endif
-
-#ifndef FIRMWARE_VERSION
-  #define FIRMWARE_VERSION   "v1.8.1"
-#endif
-
-#ifndef LORA_FREQ
-  #define LORA_FREQ   915.0
-#endif
-#ifndef LORA_BW
-  #define LORA_BW     250
-#endif
-#ifndef LORA_SF
-  #define LORA_SF     10
-#endif
-#ifndef LORA_CR
-  #define LORA_CR      5
-#endif
-#ifndef LORA_TX_POWER
-  #define LORA_TX_POWER  20
-#endif
-
-#ifndef ADVERT_NAME
-  #define  ADVERT_NAME   "Test BBS"
-#endif
-#ifndef ADVERT_LAT
-  #define  ADVERT_LAT  0.0
-#endif
-#ifndef ADVERT_LON
-  #define  ADVERT_LON  0.0
-#endif
-
-#ifndef ADMIN_PASSWORD
-  #define  ADMIN_PASSWORD  "password"
-#endif
-
-#ifndef MAX_CLIENTS
- #define MAX_CLIENTS           32
-#endif
-
-#ifndef MAX_UNSYNCED_POSTS
-  #define MAX_UNSYNCED_POSTS    32
-#endif
-
-#ifndef SERVER_RESPONSE_DELAY
-  #define SERVER_RESPONSE_DELAY   300
-#endif
-
-#ifndef TXT_ACK_DELAY
-  #define TXT_ACK_DELAY     200
-#endif
+#include "MyMesh.h"
 
 #ifdef DISPLAY_CLASS
   #include "UITask.h"
   static UITask ui_task(display);
 #endif
 
-#define FIRMWARE_ROLE "room_server"
-
-#define PACKET_LOG_FILE  "/packet_log"
-
-/* ------------------------------ Code -------------------------------- */
-
-enum RoomPermission {
-  ADMIN,
-  GUEST,
-  READ_ONLY
-};
-
-struct ClientInfo {
-  mesh::Identity id;
-  uint32_t last_timestamp;  // by THEIR clock
-  uint32_t last_activity;   // by OUR clock
-  uint32_t sync_since;  // sync messages SINCE this timestamp (by OUR clock)
-  uint32_t pending_ack;
-  uint32_t push_post_timestamp;
-  unsigned long ack_timeout;
-  RoomPermission  permission;
-  uint8_t  push_failures;
-  uint8_t  secret[PUB_KEY_SIZE];
-  int      out_path_len;
-  uint8_t  out_path[MAX_PATH_SIZE];
-};
-
-#define MAX_POST_TEXT_LEN    (160-9)
-
-struct PostInfo {
-  mesh::Identity author;
-  uint32_t post_timestamp;   // by OUR clock
-  char text[MAX_POST_TEXT_LEN+1];
-};
-
-#define REPLY_DELAY_MILLIS         1500
-#define PUSH_NOTIFY_DELAY_MILLIS   2000
-#define SYNC_PUSH_INTERVAL         1200
-
-#define PUSH_ACK_TIMEOUT_FLOOD    12000
-#define PUSH_TIMEOUT_BASE          4000
-#define PUSH_ACK_TIMEOUT_FACTOR    2000
-
-#define POST_SYNC_DELAY_SECS       6
-
-#define CLIENT_KEEP_ALIVE_SECS     0     // Now Disabled (was 128)
-
-#define REQ_TYPE_GET_STATUS          0x01   // same as _GET_STATS
-#define REQ_TYPE_KEEP_ALIVE          0x02
-#define REQ_TYPE_GET_TELEMETRY_DATA  0x03
-
-#define RESP_SERVER_LOGIN_OK      0   // response to ANON_REQ
-
-struct ServerStats {
-  uint16_t batt_milli_volts;
-  uint16_t curr_tx_queue_len;
-  int16_t  noise_floor;
-  int16_t  last_rssi;
-  uint32_t n_packets_recv;
-  uint32_t n_packets_sent;
-  uint32_t total_air_time_secs;
-  uint32_t total_up_time_secs;
-  uint32_t n_sent_flood, n_sent_direct;
-  uint32_t n_recv_flood, n_recv_direct;
-  uint16_t err_events;          // was 'n_full_events'
-  int16_t  last_snr;   // x 4
-  uint16_t n_direct_dups, n_flood_dups;
-  uint16_t n_posted, n_post_push;
-};
-
-class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
-  FILESYSTEM* _fs;
-  unsigned long next_local_advert, next_flood_advert;
-  bool _logging;
-  NodePrefs _prefs;
-  CommonCLI _cli;
-  uint8_t reply_data[MAX_PACKET_PAYLOAD];
-  int num_clients;
-  ClientInfo known_clients[MAX_CLIENTS];
-  unsigned long next_push;
-  uint16_t _num_posted, _num_post_pushes;
-  int next_client_idx;  // for round-robin polling
-  int next_post_idx;
-  PostInfo posts[MAX_UNSYNCED_POSTS];   // cyclic queue
-  CayenneLPP telemetry;
-  unsigned long set_radio_at, revert_radio_at;
-  float pending_freq;
-  float pending_bw;
-  uint8_t pending_sf;
-  uint8_t pending_cr;
-
-  ClientInfo* putClient(const mesh::Identity& id) {
-    for (int i = 0; i < num_clients; i++) {
-      if (id.matches(known_clients[i].id)) return &known_clients[i];  // already known
-    }
-    ClientInfo* newClient;
-    if (num_clients < MAX_CLIENTS) {
-      newClient = &known_clients[num_clients++];
-    } else {    // table is currently full
-      // evict least active client
-      uint32_t oldest_timestamp = 0xFFFFFFFF;
-      newClient = &known_clients[0];
-      for (int i = 0; i < num_clients; i++) {
-        auto c = &known_clients[i];
-        if (c->last_activity < oldest_timestamp) {
-          oldest_timestamp = c->last_activity;
-          newClient = c;
-        }
-      }
-    }
-    newClient->id = id;
-    newClient->out_path_len = -1;  // initially out_path is unknown
-    newClient->last_timestamp = 0;
-    return newClient;
-  }
-
-  void  evict(ClientInfo* client) {
-    client->last_activity = 0;  // this slot will now be re-used (will be oldest)
-    memset(client->id.pub_key, 0, sizeof(client->id.pub_key));
-    memset(client->secret, 0, sizeof(client->secret));
-    client->pending_ack = 0;
-  }
-
-  void addPost(ClientInfo* client, const char* postData) {
-    // TODO: suggested postData format: <title>/<descrption>
-    posts[next_post_idx].author = client->id;    // add to cyclic queue
-    StrHelper::strncpy(posts[next_post_idx].text, postData, MAX_POST_TEXT_LEN);
-
-    posts[next_post_idx].post_timestamp = getRTCClock()->getCurrentTimeUnique();
-    next_post_idx = (next_post_idx + 1) % MAX_UNSYNCED_POSTS;
-
-    next_push = futureMillis(PUSH_NOTIFY_DELAY_MILLIS);
-    _num_posted++;  // stats
-  }
-
-  void pushPostToClient(ClientInfo* client, PostInfo& post) {
-    int len = 0;
-    memcpy(&reply_data[len], &post.post_timestamp, 4); len += 4;   // this is a PAST timestamp... but should be accepted by client
-
-    uint8_t attempt;
-    getRNG()->random(&attempt, 1);   // need this for re-tries, so packet hash (and ACK) will be different
-    reply_data[len++] = (TXT_TYPE_SIGNED_PLAIN << 2) | (attempt & 3);  // 'signed' plain text
-
-    // encode prefix of post.author.pub_key
-    memcpy(&reply_data[len], post.author.pub_key, 4); len += 4;   // just first 4 bytes
-
-    int text_len = strlen(post.text);
-    memcpy(&reply_data[len], post.text, text_len); len += text_len;
-
-    // calc expected ACK reply
-    mesh::Utils::sha256((uint8_t *)&client->pending_ack, 4, reply_data, len, client->id.pub_key, PUB_KEY_SIZE);
-    client->push_post_timestamp = post.post_timestamp;
-
-    auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, client->secret, reply_data, len);
-    if (reply) {
-      if (client->out_path_len < 0) {
-        sendFlood(reply);
-        client->ack_timeout = futureMillis(PUSH_ACK_TIMEOUT_FLOOD);
-      } else {
-        sendDirect(reply, client->out_path, client->out_path_len);
-        client->ack_timeout = futureMillis(PUSH_TIMEOUT_BASE + PUSH_ACK_TIMEOUT_FACTOR * (client->out_path_len + 1));
-      }
-      _num_post_pushes++;  // stats
-    } else {
-      client->pending_ack = 0;
-      MESH_DEBUG_PRINTLN("Unable to push post to client");
-    }
-  }
-
-  uint8_t getUnsyncedCount(ClientInfo* client) {
-    uint8_t count = 0;
-    for (int k = 0; k < MAX_UNSYNCED_POSTS; k++) {
-      if (posts[k].post_timestamp > client->sync_since   // is new post for this Client?
-        && !posts[k].author.matches(client->id)) {    // don't push posts to the author
-        count++;
-      }
-    }
-    return count;
-  }
-
-  bool processAck(const uint8_t *data) {
-    for (int i = 0; i < num_clients; i++) {
-      auto client = &known_clients[i];
-      if (client->pending_ack && memcmp(data, &client->pending_ack, 4) == 0) {     // got an ACK from Client!
-        client->pending_ack = 0;    // clear this, so next push can happen
-        client->push_failures = 0;
-        client->sync_since = client->push_post_timestamp;   // advance Client's SINCE timestamp, to sync next post
-        return true;
-      }
-    }
-    return false;
-  }
-
-  mesh::Packet* createSelfAdvert() {
-    uint8_t app_data[MAX_ADVERT_DATA_SIZE];
-    uint8_t app_data_len;
-    {
-      AdvertDataBuilder builder(ADV_TYPE_ROOM, _prefs.node_name, _prefs.node_lat, _prefs.node_lon);
-      app_data_len = builder.encodeTo(app_data);
-    }
-
-   return createAdvert(self_id, app_data, app_data_len);
-  }
-
-  File openAppend(const char* fname) {
-    #if defined(NRF52_PLATFORM)
-      return _fs->open(fname, FILE_O_WRITE);
-    #elif defined(RP2040_PLATFORM)
-      return _fs->open(fname, "a");
-    #else
-      return _fs->open(fname, "a", true);
-    #endif
-    }
-
-  int handleRequest(ClientInfo* sender, uint32_t sender_timestamp, uint8_t* payload, size_t payload_len) {
-    // uint32_t now = getRTCClock()->getCurrentTimeUnique();
-    // memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
-    memcpy(reply_data, &sender_timestamp, 4);   // reflect sender_timestamp back in response packet (kind of like a 'tag')
-
-    switch (payload[0]) {
-      case REQ_TYPE_GET_STATUS: {
-        ServerStats stats;
-        stats.batt_milli_volts = board.getBattMilliVolts();
-        stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
-        stats.noise_floor = (int16_t)_radio->getNoiseFloor();
-        stats.last_rssi = (int16_t) radio_driver.getLastRSSI();
-        stats.n_packets_recv = radio_driver.getPacketsRecv();
-        stats.n_packets_sent = radio_driver.getPacketsSent();
-        stats.total_air_time_secs = getTotalAirTime() / 1000;
-        stats.total_up_time_secs = _ms->getMillis() / 1000;
-        stats.n_sent_flood = getNumSentFlood();
-        stats.n_sent_direct = getNumSentDirect();
-        stats.n_recv_flood = getNumRecvFlood();
-        stats.n_recv_direct = getNumRecvDirect();
-        stats.err_events = _err_flags;
-        stats.last_snr = (int16_t)(radio_driver.getLastSNR() * 4);
-        stats.n_direct_dups = ((SimpleMeshTables *)getTables())->getNumDirectDups();
-        stats.n_flood_dups = ((SimpleMeshTables *)getTables())->getNumFloodDups();
-        stats.n_posted = _num_posted;
-        stats.n_post_push = _num_post_pushes;
-
-        memcpy(&reply_data[4], &stats, sizeof(stats));
-        return 4 + sizeof(stats);
-      }
-
-      case REQ_TYPE_GET_TELEMETRY_DATA: {
-        uint8_t perm_mask = ~(payload[1]);    // NEW: first reserved byte (of 4), is now inverse mask to apply to permissions
-
-        telemetry.reset();
-        telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
-        // query other sensors -- target specific
-        sensors.querySensors((sender->permission == RoomPermission::ADMIN ? 0xFF : 0x00) & perm_mask, telemetry);
-
-        uint8_t tlen = telemetry.getSize();
-        memcpy(&reply_data[4], telemetry.getBuffer(), tlen);
-        return 4 + tlen;  // reply_len
-      }
-    }
-    return 0;  // unknown command
-  }
-
-protected:
-  float getAirtimeBudgetFactor() const override {
-    return _prefs.airtime_factor;
-  }
-
-  void logRxRaw(float snr, float rssi, const uint8_t raw[], int len) override {
-    #if MESH_PACKET_LOGGING
-      Serial.print(getLogDateTime());
-      Serial.print(" RAW: ");
-      mesh::Utils::printHex(Serial, raw, len);
-      Serial.println();
-    #endif
-  }
-
-  void logRx(mesh::Packet* pkt, int len, float score) override {
-    if (_logging) {
-      File f = openAppend(PACKET_LOG_FILE);
-      if (f) {
-        f.print(getLogDateTime());
-        f.printf(": RX, len=%d (type=%d, route=%s, payload_len=%d) SNR=%d RSSI=%d score=%d",
-          len, pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len,
-          (int)_radio->getLastSNR(), (int)_radio->getLastRSSI(), (int)(score*1000));
-
-        if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH || pkt->getPayloadType() == PAYLOAD_TYPE_REQ
-          || pkt->getPayloadType() == PAYLOAD_TYPE_RESPONSE || pkt->getPayloadType() == PAYLOAD_TYPE_TXT_MSG) {
-          f.printf(" [%02X -> %02X]\n", (uint32_t)pkt->payload[1], (uint32_t)pkt->payload[0]);
-        } else {
-          f.printf("\n");
-        }
-        f.close();
-      }
-    }
-  }
-  void logTx(mesh::Packet* pkt, int len) override {
-    if (_logging) {
-      File f = openAppend(PACKET_LOG_FILE);
-      if (f) {
-        f.print(getLogDateTime());
-        f.printf(": TX, len=%d (type=%d, route=%s, payload_len=%d)",
-          len, pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len);
-
-        if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH || pkt->getPayloadType() == PAYLOAD_TYPE_REQ
-          || pkt->getPayloadType() == PAYLOAD_TYPE_RESPONSE || pkt->getPayloadType() == PAYLOAD_TYPE_TXT_MSG) {
-          f.printf(" [%02X -> %02X]\n", (uint32_t)pkt->payload[1], (uint32_t)pkt->payload[0]);
-        } else {
-          f.printf("\n");
-        }
-        f.close();
-      }
-    }
-  }
-  void logTxFail(mesh::Packet* pkt, int len) override {
-    if (_logging) {
-      File f = openAppend(PACKET_LOG_FILE);
-      if (f) {
-        f.print(getLogDateTime());
-        f.printf(": TX FAIL!, len=%d (type=%d, route=%s, payload_len=%d)\n",
-          len, pkt->getPayloadType(), pkt->isRouteDirect() ? "D" : "F", pkt->payload_len);
-        f.close();
-      }
-    }
-  }
-
-  int calcRxDelay(float score, uint32_t air_time) const override {
-    if (_prefs.rx_delay_base <= 0.0f) return 0;
-    return (int) ((pow(_prefs.rx_delay_base, 0.85f - score) - 1.0) * air_time);
-  }
-
-  const char* getLogDateTime() override {
-    static char tmp[32];
-    uint32_t now = getRTCClock()->getCurrentTime();
-    DateTime dt = DateTime(now);
-    sprintf(tmp, "%02d:%02d:%02d - %d/%d/%d U", dt.hour(), dt.minute(), dt.second(), dt.day(), dt.month(), dt.year());
-    return tmp;
-  }
-
-  uint32_t getRetransmitDelay(const mesh::Packet* packet) override {
-    uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.tx_delay_factor);
-    return getRNG()->nextInt(0, 6)*t;
-  }
-  uint32_t getDirectRetransmitDelay(const mesh::Packet* packet) override {
-    uint32_t t = (_radio->getEstAirtimeFor(packet->path_len + packet->payload_len + 2) * _prefs.direct_tx_delay_factor);
-    return getRNG()->nextInt(0, 6)*t;
-  }
-  int getInterferenceThreshold() const override {
-    return _prefs.interference_threshold;
-  }
-  int getAGCResetInterval() const override {
-    return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
-  }
-  uint8_t getExtraAckTransmitCount() const override {
-    return _prefs.multi_acks;
-  }
-
-  bool allowPacketForward(const mesh::Packet* packet) override {
-    if (_prefs.disable_fwd) return false;
-    if (packet->isRouteFlood() && packet->path_len >= _prefs.flood_max) return false;
-    return true;
-  }
-
-  void onAnonDataRecv(mesh::Packet* packet, const uint8_t* secret, const mesh::Identity& sender, uint8_t* data, size_t len) override {
-    if (packet->getPayloadType() == PAYLOAD_TYPE_ANON_REQ) {  // received an initial request by a possible admin client (unknown at this stage)
-      uint32_t sender_timestamp, sender_sync_since;
-      memcpy(&sender_timestamp, data, 4);
-      memcpy(&sender_sync_since, &data[4], 4);  // sender's "sync messags SINCE x" timestamp
-
-      RoomPermission perm;
-      data[len] = 0;  // ensure null terminator
-      if (strcmp((char *) &data[8], _prefs.password) == 0) {  // check for valid admin password
-        perm = RoomPermission::ADMIN;
-      } else {
-        if (strcmp((char *) &data[8], _prefs.guest_password) == 0) {  // check the room/public password
-          perm = RoomPermission::GUEST;
-        } else if (_prefs.allow_read_only) {
-          perm = RoomPermission::READ_ONLY;
-        } else {
-          MESH_DEBUG_PRINTLN("Incorrect room password");
-          return;   // no response. Client will timeout
-        }
-      }
-
-      auto client = putClient(sender);  // add to known clients (if not already known)
-      if (sender_timestamp <= client->last_timestamp) {
-        MESH_DEBUG_PRINTLN("possible replay attack!");
-        return;
-      }
-
-      MESH_DEBUG_PRINTLN("Login success!");
-      client->permission = perm;
-      client->last_timestamp = sender_timestamp;
-      client->sync_since = sender_sync_since;
-      client->pending_ack = 0;
-      client->push_failures = 0;
-      memcpy(client->secret, secret, PUB_KEY_SIZE);
-
-      uint32_t now = getRTCClock()->getCurrentTime();
-      client->last_activity = now;
-
-      now = getRTCClock()->getCurrentTimeUnique();
-      memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
-      // TODO: maybe reply with count of messages waiting to be synced for THIS client?
-      reply_data[4] = RESP_SERVER_LOGIN_OK;
-      reply_data[5] = (CLIENT_KEEP_ALIVE_SECS >> 4);  // NEW: recommended keep-alive interval (secs / 16)
-      reply_data[6] = (perm == RoomPermission::ADMIN ? 1 : (perm == RoomPermission::GUEST ? 0 : 2));
-      reply_data[7] = getUnsyncedCount(client);  // NEW
-      memcpy(&reply_data[8], "OK", 2);  // REVISIT: not really needed
-
-      next_push = futureMillis(PUSH_NOTIFY_DELAY_MILLIS);  // delay next push, give RESPONSE packet time to arrive first
-
-      if (packet->isRouteFlood()) {
-        // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
-        mesh::Packet* path = createPathReturn(sender, client->secret, packet->path, packet->path_len,
-                                              PAYLOAD_TYPE_RESPONSE, reply_data, 8 + 2);
-        if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
-      } else {
-        mesh::Packet* reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, client->secret, reply_data, 8 + 2);
-        if (reply) {
-          if (client->out_path_len >= 0) {  // we have an out_path, so send DIRECT
-            sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
-          } else {
-            sendFlood(reply, SERVER_RESPONSE_DELAY);
-          }
-        }
-      }
-    }
-  }
-
-  int  matching_peer_indexes[MAX_CLIENTS];
-
-  int searchPeersByHash(const uint8_t* hash) override {
-    int n = 0;
-    for (int i = 0; i < num_clients; i++) {
-      if (known_clients[i].id.isHashMatch(hash)) {
-        matching_peer_indexes[n++] = i;  // store the INDEXES of matching contacts (for subsequent 'peer' methods)
-      }
-    }
-    return n;
-  }
-
-  void getPeerSharedSecret(uint8_t* dest_secret, int peer_idx) override {
-    int i = matching_peer_indexes[peer_idx];
-    if (i >= 0 && i < num_clients) {
-      // lookup pre-calculated shared_secret
-      memcpy(dest_secret, known_clients[i].secret, PUB_KEY_SIZE);
-    } else {
-      MESH_DEBUG_PRINTLN("getPeerSharedSecret: Invalid peer idx: %d", i);
-    }
-  }
-
-  void onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_idx, const uint8_t* secret, uint8_t* data, size_t len) override {
-    int i = matching_peer_indexes[sender_idx];
-    if (i < 0 || i >= num_clients) {  // get from our known_clients table (sender SHOULD already be known in this context)
-      MESH_DEBUG_PRINTLN("onPeerDataRecv: invalid peer idx: %d", i);
-      return;
-    }
-    auto client = &known_clients[i];
-    if (type == PAYLOAD_TYPE_TXT_MSG && len > 5) {   // a CLI command or new Post
-      uint32_t sender_timestamp;
-      memcpy(&sender_timestamp, data, 4);  // timestamp (by sender's RTC clock - which could be wrong)
-      uint flags = (data[4] >> 2);   // message attempt number, and other flags
-
-      if (!(flags == TXT_TYPE_PLAIN || flags == TXT_TYPE_CLI_DATA)) {
-        MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported command flags received: flags=%02x", (uint32_t)flags);
-      } else if (sender_timestamp >= client->last_timestamp) {  // prevent replay attacks, but send Acks for retries
-        bool is_retry = (sender_timestamp == client->last_timestamp);
-        client->last_timestamp = sender_timestamp;
-
-        uint32_t now = getRTCClock()->getCurrentTimeUnique();
-        client->last_activity = now;
-        client->push_failures = 0;  // reset so push can resume (if prev failed)
-
-        // len can be > original length, but 'text' will be padded with zeroes
-        data[len] = 0; // need to make a C string again, with null terminator
-
-        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]), client->id.pub_key, PUB_KEY_SIZE);
-
-        uint8_t temp[166];
-        bool send_ack;
-        if (flags == TXT_TYPE_CLI_DATA) {
-          if (client->permission == RoomPermission::ADMIN) {
-            if (is_retry) {
-              temp[5] = 0;  // no reply
-            } else {
-              handleCommand(sender_timestamp, (char *) &data[5], (char *) &temp[5]);
-              temp[4] = (TXT_TYPE_CLI_DATA << 2);  // attempt and flags,  (NOTE: legacy was: TXT_TYPE_PLAIN)
-            }
-            send_ack = false;
-          } else {
-            temp[5] = 0;  // no reply
-            send_ack = false;  // and no ACK...  user shoudn't be sending these
-          }
-        } else {   // TXT_TYPE_PLAIN
-          if (client->permission == RoomPermission::READ_ONLY) {
-            temp[5] = 0;  // no reply
-            send_ack = false;  // no ACK
-          } else {
-            if (!is_retry) {
-              addPost(client, (const char *) &data[5]);
-            }
-            temp[5] = 0;  // no reply (ACK is enough)
-            send_ack = true;
-          }
-        }
-
-        uint32_t delay_millis;
-        if (send_ack) {
-          if (client->out_path_len < 0) {
-            mesh::Packet* ack = createAck(ack_hash);
-            if (ack) sendFlood(ack, TXT_ACK_DELAY);
-            delay_millis = TXT_ACK_DELAY + REPLY_DELAY_MILLIS;
-          } else {
-            uint32_t d = TXT_ACK_DELAY;
-            if (getExtraAckTransmitCount() > 0) {
-              mesh::Packet* a1 = createMultiAck(ack_hash, 1);
-              if (a1) sendDirect(a1, client->out_path, client->out_path_len, d);
-              d += 300;
-            }
-
-            mesh::Packet* a2 = createAck(ack_hash);
-            if (a2) sendDirect(a2, client->out_path, client->out_path_len, d);
-            delay_millis = d + REPLY_DELAY_MILLIS;
-          }
-        } else {
-          delay_millis = 0;
-        }
-
-        int text_len = strlen((char *) &temp[5]);
-        if (text_len > 0) {
-          if (now == sender_timestamp) {
-            // WORKAROUND: the two timestamps need to be different, in the CLI view
-            now++;
-          }
-          memcpy(temp, &now, 4);   // mostly an extra blob to help make packet_hash unique
-
-          // calc expected ACK reply
-          //mesh::Utils::sha256((uint8_t *)&expected_ack_crc, 4, temp, 5 + text_len, self_id.pub_key, PUB_KEY_SIZE);
-
-          auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, secret, temp, 5 + text_len);
-          if (reply) {
-            if (client->out_path_len < 0) {
-              sendFlood(reply, delay_millis + SERVER_RESPONSE_DELAY);
-            } else {
-              sendDirect(reply, client->out_path, client->out_path_len, delay_millis + SERVER_RESPONSE_DELAY);
-            }
-          }
-        }
-      } else {
-        MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
-      }
-    } else if (type == PAYLOAD_TYPE_REQ && len >= 5) {
-      uint32_t sender_timestamp;
-      memcpy(&sender_timestamp, data, 4);  // timestamp (by sender's RTC clock - which could be wrong)
-      if (sender_timestamp < client->last_timestamp) {  // prevent replay attacks
-        MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
-      } else {
-        client->last_timestamp = sender_timestamp;
-
-        uint32_t now = getRTCClock()->getCurrentTime();
-        client->last_activity = now;   // <-- THIS will keep client connection alive
-        client->push_failures = 0;  // reset so push can resume (if prev failed)
-
-        if (data[4] == REQ_TYPE_KEEP_ALIVE && packet->isRouteDirect()) {   // request type
-          uint32_t forceSince = 0;
-          if (len >= 9) {   // optional - last post_timestamp client received
-            memcpy(&forceSince, &data[5], 4);    // NOTE: this may be 0, if part of decrypted PADDING!
-          } else {
-            memcpy(&data[5], &forceSince, 4);  // make sure there are zeroes in payload (for ack_hash calc below)
-          }
-          if (forceSince > 0) {
-            client->sync_since = forceSince;    // force-update the 'sync since'
-          }
-
-          client->pending_ack = 0;
-
-          // TODO: Throttle KEEP_ALIVE requests!
-          // if client sends too quickly, evict()
-
-          // RULE: only send keep_alive response DIRECT!
-          if (client->out_path_len >= 0) {
-            uint32_t ack_hash;    // calc ACK to prove to sender that we got request
-            mesh::Utils::sha256((uint8_t *) &ack_hash, 4, data, 9, client->id.pub_key, PUB_KEY_SIZE);
-
-            auto reply = createAck(ack_hash);
-            if (reply) {
-              reply->payload[reply->payload_len++] = getUnsyncedCount(client);  // NEW: add unsynced counter to end of ACK packet
-              sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
-            }
-          }
-        } else {
-          int reply_len = handleRequest(client, sender_timestamp, &data[4], len - 4);
-          if (reply_len > 0) {  // valid command
-            if (packet->isRouteFlood()) {
-              // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
-              mesh::Packet* path = createPathReturn(client->id, secret, packet->path, packet->path_len,
-                                                    PAYLOAD_TYPE_RESPONSE, reply_data, reply_len);
-              if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
-            } else {
-              mesh::Packet* reply = createDatagram(PAYLOAD_TYPE_RESPONSE, client->id, secret, reply_data, reply_len);
-              if (reply) {
-                if (client->out_path_len >= 0) {  // we have an out_path, so send DIRECT
-                  sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
-                } else {
-                  sendFlood(reply, SERVER_RESPONSE_DELAY);
-                }
-              }
-            }
-          }
-        }
-      }
-    }
-  }
-
-  bool onPeerPathRecv(mesh::Packet* packet, int sender_idx, const uint8_t* secret, uint8_t* path, uint8_t path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) override {
-    // TODO: prevent replay attacks
-    int i = matching_peer_indexes[sender_idx];
-
-    if (i >= 0 && i < num_clients) {  // get from our known_clients table (sender SHOULD already be known in this context)
-      MESH_DEBUG_PRINTLN("PATH to client, path_len=%d", (uint32_t) path_len);
-      auto client = &known_clients[i];
-      memcpy(client->out_path, path, client->out_path_len = path_len);  // store a copy of path, for sendDirect()
-    } else {
-      MESH_DEBUG_PRINTLN("onPeerPathRecv: invalid peer idx: %d", i);
-    }
-
-    if (extra_type == PAYLOAD_TYPE_ACK && extra_len >= 4) {
-      // also got an encoded ACK!
-      processAck(extra);
-    }
-
-    // NOTE: no reciprocal path send!!
-    return false;
-  }
-
-  void onAckRecv(mesh::Packet* packet, uint32_t ack_crc) override {
-    if (processAck((uint8_t *)&ack_crc)) {
-      packet->markDoNotRetransmit();   // ACK was for this node, so don't retransmit
-    }
-  }
-
-public:
-  MyMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::MeshTables& tables)
-     : mesh::Mesh(radio, ms, rng, rtc, *new StaticPoolPacketManager(32), tables),
-      _cli(board, rtc, &_prefs, this), telemetry(MAX_PACKET_PAYLOAD - 4)
-  {
-    next_local_advert = next_flood_advert = 0;
-    _logging = false;
-    set_radio_at = revert_radio_at = 0;
-
-    // defaults
-    memset(&_prefs, 0, sizeof(_prefs));
-    _prefs.airtime_factor = 1.0;    // one half
-    _prefs.rx_delay_base = 0.0f;   // off by default, was 10.0
-    _prefs.tx_delay_factor = 0.5f;   // was 0.25f;
-    StrHelper::strncpy(_prefs.node_name, ADVERT_NAME, sizeof(_prefs.node_name));
-    _prefs.node_lat = ADVERT_LAT;
-    _prefs.node_lon = ADVERT_LON;
-    StrHelper::strncpy(_prefs.password, ADMIN_PASSWORD, sizeof(_prefs.password));
-    _prefs.freq = LORA_FREQ;
-    _prefs.sf = LORA_SF;
-    _prefs.bw = LORA_BW;
-    _prefs.cr = LORA_CR;
-    _prefs.tx_power_dbm = LORA_TX_POWER;
-    _prefs.disable_fwd = 1;
-    _prefs.advert_interval = 1;  // default to 2 minutes for NEW installs
-    _prefs.flood_advert_interval = 12;   // 12 hours
-    _prefs.flood_max = 64;
-    _prefs.interference_threshold = 0;  // disabled
-  #ifdef ROOM_PASSWORD
-    StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
-  #endif
-
-    num_clients = 0;
-    next_post_idx = 0;
-    next_client_idx = 0;
-    next_push = 0;
-    memset(posts, 0, sizeof(posts));
-    _num_posted = _num_post_pushes = 0;
-  }
-
-  void begin(FILESYSTEM* fs) {
-    mesh::Mesh::begin();
-    _fs = fs;
-    // load persisted prefs
-    _cli.loadPrefs(_fs);
-
-    radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
-    radio_set_tx_power(_prefs.tx_power_dbm);
-
-    updateAdvertTimer();
-    updateFloodAdvertTimer();
-  }
-
-  const char* getFirmwareVer() override { return FIRMWARE_VERSION; }
-  const char* getBuildDate() override { return FIRMWARE_BUILD_DATE; }
-  const char* getRole() override { return FIRMWARE_ROLE; }
-  const char* getNodeName() { return _prefs.node_name; }
-  NodePrefs* getNodePrefs() {
-    return &_prefs;
-  }
-
-  void savePrefs() override {
-    _cli.savePrefs(_fs);
-  }
-
-  void applyTempRadioParams(float freq, float bw, uint8_t sf, uint8_t cr, int timeout_mins) override {
-    set_radio_at = futureMillis(2000);   // give CLI reply some time to be sent back, before applying temp radio params
-    pending_freq = freq;
-    pending_bw = bw;
-    pending_sf = sf;
-    pending_cr = cr;
-
-    revert_radio_at = futureMillis(2000 + timeout_mins*60*1000);   // schedule when to revert radio params
-  }
-
-  bool formatFileSystem() override {
-    #if defined(NRF52_PLATFORM)
-      return InternalFS.format();
-    #elif defined(RP2040_PLATFORM)
-      return LittleFS.format();
-    #elif defined(ESP32)
-      return SPIFFS.format();
-    #else
-      #error "need to implement file system erase"
-      return false;
-    #endif
-  }
-
-  void sendSelfAdvertisement(int delay_millis) override {
-    mesh::Packet* pkt = createSelfAdvert();
-    if (pkt) {
-      sendFlood(pkt, delay_millis);
-    } else {
-      MESH_DEBUG_PRINTLN("ERROR: unable to create advertisement packet!");
-    }
-  }
-
-  void updateAdvertTimer() override {
-    if (_prefs.advert_interval > 0) {  // schedule local advert timer
-      next_local_advert = futureMillis((uint32_t)_prefs.advert_interval * 2 * 60 * 1000);
-    } else {
-      next_local_advert = 0;  // stop the timer
-    }
-  }
-  void updateFloodAdvertTimer() override {
-    if (_prefs.flood_advert_interval > 0) {  // schedule flood advert timer
-      next_flood_advert = futureMillis( ((uint32_t)_prefs.flood_advert_interval) * 60 * 60 * 1000);
-    } else {
-      next_flood_advert = 0;  // stop the timer
-    }
-  }
-
-  void setLoggingOn(bool enable) override { _logging = enable; }
-
-  void eraseLogFile() override {
-    _fs->remove(PACKET_LOG_FILE);
-  }
-
-  void dumpLogFile() override {
-  #if defined(RP2040_PLATFORM)
-    File f = _fs->open(PACKET_LOG_FILE, "r");
-  #else
-    File f = _fs->open(PACKET_LOG_FILE);
-  #endif
-    if (f) {
-      while (f.available()) {
-        int c = f.read();
-        if (c < 0) break;
-        Serial.print((char)c);
-      }
-      f.close();
-    }
-  }
-
-  void setTxPower(uint8_t power_dbm) override {
-    radio_set_tx_power(power_dbm);
-  }
-
-  void formatNeighborsReply(char *reply) override {
-    strcpy(reply, "not supported");
-  }
-
-  mesh::LocalIdentity& getSelfId() override { return self_id; }
-
-  void saveIdentity(const mesh::LocalIdentity& new_id) override {
-    self_id = new_id;
-#if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
-    IdentityStore store(*_fs, "");
-#elif defined(ESP32)
-    IdentityStore store(*_fs, "/identity");
-#elif defined(RP2040_PLATFORM)
-    IdentityStore store(*_fs, "/identity");
-#else
-    #error "need to define saveIdentity()"
-#endif
-    store.save("_main", self_id);
-  }
-
-  void clearStats() override {
-    radio_driver.resetStats();
-    resetStats();
-    ((SimpleMeshTables *)getTables())->resetStats();
-  }
-
-  void handleCommand(uint32_t sender_timestamp, char* command, char* reply) {
-    while (*command == ' ') command++;   // skip leading spaces
-
-    if (strlen(command) > 4 && command[2] == '|') {  // optional prefix (for companion radio CLI)
-      memcpy(reply, command, 3);  // reflect the prefix back
-      reply += 3;
-      command += 3;
-    }
-
-    _cli.handleCommand(sender_timestamp, command, reply);  // common CLI commands
-  }
-
-  void loop() {
-    mesh::Mesh::loop();
-
-    if (millisHasNowPassed(next_push) && num_clients > 0) {
-      // check for ACK timeouts
-      for (int i = 0; i < num_clients; i++) {
-        auto c = &known_clients[i];
-        if (c->pending_ack && millisHasNowPassed(c->ack_timeout)) {
-          c->push_failures++;
-          c->pending_ack = 0;   // reset  (TODO: keep prev expected_ack's in a list, incase they arrive LATER, after we retry)
-          MESH_DEBUG_PRINTLN("pending ACK timed out: push_failures: %d", (uint32_t)c->push_failures);
-        }
-      }
-      // check next Round-Robin client, and sync next new post
-      auto client = &known_clients[next_client_idx];
-      bool did_push = false;
-      if (client->pending_ack == 0 && client->last_activity != 0 && client->push_failures < 3) {  // not already waiting for ACK, AND not evicted, AND retries not max
-        MESH_DEBUG_PRINTLN("loop - checking for client %02X", (uint32_t) client->id.pub_key[0]);
-        uint32_t now = getRTCClock()->getCurrentTime();
-        for (int k = 0, idx = next_post_idx; k < MAX_UNSYNCED_POSTS; k++) {
-          auto p = &posts[idx];
-          if (now >= p->post_timestamp + POST_SYNC_DELAY_SECS && p->post_timestamp > client->sync_since   // is new post for this Client?
-            && !p->author.matches(client->id)) {    // don't push posts to the author
-            // push this post to Client, then wait for ACK
-            pushPostToClient(client, *p);
-            did_push = true;
-            MESH_DEBUG_PRINTLN("loop - pushed to client %02X: %s", (uint32_t) client->id.pub_key[0], p->text);
-            break;
-          }
-          idx = (idx + 1) % MAX_UNSYNCED_POSTS;   // wrap to start of cyclic queue
-        }
-      } else {
-        MESH_DEBUG_PRINTLN("loop - skipping busy (or evicted) client %02X", (uint32_t) client->id.pub_key[0]);
-      }
-      next_client_idx = (next_client_idx + 1) % num_clients;  // round robin polling for each client
-
-      if (did_push) {
-        next_push = futureMillis(SYNC_PUSH_INTERVAL);
-      } else {
-        // were no unsynced posts for curr client, so proccess next client much quicker! (in next loop())
-        next_push = futureMillis(SYNC_PUSH_INTERVAL / 8);
-      }
-    }
-
-    if (next_flood_advert && millisHasNowPassed(next_flood_advert)) {
-      mesh::Packet* pkt = createSelfAdvert();
-      if (pkt) sendFlood(pkt);
-
-      updateFloodAdvertTimer();   // schedule next flood advert
-      updateAdvertTimer();   // also schedule local advert (so they don't overlap)
-    } else if (next_local_advert && millisHasNowPassed(next_local_advert)) {
-      mesh::Packet* pkt = createSelfAdvert();
-      if (pkt) sendZeroHop(pkt);
-
-      updateAdvertTimer();   // schedule next local advert
-    }
-
-    if (set_radio_at && millisHasNowPassed(set_radio_at)) {   // apply pending (temporary) radio params
-      set_radio_at = 0;  // clear timer
-      radio_set_params(pending_freq, pending_bw, pending_sf, pending_cr);
-      MESH_DEBUG_PRINTLN("Temp radio params");
-    }
-
-    if (revert_radio_at && millisHasNowPassed(revert_radio_at)) {   // revert radio params to orig
-      revert_radio_at = 0;  // clear timer
-      radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
-      MESH_DEBUG_PRINTLN("Radio params restored");
-    }
-
-  #ifdef DISPLAY_CLASS
-    ui_task.loop();
-  #endif
-
-    // TODO: periodically check for OLD/inactive entries in known_clients[], and evict
-  }
-};
-
 StdRNG fast_rng;
 SimpleMeshTables tables;
 MyMesh the_mesh(board, radio_driver, *new ArduinoMillis(), fast_rng, rtc_clock, tables);
@@ -1073,4 +107,7 @@ void loop() {
 
   the_mesh.loop();
   sensors.loop();
+#ifdef DISPLAY_CLASS
+  ui_task.loop();
+#endif
 }