firmware/src/modules/NodeInfoModule.cpp

#include "NodeInfoModule.h"
#include "Default.h"
#include "MeshService.h"
#include "NodeDB.h"
#include "NodeStatus.h"
#include "Router.h"
#include "TransmitHistory.h"
#include "configuration.h"
#include "gps/RTC.h"
#include "main.h"
#include <Throttle.h>
#include <algorithm>

#ifndef USERPREFS_NODEINFO_REPLY_SUPPRESS_SECS
#define USERPREFS_NODEINFO_REPLY_SUPPRESS_SECS (12 * 60 * 60)
#endif

NodeInfoModule *nodeInfoModule;

static constexpr uint32_t NodeInfoReplySuppressSeconds = USERPREFS_NODEINFO_REPLY_SUPPRESS_SECS;

bool NodeInfoModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, meshtastic_User *pptr)
{
    suppressReplyForCurrentRequest = false;

    if (mp.from == nodeDB->getNodeNum()) {
        LOG_WARN("Ignoring packet supposed to be from our own node: %08x", mp.from);
        return false;
    }

    auto p = *pptr;

    // Suppress replies to senders we've replied to recently (12H window)
    if (mp.decoded.want_response && !isFromUs(&mp)) {
        const NodeNum sender = getFrom(&mp);
        const uint32_t now = mp.rx_time ? mp.rx_time : getTime();
        auto it = lastNodeInfoSeen.find(sender);
        if (it != lastNodeInfoSeen.end()) {
            uint32_t sinceLast = now >= it->second ? now - it->second : 0;
            if (sinceLast < NodeInfoReplySuppressSeconds) {
                suppressReplyForCurrentRequest = true;
            }
        }
        lastNodeInfoSeen[sender] = now;
        pruneLastNodeInfoCache();
    }

    if (p.is_licensed != owner.is_licensed) {
        LOG_WARN("Invalid nodeInfo detected, is_licensed mismatch!");
        return true;
    }
    NodeNum sourceNum = getFrom(&mp);
    const meshtastic_NodeInfoLite *node = nodeDB->getMeshNode(sourceNum);
    // Broadcasts only: senders never sign unicast NodeInfo, so dropping it would break exchanges
    // with signer nodes. Backstops ingress that skips Router's downgrade drop (e.g. decoded MQTT).
    if (node && nodeInfoLiteHasXeddsaSigned(node) && !mp.xeddsa_signed && isBroadcast(mp.to)) {
        LOG_WARN("Dropping unsigned NodeInfo broadcast from node 0x%08x that previously signed", sourceNum);
        return true;
    }

    // Coerce user.id to be derived from the node number
    snprintf(p.id, sizeof(p.id), "!%08x", getFrom(&mp));

    // updateUser() refuses the identity write for a known signer sending unsigned (all unicast
    // NodeInfo), so the exchange above still proceeds but cannot spoof the stored name.
    bool hasChanged = nodeDB->updateUser(getFrom(&mp), p, mp.channel, mp.xeddsa_signed);

    bool wasBroadcast = isBroadcast(mp.to);

    // LOG_DEBUG("did encode");
    // if user has changed while packet was not for us, inform phone
    if (hasChanged && !wasBroadcast && !isToUs(&mp)) {
        auto packetCopy = packetPool.allocCopy(mp); // Keep a copy of the packet for later analysis
        if (packetCopy) {
            // Re-encode the user protobuf, as we have stripped out the user.id
            packetCopy->decoded.payload.size = pb_encode_to_bytes(
                packetCopy->decoded.payload.bytes, sizeof(packetCopy->decoded.payload.bytes), &meshtastic_User_msg, &p);

            service->sendToPhone(packetCopy);
        }
    }

    pruneLastNodeInfoCache();

    // LOG_DEBUG("did handleReceived");
    return false; // Let others look at this message also if they want
}

void NodeInfoModule::alterReceivedProtobuf(meshtastic_MeshPacket &mp, meshtastic_User *p)
{
    // Coerce user.id to be derived from the node number
    snprintf(p->id, sizeof(p->id), "!%08x", getFrom(&mp));

    // Re-encode the altered protobuf back into the packet
    mp.decoded.payload.size =
        pb_encode_to_bytes(mp.decoded.payload.bytes, sizeof(mp.decoded.payload.bytes), &meshtastic_User_msg, p);
}

void NodeInfoModule::sendOurNodeInfo(NodeNum dest, bool wantReplies, uint8_t channel, bool _shorterTimeout)
{
    // cancel any not yet sent (now stale) position packets
    if (prevPacketId) // if we wrap around to zero, we'll simply fail to cancel in that rare case (no big deal)
        service->cancelSending(prevPacketId);
    shorterTimeout = _shorterTimeout;
    DEBUG_HEAP_BEFORE;
    meshtastic_MeshPacket *p = allocReply();
    DEBUG_HEAP_AFTER("NodeInfoModule::sendOurNodeInfo", p);

    if (p) { // Check whether we didn't ignore it
        p->to = dest;
        bool requestWantResponse = (config.device.role != meshtastic_Config_DeviceConfig_Role_TRACKER &&
                                    config.device.role != meshtastic_Config_DeviceConfig_Role_SENSOR) &&
                                   wantReplies;

        p->decoded.want_response = requestWantResponse;
        if (_shorterTimeout)
            p->priority = meshtastic_MeshPacket_Priority_DEFAULT;
        else
            p->priority = meshtastic_MeshPacket_Priority_BACKGROUND;
        if (channel > 0) {
            LOG_DEBUG("Send ourNodeInfo to channel %d", channel);
            p->channel = channel;
        }

        prevPacketId = p->id;

        service->sendToMesh(p);
        shorterTimeout = false;
    }
}

void NodeInfoModule::triggerImmediateNodeInfoCheck()
{
    LOG_DEBUG("NodeInfo: scheduling immediate periodic check");
    setIntervalFromNow(0);
}

meshtastic_MeshPacket *NodeInfoModule::allocReply()
{
    // Only apply suppression when actually replying to someone else's request, not for periodic broadcasts.
    const bool isReplyingToExternalRequest = currentRequest &&
                                             currentRequest->which_payload_variant == meshtastic_MeshPacket_decoded_tag &&
                                             currentRequest->decoded.portnum == meshtastic_PortNum_NODEINFO_APP &&
                                             currentRequest->decoded.want_response && !isFromUs(currentRequest);

    if (suppressReplyForCurrentRequest && isReplyingToExternalRequest) {
        LOG_DEBUG("Skip send NodeInfo since we heard the requester <12h ago");
        ignoreRequest = true;
        suppressReplyForCurrentRequest = false;
        return NULL;
    }

    if (!airTime->isTxAllowedChannelUtil(false)) {
        ignoreRequest = true; // Mark it as ignored for MeshModule
        LOG_DEBUG("Skip send NodeInfo > 40%% ch. util");
        return NULL;
    }

    // Use graduated scaling based on active mesh size (10 minute base, scales with congestion coefficient)
    uint32_t timeoutMs = Default::getConfiguredOrDefaultMsScaled(0, 10 * 60, nodeStatus->getNumOnline());
    uint32_t lastNodeInfo = transmitHistory ? transmitHistory->getLastSentToMeshMillis(meshtastic_PortNum_NODEINFO_APP) : 0;
    if (!shorterTimeout && lastNodeInfo && Throttle::isWithinTimespanMs(lastNodeInfo, timeoutMs)) {
        LOG_DEBUG("Skip send NodeInfo since we sent it <%us ago", timeoutMs / 1000);
        ignoreRequest = true; // Mark it as ignored for MeshModule
        return NULL;
    } else if (shorterTimeout && lastNodeInfo && Throttle::isWithinTimespanMs(lastNodeInfo, 60 * 1000)) {
        // For interactive/urgent requests (e.g., user-triggered or implicit requests), use a shorter 60s timeout
        LOG_DEBUG("Skip send NodeInfo since we sent it <60s ago");
        ignoreRequest = true;
        return NULL;
    } else {
        ignoreRequest = false; // Don't ignore requests anymore
        meshtastic_User u = owner;

        // FIXME: Clear the user.id field since it should be derived from node number on the receiving end
        // u.id[0] = '\0';

        // Ensure our user.id is derived correctly
        strcpy(u.id, nodeDB->getNodeId().c_str());

        LOG_INFO("Send owner %s/%s/%s", u.id, u.long_name, u.short_name);
        if (transmitHistory)
            transmitHistory->setLastSentToMesh(meshtastic_PortNum_NODEINFO_APP);
        return allocDataProtobuf(u);
    }
}

void NodeInfoModule::pruneLastNodeInfoCache()
{
    if (!nodeDB || !nodeDB->meshNodes)
        return;

    const size_t maxEntries = nodeDB->meshNodes->size();

    for (auto it = lastNodeInfoSeen.begin(); it != lastNodeInfoSeen.end();) {
        if (!nodeDB->getMeshNode(it->first)) {
            it = lastNodeInfoSeen.erase(it);
        } else {
            ++it;
        }
    }

    while (!lastNodeInfoSeen.empty() && lastNodeInfoSeen.size() > maxEntries) {
        auto oldestIt = std::min_element(lastNodeInfoSeen.begin(), lastNodeInfoSeen.end(),
                                         [](const std::pair<const NodeNum, uint32_t> &lhs,
                                            const std::pair<const NodeNum, uint32_t> &rhs) { return lhs.second < rhs.second; });
        lastNodeInfoSeen.erase(oldestIt);
    }
}

NodeInfoModule::NodeInfoModule()
    : ProtobufModule("nodeinfo", meshtastic_PortNum_NODEINFO_APP, &meshtastic_User_msg), concurrency::OSThread("NodeInfo")
{
    isPromiscuous = true; // We always want to update our nodedb, even if we are sniffing on others

    setIntervalFromNow(setStartDelay()); // Send our initial owner announcement 30 seconds
                                         // after we start (to give network time to setup)
}

int32_t NodeInfoModule::runOnce()
{
    // If we changed channels, ask everyone else for their latest info
    bool requestReplies = currentGeneration != radioGeneration;
    currentGeneration = radioGeneration;

    if (airTime->isTxAllowedAirUtil() && config.device.role != meshtastic_Config_DeviceConfig_Role_CLIENT_HIDDEN) {
        LOG_INFO("Send our nodeinfo to mesh (wantReplies=%d)", requestReplies);
        sendOurNodeInfo(NODENUM_BROADCAST, requestReplies); // Send our info (don't request replies)
    }
    return Default::getConfiguredOrDefaultMs(config.device.node_info_broadcast_secs, default_node_info_broadcast_secs);
}