firmware/src/mesh/FloodingRouter.cpp

#include "FloodingRouter.h"
#include "configuration.h"
#include "mesh-pb-constants.h"

static bool supportFlooding = true; // Sometimes to simplify debugging we want jusT simple broadcast only

FloodingRouter::FloodingRouter() : toResend(MAX_NUM_NODES)
{
}

/**
 * Send a packet on a suitable interface.  This routine will
 * later free() the packet to pool.  This routine is not allowed to stall.
 * If the txmit queue is full it might return an error
 */
ErrorCode FloodingRouter::send(MeshPacket *p)
{
    // We update our table of recent broadcasts, even for messages we send
    if (supportFlooding)
        wasSeenRecently(p);

    return Router::send(p);
}

// Return a delay in msec before sending the next packet
uint32_t getRandomDelay()
{
    return random(200, 10 * 1000L); // between 200ms and 10s
}

/**
 * Now that our generalized packet send code has a random delay - I don't think we need to wait here
 * But I'm leaving this bool until I rip the code out for good.
 */
bool needDelay = false;

/**
 * Called from loop()
 * Handle any packet that is received by an interface on this node.
 * Note: some packets may merely being passed through this node and will be forwarded elsewhere.
 *
 * Note: this method will free the provided packet
 */
void FloodingRouter::handleReceived(MeshPacket *p)
{
    if (supportFlooding) {
        if (wasSeenRecently(p)) {
            DEBUG_MSG("Ignoring incoming floodmsg, because we've already seen it\n");
            packetPool.release(p);
        } else {
            if (p->to == NODENUM_BROADCAST) {
                if (p->id != 0) {
                    MeshPacket *tosend = packetPool.allocCopy(*p); // keep a copy because we will be sending it

                    if (needDelay) {
                        uint32_t delay = getRandomDelay();

                        DEBUG_MSG("Rebroadcasting received floodmsg to neighbors in %u msec, fr=0x%x,to=0x%x,id=%d\n", delay,
                                  p->from, p->to, p->id);

                        toResend.enqueue(tosend);
                        setPeriod(delay); // This will work even if we were already waiting a random delay
                    } else {
                        DEBUG_MSG("Rebroadcasting received floodmsg to neighbors, fr=0x%x,to=0x%x,id=%d\n", p->from, p->to,
                                  p->id);
                        // Note: we are careful to resend using the original senders node id
                        // We are careful not to call our hooked version of send() - because we don't want to check this again
                        Router::send(tosend);
                    }
                } else {
                    DEBUG_MSG("Ignoring a simple (0 hop) broadcast\n");
                }
            }

            // handle the packet as normal
            Router::handleReceived(p);
        }
    } else
        Router::handleReceived(p);
}

void FloodingRouter::doTask()
{
    MeshPacket *p = toResend.dequeuePtr(0);

    if (p) {
        DEBUG_MSG("Sending delayed message!\n");
        // Note: we are careful to resend using the original senders node id
        // We are careful not to call our hooked version of send() - because we don't want to check this again
        Router::send(p);
    }

    if (toResend.isEmpty())
        disable(); // no more work right now
    else {
        setPeriod(getRandomDelay());
    }
}