Improve ACKs for repeated packets and responses

This commit is contained in:
GUVWAF 2024-11-02 19:34:21 +01:00
parent 01344835af
commit e4c98185d2
9 changed files with 58 additions and 41 deletions

View File

@ -21,14 +21,27 @@ ErrorCode FloodingRouter::send(meshtastic_MeshPacket *p)
bool FloodingRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
{
/* Resend implicit ACKs for repeated packets (hopStart equals hopLimit);
* this way if an implicit ACK is dropped and a packet is resent we'll rebroadcast again.
* Resending real ACKs is omitted, as you might receive a packet multiple times due to flooding and
* flooding this ACK back to the original sender already adds redundancy. */
bool isRepeated = p->hop_start > 0 && (p->hop_start == p->hop_limit);
bool didRebroadcast = false;
if (wasSeenRecently(p, false) && isRepeated) {
LOG_DEBUG("Repeated floodmsg");
didRebroadcast = perhapsRebroadcast(p); // perhaps rebroadcast the packet
}
if (wasSeenRecently(p)) { // Note: this will also add a recent packet record
printPacket("Ignoring dupe incoming msg", p);
rxDupe++;
if (config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER) {
// cancel rebroadcast of this message *if* there was already one, unless we're a router/repeater!
if (Router::cancelSending(p->from, p->id))
txRelayCanceled++;
if (!didRebroadcast) { // We shouldn't cancel a rebroadcast that we just did
if (config.device.role != meshtastic_Config_DeviceConfig_Role_ROUTER &&
config.device.role != meshtastic_Config_DeviceConfig_Role_REPEATER) {
// cancel rebroadcast of this message *if* there was already one, unless we're a router/repeater!
if (Router::cancelSending(p->from, p->id))
txRelayCanceled++;
}
}
return true;
}
@ -50,6 +63,14 @@ void FloodingRouter::sniffReceived(const meshtastic_MeshPacket *p, const meshtas
LOG_DEBUG("Rxd an ACK/reply not for me, cancel rebroadcast");
Router::cancelSending(p->to, p->decoded.request_id); // cancel rebroadcast for this DM
}
perhapsRebroadcast(p);
// handle the packet as normal
Router::sniffReceived(p, c);
}
bool FloodingRouter::perhapsRebroadcast(const meshtastic_MeshPacket *p)
{
if (!isToUs(p) && (p->hop_limit > 0) && !isFromUs(p)) {
if (p->id != 0) {
if (isRebroadcaster()) {
@ -68,6 +89,8 @@ void FloodingRouter::sniffReceived(const meshtastic_MeshPacket *p, const meshtas
// 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);
return true;
} else {
LOG_DEBUG("Not rebroadcasting: Role = CLIENT_MUTE or Rebroadcast Mode = NONE");
}
@ -75,6 +98,6 @@ void FloodingRouter::sniffReceived(const meshtastic_MeshPacket *p, const meshtas
LOG_DEBUG("Ignoring 0 id broadcast");
}
}
// handle the packet as normal
Router::sniffReceived(p, c);
return false;
}

View File

@ -29,6 +29,10 @@
class FloodingRouter : public Router, protected PacketHistory
{
private:
/** Check if we should rebroadcast this packet, and do so if needed
* @return true if rebroadcasted */
bool perhapsRebroadcast(const meshtastic_MeshPacket *p);
public:
/**
* Constructor

View File

@ -33,7 +33,7 @@ MeshModule::~MeshModule()
}
meshtastic_MeshPacket *MeshModule::allocAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex,
uint8_t hopStart, uint8_t hopLimit)
uint8_t hopLimit)
{
meshtastic_Routing c = meshtastic_Routing_init_default;
@ -50,7 +50,7 @@ meshtastic_MeshPacket *MeshModule::allocAckNak(meshtastic_Routing_Error err, Nod
p->priority = meshtastic_MeshPacket_Priority_ACK;
p->hop_limit = routingModule->getHopLimitForResponse(hopStart, hopLimit); // Flood ACK back to original sender
p->hop_limit = hopLimit; // Flood ACK back to original sender
p->to = to;
p->decoded.request_id = idFrom;
p->channel = chIndex;
@ -181,8 +181,8 @@ void MeshModule::callModules(meshtastic_MeshPacket &mp, RxSource src)
// SECURITY NOTE! I considered sending back a different error code if we didn't find the psk (i.e. !isDecoded)
// but opted NOT TO. Because it is not a good idea to let remote nodes 'probe' to find out which PSKs were "good" vs
// bad.
routingModule->sendAckNak(meshtastic_Routing_Error_NO_RESPONSE, getFrom(&mp), mp.id, mp.channel, mp.hop_start,
mp.hop_limit);
routingModule->sendAckNak(meshtastic_Routing_Error_NO_RESPONSE, getFrom(&mp), mp.id, mp.channel,
routingModule->getHopLimitForResponse(mp.hop_start, mp.hop_limit));
}
}
@ -295,4 +295,4 @@ bool MeshModule::isRequestingFocus()
} else
return false;
}
#endif
#endif

View File

@ -162,7 +162,7 @@ class MeshModule
virtual Observable<const UIFrameEvent *> *getUIFrameObservable() { return NULL; }
meshtastic_MeshPacket *allocAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex,
uint8_t hopStart = 0, uint8_t hopLimit = 0);
uint8_t hopLimit = 0);
/// Send an error response for the specified packet.
meshtastic_MeshPacket *allocErrorResponse(meshtastic_Routing_Error err, const meshtastic_MeshPacket *p);

View File

@ -1,10 +1,10 @@
#include "ReliableRouter.h"
#include "Default.h"
#include "MeshModule.h"
#include "MeshTypes.h"
#include "configuration.h"
#include "mesh-pb-constants.h"
#include "modules/NodeInfoModule.h"
#include "modules/RoutingModule.h"
// ReliableRouter::ReliableRouter() {}
@ -73,18 +73,6 @@ bool ReliableRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
i->second.nextTxMsec += iface->getPacketTime(p);
}
/* Resend implicit ACKs for repeated packets (hopStart equals hopLimit);
* this way if an implicit ACK is dropped and a packet is resent we'll rebroadcast again.
* Resending real ACKs is omitted, as you might receive a packet multiple times due to flooding and
* flooding this ACK back to the original sender already adds redundancy. */
bool isRepeated = p->hop_start == 0 ? (p->hop_limit == HOP_RELIABLE) : (p->hop_start == p->hop_limit);
if (wasSeenRecently(p, false) && isRepeated && !MeshModule::currentReply && !isToUs(p)) {
LOG_DEBUG("Resending implicit ack for a repeated floodmsg");
meshtastic_MeshPacket *tosend = packetPool.allocCopy(*p);
tosend->hop_limit--; // bump down the hop count
Router::send(tosend);
}
return isBroadcast(p->to) ? FloodingRouter::shouldFilterReceived(p) : NextHopRouter::shouldFilterReceived(p);
}
@ -107,16 +95,22 @@ void ReliableRouter::sniffReceived(const meshtastic_MeshPacket *p, const meshtas
if (MeshModule::currentReply) {
LOG_DEBUG("Another module replied to this message, no need for 2nd ack");
} else if (p->which_payload_variant == meshtastic_MeshPacket_decoded_tag) {
sendAckNak(meshtastic_Routing_Error_NONE, getFrom(p), p->id, p->channel, p->hop_start, p->hop_limit);
// A response may be set to want_ack for retransmissions, but we don't need to ACK a response if it received an
// implicit ACK already. If we received it directly, only ACK with a hop limit of 0
if (!p->decoded.request_id)
sendAckNak(meshtastic_Routing_Error_NONE, getFrom(p), p->id, p->channel,
routingModule->getHopLimitForResponse(p->hop_start, p->hop_limit));
else if (p->hop_start > 0 && p->hop_start == p->hop_limit)
sendAckNak(meshtastic_Routing_Error_NONE, getFrom(p), p->id, p->channel, 0);
} else if (p->which_payload_variant == meshtastic_MeshPacket_encrypted_tag && p->channel == 0 &&
(nodeDB->getMeshNode(p->from) == nullptr || nodeDB->getMeshNode(p->from)->user.public_key.size == 0)) {
LOG_INFO("PKI packet from unknown node, send PKI_UNKNOWN_PUBKEY");
sendAckNak(meshtastic_Routing_Error_PKI_UNKNOWN_PUBKEY, getFrom(p), p->id, channels.getPrimaryIndex(),
p->hop_start, p->hop_limit);
routingModule->getHopLimitForResponse(p->hop_start, p->hop_limit));
} else {
// Send a 'NO_CHANNEL' error on the primary channel if want_ack packet destined for us cannot be decoded
sendAckNak(meshtastic_Routing_Error_NO_CHANNEL, getFrom(p), p->id, channels.getPrimaryIndex(), p->hop_start,
p->hop_limit);
sendAckNak(meshtastic_Routing_Error_NO_CHANNEL, getFrom(p), p->id, channels.getPrimaryIndex(),
routingModule->getHopLimitForResponse(p->hop_start, p->hop_limit));
}
}
if (p->which_payload_variant == meshtastic_MeshPacket_decoded_tag && c &&

View File

@ -133,10 +133,9 @@ meshtastic_MeshPacket *Router::allocForSending()
/**
* Send an ack or a nak packet back towards whoever sent idFrom
*/
void Router::sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopStart,
uint8_t hopLimit)
void Router::sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopLimit)
{
routingModule->sendAckNak(err, to, idFrom, chIndex, hopStart, hopLimit);
routingModule->sendAckNak(err, to, idFrom, chIndex, hopLimit);
}
void Router::abortSendAndNak(meshtastic_Routing_Error err, meshtastic_MeshPacket *p)

View File

@ -108,8 +108,7 @@ class Router : protected concurrency::OSThread
/**
* Send an ack or a nak packet back towards whoever sent idFrom
*/
void sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopStart = 0,
uint8_t hopLimit = 0);
void sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopLimit = 0);
private:
/**

View File

@ -49,10 +49,9 @@ meshtastic_MeshPacket *RoutingModule::allocReply()
return NULL;
}
void RoutingModule::sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopStart,
uint8_t hopLimit)
void RoutingModule::sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopLimit)
{
auto p = allocAckNak(err, to, idFrom, chIndex, hopStart, hopLimit);
auto p = allocAckNak(err, to, idFrom, chIndex, hopLimit);
router->sendLocal(p); // we sometimes send directly to the local node
}

View File

@ -13,8 +13,7 @@ class RoutingModule : public ProtobufModule<meshtastic_Routing>
*/
RoutingModule();
void sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopStart = 0,
uint8_t hopLimit = 0);
void sendAckNak(meshtastic_Routing_Error err, NodeNum to, PacketId idFrom, ChannelIndex chIndex, uint8_t hopLimit = 0);
// Given the hopStart and hopLimit upon reception of a request, return the hop limit to use for the response
uint8_t getHopLimitForResponse(uint8_t hopStart, uint8_t hopLimit);
@ -36,4 +35,4 @@ class RoutingModule : public ProtobufModule<meshtastic_Routing>
virtual bool wantPacket(const meshtastic_MeshPacket *p) override { return true; }
};
extern RoutingModule *routingModule;
extern RoutingModule *routingModule;