dash/src/sendalert.cpp

#include "alert.h"
#include "clientversion.h"
#include "chainparams.h"
#include "init.h"
#include "net.h"
#include "utilstrencodings.h"
#include "utiltime.h"

/*
If you need to broadcast an alert, here's what to do:

1. Modify alert parameters below, see alert.* and comments in the code
   for what does what.

2. run dashd with -printalert or -sendalert like this:
   /path/to/dashd -printalert

One minute after starting up the alert will be broadcast. It is then
flooded through the network until the nRelayUntil time, and will be
active until nExpiration OR the alert is cancelled.

If you screw up something, send another alert with nCancel set to cancel
the bad alert.
*/

void ThreadSendAlert(CConnman& connman)
{
    if (!IsArgSet("-sendalert") && !IsArgSet("-printalert"))
        return;

    // Wait one minute so we get well connected. If we only need to print
    // but not to broadcast - do this right away.
    if (IsArgSet("-sendalert"))
        MilliSleep(60*1000);

    //
    // Alerts are relayed around the network until nRelayUntil, flood
    // filling to every node.
    // After the relay time is past, new nodes are told about alerts
    // when they connect to peers, until either nExpiration or
    // the alert is cancelled by a newer alert.
    // Nodes never save alerts to disk, they are in-memory-only.
    //
    CAlert alert;
    alert.nRelayUntil   = GetAdjustedTime() + 15 * 60;
    alert.nExpiration   = GetAdjustedTime() + 30 * 60 * 60;
    alert.nID           = 1;  // keep track of alert IDs somewhere
    alert.nCancel       = 0;   // cancels previous messages up to this ID number

    // These versions are protocol versions
    alert.nMinVer       = 70000;
    alert.nMaxVer       = 70103;

    //
    //  1000 for Misc warnings like out of disk space and clock is wrong
    //  2000 for longer invalid proof-of-work chain
    //  Higher numbers mean higher priority
    alert.nPriority     = 5000;
    alert.strComment    = "";
    alert.strStatusBar  = "URGENT: Upgrade required: see https://www.dash.org";

    // Set specific client version/versions here. If setSubVer is empty, no filtering on subver is done:
    // alert.setSubVer.insert(std::string("/Dash Core:0.12.0.58/"));

    // Sign
    if(!alert.Sign())
    {
        LogPrintf("ThreadSendAlert() : could not sign alert\n");
        return;
    }

    // Test
    CDataStream sBuffer(SER_NETWORK, CLIENT_VERSION);
    sBuffer << alert;
    CAlert alert2;
    sBuffer >> alert2;
    if (!alert2.CheckSignature(Params().AlertKey()))
    {
        printf("ThreadSendAlert() : CheckSignature failed\n");
        return;
    }
    assert(alert2.vchMsg == alert.vchMsg);
    assert(alert2.vchSig == alert.vchSig);
    alert.SetNull();
    printf("\nThreadSendAlert:\n");
    printf("hash=%s\n", alert2.GetHash().ToString().c_str());
    printf("%s", alert2.ToString().c_str());
    printf("vchMsg=%s\n", HexStr(alert2.vchMsg).c_str());
    printf("vchSig=%s\n", HexStr(alert2.vchSig).c_str());

    // Confirm
    if (!IsArgSet("-sendalert"))
        return;
    while (connman.GetNodeCount(CConnman::CONNECTIONS_ALL) == 0 && !ShutdownRequested())
        MilliSleep(500);
    if (ShutdownRequested())
        return;

    // Send
    printf("ThreadSendAlert() : Sending alert\n");
    int nSent = 0;
    {
        connman.ForEachNode([&alert2, &connman, &nSent](CNode* pnode) {
            if (alert2.RelayTo(pnode, connman))
            {
                printf("ThreadSendAlert() : Sent alert to %s\n", pnode->addr.ToString().c_str());
                nSent++;
            }
        });
    }
    printf("ThreadSendAlert() : Alert sent to %d nodes\n", nSent);
}