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Merge bitcoin/bitcoin#29850: net: Decrease nMaxIPs when learning from DNS seeds 

f2e3662e57 net: Decrease nMaxIPs when learning from DNS seeds (laanwj)

Pull request description:

  Limit number of IPs learned from a single DNS seed to 32, to prevent the results from one DNS seed from dominating AddrMan. Note that the number of results from a UDP DNS query is bounded to 33 already, but it is possible for it to use TCP where a larger number of results can be returned.

  Closes #16070.

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Ava Chow 2024-04-22 12:09:17 -04:00
parent b3106be84f f2e3662e57
commit 3310a965bd
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1 changed files with 5 additions and 1 deletions
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6
src/net.cpp
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@ -2256,7 +2256,11 @@ void CConnman::ThreadDNSAddressSeed()
if (!resolveSource.SetInternal(host)) {
continue;
}
unsigned int nMaxIPs = 256; // Limits number of IPs learned from a DNS seed
// Limit number of IPs learned from a single DNS seed. This limit exists to prevent the results from
// one DNS seed from dominating AddrMan. Note that the number of results from a UDP DNS query is
// bounded to 33 already, but it is possible for it to use TCP where a larger number of results can be
// returned.
unsigned int nMaxIPs = 32;
const auto addresses{LookupHost(host, nMaxIPs, true)};
if (!addresses.empty()) {
for (const CNetAddr& ip : addresses) {