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| author | e0 <ethan.r.heilman@gmail.com> | 2018-03-06 18:26:29 -0500 |
|---|---|---|
| committer | fanquake <fanquake@gmail.com> | 2018-04-26 23:43:54 +0800 |
| commit | f60e84dba4723bc658ecc70f8b17db2619eb7e20 (patch) | |
| tree | c1cb459eb63ebc71172285c0c285dba80cf8de1a | |
| parent | 9ea62a3dc4bd50a139e6d3c72e4f94d909ef10f3 (diff) | |
| download | bitcoin-f60e84dba4723bc658ecc70f8b17db2619eb7e20.tar.xz | |
Limit the number of IPs we use from each DNS seeder
A risk exists where a malicious DNS seeder eclipses a node by returning an enormous number of IP addresses. In this commit we mitigate this risk by limiting the number of IP addresses addrman learns to 256 per DNS seeder.
GitHub-Pull: #12626
Rebased-From: 46e7f80
| -rw-r--r-- | src/net.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/net.cpp b/src/net.cpp index 5f4c0eecab..ff68b182f0 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1619,7 +1619,8 @@ void CConnman::ThreadDNSAddressSeed() if (!resolveSource.SetInternal(host)) { continue; } - if (LookupHost(host.c_str(), vIPs, 0, true)) + unsigned int nMaxIPs = 256; // Limits number of IPs learned from a DNS seed + if (LookupHost(host.c_str(), vIPs, nMaxIPs, true)) { for (const CNetAddr& ip : vIPs) { |