Fixes potential nil return from multiplexer.Conn.RemoteAddr()#54578
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Fixes potential nil return from multiplexer.Conn.RemoteAddr()#54578
multiplexer.Conn.RemoteAddr()#54578Conversation
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original source address in a ProxyLine's TLVs
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This PR fixes a regression that made it possible for
multiplexer.Conn.RemoteAddr()to return a nilnet.Addr. This bug was introduced by the addition of theproxy_protocol_allow_downgradefeature and happens when a genuine class E source address appears in aPROXYheader. The existing behavior assumed we would find an original source address TLV whenever a class E source address was present since they're technically reserved for experimental purposes. However GKE has a feature that allows for networking using class E addresses. I'm also fairly certain this same behavior would have appeared in conjunction with CloudFlare's pseudo IPv4 feature which was the original inspiration forproxy_protocol_allow_downgrade. The fix is to fallback to the proxy line's source address when an original address isn't found in the TLVs.changelog: Fixed an issue preventing connections due to missing client IPs when using class E address space with GKE or CloudFlare pseudo IPv4 forward headers.