net: reduce log level for PCP/NAT-PMP NOT_AUTHORIZED failures #34549

1. 
   willcl-ark commented at 2:12 pm on February 10, 2026: member

   Cherry-picks (and tweaks) a commit from #34117 which the ANAVHEOBA did not follow up with when changes were requested.

   The tweak here is to log once at LogWarning, so that users have a chance to spot misconfiguration.

   ---

   Users running on home networks with routers that don’t support PCP (Port Control Protocol) or NAT-PMP port mapping receive frequent warning-level log messages every few minutes:

   “pcp: Mapping failed with result NOT_AUTHORIZED (code 2)”

   This is expected behavior for many consumer routers that have PCP disabled by default, not an actionable error.

   Add explicit constants for the NOT_AUTHORIZED result code (value 2) for both NAT-PMP and PCP protocols. Log the first NOT_AUTHORIZED failure at warning level for visibility, then downgrade subsequent occurrences to LogDebug to avoid log noise. Other failure types continue to warn unconditionally.

   Fixes #34114

2. DrahtBot added the label P2P on Feb 10, 2026
3. 
   DrahtBot commented at 2:13 pm on February 10, 2026: contributor

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   Type	Reviewers
   Concept ACK	gmaxwell
   Stale ACK	0xB10C

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4. 
   fanquake commented at 3:15 pm on February 11, 2026: member

   cc @0xB10C
5. fanquake added the label Needs backport (30.x) on Feb 11, 2026
6. fanquake added this to the milestone 31.0 on Feb 11, 2026
7. 
   0xB10C commented at 4:56 pm on February 11, 2026: contributor

   ACK 8fdca7d70de102cf3b0659fd8ca30e8d1e69062e

   I only get one [warning] pcp: Mapping failed with result NOT_AUTHORIZED (code 2) now and not multiple every 5 minutes. The NATPMP changes look Ok to me, but I hadn’t seen any logs for that before and now.

8. net: reduce log level for PCP/NAT-PMP NOT_AUTHORIZED failures

   Users running on home networks with routers that don't support PCP (Port
   Control Protocol) or NAT-PMP port mapping receive frequent warning-level
   log messages every few minutes:
   
     "pcp: Mapping failed with result NOT_AUTHORIZED (code 2)"
   
   This is expected behavior for many consumer routers that have PCP
   disabled by default, not an actionable error.
   
   Add explicit constants for the NOT_AUTHORIZED result code (value 2)
   for both NAT-PMP and PCP protocols. Log the first NOT_AUTHORIZED
   failure at warning level for visibility, then downgrade subsequent
   occurrences to LogDebug to avoid log noise. Other failure types
   continue to warn unconditionally.
   
   Fixes #34114
   
   Co-authored-by: willcl-ark <will@256k1.dev>

   afea2af139
9. in src/common/pcp.cpp:385 in 8fdca7d70d

   377@@ -374,7 +378,17 @@ std::variant<MappingResult, MappingError> NATPMPRequestPortMap(const CNetAddr &g
   378         Assume(response.size() >= NATPMP_MAP_RESPONSE_SIZE);
   379         uint16_t result_code = ReadBE16(response.data() + NATPMP_RESPONSE_HDR_RESULT_OFS);
   380         if (result_code != NATPMP_RESULT_SUCCESS) {
   381-            LogWarning("natpmp: Port mapping failed with result %s\n", NATPMPResultString(result_code));
   382+            if (result_code == NATPMP_RESULT_NOT_AUTHORIZED) {
   383+                static bool warned{false};
   384+                if (!warned) {
   385+                    LogWarning("natpmp: Port mapping failed with result %s\n", NATPMPResultString(result_code));
   386+                    warned = true;
   

   ---

   ---

   

   ajtowns commented at 11:42 pm on February 14, 2026:

   You’re modifying a global variable here with no particular assurances that this is only ever called from a single thread (should only be called via ThreadMapPort). Is there any reason not to at least declare/name these as the globals they are (bool g_warned_natpmp_failure) and add a comment about safety? Perhaps consider making them atomic.

   ---

   

   willcl-ark commented at 11:00 am on February 16, 2026:

   Thanks, even though it is only called from one thread currently, using an atomic is for sure better practice here. Switched to that in afea2af1391314be0e5caaa0125c884da2405316
10. willcl-ark force-pushed on Feb 16, 2026
11. 
    gmaxwell commented at 5:51 am on February 17, 2026: contributor

    Concept ACK. I saw the PR subject line and came here to suggest that it log it verbosely just the first time, I think that’s exactly the right behavior.

Contributors
willcl-ark DrahtBot fanquake 0xB10C ajtowns gmaxwell

Labels
P2P Needs backport (30.x)

Milestone
31.0