fix(bitswap/network): stream.Close() blocks indefinitely on unresponsive peers

[lidel]

Problem

SendMessage() in bitswap can block indefinitely when the remote peer is unresponsive, causing goroutine leaks. Over time, this exhausts worker goroutines and bitswap stops serving blocks entirely.

Symptoms observed on production nodes:

• https://github.com/ipshipyard/waterworks-infra/issues/860
  • Bitswap stops responding (vole bitswap check returns Responded: false)
  • Goroutine profile shows 400+ goroutines stuck for 14+ days
  • libp2p identify/ping still work (connection appears "alive")

Root cause(?): When lazy multistream-select is used, stream.Close() must complete the protocol handshake read. If the peer doesn't respond (network issues, overloaded, unclean disconnect), ReadNextToken() blocks forever with no deadline.

Fix

Set a read deadline before calling stream.Close() in SendMessage():

_ = s.SetReadDeadline(time.Now().Add(timeout))
return s.Close()

This ensures Close() times out instead of blocking indefinitely.

Related

• Root cause fix in go-libp2p: fix(basic_host): stream.Close() blocks indefinitely on unresponsive peers libp2p/go-libp2p#3448
• Original issue: https://github.com/ipshipyard/waterworks-infra/issues/860

Note

This PR is a localized fix for bitswap that can be shipped independently from the go-libp2p fix (defense in depth).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 61.11%. Comparing base (de0b141) to head (9937acb).
⚠️ Report is 2 commits behind head on main.

@@            Coverage Diff             @@
##             main    #1083      +/-   ##
==========================================
+ Coverage   61.08%   61.11%   +0.02%     
==========================================
  Files         264      264              
  Lines       26225    26227       +2     
==========================================
+ Hits        16020    16028       +8     
+ Misses       8525     8520       -5     
+ Partials     1680     1679       -1     

Files with missing lines	Coverage Δ
bitswap/network/bsnet/ipfs_impl.go	74.45% <100.00%> (-0.55%)	⬇️

... and 9 files with indirect coverage changes

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