KarpelesLab / slirp / 23945403486

71%

push

github

Add nettest: network impairment simulator and TCP stress tests

New sub-package vtcp/nettest/ provides a test fixture for stress-testing
the vtcp TCP implementation under adversarial network conditions.

Link — simulated network with configurable per-direction impairments:
  - Packet loss (probabilistic drop)
  - Reordering (random delay on selected packets)
  - Delay + jitter (base latency with uniform random variation)
  - Duplication (probabilistic packet duplication)
  Delayed packets use a time-ordered priority queue with a single timer.

Pair — creates two vtcp.Conn endpoints connected through a Link with
  automatic handshake support.

Stats — per-direction counters for sent/delivered/dropped/reordered/
  duplicated packets and total bytes.

Stress tests with data integrity verification (SHA-256):
  - Clean baseline: 256KB at 291 MB/s
  - 5ms delay: 64KB at 1.7 MB/s
  - 25ms delay: 64KB at 0.4 MB/s
  - 1% loss: 32KB with RTO recovery
  - 5% loss: 32KB with heavy retransmission
  - 10% reorder: 64KB with dup ACK recovery
  - Combined (2% loss + 10ms delay + 5% reorder): 32KB
  - Bidirectional: both directions simultaneously
  - Benchmark: 430 MB/s single-segment throughput (i9-14900K)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

156 of 169 new or added lines in 1 file covered. (92.31%)

2605 of 3496 relevant lines covered (74.51%)

20.21 hits per line