Absorb upstream #20: route decrypted RX through netif->input - #5
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The decrypted-RX path called ip_input() directly on the caller's task,
entering the lwIP core concurrently with tcpip_thread. Under sustained
TCP traffic through the tunnel this double-frees a sent-segment pbuf
('pbuf_free: p->ref > 0' assert) and reboots the device.
ml_wg_mgr already sets netif->input = tcpip_input, i.e. the integration
intends all input serialized through the tcpip mailbox; the direct
ip_input() call bypassed that. Hand the pbuf to netif->input instead so
the lwIP core is only entered from tcpip_thread.
Verified on ESP32-S3 (ESP-IDF v5.3): multi-hundred-KB TCP relays that
previously crashed mid-transfer now run to completion.
Fixes #17
(cherry picked from commit e74be46)
Upstream-PR: CamM2325#20
Upstream-Issue: CamM2325#17
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Cherry-picks
e74be464from CamM2325/microlink#20 by @snowpaper (fixes CamM2325/microlink#17), plus a docs commit updating this fork'swireguard_lwip/README.mddivergence record so the fix doesn't get "rediscovered" on a future upstream sync attempt. Author attribution on the code commit preserved viagit cherry-pick -x.Why we're absorbing this ourselves: upstream has had zero maintainer activity (no comments, no reviews) on any open PR since the last commit on 2026-03-17.
What it fixes: the decrypted-RX path called
ip_input()directly on the caller's task, entering the lwIP core concurrently withtcpip_thread— under sustained TCP traffic this double-frees a pbuf (pbuf_free: p->ref > 0) and reboots the device. Notably, our own fork'sml_wg_mgr.calready setsnetif->input = tcpip_inputand has a comment claiming decrypted packets are posted to the TCPIP thread — this PR is what actually makes that true; before it, the assignment was a no-op for the RX path sinceip_input()never consultednetif->input.Applied cleanly (
git apply --check) against our diverged fork. Built clean forlilygo-t-display-s3(ESP-IDF 6.0.1) in the downstream ZenClock project.