Mercurial > hg > nginx
view src/os/win32/ngx_udp_wsarecv.c @ 9208:2ed3f57dca0a
QUIC: fixed unsent MTU probe acknowledgement.
Previously if an MTU probe send failed early in ngx_quic_frame_sendto()
due to allocation error or congestion control, the application level packet
number was not increased, but was still saved as MTU probe packet number.
Later when a packet with this number was acknowledged, the unsent MTU probe
was acknowledged as well. This could result in discovering a bigger MTU than
supported by the path, which could lead to EMSGSIZE (Message too long) errors
while sending further packets.
The problem existed since PMTUD was introduced in 58afcd72446f (1.25.2).
Back then only the unlikely memory allocation error could trigger it. However
in efcdaa66df2e congestion control was added to ngx_quic_frame_sendto() which
can now trigger the issue with a higher probability.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 14 Feb 2024 16:56:28 +0400 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ssize_t ngx_udp_wsarecv(ngx_connection_t *c, u_char *buf, size_t size) { int rc; u_long bytes, flags; WSABUF wsabuf[1]; ngx_err_t err; ngx_event_t *rev; wsabuf[0].buf = (char *) buf; wsabuf[0].len = size; flags = 0; bytes = 0; rc = WSARecv(c->fd, wsabuf, 1, &bytes, &flags, NULL, NULL); ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv: fd:%d rc:%d %ul of %z", c->fd, rc, bytes, size); rev = c->read; if (rc == -1) { rev->ready = 0; err = ngx_socket_errno; if (err == WSAEWOULDBLOCK) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSARecv() not ready"); return NGX_AGAIN; } rev->error = 1; ngx_connection_error(c, err, "WSARecv() failed"); return NGX_ERROR; } return bytes; } ssize_t ngx_udp_overlapped_wsarecv(ngx_connection_t *c, u_char *buf, size_t size) { int rc; u_long bytes, flags; WSABUF wsabuf[1]; ngx_err_t err; ngx_event_t *rev; LPWSAOVERLAPPED ovlp; rev = c->read; if (!rev->ready) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "second wsa post"); return NGX_AGAIN; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "rev->complete: %d", rev->complete); if (rev->complete) { rev->complete = 0; if (ngx_event_flags & NGX_USE_IOCP_EVENT) { if (rev->ovlp.error) { ngx_connection_error(c, rev->ovlp.error, "WSARecv() failed"); return NGX_ERROR; } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv ovlp: fd:%d %ul of %z", c->fd, rev->available, size); return rev->available; } if (WSAGetOverlappedResult(c->fd, (LPWSAOVERLAPPED) &rev->ovlp, &bytes, 0, NULL) == 0) { ngx_connection_error(c, ngx_socket_errno, "WSARecv() or WSAGetOverlappedResult() failed"); return NGX_ERROR; } ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv: fd:%d %ul of %z", c->fd, bytes, size); return bytes; } ovlp = (LPWSAOVERLAPPED) &rev->ovlp; ngx_memzero(ovlp, sizeof(WSAOVERLAPPED)); wsabuf[0].buf = (char *) buf; wsabuf[0].len = size; flags = 0; bytes = 0; rc = WSARecv(c->fd, wsabuf, 1, &bytes, &flags, ovlp, NULL); rev->complete = 0; ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv ovlp: fd:%d rc:%d %ul of %z", c->fd, rc, bytes, size); if (rc == -1) { err = ngx_socket_errno; if (err == WSA_IO_PENDING) { rev->active = 1; ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSARecv() posted"); return NGX_AGAIN; } rev->error = 1; ngx_connection_error(c, err, "WSARecv() failed"); return NGX_ERROR; } if (ngx_event_flags & NGX_USE_IOCP_EVENT) { /* * if a socket was bound with I/O completion port * then GetQueuedCompletionStatus() would anyway return its status * despite that WSARecv() was already complete */ rev->active = 1; return NGX_AGAIN; } rev->active = 0; return bytes; }