Mercurial > hg > nginx-quic
view src/os/win32/ngx_wsarecv_chain.c @ 7870:e169cce912c7 quic
Avoid retransmitting of packets with discarded keys.
Sections 4.10.1 and 4.10.2 of quic transport describe discarding of initial
and handshake keys. Since the keys are discarded, we no longer need
to retransmit packets and corresponding queues should be emptied.
This patch removes previously added workaround that did not require
acknowledgement for initial packets, resulting in avoiding retransmission,
which is wrong because a packet could be lost and we have to retransmit it.
author | Vladimir Homutov <vl@nginx.com> |
---|---|
date | Mon, 18 May 2020 13:54:53 +0300 |
parents | efd71d49bde0 |
children | ecf2a9002b37 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_WSABUFS 8 ssize_t ngx_wsarecv_chain(ngx_connection_t *c, ngx_chain_t *chain, off_t limit) { int rc; u_char *prev; u_long bytes, flags; size_t n, size; ngx_err_t err; ngx_array_t vec; ngx_event_t *rev; LPWSABUF wsabuf; WSABUF wsabufs[NGX_WSABUFS]; prev = NULL; wsabuf = NULL; flags = 0; size = 0; bytes = 0; vec.elts = wsabufs; vec.nelts = 0; vec.size = sizeof(WSABUF); vec.nalloc = NGX_WSABUFS; vec.pool = c->pool; /* coalesce the neighbouring bufs */ while (chain) { n = chain->buf->end - chain->buf->last; if (limit) { if (size >= (size_t) limit) { break; } if (size + n > (size_t) limit) { n = (size_t) limit - size; } } if (prev == chain->buf->last) { wsabuf->len += n; } else { wsabuf = ngx_array_push(&vec); if (wsabuf == NULL) { return NGX_ERROR; } wsabuf->buf = (char *) chain->buf->last; wsabuf->len = n; } size += n; prev = chain->buf->end; chain = chain->next; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv: %d:%d", vec.nelts, wsabuf->len); rc = WSARecv(c->fd, vec.elts, vec.nelts, &bytes, &flags, NULL, NULL); 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; } #if (NGX_HAVE_FIONREAD) if (rev->available >= 0 && bytes > 0) { rev->available -= bytes; /* * negative rev->available means some additional bytes * were received between kernel notification and WSARecv(), * and therefore ev->ready can be safely reset even for * edge-triggered event methods */ if (rev->available < 0) { rev->available = 0; rev->ready = 0; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv: avail:%d", rev->available); } else if (bytes == size) { if (ngx_socket_nread(c->fd, &rev->available) == -1) { rev->error = 1; ngx_connection_error(c, ngx_socket_errno, ngx_socket_nread_n " failed"); return NGX_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSARecv: avail:%d", rev->available); } #endif if (bytes < size) { rev->ready = 0; } if (bytes == 0) { rev->eof = 1; } return bytes; }