Mercurial > hg > nginx-quic
view src/os/win32/ngx_wsasend_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 | 2cd019520210 |
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 ngx_chain_t * ngx_wsasend_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc; u_char *prev; u_long size, sent, send, prev_send; ngx_err_t err; ngx_event_t *wev; ngx_array_t vec; ngx_chain_t *cl; LPWSABUF wsabuf; WSABUF wsabufs[NGX_WSABUFS]; wev = c->write; if (!wev->ready) { return in; } /* the maximum limit size is the maximum u_long value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_UINT32_VALUE - ngx_pagesize)) { limit = NGX_MAX_UINT32_VALUE - ngx_pagesize; } send = 0; /* * WSABUFs must be 4-byte aligned otherwise * WSASend() will return undocumented WSAEINVAL error. */ vec.elts = wsabufs; vec.size = sizeof(WSABUF); vec.nalloc = NGX_WSABUFS; vec.pool = c->pool; for ( ;; ) { prev = NULL; wsabuf = NULL; prev_send = send; vec.nelts = 0; /* create the WSABUF and coalesce the neighbouring bufs */ for (cl = in; cl && vec.nelts < ngx_max_wsabufs && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = (u_long) (limit - send); } if (prev == cl->buf->pos) { wsabuf->len += cl->buf->last - cl->buf->pos; } else { wsabuf = ngx_array_push(&vec); if (wsabuf == NULL) { return NGX_CHAIN_ERROR; } wsabuf->buf = (char *) cl->buf->pos; wsabuf->len = cl->buf->last - cl->buf->pos; } prev = cl->buf->last; send += size; } sent = 0; rc = WSASend(c->fd, vec.elts, vec.nelts, &sent, 0, NULL, NULL); if (rc == -1) { err = ngx_errno; if (err == WSAEWOULDBLOCK) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSASend() not ready"); } else { wev->error = 1; ngx_connection_error(c, err, "WSASend() failed"); return NGX_CHAIN_ERROR; } } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSASend: fd:%d, s:%ul", c->fd, sent); c->sent += sent; in = ngx_chain_update_sent(in, sent); if (send - prev_send != sent) { wev->ready = 0; return in; } if (send >= limit || in == NULL) { return in; } } } ngx_chain_t * ngx_overlapped_wsasend_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit) { int rc; u_char *prev; u_long size, send, sent; ngx_err_t err; ngx_event_t *wev; ngx_array_t vec; ngx_chain_t *cl; LPWSAOVERLAPPED ovlp; LPWSABUF wsabuf; WSABUF wsabufs[NGX_WSABUFS]; wev = c->write; if (!wev->ready) { return in; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "wev->complete: %d", wev->complete); if (!wev->complete) { /* post the overlapped WSASend() */ /* the maximum limit size is the maximum u_long value - the page size */ if (limit == 0 || limit > (off_t) (NGX_MAX_UINT32_VALUE - ngx_pagesize)) { limit = NGX_MAX_UINT32_VALUE - ngx_pagesize; } /* * WSABUFs must be 4-byte aligned otherwise * WSASend() will return undocumented WSAEINVAL error. */ vec.elts = wsabufs; vec.nelts = 0; vec.size = sizeof(WSABUF); vec.nalloc = NGX_WSABUFS; vec.pool = c->pool; send = 0; prev = NULL; wsabuf = NULL; /* create the WSABUF and coalesce the neighbouring bufs */ for (cl = in; cl && vec.nelts < ngx_max_wsabufs && send < limit; cl = cl->next) { if (ngx_buf_special(cl->buf)) { continue; } size = cl->buf->last - cl->buf->pos; if (send + size > limit) { size = (u_long) (limit - send); } if (prev == cl->buf->pos) { wsabuf->len += cl->buf->last - cl->buf->pos; } else { wsabuf = ngx_array_push(&vec); if (wsabuf == NULL) { return NGX_CHAIN_ERROR; } wsabuf->buf = (char *) cl->buf->pos; wsabuf->len = cl->buf->last - cl->buf->pos; } prev = cl->buf->last; send += size; } ovlp = (LPWSAOVERLAPPED) &c->write->ovlp; ngx_memzero(ovlp, sizeof(WSAOVERLAPPED)); rc = WSASend(c->fd, vec.elts, vec.nelts, &sent, 0, ovlp, NULL); wev->complete = 0; if (rc == -1) { err = ngx_errno; if (err == WSA_IO_PENDING) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "WSASend() posted"); wev->active = 1; return in; } else { wev->error = 1; ngx_connection_error(c, err, "WSASend() failed"); return NGX_CHAIN_ERROR; } } else 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 WSASend() was already complete */ wev->active = 1; return in; } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSASend: fd:%d, s:%ul", c->fd, sent); } else { /* the overlapped WSASend() complete */ wev->complete = 0; wev->active = 0; if (ngx_event_flags & NGX_USE_IOCP_EVENT) { if (wev->ovlp.error) { ngx_connection_error(c, wev->ovlp.error, "WSASend() failed"); return NGX_CHAIN_ERROR; } sent = wev->available; } else { if (WSAGetOverlappedResult(c->fd, (LPWSAOVERLAPPED) &wev->ovlp, &sent, 0, NULL) == 0) { ngx_connection_error(c, ngx_socket_errno, "WSASend() or WSAGetOverlappedResult() failed"); return NGX_CHAIN_ERROR; } } } ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "WSASend ovlp: fd:%d, s:%ul", c->fd, sent); c->sent += sent; in = ngx_chain_update_sent(in, sent); if (in) { wev->ready = 0; } else { wev->ready = 1; } return in; }