Mercurial > hg > nginx-quic
view src/os/win32/ngx_wsasend_chain.c @ 5992:174512857ccf
Cache: do not inherit last_modified and etag from stale response.
When replacing a stale cache entry, its last_modified and etag could be
inherited from the old entry if the response code is not 200 or 206. Moreover,
etag could be inherited with any response code if it's missing in the new
response. As a result, the cache entry is left with invalid last_modified or
etag which could lead to broken revalidation.
For example, when a file is deleted from backend, its last_modified is copied to
the new 404 cache entry and is used later for revalidation. Once the old file
appears again with its original timestamp, revalidation succeeds and the cached
404 response is sent to client instead of the file.
The problem appeared with etags in 44b9ab7752e3 (1.7.3) and affected
last_modified in 1573fc7875fa (1.7.9).
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 02 Mar 2015 19:47:13 +0300 |
parents | de68ed551bfb |
children | 2cd019520210 |
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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; }