Mercurial > hg > nginx
view src/os/unix/ngx_recv.c @ 8058:f3510cb959d1
Events: fixed EPOLLRDHUP with FIONREAD (ticket #2367).
When reading exactly rev->available bytes, rev->available might become 0
after FIONREAD usage introduction in efd71d49bde0. On the next call of
ngx_readv_chain() on systems with EPOLLRDHUP this resulted in return without
any actions, that is, with rev->ready set, and this in turn resulted in no
timers set in event pipe, leading to socket leaks.
Fix is to reset rev->ready in ngx_readv_chain() when returning due to
rev->available being 0 with EPOLLRDHUP, much like it is already done in
ngx_unix_recv(). This ensures that if rev->available will become 0, on
systems with EPOLLRDHUP support appropriate EPOLLRDHUP-specific handling
will happen on the next ngx_readv_chain() call.
While here, also synced ngx_readv_chain() to match ngx_unix_recv() and
reset rev->ready when returning due to rev->available being 0 with kqueue.
This is mostly cosmetic change, as rev->ready is anyway reset when
rev->available is set to 0.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 15 Jul 2022 15:19:32 +0300 |
parents | 5119c8150478 |
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_unix_recv(ngx_connection_t *c, u_char *buf, size_t size) { ssize_t n; ngx_err_t err; ngx_event_t *rev; rev = c->read; #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: eof:%d, avail:%d, err:%d", rev->pending_eof, rev->available, rev->kq_errno); if (rev->available == 0) { if (rev->pending_eof) { rev->ready = 0; rev->eof = 1; if (rev->kq_errno) { rev->error = 1; ngx_set_socket_errno(rev->kq_errno); return ngx_connection_error(c, rev->kq_errno, "kevent() reported about an closed connection"); } return 0; } else { rev->ready = 0; return NGX_AGAIN; } } } #endif #if (NGX_HAVE_EPOLLRDHUP) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: eof:%d, avail:%d", rev->pending_eof, rev->available); if (rev->available == 0 && !rev->pending_eof) { rev->ready = 0; return NGX_AGAIN; } } #endif do { n = recv(c->fd, buf, size, 0); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: fd:%d %z of %uz", c->fd, n, size); if (n == 0) { rev->ready = 0; rev->eof = 1; #if (NGX_HAVE_KQUEUE) /* * on FreeBSD recv() may return 0 on closed socket * even if kqueue reported about available data */ if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available = 0; } #endif return 0; } if (n > 0) { #if (NGX_HAVE_KQUEUE) if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { rev->available -= n; /* * rev->available may be negative here because some additional * bytes may be received between kevent() and recv() */ if (rev->available <= 0) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif #if (NGX_HAVE_FIONREAD) if (rev->available >= 0) { rev->available -= n; /* * negative rev->available means some additional bytes * were received between kernel notification and recv(), * 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, "recv: avail:%d", rev->available); } else if ((size_t) n == size) { if (ngx_socket_nread(c->fd, &rev->available) == -1) { n = ngx_connection_error(c, ngx_socket_errno, ngx_socket_nread_n " failed"); break; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "recv: avail:%d", rev->available); } #endif #if (NGX_HAVE_EPOLLRDHUP) if ((ngx_event_flags & NGX_USE_EPOLL_EVENT) && ngx_use_epoll_rdhup) { if ((size_t) n < size) { if (!rev->pending_eof) { rev->ready = 0; } rev->available = 0; } return n; } #endif if ((size_t) n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) { rev->ready = 0; } return n; } err = ngx_socket_errno; if (err == NGX_EAGAIN || err == NGX_EINTR) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err, "recv() not ready"); n = NGX_AGAIN; } else { n = ngx_connection_error(c, err, "recv() failed"); break; } } while (err == NGX_EINTR); rev->ready = 0; if (n == NGX_ERROR) { rev->error = 1; } return n; }