Mercurial > hg > nginx
view src/event/ngx_event_accept.c @ 7584:9d2ad2fb4423
SSL: available bytes handling (ticket #1431).
Added code to track number of bytes available in the socket.
This makes it possible to avoid looping for a long time while
working with fast enough peer when data are added to the socket buffer
faster than we are able to read and process data.
When kernel does not provide number of bytes available, it is
retrieved using ioctl(FIONREAD) as long as a buffer is filled by
SSL_read().
It is assumed that number of bytes returned by SSL_read() is close
to the number of bytes read from the socket, as we do not use
SSL compression. But even if it is not true for some reason, this
is not important, as we post an additional reading event anyway.
Note that data can be buffered at SSL layer, and it is not possible
to simply stop reading at some point and wait till the event will
be reported by the kernel again. This can be only done when there
are no data in SSL buffers, and there is no good way to find out if
it's the case.
Instead of trying to figure out if SSL buffers are empty, this patch
introduces events posted for the next event loop iteration - such
events will be processed only on the next event loop iteration,
after going into the kernel and retrieving additional events. This
seems to be simple and reliable approach.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 17 Oct 2019 16:02:24 +0300 |
parents | 88a624c9b491 |
children | fdc3d40979b0 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all); static void ngx_close_accepted_connection(ngx_connection_t *c); void ngx_event_accept(ngx_event_t *ev) { socklen_t socklen; ngx_err_t err; ngx_log_t *log; ngx_uint_t level; ngx_socket_t s; ngx_event_t *rev, *wev; ngx_sockaddr_t sa; ngx_listening_t *ls; ngx_connection_t *c, *lc; ngx_event_conf_t *ecf; #if (NGX_HAVE_ACCEPT4) static ngx_uint_t use_accept4 = 1; #endif if (ev->timedout) { if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) { return; } ev->timedout = 0; } ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module); if (!(ngx_event_flags & NGX_USE_KQUEUE_EVENT)) { ev->available = ecf->multi_accept; } lc = ev->data; ls = lc->listening; ev->ready = 0; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "accept on %V, ready: %d", &ls->addr_text, ev->available); do { socklen = sizeof(ngx_sockaddr_t); #if (NGX_HAVE_ACCEPT4) if (use_accept4) { s = accept4(lc->fd, &sa.sockaddr, &socklen, SOCK_NONBLOCK); } else { s = accept(lc->fd, &sa.sockaddr, &socklen); } #else s = accept(lc->fd, &sa.sockaddr, &socklen); #endif if (s == (ngx_socket_t) -1) { err = ngx_socket_errno; if (err == NGX_EAGAIN) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err, "accept() not ready"); return; } level = NGX_LOG_ALERT; if (err == NGX_ECONNABORTED) { level = NGX_LOG_ERR; } else if (err == NGX_EMFILE || err == NGX_ENFILE) { level = NGX_LOG_CRIT; } #if (NGX_HAVE_ACCEPT4) ngx_log_error(level, ev->log, err, use_accept4 ? "accept4() failed" : "accept() failed"); if (use_accept4 && err == NGX_ENOSYS) { use_accept4 = 0; ngx_inherited_nonblocking = 0; continue; } #else ngx_log_error(level, ev->log, err, "accept() failed"); #endif if (err == NGX_ECONNABORTED) { if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available--; } if (ev->available) { continue; } } if (err == NGX_EMFILE || err == NGX_ENFILE) { if (ngx_disable_accept_events((ngx_cycle_t *) ngx_cycle, 1) != NGX_OK) { return; } if (ngx_use_accept_mutex) { if (ngx_accept_mutex_held) { ngx_shmtx_unlock(&ngx_accept_mutex); ngx_accept_mutex_held = 0; } ngx_accept_disabled = 1; } else { ngx_add_timer(ev, ecf->accept_mutex_delay); } } return; } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_accepted, 1); #endif ngx_accept_disabled = ngx_cycle->connection_n / 8 - ngx_cycle->free_connection_n; c = ngx_get_connection(s, ev->log); if (c == NULL) { if (ngx_close_socket(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return; } c->type = SOCK_STREAM; #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, 1); #endif c->pool = ngx_create_pool(ls->pool_size, ev->log); if (c->pool == NULL) { ngx_close_accepted_connection(c); return; } if (socklen > (socklen_t) sizeof(ngx_sockaddr_t)) { socklen = sizeof(ngx_sockaddr_t); } c->sockaddr = ngx_palloc(c->pool, socklen); if (c->sockaddr == NULL) { ngx_close_accepted_connection(c); return; } ngx_memcpy(c->sockaddr, &sa, socklen); log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_accepted_connection(c); return; } /* set a blocking mode for iocp and non-blocking mode for others */ if (ngx_inherited_nonblocking) { if (ngx_event_flags & NGX_USE_IOCP_EVENT) { if (ngx_blocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_blocking_n " failed"); ngx_close_accepted_connection(c); return; } } } else { if (!(ngx_event_flags & NGX_USE_IOCP_EVENT)) { if (ngx_nonblocking(s) == -1) { ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_socket_errno, ngx_nonblocking_n " failed"); ngx_close_accepted_connection(c); return; } } } *log = ls->log; c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->log = log; c->pool->log = log; c->socklen = socklen; c->listening = ls; c->local_sockaddr = ls->sockaddr; c->local_socklen = ls->socklen; #if (NGX_HAVE_UNIX_DOMAIN) if (c->sockaddr->sa_family == AF_UNIX) { c->tcp_nopush = NGX_TCP_NOPUSH_DISABLED; c->tcp_nodelay = NGX_TCP_NODELAY_DISABLED; #if (NGX_SOLARIS) /* Solaris's sendfilev() supports AF_NCA, AF_INET, and AF_INET6 */ c->sendfile = 0; #endif } #endif rev = c->read; wev = c->write; wev->ready = 1; if (ngx_event_flags & NGX_USE_IOCP_EVENT) { rev->ready = 1; } if (ev->deferred_accept) { rev->ready = 1; #if (NGX_HAVE_KQUEUE || NGX_HAVE_EPOLLRDHUP) rev->available = 1; #endif } rev->log = log; wev->log = log; /* * TODO: MT: - ngx_atomic_fetch_add() * or protection by critical section or light mutex * * TODO: MP: - allocated in a shared memory * - ngx_atomic_fetch_add() * or protection by critical section or light mutex */ c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_handled, 1); #endif if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { ngx_close_accepted_connection(c); return; } c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->socklen, c->addr_text.data, ls->addr_text_max_len, 0); if (c->addr_text.len == 0) { ngx_close_accepted_connection(c); return; } } #if (NGX_DEBUG) { ngx_str_t addr; u_char text[NGX_SOCKADDR_STRLEN]; ngx_debug_accepted_connection(ecf, c); if (log->log_level & NGX_LOG_DEBUG_EVENT) { addr.data = text; addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_debug3(NGX_LOG_DEBUG_EVENT, log, 0, "*%uA accept: %V fd:%d", c->number, &addr, s); } } #endif if (ngx_add_conn && (ngx_event_flags & NGX_USE_EPOLL_EVENT) == 0) { if (ngx_add_conn(c) == NGX_ERROR) { ngx_close_accepted_connection(c); return; } } log->data = NULL; log->handler = NULL; ls->handler(c); if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available--; } } while (ev->available); } ngx_int_t ngx_trylock_accept_mutex(ngx_cycle_t *cycle) { if (ngx_shmtx_trylock(&ngx_accept_mutex)) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "accept mutex locked"); if (ngx_accept_mutex_held && ngx_accept_events == 0) { return NGX_OK; } if (ngx_enable_accept_events(cycle) == NGX_ERROR) { ngx_shmtx_unlock(&ngx_accept_mutex); return NGX_ERROR; } ngx_accept_events = 0; ngx_accept_mutex_held = 1; return NGX_OK; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "accept mutex lock failed: %ui", ngx_accept_mutex_held); if (ngx_accept_mutex_held) { if (ngx_disable_accept_events(cycle, 0) == NGX_ERROR) { return NGX_ERROR; } ngx_accept_mutex_held = 0; } return NGX_OK; } ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle) { ngx_uint_t i; ngx_listening_t *ls; ngx_connection_t *c; ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { c = ls[i].connection; if (c == NULL || c->read->active) { continue; } if (ngx_add_event(c->read, NGX_READ_EVENT, 0) == NGX_ERROR) { return NGX_ERROR; } } return NGX_OK; } static ngx_int_t ngx_disable_accept_events(ngx_cycle_t *cycle, ngx_uint_t all) { ngx_uint_t i; ngx_listening_t *ls; ngx_connection_t *c; ls = cycle->listening.elts; for (i = 0; i < cycle->listening.nelts; i++) { c = ls[i].connection; if (c == NULL || !c->read->active) { continue; } #if (NGX_HAVE_REUSEPORT) /* * do not disable accept on worker's own sockets * when disabling accept events due to accept mutex */ if (ls[i].reuseport && !all) { continue; } #endif if (ngx_del_event(c->read, NGX_READ_EVENT, NGX_DISABLE_EVENT) == NGX_ERROR) { return NGX_ERROR; } } return NGX_OK; } static void ngx_close_accepted_connection(ngx_connection_t *c) { ngx_socket_t fd; ngx_free_connection(c); fd = c->fd; c->fd = (ngx_socket_t) -1; if (ngx_close_socket(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno, ngx_close_socket_n " failed"); } if (c->pool) { ngx_destroy_pool(c->pool); } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif } u_char * ngx_accept_log_error(ngx_log_t *log, u_char *buf, size_t len) { return ngx_snprintf(buf, len, " while accepting new connection on %V", log->data); } #if (NGX_DEBUG) void ngx_debug_accepted_connection(ngx_event_conf_t *ecf, ngx_connection_t *c) { struct sockaddr_in *sin; ngx_cidr_t *cidr; ngx_uint_t i; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; ngx_uint_t n; #endif cidr = ecf->debug_connection.elts; for (i = 0; i < ecf->debug_connection.nelts; i++) { if (cidr[i].family != (ngx_uint_t) c->sockaddr->sa_family) { goto next; } switch (cidr[i].family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) c->sockaddr; for (n = 0; n < 16; n++) { if ((sin6->sin6_addr.s6_addr[n] & cidr[i].u.in6.mask.s6_addr[n]) != cidr[i].u.in6.addr.s6_addr[n]) { goto next; } } break; #endif #if (NGX_HAVE_UNIX_DOMAIN) case AF_UNIX: break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) c->sockaddr; if ((sin->sin_addr.s_addr & cidr[i].u.in.mask) != cidr[i].u.in.addr) { goto next; } break; } c->log->log_level = NGX_LOG_DEBUG_CONNECTION|NGX_LOG_DEBUG_ALL; break; next: continue; } } #endif