Mercurial > hg > nginx-quic
view src/event/ngx_event_acceptex.c @ 6957:83bae3d354ab
HTTP/2: fixed connection finalization.
All streams in connection must be finalized before the connection
itself can be finalized and all related memory is freed. That's
not always possible on the current event loop iteration.
Thus when the last stream is finalized, it sets the special read
event handler ngx_http_v2_handle_connection_handler() and posts
the event.
Previously, this handler didn't check the connection state and
could call the regular event handler on a connection that was
already in finalization stage. In the worst case that could
lead to a segmentation fault, since some data structures aren't
supposed to be used during connection finalization. Particularly,
the waiting queue can contain already freed streams, so the
WINDOW_UPDATE frame received by that moment could trigger
accessing to these freed streams.
Now, the connection error flag is explicitly checked in
ngx_http_v2_handle_connection_handler().
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 29 Mar 2017 20:21:01 +0300 |
parents | bcd442b585f0 |
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 void ngx_close_posted_connection(ngx_connection_t *c); void ngx_event_acceptex(ngx_event_t *rev) { ngx_listening_t *ls; ngx_connection_t *c; c = rev->data; ls = c->listening; c->log->handler = ngx_accept_log_error; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "AcceptEx: %d", c->fd); if (rev->ovlp.error) { ngx_log_error(NGX_LOG_CRIT, c->log, rev->ovlp.error, "AcceptEx() %V failed", &ls->addr_text); return; } /* SO_UPDATE_ACCEPT_CONTEXT is required for shutdown() to work */ if (setsockopt(c->fd, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT, (char *) &ls->fd, sizeof(ngx_socket_t)) == -1) { ngx_log_error(NGX_LOG_CRIT, c->log, ngx_socket_errno, "setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed for %V", &c->addr_text); /* TODO: close socket */ return; } ngx_getacceptexsockaddrs(c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &c->local_sockaddr, &c->local_socklen, &c->sockaddr, &c->socklen); if (ls->post_accept_buffer_size) { c->buffer->last += rev->available; c->buffer->end = c->buffer->start + ls->post_accept_buffer_size; } else { c->buffer = NULL; } if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { /* TODO: close socket */ 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) { /* TODO: close socket */ return; } } ngx_event_post_acceptex(ls, 1); c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); ls->handler(c); return; } ngx_int_t ngx_event_post_acceptex(ngx_listening_t *ls, ngx_uint_t n) { u_long rcvd; ngx_err_t err; ngx_log_t *log; ngx_uint_t i; ngx_event_t *rev, *wev; ngx_socket_t s; ngx_connection_t *c; for (i = 0; i < n; i++) { /* TODO: look up reused sockets */ s = ngx_socket(ls->sockaddr->sa_family, ls->type, 0); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, &ls->log, 0, ngx_socket_n " s:%d", s); if (s == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, &ls->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } c = ngx_get_connection(s, &ls->log); if (c == NULL) { return NGX_ERROR; } c->pool = ngx_create_pool(ls->pool_size, &ls->log); if (c->pool == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->buffer = ngx_create_temp_buf(c->pool, ls->post_accept_buffer_size + 2 * (ls->socklen + 16)); if (c->buffer == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->local_sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->local_sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } c->sockaddr = ngx_palloc(c->pool, ls->socklen); if (c->sockaddr == NULL) { ngx_close_posted_connection(c); return NGX_ERROR; } *log = ls->log; c->log = log; c->recv = ngx_recv; c->send = ngx_send; c->recv_chain = ngx_recv_chain; c->send_chain = ngx_send_chain; c->listening = ls; rev = c->read; wev = c->write; rev->ovlp.event = rev; wev->ovlp.event = wev; rev->handler = ngx_event_acceptex; rev->ready = 1; wev->ready = 1; rev->log = c->log; wev->log = c->log; if (ngx_add_event(rev, 0, NGX_IOCP_IO) == NGX_ERROR) { ngx_close_posted_connection(c); return NGX_ERROR; } if (ngx_acceptex(ls->fd, s, c->buffer->pos, ls->post_accept_buffer_size, ls->socklen + 16, ls->socklen + 16, &rcvd, (LPOVERLAPPED) &rev->ovlp) == 0) { err = ngx_socket_errno; if (err != WSA_IO_PENDING) { ngx_log_error(NGX_LOG_ALERT, &ls->log, err, "AcceptEx() %V failed", &ls->addr_text); ngx_close_posted_connection(c); return NGX_ERROR; } } } return NGX_OK; } static void ngx_close_posted_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); } } u_char * ngx_acceptex_log_error(ngx_log_t *log, u_char *buf, size_t len) { return ngx_snprintf(buf, len, " while posting AcceptEx() on %V", log->data); }