Mercurial > hg > nginx
view src/event/ngx_event_acceptex.c @ 7674:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +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); }