Mercurial > hg > nginx
view src/event/ngx_event_udp.c @ 9138:a90f79792b5d
QUIC: optimized ACK delay.
Previously ACK was not generated if max_ack_delay was not yet expired and the
number of unacknowledged ack-eliciting packets was less than two, as allowed by
RFC 9000 13.2.1-13.2.2. However this only makes sense to avoid sending ACK-only
packets, as explained by the RFC:
On the other hand, reducing the frequency of packets that carry only
acknowledgments reduces packet transmission and processing cost at both
endpoints.
Now ACK is delayed only if output frame queue is empty. Otherwise ACK is sent
immediately, which significantly improves QUIC performance with certain tests.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 27 Jul 2023 16:37:17 +0400 |
parents | adcc6d8acfd4 |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if !(NGX_WIN32) static void ngx_close_accepted_udp_connection(ngx_connection_t *c); static ssize_t ngx_udp_shared_recv(ngx_connection_t *c, u_char *buf, size_t size); static ngx_int_t ngx_insert_udp_connection(ngx_connection_t *c); static ngx_connection_t *ngx_lookup_udp_connection(ngx_listening_t *ls, struct sockaddr *sockaddr, socklen_t socklen, struct sockaddr *local_sockaddr, socklen_t local_socklen); void ngx_event_recvmsg(ngx_event_t *ev) { ssize_t n; ngx_buf_t buf; ngx_log_t *log; ngx_err_t err; socklen_t socklen, local_socklen; ngx_event_t *rev, *wev; struct iovec iov[1]; struct msghdr msg; ngx_sockaddr_t sa, lsa; struct sockaddr *sockaddr, *local_sockaddr; ngx_listening_t *ls; ngx_event_conf_t *ecf; ngx_connection_t *c, *lc; static u_char buffer[65535]; #if (NGX_HAVE_ADDRINFO_CMSG) u_char msg_control[CMSG_SPACE(sizeof(ngx_addrinfo_t))]; #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, "recvmsg on %V, ready: %d", &ls->addr_text, ev->available); do { ngx_memzero(&msg, sizeof(struct msghdr)); iov[0].iov_base = (void *) buffer; iov[0].iov_len = sizeof(buffer); msg.msg_name = &sa; msg.msg_namelen = sizeof(ngx_sockaddr_t); msg.msg_iov = iov; msg.msg_iovlen = 1; #if (NGX_HAVE_ADDRINFO_CMSG) if (ls->wildcard) { msg.msg_control = &msg_control; msg.msg_controllen = sizeof(msg_control); ngx_memzero(&msg_control, sizeof(msg_control)); } #endif n = recvmsg(lc->fd, &msg, 0); if (n == -1) { err = ngx_socket_errno; if (err == NGX_EAGAIN) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err, "recvmsg() not ready"); return; } ngx_log_error(NGX_LOG_ALERT, ev->log, err, "recvmsg() failed"); return; } #if (NGX_HAVE_ADDRINFO_CMSG) if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) { ngx_log_error(NGX_LOG_ALERT, ev->log, 0, "recvmsg() truncated data"); continue; } #endif sockaddr = msg.msg_name; socklen = msg.msg_namelen; if (socklen > (socklen_t) sizeof(ngx_sockaddr_t)) { socklen = sizeof(ngx_sockaddr_t); } if (socklen == 0) { /* * on Linux recvmsg() returns zero msg_namelen * when receiving packets from unbound AF_UNIX sockets */ socklen = sizeof(struct sockaddr); ngx_memzero(&sa, sizeof(struct sockaddr)); sa.sockaddr.sa_family = ls->sockaddr->sa_family; } local_sockaddr = ls->sockaddr; local_socklen = ls->socklen; #if (NGX_HAVE_ADDRINFO_CMSG) if (ls->wildcard) { struct cmsghdr *cmsg; ngx_memcpy(&lsa, local_sockaddr, local_socklen); local_sockaddr = &lsa.sockaddr; for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { if (ngx_get_srcaddr_cmsg(cmsg, local_sockaddr) == NGX_OK) { break; } } } #endif c = ngx_lookup_udp_connection(ls, sockaddr, socklen, local_sockaddr, local_socklen); if (c) { #if (NGX_DEBUG) if (c->log->log_level & NGX_LOG_DEBUG_EVENT) { ngx_log_handler_pt handler; handler = c->log->handler; c->log->handler = NULL; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "recvmsg: fd:%d n:%z", c->fd, n); c->log->handler = handler; } #endif ngx_memzero(&buf, sizeof(ngx_buf_t)); buf.pos = buffer; buf.last = buffer + n; rev = c->read; c->udp->buffer = &buf; rev->ready = 1; rev->active = 0; rev->handler(rev); if (c->udp) { c->udp->buffer = NULL; } rev->ready = 0; rev->active = 1; goto next; } #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(lc->fd, ev->log); if (c == NULL) { return; } c->shared = 1; c->type = SOCK_DGRAM; c->socklen = socklen; #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_udp_connection(c); return; } c->sockaddr = ngx_palloc(c->pool, socklen); if (c->sockaddr == NULL) { ngx_close_accepted_udp_connection(c); return; } ngx_memcpy(c->sockaddr, sockaddr, socklen); log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_accepted_udp_connection(c); return; } *log = ls->log; c->recv = ngx_udp_shared_recv; c->send = ngx_udp_send; c->send_chain = ngx_udp_send_chain; c->need_flush_buf = 1; c->log = log; c->pool->log = log; c->listening = ls; if (local_sockaddr == &lsa.sockaddr) { local_sockaddr = ngx_palloc(c->pool, local_socklen); if (local_sockaddr == NULL) { ngx_close_accepted_udp_connection(c); return; } ngx_memcpy(local_sockaddr, &lsa, local_socklen); } c->local_sockaddr = local_sockaddr; c->local_socklen = local_socklen; c->buffer = ngx_create_temp_buf(c->pool, n); if (c->buffer == NULL) { ngx_close_accepted_udp_connection(c); return; } c->buffer->last = ngx_cpymem(c->buffer->last, buffer, n); rev = c->read; wev = c->write; rev->active = 1; wev->ready = 1; 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); c->start_time = ngx_current_msec; #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_udp_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_udp_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_debug4(NGX_LOG_DEBUG_EVENT, log, 0, "*%uA recvmsg: %V fd:%d n:%z", c->number, &addr, c->fd, n); } } #endif if (ngx_insert_udp_connection(c) != NGX_OK) { ngx_close_accepted_udp_connection(c); return; } log->data = NULL; log->handler = NULL; ls->handler(c); next: if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available -= n; } } while (ev->available); } static void ngx_close_accepted_udp_connection(ngx_connection_t *c) { ngx_free_connection(c); c->fd = (ngx_socket_t) -1; if (c->pool) { ngx_destroy_pool(c->pool); } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif } static ssize_t ngx_udp_shared_recv(ngx_connection_t *c, u_char *buf, size_t size) { ssize_t n; ngx_buf_t *b; if (c->udp == NULL || c->udp->buffer == NULL) { return NGX_AGAIN; } b = c->udp->buffer; n = ngx_min(b->last - b->pos, (ssize_t) size); ngx_memcpy(buf, b->pos, n); c->udp->buffer = NULL; c->read->ready = 0; c->read->active = 1; return n; } void ngx_udp_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_int_t rc; ngx_connection_t *c, *ct; ngx_rbtree_node_t **p; ngx_udp_connection_t *udp, *udpt; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ udp = (ngx_udp_connection_t *) node; c = udp->connection; udpt = (ngx_udp_connection_t *) temp; ct = udpt->connection; rc = ngx_memn2cmp(udp->key.data, udpt->key.data, udp->key.len, udpt->key.len); if (rc == 0 && c->listening->wildcard) { rc = ngx_cmp_sockaddr(c->local_sockaddr, c->local_socklen, ct->local_sockaddr, ct->local_socklen, 1); } p = (rc < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } static ngx_int_t ngx_insert_udp_connection(ngx_connection_t *c) { uint32_t hash; ngx_pool_cleanup_t *cln; ngx_udp_connection_t *udp; if (c->udp) { return NGX_OK; } udp = ngx_pcalloc(c->pool, sizeof(ngx_udp_connection_t)); if (udp == NULL) { return NGX_ERROR; } udp->connection = c; ngx_crc32_init(hash); ngx_crc32_update(&hash, (u_char *) c->sockaddr, c->socklen); if (c->listening->wildcard) { ngx_crc32_update(&hash, (u_char *) c->local_sockaddr, c->local_socklen); } ngx_crc32_final(hash); udp->node.key = hash; udp->key.data = (u_char *) c->sockaddr; udp->key.len = c->socklen; cln = ngx_pool_cleanup_add(c->pool, 0); if (cln == NULL) { return NGX_ERROR; } cln->data = c; cln->handler = ngx_delete_udp_connection; ngx_rbtree_insert(&c->listening->rbtree, &udp->node); c->udp = udp; return NGX_OK; } void ngx_delete_udp_connection(void *data) { ngx_connection_t *c = data; if (c->udp == NULL) { return; } ngx_rbtree_delete(&c->listening->rbtree, &c->udp->node); c->udp = NULL; } static ngx_connection_t * ngx_lookup_udp_connection(ngx_listening_t *ls, struct sockaddr *sockaddr, socklen_t socklen, struct sockaddr *local_sockaddr, socklen_t local_socklen) { uint32_t hash; ngx_int_t rc; ngx_connection_t *c; ngx_rbtree_node_t *node, *sentinel; ngx_udp_connection_t *udp; #if (NGX_HAVE_UNIX_DOMAIN) if (sockaddr->sa_family == AF_UNIX) { struct sockaddr_un *saun = (struct sockaddr_un *) sockaddr; if (socklen <= (socklen_t) offsetof(struct sockaddr_un, sun_path) || saun->sun_path[0] == '\0') { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0, "unbound unix socket"); return NULL; } } #endif node = ls->rbtree.root; sentinel = ls->rbtree.sentinel; ngx_crc32_init(hash); ngx_crc32_update(&hash, (u_char *) sockaddr, socklen); if (ls->wildcard) { ngx_crc32_update(&hash, (u_char *) local_sockaddr, local_socklen); } ngx_crc32_final(hash); while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ udp = (ngx_udp_connection_t *) node; c = udp->connection; rc = ngx_cmp_sockaddr(sockaddr, socklen, c->sockaddr, c->socklen, 1); if (rc == 0 && ls->wildcard) { rc = ngx_cmp_sockaddr(local_sockaddr, local_socklen, c->local_sockaddr, c->local_socklen, 1); } if (rc == 0) { return c; } node = (rc < 0) ? node->left : node->right; } return NULL; } #else void ngx_delete_udp_connection(void *data) { return; } #endif