view src/event/quic/ngx_event_quic_udp.c @ 9162:f9845e4b5c14

QUIC: simplified setting close timer when closing connection. Previously, the timer was never reset due to an explicit check. The check was added in 36b59521a41c as part of connection close simplification. The reason was to retain the earliest timeout. However, the timeouts are all the same while QUIC handshake is in progress and resetting the timer for the same value has no performance implications. After handshake completion there's only application level. The change removes the check.
author Roman Arutyunyan <arut@nginx.com>
date Thu, 14 Sep 2023 14:15:20 +0400
parents 68fa4b86ed46
children
line wrap: on
line source


/*
 * Copyright (C) Roman Arutyunyan
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_event_quic_connection.h>


static void ngx_quic_close_accepted_connection(ngx_connection_t *c);
static ngx_connection_t *ngx_quic_lookup_connection(ngx_listening_t *ls,
    ngx_str_t *key, struct sockaddr *local_sockaddr, socklen_t local_socklen);


void
ngx_quic_recvmsg(ngx_event_t *ev)
{
    ssize_t             n;
    ngx_str_t           key;
    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;
    ngx_quic_socket_t  *qsock;
    static u_char       buffer[NGX_QUIC_MAX_UDP_PAYLOAD_SIZE];

#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,
                   "quic 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,
                               "quic recvmsg() not ready");
                return;
            }

            ngx_log_error(NGX_LOG_ALERT, ev->log, err, "quic 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,
                          "quic 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 (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");
                goto next;
            }
        }

#endif

        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

        if (ngx_quic_get_packet_dcid(ev->log, buffer, n, &key) != NGX_OK) {
            goto next;
        }

        c = ngx_quic_lookup_connection(ls, &key, 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,
                               "quic 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;
            buf.start = buf.pos;
            buf.end = buffer + sizeof(buffer);

            qsock = ngx_quic_get_socket(c);

            ngx_memcpy(&qsock->sockaddr, sockaddr, socklen);
            qsock->socklen = socklen;

            c->udp->buffer = &buf;

            rev = c->read;
            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_quic_close_accepted_connection(c);
            return;
        }

        c->sockaddr = ngx_palloc(c->pool, NGX_SOCKADDRLEN);
        if (c->sockaddr == NULL) {
            ngx_quic_close_accepted_connection(c);
            return;
        }

        ngx_memcpy(c->sockaddr, sockaddr, socklen);

        log = ngx_palloc(c->pool, sizeof(ngx_log_t));
        if (log == NULL) {
            ngx_quic_close_accepted_connection(c);
            return;
        }

        *log = ls->log;

        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_quic_close_accepted_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_quic_close_accepted_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_quic_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_quic_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_debug4(NGX_LOG_DEBUG_EVENT, log, 0,
                           "*%uA quic recvmsg: %V fd:%d n:%z",
                           c->number, &addr, c->fd, n);
        }

        }
#endif

        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_quic_close_accepted_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 ngx_connection_t *
ngx_quic_lookup_connection(ngx_listening_t *ls, ngx_str_t *key,
    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_quic_socket_t  *qsock;

    if (key->len == 0) {
        return NULL;
    }

    node = ls->rbtree.root;
    sentinel = ls->rbtree.sentinel;
    hash = ngx_crc32_long(key->data, key->len);

    while (node != sentinel) {

        if (hash < node->key) {
            node = node->left;
            continue;
        }

        if (hash > node->key) {
            node = node->right;
            continue;
        }

        /* hash == node->key */

        qsock = (ngx_quic_socket_t *) node;

        rc = ngx_memn2cmp(key->data, qsock->sid.id, key->len, qsock->sid.len);

        c = qsock->udp.connection;

        if (rc == 0 && ls->wildcard) {
            rc = ngx_cmp_sockaddr(local_sockaddr, local_socklen,
                                  c->local_sockaddr, c->local_socklen, 1);
        }

        if (rc == 0) {
            c->udp = &qsock->udp;
            return c;
        }

        node = (rc < 0) ? node->left : node->right;
    }

    return NULL;
}