new file mode 100644
--- /dev/null
+++ b/src/event/quic/ngx_event_quic_socket.c
@@ -0,0 +1,355 @@
+
+/*
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+#include <ngx_event_quic_connection.h>
+
+
+static ngx_int_t ngx_quic_create_temp_socket(ngx_connection_t *c,
+    ngx_quic_connection_t *qc, ngx_str_t *dcid, ngx_quic_path_t *path,
+    ngx_quic_client_id_t *cid);
+
+static void ngx_quic_unref_path(ngx_connection_t *c, ngx_quic_path_t *path);
+
+
+ngx_int_t
+ngx_quic_open_sockets(ngx_connection_t *c, ngx_quic_connection_t *qc,
+    ngx_quic_header_t *pkt)
+{
+    ngx_quic_path_t       *path;
+    ngx_quic_socket_t     *qsock;
+    ngx_quic_client_id_t  *cid;
+
+    /*
+     * qc->nclient_ids = 0
+     * qc->nsockets = 0
+     * qc->max_retired_seqnum = 0
+     * qc->client_seqnum = 0
+     */
+
+    ngx_queue_init(&qc->sockets);
+    ngx_queue_init(&qc->free_sockets);
+
+    ngx_queue_init(&qc->paths);
+    ngx_queue_init(&qc->free_paths);
+
+    ngx_queue_init(&qc->client_ids);
+    ngx_queue_init(&qc->free_client_ids);
+
+    qc->tp.original_dcid.len = pkt->odcid.len;
+    qc->tp.original_dcid.data = ngx_pstrdup(c->pool, &pkt->odcid);
+    if (qc->tp.original_dcid.data == NULL) {
+         return NGX_ERROR;
+    }
+
+    /* socket to use for further processing */
+    qsock = ngx_quic_alloc_socket(c, qc);
+    if (qsock == NULL) {
+        return NGX_ERROR;
+    }
+
+    /* socket is listening at new server id (autogenerated) */
+    if (ngx_quic_listen(c, qc, qsock) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    qc->tp.initial_scid.len = qsock->sid.len;
+    qc->tp.initial_scid.data = ngx_pnalloc(c->pool, qsock->sid.len);
+    if (qc->tp.initial_scid.data == NULL) {
+        goto failed;
+    }
+    ngx_memcpy(qc->tp.initial_scid.data, qsock->sid.id, qsock->sid.len);
+
+    /* for all packets except first, this is set at udp layer */
+    c->udp = &qsock->udp;
+
+    /* ngx_quic_get_connection(c) macro is now usable */
+
+    /* we have a client identified by scid */
+    cid = ngx_quic_create_client_id(c, &pkt->scid, 0, NULL);
+    if (cid == NULL) {
+        goto failed;
+    }
+
+    /* the client arrived from this path */
+    path = ngx_quic_add_path(c, c->sockaddr, c->socklen);
+    if (path == NULL) {
+        goto failed;
+    }
+
+    if (pkt->validated) {
+        path->state = NGX_QUIC_PATH_VALIDATED;
+        path->validated_at = ngx_time();
+    }
+
+    /* now bind socket to client and path */
+    ngx_quic_connect(c, qsock, path, cid);
+
+    if (ngx_quic_create_temp_socket(c, qc, &pkt->odcid, path, cid) != NGX_OK) {
+        goto failed;
+    }
+
+    /* use this socket as default destination */
+    qc->socket = qsock;
+
+    ngx_log_debug4(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic active socket is #%uL:%uL:%uL (%s)",
+                   qsock->sid.seqnum, qsock->cid->seqnum, qsock->path->seqnum,
+                   ngx_quic_path_state_str(qsock->path));
+
+    return NGX_OK;
+
+failed:
+
+    ngx_rbtree_delete(&c->listening->rbtree, &qsock->udp.node);
+    c->udp = NULL;
+
+    return NGX_ERROR;
+}
+
+
+static ngx_int_t
+ngx_quic_create_temp_socket(ngx_connection_t *c, ngx_quic_connection_t *qc,
+    ngx_str_t *dcid, ngx_quic_path_t *path, ngx_quic_client_id_t *cid)
+{
+    ngx_str_t              id;
+    ngx_quic_socket_t     *qsock;
+    ngx_quic_server_id_t  *sid;
+
+    qsock = ngx_quic_alloc_socket(c, qc);
+    if (qsock == NULL) {
+        return NGX_ERROR;
+    }
+
+    sid = &qsock->sid;
+
+    sid->seqnum = NGX_QUIC_UNSET_PN; /* mark socket as temporary */
+
+    sid->len = dcid->len;
+    ngx_memcpy(sid->id, dcid->data, dcid->len);
+
+    id.len = sid->len;
+    id.data = sid->id;
+
+    ngx_insert_udp_connection(c, &qsock->udp, &id);
+
+    ngx_queue_insert_tail(&qc->sockets, &qsock->queue);
+
+    qc->nsockets++;
+    qsock->quic = qc;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic socket #%L listening at sid:%xV nsock:%ui",
+                   (int64_t) sid->seqnum, &id, qc->nsockets);
+
+    ngx_quic_connect(c, qsock, path, cid);
+
+    return NGX_OK;
+}
+
+
+ngx_quic_socket_t *
+ngx_quic_alloc_socket(ngx_connection_t *c, ngx_quic_connection_t *qc)
+{
+    ngx_queue_t        *q;
+    ngx_quic_socket_t  *sock;
+
+    if (!ngx_queue_empty(&qc->free_sockets)) {
+
+        q = ngx_queue_head(&qc->free_sockets);
+        sock = ngx_queue_data(q, ngx_quic_socket_t, queue);
+
+        ngx_queue_remove(&sock->queue);
+
+        ngx_memzero(sock, sizeof(ngx_quic_socket_t));
+
+    } else {
+
+        sock = ngx_pcalloc(c->pool, sizeof(ngx_quic_socket_t));
+        if (sock == NULL) {
+            return NULL;
+        }
+    }
+
+    return sock;
+}
+
+
+void
+ngx_quic_close_socket(ngx_connection_t *c, ngx_quic_socket_t *qsock)
+{
+    ngx_quic_connection_t  *qc;
+
+    qc = ngx_quic_get_connection(c);
+
+    ngx_queue_remove(&qsock->queue);
+    ngx_queue_insert_head(&qc->free_sockets, &qsock->queue);
+
+    ngx_rbtree_delete(&c->listening->rbtree, &qsock->udp.node);
+    qc->nsockets--;
+
+    if (qsock->path) {
+        ngx_quic_unref_path(c, qsock->path);
+    }
+
+    if (qsock->cid) {
+        ngx_quic_unref_client_id(c, qsock->cid);
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic socket #%L closed nsock:%ui",
+                   (int64_t) qsock->sid.seqnum, qc->nsockets);
+}
+
+
+static void
+ngx_quic_unref_path(ngx_connection_t *c, ngx_quic_path_t *path)
+{
+    ngx_quic_connection_t  *qc;
+
+    path->refcnt--;
+
+    if (path->refcnt) {
+        return;
+    }
+
+    qc = ngx_quic_get_connection(c);
+
+    ngx_queue_remove(&path->queue);
+    ngx_queue_insert_head(&qc->free_paths, &path->queue);
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic path #%uL addr:%V removed",
+                   path->seqnum, &path->addr_text);
+}
+
+
+ngx_int_t
+ngx_quic_listen(ngx_connection_t *c, ngx_quic_connection_t *qc,
+    ngx_quic_socket_t *qsock)
+{
+    ngx_str_t              id;
+    ngx_quic_server_id_t  *sid;
+
+    sid = &qsock->sid;
+
+    sid->len = NGX_QUIC_SERVER_CID_LEN;
+
+    if (ngx_quic_create_server_id(c, sid->id) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    sid->seqnum = qc->server_seqnum++;
+
+    id.data = sid->id;
+    id.len = sid->len;
+
+    ngx_insert_udp_connection(c, &qsock->udp, &id);
+
+    ngx_queue_insert_tail(&qc->sockets, &qsock->queue);
+
+    qc->nsockets++;
+    qsock->quic = qc;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic socket #%uL listening at sid:%xV nsock:%ui",
+                   sid->seqnum, &id, qc->nsockets);
+
+    return NGX_OK;
+}
+
+
+void
+ngx_quic_connect(ngx_connection_t *c, ngx_quic_socket_t *sock,
+    ngx_quic_path_t *path, ngx_quic_client_id_t *cid)
+{
+    sock->path = path;
+    path->refcnt++;
+
+    sock->cid = cid;
+    cid->refcnt++;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "quic socket #%L connected to cid #%uL path:%uL",
+                   (int64_t) sock->sid.seqnum,
+                   sock->cid->seqnum, path->seqnum);
+}
+
+
+void
+ngx_quic_close_sockets(ngx_connection_t *c)
+{
+    ngx_queue_t            *q;
+    ngx_quic_socket_t      *qsock;
+    ngx_quic_connection_t  *qc;
+
+    qc = ngx_quic_get_connection(c);
+
+    ngx_quic_close_socket(c, qc->socket);
+
+    if (qc->backup) {
+        ngx_quic_close_socket(c, qc->backup);
+    }
+
+    while (!ngx_queue_empty(&qc->sockets)) {
+        q = ngx_queue_head(&qc->sockets);
+        qsock = ngx_queue_data(q, ngx_quic_socket_t, queue);
+
+        ngx_quic_close_socket(c, qsock);
+    }
+}
+
+
+ngx_quic_socket_t *
+ngx_quic_find_socket(ngx_connection_t *c, uint64_t seqnum)
+{
+    ngx_queue_t            *q;
+    ngx_quic_socket_t      *qsock;
+    ngx_quic_connection_t  *qc;
+
+    qc = ngx_quic_get_connection(c);
+
+    for (q = ngx_queue_head(&qc->sockets);
+         q != ngx_queue_sentinel(&qc->sockets);
+         q = ngx_queue_next(q))
+    {
+        qsock = ngx_queue_data(q, ngx_quic_socket_t, queue);
+
+        if (qsock->sid.seqnum == seqnum) {
+            return qsock;
+        }
+    }
+
+    return NULL;
+}
+
+
+ngx_quic_socket_t *
+ngx_quic_get_unconnected_socket(ngx_connection_t *c)
+{
+    ngx_queue_t            *q;
+    ngx_quic_socket_t      *sock;
+    ngx_quic_connection_t  *qc;
+
+    qc = ngx_quic_get_connection(c);
+
+    for (q = ngx_queue_head(&qc->sockets);
+         q != ngx_queue_sentinel(&qc->sockets);
+         q = ngx_queue_next(q))
+    {
+        sock = ngx_queue_data(q, ngx_quic_socket_t, queue);
+
+        if (sock->cid == NULL) {
+            return sock;
+        }
+    }
+
+    return NULL;
+ }
+
+