--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -31,10 +31,6 @@ static ngx_int_t ngx_http_process_connec
 static ngx_int_t ngx_http_process_user_agent(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 
-static ngx_int_t ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool,
-    ngx_uint_t alloc);
-static ngx_int_t ngx_http_set_virtual_server(ngx_http_request_t *r,
-    ngx_str_t *host);
 static ngx_int_t ngx_http_find_virtual_server(ngx_connection_t *c,
     ngx_http_virtual_names_t *virtual_names, ngx_str_t *host,
     ngx_http_request_t *r, ngx_http_core_srv_conf_t **cscfp);
@@ -52,7 +48,6 @@ static void ngx_http_keepalive_handler(n
 static void ngx_http_set_lingering_close(ngx_connection_t *c);
 static void ngx_http_lingering_close_handler(ngx_event_t *ev);
 static ngx_int_t ngx_http_post_action(ngx_http_request_t *r);
-static void ngx_http_close_request(ngx_http_request_t *r, ngx_int_t error);
 static void ngx_http_log_request(ngx_http_request_t *r);
 
 static u_char *ngx_http_log_error_handler(ngx_http_request_t *r,
@@ -303,54 +298,11 @@ ngx_http_init_connection(ngx_connection_
     hc->conf_ctx = hc->addr_conf->default_server->ctx;
 
 #if (NGX_HTTP_QUIC)
-
     if (hc->addr_conf->quic) {
-        ngx_quic_conf_t           *qcf;
-        ngx_http_connection_t     *phc;
-        ngx_http_core_loc_conf_t  *clcf;
-
-        hc->ssl = 1;
-
-#if (NGX_HTTP_V3)
-
-        if (hc->addr_conf->http3) {
-            ngx_int_t  rc;
-
-            rc = ngx_http_v3_init_connection(c);
-
-            if (rc == NGX_ERROR) {
-                ngx_http_close_connection(c);
-                return;
-            }
-
-            if (rc == NGX_DONE) {
-                return;
-            }
-        }
-
-#endif
-
-        if (c->quic == NULL) {
-            c->log->connection = c->number;
-
-            qcf = ngx_http_get_module_srv_conf(hc->conf_ctx,
-                                               ngx_http_quic_module);
-            ngx_quic_run(c, qcf);
+        if (ngx_http_quic_init(c) == NGX_DONE) {
             return;
         }
-
-        phc = c->quic->parent->data;
-
-        if (phc->ssl_servername) {
-            hc->ssl_servername = phc->ssl_servername;
-            hc->conf_ctx = phc->conf_ctx;
-
-            clcf = ngx_http_get_module_loc_conf(hc->conf_ctx,
-                                                ngx_http_core_module);
-            ngx_set_connection_log(c, clcf->error_log);
-        }
     }
-
 #endif
 
     ctx = ngx_palloc(c->pool, sizeof(ngx_http_log_ctx_t));
@@ -380,6 +332,13 @@ ngx_http_init_connection(ngx_connection_
     }
 #endif
 
+#if (NGX_HTTP_V3)
+    if (hc->addr_conf->http3) {
+        ngx_http_v3_init(c);
+        return;
+    }
+#endif
+
 #if (NGX_HTTP_SSL)
     {
     ngx_http_ssl_srv_conf_t  *sscf;
@@ -669,12 +628,6 @@ ngx_http_alloc_request(ngx_connection_t 
     r->method = NGX_HTTP_UNKNOWN;
     r->http_version = NGX_HTTP_VERSION_10;
 
-#if (NGX_HTTP_V3)
-    if (hc->addr_conf->http3) {
-        r->http_version = NGX_HTTP_VERSION_30;
-    }
-#endif
-
     r->headers_in.content_length_n = -1;
     r->headers_in.keep_alive_n = -1;
     r->headers_out.content_length_n = -1;
@@ -1140,16 +1093,7 @@ ngx_http_process_request_line(ngx_event_
             }
         }
 
-        switch (r->http_version) {
-#if (NGX_HTTP_V3)
-        case NGX_HTTP_VERSION_30:
-            rc = ngx_http_v3_parse_request(r, r->header_in);
-            break;
-#endif
-
-        default: /* HTTP/1.x */
-            rc = ngx_http_parse_request_line(r, r->header_in);
-        }
+        rc = ngx_http_parse_request_line(r, r->header_in);
 
         if (rc == NGX_OK) {
 
@@ -1157,7 +1101,7 @@ ngx_http_process_request_line(ngx_event_
 
             r->request_line.len = r->request_end - r->request_start;
             r->request_line.data = r->request_start;
-            r->request_length = r->header_in->pos - r->parse_start;
+            r->request_length = r->header_in->pos - r->request_start;
 
             ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                            "http request line: \"%V\"", &r->request_line);
@@ -1234,15 +1178,6 @@ ngx_http_process_request_line(ngx_event_
             break;
         }
 
-        if (rc == NGX_BUSY) {
-            if (ngx_handle_read_event(rev, 0) != NGX_OK) {
-                ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
-                return;
-            }
-
-            break;
-        }
-
         if (rc != NGX_AGAIN) {
 
             /* there was error while a request line parsing */
@@ -1272,8 +1207,8 @@ ngx_http_process_request_line(ngx_event_
             }
 
             if (rv == NGX_DECLINED) {
-                r->request_line.len = r->header_in->end - r->parse_start;
-                r->request_line.data = r->parse_start;
+                r->request_line.len = r->header_in->end - r->request_start;
+                r->request_line.data = r->request_start;
 
                 ngx_log_error(NGX_LOG_INFO, c->log, 0,
                               "client sent too long URI");
@@ -1437,7 +1372,7 @@ ngx_http_process_request_headers(ngx_eve
 
     cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
 
-    rc = NGX_OK;
+    rc = NGX_AGAIN;
 
     for ( ;; ) {
 
@@ -1453,7 +1388,7 @@ ngx_http_process_request_headers(ngx_eve
                 }
 
                 if (rv == NGX_DECLINED) {
-                    p = r->parse_start;
+                    p = r->header_name_start;
 
                     r->lingering_close = 1;
 
@@ -1473,7 +1408,7 @@ ngx_http_process_request_headers(ngx_eve
 
                     ngx_log_error(NGX_LOG_INFO, c->log, 0,
                                 "client sent too long header line: \"%*s...\"",
-                                len, r->parse_start);
+                                len, r->header_name_start);
 
                     ngx_http_finalize_request(r,
                                             NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
@@ -1491,32 +1426,21 @@ ngx_http_process_request_headers(ngx_eve
         /* the host header could change the server configuration context */
         cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
 
-        switch (r->http_version) {
-#if (NGX_HTTP_V3)
-        case NGX_HTTP_VERSION_30:
-            rc = ngx_http_v3_parse_header(r, r->header_in,
-                                          cscf->underscores_in_headers);
-            break;
-#endif
-
-        default: /* HTTP/1.x */
-            rc = ngx_http_parse_header_line(r, r->header_in,
-                                            cscf->underscores_in_headers);
-        }
+        rc = ngx_http_parse_header_line(r, r->header_in,
+                                        cscf->underscores_in_headers);
 
         if (rc == NGX_OK) {
 
-            r->request_length += r->header_in->pos - r->parse_start;
+            r->request_length += r->header_in->pos - r->header_name_start;
 
             if (r->invalid_header && cscf->ignore_invalid_headers) {
 
                 /* there was error while a header line parsing */
 
                 ngx_log_error(NGX_LOG_INFO, c->log, 0,
-                              "client sent invalid header line: \"%*s: %*s\"",
-                              r->header_name_end - r->header_name_start,
-                              r->header_name_start,
-                              r->header_end - r->header_start, r->header_start);
+                              "client sent invalid header line: \"%*s\"",
+                              r->header_end - r->header_name_start,
+                              r->header_name_start);
                 continue;
             }
 
@@ -1532,17 +1456,11 @@ ngx_http_process_request_headers(ngx_eve
 
             h->key.len = r->header_name_end - r->header_name_start;
             h->key.data = r->header_name_start;
-
-            if (h->key.data[h->key.len]) {
-                h->key.data[h->key.len] = '\0';
-            }
+            h->key.data[h->key.len] = '\0';
 
             h->value.len = r->header_end - r->header_start;
             h->value.data = r->header_start;
-
-            if (h->value.data[h->value.len]) {
-                h->value.data[h->value.len] = '\0';
-            }
+            h->value.data[h->value.len] = '\0';
 
             h->lowcase_key = ngx_pnalloc(r->pool, h->key.len);
             if (h->lowcase_key == NULL) {
@@ -1578,7 +1496,7 @@ ngx_http_process_request_headers(ngx_eve
             ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                            "http header done");
 
-            r->request_length += r->header_in->pos - r->parse_start;
+            r->request_length += r->header_in->pos - r->header_name_start;
 
             r->http_state = NGX_HTTP_PROCESS_REQUEST_STATE;
 
@@ -1693,7 +1611,7 @@ ngx_http_alloc_large_header_buffer(ngx_h
         return NGX_OK;
     }
 
-    old = r->parse_start;
+    old = request_line ? r->request_start : r->header_name_start;
 
     cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
 
@@ -1771,14 +1689,6 @@ ngx_http_alloc_large_header_buffer(ngx_h
     b->pos = new + (r->header_in->pos - old);
     b->last = new + (r->header_in->pos - old);
 
-    r->parse_start = new;
-
-    r->header_in = b;
-
-    if (r->http_version > NGX_HTTP_VERSION_11) {
-        return NGX_OK;
-    }
-
     if (request_line) {
         r->request_start = new;
 
@@ -1827,6 +1737,8 @@ ngx_http_alloc_large_header_buffer(ngx_h
         r->header_end = new + (r->header_end - old);
     }
 
+    r->header_in = b;
+
     return NGX_OK;
 }
 
@@ -2047,46 +1959,13 @@ ngx_http_process_request_header(ngx_http
         return NGX_ERROR;
     }
 
-    if (r->headers_in.host == NULL && r->http_version == NGX_HTTP_VERSION_11) {
+    if (r->headers_in.host == NULL && r->http_version > NGX_HTTP_VERSION_10) {
         ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                    "client sent HTTP/1.1 request without \"Host\" header");
         ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
         return NGX_ERROR;
     }
 
-    if (r->headers_in.host == NULL && r->http_version == NGX_HTTP_VERSION_20) {
-        ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
-                      "client sent HTTP/2 request without "
-                      "\":authority\" or \"Host\" header");
-        ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-        return NGX_ERROR;
-    }
-
-    if (r->http_version == NGX_HTTP_VERSION_30) {
-        if (r->headers_in.server.len == 0) {
-            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
-                          "client sent HTTP/3 request without "
-                          "\":authority\" or \"Host\" header");
-            ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-            return NGX_ERROR;
-        }
-
-        if (r->headers_in.host) {
-            if (r->headers_in.host->value.len != r->headers_in.server.len
-                || ngx_memcmp(r->headers_in.host->value.data,
-                              r->headers_in.server.data,
-                              r->headers_in.server.len)
-                   != 0)
-            {
-                ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
-                              "client sent HTTP/3 request with different "
-                              "values of \":authority\" and \"Host\" headers");
-                ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
-                return NGX_ERROR;
-            }
-        }
-    }
-
     if (r->headers_in.content_length) {
         r->headers_in.content_length_n =
                             ngx_atoof(r->headers_in.content_length->value.data,
@@ -2125,12 +2004,6 @@ ngx_http_process_request_header(ngx_http
         }
     }
 
-#if (NGX_HTTP_V3)
-    if (r->http_version == NGX_HTTP_VERSION_30) {
-        r->headers_in.chunked = 1;
-    }
-#endif
-
     if (r->headers_in.connection_type == NGX_HTTP_CONNECTION_KEEP_ALIVE) {
         if (r->headers_in.keep_alive) {
             r->headers_in.keep_alive_n =
@@ -2235,7 +2108,7 @@ ngx_http_process_request(ngx_http_reques
 }
 
 
-static ngx_int_t
+ngx_int_t
 ngx_http_validate_host(ngx_str_t *host, ngx_pool_t *pool, ngx_uint_t alloc)
 {
     u_char  *h, ch;
@@ -2326,7 +2199,7 @@ ngx_http_validate_host(ngx_str_t *host, 
 }
 
 
-static ngx_int_t
+ngx_int_t
 ngx_http_set_virtual_server(ngx_http_request_t *r, ngx_str_t *host)
 {
     ngx_int_t                  rc;
@@ -3744,7 +3617,7 @@ ngx_http_post_action(ngx_http_request_t 
 }
 
 
-static void
+void
 ngx_http_close_request(ngx_http_request_t *r, ngx_int_t rc)
 {
     ngx_connection_t  *c;
@@ -3965,15 +3838,15 @@ ngx_http_log_error_handler(ngx_http_requ
     len -= p - buf;
     buf = p;
 
-    if (r->request_line.data == NULL && r->parse_start) {
-        for (p = r->parse_start; p < r->header_in->last; p++) {
+    if (r->request_line.data == NULL && r->request_start) {
+        for (p = r->request_start; p < r->header_in->last; p++) {
             if (*p == CR || *p == LF) {
                 break;
             }
         }
 
-        r->request_line.len = p - r->parse_start;
-        r->request_line.data = r->parse_start;
+        r->request_line.len = p - r->request_start;
+        r->request_line.data = r->request_start;
     }
 
     if (r->request_line.len) {