[+] add resource limit for max path id update

src/transport/xqc_conn.c

@@ -736,6 +736,10 @@ xqc_conn_create(xqc_engine_t *engine, xqc_cid_t *dcid, xqc_cid_t *scid,
         xc->conn_settings.init_max_path_id = XQC_DEFAULT_INIT_MAX_PATH_ID;
     }
 
+    if (xc->max_paths_count == 0) {
+        xc->max_paths_count = XQC_MAX_PATHS_COUNT;
+    }
+
     if (xc->conn_settings.probing_pkt_out_size == 0) {
         xc->conn_settings.probing_pkt_out_size = engine->default_conn_settings.probing_pkt_out_size;
     }

src/transport/xqc_conn.h

@@ -373,6 +373,7 @@ struct xqc_connection_s {
     uint32_t                        create_path_count;
     uint32_t                        validated_path_count;
     uint32_t                        active_path_count;
+    uint64_t                        max_paths_count;
 
     uint64_t                        curr_max_path_id;
     uint64_t                        local_max_path_id;

src/transport/xqc_frame.c

@@ -2070,18 +2070,10 @@ xqc_process_path_blocked_frame(xqc_connection_t *conn, xqc_packet_in_t *packet_i
         return XQC_OK;
     }
 
-    uint64_t pre_max_path_id = conn->local_max_path_id;
-    conn->local_max_path_id += (conn->local_max_path_id + 1) / 2;
-    if (xqc_conn_add_path_cid_sets(conn, pre_max_path_id + 1, conn->local_max_path_id) != XQC_OK) {
-        xqc_log(conn->log, XQC_LOG_ERROR, "|add_path_cid_sets_error|");
-        return -XQC_EMALLOC;
-    }
-
-    ret = xqc_write_max_path_id_to_packet(conn, conn->local_max_path_id);
-    if (ret != XQC_OK) {
-        xqc_log(conn->log, XQC_LOG_ERROR,
-                "|xqc_write_max_path_id_to_packet error|");
-        return ret;
+    if (xqc_conn_check_path_id_blocked(conn)   /* check whether all path ids have been used */
+        && (uint64_t)conn->create_path_count < conn->max_paths_count)  /* check whether touched path resource limit */
+    {
+        ret = xqc_conn_update_max_path_id(conn);
     }
 
     return ret;

src/transport/xqc_multipath.c

@@ -1641,5 +1641,37 @@ xqc_conn_trigger_cid_retirement_on_path(xqc_engine_t *engine, const xqc_cid_t *s
                 "|xqc_path_last_cid_retirement error|scid:%s|path_id:%ui|", xqc_scid_str(engine, scid), path_id);
     }
 
+    return ret;
+}
+
+xqc_bool_t
+xqc_conn_check_path_id_blocked(xqc_connection_t *conn)
+{
+    if (conn->create_path_count >= conn->local_max_path_id + 1) {
+        return XQC_TRUE;
+    }
+
+    return XQC_FALSE;
+}
+
+xqc_int_t
+xqc_conn_update_max_path_id(xqc_connection_t *conn)
+{
+    xqc_int_t ret = XQC_OK;
+    uint64_t pre_max_path_id = conn->local_max_path_id;
+    conn->local_max_path_id += (conn->local_max_path_id + 1) / 2;
+    conn->local_max_path_id = xqc_max(conn->local_max_path_id, conn->max_paths_count);
+    if (xqc_conn_add_path_cid_sets(conn, pre_max_path_id + 1, conn->local_max_path_id) != XQC_OK) {
+        xqc_log(conn->log, XQC_LOG_ERROR, "|add_path_cid_sets_error|");
+        return -XQC_EMALLOC;
+    }
+
+    ret = xqc_write_max_path_id_to_packet(conn, conn->local_max_path_id);
+    if (ret != XQC_OK) {
+        xqc_log(conn->log, XQC_LOG_ERROR,
+                "|xqc_write_max_path_id_to_packet error|");
+        return ret;
+    }
+
     return ret;
 }

src/transport/xqc_multipath.h

@@ -258,6 +258,8 @@ double xqc_path_recent_loss_rate(xqc_path_ctx_t *path);
 
 double xqc_conn_recent_loss_rate(xqc_connection_t *conn);
 
+xqc_bool_t xqc_conn_check_path_id_blocked(xqc_connection_t *conn);
+xqc_int_t xqc_conn_update_max_path_id(xqc_connection_t *conn);
 
 #endif /* XQC_MULTIPATH_H */