From add6a384e9444dfba86ae493a07bf3641e74126e Mon Sep 17 00:00:00 2001 From: Arthur de Kerhor Date: Mon, 16 May 2022 19:46:22 +0200 Subject: stats: fix collector updates of symlinks A node name is not bound to a node index. For example, if an interface is deleted and re-added, the indexes of its nodes "-tx" and "-output" may change. Thus, when the collector updates the nodes stats, it should first delete all the symlinks for nodes that have changed their names before adding new symlinks. Otherwise, it could attempt to add already existing symlinks or delete valid ones. Example of a series of command that triggers a crash in the assert `ASSERT (node_data[i].symlinks[j] != CLIB_U32_MAX);`: ``` create loopback interface create loopback interface ``` Wait for the nodes stats to update, then: ``` delete loopback interface intfc loop0 delete loopback interface intfc loop1 create loopback interface create loopback interface ``` Type: fix Change-Id: Ief8e7135e5c02dc6bc64dc94b76cff21ea9ab3a9 Signed-off-by: Arthur de Kerhor --- src/vlib/stats/collector.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/vlib/stats/collector.c b/src/vlib/stats/collector.c index 36d54a4fa71..c27d2fc65d8 100644 --- a/src/vlib/stats/collector.c +++ b/src/vlib/stats/collector.c @@ -61,15 +61,21 @@ update_node_counters (vlib_stats_segment_t *sm) vlib_stats_segment_lock (); clib_bitmap_foreach (i, bmp) { - vlib_node_t *n = node_dups[0][i]; if (node_data[i].name) { vec_free (node_data[i].name); for (j = 0; j < ARRAY_LEN (node_data->symlinks); j++) vlib_stats_remove_entry (node_data[i].symlinks[j]); } - - node_data[i].name = vec_dup (node_dups[0][i]->name); + } + /* We can't merge the loops because a node index corresponding to a given + * node name can change between 2 updates. Otherwise, we could add + * already existing symlinks or delete valid ones. + */ + clib_bitmap_foreach (i, bmp) + { + vlib_node_t *n = node_dups[0][i]; + node_data[i].name = vec_dup (n->name); vlib_stats_set_string_vector (&node_names, n->index, "%v", n->name); for (int j = 0; j < ARRAY_LEN (node_counters); j++) -- cgit 1.2.3-korg