segtree: add missing non-matching segment to set in flat representation

 # cat test.nft
 add set x y { type ipv4_addr; }
 add element x y { 10.0.24.0/24 }
 # nft -f test.nft
 # nft delete element x y { 10.0.24.0/24 }

bogusly returns -ENOENT. The non-matching segment (0.0.0.0 with end-flag
set on) is not added to the set in the example above.

This patch also adds a test to cover this case.

Fixes: 4935a0d561b5 ("segtree: special handling for the first non-matching segment")
Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/shell/testcases/sets/0035add_set_elements_flat_0 b/tests/shell/testcases/sets/0035add_set_elements_flat_0
new file mode 100755
index 00000000..d914ba98
--- /dev/null
+++ b/tests/shell/testcases/sets/0035add_set_elements_flat_0
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+RULESET="add table ip x
+add set x y {type ipv4_addr; flags interval;}
+add element x y { 10.0.24.0/24 }
+"
+
+set -e
+$NFT -f - <<< "$RULESET"
+$NFT delete element x y { 10.0.24.0/24 }