intervals: do not report exact overlaps for new elements

Two new elements that represent an exact overlap should not trigger an error.

   add table t
   add set t s { type ipv4_addr; flags interval; }
   add element t s { 1.0.1.0/24 }
   ...
   add element t s { 1.0.1.0/24 }

result in a bogus error.

 # nft -f set.nft
 set.nft:1002:19-28: Error: conflicting intervals specified
 add element t s { 1.0.1.0/24 }
                   ^^^^^^^^^^

Fixes: 3da9643fb9ff ("intervals: add support to automerge with kernel elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 23 insertions, 2 deletions

diff --git a/src/intervals.c b/src/intervals.c
index bc414d6c..89f5c33d 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -540,8 +540,7 @@ static int setelem_overlap(struct list_head *msgs, struct set *set,
 		}
 
 		if (mpz_cmp(prev_range.low, range.low) == 0 &&
-		    mpz_cmp(prev_range.high, range.high) == 0 &&
-		    (elem->flags & EXPR_F_KERNEL || prev->flags & EXPR_F_KERNEL))
+		    mpz_cmp(prev_range.high, range.high) == 0)
 			goto next;
 
 		if (mpz_cmp(prev_range.low, range.low) <= 0 &&
diff --git a/tests/shell/testcases/sets/exact_overlap_0 b/tests/shell/testcases/sets/exact_overlap_0
new file mode 100755
index 00000000..1ce9304a
--- /dev/null
+++ b/tests/shell/testcases/sets/exact_overlap_0
@@ -0,0 +1,22 @@
+#!/bin/bash
+
+RULESET="add table t
+add set t s { type ipv4_addr; flags interval; }
+add element t s { 1.0.1.0/24 }
+add element t s { 1.0.2.0/23 }
+add element t s { 1.0.8.0/21 }
+add element t s { 1.0.32.0/19 }
+add element t s { 1.1.0.0/24 }
+add element t s { 1.1.2.0/23 }
+add element t s { 1.1.4.0/22 }
+add element t s { 1.1.8.0/24 }
+add element t s { 1.1.9.0/24 }
+add element t s { 1.1.10.0/23 }
+add element t s { 1.1.12.0/22 }
+add element t s { 1.1.16.0/20 }
+add element t s { 1.1.32.0/19 }
+add element t s { 1.0.1.0/24 }"
+
+$NFT -f - <<< $RULESET || exit 1
+
+$NFT add element t s { 1.0.1.0/24 }