Re: [PATCH net-next] netfilter: arptables: use xt_entry_foreach() in copy_entries_to_user()

Simon Horman [off-list ref] wrote:

On Mon, Jan 19, 2026 at 12:07:04PM +0530, Kshitiz Bartariya wrote:

quoted

Replace the manual offset-based iteration with xt_entry_foreach(),
thereby removing FIXME. The byte offset semantics and user ABI
are preserved.

Signed-off-by: Kshitiz Bartariya <redacted>
---
 net/ipv4/netfilter/arp_tables.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 1cdd9c28ab2d..9f82ce0fcaa5 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c

@@ -684,12 +684,11 @@ static int copy_entries_to_user(unsigned int total_size,
 
 	loc_cpu_entry = private->entries;
 
-	/* FIXME: use iterator macros --RR */
-	/* ... then go back and fix counters and names */
-	for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
+	num = 0;
+	xt_entry_foreach(e, loc_cpu_entry, total_size) {
 		const struct xt_entry_target *t;
 
-		e = loc_cpu_entry + off;
+		off = (unsigned char *)e - (unsigned char *)loc_cpu_entry;

This offset calculation makes me feel queasy.

Can the code start with off = 0 and increment it by e->next_offset
as the loop iterates, as was the case before this patch?
It would be similar to how num is handled.

I think this file should just be left alone resp. should be restricted
to bug fixes only.  Same for ip/ip6/ebtables.

Its too early to remove this file from the tree, but I don't see
value in making cosmetic improvements, sorry.