When passing no upper size limit, the dynset expression forces an internal 64k upperlimit. In some cases, this can result in 'nft -f' to restore the ruleset. Avoid this by always setting the EVAL flag on a set definition when we encounter packet-path update attempt in the batch. Reported-by: Yi Chen <yiche@xxxxxxxxxx> Suggested-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Florian Westphal <fw@xxxxxxxxx> --- src/evaluate.c | 10 ++++++ .../testcases/sets/dumps/dynset_missing.nft | 12 +++++++ tests/shell/testcases/sets/dynset_missing | 32 +++++++++++++++++++ 3 files changed, 54 insertions(+) create mode 100644 tests/shell/testcases/sets/dumps/dynset_missing.nft create mode 100755 tests/shell/testcases/sets/dynset_missing diff --git a/src/evaluate.c b/src/evaluate.c index 8edefbd1be21..437eacb8209f 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -3621,6 +3621,7 @@ static int stmt_evaluate_log(struct eval_ctx *ctx, struct stmt *stmt) static int stmt_evaluate_set(struct eval_ctx *ctx, struct stmt *stmt) { + struct set *this_set; struct stmt *this; expr_set_context(&ctx->ectx, NULL, 0); @@ -3650,6 +3651,15 @@ static int stmt_evaluate_set(struct eval_ctx *ctx, struct stmt *stmt) "statement must be stateful"); } + this_set = stmt->set.set->set; + + /* Make sure EVAL flag is set on set definition so that kernel + * picks a set that allows updates from the packet path. + * + * Alternatively we could error out in case 'flags dynamic' was + * not given, but we can repair this here. + */ + this_set->flags |= NFT_SET_EVAL; return 0; } diff --git a/tests/shell/testcases/sets/dumps/dynset_missing.nft b/tests/shell/testcases/sets/dumps/dynset_missing.nft new file mode 100644 index 000000000000..6c8ed323bdc9 --- /dev/null +++ b/tests/shell/testcases/sets/dumps/dynset_missing.nft @@ -0,0 +1,12 @@ +table ip test { + set dlist { + type ipv4_addr + size 65535 + flags dynamic + } + + chain output { + type filter hook output priority filter; policy accept; + udp dport 1234 update @dlist { ip daddr } counter packets 0 bytes 0 + } +} diff --git a/tests/shell/testcases/sets/dynset_missing b/tests/shell/testcases/sets/dynset_missing new file mode 100755 index 000000000000..fdf5f49edb9c --- /dev/null +++ b/tests/shell/testcases/sets/dynset_missing @@ -0,0 +1,32 @@ +#!/bin/bash + +set -e + +$NFT -f /dev/stdin <<EOF +table ip test { + chain output { type filter hook output priority 0; + } +} +EOF + +# misses 'flags dynamic' +$NFT 'add set ip test dlist {type ipv4_addr; }' + +# picks rhash backend because 'size' was also missing. +$NFT 'add rule ip test output udp dport 1234 update @dlist { ip daddr } counter' + +tmpfile=$(mktemp) + +trap "rm -rf $tmpfile" EXIT + +# kernel has forced an 64k upper size, i.e. this restore file +# has 'size 65536' but no 'flags dynamic'. +$NFT list ruleset > $tmpfile + +# this restore works, because set is still the rhash backend. +$NFT -f $tmpfile # success +$NFT flush ruleset + +# fails without commit 'attempt to set_eval flag if dynamic updates requested', +# because set in $tmpfile has 'size x' but no 'flags dynamic'. +$NFT -f $tmpfile -- 2.34.1