From: Jeremy Sowden <jeremy@azazel.net>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Netfilter Devel <netfilter-devel@vger.kernel.org>
Subject: Re: [PATCH nftables] evaluate: add support for variables in map expressions
Date: Wed, 3 Apr 2024 08:38:41 +0100 [thread overview]
Message-ID: <20240403073841.GA907770@celephais.dreamlands> (raw)
In-Reply-To: <ZgyJ8yUi8CyOpEHX@calendula>
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On 2024-04-03, at 00:42:59 +0200, Pablo Neira Ayuso wrote:
> On Sun, Mar 24, 2024 at 02:59:07PM +0000, Jeremy Sowden wrote:
> > It is possible to use a variable to initialize a map, which is then used in a
> > map statement:
> >
> > define m = { ::1234 : 5678 }
> >
> > table ip6 nat {
> > map m {
> > typeof ip6 daddr : tcp dport;
> > elements = $m
> > }
> > chain prerouting {
> > ip6 nexthdr tcp redirect to ip6 daddr map @m
> > }
> > }
> >
> > However, if one tries to use the variable directly in the statement:
> >
> > define m = { ::1234 : 5678 }
> >
> > table ip6 nat {
> > chain prerouting {
> > ip6 nexthdr tcp redirect to ip6 daddr map $m
> > }
> > }
> >
> > nft rejects it:
> >
> > /space/azazel/tmp/ruleset.1067161.nft:5:47-48: Error: invalid mapping expression variable
> > ip6 nexthdr tcp redirect to ip6 daddr map $m
> > ~~~~~~~~~ ^^
> >
> > Extend `expr_evaluate_map` to allow it.
> >
> > Add a test-case.
>
> Thanks for your patch.
>
> > Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1067161
> > Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
> > ---
> > src/evaluate.c | 1 +
> > .../shell/testcases/maps/anonymous_snat_map_1 | 16 +++++
> > .../maps/dumps/anonymous_snat_map_1.json-nft | 58 +++++++++++++++++++
> > .../maps/dumps/anonymous_snat_map_1.nft | 5 ++
> > 4 files changed, 80 insertions(+)
> > create mode 100755 tests/shell/testcases/maps/anonymous_snat_map_1
> > create mode 100644 tests/shell/testcases/maps/dumps/anonymous_snat_map_1.json-nft
> > create mode 100644 tests/shell/testcases/maps/dumps/anonymous_snat_map_1.nft
> >
> > diff --git a/src/evaluate.c b/src/evaluate.c
> > index 1682ba58989e..d49213f8d6bd 100644
> > --- a/src/evaluate.c
> > +++ b/src/evaluate.c
> > @@ -2061,6 +2061,7 @@ static int expr_evaluate_map(struct eval_ctx *ctx, struct expr **expr)
>
> expr_evaluate_objmap() also needs a similar fix.
Cool. Will update and resend.
J.
> > mappings->set_flags |= NFT_SET_MAP;
> >
> > switch (map->mappings->etype) {
> > + case EXPR_VARIABLE:
> > case EXPR_SET:
> > if (ctx->ectx.key && ctx->ectx.key->etype == EXPR_CONCAT) {
> > key = expr_clone(ctx->ectx.key);
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prev parent reply other threads:[~2024-04-03 7:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-24 14:59 [PATCH nftables] evaluate: add support for variables in map expressions Jeremy Sowden
2024-03-24 14:59 ` [PATCH nftables] tests: shell: packetpath/flowtables: open all temporary files in /tmp Jeremy Sowden
2024-04-01 15:02 ` Pablo Neira Ayuso
2024-04-02 22:42 ` [PATCH nftables] evaluate: add support for variables in map expressions Pablo Neira Ayuso
2024-04-03 7:38 ` Jeremy Sowden [this message]
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