I sorry, my e-mail client goes bananaz.
> Sergey reports:
>
> With nf_tables it is not possible to use port range for masquerading.
> Masquerade statement has option "to [:port-port]" which give no effect
> to translation behavior. But it must change source port of packet to
> one from ":port-port" range.
>
> My network:
>
> +-----------------------------+
> | ROUTER |
> | |
> | Masquerade|
> | 10.0.0.1 1.1.1.1 |
> | +------+ +------+ |
> | | eth1 | | eth2 | |
> +-+--^---+-----------+---^--+-+
> | |
> | |
> +----v------+ +------v----+
> | | | |
> | 10.0.0.2 | | 1.1.1.2 |
> | | | |
> |PC1 | |PC2 |
> +-----------+ +-----------+
>
> For testing i used rule like this:
>
> rule ip nat POSTROUTING oifname eth2 masquerade to :666
>
> Run netcat for 1.1.1.2 667(UDP) and get dump from PC2:
>
> 15:22:25.591567 a8:f9:4b:aa:08:44 > a8:f9:4b:ac:e7:8f,
ethertype IPv4 (0x0800), length 60: 1.1.1.1.34466 > 1.1.1.2.667: UDP,
length 1
>
> Address translation works fine, but source port are not belongs to
> specified range.
>
> I see in similar source code (i.e. nft_redir.c, nft_nat.c) that
> there is setting NF_NAT_RANGE_PROTO_SPECIFIED flag. After adding this,
> repeat test for kernel with this patch, and get dump:
>
> 16:16:22.324710 a8:f9:4b:aa:08:44 > a8:f9:4b:ac:e7:8f,
ethertype IPv4 (0x0800), length 60: 1.1.1.1.666 > 1.1.1.2.667: UDP, length 1
>
> Now it is works fine.
>
> Reported-by: Sergey Marinkevich <s@xxxxxxxxxxxxxx>
> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
> ---
> Sergey, could you try this userspace patch instead? Thanks.
I tried this patch with equal environment but another
net(192.168.122.0/24). Router uses vanilla kernel v5.4.19.
Translation is the same.
12:59:11.599887 08:00:27:ec:9c:b3 > 52:54:00:57:d2:7d, ethertype
IPv4 (0x0800), length 60: 192.168.122.38.666 > 192.168.122.1.667: UDP,
length 4
I think i have to add this tag:
Tested-by: Sergey Marinkevich <s@xxxxxxxxxxxxxx>
>
> src/evaluate.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/src/evaluate.c b/src/evaluate.c
> index 4a23b231c74d..d0e712dc02f0 100644
> --- a/src/evaluate.c
> +++ b/src/evaluate.c
> @@ -18,6 +18,7 @@
> #include <linux/netfilter_arp.h>
> #include <linux/netfilter/nf_tables.h>
> #include <linux/netfilter/nf_synproxy.h>
> +#include <linux/netfilter/nf_nat.h>
> #include <linux/netfilter_ipv4.h>
> #include <netinet/ip_icmp.h>
> #include <netinet/icmp6.h>
> @@ -2950,6 +2951,8 @@ static int stmt_evaluate_nat(struct eval_ctx
*ctx, struct stmt *stmt)
> err = nat_evaluate_transport(ctx, stmt, &stmt->nat.proto);
> if (err < 0)
> return err;
> +
> + stmt->nat.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
> }
>
> stmt->flags |= STMT_F_TERMINAL;
> --
> 2.11.0
