Re: kernel v4.8: iptables logs are truncated with the 4.8 kernel?

[Liping Zhang]

Hi Justin,

2016-10-05 6:02 GMT+08:00 Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx>:
> Hello,
>
> kernel 4.8 with ulogd-2.0.5- IPs are no longer logged:
>
> Oct  4 17:51:30 atom INPUT_BLOCK IN=eth1 OUT=
> MAC=00:1b:21:9c:3b:fa:3e:94:d5:d2:49:1e:08:00 LEN=0 TOS=00 PREC=0x00
> TTL=0 ID=0 PROTO=0 MARK=0
> Oct  4 17:51:31 atom INPUT_BLOCK IN=eth1 OUT=
> MAC=00:1b:21:9c:3b:fa:3e:94:d5:d2:49:1e:08:00 LEN=0 TOS=00 PREC=0x00
> TTL=0 ID=0 PROTO=0 MARK=0
> Oct  4 17:51:32 atom INPUT_BLOCK IN=eth1 OUT=
> MAC=00:1b:21:9c:3b:fa:3e:94:d5:d2:49:1e:08:00 LEN=0 TOS=00 PREC=0x00
> TTL=0 ID=0 PROTO=0 MARK=0
>
> (reboot back to kernel 4.7, works fine)
>
> kernel 4.7 with ulogd-2.0.5:
> Oct  4 17:56:44 atom INPUT_BLOCK IN=eth1 OUT=
> MAC=00:1b:21:9c:3b:fa:3e:94:d5:d2:49:1e:08:00 SRC=74.125.22.125
> DST=1.2.3.4 LEN=397 TOS=00 PREC=0x00 TTL=48 ID=58093 PROTO=TCP
> SPT=5222 DPT=19804 SEQ=2032644254 ACK=2273184383 WINDOW=55272 ACK PSH
> URGP=0 MARK=0
> Oct  4 17:56:45 atom INPUT_BLOCK IN=eth1 OUT=
> MAC=00:1b:21:9c:3b:fa:3e:94:d5:d2:49:1e:08:00 SRC=74.125.22.125
> DST=1.2.3.4 LEN=397 TOS=00 PREC=0x00 TTL=48 ID=58725 PROTO=TCP
> SPT=5222 DPT=19804 SEQ=2032644254 ACK=2273184383 WINDOW=55272 ACK PSH
> URGP=0 MARK=0
>
> Looks like there were some changes in the 4.8 kernel regarding ulogd,
> has anyone else run into this problem?
>
>                 } ulog;
> +               if ((li->u.ulog.flags & NF_LOG_F_COPY_LEN) &&
> +                   (li->u.ulog.copy_len < data_len))
> +                       data_len = li->u.ulog.copy_len;
>                 li->u.ulog.group = ntohs(nla_get_be16(tb[NFTA_LOG_GROUP]));
> +                       li->u.ulog.flags |= NF_LOG_F_COPY_LEN;
>                         li->u.ulog.copy_len =
>                 if (nla_put_be16(skb, NFTA_LOG_GROUP, htons(li->u.ulog.group)))
> -               if (li->u.ulog.copy_len) {
> +               if (li->u.ulog.flags & NF_LOG_F_COPY_LEN) {
>                                          htonl(li->u.ulog.copy_len)))
>         li.u.ulog.group      = info->group;
>         li.u.ulog.qthreshold = info->threshold;
> +               li.u.ulog.flags |= NF_LOG_F_COPY_LEN;
>
> Thanks,
>
> Justin.

Which one are you using? iptables or nftables?

Could you please paste the related iptables/nftables rules here?