| Message ID | 20160607073309.GA9381@sonyv |
|---|---|
| State | Changes Requested |
| Delegated to: | Pablo Neira |
| Headers | show |
On Tue, Jun 07, 2016 at 09:33:13AM +0200, Laura Garcia Liebana wrote: > diff --git a/extensions/libip6t_frag.c b/extensions/libip6t_frag.c > index 023df62..7871fb9 100644 > --- a/extensions/libip6t_frag.c > +++ b/extensions/libip6t_frag.c > @@ -173,6 +173,35 @@ static void frag_save(const void *ip, const struct xt_entry_match *match) > printf(" --fraglast"); > } > > +static int frag_xlate(const void *ip, const struct xt_entry_match *match, > + struct xt_xlate *xl, int numeric) > +{ > + const struct ip6t_frag *fraginfo = (struct ip6t_frag *)match->data; > + > + if (!(fraginfo->ids[0] == 0 && fraginfo->ids[1] == 0xFFFFFFFF)) { > + xt_xlate_add(xl, "frag id %s", > + (fraginfo->invflags & IP6T_FRAG_INV_IDS) ? > + "!= " : ""); > + if (fraginfo->ids[0] != fraginfo->ids[1]) > + xt_xlate_add(xl, "%u-%u ", fraginfo->ids[0], > + fraginfo->ids[1]); > + else > + xt_xlate_add(xl, "%u ", fraginfo->ids[0]); > + } > + > + if (fraginfo->flags & IP6T_FRAG_RES) > + xt_xlate_add(xl, "frag reserved 1 "); > + > + if (fraginfo->flags & IP6T_FRAG_FST) > + xt_xlate_add(xl, "frag frag-off 0 "); > + > + if ((fraginfo->flags & IP6T_FRAG_MF) || > + (fraginfo->flags & IP6T_FRAG_NMF)) > + xt_xlate_add(xl, "frag more-fragments 1 "); I think IP6T_FRAG_NMF means no more fragments, ie. frag more-fragments 0. While IP6T_FRAG_MF means more fragments, ie. frag more-fragments 1. Please, review the logic that we have in the kernel module when providing correct translations. http://lxr.free-electrons.com/source/net/ipv6/netfilter/ip6t_frag.c It would be also good if you test these rules from the packet path, by generating traffic to trigger matches, not only from a control plane perspective. Thanks. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/extensions/libip6t_frag.c b/extensions/libip6t_frag.c index 023df62..7871fb9 100644 --- a/extensions/libip6t_frag.c +++ b/extensions/libip6t_frag.c @@ -173,6 +173,35 @@ static void frag_save(const void *ip, const struct xt_entry_match *match) printf(" --fraglast"); } +static int frag_xlate(const void *ip, const struct xt_entry_match *match, + struct xt_xlate *xl, int numeric) +{ + const struct ip6t_frag *fraginfo = (struct ip6t_frag *)match->data; + + if (!(fraginfo->ids[0] == 0 && fraginfo->ids[1] == 0xFFFFFFFF)) { + xt_xlate_add(xl, "frag id %s", + (fraginfo->invflags & IP6T_FRAG_INV_IDS) ? + "!= " : ""); + if (fraginfo->ids[0] != fraginfo->ids[1]) + xt_xlate_add(xl, "%u-%u ", fraginfo->ids[0], + fraginfo->ids[1]); + else + xt_xlate_add(xl, "%u ", fraginfo->ids[0]); + } + + if (fraginfo->flags & IP6T_FRAG_RES) + xt_xlate_add(xl, "frag reserved 1 "); + + if (fraginfo->flags & IP6T_FRAG_FST) + xt_xlate_add(xl, "frag frag-off 0 "); + + if ((fraginfo->flags & IP6T_FRAG_MF) || + (fraginfo->flags & IP6T_FRAG_NMF)) + xt_xlate_add(xl, "frag more-fragments 1 "); + + return 1; +} + static struct xtables_match frag_mt6_reg = { .name = "frag", .version = XTABLES_VERSION, @@ -185,6 +214,7 @@ static struct xtables_match frag_mt6_reg = { .save = frag_save, .x6_parse = frag_parse, .x6_options = frag_opts, + .xlate = frag_xlate, }; void
Add translation for frag to nftables. According to the --fraglen code: case O_FRAGLEN: /* * As of Linux 3.0, the kernel does not check for * fraglen at all. */ In addition, the kernel code doesn't show any reference to the flag IP6T_FRAG_LEN, so this option is deprecated and won't be translated to nft. Examples: $ sudo iptables-translate -t filter -A INPUT -m frag --fragid 100:200 -j ACCEPT nft add rule ip6 filter INPUT frag id 100-200 counter accept $ sudo iptables-translate -t filter -A INPUT -m frag --fragid 100 --fragres --fragmore -j ACCEPT nft add rule ip6 filter INPUT frag id 100 frag reserved 1 frag more-fragments 1 counter accept $ sudo iptables-translate -t filter -A INPUT -m frag ! --fragid 100:200 -j ACCEPT nft add rule ip6 filter INPUT frag id != 100-200 counter accept $ sudo iptables-translate -t filter -A INPUT -m frag --fragid 100:200 --fraglast -j ACCEPT nft add rule ip6 filter INPUT frag id 100-200 frag more-fragments 1 counter accept $ sudo iptables-translate -t filter -A INPUT -m frag --fragid 100:200 --fragfirst -j ACCEPT nft add rule ip6 filter INPUT frag id 100-200 frag frag-off 0 counter accept Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> --- Changes in v2: - Include translation for fragfirst and fraglast. - fraglen is marked as deprecated. Changes in v3: - Ignore completely IP6T_FRAG_LEN. extensions/libip6t_frag.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)