On 26/06/2019 16:33, Eyal Birger wrote: > Hi Nikolay, > > On Wed, 26 Jun 2019 14:58:52 +0300 > Nikolay Aleksandrov <niko...@cumulusnetworks.com> wrote: > >> Set the family based on the protocol otherwise protocol-neutral >> matches will have wrong information (e.g. NFPROTO_UNSPEC). In >> preparation for using NFPROTO_UNSPEC xt matches. >> >> Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com> >> --- >> net/sched/em_ipt.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/net/sched/em_ipt.c b/net/sched/em_ipt.c >> index 64dbafe4e94c..23965a071177 100644 >> --- a/net/sched/em_ipt.c >> +++ b/net/sched/em_ipt.c >> @@ -189,10 +189,12 @@ static int em_ipt_match(struct sk_buff *skb, >> struct tcf_ematch *em, case htons(ETH_P_IP): >> if (!pskb_network_may_pull(skb, sizeof(struct >> iphdr))) return 0; >> + state.pf = NFPROTO_IPV4; >> break; >> case htons(ETH_P_IPV6): >> if (!pskb_network_may_pull(skb, sizeof(struct >> ipv6hdr))) return 0; >> + state.pf = NFPROTO_IPV6; >> break; >> default: >> return 0; >> @@ -203,7 +205,7 @@ static int em_ipt_match(struct sk_buff *skb, >> struct tcf_ematch *em, if (skb->skb_iif) >> indev = dev_get_by_index_rcu(em->net, skb->skb_iif); >> >> - nf_hook_state_init(&state, im->hook, im->match->family, >> + nf_hook_state_init(&state, im->hook, state.pf, >> indev ?: skb->dev, skb->dev, NULL, >> em->net, NULL); >> acpar.match = im->match; > > I think this change is incompatible with current behavior. > > Consider the 'policy' match which matches the packet's xfrm state (sec_path) > with the provided user space parameters. The sec_path includes information > about the encapsulating packet's parameters whereas the current skb points to > the encapsulated packet, and the match is done on the encapsulating > packet's info. > > So if you have an IPv6 packet encapsulated within an IPv4 packet, the match > parameters should be done using IPv4 parameters, not IPv6. > > Maybe use the packet's family only if the match family is UNSPEC? > > Eyal. >
Hi Eyal, I see your point, I was wondering about the xfrm cases. :) In such case I think we can simplify the set and do it only on UNSPEC matches as you suggest. Maybe we should enforce the tc protocol based on the user-specified nfproto at least from iproute2 otherwise people can add mismatching rules (e.g. nfproto == v6, tc proto == v4). Thanks, Nik
