Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx> wrote: > On 10/11/2017 11:06 PM, David Miller wrote: > > From: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx> > > Date: Tue, 10 Oct 2017 16:14:19 +0200 > > > >> The goal of this patch is to leave common TCP code unmodified. Thus, > >> it uses netfilter hooks to intercept TCP SYN and SYN/ACK > >> packets. For outgoing packets originating from SMC sockets, the > >> experimental option is added. For inbound packets destined for SMC > >> sockets, the experimental option is checked. > > > > I think this really isn't going to pass. > > > > It's a user experience nightmare when the kernel inserts and > > deletes filtering rules outside of what the user configures > > on their system. It depends if the hook is passive or not (i.e. mangles payload/metadata or returns verdict other than NF_ACCEPT). OUTPUT hook added here is not passive as it mangles tcp options. > > This approach was also considerd for ipv6 ILA, and the same > > pushback was given. ahem. net/ipv6/ila/ila_xlat.c: err = nf_register_net_hooks(net, ila_nf_hook_ops, FWIW at least the input hook seems ok to me provided it would use skb_header_pointer for tcp header access (there is no guarantee tcp_hdr() works or that the tcp header has been sanity checked in any way). Perhaps its time to consider moving net/netfilter/core.c into net/core and rename NF_HOOK to NET_HOOK? -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
