From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC912C4332F for ; Wed, 18 May 2022 22:15:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbiERWPM (ORCPT ); Wed, 18 May 2022 18:15:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229453AbiERWPL (ORCPT ); Wed, 18 May 2022 18:15:11 -0400 Received: from mail-qv1-xf30.google.com (mail-qv1-xf30.google.com [IPv6:2607:f8b0:4864:20::f30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1FA542044F0; Wed, 18 May 2022 15:15:10 -0700 (PDT) Received: by mail-qv1-xf30.google.com with SMTP id k8so2989368qvm.9; Wed, 18 May 2022 15:15:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=enoN8YamLTZQDCPT/IioiS3FR9i+0CD9q8GbGOVgy2E=; b=Y0dofW+vrrsSEtS+FB/J+Vo3e4uVyjyNqG9EN4QefQQpXySwr2AaCWGCi3u8DFn2rq FR9eRwL/AsDmizJ1r7aYsLYsX2pT8zeO7JjhCprp6WMw/DIcbGdIVzNFdaD48i5rE8K8 YcAp2/J3vDkG7VFhveCxnOKiQt94UNvGIi7uBf7BYGTVocyyABpmCtznjClRnCNYBoQI ogtfog6D9xGDdpe8D0aKhpljgqTypH+Xjy9j9y/fj1YyKmtAV52zjTBkYS9fxDI5yvk9 TPuZJnVflO7+AQPYTPOX9+sYG04oVeRJA05behpQTI4BK/IAuQzARIIgJyO7j/KPLLzK N7uQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=enoN8YamLTZQDCPT/IioiS3FR9i+0CD9q8GbGOVgy2E=; b=VAUQ0ntsi5TSPPfg85Ml3Wem6aFwIyRogjcFD0XydkuLP6QYPuxBWADL/G2NNH5cq7 R0Lc2BjmrRK6RJlbvhOxH83Kb2f/Re3Xo9ml6jX8mOwhotrTkqnHdq+9EennYXd8ykIq FJ9o/jTUbb1/+J7WzxwBDl5J6HeCb99XR/B/p/HfMjGW8Sn8ndjnsx8Pn78vujxSs5Ve QjfVawPalekNlGEAIaLzxJ68X4G4MIAMXl5L6ruXL/wYxhRY9R12GA+CFkH20pCMPFok +b7vQjzZfe5RHeehuHfOjI+vx78MItE+NIb+6GicUmXseLiY22YloxLLIgRPhCG93FOn vbIg== X-Gm-Message-State: AOAM530Pcr4jHMoQ0fmWw6czmURoJPJPmQdw05eslzX2TKq5wfeK2GXv fp8Iw6h4Ivz0NpOtPu114MkeEMbdckL80VF2QFsMaDu9 X-Google-Smtp-Source: ABdhPJxwW6aEFTfMhNTC0Qct8xHwec+vq6XWgLPrQqWwnegoSdKR5o9OuNKRUCwM0jEV9wFurPPCPUna5HaWBgwPv+g= X-Received: by 2002:ad4:5bea:0:b0:45b:1f7:eee7 with SMTP id k10-20020ad45bea000000b0045b01f7eee7mr1859026qvc.11.1652912109171; Wed, 18 May 2022 15:15:09 -0700 (PDT) MIME-Version: 1.0 References: <40e7ce4b79c86c46e5fbf22e9cafb51b9172da19.1652870182.git.lorenzo@kernel.org> <87y1yy8t6j.fsf@toke.dk> In-Reply-To: From: Alexei Starovoitov Date: Wed, 18 May 2022 15:14:58 -0700 Message-ID: Subject: Re: [PATCH v3 bpf-next 4/5] net: netfilter: add kfunc helper to add a new ct entry To: Lorenzo Bianconi Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , Lorenzo Bianconi , bpf , Network Development , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , "David S. Miller" , Jakub Kicinski , Eric Dumazet , Paolo Abeni , Pablo Neira Ayuso , Florian Westphal , netfilter-devel , Jesper Dangaard Brouer , Kumar Kartikeya Dwivedi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, May 18, 2022 at 2:09 PM Lorenzo Bianconi wrote: > > > Lorenzo Bianconi writes: > > > > > Introduce bpf_xdp_ct_add and bpf_skb_ct_add kfunc helpers in order to > > > add a new entry to ct map from an ebpf program. > > > Introduce bpf_nf_ct_tuple_parse utility routine. > > > > > > Signed-off-by: Lorenzo Bianconi > > > --- > > > net/netfilter/nf_conntrack_bpf.c | 212 +++++++++++++++++++++++++++---- > > > 1 file changed, 189 insertions(+), 23 deletions(-) > > > > > > diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c > > > index a9271418db88..3d31b602fdf1 100644 > > > --- a/net/netfilter/nf_conntrack_bpf.c > > > +++ b/net/netfilter/nf_conntrack_bpf.c > > > @@ -55,41 +55,114 @@ enum { > > > NF_BPF_CT_OPTS_SZ = 12, > > > }; > > > > > > -static struct nf_conn *__bpf_nf_ct_lookup(struct net *net, > > > - struct bpf_sock_tuple *bpf_tuple, > > > - u32 tuple_len, u8 protonum, > > > - s32 netns_id, u8 *dir) > > > +static int bpf_nf_ct_tuple_parse(struct bpf_sock_tuple *bpf_tuple, > > > + u32 tuple_len, u8 protonum, u8 dir, > > > + struct nf_conntrack_tuple *tuple) > > > { > > > - struct nf_conntrack_tuple_hash *hash; > > > - struct nf_conntrack_tuple tuple; > > > - struct nf_conn *ct; > > > + union nf_inet_addr *src = dir ? &tuple->dst.u3 : &tuple->src.u3; > > > + union nf_inet_addr *dst = dir ? &tuple->src.u3 : &tuple->dst.u3; > > > + union nf_conntrack_man_proto *sport = dir ? (void *)&tuple->dst.u > > > + : &tuple->src.u; > > > + union nf_conntrack_man_proto *dport = dir ? &tuple->src.u > > > + : (void *)&tuple->dst.u; > > > > > > if (unlikely(protonum != IPPROTO_TCP && protonum != IPPROTO_UDP)) > > > - return ERR_PTR(-EPROTO); > > > - if (unlikely(netns_id < BPF_F_CURRENT_NETNS)) > > > - return ERR_PTR(-EINVAL); > > > + return -EPROTO; > > > + > > > + memset(tuple, 0, sizeof(*tuple)); > > > > > > - memset(&tuple, 0, sizeof(tuple)); > > > switch (tuple_len) { > > > case sizeof(bpf_tuple->ipv4): > > > - tuple.src.l3num = AF_INET; > > > - tuple.src.u3.ip = bpf_tuple->ipv4.saddr; > > > - tuple.src.u.tcp.port = bpf_tuple->ipv4.sport; > > > - tuple.dst.u3.ip = bpf_tuple->ipv4.daddr; > > > - tuple.dst.u.tcp.port = bpf_tuple->ipv4.dport; > > > + tuple->src.l3num = AF_INET; > > > + src->ip = bpf_tuple->ipv4.saddr; > > > + sport->tcp.port = bpf_tuple->ipv4.sport; > > > + dst->ip = bpf_tuple->ipv4.daddr; > > > + dport->tcp.port = bpf_tuple->ipv4.dport; > > > break; > > > case sizeof(bpf_tuple->ipv6): > > > - tuple.src.l3num = AF_INET6; > > > - memcpy(tuple.src.u3.ip6, bpf_tuple->ipv6.saddr, sizeof(bpf_tuple->ipv6.saddr)); > > > - tuple.src.u.tcp.port = bpf_tuple->ipv6.sport; > > > - memcpy(tuple.dst.u3.ip6, bpf_tuple->ipv6.daddr, sizeof(bpf_tuple->ipv6.daddr)); > > > - tuple.dst.u.tcp.port = bpf_tuple->ipv6.dport; > > > + tuple->src.l3num = AF_INET6; > > > + memcpy(src->ip6, bpf_tuple->ipv6.saddr, sizeof(bpf_tuple->ipv6.saddr)); > > > + sport->tcp.port = bpf_tuple->ipv6.sport; > > > + memcpy(dst->ip6, bpf_tuple->ipv6.daddr, sizeof(bpf_tuple->ipv6.daddr)); > > > + dport->tcp.port = bpf_tuple->ipv6.dport; > > > break; > > > default: > > > - return ERR_PTR(-EAFNOSUPPORT); > > > + return -EAFNOSUPPORT; > > > } > > > + tuple->dst.protonum = protonum; > > > + tuple->dst.dir = dir; > > > + > > > + return 0; > > > +} > > > > > > - tuple.dst.protonum = protonum; > > > +struct nf_conn * > > > +__bpf_nf_ct_alloc_entry(struct net *net, struct bpf_sock_tuple *bpf_tuple, > > > + u32 tuple_len, u8 protonum, s32 netns_id, u32 timeout) > > > +{ > > > + struct nf_conntrack_tuple otuple, rtuple; > > > + struct nf_conn *ct; > > > + int err; > > > + > > > + if (unlikely(netns_id < BPF_F_CURRENT_NETNS)) > > > + return ERR_PTR(-EINVAL); > > > + > > > + err = bpf_nf_ct_tuple_parse(bpf_tuple, tuple_len, protonum, > > > + IP_CT_DIR_ORIGINAL, &otuple); > > > + if (err < 0) > > > + return ERR_PTR(err); > > > + > > > + err = bpf_nf_ct_tuple_parse(bpf_tuple, tuple_len, protonum, > > > + IP_CT_DIR_REPLY, &rtuple); > > > + if (err < 0) > > > + return ERR_PTR(err); > > > + > > > + if (netns_id >= 0) { > > > + net = get_net_ns_by_id(net, netns_id); > > > + if (unlikely(!net)) > > > + return ERR_PTR(-ENONET); > > > + } > > > + > > > + ct = nf_conntrack_alloc(net, &nf_ct_zone_dflt, &otuple, &rtuple, > > > + GFP_ATOMIC); > > > + if (IS_ERR(ct)) > > > + goto out; > > > + > > > + ct->timeout = timeout * HZ + jiffies; > > > + ct->status |= IPS_CONFIRMED; > > > + > > > + memset(&ct->proto, 0, sizeof(ct->proto)); > > > + if (protonum == IPPROTO_TCP) > > > + ct->proto.tcp.state = TCP_CONNTRACK_ESTABLISHED; > > > > Hmm, isn't it a bit limiting to hard-code this to ESTABLISHED > > connections? Presumably for TCP you'd want to use this when you see a > > SYN and then rely on conntrack to help with the subsequent state > > tracking for when the SYN-ACK comes back? What's the usecase for > > creating an entry in ESTABLISHED state, exactly? > > I guess we can even add a parameter and pass the state from the caller. > I was not sure if it is mandatory. It's probably cleaner and more flexible to split _alloc and _insert into two kfuncs and let bpf prog populate ct directly.