From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sargun Dhillon Subject: Re: [PATCH v3 5/6] net: core: run cgroup eBPF egress programs Date: Mon, 29 Aug 2016 15:23:36 -0700 Message-ID: <20160829222335.GA29919@ircssh.c.rugged-nimbus-611.internal> References: <1472241532-11682-1-git-send-email-daniel@zonque.org> <1472241532-11682-6-git-send-email-daniel@zonque.org> <57C4B12B.2070302@iogearbox.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Daniel Mack , htejun@fb.com, ast@fb.com, davem@davemloft.net, kafai@fb.com, fw@strlen.de, pablo@netfilter.org, harald@redhat.com, netdev@vger.kernel.org To: Daniel Borkmann Return-path: Received: from mail-it0-f48.google.com ([209.85.214.48]:34461 "EHLO mail-it0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbcH2WYP (ORCPT ); Mon, 29 Aug 2016 18:24:15 -0400 Received: by mail-it0-f48.google.com with SMTP id e63so19722411ith.1 for ; Mon, 29 Aug 2016 15:23:39 -0700 (PDT) Content-Disposition: inline In-Reply-To: <57C4B12B.2070302@iogearbox.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Aug 30, 2016 at 12:03:23AM +0200, Daniel Borkmann wrote: > On 08/26/2016 09:58 PM, Daniel Mack wrote: > >If the cgroup associated with the receiving socket has an eBPF > >programs installed, run them from __dev_queue_xmit(). > > > >eBPF programs used in this context are expected to either return 1 to > >let the packet pass, or != 1 to drop them. The programs have access to > >the full skb, including the MAC headers. > > > >Note that cgroup_bpf_run_filter() is stubbed out as static inline nop > >for !CONFIG_CGROUP_BPF, and is otherwise guarded by a static key if > >the feature is unused. > > > >Signed-off-by: Daniel Mack > >--- > > net/core/dev.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > >diff --git a/net/core/dev.c b/net/core/dev.c > >index a75df86..17484e6 100644 > >--- a/net/core/dev.c > >+++ b/net/core/dev.c > >@@ -141,6 +141,7 @@ > > #include > > #include > > #include > >+#include > > > > #include "net-sysfs.h" > > > >@@ -3329,6 +3330,11 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) > > if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP)) > > __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED); > > > >+ rc = cgroup_bpf_run_filter(skb->sk, skb, > >+ BPF_ATTACH_TYPE_CGROUP_INET_EGRESS); > >+ if (rc) > >+ return rc; > > This would leak the whole skb by the way. > > Apart from that, could this be modeled w/o affecting the forwarding path (at some > local output point where we know to have a valid socket)? Then you could also drop > the !sk and sk->sk_family tests, and we wouldn't need to replicate parts of what > clsact is doing as well. Hmm, maybe access to src/dst mac could be handled to be > just zeroes since not available at that point? > > > /* Disable soft irqs for various locks below. Also > > * stops preemption for RCU. > > */ > > Given this patchset only effects AF_INET, and AF_INET6, why not put the hooks at ip_output, and ip6_output