From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v2 net-next 0/6] allow eBPF programs to be attached to sockets Date: Fri, 05 Dec 2014 21:48:18 -0800 (PST) Message-ID: <20141205.214818.1275634074992727284.davem@davemloft.net> References: <1417475199-15950-1-git-send-email-ast@plumgrid.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org, dborkman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, hannes-tFNcAqjVMyqKXQKiL6tip0B+6BGkLq7r@public.gmane.org, edumazet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org Return-path: In-Reply-To: <1417475199-15950-1-git-send-email-ast-uqk4Ao+rVK5Wk0Htik3J/w@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Alexei Starovoitov Date: Mon, 1 Dec 2014 15:06:33 -0800 > V1->V2: > > fixed comments in sample code to state clearly that packet data is accessed > with LD_ABS instructions and not internal skb fields. > Also replaced constants in: > BPF_LD_ABS(BPF_B, 14 + 9 /* R0 = ip->proto */), > with: > BPF_LD_ABS(BPF_B, ETH_HLEN + offsetof(struct iphdr, protocol) /* R0 = ip->proto */), > > V1 cover: > > Introduce BPF_PROG_TYPE_SOCKET_FILTER type of eBPF programs that can be > attached to sockets with setsockopt(). > Allow such programs to access maps via lookup/update/delete helpers. > > This feature was previewed by bpf manpage in commit b4fc1a460f30("Merge branch 'bpf-next'") > Now it can actually run. > > 1st patch adds LD_ABS/LD_IND instruction verification and > 2nd patch adds new setsockopt() flag. > Patches 3-6 are examples in assembler and in C. > > Though native eBPF programs are way more powerful than classic filters > (attachable through similar setsockopt() call), they don't have skb field > accessors yet. Like skb->pkt_type, skb->dev->ifindex are not accessible. > There are sevaral ways to achieve that. That will be in the next set of patches. > So in this set native eBPF programs can only read data from packet and > access maps. > > The most powerful example is sockex2_kern.c from patch 6 where ~200 lines of C > are compiled into ~300 of eBPF instructions. > It shows how quite complex packet parsing can be done. > > LLVM used to build examples is at https://github.com/iovisor/llvm > which is fork of llvm trunk that I'm cleaning up for upstreaming. Series applied, thanks.