From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next 2/2] Add a eBPF helper function to retrieve socket uid Date: Thu, 02 Feb 2017 22:32:55 +0100 Message-ID: <5893A587.6090000@iogearbox.net> References: <20170202205950.100334-1-chenbofeng.kernel@gmail.com> <20170202205950.100334-3-chenbofeng.kernel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Willem de Bruijn , Lorenzo Colitti , Chenbo Feng To: Chenbo Feng , "David S . Miller" , Alexei Starovoitov , netdev@vger.kernel.org Return-path: Received: from www62.your-server.de ([213.133.104.62]:48625 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751298AbdBBVdO (ORCPT ); Thu, 2 Feb 2017 16:33:14 -0500 In-Reply-To: <20170202205950.100334-3-chenbofeng.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 02/02/2017 09:59 PM, Chenbo Feng wrote: > From: Chenbo Feng > > Returns the owner uid of the socket inside a sk_buff. This is useful to > perform per-UID accounting of network traffic or per-UID packet > filtering. > > Signed-off-by: Chenbo Feng > --- > include/linux/bpf.h | 1 + > include/uapi/linux/bpf.h | 9 ++++++++- > net/core/filter.c | 19 +++++++++++++++++++ > 3 files changed, 28 insertions(+), 1 deletion(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 3f2e0af28c6e..c775ca4678b7 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -350,6 +350,7 @@ extern const struct bpf_func_proto bpf_skb_vlan_push_proto; > extern const struct bpf_func_proto bpf_skb_vlan_pop_proto; > extern const struct bpf_func_proto bpf_get_stackid_proto; > extern const struct bpf_func_proto bpf_get_socket_cookie_proto; > +extern const struct bpf_func_proto bpf_get_socket_uid_proto; Likewise, no need to add it here. > /* Shared helpers among cBPF and eBPF. */ > void bpf_user_rnd_init_once(void); > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 62ee5fab08e5..dad4dc7aca49 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -436,6 +436,12 @@ union bpf_attr { > * @skb: pointer to skb > * Return: 8 Bytes non-decreasing number on success or 0 if the socket > * field is missing inside sk_buff > + * > + * u32 bpf_get_socket_uid(skb) > + * Get the owner uid of the socket stored inside sk_buff. > + * @skb: pointer to skb > + * Return: uid of the socket owner on success or 0 if the socket pointer > + * inside sk_buff is NULL > */ > #define __BPF_FUNC_MAPPER(FN) \ > FN(unspec), \ > @@ -483,7 +489,8 @@ union bpf_attr { > FN(get_numa_node_id), \ > FN(skb_change_head), \ > FN(xdp_adjust_head), \ > - FN(get_socket_cookie), > + FN(get_socket_cookie), \ > + FN(get_socket_uid), > > /* integer value in 'imm' field of BPF_CALL instruction selects which helper > * function eBPF program intends to call > diff --git a/net/core/filter.c b/net/core/filter.c > index 913b14d3b484..bc36ed72551f 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -2610,6 +2610,23 @@ const struct bpf_func_proto bpf_get_socket_cookie_proto = { > .arg1_type = ARG_PTR_TO_CTX, > }; > > +BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb) > +{ > + struct sock *sk; > + kuid_t kuid; Nit: already init them above. > + sk = skb->sk; > + kuid = sock_net_uid(dev_net(skb->dev), sk); Don't you need to test for fullsock? Do you mean something like below? struct sock *sk = skb->sk; kuid_t kuid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); > + return (u32)kuid.val; > +} > + > +const struct bpf_func_proto bpf_get_socket_uid_proto = { static ... > + .func = bpf_get_socket_uid, > + .gpl_only = false, > + .ret_type = RET_INTEGER, > + .arg1_type = ARG_PTR_TO_CTX, > +}; > + > static const struct bpf_func_proto * > sk_filter_func_proto(enum bpf_func_id func_id) > { > @@ -2635,6 +2652,8 @@ sk_filter_func_proto(enum bpf_func_id func_id) > return bpf_get_trace_printk_proto(); > case BPF_FUNC_get_socket_cookie: > return &bpf_get_socket_cookie_proto; > + case BPF_FUNC_get_socket_uid: > + return &bpf_get_socket_uid_proto; > default: > return NULL; > } >