From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next 1/2] Add a helper function to get socket cookie in eBPF Date: Thu, 02 Feb 2017 22:23:04 +0100 Message-ID: <5893A338.3070702@iogearbox.net> References: <20170202205950.100334-1-chenbofeng.kernel@gmail.com> <20170202205950.100334-2-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]:47293 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751245AbdBBVXJ (ORCPT ); Thu, 2 Feb 2017 16:23:09 -0500 In-Reply-To: <20170202205950.100334-2-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 > > Retrieve the socket cookie generated by sock_gen_cookie() from a sk_buff > with a known socket. Generates a new cookie if one was not yet set.If > the socket pointer inside sk_buff is NULL, 0 is returned. The helper > function coud be useful in monitoring per socket networking traffic > statistics and provide a unique socket identifier per namespace. > > Signed-off-by: Chenbo Feng > --- > include/linux/bpf.h | 1 + > include/linux/sock_diag.h | 1 + > include/uapi/linux/bpf.h | 9 ++++++++- > net/core/filter.c | 15 +++++++++++++++ > net/core/sock_diag.c | 3 ++- > 5 files changed, 27 insertions(+), 2 deletions(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 3ed1f3b1d594..3f2e0af28c6e 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -349,6 +349,7 @@ extern const struct bpf_func_proto bpf_get_current_comm_proto; > 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; I don't think this needs to be added here. > /* Shared helpers among cBPF and eBPF. */ > void bpf_user_rnd_init_once(void); > diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h > index a0596ca0e80a..a2f8109bb215 100644 > --- a/include/linux/sock_diag.h > +++ b/include/linux/sock_diag.h > @@ -24,6 +24,7 @@ void sock_diag_unregister(const struct sock_diag_handler *h); > void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)); > void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)); > > +u64 sock_gen_cookie(struct sock *sk); > int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie); > void sock_diag_save_cookie(struct sock *sk, __u32 *cookie); > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 0eb0e87dbe9f..62ee5fab08e5 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -430,6 +430,12 @@ union bpf_attr { > * @xdp_md: pointer to xdp_md > * @delta: An positive/negative integer to be added to xdp_md.data > * Return: 0 on success or negative on error > + * > + * u64 bpf_bpf_get_socket_cookie(skb) > + * Get the cookie for the socket stored inside sk_buff. > + * @skb: pointer to skb > + * Return: 8 Bytes non-decreasing number on success or 0 if the socket > + * field is missing inside sk_buff > */ > #define __BPF_FUNC_MAPPER(FN) \ > FN(unspec), \ > @@ -476,7 +482,8 @@ union bpf_attr { > FN(set_hash_invalid), \ > FN(get_numa_node_id), \ > FN(skb_change_head), \ > - FN(xdp_adjust_head), > + FN(xdp_adjust_head), \ > + FN(get_socket_cookie), Looks like you need a rebase to net-next, since probe_read_str() helper was added in the meantime. > /* 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 1969b3f118c1..913b14d3b484 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -2597,6 +2598,18 @@ static const struct bpf_func_proto bpf_xdp_event_output_proto = { > .arg5_type = ARG_CONST_STACK_SIZE, > }; > > +BPF_CALL_1(bpf_get_socket_cookie, struct sk_buff *, skb) > +{ > + return skb->sk ? sock_gen_cookie(skb->sk) : 0; > +} > + > +const struct bpf_func_proto bpf_get_socket_cookie_proto = { static const struct bpf_func_proto ... > + .func = bpf_get_socket_cookie, > + .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) > { > @@ -2620,6 +2633,8 @@ sk_filter_func_proto(enum bpf_func_id func_id) > case BPF_FUNC_trace_printk: > if (capable(CAP_SYS_ADMIN)) > return bpf_get_trace_printk_proto(); > + case BPF_FUNC_get_socket_cookie: > + return &bpf_get_socket_cookie_proto; > default: > return NULL; > } > diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c > index 6b10573cc9fa..b07b0a784f33 100644 > --- a/net/core/sock_diag.c > +++ b/net/core/sock_diag.c > @@ -19,7 +19,7 @@ static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); > static DEFINE_MUTEX(sock_diag_table_mutex); > static struct workqueue_struct *broadcast_wq; > > -static u64 sock_gen_cookie(struct sock *sk) > +u64 sock_gen_cookie(struct sock *sk) > { > while (1) { > u64 res = atomic64_read(&sk->sk_cookie); > @@ -30,6 +30,7 @@ static u64 sock_gen_cookie(struct sock *sk) > atomic64_cmpxchg(&sk->sk_cookie, 0, res); > } > } > +EXPORT_SYMBOL_GPL(sock_gen_cookie); Also no need to export via EXPORT_SYMBOL_GPL(). > int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) > { >