From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Blakey Subject: Re: [PATCH net-next v4 1/2] net sched actions: Add support for user cookies Date: Wed, 18 Jan 2017 13:47:15 +0200 Message-ID: <7f598705-4cef-e2d4-0da2-1068baabf4fe@mellanox.com> References: <1484651509-27500-1-git-send-email-jhs@emojatatu.com> <1484651509-27500-2-git-send-email-jhs@emojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1255"; format=flowed Content-Transfer-Encoding: 7bit Cc: , , , , , , , , , , To: Jamal Hadi Salim , Return-path: Received: from mail-eopbgr50052.outbound.protection.outlook.com ([40.107.5.52]:21780 "EHLO EUR03-VE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753012AbdARLsW (ORCPT ); Wed, 18 Jan 2017 06:48:22 -0500 In-Reply-To: <1484651509-27500-2-git-send-email-jhs@emojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 17/01/2017 13:11, Jamal Hadi Salim wrote: > From: Jamal Hadi Salim > > Introduce optional 128-bit action cookie. > Like all other cookie schemes in the networking world (eg in protocols > like http or existing kernel fib protocol field, etc) the idea is to save > user state that when retrieved serves as a correlator. The kernel > _should not_ intepret it. The user can store whatever they wish in the > 128 bits. > > Sample exercise(showing variable length use of cookie) > > .. create an accept action with cookie a1b2c3d4 > sudo $TC actions add action ok index 1 cookie a1b2c3d4 > > .. dump all gact actions.. > sudo $TC -s actions ls action gact > > action order 0: gact action pass > random type none pass val 0 > index 1 ref 1 bind 0 installed 5 sec used 5 sec > Action statistics: > Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > cookie a1b2c3d4 > > .. bind the accept action to a filter.. > sudo $TC filter add dev lo parent ffff: protocol ip prio 1 \ > u32 match ip dst 127.0.0.1/32 flowid 1:1 action gact index 1 > > ... send some traffic.. > $ ping 127.0.0.1 -c 3 > PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data. > 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.020 ms > 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms > 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.038 ms > > --- 127.0.0.1 ping statistics --- > 3 packets transmitted, 3 received, 0% packet loss, time 2109ms > rtt min/avg/max/mdev = 0.020/0.028/0.038/0.008 ms 1 > > ... show some stats > $ sudo $TC -s actions get action gact index 1 > > action order 1: gact action pass > random type none pass val 0 > index 1 ref 2 bind 1 installed 204 sec used 5 sec > Action statistics: > Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > cookie a1b2c3d4 > > .. try longer cookie... > $ sudo $TC actions replace action ok index 1 cookie 1234567890abcdef > .. dump.. > $ sudo $TC -s actions ls action gact > > action order 1: gact action pass > random type none pass val 0 > index 1 ref 2 bind 1 installed 204 sec used 5 sec > Action statistics: > Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0) > backlog 0b 0p requeues 0 > cookie 1234567890abcdef > > Signed-off-by: Jamal Hadi Salim > --- > include/net/act_api.h | 1 + > include/net/pkt_cls.h | 8 ++++++++ > include/uapi/linux/pkt_cls.h | 3 +++ > net/sched/act_api.c | 25 +++++++++++++++++++++++++ > 4 files changed, 37 insertions(+) > > diff --git a/include/net/act_api.h b/include/net/act_api.h > index 1d71644..0692458 100644 > --- a/include/net/act_api.h > +++ b/include/net/act_api.h > @@ -41,6 +41,7 @@ struct tc_action { > struct rcu_head tcfa_rcu; > struct gnet_stats_basic_cpu __percpu *cpu_bstats; > struct gnet_stats_queue __percpu *cpu_qstats; > + struct tc_cookie *act_ck; > }; > #define tcf_head common.tcfa_head > #define tcf_index common.tcfa_index > diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h > index f0a0514..e0bc7e8 100644 > --- a/include/net/pkt_cls.h > +++ b/include/net/pkt_cls.h > @@ -515,4 +515,12 @@ struct tc_cls_bpf_offload { > u32 gen_flags; > }; > > + > +/* This structure holds cookie structure that is passed from user > + * to the kernel for actions and classifiers > + */ > +struct tc_cookie { > + unsigned char ck[TC_COOKIE_MAX_SIZE]; > + unsigned char ck_len; > +}; > #endif > diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h > index 1e5e1dd..2d2414e 100644 > --- a/include/uapi/linux/pkt_cls.h > +++ b/include/uapi/linux/pkt_cls.h > @@ -4,6 +4,8 @@ > #include > #include > > +#define TC_COOKIE_MAX_SIZE 16 > + > /* Action attributes */ > enum { > TCA_ACT_UNSPEC, > @@ -12,6 +14,7 @@ enum { > TCA_ACT_INDEX, > TCA_ACT_STATS, > TCA_ACT_PAD, > + TCA_ACT_COOKIE, > __TCA_ACT_MAX > }; > > diff --git a/net/sched/act_api.c b/net/sched/act_api.c > index f04715a..43f1f42 100644 > --- a/net/sched/act_api.c > +++ b/net/sched/act_api.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -33,6 +34,7 @@ static void free_tcf(struct rcu_head *head) > > free_percpu(p->cpu_bstats); > free_percpu(p->cpu_qstats); > + kfree(p->act_ck); > kfree(p); > } > > @@ -475,6 +477,12 @@ int tcf_action_destroy(struct list_head *actions, int bind) > goto nla_put_failure; > if (tcf_action_copy_stats(skb, a, 0)) > goto nla_put_failure; > + if (a->act_ck) { > + if (nla_put(skb, TCA_ACT_COOKIE, a->act_ck->ck_len, > + a->act_ck)) > + goto nla_put_failure; > + } > + > nest = nla_nest_start(skb, TCA_OPTIONS); > if (nest == NULL) > goto nla_put_failure; > @@ -575,6 +583,23 @@ struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla, > if (err < 0) > goto err_mod; > > + if (tb[TCA_ACT_COOKIE]) { > + if (nla_len(tb[TCA_ACT_COOKIE]) > TC_COOKIE_MAX_SIZE) { > + err = -EINVAL; > + goto err_mod; > + } > + > + a->act_ck = kzalloc(sizeof(*a->act_ck), GFP_KERNEL); Hi Jamal, How about struct tc_cookie { unsigned int len; unsigned long ck[0]; }; and then: a->act_ck = kzalloc(sizeof(*a->act_ck) + nla_len(tb[TCA_ACT_COOKIE]), GFP_KERNEL); to save some space? > + if (unlikely(!a->act_ck)) { > + err = -ENOMEM; > + goto err_mod; > + } > + > + memcpy(a->act_ck->ck, nla_data(tb[TCA_ACT_COOKIE]), > + nla_len(tb[TCA_ACT_COOKIE])); > + a->act_ck->ck_len = nla_len(tb[TCA_ACT_COOKIE]); > + } > + > /* module count goes up only when brand new policy is created > * if it exists and is only bound to in a_o->init() then > * ACT_P_CREATED is not returned (a zero is). > Besides if I'll reuse tc_cookie for classifiers, I'll need 20 bytes :)