[net-next,v2,2/4] net/sched: Introduce sample tc action

Message ID	1485166031-4773-3-git-send-email-jiri@resnulli.us
State	Accepted, archived
Delegated to:	David Miller
Headers	show Return-Path: <netdev-owner@vger.kernel.org> From: Jiri Pirko <jiri@resnulli.us> To: netdev@vger.kernel.org Cc: davem@davemloft.net, yotamg@mellanox.com, idosch@mellanox.com, eladr@mellanox.com, nogahf@mellanox.com, ogerlitz@mellanox.com, jhs@mojatatu.com, geert+renesas@glider.be, stephen@networkplumber.org, xiyou.wangcong@gmail.com, linux@roeck-us.net, roopa@cumulusnetworks.com, john.fastabend@gmail.com, simon.horman@netronome.com, mrv@mojatatu.com Subject: [patch net-next v2 2/4] net/sched: Introduce sample tc action Date: Mon, 23 Jan 2017 11:07:09 +0100 Message-Id: <1485166031-4773-3-git-send-email-jiri@resnulli.us> In-Reply-To: <1485166031-4773-1-git-send-email-jiri@resnulli.us> References: <1485166031-4773-1-git-send-email-jiri@resnulli.us> Sender: netdev-owner@vger.kernel.org Precedence: bulk

diff --git a/include/net/tc_act/tc_sample.h b/include/net/tc_act/tc_sample.h new file mode 100644 index 0000000..89e9305 --- /dev/null +++ b/include/net/tc_act/tc_sample.h @@ -0,0 +1,50 @@ +#ifndef __NET_TC_SAMPLE_H +#define __NET_TC_SAMPLE_H + +#include <net/act_api.h> +#include <linux/tc_act/tc_sample.h> +#include <net/psample.h> + +struct tcf_sample { + struct tc_action common; + u32 rate; + bool truncate; + u32 trunc_size; + struct psample_group __rcu *psample_group; + u32 psample_group_num; + struct list_head tcfm_list; + struct rcu_head rcu; +}; +#define to_sample(a) ((struct tcf_sample *)a) + +static inline bool is_tcf_sample(const struct tc_action *a) +{ +#ifdef CONFIG_NET_CLS_ACT + return a->ops && a->ops->type == TCA_ACT_SAMPLE; +#else + return false; +#endif +} + +static inline __u32 tcf_sample_rate(const struct tc_action *a) +{ + return to_sample(a)->rate; +} + +static inline bool tcf_sample_truncate(const struct tc_action *a) +{ + return to_sample(a)->truncate; +} + +static inline int tcf_sample_trunc_size(const struct tc_action *a) +{ + return to_sample(a)->trunc_size; +} + +static inline struct psample_group * +tcf_sample_psample_group(const struct tc_action *a) +{ + return rcu_dereference(to_sample(a)->psample_group); +} + +#endif /* __NET_TC_SAMPLE_H */ diff --git a/include/uapi/linux/tc_act/Kbuild b/include/uapi/linux/tc_act/Kbuild index e3db740..ba62ddf 100644 --- a/include/uapi/linux/tc_act/Kbuild +++ b/include/uapi/linux/tc_act/Kbuild @@ -4,6 +4,7 @@ header-y += tc_defact.h header-y += tc_gact.h header-y += tc_ipt.h header-y += tc_mirred.h +header-y += tc_sample.h header-y += tc_nat.h header-y += tc_pedit.h header-y += tc_skbedit.h diff --git a/include/uapi/linux/tc_act/tc_sample.h b/include/uapi/linux/tc_act/tc_sample.h new file mode 100644 index 0000000..edc9058 --- /dev/null +++ b/include/uapi/linux/tc_act/tc_sample.h @@ -0,0 +1,26 @@ +#ifndef __LINUX_TC_SAMPLE_H +#define __LINUX_TC_SAMPLE_H + +#include <linux/types.h> +#include <linux/pkt_cls.h> +#include <linux/if_ether.h> + +#define TCA_ACT_SAMPLE 26 + +struct tc_sample { + tc_gen; +}; + +enum { + TCA_SAMPLE_UNSPEC, + TCA_SAMPLE_TM, + TCA_SAMPLE_PARMS, + TCA_SAMPLE_RATE, + TCA_SAMPLE_TRUNC_SIZE, + TCA_SAMPLE_PSAMPLE_GROUP, + TCA_SAMPLE_PAD, + __TCA_SAMPLE_MAX +}; +#define TCA_SAMPLE_MAX (__TCA_SAMPLE_MAX - 1) + +#endif diff --git a/net/sched/Kconfig b/net/sched/Kconfig index a9aa38d..72cfa3a 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -650,6 +650,18 @@ config NET_ACT_MIRRED To compile this code as a module, choose M here: the module will be called act_mirred. +config NET_ACT_SAMPLE + tristate "Traffic Sampling" + depends on NET_CLS_ACT + select PSAMPLE + ---help--- + Say Y here to allow packet sampling tc action. The packet sample + action consists of statistically choosing packets and sampling + them using the psample module. + + To compile this code as a module, choose M here: the + module will be called act_sample. + config NET_ACT_IPT tristate "IPtables targets" depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES diff --git a/net/sched/Makefile b/net/sched/Makefile index 4bdda36..7b915d2 100644 --- a/net/sched/Makefile +++ b/net/sched/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_NET_CLS_ACT) += act_api.o obj-$(CONFIG_NET_ACT_POLICE) += act_police.o obj-$(CONFIG_NET_ACT_GACT) += act_gact.o obj-$(CONFIG_NET_ACT_MIRRED) += act_mirred.o +obj-$(CONFIG_NET_ACT_SAMPLE) += act_sample.o obj-$(CONFIG_NET_ACT_IPT) += act_ipt.o obj-$(CONFIG_NET_ACT_NAT) += act_nat.o obj-$(CONFIG_NET_ACT_PEDIT) += act_pedit.o diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c new file mode 100644 index 0000000..3922975 --- /dev/null +++ b/net/sched/act_sample.c @@ -0,0 +1,274 @@ +/* + * net/sched/act_sample.c - Packet sampling tc action + * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/gfp.h> +#include <net/net_namespace.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <linux/tc_act/tc_sample.h> +#include <net/tc_act/tc_sample.h> +#include <net/psample.h> + +#include <linux/if_arp.h> + +#define SAMPLE_TAB_MASK 7 +static unsigned int sample_net_id; +static struct tc_action_ops act_sample_ops; + +static const struct nla_policy sample_policy[TCA_SAMPLE_MAX + 1] = { + [TCA_SAMPLE_PARMS] = { .len = sizeof(struct tc_sample) }, + [TCA_SAMPLE_RATE] = { .type = NLA_U32 }, + [TCA_SAMPLE_TRUNC_SIZE] = { .type = NLA_U32 }, + [TCA_SAMPLE_PSAMPLE_GROUP] = { .type = NLA_U32 }, +}; + +static int tcf_sample_init(struct net *net, struct nlattr *nla, + struct nlattr *est, struct tc_action **a, int ovr, + int bind) +{ + struct tc_action_net *tn = net_generic(net, sample_net_id); + struct nlattr *tb[TCA_SAMPLE_MAX + 1]; + struct psample_group *psample_group; + struct tc_sample *parm; + struct tcf_sample *s; + bool exists = false; + int ret; + + if (!nla) + return -EINVAL; + ret = nla_parse_nested(tb, TCA_SAMPLE_MAX, nla, sample_policy); + if (ret < 0) + return ret; + if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] || + !tb[TCA_SAMPLE_PSAMPLE_GROUP]) + return -EINVAL; + + parm = nla_data(tb[TCA_SAMPLE_PARMS]); + + exists = tcf_hash_check(tn, parm->index, a, bind); + if (exists && bind) + return 0; + + if (!exists) { + ret = tcf_hash_create(tn, parm->index, est, a, + &act_sample_ops, bind, false); + if (ret) + return ret; + ret = ACT_P_CREATED; + } else { + tcf_hash_release(*a, bind); + if (!ovr) + return -EEXIST; + } + s = to_sample(*a); + + ASSERT_RTNL(); + s->tcf_action = parm->action; + s->rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); + s->psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); + psample_group = psample_group_get(net, s->psample_group_num); + if (!psample_group) + return -ENOMEM; + RCU_INIT_POINTER(s->psample_group, psample_group); + + if (tb[TCA_SAMPLE_TRUNC_SIZE]) { + s->truncate = true; + s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]); + } + + if (ret == ACT_P_CREATED) + tcf_hash_insert(tn, *a); + return ret; +} + +static void tcf_sample_cleanup_rcu(struct rcu_head *rcu) +{ + struct tcf_sample *s = container_of(rcu, struct tcf_sample, rcu); + struct psample_group *psample_group; + + psample_group = rcu_dereference_protected(s->psample_group, 1); + RCU_INIT_POINTER(s->psample_group, NULL); + psample_group_put(psample_group); +} + +static void tcf_sample_cleanup(struct tc_action *a, int bind) +{ + struct tcf_sample *s = to_sample(a); + + call_rcu(&s->rcu, tcf_sample_cleanup_rcu); +} + +static bool tcf_sample_dev_ok_push(struct net_device *dev) +{ + switch (dev->type) { + case ARPHRD_TUNNEL: + case ARPHRD_TUNNEL6: + case ARPHRD_SIT: + case ARPHRD_IPGRE: + case ARPHRD_VOID: + case ARPHRD_NONE: + return false; + default: + return true; + } +} + +static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a, + struct tcf_result *res) +{ + struct tcf_sample *s = to_sample(a); + struct psample_group *psample_group; + int retval; + int size; + int iif; + int oif; + + tcf_lastuse_update(&s->tcf_tm); + bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb); + retval = READ_ONCE(s->tcf_action); + + rcu_read_lock(); + psample_group = rcu_dereference(s->psample_group); + + /* randomly sample packets according to rate */ + if (psample_group && (prandom_u32() % s->rate == 0)) { + if (!skb_at_tc_ingress(skb)) { + iif = skb->skb_iif; + oif = skb->dev->ifindex; + } else { + iif = skb->dev->ifindex; + oif = 0; + } + + /* on ingress, the mac header gets popped, so push it back */ + if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) + skb_push(skb, skb->mac_len); + + size = s->truncate ? s->trunc_size : skb->len; + psample_sample_packet(psample_group, skb, size, iif, oif, + s->rate); + + if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) + skb_pull(skb, skb->mac_len); + } + + rcu_read_unlock(); + return retval; +} + +static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, + int bind, int ref) +{ + unsigned char *b = skb_tail_pointer(skb); + struct tcf_sample *s = to_sample(a); + struct tc_sample opt = { + .index = s->tcf_index, + .action = s->tcf_action, + .refcnt = s->tcf_refcnt - ref, + .bindcnt = s->tcf_bindcnt - bind, + }; + struct tcf_t t; + + if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt)) + goto nla_put_failure; + + tcf_tm_dump(&t, &s->tcf_tm); + if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD)) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate)) + goto nla_put_failure; + + if (s->truncate) + if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size)) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num)) + goto nla_put_failure; + return skb->len; + +nla_put_failure: + nlmsg_trim(skb, b); + return -1; +} + +static int tcf_sample_walker(struct net *net, struct sk_buff *skb, + struct netlink_callback *cb, int type, + const struct tc_action_ops *ops) +{ + struct tc_action_net *tn = net_generic(net, sample_net_id); + + return tcf_generic_walker(tn, skb, cb, type, ops); +} + +static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index) +{ + struct tc_action_net *tn = net_generic(net, sample_net_id); + + return tcf_hash_search(tn, a, index); +} + +static struct tc_action_ops act_sample_ops = { + .kind = "sample", + .type = TCA_ACT_SAMPLE, + .owner = THIS_MODULE, + .act = tcf_sample_act, + .dump = tcf_sample_dump, + .init = tcf_sample_init, + .cleanup = tcf_sample_cleanup, + .walk = tcf_sample_walker, + .lookup = tcf_sample_search, + .size = sizeof(struct tcf_sample), +}; + +static __net_init int sample_init_net(struct net *net) +{ + struct tc_action_net *tn = net_generic(net, sample_net_id); + + return tc_action_net_init(tn, &act_sample_ops, SAMPLE_TAB_MASK); +} + +static void __net_exit sample_exit_net(struct net *net) +{ + struct tc_action_net *tn = net_generic(net, sample_net_id); + + tc_action_net_exit(tn); +} + +static struct pernet_operations sample_net_ops = { + .init = sample_init_net, + .exit = sample_exit_net, + .id = &sample_net_id, + .size = sizeof(struct tc_action_net), +}; + +static int __init sample_init_module(void) +{ + return tcf_register_action(&act_sample_ops, &sample_net_ops); +} + +static void __exit sample_cleanup_module(void) +{ + tcf_unregister_action(&act_sample_ops, &sample_net_ops); +} + +module_init(sample_init_module); +module_exit(sample_cleanup_module); + +MODULE_AUTHOR("Yotam Gigi <yotamg@mellanox.com>"); +MODULE_DESCRIPTION("Packet sampling action"); +MODULE_LICENSE("GPL v2");

[net-next,v2,2/4] net/sched: Introduce sample tc action

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