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Message-ID: <20231005184228.467845-4-victor@mojatatu.com> Date: Thu, 5 Oct 2023 15:42:28 -0300 From: Victor Nogueira <victor@...atatu.com> To: jhs@...atatu.com, xiyou.wangcong@...il.com, jiri@...nulli.us, davem@...emloft.net, pabeni@...hat.com, edumazet@...gle.com, kuba@...nel.org Cc: mleitner@...hat.com, vladbu@...dia.com, simon.horman@...igine.com, pctammela@...atatu.com, netdev@...r.kernel.org, kernel@...atatu.com Subject: [PATCH net-next v4 3/3] net/sched: act_blockcast: Introduce blockcast tc action This action takes advantage of the presence of tc block ports set in the datapath and broadcast a packet to all ports on that set with exception of the port in which it arrived on. Example usage: $ tc qdisc add dev ens7 ingress block 22 $ tc qdisc add dev ens8 ingress block 22 Now we can add a filter using the block index: $ tc filter add block 22 protocol ip pref 25 \ flower dst_ip 192.168.0.0/16 action blockcast Co-developed-by: Jamal Hadi Salim <jhs@...atatu.com> Signed-off-by: Jamal Hadi Salim <jhs@...atatu.com> Co-developed-by: Pedro Tammela <pctammela@...atatu.com> Signed-off-by: Pedro Tammela <pctammela@...atatu.com> Signed-off-by: Victor Nogueira <victor@...atatu.com> --- include/net/tc_wrapper.h | 5 + include/uapi/linux/pkt_cls.h | 1 + net/sched/Kconfig | 13 ++ net/sched/Makefile | 1 + net/sched/act_blockcast.c | 297 +++++++++++++++++++++++++++++++++++ 5 files changed, 317 insertions(+) create mode 100644 net/sched/act_blockcast.c diff --git a/include/net/tc_wrapper.h b/include/net/tc_wrapper.h index a6d481b5bcbc..8ef848968be7 100644 --- a/include/net/tc_wrapper.h +++ b/include/net/tc_wrapper.h @@ -28,6 +28,7 @@ TC_INDIRECT_ACTION_DECLARE(tcf_csum_act); TC_INDIRECT_ACTION_DECLARE(tcf_ct_act); TC_INDIRECT_ACTION_DECLARE(tcf_ctinfo_act); TC_INDIRECT_ACTION_DECLARE(tcf_gact_act); +TC_INDIRECT_ACTION_DECLARE(tcf_blockcast_run); TC_INDIRECT_ACTION_DECLARE(tcf_gate_act); TC_INDIRECT_ACTION_DECLARE(tcf_ife_act); TC_INDIRECT_ACTION_DECLARE(tcf_ipt_act); @@ -57,6 +58,10 @@ static inline int tc_act(struct sk_buff *skb, const struct tc_action *a, if (a->ops->act == tcf_mirred_act) return tcf_mirred_act(skb, a, res); #endif +#if IS_BUILTIN(CONFIG_NET_ACT_BLOCKCAST) + if (a->ops->act == tcf_blockcast_run) + return tcf_blockcast_run(skb, a, res); +#endif #if IS_BUILTIN(CONFIG_NET_ACT_PEDIT) if (a->ops->act == tcf_pedit_act) return tcf_pedit_act(skb, a, res); diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index c7082cc60d21..e12fc51c1be1 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -139,6 +139,7 @@ enum tca_id { TCA_ID_MPLS, TCA_ID_CT, TCA_ID_GATE, + TCA_ID_BLOCKCAST, /* other actions go here */ __TCA_ID_MAX = 255 }; diff --git a/net/sched/Kconfig b/net/sched/Kconfig index 470c70deffe2..abf26f0c921f 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -780,6 +780,19 @@ config NET_ACT_SIMP To compile this code as a module, choose M here: the module will be called act_simple. +config NET_ACT_BLOCKCAST + tristate "TC block Multicast" + depends on NET_CLS_ACT + help + Say Y here to add an action that will multicast an skb to egress of + all netdevs that belong to a tc block except for the netdev on which + the skb arrived on + + If unsure, say N. + + To compile this code as a module, choose M here: the + module will be called act_blockcast. + config NET_ACT_SKBEDIT tristate "SKB Editing" depends on NET_CLS_ACT diff --git a/net/sched/Makefile b/net/sched/Makefile index b5fd49641d91..2cdcf30645eb 100644 --- a/net/sched/Makefile +++ b/net/sched/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_NET_ACT_IPT) += act_ipt.o obj-$(CONFIG_NET_ACT_NAT) += act_nat.o obj-$(CONFIG_NET_ACT_PEDIT) += act_pedit.o obj-$(CONFIG_NET_ACT_SIMP) += act_simple.o +obj-$(CONFIG_NET_ACT_BLOCKCAST) += act_blockcast.o obj-$(CONFIG_NET_ACT_SKBEDIT) += act_skbedit.o obj-$(CONFIG_NET_ACT_CSUM) += act_csum.o obj-$(CONFIG_NET_ACT_MPLS) += act_mpls.o diff --git a/net/sched/act_blockcast.c b/net/sched/act_blockcast.c new file mode 100644 index 000000000000..047023cba749 --- /dev/null +++ b/net/sched/act_blockcast.c @@ -0,0 +1,297 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/sched/act_blockcast.c Block Cast action + * Copyright (c) 2023, Mojatatu Networks + * Authors: Jamal Hadi Salim <jhs@...atatu.com> + * Victor Nogueira <victor@...atatu.com> + * Pedro Tammela <pctammela@...atatu.com> + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <net/pkt_cls.h> +#include <linux/if_arp.h> +#include <net/tc_wrapper.h> + +#include <linux/tc_act/tc_defact.h> + +static struct tc_action_ops act_blockcast_ops; + +struct tcf_blockcast_act { + struct tc_action common; +}; + +#define to_blockcast_act(a) ((struct tcf_blockcast_act *)a) + +#define CAST_RECURSION_LIMIT 4 + +static DEFINE_PER_CPU(unsigned int, redirect_rec_level); + +static int cast_one(struct sk_buff *skb, const u32 ifindex) +{ + struct sk_buff *skb2 = skb; + int retval = TC_ACT_PIPE; + struct net_device *dev; + unsigned int rec_level; + bool expects_nh; + int mac_len; + bool at_nh; + int err; + + rec_level = __this_cpu_inc_return(redirect_rec_level); + if (unlikely(rec_level > CAST_RECURSION_LIMIT)) { + net_warn_ratelimited("blockcast: exceeded redirect recursion limit on dev %s\n", + netdev_name(skb->dev)); + goto out_shot; + } + + dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex); + if (unlikely(!dev)) + goto out_shot; + + if (unlikely(!(dev->flags & IFF_UP) || !netif_carrier_ok(dev))) + goto out_shot; + + skb2 = skb_clone(skb, GFP_ATOMIC); + if (!skb2) + goto out_shot; + + nf_reset_ct(skb2); + + expects_nh = !dev_is_mac_header_xmit(dev); + at_nh = skb->data == skb_network_header(skb); + if (at_nh != expects_nh) { + mac_len = skb_at_tc_ingress(skb) ? + skb->mac_len : + skb_network_header(skb) - skb_mac_header(skb); + + if (expects_nh) { + /* target device/action expect data at nh */ + skb_pull_rcsum(skb2, mac_len); + } else { + /* target device/action expect data at mac */ + skb_push_rcsum(skb2, mac_len); + } + } + + skb2->skb_iif = skb->dev->ifindex; + skb2->dev = dev; + + err = dev_queue_xmit(skb2); + if (err) + goto out_shot; + + goto rec_level_dec; + +out_shot: + retval = TC_ACT_SHOT; + +rec_level_dec: + __this_cpu_dec(redirect_rec_level); + + return retval; +} + +TC_INDIRECT_SCOPE int tcf_blockcast_run(struct sk_buff *skb, + const struct tc_action *a, + struct tcf_result *res) +{ + u32 block_index = qdisc_skb_cb(skb)->block_index; + struct tcf_blockcast_act *p = to_blockcast_act(a); + int action = READ_ONCE(p->tcf_action); + struct net *net = dev_net(skb->dev); + struct tcf_block *block; + struct net_device *dev; + u32 exception_ifindex; + unsigned long index; + + block = tcf_block_lookup(net, block_index); + exception_ifindex = skb->dev->ifindex; + + tcf_action_update_bstats(&p->common, skb); + tcf_lastuse_update(&p->tcf_tm); + + if (!block || xa_empty(&block->ports)) + goto act_done; + + /* we are already under rcu protection, so iterating block is safe*/ + xa_for_each(&block->ports, index, dev) { + int err; + + if (index == exception_ifindex) + continue; + + err = cast_one(skb, dev->ifindex); + if (err != TC_ACT_PIPE) + tcf_action_inc_overlimit_qstats(&p->common); + } + +act_done: + if (action == TC_ACT_SHOT) + tcf_action_inc_drop_qstats(&p->common); + return action; +} + +static const struct nla_policy blockcast_policy[TCA_DEF_MAX + 1] = { + [TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) }, +}; + +static int tcf_blockcast_init(struct net *net, struct nlattr *nla, + struct nlattr *est, struct tc_action **a, + struct tcf_proto *tp, u32 flags, + struct netlink_ext_ack *extack) +{ + struct tc_action_net *tn = net_generic(net, act_blockcast_ops.net_id); + struct tcf_blockcast_act *p = to_blockcast_act(a); + bool bind = flags & TCA_ACT_FLAGS_BIND; + struct nlattr *tb[TCA_DEF_MAX + 1]; + struct tcf_chain *goto_ch = NULL; + struct tc_defact *parm; + bool exists = false; + int ret = 0, err; + u32 index; + + if (!nla) + return -EINVAL; + + err = nla_parse_nested(tb, TCA_DEF_MAX, nla, + blockcast_policy, extack); + if (err < 0) + return err; + + if (!tb[TCA_DEF_PARMS]) + return -EINVAL; + + parm = nla_data(tb[TCA_DEF_PARMS]); + index = parm->index; + + err = tcf_idr_check_alloc(tn, &index, a, bind); + if (err < 0) + return err; + + exists = err; + if (exists && bind) + return 0; + + if (!exists) { + ret = tcf_idr_create_from_flags(tn, index, est, a, + &act_blockcast_ops, bind, flags); + if (ret) { + tcf_idr_cleanup(tn, index); + return ret; + } + + ret = ACT_P_CREATED; + } else { + if (!(flags & TCA_ACT_FLAGS_REPLACE)) { + err = -EEXIST; + goto release_idr; + } + } + + err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); + if (err < 0) + goto release_idr; + + if (exists) { + spin_lock_bh(&p->tcf_lock); + goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); + spin_unlock_bh(&p->tcf_lock); + } else { + goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); + } + + if (goto_ch) + tcf_chain_put_by_act(goto_ch); + + return ret; +release_idr: + tcf_idr_release(*a, bind); + return err; +} + +static int tcf_blockcast_dump(struct sk_buff *skb, struct tc_action *a, + int bind, int ref) +{ + unsigned char *b = skb_tail_pointer(skb); + struct tcf_blockcast_act *p = to_blockcast_act(a); + struct tc_defact opt = { + .index = p->tcf_index, + .refcnt = refcount_read(&p->tcf_refcnt) - ref, + .bindcnt = atomic_read(&p->tcf_bindcnt) - bind, + }; + struct tcf_t t; + + spin_lock_bh(&p->tcf_lock); + opt.action = p->tcf_action; + if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt)) + goto nla_put_failure; + + tcf_tm_dump(&t, &p->tcf_tm); + if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD)) + goto nla_put_failure; + spin_unlock_bh(&p->tcf_lock); + + return skb->len; + +nla_put_failure: + spin_unlock_bh(&p->tcf_lock); + nlmsg_trim(skb, b); + return -1; +} + +static struct tc_action_ops act_blockcast_ops = { + .kind = "blockcast", + .id = TCA_ID_BLOCKCAST, + .owner = THIS_MODULE, + .act = tcf_blockcast_run, + .dump = tcf_blockcast_dump, + .init = tcf_blockcast_init, + .size = sizeof(struct tcf_blockcast_act), +}; + +static __net_init int blockcast_init_net(struct net *net) +{ + struct tc_action_net *tn = net_generic(net, act_blockcast_ops.net_id); + + return tc_action_net_init(net, tn, &act_blockcast_ops); +} + +static void __net_exit blockcast_exit_net(struct list_head *net_list) +{ + tc_action_net_exit(net_list, act_blockcast_ops.net_id); +} + +static struct pernet_operations blockcast_net_ops = { + .init = blockcast_init_net, + .exit_batch = blockcast_exit_net, + .id = &act_blockcast_ops.net_id, + .size = sizeof(struct tc_action_net), +}; + +MODULE_AUTHOR("Mojatatu Networks, Inc"); +MODULE_DESCRIPTION("Action to broadcast to devices on a block"); +MODULE_LICENSE("GPL"); + +static int __init blockcast_init_module(void) +{ + int ret = tcf_register_action(&act_blockcast_ops, &blockcast_net_ops); + + if (!ret) + pr_info("blockcast TC action Loaded\n"); + return ret; +} + +static void __exit blockcast_cleanup_module(void) +{ + tcf_unregister_action(&act_blockcast_ops, &blockcast_net_ops); +} + +module_init(blockcast_init_module); +module_exit(blockcast_cleanup_module); -- 2.25.1
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