| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * net/sched/act_sample.c - Packet sampling tc action |
| * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com> |
| */ |
| |
| #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 <net/pkt_cls.h> |
| |
| #include <linux/if_arp.h> |
| |
| 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, |
| struct tcf_proto *tp, |
| u32 flags, struct netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, sample_net_id); |
| bool bind = flags & TCA_ACT_FLAGS_BIND; |
| struct nlattr *tb[TCA_SAMPLE_MAX + 1]; |
| struct psample_group *psample_group; |
| u32 psample_group_num, rate, index; |
| struct tcf_chain *goto_ch = NULL; |
| struct tc_sample *parm; |
| struct tcf_sample *s; |
| bool exists = false; |
| int ret, err; |
| |
| if (!nla) |
| return -EINVAL; |
| ret = nla_parse_nested_deprecated(tb, TCA_SAMPLE_MAX, nla, |
| sample_policy, NULL); |
| 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]); |
| 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(tn, index, est, a, |
| &act_sample_ops, bind, true, flags); |
| if (ret) { |
| tcf_idr_cleanup(tn, index); |
| return ret; |
| } |
| ret = ACT_P_CREATED; |
| } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
| tcf_idr_release(*a, bind); |
| return -EEXIST; |
| } |
| err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); |
| if (err < 0) |
| goto release_idr; |
| |
| rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); |
| if (!rate) { |
| NL_SET_ERR_MSG(extack, "invalid sample rate"); |
| err = -EINVAL; |
| goto put_chain; |
| } |
| psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); |
| psample_group = psample_group_get(net, psample_group_num); |
| if (!psample_group) { |
| err = -ENOMEM; |
| goto put_chain; |
| } |
| |
| s = to_sample(*a); |
| |
| spin_lock_bh(&s->tcf_lock); |
| goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); |
| s->rate = rate; |
| s->psample_group_num = psample_group_num; |
| psample_group = rcu_replace_pointer(s->psample_group, psample_group, |
| lockdep_is_held(&s->tcf_lock)); |
| |
| if (tb[TCA_SAMPLE_TRUNC_SIZE]) { |
| s->truncate = true; |
| s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]); |
| } |
| spin_unlock_bh(&s->tcf_lock); |
| |
| if (psample_group) |
| psample_group_put(psample_group); |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| |
| return ret; |
| put_chain: |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| release_idr: |
| tcf_idr_release(*a, bind); |
| return err; |
| } |
| |
| static void tcf_sample_cleanup(struct tc_action *a) |
| { |
| struct tcf_sample *s = to_sample(a); |
| struct psample_group *psample_group; |
| |
| /* last reference to action, no need to lock */ |
| psample_group = rcu_dereference_protected(s->psample_group, 1); |
| RCU_INIT_POINTER(s->psample_group, NULL); |
| if (psample_group) |
| psample_group_put(psample_group); |
| } |
| |
| 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_IP6GRE: |
| 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; |
| struct psample_metadata md = {}; |
| int retval; |
| |
| tcf_lastuse_update(&s->tcf_tm); |
| bstats_update(this_cpu_ptr(s->common.cpu_bstats), skb); |
| retval = READ_ONCE(s->tcf_action); |
| |
| psample_group = rcu_dereference_bh(s->psample_group); |
| |
| /* randomly sample packets according to rate */ |
| if (psample_group && (prandom_u32() % s->rate == 0)) { |
| if (!skb_at_tc_ingress(skb)) { |
| md.in_ifindex = skb->skb_iif; |
| md.out_ifindex = skb->dev->ifindex; |
| } else { |
| md.in_ifindex = skb->dev->ifindex; |
| } |
| |
| /* 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); |
| |
| md.trunc_size = s->truncate ? s->trunc_size : skb->len; |
| psample_sample_packet(psample_group, skb, s->rate, &md); |
| |
| if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) |
| skb_pull(skb, skb->mac_len); |
| } |
| |
| return retval; |
| } |
| |
| static void tcf_sample_stats_update(struct tc_action *a, u64 bytes, u64 packets, |
| u64 drops, u64 lastuse, bool hw) |
| { |
| struct tcf_sample *s = to_sample(a); |
| struct tcf_t *tm = &s->tcf_tm; |
| |
| tcf_action_update_stats(a, bytes, packets, drops, hw); |
| tm->lastuse = max_t(u64, tm->lastuse, lastuse); |
| } |
| |
| 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, |
| .refcnt = refcount_read(&s->tcf_refcnt) - ref, |
| .bindcnt = atomic_read(&s->tcf_bindcnt) - bind, |
| }; |
| struct tcf_t t; |
| |
| spin_lock_bh(&s->tcf_lock); |
| opt.action = s->tcf_action; |
| 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; |
| spin_unlock_bh(&s->tcf_lock); |
| |
| return skb->len; |
| |
| nla_put_failure: |
| spin_unlock_bh(&s->tcf_lock); |
| 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 netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, sample_net_id); |
| |
| return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
| } |
| |
| 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_idr_search(tn, a, index); |
| } |
| |
| static void tcf_psample_group_put(void *priv) |
| { |
| struct psample_group *group = priv; |
| |
| psample_group_put(group); |
| } |
| |
| static struct psample_group * |
| tcf_sample_get_group(const struct tc_action *a, |
| tc_action_priv_destructor *destructor) |
| { |
| struct tcf_sample *s = to_sample(a); |
| struct psample_group *group; |
| |
| group = rcu_dereference_protected(s->psample_group, |
| lockdep_is_held(&s->tcf_lock)); |
| if (group) { |
| psample_group_take(group); |
| *destructor = tcf_psample_group_put; |
| } |
| |
| return group; |
| } |
| |
| static void tcf_offload_sample_get_group(struct flow_action_entry *entry, |
| const struct tc_action *act) |
| { |
| entry->sample.psample_group = |
| act->ops->get_psample_group(act, &entry->destructor); |
| entry->destructor_priv = entry->sample.psample_group; |
| } |
| |
| static int tcf_sample_offload_act_setup(struct tc_action *act, void *entry_data, |
| u32 *index_inc, bool bind, |
| struct netlink_ext_ack *extack) |
| { |
| if (bind) { |
| struct flow_action_entry *entry = entry_data; |
| |
| entry->id = FLOW_ACTION_SAMPLE; |
| entry->sample.trunc_size = tcf_sample_trunc_size(act); |
| entry->sample.truncate = tcf_sample_truncate(act); |
| entry->sample.rate = tcf_sample_rate(act); |
| tcf_offload_sample_get_group(entry, act); |
| *index_inc = 1; |
| } else { |
| struct flow_offload_action *fl_action = entry_data; |
| |
| fl_action->id = FLOW_ACTION_SAMPLE; |
| } |
| |
| return 0; |
| } |
| |
| static struct tc_action_ops act_sample_ops = { |
| .kind = "sample", |
| .id = TCA_ID_SAMPLE, |
| .owner = THIS_MODULE, |
| .act = tcf_sample_act, |
| .stats_update = tcf_sample_stats_update, |
| .dump = tcf_sample_dump, |
| .init = tcf_sample_init, |
| .cleanup = tcf_sample_cleanup, |
| .walk = tcf_sample_walker, |
| .lookup = tcf_sample_search, |
| .get_psample_group = tcf_sample_get_group, |
| .offload_act_setup = tcf_sample_offload_act_setup, |
| .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(net, tn, &act_sample_ops); |
| } |
| |
| static void __net_exit sample_exit_net(struct list_head *net_list) |
| { |
| tc_action_net_exit(net_list, sample_net_id); |
| } |
| |
| static struct pernet_operations sample_net_ops = { |
| .init = sample_init_net, |
| .exit_batch = 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 <yotam.gi@gmail.com>"); |
| MODULE_DESCRIPTION("Packet sampling action"); |
| MODULE_LICENSE("GPL v2"); |