Loading...
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sched/act_sample.c - Packet sampling tc action
4 * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
5 */
6
7#include <linux/types.h>
8#include <linux/kernel.h>
9#include <linux/string.h>
10#include <linux/errno.h>
11#include <linux/skbuff.h>
12#include <linux/rtnetlink.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/gfp.h>
16#include <net/net_namespace.h>
17#include <net/netlink.h>
18#include <net/pkt_sched.h>
19#include <linux/tc_act/tc_sample.h>
20#include <net/tc_act/tc_sample.h>
21#include <net/psample.h>
22#include <net/pkt_cls.h>
23
24#include <linux/if_arp.h>
25
26static unsigned int sample_net_id;
27static struct tc_action_ops act_sample_ops;
28
29static const struct nla_policy sample_policy[TCA_SAMPLE_MAX + 1] = {
30 [TCA_SAMPLE_PARMS] = { .len = sizeof(struct tc_sample) },
31 [TCA_SAMPLE_RATE] = { .type = NLA_U32 },
32 [TCA_SAMPLE_TRUNC_SIZE] = { .type = NLA_U32 },
33 [TCA_SAMPLE_PSAMPLE_GROUP] = { .type = NLA_U32 },
34};
35
36static int tcf_sample_init(struct net *net, struct nlattr *nla,
37 struct nlattr *est, struct tc_action **a, int ovr,
38 int bind, bool rtnl_held, struct tcf_proto *tp,
39 struct netlink_ext_ack *extack)
40{
41 struct tc_action_net *tn = net_generic(net, sample_net_id);
42 struct nlattr *tb[TCA_SAMPLE_MAX + 1];
43 struct psample_group *psample_group;
44 u32 psample_group_num, rate, index;
45 struct tcf_chain *goto_ch = NULL;
46 struct tc_sample *parm;
47 struct tcf_sample *s;
48 bool exists = false;
49 int ret, err;
50
51 if (!nla)
52 return -EINVAL;
53 ret = nla_parse_nested_deprecated(tb, TCA_SAMPLE_MAX, nla,
54 sample_policy, NULL);
55 if (ret < 0)
56 return ret;
57 if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] ||
58 !tb[TCA_SAMPLE_PSAMPLE_GROUP])
59 return -EINVAL;
60
61 parm = nla_data(tb[TCA_SAMPLE_PARMS]);
62 index = parm->index;
63 err = tcf_idr_check_alloc(tn, &index, a, bind);
64 if (err < 0)
65 return err;
66 exists = err;
67 if (exists && bind)
68 return 0;
69
70 if (!exists) {
71 ret = tcf_idr_create(tn, index, est, a,
72 &act_sample_ops, bind, true);
73 if (ret) {
74 tcf_idr_cleanup(tn, index);
75 return ret;
76 }
77 ret = ACT_P_CREATED;
78 } else if (!ovr) {
79 tcf_idr_release(*a, bind);
80 return -EEXIST;
81 }
82 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
83 if (err < 0)
84 goto release_idr;
85
86 rate = nla_get_u32(tb[TCA_SAMPLE_RATE]);
87 if (!rate) {
88 NL_SET_ERR_MSG(extack, "invalid sample rate");
89 err = -EINVAL;
90 goto put_chain;
91 }
92 psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]);
93 psample_group = psample_group_get(net, psample_group_num);
94 if (!psample_group) {
95 err = -ENOMEM;
96 goto put_chain;
97 }
98
99 s = to_sample(*a);
100
101 spin_lock_bh(&s->tcf_lock);
102 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
103 s->rate = rate;
104 s->psample_group_num = psample_group_num;
105 rcu_swap_protected(s->psample_group, psample_group,
106 lockdep_is_held(&s->tcf_lock));
107
108 if (tb[TCA_SAMPLE_TRUNC_SIZE]) {
109 s->truncate = true;
110 s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]);
111 }
112 spin_unlock_bh(&s->tcf_lock);
113
114 if (psample_group)
115 psample_group_put(psample_group);
116 if (goto_ch)
117 tcf_chain_put_by_act(goto_ch);
118
119 if (ret == ACT_P_CREATED)
120 tcf_idr_insert(tn, *a);
121 return ret;
122put_chain:
123 if (goto_ch)
124 tcf_chain_put_by_act(goto_ch);
125release_idr:
126 tcf_idr_release(*a, bind);
127 return err;
128}
129
130static void tcf_sample_cleanup(struct tc_action *a)
131{
132 struct tcf_sample *s = to_sample(a);
133 struct psample_group *psample_group;
134
135 /* last reference to action, no need to lock */
136 psample_group = rcu_dereference_protected(s->psample_group, 1);
137 RCU_INIT_POINTER(s->psample_group, NULL);
138 if (psample_group)
139 psample_group_put(psample_group);
140}
141
142static bool tcf_sample_dev_ok_push(struct net_device *dev)
143{
144 switch (dev->type) {
145 case ARPHRD_TUNNEL:
146 case ARPHRD_TUNNEL6:
147 case ARPHRD_SIT:
148 case ARPHRD_IPGRE:
149 case ARPHRD_IP6GRE:
150 case ARPHRD_VOID:
151 case ARPHRD_NONE:
152 return false;
153 default:
154 return true;
155 }
156}
157
158static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
159 struct tcf_result *res)
160{
161 struct tcf_sample *s = to_sample(a);
162 struct psample_group *psample_group;
163 int retval;
164 int size;
165 int iif;
166 int oif;
167
168 tcf_lastuse_update(&s->tcf_tm);
169 bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
170 retval = READ_ONCE(s->tcf_action);
171
172 psample_group = rcu_dereference_bh(s->psample_group);
173
174 /* randomly sample packets according to rate */
175 if (psample_group && (prandom_u32() % s->rate == 0)) {
176 if (!skb_at_tc_ingress(skb)) {
177 iif = skb->skb_iif;
178 oif = skb->dev->ifindex;
179 } else {
180 iif = skb->dev->ifindex;
181 oif = 0;
182 }
183
184 /* on ingress, the mac header gets popped, so push it back */
185 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
186 skb_push(skb, skb->mac_len);
187
188 size = s->truncate ? s->trunc_size : skb->len;
189 psample_sample_packet(psample_group, skb, size, iif, oif,
190 s->rate);
191
192 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
193 skb_pull(skb, skb->mac_len);
194 }
195
196 return retval;
197}
198
199static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
200 int bind, int ref)
201{
202 unsigned char *b = skb_tail_pointer(skb);
203 struct tcf_sample *s = to_sample(a);
204 struct tc_sample opt = {
205 .index = s->tcf_index,
206 .refcnt = refcount_read(&s->tcf_refcnt) - ref,
207 .bindcnt = atomic_read(&s->tcf_bindcnt) - bind,
208 };
209 struct tcf_t t;
210
211 spin_lock_bh(&s->tcf_lock);
212 opt.action = s->tcf_action;
213 if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt))
214 goto nla_put_failure;
215
216 tcf_tm_dump(&t, &s->tcf_tm);
217 if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD))
218 goto nla_put_failure;
219
220 if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate))
221 goto nla_put_failure;
222
223 if (s->truncate)
224 if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size))
225 goto nla_put_failure;
226
227 if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num))
228 goto nla_put_failure;
229 spin_unlock_bh(&s->tcf_lock);
230
231 return skb->len;
232
233nla_put_failure:
234 spin_unlock_bh(&s->tcf_lock);
235 nlmsg_trim(skb, b);
236 return -1;
237}
238
239static int tcf_sample_walker(struct net *net, struct sk_buff *skb,
240 struct netlink_callback *cb, int type,
241 const struct tc_action_ops *ops,
242 struct netlink_ext_ack *extack)
243{
244 struct tc_action_net *tn = net_generic(net, sample_net_id);
245
246 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
247}
248
249static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index)
250{
251 struct tc_action_net *tn = net_generic(net, sample_net_id);
252
253 return tcf_idr_search(tn, a, index);
254}
255
256static void tcf_psample_group_put(void *priv)
257{
258 struct psample_group *group = priv;
259
260 psample_group_put(group);
261}
262
263static struct psample_group *
264tcf_sample_get_group(const struct tc_action *a,
265 tc_action_priv_destructor *destructor)
266{
267 struct tcf_sample *s = to_sample(a);
268 struct psample_group *group;
269
270 spin_lock_bh(&s->tcf_lock);
271 group = rcu_dereference_protected(s->psample_group,
272 lockdep_is_held(&s->tcf_lock));
273 if (group) {
274 psample_group_take(group);
275 *destructor = tcf_psample_group_put;
276 }
277 spin_unlock_bh(&s->tcf_lock);
278
279 return group;
280}
281
282static struct tc_action_ops act_sample_ops = {
283 .kind = "sample",
284 .id = TCA_ID_SAMPLE,
285 .owner = THIS_MODULE,
286 .act = tcf_sample_act,
287 .dump = tcf_sample_dump,
288 .init = tcf_sample_init,
289 .cleanup = tcf_sample_cleanup,
290 .walk = tcf_sample_walker,
291 .lookup = tcf_sample_search,
292 .get_psample_group = tcf_sample_get_group,
293 .size = sizeof(struct tcf_sample),
294};
295
296static __net_init int sample_init_net(struct net *net)
297{
298 struct tc_action_net *tn = net_generic(net, sample_net_id);
299
300 return tc_action_net_init(net, tn, &act_sample_ops);
301}
302
303static void __net_exit sample_exit_net(struct list_head *net_list)
304{
305 tc_action_net_exit(net_list, sample_net_id);
306}
307
308static struct pernet_operations sample_net_ops = {
309 .init = sample_init_net,
310 .exit_batch = sample_exit_net,
311 .id = &sample_net_id,
312 .size = sizeof(struct tc_action_net),
313};
314
315static int __init sample_init_module(void)
316{
317 return tcf_register_action(&act_sample_ops, &sample_net_ops);
318}
319
320static void __exit sample_cleanup_module(void)
321{
322 tcf_unregister_action(&act_sample_ops, &sample_net_ops);
323}
324
325module_init(sample_init_module);
326module_exit(sample_cleanup_module);
327
328MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
329MODULE_DESCRIPTION("Packet sampling action");
330MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/sched/act_sample.c - Packet sampling tc action
4 * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
5 */
6
7#include <linux/types.h>
8#include <linux/kernel.h>
9#include <linux/string.h>
10#include <linux/errno.h>
11#include <linux/skbuff.h>
12#include <linux/rtnetlink.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/gfp.h>
16#include <net/net_namespace.h>
17#include <net/netlink.h>
18#include <net/pkt_sched.h>
19#include <linux/tc_act/tc_sample.h>
20#include <net/tc_act/tc_sample.h>
21#include <net/psample.h>
22#include <net/pkt_cls.h>
23#include <net/tc_wrapper.h>
24
25#include <linux/if_arp.h>
26
27static struct tc_action_ops act_sample_ops;
28
29static const struct nla_policy sample_policy[TCA_SAMPLE_MAX + 1] = {
30 [TCA_SAMPLE_PARMS] = { .len = sizeof(struct tc_sample) },
31 [TCA_SAMPLE_RATE] = { .type = NLA_U32 },
32 [TCA_SAMPLE_TRUNC_SIZE] = { .type = NLA_U32 },
33 [TCA_SAMPLE_PSAMPLE_GROUP] = { .type = NLA_U32 },
34};
35
36static int tcf_sample_init(struct net *net, struct nlattr *nla,
37 struct nlattr *est, struct tc_action **a,
38 struct tcf_proto *tp,
39 u32 flags, struct netlink_ext_ack *extack)
40{
41 struct tc_action_net *tn = net_generic(net, act_sample_ops.net_id);
42 bool bind = flags & TCA_ACT_FLAGS_BIND;
43 struct nlattr *tb[TCA_SAMPLE_MAX + 1];
44 struct psample_group *psample_group;
45 u32 psample_group_num, rate, index;
46 struct tcf_chain *goto_ch = NULL;
47 struct tc_sample *parm;
48 struct tcf_sample *s;
49 bool exists = false;
50 int ret, err;
51
52 if (!nla)
53 return -EINVAL;
54 ret = nla_parse_nested_deprecated(tb, TCA_SAMPLE_MAX, nla,
55 sample_policy, NULL);
56 if (ret < 0)
57 return ret;
58
59 if (!tb[TCA_SAMPLE_PARMS])
60 return -EINVAL;
61
62 parm = nla_data(tb[TCA_SAMPLE_PARMS]);
63 index = parm->index;
64 err = tcf_idr_check_alloc(tn, &index, a, bind);
65 if (err < 0)
66 return err;
67 exists = err;
68 if (exists && bind)
69 return ACT_P_BOUND;
70
71 if (!exists) {
72 ret = tcf_idr_create(tn, index, est, a,
73 &act_sample_ops, bind, true, flags);
74 if (ret) {
75 tcf_idr_cleanup(tn, index);
76 return ret;
77 }
78 ret = ACT_P_CREATED;
79 } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
80 tcf_idr_release(*a, bind);
81 return -EEXIST;
82 }
83
84 if (!tb[TCA_SAMPLE_RATE] || !tb[TCA_SAMPLE_PSAMPLE_GROUP]) {
85 NL_SET_ERR_MSG(extack, "sample rate and group are required");
86 err = -EINVAL;
87 goto release_idr;
88 }
89
90 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
91 if (err < 0)
92 goto release_idr;
93
94 rate = nla_get_u32(tb[TCA_SAMPLE_RATE]);
95 if (!rate) {
96 NL_SET_ERR_MSG(extack, "invalid sample rate");
97 err = -EINVAL;
98 goto put_chain;
99 }
100 psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]);
101 psample_group = psample_group_get(net, psample_group_num);
102 if (!psample_group) {
103 err = -ENOMEM;
104 goto put_chain;
105 }
106
107 s = to_sample(*a);
108
109 spin_lock_bh(&s->tcf_lock);
110 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
111 s->rate = rate;
112 s->psample_group_num = psample_group_num;
113 psample_group = rcu_replace_pointer(s->psample_group, psample_group,
114 lockdep_is_held(&s->tcf_lock));
115
116 if (tb[TCA_SAMPLE_TRUNC_SIZE]) {
117 s->truncate = true;
118 s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]);
119 }
120 spin_unlock_bh(&s->tcf_lock);
121
122 if (psample_group)
123 psample_group_put(psample_group);
124 if (goto_ch)
125 tcf_chain_put_by_act(goto_ch);
126
127 return ret;
128put_chain:
129 if (goto_ch)
130 tcf_chain_put_by_act(goto_ch);
131release_idr:
132 tcf_idr_release(*a, bind);
133 return err;
134}
135
136static void tcf_sample_cleanup(struct tc_action *a)
137{
138 struct tcf_sample *s = to_sample(a);
139 struct psample_group *psample_group;
140
141 /* last reference to action, no need to lock */
142 psample_group = rcu_dereference_protected(s->psample_group, 1);
143 RCU_INIT_POINTER(s->psample_group, NULL);
144 if (psample_group)
145 psample_group_put(psample_group);
146}
147
148static bool tcf_sample_dev_ok_push(struct net_device *dev)
149{
150 switch (dev->type) {
151 case ARPHRD_TUNNEL:
152 case ARPHRD_TUNNEL6:
153 case ARPHRD_SIT:
154 case ARPHRD_IPGRE:
155 case ARPHRD_IP6GRE:
156 case ARPHRD_VOID:
157 case ARPHRD_NONE:
158 return false;
159 default:
160 return true;
161 }
162}
163
164TC_INDIRECT_SCOPE int tcf_sample_act(struct sk_buff *skb,
165 const struct tc_action *a,
166 struct tcf_result *res)
167{
168 struct tcf_sample *s = to_sample(a);
169 struct psample_group *psample_group;
170 struct psample_metadata md = {};
171 int retval;
172
173 tcf_lastuse_update(&s->tcf_tm);
174 bstats_update(this_cpu_ptr(s->common.cpu_bstats), skb);
175 retval = READ_ONCE(s->tcf_action);
176
177 psample_group = rcu_dereference_bh(s->psample_group);
178
179 /* randomly sample packets according to rate */
180 if (psample_group && (get_random_u32_below(s->rate) == 0)) {
181 if (!skb_at_tc_ingress(skb)) {
182 md.in_ifindex = skb->skb_iif;
183 md.out_ifindex = skb->dev->ifindex;
184 } else {
185 md.in_ifindex = skb->dev->ifindex;
186 }
187
188 /* on ingress, the mac header gets popped, so push it back */
189 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
190 skb_push(skb, skb->mac_len);
191
192 md.trunc_size = s->truncate ? s->trunc_size : skb->len;
193 psample_sample_packet(psample_group, skb, s->rate, &md);
194
195 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
196 skb_pull(skb, skb->mac_len);
197 }
198
199 return retval;
200}
201
202static void tcf_sample_stats_update(struct tc_action *a, u64 bytes, u64 packets,
203 u64 drops, u64 lastuse, bool hw)
204{
205 struct tcf_sample *s = to_sample(a);
206 struct tcf_t *tm = &s->tcf_tm;
207
208 tcf_action_update_stats(a, bytes, packets, drops, hw);
209 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
210}
211
212static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
213 int bind, int ref)
214{
215 unsigned char *b = skb_tail_pointer(skb);
216 struct tcf_sample *s = to_sample(a);
217 struct tc_sample opt = {
218 .index = s->tcf_index,
219 .refcnt = refcount_read(&s->tcf_refcnt) - ref,
220 .bindcnt = atomic_read(&s->tcf_bindcnt) - bind,
221 };
222 struct tcf_t t;
223
224 spin_lock_bh(&s->tcf_lock);
225 opt.action = s->tcf_action;
226 if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt))
227 goto nla_put_failure;
228
229 tcf_tm_dump(&t, &s->tcf_tm);
230 if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD))
231 goto nla_put_failure;
232
233 if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate))
234 goto nla_put_failure;
235
236 if (s->truncate)
237 if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size))
238 goto nla_put_failure;
239
240 if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num))
241 goto nla_put_failure;
242 spin_unlock_bh(&s->tcf_lock);
243
244 return skb->len;
245
246nla_put_failure:
247 spin_unlock_bh(&s->tcf_lock);
248 nlmsg_trim(skb, b);
249 return -1;
250}
251
252static void tcf_psample_group_put(void *priv)
253{
254 struct psample_group *group = priv;
255
256 psample_group_put(group);
257}
258
259static struct psample_group *
260tcf_sample_get_group(const struct tc_action *a,
261 tc_action_priv_destructor *destructor)
262{
263 struct tcf_sample *s = to_sample(a);
264 struct psample_group *group;
265
266 group = rcu_dereference_protected(s->psample_group,
267 lockdep_is_held(&s->tcf_lock));
268 if (group) {
269 psample_group_take(group);
270 *destructor = tcf_psample_group_put;
271 }
272
273 return group;
274}
275
276static void tcf_offload_sample_get_group(struct flow_action_entry *entry,
277 const struct tc_action *act)
278{
279 entry->sample.psample_group =
280 act->ops->get_psample_group(act, &entry->destructor);
281 entry->destructor_priv = entry->sample.psample_group;
282}
283
284static int tcf_sample_offload_act_setup(struct tc_action *act, void *entry_data,
285 u32 *index_inc, bool bind,
286 struct netlink_ext_ack *extack)
287{
288 if (bind) {
289 struct flow_action_entry *entry = entry_data;
290
291 entry->id = FLOW_ACTION_SAMPLE;
292 entry->sample.trunc_size = tcf_sample_trunc_size(act);
293 entry->sample.truncate = tcf_sample_truncate(act);
294 entry->sample.rate = tcf_sample_rate(act);
295 tcf_offload_sample_get_group(entry, act);
296 *index_inc = 1;
297 } else {
298 struct flow_offload_action *fl_action = entry_data;
299
300 fl_action->id = FLOW_ACTION_SAMPLE;
301 }
302
303 return 0;
304}
305
306static struct tc_action_ops act_sample_ops = {
307 .kind = "sample",
308 .id = TCA_ID_SAMPLE,
309 .owner = THIS_MODULE,
310 .act = tcf_sample_act,
311 .stats_update = tcf_sample_stats_update,
312 .dump = tcf_sample_dump,
313 .init = tcf_sample_init,
314 .cleanup = tcf_sample_cleanup,
315 .get_psample_group = tcf_sample_get_group,
316 .offload_act_setup = tcf_sample_offload_act_setup,
317 .size = sizeof(struct tcf_sample),
318};
319
320static __net_init int sample_init_net(struct net *net)
321{
322 struct tc_action_net *tn = net_generic(net, act_sample_ops.net_id);
323
324 return tc_action_net_init(net, tn, &act_sample_ops);
325}
326
327static void __net_exit sample_exit_net(struct list_head *net_list)
328{
329 tc_action_net_exit(net_list, act_sample_ops.net_id);
330}
331
332static struct pernet_operations sample_net_ops = {
333 .init = sample_init_net,
334 .exit_batch = sample_exit_net,
335 .id = &act_sample_ops.net_id,
336 .size = sizeof(struct tc_action_net),
337};
338
339static int __init sample_init_module(void)
340{
341 return tcf_register_action(&act_sample_ops, &sample_net_ops);
342}
343
344static void __exit sample_cleanup_module(void)
345{
346 tcf_unregister_action(&act_sample_ops, &sample_net_ops);
347}
348
349module_init(sample_init_module);
350module_exit(sample_cleanup_module);
351
352MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
353MODULE_DESCRIPTION("Packet sampling action");
354MODULE_LICENSE("GPL v2");