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1/*
2 * net/sched/act_sample.c - Packet sampling tc action
3 * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/errno.h>
14#include <linux/skbuff.h>
15#include <linux/rtnetlink.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/gfp.h>
19#include <net/net_namespace.h>
20#include <net/netlink.h>
21#include <net/pkt_sched.h>
22#include <linux/tc_act/tc_sample.h>
23#include <net/tc_act/tc_sample.h>
24#include <net/psample.h>
25
26#include <linux/if_arp.h>
27
28static unsigned int sample_net_id;
29static struct tc_action_ops act_sample_ops;
30
31static const struct nla_policy sample_policy[TCA_SAMPLE_MAX + 1] = {
32 [TCA_SAMPLE_PARMS] = { .len = sizeof(struct tc_sample) },
33 [TCA_SAMPLE_RATE] = { .type = NLA_U32 },
34 [TCA_SAMPLE_TRUNC_SIZE] = { .type = NLA_U32 },
35 [TCA_SAMPLE_PSAMPLE_GROUP] = { .type = NLA_U32 },
36};
37
38static int tcf_sample_init(struct net *net, struct nlattr *nla,
39 struct nlattr *est, struct tc_action **a, int ovr,
40 int bind, struct netlink_ext_ack *extack)
41{
42 struct tc_action_net *tn = net_generic(net, sample_net_id);
43 struct nlattr *tb[TCA_SAMPLE_MAX + 1];
44 struct psample_group *psample_group;
45 struct tc_sample *parm;
46 struct tcf_sample *s;
47 bool exists = false;
48 int ret;
49
50 if (!nla)
51 return -EINVAL;
52 ret = nla_parse_nested(tb, TCA_SAMPLE_MAX, nla, sample_policy, NULL);
53 if (ret < 0)
54 return ret;
55 if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] ||
56 !tb[TCA_SAMPLE_PSAMPLE_GROUP])
57 return -EINVAL;
58
59 parm = nla_data(tb[TCA_SAMPLE_PARMS]);
60
61 exists = tcf_idr_check(tn, parm->index, a, bind);
62 if (exists && bind)
63 return 0;
64
65 if (!exists) {
66 ret = tcf_idr_create(tn, parm->index, est, a,
67 &act_sample_ops, bind, false);
68 if (ret)
69 return ret;
70 ret = ACT_P_CREATED;
71 } else {
72 tcf_idr_release(*a, bind);
73 if (!ovr)
74 return -EEXIST;
75 }
76 s = to_sample(*a);
77
78 s->tcf_action = parm->action;
79 s->rate = nla_get_u32(tb[TCA_SAMPLE_RATE]);
80 s->psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]);
81 psample_group = psample_group_get(net, s->psample_group_num);
82 if (!psample_group) {
83 if (ret == ACT_P_CREATED)
84 tcf_idr_release(*a, bind);
85 return -ENOMEM;
86 }
87 RCU_INIT_POINTER(s->psample_group, psample_group);
88
89 if (tb[TCA_SAMPLE_TRUNC_SIZE]) {
90 s->truncate = true;
91 s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]);
92 }
93
94 if (ret == ACT_P_CREATED)
95 tcf_idr_insert(tn, *a);
96 return ret;
97}
98
99static void tcf_sample_cleanup(struct tc_action *a)
100{
101 struct tcf_sample *s = to_sample(a);
102 struct psample_group *psample_group;
103
104 psample_group = rtnl_dereference(s->psample_group);
105 RCU_INIT_POINTER(s->psample_group, NULL);
106 if (psample_group)
107 psample_group_put(psample_group);
108}
109
110static bool tcf_sample_dev_ok_push(struct net_device *dev)
111{
112 switch (dev->type) {
113 case ARPHRD_TUNNEL:
114 case ARPHRD_TUNNEL6:
115 case ARPHRD_SIT:
116 case ARPHRD_IPGRE:
117 case ARPHRD_VOID:
118 case ARPHRD_NONE:
119 return false;
120 default:
121 return true;
122 }
123}
124
125static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
126 struct tcf_result *res)
127{
128 struct tcf_sample *s = to_sample(a);
129 struct psample_group *psample_group;
130 int retval;
131 int size;
132 int iif;
133 int oif;
134
135 tcf_lastuse_update(&s->tcf_tm);
136 bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
137 retval = READ_ONCE(s->tcf_action);
138
139 rcu_read_lock();
140 psample_group = rcu_dereference(s->psample_group);
141
142 /* randomly sample packets according to rate */
143 if (psample_group && (prandom_u32() % s->rate == 0)) {
144 if (!skb_at_tc_ingress(skb)) {
145 iif = skb->skb_iif;
146 oif = skb->dev->ifindex;
147 } else {
148 iif = skb->dev->ifindex;
149 oif = 0;
150 }
151
152 /* on ingress, the mac header gets popped, so push it back */
153 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
154 skb_push(skb, skb->mac_len);
155
156 size = s->truncate ? s->trunc_size : skb->len;
157 psample_sample_packet(psample_group, skb, size, iif, oif,
158 s->rate);
159
160 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
161 skb_pull(skb, skb->mac_len);
162 }
163
164 rcu_read_unlock();
165 return retval;
166}
167
168static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
169 int bind, int ref)
170{
171 unsigned char *b = skb_tail_pointer(skb);
172 struct tcf_sample *s = to_sample(a);
173 struct tc_sample opt = {
174 .index = s->tcf_index,
175 .action = s->tcf_action,
176 .refcnt = s->tcf_refcnt - ref,
177 .bindcnt = s->tcf_bindcnt - bind,
178 };
179 struct tcf_t t;
180
181 if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt))
182 goto nla_put_failure;
183
184 tcf_tm_dump(&t, &s->tcf_tm);
185 if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD))
186 goto nla_put_failure;
187
188 if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate))
189 goto nla_put_failure;
190
191 if (s->truncate)
192 if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size))
193 goto nla_put_failure;
194
195 if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num))
196 goto nla_put_failure;
197 return skb->len;
198
199nla_put_failure:
200 nlmsg_trim(skb, b);
201 return -1;
202}
203
204static int tcf_sample_walker(struct net *net, struct sk_buff *skb,
205 struct netlink_callback *cb, int type,
206 const struct tc_action_ops *ops,
207 struct netlink_ext_ack *extack)
208{
209 struct tc_action_net *tn = net_generic(net, sample_net_id);
210
211 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
212}
213
214static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index,
215 struct netlink_ext_ack *extack)
216{
217 struct tc_action_net *tn = net_generic(net, sample_net_id);
218
219 return tcf_idr_search(tn, a, index);
220}
221
222static struct tc_action_ops act_sample_ops = {
223 .kind = "sample",
224 .type = TCA_ACT_SAMPLE,
225 .owner = THIS_MODULE,
226 .act = tcf_sample_act,
227 .dump = tcf_sample_dump,
228 .init = tcf_sample_init,
229 .cleanup = tcf_sample_cleanup,
230 .walk = tcf_sample_walker,
231 .lookup = tcf_sample_search,
232 .size = sizeof(struct tcf_sample),
233};
234
235static __net_init int sample_init_net(struct net *net)
236{
237 struct tc_action_net *tn = net_generic(net, sample_net_id);
238
239 return tc_action_net_init(tn, &act_sample_ops);
240}
241
242static void __net_exit sample_exit_net(struct list_head *net_list)
243{
244 tc_action_net_exit(net_list, sample_net_id);
245}
246
247static struct pernet_operations sample_net_ops = {
248 .init = sample_init_net,
249 .exit_batch = sample_exit_net,
250 .id = &sample_net_id,
251 .size = sizeof(struct tc_action_net),
252};
253
254static int __init sample_init_module(void)
255{
256 return tcf_register_action(&act_sample_ops, &sample_net_ops);
257}
258
259static void __exit sample_cleanup_module(void)
260{
261 tcf_unregister_action(&act_sample_ops, &sample_net_ops);
262}
263
264module_init(sample_init_module);
265module_exit(sample_cleanup_module);
266
267MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
268MODULE_DESCRIPTION("Packet sampling action");
269MODULE_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
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");