1
2
3
4
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,
38 struct tcf_proto *tp,
39 u32 flags, struct netlink_ext_ack *extack)
40{
41 struct tc_action_net *tn = net_generic(net, sample_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 if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] ||
59 !tb[TCA_SAMPLE_PSAMPLE_GROUP])
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 0;
70
71 if (!exists) {
72 ret = tcf_idr_create(tn, index, est, a,
73 &act_sample_ops, bind, true, 0);
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 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
84 if (err < 0)
85 goto release_idr;
86
87 rate = nla_get_u32(tb[TCA_SAMPLE_RATE]);
88 if (!rate) {
89 NL_SET_ERR_MSG(extack, "invalid sample rate");
90 err = -EINVAL;
91 goto put_chain;
92 }
93 psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]);
94 psample_group = psample_group_get(net, psample_group_num);
95 if (!psample_group) {
96 err = -ENOMEM;
97 goto put_chain;
98 }
99
100 s = to_sample(*a);
101
102 spin_lock_bh(&s->tcf_lock);
103 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
104 s->rate = rate;
105 s->psample_group_num = psample_group_num;
106 psample_group = rcu_replace_pointer(s->psample_group, psample_group,
107 lockdep_is_held(&s->tcf_lock));
108
109 if (tb[TCA_SAMPLE_TRUNC_SIZE]) {
110 s->truncate = true;
111 s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]);
112 }
113 spin_unlock_bh(&s->tcf_lock);
114
115 if (psample_group)
116 psample_group_put(psample_group);
117 if (goto_ch)
118 tcf_chain_put_by_act(goto_ch);
119
120 return ret;
121put_chain:
122 if (goto_ch)
123 tcf_chain_put_by_act(goto_ch);
124release_idr:
125 tcf_idr_release(*a, bind);
126 return err;
127}
128
129static void tcf_sample_cleanup(struct tc_action *a)
130{
131 struct tcf_sample *s = to_sample(a);
132 struct psample_group *psample_group;
133
134
135 psample_group = rcu_dereference_protected(s->psample_group, 1);
136 RCU_INIT_POINTER(s->psample_group, NULL);
137 if (psample_group)
138 psample_group_put(psample_group);
139}
140
141static bool tcf_sample_dev_ok_push(struct net_device *dev)
142{
143 switch (dev->type) {
144 case ARPHRD_TUNNEL:
145 case ARPHRD_TUNNEL6:
146 case ARPHRD_SIT:
147 case ARPHRD_IPGRE:
148 case ARPHRD_IP6GRE:
149 case ARPHRD_VOID:
150 case ARPHRD_NONE:
151 return false;
152 default:
153 return true;
154 }
155}
156
157static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
158 struct tcf_result *res)
159{
160 struct tcf_sample *s = to_sample(a);
161 struct psample_group *psample_group;
162 struct psample_metadata md = {};
163 int retval;
164
165 tcf_lastuse_update(&s->tcf_tm);
166 bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
167 retval = READ_ONCE(s->tcf_action);
168
169 psample_group = rcu_dereference_bh(s->psample_group);
170
171
172 if (psample_group && (prandom_u32() % s->rate == 0)) {
173 if (!skb_at_tc_ingress(skb)) {
174 md.in_ifindex = skb->skb_iif;
175 md.out_ifindex = skb->dev->ifindex;
176 } else {
177 md.in_ifindex = skb->dev->ifindex;
178 }
179
180
181 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
182 skb_push(skb, skb->mac_len);
183
184 md.trunc_size = s->truncate ? s->trunc_size : skb->len;
185 psample_sample_packet(psample_group, skb, s->rate, &md);
186
187 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
188 skb_pull(skb, skb->mac_len);
189 }
190
191 return retval;
192}
193
194static void tcf_sample_stats_update(struct tc_action *a, u64 bytes, u64 packets,
195 u64 drops, u64 lastuse, bool hw)
196{
197 struct tcf_sample *s = to_sample(a);
198 struct tcf_t *tm = &s->tcf_tm;
199
200 tcf_action_update_stats(a, bytes, packets, drops, hw);
201 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
202}
203
204static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
205 int bind, int ref)
206{
207 unsigned char *b = skb_tail_pointer(skb);
208 struct tcf_sample *s = to_sample(a);
209 struct tc_sample opt = {
210 .index = s->tcf_index,
211 .refcnt = refcount_read(&s->tcf_refcnt) - ref,
212 .bindcnt = atomic_read(&s->tcf_bindcnt) - bind,
213 };
214 struct tcf_t t;
215
216 spin_lock_bh(&s->tcf_lock);
217 opt.action = s->tcf_action;
218 if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt))
219 goto nla_put_failure;
220
221 tcf_tm_dump(&t, &s->tcf_tm);
222 if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD))
223 goto nla_put_failure;
224
225 if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate))
226 goto nla_put_failure;
227
228 if (s->truncate)
229 if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size))
230 goto nla_put_failure;
231
232 if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num))
233 goto nla_put_failure;
234 spin_unlock_bh(&s->tcf_lock);
235
236 return skb->len;
237
238nla_put_failure:
239 spin_unlock_bh(&s->tcf_lock);
240 nlmsg_trim(skb, b);
241 return -1;
242}
243
244static int tcf_sample_walker(struct net *net, struct sk_buff *skb,
245 struct netlink_callback *cb, int type,
246 const struct tc_action_ops *ops,
247 struct netlink_ext_ack *extack)
248{
249 struct tc_action_net *tn = net_generic(net, sample_net_id);
250
251 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
252}
253
254static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index)
255{
256 struct tc_action_net *tn = net_generic(net, sample_net_id);
257
258 return tcf_idr_search(tn, a, index);
259}
260
261static void tcf_psample_group_put(void *priv)
262{
263 struct psample_group *group = priv;
264
265 psample_group_put(group);
266}
267
268static struct psample_group *
269tcf_sample_get_group(const struct tc_action *a,
270 tc_action_priv_destructor *destructor)
271{
272 struct tcf_sample *s = to_sample(a);
273 struct psample_group *group;
274
275 group = rcu_dereference_protected(s->psample_group,
276 lockdep_is_held(&s->tcf_lock));
277 if (group) {
278 psample_group_take(group);
279 *destructor = tcf_psample_group_put;
280 }
281
282 return group;
283}
284
285static struct tc_action_ops act_sample_ops = {
286 .kind = "sample",
287 .id = TCA_ID_SAMPLE,
288 .owner = THIS_MODULE,
289 .act = tcf_sample_act,
290 .stats_update = tcf_sample_stats_update,
291 .dump = tcf_sample_dump,
292 .init = tcf_sample_init,
293 .cleanup = tcf_sample_cleanup,
294 .walk = tcf_sample_walker,
295 .lookup = tcf_sample_search,
296 .get_psample_group = tcf_sample_get_group,
297 .size = sizeof(struct tcf_sample),
298};
299
300static __net_init int sample_init_net(struct net *net)
301{
302 struct tc_action_net *tn = net_generic(net, sample_net_id);
303
304 return tc_action_net_init(net, tn, &act_sample_ops);
305}
306
307static void __net_exit sample_exit_net(struct list_head *net_list)
308{
309 tc_action_net_exit(net_list, sample_net_id);
310}
311
312static struct pernet_operations sample_net_ops = {
313 .init = sample_init_net,
314 .exit_batch = sample_exit_net,
315 .id = &sample_net_id,
316 .size = sizeof(struct tc_action_net),
317};
318
319static int __init sample_init_module(void)
320{
321 return tcf_register_action(&act_sample_ops, &sample_net_ops);
322}
323
324static void __exit sample_cleanup_module(void)
325{
326 tcf_unregister_action(&act_sample_ops, &sample_net_ops);
327}
328
329module_init(sample_init_module);
330module_exit(sample_cleanup_module);
331
332MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
333MODULE_DESCRIPTION("Packet sampling action");
334MODULE_LICENSE("GPL v2");
335
