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