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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
5c5670fa YG |
2 | /* |
3 | * net/sched/act_sample.c - Packet sampling tc action | |
4 | * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com> | |
5c5670fa YG |
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> | |
e8c87c64 | 22 | #include <net/pkt_cls.h> |
5c5670fa YG |
23 | |
24 | #include <linux/if_arp.h> | |
25 | ||
5c5670fa YG |
26 | static unsigned int sample_net_id; |
27 | static struct tc_action_ops act_sample_ops; | |
28 | ||
29 | static 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 | ||
36 | static int tcf_sample_init(struct net *net, struct nlattr *nla, | |
37 | struct nlattr *est, struct tc_action **a, int ovr, | |
85d0966f | 38 | int bind, bool rtnl_held, struct tcf_proto *tp, |
abbb0d33 | 39 | u32 flags, struct netlink_ext_ack *extack) |
5c5670fa YG |
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; | |
7be8ef2c | 44 | u32 psample_group_num, rate, index; |
e8c87c64 | 45 | struct tcf_chain *goto_ch = NULL; |
5c5670fa YG |
46 | struct tc_sample *parm; |
47 | struct tcf_sample *s; | |
48 | bool exists = false; | |
0190c1d4 | 49 | int ret, err; |
5c5670fa YG |
50 | |
51 | if (!nla) | |
52 | return -EINVAL; | |
8cb08174 JB |
53 | ret = nla_parse_nested_deprecated(tb, TCA_SAMPLE_MAX, nla, |
54 | sample_policy, NULL); | |
5c5670fa YG |
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]); | |
7be8ef2c DL |
62 | index = parm->index; |
63 | err = tcf_idr_check_alloc(tn, &index, a, bind); | |
0190c1d4 VB |
64 | if (err < 0) |
65 | return err; | |
66 | exists = err; | |
5c5670fa YG |
67 | if (exists && bind) |
68 | return 0; | |
69 | ||
70 | if (!exists) { | |
7be8ef2c | 71 | ret = tcf_idr_create(tn, index, est, a, |
e3822678 | 72 | &act_sample_ops, bind, true, 0); |
0190c1d4 | 73 | if (ret) { |
7be8ef2c | 74 | tcf_idr_cleanup(tn, index); |
5c5670fa | 75 | return ret; |
0190c1d4 | 76 | } |
5c5670fa | 77 | ret = ACT_P_CREATED; |
4e8ddd7f | 78 | } else if (!ovr) { |
65a206c0 | 79 | tcf_idr_release(*a, bind); |
4e8ddd7f | 80 | return -EEXIST; |
5c5670fa | 81 | } |
e8c87c64 DC |
82 | err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); |
83 | if (err < 0) | |
84 | goto release_idr; | |
5c5670fa | 85 | |
fae27081 DC |
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 | } | |
653cd284 VB |
92 | psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); |
93 | psample_group = psample_group_get(net, psample_group_num); | |
cadb9c9f | 94 | if (!psample_group) { |
e8c87c64 DC |
95 | err = -ENOMEM; |
96 | goto put_chain; | |
cadb9c9f | 97 | } |
653cd284 VB |
98 | |
99 | s = to_sample(*a); | |
100 | ||
101 | spin_lock_bh(&s->tcf_lock); | |
e8c87c64 | 102 | goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); |
fae27081 | 103 | s->rate = rate; |
653cd284 | 104 | s->psample_group_num = psample_group_num; |
445d3749 PM |
105 | psample_group = rcu_replace_pointer(s->psample_group, psample_group, |
106 | lockdep_is_held(&s->tcf_lock)); | |
5c5670fa YG |
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 | } | |
653cd284 | 112 | spin_unlock_bh(&s->tcf_lock); |
dbf47a2a VB |
113 | |
114 | if (psample_group) | |
115 | psample_group_put(psample_group); | |
e8c87c64 DC |
116 | if (goto_ch) |
117 | tcf_chain_put_by_act(goto_ch); | |
5c5670fa | 118 | |
5c5670fa | 119 | return ret; |
e8c87c64 DC |
120 | put_chain: |
121 | if (goto_ch) | |
122 | tcf_chain_put_by_act(goto_ch); | |
123 | release_idr: | |
124 | tcf_idr_release(*a, bind); | |
125 | return err; | |
5c5670fa YG |
126 | } |
127 | ||
9a63b255 | 128 | static void tcf_sample_cleanup(struct tc_action *a) |
5c5670fa | 129 | { |
90a6ec85 | 130 | struct tcf_sample *s = to_sample(a); |
5c5670fa YG |
131 | struct psample_group *psample_group; |
132 | ||
d7728495 VB |
133 | /* last reference to action, no need to lock */ |
134 | psample_group = rcu_dereference_protected(s->psample_group, 1); | |
5c5670fa | 135 | RCU_INIT_POINTER(s->psample_group, NULL); |
1f110e7c DC |
136 | if (psample_group) |
137 | psample_group_put(psample_group); | |
5c5670fa YG |
138 | } |
139 | ||
5c5670fa YG |
140 | static 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: | |
92974a1d | 147 | case ARPHRD_IP6GRE: |
5c5670fa YG |
148 | case ARPHRD_VOID: |
149 | case ARPHRD_NONE: | |
150 | return false; | |
151 | default: | |
152 | return true; | |
153 | } | |
154 | } | |
155 | ||
156 | static 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 | int retval; | |
162 | int size; | |
163 | int iif; | |
164 | int oif; | |
165 | ||
166 | tcf_lastuse_update(&s->tcf_tm); | |
167 | bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb); | |
168 | retval = READ_ONCE(s->tcf_action); | |
169 | ||
7fd4b288 | 170 | psample_group = rcu_dereference_bh(s->psample_group); |
5c5670fa YG |
171 | |
172 | /* randomly sample packets according to rate */ | |
173 | if (psample_group && (prandom_u32() % s->rate == 0)) { | |
174 | if (!skb_at_tc_ingress(skb)) { | |
175 | iif = skb->skb_iif; | |
176 | oif = skb->dev->ifindex; | |
177 | } else { | |
178 | iif = skb->dev->ifindex; | |
179 | oif = 0; | |
180 | } | |
181 | ||
182 | /* on ingress, the mac header gets popped, so push it back */ | |
183 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
184 | skb_push(skb, skb->mac_len); | |
185 | ||
186 | size = s->truncate ? s->trunc_size : skb->len; | |
187 | psample_sample_packet(psample_group, skb, size, iif, oif, | |
188 | s->rate); | |
189 | ||
190 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
191 | skb_pull(skb, skb->mac_len); | |
192 | } | |
193 | ||
5c5670fa YG |
194 | return retval; |
195 | } | |
196 | ||
197 | static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, | |
198 | int bind, int ref) | |
199 | { | |
200 | unsigned char *b = skb_tail_pointer(skb); | |
201 | struct tcf_sample *s = to_sample(a); | |
202 | struct tc_sample opt = { | |
203 | .index = s->tcf_index, | |
036bb443 VB |
204 | .refcnt = refcount_read(&s->tcf_refcnt) - ref, |
205 | .bindcnt = atomic_read(&s->tcf_bindcnt) - bind, | |
5c5670fa YG |
206 | }; |
207 | struct tcf_t t; | |
208 | ||
653cd284 | 209 | spin_lock_bh(&s->tcf_lock); |
d7728495 | 210 | opt.action = s->tcf_action; |
5c5670fa YG |
211 | if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt)) |
212 | goto nla_put_failure; | |
213 | ||
214 | tcf_tm_dump(&t, &s->tcf_tm); | |
215 | if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD)) | |
216 | goto nla_put_failure; | |
217 | ||
218 | if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate)) | |
219 | goto nla_put_failure; | |
220 | ||
221 | if (s->truncate) | |
222 | if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size)) | |
223 | goto nla_put_failure; | |
224 | ||
225 | if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num)) | |
226 | goto nla_put_failure; | |
653cd284 | 227 | spin_unlock_bh(&s->tcf_lock); |
d7728495 | 228 | |
5c5670fa YG |
229 | return skb->len; |
230 | ||
231 | nla_put_failure: | |
653cd284 | 232 | spin_unlock_bh(&s->tcf_lock); |
5c5670fa YG |
233 | nlmsg_trim(skb, b); |
234 | return -1; | |
235 | } | |
236 | ||
237 | static int tcf_sample_walker(struct net *net, struct sk_buff *skb, | |
238 | struct netlink_callback *cb, int type, | |
41780105 AA |
239 | const struct tc_action_ops *ops, |
240 | struct netlink_ext_ack *extack) | |
5c5670fa YG |
241 | { |
242 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
243 | ||
b3620145 | 244 | return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
5c5670fa YG |
245 | } |
246 | ||
f061b48c | 247 | static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index) |
5c5670fa YG |
248 | { |
249 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
250 | ||
65a206c0 | 251 | return tcf_idr_search(tn, a, index); |
5c5670fa YG |
252 | } |
253 | ||
4a5da47d VB |
254 | static void tcf_psample_group_put(void *priv) |
255 | { | |
256 | struct psample_group *group = priv; | |
257 | ||
258 | psample_group_put(group); | |
259 | } | |
260 | ||
261 | static struct psample_group * | |
262 | tcf_sample_get_group(const struct tc_action *a, | |
263 | tc_action_priv_destructor *destructor) | |
264 | { | |
265 | struct tcf_sample *s = to_sample(a); | |
266 | struct psample_group *group; | |
267 | ||
4a5da47d VB |
268 | group = rcu_dereference_protected(s->psample_group, |
269 | lockdep_is_held(&s->tcf_lock)); | |
270 | if (group) { | |
271 | psample_group_take(group); | |
272 | *destructor = tcf_psample_group_put; | |
273 | } | |
4a5da47d VB |
274 | |
275 | return group; | |
276 | } | |
277 | ||
5c5670fa YG |
278 | static struct tc_action_ops act_sample_ops = { |
279 | .kind = "sample", | |
eddd2cf1 | 280 | .id = TCA_ID_SAMPLE, |
5c5670fa YG |
281 | .owner = THIS_MODULE, |
282 | .act = tcf_sample_act, | |
283 | .dump = tcf_sample_dump, | |
284 | .init = tcf_sample_init, | |
285 | .cleanup = tcf_sample_cleanup, | |
286 | .walk = tcf_sample_walker, | |
287 | .lookup = tcf_sample_search, | |
4a5da47d | 288 | .get_psample_group = tcf_sample_get_group, |
5c5670fa YG |
289 | .size = sizeof(struct tcf_sample), |
290 | }; | |
291 | ||
292 | static __net_init int sample_init_net(struct net *net) | |
293 | { | |
294 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
295 | ||
981471bd | 296 | return tc_action_net_init(net, tn, &act_sample_ops); |
5c5670fa YG |
297 | } |
298 | ||
039af9c6 | 299 | static void __net_exit sample_exit_net(struct list_head *net_list) |
5c5670fa | 300 | { |
039af9c6 | 301 | tc_action_net_exit(net_list, sample_net_id); |
5c5670fa YG |
302 | } |
303 | ||
304 | static struct pernet_operations sample_net_ops = { | |
305 | .init = sample_init_net, | |
039af9c6 | 306 | .exit_batch = sample_exit_net, |
5c5670fa YG |
307 | .id = &sample_net_id, |
308 | .size = sizeof(struct tc_action_net), | |
309 | }; | |
310 | ||
311 | static int __init sample_init_module(void) | |
312 | { | |
313 | return tcf_register_action(&act_sample_ops, &sample_net_ops); | |
314 | } | |
315 | ||
316 | static void __exit sample_cleanup_module(void) | |
317 | { | |
318 | tcf_unregister_action(&act_sample_ops, &sample_net_ops); | |
319 | } | |
320 | ||
321 | module_init(sample_init_module); | |
322 | module_exit(sample_cleanup_module); | |
323 | ||
f1fd20c3 | 324 | MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>"); |
5c5670fa YG |
325 | MODULE_DESCRIPTION("Packet sampling action"); |
326 | MODULE_LICENSE("GPL v2"); |