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5c5670fa YG |
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 | ||
5c5670fa YG |
28 | static unsigned int sample_net_id; |
29 | static struct tc_action_ops act_sample_ops; | |
30 | ||
31 | static 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 | ||
38 | static int tcf_sample_init(struct net *net, struct nlattr *nla, | |
39 | struct nlattr *est, struct tc_action **a, int ovr, | |
789871bb VB |
40 | int bind, bool rtnl_held, |
41 | struct netlink_ext_ack *extack) | |
5c5670fa YG |
42 | { |
43 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
44 | struct nlattr *tb[TCA_SAMPLE_MAX + 1]; | |
45 | struct psample_group *psample_group; | |
46 | struct tc_sample *parm; | |
653cd284 | 47 | u32 psample_group_num; |
5c5670fa YG |
48 | struct tcf_sample *s; |
49 | bool exists = false; | |
0190c1d4 | 50 | int ret, err; |
5c5670fa YG |
51 | |
52 | if (!nla) | |
53 | return -EINVAL; | |
fceb6435 | 54 | ret = nla_parse_nested(tb, TCA_SAMPLE_MAX, nla, 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]); | |
62 | ||
0190c1d4 VB |
63 | err = tcf_idr_check_alloc(tn, &parm->index, a, bind); |
64 | if (err < 0) | |
65 | return err; | |
66 | exists = err; | |
5c5670fa YG |
67 | if (exists && bind) |
68 | return 0; | |
69 | ||
70 | if (!exists) { | |
65a206c0 | 71 | ret = tcf_idr_create(tn, parm->index, est, a, |
34043d25 | 72 | &act_sample_ops, bind, true); |
0190c1d4 VB |
73 | if (ret) { |
74 | tcf_idr_cleanup(tn, parm->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 | } |
5c5670fa | 82 | |
653cd284 VB |
83 | psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); |
84 | psample_group = psample_group_get(net, psample_group_num); | |
cadb9c9f | 85 | if (!psample_group) { |
4e8ddd7f | 86 | tcf_idr_release(*a, bind); |
5c5670fa | 87 | return -ENOMEM; |
cadb9c9f | 88 | } |
653cd284 VB |
89 | |
90 | s = to_sample(*a); | |
91 | ||
92 | spin_lock_bh(&s->tcf_lock); | |
93 | s->tcf_action = parm->action; | |
94 | s->rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); | |
95 | s->psample_group_num = psample_group_num; | |
5c5670fa YG |
96 | RCU_INIT_POINTER(s->psample_group, psample_group); |
97 | ||
98 | if (tb[TCA_SAMPLE_TRUNC_SIZE]) { | |
99 | s->truncate = true; | |
100 | s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]); | |
101 | } | |
653cd284 | 102 | spin_unlock_bh(&s->tcf_lock); |
5c5670fa YG |
103 | |
104 | if (ret == ACT_P_CREATED) | |
65a206c0 | 105 | tcf_idr_insert(tn, *a); |
5c5670fa YG |
106 | return ret; |
107 | } | |
108 | ||
9a63b255 | 109 | static void tcf_sample_cleanup(struct tc_action *a) |
5c5670fa | 110 | { |
90a6ec85 | 111 | struct tcf_sample *s = to_sample(a); |
5c5670fa YG |
112 | struct psample_group *psample_group; |
113 | ||
d7728495 VB |
114 | /* last reference to action, no need to lock */ |
115 | psample_group = rcu_dereference_protected(s->psample_group, 1); | |
5c5670fa | 116 | RCU_INIT_POINTER(s->psample_group, NULL); |
1f110e7c DC |
117 | if (psample_group) |
118 | psample_group_put(psample_group); | |
5c5670fa YG |
119 | } |
120 | ||
5c5670fa YG |
121 | static bool tcf_sample_dev_ok_push(struct net_device *dev) |
122 | { | |
123 | switch (dev->type) { | |
124 | case ARPHRD_TUNNEL: | |
125 | case ARPHRD_TUNNEL6: | |
126 | case ARPHRD_SIT: | |
127 | case ARPHRD_IPGRE: | |
128 | case ARPHRD_VOID: | |
129 | case ARPHRD_NONE: | |
130 | return false; | |
131 | default: | |
132 | return true; | |
133 | } | |
134 | } | |
135 | ||
136 | static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a, | |
137 | struct tcf_result *res) | |
138 | { | |
139 | struct tcf_sample *s = to_sample(a); | |
140 | struct psample_group *psample_group; | |
141 | int retval; | |
142 | int size; | |
143 | int iif; | |
144 | int oif; | |
145 | ||
146 | tcf_lastuse_update(&s->tcf_tm); | |
147 | bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb); | |
148 | retval = READ_ONCE(s->tcf_action); | |
149 | ||
7fd4b288 | 150 | psample_group = rcu_dereference_bh(s->psample_group); |
5c5670fa YG |
151 | |
152 | /* randomly sample packets according to rate */ | |
153 | if (psample_group && (prandom_u32() % s->rate == 0)) { | |
154 | if (!skb_at_tc_ingress(skb)) { | |
155 | iif = skb->skb_iif; | |
156 | oif = skb->dev->ifindex; | |
157 | } else { | |
158 | iif = skb->dev->ifindex; | |
159 | oif = 0; | |
160 | } | |
161 | ||
162 | /* on ingress, the mac header gets popped, so push it back */ | |
163 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
164 | skb_push(skb, skb->mac_len); | |
165 | ||
166 | size = s->truncate ? s->trunc_size : skb->len; | |
167 | psample_sample_packet(psample_group, skb, size, iif, oif, | |
168 | s->rate); | |
169 | ||
170 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
171 | skb_pull(skb, skb->mac_len); | |
172 | } | |
173 | ||
5c5670fa YG |
174 | return retval; |
175 | } | |
176 | ||
177 | static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, | |
178 | int bind, int ref) | |
179 | { | |
180 | unsigned char *b = skb_tail_pointer(skb); | |
181 | struct tcf_sample *s = to_sample(a); | |
182 | struct tc_sample opt = { | |
183 | .index = s->tcf_index, | |
036bb443 VB |
184 | .refcnt = refcount_read(&s->tcf_refcnt) - ref, |
185 | .bindcnt = atomic_read(&s->tcf_bindcnt) - bind, | |
5c5670fa YG |
186 | }; |
187 | struct tcf_t t; | |
188 | ||
653cd284 | 189 | spin_lock_bh(&s->tcf_lock); |
d7728495 | 190 | opt.action = s->tcf_action; |
5c5670fa YG |
191 | if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt)) |
192 | goto nla_put_failure; | |
193 | ||
194 | tcf_tm_dump(&t, &s->tcf_tm); | |
195 | if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD)) | |
196 | goto nla_put_failure; | |
197 | ||
198 | if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate)) | |
199 | goto nla_put_failure; | |
200 | ||
201 | if (s->truncate) | |
202 | if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size)) | |
203 | goto nla_put_failure; | |
204 | ||
205 | if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num)) | |
206 | goto nla_put_failure; | |
653cd284 | 207 | spin_unlock_bh(&s->tcf_lock); |
d7728495 | 208 | |
5c5670fa YG |
209 | return skb->len; |
210 | ||
211 | nla_put_failure: | |
653cd284 | 212 | spin_unlock_bh(&s->tcf_lock); |
5c5670fa YG |
213 | nlmsg_trim(skb, b); |
214 | return -1; | |
215 | } | |
216 | ||
217 | static int tcf_sample_walker(struct net *net, struct sk_buff *skb, | |
218 | struct netlink_callback *cb, int type, | |
41780105 AA |
219 | const struct tc_action_ops *ops, |
220 | struct netlink_ext_ack *extack) | |
5c5670fa YG |
221 | { |
222 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
223 | ||
b3620145 | 224 | return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
5c5670fa YG |
225 | } |
226 | ||
f061b48c | 227 | static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index) |
5c5670fa YG |
228 | { |
229 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
230 | ||
65a206c0 | 231 | return tcf_idr_search(tn, a, index); |
5c5670fa YG |
232 | } |
233 | ||
234 | static struct tc_action_ops act_sample_ops = { | |
235 | .kind = "sample", | |
eddd2cf1 | 236 | .id = TCA_ID_SAMPLE, |
5c5670fa YG |
237 | .owner = THIS_MODULE, |
238 | .act = tcf_sample_act, | |
239 | .dump = tcf_sample_dump, | |
240 | .init = tcf_sample_init, | |
241 | .cleanup = tcf_sample_cleanup, | |
242 | .walk = tcf_sample_walker, | |
243 | .lookup = tcf_sample_search, | |
244 | .size = sizeof(struct tcf_sample), | |
245 | }; | |
246 | ||
247 | static __net_init int sample_init_net(struct net *net) | |
248 | { | |
249 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
250 | ||
c7e460ce | 251 | return tc_action_net_init(tn, &act_sample_ops); |
5c5670fa YG |
252 | } |
253 | ||
039af9c6 | 254 | static void __net_exit sample_exit_net(struct list_head *net_list) |
5c5670fa | 255 | { |
039af9c6 | 256 | tc_action_net_exit(net_list, sample_net_id); |
5c5670fa YG |
257 | } |
258 | ||
259 | static struct pernet_operations sample_net_ops = { | |
260 | .init = sample_init_net, | |
039af9c6 | 261 | .exit_batch = sample_exit_net, |
5c5670fa YG |
262 | .id = &sample_net_id, |
263 | .size = sizeof(struct tc_action_net), | |
264 | }; | |
265 | ||
266 | static int __init sample_init_module(void) | |
267 | { | |
268 | return tcf_register_action(&act_sample_ops, &sample_net_ops); | |
269 | } | |
270 | ||
271 | static void __exit sample_cleanup_module(void) | |
272 | { | |
273 | tcf_unregister_action(&act_sample_ops, &sample_net_ops); | |
274 | } | |
275 | ||
276 | module_init(sample_init_module); | |
277 | module_exit(sample_cleanup_module); | |
278 | ||
f1fd20c3 | 279 | MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>"); |
5c5670fa YG |
280 | MODULE_DESCRIPTION("Packet sampling action"); |
281 | MODULE_LICENSE("GPL v2"); |