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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, | |
40 | int bind) | |
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; | |
4aa971ec | 48 | u32 rate; |
5c5670fa YG |
49 | int ret; |
50 | ||
51 | if (!nla) | |
52 | return -EINVAL; | |
fceb6435 | 53 | ret = nla_parse_nested(tb, TCA_SAMPLE_MAX, nla, sample_policy, NULL); |
5c5670fa YG |
54 | if (ret < 0) |
55 | return ret; | |
56 | if (!tb[TCA_SAMPLE_PARMS] || !tb[TCA_SAMPLE_RATE] || | |
57 | !tb[TCA_SAMPLE_PSAMPLE_GROUP]) | |
58 | return -EINVAL; | |
59 | ||
60 | parm = nla_data(tb[TCA_SAMPLE_PARMS]); | |
61 | ||
65a206c0 | 62 | exists = tcf_idr_check(tn, parm->index, a, bind); |
5c5670fa YG |
63 | if (exists && bind) |
64 | return 0; | |
65 | ||
66 | if (!exists) { | |
65a206c0 | 67 | ret = tcf_idr_create(tn, parm->index, est, a, |
511b1e5c | 68 | &act_sample_ops, bind, true); |
5c5670fa YG |
69 | if (ret) |
70 | return ret; | |
71 | ret = ACT_P_CREATED; | |
72 | } else { | |
65a206c0 | 73 | tcf_idr_release(*a, bind); |
5c5670fa YG |
74 | if (!ovr) |
75 | return -EEXIST; | |
76 | } | |
5c5670fa | 77 | |
4aa971ec DC |
78 | rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); |
79 | if (!rate) { | |
80 | tcf_idr_release(*a, bind); | |
81 | return -EINVAL; | |
82 | } | |
83 | ||
84 | s = to_sample(*a); | |
5c5670fa YG |
85 | s->tcf_action = parm->action; |
86 | s->rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); | |
4aa971ec | 87 | s->rate = rate; |
5c5670fa YG |
88 | s->psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); |
89 | psample_group = psample_group_get(net, s->psample_group_num); | |
cadb9c9f YG |
90 | if (!psample_group) { |
91 | if (ret == ACT_P_CREATED) | |
65a206c0 | 92 | tcf_idr_release(*a, bind); |
5c5670fa | 93 | return -ENOMEM; |
cadb9c9f | 94 | } |
a0c82d24 VB |
95 | rcu_swap_protected(s->psample_group, psample_group, |
96 | lockdep_is_held(&s->tcf_lock)); | |
5c5670fa YG |
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 | } | |
102 | ||
a0c82d24 VB |
103 | if (psample_group) |
104 | psample_group_put(psample_group); | |
5c5670fa | 105 | if (ret == ACT_P_CREATED) |
65a206c0 | 106 | tcf_idr_insert(tn, *a); |
5c5670fa YG |
107 | return ret; |
108 | } | |
109 | ||
90a6ec85 | 110 | static void tcf_sample_cleanup(struct tc_action *a, int bind) |
5c5670fa | 111 | { |
90a6ec85 | 112 | struct tcf_sample *s = to_sample(a); |
5c5670fa YG |
113 | struct psample_group *psample_group; |
114 | ||
90a6ec85 | 115 | psample_group = rtnl_dereference(s->psample_group); |
5c5670fa | 116 | RCU_INIT_POINTER(s->psample_group, NULL); |
c65dc67b 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 | ||
150 | rcu_read_lock(); | |
151 | psample_group = rcu_dereference(s->psample_group); | |
152 | ||
153 | /* randomly sample packets according to rate */ | |
154 | if (psample_group && (prandom_u32() % s->rate == 0)) { | |
155 | if (!skb_at_tc_ingress(skb)) { | |
156 | iif = skb->skb_iif; | |
157 | oif = skb->dev->ifindex; | |
158 | } else { | |
159 | iif = skb->dev->ifindex; | |
160 | oif = 0; | |
161 | } | |
162 | ||
163 | /* on ingress, the mac header gets popped, so push it back */ | |
164 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
165 | skb_push(skb, skb->mac_len); | |
166 | ||
167 | size = s->truncate ? s->trunc_size : skb->len; | |
168 | psample_sample_packet(psample_group, skb, size, iif, oif, | |
169 | s->rate); | |
170 | ||
171 | if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev)) | |
172 | skb_pull(skb, skb->mac_len); | |
173 | } | |
174 | ||
175 | rcu_read_unlock(); | |
176 | return retval; | |
177 | } | |
178 | ||
179 | static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, | |
180 | int bind, int ref) | |
181 | { | |
182 | unsigned char *b = skb_tail_pointer(skb); | |
183 | struct tcf_sample *s = to_sample(a); | |
184 | struct tc_sample opt = { | |
185 | .index = s->tcf_index, | |
186 | .action = s->tcf_action, | |
187 | .refcnt = s->tcf_refcnt - ref, | |
188 | .bindcnt = s->tcf_bindcnt - bind, | |
189 | }; | |
190 | struct tcf_t t; | |
191 | ||
192 | if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt)) | |
193 | goto nla_put_failure; | |
194 | ||
195 | tcf_tm_dump(&t, &s->tcf_tm); | |
196 | if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD)) | |
197 | goto nla_put_failure; | |
198 | ||
199 | if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate)) | |
200 | goto nla_put_failure; | |
201 | ||
202 | if (s->truncate) | |
203 | if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size)) | |
204 | goto nla_put_failure; | |
205 | ||
206 | if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num)) | |
207 | goto nla_put_failure; | |
208 | return skb->len; | |
209 | ||
210 | nla_put_failure: | |
211 | nlmsg_trim(skb, b); | |
212 | return -1; | |
213 | } | |
214 | ||
215 | static int tcf_sample_walker(struct net *net, struct sk_buff *skb, | |
216 | struct netlink_callback *cb, int type, | |
217 | const struct tc_action_ops *ops) | |
218 | { | |
219 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
220 | ||
221 | return tcf_generic_walker(tn, skb, cb, type, ops); | |
222 | } | |
223 | ||
224 | static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index) | |
225 | { | |
226 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
227 | ||
65a206c0 | 228 | return tcf_idr_search(tn, a, index); |
5c5670fa YG |
229 | } |
230 | ||
231 | static struct tc_action_ops act_sample_ops = { | |
232 | .kind = "sample", | |
233 | .type = TCA_ACT_SAMPLE, | |
234 | .owner = THIS_MODULE, | |
235 | .act = tcf_sample_act, | |
236 | .dump = tcf_sample_dump, | |
237 | .init = tcf_sample_init, | |
238 | .cleanup = tcf_sample_cleanup, | |
239 | .walk = tcf_sample_walker, | |
240 | .lookup = tcf_sample_search, | |
241 | .size = sizeof(struct tcf_sample), | |
242 | }; | |
243 | ||
244 | static __net_init int sample_init_net(struct net *net) | |
245 | { | |
246 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
247 | ||
8f4d0354 | 248 | return tc_action_net_init(net, tn, &act_sample_ops); |
5c5670fa YG |
249 | } |
250 | ||
251 | static void __net_exit sample_exit_net(struct net *net) | |
252 | { | |
253 | struct tc_action_net *tn = net_generic(net, sample_net_id); | |
254 | ||
255 | tc_action_net_exit(tn); | |
256 | } | |
257 | ||
258 | static struct pernet_operations sample_net_ops = { | |
259 | .init = sample_init_net, | |
260 | .exit = sample_exit_net, | |
261 | .id = &sample_net_id, | |
262 | .size = sizeof(struct tc_action_net), | |
263 | }; | |
264 | ||
265 | static int __init sample_init_module(void) | |
266 | { | |
267 | return tcf_register_action(&act_sample_ops, &sample_net_ops); | |
268 | } | |
269 | ||
270 | static void __exit sample_cleanup_module(void) | |
271 | { | |
272 | tcf_unregister_action(&act_sample_ops, &sample_net_ops); | |
273 | } | |
274 | ||
275 | module_init(sample_init_module); | |
276 | module_exit(sample_cleanup_module); | |
277 | ||
f1fd20c3 | 278 | MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>"); |
5c5670fa YG |
279 | MODULE_DESCRIPTION("Packet sampling action"); |
280 | MODULE_LICENSE("GPL v2"); |