~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sched/act_sample.c

Version: ~ [ linux-5.11-rc3 ] ~ [ linux-5.10.7 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.89 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.167 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.215 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.251 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.251 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * net/sched/act_sample.c - Packet sampling tc action
  4  * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
  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 
 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,
 38                            int bind, bool rtnl_held, struct tcf_proto *tp,
 39                            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);
 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         rcu_swap_protected(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         if (ret == ACT_P_CREATED)
120                 tcf_idr_insert(tn, *a);
121         return ret;
122 put_chain:
123         if (goto_ch)
124                 tcf_chain_put_by_act(goto_ch);
125 release_idr:
126         tcf_idr_release(*a, bind);
127         return err;
128 }
129 
130 static void tcf_sample_cleanup(struct tc_action *a)
131 {
132         struct tcf_sample *s = to_sample(a);
133         struct psample_group *psample_group;
134 
135         /* last reference to action, no need to lock */
136         psample_group = rcu_dereference_protected(s->psample_group, 1);
137         RCU_INIT_POINTER(s->psample_group, NULL);
138         if (psample_group)
139                 psample_group_put(psample_group);
140 }
141 
142 static bool tcf_sample_dev_ok_push(struct net_device *dev)
143 {
144         switch (dev->type) {
145         case ARPHRD_TUNNEL:
146         case ARPHRD_TUNNEL6:
147         case ARPHRD_SIT:
148         case ARPHRD_IPGRE:
149         case ARPHRD_IP6GRE:
150         case ARPHRD_VOID:
151         case ARPHRD_NONE:
152                 return false;
153         default:
154                 return true;
155         }
156 }
157 
158 static int tcf_sample_act(struct sk_buff *skb, const struct tc_action *a,
159                           struct tcf_result *res)
160 {
161         struct tcf_sample *s = to_sample(a);
162         struct psample_group *psample_group;
163         int retval;
164         int size;
165         int iif;
166         int oif;
167 
168         tcf_lastuse_update(&s->tcf_tm);
169         bstats_cpu_update(this_cpu_ptr(s->common.cpu_bstats), skb);
170         retval = READ_ONCE(s->tcf_action);
171 
172         psample_group = rcu_dereference_bh(s->psample_group);
173 
174         /* randomly sample packets according to rate */
175         if (psample_group && (prandom_u32() % s->rate == 0)) {
176                 if (!skb_at_tc_ingress(skb)) {
177                         iif = skb->skb_iif;
178                         oif = skb->dev->ifindex;
179                 } else {
180                         iif = skb->dev->ifindex;
181                         oif = 0;
182                 }
183 
184                 /* on ingress, the mac header gets popped, so push it back */
185                 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
186                         skb_push(skb, skb->mac_len);
187 
188                 size = s->truncate ? s->trunc_size : skb->len;
189                 psample_sample_packet(psample_group, skb, size, iif, oif,
190                                       s->rate);
191 
192                 if (skb_at_tc_ingress(skb) && tcf_sample_dev_ok_push(skb->dev))
193                         skb_pull(skb, skb->mac_len);
194         }
195 
196         return retval;
197 }
198 
199 static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a,
200                            int bind, int ref)
201 {
202         unsigned char *b = skb_tail_pointer(skb);
203         struct tcf_sample *s = to_sample(a);
204         struct tc_sample opt = {
205                 .index      = s->tcf_index,
206                 .refcnt     = refcount_read(&s->tcf_refcnt) - ref,
207                 .bindcnt    = atomic_read(&s->tcf_bindcnt) - bind,
208         };
209         struct tcf_t t;
210 
211         spin_lock_bh(&s->tcf_lock);
212         opt.action = s->tcf_action;
213         if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt))
214                 goto nla_put_failure;
215 
216         tcf_tm_dump(&t, &s->tcf_tm);
217         if (nla_put_64bit(skb, TCA_SAMPLE_TM, sizeof(t), &t, TCA_SAMPLE_PAD))
218                 goto nla_put_failure;
219 
220         if (nla_put_u32(skb, TCA_SAMPLE_RATE, s->rate))
221                 goto nla_put_failure;
222 
223         if (s->truncate)
224                 if (nla_put_u32(skb, TCA_SAMPLE_TRUNC_SIZE, s->trunc_size))
225                         goto nla_put_failure;
226 
227         if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num))
228                 goto nla_put_failure;
229         spin_unlock_bh(&s->tcf_lock);
230 
231         return skb->len;
232 
233 nla_put_failure:
234         spin_unlock_bh(&s->tcf_lock);
235         nlmsg_trim(skb, b);
236         return -1;
237 }
238 
239 static int tcf_sample_walker(struct net *net, struct sk_buff *skb,
240                              struct netlink_callback *cb, int type,
241                              const struct tc_action_ops *ops,
242                              struct netlink_ext_ack *extack)
243 {
244         struct tc_action_net *tn = net_generic(net, sample_net_id);
245 
246         return tcf_generic_walker(tn, skb, cb, type, ops, extack);
247 }
248 
249 static int tcf_sample_search(struct net *net, struct tc_action **a, u32 index)
250 {
251         struct tc_action_net *tn = net_generic(net, sample_net_id);
252 
253         return tcf_idr_search(tn, a, index);
254 }
255 
256 static struct tc_action_ops act_sample_ops = {
257         .kind     = "sample",
258         .id       = TCA_ID_SAMPLE,
259         .owner    = THIS_MODULE,
260         .act      = tcf_sample_act,
261         .dump     = tcf_sample_dump,
262         .init     = tcf_sample_init,
263         .cleanup  = tcf_sample_cleanup,
264         .walk     = tcf_sample_walker,
265         .lookup   = tcf_sample_search,
266         .size     = sizeof(struct tcf_sample),
267 };
268 
269 static __net_init int sample_init_net(struct net *net)
270 {
271         struct tc_action_net *tn = net_generic(net, sample_net_id);
272 
273         return tc_action_net_init(net, tn, &act_sample_ops);
274 }
275 
276 static void __net_exit sample_exit_net(struct list_head *net_list)
277 {
278         tc_action_net_exit(net_list, sample_net_id);
279 }
280 
281 static struct pernet_operations sample_net_ops = {
282         .init = sample_init_net,
283         .exit_batch = sample_exit_net,
284         .id   = &sample_net_id,
285         .size = sizeof(struct tc_action_net),
286 };
287 
288 static int __init sample_init_module(void)
289 {
290         return tcf_register_action(&act_sample_ops, &sample_net_ops);
291 }
292 
293 static void __exit sample_cleanup_module(void)
294 {
295         tcf_unregister_action(&act_sample_ops, &sample_net_ops);
296 }
297 
298 module_init(sample_init_module);
299 module_exit(sample_cleanup_module);
300 
301 MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
302 MODULE_DESCRIPTION("Packet sampling action");
303 MODULE_LICENSE("GPL v2");
304 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp