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

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

Version: ~ [ linux-5.15-rc1 ] ~ [ linux-5.14.5 ] ~ [ linux-5.13.18 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.66 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.147 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.206 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.246 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.282 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.283 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ 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 /*
  2  * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us>
  3  *
  4  * This program is free software; you can redistribute it and/or modify
  5  * it under the terms of the GNU General Public License as published by
  6  * the Free Software Foundation; either version 2 of the License, or
  7  * (at your option) any later version.
  8  */
  9 
 10 #include <linux/module.h>
 11 #include <linux/init.h>
 12 #include <linux/kernel.h>
 13 #include <linux/skbuff.h>
 14 #include <linux/rtnetlink.h>
 15 #include <linux/filter.h>
 16 #include <linux/bpf.h>
 17 
 18 #include <net/netlink.h>
 19 #include <net/pkt_sched.h>
 20 
 21 #include <linux/tc_act/tc_bpf.h>
 22 #include <net/tc_act/tc_bpf.h>
 23 
 24 #define BPF_TAB_MASK            15
 25 #define ACT_BPF_NAME_LEN        256
 26 
 27 struct tcf_bpf_cfg {
 28         struct bpf_prog *filter;
 29         struct sock_filter *bpf_ops;
 30         const char *bpf_name;
 31         u32 bpf_fd;
 32         u16 bpf_num_ops;
 33         bool is_ebpf;
 34 };
 35 
 36 static int bpf_net_id;
 37 
 38 static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act,
 39                    struct tcf_result *res)
 40 {
 41         struct tcf_bpf *prog = act->priv;
 42         struct bpf_prog *filter;
 43         int action, filter_res;
 44         bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS;
 45 
 46         if (unlikely(!skb_mac_header_was_set(skb)))
 47                 return TC_ACT_UNSPEC;
 48 
 49         tcf_lastuse_update(&prog->tcf_tm);
 50         bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
 51 
 52         rcu_read_lock();
 53         filter = rcu_dereference(prog->filter);
 54         if (at_ingress) {
 55                 __skb_push(skb, skb->mac_len);
 56                 filter_res = BPF_PROG_RUN(filter, skb);
 57                 __skb_pull(skb, skb->mac_len);
 58         } else {
 59                 filter_res = BPF_PROG_RUN(filter, skb);
 60         }
 61         rcu_read_unlock();
 62 
 63         /* A BPF program may overwrite the default action opcode.
 64          * Similarly as in cls_bpf, if filter_res == -1 we use the
 65          * default action specified from tc.
 66          *
 67          * In case a different well-known TC_ACT opcode has been
 68          * returned, it will overwrite the default one.
 69          *
 70          * For everything else that is unkown, TC_ACT_UNSPEC is
 71          * returned.
 72          */
 73         switch (filter_res) {
 74         case TC_ACT_PIPE:
 75         case TC_ACT_RECLASSIFY:
 76         case TC_ACT_OK:
 77         case TC_ACT_REDIRECT:
 78                 action = filter_res;
 79                 break;
 80         case TC_ACT_SHOT:
 81                 action = filter_res;
 82                 qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats));
 83                 break;
 84         case TC_ACT_UNSPEC:
 85                 action = prog->tcf_action;
 86                 break;
 87         default:
 88                 action = TC_ACT_UNSPEC;
 89                 break;
 90         }
 91 
 92         return action;
 93 }
 94 
 95 static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog)
 96 {
 97         return !prog->bpf_ops;
 98 }
 99 
100 static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog,
101                                  struct sk_buff *skb)
102 {
103         struct nlattr *nla;
104 
105         if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops))
106                 return -EMSGSIZE;
107 
108         nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops *
109                           sizeof(struct sock_filter));
110         if (nla == NULL)
111                 return -EMSGSIZE;
112 
113         memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
114 
115         return 0;
116 }
117 
118 static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog,
119                                   struct sk_buff *skb)
120 {
121         if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd))
122                 return -EMSGSIZE;
123 
124         if (prog->bpf_name &&
125             nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
126                 return -EMSGSIZE;
127 
128         return 0;
129 }
130 
131 static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act,
132                         int bind, int ref)
133 {
134         unsigned char *tp = skb_tail_pointer(skb);
135         struct tcf_bpf *prog = act->priv;
136         struct tc_act_bpf opt = {
137                 .index   = prog->tcf_index,
138                 .refcnt  = prog->tcf_refcnt - ref,
139                 .bindcnt = prog->tcf_bindcnt - bind,
140                 .action  = prog->tcf_action,
141         };
142         struct tcf_t tm;
143         int ret;
144 
145         if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
146                 goto nla_put_failure;
147 
148         if (tcf_bpf_is_ebpf(prog))
149                 ret = tcf_bpf_dump_ebpf_info(prog, skb);
150         else
151                 ret = tcf_bpf_dump_bpf_info(prog, skb);
152         if (ret)
153                 goto nla_put_failure;
154 
155         tm.install = jiffies_to_clock_t(jiffies - prog->tcf_tm.install);
156         tm.lastuse = jiffies_to_clock_t(jiffies - prog->tcf_tm.lastuse);
157         tm.expires = jiffies_to_clock_t(prog->tcf_tm.expires);
158 
159         if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm))
160                 goto nla_put_failure;
161 
162         return skb->len;
163 
164 nla_put_failure:
165         nlmsg_trim(skb, tp);
166         return -1;
167 }
168 
169 static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
170         [TCA_ACT_BPF_PARMS]     = { .len = sizeof(struct tc_act_bpf) },
171         [TCA_ACT_BPF_FD]        = { .type = NLA_U32 },
172         [TCA_ACT_BPF_NAME]      = { .type = NLA_NUL_STRING, .len = ACT_BPF_NAME_LEN },
173         [TCA_ACT_BPF_OPS_LEN]   = { .type = NLA_U16 },
174         [TCA_ACT_BPF_OPS]       = { .type = NLA_BINARY,
175                                     .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
176 };
177 
178 static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
179 {
180         struct sock_filter *bpf_ops;
181         struct sock_fprog_kern fprog_tmp;
182         struct bpf_prog *fp;
183         u16 bpf_size, bpf_num_ops;
184         int ret;
185 
186         bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
187         if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
188                 return -EINVAL;
189 
190         bpf_size = bpf_num_ops * sizeof(*bpf_ops);
191         if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
192                 return -EINVAL;
193 
194         bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
195         if (bpf_ops == NULL)
196                 return -ENOMEM;
197 
198         memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
199 
200         fprog_tmp.len = bpf_num_ops;
201         fprog_tmp.filter = bpf_ops;
202 
203         ret = bpf_prog_create(&fp, &fprog_tmp);
204         if (ret < 0) {
205                 kfree(bpf_ops);
206                 return ret;
207         }
208 
209         cfg->bpf_ops = bpf_ops;
210         cfg->bpf_num_ops = bpf_num_ops;
211         cfg->filter = fp;
212         cfg->is_ebpf = false;
213 
214         return 0;
215 }
216 
217 static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
218 {
219         struct bpf_prog *fp;
220         char *name = NULL;
221         u32 bpf_fd;
222 
223         bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]);
224 
225         fp = bpf_prog_get(bpf_fd);
226         if (IS_ERR(fp))
227                 return PTR_ERR(fp);
228 
229         if (fp->type != BPF_PROG_TYPE_SCHED_ACT) {
230                 bpf_prog_put(fp);
231                 return -EINVAL;
232         }
233 
234         if (tb[TCA_ACT_BPF_NAME]) {
235                 name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]),
236                                nla_len(tb[TCA_ACT_BPF_NAME]),
237                                GFP_KERNEL);
238                 if (!name) {
239                         bpf_prog_put(fp);
240                         return -ENOMEM;
241                 }
242         }
243 
244         cfg->bpf_fd = bpf_fd;
245         cfg->bpf_name = name;
246         cfg->filter = fp;
247         cfg->is_ebpf = true;
248 
249         return 0;
250 }
251 
252 static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg)
253 {
254         if (cfg->is_ebpf)
255                 bpf_prog_put(cfg->filter);
256         else
257                 bpf_prog_destroy(cfg->filter);
258 
259         kfree(cfg->bpf_ops);
260         kfree(cfg->bpf_name);
261 }
262 
263 static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog,
264                                   struct tcf_bpf_cfg *cfg)
265 {
266         cfg->is_ebpf = tcf_bpf_is_ebpf(prog);
267         /* updates to prog->filter are prevented, since it's called either
268          * with rtnl lock or during final cleanup in rcu callback
269          */
270         cfg->filter = rcu_dereference_protected(prog->filter, 1);
271 
272         cfg->bpf_ops = prog->bpf_ops;
273         cfg->bpf_name = prog->bpf_name;
274 }
275 
276 static int tcf_bpf_init(struct net *net, struct nlattr *nla,
277                         struct nlattr *est, struct tc_action *act,
278                         int replace, int bind)
279 {
280         struct tc_action_net *tn = net_generic(net, bpf_net_id);
281         struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
282         struct tcf_bpf_cfg cfg, old;
283         struct tc_act_bpf *parm;
284         struct tcf_bpf *prog;
285         bool is_bpf, is_ebpf;
286         int ret, res = 0;
287 
288         if (!nla)
289                 return -EINVAL;
290 
291         ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy);
292         if (ret < 0)
293                 return ret;
294 
295         if (!tb[TCA_ACT_BPF_PARMS])
296                 return -EINVAL;
297 
298         parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
299 
300         if (!tcf_hash_check(tn, parm->index, act, bind)) {
301                 ret = tcf_hash_create(tn, parm->index, est, act,
302                                       sizeof(*prog), bind, true);
303                 if (ret < 0)
304                         return ret;
305 
306                 res = ACT_P_CREATED;
307         } else {
308                 /* Don't override defaults. */
309                 if (bind)
310                         return 0;
311 
312                 tcf_hash_release(act, bind);
313                 if (!replace)
314                         return -EEXIST;
315         }
316 
317         is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS];
318         is_ebpf = tb[TCA_ACT_BPF_FD];
319 
320         if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
321                 ret = -EINVAL;
322                 goto out;
323         }
324 
325         memset(&cfg, 0, sizeof(cfg));
326 
327         ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) :
328                        tcf_bpf_init_from_efd(tb, &cfg);
329         if (ret < 0)
330                 goto out;
331 
332         prog = to_bpf(act);
333         ASSERT_RTNL();
334 
335         if (res != ACT_P_CREATED)
336                 tcf_bpf_prog_fill_cfg(prog, &old);
337 
338         prog->bpf_ops = cfg.bpf_ops;
339         prog->bpf_name = cfg.bpf_name;
340 
341         if (cfg.bpf_num_ops)
342                 prog->bpf_num_ops = cfg.bpf_num_ops;
343         if (cfg.bpf_fd)
344                 prog->bpf_fd = cfg.bpf_fd;
345 
346         prog->tcf_action = parm->action;
347         rcu_assign_pointer(prog->filter, cfg.filter);
348 
349         if (res == ACT_P_CREATED) {
350                 tcf_hash_insert(tn, act);
351         } else {
352                 /* make sure the program being replaced is no longer executing */
353                 synchronize_rcu();
354                 tcf_bpf_cfg_cleanup(&old);
355         }
356 
357         return res;
358 out:
359         if (res == ACT_P_CREATED)
360                 tcf_hash_cleanup(act, est);
361 
362         return ret;
363 }
364 
365 static void tcf_bpf_cleanup(struct tc_action *act, int bind)
366 {
367         struct tcf_bpf_cfg tmp;
368 
369         tcf_bpf_prog_fill_cfg(act->priv, &tmp);
370         tcf_bpf_cfg_cleanup(&tmp);
371 }
372 
373 static int tcf_bpf_walker(struct net *net, struct sk_buff *skb,
374                           struct netlink_callback *cb, int type,
375                           struct tc_action *a)
376 {
377         struct tc_action_net *tn = net_generic(net, bpf_net_id);
378 
379         return tcf_generic_walker(tn, skb, cb, type, a);
380 }
381 
382 static int tcf_bpf_search(struct net *net, struct tc_action *a, u32 index)
383 {
384         struct tc_action_net *tn = net_generic(net, bpf_net_id);
385 
386         return tcf_hash_search(tn, a, index);
387 }
388 
389 static struct tc_action_ops act_bpf_ops __read_mostly = {
390         .kind           =       "bpf",
391         .type           =       TCA_ACT_BPF,
392         .owner          =       THIS_MODULE,
393         .act            =       tcf_bpf,
394         .dump           =       tcf_bpf_dump,
395         .cleanup        =       tcf_bpf_cleanup,
396         .init           =       tcf_bpf_init,
397         .walk           =       tcf_bpf_walker,
398         .lookup         =       tcf_bpf_search,
399 };
400 
401 static __net_init int bpf_init_net(struct net *net)
402 {
403         struct tc_action_net *tn = net_generic(net, bpf_net_id);
404 
405         return tc_action_net_init(tn, &act_bpf_ops, BPF_TAB_MASK);
406 }
407 
408 static void __net_exit bpf_exit_net(struct net *net)
409 {
410         struct tc_action_net *tn = net_generic(net, bpf_net_id);
411 
412         tc_action_net_exit(tn);
413 }
414 
415 static struct pernet_operations bpf_net_ops = {
416         .init = bpf_init_net,
417         .exit = bpf_exit_net,
418         .id   = &bpf_net_id,
419         .size = sizeof(struct tc_action_net),
420 };
421 
422 static int __init bpf_init_module(void)
423 {
424         return tcf_register_action(&act_bpf_ops, &bpf_net_ops);
425 }
426 
427 static void __exit bpf_cleanup_module(void)
428 {
429         tcf_unregister_action(&act_bpf_ops, &bpf_net_ops);
430 }
431 
432 module_init(bpf_init_module);
433 module_exit(bpf_cleanup_module);
434 
435 MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
436 MODULE_DESCRIPTION("TC BPF based action");
437 MODULE_LICENSE("GPL v2");
438 

~ [ 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