Commit | Line | Data |
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d23b8ad8 JP |
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> | |
a8cb5f55 DB |
16 | #include <linux/bpf.h> |
17 | ||
d23b8ad8 JP |
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 | ||
a8cb5f55 DB |
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; | |
f4eaed28 | 30 | const char *bpf_name; |
a8cb5f55 DB |
31 | u32 bpf_fd; |
32 | u16 bpf_num_ops; | |
f4eaed28 | 33 | bool is_ebpf; |
a8cb5f55 | 34 | }; |
d23b8ad8 | 35 | |
ddf97ccd WC |
36 | static int bpf_net_id; |
37 | ||
a8cb5f55 | 38 | static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act, |
d23b8ad8 JP |
39 | struct tcf_result *res) |
40 | { | |
a8cb5f55 | 41 | struct tcf_bpf *prog = act->priv; |
cff82457 | 42 | struct bpf_prog *filter; |
ced585c8 | 43 | int action, filter_res; |
3431205e | 44 | bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS; |
d23b8ad8 | 45 | |
a166151c AS |
46 | if (unlikely(!skb_mac_header_was_set(skb))) |
47 | return TC_ACT_UNSPEC; | |
48 | ||
cff82457 AS |
49 | tcf_lastuse_update(&prog->tcf_tm); |
50 | bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb); | |
d23b8ad8 | 51 | |
a8cb5f55 | 52 | rcu_read_lock(); |
cff82457 | 53 | filter = rcu_dereference(prog->filter); |
3431205e AS |
54 | if (at_ingress) { |
55 | __skb_push(skb, skb->mac_len); | |
db58ba45 | 56 | bpf_compute_data_end(skb); |
cff82457 | 57 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e AS |
58 | __skb_pull(skb, skb->mac_len); |
59 | } else { | |
db58ba45 | 60 | bpf_compute_data_end(skb); |
cff82457 | 61 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e | 62 | } |
a8cb5f55 | 63 | rcu_read_unlock(); |
ced585c8 DB |
64 | |
65 | /* A BPF program may overwrite the default action opcode. | |
66 | * Similarly as in cls_bpf, if filter_res == -1 we use the | |
67 | * default action specified from tc. | |
68 | * | |
69 | * In case a different well-known TC_ACT opcode has been | |
70 | * returned, it will overwrite the default one. | |
71 | * | |
72 | * For everything else that is unkown, TC_ACT_UNSPEC is | |
73 | * returned. | |
74 | */ | |
75 | switch (filter_res) { | |
76 | case TC_ACT_PIPE: | |
77 | case TC_ACT_RECLASSIFY: | |
78 | case TC_ACT_OK: | |
27b29f63 | 79 | case TC_ACT_REDIRECT: |
ced585c8 DB |
80 | action = filter_res; |
81 | break; | |
82 | case TC_ACT_SHOT: | |
83 | action = filter_res; | |
cff82457 | 84 | qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats)); |
ced585c8 DB |
85 | break; |
86 | case TC_ACT_UNSPEC: | |
a8cb5f55 | 87 | action = prog->tcf_action; |
ced585c8 DB |
88 | break; |
89 | default: | |
90 | action = TC_ACT_UNSPEC; | |
91 | break; | |
d23b8ad8 JP |
92 | } |
93 | ||
d23b8ad8 JP |
94 | return action; |
95 | } | |
96 | ||
a8cb5f55 DB |
97 | static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog) |
98 | { | |
99 | return !prog->bpf_ops; | |
100 | } | |
101 | ||
102 | static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog, | |
103 | struct sk_buff *skb) | |
104 | { | |
105 | struct nlattr *nla; | |
106 | ||
107 | if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops)) | |
108 | return -EMSGSIZE; | |
109 | ||
110 | nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops * | |
111 | sizeof(struct sock_filter)); | |
112 | if (nla == NULL) | |
113 | return -EMSGSIZE; | |
114 | ||
115 | memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla)); | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog, | |
121 | struct sk_buff *skb) | |
122 | { | |
123 | if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd)) | |
124 | return -EMSGSIZE; | |
125 | ||
126 | if (prog->bpf_name && | |
127 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
128 | return -EMSGSIZE; | |
129 | ||
130 | return 0; | |
131 | } | |
132 | ||
133 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
134 | int bind, int ref) |
135 | { | |
136 | unsigned char *tp = skb_tail_pointer(skb); | |
a8cb5f55 | 137 | struct tcf_bpf *prog = act->priv; |
d23b8ad8 | 138 | struct tc_act_bpf opt = { |
a8cb5f55 DB |
139 | .index = prog->tcf_index, |
140 | .refcnt = prog->tcf_refcnt - ref, | |
141 | .bindcnt = prog->tcf_bindcnt - bind, | |
142 | .action = prog->tcf_action, | |
d23b8ad8 | 143 | }; |
a8cb5f55 DB |
144 | struct tcf_t tm; |
145 | int ret; | |
d23b8ad8 JP |
146 | |
147 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) | |
148 | goto nla_put_failure; | |
149 | ||
a8cb5f55 DB |
150 | if (tcf_bpf_is_ebpf(prog)) |
151 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
152 | else | |
153 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
154 | if (ret) | |
d23b8ad8 JP |
155 | goto nla_put_failure; |
156 | ||
a8cb5f55 DB |
157 | tm.install = jiffies_to_clock_t(jiffies - prog->tcf_tm.install); |
158 | tm.lastuse = jiffies_to_clock_t(jiffies - prog->tcf_tm.lastuse); | |
159 | tm.expires = jiffies_to_clock_t(prog->tcf_tm.expires); | |
d23b8ad8 | 160 | |
9854518e ND |
161 | if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm, |
162 | TCA_ACT_BPF_PAD)) | |
d23b8ad8 | 163 | goto nla_put_failure; |
a8cb5f55 | 164 | |
d23b8ad8 JP |
165 | return skb->len; |
166 | ||
167 | nla_put_failure: | |
168 | nlmsg_trim(skb, tp); | |
169 | return -1; | |
170 | } | |
171 | ||
172 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
173 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 DB |
174 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
175 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
176 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
177 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
178 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
179 | }; | |
180 | ||
a8cb5f55 | 181 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 182 | { |
d23b8ad8 | 183 | struct sock_filter *bpf_ops; |
a8cb5f55 | 184 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 185 | struct bpf_prog *fp; |
a8cb5f55 | 186 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
187 | int ret; |
188 | ||
d23b8ad8 JP |
189 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
190 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
191 | return -EINVAL; | |
192 | ||
193 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
194 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
195 | return -EINVAL; | |
196 | ||
d23b8ad8 | 197 | bpf_ops = kzalloc(bpf_size, GFP_KERNEL); |
a8cb5f55 | 198 | if (bpf_ops == NULL) |
d23b8ad8 JP |
199 | return -ENOMEM; |
200 | ||
201 | memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size); | |
202 | ||
a8cb5f55 DB |
203 | fprog_tmp.len = bpf_num_ops; |
204 | fprog_tmp.filter = bpf_ops; | |
d23b8ad8 | 205 | |
a8cb5f55 DB |
206 | ret = bpf_prog_create(&fp, &fprog_tmp); |
207 | if (ret < 0) { | |
208 | kfree(bpf_ops); | |
209 | return ret; | |
210 | } | |
d23b8ad8 | 211 | |
a8cb5f55 DB |
212 | cfg->bpf_ops = bpf_ops; |
213 | cfg->bpf_num_ops = bpf_num_ops; | |
214 | cfg->filter = fp; | |
f4eaed28 | 215 | cfg->is_ebpf = false; |
a8cb5f55 DB |
216 | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg) | |
221 | { | |
222 | struct bpf_prog *fp; | |
223 | char *name = NULL; | |
224 | u32 bpf_fd; | |
225 | ||
226 | bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]); | |
227 | ||
228 | fp = bpf_prog_get(bpf_fd); | |
229 | if (IS_ERR(fp)) | |
230 | return PTR_ERR(fp); | |
231 | ||
232 | if (fp->type != BPF_PROG_TYPE_SCHED_ACT) { | |
233 | bpf_prog_put(fp); | |
234 | return -EINVAL; | |
235 | } | |
236 | ||
237 | if (tb[TCA_ACT_BPF_NAME]) { | |
238 | name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]), | |
239 | nla_len(tb[TCA_ACT_BPF_NAME]), | |
240 | GFP_KERNEL); | |
241 | if (!name) { | |
242 | bpf_prog_put(fp); | |
243 | return -ENOMEM; | |
244 | } | |
245 | } | |
246 | ||
247 | cfg->bpf_fd = bpf_fd; | |
248 | cfg->bpf_name = name; | |
249 | cfg->filter = fp; | |
f4eaed28 | 250 | cfg->is_ebpf = true; |
a8cb5f55 DB |
251 | |
252 | return 0; | |
253 | } | |
254 | ||
f4eaed28 DB |
255 | static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg) |
256 | { | |
257 | if (cfg->is_ebpf) | |
258 | bpf_prog_put(cfg->filter); | |
259 | else | |
260 | bpf_prog_destroy(cfg->filter); | |
261 | ||
262 | kfree(cfg->bpf_ops); | |
263 | kfree(cfg->bpf_name); | |
264 | } | |
265 | ||
266 | static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog, | |
267 | struct tcf_bpf_cfg *cfg) | |
268 | { | |
269 | cfg->is_ebpf = tcf_bpf_is_ebpf(prog); | |
cff82457 AS |
270 | /* updates to prog->filter are prevented, since it's called either |
271 | * with rtnl lock or during final cleanup in rcu callback | |
272 | */ | |
273 | cfg->filter = rcu_dereference_protected(prog->filter, 1); | |
f4eaed28 DB |
274 | |
275 | cfg->bpf_ops = prog->bpf_ops; | |
276 | cfg->bpf_name = prog->bpf_name; | |
277 | } | |
278 | ||
a8cb5f55 DB |
279 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
280 | struct nlattr *est, struct tc_action *act, | |
281 | int replace, int bind) | |
282 | { | |
ddf97ccd | 283 | struct tc_action_net *tn = net_generic(net, bpf_net_id); |
a8cb5f55 | 284 | struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; |
f4eaed28 | 285 | struct tcf_bpf_cfg cfg, old; |
a8cb5f55 DB |
286 | struct tc_act_bpf *parm; |
287 | struct tcf_bpf *prog; | |
a8cb5f55 | 288 | bool is_bpf, is_ebpf; |
a5c90b29 | 289 | int ret, res = 0; |
a8cb5f55 DB |
290 | |
291 | if (!nla) | |
292 | return -EINVAL; | |
293 | ||
294 | ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy); | |
295 | if (ret < 0) | |
296 | return ret; | |
297 | ||
a5c90b29 | 298 | if (!tb[TCA_ACT_BPF_PARMS]) |
a8cb5f55 DB |
299 | return -EINVAL; |
300 | ||
301 | parm = nla_data(tb[TCA_ACT_BPF_PARMS]); | |
302 | ||
ddf97ccd WC |
303 | if (!tcf_hash_check(tn, parm->index, act, bind)) { |
304 | ret = tcf_hash_create(tn, parm->index, est, act, | |
cff82457 | 305 | sizeof(*prog), bind, true); |
a8cb5f55 | 306 | if (ret < 0) |
a5c90b29 | 307 | return ret; |
d23b8ad8 | 308 | |
a5c90b29 | 309 | res = ACT_P_CREATED; |
d23b8ad8 | 310 | } else { |
a8cb5f55 | 311 | /* Don't override defaults. */ |
d23b8ad8 | 312 | if (bind) |
a5c90b29 | 313 | return 0; |
a8cb5f55 DB |
314 | |
315 | tcf_hash_release(act, bind); | |
a5c90b29 DB |
316 | if (!replace) |
317 | return -EEXIST; | |
d23b8ad8 JP |
318 | } |
319 | ||
a5c90b29 DB |
320 | is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; |
321 | is_ebpf = tb[TCA_ACT_BPF_FD]; | |
322 | ||
323 | if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) { | |
324 | ret = -EINVAL; | |
325 | goto out; | |
326 | } | |
327 | ||
328 | memset(&cfg, 0, sizeof(cfg)); | |
329 | ||
330 | ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) : | |
331 | tcf_bpf_init_from_efd(tb, &cfg); | |
332 | if (ret < 0) | |
333 | goto out; | |
334 | ||
a8cb5f55 | 335 | prog = to_bpf(act); |
cff82457 | 336 | ASSERT_RTNL(); |
a8cb5f55 | 337 | |
faa54be4 | 338 | if (res != ACT_P_CREATED) |
f4eaed28 DB |
339 | tcf_bpf_prog_fill_cfg(prog, &old); |
340 | ||
a8cb5f55 DB |
341 | prog->bpf_ops = cfg.bpf_ops; |
342 | prog->bpf_name = cfg.bpf_name; | |
343 | ||
344 | if (cfg.bpf_num_ops) | |
345 | prog->bpf_num_ops = cfg.bpf_num_ops; | |
346 | if (cfg.bpf_fd) | |
347 | prog->bpf_fd = cfg.bpf_fd; | |
348 | ||
349 | prog->tcf_action = parm->action; | |
cff82457 | 350 | rcu_assign_pointer(prog->filter, cfg.filter); |
d23b8ad8 | 351 | |
cff82457 | 352 | if (res == ACT_P_CREATED) { |
ddf97ccd | 353 | tcf_hash_insert(tn, act); |
cff82457 AS |
354 | } else { |
355 | /* make sure the program being replaced is no longer executing */ | |
356 | synchronize_rcu(); | |
f4eaed28 | 357 | tcf_bpf_cfg_cleanup(&old); |
cff82457 | 358 | } |
a8cb5f55 | 359 | |
a5c90b29 DB |
360 | return res; |
361 | out: | |
362 | if (res == ACT_P_CREATED) | |
363 | tcf_hash_cleanup(act, est); | |
d23b8ad8 | 364 | |
d23b8ad8 JP |
365 | return ret; |
366 | } | |
367 | ||
a8cb5f55 | 368 | static void tcf_bpf_cleanup(struct tc_action *act, int bind) |
d23b8ad8 | 369 | { |
f4eaed28 | 370 | struct tcf_bpf_cfg tmp; |
ddf06c1e | 371 | |
f4eaed28 DB |
372 | tcf_bpf_prog_fill_cfg(act->priv, &tmp); |
373 | tcf_bpf_cfg_cleanup(&tmp); | |
d23b8ad8 JP |
374 | } |
375 | ||
ddf97ccd WC |
376 | static int tcf_bpf_walker(struct net *net, struct sk_buff *skb, |
377 | struct netlink_callback *cb, int type, | |
378 | struct tc_action *a) | |
379 | { | |
380 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
381 | ||
382 | return tcf_generic_walker(tn, skb, cb, type, a); | |
383 | } | |
384 | ||
385 | static int tcf_bpf_search(struct net *net, struct tc_action *a, u32 index) | |
386 | { | |
387 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
388 | ||
389 | return tcf_hash_search(tn, a, index); | |
390 | } | |
391 | ||
a8cb5f55 DB |
392 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
393 | .kind = "bpf", | |
394 | .type = TCA_ACT_BPF, | |
395 | .owner = THIS_MODULE, | |
396 | .act = tcf_bpf, | |
397 | .dump = tcf_bpf_dump, | |
398 | .cleanup = tcf_bpf_cleanup, | |
399 | .init = tcf_bpf_init, | |
ddf97ccd WC |
400 | .walk = tcf_bpf_walker, |
401 | .lookup = tcf_bpf_search, | |
402 | }; | |
403 | ||
404 | static __net_init int bpf_init_net(struct net *net) | |
405 | { | |
406 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
407 | ||
408 | return tc_action_net_init(tn, &act_bpf_ops, BPF_TAB_MASK); | |
409 | } | |
410 | ||
411 | static void __net_exit bpf_exit_net(struct net *net) | |
412 | { | |
413 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
414 | ||
415 | tc_action_net_exit(tn); | |
416 | } | |
417 | ||
418 | static struct pernet_operations bpf_net_ops = { | |
419 | .init = bpf_init_net, | |
420 | .exit = bpf_exit_net, | |
421 | .id = &bpf_net_id, | |
422 | .size = sizeof(struct tc_action_net), | |
d23b8ad8 JP |
423 | }; |
424 | ||
425 | static int __init bpf_init_module(void) | |
426 | { | |
ddf97ccd | 427 | return tcf_register_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
428 | } |
429 | ||
430 | static void __exit bpf_cleanup_module(void) | |
431 | { | |
ddf97ccd | 432 | tcf_unregister_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
433 | } |
434 | ||
435 | module_init(bpf_init_module); | |
436 | module_exit(bpf_cleanup_module); | |
437 | ||
438 | MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>"); | |
439 | MODULE_DESCRIPTION("TC BPF based action"); | |
440 | MODULE_LICENSE("GPL v2"); |