Commit | Line | Data |
---|---|---|
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 | 36 | static int bpf_net_id; |
a85a970a | 37 | static struct tc_action_ops act_bpf_ops; |
ddf97ccd | 38 | |
a8cb5f55 | 39 | static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act, |
d23b8ad8 JP |
40 | struct tcf_result *res) |
41 | { | |
a85a970a | 42 | struct tcf_bpf *prog = to_bpf(act); |
cff82457 | 43 | struct bpf_prog *filter; |
ced585c8 | 44 | int action, filter_res; |
3431205e | 45 | bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS; |
d23b8ad8 | 46 | |
a166151c AS |
47 | if (unlikely(!skb_mac_header_was_set(skb))) |
48 | return TC_ACT_UNSPEC; | |
49 | ||
cff82457 AS |
50 | tcf_lastuse_update(&prog->tcf_tm); |
51 | bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb); | |
d23b8ad8 | 52 | |
a8cb5f55 | 53 | rcu_read_lock(); |
cff82457 | 54 | filter = rcu_dereference(prog->filter); |
3431205e AS |
55 | if (at_ingress) { |
56 | __skb_push(skb, skb->mac_len); | |
db58ba45 | 57 | bpf_compute_data_end(skb); |
cff82457 | 58 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e AS |
59 | __skb_pull(skb, skb->mac_len); |
60 | } else { | |
db58ba45 | 61 | bpf_compute_data_end(skb); |
cff82457 | 62 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e | 63 | } |
a8cb5f55 | 64 | rcu_read_unlock(); |
ced585c8 DB |
65 | |
66 | /* A BPF program may overwrite the default action opcode. | |
67 | * Similarly as in cls_bpf, if filter_res == -1 we use the | |
68 | * default action specified from tc. | |
69 | * | |
70 | * In case a different well-known TC_ACT opcode has been | |
71 | * returned, it will overwrite the default one. | |
72 | * | |
73 | * For everything else that is unkown, TC_ACT_UNSPEC is | |
74 | * returned. | |
75 | */ | |
76 | switch (filter_res) { | |
77 | case TC_ACT_PIPE: | |
78 | case TC_ACT_RECLASSIFY: | |
79 | case TC_ACT_OK: | |
27b29f63 | 80 | case TC_ACT_REDIRECT: |
ced585c8 DB |
81 | action = filter_res; |
82 | break; | |
83 | case TC_ACT_SHOT: | |
84 | action = filter_res; | |
cff82457 | 85 | qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats)); |
ced585c8 DB |
86 | break; |
87 | case TC_ACT_UNSPEC: | |
a8cb5f55 | 88 | action = prog->tcf_action; |
ced585c8 DB |
89 | break; |
90 | default: | |
91 | action = TC_ACT_UNSPEC; | |
92 | break; | |
d23b8ad8 JP |
93 | } |
94 | ||
d23b8ad8 JP |
95 | return action; |
96 | } | |
97 | ||
a8cb5f55 DB |
98 | static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog) |
99 | { | |
100 | return !prog->bpf_ops; | |
101 | } | |
102 | ||
103 | static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog, | |
104 | struct sk_buff *skb) | |
105 | { | |
106 | struct nlattr *nla; | |
107 | ||
108 | if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops)) | |
109 | return -EMSGSIZE; | |
110 | ||
111 | nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops * | |
112 | sizeof(struct sock_filter)); | |
113 | if (nla == NULL) | |
114 | return -EMSGSIZE; | |
115 | ||
116 | memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla)); | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
121 | static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog, | |
122 | struct sk_buff *skb) | |
123 | { | |
124 | if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd)) | |
125 | return -EMSGSIZE; | |
126 | ||
127 | if (prog->bpf_name && | |
128 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
129 | return -EMSGSIZE; | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
135 | int bind, int ref) |
136 | { | |
137 | unsigned char *tp = skb_tail_pointer(skb); | |
a85a970a | 138 | struct tcf_bpf *prog = to_bpf(act); |
d23b8ad8 | 139 | struct tc_act_bpf opt = { |
a8cb5f55 DB |
140 | .index = prog->tcf_index, |
141 | .refcnt = prog->tcf_refcnt - ref, | |
142 | .bindcnt = prog->tcf_bindcnt - bind, | |
143 | .action = prog->tcf_action, | |
d23b8ad8 | 144 | }; |
a8cb5f55 DB |
145 | struct tcf_t tm; |
146 | int ret; | |
d23b8ad8 JP |
147 | |
148 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) | |
149 | goto nla_put_failure; | |
150 | ||
a8cb5f55 DB |
151 | if (tcf_bpf_is_ebpf(prog)) |
152 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
153 | else | |
154 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
155 | if (ret) | |
d23b8ad8 JP |
156 | goto nla_put_failure; |
157 | ||
48d8ee16 | 158 | tcf_tm_dump(&tm, &prog->tcf_tm); |
9854518e ND |
159 | if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm, |
160 | TCA_ACT_BPF_PAD)) | |
d23b8ad8 | 161 | goto nla_put_failure; |
a8cb5f55 | 162 | |
d23b8ad8 JP |
163 | return skb->len; |
164 | ||
165 | nla_put_failure: | |
166 | nlmsg_trim(skb, tp); | |
167 | return -1; | |
168 | } | |
169 | ||
170 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
171 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 | 172 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
0b0f43fe JHS |
173 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, |
174 | .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
175 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
176 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
177 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
178 | }; | |
179 | ||
a8cb5f55 | 180 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 181 | { |
d23b8ad8 | 182 | struct sock_filter *bpf_ops; |
a8cb5f55 | 183 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 184 | struct bpf_prog *fp; |
a8cb5f55 | 185 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
186 | int ret; |
187 | ||
d23b8ad8 JP |
188 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
189 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
190 | return -EINVAL; | |
191 | ||
192 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
193 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
194 | return -EINVAL; | |
195 | ||
d23b8ad8 | 196 | bpf_ops = kzalloc(bpf_size, GFP_KERNEL); |
a8cb5f55 | 197 | if (bpf_ops == NULL) |
d23b8ad8 JP |
198 | return -ENOMEM; |
199 | ||
200 | memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size); | |
201 | ||
a8cb5f55 DB |
202 | fprog_tmp.len = bpf_num_ops; |
203 | fprog_tmp.filter = bpf_ops; | |
d23b8ad8 | 204 | |
a8cb5f55 DB |
205 | ret = bpf_prog_create(&fp, &fprog_tmp); |
206 | if (ret < 0) { | |
207 | kfree(bpf_ops); | |
208 | return ret; | |
209 | } | |
d23b8ad8 | 210 | |
a8cb5f55 DB |
211 | cfg->bpf_ops = bpf_ops; |
212 | cfg->bpf_num_ops = bpf_num_ops; | |
213 | cfg->filter = fp; | |
f4eaed28 | 214 | cfg->is_ebpf = false; |
a8cb5f55 DB |
215 | |
216 | return 0; | |
217 | } | |
218 | ||
219 | static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg) | |
220 | { | |
221 | struct bpf_prog *fp; | |
222 | char *name = NULL; | |
223 | u32 bpf_fd; | |
224 | ||
225 | bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]); | |
226 | ||
113214be | 227 | fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT); |
a8cb5f55 DB |
228 | if (IS_ERR(fp)) |
229 | return PTR_ERR(fp); | |
230 | ||
a8cb5f55 DB |
231 | if (tb[TCA_ACT_BPF_NAME]) { |
232 | name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]), | |
233 | nla_len(tb[TCA_ACT_BPF_NAME]), | |
234 | GFP_KERNEL); | |
235 | if (!name) { | |
236 | bpf_prog_put(fp); | |
237 | return -ENOMEM; | |
238 | } | |
239 | } | |
240 | ||
241 | cfg->bpf_fd = bpf_fd; | |
242 | cfg->bpf_name = name; | |
243 | cfg->filter = fp; | |
f4eaed28 | 244 | cfg->is_ebpf = true; |
a8cb5f55 DB |
245 | |
246 | return 0; | |
247 | } | |
248 | ||
f4eaed28 DB |
249 | static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg) |
250 | { | |
251 | if (cfg->is_ebpf) | |
252 | bpf_prog_put(cfg->filter); | |
253 | else | |
254 | bpf_prog_destroy(cfg->filter); | |
255 | ||
256 | kfree(cfg->bpf_ops); | |
257 | kfree(cfg->bpf_name); | |
258 | } | |
259 | ||
260 | static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog, | |
261 | struct tcf_bpf_cfg *cfg) | |
262 | { | |
263 | cfg->is_ebpf = tcf_bpf_is_ebpf(prog); | |
cff82457 AS |
264 | /* updates to prog->filter are prevented, since it's called either |
265 | * with rtnl lock or during final cleanup in rcu callback | |
266 | */ | |
267 | cfg->filter = rcu_dereference_protected(prog->filter, 1); | |
f4eaed28 DB |
268 | |
269 | cfg->bpf_ops = prog->bpf_ops; | |
270 | cfg->bpf_name = prog->bpf_name; | |
271 | } | |
272 | ||
a8cb5f55 | 273 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
a85a970a | 274 | struct nlattr *est, struct tc_action **act, |
a8cb5f55 DB |
275 | int replace, int bind) |
276 | { | |
ddf97ccd | 277 | struct tc_action_net *tn = net_generic(net, bpf_net_id); |
a8cb5f55 | 278 | struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; |
f4eaed28 | 279 | struct tcf_bpf_cfg cfg, old; |
a8cb5f55 DB |
280 | struct tc_act_bpf *parm; |
281 | struct tcf_bpf *prog; | |
a8cb5f55 | 282 | bool is_bpf, is_ebpf; |
a5c90b29 | 283 | int ret, res = 0; |
a8cb5f55 DB |
284 | |
285 | if (!nla) | |
286 | return -EINVAL; | |
287 | ||
288 | ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy); | |
289 | if (ret < 0) | |
290 | return ret; | |
291 | ||
a5c90b29 | 292 | if (!tb[TCA_ACT_BPF_PARMS]) |
a8cb5f55 DB |
293 | return -EINVAL; |
294 | ||
295 | parm = nla_data(tb[TCA_ACT_BPF_PARMS]); | |
296 | ||
ddf97ccd WC |
297 | if (!tcf_hash_check(tn, parm->index, act, bind)) { |
298 | ret = tcf_hash_create(tn, parm->index, est, act, | |
a85a970a | 299 | &act_bpf_ops, bind, true); |
a8cb5f55 | 300 | if (ret < 0) |
a5c90b29 | 301 | return ret; |
d23b8ad8 | 302 | |
a5c90b29 | 303 | res = ACT_P_CREATED; |
d23b8ad8 | 304 | } else { |
a8cb5f55 | 305 | /* Don't override defaults. */ |
d23b8ad8 | 306 | if (bind) |
a5c90b29 | 307 | return 0; |
a8cb5f55 | 308 | |
a85a970a | 309 | tcf_hash_release(*act, bind); |
a5c90b29 DB |
310 | if (!replace) |
311 | return -EEXIST; | |
d23b8ad8 JP |
312 | } |
313 | ||
a5c90b29 DB |
314 | is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; |
315 | is_ebpf = tb[TCA_ACT_BPF_FD]; | |
316 | ||
317 | if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) { | |
318 | ret = -EINVAL; | |
319 | goto out; | |
320 | } | |
321 | ||
322 | memset(&cfg, 0, sizeof(cfg)); | |
323 | ||
324 | ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) : | |
325 | tcf_bpf_init_from_efd(tb, &cfg); | |
326 | if (ret < 0) | |
327 | goto out; | |
328 | ||
a85a970a | 329 | prog = to_bpf(*act); |
cff82457 | 330 | ASSERT_RTNL(); |
a8cb5f55 | 331 | |
faa54be4 | 332 | if (res != ACT_P_CREATED) |
f4eaed28 DB |
333 | tcf_bpf_prog_fill_cfg(prog, &old); |
334 | ||
a8cb5f55 DB |
335 | prog->bpf_ops = cfg.bpf_ops; |
336 | prog->bpf_name = cfg.bpf_name; | |
337 | ||
338 | if (cfg.bpf_num_ops) | |
339 | prog->bpf_num_ops = cfg.bpf_num_ops; | |
340 | if (cfg.bpf_fd) | |
341 | prog->bpf_fd = cfg.bpf_fd; | |
342 | ||
343 | prog->tcf_action = parm->action; | |
cff82457 | 344 | rcu_assign_pointer(prog->filter, cfg.filter); |
d23b8ad8 | 345 | |
cff82457 | 346 | if (res == ACT_P_CREATED) { |
a85a970a | 347 | tcf_hash_insert(tn, *act); |
cff82457 AS |
348 | } else { |
349 | /* make sure the program being replaced is no longer executing */ | |
350 | synchronize_rcu(); | |
f4eaed28 | 351 | tcf_bpf_cfg_cleanup(&old); |
cff82457 | 352 | } |
a8cb5f55 | 353 | |
a5c90b29 DB |
354 | return res; |
355 | out: | |
356 | if (res == ACT_P_CREATED) | |
a85a970a | 357 | tcf_hash_cleanup(*act, est); |
d23b8ad8 | 358 | |
d23b8ad8 JP |
359 | return ret; |
360 | } | |
361 | ||
a8cb5f55 | 362 | static void tcf_bpf_cleanup(struct tc_action *act, int bind) |
d23b8ad8 | 363 | { |
f4eaed28 | 364 | struct tcf_bpf_cfg tmp; |
ddf06c1e | 365 | |
a85a970a | 366 | tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp); |
f4eaed28 | 367 | tcf_bpf_cfg_cleanup(&tmp); |
d23b8ad8 JP |
368 | } |
369 | ||
ddf97ccd WC |
370 | static int tcf_bpf_walker(struct net *net, struct sk_buff *skb, |
371 | struct netlink_callback *cb, int type, | |
a85a970a | 372 | const struct tc_action_ops *ops) |
ddf97ccd WC |
373 | { |
374 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
375 | ||
a85a970a | 376 | return tcf_generic_walker(tn, skb, cb, type, ops); |
ddf97ccd WC |
377 | } |
378 | ||
a85a970a | 379 | static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index) |
ddf97ccd WC |
380 | { |
381 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
382 | ||
383 | return tcf_hash_search(tn, a, index); | |
384 | } | |
385 | ||
a8cb5f55 DB |
386 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
387 | .kind = "bpf", | |
388 | .type = TCA_ACT_BPF, | |
389 | .owner = THIS_MODULE, | |
390 | .act = tcf_bpf, | |
391 | .dump = tcf_bpf_dump, | |
392 | .cleanup = tcf_bpf_cleanup, | |
393 | .init = tcf_bpf_init, | |
ddf97ccd WC |
394 | .walk = tcf_bpf_walker, |
395 | .lookup = tcf_bpf_search, | |
a85a970a | 396 | .size = sizeof(struct tcf_bpf), |
ddf97ccd WC |
397 | }; |
398 | ||
399 | static __net_init int bpf_init_net(struct net *net) | |
400 | { | |
401 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
402 | ||
403 | return tc_action_net_init(tn, &act_bpf_ops, BPF_TAB_MASK); | |
404 | } | |
405 | ||
406 | static void __net_exit bpf_exit_net(struct net *net) | |
407 | { | |
408 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
409 | ||
410 | tc_action_net_exit(tn); | |
411 | } | |
412 | ||
413 | static struct pernet_operations bpf_net_ops = { | |
414 | .init = bpf_init_net, | |
415 | .exit = bpf_exit_net, | |
416 | .id = &bpf_net_id, | |
417 | .size = sizeof(struct tc_action_net), | |
d23b8ad8 JP |
418 | }; |
419 | ||
420 | static int __init bpf_init_module(void) | |
421 | { | |
ddf97ccd | 422 | return tcf_register_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
423 | } |
424 | ||
425 | static void __exit bpf_cleanup_module(void) | |
426 | { | |
ddf97ccd | 427 | tcf_unregister_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
428 | } |
429 | ||
430 | module_init(bpf_init_module); | |
431 | module_exit(bpf_cleanup_module); | |
432 | ||
433 | MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>"); | |
434 | MODULE_DESCRIPTION("TC BPF based action"); | |
435 | MODULE_LICENSE("GPL v2"); |