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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 ACT_BPF_NAME_LEN 256 |
25 | ||
26 | struct tcf_bpf_cfg { | |
27 | struct bpf_prog *filter; | |
28 | struct sock_filter *bpf_ops; | |
f4eaed28 | 29 | const char *bpf_name; |
a8cb5f55 | 30 | u16 bpf_num_ops; |
f4eaed28 | 31 | bool is_ebpf; |
a8cb5f55 | 32 | }; |
d23b8ad8 | 33 | |
c7d03a00 | 34 | static unsigned int bpf_net_id; |
a85a970a | 35 | static struct tc_action_ops act_bpf_ops; |
ddf97ccd | 36 | |
a8cb5f55 | 37 | static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act, |
d23b8ad8 JP |
38 | struct tcf_result *res) |
39 | { | |
f53d8c7b | 40 | bool at_ingress = skb_at_tc_ingress(skb); |
a85a970a | 41 | struct tcf_bpf *prog = to_bpf(act); |
cff82457 | 42 | struct bpf_prog *filter; |
ced585c8 | 43 | int action, filter_res; |
d23b8ad8 | 44 | |
cff82457 AS |
45 | tcf_lastuse_update(&prog->tcf_tm); |
46 | bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb); | |
d23b8ad8 | 47 | |
a8cb5f55 | 48 | rcu_read_lock(); |
cff82457 | 49 | filter = rcu_dereference(prog->filter); |
3431205e AS |
50 | if (at_ingress) { |
51 | __skb_push(skb, skb->mac_len); | |
6aaae2b6 | 52 | bpf_compute_data_pointers(skb); |
cff82457 | 53 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e AS |
54 | __skb_pull(skb, skb->mac_len); |
55 | } else { | |
6aaae2b6 | 56 | bpf_compute_data_pointers(skb); |
cff82457 | 57 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e | 58 | } |
a8cb5f55 | 59 | rcu_read_unlock(); |
ced585c8 DB |
60 | |
61 | /* A BPF program may overwrite the default action opcode. | |
62 | * Similarly as in cls_bpf, if filter_res == -1 we use the | |
63 | * default action specified from tc. | |
64 | * | |
65 | * In case a different well-known TC_ACT opcode has been | |
66 | * returned, it will overwrite the default one. | |
67 | * | |
68 | * For everything else that is unkown, TC_ACT_UNSPEC is | |
69 | * returned. | |
70 | */ | |
71 | switch (filter_res) { | |
72 | case TC_ACT_PIPE: | |
73 | case TC_ACT_RECLASSIFY: | |
74 | case TC_ACT_OK: | |
27b29f63 | 75 | case TC_ACT_REDIRECT: |
ced585c8 DB |
76 | action = filter_res; |
77 | break; | |
78 | case TC_ACT_SHOT: | |
79 | action = filter_res; | |
cff82457 | 80 | qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats)); |
ced585c8 DB |
81 | break; |
82 | case TC_ACT_UNSPEC: | |
a8cb5f55 | 83 | action = prog->tcf_action; |
ced585c8 DB |
84 | break; |
85 | default: | |
86 | action = TC_ACT_UNSPEC; | |
87 | break; | |
d23b8ad8 JP |
88 | } |
89 | ||
d23b8ad8 JP |
90 | return action; |
91 | } | |
92 | ||
a8cb5f55 DB |
93 | static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog) |
94 | { | |
95 | return !prog->bpf_ops; | |
96 | } | |
97 | ||
98 | static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog, | |
99 | struct sk_buff *skb) | |
100 | { | |
101 | struct nlattr *nla; | |
102 | ||
103 | if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops)) | |
104 | return -EMSGSIZE; | |
105 | ||
106 | nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops * | |
107 | sizeof(struct sock_filter)); | |
108 | if (nla == NULL) | |
109 | return -EMSGSIZE; | |
110 | ||
111 | memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla)); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
116 | static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog, | |
117 | struct sk_buff *skb) | |
118 | { | |
7bd509e3 DB |
119 | struct nlattr *nla; |
120 | ||
a8cb5f55 DB |
121 | if (prog->bpf_name && |
122 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
123 | return -EMSGSIZE; | |
124 | ||
e8628307 DB |
125 | if (nla_put_u32(skb, TCA_ACT_BPF_ID, prog->filter->aux->id)) |
126 | return -EMSGSIZE; | |
127 | ||
f1f7714e | 128 | nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag)); |
7bd509e3 DB |
129 | if (nla == NULL) |
130 | return -EMSGSIZE; | |
131 | ||
f1f7714e | 132 | memcpy(nla_data(nla), prog->filter->tag, nla_len(nla)); |
7bd509e3 | 133 | |
a8cb5f55 DB |
134 | return 0; |
135 | } | |
136 | ||
137 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
138 | int bind, int ref) |
139 | { | |
140 | unsigned char *tp = skb_tail_pointer(skb); | |
a85a970a | 141 | struct tcf_bpf *prog = to_bpf(act); |
d23b8ad8 | 142 | struct tc_act_bpf opt = { |
a8cb5f55 | 143 | .index = prog->tcf_index, |
036bb443 VB |
144 | .refcnt = refcount_read(&prog->tcf_refcnt) - ref, |
145 | .bindcnt = atomic_read(&prog->tcf_bindcnt) - bind, | |
a8cb5f55 | 146 | .action = prog->tcf_action, |
d23b8ad8 | 147 | }; |
a8cb5f55 DB |
148 | struct tcf_t tm; |
149 | int ret; | |
d23b8ad8 JP |
150 | |
151 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) | |
152 | goto nla_put_failure; | |
153 | ||
a8cb5f55 DB |
154 | if (tcf_bpf_is_ebpf(prog)) |
155 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
156 | else | |
157 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
158 | if (ret) | |
d23b8ad8 JP |
159 | goto nla_put_failure; |
160 | ||
48d8ee16 | 161 | tcf_tm_dump(&tm, &prog->tcf_tm); |
9854518e ND |
162 | if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm, |
163 | TCA_ACT_BPF_PAD)) | |
d23b8ad8 | 164 | goto nla_put_failure; |
a8cb5f55 | 165 | |
d23b8ad8 JP |
166 | return skb->len; |
167 | ||
168 | nla_put_failure: | |
169 | nlmsg_trim(skb, tp); | |
170 | return -1; | |
171 | } | |
172 | ||
173 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
174 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 | 175 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
0b0f43fe JHS |
176 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, |
177 | .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
178 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
179 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
180 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
181 | }; | |
182 | ||
a8cb5f55 | 183 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 184 | { |
d23b8ad8 | 185 | struct sock_filter *bpf_ops; |
a8cb5f55 | 186 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 187 | struct bpf_prog *fp; |
a8cb5f55 | 188 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
189 | int ret; |
190 | ||
d23b8ad8 JP |
191 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
192 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
193 | return -EINVAL; | |
194 | ||
195 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
196 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
197 | return -EINVAL; | |
198 | ||
3f6bcc51 | 199 | bpf_ops = kmemdup(nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size, GFP_KERNEL); |
a8cb5f55 | 200 | if (bpf_ops == NULL) |
d23b8ad8 JP |
201 | return -ENOMEM; |
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 | ||
113214be | 228 | fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT); |
a8cb5f55 DB |
229 | if (IS_ERR(fp)) |
230 | return PTR_ERR(fp); | |
231 | ||
a8cb5f55 | 232 | if (tb[TCA_ACT_BPF_NAME]) { |
b15ca182 | 233 | name = nla_memdup(tb[TCA_ACT_BPF_NAME], GFP_KERNEL); |
a8cb5f55 DB |
234 | if (!name) { |
235 | bpf_prog_put(fp); | |
236 | return -ENOMEM; | |
237 | } | |
238 | } | |
239 | ||
a8cb5f55 DB |
240 | cfg->bpf_name = name; |
241 | cfg->filter = fp; | |
f4eaed28 | 242 | cfg->is_ebpf = true; |
a8cb5f55 DB |
243 | |
244 | return 0; | |
245 | } | |
246 | ||
f4eaed28 DB |
247 | static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg) |
248 | { | |
3239534a DC |
249 | struct bpf_prog *filter = cfg->filter; |
250 | ||
251 | if (filter) { | |
252 | if (cfg->is_ebpf) | |
253 | bpf_prog_put(filter); | |
254 | else | |
255 | bpf_prog_destroy(filter); | |
256 | } | |
f4eaed28 DB |
257 | |
258 | kfree(cfg->bpf_ops); | |
259 | kfree(cfg->bpf_name); | |
260 | } | |
261 | ||
262 | static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog, | |
263 | struct tcf_bpf_cfg *cfg) | |
264 | { | |
265 | cfg->is_ebpf = tcf_bpf_is_ebpf(prog); | |
cff82457 AS |
266 | /* updates to prog->filter are prevented, since it's called either |
267 | * with rtnl lock or during final cleanup in rcu callback | |
268 | */ | |
269 | cfg->filter = rcu_dereference_protected(prog->filter, 1); | |
f4eaed28 DB |
270 | |
271 | cfg->bpf_ops = prog->bpf_ops; | |
272 | cfg->bpf_name = prog->bpf_name; | |
273 | } | |
274 | ||
a8cb5f55 | 275 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
a85a970a | 276 | struct nlattr *est, struct tc_action **act, |
789871bb VB |
277 | int replace, int bind, bool rtnl_held, |
278 | struct netlink_ext_ack *extack) | |
a8cb5f55 | 279 | { |
ddf97ccd | 280 | struct tc_action_net *tn = net_generic(net, bpf_net_id); |
a8cb5f55 | 281 | struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; |
f4eaed28 | 282 | struct tcf_bpf_cfg cfg, old; |
a8cb5f55 DB |
283 | struct tc_act_bpf *parm; |
284 | struct tcf_bpf *prog; | |
a8cb5f55 | 285 | bool is_bpf, is_ebpf; |
a5c90b29 | 286 | int ret, res = 0; |
a8cb5f55 DB |
287 | |
288 | if (!nla) | |
289 | return -EINVAL; | |
290 | ||
fceb6435 | 291 | ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy, NULL); |
a8cb5f55 DB |
292 | if (ret < 0) |
293 | return ret; | |
294 | ||
a5c90b29 | 295 | if (!tb[TCA_ACT_BPF_PARMS]) |
a8cb5f55 DB |
296 | return -EINVAL; |
297 | ||
298 | parm = nla_data(tb[TCA_ACT_BPF_PARMS]); | |
299 | ||
0190c1d4 VB |
300 | ret = tcf_idr_check_alloc(tn, &parm->index, act, bind); |
301 | if (!ret) { | |
65a206c0 CM |
302 | ret = tcf_idr_create(tn, parm->index, est, act, |
303 | &act_bpf_ops, bind, true); | |
0190c1d4 VB |
304 | if (ret < 0) { |
305 | tcf_idr_cleanup(tn, parm->index); | |
a5c90b29 | 306 | return ret; |
0190c1d4 | 307 | } |
d23b8ad8 | 308 | |
a5c90b29 | 309 | res = ACT_P_CREATED; |
0190c1d4 | 310 | } else if (ret > 0) { |
a8cb5f55 | 311 | /* Don't override defaults. */ |
d23b8ad8 | 312 | if (bind) |
a5c90b29 | 313 | return 0; |
a8cb5f55 | 314 | |
4e8ddd7f VB |
315 | if (!replace) { |
316 | tcf_idr_release(*act, bind); | |
a5c90b29 | 317 | return -EEXIST; |
4e8ddd7f | 318 | } |
0190c1d4 VB |
319 | } else { |
320 | return ret; | |
d23b8ad8 JP |
321 | } |
322 | ||
a5c90b29 DB |
323 | is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; |
324 | is_ebpf = tb[TCA_ACT_BPF_FD]; | |
325 | ||
326 | if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) { | |
327 | ret = -EINVAL; | |
328 | goto out; | |
329 | } | |
330 | ||
331 | memset(&cfg, 0, sizeof(cfg)); | |
332 | ||
333 | ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) : | |
334 | tcf_bpf_init_from_efd(tb, &cfg); | |
335 | if (ret < 0) | |
336 | goto out; | |
337 | ||
a85a970a | 338 | prog = to_bpf(*act); |
cff82457 | 339 | ASSERT_RTNL(); |
a8cb5f55 | 340 | |
faa54be4 | 341 | if (res != ACT_P_CREATED) |
f4eaed28 DB |
342 | tcf_bpf_prog_fill_cfg(prog, &old); |
343 | ||
a8cb5f55 DB |
344 | prog->bpf_ops = cfg.bpf_ops; |
345 | prog->bpf_name = cfg.bpf_name; | |
346 | ||
347 | if (cfg.bpf_num_ops) | |
348 | prog->bpf_num_ops = cfg.bpf_num_ops; | |
a8cb5f55 DB |
349 | |
350 | prog->tcf_action = parm->action; | |
cff82457 | 351 | rcu_assign_pointer(prog->filter, cfg.filter); |
d23b8ad8 | 352 | |
cff82457 | 353 | if (res == ACT_P_CREATED) { |
65a206c0 | 354 | tcf_idr_insert(tn, *act); |
cff82457 AS |
355 | } else { |
356 | /* make sure the program being replaced is no longer executing */ | |
357 | synchronize_rcu(); | |
f4eaed28 | 358 | tcf_bpf_cfg_cleanup(&old); |
cff82457 | 359 | } |
a8cb5f55 | 360 | |
a5c90b29 DB |
361 | return res; |
362 | out: | |
4e8ddd7f | 363 | tcf_idr_release(*act, bind); |
d23b8ad8 | 364 | |
d23b8ad8 JP |
365 | return ret; |
366 | } | |
367 | ||
9a63b255 | 368 | static void tcf_bpf_cleanup(struct tc_action *act) |
d23b8ad8 | 369 | { |
f4eaed28 | 370 | struct tcf_bpf_cfg tmp; |
ddf06c1e | 371 | |
a85a970a | 372 | tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp); |
f4eaed28 | 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, | |
41780105 AA |
378 | const struct tc_action_ops *ops, |
379 | struct netlink_ext_ack *extack) | |
ddf97ccd WC |
380 | { |
381 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
382 | ||
b3620145 | 383 | return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
ddf97ccd WC |
384 | } |
385 | ||
331a9295 AA |
386 | static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index, |
387 | struct netlink_ext_ack *extack) | |
ddf97ccd WC |
388 | { |
389 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
390 | ||
65a206c0 | 391 | return tcf_idr_search(tn, a, index); |
ddf97ccd WC |
392 | } |
393 | ||
b409074e VB |
394 | static int tcf_bpf_delete(struct net *net, u32 index) |
395 | { | |
396 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
397 | ||
398 | return tcf_idr_delete_index(tn, index); | |
399 | } | |
400 | ||
a8cb5f55 DB |
401 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
402 | .kind = "bpf", | |
403 | .type = TCA_ACT_BPF, | |
404 | .owner = THIS_MODULE, | |
405 | .act = tcf_bpf, | |
406 | .dump = tcf_bpf_dump, | |
407 | .cleanup = tcf_bpf_cleanup, | |
408 | .init = tcf_bpf_init, | |
ddf97ccd WC |
409 | .walk = tcf_bpf_walker, |
410 | .lookup = tcf_bpf_search, | |
b409074e | 411 | .delete = tcf_bpf_delete, |
a85a970a | 412 | .size = sizeof(struct tcf_bpf), |
ddf97ccd WC |
413 | }; |
414 | ||
415 | static __net_init int bpf_init_net(struct net *net) | |
416 | { | |
417 | struct tc_action_net *tn = net_generic(net, bpf_net_id); | |
418 | ||
c7e460ce | 419 | return tc_action_net_init(tn, &act_bpf_ops); |
ddf97ccd WC |
420 | } |
421 | ||
039af9c6 | 422 | static void __net_exit bpf_exit_net(struct list_head *net_list) |
ddf97ccd | 423 | { |
039af9c6 | 424 | tc_action_net_exit(net_list, bpf_net_id); |
ddf97ccd WC |
425 | } |
426 | ||
427 | static struct pernet_operations bpf_net_ops = { | |
428 | .init = bpf_init_net, | |
039af9c6 | 429 | .exit_batch = bpf_exit_net, |
ddf97ccd WC |
430 | .id = &bpf_net_id, |
431 | .size = sizeof(struct tc_action_net), | |
d23b8ad8 JP |
432 | }; |
433 | ||
434 | static int __init bpf_init_module(void) | |
435 | { | |
ddf97ccd | 436 | return tcf_register_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
437 | } |
438 | ||
439 | static void __exit bpf_cleanup_module(void) | |
440 | { | |
ddf97ccd | 441 | tcf_unregister_action(&act_bpf_ops, &bpf_net_ops); |
d23b8ad8 JP |
442 | } |
443 | ||
444 | module_init(bpf_init_module); | |
445 | module_exit(bpf_cleanup_module); | |
446 | ||
447 | MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>"); | |
448 | MODULE_DESCRIPTION("TC BPF based action"); | |
449 | MODULE_LICENSE("GPL v2"); |