Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
d23b8ad8 JP |
2 | /* |
3 | * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us> | |
d23b8ad8 JP |
4 | */ |
5 | ||
6 | #include <linux/module.h> | |
7 | #include <linux/init.h> | |
8 | #include <linux/kernel.h> | |
9 | #include <linux/skbuff.h> | |
10 | #include <linux/rtnetlink.h> | |
11 | #include <linux/filter.h> | |
a8cb5f55 DB |
12 | #include <linux/bpf.h> |
13 | ||
d23b8ad8 | 14 | #include <net/netlink.h> |
cf7fbe66 | 15 | #include <net/sock.h> |
d23b8ad8 | 16 | #include <net/pkt_sched.h> |
4e181004 | 17 | #include <net/pkt_cls.h> |
d23b8ad8 JP |
18 | |
19 | #include <linux/tc_act/tc_bpf.h> | |
20 | #include <net/tc_act/tc_bpf.h> | |
871cf386 | 21 | #include <net/tc_wrapper.h> |
d23b8ad8 | 22 | |
a8cb5f55 DB |
23 | #define ACT_BPF_NAME_LEN 256 |
24 | ||
25 | struct tcf_bpf_cfg { | |
26 | struct bpf_prog *filter; | |
27 | struct sock_filter *bpf_ops; | |
f4eaed28 | 28 | const char *bpf_name; |
a8cb5f55 | 29 | u16 bpf_num_ops; |
f4eaed28 | 30 | bool is_ebpf; |
a8cb5f55 | 31 | }; |
d23b8ad8 | 32 | |
a85a970a | 33 | static struct tc_action_ops act_bpf_ops; |
ddf97ccd | 34 | |
871cf386 PT |
35 | TC_INDIRECT_SCOPE int tcf_bpf_act(struct sk_buff *skb, |
36 | const struct tc_action *act, | |
37 | struct tcf_result *res) | |
d23b8ad8 | 38 | { |
f53d8c7b | 39 | bool at_ingress = skb_at_tc_ingress(skb); |
a85a970a | 40 | struct tcf_bpf *prog = to_bpf(act); |
cff82457 | 41 | struct bpf_prog *filter; |
ced585c8 | 42 | int action, filter_res; |
d23b8ad8 | 43 | |
cff82457 | 44 | tcf_lastuse_update(&prog->tcf_tm); |
50dc9a85 | 45 | bstats_update(this_cpu_ptr(prog->common.cpu_bstats), skb); |
d23b8ad8 | 46 | |
cff82457 | 47 | filter = rcu_dereference(prog->filter); |
3431205e AS |
48 | if (at_ingress) { |
49 | __skb_push(skb, skb->mac_len); | |
6aaae2b6 | 50 | bpf_compute_data_pointers(skb); |
fb7dd8bc | 51 | filter_res = bpf_prog_run(filter, skb); |
3431205e AS |
52 | __skb_pull(skb, skb->mac_len); |
53 | } else { | |
6aaae2b6 | 54 | bpf_compute_data_pointers(skb); |
fb7dd8bc | 55 | filter_res = bpf_prog_run(filter, skb); |
3431205e | 56 | } |
7449197d MKL |
57 | if (unlikely(!skb->tstamp && skb->mono_delivery_time)) |
58 | skb->mono_delivery_time = 0; | |
cf7fbe66 JS |
59 | if (skb_sk_is_prefetched(skb) && filter_res != TC_ACT_OK) |
60 | skb_orphan(skb); | |
ced585c8 DB |
61 | |
62 | /* A BPF program may overwrite the default action opcode. | |
63 | * Similarly as in cls_bpf, if filter_res == -1 we use the | |
64 | * default action specified from tc. | |
65 | * | |
66 | * In case a different well-known TC_ACT opcode has been | |
67 | * returned, it will overwrite the default one. | |
68 | * | |
e5a4b17d | 69 | * For everything else that is unknown, TC_ACT_UNSPEC is |
ced585c8 DB |
70 | * returned. |
71 | */ | |
72 | switch (filter_res) { | |
73 | case TC_ACT_PIPE: | |
74 | case TC_ACT_RECLASSIFY: | |
75 | case TC_ACT_OK: | |
27b29f63 | 76 | case TC_ACT_REDIRECT: |
ced585c8 DB |
77 | action = filter_res; |
78 | break; | |
79 | case TC_ACT_SHOT: | |
80 | action = filter_res; | |
cff82457 | 81 | qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats)); |
ced585c8 DB |
82 | break; |
83 | case TC_ACT_UNSPEC: | |
a8cb5f55 | 84 | action = prog->tcf_action; |
ced585c8 DB |
85 | break; |
86 | default: | |
87 | action = TC_ACT_UNSPEC; | |
88 | break; | |
d23b8ad8 JP |
89 | } |
90 | ||
d23b8ad8 JP |
91 | return action; |
92 | } | |
93 | ||
a8cb5f55 DB |
94 | static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog) |
95 | { | |
96 | return !prog->bpf_ops; | |
97 | } | |
98 | ||
99 | static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog, | |
100 | struct sk_buff *skb) | |
101 | { | |
102 | struct nlattr *nla; | |
103 | ||
104 | if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops)) | |
105 | return -EMSGSIZE; | |
106 | ||
107 | nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops * | |
108 | sizeof(struct sock_filter)); | |
109 | if (nla == NULL) | |
110 | return -EMSGSIZE; | |
111 | ||
112 | memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla)); | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog, | |
118 | struct sk_buff *skb) | |
119 | { | |
7bd509e3 DB |
120 | struct nlattr *nla; |
121 | ||
a8cb5f55 DB |
122 | if (prog->bpf_name && |
123 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
124 | return -EMSGSIZE; | |
125 | ||
e8628307 DB |
126 | if (nla_put_u32(skb, TCA_ACT_BPF_ID, prog->filter->aux->id)) |
127 | return -EMSGSIZE; | |
128 | ||
f1f7714e | 129 | nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag)); |
7bd509e3 DB |
130 | if (nla == NULL) |
131 | return -EMSGSIZE; | |
132 | ||
f1f7714e | 133 | memcpy(nla_data(nla), prog->filter->tag, nla_len(nla)); |
7bd509e3 | 134 | |
a8cb5f55 DB |
135 | return 0; |
136 | } | |
137 | ||
138 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
139 | int bind, int ref) |
140 | { | |
141 | unsigned char *tp = skb_tail_pointer(skb); | |
a85a970a | 142 | struct tcf_bpf *prog = to_bpf(act); |
d23b8ad8 | 143 | struct tc_act_bpf opt = { |
a8cb5f55 | 144 | .index = prog->tcf_index, |
036bb443 VB |
145 | .refcnt = refcount_read(&prog->tcf_refcnt) - ref, |
146 | .bindcnt = atomic_read(&prog->tcf_bindcnt) - bind, | |
d23b8ad8 | 147 | }; |
a8cb5f55 DB |
148 | struct tcf_t tm; |
149 | int ret; | |
d23b8ad8 | 150 | |
653cd284 | 151 | spin_lock_bh(&prog->tcf_lock); |
2142236b | 152 | opt.action = prog->tcf_action; |
d23b8ad8 JP |
153 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) |
154 | goto nla_put_failure; | |
155 | ||
a8cb5f55 DB |
156 | if (tcf_bpf_is_ebpf(prog)) |
157 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
158 | else | |
159 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
160 | if (ret) | |
d23b8ad8 JP |
161 | goto nla_put_failure; |
162 | ||
48d8ee16 | 163 | tcf_tm_dump(&tm, &prog->tcf_tm); |
9854518e ND |
164 | if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm, |
165 | TCA_ACT_BPF_PAD)) | |
d23b8ad8 | 166 | goto nla_put_failure; |
a8cb5f55 | 167 | |
653cd284 | 168 | spin_unlock_bh(&prog->tcf_lock); |
d23b8ad8 JP |
169 | return skb->len; |
170 | ||
171 | nla_put_failure: | |
653cd284 | 172 | spin_unlock_bh(&prog->tcf_lock); |
d23b8ad8 JP |
173 | nlmsg_trim(skb, tp); |
174 | return -1; | |
175 | } | |
176 | ||
177 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
178 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 | 179 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
0b0f43fe JHS |
180 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, |
181 | .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
182 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
183 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
184 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
185 | }; | |
186 | ||
a8cb5f55 | 187 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 188 | { |
d23b8ad8 | 189 | struct sock_filter *bpf_ops; |
a8cb5f55 | 190 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 191 | struct bpf_prog *fp; |
a8cb5f55 | 192 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
193 | int ret; |
194 | ||
d23b8ad8 JP |
195 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
196 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
197 | return -EINVAL; | |
198 | ||
199 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
200 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
201 | return -EINVAL; | |
202 | ||
3f6bcc51 | 203 | bpf_ops = kmemdup(nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size, GFP_KERNEL); |
a8cb5f55 | 204 | if (bpf_ops == NULL) |
d23b8ad8 JP |
205 | return -ENOMEM; |
206 | ||
a8cb5f55 DB |
207 | fprog_tmp.len = bpf_num_ops; |
208 | fprog_tmp.filter = bpf_ops; | |
d23b8ad8 | 209 | |
a8cb5f55 DB |
210 | ret = bpf_prog_create(&fp, &fprog_tmp); |
211 | if (ret < 0) { | |
212 | kfree(bpf_ops); | |
213 | return ret; | |
214 | } | |
d23b8ad8 | 215 | |
a8cb5f55 DB |
216 | cfg->bpf_ops = bpf_ops; |
217 | cfg->bpf_num_ops = bpf_num_ops; | |
218 | cfg->filter = fp; | |
f4eaed28 | 219 | cfg->is_ebpf = false; |
a8cb5f55 DB |
220 | |
221 | return 0; | |
222 | } | |
223 | ||
224 | static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg) | |
225 | { | |
226 | struct bpf_prog *fp; | |
227 | char *name = NULL; | |
228 | u32 bpf_fd; | |
229 | ||
230 | bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]); | |
231 | ||
113214be | 232 | fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT); |
a8cb5f55 DB |
233 | if (IS_ERR(fp)) |
234 | return PTR_ERR(fp); | |
235 | ||
a8cb5f55 | 236 | if (tb[TCA_ACT_BPF_NAME]) { |
b15ca182 | 237 | name = nla_memdup(tb[TCA_ACT_BPF_NAME], GFP_KERNEL); |
a8cb5f55 DB |
238 | if (!name) { |
239 | bpf_prog_put(fp); | |
240 | return -ENOMEM; | |
241 | } | |
242 | } | |
243 | ||
a8cb5f55 DB |
244 | cfg->bpf_name = name; |
245 | cfg->filter = fp; | |
f4eaed28 | 246 | cfg->is_ebpf = true; |
a8cb5f55 DB |
247 | |
248 | return 0; | |
249 | } | |
250 | ||
f4eaed28 DB |
251 | static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg) |
252 | { | |
3239534a DC |
253 | struct bpf_prog *filter = cfg->filter; |
254 | ||
255 | if (filter) { | |
256 | if (cfg->is_ebpf) | |
257 | bpf_prog_put(filter); | |
258 | else | |
259 | bpf_prog_destroy(filter); | |
260 | } | |
f4eaed28 DB |
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 | 270 | /* updates to prog->filter are prevented, since it's called either |
2142236b | 271 | * with tcf lock or during final cleanup in rcu callback |
cff82457 AS |
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 | 279 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
a85a970a | 280 | struct nlattr *est, struct tc_action **act, |
abbb0d33 VB |
281 | struct tcf_proto *tp, u32 flags, |
282 | struct netlink_ext_ack *extack) | |
a8cb5f55 | 283 | { |
acd0a7ab | 284 | struct tc_action_net *tn = net_generic(net, act_bpf_ops.net_id); |
695176bf | 285 | bool bind = flags & TCA_ACT_FLAGS_BIND; |
a8cb5f55 | 286 | struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; |
4e181004 | 287 | struct tcf_chain *goto_ch = NULL; |
f4eaed28 | 288 | struct tcf_bpf_cfg cfg, old; |
a8cb5f55 DB |
289 | struct tc_act_bpf *parm; |
290 | struct tcf_bpf *prog; | |
a8cb5f55 | 291 | bool is_bpf, is_ebpf; |
a5c90b29 | 292 | int ret, res = 0; |
7be8ef2c | 293 | u32 index; |
a8cb5f55 DB |
294 | |
295 | if (!nla) | |
296 | return -EINVAL; | |
297 | ||
8cb08174 JB |
298 | ret = nla_parse_nested_deprecated(tb, TCA_ACT_BPF_MAX, nla, |
299 | act_bpf_policy, NULL); | |
a8cb5f55 DB |
300 | if (ret < 0) |
301 | return ret; | |
302 | ||
a5c90b29 | 303 | if (!tb[TCA_ACT_BPF_PARMS]) |
a8cb5f55 DB |
304 | return -EINVAL; |
305 | ||
306 | parm = nla_data(tb[TCA_ACT_BPF_PARMS]); | |
7be8ef2c DL |
307 | index = parm->index; |
308 | ret = tcf_idr_check_alloc(tn, &index, act, bind); | |
0190c1d4 | 309 | if (!ret) { |
7be8ef2c | 310 | ret = tcf_idr_create(tn, index, est, act, |
40bd094d | 311 | &act_bpf_ops, bind, true, flags); |
0190c1d4 | 312 | if (ret < 0) { |
7be8ef2c | 313 | tcf_idr_cleanup(tn, index); |
a5c90b29 | 314 | return ret; |
0190c1d4 | 315 | } |
d23b8ad8 | 316 | |
a5c90b29 | 317 | res = ACT_P_CREATED; |
0190c1d4 | 318 | } else if (ret > 0) { |
a8cb5f55 | 319 | /* Don't override defaults. */ |
d23b8ad8 | 320 | if (bind) |
c2a67de9 | 321 | return ACT_P_BOUND; |
a8cb5f55 | 322 | |
695176bf | 323 | if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
4e8ddd7f | 324 | tcf_idr_release(*act, bind); |
a5c90b29 | 325 | return -EEXIST; |
4e8ddd7f | 326 | } |
0190c1d4 VB |
327 | } else { |
328 | return ret; | |
d23b8ad8 JP |
329 | } |
330 | ||
4e181004 DC |
331 | ret = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); |
332 | if (ret < 0) | |
333 | goto release_idr; | |
334 | ||
a5c90b29 DB |
335 | is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; |
336 | is_ebpf = tb[TCA_ACT_BPF_FD]; | |
337 | ||
8fff09ef | 338 | if (is_bpf == is_ebpf) { |
a5c90b29 | 339 | ret = -EINVAL; |
4e181004 | 340 | goto put_chain; |
a5c90b29 DB |
341 | } |
342 | ||
343 | memset(&cfg, 0, sizeof(cfg)); | |
344 | ||
345 | ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) : | |
346 | tcf_bpf_init_from_efd(tb, &cfg); | |
347 | if (ret < 0) | |
4e181004 | 348 | goto put_chain; |
a5c90b29 | 349 | |
a85a970a | 350 | prog = to_bpf(*act); |
a8cb5f55 | 351 | |
653cd284 | 352 | spin_lock_bh(&prog->tcf_lock); |
faa54be4 | 353 | if (res != ACT_P_CREATED) |
f4eaed28 DB |
354 | tcf_bpf_prog_fill_cfg(prog, &old); |
355 | ||
a8cb5f55 DB |
356 | prog->bpf_ops = cfg.bpf_ops; |
357 | prog->bpf_name = cfg.bpf_name; | |
358 | ||
359 | if (cfg.bpf_num_ops) | |
360 | prog->bpf_num_ops = cfg.bpf_num_ops; | |
a8cb5f55 | 361 | |
4e181004 | 362 | goto_ch = tcf_action_set_ctrlact(*act, parm->action, goto_ch); |
cff82457 | 363 | rcu_assign_pointer(prog->filter, cfg.filter); |
653cd284 | 364 | spin_unlock_bh(&prog->tcf_lock); |
d23b8ad8 | 365 | |
4e181004 DC |
366 | if (goto_ch) |
367 | tcf_chain_put_by_act(goto_ch); | |
368 | ||
e49d8c22 | 369 | if (res != ACT_P_CREATED) { |
cff82457 AS |
370 | /* make sure the program being replaced is no longer executing */ |
371 | synchronize_rcu(); | |
f4eaed28 | 372 | tcf_bpf_cfg_cleanup(&old); |
cff82457 | 373 | } |
a8cb5f55 | 374 | |
a5c90b29 | 375 | return res; |
d23b8ad8 | 376 | |
4e181004 DC |
377 | put_chain: |
378 | if (goto_ch) | |
379 | tcf_chain_put_by_act(goto_ch); | |
380 | ||
381 | release_idr: | |
382 | tcf_idr_release(*act, bind); | |
d23b8ad8 JP |
383 | return ret; |
384 | } | |
385 | ||
9a63b255 | 386 | static void tcf_bpf_cleanup(struct tc_action *act) |
d23b8ad8 | 387 | { |
f4eaed28 | 388 | struct tcf_bpf_cfg tmp; |
ddf06c1e | 389 | |
a85a970a | 390 | tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp); |
f4eaed28 | 391 | tcf_bpf_cfg_cleanup(&tmp); |
d23b8ad8 JP |
392 | } |
393 | ||
a8cb5f55 DB |
394 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
395 | .kind = "bpf", | |
eddd2cf1 | 396 | .id = TCA_ID_BPF, |
a8cb5f55 | 397 | .owner = THIS_MODULE, |
2fbec27f | 398 | .act = tcf_bpf_act, |
a8cb5f55 DB |
399 | .dump = tcf_bpf_dump, |
400 | .cleanup = tcf_bpf_cleanup, | |
401 | .init = tcf_bpf_init, | |
a85a970a | 402 | .size = sizeof(struct tcf_bpf), |
ddf97ccd | 403 | }; |
241a94ab | 404 | MODULE_ALIAS_NET_ACT("bpf"); |
ddf97ccd WC |
405 | |
406 | static __net_init int bpf_init_net(struct net *net) | |
407 | { | |
acd0a7ab | 408 | struct tc_action_net *tn = net_generic(net, act_bpf_ops.net_id); |
ddf97ccd | 409 | |
981471bd | 410 | return tc_action_net_init(net, tn, &act_bpf_ops); |
ddf97ccd WC |
411 | } |
412 | ||
039af9c6 | 413 | static void __net_exit bpf_exit_net(struct list_head *net_list) |
ddf97ccd | 414 | { |
acd0a7ab | 415 | tc_action_net_exit(net_list, act_bpf_ops.net_id); |
ddf97ccd WC |
416 | } |
417 | ||
418 | static struct pernet_operations bpf_net_ops = { | |
419 | .init = bpf_init_net, | |
039af9c6 | 420 | .exit_batch = bpf_exit_net, |
acd0a7ab | 421 | .id = &act_bpf_ops.net_id, |
ddf97ccd | 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"); |