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 | |
a8cb5f55 | 36 | static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act, |
d23b8ad8 JP |
37 | struct tcf_result *res) |
38 | { | |
a8cb5f55 | 39 | struct tcf_bpf *prog = act->priv; |
cff82457 | 40 | struct bpf_prog *filter; |
ced585c8 | 41 | int action, filter_res; |
3431205e | 42 | bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS; |
d23b8ad8 | 43 | |
a166151c AS |
44 | if (unlikely(!skb_mac_header_was_set(skb))) |
45 | return TC_ACT_UNSPEC; | |
46 | ||
cff82457 AS |
47 | tcf_lastuse_update(&prog->tcf_tm); |
48 | bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb); | |
d23b8ad8 | 49 | |
a8cb5f55 | 50 | rcu_read_lock(); |
cff82457 | 51 | filter = rcu_dereference(prog->filter); |
3431205e AS |
52 | if (at_ingress) { |
53 | __skb_push(skb, skb->mac_len); | |
cff82457 | 54 | filter_res = BPF_PROG_RUN(filter, skb); |
3431205e AS |
55 | __skb_pull(skb, skb->mac_len); |
56 | } else { | |
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 | { | |
119 | if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd)) | |
120 | return -EMSGSIZE; | |
121 | ||
122 | if (prog->bpf_name && | |
123 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
124 | return -EMSGSIZE; | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
129 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
130 | int bind, int ref) |
131 | { | |
132 | unsigned char *tp = skb_tail_pointer(skb); | |
a8cb5f55 | 133 | struct tcf_bpf *prog = act->priv; |
d23b8ad8 | 134 | struct tc_act_bpf opt = { |
a8cb5f55 DB |
135 | .index = prog->tcf_index, |
136 | .refcnt = prog->tcf_refcnt - ref, | |
137 | .bindcnt = prog->tcf_bindcnt - bind, | |
138 | .action = prog->tcf_action, | |
d23b8ad8 | 139 | }; |
a8cb5f55 DB |
140 | struct tcf_t tm; |
141 | int ret; | |
d23b8ad8 JP |
142 | |
143 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) | |
144 | goto nla_put_failure; | |
145 | ||
a8cb5f55 DB |
146 | if (tcf_bpf_is_ebpf(prog)) |
147 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
148 | else | |
149 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
150 | if (ret) | |
d23b8ad8 JP |
151 | goto nla_put_failure; |
152 | ||
a8cb5f55 DB |
153 | tm.install = jiffies_to_clock_t(jiffies - prog->tcf_tm.install); |
154 | tm.lastuse = jiffies_to_clock_t(jiffies - prog->tcf_tm.lastuse); | |
155 | tm.expires = jiffies_to_clock_t(prog->tcf_tm.expires); | |
d23b8ad8 | 156 | |
a8cb5f55 | 157 | if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm)) |
d23b8ad8 | 158 | goto nla_put_failure; |
a8cb5f55 | 159 | |
d23b8ad8 JP |
160 | return skb->len; |
161 | ||
162 | nla_put_failure: | |
163 | nlmsg_trim(skb, tp); | |
164 | return -1; | |
165 | } | |
166 | ||
167 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
168 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 DB |
169 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
170 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
171 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
172 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
173 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
174 | }; | |
175 | ||
a8cb5f55 | 176 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 177 | { |
d23b8ad8 | 178 | struct sock_filter *bpf_ops; |
a8cb5f55 | 179 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 180 | struct bpf_prog *fp; |
a8cb5f55 | 181 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
182 | int ret; |
183 | ||
d23b8ad8 JP |
184 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
185 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
186 | return -EINVAL; | |
187 | ||
188 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
189 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
190 | return -EINVAL; | |
191 | ||
d23b8ad8 | 192 | bpf_ops = kzalloc(bpf_size, GFP_KERNEL); |
a8cb5f55 | 193 | if (bpf_ops == NULL) |
d23b8ad8 JP |
194 | return -ENOMEM; |
195 | ||
196 | memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size); | |
197 | ||
a8cb5f55 DB |
198 | fprog_tmp.len = bpf_num_ops; |
199 | fprog_tmp.filter = bpf_ops; | |
d23b8ad8 | 200 | |
a8cb5f55 DB |
201 | ret = bpf_prog_create(&fp, &fprog_tmp); |
202 | if (ret < 0) { | |
203 | kfree(bpf_ops); | |
204 | return ret; | |
205 | } | |
d23b8ad8 | 206 | |
a8cb5f55 DB |
207 | cfg->bpf_ops = bpf_ops; |
208 | cfg->bpf_num_ops = bpf_num_ops; | |
209 | cfg->filter = fp; | |
f4eaed28 | 210 | cfg->is_ebpf = false; |
a8cb5f55 DB |
211 | |
212 | return 0; | |
213 | } | |
214 | ||
215 | static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg) | |
216 | { | |
217 | struct bpf_prog *fp; | |
218 | char *name = NULL; | |
219 | u32 bpf_fd; | |
220 | ||
221 | bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]); | |
222 | ||
223 | fp = bpf_prog_get(bpf_fd); | |
224 | if (IS_ERR(fp)) | |
225 | return PTR_ERR(fp); | |
226 | ||
227 | if (fp->type != BPF_PROG_TYPE_SCHED_ACT) { | |
228 | bpf_prog_put(fp); | |
229 | return -EINVAL; | |
230 | } | |
231 | ||
232 | if (tb[TCA_ACT_BPF_NAME]) { | |
233 | name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]), | |
234 | nla_len(tb[TCA_ACT_BPF_NAME]), | |
235 | GFP_KERNEL); | |
236 | if (!name) { | |
237 | bpf_prog_put(fp); | |
238 | return -ENOMEM; | |
239 | } | |
240 | } | |
241 | ||
242 | cfg->bpf_fd = bpf_fd; | |
243 | cfg->bpf_name = name; | |
244 | cfg->filter = fp; | |
f4eaed28 | 245 | cfg->is_ebpf = true; |
a8cb5f55 DB |
246 | |
247 | return 0; | |
248 | } | |
249 | ||
f4eaed28 DB |
250 | static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg) |
251 | { | |
252 | if (cfg->is_ebpf) | |
253 | bpf_prog_put(cfg->filter); | |
254 | else | |
255 | bpf_prog_destroy(cfg->filter); | |
256 | ||
257 | kfree(cfg->bpf_ops); | |
258 | kfree(cfg->bpf_name); | |
259 | } | |
260 | ||
261 | static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog, | |
262 | struct tcf_bpf_cfg *cfg) | |
263 | { | |
264 | cfg->is_ebpf = tcf_bpf_is_ebpf(prog); | |
cff82457 AS |
265 | /* updates to prog->filter are prevented, since it's called either |
266 | * with rtnl lock or during final cleanup in rcu callback | |
267 | */ | |
268 | cfg->filter = rcu_dereference_protected(prog->filter, 1); | |
f4eaed28 DB |
269 | |
270 | cfg->bpf_ops = prog->bpf_ops; | |
271 | cfg->bpf_name = prog->bpf_name; | |
272 | } | |
273 | ||
a8cb5f55 DB |
274 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
275 | struct nlattr *est, struct tc_action *act, | |
276 | int replace, int bind) | |
277 | { | |
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 | ||
a8cb5f55 DB |
297 | if (!tcf_hash_check(parm->index, act, bind)) { |
298 | ret = tcf_hash_create(parm->index, est, act, | |
cff82457 | 299 | sizeof(*prog), 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 DB |
308 | |
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 | ||
a8cb5f55 | 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) { |
a8cb5f55 | 347 | tcf_hash_insert(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) | |
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 | |
f4eaed28 DB |
366 | tcf_bpf_prog_fill_cfg(act->priv, &tmp); |
367 | tcf_bpf_cfg_cleanup(&tmp); | |
d23b8ad8 JP |
368 | } |
369 | ||
a8cb5f55 DB |
370 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
371 | .kind = "bpf", | |
372 | .type = TCA_ACT_BPF, | |
373 | .owner = THIS_MODULE, | |
374 | .act = tcf_bpf, | |
375 | .dump = tcf_bpf_dump, | |
376 | .cleanup = tcf_bpf_cleanup, | |
377 | .init = tcf_bpf_init, | |
d23b8ad8 JP |
378 | }; |
379 | ||
380 | static int __init bpf_init_module(void) | |
381 | { | |
382 | return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK); | |
383 | } | |
384 | ||
385 | static void __exit bpf_cleanup_module(void) | |
386 | { | |
387 | tcf_unregister_action(&act_bpf_ops); | |
388 | } | |
389 | ||
390 | module_init(bpf_init_module); | |
391 | module_exit(bpf_cleanup_module); | |
392 | ||
393 | MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>"); | |
394 | MODULE_DESCRIPTION("TC BPF based action"); | |
395 | MODULE_LICENSE("GPL v2"); |