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 | |
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; |
ced585c8 | 40 | int action, filter_res; |
3431205e | 41 | bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS; |
d23b8ad8 | 42 | |
a166151c AS |
43 | if (unlikely(!skb_mac_header_was_set(skb))) |
44 | return TC_ACT_UNSPEC; | |
45 | ||
a8cb5f55 | 46 | spin_lock(&prog->tcf_lock); |
ced585c8 | 47 | |
a8cb5f55 DB |
48 | prog->tcf_tm.lastuse = jiffies; |
49 | bstats_update(&prog->tcf_bstats, skb); | |
d23b8ad8 | 50 | |
a8cb5f55 DB |
51 | /* Needed here for accessing maps. */ |
52 | rcu_read_lock(); | |
3431205e AS |
53 | if (at_ingress) { |
54 | __skb_push(skb, skb->mac_len); | |
55 | filter_res = BPF_PROG_RUN(prog->filter, skb); | |
56 | __skb_pull(skb, skb->mac_len); | |
57 | } else { | |
58 | filter_res = BPF_PROG_RUN(prog->filter, skb); | |
59 | } | |
a8cb5f55 | 60 | rcu_read_unlock(); |
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 | * | |
69 | * For everything else that is unkown, TC_ACT_UNSPEC is | |
70 | * returned. | |
71 | */ | |
72 | switch (filter_res) { | |
73 | case TC_ACT_PIPE: | |
74 | case TC_ACT_RECLASSIFY: | |
75 | case TC_ACT_OK: | |
76 | action = filter_res; | |
77 | break; | |
78 | case TC_ACT_SHOT: | |
79 | action = filter_res; | |
a8cb5f55 | 80 | prog->tcf_qstats.drops++; |
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 | ||
a8cb5f55 | 90 | spin_unlock(&prog->tcf_lock); |
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 | { | |
120 | if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd)) | |
121 | return -EMSGSIZE; | |
122 | ||
123 | if (prog->bpf_name && | |
124 | nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name)) | |
125 | return -EMSGSIZE; | |
126 | ||
127 | return 0; | |
128 | } | |
129 | ||
130 | static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, | |
d23b8ad8 JP |
131 | int bind, int ref) |
132 | { | |
133 | unsigned char *tp = skb_tail_pointer(skb); | |
a8cb5f55 | 134 | struct tcf_bpf *prog = act->priv; |
d23b8ad8 | 135 | struct tc_act_bpf opt = { |
a8cb5f55 DB |
136 | .index = prog->tcf_index, |
137 | .refcnt = prog->tcf_refcnt - ref, | |
138 | .bindcnt = prog->tcf_bindcnt - bind, | |
139 | .action = prog->tcf_action, | |
d23b8ad8 | 140 | }; |
a8cb5f55 DB |
141 | struct tcf_t tm; |
142 | int ret; | |
d23b8ad8 JP |
143 | |
144 | if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) | |
145 | goto nla_put_failure; | |
146 | ||
a8cb5f55 DB |
147 | if (tcf_bpf_is_ebpf(prog)) |
148 | ret = tcf_bpf_dump_ebpf_info(prog, skb); | |
149 | else | |
150 | ret = tcf_bpf_dump_bpf_info(prog, skb); | |
151 | if (ret) | |
d23b8ad8 JP |
152 | goto nla_put_failure; |
153 | ||
a8cb5f55 DB |
154 | tm.install = jiffies_to_clock_t(jiffies - prog->tcf_tm.install); |
155 | tm.lastuse = jiffies_to_clock_t(jiffies - prog->tcf_tm.lastuse); | |
156 | tm.expires = jiffies_to_clock_t(prog->tcf_tm.expires); | |
d23b8ad8 | 157 | |
a8cb5f55 | 158 | if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm)) |
d23b8ad8 | 159 | goto nla_put_failure; |
a8cb5f55 | 160 | |
d23b8ad8 JP |
161 | return skb->len; |
162 | ||
163 | nla_put_failure: | |
164 | nlmsg_trim(skb, tp); | |
165 | return -1; | |
166 | } | |
167 | ||
168 | static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = { | |
169 | [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) }, | |
a8cb5f55 DB |
170 | [TCA_ACT_BPF_FD] = { .type = NLA_U32 }, |
171 | [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING, .len = ACT_BPF_NAME_LEN }, | |
d23b8ad8 JP |
172 | [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 }, |
173 | [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, | |
174 | .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, | |
175 | }; | |
176 | ||
a8cb5f55 | 177 | static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg) |
d23b8ad8 | 178 | { |
d23b8ad8 | 179 | struct sock_filter *bpf_ops; |
a8cb5f55 | 180 | struct sock_fprog_kern fprog_tmp; |
d23b8ad8 | 181 | struct bpf_prog *fp; |
a8cb5f55 | 182 | u16 bpf_size, bpf_num_ops; |
d23b8ad8 JP |
183 | int ret; |
184 | ||
d23b8ad8 JP |
185 | bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]); |
186 | if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0) | |
187 | return -EINVAL; | |
188 | ||
189 | bpf_size = bpf_num_ops * sizeof(*bpf_ops); | |
fd3e646c DB |
190 | if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS])) |
191 | return -EINVAL; | |
192 | ||
d23b8ad8 | 193 | bpf_ops = kzalloc(bpf_size, GFP_KERNEL); |
a8cb5f55 | 194 | if (bpf_ops == NULL) |
d23b8ad8 JP |
195 | return -ENOMEM; |
196 | ||
197 | memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size); | |
198 | ||
a8cb5f55 DB |
199 | fprog_tmp.len = bpf_num_ops; |
200 | fprog_tmp.filter = bpf_ops; | |
d23b8ad8 | 201 | |
a8cb5f55 DB |
202 | ret = bpf_prog_create(&fp, &fprog_tmp); |
203 | if (ret < 0) { | |
204 | kfree(bpf_ops); | |
205 | return ret; | |
206 | } | |
d23b8ad8 | 207 | |
a8cb5f55 DB |
208 | cfg->bpf_ops = bpf_ops; |
209 | cfg->bpf_num_ops = bpf_num_ops; | |
210 | cfg->filter = fp; | |
f4eaed28 | 211 | cfg->is_ebpf = false; |
a8cb5f55 DB |
212 | |
213 | return 0; | |
214 | } | |
215 | ||
216 | static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg) | |
217 | { | |
218 | struct bpf_prog *fp; | |
219 | char *name = NULL; | |
220 | u32 bpf_fd; | |
221 | ||
222 | bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]); | |
223 | ||
224 | fp = bpf_prog_get(bpf_fd); | |
225 | if (IS_ERR(fp)) | |
226 | return PTR_ERR(fp); | |
227 | ||
228 | if (fp->type != BPF_PROG_TYPE_SCHED_ACT) { | |
229 | bpf_prog_put(fp); | |
230 | return -EINVAL; | |
231 | } | |
232 | ||
233 | if (tb[TCA_ACT_BPF_NAME]) { | |
234 | name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]), | |
235 | nla_len(tb[TCA_ACT_BPF_NAME]), | |
236 | GFP_KERNEL); | |
237 | if (!name) { | |
238 | bpf_prog_put(fp); | |
239 | return -ENOMEM; | |
240 | } | |
241 | } | |
242 | ||
243 | cfg->bpf_fd = bpf_fd; | |
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 | { | |
253 | if (cfg->is_ebpf) | |
254 | bpf_prog_put(cfg->filter); | |
255 | else | |
256 | bpf_prog_destroy(cfg->filter); | |
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); | |
266 | cfg->filter = prog->filter; | |
267 | ||
268 | cfg->bpf_ops = prog->bpf_ops; | |
269 | cfg->bpf_name = prog->bpf_name; | |
270 | } | |
271 | ||
a8cb5f55 DB |
272 | static int tcf_bpf_init(struct net *net, struct nlattr *nla, |
273 | struct nlattr *est, struct tc_action *act, | |
274 | int replace, int bind) | |
275 | { | |
276 | struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; | |
f4eaed28 | 277 | struct tcf_bpf_cfg cfg, old; |
a8cb5f55 DB |
278 | struct tc_act_bpf *parm; |
279 | struct tcf_bpf *prog; | |
a8cb5f55 DB |
280 | bool is_bpf, is_ebpf; |
281 | int ret; | |
282 | ||
283 | if (!nla) | |
284 | return -EINVAL; | |
285 | ||
286 | ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy); | |
287 | if (ret < 0) | |
288 | return ret; | |
289 | ||
290 | is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS]; | |
291 | is_ebpf = tb[TCA_ACT_BPF_FD]; | |
292 | ||
293 | if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf) || | |
294 | !tb[TCA_ACT_BPF_PARMS]) | |
295 | return -EINVAL; | |
296 | ||
297 | parm = nla_data(tb[TCA_ACT_BPF_PARMS]); | |
298 | ||
299 | memset(&cfg, 0, sizeof(cfg)); | |
300 | ||
301 | ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) : | |
302 | tcf_bpf_init_from_efd(tb, &cfg); | |
303 | if (ret < 0) | |
304 | return ret; | |
305 | ||
306 | if (!tcf_hash_check(parm->index, act, bind)) { | |
307 | ret = tcf_hash_create(parm->index, est, act, | |
308 | sizeof(*prog), bind); | |
309 | if (ret < 0) | |
d23b8ad8 JP |
310 | goto destroy_fp; |
311 | ||
312 | ret = ACT_P_CREATED; | |
313 | } else { | |
a8cb5f55 | 314 | /* Don't override defaults. */ |
d23b8ad8 JP |
315 | if (bind) |
316 | goto destroy_fp; | |
a8cb5f55 DB |
317 | |
318 | tcf_hash_release(act, bind); | |
319 | if (!replace) { | |
d23b8ad8 JP |
320 | ret = -EEXIST; |
321 | goto destroy_fp; | |
322 | } | |
323 | } | |
324 | ||
a8cb5f55 DB |
325 | prog = to_bpf(act); |
326 | spin_lock_bh(&prog->tcf_lock); | |
327 | ||
f4eaed28 DB |
328 | if (ret != ACT_P_CREATED) |
329 | tcf_bpf_prog_fill_cfg(prog, &old); | |
330 | ||
a8cb5f55 DB |
331 | prog->bpf_ops = cfg.bpf_ops; |
332 | prog->bpf_name = cfg.bpf_name; | |
333 | ||
334 | if (cfg.bpf_num_ops) | |
335 | prog->bpf_num_ops = cfg.bpf_num_ops; | |
336 | if (cfg.bpf_fd) | |
337 | prog->bpf_fd = cfg.bpf_fd; | |
338 | ||
339 | prog->tcf_action = parm->action; | |
340 | prog->filter = cfg.filter; | |
341 | ||
342 | spin_unlock_bh(&prog->tcf_lock); | |
d23b8ad8 JP |
343 | |
344 | if (ret == ACT_P_CREATED) | |
a8cb5f55 | 345 | tcf_hash_insert(act); |
f4eaed28 DB |
346 | else |
347 | tcf_bpf_cfg_cleanup(&old); | |
a8cb5f55 | 348 | |
d23b8ad8 JP |
349 | return ret; |
350 | ||
351 | destroy_fp: | |
f4eaed28 | 352 | tcf_bpf_cfg_cleanup(&cfg); |
d23b8ad8 JP |
353 | return ret; |
354 | } | |
355 | ||
a8cb5f55 | 356 | static void tcf_bpf_cleanup(struct tc_action *act, int bind) |
d23b8ad8 | 357 | { |
f4eaed28 | 358 | struct tcf_bpf_cfg tmp; |
ddf06c1e | 359 | |
f4eaed28 DB |
360 | tcf_bpf_prog_fill_cfg(act->priv, &tmp); |
361 | tcf_bpf_cfg_cleanup(&tmp); | |
d23b8ad8 JP |
362 | } |
363 | ||
a8cb5f55 DB |
364 | static struct tc_action_ops act_bpf_ops __read_mostly = { |
365 | .kind = "bpf", | |
366 | .type = TCA_ACT_BPF, | |
367 | .owner = THIS_MODULE, | |
368 | .act = tcf_bpf, | |
369 | .dump = tcf_bpf_dump, | |
370 | .cleanup = tcf_bpf_cleanup, | |
371 | .init = tcf_bpf_init, | |
d23b8ad8 JP |
372 | }; |
373 | ||
374 | static int __init bpf_init_module(void) | |
375 | { | |
376 | return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK); | |
377 | } | |
378 | ||
379 | static void __exit bpf_cleanup_module(void) | |
380 | { | |
381 | tcf_unregister_action(&act_bpf_ops); | |
382 | } | |
383 | ||
384 | module_init(bpf_init_module); | |
385 | module_exit(bpf_cleanup_module); | |
386 | ||
387 | MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>"); | |
388 | MODULE_DESCRIPTION("TC BPF based action"); | |
389 | MODULE_LICENSE("GPL v2"); |