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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us>
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>
12#include <linux/bpf.h>
13
14#include <net/netlink.h>
15#include <net/pkt_sched.h>
16#include <net/pkt_cls.h>
17
18#include <linux/tc_act/tc_bpf.h>
19#include <net/tc_act/tc_bpf.h>
20
21#define ACT_BPF_NAME_LEN 256
22
23struct tcf_bpf_cfg {
24 struct bpf_prog *filter;
25 struct sock_filter *bpf_ops;
26 const char *bpf_name;
27 u16 bpf_num_ops;
28 bool is_ebpf;
29};
30
31static unsigned int bpf_net_id;
32static struct tc_action_ops act_bpf_ops;
33
34static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act,
35 struct tcf_result *res)
36{
37 bool at_ingress = skb_at_tc_ingress(skb);
38 struct tcf_bpf *prog = to_bpf(act);
39 struct bpf_prog *filter;
40 int action, filter_res;
41
42 tcf_lastuse_update(&prog->tcf_tm);
43 bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
44
45 rcu_read_lock();
46 filter = rcu_dereference(prog->filter);
47 if (at_ingress) {
48 __skb_push(skb, skb->mac_len);
49 bpf_compute_data_pointers(skb);
50 filter_res = BPF_PROG_RUN(filter, skb);
51 __skb_pull(skb, skb->mac_len);
52 } else {
53 bpf_compute_data_pointers(skb);
54 filter_res = BPF_PROG_RUN(filter, skb);
55 }
56 rcu_read_unlock();
57
58 /* A BPF program may overwrite the default action opcode.
59 * Similarly as in cls_bpf, if filter_res == -1 we use the
60 * default action specified from tc.
61 *
62 * In case a different well-known TC_ACT opcode has been
63 * returned, it will overwrite the default one.
64 *
65 * For everything else that is unkown, TC_ACT_UNSPEC is
66 * returned.
67 */
68 switch (filter_res) {
69 case TC_ACT_PIPE:
70 case TC_ACT_RECLASSIFY:
71 case TC_ACT_OK:
72 case TC_ACT_REDIRECT:
73 action = filter_res;
74 break;
75 case TC_ACT_SHOT:
76 action = filter_res;
77 qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats));
78 break;
79 case TC_ACT_UNSPEC:
80 action = prog->tcf_action;
81 break;
82 default:
83 action = TC_ACT_UNSPEC;
84 break;
85 }
86
87 return action;
88}
89
90static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog)
91{
92 return !prog->bpf_ops;
93}
94
95static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog,
96 struct sk_buff *skb)
97{
98 struct nlattr *nla;
99
100 if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops))
101 return -EMSGSIZE;
102
103 nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops *
104 sizeof(struct sock_filter));
105 if (nla == NULL)
106 return -EMSGSIZE;
107
108 memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
109
110 return 0;
111}
112
113static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog,
114 struct sk_buff *skb)
115{
116 struct nlattr *nla;
117
118 if (prog->bpf_name &&
119 nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
120 return -EMSGSIZE;
121
122 if (nla_put_u32(skb, TCA_ACT_BPF_ID, prog->filter->aux->id))
123 return -EMSGSIZE;
124
125 nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag));
126 if (nla == NULL)
127 return -EMSGSIZE;
128
129 memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
130
131 return 0;
132}
133
134static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act,
135 int bind, int ref)
136{
137 unsigned char *tp = skb_tail_pointer(skb);
138 struct tcf_bpf *prog = to_bpf(act);
139 struct tc_act_bpf opt = {
140 .index = prog->tcf_index,
141 .refcnt = refcount_read(&prog->tcf_refcnt) - ref,
142 .bindcnt = atomic_read(&prog->tcf_bindcnt) - bind,
143 };
144 struct tcf_t tm;
145 int ret;
146
147 spin_lock_bh(&prog->tcf_lock);
148 opt.action = prog->tcf_action;
149 if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
150 goto nla_put_failure;
151
152 if (tcf_bpf_is_ebpf(prog))
153 ret = tcf_bpf_dump_ebpf_info(prog, skb);
154 else
155 ret = tcf_bpf_dump_bpf_info(prog, skb);
156 if (ret)
157 goto nla_put_failure;
158
159 tcf_tm_dump(&tm, &prog->tcf_tm);
160 if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm,
161 TCA_ACT_BPF_PAD))
162 goto nla_put_failure;
163
164 spin_unlock_bh(&prog->tcf_lock);
165 return skb->len;
166
167nla_put_failure:
168 spin_unlock_bh(&prog->tcf_lock);
169 nlmsg_trim(skb, tp);
170 return -1;
171}
172
173static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
174 [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) },
175 [TCA_ACT_BPF_FD] = { .type = NLA_U32 },
176 [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING,
177 .len = ACT_BPF_NAME_LEN },
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
183static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
184{
185 struct sock_filter *bpf_ops;
186 struct sock_fprog_kern fprog_tmp;
187 struct bpf_prog *fp;
188 u16 bpf_size, bpf_num_ops;
189 int ret;
190
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);
196 if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
197 return -EINVAL;
198
199 bpf_ops = kmemdup(nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size, GFP_KERNEL);
200 if (bpf_ops == NULL)
201 return -ENOMEM;
202
203 fprog_tmp.len = bpf_num_ops;
204 fprog_tmp.filter = bpf_ops;
205
206 ret = bpf_prog_create(&fp, &fprog_tmp);
207 if (ret < 0) {
208 kfree(bpf_ops);
209 return ret;
210 }
211
212 cfg->bpf_ops = bpf_ops;
213 cfg->bpf_num_ops = bpf_num_ops;
214 cfg->filter = fp;
215 cfg->is_ebpf = false;
216
217 return 0;
218}
219
220static 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
228 fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT);
229 if (IS_ERR(fp))
230 return PTR_ERR(fp);
231
232 if (tb[TCA_ACT_BPF_NAME]) {
233 name = nla_memdup(tb[TCA_ACT_BPF_NAME], GFP_KERNEL);
234 if (!name) {
235 bpf_prog_put(fp);
236 return -ENOMEM;
237 }
238 }
239
240 cfg->bpf_name = name;
241 cfg->filter = fp;
242 cfg->is_ebpf = true;
243
244 return 0;
245}
246
247static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg)
248{
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 }
257
258 kfree(cfg->bpf_ops);
259 kfree(cfg->bpf_name);
260}
261
262static 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 /* updates to prog->filter are prevented, since it's called either
267 * with tcf lock or during final cleanup in rcu callback
268 */
269 cfg->filter = rcu_dereference_protected(prog->filter, 1);
270
271 cfg->bpf_ops = prog->bpf_ops;
272 cfg->bpf_name = prog->bpf_name;
273}
274
275static int tcf_bpf_init(struct net *net, struct nlattr *nla,
276 struct nlattr *est, struct tc_action **act,
277 int replace, int bind, bool rtnl_held,
278 struct tcf_proto *tp, struct netlink_ext_ack *extack)
279{
280 struct tc_action_net *tn = net_generic(net, bpf_net_id);
281 struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
282 struct tcf_chain *goto_ch = NULL;
283 struct tcf_bpf_cfg cfg, old;
284 struct tc_act_bpf *parm;
285 struct tcf_bpf *prog;
286 bool is_bpf, is_ebpf;
287 int ret, res = 0;
288 u32 index;
289
290 if (!nla)
291 return -EINVAL;
292
293 ret = nla_parse_nested_deprecated(tb, TCA_ACT_BPF_MAX, nla,
294 act_bpf_policy, NULL);
295 if (ret < 0)
296 return ret;
297
298 if (!tb[TCA_ACT_BPF_PARMS])
299 return -EINVAL;
300
301 parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
302 index = parm->index;
303 ret = tcf_idr_check_alloc(tn, &index, act, bind);
304 if (!ret) {
305 ret = tcf_idr_create(tn, index, est, act,
306 &act_bpf_ops, bind, true);
307 if (ret < 0) {
308 tcf_idr_cleanup(tn, index);
309 return ret;
310 }
311
312 res = ACT_P_CREATED;
313 } else if (ret > 0) {
314 /* Don't override defaults. */
315 if (bind)
316 return 0;
317
318 if (!replace) {
319 tcf_idr_release(*act, bind);
320 return -EEXIST;
321 }
322 } else {
323 return ret;
324 }
325
326 ret = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
327 if (ret < 0)
328 goto release_idr;
329
330 is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS];
331 is_ebpf = tb[TCA_ACT_BPF_FD];
332
333 if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
334 ret = -EINVAL;
335 goto put_chain;
336 }
337
338 memset(&cfg, 0, sizeof(cfg));
339
340 ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) :
341 tcf_bpf_init_from_efd(tb, &cfg);
342 if (ret < 0)
343 goto put_chain;
344
345 prog = to_bpf(*act);
346
347 spin_lock_bh(&prog->tcf_lock);
348 if (res != ACT_P_CREATED)
349 tcf_bpf_prog_fill_cfg(prog, &old);
350
351 prog->bpf_ops = cfg.bpf_ops;
352 prog->bpf_name = cfg.bpf_name;
353
354 if (cfg.bpf_num_ops)
355 prog->bpf_num_ops = cfg.bpf_num_ops;
356
357 goto_ch = tcf_action_set_ctrlact(*act, parm->action, goto_ch);
358 rcu_assign_pointer(prog->filter, cfg.filter);
359 spin_unlock_bh(&prog->tcf_lock);
360
361 if (goto_ch)
362 tcf_chain_put_by_act(goto_ch);
363
364 if (res == ACT_P_CREATED) {
365 tcf_idr_insert(tn, *act);
366 } else {
367 /* make sure the program being replaced is no longer executing */
368 synchronize_rcu();
369 tcf_bpf_cfg_cleanup(&old);
370 }
371
372 return res;
373
374put_chain:
375 if (goto_ch)
376 tcf_chain_put_by_act(goto_ch);
377
378release_idr:
379 tcf_idr_release(*act, bind);
380 return ret;
381}
382
383static void tcf_bpf_cleanup(struct tc_action *act)
384{
385 struct tcf_bpf_cfg tmp;
386
387 tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp);
388 tcf_bpf_cfg_cleanup(&tmp);
389}
390
391static int tcf_bpf_walker(struct net *net, struct sk_buff *skb,
392 struct netlink_callback *cb, int type,
393 const struct tc_action_ops *ops,
394 struct netlink_ext_ack *extack)
395{
396 struct tc_action_net *tn = net_generic(net, bpf_net_id);
397
398 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
399}
400
401static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index)
402{
403 struct tc_action_net *tn = net_generic(net, bpf_net_id);
404
405 return tcf_idr_search(tn, a, index);
406}
407
408static struct tc_action_ops act_bpf_ops __read_mostly = {
409 .kind = "bpf",
410 .id = TCA_ID_BPF,
411 .owner = THIS_MODULE,
412 .act = tcf_bpf_act,
413 .dump = tcf_bpf_dump,
414 .cleanup = tcf_bpf_cleanup,
415 .init = tcf_bpf_init,
416 .walk = tcf_bpf_walker,
417 .lookup = tcf_bpf_search,
418 .size = sizeof(struct tcf_bpf),
419};
420
421static __net_init int bpf_init_net(struct net *net)
422{
423 struct tc_action_net *tn = net_generic(net, bpf_net_id);
424
425 return tc_action_net_init(net, tn, &act_bpf_ops);
426}
427
428static void __net_exit bpf_exit_net(struct list_head *net_list)
429{
430 tc_action_net_exit(net_list, bpf_net_id);
431}
432
433static struct pernet_operations bpf_net_ops = {
434 .init = bpf_init_net,
435 .exit_batch = bpf_exit_net,
436 .id = &bpf_net_id,
437 .size = sizeof(struct tc_action_net),
438};
439
440static int __init bpf_init_module(void)
441{
442 return tcf_register_action(&act_bpf_ops, &bpf_net_ops);
443}
444
445static void __exit bpf_cleanup_module(void)
446{
447 tcf_unregister_action(&act_bpf_ops, &bpf_net_ops);
448}
449
450module_init(bpf_init_module);
451module_exit(bpf_cleanup_module);
452
453MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
454MODULE_DESCRIPTION("TC BPF based action");
455MODULE_LICENSE("GPL v2");
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>
16#include <linux/bpf.h>
17
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
24#define BPF_TAB_MASK 15
25#define ACT_BPF_NAME_LEN 256
26
27struct tcf_bpf_cfg {
28 struct bpf_prog *filter;
29 struct sock_filter *bpf_ops;
30 const char *bpf_name;
31 u16 bpf_num_ops;
32 bool is_ebpf;
33};
34
35static unsigned int bpf_net_id;
36static struct tc_action_ops act_bpf_ops;
37
38static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act,
39 struct tcf_result *res)
40{
41 bool at_ingress = skb_at_tc_ingress(skb);
42 struct tcf_bpf *prog = to_bpf(act);
43 struct bpf_prog *filter;
44 int action, filter_res;
45
46 tcf_lastuse_update(&prog->tcf_tm);
47 bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
48
49 rcu_read_lock();
50 filter = rcu_dereference(prog->filter);
51 if (at_ingress) {
52 __skb_push(skb, skb->mac_len);
53 bpf_compute_data_end(skb);
54 filter_res = BPF_PROG_RUN(filter, skb);
55 __skb_pull(skb, skb->mac_len);
56 } else {
57 bpf_compute_data_end(skb);
58 filter_res = BPF_PROG_RUN(filter, skb);
59 }
60 rcu_read_unlock();
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 case TC_ACT_REDIRECT:
77 action = filter_res;
78 break;
79 case TC_ACT_SHOT:
80 action = filter_res;
81 qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats));
82 break;
83 case TC_ACT_UNSPEC:
84 action = prog->tcf_action;
85 break;
86 default:
87 action = TC_ACT_UNSPEC;
88 break;
89 }
90
91 return action;
92}
93
94static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog)
95{
96 return !prog->bpf_ops;
97}
98
99static 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
117static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog,
118 struct sk_buff *skb)
119{
120 struct nlattr *nla;
121
122 if (prog->bpf_name &&
123 nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
124 return -EMSGSIZE;
125
126 nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag));
127 if (nla == NULL)
128 return -EMSGSIZE;
129
130 memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
131
132 return 0;
133}
134
135static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act,
136 int bind, int ref)
137{
138 unsigned char *tp = skb_tail_pointer(skb);
139 struct tcf_bpf *prog = to_bpf(act);
140 struct tc_act_bpf opt = {
141 .index = prog->tcf_index,
142 .refcnt = prog->tcf_refcnt - ref,
143 .bindcnt = prog->tcf_bindcnt - bind,
144 .action = prog->tcf_action,
145 };
146 struct tcf_t tm;
147 int ret;
148
149 if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
150 goto nla_put_failure;
151
152 if (tcf_bpf_is_ebpf(prog))
153 ret = tcf_bpf_dump_ebpf_info(prog, skb);
154 else
155 ret = tcf_bpf_dump_bpf_info(prog, skb);
156 if (ret)
157 goto nla_put_failure;
158
159 tcf_tm_dump(&tm, &prog->tcf_tm);
160 if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm,
161 TCA_ACT_BPF_PAD))
162 goto nla_put_failure;
163
164 return skb->len;
165
166nla_put_failure:
167 nlmsg_trim(skb, tp);
168 return -1;
169}
170
171static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
172 [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) },
173 [TCA_ACT_BPF_FD] = { .type = NLA_U32 },
174 [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING,
175 .len = ACT_BPF_NAME_LEN },
176 [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 },
177 [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY,
178 .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
179};
180
181static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
182{
183 struct sock_filter *bpf_ops;
184 struct sock_fprog_kern fprog_tmp;
185 struct bpf_prog *fp;
186 u16 bpf_size, bpf_num_ops;
187 int ret;
188
189 bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
190 if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
191 return -EINVAL;
192
193 bpf_size = bpf_num_ops * sizeof(*bpf_ops);
194 if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
195 return -EINVAL;
196
197 bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
198 if (bpf_ops == NULL)
199 return -ENOMEM;
200
201 memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
202
203 fprog_tmp.len = bpf_num_ops;
204 fprog_tmp.filter = bpf_ops;
205
206 ret = bpf_prog_create(&fp, &fprog_tmp);
207 if (ret < 0) {
208 kfree(bpf_ops);
209 return ret;
210 }
211
212 cfg->bpf_ops = bpf_ops;
213 cfg->bpf_num_ops = bpf_num_ops;
214 cfg->filter = fp;
215 cfg->is_ebpf = false;
216
217 return 0;
218}
219
220static 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
228 fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT);
229 if (IS_ERR(fp))
230 return PTR_ERR(fp);
231
232 if (tb[TCA_ACT_BPF_NAME]) {
233 name = nla_memdup(tb[TCA_ACT_BPF_NAME], GFP_KERNEL);
234 if (!name) {
235 bpf_prog_put(fp);
236 return -ENOMEM;
237 }
238 }
239
240 cfg->bpf_name = name;
241 cfg->filter = fp;
242 cfg->is_ebpf = true;
243
244 return 0;
245}
246
247static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg)
248{
249 if (cfg->is_ebpf)
250 bpf_prog_put(cfg->filter);
251 else
252 bpf_prog_destroy(cfg->filter);
253
254 kfree(cfg->bpf_ops);
255 kfree(cfg->bpf_name);
256}
257
258static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog,
259 struct tcf_bpf_cfg *cfg)
260{
261 cfg->is_ebpf = tcf_bpf_is_ebpf(prog);
262 /* updates to prog->filter are prevented, since it's called either
263 * with rtnl lock or during final cleanup in rcu callback
264 */
265 cfg->filter = rcu_dereference_protected(prog->filter, 1);
266
267 cfg->bpf_ops = prog->bpf_ops;
268 cfg->bpf_name = prog->bpf_name;
269}
270
271static int tcf_bpf_init(struct net *net, struct nlattr *nla,
272 struct nlattr *est, struct tc_action **act,
273 int replace, int bind)
274{
275 struct tc_action_net *tn = net_generic(net, bpf_net_id);
276 struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
277 struct tcf_bpf_cfg cfg, old;
278 struct tc_act_bpf *parm;
279 struct tcf_bpf *prog;
280 bool is_bpf, is_ebpf;
281 int ret, res = 0;
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 if (!tb[TCA_ACT_BPF_PARMS])
291 return -EINVAL;
292
293 parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
294
295 if (!tcf_hash_check(tn, parm->index, act, bind)) {
296 ret = tcf_hash_create(tn, parm->index, est, act,
297 &act_bpf_ops, bind, true);
298 if (ret < 0)
299 return ret;
300
301 res = ACT_P_CREATED;
302 } else {
303 /* Don't override defaults. */
304 if (bind)
305 return 0;
306
307 tcf_hash_release(*act, bind);
308 if (!replace)
309 return -EEXIST;
310 }
311
312 is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS];
313 is_ebpf = tb[TCA_ACT_BPF_FD];
314
315 if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
316 ret = -EINVAL;
317 goto out;
318 }
319
320 memset(&cfg, 0, sizeof(cfg));
321
322 ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) :
323 tcf_bpf_init_from_efd(tb, &cfg);
324 if (ret < 0)
325 goto out;
326
327 prog = to_bpf(*act);
328 ASSERT_RTNL();
329
330 if (res != ACT_P_CREATED)
331 tcf_bpf_prog_fill_cfg(prog, &old);
332
333 prog->bpf_ops = cfg.bpf_ops;
334 prog->bpf_name = cfg.bpf_name;
335
336 if (cfg.bpf_num_ops)
337 prog->bpf_num_ops = cfg.bpf_num_ops;
338
339 prog->tcf_action = parm->action;
340 rcu_assign_pointer(prog->filter, cfg.filter);
341
342 if (res == ACT_P_CREATED) {
343 tcf_hash_insert(tn, *act);
344 } else {
345 /* make sure the program being replaced is no longer executing */
346 synchronize_rcu();
347 tcf_bpf_cfg_cleanup(&old);
348 }
349
350 return res;
351out:
352 if (res == ACT_P_CREATED)
353 tcf_hash_cleanup(*act, est);
354
355 return ret;
356}
357
358static void tcf_bpf_cleanup(struct tc_action *act, int bind)
359{
360 struct tcf_bpf_cfg tmp;
361
362 tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp);
363 tcf_bpf_cfg_cleanup(&tmp);
364}
365
366static int tcf_bpf_walker(struct net *net, struct sk_buff *skb,
367 struct netlink_callback *cb, int type,
368 const struct tc_action_ops *ops)
369{
370 struct tc_action_net *tn = net_generic(net, bpf_net_id);
371
372 return tcf_generic_walker(tn, skb, cb, type, ops);
373}
374
375static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index)
376{
377 struct tc_action_net *tn = net_generic(net, bpf_net_id);
378
379 return tcf_hash_search(tn, a, index);
380}
381
382static struct tc_action_ops act_bpf_ops __read_mostly = {
383 .kind = "bpf",
384 .type = TCA_ACT_BPF,
385 .owner = THIS_MODULE,
386 .act = tcf_bpf,
387 .dump = tcf_bpf_dump,
388 .cleanup = tcf_bpf_cleanup,
389 .init = tcf_bpf_init,
390 .walk = tcf_bpf_walker,
391 .lookup = tcf_bpf_search,
392 .size = sizeof(struct tcf_bpf),
393};
394
395static __net_init int bpf_init_net(struct net *net)
396{
397 struct tc_action_net *tn = net_generic(net, bpf_net_id);
398
399 return tc_action_net_init(tn, &act_bpf_ops, BPF_TAB_MASK);
400}
401
402static void __net_exit bpf_exit_net(struct net *net)
403{
404 struct tc_action_net *tn = net_generic(net, bpf_net_id);
405
406 tc_action_net_exit(tn);
407}
408
409static struct pernet_operations bpf_net_ops = {
410 .init = bpf_init_net,
411 .exit = bpf_exit_net,
412 .id = &bpf_net_id,
413 .size = sizeof(struct tc_action_net),
414};
415
416static int __init bpf_init_module(void)
417{
418 return tcf_register_action(&act_bpf_ops, &bpf_net_ops);
419}
420
421static void __exit bpf_cleanup_module(void)
422{
423 tcf_unregister_action(&act_bpf_ops, &bpf_net_ops);
424}
425
426module_init(bpf_init_module);
427module_exit(bpf_cleanup_module);
428
429MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
430MODULE_DESCRIPTION("TC BPF based action");
431MODULE_LICENSE("GPL v2");