1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/act_pedit.c Generic packet editor
4 *
5 * Authors: Jamal Hadi Salim (2002-4)
6 */
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/skbuff.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <net/netlink.h>
18 #include <net/pkt_sched.h>
19 #include <linux/tc_act/tc_pedit.h>
20 #include <net/tc_act/tc_pedit.h>
21 #include <uapi/linux/tc_act/tc_pedit.h>
22 #include <net/pkt_cls.h>
23 #include <net/tc_wrapper.h>
24
25 static struct tc_action_ops act_pedit_ops;
26
27 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
28 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
29 [TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED },
30 };
31
32 static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = {
33 [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 },
34 [TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 },
35 };
36
tcf_pedit_keys_ex_parse(struct nlattr * nla,u8 n)37 static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla,
38 u8 n)
39 {
40 struct tcf_pedit_key_ex *keys_ex;
41 struct tcf_pedit_key_ex *k;
42 const struct nlattr *ka;
43 int err = -EINVAL;
44 int rem;
45
46 if (!nla)
47 return NULL;
48
49 keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL);
50 if (!keys_ex)
51 return ERR_PTR(-ENOMEM);
52
53 k = keys_ex;
54
55 nla_for_each_nested(ka, nla, rem) {
56 struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1];
57
58 if (!n) {
59 err = -EINVAL;
60 goto err_out;
61 }
62 n--;
63
64 if (nla_type(ka) != TCA_PEDIT_KEY_EX) {
65 err = -EINVAL;
66 goto err_out;
67 }
68
69 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX,
70 ka, pedit_key_ex_policy,
71 NULL);
72 if (err)
73 goto err_out;
74
75 if (!tb[TCA_PEDIT_KEY_EX_HTYPE] ||
76 !tb[TCA_PEDIT_KEY_EX_CMD]) {
77 err = -EINVAL;
78 goto err_out;
79 }
80
81 k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]);
82 k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]);
83
84 if (k->htype > TCA_PEDIT_HDR_TYPE_MAX ||
85 k->cmd > TCA_PEDIT_CMD_MAX) {
86 err = -EINVAL;
87 goto err_out;
88 }
89
90 k++;
91 }
92
93 if (n) {
94 err = -EINVAL;
95 goto err_out;
96 }
97
98 return keys_ex;
99
100 err_out:
101 kfree(keys_ex);
102 return ERR_PTR(err);
103 }
104
tcf_pedit_key_ex_dump(struct sk_buff * skb,struct tcf_pedit_key_ex * keys_ex,int n)105 static int tcf_pedit_key_ex_dump(struct sk_buff *skb,
106 struct tcf_pedit_key_ex *keys_ex, int n)
107 {
108 struct nlattr *keys_start = nla_nest_start_noflag(skb,
109 TCA_PEDIT_KEYS_EX);
110
111 if (!keys_start)
112 goto nla_failure;
113 for (; n > 0; n--) {
114 struct nlattr *key_start;
115
116 key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX);
117 if (!key_start)
118 goto nla_failure;
119
120 if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) ||
121 nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd))
122 goto nla_failure;
123
124 nla_nest_end(skb, key_start);
125
126 keys_ex++;
127 }
128
129 nla_nest_end(skb, keys_start);
130
131 return 0;
132 nla_failure:
133 nla_nest_cancel(skb, keys_start);
134 return -EINVAL;
135 }
136
tcf_pedit_cleanup_rcu(struct rcu_head * head)137 static void tcf_pedit_cleanup_rcu(struct rcu_head *head)
138 {
139 struct tcf_pedit_parms *parms =
140 container_of(head, struct tcf_pedit_parms, rcu);
141
142 kfree(parms->tcfp_keys_ex);
143 kfree(parms->tcfp_keys);
144
145 kfree(parms);
146 }
147
tcf_pedit_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)148 static int tcf_pedit_init(struct net *net, struct nlattr *nla,
149 struct nlattr *est, struct tc_action **a,
150 struct tcf_proto *tp, u32 flags,
151 struct netlink_ext_ack *extack)
152 {
153 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
154 bool bind = flags & TCA_ACT_FLAGS_BIND;
155 struct tcf_chain *goto_ch = NULL;
156 struct tcf_pedit_parms *oparms, *nparms;
157 struct nlattr *tb[TCA_PEDIT_MAX + 1];
158 struct tc_pedit *parm;
159 struct nlattr *pattr;
160 struct tcf_pedit *p;
161 int ret = 0, err;
162 int i, ksize;
163 u32 index;
164
165 if (!nla) {
166 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed");
167 return -EINVAL;
168 }
169
170 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla,
171 pedit_policy, NULL);
172 if (err < 0)
173 return err;
174
175 pattr = tb[TCA_PEDIT_PARMS];
176 if (!pattr)
177 pattr = tb[TCA_PEDIT_PARMS_EX];
178 if (!pattr) {
179 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute");
180 return -EINVAL;
181 }
182
183 parm = nla_data(pattr);
184
185 index = parm->index;
186 err = tcf_idr_check_alloc(tn, &index, a, bind);
187 if (!err) {
188 ret = tcf_idr_create_from_flags(tn, index, est, a,
189 &act_pedit_ops, bind, flags);
190 if (ret) {
191 tcf_idr_cleanup(tn, index);
192 return ret;
193 }
194 ret = ACT_P_CREATED;
195 } else if (err > 0) {
196 if (bind)
197 return 0;
198 if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
199 ret = -EEXIST;
200 goto out_release;
201 }
202 } else {
203 return err;
204 }
205
206 if (!parm->nkeys) {
207 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed");
208 ret = -EINVAL;
209 goto out_release;
210 }
211 ksize = parm->nkeys * sizeof(struct tc_pedit_key);
212 if (nla_len(pattr) < sizeof(*parm) + ksize) {
213 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid");
214 ret = -EINVAL;
215 goto out_release;
216 }
217
218 nparms = kzalloc(sizeof(*nparms), GFP_KERNEL);
219 if (!nparms) {
220 ret = -ENOMEM;
221 goto out_release;
222 }
223
224 nparms->tcfp_keys_ex =
225 tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys);
226 if (IS_ERR(nparms->tcfp_keys_ex)) {
227 ret = PTR_ERR(nparms->tcfp_keys_ex);
228 goto out_free;
229 }
230
231 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
232 if (err < 0) {
233 ret = err;
234 goto out_free_ex;
235 }
236
237 nparms->tcfp_off_max_hint = 0;
238 nparms->tcfp_flags = parm->flags;
239 nparms->tcfp_nkeys = parm->nkeys;
240
241 nparms->tcfp_keys = kmalloc(ksize, GFP_KERNEL);
242 if (!nparms->tcfp_keys) {
243 ret = -ENOMEM;
244 goto put_chain;
245 }
246
247 memcpy(nparms->tcfp_keys, parm->keys, ksize);
248
249 for (i = 0; i < nparms->tcfp_nkeys; ++i) {
250 u32 cur = nparms->tcfp_keys[i].off;
251
252 /* sanitize the shift value for any later use */
253 nparms->tcfp_keys[i].shift = min_t(size_t,
254 BITS_PER_TYPE(int) - 1,
255 nparms->tcfp_keys[i].shift);
256
257 /* The AT option can read a single byte, we can bound the actual
258 * value with uchar max.
259 */
260 cur += (0xff & nparms->tcfp_keys[i].offmask) >> nparms->tcfp_keys[i].shift;
261
262 /* Each key touches 4 bytes starting from the computed offset */
263 nparms->tcfp_off_max_hint =
264 max(nparms->tcfp_off_max_hint, cur + 4);
265 }
266
267 p = to_pedit(*a);
268
269 spin_lock_bh(&p->tcf_lock);
270 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
271 oparms = rcu_replace_pointer(p->parms, nparms, 1);
272 spin_unlock_bh(&p->tcf_lock);
273
274 if (oparms)
275 call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);
276
277 if (goto_ch)
278 tcf_chain_put_by_act(goto_ch);
279
280 return ret;
281
282 put_chain:
283 if (goto_ch)
284 tcf_chain_put_by_act(goto_ch);
285 out_free_ex:
286 kfree(nparms->tcfp_keys_ex);
287 out_free:
288 kfree(nparms);
289 out_release:
290 tcf_idr_release(*a, bind);
291 return ret;
292 }
293
tcf_pedit_cleanup(struct tc_action * a)294 static void tcf_pedit_cleanup(struct tc_action *a)
295 {
296 struct tcf_pedit *p = to_pedit(a);
297 struct tcf_pedit_parms *parms;
298
299 parms = rcu_dereference_protected(p->parms, 1);
300
301 if (parms)
302 call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu);
303 }
304
offset_valid(struct sk_buff * skb,int offset)305 static bool offset_valid(struct sk_buff *skb, int offset)
306 {
307 if (offset > 0 && offset > skb->len)
308 return false;
309
310 if (offset < 0 && -offset > skb_headroom(skb))
311 return false;
312
313 return true;
314 }
315
pedit_skb_hdr_offset(struct sk_buff * skb,enum pedit_header_type htype,int * hoffset)316 static int pedit_skb_hdr_offset(struct sk_buff *skb,
317 enum pedit_header_type htype, int *hoffset)
318 {
319 int ret = -EINVAL;
320
321 switch (htype) {
322 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
323 if (skb_mac_header_was_set(skb)) {
324 *hoffset = skb_mac_offset(skb);
325 ret = 0;
326 }
327 break;
328 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
329 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
330 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
331 *hoffset = skb_network_offset(skb);
332 ret = 0;
333 break;
334 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
335 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
336 if (skb_transport_header_was_set(skb)) {
337 *hoffset = skb_transport_offset(skb);
338 ret = 0;
339 }
340 break;
341 default:
342 ret = -EINVAL;
343 break;
344 }
345
346 return ret;
347 }
348
tcf_pedit_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)349 TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
350 const struct tc_action *a,
351 struct tcf_result *res)
352 {
353 enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK;
354 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET;
355 struct tcf_pedit *p = to_pedit(a);
356 struct tcf_pedit_key_ex *tkey_ex;
357 struct tcf_pedit_parms *parms;
358 struct tc_pedit_key *tkey;
359 u32 max_offset;
360 int i;
361
362 parms = rcu_dereference_bh(p->parms);
363
364 max_offset = (skb_transport_header_was_set(skb) ?
365 skb_transport_offset(skb) :
366 skb_network_offset(skb)) +
367 parms->tcfp_off_max_hint;
368 if (skb_ensure_writable(skb, min(skb->len, max_offset)))
369 goto done;
370
371 tcf_lastuse_update(&p->tcf_tm);
372 tcf_action_update_bstats(&p->common, skb);
373
374 tkey = parms->tcfp_keys;
375 tkey_ex = parms->tcfp_keys_ex;
376
377 for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) {
378 int offset = tkey->off;
379 u32 *ptr, hdata;
380 int hoffset;
381 u32 val;
382 int rc;
383
384 if (tkey_ex) {
385 htype = tkey_ex->htype;
386 cmd = tkey_ex->cmd;
387
388 tkey_ex++;
389 }
390
391 rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
392 if (rc) {
393 pr_info("tc action pedit bad header type specified (0x%x)\n",
394 htype);
395 goto bad;
396 }
397
398 if (tkey->offmask) {
399 u8 *d, _d;
400
401 if (!offset_valid(skb, hoffset + tkey->at)) {
402 pr_info("tc action pedit 'at' offset %d out of bounds\n",
403 hoffset + tkey->at);
404 goto bad;
405 }
406 d = skb_header_pointer(skb, hoffset + tkey->at,
407 sizeof(_d), &_d);
408 if (!d)
409 goto bad;
410 offset += (*d & tkey->offmask) >> tkey->shift;
411 }
412
413 if (offset % 4) {
414 pr_info("tc action pedit offset must be on 32 bit boundaries\n");
415 goto bad;
416 }
417
418 if (!offset_valid(skb, hoffset + offset)) {
419 pr_info("tc action pedit offset %d out of bounds\n",
420 hoffset + offset);
421 goto bad;
422 }
423
424 ptr = skb_header_pointer(skb, hoffset + offset,
425 sizeof(hdata), &hdata);
426 if (!ptr)
427 goto bad;
428 /* just do it, baby */
429 switch (cmd) {
430 case TCA_PEDIT_KEY_EX_CMD_SET:
431 val = tkey->val;
432 break;
433 case TCA_PEDIT_KEY_EX_CMD_ADD:
434 val = (*ptr + tkey->val) & ~tkey->mask;
435 break;
436 default:
437 pr_info("tc action pedit bad command (%d)\n",
438 cmd);
439 goto bad;
440 }
441
442 *ptr = ((*ptr & tkey->mask) ^ val);
443 if (ptr == &hdata)
444 skb_store_bits(skb, hoffset + offset, ptr, 4);
445 }
446
447 goto done;
448
449 bad:
450 tcf_action_inc_overlimit_qstats(&p->common);
451 done:
452 return p->tcf_action;
453 }
454
tcf_pedit_stats_update(struct tc_action * a,u64 bytes,u64 packets,u64 drops,u64 lastuse,bool hw)455 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets,
456 u64 drops, u64 lastuse, bool hw)
457 {
458 struct tcf_pedit *d = to_pedit(a);
459 struct tcf_t *tm = &d->tcf_tm;
460
461 tcf_action_update_stats(a, bytes, packets, drops, hw);
462 tm->lastuse = max_t(u64, tm->lastuse, lastuse);
463 }
464
tcf_pedit_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)465 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
466 int bind, int ref)
467 {
468 unsigned char *b = skb_tail_pointer(skb);
469 struct tcf_pedit *p = to_pedit(a);
470 struct tcf_pedit_parms *parms;
471 struct tc_pedit *opt;
472 struct tcf_t t;
473 int s;
474
475 spin_lock_bh(&p->tcf_lock);
476 parms = rcu_dereference_protected(p->parms, 1);
477 s = struct_size(opt, keys, parms->tcfp_nkeys);
478
479 opt = kzalloc(s, GFP_ATOMIC);
480 if (unlikely(!opt)) {
481 spin_unlock_bh(&p->tcf_lock);
482 return -ENOBUFS;
483 }
484
485 memcpy(opt->keys, parms->tcfp_keys,
486 flex_array_size(opt, keys, parms->tcfp_nkeys));
487 opt->index = p->tcf_index;
488 opt->nkeys = parms->tcfp_nkeys;
489 opt->flags = parms->tcfp_flags;
490 opt->action = p->tcf_action;
491 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref;
492 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind;
493
494 if (parms->tcfp_keys_ex) {
495 if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex,
496 parms->tcfp_nkeys))
497 goto nla_put_failure;
498
499 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt))
500 goto nla_put_failure;
501 } else {
502 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
503 goto nla_put_failure;
504 }
505
506 tcf_tm_dump(&t, &p->tcf_tm);
507 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
508 goto nla_put_failure;
509 spin_unlock_bh(&p->tcf_lock);
510
511 kfree(opt);
512 return skb->len;
513
514 nla_put_failure:
515 spin_unlock_bh(&p->tcf_lock);
516 nlmsg_trim(skb, b);
517 kfree(opt);
518 return -1;
519 }
520
tcf_pedit_offload_act_setup(struct tc_action * act,void * entry_data,u32 * index_inc,bool bind,struct netlink_ext_ack * extack)521 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data,
522 u32 *index_inc, bool bind,
523 struct netlink_ext_ack *extack)
524 {
525 if (bind) {
526 struct flow_action_entry *entry = entry_data;
527 int k;
528
529 for (k = 0; k < tcf_pedit_nkeys(act); k++) {
530 switch (tcf_pedit_cmd(act, k)) {
531 case TCA_PEDIT_KEY_EX_CMD_SET:
532 entry->id = FLOW_ACTION_MANGLE;
533 break;
534 case TCA_PEDIT_KEY_EX_CMD_ADD:
535 entry->id = FLOW_ACTION_ADD;
536 break;
537 default:
538 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
539 return -EOPNOTSUPP;
540 }
541 entry->mangle.htype = tcf_pedit_htype(act, k);
542 entry->mangle.mask = tcf_pedit_mask(act, k);
543 entry->mangle.val = tcf_pedit_val(act, k);
544 entry->mangle.offset = tcf_pedit_offset(act, k);
545 entry->hw_stats = tc_act_hw_stats(act->hw_stats);
546 entry++;
547 }
548 *index_inc = k;
549 } else {
550 struct flow_offload_action *fl_action = entry_data;
551 u32 cmd = tcf_pedit_cmd(act, 0);
552 int k;
553
554 switch (cmd) {
555 case TCA_PEDIT_KEY_EX_CMD_SET:
556 fl_action->id = FLOW_ACTION_MANGLE;
557 break;
558 case TCA_PEDIT_KEY_EX_CMD_ADD:
559 fl_action->id = FLOW_ACTION_ADD;
560 break;
561 default:
562 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
563 return -EOPNOTSUPP;
564 }
565
566 for (k = 1; k < tcf_pedit_nkeys(act); k++) {
567 if (cmd != tcf_pedit_cmd(act, k)) {
568 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload");
569 return -EOPNOTSUPP;
570 }
571 }
572 }
573
574 return 0;
575 }
576
577 static struct tc_action_ops act_pedit_ops = {
578 .kind = "pedit",
579 .id = TCA_ID_PEDIT,
580 .owner = THIS_MODULE,
581 .act = tcf_pedit_act,
582 .stats_update = tcf_pedit_stats_update,
583 .dump = tcf_pedit_dump,
584 .cleanup = tcf_pedit_cleanup,
585 .init = tcf_pedit_init,
586 .offload_act_setup = tcf_pedit_offload_act_setup,
587 .size = sizeof(struct tcf_pedit),
588 };
589
pedit_init_net(struct net * net)590 static __net_init int pedit_init_net(struct net *net)
591 {
592 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id);
593
594 return tc_action_net_init(net, tn, &act_pedit_ops);
595 }
596
pedit_exit_net(struct list_head * net_list)597 static void __net_exit pedit_exit_net(struct list_head *net_list)
598 {
599 tc_action_net_exit(net_list, act_pedit_ops.net_id);
600 }
601
602 static struct pernet_operations pedit_net_ops = {
603 .init = pedit_init_net,
604 .exit_batch = pedit_exit_net,
605 .id = &act_pedit_ops.net_id,
606 .size = sizeof(struct tc_action_net),
607 };
608
609 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
610 MODULE_DESCRIPTION("Generic Packet Editor actions");
611 MODULE_LICENSE("GPL");
612
pedit_init_module(void)613 static int __init pedit_init_module(void)
614 {
615 return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
616 }
617
pedit_cleanup_module(void)618 static void __exit pedit_cleanup_module(void)
619 {
620 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
621 }
622
623 module_init(pedit_init_module);
624 module_exit(pedit_cleanup_module);
625