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