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