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 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 } 104 105 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 } 136 137 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 } 147 148 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 } 293 294 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 } 304 305 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 } 315 316 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 } 348 349 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 } 454 455 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 } 464 465 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 } 520 521 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 }; 589 590 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 } 596 597 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"); 612 613 static int __init pedit_init_module(void) 614 { 615 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 616 } 617 618 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