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 if (!parm->nkeys) { 185 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); 186 return -EINVAL; 187 } 188 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 189 if (nla_len(pattr) < sizeof(*parm) + ksize) { 190 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); 191 return -EINVAL; 192 } 193 194 nparms = kzalloc(sizeof(*nparms), GFP_KERNEL); 195 if (!nparms) 196 return -ENOMEM; 197 198 nparms->tcfp_keys_ex = 199 tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); 200 if (IS_ERR(nparms->tcfp_keys_ex)) { 201 ret = PTR_ERR(nparms->tcfp_keys_ex); 202 goto out_free; 203 } 204 205 index = parm->index; 206 err = tcf_idr_check_alloc(tn, &index, a, bind); 207 if (!err) { 208 ret = tcf_idr_create_from_flags(tn, index, est, a, 209 &act_pedit_ops, bind, flags); 210 if (ret) { 211 tcf_idr_cleanup(tn, index); 212 goto out_free_ex; 213 } 214 ret = ACT_P_CREATED; 215 } else if (err > 0) { 216 if (bind) 217 goto out_free; 218 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 219 ret = -EEXIST; 220 goto out_release; 221 } 222 } else { 223 ret = err; 224 goto out_free_ex; 225 } 226 227 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 228 if (err < 0) { 229 ret = err; 230 goto out_release; 231 } 232 233 nparms->tcfp_off_max_hint = 0; 234 nparms->tcfp_flags = parm->flags; 235 nparms->tcfp_nkeys = parm->nkeys; 236 237 nparms->tcfp_keys = kmalloc(ksize, GFP_KERNEL); 238 if (!nparms->tcfp_keys) { 239 ret = -ENOMEM; 240 goto put_chain; 241 } 242 243 memcpy(nparms->tcfp_keys, parm->keys, ksize); 244 245 for (i = 0; i < nparms->tcfp_nkeys; ++i) { 246 u32 cur = nparms->tcfp_keys[i].off; 247 248 /* sanitize the shift value for any later use */ 249 nparms->tcfp_keys[i].shift = min_t(size_t, 250 BITS_PER_TYPE(int) - 1, 251 nparms->tcfp_keys[i].shift); 252 253 /* The AT option can read a single byte, we can bound the actual 254 * value with uchar max. 255 */ 256 cur += (0xff & nparms->tcfp_keys[i].offmask) >> nparms->tcfp_keys[i].shift; 257 258 /* Each key touches 4 bytes starting from the computed offset */ 259 nparms->tcfp_off_max_hint = 260 max(nparms->tcfp_off_max_hint, cur + 4); 261 } 262 263 p = to_pedit(*a); 264 265 spin_lock_bh(&p->tcf_lock); 266 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 267 oparms = rcu_replace_pointer(p->parms, nparms, 1); 268 spin_unlock_bh(&p->tcf_lock); 269 270 if (oparms) 271 call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu); 272 273 if (goto_ch) 274 tcf_chain_put_by_act(goto_ch); 275 276 return ret; 277 278 put_chain: 279 if (goto_ch) 280 tcf_chain_put_by_act(goto_ch); 281 out_release: 282 tcf_idr_release(*a, bind); 283 out_free_ex: 284 kfree(nparms->tcfp_keys_ex); 285 out_free: 286 kfree(nparms); 287 return ret; 288 } 289 290 static void tcf_pedit_cleanup(struct tc_action *a) 291 { 292 struct tcf_pedit *p = to_pedit(a); 293 struct tcf_pedit_parms *parms; 294 295 parms = rcu_dereference_protected(p->parms, 1); 296 297 if (parms) 298 call_rcu(&parms->rcu, tcf_pedit_cleanup_rcu); 299 } 300 301 static bool offset_valid(struct sk_buff *skb, int offset) 302 { 303 if (offset > 0 && offset > skb->len) 304 return false; 305 306 if (offset < 0 && -offset > skb_headroom(skb)) 307 return false; 308 309 return true; 310 } 311 312 static int pedit_skb_hdr_offset(struct sk_buff *skb, 313 enum pedit_header_type htype, int *hoffset) 314 { 315 int ret = -EINVAL; 316 317 switch (htype) { 318 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 319 if (skb_mac_header_was_set(skb)) { 320 *hoffset = skb_mac_offset(skb); 321 ret = 0; 322 } 323 break; 324 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 325 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 326 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 327 *hoffset = skb_network_offset(skb); 328 ret = 0; 329 break; 330 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 331 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 332 if (skb_transport_header_was_set(skb)) { 333 *hoffset = skb_transport_offset(skb); 334 ret = 0; 335 } 336 break; 337 default: 338 ret = -EINVAL; 339 break; 340 } 341 342 return ret; 343 } 344 345 TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb, 346 const struct tc_action *a, 347 struct tcf_result *res) 348 { 349 enum pedit_header_type htype = TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 350 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 351 struct tcf_pedit *p = to_pedit(a); 352 struct tcf_pedit_key_ex *tkey_ex; 353 struct tcf_pedit_parms *parms; 354 struct tc_pedit_key *tkey; 355 u32 max_offset; 356 int i; 357 358 parms = rcu_dereference_bh(p->parms); 359 360 max_offset = (skb_transport_header_was_set(skb) ? 361 skb_transport_offset(skb) : 362 skb_network_offset(skb)) + 363 parms->tcfp_off_max_hint; 364 if (skb_ensure_writable(skb, min(skb->len, max_offset))) 365 goto done; 366 367 tcf_lastuse_update(&p->tcf_tm); 368 tcf_action_update_bstats(&p->common, skb); 369 370 tkey = parms->tcfp_keys; 371 tkey_ex = parms->tcfp_keys_ex; 372 373 for (i = parms->tcfp_nkeys; i > 0; i--, tkey++) { 374 int offset = tkey->off; 375 u32 *ptr, hdata; 376 int hoffset; 377 u32 val; 378 int rc; 379 380 if (tkey_ex) { 381 htype = tkey_ex->htype; 382 cmd = tkey_ex->cmd; 383 384 tkey_ex++; 385 } 386 387 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 388 if (rc) { 389 pr_info("tc action pedit bad header type specified (0x%x)\n", 390 htype); 391 goto bad; 392 } 393 394 if (tkey->offmask) { 395 u8 *d, _d; 396 397 if (!offset_valid(skb, hoffset + tkey->at)) { 398 pr_info("tc action pedit 'at' offset %d out of bounds\n", 399 hoffset + tkey->at); 400 goto bad; 401 } 402 d = skb_header_pointer(skb, hoffset + tkey->at, 403 sizeof(_d), &_d); 404 if (!d) 405 goto bad; 406 offset += (*d & tkey->offmask) >> tkey->shift; 407 } 408 409 if (offset % 4) { 410 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 411 goto bad; 412 } 413 414 if (!offset_valid(skb, hoffset + offset)) { 415 pr_info("tc action pedit offset %d out of bounds\n", 416 hoffset + offset); 417 goto bad; 418 } 419 420 ptr = skb_header_pointer(skb, hoffset + offset, 421 sizeof(hdata), &hdata); 422 if (!ptr) 423 goto bad; 424 /* just do it, baby */ 425 switch (cmd) { 426 case TCA_PEDIT_KEY_EX_CMD_SET: 427 val = tkey->val; 428 break; 429 case TCA_PEDIT_KEY_EX_CMD_ADD: 430 val = (*ptr + tkey->val) & ~tkey->mask; 431 break; 432 default: 433 pr_info("tc action pedit bad command (%d)\n", 434 cmd); 435 goto bad; 436 } 437 438 *ptr = ((*ptr & tkey->mask) ^ val); 439 if (ptr == &hdata) 440 skb_store_bits(skb, hoffset + offset, ptr, 4); 441 } 442 443 goto done; 444 445 bad: 446 spin_lock(&p->tcf_lock); 447 p->tcf_qstats.overlimits++; 448 spin_unlock(&p->tcf_lock); 449 done: 450 return p->tcf_action; 451 } 452 453 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 454 u64 drops, u64 lastuse, bool hw) 455 { 456 struct tcf_pedit *d = to_pedit(a); 457 struct tcf_t *tm = &d->tcf_tm; 458 459 tcf_action_update_stats(a, bytes, packets, drops, hw); 460 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 461 } 462 463 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 464 int bind, int ref) 465 { 466 unsigned char *b = skb_tail_pointer(skb); 467 struct tcf_pedit *p = to_pedit(a); 468 struct tcf_pedit_parms *parms; 469 struct tc_pedit *opt; 470 struct tcf_t t; 471 int s; 472 473 spin_lock_bh(&p->tcf_lock); 474 parms = rcu_dereference_protected(p->parms, 1); 475 s = struct_size(opt, keys, parms->tcfp_nkeys); 476 477 opt = kzalloc(s, GFP_ATOMIC); 478 if (unlikely(!opt)) { 479 spin_unlock_bh(&p->tcf_lock); 480 return -ENOBUFS; 481 } 482 483 memcpy(opt->keys, parms->tcfp_keys, 484 flex_array_size(opt, keys, parms->tcfp_nkeys)); 485 opt->index = p->tcf_index; 486 opt->nkeys = parms->tcfp_nkeys; 487 opt->flags = parms->tcfp_flags; 488 opt->action = p->tcf_action; 489 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 490 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 491 492 if (parms->tcfp_keys_ex) { 493 if (tcf_pedit_key_ex_dump(skb, parms->tcfp_keys_ex, 494 parms->tcfp_nkeys)) 495 goto nla_put_failure; 496 497 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 498 goto nla_put_failure; 499 } else { 500 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 501 goto nla_put_failure; 502 } 503 504 tcf_tm_dump(&t, &p->tcf_tm); 505 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 506 goto nla_put_failure; 507 spin_unlock_bh(&p->tcf_lock); 508 509 kfree(opt); 510 return skb->len; 511 512 nla_put_failure: 513 spin_unlock_bh(&p->tcf_lock); 514 nlmsg_trim(skb, b); 515 kfree(opt); 516 return -1; 517 } 518 519 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data, 520 u32 *index_inc, bool bind, 521 struct netlink_ext_ack *extack) 522 { 523 if (bind) { 524 struct flow_action_entry *entry = entry_data; 525 int k; 526 527 for (k = 0; k < tcf_pedit_nkeys(act); k++) { 528 switch (tcf_pedit_cmd(act, k)) { 529 case TCA_PEDIT_KEY_EX_CMD_SET: 530 entry->id = FLOW_ACTION_MANGLE; 531 break; 532 case TCA_PEDIT_KEY_EX_CMD_ADD: 533 entry->id = FLOW_ACTION_ADD; 534 break; 535 default: 536 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 537 return -EOPNOTSUPP; 538 } 539 entry->mangle.htype = tcf_pedit_htype(act, k); 540 entry->mangle.mask = tcf_pedit_mask(act, k); 541 entry->mangle.val = tcf_pedit_val(act, k); 542 entry->mangle.offset = tcf_pedit_offset(act, k); 543 entry->hw_stats = tc_act_hw_stats(act->hw_stats); 544 entry++; 545 } 546 *index_inc = k; 547 } else { 548 struct flow_offload_action *fl_action = entry_data; 549 u32 cmd = tcf_pedit_cmd(act, 0); 550 int k; 551 552 switch (cmd) { 553 case TCA_PEDIT_KEY_EX_CMD_SET: 554 fl_action->id = FLOW_ACTION_MANGLE; 555 break; 556 case TCA_PEDIT_KEY_EX_CMD_ADD: 557 fl_action->id = FLOW_ACTION_ADD; 558 break; 559 default: 560 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 561 return -EOPNOTSUPP; 562 } 563 564 for (k = 1; k < tcf_pedit_nkeys(act); k++) { 565 if (cmd != tcf_pedit_cmd(act, k)) { 566 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 567 return -EOPNOTSUPP; 568 } 569 } 570 } 571 572 return 0; 573 } 574 575 static struct tc_action_ops act_pedit_ops = { 576 .kind = "pedit", 577 .id = TCA_ID_PEDIT, 578 .owner = THIS_MODULE, 579 .act = tcf_pedit_act, 580 .stats_update = tcf_pedit_stats_update, 581 .dump = tcf_pedit_dump, 582 .cleanup = tcf_pedit_cleanup, 583 .init = tcf_pedit_init, 584 .offload_act_setup = tcf_pedit_offload_act_setup, 585 .size = sizeof(struct tcf_pedit), 586 }; 587 588 static __net_init int pedit_init_net(struct net *net) 589 { 590 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id); 591 592 return tc_action_net_init(net, tn, &act_pedit_ops); 593 } 594 595 static void __net_exit pedit_exit_net(struct list_head *net_list) 596 { 597 tc_action_net_exit(net_list, act_pedit_ops.net_id); 598 } 599 600 static struct pernet_operations pedit_net_ops = { 601 .init = pedit_init_net, 602 .exit_batch = pedit_exit_net, 603 .id = &act_pedit_ops.net_id, 604 .size = sizeof(struct tc_action_net), 605 }; 606 607 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 608 MODULE_DESCRIPTION("Generic Packet Editor actions"); 609 MODULE_LICENSE("GPL"); 610 611 static int __init pedit_init_module(void) 612 { 613 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 614 } 615 616 static void __exit pedit_cleanup_module(void) 617 { 618 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 619 } 620 621 module_init(pedit_init_module); 622 module_exit(pedit_cleanup_module); 623