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 24 static unsigned int pedit_net_id; 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 int tcf_pedit_init(struct net *net, struct nlattr *nla, 138 struct nlattr *est, struct tc_action **a, 139 struct tcf_proto *tp, u32 flags, 140 struct netlink_ext_ack *extack) 141 { 142 struct tc_action_net *tn = net_generic(net, pedit_net_id); 143 bool bind = flags & TCA_ACT_FLAGS_BIND; 144 struct nlattr *tb[TCA_PEDIT_MAX + 1]; 145 struct tcf_chain *goto_ch = NULL; 146 struct tc_pedit_key *keys = NULL; 147 struct tcf_pedit_key_ex *keys_ex; 148 struct tc_pedit *parm; 149 struct nlattr *pattr; 150 struct tcf_pedit *p; 151 int ret = 0, err; 152 int i, ksize; 153 u32 index; 154 155 if (!nla) { 156 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed"); 157 return -EINVAL; 158 } 159 160 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla, 161 pedit_policy, NULL); 162 if (err < 0) 163 return err; 164 165 pattr = tb[TCA_PEDIT_PARMS]; 166 if (!pattr) 167 pattr = tb[TCA_PEDIT_PARMS_EX]; 168 if (!pattr) { 169 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute"); 170 return -EINVAL; 171 } 172 173 parm = nla_data(pattr); 174 if (!parm->nkeys) { 175 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); 176 return -EINVAL; 177 } 178 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 179 if (nla_len(pattr) < sizeof(*parm) + ksize) { 180 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); 181 return -EINVAL; 182 } 183 184 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); 185 if (IS_ERR(keys_ex)) 186 return PTR_ERR(keys_ex); 187 188 index = parm->index; 189 err = tcf_idr_check_alloc(tn, &index, a, bind); 190 if (!err) { 191 ret = tcf_idr_create(tn, index, est, a, 192 &act_pedit_ops, bind, false, flags); 193 if (ret) { 194 tcf_idr_cleanup(tn, index); 195 goto out_free; 196 } 197 ret = ACT_P_CREATED; 198 } else if (err > 0) { 199 if (bind) 200 goto out_free; 201 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 202 ret = -EEXIST; 203 goto out_release; 204 } 205 } else { 206 ret = err; 207 goto out_free; 208 } 209 210 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 211 if (err < 0) { 212 ret = err; 213 goto out_release; 214 } 215 p = to_pedit(*a); 216 spin_lock_bh(&p->tcf_lock); 217 218 if (ret == ACT_P_CREATED || 219 (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) { 220 keys = kmalloc(ksize, GFP_ATOMIC); 221 if (!keys) { 222 spin_unlock_bh(&p->tcf_lock); 223 ret = -ENOMEM; 224 goto put_chain; 225 } 226 kfree(p->tcfp_keys); 227 p->tcfp_keys = keys; 228 p->tcfp_nkeys = parm->nkeys; 229 } 230 memcpy(p->tcfp_keys, parm->keys, ksize); 231 p->tcfp_off_max_hint = 0; 232 for (i = 0; i < p->tcfp_nkeys; ++i) { 233 u32 cur = p->tcfp_keys[i].off; 234 235 /* sanitize the shift value for any later use */ 236 p->tcfp_keys[i].shift = min_t(size_t, BITS_PER_TYPE(int) - 1, 237 p->tcfp_keys[i].shift); 238 239 /* The AT option can read a single byte, we can bound the actual 240 * value with uchar max. 241 */ 242 cur += (0xff & p->tcfp_keys[i].offmask) >> p->tcfp_keys[i].shift; 243 244 /* Each key touches 4 bytes starting from the computed offset */ 245 p->tcfp_off_max_hint = max(p->tcfp_off_max_hint, cur + 4); 246 } 247 248 p->tcfp_flags = parm->flags; 249 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 250 251 kfree(p->tcfp_keys_ex); 252 p->tcfp_keys_ex = keys_ex; 253 254 spin_unlock_bh(&p->tcf_lock); 255 if (goto_ch) 256 tcf_chain_put_by_act(goto_ch); 257 return ret; 258 259 put_chain: 260 if (goto_ch) 261 tcf_chain_put_by_act(goto_ch); 262 out_release: 263 tcf_idr_release(*a, bind); 264 out_free: 265 kfree(keys_ex); 266 return ret; 267 268 } 269 270 static void tcf_pedit_cleanup(struct tc_action *a) 271 { 272 struct tcf_pedit *p = to_pedit(a); 273 struct tc_pedit_key *keys = p->tcfp_keys; 274 275 kfree(keys); 276 kfree(p->tcfp_keys_ex); 277 } 278 279 static bool offset_valid(struct sk_buff *skb, int offset) 280 { 281 if (offset > 0 && offset > skb->len) 282 return false; 283 284 if (offset < 0 && -offset > skb_headroom(skb)) 285 return false; 286 287 return true; 288 } 289 290 static int pedit_skb_hdr_offset(struct sk_buff *skb, 291 enum pedit_header_type htype, int *hoffset) 292 { 293 int ret = -EINVAL; 294 295 switch (htype) { 296 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 297 if (skb_mac_header_was_set(skb)) { 298 *hoffset = skb_mac_offset(skb); 299 ret = 0; 300 } 301 break; 302 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 303 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 304 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 305 *hoffset = skb_network_offset(skb); 306 ret = 0; 307 break; 308 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 309 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 310 if (skb_transport_header_was_set(skb)) { 311 *hoffset = skb_transport_offset(skb); 312 ret = 0; 313 } 314 break; 315 default: 316 ret = -EINVAL; 317 break; 318 } 319 320 return ret; 321 } 322 323 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 324 struct tcf_result *res) 325 { 326 struct tcf_pedit *p = to_pedit(a); 327 u32 max_offset; 328 int i; 329 330 spin_lock(&p->tcf_lock); 331 332 max_offset = (skb_transport_header_was_set(skb) ? 333 skb_transport_offset(skb) : 334 skb_network_offset(skb)) + 335 p->tcfp_off_max_hint; 336 if (skb_ensure_writable(skb, min(skb->len, max_offset))) 337 goto unlock; 338 339 tcf_lastuse_update(&p->tcf_tm); 340 341 if (p->tcfp_nkeys > 0) { 342 struct tc_pedit_key *tkey = p->tcfp_keys; 343 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 344 enum pedit_header_type htype = 345 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 346 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 347 348 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 349 u32 *ptr, hdata; 350 int offset = tkey->off; 351 int hoffset; 352 u32 val; 353 int rc; 354 355 if (tkey_ex) { 356 htype = tkey_ex->htype; 357 cmd = tkey_ex->cmd; 358 359 tkey_ex++; 360 } 361 362 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 363 if (rc) { 364 pr_info("tc action pedit bad header type specified (0x%x)\n", 365 htype); 366 goto bad; 367 } 368 369 if (tkey->offmask) { 370 u8 *d, _d; 371 372 if (!offset_valid(skb, hoffset + tkey->at)) { 373 pr_info("tc action pedit 'at' offset %d out of bounds\n", 374 hoffset + tkey->at); 375 goto bad; 376 } 377 d = skb_header_pointer(skb, hoffset + tkey->at, 378 sizeof(_d), &_d); 379 if (!d) 380 goto bad; 381 offset += (*d & tkey->offmask) >> tkey->shift; 382 } 383 384 if (offset % 4) { 385 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 386 goto bad; 387 } 388 389 if (!offset_valid(skb, hoffset + offset)) { 390 pr_info("tc action pedit offset %d out of bounds\n", 391 hoffset + offset); 392 goto bad; 393 } 394 395 ptr = skb_header_pointer(skb, hoffset + offset, 396 sizeof(hdata), &hdata); 397 if (!ptr) 398 goto bad; 399 /* just do it, baby */ 400 switch (cmd) { 401 case TCA_PEDIT_KEY_EX_CMD_SET: 402 val = tkey->val; 403 break; 404 case TCA_PEDIT_KEY_EX_CMD_ADD: 405 val = (*ptr + tkey->val) & ~tkey->mask; 406 break; 407 default: 408 pr_info("tc action pedit bad command (%d)\n", 409 cmd); 410 goto bad; 411 } 412 413 *ptr = ((*ptr & tkey->mask) ^ val); 414 if (ptr == &hdata) 415 skb_store_bits(skb, hoffset + offset, ptr, 4); 416 } 417 418 goto done; 419 } else { 420 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 421 } 422 423 bad: 424 p->tcf_qstats.overlimits++; 425 done: 426 bstats_update(&p->tcf_bstats, skb); 427 unlock: 428 spin_unlock(&p->tcf_lock); 429 return p->tcf_action; 430 } 431 432 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 433 u64 drops, u64 lastuse, bool hw) 434 { 435 struct tcf_pedit *d = to_pedit(a); 436 struct tcf_t *tm = &d->tcf_tm; 437 438 tcf_action_update_stats(a, bytes, packets, drops, hw); 439 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 440 } 441 442 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 443 int bind, int ref) 444 { 445 unsigned char *b = skb_tail_pointer(skb); 446 struct tcf_pedit *p = to_pedit(a); 447 struct tc_pedit *opt; 448 struct tcf_t t; 449 int s; 450 451 s = struct_size(opt, keys, p->tcfp_nkeys); 452 453 /* netlink spinlocks held above us - must use ATOMIC */ 454 opt = kzalloc(s, GFP_ATOMIC); 455 if (unlikely(!opt)) 456 return -ENOBUFS; 457 458 spin_lock_bh(&p->tcf_lock); 459 memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); 460 opt->index = p->tcf_index; 461 opt->nkeys = p->tcfp_nkeys; 462 opt->flags = p->tcfp_flags; 463 opt->action = p->tcf_action; 464 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 465 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 466 467 if (p->tcfp_keys_ex) { 468 if (tcf_pedit_key_ex_dump(skb, 469 p->tcfp_keys_ex, 470 p->tcfp_nkeys)) 471 goto nla_put_failure; 472 473 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 474 goto nla_put_failure; 475 } else { 476 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 477 goto nla_put_failure; 478 } 479 480 tcf_tm_dump(&t, &p->tcf_tm); 481 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 482 goto nla_put_failure; 483 spin_unlock_bh(&p->tcf_lock); 484 485 kfree(opt); 486 return skb->len; 487 488 nla_put_failure: 489 spin_unlock_bh(&p->tcf_lock); 490 nlmsg_trim(skb, b); 491 kfree(opt); 492 return -1; 493 } 494 495 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 496 struct netlink_callback *cb, int type, 497 const struct tc_action_ops *ops, 498 struct netlink_ext_ack *extack) 499 { 500 struct tc_action_net *tn = net_generic(net, pedit_net_id); 501 502 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 503 } 504 505 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 506 { 507 struct tc_action_net *tn = net_generic(net, pedit_net_id); 508 509 return tcf_idr_search(tn, a, index); 510 } 511 512 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data, 513 u32 *index_inc, bool bind, 514 struct netlink_ext_ack *extack) 515 { 516 if (bind) { 517 struct flow_action_entry *entry = entry_data; 518 int k; 519 520 for (k = 0; k < tcf_pedit_nkeys(act); k++) { 521 switch (tcf_pedit_cmd(act, k)) { 522 case TCA_PEDIT_KEY_EX_CMD_SET: 523 entry->id = FLOW_ACTION_MANGLE; 524 break; 525 case TCA_PEDIT_KEY_EX_CMD_ADD: 526 entry->id = FLOW_ACTION_ADD; 527 break; 528 default: 529 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 530 return -EOPNOTSUPP; 531 } 532 entry->mangle.htype = tcf_pedit_htype(act, k); 533 entry->mangle.mask = tcf_pedit_mask(act, k); 534 entry->mangle.val = tcf_pedit_val(act, k); 535 entry->mangle.offset = tcf_pedit_offset(act, k); 536 entry->hw_stats = tc_act_hw_stats(act->hw_stats); 537 entry++; 538 } 539 *index_inc = k; 540 } else { 541 return -EOPNOTSUPP; 542 } 543 544 return 0; 545 } 546 547 static struct tc_action_ops act_pedit_ops = { 548 .kind = "pedit", 549 .id = TCA_ID_PEDIT, 550 .owner = THIS_MODULE, 551 .act = tcf_pedit_act, 552 .stats_update = tcf_pedit_stats_update, 553 .dump = tcf_pedit_dump, 554 .cleanup = tcf_pedit_cleanup, 555 .init = tcf_pedit_init, 556 .walk = tcf_pedit_walker, 557 .lookup = tcf_pedit_search, 558 .offload_act_setup = tcf_pedit_offload_act_setup, 559 .size = sizeof(struct tcf_pedit), 560 }; 561 562 static __net_init int pedit_init_net(struct net *net) 563 { 564 struct tc_action_net *tn = net_generic(net, pedit_net_id); 565 566 return tc_action_net_init(net, tn, &act_pedit_ops); 567 } 568 569 static void __net_exit pedit_exit_net(struct list_head *net_list) 570 { 571 tc_action_net_exit(net_list, pedit_net_id); 572 } 573 574 static struct pernet_operations pedit_net_ops = { 575 .init = pedit_init_net, 576 .exit_batch = pedit_exit_net, 577 .id = &pedit_net_id, 578 .size = sizeof(struct tc_action_net), 579 }; 580 581 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 582 MODULE_DESCRIPTION("Generic Packet Editor actions"); 583 MODULE_LICENSE("GPL"); 584 585 static int __init pedit_init_module(void) 586 { 587 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 588 } 589 590 static void __exit pedit_cleanup_module(void) 591 { 592 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 593 } 594 595 module_init(pedit_init_module); 596 module_exit(pedit_cleanup_module); 597