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 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, act_pedit_ops.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 TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb, 324 const struct tc_action *a, 325 struct tcf_result *res) 326 { 327 struct tcf_pedit *p = to_pedit(a); 328 u32 max_offset; 329 int i; 330 331 spin_lock(&p->tcf_lock); 332 333 max_offset = (skb_transport_header_was_set(skb) ? 334 skb_transport_offset(skb) : 335 skb_network_offset(skb)) + 336 p->tcfp_off_max_hint; 337 if (skb_ensure_writable(skb, min(skb->len, max_offset))) 338 goto unlock; 339 340 tcf_lastuse_update(&p->tcf_tm); 341 342 if (p->tcfp_nkeys > 0) { 343 struct tc_pedit_key *tkey = p->tcfp_keys; 344 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 345 enum pedit_header_type htype = 346 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 347 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 348 349 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 350 u32 *ptr, hdata; 351 int offset = tkey->off; 352 int hoffset; 353 u32 val; 354 int rc; 355 356 if (tkey_ex) { 357 htype = tkey_ex->htype; 358 cmd = tkey_ex->cmd; 359 360 tkey_ex++; 361 } 362 363 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 364 if (rc) { 365 pr_info("tc action pedit bad header type specified (0x%x)\n", 366 htype); 367 goto bad; 368 } 369 370 if (tkey->offmask) { 371 u8 *d, _d; 372 373 if (!offset_valid(skb, hoffset + tkey->at)) { 374 pr_info("tc action pedit 'at' offset %d out of bounds\n", 375 hoffset + tkey->at); 376 goto bad; 377 } 378 d = skb_header_pointer(skb, hoffset + tkey->at, 379 sizeof(_d), &_d); 380 if (!d) 381 goto bad; 382 offset += (*d & tkey->offmask) >> tkey->shift; 383 } 384 385 if (offset % 4) { 386 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 387 goto bad; 388 } 389 390 if (!offset_valid(skb, hoffset + offset)) { 391 pr_info("tc action pedit offset %d out of bounds\n", 392 hoffset + offset); 393 goto bad; 394 } 395 396 ptr = skb_header_pointer(skb, hoffset + offset, 397 sizeof(hdata), &hdata); 398 if (!ptr) 399 goto bad; 400 /* just do it, baby */ 401 switch (cmd) { 402 case TCA_PEDIT_KEY_EX_CMD_SET: 403 val = tkey->val; 404 break; 405 case TCA_PEDIT_KEY_EX_CMD_ADD: 406 val = (*ptr + tkey->val) & ~tkey->mask; 407 break; 408 default: 409 pr_info("tc action pedit bad command (%d)\n", 410 cmd); 411 goto bad; 412 } 413 414 *ptr = ((*ptr & tkey->mask) ^ val); 415 if (ptr == &hdata) 416 skb_store_bits(skb, hoffset + offset, ptr, 4); 417 } 418 419 goto done; 420 } else { 421 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 422 } 423 424 bad: 425 p->tcf_qstats.overlimits++; 426 done: 427 bstats_update(&p->tcf_bstats, skb); 428 unlock: 429 spin_unlock(&p->tcf_lock); 430 return p->tcf_action; 431 } 432 433 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 434 u64 drops, u64 lastuse, bool hw) 435 { 436 struct tcf_pedit *d = to_pedit(a); 437 struct tcf_t *tm = &d->tcf_tm; 438 439 tcf_action_update_stats(a, bytes, packets, drops, hw); 440 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 441 } 442 443 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 444 int bind, int ref) 445 { 446 unsigned char *b = skb_tail_pointer(skb); 447 struct tcf_pedit *p = to_pedit(a); 448 struct tc_pedit *opt; 449 struct tcf_t t; 450 int s; 451 452 s = struct_size(opt, keys, p->tcfp_nkeys); 453 454 /* netlink spinlocks held above us - must use ATOMIC */ 455 opt = kzalloc(s, GFP_ATOMIC); 456 if (unlikely(!opt)) 457 return -ENOBUFS; 458 459 spin_lock_bh(&p->tcf_lock); 460 memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); 461 opt->index = p->tcf_index; 462 opt->nkeys = p->tcfp_nkeys; 463 opt->flags = p->tcfp_flags; 464 opt->action = p->tcf_action; 465 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 466 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 467 468 if (p->tcfp_keys_ex) { 469 if (tcf_pedit_key_ex_dump(skb, 470 p->tcfp_keys_ex, 471 p->tcfp_nkeys)) 472 goto nla_put_failure; 473 474 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 475 goto nla_put_failure; 476 } else { 477 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 478 goto nla_put_failure; 479 } 480 481 tcf_tm_dump(&t, &p->tcf_tm); 482 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 483 goto nla_put_failure; 484 spin_unlock_bh(&p->tcf_lock); 485 486 kfree(opt); 487 return skb->len; 488 489 nla_put_failure: 490 spin_unlock_bh(&p->tcf_lock); 491 nlmsg_trim(skb, b); 492 kfree(opt); 493 return -1; 494 } 495 496 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data, 497 u32 *index_inc, bool bind, 498 struct netlink_ext_ack *extack) 499 { 500 if (bind) { 501 struct flow_action_entry *entry = entry_data; 502 int k; 503 504 for (k = 0; k < tcf_pedit_nkeys(act); k++) { 505 switch (tcf_pedit_cmd(act, k)) { 506 case TCA_PEDIT_KEY_EX_CMD_SET: 507 entry->id = FLOW_ACTION_MANGLE; 508 break; 509 case TCA_PEDIT_KEY_EX_CMD_ADD: 510 entry->id = FLOW_ACTION_ADD; 511 break; 512 default: 513 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 514 return -EOPNOTSUPP; 515 } 516 entry->mangle.htype = tcf_pedit_htype(act, k); 517 entry->mangle.mask = tcf_pedit_mask(act, k); 518 entry->mangle.val = tcf_pedit_val(act, k); 519 entry->mangle.offset = tcf_pedit_offset(act, k); 520 entry->hw_stats = tc_act_hw_stats(act->hw_stats); 521 entry++; 522 } 523 *index_inc = k; 524 } else { 525 return -EOPNOTSUPP; 526 } 527 528 return 0; 529 } 530 531 static struct tc_action_ops act_pedit_ops = { 532 .kind = "pedit", 533 .id = TCA_ID_PEDIT, 534 .owner = THIS_MODULE, 535 .act = tcf_pedit_act, 536 .stats_update = tcf_pedit_stats_update, 537 .dump = tcf_pedit_dump, 538 .cleanup = tcf_pedit_cleanup, 539 .init = tcf_pedit_init, 540 .offload_act_setup = tcf_pedit_offload_act_setup, 541 .size = sizeof(struct tcf_pedit), 542 }; 543 544 static __net_init int pedit_init_net(struct net *net) 545 { 546 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id); 547 548 return tc_action_net_init(net, tn, &act_pedit_ops); 549 } 550 551 static void __net_exit pedit_exit_net(struct list_head *net_list) 552 { 553 tc_action_net_exit(net_list, act_pedit_ops.net_id); 554 } 555 556 static struct pernet_operations pedit_net_ops = { 557 .init = pedit_init_net, 558 .exit_batch = pedit_exit_net, 559 .id = &act_pedit_ops.net_id, 560 .size = sizeof(struct tc_action_net), 561 }; 562 563 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 564 MODULE_DESCRIPTION("Generic Packet Editor actions"); 565 MODULE_LICENSE("GPL"); 566 567 static int __init pedit_init_module(void) 568 { 569 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 570 } 571 572 static void __exit pedit_cleanup_module(void) 573 { 574 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 575 } 576 577 module_init(pedit_init_module); 578 module_exit(pedit_cleanup_module); 579