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 struct tc_action_ops act_pedit_ops; 25 26 static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { 27 [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) }, 28 [TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED }, 29 }; 30 31 static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = { 32 [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 }, 33 [TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 }, 34 }; 35 36 static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla, 37 u8 n) 38 { 39 struct tcf_pedit_key_ex *keys_ex; 40 struct tcf_pedit_key_ex *k; 41 const struct nlattr *ka; 42 int err = -EINVAL; 43 int rem; 44 45 if (!nla) 46 return NULL; 47 48 keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL); 49 if (!keys_ex) 50 return ERR_PTR(-ENOMEM); 51 52 k = keys_ex; 53 54 nla_for_each_nested(ka, nla, rem) { 55 struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1]; 56 57 if (!n) { 58 err = -EINVAL; 59 goto err_out; 60 } 61 n--; 62 63 if (nla_type(ka) != TCA_PEDIT_KEY_EX) { 64 err = -EINVAL; 65 goto err_out; 66 } 67 68 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX, 69 ka, pedit_key_ex_policy, 70 NULL); 71 if (err) 72 goto err_out; 73 74 if (!tb[TCA_PEDIT_KEY_EX_HTYPE] || 75 !tb[TCA_PEDIT_KEY_EX_CMD]) { 76 err = -EINVAL; 77 goto err_out; 78 } 79 80 k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]); 81 k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]); 82 83 if (k->htype > TCA_PEDIT_HDR_TYPE_MAX || 84 k->cmd > TCA_PEDIT_CMD_MAX) { 85 err = -EINVAL; 86 goto err_out; 87 } 88 89 k++; 90 } 91 92 if (n) { 93 err = -EINVAL; 94 goto err_out; 95 } 96 97 return keys_ex; 98 99 err_out: 100 kfree(keys_ex); 101 return ERR_PTR(err); 102 } 103 104 static int tcf_pedit_key_ex_dump(struct sk_buff *skb, 105 struct tcf_pedit_key_ex *keys_ex, int n) 106 { 107 struct nlattr *keys_start = nla_nest_start_noflag(skb, 108 TCA_PEDIT_KEYS_EX); 109 110 if (!keys_start) 111 goto nla_failure; 112 for (; n > 0; n--) { 113 struct nlattr *key_start; 114 115 key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX); 116 if (!key_start) 117 goto nla_failure; 118 119 if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) || 120 nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd)) 121 goto nla_failure; 122 123 nla_nest_end(skb, key_start); 124 125 keys_ex++; 126 } 127 128 nla_nest_end(skb, keys_start); 129 130 return 0; 131 nla_failure: 132 nla_nest_cancel(skb, keys_start); 133 return -EINVAL; 134 } 135 136 static int tcf_pedit_init(struct net *net, struct nlattr *nla, 137 struct nlattr *est, struct tc_action **a, 138 struct tcf_proto *tp, u32 flags, 139 struct netlink_ext_ack *extack) 140 { 141 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id); 142 bool bind = flags & TCA_ACT_FLAGS_BIND; 143 struct nlattr *tb[TCA_PEDIT_MAX + 1]; 144 struct tcf_chain *goto_ch = NULL; 145 struct tc_pedit_key *keys = NULL; 146 struct tcf_pedit_key_ex *keys_ex; 147 struct tc_pedit *parm; 148 struct nlattr *pattr; 149 struct tcf_pedit *p; 150 int ret = 0, err; 151 int i, ksize; 152 u32 index; 153 154 if (!nla) { 155 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed"); 156 return -EINVAL; 157 } 158 159 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla, 160 pedit_policy, NULL); 161 if (err < 0) 162 return err; 163 164 pattr = tb[TCA_PEDIT_PARMS]; 165 if (!pattr) 166 pattr = tb[TCA_PEDIT_PARMS_EX]; 167 if (!pattr) { 168 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute"); 169 return -EINVAL; 170 } 171 172 parm = nla_data(pattr); 173 if (!parm->nkeys) { 174 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); 175 return -EINVAL; 176 } 177 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 178 if (nla_len(pattr) < sizeof(*parm) + ksize) { 179 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); 180 return -EINVAL; 181 } 182 183 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); 184 if (IS_ERR(keys_ex)) 185 return PTR_ERR(keys_ex); 186 187 index = parm->index; 188 err = tcf_idr_check_alloc(tn, &index, a, bind); 189 if (!err) { 190 ret = tcf_idr_create(tn, index, est, a, 191 &act_pedit_ops, bind, false, flags); 192 if (ret) { 193 tcf_idr_cleanup(tn, index); 194 goto out_free; 195 } 196 ret = ACT_P_CREATED; 197 } else if (err > 0) { 198 if (bind) 199 goto out_free; 200 if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 201 ret = -EEXIST; 202 goto out_release; 203 } 204 } else { 205 ret = err; 206 goto out_free; 207 } 208 209 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 210 if (err < 0) { 211 ret = err; 212 goto out_release; 213 } 214 p = to_pedit(*a); 215 spin_lock_bh(&p->tcf_lock); 216 217 if (ret == ACT_P_CREATED || 218 (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) { 219 keys = kmalloc(ksize, GFP_ATOMIC); 220 if (!keys) { 221 spin_unlock_bh(&p->tcf_lock); 222 ret = -ENOMEM; 223 goto put_chain; 224 } 225 kfree(p->tcfp_keys); 226 p->tcfp_keys = keys; 227 p->tcfp_nkeys = parm->nkeys; 228 } 229 memcpy(p->tcfp_keys, parm->keys, ksize); 230 p->tcfp_off_max_hint = 0; 231 for (i = 0; i < p->tcfp_nkeys; ++i) { 232 u32 cur = p->tcfp_keys[i].off; 233 234 /* sanitize the shift value for any later use */ 235 p->tcfp_keys[i].shift = min_t(size_t, BITS_PER_TYPE(int) - 1, 236 p->tcfp_keys[i].shift); 237 238 /* The AT option can read a single byte, we can bound the actual 239 * value with uchar max. 240 */ 241 cur += (0xff & p->tcfp_keys[i].offmask) >> p->tcfp_keys[i].shift; 242 243 /* Each key touches 4 bytes starting from the computed offset */ 244 p->tcfp_off_max_hint = max(p->tcfp_off_max_hint, cur + 4); 245 } 246 247 p->tcfp_flags = parm->flags; 248 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 249 250 kfree(p->tcfp_keys_ex); 251 p->tcfp_keys_ex = keys_ex; 252 253 spin_unlock_bh(&p->tcf_lock); 254 if (goto_ch) 255 tcf_chain_put_by_act(goto_ch); 256 return ret; 257 258 put_chain: 259 if (goto_ch) 260 tcf_chain_put_by_act(goto_ch); 261 out_release: 262 tcf_idr_release(*a, bind); 263 out_free: 264 kfree(keys_ex); 265 return ret; 266 267 } 268 269 static void tcf_pedit_cleanup(struct tc_action *a) 270 { 271 struct tcf_pedit *p = to_pedit(a); 272 struct tc_pedit_key *keys = p->tcfp_keys; 273 274 kfree(keys); 275 kfree(p->tcfp_keys_ex); 276 } 277 278 static bool offset_valid(struct sk_buff *skb, int offset) 279 { 280 if (offset > 0 && offset > skb->len) 281 return false; 282 283 if (offset < 0 && -offset > skb_headroom(skb)) 284 return false; 285 286 return true; 287 } 288 289 static int pedit_skb_hdr_offset(struct sk_buff *skb, 290 enum pedit_header_type htype, int *hoffset) 291 { 292 int ret = -EINVAL; 293 294 switch (htype) { 295 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 296 if (skb_mac_header_was_set(skb)) { 297 *hoffset = skb_mac_offset(skb); 298 ret = 0; 299 } 300 break; 301 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 302 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 303 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 304 *hoffset = skb_network_offset(skb); 305 ret = 0; 306 break; 307 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 308 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 309 if (skb_transport_header_was_set(skb)) { 310 *hoffset = skb_transport_offset(skb); 311 ret = 0; 312 } 313 break; 314 default: 315 ret = -EINVAL; 316 break; 317 } 318 319 return ret; 320 } 321 322 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 323 struct tcf_result *res) 324 { 325 struct tcf_pedit *p = to_pedit(a); 326 u32 max_offset; 327 int i; 328 329 spin_lock(&p->tcf_lock); 330 331 max_offset = (skb_transport_header_was_set(skb) ? 332 skb_transport_offset(skb) : 333 skb_network_offset(skb)) + 334 p->tcfp_off_max_hint; 335 if (skb_ensure_writable(skb, min(skb->len, max_offset))) 336 goto unlock; 337 338 tcf_lastuse_update(&p->tcf_tm); 339 340 if (p->tcfp_nkeys > 0) { 341 struct tc_pedit_key *tkey = p->tcfp_keys; 342 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 343 enum pedit_header_type htype = 344 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 345 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 346 347 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 348 u32 *ptr, hdata; 349 int offset = tkey->off; 350 int hoffset; 351 u32 val; 352 int rc; 353 354 if (tkey_ex) { 355 htype = tkey_ex->htype; 356 cmd = tkey_ex->cmd; 357 358 tkey_ex++; 359 } 360 361 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 362 if (rc) { 363 pr_info("tc action pedit bad header type specified (0x%x)\n", 364 htype); 365 goto bad; 366 } 367 368 if (tkey->offmask) { 369 u8 *d, _d; 370 371 if (!offset_valid(skb, hoffset + tkey->at)) { 372 pr_info("tc action pedit 'at' offset %d out of bounds\n", 373 hoffset + tkey->at); 374 goto bad; 375 } 376 d = skb_header_pointer(skb, hoffset + tkey->at, 377 sizeof(_d), &_d); 378 if (!d) 379 goto bad; 380 offset += (*d & tkey->offmask) >> tkey->shift; 381 } 382 383 if (offset % 4) { 384 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 385 goto bad; 386 } 387 388 if (!offset_valid(skb, hoffset + offset)) { 389 pr_info("tc action pedit offset %d out of bounds\n", 390 hoffset + offset); 391 goto bad; 392 } 393 394 ptr = skb_header_pointer(skb, hoffset + offset, 395 sizeof(hdata), &hdata); 396 if (!ptr) 397 goto bad; 398 /* just do it, baby */ 399 switch (cmd) { 400 case TCA_PEDIT_KEY_EX_CMD_SET: 401 val = tkey->val; 402 break; 403 case TCA_PEDIT_KEY_EX_CMD_ADD: 404 val = (*ptr + tkey->val) & ~tkey->mask; 405 break; 406 default: 407 pr_info("tc action pedit bad command (%d)\n", 408 cmd); 409 goto bad; 410 } 411 412 *ptr = ((*ptr & tkey->mask) ^ val); 413 if (ptr == &hdata) 414 skb_store_bits(skb, hoffset + offset, ptr, 4); 415 } 416 417 goto done; 418 } else { 419 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 420 } 421 422 bad: 423 p->tcf_qstats.overlimits++; 424 done: 425 bstats_update(&p->tcf_bstats, skb); 426 unlock: 427 spin_unlock(&p->tcf_lock); 428 return p->tcf_action; 429 } 430 431 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 432 u64 drops, u64 lastuse, bool hw) 433 { 434 struct tcf_pedit *d = to_pedit(a); 435 struct tcf_t *tm = &d->tcf_tm; 436 437 tcf_action_update_stats(a, bytes, packets, drops, hw); 438 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 439 } 440 441 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 442 int bind, int ref) 443 { 444 unsigned char *b = skb_tail_pointer(skb); 445 struct tcf_pedit *p = to_pedit(a); 446 struct tc_pedit *opt; 447 struct tcf_t t; 448 int s; 449 450 s = struct_size(opt, keys, p->tcfp_nkeys); 451 452 /* netlink spinlocks held above us - must use ATOMIC */ 453 opt = kzalloc(s, GFP_ATOMIC); 454 if (unlikely(!opt)) 455 return -ENOBUFS; 456 457 spin_lock_bh(&p->tcf_lock); 458 memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); 459 opt->index = p->tcf_index; 460 opt->nkeys = p->tcfp_nkeys; 461 opt->flags = p->tcfp_flags; 462 opt->action = p->tcf_action; 463 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 464 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 465 466 if (p->tcfp_keys_ex) { 467 if (tcf_pedit_key_ex_dump(skb, 468 p->tcfp_keys_ex, 469 p->tcfp_nkeys)) 470 goto nla_put_failure; 471 472 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 473 goto nla_put_failure; 474 } else { 475 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 476 goto nla_put_failure; 477 } 478 479 tcf_tm_dump(&t, &p->tcf_tm); 480 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 481 goto nla_put_failure; 482 spin_unlock_bh(&p->tcf_lock); 483 484 kfree(opt); 485 return skb->len; 486 487 nla_put_failure: 488 spin_unlock_bh(&p->tcf_lock); 489 nlmsg_trim(skb, b); 490 kfree(opt); 491 return -1; 492 } 493 494 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data, 495 u32 *index_inc, bool bind, 496 struct netlink_ext_ack *extack) 497 { 498 if (bind) { 499 struct flow_action_entry *entry = entry_data; 500 int k; 501 502 for (k = 0; k < tcf_pedit_nkeys(act); k++) { 503 switch (tcf_pedit_cmd(act, k)) { 504 case TCA_PEDIT_KEY_EX_CMD_SET: 505 entry->id = FLOW_ACTION_MANGLE; 506 break; 507 case TCA_PEDIT_KEY_EX_CMD_ADD: 508 entry->id = FLOW_ACTION_ADD; 509 break; 510 default: 511 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 512 return -EOPNOTSUPP; 513 } 514 entry->mangle.htype = tcf_pedit_htype(act, k); 515 entry->mangle.mask = tcf_pedit_mask(act, k); 516 entry->mangle.val = tcf_pedit_val(act, k); 517 entry->mangle.offset = tcf_pedit_offset(act, k); 518 entry->hw_stats = tc_act_hw_stats(act->hw_stats); 519 entry++; 520 } 521 *index_inc = k; 522 } else { 523 return -EOPNOTSUPP; 524 } 525 526 return 0; 527 } 528 529 static struct tc_action_ops act_pedit_ops = { 530 .kind = "pedit", 531 .id = TCA_ID_PEDIT, 532 .owner = THIS_MODULE, 533 .act = tcf_pedit_act, 534 .stats_update = tcf_pedit_stats_update, 535 .dump = tcf_pedit_dump, 536 .cleanup = tcf_pedit_cleanup, 537 .init = tcf_pedit_init, 538 .offload_act_setup = tcf_pedit_offload_act_setup, 539 .size = sizeof(struct tcf_pedit), 540 }; 541 542 static __net_init int pedit_init_net(struct net *net) 543 { 544 struct tc_action_net *tn = net_generic(net, act_pedit_ops.net_id); 545 546 return tc_action_net_init(net, tn, &act_pedit_ops); 547 } 548 549 static void __net_exit pedit_exit_net(struct list_head *net_list) 550 { 551 tc_action_net_exit(net_list, act_pedit_ops.net_id); 552 } 553 554 static struct pernet_operations pedit_net_ops = { 555 .init = pedit_init_net, 556 .exit_batch = pedit_exit_net, 557 .id = &act_pedit_ops.net_id, 558 .size = sizeof(struct tc_action_net), 559 }; 560 561 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 562 MODULE_DESCRIPTION("Generic Packet Editor actions"); 563 MODULE_LICENSE("GPL"); 564 565 static int __init pedit_init_module(void) 566 { 567 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 568 } 569 570 static void __exit pedit_cleanup_module(void) 571 { 572 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 573 } 574 575 module_init(pedit_init_module); 576 module_exit(pedit_cleanup_module); 577