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 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); 231 232 p->tcfp_flags = parm->flags; 233 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 234 235 kfree(p->tcfp_keys_ex); 236 p->tcfp_keys_ex = keys_ex; 237 238 spin_unlock_bh(&p->tcf_lock); 239 if (goto_ch) 240 tcf_chain_put_by_act(goto_ch); 241 return ret; 242 243 put_chain: 244 if (goto_ch) 245 tcf_chain_put_by_act(goto_ch); 246 out_release: 247 tcf_idr_release(*a, bind); 248 out_free: 249 kfree(keys_ex); 250 return ret; 251 252 } 253 254 static void tcf_pedit_cleanup(struct tc_action *a) 255 { 256 struct tcf_pedit *p = to_pedit(a); 257 struct tc_pedit_key *keys = p->tcfp_keys; 258 259 kfree(keys); 260 kfree(p->tcfp_keys_ex); 261 } 262 263 static bool offset_valid(struct sk_buff *skb, int offset) 264 { 265 if (offset > 0 && offset > skb->len) 266 return false; 267 268 if (offset < 0 && -offset > skb_headroom(skb)) 269 return false; 270 271 return true; 272 } 273 274 static int pedit_skb_hdr_offset(struct sk_buff *skb, 275 enum pedit_header_type htype, int *hoffset) 276 { 277 int ret = -EINVAL; 278 279 switch (htype) { 280 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 281 if (skb_mac_header_was_set(skb)) { 282 *hoffset = skb_mac_offset(skb); 283 ret = 0; 284 } 285 break; 286 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 287 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 288 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 289 *hoffset = skb_network_offset(skb); 290 ret = 0; 291 break; 292 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 293 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 294 if (skb_transport_header_was_set(skb)) { 295 *hoffset = skb_transport_offset(skb); 296 ret = 0; 297 } 298 break; 299 default: 300 ret = -EINVAL; 301 break; 302 } 303 304 return ret; 305 } 306 307 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 308 struct tcf_result *res) 309 { 310 struct tcf_pedit *p = to_pedit(a); 311 int i; 312 313 if (skb_unclone(skb, GFP_ATOMIC)) 314 return p->tcf_action; 315 316 spin_lock(&p->tcf_lock); 317 318 tcf_lastuse_update(&p->tcf_tm); 319 320 if (p->tcfp_nkeys > 0) { 321 struct tc_pedit_key *tkey = p->tcfp_keys; 322 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 323 enum pedit_header_type htype = 324 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 325 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 326 327 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 328 u32 *ptr, hdata; 329 int offset = tkey->off; 330 int hoffset; 331 u32 val; 332 int rc; 333 334 if (tkey_ex) { 335 htype = tkey_ex->htype; 336 cmd = tkey_ex->cmd; 337 338 tkey_ex++; 339 } 340 341 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 342 if (rc) { 343 pr_info("tc action pedit bad header type specified (0x%x)\n", 344 htype); 345 goto bad; 346 } 347 348 if (tkey->offmask) { 349 u8 *d, _d; 350 351 if (!offset_valid(skb, hoffset + tkey->at)) { 352 pr_info("tc action pedit 'at' offset %d out of bounds\n", 353 hoffset + tkey->at); 354 goto bad; 355 } 356 d = skb_header_pointer(skb, hoffset + tkey->at, 357 sizeof(_d), &_d); 358 if (!d) 359 goto bad; 360 offset += (*d & tkey->offmask) >> tkey->shift; 361 } 362 363 if (offset % 4) { 364 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 365 goto bad; 366 } 367 368 if (!offset_valid(skb, hoffset + offset)) { 369 pr_info("tc action pedit offset %d out of bounds\n", 370 hoffset + offset); 371 goto bad; 372 } 373 374 ptr = skb_header_pointer(skb, hoffset + offset, 375 sizeof(hdata), &hdata); 376 if (!ptr) 377 goto bad; 378 /* just do it, baby */ 379 switch (cmd) { 380 case TCA_PEDIT_KEY_EX_CMD_SET: 381 val = tkey->val; 382 break; 383 case TCA_PEDIT_KEY_EX_CMD_ADD: 384 val = (*ptr + tkey->val) & ~tkey->mask; 385 break; 386 default: 387 pr_info("tc action pedit bad command (%d)\n", 388 cmd); 389 goto bad; 390 } 391 392 *ptr = ((*ptr & tkey->mask) ^ val); 393 if (ptr == &hdata) 394 skb_store_bits(skb, hoffset + offset, ptr, 4); 395 } 396 397 goto done; 398 } else { 399 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 400 } 401 402 bad: 403 p->tcf_qstats.overlimits++; 404 done: 405 bstats_update(&p->tcf_bstats, skb); 406 spin_unlock(&p->tcf_lock); 407 return p->tcf_action; 408 } 409 410 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 411 u64 drops, u64 lastuse, bool hw) 412 { 413 struct tcf_pedit *d = to_pedit(a); 414 struct tcf_t *tm = &d->tcf_tm; 415 416 tcf_action_update_stats(a, bytes, packets, drops, hw); 417 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 418 } 419 420 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 421 int bind, int ref) 422 { 423 unsigned char *b = skb_tail_pointer(skb); 424 struct tcf_pedit *p = to_pedit(a); 425 struct tc_pedit *opt; 426 struct tcf_t t; 427 int s; 428 429 s = struct_size(opt, keys, p->tcfp_nkeys); 430 431 /* netlink spinlocks held above us - must use ATOMIC */ 432 opt = kzalloc(s, GFP_ATOMIC); 433 if (unlikely(!opt)) 434 return -ENOBUFS; 435 436 spin_lock_bh(&p->tcf_lock); 437 memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); 438 opt->index = p->tcf_index; 439 opt->nkeys = p->tcfp_nkeys; 440 opt->flags = p->tcfp_flags; 441 opt->action = p->tcf_action; 442 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 443 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 444 445 if (p->tcfp_keys_ex) { 446 if (tcf_pedit_key_ex_dump(skb, 447 p->tcfp_keys_ex, 448 p->tcfp_nkeys)) 449 goto nla_put_failure; 450 451 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 452 goto nla_put_failure; 453 } else { 454 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 455 goto nla_put_failure; 456 } 457 458 tcf_tm_dump(&t, &p->tcf_tm); 459 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 460 goto nla_put_failure; 461 spin_unlock_bh(&p->tcf_lock); 462 463 kfree(opt); 464 return skb->len; 465 466 nla_put_failure: 467 spin_unlock_bh(&p->tcf_lock); 468 nlmsg_trim(skb, b); 469 kfree(opt); 470 return -1; 471 } 472 473 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 474 struct netlink_callback *cb, int type, 475 const struct tc_action_ops *ops, 476 struct netlink_ext_ack *extack) 477 { 478 struct tc_action_net *tn = net_generic(net, pedit_net_id); 479 480 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 481 } 482 483 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 484 { 485 struct tc_action_net *tn = net_generic(net, pedit_net_id); 486 487 return tcf_idr_search(tn, a, index); 488 } 489 490 static int tcf_pedit_offload_act_setup(struct tc_action *act, void *entry_data, 491 u32 *index_inc, bool bind, 492 struct netlink_ext_ack *extack) 493 { 494 if (bind) { 495 struct flow_action_entry *entry = entry_data; 496 int k; 497 498 for (k = 0; k < tcf_pedit_nkeys(act); k++) { 499 switch (tcf_pedit_cmd(act, k)) { 500 case TCA_PEDIT_KEY_EX_CMD_SET: 501 entry->id = FLOW_ACTION_MANGLE; 502 break; 503 case TCA_PEDIT_KEY_EX_CMD_ADD: 504 entry->id = FLOW_ACTION_ADD; 505 break; 506 default: 507 NL_SET_ERR_MSG_MOD(extack, "Unsupported pedit command offload"); 508 return -EOPNOTSUPP; 509 } 510 entry->mangle.htype = tcf_pedit_htype(act, k); 511 entry->mangle.mask = tcf_pedit_mask(act, k); 512 entry->mangle.val = tcf_pedit_val(act, k); 513 entry->mangle.offset = tcf_pedit_offset(act, k); 514 entry->hw_stats = tc_act_hw_stats(act->hw_stats); 515 entry++; 516 } 517 *index_inc = k; 518 } else { 519 return -EOPNOTSUPP; 520 } 521 522 return 0; 523 } 524 525 static struct tc_action_ops act_pedit_ops = { 526 .kind = "pedit", 527 .id = TCA_ID_PEDIT, 528 .owner = THIS_MODULE, 529 .act = tcf_pedit_act, 530 .stats_update = tcf_pedit_stats_update, 531 .dump = tcf_pedit_dump, 532 .cleanup = tcf_pedit_cleanup, 533 .init = tcf_pedit_init, 534 .walk = tcf_pedit_walker, 535 .lookup = tcf_pedit_search, 536 .offload_act_setup = tcf_pedit_offload_act_setup, 537 .size = sizeof(struct tcf_pedit), 538 }; 539 540 static __net_init int pedit_init_net(struct net *net) 541 { 542 struct tc_action_net *tn = net_generic(net, pedit_net_id); 543 544 return tc_action_net_init(net, tn, &act_pedit_ops); 545 } 546 547 static void __net_exit pedit_exit_net(struct list_head *net_list) 548 { 549 tc_action_net_exit(net_list, pedit_net_id); 550 } 551 552 static struct pernet_operations pedit_net_ops = { 553 .init = pedit_init_net, 554 .exit_batch = pedit_exit_net, 555 .id = &pedit_net_id, 556 .size = sizeof(struct tc_action_net), 557 }; 558 559 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 560 MODULE_DESCRIPTION("Generic Packet Editor actions"); 561 MODULE_LICENSE("GPL"); 562 563 static int __init pedit_init_module(void) 564 { 565 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 566 } 567 568 static void __exit pedit_cleanup_module(void) 569 { 570 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 571 } 572 573 module_init(pedit_init_module); 574 module_exit(pedit_cleanup_module); 575