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 int ovr, int bind, bool rtnl_held, 140 struct tcf_proto *tp, u32 flags, 141 struct netlink_ext_ack *extack) 142 { 143 struct tc_action_net *tn = net_generic(net, pedit_net_id); 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, 0); 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 (!ovr) { 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 if (ret == ACT_P_CREATED) 242 tcf_idr_insert(tn, *a); 243 return ret; 244 245 put_chain: 246 if (goto_ch) 247 tcf_chain_put_by_act(goto_ch); 248 out_release: 249 tcf_idr_release(*a, bind); 250 out_free: 251 kfree(keys_ex); 252 return ret; 253 254 } 255 256 static void tcf_pedit_cleanup(struct tc_action *a) 257 { 258 struct tcf_pedit *p = to_pedit(a); 259 struct tc_pedit_key *keys = p->tcfp_keys; 260 261 kfree(keys); 262 kfree(p->tcfp_keys_ex); 263 } 264 265 static bool offset_valid(struct sk_buff *skb, int offset) 266 { 267 if (offset > 0 && offset > skb->len) 268 return false; 269 270 if (offset < 0 && -offset > skb_headroom(skb)) 271 return false; 272 273 return true; 274 } 275 276 static int pedit_skb_hdr_offset(struct sk_buff *skb, 277 enum pedit_header_type htype, int *hoffset) 278 { 279 int ret = -EINVAL; 280 281 switch (htype) { 282 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 283 if (skb_mac_header_was_set(skb)) { 284 *hoffset = skb_mac_offset(skb); 285 ret = 0; 286 } 287 break; 288 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 289 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 290 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 291 *hoffset = skb_network_offset(skb); 292 ret = 0; 293 break; 294 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 295 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 296 if (skb_transport_header_was_set(skb)) { 297 *hoffset = skb_transport_offset(skb); 298 ret = 0; 299 } 300 break; 301 default: 302 ret = -EINVAL; 303 break; 304 } 305 306 return ret; 307 } 308 309 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 310 struct tcf_result *res) 311 { 312 struct tcf_pedit *p = to_pedit(a); 313 int i; 314 315 if (skb_unclone(skb, GFP_ATOMIC)) 316 return p->tcf_action; 317 318 spin_lock(&p->tcf_lock); 319 320 tcf_lastuse_update(&p->tcf_tm); 321 322 if (p->tcfp_nkeys > 0) { 323 struct tc_pedit_key *tkey = p->tcfp_keys; 324 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 325 enum pedit_header_type htype = 326 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 327 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 328 329 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 330 u32 *ptr, hdata; 331 int offset = tkey->off; 332 int hoffset; 333 u32 val; 334 int rc; 335 336 if (tkey_ex) { 337 htype = tkey_ex->htype; 338 cmd = tkey_ex->cmd; 339 340 tkey_ex++; 341 } 342 343 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 344 if (rc) { 345 pr_info("tc action pedit bad header type specified (0x%x)\n", 346 htype); 347 goto bad; 348 } 349 350 if (tkey->offmask) { 351 u8 *d, _d; 352 353 if (!offset_valid(skb, hoffset + tkey->at)) { 354 pr_info("tc action pedit 'at' offset %d out of bounds\n", 355 hoffset + tkey->at); 356 goto bad; 357 } 358 d = skb_header_pointer(skb, hoffset + tkey->at, 359 sizeof(_d), &_d); 360 if (!d) 361 goto bad; 362 offset += (*d & tkey->offmask) >> tkey->shift; 363 } 364 365 if (offset % 4) { 366 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 367 goto bad; 368 } 369 370 if (!offset_valid(skb, hoffset + offset)) { 371 pr_info("tc action pedit offset %d out of bounds\n", 372 hoffset + offset); 373 goto bad; 374 } 375 376 ptr = skb_header_pointer(skb, hoffset + offset, 377 sizeof(hdata), &hdata); 378 if (!ptr) 379 goto bad; 380 /* just do it, baby */ 381 switch (cmd) { 382 case TCA_PEDIT_KEY_EX_CMD_SET: 383 val = tkey->val; 384 break; 385 case TCA_PEDIT_KEY_EX_CMD_ADD: 386 val = (*ptr + tkey->val) & ~tkey->mask; 387 break; 388 default: 389 pr_info("tc action pedit bad command (%d)\n", 390 cmd); 391 goto bad; 392 } 393 394 *ptr = ((*ptr & tkey->mask) ^ val); 395 if (ptr == &hdata) 396 skb_store_bits(skb, hoffset + offset, ptr, 4); 397 } 398 399 goto done; 400 } else { 401 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 402 } 403 404 bad: 405 p->tcf_qstats.overlimits++; 406 done: 407 bstats_update(&p->tcf_bstats, skb); 408 spin_unlock(&p->tcf_lock); 409 return p->tcf_action; 410 } 411 412 static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, 413 u64 drops, u64 lastuse, bool hw) 414 { 415 struct tcf_pedit *d = to_pedit(a); 416 struct tcf_t *tm = &d->tcf_tm; 417 418 tcf_action_update_stats(a, bytes, packets, drops, hw); 419 tm->lastuse = max_t(u64, tm->lastuse, lastuse); 420 } 421 422 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 423 int bind, int ref) 424 { 425 unsigned char *b = skb_tail_pointer(skb); 426 struct tcf_pedit *p = to_pedit(a); 427 struct tc_pedit *opt; 428 struct tcf_t t; 429 int s; 430 431 s = struct_size(opt, keys, p->tcfp_nkeys); 432 433 /* netlink spinlocks held above us - must use ATOMIC */ 434 opt = kzalloc(s, GFP_ATOMIC); 435 if (unlikely(!opt)) 436 return -ENOBUFS; 437 438 spin_lock_bh(&p->tcf_lock); 439 memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); 440 opt->index = p->tcf_index; 441 opt->nkeys = p->tcfp_nkeys; 442 opt->flags = p->tcfp_flags; 443 opt->action = p->tcf_action; 444 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 445 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 446 447 if (p->tcfp_keys_ex) { 448 if (tcf_pedit_key_ex_dump(skb, 449 p->tcfp_keys_ex, 450 p->tcfp_nkeys)) 451 goto nla_put_failure; 452 453 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 454 goto nla_put_failure; 455 } else { 456 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 457 goto nla_put_failure; 458 } 459 460 tcf_tm_dump(&t, &p->tcf_tm); 461 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 462 goto nla_put_failure; 463 spin_unlock_bh(&p->tcf_lock); 464 465 kfree(opt); 466 return skb->len; 467 468 nla_put_failure: 469 spin_unlock_bh(&p->tcf_lock); 470 nlmsg_trim(skb, b); 471 kfree(opt); 472 return -1; 473 } 474 475 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 476 struct netlink_callback *cb, int type, 477 const struct tc_action_ops *ops, 478 struct netlink_ext_ack *extack) 479 { 480 struct tc_action_net *tn = net_generic(net, pedit_net_id); 481 482 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 483 } 484 485 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 486 { 487 struct tc_action_net *tn = net_generic(net, pedit_net_id); 488 489 return tcf_idr_search(tn, a, index); 490 } 491 492 static struct tc_action_ops act_pedit_ops = { 493 .kind = "pedit", 494 .id = TCA_ID_PEDIT, 495 .owner = THIS_MODULE, 496 .act = tcf_pedit_act, 497 .stats_update = tcf_pedit_stats_update, 498 .dump = tcf_pedit_dump, 499 .cleanup = tcf_pedit_cleanup, 500 .init = tcf_pedit_init, 501 .walk = tcf_pedit_walker, 502 .lookup = tcf_pedit_search, 503 .size = sizeof(struct tcf_pedit), 504 }; 505 506 static __net_init int pedit_init_net(struct net *net) 507 { 508 struct tc_action_net *tn = net_generic(net, pedit_net_id); 509 510 return tc_action_net_init(net, tn, &act_pedit_ops); 511 } 512 513 static void __net_exit pedit_exit_net(struct list_head *net_list) 514 { 515 tc_action_net_exit(net_list, pedit_net_id); 516 } 517 518 static struct pernet_operations pedit_net_ops = { 519 .init = pedit_init_net, 520 .exit_batch = pedit_exit_net, 521 .id = &pedit_net_id, 522 .size = sizeof(struct tc_action_net), 523 }; 524 525 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 526 MODULE_DESCRIPTION("Generic Packet Editor actions"); 527 MODULE_LICENSE("GPL"); 528 529 static int __init pedit_init_module(void) 530 { 531 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 532 } 533 534 static void __exit pedit_cleanup_module(void) 535 { 536 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 537 } 538 539 module_init(pedit_init_module); 540 module_exit(pedit_cleanup_module); 541