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 || !n) 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, struct netlink_ext_ack *extack) 141 { 142 struct tc_action_net *tn = net_generic(net, pedit_net_id); 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 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 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 174 if (nla_len(pattr) < sizeof(*parm) + ksize) { 175 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); 176 return -EINVAL; 177 } 178 179 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); 180 if (IS_ERR(keys_ex)) 181 return PTR_ERR(keys_ex); 182 183 index = parm->index; 184 err = tcf_idr_check_alloc(tn, &index, a, bind); 185 if (!err) { 186 if (!parm->nkeys) { 187 tcf_idr_cleanup(tn, index); 188 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); 189 ret = -EINVAL; 190 goto out_free; 191 } 192 ret = tcf_idr_create(tn, index, est, a, 193 &act_pedit_ops, bind, false); 194 if (ret) { 195 tcf_idr_cleanup(tn, index); 196 goto out_free; 197 } 198 ret = ACT_P_CREATED; 199 } else if (err > 0) { 200 if (bind) 201 goto out_free; 202 if (!ovr) { 203 ret = -EEXIST; 204 goto out_release; 205 } 206 } else { 207 ret = err; 208 goto out_free; 209 } 210 211 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 212 if (err < 0) { 213 ret = err; 214 goto out_release; 215 } 216 p = to_pedit(*a); 217 spin_lock_bh(&p->tcf_lock); 218 219 if (ret == ACT_P_CREATED || 220 (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) { 221 keys = kmalloc(ksize, GFP_ATOMIC); 222 if (!keys) { 223 spin_unlock_bh(&p->tcf_lock); 224 ret = -ENOMEM; 225 goto put_chain; 226 } 227 kfree(p->tcfp_keys); 228 p->tcfp_keys = keys; 229 p->tcfp_nkeys = parm->nkeys; 230 } 231 memcpy(p->tcfp_keys, parm->keys, ksize); 232 233 p->tcfp_flags = parm->flags; 234 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 235 236 kfree(p->tcfp_keys_ex); 237 p->tcfp_keys_ex = keys_ex; 238 239 spin_unlock_bh(&p->tcf_lock); 240 if (goto_ch) 241 tcf_chain_put_by_act(goto_ch); 242 if (ret == ACT_P_CREATED) 243 tcf_idr_insert(tn, *a); 244 return ret; 245 246 put_chain: 247 if (goto_ch) 248 tcf_chain_put_by_act(goto_ch); 249 out_release: 250 tcf_idr_release(*a, bind); 251 out_free: 252 kfree(keys_ex); 253 return ret; 254 255 } 256 257 static void tcf_pedit_cleanup(struct tc_action *a) 258 { 259 struct tcf_pedit *p = to_pedit(a); 260 struct tc_pedit_key *keys = p->tcfp_keys; 261 262 kfree(keys); 263 kfree(p->tcfp_keys_ex); 264 } 265 266 static bool offset_valid(struct sk_buff *skb, int offset) 267 { 268 if (offset > 0 && offset > skb->len) 269 return false; 270 271 if (offset < 0 && -offset > skb_headroom(skb)) 272 return false; 273 274 return true; 275 } 276 277 static int pedit_skb_hdr_offset(struct sk_buff *skb, 278 enum pedit_header_type htype, int *hoffset) 279 { 280 int ret = -EINVAL; 281 282 switch (htype) { 283 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 284 if (skb_mac_header_was_set(skb)) { 285 *hoffset = skb_mac_offset(skb); 286 ret = 0; 287 } 288 break; 289 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 290 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 291 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 292 *hoffset = skb_network_offset(skb); 293 ret = 0; 294 break; 295 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 296 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 297 if (skb_transport_header_was_set(skb)) { 298 *hoffset = skb_transport_offset(skb); 299 ret = 0; 300 } 301 break; 302 default: 303 ret = -EINVAL; 304 break; 305 } 306 307 return ret; 308 } 309 310 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 311 struct tcf_result *res) 312 { 313 struct tcf_pedit *p = to_pedit(a); 314 int i; 315 316 if (skb_unclone(skb, GFP_ATOMIC)) 317 return p->tcf_action; 318 319 spin_lock(&p->tcf_lock); 320 321 tcf_lastuse_update(&p->tcf_tm); 322 323 if (p->tcfp_nkeys > 0) { 324 struct tc_pedit_key *tkey = p->tcfp_keys; 325 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 326 enum pedit_header_type htype = 327 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 328 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 329 330 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 331 u32 *ptr, hdata; 332 int offset = tkey->off; 333 int hoffset; 334 u32 val; 335 int rc; 336 337 if (tkey_ex) { 338 htype = tkey_ex->htype; 339 cmd = tkey_ex->cmd; 340 341 tkey_ex++; 342 } 343 344 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 345 if (rc) { 346 pr_info("tc action pedit bad header type specified (0x%x)\n", 347 htype); 348 goto bad; 349 } 350 351 if (tkey->offmask) { 352 u8 *d, _d; 353 354 if (!offset_valid(skb, hoffset + tkey->at)) { 355 pr_info("tc action pedit 'at' offset %d out of bounds\n", 356 hoffset + tkey->at); 357 goto bad; 358 } 359 d = skb_header_pointer(skb, hoffset + tkey->at, 360 sizeof(_d), &_d); 361 if (!d) 362 goto bad; 363 offset += (*d & tkey->offmask) >> tkey->shift; 364 } 365 366 if (offset % 4) { 367 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 368 goto bad; 369 } 370 371 if (!offset_valid(skb, hoffset + offset)) { 372 pr_info("tc action pedit offset %d out of bounds\n", 373 hoffset + offset); 374 goto bad; 375 } 376 377 ptr = skb_header_pointer(skb, hoffset + offset, 378 sizeof(hdata), &hdata); 379 if (!ptr) 380 goto bad; 381 /* just do it, baby */ 382 switch (cmd) { 383 case TCA_PEDIT_KEY_EX_CMD_SET: 384 val = tkey->val; 385 break; 386 case TCA_PEDIT_KEY_EX_CMD_ADD: 387 val = (*ptr + tkey->val) & ~tkey->mask; 388 break; 389 default: 390 pr_info("tc action pedit bad command (%d)\n", 391 cmd); 392 goto bad; 393 } 394 395 *ptr = ((*ptr & tkey->mask) ^ val); 396 if (ptr == &hdata) 397 skb_store_bits(skb, hoffset + offset, ptr, 4); 398 } 399 400 goto done; 401 } else { 402 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 403 } 404 405 bad: 406 p->tcf_qstats.overlimits++; 407 done: 408 bstats_update(&p->tcf_bstats, skb); 409 spin_unlock(&p->tcf_lock); 410 return p->tcf_action; 411 } 412 413 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 414 int bind, int ref) 415 { 416 unsigned char *b = skb_tail_pointer(skb); 417 struct tcf_pedit *p = to_pedit(a); 418 struct tc_pedit *opt; 419 struct tcf_t t; 420 int s; 421 422 s = struct_size(opt, keys, p->tcfp_nkeys); 423 424 /* netlink spinlocks held above us - must use ATOMIC */ 425 opt = kzalloc(s, GFP_ATOMIC); 426 if (unlikely(!opt)) 427 return -ENOBUFS; 428 429 spin_lock_bh(&p->tcf_lock); 430 memcpy(opt->keys, p->tcfp_keys, 431 p->tcfp_nkeys * sizeof(struct tc_pedit_key)); 432 opt->index = p->tcf_index; 433 opt->nkeys = p->tcfp_nkeys; 434 opt->flags = p->tcfp_flags; 435 opt->action = p->tcf_action; 436 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 437 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 438 439 if (p->tcfp_keys_ex) { 440 if (tcf_pedit_key_ex_dump(skb, 441 p->tcfp_keys_ex, 442 p->tcfp_nkeys)) 443 goto nla_put_failure; 444 445 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 446 goto nla_put_failure; 447 } else { 448 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 449 goto nla_put_failure; 450 } 451 452 tcf_tm_dump(&t, &p->tcf_tm); 453 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 454 goto nla_put_failure; 455 spin_unlock_bh(&p->tcf_lock); 456 457 kfree(opt); 458 return skb->len; 459 460 nla_put_failure: 461 spin_unlock_bh(&p->tcf_lock); 462 nlmsg_trim(skb, b); 463 kfree(opt); 464 return -1; 465 } 466 467 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 468 struct netlink_callback *cb, int type, 469 const struct tc_action_ops *ops, 470 struct netlink_ext_ack *extack) 471 { 472 struct tc_action_net *tn = net_generic(net, pedit_net_id); 473 474 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 475 } 476 477 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 478 { 479 struct tc_action_net *tn = net_generic(net, pedit_net_id); 480 481 return tcf_idr_search(tn, a, index); 482 } 483 484 static struct tc_action_ops act_pedit_ops = { 485 .kind = "pedit", 486 .id = TCA_ID_PEDIT, 487 .owner = THIS_MODULE, 488 .act = tcf_pedit_act, 489 .dump = tcf_pedit_dump, 490 .cleanup = tcf_pedit_cleanup, 491 .init = tcf_pedit_init, 492 .walk = tcf_pedit_walker, 493 .lookup = tcf_pedit_search, 494 .size = sizeof(struct tcf_pedit), 495 }; 496 497 static __net_init int pedit_init_net(struct net *net) 498 { 499 struct tc_action_net *tn = net_generic(net, pedit_net_id); 500 501 return tc_action_net_init(net, tn, &act_pedit_ops); 502 } 503 504 static void __net_exit pedit_exit_net(struct list_head *net_list) 505 { 506 tc_action_net_exit(net_list, pedit_net_id); 507 } 508 509 static struct pernet_operations pedit_net_ops = { 510 .init = pedit_init_net, 511 .exit_batch = pedit_exit_net, 512 .id = &pedit_net_id, 513 .size = sizeof(struct tc_action_net), 514 }; 515 516 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 517 MODULE_DESCRIPTION("Generic Packet Editor actions"); 518 MODULE_LICENSE("GPL"); 519 520 static int __init pedit_init_module(void) 521 { 522 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 523 } 524 525 static void __exit pedit_cleanup_module(void) 526 { 527 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 528 } 529 530 module_init(pedit_init_module); 531 module_exit(pedit_cleanup_module); 532