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; 152 153 if (!nla) { 154 NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed"); 155 return -EINVAL; 156 } 157 158 err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla, 159 pedit_policy, NULL); 160 if (err < 0) 161 return err; 162 163 pattr = tb[TCA_PEDIT_PARMS]; 164 if (!pattr) 165 pattr = tb[TCA_PEDIT_PARMS_EX]; 166 if (!pattr) { 167 NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute"); 168 return -EINVAL; 169 } 170 171 parm = nla_data(pattr); 172 ksize = parm->nkeys * sizeof(struct tc_pedit_key); 173 if (nla_len(pattr) < sizeof(*parm) + ksize) { 174 NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); 175 return -EINVAL; 176 } 177 178 keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); 179 if (IS_ERR(keys_ex)) 180 return PTR_ERR(keys_ex); 181 182 err = tcf_idr_check_alloc(tn, &parm->index, a, bind); 183 if (!err) { 184 if (!parm->nkeys) { 185 tcf_idr_cleanup(tn, parm->index); 186 NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); 187 ret = -EINVAL; 188 goto out_free; 189 } 190 ret = tcf_idr_create(tn, parm->index, est, a, 191 &act_pedit_ops, bind, false); 192 if (ret) { 193 tcf_idr_cleanup(tn, parm->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 (!ovr) { 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); 230 231 p->tcfp_flags = parm->flags; 232 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 233 234 kfree(p->tcfp_keys_ex); 235 p->tcfp_keys_ex = keys_ex; 236 237 spin_unlock_bh(&p->tcf_lock); 238 if (goto_ch) 239 tcf_chain_put_by_act(goto_ch); 240 if (ret == ACT_P_CREATED) 241 tcf_idr_insert(tn, *a); 242 return ret; 243 244 put_chain: 245 if (goto_ch) 246 tcf_chain_put_by_act(goto_ch); 247 out_release: 248 tcf_idr_release(*a, bind); 249 out_free: 250 kfree(keys_ex); 251 return ret; 252 253 } 254 255 static void tcf_pedit_cleanup(struct tc_action *a) 256 { 257 struct tcf_pedit *p = to_pedit(a); 258 struct tc_pedit_key *keys = p->tcfp_keys; 259 260 kfree(keys); 261 kfree(p->tcfp_keys_ex); 262 } 263 264 static bool offset_valid(struct sk_buff *skb, int offset) 265 { 266 if (offset > 0 && offset > skb->len) 267 return false; 268 269 if (offset < 0 && -offset > skb_headroom(skb)) 270 return false; 271 272 return true; 273 } 274 275 static int pedit_skb_hdr_offset(struct sk_buff *skb, 276 enum pedit_header_type htype, int *hoffset) 277 { 278 int ret = -EINVAL; 279 280 switch (htype) { 281 case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: 282 if (skb_mac_header_was_set(skb)) { 283 *hoffset = skb_mac_offset(skb); 284 ret = 0; 285 } 286 break; 287 case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: 288 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: 289 case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: 290 *hoffset = skb_network_offset(skb); 291 ret = 0; 292 break; 293 case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: 294 case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: 295 if (skb_transport_header_was_set(skb)) { 296 *hoffset = skb_transport_offset(skb); 297 ret = 0; 298 } 299 break; 300 default: 301 ret = -EINVAL; 302 break; 303 } 304 305 return ret; 306 } 307 308 static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, 309 struct tcf_result *res) 310 { 311 struct tcf_pedit *p = to_pedit(a); 312 int i; 313 314 if (skb_unclone(skb, GFP_ATOMIC)) 315 return p->tcf_action; 316 317 spin_lock(&p->tcf_lock); 318 319 tcf_lastuse_update(&p->tcf_tm); 320 321 if (p->tcfp_nkeys > 0) { 322 struct tc_pedit_key *tkey = p->tcfp_keys; 323 struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; 324 enum pedit_header_type htype = 325 TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; 326 enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; 327 328 for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { 329 u32 *ptr, hdata; 330 int offset = tkey->off; 331 int hoffset; 332 u32 val; 333 int rc; 334 335 if (tkey_ex) { 336 htype = tkey_ex->htype; 337 cmd = tkey_ex->cmd; 338 339 tkey_ex++; 340 } 341 342 rc = pedit_skb_hdr_offset(skb, htype, &hoffset); 343 if (rc) { 344 pr_info("tc action pedit bad header type specified (0x%x)\n", 345 htype); 346 goto bad; 347 } 348 349 if (tkey->offmask) { 350 u8 *d, _d; 351 352 if (!offset_valid(skb, hoffset + tkey->at)) { 353 pr_info("tc action pedit 'at' offset %d out of bounds\n", 354 hoffset + tkey->at); 355 goto bad; 356 } 357 d = skb_header_pointer(skb, hoffset + tkey->at, 358 sizeof(_d), &_d); 359 if (!d) 360 goto bad; 361 offset += (*d & tkey->offmask) >> tkey->shift; 362 } 363 364 if (offset % 4) { 365 pr_info("tc action pedit offset must be on 32 bit boundaries\n"); 366 goto bad; 367 } 368 369 if (!offset_valid(skb, hoffset + offset)) { 370 pr_info("tc action pedit offset %d out of bounds\n", 371 hoffset + offset); 372 goto bad; 373 } 374 375 ptr = skb_header_pointer(skb, hoffset + offset, 376 sizeof(hdata), &hdata); 377 if (!ptr) 378 goto bad; 379 /* just do it, baby */ 380 switch (cmd) { 381 case TCA_PEDIT_KEY_EX_CMD_SET: 382 val = tkey->val; 383 break; 384 case TCA_PEDIT_KEY_EX_CMD_ADD: 385 val = (*ptr + tkey->val) & ~tkey->mask; 386 break; 387 default: 388 pr_info("tc action pedit bad command (%d)\n", 389 cmd); 390 goto bad; 391 } 392 393 *ptr = ((*ptr & tkey->mask) ^ val); 394 if (ptr == &hdata) 395 skb_store_bits(skb, hoffset + offset, ptr, 4); 396 } 397 398 goto done; 399 } else { 400 WARN(1, "pedit BUG: index %d\n", p->tcf_index); 401 } 402 403 bad: 404 p->tcf_qstats.overlimits++; 405 done: 406 bstats_update(&p->tcf_bstats, skb); 407 spin_unlock(&p->tcf_lock); 408 return p->tcf_action; 409 } 410 411 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, 412 int bind, int ref) 413 { 414 unsigned char *b = skb_tail_pointer(skb); 415 struct tcf_pedit *p = to_pedit(a); 416 struct tc_pedit *opt; 417 struct tcf_t t; 418 int s; 419 420 s = struct_size(opt, keys, p->tcfp_nkeys); 421 422 /* netlink spinlocks held above us - must use ATOMIC */ 423 opt = kzalloc(s, GFP_ATOMIC); 424 if (unlikely(!opt)) 425 return -ENOBUFS; 426 427 spin_lock_bh(&p->tcf_lock); 428 memcpy(opt->keys, p->tcfp_keys, 429 p->tcfp_nkeys * sizeof(struct tc_pedit_key)); 430 opt->index = p->tcf_index; 431 opt->nkeys = p->tcfp_nkeys; 432 opt->flags = p->tcfp_flags; 433 opt->action = p->tcf_action; 434 opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; 435 opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; 436 437 if (p->tcfp_keys_ex) { 438 if (tcf_pedit_key_ex_dump(skb, 439 p->tcfp_keys_ex, 440 p->tcfp_nkeys)) 441 goto nla_put_failure; 442 443 if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) 444 goto nla_put_failure; 445 } else { 446 if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) 447 goto nla_put_failure; 448 } 449 450 tcf_tm_dump(&t, &p->tcf_tm); 451 if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) 452 goto nla_put_failure; 453 spin_unlock_bh(&p->tcf_lock); 454 455 kfree(opt); 456 return skb->len; 457 458 nla_put_failure: 459 spin_unlock_bh(&p->tcf_lock); 460 nlmsg_trim(skb, b); 461 kfree(opt); 462 return -1; 463 } 464 465 static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, 466 struct netlink_callback *cb, int type, 467 const struct tc_action_ops *ops, 468 struct netlink_ext_ack *extack) 469 { 470 struct tc_action_net *tn = net_generic(net, pedit_net_id); 471 472 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 473 } 474 475 static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) 476 { 477 struct tc_action_net *tn = net_generic(net, pedit_net_id); 478 479 return tcf_idr_search(tn, a, index); 480 } 481 482 static struct tc_action_ops act_pedit_ops = { 483 .kind = "pedit", 484 .id = TCA_ID_PEDIT, 485 .owner = THIS_MODULE, 486 .act = tcf_pedit_act, 487 .dump = tcf_pedit_dump, 488 .cleanup = tcf_pedit_cleanup, 489 .init = tcf_pedit_init, 490 .walk = tcf_pedit_walker, 491 .lookup = tcf_pedit_search, 492 .size = sizeof(struct tcf_pedit), 493 }; 494 495 static __net_init int pedit_init_net(struct net *net) 496 { 497 struct tc_action_net *tn = net_generic(net, pedit_net_id); 498 499 return tc_action_net_init(tn, &act_pedit_ops); 500 } 501 502 static void __net_exit pedit_exit_net(struct list_head *net_list) 503 { 504 tc_action_net_exit(net_list, pedit_net_id); 505 } 506 507 static struct pernet_operations pedit_net_ops = { 508 .init = pedit_init_net, 509 .exit_batch = pedit_exit_net, 510 .id = &pedit_net_id, 511 .size = sizeof(struct tc_action_net), 512 }; 513 514 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); 515 MODULE_DESCRIPTION("Generic Packet Editor actions"); 516 MODULE_LICENSE("GPL"); 517 518 static int __init pedit_init_module(void) 519 { 520 return tcf_register_action(&act_pedit_ops, &pedit_net_ops); 521 } 522 523 static void __exit pedit_cleanup_module(void) 524 { 525 tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); 526 } 527 528 module_init(pedit_init_module); 529 module_exit(pedit_cleanup_module); 530