1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 /* Copyright (C) 2019 Netronome Systems, Inc. */ 3 4 #include <linux/if_arp.h> 5 #include <linux/init.h> 6 #include <linux/kernel.h> 7 #include <linux/module.h> 8 #include <linux/mpls.h> 9 #include <linux/rtnetlink.h> 10 #include <linux/skbuff.h> 11 #include <linux/tc_act/tc_mpls.h> 12 #include <net/mpls.h> 13 #include <net/netlink.h> 14 #include <net/pkt_sched.h> 15 #include <net/pkt_cls.h> 16 #include <net/tc_act/tc_mpls.h> 17 #include <net/tc_wrapper.h> 18 19 static struct tc_action_ops act_mpls_ops; 20 21 #define ACT_MPLS_TTL_DEFAULT 255 22 23 static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse, 24 struct tcf_mpls_params *p, bool set_bos) 25 { 26 u32 new_lse = 0; 27 28 if (lse) 29 new_lse = be32_to_cpu(lse->label_stack_entry); 30 31 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) { 32 new_lse &= ~MPLS_LS_LABEL_MASK; 33 new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT; 34 } 35 if (p->tcfm_ttl) { 36 new_lse &= ~MPLS_LS_TTL_MASK; 37 new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT; 38 } 39 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) { 40 new_lse &= ~MPLS_LS_TC_MASK; 41 new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT; 42 } 43 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) { 44 new_lse &= ~MPLS_LS_S_MASK; 45 new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT; 46 } else if (set_bos) { 47 new_lse |= 1 << MPLS_LS_S_SHIFT; 48 } 49 50 return cpu_to_be32(new_lse); 51 } 52 53 TC_INDIRECT_SCOPE int tcf_mpls_act(struct sk_buff *skb, 54 const struct tc_action *a, 55 struct tcf_result *res) 56 { 57 struct tcf_mpls *m = to_mpls(a); 58 struct tcf_mpls_params *p; 59 __be32 new_lse; 60 int ret, mac_len; 61 62 tcf_lastuse_update(&m->tcf_tm); 63 bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb); 64 65 /* Ensure 'data' points at mac_header prior calling mpls manipulating 66 * functions. 67 */ 68 if (skb_at_tc_ingress(skb)) { 69 skb_push_rcsum(skb, skb->mac_len); 70 mac_len = skb->mac_len; 71 } else { 72 mac_len = skb_network_offset(skb); 73 } 74 75 ret = READ_ONCE(m->tcf_action); 76 77 p = rcu_dereference_bh(m->mpls_p); 78 79 switch (p->tcfm_action) { 80 case TCA_MPLS_ACT_POP: 81 if (skb_mpls_pop(skb, p->tcfm_proto, mac_len, 82 skb->dev && skb->dev->type == ARPHRD_ETHER)) 83 goto drop; 84 break; 85 case TCA_MPLS_ACT_PUSH: 86 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true))); 87 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len, 88 skb->dev && skb->dev->type == ARPHRD_ETHER)) 89 goto drop; 90 break; 91 case TCA_MPLS_ACT_MAC_PUSH: 92 if (skb_vlan_tag_present(skb)) { 93 if (__vlan_insert_inner_tag(skb, skb->vlan_proto, 94 skb_vlan_tag_get(skb), 95 ETH_HLEN) < 0) 96 goto drop; 97 98 skb->protocol = skb->vlan_proto; 99 __vlan_hwaccel_clear_tag(skb); 100 } 101 102 new_lse = tcf_mpls_get_lse(NULL, p, mac_len || 103 !eth_p_mpls(skb->protocol)); 104 105 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false)) 106 goto drop; 107 break; 108 case TCA_MPLS_ACT_MODIFY: 109 if (!pskb_may_pull(skb, 110 skb_network_offset(skb) + MPLS_HLEN)) 111 goto drop; 112 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false); 113 if (skb_mpls_update_lse(skb, new_lse)) 114 goto drop; 115 break; 116 case TCA_MPLS_ACT_DEC_TTL: 117 if (skb_mpls_dec_ttl(skb)) 118 goto drop; 119 break; 120 } 121 122 if (skb_at_tc_ingress(skb)) 123 skb_pull_rcsum(skb, skb->mac_len); 124 125 return ret; 126 127 drop: 128 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats)); 129 return TC_ACT_SHOT; 130 } 131 132 static int valid_label(const struct nlattr *attr, 133 struct netlink_ext_ack *extack) 134 { 135 const u32 *label = nla_data(attr); 136 137 if (nla_len(attr) != sizeof(*label)) { 138 NL_SET_ERR_MSG_MOD(extack, "Invalid MPLS label length"); 139 return -EINVAL; 140 } 141 142 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) { 143 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range"); 144 return -EINVAL; 145 } 146 147 return 0; 148 } 149 150 static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = { 151 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)), 152 [TCA_MPLS_PROTO] = { .type = NLA_U16 }, 153 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_BINARY, 154 valid_label), 155 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7), 156 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1), 157 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1), 158 }; 159 160 static int tcf_mpls_init(struct net *net, struct nlattr *nla, 161 struct nlattr *est, struct tc_action **a, 162 struct tcf_proto *tp, u32 flags, 163 struct netlink_ext_ack *extack) 164 { 165 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id); 166 bool bind = flags & TCA_ACT_FLAGS_BIND; 167 struct nlattr *tb[TCA_MPLS_MAX + 1]; 168 struct tcf_chain *goto_ch = NULL; 169 struct tcf_mpls_params *p; 170 struct tc_mpls *parm; 171 bool exists = false; 172 struct tcf_mpls *m; 173 int ret = 0, err; 174 u8 mpls_ttl = 0; 175 u32 index; 176 177 if (!nla) { 178 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes"); 179 return -EINVAL; 180 } 181 182 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack); 183 if (err < 0) 184 return err; 185 186 if (!tb[TCA_MPLS_PARMS]) { 187 NL_SET_ERR_MSG_MOD(extack, "No MPLS params"); 188 return -EINVAL; 189 } 190 parm = nla_data(tb[TCA_MPLS_PARMS]); 191 index = parm->index; 192 193 err = tcf_idr_check_alloc(tn, &index, a, bind); 194 if (err < 0) 195 return err; 196 exists = err; 197 if (exists && bind) 198 return ACT_P_BOUND; 199 200 if (!exists) { 201 ret = tcf_idr_create(tn, index, est, a, &act_mpls_ops, bind, 202 true, flags); 203 if (ret) { 204 tcf_idr_cleanup(tn, index); 205 return ret; 206 } 207 208 ret = ACT_P_CREATED; 209 } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 210 tcf_idr_release(*a, bind); 211 return -EEXIST; 212 } 213 214 /* Verify parameters against action type. */ 215 switch (parm->m_action) { 216 case TCA_MPLS_ACT_POP: 217 if (!tb[TCA_MPLS_PROTO]) { 218 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop"); 219 err = -EINVAL; 220 goto release_idr; 221 } 222 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 223 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop"); 224 err = -EINVAL; 225 goto release_idr; 226 } 227 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || 228 tb[TCA_MPLS_BOS]) { 229 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop"); 230 err = -EINVAL; 231 goto release_idr; 232 } 233 break; 234 case TCA_MPLS_ACT_DEC_TTL: 235 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] || 236 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) { 237 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl"); 238 err = -EINVAL; 239 goto release_idr; 240 } 241 break; 242 case TCA_MPLS_ACT_PUSH: 243 case TCA_MPLS_ACT_MAC_PUSH: 244 if (!tb[TCA_MPLS_LABEL]) { 245 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push"); 246 err = -EINVAL; 247 goto release_idr; 248 } 249 if (tb[TCA_MPLS_PROTO] && 250 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 251 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push"); 252 err = -EPROTONOSUPPORT; 253 goto release_idr; 254 } 255 /* Push needs a TTL - if not specified, set a default value. */ 256 if (!tb[TCA_MPLS_TTL]) { 257 #if IS_ENABLED(CONFIG_MPLS) 258 mpls_ttl = net->mpls.default_ttl ? 259 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT; 260 #else 261 mpls_ttl = ACT_MPLS_TTL_DEFAULT; 262 #endif 263 } 264 break; 265 case TCA_MPLS_ACT_MODIFY: 266 if (tb[TCA_MPLS_PROTO]) { 267 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify"); 268 err = -EINVAL; 269 goto release_idr; 270 } 271 break; 272 default: 273 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action"); 274 err = -EINVAL; 275 goto release_idr; 276 } 277 278 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 279 if (err < 0) 280 goto release_idr; 281 282 m = to_mpls(*a); 283 284 p = kzalloc(sizeof(*p), GFP_KERNEL); 285 if (!p) { 286 err = -ENOMEM; 287 goto put_chain; 288 } 289 290 p->tcfm_action = parm->m_action; 291 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) : 292 ACT_MPLS_LABEL_NOT_SET; 293 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) : 294 ACT_MPLS_TC_NOT_SET; 295 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) : 296 mpls_ttl; 297 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) : 298 ACT_MPLS_BOS_NOT_SET; 299 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) : 300 htons(ETH_P_MPLS_UC); 301 302 spin_lock_bh(&m->tcf_lock); 303 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 304 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock)); 305 spin_unlock_bh(&m->tcf_lock); 306 307 if (goto_ch) 308 tcf_chain_put_by_act(goto_ch); 309 if (p) 310 kfree_rcu(p, rcu); 311 312 return ret; 313 put_chain: 314 if (goto_ch) 315 tcf_chain_put_by_act(goto_ch); 316 release_idr: 317 tcf_idr_release(*a, bind); 318 return err; 319 } 320 321 static void tcf_mpls_cleanup(struct tc_action *a) 322 { 323 struct tcf_mpls *m = to_mpls(a); 324 struct tcf_mpls_params *p; 325 326 p = rcu_dereference_protected(m->mpls_p, 1); 327 if (p) 328 kfree_rcu(p, rcu); 329 } 330 331 static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a, 332 int bind, int ref) 333 { 334 unsigned char *b = skb_tail_pointer(skb); 335 struct tcf_mpls *m = to_mpls(a); 336 struct tcf_mpls_params *p; 337 struct tc_mpls opt = { 338 .index = m->tcf_index, 339 .refcnt = refcount_read(&m->tcf_refcnt) - ref, 340 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind, 341 }; 342 struct tcf_t t; 343 344 spin_lock_bh(&m->tcf_lock); 345 opt.action = m->tcf_action; 346 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock)); 347 opt.m_action = p->tcfm_action; 348 349 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt)) 350 goto nla_put_failure; 351 352 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET && 353 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label)) 354 goto nla_put_failure; 355 356 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET && 357 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc)) 358 goto nla_put_failure; 359 360 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl)) 361 goto nla_put_failure; 362 363 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET && 364 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos)) 365 goto nla_put_failure; 366 367 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto)) 368 goto nla_put_failure; 369 370 tcf_tm_dump(&t, &m->tcf_tm); 371 372 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD)) 373 goto nla_put_failure; 374 375 spin_unlock_bh(&m->tcf_lock); 376 377 return skb->len; 378 379 nla_put_failure: 380 spin_unlock_bh(&m->tcf_lock); 381 nlmsg_trim(skb, b); 382 return -EMSGSIZE; 383 } 384 385 static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data, 386 u32 *index_inc, bool bind, 387 struct netlink_ext_ack *extack) 388 { 389 if (bind) { 390 struct flow_action_entry *entry = entry_data; 391 392 switch (tcf_mpls_action(act)) { 393 case TCA_MPLS_ACT_PUSH: 394 entry->id = FLOW_ACTION_MPLS_PUSH; 395 entry->mpls_push.proto = tcf_mpls_proto(act); 396 entry->mpls_push.label = tcf_mpls_label(act); 397 entry->mpls_push.tc = tcf_mpls_tc(act); 398 entry->mpls_push.bos = tcf_mpls_bos(act); 399 entry->mpls_push.ttl = tcf_mpls_ttl(act); 400 break; 401 case TCA_MPLS_ACT_POP: 402 entry->id = FLOW_ACTION_MPLS_POP; 403 entry->mpls_pop.proto = tcf_mpls_proto(act); 404 break; 405 case TCA_MPLS_ACT_MODIFY: 406 entry->id = FLOW_ACTION_MPLS_MANGLE; 407 entry->mpls_mangle.label = tcf_mpls_label(act); 408 entry->mpls_mangle.tc = tcf_mpls_tc(act); 409 entry->mpls_mangle.bos = tcf_mpls_bos(act); 410 entry->mpls_mangle.ttl = tcf_mpls_ttl(act); 411 break; 412 case TCA_MPLS_ACT_DEC_TTL: 413 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"dec_ttl\" option is used"); 414 return -EOPNOTSUPP; 415 case TCA_MPLS_ACT_MAC_PUSH: 416 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"mac_push\" option is used"); 417 return -EOPNOTSUPP; 418 default: 419 NL_SET_ERR_MSG_MOD(extack, "Unsupported MPLS mode offload"); 420 return -EOPNOTSUPP; 421 } 422 *index_inc = 1; 423 } else { 424 struct flow_offload_action *fl_action = entry_data; 425 426 switch (tcf_mpls_action(act)) { 427 case TCA_MPLS_ACT_PUSH: 428 fl_action->id = FLOW_ACTION_MPLS_PUSH; 429 break; 430 case TCA_MPLS_ACT_POP: 431 fl_action->id = FLOW_ACTION_MPLS_POP; 432 break; 433 case TCA_MPLS_ACT_MODIFY: 434 fl_action->id = FLOW_ACTION_MPLS_MANGLE; 435 break; 436 default: 437 return -EOPNOTSUPP; 438 } 439 } 440 441 return 0; 442 } 443 444 static struct tc_action_ops act_mpls_ops = { 445 .kind = "mpls", 446 .id = TCA_ID_MPLS, 447 .owner = THIS_MODULE, 448 .act = tcf_mpls_act, 449 .dump = tcf_mpls_dump, 450 .init = tcf_mpls_init, 451 .cleanup = tcf_mpls_cleanup, 452 .offload_act_setup = tcf_mpls_offload_act_setup, 453 .size = sizeof(struct tcf_mpls), 454 }; 455 MODULE_ALIAS_NET_ACT("mpls"); 456 457 static __net_init int mpls_init_net(struct net *net) 458 { 459 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id); 460 461 return tc_action_net_init(net, tn, &act_mpls_ops); 462 } 463 464 static void __net_exit mpls_exit_net(struct list_head *net_list) 465 { 466 tc_action_net_exit(net_list, act_mpls_ops.net_id); 467 } 468 469 static struct pernet_operations mpls_net_ops = { 470 .init = mpls_init_net, 471 .exit_batch = mpls_exit_net, 472 .id = &act_mpls_ops.net_id, 473 .size = sizeof(struct tc_action_net), 474 }; 475 476 static int __init mpls_init_module(void) 477 { 478 return tcf_register_action(&act_mpls_ops, &mpls_net_ops); 479 } 480 481 static void __exit mpls_cleanup_module(void) 482 { 483 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops); 484 } 485 486 module_init(mpls_init_module); 487 module_exit(mpls_cleanup_module); 488 489 MODULE_SOFTDEP("post: mpls_gso"); 490 MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>"); 491 MODULE_LICENSE("GPL"); 492 MODULE_DESCRIPTION("MPLS manipulation actions"); 493