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 18 static struct tc_action_ops act_mpls_ops; 19 20 #define ACT_MPLS_TTL_DEFAULT 255 21 22 static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse, 23 struct tcf_mpls_params *p, bool set_bos) 24 { 25 u32 new_lse = 0; 26 27 if (lse) 28 new_lse = be32_to_cpu(lse->label_stack_entry); 29 30 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) { 31 new_lse &= ~MPLS_LS_LABEL_MASK; 32 new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT; 33 } 34 if (p->tcfm_ttl) { 35 new_lse &= ~MPLS_LS_TTL_MASK; 36 new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT; 37 } 38 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) { 39 new_lse &= ~MPLS_LS_TC_MASK; 40 new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT; 41 } 42 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) { 43 new_lse &= ~MPLS_LS_S_MASK; 44 new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT; 45 } else if (set_bos) { 46 new_lse |= 1 << MPLS_LS_S_SHIFT; 47 } 48 49 return cpu_to_be32(new_lse); 50 } 51 52 static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a, 53 struct tcf_result *res) 54 { 55 struct tcf_mpls *m = to_mpls(a); 56 struct tcf_mpls_params *p; 57 __be32 new_lse; 58 int ret, mac_len; 59 60 tcf_lastuse_update(&m->tcf_tm); 61 bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb); 62 63 /* Ensure 'data' points at mac_header prior calling mpls manipulating 64 * functions. 65 */ 66 if (skb_at_tc_ingress(skb)) { 67 skb_push_rcsum(skb, skb->mac_len); 68 mac_len = skb->mac_len; 69 } else { 70 mac_len = skb_network_header(skb) - skb_mac_header(skb); 71 } 72 73 ret = READ_ONCE(m->tcf_action); 74 75 p = rcu_dereference_bh(m->mpls_p); 76 77 switch (p->tcfm_action) { 78 case TCA_MPLS_ACT_POP: 79 if (skb_mpls_pop(skb, p->tcfm_proto, mac_len, 80 skb->dev && skb->dev->type == ARPHRD_ETHER)) 81 goto drop; 82 break; 83 case TCA_MPLS_ACT_PUSH: 84 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true))); 85 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len, 86 skb->dev && skb->dev->type == ARPHRD_ETHER)) 87 goto drop; 88 break; 89 case TCA_MPLS_ACT_MAC_PUSH: 90 if (skb_vlan_tag_present(skb)) { 91 if (__vlan_insert_inner_tag(skb, skb->vlan_proto, 92 skb_vlan_tag_get(skb), 93 ETH_HLEN) < 0) 94 goto drop; 95 96 skb->protocol = skb->vlan_proto; 97 __vlan_hwaccel_clear_tag(skb); 98 } 99 100 new_lse = tcf_mpls_get_lse(NULL, p, mac_len || 101 !eth_p_mpls(skb->protocol)); 102 103 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false)) 104 goto drop; 105 break; 106 case TCA_MPLS_ACT_MODIFY: 107 if (!pskb_may_pull(skb, 108 skb_network_offset(skb) + MPLS_HLEN)) 109 goto drop; 110 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false); 111 if (skb_mpls_update_lse(skb, new_lse)) 112 goto drop; 113 break; 114 case TCA_MPLS_ACT_DEC_TTL: 115 if (skb_mpls_dec_ttl(skb)) 116 goto drop; 117 break; 118 } 119 120 if (skb_at_tc_ingress(skb)) 121 skb_pull_rcsum(skb, skb->mac_len); 122 123 return ret; 124 125 drop: 126 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats)); 127 return TC_ACT_SHOT; 128 } 129 130 static int valid_label(const struct nlattr *attr, 131 struct netlink_ext_ack *extack) 132 { 133 const u32 *label = nla_data(attr); 134 135 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) { 136 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range"); 137 return -EINVAL; 138 } 139 140 return 0; 141 } 142 143 static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = { 144 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)), 145 [TCA_MPLS_PROTO] = { .type = NLA_U16 }, 146 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label), 147 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7), 148 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1), 149 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1), 150 }; 151 152 static int tcf_mpls_init(struct net *net, struct nlattr *nla, 153 struct nlattr *est, struct tc_action **a, 154 struct tcf_proto *tp, u32 flags, 155 struct netlink_ext_ack *extack) 156 { 157 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id); 158 bool bind = flags & TCA_ACT_FLAGS_BIND; 159 struct nlattr *tb[TCA_MPLS_MAX + 1]; 160 struct tcf_chain *goto_ch = NULL; 161 struct tcf_mpls_params *p; 162 struct tc_mpls *parm; 163 bool exists = false; 164 struct tcf_mpls *m; 165 int ret = 0, err; 166 u8 mpls_ttl = 0; 167 u32 index; 168 169 if (!nla) { 170 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes"); 171 return -EINVAL; 172 } 173 174 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack); 175 if (err < 0) 176 return err; 177 178 if (!tb[TCA_MPLS_PARMS]) { 179 NL_SET_ERR_MSG_MOD(extack, "No MPLS params"); 180 return -EINVAL; 181 } 182 parm = nla_data(tb[TCA_MPLS_PARMS]); 183 index = parm->index; 184 185 /* Verify parameters against action type. */ 186 switch (parm->m_action) { 187 case TCA_MPLS_ACT_POP: 188 if (!tb[TCA_MPLS_PROTO]) { 189 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop"); 190 return -EINVAL; 191 } 192 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 193 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop"); 194 return -EINVAL; 195 } 196 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || 197 tb[TCA_MPLS_BOS]) { 198 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop"); 199 return -EINVAL; 200 } 201 break; 202 case TCA_MPLS_ACT_DEC_TTL: 203 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] || 204 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) { 205 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl"); 206 return -EINVAL; 207 } 208 break; 209 case TCA_MPLS_ACT_PUSH: 210 case TCA_MPLS_ACT_MAC_PUSH: 211 if (!tb[TCA_MPLS_LABEL]) { 212 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push"); 213 return -EINVAL; 214 } 215 if (tb[TCA_MPLS_PROTO] && 216 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 217 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push"); 218 return -EPROTONOSUPPORT; 219 } 220 /* Push needs a TTL - if not specified, set a default value. */ 221 if (!tb[TCA_MPLS_TTL]) { 222 #if IS_ENABLED(CONFIG_MPLS) 223 mpls_ttl = net->mpls.default_ttl ? 224 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT; 225 #else 226 mpls_ttl = ACT_MPLS_TTL_DEFAULT; 227 #endif 228 } 229 break; 230 case TCA_MPLS_ACT_MODIFY: 231 if (tb[TCA_MPLS_PROTO]) { 232 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify"); 233 return -EINVAL; 234 } 235 break; 236 default: 237 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action"); 238 return -EINVAL; 239 } 240 241 err = tcf_idr_check_alloc(tn, &index, a, bind); 242 if (err < 0) 243 return err; 244 exists = err; 245 if (exists && bind) 246 return 0; 247 248 if (!exists) { 249 ret = tcf_idr_create(tn, index, est, a, 250 &act_mpls_ops, bind, true, flags); 251 if (ret) { 252 tcf_idr_cleanup(tn, index); 253 return ret; 254 } 255 256 ret = ACT_P_CREATED; 257 } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) { 258 tcf_idr_release(*a, bind); 259 return -EEXIST; 260 } 261 262 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 263 if (err < 0) 264 goto release_idr; 265 266 m = to_mpls(*a); 267 268 p = kzalloc(sizeof(*p), GFP_KERNEL); 269 if (!p) { 270 err = -ENOMEM; 271 goto put_chain; 272 } 273 274 p->tcfm_action = parm->m_action; 275 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) : 276 ACT_MPLS_LABEL_NOT_SET; 277 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) : 278 ACT_MPLS_TC_NOT_SET; 279 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) : 280 mpls_ttl; 281 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) : 282 ACT_MPLS_BOS_NOT_SET; 283 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) : 284 htons(ETH_P_MPLS_UC); 285 286 spin_lock_bh(&m->tcf_lock); 287 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 288 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock)); 289 spin_unlock_bh(&m->tcf_lock); 290 291 if (goto_ch) 292 tcf_chain_put_by_act(goto_ch); 293 if (p) 294 kfree_rcu(p, rcu); 295 296 return ret; 297 put_chain: 298 if (goto_ch) 299 tcf_chain_put_by_act(goto_ch); 300 release_idr: 301 tcf_idr_release(*a, bind); 302 return err; 303 } 304 305 static void tcf_mpls_cleanup(struct tc_action *a) 306 { 307 struct tcf_mpls *m = to_mpls(a); 308 struct tcf_mpls_params *p; 309 310 p = rcu_dereference_protected(m->mpls_p, 1); 311 if (p) 312 kfree_rcu(p, rcu); 313 } 314 315 static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a, 316 int bind, int ref) 317 { 318 unsigned char *b = skb_tail_pointer(skb); 319 struct tcf_mpls *m = to_mpls(a); 320 struct tcf_mpls_params *p; 321 struct tc_mpls opt = { 322 .index = m->tcf_index, 323 .refcnt = refcount_read(&m->tcf_refcnt) - ref, 324 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind, 325 }; 326 struct tcf_t t; 327 328 spin_lock_bh(&m->tcf_lock); 329 opt.action = m->tcf_action; 330 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock)); 331 opt.m_action = p->tcfm_action; 332 333 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt)) 334 goto nla_put_failure; 335 336 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET && 337 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label)) 338 goto nla_put_failure; 339 340 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET && 341 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc)) 342 goto nla_put_failure; 343 344 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl)) 345 goto nla_put_failure; 346 347 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET && 348 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos)) 349 goto nla_put_failure; 350 351 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto)) 352 goto nla_put_failure; 353 354 tcf_tm_dump(&t, &m->tcf_tm); 355 356 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD)) 357 goto nla_put_failure; 358 359 spin_unlock_bh(&m->tcf_lock); 360 361 return skb->len; 362 363 nla_put_failure: 364 spin_unlock_bh(&m->tcf_lock); 365 nlmsg_trim(skb, b); 366 return -EMSGSIZE; 367 } 368 369 static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data, 370 u32 *index_inc, bool bind, 371 struct netlink_ext_ack *extack) 372 { 373 if (bind) { 374 struct flow_action_entry *entry = entry_data; 375 376 switch (tcf_mpls_action(act)) { 377 case TCA_MPLS_ACT_PUSH: 378 entry->id = FLOW_ACTION_MPLS_PUSH; 379 entry->mpls_push.proto = tcf_mpls_proto(act); 380 entry->mpls_push.label = tcf_mpls_label(act); 381 entry->mpls_push.tc = tcf_mpls_tc(act); 382 entry->mpls_push.bos = tcf_mpls_bos(act); 383 entry->mpls_push.ttl = tcf_mpls_ttl(act); 384 break; 385 case TCA_MPLS_ACT_POP: 386 entry->id = FLOW_ACTION_MPLS_POP; 387 entry->mpls_pop.proto = tcf_mpls_proto(act); 388 break; 389 case TCA_MPLS_ACT_MODIFY: 390 entry->id = FLOW_ACTION_MPLS_MANGLE; 391 entry->mpls_mangle.label = tcf_mpls_label(act); 392 entry->mpls_mangle.tc = tcf_mpls_tc(act); 393 entry->mpls_mangle.bos = tcf_mpls_bos(act); 394 entry->mpls_mangle.ttl = tcf_mpls_ttl(act); 395 break; 396 case TCA_MPLS_ACT_DEC_TTL: 397 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"dec_ttl\" option is used"); 398 return -EOPNOTSUPP; 399 case TCA_MPLS_ACT_MAC_PUSH: 400 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"mac_push\" option is used"); 401 return -EOPNOTSUPP; 402 default: 403 NL_SET_ERR_MSG_MOD(extack, "Unsupported MPLS mode offload"); 404 return -EOPNOTSUPP; 405 } 406 *index_inc = 1; 407 } else { 408 struct flow_offload_action *fl_action = entry_data; 409 410 switch (tcf_mpls_action(act)) { 411 case TCA_MPLS_ACT_PUSH: 412 fl_action->id = FLOW_ACTION_MPLS_PUSH; 413 break; 414 case TCA_MPLS_ACT_POP: 415 fl_action->id = FLOW_ACTION_MPLS_POP; 416 break; 417 case TCA_MPLS_ACT_MODIFY: 418 fl_action->id = FLOW_ACTION_MPLS_MANGLE; 419 break; 420 default: 421 return -EOPNOTSUPP; 422 } 423 } 424 425 return 0; 426 } 427 428 static struct tc_action_ops act_mpls_ops = { 429 .kind = "mpls", 430 .id = TCA_ID_MPLS, 431 .owner = THIS_MODULE, 432 .act = tcf_mpls_act, 433 .dump = tcf_mpls_dump, 434 .init = tcf_mpls_init, 435 .cleanup = tcf_mpls_cleanup, 436 .offload_act_setup = tcf_mpls_offload_act_setup, 437 .size = sizeof(struct tcf_mpls), 438 }; 439 440 static __net_init int mpls_init_net(struct net *net) 441 { 442 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id); 443 444 return tc_action_net_init(net, tn, &act_mpls_ops); 445 } 446 447 static void __net_exit mpls_exit_net(struct list_head *net_list) 448 { 449 tc_action_net_exit(net_list, act_mpls_ops.net_id); 450 } 451 452 static struct pernet_operations mpls_net_ops = { 453 .init = mpls_init_net, 454 .exit_batch = mpls_exit_net, 455 .id = &act_mpls_ops.net_id, 456 .size = sizeof(struct tc_action_net), 457 }; 458 459 static int __init mpls_init_module(void) 460 { 461 return tcf_register_action(&act_mpls_ops, &mpls_net_ops); 462 } 463 464 static void __exit mpls_cleanup_module(void) 465 { 466 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops); 467 } 468 469 module_init(mpls_init_module); 470 module_exit(mpls_cleanup_module); 471 472 MODULE_SOFTDEP("post: mpls_gso"); 473 MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>"); 474 MODULE_LICENSE("GPL"); 475 MODULE_DESCRIPTION("MPLS manipulation actions"); 476