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