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