1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 2 /* Copyright (C) 2019 Netronome Systems, Inc. */ 3 4 #include <linux/init.h> 5 #include <linux/kernel.h> 6 #include <linux/module.h> 7 #include <linux/mpls.h> 8 #include <linux/rtnetlink.h> 9 #include <linux/skbuff.h> 10 #include <linux/tc_act/tc_mpls.h> 11 #include <net/mpls.h> 12 #include <net/netlink.h> 13 #include <net/pkt_sched.h> 14 #include <net/pkt_cls.h> 15 #include <net/tc_act/tc_mpls.h> 16 17 static unsigned int mpls_net_id; 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_cpu_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 goto drop; 81 break; 82 case TCA_MPLS_ACT_PUSH: 83 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb->protocol)); 84 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len)) 85 goto drop; 86 break; 87 case TCA_MPLS_ACT_MODIFY: 88 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false); 89 if (skb_mpls_update_lse(skb, new_lse)) 90 goto drop; 91 break; 92 case TCA_MPLS_ACT_DEC_TTL: 93 if (skb_mpls_dec_ttl(skb)) 94 goto drop; 95 break; 96 } 97 98 if (skb_at_tc_ingress(skb)) 99 skb_pull_rcsum(skb, skb->mac_len); 100 101 return ret; 102 103 drop: 104 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats)); 105 return TC_ACT_SHOT; 106 } 107 108 static int valid_label(const struct nlattr *attr, 109 struct netlink_ext_ack *extack) 110 { 111 const u32 *label = nla_data(attr); 112 113 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) { 114 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range"); 115 return -EINVAL; 116 } 117 118 return 0; 119 } 120 121 static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = { 122 [TCA_MPLS_UNSPEC] = { .strict_start_type = TCA_MPLS_UNSPEC + 1 }, 123 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)), 124 [TCA_MPLS_PROTO] = { .type = NLA_U16 }, 125 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label), 126 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7), 127 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1), 128 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1), 129 }; 130 131 static int tcf_mpls_init(struct net *net, struct nlattr *nla, 132 struct nlattr *est, struct tc_action **a, 133 int ovr, int bind, bool rtnl_held, 134 struct tcf_proto *tp, struct netlink_ext_ack *extack) 135 { 136 struct tc_action_net *tn = net_generic(net, mpls_net_id); 137 struct nlattr *tb[TCA_MPLS_MAX + 1]; 138 struct tcf_chain *goto_ch = NULL; 139 struct tcf_mpls_params *p; 140 struct tc_mpls *parm; 141 bool exists = false; 142 struct tcf_mpls *m; 143 int ret = 0, err; 144 u8 mpls_ttl = 0; 145 u32 index; 146 147 if (!nla) { 148 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes"); 149 return -EINVAL; 150 } 151 152 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack); 153 if (err < 0) 154 return err; 155 156 if (!tb[TCA_MPLS_PARMS]) { 157 NL_SET_ERR_MSG_MOD(extack, "No MPLS params"); 158 return -EINVAL; 159 } 160 parm = nla_data(tb[TCA_MPLS_PARMS]); 161 index = parm->index; 162 163 /* Verify parameters against action type. */ 164 switch (parm->m_action) { 165 case TCA_MPLS_ACT_POP: 166 if (!tb[TCA_MPLS_PROTO]) { 167 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop"); 168 return -EINVAL; 169 } 170 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 171 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop"); 172 return -EINVAL; 173 } 174 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || 175 tb[TCA_MPLS_BOS]) { 176 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop"); 177 return -EINVAL; 178 } 179 break; 180 case TCA_MPLS_ACT_DEC_TTL: 181 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] || 182 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) { 183 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl"); 184 return -EINVAL; 185 } 186 break; 187 case TCA_MPLS_ACT_PUSH: 188 if (!tb[TCA_MPLS_LABEL]) { 189 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push"); 190 return -EINVAL; 191 } 192 if (tb[TCA_MPLS_PROTO] && 193 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) { 194 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push"); 195 return -EPROTONOSUPPORT; 196 } 197 /* Push needs a TTL - if not specified, set a default value. */ 198 if (!tb[TCA_MPLS_TTL]) { 199 #if IS_ENABLED(CONFIG_MPLS) 200 mpls_ttl = net->mpls.default_ttl ? 201 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT; 202 #else 203 mpls_ttl = ACT_MPLS_TTL_DEFAULT; 204 #endif 205 } 206 break; 207 case TCA_MPLS_ACT_MODIFY: 208 if (tb[TCA_MPLS_PROTO]) { 209 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify"); 210 return -EINVAL; 211 } 212 break; 213 default: 214 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action"); 215 return -EINVAL; 216 } 217 218 err = tcf_idr_check_alloc(tn, &index, a, bind); 219 if (err < 0) 220 return err; 221 exists = err; 222 if (exists && bind) 223 return 0; 224 225 if (!exists) { 226 ret = tcf_idr_create(tn, index, est, a, 227 &act_mpls_ops, bind, true); 228 if (ret) { 229 tcf_idr_cleanup(tn, index); 230 return ret; 231 } 232 233 ret = ACT_P_CREATED; 234 } else if (!ovr) { 235 tcf_idr_release(*a, bind); 236 return -EEXIST; 237 } 238 239 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); 240 if (err < 0) 241 goto release_idr; 242 243 m = to_mpls(*a); 244 245 p = kzalloc(sizeof(*p), GFP_KERNEL); 246 if (!p) { 247 err = -ENOMEM; 248 goto put_chain; 249 } 250 251 p->tcfm_action = parm->m_action; 252 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) : 253 ACT_MPLS_LABEL_NOT_SET; 254 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) : 255 ACT_MPLS_TC_NOT_SET; 256 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) : 257 mpls_ttl; 258 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) : 259 ACT_MPLS_BOS_NOT_SET; 260 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) : 261 htons(ETH_P_MPLS_UC); 262 263 spin_lock_bh(&m->tcf_lock); 264 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); 265 rcu_swap_protected(m->mpls_p, p, lockdep_is_held(&m->tcf_lock)); 266 spin_unlock_bh(&m->tcf_lock); 267 268 if (goto_ch) 269 tcf_chain_put_by_act(goto_ch); 270 if (p) 271 kfree_rcu(p, rcu); 272 273 if (ret == ACT_P_CREATED) 274 tcf_idr_insert(tn, *a); 275 return ret; 276 put_chain: 277 if (goto_ch) 278 tcf_chain_put_by_act(goto_ch); 279 release_idr: 280 tcf_idr_release(*a, bind); 281 return err; 282 } 283 284 static void tcf_mpls_cleanup(struct tc_action *a) 285 { 286 struct tcf_mpls *m = to_mpls(a); 287 struct tcf_mpls_params *p; 288 289 p = rcu_dereference_protected(m->mpls_p, 1); 290 if (p) 291 kfree_rcu(p, rcu); 292 } 293 294 static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a, 295 int bind, int ref) 296 { 297 unsigned char *b = skb_tail_pointer(skb); 298 struct tcf_mpls *m = to_mpls(a); 299 struct tcf_mpls_params *p; 300 struct tc_mpls opt = { 301 .index = m->tcf_index, 302 .refcnt = refcount_read(&m->tcf_refcnt) - ref, 303 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind, 304 }; 305 struct tcf_t t; 306 307 spin_lock_bh(&m->tcf_lock); 308 opt.action = m->tcf_action; 309 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock)); 310 opt.m_action = p->tcfm_action; 311 312 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt)) 313 goto nla_put_failure; 314 315 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET && 316 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label)) 317 goto nla_put_failure; 318 319 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET && 320 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc)) 321 goto nla_put_failure; 322 323 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl)) 324 goto nla_put_failure; 325 326 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET && 327 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos)) 328 goto nla_put_failure; 329 330 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto)) 331 goto nla_put_failure; 332 333 tcf_tm_dump(&t, &m->tcf_tm); 334 335 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD)) 336 goto nla_put_failure; 337 338 spin_unlock_bh(&m->tcf_lock); 339 340 return skb->len; 341 342 nla_put_failure: 343 spin_unlock_bh(&m->tcf_lock); 344 nlmsg_trim(skb, b); 345 return -EMSGSIZE; 346 } 347 348 static int tcf_mpls_walker(struct net *net, struct sk_buff *skb, 349 struct netlink_callback *cb, int type, 350 const struct tc_action_ops *ops, 351 struct netlink_ext_ack *extack) 352 { 353 struct tc_action_net *tn = net_generic(net, mpls_net_id); 354 355 return tcf_generic_walker(tn, skb, cb, type, ops, extack); 356 } 357 358 static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index) 359 { 360 struct tc_action_net *tn = net_generic(net, mpls_net_id); 361 362 return tcf_idr_search(tn, a, index); 363 } 364 365 static struct tc_action_ops act_mpls_ops = { 366 .kind = "mpls", 367 .id = TCA_ID_MPLS, 368 .owner = THIS_MODULE, 369 .act = tcf_mpls_act, 370 .dump = tcf_mpls_dump, 371 .init = tcf_mpls_init, 372 .cleanup = tcf_mpls_cleanup, 373 .walk = tcf_mpls_walker, 374 .lookup = tcf_mpls_search, 375 .size = sizeof(struct tcf_mpls), 376 }; 377 378 static __net_init int mpls_init_net(struct net *net) 379 { 380 struct tc_action_net *tn = net_generic(net, mpls_net_id); 381 382 return tc_action_net_init(net, tn, &act_mpls_ops); 383 } 384 385 static void __net_exit mpls_exit_net(struct list_head *net_list) 386 { 387 tc_action_net_exit(net_list, mpls_net_id); 388 } 389 390 static struct pernet_operations mpls_net_ops = { 391 .init = mpls_init_net, 392 .exit_batch = mpls_exit_net, 393 .id = &mpls_net_id, 394 .size = sizeof(struct tc_action_net), 395 }; 396 397 static int __init mpls_init_module(void) 398 { 399 return tcf_register_action(&act_mpls_ops, &mpls_net_ops); 400 } 401 402 static void __exit mpls_cleanup_module(void) 403 { 404 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops); 405 } 406 407 module_init(mpls_init_module); 408 module_exit(mpls_cleanup_module); 409 410 MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>"); 411 MODULE_LICENSE("GPL"); 412 MODULE_DESCRIPTION("MPLS manipulation actions"); 413