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