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