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 #include <net/tc_wrapper.h>
18
19 static struct tc_action_ops act_mpls_ops;
20
21 #define ACT_MPLS_TTL_DEFAULT 255
22
tcf_mpls_get_lse(struct mpls_shim_hdr * lse,struct tcf_mpls_params * p,bool set_bos)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
tcf_mpls_act(struct sk_buff * skb,const struct tc_action * a,struct tcf_result * res)53 TC_INDIRECT_SCOPE int tcf_mpls_act(struct sk_buff *skb,
54 const struct tc_action *a,
55 struct tcf_result *res)
56 {
57 struct tcf_mpls *m = to_mpls(a);
58 struct tcf_mpls_params *p;
59 __be32 new_lse;
60 int ret, mac_len;
61
62 tcf_lastuse_update(&m->tcf_tm);
63 bstats_update(this_cpu_ptr(m->common.cpu_bstats), skb);
64
65 /* Ensure 'data' points at mac_header prior calling mpls manipulating
66 * functions.
67 */
68 if (skb_at_tc_ingress(skb)) {
69 skb_push_rcsum(skb, skb->mac_len);
70 mac_len = skb->mac_len;
71 } else {
72 mac_len = skb_network_offset(skb);
73 }
74
75 ret = READ_ONCE(m->tcf_action);
76
77 p = rcu_dereference_bh(m->mpls_p);
78
79 switch (p->tcfm_action) {
80 case TCA_MPLS_ACT_POP:
81 if (skb_mpls_pop(skb, p->tcfm_proto, mac_len,
82 skb->dev && skb->dev->type == ARPHRD_ETHER))
83 goto drop;
84 break;
85 case TCA_MPLS_ACT_PUSH:
86 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true)));
87 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len,
88 skb->dev && skb->dev->type == ARPHRD_ETHER))
89 goto drop;
90 break;
91 case TCA_MPLS_ACT_MAC_PUSH:
92 if (skb_vlan_tag_present(skb)) {
93 if (__vlan_insert_inner_tag(skb, skb->vlan_proto,
94 skb_vlan_tag_get(skb),
95 ETH_HLEN) < 0)
96 goto drop;
97
98 skb->protocol = skb->vlan_proto;
99 __vlan_hwaccel_clear_tag(skb);
100 }
101
102 new_lse = tcf_mpls_get_lse(NULL, p, mac_len ||
103 !eth_p_mpls(skb->protocol));
104
105 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false))
106 goto drop;
107 break;
108 case TCA_MPLS_ACT_MODIFY:
109 if (!pskb_may_pull(skb,
110 skb_network_offset(skb) + MPLS_HLEN))
111 goto drop;
112 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
113 if (skb_mpls_update_lse(skb, new_lse))
114 goto drop;
115 break;
116 case TCA_MPLS_ACT_DEC_TTL:
117 if (skb_mpls_dec_ttl(skb))
118 goto drop;
119 break;
120 }
121
122 if (skb_at_tc_ingress(skb))
123 skb_pull_rcsum(skb, skb->mac_len);
124
125 return ret;
126
127 drop:
128 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
129 return TC_ACT_SHOT;
130 }
131
valid_label(const struct nlattr * attr,struct netlink_ext_ack * extack)132 static int valid_label(const struct nlattr *attr,
133 struct netlink_ext_ack *extack)
134 {
135 const u32 *label = nla_data(attr);
136
137 if (nla_len(attr) != sizeof(*label)) {
138 NL_SET_ERR_MSG_MOD(extack, "Invalid MPLS label length");
139 return -EINVAL;
140 }
141
142 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
143 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
144 return -EINVAL;
145 }
146
147 return 0;
148 }
149
150 static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
151 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
152 [TCA_MPLS_PROTO] = { .type = NLA_U16 },
153 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_BINARY,
154 valid_label),
155 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
156 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
157 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
158 };
159
tcf_mpls_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)160 static int tcf_mpls_init(struct net *net, struct nlattr *nla,
161 struct nlattr *est, struct tc_action **a,
162 struct tcf_proto *tp, u32 flags,
163 struct netlink_ext_ack *extack)
164 {
165 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id);
166 bool bind = flags & TCA_ACT_FLAGS_BIND;
167 struct nlattr *tb[TCA_MPLS_MAX + 1];
168 struct tcf_chain *goto_ch = NULL;
169 struct tcf_mpls_params *p;
170 struct tc_mpls *parm;
171 bool exists = false;
172 struct tcf_mpls *m;
173 int ret = 0, err;
174 u8 mpls_ttl = 0;
175 u32 index;
176
177 if (!nla) {
178 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
179 return -EINVAL;
180 }
181
182 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
183 if (err < 0)
184 return err;
185
186 if (!tb[TCA_MPLS_PARMS]) {
187 NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
188 return -EINVAL;
189 }
190 parm = nla_data(tb[TCA_MPLS_PARMS]);
191 index = parm->index;
192
193 err = tcf_idr_check_alloc(tn, &index, a, bind);
194 if (err < 0)
195 return err;
196 exists = err;
197 if (exists && bind)
198 return ACT_P_BOUND;
199
200 if (!exists) {
201 ret = tcf_idr_create(tn, index, est, a, &act_mpls_ops, bind,
202 true, flags);
203 if (ret) {
204 tcf_idr_cleanup(tn, index);
205 return ret;
206 }
207
208 ret = ACT_P_CREATED;
209 } else if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
210 tcf_idr_release(*a, bind);
211 return -EEXIST;
212 }
213
214 /* Verify parameters against action type. */
215 switch (parm->m_action) {
216 case TCA_MPLS_ACT_POP:
217 if (!tb[TCA_MPLS_PROTO]) {
218 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
219 err = -EINVAL;
220 goto release_idr;
221 }
222 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
223 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
224 err = -EINVAL;
225 goto release_idr;
226 }
227 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
228 tb[TCA_MPLS_BOS]) {
229 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
230 err = -EINVAL;
231 goto release_idr;
232 }
233 break;
234 case TCA_MPLS_ACT_DEC_TTL:
235 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
236 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
237 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
238 err = -EINVAL;
239 goto release_idr;
240 }
241 break;
242 case TCA_MPLS_ACT_PUSH:
243 case TCA_MPLS_ACT_MAC_PUSH:
244 if (!tb[TCA_MPLS_LABEL]) {
245 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
246 err = -EINVAL;
247 goto release_idr;
248 }
249 if (tb[TCA_MPLS_PROTO] &&
250 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
251 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
252 err = -EPROTONOSUPPORT;
253 goto release_idr;
254 }
255 /* Push needs a TTL - if not specified, set a default value. */
256 if (!tb[TCA_MPLS_TTL]) {
257 #if IS_ENABLED(CONFIG_MPLS)
258 mpls_ttl = net->mpls.default_ttl ?
259 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
260 #else
261 mpls_ttl = ACT_MPLS_TTL_DEFAULT;
262 #endif
263 }
264 break;
265 case TCA_MPLS_ACT_MODIFY:
266 if (tb[TCA_MPLS_PROTO]) {
267 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
268 err = -EINVAL;
269 goto release_idr;
270 }
271 break;
272 default:
273 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
274 err = -EINVAL;
275 goto release_idr;
276 }
277
278 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
279 if (err < 0)
280 goto release_idr;
281
282 m = to_mpls(*a);
283
284 p = kzalloc(sizeof(*p), GFP_KERNEL);
285 if (!p) {
286 err = -ENOMEM;
287 goto put_chain;
288 }
289
290 p->tcfm_action = parm->m_action;
291 p->tcfm_label = nla_get_u32_default(tb[TCA_MPLS_LABEL],
292 ACT_MPLS_LABEL_NOT_SET);
293 p->tcfm_tc = nla_get_u8_default(tb[TCA_MPLS_TC], ACT_MPLS_TC_NOT_SET);
294 p->tcfm_ttl = nla_get_u8_default(tb[TCA_MPLS_TTL], mpls_ttl);
295 p->tcfm_bos = nla_get_u8_default(tb[TCA_MPLS_BOS],
296 ACT_MPLS_BOS_NOT_SET);
297 p->tcfm_proto = nla_get_be16_default(tb[TCA_MPLS_PROTO],
298 htons(ETH_P_MPLS_UC));
299
300 spin_lock_bh(&m->tcf_lock);
301 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
302 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
303 spin_unlock_bh(&m->tcf_lock);
304
305 if (goto_ch)
306 tcf_chain_put_by_act(goto_ch);
307 if (p)
308 kfree_rcu(p, rcu);
309
310 return ret;
311 put_chain:
312 if (goto_ch)
313 tcf_chain_put_by_act(goto_ch);
314 release_idr:
315 tcf_idr_release(*a, bind);
316 return err;
317 }
318
tcf_mpls_cleanup(struct tc_action * a)319 static void tcf_mpls_cleanup(struct tc_action *a)
320 {
321 struct tcf_mpls *m = to_mpls(a);
322 struct tcf_mpls_params *p;
323
324 p = rcu_dereference_protected(m->mpls_p, 1);
325 if (p)
326 kfree_rcu(p, rcu);
327 }
328
tcf_mpls_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)329 static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
330 int bind, int ref)
331 {
332 unsigned char *b = skb_tail_pointer(skb);
333 struct tcf_mpls *m = to_mpls(a);
334 struct tcf_mpls_params *p;
335 struct tc_mpls opt = {
336 .index = m->tcf_index,
337 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
338 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
339 };
340 struct tcf_t t;
341
342 spin_lock_bh(&m->tcf_lock);
343 opt.action = m->tcf_action;
344 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
345 opt.m_action = p->tcfm_action;
346
347 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
348 goto nla_put_failure;
349
350 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
351 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
352 goto nla_put_failure;
353
354 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
355 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
356 goto nla_put_failure;
357
358 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
359 goto nla_put_failure;
360
361 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
362 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
363 goto nla_put_failure;
364
365 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
366 goto nla_put_failure;
367
368 tcf_tm_dump(&t, &m->tcf_tm);
369
370 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
371 goto nla_put_failure;
372
373 spin_unlock_bh(&m->tcf_lock);
374
375 return skb->len;
376
377 nla_put_failure:
378 spin_unlock_bh(&m->tcf_lock);
379 nlmsg_trim(skb, b);
380 return -EMSGSIZE;
381 }
382
tcf_mpls_offload_act_setup(struct tc_action * act,void * entry_data,u32 * index_inc,bool bind,struct netlink_ext_ack * extack)383 static int tcf_mpls_offload_act_setup(struct tc_action *act, void *entry_data,
384 u32 *index_inc, bool bind,
385 struct netlink_ext_ack *extack)
386 {
387 if (bind) {
388 struct flow_action_entry *entry = entry_data;
389
390 switch (tcf_mpls_action(act)) {
391 case TCA_MPLS_ACT_PUSH:
392 entry->id = FLOW_ACTION_MPLS_PUSH;
393 entry->mpls_push.proto = tcf_mpls_proto(act);
394 entry->mpls_push.label = tcf_mpls_label(act);
395 entry->mpls_push.tc = tcf_mpls_tc(act);
396 entry->mpls_push.bos = tcf_mpls_bos(act);
397 entry->mpls_push.ttl = tcf_mpls_ttl(act);
398 break;
399 case TCA_MPLS_ACT_POP:
400 entry->id = FLOW_ACTION_MPLS_POP;
401 entry->mpls_pop.proto = tcf_mpls_proto(act);
402 break;
403 case TCA_MPLS_ACT_MODIFY:
404 entry->id = FLOW_ACTION_MPLS_MANGLE;
405 entry->mpls_mangle.label = tcf_mpls_label(act);
406 entry->mpls_mangle.tc = tcf_mpls_tc(act);
407 entry->mpls_mangle.bos = tcf_mpls_bos(act);
408 entry->mpls_mangle.ttl = tcf_mpls_ttl(act);
409 break;
410 case TCA_MPLS_ACT_DEC_TTL:
411 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"dec_ttl\" option is used");
412 return -EOPNOTSUPP;
413 case TCA_MPLS_ACT_MAC_PUSH:
414 NL_SET_ERR_MSG_MOD(extack, "Offload not supported when \"mac_push\" option is used");
415 return -EOPNOTSUPP;
416 default:
417 NL_SET_ERR_MSG_MOD(extack, "Unsupported MPLS mode offload");
418 return -EOPNOTSUPP;
419 }
420 *index_inc = 1;
421 } else {
422 struct flow_offload_action *fl_action = entry_data;
423
424 switch (tcf_mpls_action(act)) {
425 case TCA_MPLS_ACT_PUSH:
426 fl_action->id = FLOW_ACTION_MPLS_PUSH;
427 break;
428 case TCA_MPLS_ACT_POP:
429 fl_action->id = FLOW_ACTION_MPLS_POP;
430 break;
431 case TCA_MPLS_ACT_MODIFY:
432 fl_action->id = FLOW_ACTION_MPLS_MANGLE;
433 break;
434 default:
435 return -EOPNOTSUPP;
436 }
437 }
438
439 return 0;
440 }
441
442 static struct tc_action_ops act_mpls_ops = {
443 .kind = "mpls",
444 .id = TCA_ID_MPLS,
445 .owner = THIS_MODULE,
446 .act = tcf_mpls_act,
447 .dump = tcf_mpls_dump,
448 .init = tcf_mpls_init,
449 .cleanup = tcf_mpls_cleanup,
450 .offload_act_setup = tcf_mpls_offload_act_setup,
451 .size = sizeof(struct tcf_mpls),
452 };
453 MODULE_ALIAS_NET_ACT("mpls");
454
mpls_init_net(struct net * net)455 static __net_init int mpls_init_net(struct net *net)
456 {
457 struct tc_action_net *tn = net_generic(net, act_mpls_ops.net_id);
458
459 return tc_action_net_init(net, tn, &act_mpls_ops);
460 }
461
mpls_exit_net(struct list_head * net_list)462 static void __net_exit mpls_exit_net(struct list_head *net_list)
463 {
464 tc_action_net_exit(net_list, act_mpls_ops.net_id);
465 }
466
467 static struct pernet_operations mpls_net_ops = {
468 .init = mpls_init_net,
469 .exit_batch = mpls_exit_net,
470 .id = &act_mpls_ops.net_id,
471 .size = sizeof(struct tc_action_net),
472 };
473
mpls_init_module(void)474 static int __init mpls_init_module(void)
475 {
476 return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
477 }
478
mpls_cleanup_module(void)479 static void __exit mpls_cleanup_module(void)
480 {
481 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
482 }
483
484 module_init(mpls_init_module);
485 module_exit(mpls_cleanup_module);
486
487 MODULE_SOFTDEP("post: mpls_gso");
488 MODULE_AUTHOR("Netronome Systems <[email protected]>");
489 MODULE_LICENSE("GPL");
490 MODULE_DESCRIPTION("MPLS manipulation actions");
491