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