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
18 static unsigned int mpls_net_id;
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 static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
54 struct tcf_result *res)
55 {
56 struct tcf_mpls *m = to_mpls(a);
57 struct tcf_mpls_params *p;
58 __be32 new_lse;
59 int ret, mac_len;
60
61 tcf_lastuse_update(&m->tcf_tm);
62 bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
63
64 /* Ensure 'data' points at mac_header prior calling mpls manipulating
65 * functions.
66 */
67 if (skb_at_tc_ingress(skb)) {
68 skb_push_rcsum(skb, skb->mac_len);
69 mac_len = skb->mac_len;
70 } else {
71 mac_len = skb_network_header(skb) - skb_mac_header(skb);
72 }
73
74 ret = READ_ONCE(m->tcf_action);
75
76 p = rcu_dereference_bh(m->mpls_p);
77
78 switch (p->tcfm_action) {
79 case TCA_MPLS_ACT_POP:
80 if (skb_mpls_pop(skb, p->tcfm_proto, mac_len,
81 skb->dev && skb->dev->type == ARPHRD_ETHER))
82 goto drop;
83 break;
84 case TCA_MPLS_ACT_PUSH:
85 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true)));
86 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len,
87 skb->dev && skb->dev->type == ARPHRD_ETHER))
88 goto drop;
89 break;
90 case TCA_MPLS_ACT_MAC_PUSH:
91 if (skb_vlan_tag_present(skb)) {
92 if (__vlan_insert_inner_tag(skb, skb->vlan_proto,
93 skb_vlan_tag_get(skb),
94 ETH_HLEN) < 0)
95 goto drop;
96
97 skb->protocol = skb->vlan_proto;
98 __vlan_hwaccel_clear_tag(skb);
99 }
100
101 new_lse = tcf_mpls_get_lse(NULL, p, mac_len ||
102 !eth_p_mpls(skb->protocol));
103
104 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false))
105 goto drop;
106 break;
107 case TCA_MPLS_ACT_MODIFY:
108 if (!pskb_may_pull(skb,
109 skb_network_offset(skb) + MPLS_HLEN))
110 goto drop;
111 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
112 if (skb_mpls_update_lse(skb, new_lse))
113 goto drop;
114 break;
115 case TCA_MPLS_ACT_DEC_TTL:
116 if (skb_mpls_dec_ttl(skb))
117 goto drop;
118 break;
119 }
120
121 if (skb_at_tc_ingress(skb))
122 skb_pull_rcsum(skb, skb->mac_len);
123
124 return ret;
125
126 drop:
127 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
128 return TC_ACT_SHOT;
129 }
130
valid_label(const struct nlattr * attr,struct netlink_ext_ack * extack)131 static int valid_label(const struct nlattr *attr,
132 struct netlink_ext_ack *extack)
133 {
134 const u32 *label = nla_data(attr);
135
136 if (nla_len(attr) != sizeof(*label)) {
137 NL_SET_ERR_MSG_MOD(extack, "Invalid MPLS label length");
138 return -EINVAL;
139 }
140
141 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
142 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
143 return -EINVAL;
144 }
145
146 return 0;
147 }
148
149 static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
150 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
151 [TCA_MPLS_PROTO] = { .type = NLA_U16 },
152 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_BINARY,
153 valid_label),
154 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
155 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
156 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
157 };
158
tcf_mpls_init(struct net * net,struct nlattr * nla,struct nlattr * est,struct tc_action ** a,int ovr,int bind,bool rtnl_held,struct tcf_proto * tp,u32 flags,struct netlink_ext_ack * extack)159 static int tcf_mpls_init(struct net *net, struct nlattr *nla,
160 struct nlattr *est, struct tc_action **a,
161 int ovr, int bind, bool rtnl_held,
162 struct tcf_proto *tp, u32 flags,
163 struct netlink_ext_ack *extack)
164 {
165 struct tc_action_net *tn = net_generic(net, mpls_net_id);
166 struct nlattr *tb[TCA_MPLS_MAX + 1];
167 struct tcf_chain *goto_ch = NULL;
168 struct tcf_mpls_params *p;
169 struct tc_mpls *parm;
170 bool exists = false;
171 struct tcf_mpls *m;
172 int ret = 0, err;
173 u8 mpls_ttl = 0;
174 u32 index;
175
176 if (!nla) {
177 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
178 return -EINVAL;
179 }
180
181 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
182 if (err < 0)
183 return err;
184
185 if (!tb[TCA_MPLS_PARMS]) {
186 NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
187 return -EINVAL;
188 }
189 parm = nla_data(tb[TCA_MPLS_PARMS]);
190 index = parm->index;
191
192 /* Verify parameters against action type. */
193 switch (parm->m_action) {
194 case TCA_MPLS_ACT_POP:
195 if (!tb[TCA_MPLS_PROTO]) {
196 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
197 return -EINVAL;
198 }
199 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
200 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
201 return -EINVAL;
202 }
203 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
204 tb[TCA_MPLS_BOS]) {
205 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
206 return -EINVAL;
207 }
208 break;
209 case TCA_MPLS_ACT_DEC_TTL:
210 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
211 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
212 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
213 return -EINVAL;
214 }
215 break;
216 case TCA_MPLS_ACT_PUSH:
217 case TCA_MPLS_ACT_MAC_PUSH:
218 if (!tb[TCA_MPLS_LABEL]) {
219 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
220 return -EINVAL;
221 }
222 if (tb[TCA_MPLS_PROTO] &&
223 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
224 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
225 return -EPROTONOSUPPORT;
226 }
227 /* Push needs a TTL - if not specified, set a default value. */
228 if (!tb[TCA_MPLS_TTL]) {
229 #if IS_ENABLED(CONFIG_MPLS)
230 mpls_ttl = net->mpls.default_ttl ?
231 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
232 #else
233 mpls_ttl = ACT_MPLS_TTL_DEFAULT;
234 #endif
235 }
236 break;
237 case TCA_MPLS_ACT_MODIFY:
238 if (tb[TCA_MPLS_PROTO]) {
239 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
240 return -EINVAL;
241 }
242 break;
243 default:
244 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
245 return -EINVAL;
246 }
247
248 err = tcf_idr_check_alloc(tn, &index, a, bind);
249 if (err < 0)
250 return err;
251 exists = err;
252 if (exists && bind)
253 return 0;
254
255 if (!exists) {
256 ret = tcf_idr_create(tn, index, est, a,
257 &act_mpls_ops, bind, true, flags);
258 if (ret) {
259 tcf_idr_cleanup(tn, index);
260 return ret;
261 }
262
263 ret = ACT_P_CREATED;
264 } else if (!ovr) {
265 tcf_idr_release(*a, bind);
266 return -EEXIST;
267 }
268
269 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
270 if (err < 0)
271 goto release_idr;
272
273 m = to_mpls(*a);
274
275 p = kzalloc(sizeof(*p), GFP_KERNEL);
276 if (!p) {
277 err = -ENOMEM;
278 goto put_chain;
279 }
280
281 p->tcfm_action = parm->m_action;
282 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
283 ACT_MPLS_LABEL_NOT_SET;
284 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
285 ACT_MPLS_TC_NOT_SET;
286 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
287 mpls_ttl;
288 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
289 ACT_MPLS_BOS_NOT_SET;
290 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
291 htons(ETH_P_MPLS_UC);
292
293 spin_lock_bh(&m->tcf_lock);
294 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
295 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
296 spin_unlock_bh(&m->tcf_lock);
297
298 if (goto_ch)
299 tcf_chain_put_by_act(goto_ch);
300 if (p)
301 kfree_rcu(p, rcu);
302
303 return ret;
304 put_chain:
305 if (goto_ch)
306 tcf_chain_put_by_act(goto_ch);
307 release_idr:
308 tcf_idr_release(*a, bind);
309 return err;
310 }
311
tcf_mpls_cleanup(struct tc_action * a)312 static void tcf_mpls_cleanup(struct tc_action *a)
313 {
314 struct tcf_mpls *m = to_mpls(a);
315 struct tcf_mpls_params *p;
316
317 p = rcu_dereference_protected(m->mpls_p, 1);
318 if (p)
319 kfree_rcu(p, rcu);
320 }
321
tcf_mpls_dump(struct sk_buff * skb,struct tc_action * a,int bind,int ref)322 static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
323 int bind, int ref)
324 {
325 unsigned char *b = skb_tail_pointer(skb);
326 struct tcf_mpls *m = to_mpls(a);
327 struct tcf_mpls_params *p;
328 struct tc_mpls opt = {
329 .index = m->tcf_index,
330 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
331 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
332 };
333 struct tcf_t t;
334
335 spin_lock_bh(&m->tcf_lock);
336 opt.action = m->tcf_action;
337 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
338 opt.m_action = p->tcfm_action;
339
340 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
341 goto nla_put_failure;
342
343 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
344 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
345 goto nla_put_failure;
346
347 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
348 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
349 goto nla_put_failure;
350
351 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
352 goto nla_put_failure;
353
354 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
355 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
356 goto nla_put_failure;
357
358 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
359 goto nla_put_failure;
360
361 tcf_tm_dump(&t, &m->tcf_tm);
362
363 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
364 goto nla_put_failure;
365
366 spin_unlock_bh(&m->tcf_lock);
367
368 return skb->len;
369
370 nla_put_failure:
371 spin_unlock_bh(&m->tcf_lock);
372 nlmsg_trim(skb, b);
373 return -EMSGSIZE;
374 }
375
tcf_mpls_walker(struct net * net,struct sk_buff * skb,struct netlink_callback * cb,int type,const struct tc_action_ops * ops,struct netlink_ext_ack * extack)376 static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
377 struct netlink_callback *cb, int type,
378 const struct tc_action_ops *ops,
379 struct netlink_ext_ack *extack)
380 {
381 struct tc_action_net *tn = net_generic(net, mpls_net_id);
382
383 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
384 }
385
tcf_mpls_search(struct net * net,struct tc_action ** a,u32 index)386 static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
387 {
388 struct tc_action_net *tn = net_generic(net, mpls_net_id);
389
390 return tcf_idr_search(tn, a, index);
391 }
392
393 static struct tc_action_ops act_mpls_ops = {
394 .kind = "mpls",
395 .id = TCA_ID_MPLS,
396 .owner = THIS_MODULE,
397 .act = tcf_mpls_act,
398 .dump = tcf_mpls_dump,
399 .init = tcf_mpls_init,
400 .cleanup = tcf_mpls_cleanup,
401 .walk = tcf_mpls_walker,
402 .lookup = tcf_mpls_search,
403 .size = sizeof(struct tcf_mpls),
404 };
405
mpls_init_net(struct net * net)406 static __net_init int mpls_init_net(struct net *net)
407 {
408 struct tc_action_net *tn = net_generic(net, mpls_net_id);
409
410 return tc_action_net_init(net, tn, &act_mpls_ops);
411 }
412
mpls_exit_net(struct list_head * net_list)413 static void __net_exit mpls_exit_net(struct list_head *net_list)
414 {
415 tc_action_net_exit(net_list, mpls_net_id);
416 }
417
418 static struct pernet_operations mpls_net_ops = {
419 .init = mpls_init_net,
420 .exit_batch = mpls_exit_net,
421 .id = &mpls_net_id,
422 .size = sizeof(struct tc_action_net),
423 };
424
mpls_init_module(void)425 static int __init mpls_init_module(void)
426 {
427 return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
428 }
429
mpls_cleanup_module(void)430 static void __exit mpls_cleanup_module(void)
431 {
432 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
433 }
434
435 module_init(mpls_init_module);
436 module_exit(mpls_cleanup_module);
437
438 MODULE_SOFTDEP("post: mpls_gso");
439 MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
440 MODULE_LICENSE("GPL");
441 MODULE_DESCRIPTION("MPLS manipulation actions");
442