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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
18static unsigned int mpls_net_id;
19static struct tc_action_ops act_mpls_ops;
20
21#define ACT_MPLS_TTL_DEFAULT 255
22
23static __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
53static 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
126drop:
127 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
128 return TC_ACT_SHOT;
129}
130
131static int valid_label(const struct nlattr *attr,
132 struct netlink_ext_ack *extack)
133{
134 const u32 *label = nla_data(attr);
135
136 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
137 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
138 return -EINVAL;
139 }
140
141 return 0;
142}
143
144static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
145 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
146 [TCA_MPLS_PROTO] = { .type = NLA_U16 },
147 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
148 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
149 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
150 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
151};
152
153static int tcf_mpls_init(struct net *net, struct nlattr *nla,
154 struct nlattr *est, struct tc_action **a,
155 int ovr, int bind, bool rtnl_held,
156 struct tcf_proto *tp, u32 flags,
157 struct netlink_ext_ack *extack)
158{
159 struct tc_action_net *tn = net_generic(net, mpls_net_id);
160 struct nlattr *tb[TCA_MPLS_MAX + 1];
161 struct tcf_chain *goto_ch = NULL;
162 struct tcf_mpls_params *p;
163 struct tc_mpls *parm;
164 bool exists = false;
165 struct tcf_mpls *m;
166 int ret = 0, err;
167 u8 mpls_ttl = 0;
168 u32 index;
169
170 if (!nla) {
171 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
172 return -EINVAL;
173 }
174
175 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
176 if (err < 0)
177 return err;
178
179 if (!tb[TCA_MPLS_PARMS]) {
180 NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
181 return -EINVAL;
182 }
183 parm = nla_data(tb[TCA_MPLS_PARMS]);
184 index = parm->index;
185
186 /* Verify parameters against action type. */
187 switch (parm->m_action) {
188 case TCA_MPLS_ACT_POP:
189 if (!tb[TCA_MPLS_PROTO]) {
190 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
191 return -EINVAL;
192 }
193 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
194 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
195 return -EINVAL;
196 }
197 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
198 tb[TCA_MPLS_BOS]) {
199 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
200 return -EINVAL;
201 }
202 break;
203 case TCA_MPLS_ACT_DEC_TTL:
204 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
205 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
206 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
207 return -EINVAL;
208 }
209 break;
210 case TCA_MPLS_ACT_PUSH:
211 case TCA_MPLS_ACT_MAC_PUSH:
212 if (!tb[TCA_MPLS_LABEL]) {
213 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
214 return -EINVAL;
215 }
216 if (tb[TCA_MPLS_PROTO] &&
217 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
218 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
219 return -EPROTONOSUPPORT;
220 }
221 /* Push needs a TTL - if not specified, set a default value. */
222 if (!tb[TCA_MPLS_TTL]) {
223#if IS_ENABLED(CONFIG_MPLS)
224 mpls_ttl = net->mpls.default_ttl ?
225 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
226#else
227 mpls_ttl = ACT_MPLS_TTL_DEFAULT;
228#endif
229 }
230 break;
231 case TCA_MPLS_ACT_MODIFY:
232 if (tb[TCA_MPLS_PROTO]) {
233 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
234 return -EINVAL;
235 }
236 break;
237 default:
238 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
239 return -EINVAL;
240 }
241
242 err = tcf_idr_check_alloc(tn, &index, a, bind);
243 if (err < 0)
244 return err;
245 exists = err;
246 if (exists && bind)
247 return 0;
248
249 if (!exists) {
250 ret = tcf_idr_create(tn, index, est, a,
251 &act_mpls_ops, bind, true, 0);
252 if (ret) {
253 tcf_idr_cleanup(tn, index);
254 return ret;
255 }
256
257 ret = ACT_P_CREATED;
258 } else if (!ovr) {
259 tcf_idr_release(*a, bind);
260 return -EEXIST;
261 }
262
263 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
264 if (err < 0)
265 goto release_idr;
266
267 m = to_mpls(*a);
268
269 p = kzalloc(sizeof(*p), GFP_KERNEL);
270 if (!p) {
271 err = -ENOMEM;
272 goto put_chain;
273 }
274
275 p->tcfm_action = parm->m_action;
276 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
277 ACT_MPLS_LABEL_NOT_SET;
278 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
279 ACT_MPLS_TC_NOT_SET;
280 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
281 mpls_ttl;
282 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
283 ACT_MPLS_BOS_NOT_SET;
284 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
285 htons(ETH_P_MPLS_UC);
286
287 spin_lock_bh(&m->tcf_lock);
288 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
289 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
290 spin_unlock_bh(&m->tcf_lock);
291
292 if (goto_ch)
293 tcf_chain_put_by_act(goto_ch);
294 if (p)
295 kfree_rcu(p, rcu);
296
297 return ret;
298put_chain:
299 if (goto_ch)
300 tcf_chain_put_by_act(goto_ch);
301release_idr:
302 tcf_idr_release(*a, bind);
303 return err;
304}
305
306static void tcf_mpls_cleanup(struct tc_action *a)
307{
308 struct tcf_mpls *m = to_mpls(a);
309 struct tcf_mpls_params *p;
310
311 p = rcu_dereference_protected(m->mpls_p, 1);
312 if (p)
313 kfree_rcu(p, rcu);
314}
315
316static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
317 int bind, int ref)
318{
319 unsigned char *b = skb_tail_pointer(skb);
320 struct tcf_mpls *m = to_mpls(a);
321 struct tcf_mpls_params *p;
322 struct tc_mpls opt = {
323 .index = m->tcf_index,
324 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
325 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
326 };
327 struct tcf_t t;
328
329 spin_lock_bh(&m->tcf_lock);
330 opt.action = m->tcf_action;
331 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
332 opt.m_action = p->tcfm_action;
333
334 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
335 goto nla_put_failure;
336
337 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
338 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
339 goto nla_put_failure;
340
341 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
342 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
343 goto nla_put_failure;
344
345 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
346 goto nla_put_failure;
347
348 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
349 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
350 goto nla_put_failure;
351
352 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
353 goto nla_put_failure;
354
355 tcf_tm_dump(&t, &m->tcf_tm);
356
357 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
358 goto nla_put_failure;
359
360 spin_unlock_bh(&m->tcf_lock);
361
362 return skb->len;
363
364nla_put_failure:
365 spin_unlock_bh(&m->tcf_lock);
366 nlmsg_trim(skb, b);
367 return -EMSGSIZE;
368}
369
370static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
371 struct netlink_callback *cb, int type,
372 const struct tc_action_ops *ops,
373 struct netlink_ext_ack *extack)
374{
375 struct tc_action_net *tn = net_generic(net, mpls_net_id);
376
377 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
378}
379
380static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
381{
382 struct tc_action_net *tn = net_generic(net, mpls_net_id);
383
384 return tcf_idr_search(tn, a, index);
385}
386
387static struct tc_action_ops act_mpls_ops = {
388 .kind = "mpls",
389 .id = TCA_ID_MPLS,
390 .owner = THIS_MODULE,
391 .act = tcf_mpls_act,
392 .dump = tcf_mpls_dump,
393 .init = tcf_mpls_init,
394 .cleanup = tcf_mpls_cleanup,
395 .walk = tcf_mpls_walker,
396 .lookup = tcf_mpls_search,
397 .size = sizeof(struct tcf_mpls),
398};
399
400static __net_init int mpls_init_net(struct net *net)
401{
402 struct tc_action_net *tn = net_generic(net, mpls_net_id);
403
404 return tc_action_net_init(net, tn, &act_mpls_ops);
405}
406
407static void __net_exit mpls_exit_net(struct list_head *net_list)
408{
409 tc_action_net_exit(net_list, mpls_net_id);
410}
411
412static struct pernet_operations mpls_net_ops = {
413 .init = mpls_init_net,
414 .exit_batch = mpls_exit_net,
415 .id = &mpls_net_id,
416 .size = sizeof(struct tc_action_net),
417};
418
419static int __init mpls_init_module(void)
420{
421 return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
422}
423
424static void __exit mpls_cleanup_module(void)
425{
426 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
427}
428
429module_init(mpls_init_module);
430module_exit(mpls_cleanup_module);
431
432MODULE_SOFTDEP("post: mpls_gso");
433MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
434MODULE_LICENSE("GPL");
435MODULE_DESCRIPTION("MPLS manipulation actions");