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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/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
17static unsigned int mpls_net_id;
18static struct tc_action_ops act_mpls_ops;
19
20#define ACT_MPLS_TTL_DEFAULT 255
21
22static __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
52static 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, mac_len;
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 mac_len = skb->mac_len;
69 } else {
70 mac_len = skb_network_header(skb) - skb_mac_header(skb);
71 }
72
73 ret = READ_ONCE(m->tcf_action);
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 goto drop;
81 break;
82 case TCA_MPLS_ACT_PUSH:
83 new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb->protocol));
84 if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len))
85 goto drop;
86 break;
87 case TCA_MPLS_ACT_MODIFY:
88 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
89 if (skb_mpls_update_lse(skb, new_lse))
90 goto drop;
91 break;
92 case TCA_MPLS_ACT_DEC_TTL:
93 if (skb_mpls_dec_ttl(skb))
94 goto drop;
95 break;
96 }
97
98 if (skb_at_tc_ingress(skb))
99 skb_pull_rcsum(skb, skb->mac_len);
100
101 return ret;
102
103drop:
104 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
105 return TC_ACT_SHOT;
106}
107
108static int valid_label(const struct nlattr *attr,
109 struct netlink_ext_ack *extack)
110{
111 const u32 *label = nla_data(attr);
112
113 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
114 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
115 return -EINVAL;
116 }
117
118 return 0;
119}
120
121static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
122 [TCA_MPLS_UNSPEC] = { .strict_start_type = TCA_MPLS_UNSPEC + 1 },
123 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
124 [TCA_MPLS_PROTO] = { .type = NLA_U16 },
125 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
126 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
127 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
128 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
129};
130
131static int tcf_mpls_init(struct net *net, struct nlattr *nla,
132 struct nlattr *est, struct tc_action **a,
133 int ovr, int bind, bool rtnl_held,
134 struct tcf_proto *tp, struct netlink_ext_ack *extack)
135{
136 struct tc_action_net *tn = net_generic(net, mpls_net_id);
137 struct nlattr *tb[TCA_MPLS_MAX + 1];
138 struct tcf_chain *goto_ch = NULL;
139 struct tcf_mpls_params *p;
140 struct tc_mpls *parm;
141 bool exists = false;
142 struct tcf_mpls *m;
143 int ret = 0, err;
144 u8 mpls_ttl = 0;
145 u32 index;
146
147 if (!nla) {
148 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
149 return -EINVAL;
150 }
151
152 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
153 if (err < 0)
154 return err;
155
156 if (!tb[TCA_MPLS_PARMS]) {
157 NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
158 return -EINVAL;
159 }
160 parm = nla_data(tb[TCA_MPLS_PARMS]);
161 index = parm->index;
162
163 /* Verify parameters against action type. */
164 switch (parm->m_action) {
165 case TCA_MPLS_ACT_POP:
166 if (!tb[TCA_MPLS_PROTO]) {
167 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
168 return -EINVAL;
169 }
170 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
171 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
172 return -EINVAL;
173 }
174 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
175 tb[TCA_MPLS_BOS]) {
176 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
177 return -EINVAL;
178 }
179 break;
180 case TCA_MPLS_ACT_DEC_TTL:
181 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
182 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
183 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
184 return -EINVAL;
185 }
186 break;
187 case TCA_MPLS_ACT_PUSH:
188 if (!tb[TCA_MPLS_LABEL]) {
189 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
190 return -EINVAL;
191 }
192 if (tb[TCA_MPLS_PROTO] &&
193 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
194 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
195 return -EPROTONOSUPPORT;
196 }
197 /* Push needs a TTL - if not specified, set a default value. */
198 if (!tb[TCA_MPLS_TTL]) {
199#if IS_ENABLED(CONFIG_MPLS)
200 mpls_ttl = net->mpls.default_ttl ?
201 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
202#else
203 mpls_ttl = ACT_MPLS_TTL_DEFAULT;
204#endif
205 }
206 break;
207 case TCA_MPLS_ACT_MODIFY:
208 if (tb[TCA_MPLS_PROTO]) {
209 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
210 return -EINVAL;
211 }
212 break;
213 default:
214 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
215 return -EINVAL;
216 }
217
218 err = tcf_idr_check_alloc(tn, &index, a, bind);
219 if (err < 0)
220 return err;
221 exists = err;
222 if (exists && bind)
223 return 0;
224
225 if (!exists) {
226 ret = tcf_idr_create(tn, index, est, a,
227 &act_mpls_ops, bind, true);
228 if (ret) {
229 tcf_idr_cleanup(tn, index);
230 return ret;
231 }
232
233 ret = ACT_P_CREATED;
234 } else if (!ovr) {
235 tcf_idr_release(*a, bind);
236 return -EEXIST;
237 }
238
239 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
240 if (err < 0)
241 goto release_idr;
242
243 m = to_mpls(*a);
244
245 p = kzalloc(sizeof(*p), GFP_KERNEL);
246 if (!p) {
247 err = -ENOMEM;
248 goto put_chain;
249 }
250
251 p->tcfm_action = parm->m_action;
252 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
253 ACT_MPLS_LABEL_NOT_SET;
254 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
255 ACT_MPLS_TC_NOT_SET;
256 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
257 mpls_ttl;
258 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
259 ACT_MPLS_BOS_NOT_SET;
260 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
261 htons(ETH_P_MPLS_UC);
262
263 spin_lock_bh(&m->tcf_lock);
264 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
265 rcu_swap_protected(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
266 spin_unlock_bh(&m->tcf_lock);
267
268 if (goto_ch)
269 tcf_chain_put_by_act(goto_ch);
270 if (p)
271 kfree_rcu(p, rcu);
272
273 if (ret == ACT_P_CREATED)
274 tcf_idr_insert(tn, *a);
275 return ret;
276put_chain:
277 if (goto_ch)
278 tcf_chain_put_by_act(goto_ch);
279release_idr:
280 tcf_idr_release(*a, bind);
281 return err;
282}
283
284static void tcf_mpls_cleanup(struct tc_action *a)
285{
286 struct tcf_mpls *m = to_mpls(a);
287 struct tcf_mpls_params *p;
288
289 p = rcu_dereference_protected(m->mpls_p, 1);
290 if (p)
291 kfree_rcu(p, rcu);
292}
293
294static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
295 int bind, int ref)
296{
297 unsigned char *b = skb_tail_pointer(skb);
298 struct tcf_mpls *m = to_mpls(a);
299 struct tcf_mpls_params *p;
300 struct tc_mpls opt = {
301 .index = m->tcf_index,
302 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
303 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
304 };
305 struct tcf_t t;
306
307 spin_lock_bh(&m->tcf_lock);
308 opt.action = m->tcf_action;
309 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
310 opt.m_action = p->tcfm_action;
311
312 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
313 goto nla_put_failure;
314
315 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
316 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
317 goto nla_put_failure;
318
319 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
320 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
321 goto nla_put_failure;
322
323 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
324 goto nla_put_failure;
325
326 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
327 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
328 goto nla_put_failure;
329
330 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
331 goto nla_put_failure;
332
333 tcf_tm_dump(&t, &m->tcf_tm);
334
335 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
336 goto nla_put_failure;
337
338 spin_unlock_bh(&m->tcf_lock);
339
340 return skb->len;
341
342nla_put_failure:
343 spin_unlock_bh(&m->tcf_lock);
344 nlmsg_trim(skb, b);
345 return -EMSGSIZE;
346}
347
348static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
349 struct netlink_callback *cb, int type,
350 const struct tc_action_ops *ops,
351 struct netlink_ext_ack *extack)
352{
353 struct tc_action_net *tn = net_generic(net, mpls_net_id);
354
355 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
356}
357
358static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
359{
360 struct tc_action_net *tn = net_generic(net, mpls_net_id);
361
362 return tcf_idr_search(tn, a, index);
363}
364
365static struct tc_action_ops act_mpls_ops = {
366 .kind = "mpls",
367 .id = TCA_ID_MPLS,
368 .owner = THIS_MODULE,
369 .act = tcf_mpls_act,
370 .dump = tcf_mpls_dump,
371 .init = tcf_mpls_init,
372 .cleanup = tcf_mpls_cleanup,
373 .walk = tcf_mpls_walker,
374 .lookup = tcf_mpls_search,
375 .size = sizeof(struct tcf_mpls),
376};
377
378static __net_init int mpls_init_net(struct net *net)
379{
380 struct tc_action_net *tn = net_generic(net, mpls_net_id);
381
382 return tc_action_net_init(net, tn, &act_mpls_ops);
383}
384
385static void __net_exit mpls_exit_net(struct list_head *net_list)
386{
387 tc_action_net_exit(net_list, mpls_net_id);
388}
389
390static struct pernet_operations mpls_net_ops = {
391 .init = mpls_init_net,
392 .exit_batch = mpls_exit_net,
393 .id = &mpls_net_id,
394 .size = sizeof(struct tc_action_net),
395};
396
397static int __init mpls_init_module(void)
398{
399 return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
400}
401
402static void __exit mpls_cleanup_module(void)
403{
404 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
405}
406
407module_init(mpls_init_module);
408module_exit(mpls_cleanup_module);
409
410MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
411MODULE_LICENSE("GPL");
412MODULE_DESCRIPTION("MPLS manipulation actions");