1
2
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
65
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));
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_MODIFY:
91 new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
92 if (skb_mpls_update_lse(skb, new_lse))
93 goto drop;
94 break;
95 case TCA_MPLS_ACT_DEC_TTL:
96 if (skb_mpls_dec_ttl(skb))
97 goto drop;
98 break;
99 }
100
101 if (skb_at_tc_ingress(skb))
102 skb_pull_rcsum(skb, skb->mac_len);
103
104 return ret;
105
106drop:
107 qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
108 return TC_ACT_SHOT;
109}
110
111static int valid_label(const struct nlattr *attr,
112 struct netlink_ext_ack *extack)
113{
114 const u32 *label = nla_data(attr);
115
116 if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
117 NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
118 return -EINVAL;
119 }
120
121 return 0;
122}
123
124static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
125 [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
126 [TCA_MPLS_PROTO] = { .type = NLA_U16 },
127 [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
128 [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
129 [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
130 [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
131};
132
133static int tcf_mpls_init(struct net *net, struct nlattr *nla,
134 struct nlattr *est, struct tc_action **a,
135 int ovr, int bind, bool rtnl_held,
136 struct tcf_proto *tp, u32 flags,
137 struct netlink_ext_ack *extack)
138{
139 struct tc_action_net *tn = net_generic(net, mpls_net_id);
140 struct nlattr *tb[TCA_MPLS_MAX + 1];
141 struct tcf_chain *goto_ch = NULL;
142 struct tcf_mpls_params *p;
143 struct tc_mpls *parm;
144 bool exists = false;
145 struct tcf_mpls *m;
146 int ret = 0, err;
147 u8 mpls_ttl = 0;
148 u32 index;
149
150 if (!nla) {
151 NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
152 return -EINVAL;
153 }
154
155 err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
156 if (err < 0)
157 return err;
158
159 if (!tb[TCA_MPLS_PARMS]) {
160 NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
161 return -EINVAL;
162 }
163 parm = nla_data(tb[TCA_MPLS_PARMS]);
164 index = parm->index;
165
166
167 switch (parm->m_action) {
168 case TCA_MPLS_ACT_POP:
169 if (!tb[TCA_MPLS_PROTO]) {
170 NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
171 return -EINVAL;
172 }
173 if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
174 NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
175 return -EINVAL;
176 }
177 if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
178 tb[TCA_MPLS_BOS]) {
179 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
180 return -EINVAL;
181 }
182 break;
183 case TCA_MPLS_ACT_DEC_TTL:
184 if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
185 tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
186 NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
187 return -EINVAL;
188 }
189 break;
190 case TCA_MPLS_ACT_PUSH:
191 if (!tb[TCA_MPLS_LABEL]) {
192 NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
193 return -EINVAL;
194 }
195 if (tb[TCA_MPLS_PROTO] &&
196 !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
197 NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
198 return -EPROTONOSUPPORT;
199 }
200
201 if (!tb[TCA_MPLS_TTL]) {
202#if IS_ENABLED(CONFIG_MPLS)
203 mpls_ttl = net->mpls.default_ttl ?
204 net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
205#else
206 mpls_ttl = ACT_MPLS_TTL_DEFAULT;
207#endif
208 }
209 break;
210 case TCA_MPLS_ACT_MODIFY:
211 if (tb[TCA_MPLS_PROTO]) {
212 NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
213 return -EINVAL;
214 }
215 break;
216 default:
217 NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
218 return -EINVAL;
219 }
220
221 err = tcf_idr_check_alloc(tn, &index, a, bind);
222 if (err < 0)
223 return err;
224 exists = err;
225 if (exists && bind)
226 return 0;
227
228 if (!exists) {
229 ret = tcf_idr_create(tn, index, est, a,
230 &act_mpls_ops, bind, true, 0);
231 if (ret) {
232 tcf_idr_cleanup(tn, index);
233 return ret;
234 }
235
236 ret = ACT_P_CREATED;
237 } else if (!ovr) {
238 tcf_idr_release(*a, bind);
239 return -EEXIST;
240 }
241
242 err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
243 if (err < 0)
244 goto release_idr;
245
246 m = to_mpls(*a);
247
248 p = kzalloc(sizeof(*p), GFP_KERNEL);
249 if (!p) {
250 err = -ENOMEM;
251 goto put_chain;
252 }
253
254 p->tcfm_action = parm->m_action;
255 p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
256 ACT_MPLS_LABEL_NOT_SET;
257 p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
258 ACT_MPLS_TC_NOT_SET;
259 p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
260 mpls_ttl;
261 p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
262 ACT_MPLS_BOS_NOT_SET;
263 p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
264 htons(ETH_P_MPLS_UC);
265
266 spin_lock_bh(&m->tcf_lock);
267 goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
268 p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
269 spin_unlock_bh(&m->tcf_lock);
270
271 if (goto_ch)
272 tcf_chain_put_by_act(goto_ch);
273 if (p)
274 kfree_rcu(p, rcu);
275
276 if (ret == ACT_P_CREATED)
277 tcf_idr_insert(tn, *a);
278 return ret;
279put_chain:
280 if (goto_ch)
281 tcf_chain_put_by_act(goto_ch);
282release_idr:
283 tcf_idr_release(*a, bind);
284 return err;
285}
286
287static void tcf_mpls_cleanup(struct tc_action *a)
288{
289 struct tcf_mpls *m = to_mpls(a);
290 struct tcf_mpls_params *p;
291
292 p = rcu_dereference_protected(m->mpls_p, 1);
293 if (p)
294 kfree_rcu(p, rcu);
295}
296
297static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
298 int bind, int ref)
299{
300 unsigned char *b = skb_tail_pointer(skb);
301 struct tcf_mpls *m = to_mpls(a);
302 struct tcf_mpls_params *p;
303 struct tc_mpls opt = {
304 .index = m->tcf_index,
305 .refcnt = refcount_read(&m->tcf_refcnt) - ref,
306 .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
307 };
308 struct tcf_t t;
309
310 spin_lock_bh(&m->tcf_lock);
311 opt.action = m->tcf_action;
312 p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
313 opt.m_action = p->tcfm_action;
314
315 if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
316 goto nla_put_failure;
317
318 if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
319 nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
320 goto nla_put_failure;
321
322 if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
323 nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
324 goto nla_put_failure;
325
326 if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
327 goto nla_put_failure;
328
329 if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
330 nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
331 goto nla_put_failure;
332
333 if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
334 goto nla_put_failure;
335
336 tcf_tm_dump(&t, &m->tcf_tm);
337
338 if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
339 goto nla_put_failure;
340
341 spin_unlock_bh(&m->tcf_lock);
342
343 return skb->len;
344
345nla_put_failure:
346 spin_unlock_bh(&m->tcf_lock);
347 nlmsg_trim(skb, b);
348 return -EMSGSIZE;
349}
350
351static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
352 struct netlink_callback *cb, int type,
353 const struct tc_action_ops *ops,
354 struct netlink_ext_ack *extack)
355{
356 struct tc_action_net *tn = net_generic(net, mpls_net_id);
357
358 return tcf_generic_walker(tn, skb, cb, type, ops, extack);
359}
360
361static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
362{
363 struct tc_action_net *tn = net_generic(net, mpls_net_id);
364
365 return tcf_idr_search(tn, a, index);
366}
367
368static struct tc_action_ops act_mpls_ops = {
369 .kind = "mpls",
370 .id = TCA_ID_MPLS,
371 .owner = THIS_MODULE,
372 .act = tcf_mpls_act,
373 .dump = tcf_mpls_dump,
374 .init = tcf_mpls_init,
375 .cleanup = tcf_mpls_cleanup,
376 .walk = tcf_mpls_walker,
377 .lookup = tcf_mpls_search,
378 .size = sizeof(struct tcf_mpls),
379};
380
381static __net_init int mpls_init_net(struct net *net)
382{
383 struct tc_action_net *tn = net_generic(net, mpls_net_id);
384
385 return tc_action_net_init(net, tn, &act_mpls_ops);
386}
387
388static void __net_exit mpls_exit_net(struct list_head *net_list)
389{
390 tc_action_net_exit(net_list, mpls_net_id);
391}
392
393static struct pernet_operations mpls_net_ops = {
394 .init = mpls_init_net,
395 .exit_batch = mpls_exit_net,
396 .id = &mpls_net_id,
397 .size = sizeof(struct tc_action_net),
398};
399
400static int __init mpls_init_module(void)
401{
402 return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
403}
404
405static void __exit mpls_cleanup_module(void)
406{
407 tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
408}
409
410module_init(mpls_init_module);
411module_exit(mpls_cleanup_module);
412
413MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
414MODULE_LICENSE("GPL");
415MODULE_DESCRIPTION("MPLS manipulation actions");
416
