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2a2ea508 JH |
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 | ||
17 | static unsigned int mpls_net_id; | |
18 | static struct tc_action_ops act_mpls_ops; | |
19 | ||
20 | #define ACT_MPLS_TTL_DEFAULT 255 | |
21 | ||
22 | static __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 | ||
52 | static 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; | |
fa4e0f88 | 58 | int ret, mac_len; |
2a2ea508 JH |
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 | */ | |
fa4e0f88 | 66 | if (skb_at_tc_ingress(skb)) { |
2a2ea508 | 67 | skb_push_rcsum(skb, skb->mac_len); |
fa4e0f88 DC |
68 | mac_len = skb->mac_len; |
69 | } else { | |
70 | mac_len = skb_network_header(skb) - skb_mac_header(skb); | |
71 | } | |
2a2ea508 JH |
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: | |
fa4e0f88 | 79 | if (skb_mpls_pop(skb, p->tcfm_proto, mac_len)) |
2a2ea508 JH |
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)); | |
fa4e0f88 | 84 | if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len)) |
2a2ea508 JH |
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 | ||
103 | drop: | |
104 | qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats)); | |
105 | return TC_ACT_SHOT; | |
106 | } | |
107 | ||
108 | static 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 | ||
121 | static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = { | |
2a2ea508 JH |
122 | [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)), |
123 | [TCA_MPLS_PROTO] = { .type = NLA_U16 }, | |
124 | [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label), | |
125 | [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7), | |
126 | [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1), | |
127 | [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1), | |
128 | }; | |
129 | ||
130 | static int tcf_mpls_init(struct net *net, struct nlattr *nla, | |
131 | struct nlattr *est, struct tc_action **a, | |
132 | int ovr, int bind, bool rtnl_held, | |
abbb0d33 VB |
133 | struct tcf_proto *tp, u32 flags, |
134 | struct netlink_ext_ack *extack) | |
2a2ea508 JH |
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; | |
7be8ef2c | 145 | u32 index; |
2a2ea508 JH |
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]); | |
7be8ef2c | 161 | index = parm->index; |
2a2ea508 JH |
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 | ||
7be8ef2c | 218 | err = tcf_idr_check_alloc(tn, &index, a, bind); |
2a2ea508 JH |
219 | if (err < 0) |
220 | return err; | |
221 | exists = err; | |
222 | if (exists && bind) | |
223 | return 0; | |
224 | ||
225 | if (!exists) { | |
7be8ef2c | 226 | ret = tcf_idr_create(tn, index, est, a, |
e3822678 | 227 | &act_mpls_ops, bind, true, 0); |
2a2ea508 | 228 | if (ret) { |
7be8ef2c | 229 | tcf_idr_cleanup(tn, index); |
2a2ea508 JH |
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); | |
445d3749 | 265 | p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock)); |
2a2ea508 JH |
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; | |
276 | put_chain: | |
277 | if (goto_ch) | |
278 | tcf_chain_put_by_act(goto_ch); | |
279 | release_idr: | |
280 | tcf_idr_release(*a, bind); | |
281 | return err; | |
282 | } | |
283 | ||
284 | static 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 | ||
294 | static 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 | ||
342 | nla_put_failure: | |
343 | spin_unlock_bh(&m->tcf_lock); | |
344 | nlmsg_trim(skb, b); | |
345 | return -EMSGSIZE; | |
346 | } | |
347 | ||
348 | static 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 | ||
358 | static 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 | ||
365 | static 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 | ||
378 | static __net_init int mpls_init_net(struct net *net) | |
379 | { | |
380 | struct tc_action_net *tn = net_generic(net, mpls_net_id); | |
381 | ||
981471bd | 382 | return tc_action_net_init(net, tn, &act_mpls_ops); |
2a2ea508 JH |
383 | } |
384 | ||
385 | static void __net_exit mpls_exit_net(struct list_head *net_list) | |
386 | { | |
387 | tc_action_net_exit(net_list, mpls_net_id); | |
388 | } | |
389 | ||
390 | static 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 | ||
397 | static int __init mpls_init_module(void) | |
398 | { | |
399 | return tcf_register_action(&act_mpls_ops, &mpls_net_ops); | |
400 | } | |
401 | ||
402 | static void __exit mpls_cleanup_module(void) | |
403 | { | |
404 | tcf_unregister_action(&act_mpls_ops, &mpls_net_ops); | |
405 | } | |
406 | ||
407 | module_init(mpls_init_module); | |
408 | module_exit(mpls_cleanup_module); | |
409 | ||
410 | MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>"); | |
411 | MODULE_LICENSE("GPL"); | |
412 | MODULE_DESCRIPTION("MPLS manipulation actions"); |