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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; | |
58 | int ret; | |
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 | ||
69 | ret = READ_ONCE(m->tcf_action); | |
70 | ||
71 | p = rcu_dereference_bh(m->mpls_p); | |
72 | ||
73 | switch (p->tcfm_action) { | |
74 | case TCA_MPLS_ACT_POP: | |
75 | if (skb_mpls_pop(skb, p->tcfm_proto)) | |
76 | goto drop; | |
77 | break; | |
78 | case TCA_MPLS_ACT_PUSH: | |
79 | new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb->protocol)); | |
80 | if (skb_mpls_push(skb, new_lse, p->tcfm_proto)) | |
81 | goto drop; | |
82 | break; | |
83 | case TCA_MPLS_ACT_MODIFY: | |
84 | new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false); | |
85 | if (skb_mpls_update_lse(skb, new_lse)) | |
86 | goto drop; | |
87 | break; | |
88 | case TCA_MPLS_ACT_DEC_TTL: | |
89 | if (skb_mpls_dec_ttl(skb)) | |
90 | goto drop; | |
91 | break; | |
92 | } | |
93 | ||
94 | if (skb_at_tc_ingress(skb)) | |
95 | skb_pull_rcsum(skb, skb->mac_len); | |
96 | ||
97 | return ret; | |
98 | ||
99 | drop: | |
100 | qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats)); | |
101 | return TC_ACT_SHOT; | |
102 | } | |
103 | ||
104 | static int valid_label(const struct nlattr *attr, | |
105 | struct netlink_ext_ack *extack) | |
106 | { | |
107 | const u32 *label = nla_data(attr); | |
108 | ||
109 | if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) { | |
110 | NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range"); | |
111 | return -EINVAL; | |
112 | } | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = { | |
118 | [TCA_MPLS_UNSPEC] = { .strict_start_type = TCA_MPLS_UNSPEC + 1 }, | |
119 | [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)), | |
120 | [TCA_MPLS_PROTO] = { .type = NLA_U16 }, | |
121 | [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label), | |
122 | [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7), | |
123 | [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1), | |
124 | [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1), | |
125 | }; | |
126 | ||
127 | static int tcf_mpls_init(struct net *net, struct nlattr *nla, | |
128 | struct nlattr *est, struct tc_action **a, | |
129 | int ovr, int bind, bool rtnl_held, | |
130 | struct tcf_proto *tp, struct netlink_ext_ack *extack) | |
131 | { | |
132 | struct tc_action_net *tn = net_generic(net, mpls_net_id); | |
133 | struct nlattr *tb[TCA_MPLS_MAX + 1]; | |
134 | struct tcf_chain *goto_ch = NULL; | |
135 | struct tcf_mpls_params *p; | |
136 | struct tc_mpls *parm; | |
137 | bool exists = false; | |
138 | struct tcf_mpls *m; | |
139 | int ret = 0, err; | |
140 | u8 mpls_ttl = 0; | |
7be8ef2c | 141 | u32 index; |
2a2ea508 JH |
142 | |
143 | if (!nla) { | |
144 | NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes"); | |
145 | return -EINVAL; | |
146 | } | |
147 | ||
148 | err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack); | |
149 | if (err < 0) | |
150 | return err; | |
151 | ||
152 | if (!tb[TCA_MPLS_PARMS]) { | |
153 | NL_SET_ERR_MSG_MOD(extack, "No MPLS params"); | |
154 | return -EINVAL; | |
155 | } | |
156 | parm = nla_data(tb[TCA_MPLS_PARMS]); | |
7be8ef2c | 157 | index = parm->index; |
2a2ea508 JH |
158 | |
159 | /* Verify parameters against action type. */ | |
160 | switch (parm->m_action) { | |
161 | case TCA_MPLS_ACT_POP: | |
162 | if (!tb[TCA_MPLS_PROTO]) { | |
163 | NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop"); | |
164 | return -EINVAL; | |
165 | } | |
166 | if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) { | |
167 | NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop"); | |
168 | return -EINVAL; | |
169 | } | |
170 | if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || | |
171 | tb[TCA_MPLS_BOS]) { | |
172 | NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop"); | |
173 | return -EINVAL; | |
174 | } | |
175 | break; | |
176 | case TCA_MPLS_ACT_DEC_TTL: | |
177 | if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] || | |
178 | tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) { | |
179 | NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl"); | |
180 | return -EINVAL; | |
181 | } | |
182 | break; | |
183 | case TCA_MPLS_ACT_PUSH: | |
184 | if (!tb[TCA_MPLS_LABEL]) { | |
185 | NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push"); | |
186 | return -EINVAL; | |
187 | } | |
188 | if (tb[TCA_MPLS_PROTO] && | |
189 | !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) { | |
190 | NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push"); | |
191 | return -EPROTONOSUPPORT; | |
192 | } | |
193 | /* Push needs a TTL - if not specified, set a default value. */ | |
194 | if (!tb[TCA_MPLS_TTL]) { | |
195 | #if IS_ENABLED(CONFIG_MPLS) | |
196 | mpls_ttl = net->mpls.default_ttl ? | |
197 | net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT; | |
198 | #else | |
199 | mpls_ttl = ACT_MPLS_TTL_DEFAULT; | |
200 | #endif | |
201 | } | |
202 | break; | |
203 | case TCA_MPLS_ACT_MODIFY: | |
204 | if (tb[TCA_MPLS_PROTO]) { | |
205 | NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify"); | |
206 | return -EINVAL; | |
207 | } | |
208 | break; | |
209 | default: | |
210 | NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action"); | |
211 | return -EINVAL; | |
212 | } | |
213 | ||
7be8ef2c | 214 | err = tcf_idr_check_alloc(tn, &index, a, bind); |
2a2ea508 JH |
215 | if (err < 0) |
216 | return err; | |
217 | exists = err; | |
218 | if (exists && bind) | |
219 | return 0; | |
220 | ||
221 | if (!exists) { | |
7be8ef2c | 222 | ret = tcf_idr_create(tn, index, est, a, |
2a2ea508 JH |
223 | &act_mpls_ops, bind, true); |
224 | if (ret) { | |
7be8ef2c | 225 | tcf_idr_cleanup(tn, index); |
2a2ea508 JH |
226 | return ret; |
227 | } | |
228 | ||
229 | ret = ACT_P_CREATED; | |
230 | } else if (!ovr) { | |
231 | tcf_idr_release(*a, bind); | |
232 | return -EEXIST; | |
233 | } | |
234 | ||
235 | err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); | |
236 | if (err < 0) | |
237 | goto release_idr; | |
238 | ||
239 | m = to_mpls(*a); | |
240 | ||
241 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
242 | if (!p) { | |
243 | err = -ENOMEM; | |
244 | goto put_chain; | |
245 | } | |
246 | ||
247 | p->tcfm_action = parm->m_action; | |
248 | p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) : | |
249 | ACT_MPLS_LABEL_NOT_SET; | |
250 | p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) : | |
251 | ACT_MPLS_TC_NOT_SET; | |
252 | p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) : | |
253 | mpls_ttl; | |
254 | p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) : | |
255 | ACT_MPLS_BOS_NOT_SET; | |
256 | p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) : | |
257 | htons(ETH_P_MPLS_UC); | |
258 | ||
259 | spin_lock_bh(&m->tcf_lock); | |
260 | goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); | |
261 | rcu_swap_protected(m->mpls_p, p, lockdep_is_held(&m->tcf_lock)); | |
262 | spin_unlock_bh(&m->tcf_lock); | |
263 | ||
264 | if (goto_ch) | |
265 | tcf_chain_put_by_act(goto_ch); | |
266 | if (p) | |
267 | kfree_rcu(p, rcu); | |
268 | ||
269 | if (ret == ACT_P_CREATED) | |
270 | tcf_idr_insert(tn, *a); | |
271 | return ret; | |
272 | put_chain: | |
273 | if (goto_ch) | |
274 | tcf_chain_put_by_act(goto_ch); | |
275 | release_idr: | |
276 | tcf_idr_release(*a, bind); | |
277 | return err; | |
278 | } | |
279 | ||
280 | static void tcf_mpls_cleanup(struct tc_action *a) | |
281 | { | |
282 | struct tcf_mpls *m = to_mpls(a); | |
283 | struct tcf_mpls_params *p; | |
284 | ||
285 | p = rcu_dereference_protected(m->mpls_p, 1); | |
286 | if (p) | |
287 | kfree_rcu(p, rcu); | |
288 | } | |
289 | ||
290 | static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a, | |
291 | int bind, int ref) | |
292 | { | |
293 | unsigned char *b = skb_tail_pointer(skb); | |
294 | struct tcf_mpls *m = to_mpls(a); | |
295 | struct tcf_mpls_params *p; | |
296 | struct tc_mpls opt = { | |
297 | .index = m->tcf_index, | |
298 | .refcnt = refcount_read(&m->tcf_refcnt) - ref, | |
299 | .bindcnt = atomic_read(&m->tcf_bindcnt) - bind, | |
300 | }; | |
301 | struct tcf_t t; | |
302 | ||
303 | spin_lock_bh(&m->tcf_lock); | |
304 | opt.action = m->tcf_action; | |
305 | p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock)); | |
306 | opt.m_action = p->tcfm_action; | |
307 | ||
308 | if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt)) | |
309 | goto nla_put_failure; | |
310 | ||
311 | if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET && | |
312 | nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label)) | |
313 | goto nla_put_failure; | |
314 | ||
315 | if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET && | |
316 | nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc)) | |
317 | goto nla_put_failure; | |
318 | ||
319 | if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl)) | |
320 | goto nla_put_failure; | |
321 | ||
322 | if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET && | |
323 | nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos)) | |
324 | goto nla_put_failure; | |
325 | ||
326 | if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto)) | |
327 | goto nla_put_failure; | |
328 | ||
329 | tcf_tm_dump(&t, &m->tcf_tm); | |
330 | ||
331 | if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD)) | |
332 | goto nla_put_failure; | |
333 | ||
334 | spin_unlock_bh(&m->tcf_lock); | |
335 | ||
336 | return skb->len; | |
337 | ||
338 | nla_put_failure: | |
339 | spin_unlock_bh(&m->tcf_lock); | |
340 | nlmsg_trim(skb, b); | |
341 | return -EMSGSIZE; | |
342 | } | |
343 | ||
344 | static int tcf_mpls_walker(struct net *net, struct sk_buff *skb, | |
345 | struct netlink_callback *cb, int type, | |
346 | const struct tc_action_ops *ops, | |
347 | struct netlink_ext_ack *extack) | |
348 | { | |
349 | struct tc_action_net *tn = net_generic(net, mpls_net_id); | |
350 | ||
351 | return tcf_generic_walker(tn, skb, cb, type, ops, extack); | |
352 | } | |
353 | ||
354 | static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index) | |
355 | { | |
356 | struct tc_action_net *tn = net_generic(net, mpls_net_id); | |
357 | ||
358 | return tcf_idr_search(tn, a, index); | |
359 | } | |
360 | ||
361 | static struct tc_action_ops act_mpls_ops = { | |
362 | .kind = "mpls", | |
363 | .id = TCA_ID_MPLS, | |
364 | .owner = THIS_MODULE, | |
365 | .act = tcf_mpls_act, | |
366 | .dump = tcf_mpls_dump, | |
367 | .init = tcf_mpls_init, | |
368 | .cleanup = tcf_mpls_cleanup, | |
369 | .walk = tcf_mpls_walker, | |
370 | .lookup = tcf_mpls_search, | |
371 | .size = sizeof(struct tcf_mpls), | |
372 | }; | |
373 | ||
374 | static __net_init int mpls_init_net(struct net *net) | |
375 | { | |
376 | struct tc_action_net *tn = net_generic(net, mpls_net_id); | |
377 | ||
981471bd | 378 | return tc_action_net_init(net, tn, &act_mpls_ops); |
2a2ea508 JH |
379 | } |
380 | ||
381 | static void __net_exit mpls_exit_net(struct list_head *net_list) | |
382 | { | |
383 | tc_action_net_exit(net_list, mpls_net_id); | |
384 | } | |
385 | ||
386 | static struct pernet_operations mpls_net_ops = { | |
387 | .init = mpls_init_net, | |
388 | .exit_batch = mpls_exit_net, | |
389 | .id = &mpls_net_id, | |
390 | .size = sizeof(struct tc_action_net), | |
391 | }; | |
392 | ||
393 | static int __init mpls_init_module(void) | |
394 | { | |
395 | return tcf_register_action(&act_mpls_ops, &mpls_net_ops); | |
396 | } | |
397 | ||
398 | static void __exit mpls_cleanup_module(void) | |
399 | { | |
400 | tcf_unregister_action(&act_mpls_ops, &mpls_net_ops); | |
401 | } | |
402 | ||
403 | module_init(mpls_init_module); | |
404 | module_exit(mpls_cleanup_module); | |
405 | ||
406 | MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>"); | |
407 | MODULE_LICENSE("GPL"); | |
408 | MODULE_DESCRIPTION("MPLS manipulation actions"); |