Merge tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
[linux-2.6-microblaze.git] / net / ipv6 / seg6.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  SR-IPv6 implementation
4  *
5  *  Author:
6  *  David Lebrun <david.lebrun@uclouvain.be>
7  */
8
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/net.h>
13 #include <linux/in6.h>
14 #include <linux/slab.h>
15 #include <linux/rhashtable.h>
16
17 #include <net/ipv6.h>
18 #include <net/protocol.h>
19
20 #include <net/seg6.h>
21 #include <net/genetlink.h>
22 #include <linux/seg6.h>
23 #include <linux/seg6_genl.h>
24 #ifdef CONFIG_IPV6_SEG6_HMAC
25 #include <net/seg6_hmac.h>
26 #endif
27
28 bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len)
29 {
30         unsigned int tlv_offset;
31         int max_last_entry;
32         int trailing;
33
34         if (srh->type != IPV6_SRCRT_TYPE_4)
35                 return false;
36
37         if (((srh->hdrlen + 1) << 3) != len)
38                 return false;
39
40         max_last_entry = (srh->hdrlen / 2) - 1;
41
42         if (srh->first_segment > max_last_entry)
43                 return false;
44
45         if (srh->segments_left > srh->first_segment + 1)
46                 return false;
47
48         tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);
49
50         trailing = len - tlv_offset;
51         if (trailing < 0)
52                 return false;
53
54         while (trailing) {
55                 struct sr6_tlv *tlv;
56                 unsigned int tlv_len;
57
58                 if (trailing < sizeof(*tlv))
59                         return false;
60
61                 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
62                 tlv_len = sizeof(*tlv) + tlv->len;
63
64                 trailing -= tlv_len;
65                 if (trailing < 0)
66                         return false;
67
68                 tlv_offset += tlv_len;
69         }
70
71         return true;
72 }
73
74 static struct genl_family seg6_genl_family;
75
76 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
77         [SEG6_ATTR_DST]                         = { .type = NLA_BINARY,
78                 .len = sizeof(struct in6_addr) },
79         [SEG6_ATTR_DSTLEN]                      = { .type = NLA_S32, },
80         [SEG6_ATTR_HMACKEYID]           = { .type = NLA_U32, },
81         [SEG6_ATTR_SECRET]                      = { .type = NLA_BINARY, },
82         [SEG6_ATTR_SECRETLEN]           = { .type = NLA_U8, },
83         [SEG6_ATTR_ALGID]                       = { .type = NLA_U8, },
84         [SEG6_ATTR_HMACINFO]            = { .type = NLA_NESTED, },
85 };
86
87 #ifdef CONFIG_IPV6_SEG6_HMAC
88
89 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
90 {
91         struct net *net = genl_info_net(info);
92         struct seg6_pernet_data *sdata;
93         struct seg6_hmac_info *hinfo;
94         u32 hmackeyid;
95         char *secret;
96         int err = 0;
97         u8 algid;
98         u8 slen;
99
100         sdata = seg6_pernet(net);
101
102         if (!info->attrs[SEG6_ATTR_HMACKEYID] ||
103             !info->attrs[SEG6_ATTR_SECRETLEN] ||
104             !info->attrs[SEG6_ATTR_ALGID])
105                 return -EINVAL;
106
107         hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]);
108         slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]);
109         algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]);
110
111         if (hmackeyid == 0)
112                 return -EINVAL;
113
114         if (slen > SEG6_HMAC_SECRET_LEN)
115                 return -EINVAL;
116
117         mutex_lock(&sdata->lock);
118         hinfo = seg6_hmac_info_lookup(net, hmackeyid);
119
120         if (!slen) {
121                 if (!hinfo)
122                         err = -ENOENT;
123
124                 err = seg6_hmac_info_del(net, hmackeyid);
125
126                 goto out_unlock;
127         }
128
129         if (!info->attrs[SEG6_ATTR_SECRET]) {
130                 err = -EINVAL;
131                 goto out_unlock;
132         }
133
134         if (hinfo) {
135                 err = seg6_hmac_info_del(net, hmackeyid);
136                 if (err)
137                         goto out_unlock;
138         }
139
140         secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]);
141
142         hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL);
143         if (!hinfo) {
144                 err = -ENOMEM;
145                 goto out_unlock;
146         }
147
148         memcpy(hinfo->secret, secret, slen);
149         hinfo->slen = slen;
150         hinfo->alg_id = algid;
151         hinfo->hmackeyid = hmackeyid;
152
153         err = seg6_hmac_info_add(net, hmackeyid, hinfo);
154         if (err)
155                 kfree(hinfo);
156
157 out_unlock:
158         mutex_unlock(&sdata->lock);
159         return err;
160 }
161
162 #else
163
164 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
165 {
166         return -ENOTSUPP;
167 }
168
169 #endif
170
171 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info)
172 {
173         struct net *net = genl_info_net(info);
174         struct in6_addr *val, *t_old, *t_new;
175         struct seg6_pernet_data *sdata;
176
177         sdata = seg6_pernet(net);
178
179         if (!info->attrs[SEG6_ATTR_DST])
180                 return -EINVAL;
181
182         val = nla_data(info->attrs[SEG6_ATTR_DST]);
183         t_new = kmemdup(val, sizeof(*val), GFP_KERNEL);
184         if (!t_new)
185                 return -ENOMEM;
186
187         mutex_lock(&sdata->lock);
188
189         t_old = sdata->tun_src;
190         rcu_assign_pointer(sdata->tun_src, t_new);
191
192         mutex_unlock(&sdata->lock);
193
194         synchronize_net();
195         kfree(t_old);
196
197         return 0;
198 }
199
200 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info)
201 {
202         struct net *net = genl_info_net(info);
203         struct in6_addr *tun_src;
204         struct sk_buff *msg;
205         void *hdr;
206
207         msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
208         if (!msg)
209                 return -ENOMEM;
210
211         hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
212                           &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC);
213         if (!hdr)
214                 goto free_msg;
215
216         rcu_read_lock();
217         tun_src = rcu_dereference(seg6_pernet(net)->tun_src);
218
219         if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src))
220                 goto nla_put_failure;
221
222         rcu_read_unlock();
223
224         genlmsg_end(msg, hdr);
225         return genlmsg_reply(msg, info);
226
227 nla_put_failure:
228         rcu_read_unlock();
229 free_msg:
230         nlmsg_free(msg);
231         return -ENOMEM;
232 }
233
234 #ifdef CONFIG_IPV6_SEG6_HMAC
235
236 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo,
237                                  struct sk_buff *msg)
238 {
239         if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) ||
240             nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) ||
241             nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) ||
242             nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id))
243                 return -1;
244
245         return 0;
246 }
247
248 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo,
249                                         u32 portid, u32 seq, u32 flags,
250                                         struct sk_buff *skb, u8 cmd)
251 {
252         void *hdr;
253
254         hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd);
255         if (!hdr)
256                 return -ENOMEM;
257
258         if (__seg6_hmac_fill_info(hinfo, skb) < 0)
259                 goto nla_put_failure;
260
261         genlmsg_end(skb, hdr);
262         return 0;
263
264 nla_put_failure:
265         genlmsg_cancel(skb, hdr);
266         return -EMSGSIZE;
267 }
268
269 static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
270 {
271         struct net *net = sock_net(cb->skb->sk);
272         struct seg6_pernet_data *sdata;
273         struct rhashtable_iter *iter;
274
275         sdata = seg6_pernet(net);
276         iter = (struct rhashtable_iter *)cb->args[0];
277
278         if (!iter) {
279                 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
280                 if (!iter)
281                         return -ENOMEM;
282
283                 cb->args[0] = (long)iter;
284         }
285
286         rhashtable_walk_enter(&sdata->hmac_infos, iter);
287
288         return 0;
289 }
290
291 static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
292 {
293         struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
294
295         rhashtable_walk_exit(iter);
296
297         kfree(iter);
298
299         return 0;
300 }
301
302 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
303 {
304         struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
305         struct seg6_hmac_info *hinfo;
306         int ret;
307
308         rhashtable_walk_start(iter);
309
310         for (;;) {
311                 hinfo = rhashtable_walk_next(iter);
312
313                 if (IS_ERR(hinfo)) {
314                         if (PTR_ERR(hinfo) == -EAGAIN)
315                                 continue;
316                         ret = PTR_ERR(hinfo);
317                         goto done;
318                 } else if (!hinfo) {
319                         break;
320                 }
321
322                 ret = __seg6_genl_dumphmac_element(hinfo,
323                                                    NETLINK_CB(cb->skb).portid,
324                                                    cb->nlh->nlmsg_seq,
325                                                    NLM_F_MULTI,
326                                                    skb, SEG6_CMD_DUMPHMAC);
327                 if (ret)
328                         goto done;
329         }
330
331         ret = skb->len;
332
333 done:
334         rhashtable_walk_stop(iter);
335         return ret;
336 }
337
338 #else
339
340 static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
341 {
342         return 0;
343 }
344
345 static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
346 {
347         return 0;
348 }
349
350 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
351 {
352         return -ENOTSUPP;
353 }
354
355 #endif
356
357 static int __net_init seg6_net_init(struct net *net)
358 {
359         struct seg6_pernet_data *sdata;
360
361         sdata = kzalloc(sizeof(*sdata), GFP_KERNEL);
362         if (!sdata)
363                 return -ENOMEM;
364
365         mutex_init(&sdata->lock);
366
367         sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL);
368         if (!sdata->tun_src) {
369                 kfree(sdata);
370                 return -ENOMEM;
371         }
372
373         net->ipv6.seg6_data = sdata;
374
375 #ifdef CONFIG_IPV6_SEG6_HMAC
376         seg6_hmac_net_init(net);
377 #endif
378
379         return 0;
380 }
381
382 static void __net_exit seg6_net_exit(struct net *net)
383 {
384         struct seg6_pernet_data *sdata = seg6_pernet(net);
385
386 #ifdef CONFIG_IPV6_SEG6_HMAC
387         seg6_hmac_net_exit(net);
388 #endif
389
390         kfree(sdata->tun_src);
391         kfree(sdata);
392 }
393
394 static struct pernet_operations ip6_segments_ops = {
395         .init = seg6_net_init,
396         .exit = seg6_net_exit,
397 };
398
399 static const struct genl_ops seg6_genl_ops[] = {
400         {
401                 .cmd    = SEG6_CMD_SETHMAC,
402                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
403                 .doit   = seg6_genl_sethmac,
404                 .flags  = GENL_ADMIN_PERM,
405         },
406         {
407                 .cmd    = SEG6_CMD_DUMPHMAC,
408                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
409                 .start  = seg6_genl_dumphmac_start,
410                 .dumpit = seg6_genl_dumphmac,
411                 .done   = seg6_genl_dumphmac_done,
412                 .flags  = GENL_ADMIN_PERM,
413         },
414         {
415                 .cmd    = SEG6_CMD_SET_TUNSRC,
416                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
417                 .doit   = seg6_genl_set_tunsrc,
418                 .flags  = GENL_ADMIN_PERM,
419         },
420         {
421                 .cmd    = SEG6_CMD_GET_TUNSRC,
422                 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
423                 .doit   = seg6_genl_get_tunsrc,
424                 .flags  = GENL_ADMIN_PERM,
425         },
426 };
427
428 static struct genl_family seg6_genl_family __ro_after_init = {
429         .hdrsize        = 0,
430         .name           = SEG6_GENL_NAME,
431         .version        = SEG6_GENL_VERSION,
432         .maxattr        = SEG6_ATTR_MAX,
433         .policy = seg6_genl_policy,
434         .netnsok        = true,
435         .parallel_ops   = true,
436         .ops            = seg6_genl_ops,
437         .n_ops          = ARRAY_SIZE(seg6_genl_ops),
438         .module         = THIS_MODULE,
439 };
440
441 int __init seg6_init(void)
442 {
443         int err;
444
445         err = genl_register_family(&seg6_genl_family);
446         if (err)
447                 goto out;
448
449         err = register_pernet_subsys(&ip6_segments_ops);
450         if (err)
451                 goto out_unregister_genl;
452
453 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
454         err = seg6_iptunnel_init();
455         if (err)
456                 goto out_unregister_pernet;
457
458         err = seg6_local_init();
459         if (err)
460                 goto out_unregister_pernet;
461 #endif
462
463 #ifdef CONFIG_IPV6_SEG6_HMAC
464         err = seg6_hmac_init();
465         if (err)
466                 goto out_unregister_iptun;
467 #endif
468
469         pr_info("Segment Routing with IPv6\n");
470
471 out:
472         return err;
473 #ifdef CONFIG_IPV6_SEG6_HMAC
474 out_unregister_iptun:
475 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
476         seg6_local_exit();
477         seg6_iptunnel_exit();
478 #endif
479 #endif
480 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
481 out_unregister_pernet:
482         unregister_pernet_subsys(&ip6_segments_ops);
483 #endif
484 out_unregister_genl:
485         genl_unregister_family(&seg6_genl_family);
486         goto out;
487 }
488
489 void seg6_exit(void)
490 {
491 #ifdef CONFIG_IPV6_SEG6_HMAC
492         seg6_hmac_exit();
493 #endif
494 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
495         seg6_iptunnel_exit();
496 #endif
497         unregister_pernet_subsys(&ip6_segments_ops);
498         genl_unregister_family(&seg6_genl_family);
499 }