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
seg6_validate_srh(struct ipv6_sr_hdr * srh,int len,bool reduced)28 bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced)
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 if (!reduced && srh->segments_left > srh->first_segment) {
41 return false;
42 } else {
43 max_last_entry = (srh->hdrlen / 2) - 1;
44
45 if (srh->first_segment > max_last_entry)
46 return false;
47
48 if (srh->segments_left > srh->first_segment + 1)
49 return false;
50 }
51
52 tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);
53
54 trailing = len - tlv_offset;
55 if (trailing < 0)
56 return false;
57
58 while (trailing) {
59 struct sr6_tlv *tlv;
60 unsigned int tlv_len;
61
62 if (trailing < sizeof(*tlv))
63 return false;
64
65 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
66 tlv_len = sizeof(*tlv) + tlv->len;
67
68 trailing -= tlv_len;
69 if (trailing < 0)
70 return false;
71
72 tlv_offset += tlv_len;
73 }
74
75 return true;
76 }
77
78 static struct genl_family seg6_genl_family;
79
80 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
81 [SEG6_ATTR_DST] = { .type = NLA_BINARY,
82 .len = sizeof(struct in6_addr) },
83 [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, },
84 [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, },
85 [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, },
86 [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, },
87 [SEG6_ATTR_ALGID] = { .type = NLA_U8, },
88 [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, },
89 };
90
91 #ifdef CONFIG_IPV6_SEG6_HMAC
92
seg6_genl_sethmac(struct sk_buff * skb,struct genl_info * info)93 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
94 {
95 struct net *net = genl_info_net(info);
96 struct seg6_pernet_data *sdata;
97 struct seg6_hmac_info *hinfo;
98 u32 hmackeyid;
99 char *secret;
100 int err = 0;
101 u8 algid;
102 u8 slen;
103
104 sdata = seg6_pernet(net);
105
106 if (!info->attrs[SEG6_ATTR_HMACKEYID] ||
107 !info->attrs[SEG6_ATTR_SECRETLEN] ||
108 !info->attrs[SEG6_ATTR_ALGID])
109 return -EINVAL;
110
111 hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]);
112 slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]);
113 algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]);
114
115 if (hmackeyid == 0)
116 return -EINVAL;
117
118 if (slen > SEG6_HMAC_SECRET_LEN)
119 return -EINVAL;
120
121 mutex_lock(&sdata->lock);
122 hinfo = seg6_hmac_info_lookup(net, hmackeyid);
123
124 if (!slen) {
125 if (!hinfo)
126 err = -ENOENT;
127
128 err = seg6_hmac_info_del(net, hmackeyid);
129
130 goto out_unlock;
131 }
132
133 if (!info->attrs[SEG6_ATTR_SECRET]) {
134 err = -EINVAL;
135 goto out_unlock;
136 }
137
138 if (slen > nla_len(info->attrs[SEG6_ATTR_SECRET])) {
139 err = -EINVAL;
140 goto out_unlock;
141 }
142
143 if (hinfo) {
144 err = seg6_hmac_info_del(net, hmackeyid);
145 if (err)
146 goto out_unlock;
147 }
148
149 secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]);
150
151 hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL);
152 if (!hinfo) {
153 err = -ENOMEM;
154 goto out_unlock;
155 }
156
157 memcpy(hinfo->secret, secret, slen);
158 hinfo->slen = slen;
159 hinfo->alg_id = algid;
160 hinfo->hmackeyid = hmackeyid;
161
162 err = seg6_hmac_info_add(net, hmackeyid, hinfo);
163 if (err)
164 kfree(hinfo);
165
166 out_unlock:
167 mutex_unlock(&sdata->lock);
168 return err;
169 }
170
171 #else
172
seg6_genl_sethmac(struct sk_buff * skb,struct genl_info * info)173 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
174 {
175 return -ENOTSUPP;
176 }
177
178 #endif
179
seg6_genl_set_tunsrc(struct sk_buff * skb,struct genl_info * info)180 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info)
181 {
182 struct net *net = genl_info_net(info);
183 struct in6_addr *val, *t_old, *t_new;
184 struct seg6_pernet_data *sdata;
185
186 sdata = seg6_pernet(net);
187
188 if (!info->attrs[SEG6_ATTR_DST])
189 return -EINVAL;
190
191 val = nla_data(info->attrs[SEG6_ATTR_DST]);
192 t_new = kmemdup(val, sizeof(*val), GFP_KERNEL);
193 if (!t_new)
194 return -ENOMEM;
195
196 mutex_lock(&sdata->lock);
197
198 t_old = sdata->tun_src;
199 rcu_assign_pointer(sdata->tun_src, t_new);
200
201 mutex_unlock(&sdata->lock);
202
203 synchronize_net();
204 kfree(t_old);
205
206 return 0;
207 }
208
seg6_genl_get_tunsrc(struct sk_buff * skb,struct genl_info * info)209 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info)
210 {
211 struct net *net = genl_info_net(info);
212 struct in6_addr *tun_src;
213 struct sk_buff *msg;
214 void *hdr;
215
216 msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
217 if (!msg)
218 return -ENOMEM;
219
220 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
221 &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC);
222 if (!hdr)
223 goto free_msg;
224
225 rcu_read_lock();
226 tun_src = rcu_dereference(seg6_pernet(net)->tun_src);
227
228 if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src))
229 goto nla_put_failure;
230
231 rcu_read_unlock();
232
233 genlmsg_end(msg, hdr);
234 return genlmsg_reply(msg, info);
235
236 nla_put_failure:
237 rcu_read_unlock();
238 free_msg:
239 nlmsg_free(msg);
240 return -ENOMEM;
241 }
242
243 #ifdef CONFIG_IPV6_SEG6_HMAC
244
__seg6_hmac_fill_info(struct seg6_hmac_info * hinfo,struct sk_buff * msg)245 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo,
246 struct sk_buff *msg)
247 {
248 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) ||
249 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) ||
250 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) ||
251 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id))
252 return -1;
253
254 return 0;
255 }
256
__seg6_genl_dumphmac_element(struct seg6_hmac_info * hinfo,u32 portid,u32 seq,u32 flags,struct sk_buff * skb,u8 cmd)257 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo,
258 u32 portid, u32 seq, u32 flags,
259 struct sk_buff *skb, u8 cmd)
260 {
261 void *hdr;
262
263 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd);
264 if (!hdr)
265 return -ENOMEM;
266
267 if (__seg6_hmac_fill_info(hinfo, skb) < 0)
268 goto nla_put_failure;
269
270 genlmsg_end(skb, hdr);
271 return 0;
272
273 nla_put_failure:
274 genlmsg_cancel(skb, hdr);
275 return -EMSGSIZE;
276 }
277
seg6_genl_dumphmac_start(struct netlink_callback * cb)278 static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
279 {
280 struct net *net = sock_net(cb->skb->sk);
281 struct seg6_pernet_data *sdata;
282 struct rhashtable_iter *iter;
283
284 sdata = seg6_pernet(net);
285 iter = (struct rhashtable_iter *)cb->args[0];
286
287 if (!iter) {
288 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
289 if (!iter)
290 return -ENOMEM;
291
292 cb->args[0] = (long)iter;
293 }
294
295 rhashtable_walk_enter(&sdata->hmac_infos, iter);
296
297 return 0;
298 }
299
seg6_genl_dumphmac_done(struct netlink_callback * cb)300 static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
301 {
302 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
303
304 rhashtable_walk_exit(iter);
305
306 kfree(iter);
307
308 return 0;
309 }
310
seg6_genl_dumphmac(struct sk_buff * skb,struct netlink_callback * cb)311 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
312 {
313 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
314 struct seg6_hmac_info *hinfo;
315 int ret;
316
317 rhashtable_walk_start(iter);
318
319 for (;;) {
320 hinfo = rhashtable_walk_next(iter);
321
322 if (IS_ERR(hinfo)) {
323 if (PTR_ERR(hinfo) == -EAGAIN)
324 continue;
325 ret = PTR_ERR(hinfo);
326 goto done;
327 } else if (!hinfo) {
328 break;
329 }
330
331 ret = __seg6_genl_dumphmac_element(hinfo,
332 NETLINK_CB(cb->skb).portid,
333 cb->nlh->nlmsg_seq,
334 NLM_F_MULTI,
335 skb, SEG6_CMD_DUMPHMAC);
336 if (ret)
337 goto done;
338 }
339
340 ret = skb->len;
341
342 done:
343 rhashtable_walk_stop(iter);
344 return ret;
345 }
346
347 #else
348
seg6_genl_dumphmac_start(struct netlink_callback * cb)349 static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
350 {
351 return 0;
352 }
353
seg6_genl_dumphmac_done(struct netlink_callback * cb)354 static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
355 {
356 return 0;
357 }
358
seg6_genl_dumphmac(struct sk_buff * skb,struct netlink_callback * cb)359 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
360 {
361 return -ENOTSUPP;
362 }
363
364 #endif
365
seg6_net_init(struct net * net)366 static int __net_init seg6_net_init(struct net *net)
367 {
368 struct seg6_pernet_data *sdata;
369
370 sdata = kzalloc(sizeof(*sdata), GFP_KERNEL);
371 if (!sdata)
372 return -ENOMEM;
373
374 mutex_init(&sdata->lock);
375
376 sdata->tun_src = kzalloc(sizeof(*sdata->tun_src), GFP_KERNEL);
377 if (!sdata->tun_src) {
378 kfree(sdata);
379 return -ENOMEM;
380 }
381
382 net->ipv6.seg6_data = sdata;
383
384 #ifdef CONFIG_IPV6_SEG6_HMAC
385 seg6_hmac_net_init(net);
386 #endif
387
388 return 0;
389 }
390
seg6_net_exit(struct net * net)391 static void __net_exit seg6_net_exit(struct net *net)
392 {
393 struct seg6_pernet_data *sdata = seg6_pernet(net);
394
395 #ifdef CONFIG_IPV6_SEG6_HMAC
396 seg6_hmac_net_exit(net);
397 #endif
398
399 kfree(sdata->tun_src);
400 kfree(sdata);
401 }
402
403 static struct pernet_operations ip6_segments_ops = {
404 .init = seg6_net_init,
405 .exit = seg6_net_exit,
406 };
407
408 static const struct genl_ops seg6_genl_ops[] = {
409 {
410 .cmd = SEG6_CMD_SETHMAC,
411 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
412 .doit = seg6_genl_sethmac,
413 .flags = GENL_ADMIN_PERM,
414 },
415 {
416 .cmd = SEG6_CMD_DUMPHMAC,
417 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
418 .start = seg6_genl_dumphmac_start,
419 .dumpit = seg6_genl_dumphmac,
420 .done = seg6_genl_dumphmac_done,
421 .flags = GENL_ADMIN_PERM,
422 },
423 {
424 .cmd = SEG6_CMD_SET_TUNSRC,
425 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
426 .doit = seg6_genl_set_tunsrc,
427 .flags = GENL_ADMIN_PERM,
428 },
429 {
430 .cmd = SEG6_CMD_GET_TUNSRC,
431 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
432 .doit = seg6_genl_get_tunsrc,
433 .flags = GENL_ADMIN_PERM,
434 },
435 };
436
437 static struct genl_family seg6_genl_family __ro_after_init = {
438 .hdrsize = 0,
439 .name = SEG6_GENL_NAME,
440 .version = SEG6_GENL_VERSION,
441 .maxattr = SEG6_ATTR_MAX,
442 .policy = seg6_genl_policy,
443 .netnsok = true,
444 .parallel_ops = true,
445 .ops = seg6_genl_ops,
446 .n_ops = ARRAY_SIZE(seg6_genl_ops),
447 .module = THIS_MODULE,
448 };
449
seg6_init(void)450 int __init seg6_init(void)
451 {
452 int err;
453
454 err = genl_register_family(&seg6_genl_family);
455 if (err)
456 goto out;
457
458 err = register_pernet_subsys(&ip6_segments_ops);
459 if (err)
460 goto out_unregister_genl;
461
462 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
463 err = seg6_iptunnel_init();
464 if (err)
465 goto out_unregister_pernet;
466
467 err = seg6_local_init();
468 if (err)
469 goto out_unregister_pernet;
470 #endif
471
472 #ifdef CONFIG_IPV6_SEG6_HMAC
473 err = seg6_hmac_init();
474 if (err)
475 goto out_unregister_iptun;
476 #endif
477
478 pr_info("Segment Routing with IPv6\n");
479
480 out:
481 return err;
482 #ifdef CONFIG_IPV6_SEG6_HMAC
483 out_unregister_iptun:
484 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
485 seg6_local_exit();
486 seg6_iptunnel_exit();
487 #endif
488 #endif
489 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
490 out_unregister_pernet:
491 unregister_pernet_subsys(&ip6_segments_ops);
492 #endif
493 out_unregister_genl:
494 genl_unregister_family(&seg6_genl_family);
495 goto out;
496 }
497
seg6_exit(void)498 void seg6_exit(void)
499 {
500 #ifdef CONFIG_IPV6_SEG6_HMAC
501 seg6_hmac_exit();
502 #endif
503 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
504 seg6_iptunnel_exit();
505 #endif
506 unregister_pernet_subsys(&ip6_segments_ops);
507 genl_unregister_family(&seg6_genl_family);
508 }
509