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