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