1 /*
2 * SR-IPv6 implementation
3 *
4 * Author:
5 * David Lebrun <david.lebrun@uclouvain.be>
6 *
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/socket.h>
17 #include <linux/net.h>
18 #include <linux/in6.h>
19 #include <linux/slab.h>
20
21 #include <net/ipv6.h>
22 #include <net/protocol.h>
23
24 #include <net/seg6.h>
25 #include <net/genetlink.h>
26 #include <linux/seg6.h>
27 #include <linux/seg6_genl.h>
28 #ifdef CONFIG_IPV6_SEG6_HMAC
29 #include <net/seg6_hmac.h>
30 #endif
31
seg6_validate_srh(struct ipv6_sr_hdr * srh,int len)32 bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len)
33 {
34 int trailing;
35 unsigned int tlv_offset;
36
37 if (srh->type != IPV6_SRCRT_TYPE_4)
38 return false;
39
40 if (((srh->hdrlen + 1) << 3) != len)
41 return false;
42
43 if (srh->segments_left > srh->first_segment)
44 return false;
45
46 tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);
47
48 trailing = len - tlv_offset;
49 if (trailing < 0)
50 return false;
51
52 while (trailing) {
53 struct sr6_tlv *tlv;
54 unsigned int tlv_len;
55
56 if (trailing < sizeof(*tlv))
57 return false;
58
59 tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
60 tlv_len = sizeof(*tlv) + tlv->len;
61
62 trailing -= tlv_len;
63 if (trailing < 0)
64 return false;
65
66 tlv_offset += tlv_len;
67 }
68
69 return true;
70 }
71
72 static struct genl_family seg6_genl_family;
73
74 static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
75 [SEG6_ATTR_DST] = { .type = NLA_BINARY,
76 .len = sizeof(struct in6_addr) },
77 [SEG6_ATTR_DSTLEN] = { .type = NLA_S32, },
78 [SEG6_ATTR_HMACKEYID] = { .type = NLA_U32, },
79 [SEG6_ATTR_SECRET] = { .type = NLA_BINARY, },
80 [SEG6_ATTR_SECRETLEN] = { .type = NLA_U8, },
81 [SEG6_ATTR_ALGID] = { .type = NLA_U8, },
82 [SEG6_ATTR_HMACINFO] = { .type = NLA_NESTED, },
83 };
84
85 #ifdef CONFIG_IPV6_SEG6_HMAC
86
seg6_genl_sethmac(struct sk_buff * skb,struct genl_info * info)87 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
88 {
89 struct net *net = genl_info_net(info);
90 struct seg6_pernet_data *sdata;
91 struct seg6_hmac_info *hinfo;
92 u32 hmackeyid;
93 char *secret;
94 int err = 0;
95 u8 algid;
96 u8 slen;
97
98 sdata = seg6_pernet(net);
99
100 if (!info->attrs[SEG6_ATTR_HMACKEYID] ||
101 !info->attrs[SEG6_ATTR_SECRETLEN] ||
102 !info->attrs[SEG6_ATTR_ALGID])
103 return -EINVAL;
104
105 hmackeyid = nla_get_u32(info->attrs[SEG6_ATTR_HMACKEYID]);
106 slen = nla_get_u8(info->attrs[SEG6_ATTR_SECRETLEN]);
107 algid = nla_get_u8(info->attrs[SEG6_ATTR_ALGID]);
108
109 if (hmackeyid == 0)
110 return -EINVAL;
111
112 if (slen > SEG6_HMAC_SECRET_LEN)
113 return -EINVAL;
114
115 mutex_lock(&sdata->lock);
116 hinfo = seg6_hmac_info_lookup(net, hmackeyid);
117
118 if (!slen) {
119 if (!hinfo)
120 err = -ENOENT;
121
122 err = seg6_hmac_info_del(net, hmackeyid);
123
124 goto out_unlock;
125 }
126
127 if (!info->attrs[SEG6_ATTR_SECRET]) {
128 err = -EINVAL;
129 goto out_unlock;
130 }
131
132 if (hinfo) {
133 err = seg6_hmac_info_del(net, hmackeyid);
134 if (err)
135 goto out_unlock;
136 }
137
138 secret = (char *)nla_data(info->attrs[SEG6_ATTR_SECRET]);
139
140 hinfo = kzalloc(sizeof(*hinfo), GFP_KERNEL);
141 if (!hinfo) {
142 err = -ENOMEM;
143 goto out_unlock;
144 }
145
146 memcpy(hinfo->secret, secret, slen);
147 hinfo->slen = slen;
148 hinfo->alg_id = algid;
149 hinfo->hmackeyid = hmackeyid;
150
151 err = seg6_hmac_info_add(net, hmackeyid, hinfo);
152 if (err)
153 kfree(hinfo);
154
155 out_unlock:
156 mutex_unlock(&sdata->lock);
157 return err;
158 }
159
160 #else
161
seg6_genl_sethmac(struct sk_buff * skb,struct genl_info * info)162 static int seg6_genl_sethmac(struct sk_buff *skb, struct genl_info *info)
163 {
164 return -ENOTSUPP;
165 }
166
167 #endif
168
seg6_genl_set_tunsrc(struct sk_buff * skb,struct genl_info * info)169 static int seg6_genl_set_tunsrc(struct sk_buff *skb, struct genl_info *info)
170 {
171 struct net *net = genl_info_net(info);
172 struct in6_addr *val, *t_old, *t_new;
173 struct seg6_pernet_data *sdata;
174
175 sdata = seg6_pernet(net);
176
177 if (!info->attrs[SEG6_ATTR_DST])
178 return -EINVAL;
179
180 val = nla_data(info->attrs[SEG6_ATTR_DST]);
181 t_new = kmemdup(val, sizeof(*val), GFP_KERNEL);
182 if (!t_new)
183 return -ENOMEM;
184
185 mutex_lock(&sdata->lock);
186
187 t_old = sdata->tun_src;
188 rcu_assign_pointer(sdata->tun_src, t_new);
189
190 mutex_unlock(&sdata->lock);
191
192 synchronize_net();
193 kfree(t_old);
194
195 return 0;
196 }
197
seg6_genl_get_tunsrc(struct sk_buff * skb,struct genl_info * info)198 static int seg6_genl_get_tunsrc(struct sk_buff *skb, struct genl_info *info)
199 {
200 struct net *net = genl_info_net(info);
201 struct in6_addr *tun_src;
202 struct sk_buff *msg;
203 void *hdr;
204
205 msg = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
206 if (!msg)
207 return -ENOMEM;
208
209 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq,
210 &seg6_genl_family, 0, SEG6_CMD_GET_TUNSRC);
211 if (!hdr)
212 goto free_msg;
213
214 rcu_read_lock();
215 tun_src = rcu_dereference(seg6_pernet(net)->tun_src);
216
217 if (nla_put(msg, SEG6_ATTR_DST, sizeof(struct in6_addr), tun_src))
218 goto nla_put_failure;
219
220 rcu_read_unlock();
221
222 genlmsg_end(msg, hdr);
223 return genlmsg_reply(msg, info);
224
225 nla_put_failure:
226 rcu_read_unlock();
227 genlmsg_cancel(msg, hdr);
228 free_msg:
229 nlmsg_free(msg);
230 return -ENOMEM;
231 }
232
233 #ifdef CONFIG_IPV6_SEG6_HMAC
234
__seg6_hmac_fill_info(struct seg6_hmac_info * hinfo,struct sk_buff * msg)235 static int __seg6_hmac_fill_info(struct seg6_hmac_info *hinfo,
236 struct sk_buff *msg)
237 {
238 if (nla_put_u32(msg, SEG6_ATTR_HMACKEYID, hinfo->hmackeyid) ||
239 nla_put_u8(msg, SEG6_ATTR_SECRETLEN, hinfo->slen) ||
240 nla_put(msg, SEG6_ATTR_SECRET, hinfo->slen, hinfo->secret) ||
241 nla_put_u8(msg, SEG6_ATTR_ALGID, hinfo->alg_id))
242 return -1;
243
244 return 0;
245 }
246
__seg6_genl_dumphmac_element(struct seg6_hmac_info * hinfo,u32 portid,u32 seq,u32 flags,struct sk_buff * skb,u8 cmd)247 static int __seg6_genl_dumphmac_element(struct seg6_hmac_info *hinfo,
248 u32 portid, u32 seq, u32 flags,
249 struct sk_buff *skb, u8 cmd)
250 {
251 void *hdr;
252
253 hdr = genlmsg_put(skb, portid, seq, &seg6_genl_family, flags, cmd);
254 if (!hdr)
255 return -ENOMEM;
256
257 if (__seg6_hmac_fill_info(hinfo, skb) < 0)
258 goto nla_put_failure;
259
260 genlmsg_end(skb, hdr);
261 return 0;
262
263 nla_put_failure:
264 genlmsg_cancel(skb, hdr);
265 return -EMSGSIZE;
266 }
267
seg6_genl_dumphmac_start(struct netlink_callback * cb)268 static int seg6_genl_dumphmac_start(struct netlink_callback *cb)
269 {
270 struct net *net = sock_net(cb->skb->sk);
271 struct seg6_pernet_data *sdata;
272 struct rhashtable_iter *iter;
273
274 sdata = seg6_pernet(net);
275 iter = (struct rhashtable_iter *)cb->args[0];
276
277 if (!iter) {
278 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
279 if (!iter)
280 return -ENOMEM;
281
282 cb->args[0] = (long)iter;
283 }
284
285 rhashtable_walk_enter(&sdata->hmac_infos, iter);
286
287 return 0;
288 }
289
seg6_genl_dumphmac_done(struct netlink_callback * cb)290 static int seg6_genl_dumphmac_done(struct netlink_callback *cb)
291 {
292 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
293
294 rhashtable_walk_exit(iter);
295
296 kfree(iter);
297
298 return 0;
299 }
300
seg6_genl_dumphmac(struct sk_buff * skb,struct netlink_callback * cb)301 static int seg6_genl_dumphmac(struct sk_buff *skb, struct netlink_callback *cb)
302 {
303 struct rhashtable_iter *iter = (struct rhashtable_iter *)cb->args[0];
304 struct seg6_hmac_info *hinfo;
305 int ret;
306
307 ret = rhashtable_walk_start(iter);
308 if (ret && ret != -EAGAIN)
309 goto done;
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 .doit = seg6_genl_sethmac,
404 .policy = seg6_genl_policy,
405 .flags = GENL_ADMIN_PERM,
406 },
407 {
408 .cmd = SEG6_CMD_DUMPHMAC,
409 .start = seg6_genl_dumphmac_start,
410 .dumpit = seg6_genl_dumphmac,
411 .done = seg6_genl_dumphmac_done,
412 .policy = seg6_genl_policy,
413 .flags = GENL_ADMIN_PERM,
414 },
415 {
416 .cmd = SEG6_CMD_SET_TUNSRC,
417 .doit = seg6_genl_set_tunsrc,
418 .policy = seg6_genl_policy,
419 .flags = GENL_ADMIN_PERM,
420 },
421 {
422 .cmd = SEG6_CMD_GET_TUNSRC,
423 .doit = seg6_genl_get_tunsrc,
424 .policy = seg6_genl_policy,
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 .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
seg6_init(void)441 int __init seg6_init(void)
442 {
443 int err = -ENOMEM;
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
seg6_exit(void)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 }
500