1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * ip6_flowlabel.c IPv6 flowlabel manager.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 */
7
8 #include <linux/capability.h>
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/net.h>
13 #include <linux/netdevice.h>
14 #include <linux/in6.h>
15 #include <linux/proc_fs.h>
16 #include <linux/seq_file.h>
17 #include <linux/slab.h>
18 #include <linux/export.h>
19 #include <linux/pid_namespace.h>
20 #include <linux/jump_label_ratelimit.h>
21
22 #include <net/net_namespace.h>
23 #include <net/sock.h>
24
25 #include <net/ipv6.h>
26 #include <net/rawv6.h>
27 #include <net/transp_v6.h>
28
29 #include <linux/uaccess.h>
30
31 #define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
32 in old IPv6 RFC. Well, it was reasonable value.
33 */
34 #define FL_MAX_LINGER 150 /* Maximal linger timeout */
35
36 /* FL hash table */
37
38 #define FL_MAX_PER_SOCK 32
39 #define FL_MAX_SIZE 4096
40 #define FL_HASH_MASK 255
41 #define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
42
43 static atomic_t fl_size = ATOMIC_INIT(0);
44 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
45
46 static void ip6_fl_gc(struct timer_list *unused);
47 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc);
48
49 /* FL hash table lock: it protects only of GC */
50
51 static DEFINE_SPINLOCK(ip6_fl_lock);
52
53 /* Big socket sock */
54
55 static DEFINE_SPINLOCK(ip6_sk_fl_lock);
56
57 DEFINE_STATIC_KEY_DEFERRED_FALSE(ipv6_flowlabel_exclusive, HZ);
58 EXPORT_SYMBOL(ipv6_flowlabel_exclusive);
59
60 #define for_each_fl_rcu(hash, fl) \
61 for (fl = rcu_dereference(fl_ht[(hash)]); \
62 fl != NULL; \
63 fl = rcu_dereference(fl->next))
64 #define for_each_fl_continue_rcu(fl) \
65 for (fl = rcu_dereference(fl->next); \
66 fl != NULL; \
67 fl = rcu_dereference(fl->next))
68
69 #define for_each_sk_fl_rcu(np, sfl) \
70 for (sfl = rcu_dereference(np->ipv6_fl_list); \
71 sfl != NULL; \
72 sfl = rcu_dereference(sfl->next))
73
__fl_lookup(struct net * net,__be32 label)74 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
75 {
76 struct ip6_flowlabel *fl;
77
78 for_each_fl_rcu(FL_HASH(label), fl) {
79 if (fl->label == label && net_eq(fl->fl_net, net))
80 return fl;
81 }
82 return NULL;
83 }
84
fl_lookup(struct net * net,__be32 label)85 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
86 {
87 struct ip6_flowlabel *fl;
88
89 rcu_read_lock();
90 fl = __fl_lookup(net, label);
91 if (fl && !atomic_inc_not_zero(&fl->users))
92 fl = NULL;
93 rcu_read_unlock();
94 return fl;
95 }
96
fl_shared_exclusive(struct ip6_flowlabel * fl)97 static bool fl_shared_exclusive(struct ip6_flowlabel *fl)
98 {
99 return fl->share == IPV6_FL_S_EXCL ||
100 fl->share == IPV6_FL_S_PROCESS ||
101 fl->share == IPV6_FL_S_USER;
102 }
103
fl_free_rcu(struct rcu_head * head)104 static void fl_free_rcu(struct rcu_head *head)
105 {
106 struct ip6_flowlabel *fl = container_of(head, struct ip6_flowlabel, rcu);
107
108 if (fl->share == IPV6_FL_S_PROCESS)
109 put_pid(fl->owner.pid);
110 kfree(fl->opt);
111 kfree(fl);
112 }
113
114
fl_free(struct ip6_flowlabel * fl)115 static void fl_free(struct ip6_flowlabel *fl)
116 {
117 if (!fl)
118 return;
119
120 if (fl_shared_exclusive(fl) || fl->opt)
121 static_branch_slow_dec_deferred(&ipv6_flowlabel_exclusive);
122
123 call_rcu(&fl->rcu, fl_free_rcu);
124 }
125
fl_release(struct ip6_flowlabel * fl)126 static void fl_release(struct ip6_flowlabel *fl)
127 {
128 spin_lock_bh(&ip6_fl_lock);
129
130 fl->lastuse = jiffies;
131 if (atomic_dec_and_test(&fl->users)) {
132 unsigned long ttd = fl->lastuse + fl->linger;
133 if (time_after(ttd, fl->expires))
134 fl->expires = ttd;
135 ttd = fl->expires;
136 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
137 struct ipv6_txoptions *opt = fl->opt;
138 fl->opt = NULL;
139 kfree(opt);
140 }
141 if (!timer_pending(&ip6_fl_gc_timer) ||
142 time_after(ip6_fl_gc_timer.expires, ttd))
143 mod_timer(&ip6_fl_gc_timer, ttd);
144 }
145 spin_unlock_bh(&ip6_fl_lock);
146 }
147
ip6_fl_gc(struct timer_list * unused)148 static void ip6_fl_gc(struct timer_list *unused)
149 {
150 int i;
151 unsigned long now = jiffies;
152 unsigned long sched = 0;
153
154 spin_lock(&ip6_fl_lock);
155
156 for (i = 0; i <= FL_HASH_MASK; i++) {
157 struct ip6_flowlabel *fl;
158 struct ip6_flowlabel __rcu **flp;
159
160 flp = &fl_ht[i];
161 while ((fl = rcu_dereference_protected(*flp,
162 lockdep_is_held(&ip6_fl_lock))) != NULL) {
163 if (atomic_read(&fl->users) == 0) {
164 unsigned long ttd = fl->lastuse + fl->linger;
165 if (time_after(ttd, fl->expires))
166 fl->expires = ttd;
167 ttd = fl->expires;
168 if (time_after_eq(now, ttd)) {
169 *flp = fl->next;
170 fl_free(fl);
171 atomic_dec(&fl_size);
172 continue;
173 }
174 if (!sched || time_before(ttd, sched))
175 sched = ttd;
176 }
177 flp = &fl->next;
178 }
179 }
180 if (!sched && atomic_read(&fl_size))
181 sched = now + FL_MAX_LINGER;
182 if (sched) {
183 mod_timer(&ip6_fl_gc_timer, sched);
184 }
185 spin_unlock(&ip6_fl_lock);
186 }
187
ip6_fl_purge(struct net * net)188 static void __net_exit ip6_fl_purge(struct net *net)
189 {
190 int i;
191
192 spin_lock_bh(&ip6_fl_lock);
193 for (i = 0; i <= FL_HASH_MASK; i++) {
194 struct ip6_flowlabel *fl;
195 struct ip6_flowlabel __rcu **flp;
196
197 flp = &fl_ht[i];
198 while ((fl = rcu_dereference_protected(*flp,
199 lockdep_is_held(&ip6_fl_lock))) != NULL) {
200 if (net_eq(fl->fl_net, net) &&
201 atomic_read(&fl->users) == 0) {
202 *flp = fl->next;
203 fl_free(fl);
204 atomic_dec(&fl_size);
205 continue;
206 }
207 flp = &fl->next;
208 }
209 }
210 spin_unlock_bh(&ip6_fl_lock);
211 }
212
fl_intern(struct net * net,struct ip6_flowlabel * fl,__be32 label)213 static struct ip6_flowlabel *fl_intern(struct net *net,
214 struct ip6_flowlabel *fl, __be32 label)
215 {
216 struct ip6_flowlabel *lfl;
217
218 fl->label = label & IPV6_FLOWLABEL_MASK;
219
220 rcu_read_lock();
221 spin_lock_bh(&ip6_fl_lock);
222 if (label == 0) {
223 for (;;) {
224 fl->label = htonl(get_random_u32())&IPV6_FLOWLABEL_MASK;
225 if (fl->label) {
226 lfl = __fl_lookup(net, fl->label);
227 if (!lfl)
228 break;
229 }
230 }
231 } else {
232 /*
233 * we dropper the ip6_fl_lock, so this entry could reappear
234 * and we need to recheck with it.
235 *
236 * OTOH no need to search the active socket first, like it is
237 * done in ipv6_flowlabel_opt - sock is locked, so new entry
238 * with the same label can only appear on another sock
239 */
240 lfl = __fl_lookup(net, fl->label);
241 if (lfl) {
242 atomic_inc(&lfl->users);
243 spin_unlock_bh(&ip6_fl_lock);
244 rcu_read_unlock();
245 return lfl;
246 }
247 }
248
249 fl->lastuse = jiffies;
250 fl->next = fl_ht[FL_HASH(fl->label)];
251 rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
252 atomic_inc(&fl_size);
253 spin_unlock_bh(&ip6_fl_lock);
254 rcu_read_unlock();
255 return NULL;
256 }
257
258
259
260 /* Socket flowlabel lists */
261
__fl6_sock_lookup(struct sock * sk,__be32 label)262 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
263 {
264 struct ipv6_fl_socklist *sfl;
265 struct ipv6_pinfo *np = inet6_sk(sk);
266
267 label &= IPV6_FLOWLABEL_MASK;
268
269 rcu_read_lock();
270 for_each_sk_fl_rcu(np, sfl) {
271 struct ip6_flowlabel *fl = sfl->fl;
272
273 if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
274 fl->lastuse = jiffies;
275 rcu_read_unlock();
276 return fl;
277 }
278 }
279 rcu_read_unlock();
280 return NULL;
281 }
282 EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
283
fl6_free_socklist(struct sock * sk)284 void fl6_free_socklist(struct sock *sk)
285 {
286 struct ipv6_pinfo *np = inet6_sk(sk);
287 struct ipv6_fl_socklist *sfl;
288
289 if (!rcu_access_pointer(np->ipv6_fl_list))
290 return;
291
292 spin_lock_bh(&ip6_sk_fl_lock);
293 while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
294 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
295 np->ipv6_fl_list = sfl->next;
296 spin_unlock_bh(&ip6_sk_fl_lock);
297
298 fl_release(sfl->fl);
299 kfree_rcu(sfl, rcu);
300
301 spin_lock_bh(&ip6_sk_fl_lock);
302 }
303 spin_unlock_bh(&ip6_sk_fl_lock);
304 }
305
306 /* Service routines */
307
308
309 /*
310 It is the only difficult place. flowlabel enforces equal headers
311 before and including routing header, however user may supply options
312 following rthdr.
313 */
314
fl6_merge_options(struct ipv6_txoptions * opt_space,struct ip6_flowlabel * fl,struct ipv6_txoptions * fopt)315 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
316 struct ip6_flowlabel *fl,
317 struct ipv6_txoptions *fopt)
318 {
319 struct ipv6_txoptions *fl_opt = fl->opt;
320
321 if (!fopt || fopt->opt_flen == 0)
322 return fl_opt;
323
324 if (fl_opt) {
325 opt_space->hopopt = fl_opt->hopopt;
326 opt_space->dst0opt = fl_opt->dst0opt;
327 opt_space->srcrt = fl_opt->srcrt;
328 opt_space->opt_nflen = fl_opt->opt_nflen;
329 } else {
330 if (fopt->opt_nflen == 0)
331 return fopt;
332 opt_space->hopopt = NULL;
333 opt_space->dst0opt = NULL;
334 opt_space->srcrt = NULL;
335 opt_space->opt_nflen = 0;
336 }
337 opt_space->dst1opt = fopt->dst1opt;
338 opt_space->opt_flen = fopt->opt_flen;
339 opt_space->tot_len = fopt->tot_len;
340 return opt_space;
341 }
342 EXPORT_SYMBOL_GPL(fl6_merge_options);
343
check_linger(unsigned long ttl)344 static unsigned long check_linger(unsigned long ttl)
345 {
346 if (ttl < FL_MIN_LINGER)
347 return FL_MIN_LINGER*HZ;
348 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
349 return 0;
350 return ttl*HZ;
351 }
352
fl6_renew(struct ip6_flowlabel * fl,unsigned long linger,unsigned long expires)353 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
354 {
355 linger = check_linger(linger);
356 if (!linger)
357 return -EPERM;
358 expires = check_linger(expires);
359 if (!expires)
360 return -EPERM;
361
362 spin_lock_bh(&ip6_fl_lock);
363 fl->lastuse = jiffies;
364 if (time_before(fl->linger, linger))
365 fl->linger = linger;
366 if (time_before(expires, fl->linger))
367 expires = fl->linger;
368 if (time_before(fl->expires, fl->lastuse + expires))
369 fl->expires = fl->lastuse + expires;
370 spin_unlock_bh(&ip6_fl_lock);
371
372 return 0;
373 }
374
375 static struct ip6_flowlabel *
fl_create(struct net * net,struct sock * sk,struct in6_flowlabel_req * freq,sockptr_t optval,int optlen,int * err_p)376 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
377 sockptr_t optval, int optlen, int *err_p)
378 {
379 struct ip6_flowlabel *fl = NULL;
380 int olen;
381 int addr_type;
382 int err;
383
384 olen = optlen - CMSG_ALIGN(sizeof(*freq));
385 err = -EINVAL;
386 if (olen > 64 * 1024)
387 goto done;
388
389 err = -ENOMEM;
390 fl = kzalloc(sizeof(*fl), GFP_KERNEL);
391 if (!fl)
392 goto done;
393
394 if (olen > 0) {
395 struct msghdr msg;
396 struct flowi6 flowi6;
397 struct ipcm6_cookie ipc6;
398
399 err = -ENOMEM;
400 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
401 if (!fl->opt)
402 goto done;
403
404 memset(fl->opt, 0, sizeof(*fl->opt));
405 fl->opt->tot_len = sizeof(*fl->opt) + olen;
406 err = -EFAULT;
407 if (copy_from_sockptr_offset(fl->opt + 1, optval,
408 CMSG_ALIGN(sizeof(*freq)), olen))
409 goto done;
410
411 msg.msg_controllen = olen;
412 msg.msg_control = (void *)(fl->opt+1);
413 memset(&flowi6, 0, sizeof(flowi6));
414
415 ipc6.opt = fl->opt;
416 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6);
417 if (err)
418 goto done;
419 err = -EINVAL;
420 if (fl->opt->opt_flen)
421 goto done;
422 if (fl->opt->opt_nflen == 0) {
423 kfree(fl->opt);
424 fl->opt = NULL;
425 }
426 }
427
428 fl->fl_net = net;
429 fl->expires = jiffies;
430 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
431 if (err)
432 goto done;
433 fl->share = freq->flr_share;
434 addr_type = ipv6_addr_type(&freq->flr_dst);
435 if ((addr_type & IPV6_ADDR_MAPPED) ||
436 addr_type == IPV6_ADDR_ANY) {
437 err = -EINVAL;
438 goto done;
439 }
440 fl->dst = freq->flr_dst;
441 atomic_set(&fl->users, 1);
442 switch (fl->share) {
443 case IPV6_FL_S_EXCL:
444 case IPV6_FL_S_ANY:
445 break;
446 case IPV6_FL_S_PROCESS:
447 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
448 break;
449 case IPV6_FL_S_USER:
450 fl->owner.uid = current_euid();
451 break;
452 default:
453 err = -EINVAL;
454 goto done;
455 }
456 if (fl_shared_exclusive(fl) || fl->opt) {
457 WRITE_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl, 1);
458 static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
459 }
460 return fl;
461
462 done:
463 if (fl) {
464 kfree(fl->opt);
465 kfree(fl);
466 }
467 *err_p = err;
468 return NULL;
469 }
470
mem_check(struct sock * sk)471 static int mem_check(struct sock *sk)
472 {
473 struct ipv6_pinfo *np = inet6_sk(sk);
474 struct ipv6_fl_socklist *sfl;
475 int room = FL_MAX_SIZE - atomic_read(&fl_size);
476 int count = 0;
477
478 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
479 return 0;
480
481 rcu_read_lock();
482 for_each_sk_fl_rcu(np, sfl)
483 count++;
484 rcu_read_unlock();
485
486 if (room <= 0 ||
487 ((count >= FL_MAX_PER_SOCK ||
488 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
489 !capable(CAP_NET_ADMIN)))
490 return -ENOBUFS;
491
492 return 0;
493 }
494
fl_link(struct ipv6_pinfo * np,struct ipv6_fl_socklist * sfl,struct ip6_flowlabel * fl)495 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
496 struct ip6_flowlabel *fl)
497 {
498 spin_lock_bh(&ip6_sk_fl_lock);
499 sfl->fl = fl;
500 sfl->next = np->ipv6_fl_list;
501 rcu_assign_pointer(np->ipv6_fl_list, sfl);
502 spin_unlock_bh(&ip6_sk_fl_lock);
503 }
504
ipv6_flowlabel_opt_get(struct sock * sk,struct in6_flowlabel_req * freq,int flags)505 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
506 int flags)
507 {
508 struct ipv6_pinfo *np = inet6_sk(sk);
509 struct ipv6_fl_socklist *sfl;
510
511 if (flags & IPV6_FL_F_REMOTE) {
512 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
513 return 0;
514 }
515
516 if (np->repflow) {
517 freq->flr_label = np->flow_label;
518 return 0;
519 }
520
521 rcu_read_lock();
522
523 for_each_sk_fl_rcu(np, sfl) {
524 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
525 spin_lock_bh(&ip6_fl_lock);
526 freq->flr_label = sfl->fl->label;
527 freq->flr_dst = sfl->fl->dst;
528 freq->flr_share = sfl->fl->share;
529 freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
530 freq->flr_linger = sfl->fl->linger / HZ;
531
532 spin_unlock_bh(&ip6_fl_lock);
533 rcu_read_unlock();
534 return 0;
535 }
536 }
537 rcu_read_unlock();
538
539 return -ENOENT;
540 }
541
542 #define socklist_dereference(__sflp) \
543 rcu_dereference_protected(__sflp, lockdep_is_held(&ip6_sk_fl_lock))
544
ipv6_flowlabel_put(struct sock * sk,struct in6_flowlabel_req * freq)545 static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq)
546 {
547 struct ipv6_pinfo *np = inet6_sk(sk);
548 struct ipv6_fl_socklist __rcu **sflp;
549 struct ipv6_fl_socklist *sfl;
550
551 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
552 if (sk->sk_protocol != IPPROTO_TCP)
553 return -ENOPROTOOPT;
554 if (!np->repflow)
555 return -ESRCH;
556 np->flow_label = 0;
557 np->repflow = 0;
558 return 0;
559 }
560
561 spin_lock_bh(&ip6_sk_fl_lock);
562 for (sflp = &np->ipv6_fl_list;
563 (sfl = socklist_dereference(*sflp)) != NULL;
564 sflp = &sfl->next) {
565 if (sfl->fl->label == freq->flr_label)
566 goto found;
567 }
568 spin_unlock_bh(&ip6_sk_fl_lock);
569 return -ESRCH;
570 found:
571 if (freq->flr_label == (np->flow_label & IPV6_FLOWLABEL_MASK))
572 np->flow_label &= ~IPV6_FLOWLABEL_MASK;
573 *sflp = sfl->next;
574 spin_unlock_bh(&ip6_sk_fl_lock);
575 fl_release(sfl->fl);
576 kfree_rcu(sfl, rcu);
577 return 0;
578 }
579
ipv6_flowlabel_renew(struct sock * sk,struct in6_flowlabel_req * freq)580 static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
581 {
582 struct ipv6_pinfo *np = inet6_sk(sk);
583 struct net *net = sock_net(sk);
584 struct ipv6_fl_socklist *sfl;
585 int err;
586
587 rcu_read_lock();
588 for_each_sk_fl_rcu(np, sfl) {
589 if (sfl->fl->label == freq->flr_label) {
590 err = fl6_renew(sfl->fl, freq->flr_linger,
591 freq->flr_expires);
592 rcu_read_unlock();
593 return err;
594 }
595 }
596 rcu_read_unlock();
597
598 if (freq->flr_share == IPV6_FL_S_NONE &&
599 ns_capable(net->user_ns, CAP_NET_ADMIN)) {
600 struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
601
602 if (fl) {
603 err = fl6_renew(fl, freq->flr_linger,
604 freq->flr_expires);
605 fl_release(fl);
606 return err;
607 }
608 }
609 return -ESRCH;
610 }
611
ipv6_flowlabel_get(struct sock * sk,struct in6_flowlabel_req * freq,sockptr_t optval,int optlen)612 static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
613 sockptr_t optval, int optlen)
614 {
615 struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
616 struct ip6_flowlabel *fl, *fl1 = NULL;
617 struct ipv6_pinfo *np = inet6_sk(sk);
618 struct net *net = sock_net(sk);
619 int err;
620
621 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
622 if (net->ipv6.sysctl.flowlabel_consistency) {
623 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
624 return -EPERM;
625 }
626
627 if (sk->sk_protocol != IPPROTO_TCP)
628 return -ENOPROTOOPT;
629 np->repflow = 1;
630 return 0;
631 }
632
633 if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
634 return -EINVAL;
635 if (net->ipv6.sysctl.flowlabel_state_ranges &&
636 (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
637 return -ERANGE;
638
639 fl = fl_create(net, sk, freq, optval, optlen, &err);
640 if (!fl)
641 return err;
642
643 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
644
645 if (freq->flr_label) {
646 err = -EEXIST;
647 rcu_read_lock();
648 for_each_sk_fl_rcu(np, sfl) {
649 if (sfl->fl->label == freq->flr_label) {
650 if (freq->flr_flags & IPV6_FL_F_EXCL) {
651 rcu_read_unlock();
652 goto done;
653 }
654 fl1 = sfl->fl;
655 if (!atomic_inc_not_zero(&fl1->users))
656 fl1 = NULL;
657 break;
658 }
659 }
660 rcu_read_unlock();
661
662 if (!fl1)
663 fl1 = fl_lookup(net, freq->flr_label);
664 if (fl1) {
665 recheck:
666 err = -EEXIST;
667 if (freq->flr_flags&IPV6_FL_F_EXCL)
668 goto release;
669 err = -EPERM;
670 if (fl1->share == IPV6_FL_S_EXCL ||
671 fl1->share != fl->share ||
672 ((fl1->share == IPV6_FL_S_PROCESS) &&
673 (fl1->owner.pid != fl->owner.pid)) ||
674 ((fl1->share == IPV6_FL_S_USER) &&
675 !uid_eq(fl1->owner.uid, fl->owner.uid)))
676 goto release;
677
678 err = -ENOMEM;
679 if (!sfl1)
680 goto release;
681 if (fl->linger > fl1->linger)
682 fl1->linger = fl->linger;
683 if ((long)(fl->expires - fl1->expires) > 0)
684 fl1->expires = fl->expires;
685 fl_link(np, sfl1, fl1);
686 fl_free(fl);
687 return 0;
688
689 release:
690 fl_release(fl1);
691 goto done;
692 }
693 }
694 err = -ENOENT;
695 if (!(freq->flr_flags & IPV6_FL_F_CREATE))
696 goto done;
697
698 err = -ENOMEM;
699 if (!sfl1)
700 goto done;
701
702 err = mem_check(sk);
703 if (err != 0)
704 goto done;
705
706 fl1 = fl_intern(net, fl, freq->flr_label);
707 if (fl1)
708 goto recheck;
709
710 if (!freq->flr_label) {
711 size_t offset = offsetof(struct in6_flowlabel_req, flr_label);
712
713 if (copy_to_sockptr_offset(optval, offset, &fl->label,
714 sizeof(fl->label))) {
715 /* Intentionally ignore fault. */
716 }
717 }
718
719 fl_link(np, sfl1, fl);
720 return 0;
721 done:
722 fl_free(fl);
723 kfree(sfl1);
724 return err;
725 }
726
ipv6_flowlabel_opt(struct sock * sk,sockptr_t optval,int optlen)727 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
728 {
729 struct in6_flowlabel_req freq;
730
731 if (optlen < sizeof(freq))
732 return -EINVAL;
733 if (copy_from_sockptr(&freq, optval, sizeof(freq)))
734 return -EFAULT;
735
736 switch (freq.flr_action) {
737 case IPV6_FL_A_PUT:
738 return ipv6_flowlabel_put(sk, &freq);
739 case IPV6_FL_A_RENEW:
740 return ipv6_flowlabel_renew(sk, &freq);
741 case IPV6_FL_A_GET:
742 return ipv6_flowlabel_get(sk, &freq, optval, optlen);
743 default:
744 return -EINVAL;
745 }
746 }
747
748 #ifdef CONFIG_PROC_FS
749
750 struct ip6fl_iter_state {
751 struct seq_net_private p;
752 struct pid_namespace *pid_ns;
753 int bucket;
754 };
755
756 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
757
ip6fl_get_first(struct seq_file * seq)758 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
759 {
760 struct ip6_flowlabel *fl = NULL;
761 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
762 struct net *net = seq_file_net(seq);
763
764 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
765 for_each_fl_rcu(state->bucket, fl) {
766 if (net_eq(fl->fl_net, net))
767 goto out;
768 }
769 }
770 fl = NULL;
771 out:
772 return fl;
773 }
774
ip6fl_get_next(struct seq_file * seq,struct ip6_flowlabel * fl)775 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
776 {
777 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
778 struct net *net = seq_file_net(seq);
779
780 for_each_fl_continue_rcu(fl) {
781 if (net_eq(fl->fl_net, net))
782 goto out;
783 }
784
785 try_again:
786 if (++state->bucket <= FL_HASH_MASK) {
787 for_each_fl_rcu(state->bucket, fl) {
788 if (net_eq(fl->fl_net, net))
789 goto out;
790 }
791 goto try_again;
792 }
793 fl = NULL;
794
795 out:
796 return fl;
797 }
798
ip6fl_get_idx(struct seq_file * seq,loff_t pos)799 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
800 {
801 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
802 if (fl)
803 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
804 --pos;
805 return pos ? NULL : fl;
806 }
807
ip6fl_seq_start(struct seq_file * seq,loff_t * pos)808 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
809 __acquires(RCU)
810 {
811 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
812
813 state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
814
815 rcu_read_lock();
816 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
817 }
818
ip6fl_seq_next(struct seq_file * seq,void * v,loff_t * pos)819 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
820 {
821 struct ip6_flowlabel *fl;
822
823 if (v == SEQ_START_TOKEN)
824 fl = ip6fl_get_first(seq);
825 else
826 fl = ip6fl_get_next(seq, v);
827 ++*pos;
828 return fl;
829 }
830
ip6fl_seq_stop(struct seq_file * seq,void * v)831 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
832 __releases(RCU)
833 {
834 rcu_read_unlock();
835 }
836
ip6fl_seq_show(struct seq_file * seq,void * v)837 static int ip6fl_seq_show(struct seq_file *seq, void *v)
838 {
839 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
840 if (v == SEQ_START_TOKEN) {
841 seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n");
842 } else {
843 struct ip6_flowlabel *fl = v;
844 seq_printf(seq,
845 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
846 (unsigned int)ntohl(fl->label),
847 fl->share,
848 ((fl->share == IPV6_FL_S_PROCESS) ?
849 pid_nr_ns(fl->owner.pid, state->pid_ns) :
850 ((fl->share == IPV6_FL_S_USER) ?
851 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
852 0)),
853 atomic_read(&fl->users),
854 fl->linger/HZ,
855 (long)(fl->expires - jiffies)/HZ,
856 &fl->dst,
857 fl->opt ? fl->opt->opt_nflen : 0);
858 }
859 return 0;
860 }
861
862 static const struct seq_operations ip6fl_seq_ops = {
863 .start = ip6fl_seq_start,
864 .next = ip6fl_seq_next,
865 .stop = ip6fl_seq_stop,
866 .show = ip6fl_seq_show,
867 };
868
ip6_flowlabel_proc_init(struct net * net)869 static int __net_init ip6_flowlabel_proc_init(struct net *net)
870 {
871 if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
872 &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
873 return -ENOMEM;
874 return 0;
875 }
876
ip6_flowlabel_proc_fini(struct net * net)877 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
878 {
879 remove_proc_entry("ip6_flowlabel", net->proc_net);
880 }
881 #else
ip6_flowlabel_proc_init(struct net * net)882 static inline int ip6_flowlabel_proc_init(struct net *net)
883 {
884 return 0;
885 }
ip6_flowlabel_proc_fini(struct net * net)886 static inline void ip6_flowlabel_proc_fini(struct net *net)
887 {
888 }
889 #endif
890
ip6_flowlabel_net_exit(struct net * net)891 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
892 {
893 ip6_fl_purge(net);
894 ip6_flowlabel_proc_fini(net);
895 }
896
897 static struct pernet_operations ip6_flowlabel_net_ops = {
898 .init = ip6_flowlabel_proc_init,
899 .exit = ip6_flowlabel_net_exit,
900 };
901
ip6_flowlabel_init(void)902 int ip6_flowlabel_init(void)
903 {
904 return register_pernet_subsys(&ip6_flowlabel_net_ops);
905 }
906
ip6_flowlabel_cleanup(void)907 void ip6_flowlabel_cleanup(void)
908 {
909 static_key_deferred_flush(&ipv6_flowlabel_exclusive);
910 del_timer(&ip6_fl_gc_timer);
911 unregister_pernet_subsys(&ip6_flowlabel_net_ops);
912 }
913