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(sk, sfl) \
70 for (sfl = rcu_dereference(inet_sk(sk)->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 (!timer_pending(&ip6_fl_gc_timer) ||
137 time_after(ip6_fl_gc_timer.expires, ttd))
138 mod_timer(&ip6_fl_gc_timer, ttd);
139 }
140 spin_unlock_bh(&ip6_fl_lock);
141 }
142
ip6_fl_gc(struct timer_list * unused)143 static void ip6_fl_gc(struct timer_list *unused)
144 {
145 int i;
146 unsigned long now = jiffies;
147 unsigned long sched = 0;
148
149 spin_lock(&ip6_fl_lock);
150
151 for (i = 0; i <= FL_HASH_MASK; i++) {
152 struct ip6_flowlabel *fl;
153 struct ip6_flowlabel __rcu **flp;
154
155 flp = &fl_ht[i];
156 while ((fl = rcu_dereference_protected(*flp,
157 lockdep_is_held(&ip6_fl_lock))) != NULL) {
158 if (atomic_read(&fl->users) == 0) {
159 unsigned long ttd = fl->lastuse + fl->linger;
160 if (time_after(ttd, fl->expires))
161 fl->expires = ttd;
162 ttd = fl->expires;
163 if (time_after_eq(now, ttd)) {
164 *flp = fl->next;
165 fl_free(fl);
166 atomic_dec(&fl_size);
167 continue;
168 }
169 if (!sched || time_before(ttd, sched))
170 sched = ttd;
171 }
172 flp = &fl->next;
173 }
174 }
175 if (!sched && atomic_read(&fl_size))
176 sched = now + FL_MAX_LINGER;
177 if (sched) {
178 mod_timer(&ip6_fl_gc_timer, sched);
179 }
180 spin_unlock(&ip6_fl_lock);
181 }
182
ip6_fl_purge(struct net * net)183 static void __net_exit ip6_fl_purge(struct net *net)
184 {
185 int i;
186
187 spin_lock_bh(&ip6_fl_lock);
188 for (i = 0; i <= FL_HASH_MASK; i++) {
189 struct ip6_flowlabel *fl;
190 struct ip6_flowlabel __rcu **flp;
191
192 flp = &fl_ht[i];
193 while ((fl = rcu_dereference_protected(*flp,
194 lockdep_is_held(&ip6_fl_lock))) != NULL) {
195 if (net_eq(fl->fl_net, net) &&
196 atomic_read(&fl->users) == 0) {
197 *flp = fl->next;
198 fl_free(fl);
199 atomic_dec(&fl_size);
200 continue;
201 }
202 flp = &fl->next;
203 }
204 }
205 spin_unlock_bh(&ip6_fl_lock);
206 }
207
fl_intern(struct net * net,struct ip6_flowlabel * fl,__be32 label)208 static struct ip6_flowlabel *fl_intern(struct net *net,
209 struct ip6_flowlabel *fl, __be32 label)
210 {
211 struct ip6_flowlabel *lfl;
212
213 fl->label = label & IPV6_FLOWLABEL_MASK;
214
215 rcu_read_lock();
216 spin_lock_bh(&ip6_fl_lock);
217 if (label == 0) {
218 for (;;) {
219 fl->label = htonl(get_random_u32())&IPV6_FLOWLABEL_MASK;
220 if (fl->label) {
221 lfl = __fl_lookup(net, fl->label);
222 if (!lfl)
223 break;
224 }
225 }
226 } else {
227 /*
228 * we dropper the ip6_fl_lock, so this entry could reappear
229 * and we need to recheck with it.
230 *
231 * OTOH no need to search the active socket first, like it is
232 * done in ipv6_flowlabel_opt - sock is locked, so new entry
233 * with the same label can only appear on another sock
234 */
235 lfl = __fl_lookup(net, fl->label);
236 if (lfl) {
237 atomic_inc(&lfl->users);
238 spin_unlock_bh(&ip6_fl_lock);
239 rcu_read_unlock();
240 return lfl;
241 }
242 }
243
244 fl->lastuse = jiffies;
245 fl->next = fl_ht[FL_HASH(fl->label)];
246 rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
247 atomic_inc(&fl_size);
248 spin_unlock_bh(&ip6_fl_lock);
249 rcu_read_unlock();
250 return NULL;
251 }
252
253
254
255 /* Socket flowlabel lists */
256
__fl6_sock_lookup(struct sock * sk,__be32 label)257 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
258 {
259 struct ipv6_fl_socklist *sfl;
260
261 label &= IPV6_FLOWLABEL_MASK;
262
263 rcu_read_lock();
264 for_each_sk_fl_rcu(sk, sfl) {
265 struct ip6_flowlabel *fl = sfl->fl;
266
267 if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
268 fl->lastuse = jiffies;
269 rcu_read_unlock();
270 return fl;
271 }
272 }
273 rcu_read_unlock();
274 return NULL;
275 }
276 EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
277
fl6_free_socklist(struct sock * sk)278 void fl6_free_socklist(struct sock *sk)
279 {
280 struct inet_sock *inet = inet_sk(sk);
281 struct ipv6_fl_socklist *sfl;
282
283 if (!rcu_access_pointer(inet->ipv6_fl_list))
284 return;
285
286 spin_lock_bh(&ip6_sk_fl_lock);
287 while ((sfl = rcu_dereference_protected(inet->ipv6_fl_list,
288 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
289 inet->ipv6_fl_list = sfl->next;
290 spin_unlock_bh(&ip6_sk_fl_lock);
291
292 fl_release(sfl->fl);
293 kfree_rcu(sfl, rcu);
294
295 spin_lock_bh(&ip6_sk_fl_lock);
296 }
297 spin_unlock_bh(&ip6_sk_fl_lock);
298 }
299
300 /* Service routines */
301
302
303 /*
304 It is the only difficult place. flowlabel enforces equal headers
305 before and including routing header, however user may supply options
306 following rthdr.
307 */
308
fl6_merge_options(struct ipv6_txoptions * opt_space,struct ip6_flowlabel * fl,struct ipv6_txoptions * fopt)309 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
310 struct ip6_flowlabel *fl,
311 struct ipv6_txoptions *fopt)
312 {
313 struct ipv6_txoptions *fl_opt = fl->opt;
314
315 if (!fopt || fopt->opt_flen == 0)
316 return fl_opt;
317
318 if (fl_opt) {
319 opt_space->hopopt = fl_opt->hopopt;
320 opt_space->dst0opt = fl_opt->dst0opt;
321 opt_space->srcrt = fl_opt->srcrt;
322 opt_space->opt_nflen = fl_opt->opt_nflen;
323 } else {
324 if (fopt->opt_nflen == 0)
325 return fopt;
326 opt_space->hopopt = NULL;
327 opt_space->dst0opt = NULL;
328 opt_space->srcrt = NULL;
329 opt_space->opt_nflen = 0;
330 }
331 opt_space->dst1opt = fopt->dst1opt;
332 opt_space->opt_flen = fopt->opt_flen;
333 opt_space->tot_len = fopt->tot_len;
334 return opt_space;
335 }
336 EXPORT_SYMBOL_GPL(fl6_merge_options);
337
check_linger(unsigned long ttl)338 static unsigned long check_linger(unsigned long ttl)
339 {
340 if (ttl < FL_MIN_LINGER)
341 return FL_MIN_LINGER*HZ;
342 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
343 return 0;
344 return ttl*HZ;
345 }
346
fl6_renew(struct ip6_flowlabel * fl,unsigned long linger,unsigned long expires)347 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
348 {
349 linger = check_linger(linger);
350 if (!linger)
351 return -EPERM;
352 expires = check_linger(expires);
353 if (!expires)
354 return -EPERM;
355
356 spin_lock_bh(&ip6_fl_lock);
357 fl->lastuse = jiffies;
358 if (time_before(fl->linger, linger))
359 fl->linger = linger;
360 if (time_before(expires, fl->linger))
361 expires = fl->linger;
362 if (time_before(fl->expires, fl->lastuse + expires))
363 fl->expires = fl->lastuse + expires;
364 spin_unlock_bh(&ip6_fl_lock);
365
366 return 0;
367 }
368
369 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)370 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
371 sockptr_t optval, int optlen, int *err_p)
372 {
373 struct ip6_flowlabel *fl = NULL;
374 int olen;
375 int addr_type;
376 int err;
377
378 olen = optlen - CMSG_ALIGN(sizeof(*freq));
379 err = -EINVAL;
380 if (olen > 64 * 1024)
381 goto done;
382
383 err = -ENOMEM;
384 fl = kzalloc_obj(*fl);
385 if (!fl)
386 goto done;
387
388 if (olen > 0) {
389 struct msghdr msg;
390 struct flowi6 flowi6;
391 struct ipcm6_cookie ipc6;
392
393 err = -ENOMEM;
394 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
395 if (!fl->opt)
396 goto done;
397
398 memset(fl->opt, 0, sizeof(*fl->opt));
399 fl->opt->tot_len = sizeof(*fl->opt) + olen;
400 err = -EFAULT;
401 if (copy_from_sockptr_offset(fl->opt + 1, optval,
402 CMSG_ALIGN(sizeof(*freq)), olen))
403 goto done;
404
405 msg.msg_controllen = olen;
406 msg.msg_control = (void *)(fl->opt+1);
407 memset(&flowi6, 0, sizeof(flowi6));
408
409 ipc6.opt = fl->opt;
410 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6);
411 if (err)
412 goto done;
413 err = -EINVAL;
414 if (fl->opt->opt_flen)
415 goto done;
416 if (fl->opt->opt_nflen == 0) {
417 kfree(fl->opt);
418 fl->opt = NULL;
419 }
420 }
421
422 fl->fl_net = net;
423 fl->expires = jiffies;
424 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
425 if (err)
426 goto done;
427 fl->share = freq->flr_share;
428 addr_type = ipv6_addr_type(&freq->flr_dst);
429 if ((addr_type & IPV6_ADDR_MAPPED) ||
430 addr_type == IPV6_ADDR_ANY) {
431 err = -EINVAL;
432 goto done;
433 }
434 fl->dst = freq->flr_dst;
435 atomic_set(&fl->users, 1);
436 switch (fl->share) {
437 case IPV6_FL_S_EXCL:
438 case IPV6_FL_S_ANY:
439 break;
440 case IPV6_FL_S_PROCESS:
441 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
442 break;
443 case IPV6_FL_S_USER:
444 fl->owner.uid = current_euid();
445 break;
446 default:
447 err = -EINVAL;
448 goto done;
449 }
450 if (fl_shared_exclusive(fl) || fl->opt) {
451 WRITE_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl, 1);
452 static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
453 }
454 return fl;
455
456 done:
457 if (fl) {
458 kfree(fl->opt);
459 kfree(fl);
460 }
461 *err_p = err;
462 return NULL;
463 }
464
mem_check(struct sock * sk)465 static int mem_check(struct sock *sk)
466 {
467 int room = FL_MAX_SIZE - atomic_read(&fl_size);
468 struct ipv6_fl_socklist *sfl;
469 int count = 0;
470
471 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
472 return 0;
473
474 rcu_read_lock();
475 for_each_sk_fl_rcu(sk, sfl)
476 count++;
477 rcu_read_unlock();
478
479 if (room <= 0 ||
480 ((count >= FL_MAX_PER_SOCK ||
481 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
482 !capable(CAP_NET_ADMIN)))
483 return -ENOBUFS;
484
485 return 0;
486 }
487
fl_link(struct sock * sk,struct ipv6_fl_socklist * sfl,struct ip6_flowlabel * fl)488 static inline void fl_link(struct sock *sk, struct ipv6_fl_socklist *sfl,
489 struct ip6_flowlabel *fl)
490 {
491 struct inet_sock *inet = inet_sk(sk);
492
493 spin_lock_bh(&ip6_sk_fl_lock);
494 sfl->fl = fl;
495 sfl->next = inet->ipv6_fl_list;
496 rcu_assign_pointer(inet->ipv6_fl_list, sfl);
497 spin_unlock_bh(&ip6_sk_fl_lock);
498 }
499
ipv6_flowlabel_opt_get(struct sock * sk,struct in6_flowlabel_req * freq,int flags)500 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
501 int flags)
502 {
503 struct ipv6_pinfo *np = inet6_sk(sk);
504 struct ipv6_fl_socklist *sfl;
505
506 if (flags & IPV6_FL_F_REMOTE) {
507 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
508 return 0;
509 }
510
511 if (inet6_test_bit(REPFLOW, sk)) {
512 freq->flr_label = np->flow_label;
513 return 0;
514 }
515
516 rcu_read_lock();
517
518 for_each_sk_fl_rcu(sk, sfl) {
519 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
520 spin_lock_bh(&ip6_fl_lock);
521 freq->flr_label = sfl->fl->label;
522 freq->flr_dst = sfl->fl->dst;
523 freq->flr_share = sfl->fl->share;
524 freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
525 freq->flr_linger = sfl->fl->linger / HZ;
526
527 spin_unlock_bh(&ip6_fl_lock);
528 rcu_read_unlock();
529 return 0;
530 }
531 }
532 rcu_read_unlock();
533
534 return -ENOENT;
535 }
536
537 #define socklist_dereference(__sflp) \
538 rcu_dereference_protected(__sflp, lockdep_is_held(&ip6_sk_fl_lock))
539
ipv6_flowlabel_put(struct sock * sk,struct in6_flowlabel_req * freq)540 static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq)
541 {
542 struct ipv6_pinfo *np = inet6_sk(sk);
543 struct ipv6_fl_socklist __rcu **sflp;
544 struct ipv6_fl_socklist *sfl;
545
546 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
547 if (sk->sk_protocol != IPPROTO_TCP)
548 return -ENOPROTOOPT;
549 if (!inet6_test_bit(REPFLOW, sk))
550 return -ESRCH;
551 np->flow_label = 0;
552 inet6_clear_bit(REPFLOW, sk);
553 return 0;
554 }
555
556 spin_lock_bh(&ip6_sk_fl_lock);
557 for (sflp = &inet_sk(sk)->ipv6_fl_list;
558 (sfl = socklist_dereference(*sflp)) != NULL;
559 sflp = &sfl->next) {
560 if (sfl->fl->label == freq->flr_label)
561 goto found;
562 }
563 spin_unlock_bh(&ip6_sk_fl_lock);
564 return -ESRCH;
565 found:
566 if (freq->flr_label == (np->flow_label & IPV6_FLOWLABEL_MASK))
567 np->flow_label &= ~IPV6_FLOWLABEL_MASK;
568 *sflp = sfl->next;
569 spin_unlock_bh(&ip6_sk_fl_lock);
570 fl_release(sfl->fl);
571 kfree_rcu(sfl, rcu);
572 return 0;
573 }
574
ipv6_flowlabel_renew(struct sock * sk,struct in6_flowlabel_req * freq)575 static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
576 {
577 struct net *net = sock_net(sk);
578 struct ipv6_fl_socklist *sfl;
579 int err;
580
581 rcu_read_lock();
582 for_each_sk_fl_rcu(sk, sfl) {
583 if (sfl->fl->label == freq->flr_label) {
584 err = fl6_renew(sfl->fl, freq->flr_linger,
585 freq->flr_expires);
586 rcu_read_unlock();
587 return err;
588 }
589 }
590 rcu_read_unlock();
591
592 if (freq->flr_share == IPV6_FL_S_NONE &&
593 ns_capable(net->user_ns, CAP_NET_ADMIN)) {
594 struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
595
596 if (fl) {
597 err = fl6_renew(fl, freq->flr_linger,
598 freq->flr_expires);
599 fl_release(fl);
600 return err;
601 }
602 }
603 return -ESRCH;
604 }
605
ipv6_flowlabel_get(struct sock * sk,struct in6_flowlabel_req * freq,sockptr_t optval,int optlen)606 static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
607 sockptr_t optval, int optlen)
608 {
609 struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
610 struct ip6_flowlabel *fl, *fl1 = NULL;
611 struct net *net = sock_net(sk);
612 int err;
613
614 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
615 if (net->ipv6.sysctl.flowlabel_consistency) {
616 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
617 return -EPERM;
618 }
619
620 if (sk->sk_protocol != IPPROTO_TCP)
621 return -ENOPROTOOPT;
622 inet6_set_bit(REPFLOW, sk);
623 return 0;
624 }
625
626 if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
627 return -EINVAL;
628 if (net->ipv6.sysctl.flowlabel_state_ranges &&
629 (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
630 return -ERANGE;
631
632 fl = fl_create(net, sk, freq, optval, optlen, &err);
633 if (!fl)
634 return err;
635
636 sfl1 = kmalloc_obj(*sfl1);
637
638 if (freq->flr_label) {
639 err = -EEXIST;
640 rcu_read_lock();
641 for_each_sk_fl_rcu(sk, sfl) {
642 if (sfl->fl->label == freq->flr_label) {
643 if (freq->flr_flags & IPV6_FL_F_EXCL) {
644 rcu_read_unlock();
645 goto done;
646 }
647 fl1 = sfl->fl;
648 if (!atomic_inc_not_zero(&fl1->users))
649 fl1 = NULL;
650 break;
651 }
652 }
653 rcu_read_unlock();
654
655 if (!fl1)
656 fl1 = fl_lookup(net, freq->flr_label);
657 if (fl1) {
658 recheck:
659 err = -EEXIST;
660 if (freq->flr_flags&IPV6_FL_F_EXCL)
661 goto release;
662 err = -EPERM;
663 if (fl1->share == IPV6_FL_S_EXCL ||
664 fl1->share != fl->share ||
665 ((fl1->share == IPV6_FL_S_PROCESS) &&
666 (fl1->owner.pid != fl->owner.pid)) ||
667 ((fl1->share == IPV6_FL_S_USER) &&
668 !uid_eq(fl1->owner.uid, fl->owner.uid)))
669 goto release;
670
671 err = -ENOMEM;
672 if (!sfl1)
673 goto release;
674 if (fl->linger > fl1->linger)
675 fl1->linger = fl->linger;
676 if ((long)(fl->expires - fl1->expires) > 0)
677 fl1->expires = fl->expires;
678 fl_link(sk, sfl1, fl1);
679 fl_free(fl);
680 return 0;
681
682 release:
683 fl_release(fl1);
684 goto done;
685 }
686 }
687 err = -ENOENT;
688 if (!(freq->flr_flags & IPV6_FL_F_CREATE))
689 goto done;
690
691 err = -ENOMEM;
692 if (!sfl1)
693 goto done;
694
695 err = mem_check(sk);
696 if (err != 0)
697 goto done;
698
699 fl1 = fl_intern(net, fl, freq->flr_label);
700 if (fl1)
701 goto recheck;
702
703 if (!freq->flr_label) {
704 size_t offset = offsetof(struct in6_flowlabel_req, flr_label);
705
706 if (copy_to_sockptr_offset(optval, offset, &fl->label,
707 sizeof(fl->label))) {
708 /* Intentionally ignore fault. */
709 }
710 }
711
712 fl_link(sk, sfl1, fl);
713 return 0;
714 done:
715 fl_free(fl);
716 kfree(sfl1);
717 return err;
718 }
719
ipv6_flowlabel_opt(struct sock * sk,sockptr_t optval,int optlen)720 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
721 {
722 struct in6_flowlabel_req freq;
723
724 if (optlen < sizeof(freq))
725 return -EINVAL;
726 if (copy_from_sockptr(&freq, optval, sizeof(freq)))
727 return -EFAULT;
728
729 switch (freq.flr_action) {
730 case IPV6_FL_A_PUT:
731 return ipv6_flowlabel_put(sk, &freq);
732 case IPV6_FL_A_RENEW:
733 return ipv6_flowlabel_renew(sk, &freq);
734 case IPV6_FL_A_GET:
735 return ipv6_flowlabel_get(sk, &freq, optval, optlen);
736 default:
737 return -EINVAL;
738 }
739 }
740
741 #ifdef CONFIG_PROC_FS
742
743 struct ip6fl_iter_state {
744 struct seq_net_private p;
745 struct pid_namespace *pid_ns;
746 int bucket;
747 };
748
749 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
750
ip6fl_get_first(struct seq_file * seq)751 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
752 {
753 struct ip6_flowlabel *fl = NULL;
754 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
755 struct net *net = seq_file_net(seq);
756
757 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
758 for_each_fl_rcu(state->bucket, fl) {
759 if (net_eq(fl->fl_net, net))
760 goto out;
761 }
762 }
763 fl = NULL;
764 out:
765 return fl;
766 }
767
ip6fl_get_next(struct seq_file * seq,struct ip6_flowlabel * fl)768 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
769 {
770 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
771 struct net *net = seq_file_net(seq);
772
773 for_each_fl_continue_rcu(fl) {
774 if (net_eq(fl->fl_net, net))
775 goto out;
776 }
777
778 try_again:
779 if (++state->bucket <= FL_HASH_MASK) {
780 for_each_fl_rcu(state->bucket, fl) {
781 if (net_eq(fl->fl_net, net))
782 goto out;
783 }
784 goto try_again;
785 }
786 fl = NULL;
787
788 out:
789 return fl;
790 }
791
ip6fl_get_idx(struct seq_file * seq,loff_t pos)792 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
793 {
794 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
795 if (fl)
796 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
797 --pos;
798 return pos ? NULL : fl;
799 }
800
ip6fl_seq_start(struct seq_file * seq,loff_t * pos)801 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
802 __acquires(RCU)
803 {
804 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
805
806 state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
807
808 rcu_read_lock();
809 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
810 }
811
ip6fl_seq_next(struct seq_file * seq,void * v,loff_t * pos)812 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
813 {
814 struct ip6_flowlabel *fl;
815
816 if (v == SEQ_START_TOKEN)
817 fl = ip6fl_get_first(seq);
818 else
819 fl = ip6fl_get_next(seq, v);
820 ++*pos;
821 return fl;
822 }
823
ip6fl_seq_stop(struct seq_file * seq,void * v)824 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
825 __releases(RCU)
826 {
827 rcu_read_unlock();
828 }
829
ip6fl_seq_show(struct seq_file * seq,void * v)830 static int ip6fl_seq_show(struct seq_file *seq, void *v)
831 {
832 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
833 if (v == SEQ_START_TOKEN) {
834 seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n");
835 } else {
836 struct ip6_flowlabel *fl = v;
837 seq_printf(seq,
838 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
839 (unsigned int)ntohl(fl->label),
840 fl->share,
841 ((fl->share == IPV6_FL_S_PROCESS) ?
842 pid_nr_ns(fl->owner.pid, state->pid_ns) :
843 ((fl->share == IPV6_FL_S_USER) ?
844 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
845 0)),
846 atomic_read(&fl->users),
847 fl->linger/HZ,
848 (long)(fl->expires - jiffies)/HZ,
849 &fl->dst,
850 fl->opt ? fl->opt->opt_nflen : 0);
851 }
852 return 0;
853 }
854
855 static const struct seq_operations ip6fl_seq_ops = {
856 .start = ip6fl_seq_start,
857 .next = ip6fl_seq_next,
858 .stop = ip6fl_seq_stop,
859 .show = ip6fl_seq_show,
860 };
861
ip6_flowlabel_proc_init(struct net * net)862 static int __net_init ip6_flowlabel_proc_init(struct net *net)
863 {
864 if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
865 &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
866 return -ENOMEM;
867 return 0;
868 }
869
ip6_flowlabel_proc_fini(struct net * net)870 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
871 {
872 remove_proc_entry("ip6_flowlabel", net->proc_net);
873 }
874 #else
ip6_flowlabel_proc_init(struct net * net)875 static inline int ip6_flowlabel_proc_init(struct net *net)
876 {
877 return 0;
878 }
ip6_flowlabel_proc_fini(struct net * net)879 static inline void ip6_flowlabel_proc_fini(struct net *net)
880 {
881 }
882 #endif
883
ip6_flowlabel_net_exit(struct net * net)884 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
885 {
886 ip6_fl_purge(net);
887 ip6_flowlabel_proc_fini(net);
888 }
889
890 static struct pernet_operations ip6_flowlabel_net_ops = {
891 .init = ip6_flowlabel_proc_init,
892 .exit = ip6_flowlabel_net_exit,
893 };
894
ip6_flowlabel_init(void)895 int ip6_flowlabel_init(void)
896 {
897 return register_pernet_subsys(&ip6_flowlabel_net_ops);
898 }
899
ip6_flowlabel_cleanup(void)900 void ip6_flowlabel_cleanup(void)
901 {
902 static_key_deferred_flush(&ipv6_flowlabel_exclusive);
903 timer_delete(&ip6_fl_gc_timer);
904 unregister_pernet_subsys(&ip6_flowlabel_net_ops);
905 }
906