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_bh(fl_ht[(hash)]); \
62 fl != NULL; \
63 fl = rcu_dereference_bh(fl->next))
64 #define for_each_fl_continue_rcu(fl) \
65 for (fl = rcu_dereference_bh(fl->next); \
66 fl != NULL; \
67 fl = rcu_dereference_bh(fl->next))
68
69 #define for_each_sk_fl_rcu(np, sfl) \
70 for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \
71 sfl != NULL; \
72 sfl = rcu_dereference_bh(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_bh();
90 fl = __fl_lookup(net, label);
91 if (fl && !atomic_inc_not_zero(&fl->users))
92 fl = NULL;
93 rcu_read_unlock_bh();
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 spin_lock_bh(&ip6_fl_lock);
221 if (label == 0) {
222 for (;;) {
223 fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
224 if (fl->label) {
225 lfl = __fl_lookup(net, fl->label);
226 if (!lfl)
227 break;
228 }
229 }
230 } else {
231 /*
232 * we dropper the ip6_fl_lock, so this entry could reappear
233 * and we need to recheck with it.
234 *
235 * OTOH no need to search the active socket first, like it is
236 * done in ipv6_flowlabel_opt - sock is locked, so new entry
237 * with the same label can only appear on another sock
238 */
239 lfl = __fl_lookup(net, fl->label);
240 if (lfl) {
241 atomic_inc(&lfl->users);
242 spin_unlock_bh(&ip6_fl_lock);
243 return lfl;
244 }
245 }
246
247 fl->lastuse = jiffies;
248 fl->next = fl_ht[FL_HASH(fl->label)];
249 rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
250 atomic_inc(&fl_size);
251 spin_unlock_bh(&ip6_fl_lock);
252 return NULL;
253 }
254
255
256
257 /* Socket flowlabel lists */
258
__fl6_sock_lookup(struct sock * sk,__be32 label)259 struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
260 {
261 struct ipv6_fl_socklist *sfl;
262 struct ipv6_pinfo *np = inet6_sk(sk);
263
264 label &= IPV6_FLOWLABEL_MASK;
265
266 rcu_read_lock_bh();
267 for_each_sk_fl_rcu(np, sfl) {
268 struct ip6_flowlabel *fl = sfl->fl;
269
270 if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
271 fl->lastuse = jiffies;
272 rcu_read_unlock_bh();
273 return fl;
274 }
275 }
276 rcu_read_unlock_bh();
277 return NULL;
278 }
279 EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
280
fl6_free_socklist(struct sock * sk)281 void fl6_free_socklist(struct sock *sk)
282 {
283 struct ipv6_pinfo *np = inet6_sk(sk);
284 struct ipv6_fl_socklist *sfl;
285
286 if (!rcu_access_pointer(np->ipv6_fl_list))
287 return;
288
289 spin_lock_bh(&ip6_sk_fl_lock);
290 while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
291 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
292 np->ipv6_fl_list = sfl->next;
293 spin_unlock_bh(&ip6_sk_fl_lock);
294
295 fl_release(sfl->fl);
296 kfree_rcu(sfl, rcu);
297
298 spin_lock_bh(&ip6_sk_fl_lock);
299 }
300 spin_unlock_bh(&ip6_sk_fl_lock);
301 }
302
303 /* Service routines */
304
305
306 /*
307 It is the only difficult place. flowlabel enforces equal headers
308 before and including routing header, however user may supply options
309 following rthdr.
310 */
311
fl6_merge_options(struct ipv6_txoptions * opt_space,struct ip6_flowlabel * fl,struct ipv6_txoptions * fopt)312 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
313 struct ip6_flowlabel *fl,
314 struct ipv6_txoptions *fopt)
315 {
316 struct ipv6_txoptions *fl_opt = fl->opt;
317
318 if (!fopt || fopt->opt_flen == 0)
319 return fl_opt;
320
321 if (fl_opt) {
322 opt_space->hopopt = fl_opt->hopopt;
323 opt_space->dst0opt = fl_opt->dst0opt;
324 opt_space->srcrt = fl_opt->srcrt;
325 opt_space->opt_nflen = fl_opt->opt_nflen;
326 } else {
327 if (fopt->opt_nflen == 0)
328 return fopt;
329 opt_space->hopopt = NULL;
330 opt_space->dst0opt = NULL;
331 opt_space->srcrt = NULL;
332 opt_space->opt_nflen = 0;
333 }
334 opt_space->dst1opt = fopt->dst1opt;
335 opt_space->opt_flen = fopt->opt_flen;
336 opt_space->tot_len = fopt->tot_len;
337 return opt_space;
338 }
339 EXPORT_SYMBOL_GPL(fl6_merge_options);
340
check_linger(unsigned long ttl)341 static unsigned long check_linger(unsigned long ttl)
342 {
343 if (ttl < FL_MIN_LINGER)
344 return FL_MIN_LINGER*HZ;
345 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
346 return 0;
347 return ttl*HZ;
348 }
349
fl6_renew(struct ip6_flowlabel * fl,unsigned long linger,unsigned long expires)350 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
351 {
352 linger = check_linger(linger);
353 if (!linger)
354 return -EPERM;
355 expires = check_linger(expires);
356 if (!expires)
357 return -EPERM;
358
359 spin_lock_bh(&ip6_fl_lock);
360 fl->lastuse = jiffies;
361 if (time_before(fl->linger, linger))
362 fl->linger = linger;
363 if (time_before(expires, fl->linger))
364 expires = fl->linger;
365 if (time_before(fl->expires, fl->lastuse + expires))
366 fl->expires = fl->lastuse + expires;
367 spin_unlock_bh(&ip6_fl_lock);
368
369 return 0;
370 }
371
372 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)373 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
374 sockptr_t optval, int optlen, int *err_p)
375 {
376 struct ip6_flowlabel *fl = NULL;
377 int olen;
378 int addr_type;
379 int err;
380
381 olen = optlen - CMSG_ALIGN(sizeof(*freq));
382 err = -EINVAL;
383 if (olen > 64 * 1024)
384 goto done;
385
386 err = -ENOMEM;
387 fl = kzalloc(sizeof(*fl), GFP_KERNEL);
388 if (!fl)
389 goto done;
390
391 if (olen > 0) {
392 struct msghdr msg;
393 struct flowi6 flowi6;
394 struct ipcm6_cookie ipc6;
395
396 err = -ENOMEM;
397 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
398 if (!fl->opt)
399 goto done;
400
401 memset(fl->opt, 0, sizeof(*fl->opt));
402 fl->opt->tot_len = sizeof(*fl->opt) + olen;
403 err = -EFAULT;
404 if (copy_from_sockptr_offset(fl->opt + 1, optval,
405 CMSG_ALIGN(sizeof(*freq)), olen))
406 goto done;
407
408 msg.msg_controllen = olen;
409 msg.msg_control = (void *)(fl->opt+1);
410 memset(&flowi6, 0, sizeof(flowi6));
411
412 ipc6.opt = fl->opt;
413 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6);
414 if (err)
415 goto done;
416 err = -EINVAL;
417 if (fl->opt->opt_flen)
418 goto done;
419 if (fl->opt->opt_nflen == 0) {
420 kfree(fl->opt);
421 fl->opt = NULL;
422 }
423 }
424
425 fl->fl_net = net;
426 fl->expires = jiffies;
427 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
428 if (err)
429 goto done;
430 fl->share = freq->flr_share;
431 addr_type = ipv6_addr_type(&freq->flr_dst);
432 if ((addr_type & IPV6_ADDR_MAPPED) ||
433 addr_type == IPV6_ADDR_ANY) {
434 err = -EINVAL;
435 goto done;
436 }
437 fl->dst = freq->flr_dst;
438 atomic_set(&fl->users, 1);
439 switch (fl->share) {
440 case IPV6_FL_S_EXCL:
441 case IPV6_FL_S_ANY:
442 break;
443 case IPV6_FL_S_PROCESS:
444 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
445 break;
446 case IPV6_FL_S_USER:
447 fl->owner.uid = current_euid();
448 break;
449 default:
450 err = -EINVAL;
451 goto done;
452 }
453 if (fl_shared_exclusive(fl) || fl->opt) {
454 WRITE_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl, 1);
455 static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
456 }
457 return fl;
458
459 done:
460 if (fl) {
461 kfree(fl->opt);
462 kfree(fl);
463 }
464 *err_p = err;
465 return NULL;
466 }
467
mem_check(struct sock * sk)468 static int mem_check(struct sock *sk)
469 {
470 struct ipv6_pinfo *np = inet6_sk(sk);
471 struct ipv6_fl_socklist *sfl;
472 int room = FL_MAX_SIZE - atomic_read(&fl_size);
473 int count = 0;
474
475 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
476 return 0;
477
478 rcu_read_lock_bh();
479 for_each_sk_fl_rcu(np, sfl)
480 count++;
481 rcu_read_unlock_bh();
482
483 if (room <= 0 ||
484 ((count >= FL_MAX_PER_SOCK ||
485 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
486 !capable(CAP_NET_ADMIN)))
487 return -ENOBUFS;
488
489 return 0;
490 }
491
fl_link(struct ipv6_pinfo * np,struct ipv6_fl_socklist * sfl,struct ip6_flowlabel * fl)492 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
493 struct ip6_flowlabel *fl)
494 {
495 spin_lock_bh(&ip6_sk_fl_lock);
496 sfl->fl = fl;
497 sfl->next = np->ipv6_fl_list;
498 rcu_assign_pointer(np->ipv6_fl_list, sfl);
499 spin_unlock_bh(&ip6_sk_fl_lock);
500 }
501
ipv6_flowlabel_opt_get(struct sock * sk,struct in6_flowlabel_req * freq,int flags)502 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
503 int flags)
504 {
505 struct ipv6_pinfo *np = inet6_sk(sk);
506 struct ipv6_fl_socklist *sfl;
507
508 if (flags & IPV6_FL_F_REMOTE) {
509 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
510 return 0;
511 }
512
513 if (np->repflow) {
514 freq->flr_label = np->flow_label;
515 return 0;
516 }
517
518 rcu_read_lock_bh();
519
520 for_each_sk_fl_rcu(np, sfl) {
521 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
522 spin_lock_bh(&ip6_fl_lock);
523 freq->flr_label = sfl->fl->label;
524 freq->flr_dst = sfl->fl->dst;
525 freq->flr_share = sfl->fl->share;
526 freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
527 freq->flr_linger = sfl->fl->linger / HZ;
528
529 spin_unlock_bh(&ip6_fl_lock);
530 rcu_read_unlock_bh();
531 return 0;
532 }
533 }
534 rcu_read_unlock_bh();
535
536 return -ENOENT;
537 }
538
539 #define socklist_dereference(__sflp) \
540 rcu_dereference_protected(__sflp, lockdep_is_held(&ip6_sk_fl_lock))
541
ipv6_flowlabel_put(struct sock * sk,struct in6_flowlabel_req * freq)542 static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq)
543 {
544 struct ipv6_pinfo *np = inet6_sk(sk);
545 struct ipv6_fl_socklist __rcu **sflp;
546 struct ipv6_fl_socklist *sfl;
547
548 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
549 if (sk->sk_protocol != IPPROTO_TCP)
550 return -ENOPROTOOPT;
551 if (!np->repflow)
552 return -ESRCH;
553 np->flow_label = 0;
554 np->repflow = 0;
555 return 0;
556 }
557
558 spin_lock_bh(&ip6_sk_fl_lock);
559 for (sflp = &np->ipv6_fl_list;
560 (sfl = socklist_dereference(*sflp)) != NULL;
561 sflp = &sfl->next) {
562 if (sfl->fl->label == freq->flr_label)
563 goto found;
564 }
565 spin_unlock_bh(&ip6_sk_fl_lock);
566 return -ESRCH;
567 found:
568 if (freq->flr_label == (np->flow_label & IPV6_FLOWLABEL_MASK))
569 np->flow_label &= ~IPV6_FLOWLABEL_MASK;
570 *sflp = sfl->next;
571 spin_unlock_bh(&ip6_sk_fl_lock);
572 fl_release(sfl->fl);
573 kfree_rcu(sfl, rcu);
574 return 0;
575 }
576
ipv6_flowlabel_renew(struct sock * sk,struct in6_flowlabel_req * freq)577 static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
578 {
579 struct ipv6_pinfo *np = inet6_sk(sk);
580 struct net *net = sock_net(sk);
581 struct ipv6_fl_socklist *sfl;
582 int err;
583
584 rcu_read_lock_bh();
585 for_each_sk_fl_rcu(np, sfl) {
586 if (sfl->fl->label == freq->flr_label) {
587 err = fl6_renew(sfl->fl, freq->flr_linger,
588 freq->flr_expires);
589 rcu_read_unlock_bh();
590 return err;
591 }
592 }
593 rcu_read_unlock_bh();
594
595 if (freq->flr_share == IPV6_FL_S_NONE &&
596 ns_capable(net->user_ns, CAP_NET_ADMIN)) {
597 struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
598
599 if (fl) {
600 err = fl6_renew(fl, freq->flr_linger,
601 freq->flr_expires);
602 fl_release(fl);
603 return err;
604 }
605 }
606 return -ESRCH;
607 }
608
ipv6_flowlabel_get(struct sock * sk,struct in6_flowlabel_req * freq,sockptr_t optval,int optlen)609 static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
610 sockptr_t optval, int optlen)
611 {
612 struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
613 struct ip6_flowlabel *fl, *fl1 = NULL;
614 struct ipv6_pinfo *np = inet6_sk(sk);
615 struct net *net = sock_net(sk);
616 int err;
617
618 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
619 if (net->ipv6.sysctl.flowlabel_consistency) {
620 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
621 return -EPERM;
622 }
623
624 if (sk->sk_protocol != IPPROTO_TCP)
625 return -ENOPROTOOPT;
626 np->repflow = 1;
627 return 0;
628 }
629
630 if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
631 return -EINVAL;
632 if (net->ipv6.sysctl.flowlabel_state_ranges &&
633 (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
634 return -ERANGE;
635
636 fl = fl_create(net, sk, freq, optval, optlen, &err);
637 if (!fl)
638 return err;
639
640 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
641
642 if (freq->flr_label) {
643 err = -EEXIST;
644 rcu_read_lock_bh();
645 for_each_sk_fl_rcu(np, sfl) {
646 if (sfl->fl->label == freq->flr_label) {
647 if (freq->flr_flags & IPV6_FL_F_EXCL) {
648 rcu_read_unlock_bh();
649 goto done;
650 }
651 fl1 = sfl->fl;
652 if (!atomic_inc_not_zero(&fl1->users))
653 fl1 = NULL;
654 break;
655 }
656 }
657 rcu_read_unlock_bh();
658
659 if (!fl1)
660 fl1 = fl_lookup(net, freq->flr_label);
661 if (fl1) {
662 recheck:
663 err = -EEXIST;
664 if (freq->flr_flags&IPV6_FL_F_EXCL)
665 goto release;
666 err = -EPERM;
667 if (fl1->share == IPV6_FL_S_EXCL ||
668 fl1->share != fl->share ||
669 ((fl1->share == IPV6_FL_S_PROCESS) &&
670 (fl1->owner.pid != fl->owner.pid)) ||
671 ((fl1->share == IPV6_FL_S_USER) &&
672 !uid_eq(fl1->owner.uid, fl->owner.uid)))
673 goto release;
674
675 err = -ENOMEM;
676 if (!sfl1)
677 goto release;
678 if (fl->linger > fl1->linger)
679 fl1->linger = fl->linger;
680 if ((long)(fl->expires - fl1->expires) > 0)
681 fl1->expires = fl->expires;
682 fl_link(np, sfl1, fl1);
683 fl_free(fl);
684 return 0;
685
686 release:
687 fl_release(fl1);
688 goto done;
689 }
690 }
691 err = -ENOENT;
692 if (!(freq->flr_flags & IPV6_FL_F_CREATE))
693 goto done;
694
695 err = -ENOMEM;
696 if (!sfl1)
697 goto done;
698
699 err = mem_check(sk);
700 if (err != 0)
701 goto done;
702
703 fl1 = fl_intern(net, fl, freq->flr_label);
704 if (fl1)
705 goto recheck;
706
707 if (!freq->flr_label) {
708 size_t offset = offsetof(struct in6_flowlabel_req, flr_label);
709
710 if (copy_to_sockptr_offset(optval, offset, &fl->label,
711 sizeof(fl->label))) {
712 /* Intentionally ignore fault. */
713 }
714 }
715
716 fl_link(np, sfl1, fl);
717 return 0;
718 done:
719 fl_free(fl);
720 kfree(sfl1);
721 return err;
722 }
723
ipv6_flowlabel_opt(struct sock * sk,sockptr_t optval,int optlen)724 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
725 {
726 struct in6_flowlabel_req freq;
727
728 if (optlen < sizeof(freq))
729 return -EINVAL;
730 if (copy_from_sockptr(&freq, optval, sizeof(freq)))
731 return -EFAULT;
732
733 switch (freq.flr_action) {
734 case IPV6_FL_A_PUT:
735 return ipv6_flowlabel_put(sk, &freq);
736 case IPV6_FL_A_RENEW:
737 return ipv6_flowlabel_renew(sk, &freq);
738 case IPV6_FL_A_GET:
739 return ipv6_flowlabel_get(sk, &freq, optval, optlen);
740 default:
741 return -EINVAL;
742 }
743 }
744
745 #ifdef CONFIG_PROC_FS
746
747 struct ip6fl_iter_state {
748 struct seq_net_private p;
749 struct pid_namespace *pid_ns;
750 int bucket;
751 };
752
753 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
754
ip6fl_get_first(struct seq_file * seq)755 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
756 {
757 struct ip6_flowlabel *fl = NULL;
758 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
759 struct net *net = seq_file_net(seq);
760
761 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
762 for_each_fl_rcu(state->bucket, fl) {
763 if (net_eq(fl->fl_net, net))
764 goto out;
765 }
766 }
767 fl = NULL;
768 out:
769 return fl;
770 }
771
ip6fl_get_next(struct seq_file * seq,struct ip6_flowlabel * fl)772 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
773 {
774 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
775 struct net *net = seq_file_net(seq);
776
777 for_each_fl_continue_rcu(fl) {
778 if (net_eq(fl->fl_net, net))
779 goto out;
780 }
781
782 try_again:
783 if (++state->bucket <= FL_HASH_MASK) {
784 for_each_fl_rcu(state->bucket, fl) {
785 if (net_eq(fl->fl_net, net))
786 goto out;
787 }
788 goto try_again;
789 }
790 fl = NULL;
791
792 out:
793 return fl;
794 }
795
ip6fl_get_idx(struct seq_file * seq,loff_t pos)796 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
797 {
798 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
799 if (fl)
800 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
801 --pos;
802 return pos ? NULL : fl;
803 }
804
ip6fl_seq_start(struct seq_file * seq,loff_t * pos)805 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
806 __acquires(RCU)
807 {
808 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
809
810 state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
811
812 rcu_read_lock_bh();
813 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
814 }
815
ip6fl_seq_next(struct seq_file * seq,void * v,loff_t * pos)816 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
817 {
818 struct ip6_flowlabel *fl;
819
820 if (v == SEQ_START_TOKEN)
821 fl = ip6fl_get_first(seq);
822 else
823 fl = ip6fl_get_next(seq, v);
824 ++*pos;
825 return fl;
826 }
827
ip6fl_seq_stop(struct seq_file * seq,void * v)828 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
829 __releases(RCU)
830 {
831 rcu_read_unlock_bh();
832 }
833
ip6fl_seq_show(struct seq_file * seq,void * v)834 static int ip6fl_seq_show(struct seq_file *seq, void *v)
835 {
836 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
837 if (v == SEQ_START_TOKEN) {
838 seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n");
839 } else {
840 struct ip6_flowlabel *fl = v;
841 seq_printf(seq,
842 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
843 (unsigned int)ntohl(fl->label),
844 fl->share,
845 ((fl->share == IPV6_FL_S_PROCESS) ?
846 pid_nr_ns(fl->owner.pid, state->pid_ns) :
847 ((fl->share == IPV6_FL_S_USER) ?
848 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
849 0)),
850 atomic_read(&fl->users),
851 fl->linger/HZ,
852 (long)(fl->expires - jiffies)/HZ,
853 &fl->dst,
854 fl->opt ? fl->opt->opt_nflen : 0);
855 }
856 return 0;
857 }
858
859 static const struct seq_operations ip6fl_seq_ops = {
860 .start = ip6fl_seq_start,
861 .next = ip6fl_seq_next,
862 .stop = ip6fl_seq_stop,
863 .show = ip6fl_seq_show,
864 };
865
ip6_flowlabel_proc_init(struct net * net)866 static int __net_init ip6_flowlabel_proc_init(struct net *net)
867 {
868 if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
869 &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
870 return -ENOMEM;
871 return 0;
872 }
873
ip6_flowlabel_proc_fini(struct net * net)874 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
875 {
876 remove_proc_entry("ip6_flowlabel", net->proc_net);
877 }
878 #else
ip6_flowlabel_proc_init(struct net * net)879 static inline int ip6_flowlabel_proc_init(struct net *net)
880 {
881 return 0;
882 }
ip6_flowlabel_proc_fini(struct net * net)883 static inline void ip6_flowlabel_proc_fini(struct net *net)
884 {
885 }
886 #endif
887
ip6_flowlabel_net_exit(struct net * net)888 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
889 {
890 ip6_fl_purge(net);
891 ip6_flowlabel_proc_fini(net);
892 }
893
894 static struct pernet_operations ip6_flowlabel_net_ops = {
895 .init = ip6_flowlabel_proc_init,
896 .exit = ip6_flowlabel_net_exit,
897 };
898
ip6_flowlabel_init(void)899 int ip6_flowlabel_init(void)
900 {
901 return register_pernet_subsys(&ip6_flowlabel_net_ops);
902 }
903
ip6_flowlabel_cleanup(void)904 void ip6_flowlabel_cleanup(void)
905 {
906 static_key_deferred_flush(&ipv6_flowlabel_exclusive);
907 del_timer(&ip6_fl_gc_timer);
908 unregister_pernet_subsys(&ip6_flowlabel_net_ops);
909 }
910