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 static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
455 return fl;
456
457 done:
458 if (fl) {
459 kfree(fl->opt);
460 kfree(fl);
461 }
462 *err_p = err;
463 return NULL;
464 }
465
mem_check(struct sock * sk)466 static int mem_check(struct sock *sk)
467 {
468 struct ipv6_pinfo *np = inet6_sk(sk);
469 struct ipv6_fl_socklist *sfl;
470 int room = FL_MAX_SIZE - atomic_read(&fl_size);
471 int count = 0;
472
473 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
474 return 0;
475
476 rcu_read_lock_bh();
477 for_each_sk_fl_rcu(np, sfl)
478 count++;
479 rcu_read_unlock_bh();
480
481 if (room <= 0 ||
482 ((count >= FL_MAX_PER_SOCK ||
483 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
484 !capable(CAP_NET_ADMIN)))
485 return -ENOBUFS;
486
487 return 0;
488 }
489
fl_link(struct ipv6_pinfo * np,struct ipv6_fl_socklist * sfl,struct ip6_flowlabel * fl)490 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
491 struct ip6_flowlabel *fl)
492 {
493 spin_lock_bh(&ip6_sk_fl_lock);
494 sfl->fl = fl;
495 sfl->next = np->ipv6_fl_list;
496 rcu_assign_pointer(np->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 (np->repflow) {
512 freq->flr_label = np->flow_label;
513 return 0;
514 }
515
516 rcu_read_lock_bh();
517
518 for_each_sk_fl_rcu(np, 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_bh();
529 return 0;
530 }
531 }
532 rcu_read_unlock_bh();
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 (!np->repflow)
550 return -ESRCH;
551 np->flow_label = 0;
552 np->repflow = 0;
553 return 0;
554 }
555
556 spin_lock_bh(&ip6_sk_fl_lock);
557 for (sflp = &np->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 ipv6_pinfo *np = inet6_sk(sk);
578 struct net *net = sock_net(sk);
579 struct ipv6_fl_socklist *sfl;
580 int err;
581
582 rcu_read_lock_bh();
583 for_each_sk_fl_rcu(np, sfl) {
584 if (sfl->fl->label == freq->flr_label) {
585 err = fl6_renew(sfl->fl, freq->flr_linger,
586 freq->flr_expires);
587 rcu_read_unlock_bh();
588 return err;
589 }
590 }
591 rcu_read_unlock_bh();
592
593 if (freq->flr_share == IPV6_FL_S_NONE &&
594 ns_capable(net->user_ns, CAP_NET_ADMIN)) {
595 struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
596
597 if (fl) {
598 err = fl6_renew(fl, freq->flr_linger,
599 freq->flr_expires);
600 fl_release(fl);
601 return err;
602 }
603 }
604 return -ESRCH;
605 }
606
ipv6_flowlabel_get(struct sock * sk,struct in6_flowlabel_req * freq,sockptr_t optval,int optlen)607 static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
608 sockptr_t optval, int optlen)
609 {
610 struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
611 struct ip6_flowlabel *fl, *fl1 = NULL;
612 struct ipv6_pinfo *np = inet6_sk(sk);
613 struct net *net = sock_net(sk);
614 int err;
615
616 if (freq->flr_flags & IPV6_FL_F_REFLECT) {
617 if (net->ipv6.sysctl.flowlabel_consistency) {
618 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
619 return -EPERM;
620 }
621
622 if (sk->sk_protocol != IPPROTO_TCP)
623 return -ENOPROTOOPT;
624 np->repflow = 1;
625 return 0;
626 }
627
628 if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
629 return -EINVAL;
630 if (net->ipv6.sysctl.flowlabel_state_ranges &&
631 (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
632 return -ERANGE;
633
634 fl = fl_create(net, sk, freq, optval, optlen, &err);
635 if (!fl)
636 return err;
637
638 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
639
640 if (freq->flr_label) {
641 err = -EEXIST;
642 rcu_read_lock_bh();
643 for_each_sk_fl_rcu(np, sfl) {
644 if (sfl->fl->label == freq->flr_label) {
645 if (freq->flr_flags & IPV6_FL_F_EXCL) {
646 rcu_read_unlock_bh();
647 goto done;
648 }
649 fl1 = sfl->fl;
650 if (!atomic_inc_not_zero(&fl1->users))
651 fl1 = NULL;
652 break;
653 }
654 }
655 rcu_read_unlock_bh();
656
657 if (!fl1)
658 fl1 = fl_lookup(net, freq->flr_label);
659 if (fl1) {
660 recheck:
661 err = -EEXIST;
662 if (freq->flr_flags&IPV6_FL_F_EXCL)
663 goto release;
664 err = -EPERM;
665 if (fl1->share == IPV6_FL_S_EXCL ||
666 fl1->share != fl->share ||
667 ((fl1->share == IPV6_FL_S_PROCESS) &&
668 (fl1->owner.pid != fl->owner.pid)) ||
669 ((fl1->share == IPV6_FL_S_USER) &&
670 !uid_eq(fl1->owner.uid, fl->owner.uid)))
671 goto release;
672
673 err = -ENOMEM;
674 if (!sfl1)
675 goto release;
676 if (fl->linger > fl1->linger)
677 fl1->linger = fl->linger;
678 if ((long)(fl->expires - fl1->expires) > 0)
679 fl1->expires = fl->expires;
680 fl_link(np, sfl1, fl1);
681 fl_free(fl);
682 return 0;
683
684 release:
685 fl_release(fl1);
686 goto done;
687 }
688 }
689 err = -ENOENT;
690 if (!(freq->flr_flags & IPV6_FL_F_CREATE))
691 goto done;
692
693 err = -ENOMEM;
694 if (!sfl1)
695 goto done;
696
697 err = mem_check(sk);
698 if (err != 0)
699 goto done;
700
701 fl1 = fl_intern(net, fl, freq->flr_label);
702 if (fl1)
703 goto recheck;
704
705 if (!freq->flr_label) {
706 size_t offset = offsetof(struct in6_flowlabel_req, flr_label);
707
708 if (copy_to_sockptr_offset(optval, offset, &fl->label,
709 sizeof(fl->label))) {
710 /* Intentionally ignore fault. */
711 }
712 }
713
714 fl_link(np, sfl1, fl);
715 return 0;
716 done:
717 fl_free(fl);
718 kfree(sfl1);
719 return err;
720 }
721
ipv6_flowlabel_opt(struct sock * sk,sockptr_t optval,int optlen)722 int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
723 {
724 struct in6_flowlabel_req freq;
725
726 if (optlen < sizeof(freq))
727 return -EINVAL;
728 if (copy_from_sockptr(&freq, optval, sizeof(freq)))
729 return -EFAULT;
730
731 switch (freq.flr_action) {
732 case IPV6_FL_A_PUT:
733 return ipv6_flowlabel_put(sk, &freq);
734 case IPV6_FL_A_RENEW:
735 return ipv6_flowlabel_renew(sk, &freq);
736 case IPV6_FL_A_GET:
737 return ipv6_flowlabel_get(sk, &freq, optval, optlen);
738 default:
739 return -EINVAL;
740 }
741 }
742
743 #ifdef CONFIG_PROC_FS
744
745 struct ip6fl_iter_state {
746 struct seq_net_private p;
747 struct pid_namespace *pid_ns;
748 int bucket;
749 };
750
751 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
752
ip6fl_get_first(struct seq_file * seq)753 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
754 {
755 struct ip6_flowlabel *fl = NULL;
756 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
757 struct net *net = seq_file_net(seq);
758
759 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
760 for_each_fl_rcu(state->bucket, fl) {
761 if (net_eq(fl->fl_net, net))
762 goto out;
763 }
764 }
765 fl = NULL;
766 out:
767 return fl;
768 }
769
ip6fl_get_next(struct seq_file * seq,struct ip6_flowlabel * fl)770 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
771 {
772 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
773 struct net *net = seq_file_net(seq);
774
775 for_each_fl_continue_rcu(fl) {
776 if (net_eq(fl->fl_net, net))
777 goto out;
778 }
779
780 try_again:
781 if (++state->bucket <= FL_HASH_MASK) {
782 for_each_fl_rcu(state->bucket, fl) {
783 if (net_eq(fl->fl_net, net))
784 goto out;
785 }
786 goto try_again;
787 }
788 fl = NULL;
789
790 out:
791 return fl;
792 }
793
ip6fl_get_idx(struct seq_file * seq,loff_t pos)794 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
795 {
796 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
797 if (fl)
798 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
799 --pos;
800 return pos ? NULL : fl;
801 }
802
ip6fl_seq_start(struct seq_file * seq,loff_t * pos)803 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
804 __acquires(RCU)
805 {
806 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
807
808 state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
809
810 rcu_read_lock_bh();
811 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
812 }
813
ip6fl_seq_next(struct seq_file * seq,void * v,loff_t * pos)814 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
815 {
816 struct ip6_flowlabel *fl;
817
818 if (v == SEQ_START_TOKEN)
819 fl = ip6fl_get_first(seq);
820 else
821 fl = ip6fl_get_next(seq, v);
822 ++*pos;
823 return fl;
824 }
825
ip6fl_seq_stop(struct seq_file * seq,void * v)826 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
827 __releases(RCU)
828 {
829 rcu_read_unlock_bh();
830 }
831
ip6fl_seq_show(struct seq_file * seq,void * v)832 static int ip6fl_seq_show(struct seq_file *seq, void *v)
833 {
834 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
835 if (v == SEQ_START_TOKEN) {
836 seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n");
837 } else {
838 struct ip6_flowlabel *fl = v;
839 seq_printf(seq,
840 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
841 (unsigned int)ntohl(fl->label),
842 fl->share,
843 ((fl->share == IPV6_FL_S_PROCESS) ?
844 pid_nr_ns(fl->owner.pid, state->pid_ns) :
845 ((fl->share == IPV6_FL_S_USER) ?
846 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
847 0)),
848 atomic_read(&fl->users),
849 fl->linger/HZ,
850 (long)(fl->expires - jiffies)/HZ,
851 &fl->dst,
852 fl->opt ? fl->opt->opt_nflen : 0);
853 }
854 return 0;
855 }
856
857 static const struct seq_operations ip6fl_seq_ops = {
858 .start = ip6fl_seq_start,
859 .next = ip6fl_seq_next,
860 .stop = ip6fl_seq_stop,
861 .show = ip6fl_seq_show,
862 };
863
ip6_flowlabel_proc_init(struct net * net)864 static int __net_init ip6_flowlabel_proc_init(struct net *net)
865 {
866 if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
867 &ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
868 return -ENOMEM;
869 return 0;
870 }
871
ip6_flowlabel_proc_fini(struct net * net)872 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
873 {
874 remove_proc_entry("ip6_flowlabel", net->proc_net);
875 }
876 #else
ip6_flowlabel_proc_init(struct net * net)877 static inline int ip6_flowlabel_proc_init(struct net *net)
878 {
879 return 0;
880 }
ip6_flowlabel_proc_fini(struct net * net)881 static inline void ip6_flowlabel_proc_fini(struct net *net)
882 {
883 }
884 #endif
885
ip6_flowlabel_net_exit(struct net * net)886 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
887 {
888 ip6_fl_purge(net);
889 ip6_flowlabel_proc_fini(net);
890 }
891
892 static struct pernet_operations ip6_flowlabel_net_ops = {
893 .init = ip6_flowlabel_proc_init,
894 .exit = ip6_flowlabel_net_exit,
895 };
896
ip6_flowlabel_init(void)897 int ip6_flowlabel_init(void)
898 {
899 return register_pernet_subsys(&ip6_flowlabel_net_ops);
900 }
901
ip6_flowlabel_cleanup(void)902 void ip6_flowlabel_cleanup(void)
903 {
904 static_key_deferred_flush(&ipv6_flowlabel_exclusive);
905 del_timer(&ip6_fl_gc_timer);
906 unregister_pernet_subsys(&ip6_flowlabel_net_ops);
907 }
908
