2 * ip6_flowlabel.c IPv6 flowlabel manager.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
12 #include <linux/capability.h>
13 #include <linux/errno.h>
14 #include <linux/types.h>
15 #include <linux/socket.h>
16 #include <linux/net.h>
17 #include <linux/netdevice.h>
18 #include <linux/if_arp.h>
19 #include <linux/in6.h>
20 #include <linux/route.h>
21 #include <linux/proc_fs.h>
22 #include <linux/seq_file.h>
23 #include <linux/slab.h>
24 #include <linux/export.h>
26 #include <net/net_namespace.h>
30 #include <net/ndisc.h>
31 #include <net/protocol.h>
32 #include <net/ip6_route.h>
33 #include <net/addrconf.h>
34 #include <net/rawv6.h>
36 #include <net/transp_v6.h>
38 #include <asm/uaccess.h>
40 #define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
41 in old IPv6 RFC. Well, it was reasonable value.
43 #define FL_MAX_LINGER 60 /* Maximal linger timeout */
47 #define FL_MAX_PER_SOCK 32
48 #define FL_MAX_SIZE 4096
49 #define FL_HASH_MASK 255
50 #define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
52 static atomic_t fl_size = ATOMIC_INIT(0);
53 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
55 static void ip6_fl_gc(unsigned long dummy);
56 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
58 /* FL hash table lock: it protects only of GC */
60 static DEFINE_RWLOCK(ip6_fl_lock);
64 static DEFINE_RWLOCK(ip6_sk_fl_lock);
67 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
69 struct ip6_flowlabel *fl;
71 for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
72 if (fl->label == label && net_eq(fl->fl_net, net))
78 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
80 struct ip6_flowlabel *fl;
82 read_lock_bh(&ip6_fl_lock);
83 fl = __fl_lookup(net, label);
85 atomic_inc(&fl->users);
86 read_unlock_bh(&ip6_fl_lock);
91 static void fl_free(struct ip6_flowlabel *fl)
94 release_net(fl->fl_net);
100 static void fl_release(struct ip6_flowlabel *fl)
102 write_lock_bh(&ip6_fl_lock);
104 fl->lastuse = jiffies;
105 if (atomic_dec_and_test(&fl->users)) {
106 unsigned long ttd = fl->lastuse + fl->linger;
107 if (time_after(ttd, fl->expires))
110 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
111 struct ipv6_txoptions *opt = fl->opt;
115 if (!timer_pending(&ip6_fl_gc_timer) ||
116 time_after(ip6_fl_gc_timer.expires, ttd))
117 mod_timer(&ip6_fl_gc_timer, ttd);
119 write_unlock_bh(&ip6_fl_lock);
122 static void ip6_fl_gc(unsigned long dummy)
125 unsigned long now = jiffies;
126 unsigned long sched = 0;
128 write_lock(&ip6_fl_lock);
130 for (i=0; i<=FL_HASH_MASK; i++) {
131 struct ip6_flowlabel *fl, **flp;
133 while ((fl=*flp) != NULL) {
134 if (atomic_read(&fl->users) == 0) {
135 unsigned long ttd = fl->lastuse + fl->linger;
136 if (time_after(ttd, fl->expires))
139 if (time_after_eq(now, ttd)) {
142 atomic_dec(&fl_size);
145 if (!sched || time_before(ttd, sched))
151 if (!sched && atomic_read(&fl_size))
152 sched = now + FL_MAX_LINGER;
154 mod_timer(&ip6_fl_gc_timer, sched);
156 write_unlock(&ip6_fl_lock);
159 static void __net_exit ip6_fl_purge(struct net *net)
163 write_lock(&ip6_fl_lock);
164 for (i = 0; i <= FL_HASH_MASK; i++) {
165 struct ip6_flowlabel *fl, **flp;
167 while ((fl = *flp) != NULL) {
168 if (net_eq(fl->fl_net, net) &&
169 atomic_read(&fl->users) == 0) {
172 atomic_dec(&fl_size);
178 write_unlock(&ip6_fl_lock);
181 static struct ip6_flowlabel *fl_intern(struct net *net,
182 struct ip6_flowlabel *fl, __be32 label)
184 struct ip6_flowlabel *lfl;
186 fl->label = label & IPV6_FLOWLABEL_MASK;
188 write_lock_bh(&ip6_fl_lock);
191 fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
193 lfl = __fl_lookup(net, fl->label);
200 * we dropper the ip6_fl_lock, so this entry could reappear
201 * and we need to recheck with it.
203 * OTOH no need to search the active socket first, like it is
204 * done in ipv6_flowlabel_opt - sock is locked, so new entry
205 * with the same label can only appear on another sock
207 lfl = __fl_lookup(net, fl->label);
209 atomic_inc(&lfl->users);
210 write_unlock_bh(&ip6_fl_lock);
215 fl->lastuse = jiffies;
216 fl->next = fl_ht[FL_HASH(fl->label)];
217 fl_ht[FL_HASH(fl->label)] = fl;
218 atomic_inc(&fl_size);
219 write_unlock_bh(&ip6_fl_lock);
225 /* Socket flowlabel lists */
227 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
229 struct ipv6_fl_socklist *sfl;
230 struct ipv6_pinfo *np = inet6_sk(sk);
232 label &= IPV6_FLOWLABEL_MASK;
234 read_lock_bh(&ip6_sk_fl_lock);
235 for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
236 struct ip6_flowlabel *fl = sfl->fl;
237 if (fl->label == label) {
238 fl->lastuse = jiffies;
239 atomic_inc(&fl->users);
240 read_unlock_bh(&ip6_sk_fl_lock);
244 read_unlock_bh(&ip6_sk_fl_lock);
248 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
250 void fl6_free_socklist(struct sock *sk)
252 struct ipv6_pinfo *np = inet6_sk(sk);
253 struct ipv6_fl_socklist *sfl;
255 while ((sfl = np->ipv6_fl_list) != NULL) {
256 np->ipv6_fl_list = sfl->next;
262 /* Service routines */
266 It is the only difficult place. flowlabel enforces equal headers
267 before and including routing header, however user may supply options
271 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
272 struct ip6_flowlabel * fl,
273 struct ipv6_txoptions * fopt)
275 struct ipv6_txoptions * fl_opt = fl->opt;
277 if (fopt == NULL || fopt->opt_flen == 0)
280 if (fl_opt != NULL) {
281 opt_space->hopopt = fl_opt->hopopt;
282 opt_space->dst0opt = fl_opt->dst0opt;
283 opt_space->srcrt = fl_opt->srcrt;
284 opt_space->opt_nflen = fl_opt->opt_nflen;
286 if (fopt->opt_nflen == 0)
288 opt_space->hopopt = NULL;
289 opt_space->dst0opt = NULL;
290 opt_space->srcrt = NULL;
291 opt_space->opt_nflen = 0;
293 opt_space->dst1opt = fopt->dst1opt;
294 opt_space->opt_flen = fopt->opt_flen;
297 EXPORT_SYMBOL_GPL(fl6_merge_options);
299 static unsigned long check_linger(unsigned long ttl)
301 if (ttl < FL_MIN_LINGER)
302 return FL_MIN_LINGER*HZ;
303 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
308 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
310 linger = check_linger(linger);
313 expires = check_linger(expires);
316 fl->lastuse = jiffies;
317 if (time_before(fl->linger, linger))
319 if (time_before(expires, fl->linger))
320 expires = fl->linger;
321 if (time_before(fl->expires, fl->lastuse + expires))
322 fl->expires = fl->lastuse + expires;
326 static struct ip6_flowlabel *
327 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
328 char __user *optval, int optlen, int *err_p)
330 struct ip6_flowlabel *fl = NULL;
335 olen = optlen - CMSG_ALIGN(sizeof(*freq));
337 if (olen > 64 * 1024)
341 fl = kzalloc(sizeof(*fl), GFP_KERNEL);
347 struct flowi6 flowi6;
351 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
355 memset(fl->opt, 0, sizeof(*fl->opt));
356 fl->opt->tot_len = sizeof(*fl->opt) + olen;
358 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
361 msg.msg_controllen = olen;
362 msg.msg_control = (void*)(fl->opt+1);
363 memset(&flowi6, 0, sizeof(flowi6));
365 err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
370 if (fl->opt->opt_flen)
372 if (fl->opt->opt_nflen == 0) {
378 fl->fl_net = hold_net(net);
379 fl->expires = jiffies;
380 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
383 fl->share = freq->flr_share;
384 addr_type = ipv6_addr_type(&freq->flr_dst);
385 if ((addr_type & IPV6_ADDR_MAPPED) ||
386 addr_type == IPV6_ADDR_ANY) {
390 fl->dst = freq->flr_dst;
391 atomic_set(&fl->users, 1);
396 case IPV6_FL_S_PROCESS:
397 fl->owner = current->pid;
400 fl->owner = current_euid();
414 static int mem_check(struct sock *sk)
416 struct ipv6_pinfo *np = inet6_sk(sk);
417 struct ipv6_fl_socklist *sfl;
418 int room = FL_MAX_SIZE - atomic_read(&fl_size);
421 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
424 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
428 ((count >= FL_MAX_PER_SOCK ||
429 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
430 !capable(CAP_NET_ADMIN)))
436 static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
440 if (h1 == NULL || h2 == NULL)
442 if (h1->hdrlen != h2->hdrlen)
444 return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
447 static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
451 if (o1 == NULL || o2 == NULL)
453 if (o1->opt_nflen != o2->opt_nflen)
455 if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
457 if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
459 if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
464 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
465 struct ip6_flowlabel *fl)
467 write_lock_bh(&ip6_sk_fl_lock);
469 sfl->next = np->ipv6_fl_list;
470 np->ipv6_fl_list = sfl;
471 write_unlock_bh(&ip6_sk_fl_lock);
474 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
476 int uninitialized_var(err);
477 struct net *net = sock_net(sk);
478 struct ipv6_pinfo *np = inet6_sk(sk);
479 struct in6_flowlabel_req freq;
480 struct ipv6_fl_socklist *sfl1=NULL;
481 struct ipv6_fl_socklist *sfl, **sflp;
482 struct ip6_flowlabel *fl, *fl1 = NULL;
485 if (optlen < sizeof(freq))
488 if (copy_from_user(&freq, optval, sizeof(freq)))
491 switch (freq.flr_action) {
493 write_lock_bh(&ip6_sk_fl_lock);
494 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
495 if (sfl->fl->label == freq.flr_label) {
496 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
497 np->flow_label &= ~IPV6_FLOWLABEL_MASK;
499 write_unlock_bh(&ip6_sk_fl_lock);
505 write_unlock_bh(&ip6_sk_fl_lock);
508 case IPV6_FL_A_RENEW:
509 read_lock_bh(&ip6_sk_fl_lock);
510 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
511 if (sfl->fl->label == freq.flr_label) {
512 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
513 read_unlock_bh(&ip6_sk_fl_lock);
517 read_unlock_bh(&ip6_sk_fl_lock);
519 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
520 fl = fl_lookup(net, freq.flr_label);
522 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
530 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
533 fl = fl_create(net, sk, &freq, optval, optlen, &err);
536 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
538 if (freq.flr_label) {
540 read_lock_bh(&ip6_sk_fl_lock);
541 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
542 if (sfl->fl->label == freq.flr_label) {
543 if (freq.flr_flags&IPV6_FL_F_EXCL) {
544 read_unlock_bh(&ip6_sk_fl_lock);
548 atomic_inc(&fl1->users);
552 read_unlock_bh(&ip6_sk_fl_lock);
555 fl1 = fl_lookup(net, freq.flr_label);
559 if (freq.flr_flags&IPV6_FL_F_EXCL)
562 if (fl1->share == IPV6_FL_S_EXCL ||
563 fl1->share != fl->share ||
564 fl1->owner != fl->owner)
568 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
569 ipv6_opt_cmp(fl1->opt, fl->opt))
575 if (fl->linger > fl1->linger)
576 fl1->linger = fl->linger;
577 if ((long)(fl->expires - fl1->expires) > 0)
578 fl1->expires = fl->expires;
579 fl_link(np, sfl1, fl1);
589 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
593 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
596 fl1 = fl_intern(net, fl, freq.flr_label);
600 if (!freq.flr_label) {
601 if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
602 &fl->label, sizeof(fl->label))) {
603 /* Intentionally ignore fault. */
607 fl_link(np, sfl1, fl);
620 #ifdef CONFIG_PROC_FS
622 struct ip6fl_iter_state {
623 struct seq_net_private p;
627 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
629 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
631 struct ip6_flowlabel *fl = NULL;
632 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
633 struct net *net = seq_file_net(seq);
635 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
636 fl = fl_ht[state->bucket];
638 while (fl && !net_eq(fl->fl_net, net))
646 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
648 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
649 struct net *net = seq_file_net(seq);
653 while (fl && !net_eq(fl->fl_net, net))
657 if (++state->bucket <= FL_HASH_MASK) {
658 fl = fl_ht[state->bucket];
666 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
668 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
670 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
672 return pos ? NULL : fl;
675 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
676 __acquires(ip6_fl_lock)
678 read_lock_bh(&ip6_fl_lock);
679 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
682 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
684 struct ip6_flowlabel *fl;
686 if (v == SEQ_START_TOKEN)
687 fl = ip6fl_get_first(seq);
689 fl = ip6fl_get_next(seq, v);
694 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
695 __releases(ip6_fl_lock)
697 read_unlock_bh(&ip6_fl_lock);
700 static int ip6fl_seq_show(struct seq_file *seq, void *v)
702 if (v == SEQ_START_TOKEN)
703 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
704 "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
706 struct ip6_flowlabel *fl = v;
708 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
709 (unsigned int)ntohl(fl->label),
712 atomic_read(&fl->users),
714 (long)(fl->expires - jiffies)/HZ,
716 fl->opt ? fl->opt->opt_nflen : 0);
721 static const struct seq_operations ip6fl_seq_ops = {
722 .start = ip6fl_seq_start,
723 .next = ip6fl_seq_next,
724 .stop = ip6fl_seq_stop,
725 .show = ip6fl_seq_show,
728 static int ip6fl_seq_open(struct inode *inode, struct file *file)
730 return seq_open_net(inode, file, &ip6fl_seq_ops,
731 sizeof(struct ip6fl_iter_state));
734 static const struct file_operations ip6fl_seq_fops = {
735 .owner = THIS_MODULE,
736 .open = ip6fl_seq_open,
739 .release = seq_release_net,
742 static int __net_init ip6_flowlabel_proc_init(struct net *net)
744 if (!proc_net_fops_create(net, "ip6_flowlabel",
745 S_IRUGO, &ip6fl_seq_fops))
750 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
752 proc_net_remove(net, "ip6_flowlabel");
755 static inline int ip6_flowlabel_proc_init(struct net *net)
759 static inline void ip6_flowlabel_proc_fini(struct net *net)
764 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
767 ip6_flowlabel_proc_fini(net);
770 static struct pernet_operations ip6_flowlabel_net_ops = {
771 .init = ip6_flowlabel_proc_init,
772 .exit = ip6_flowlabel_net_exit,
775 int ip6_flowlabel_init(void)
777 return register_pernet_subsys(&ip6_flowlabel_net_ops);
780 void ip6_flowlabel_cleanup(void)
782 del_timer(&ip6_fl_gc_timer);
783 unregister_pernet_subsys(&ip6_flowlabel_net_ops);