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>
25 #include <linux/pid_namespace.h>
27 #include <net/net_namespace.h>
31 #include <net/ndisc.h>
32 #include <net/protocol.h>
33 #include <net/ip6_route.h>
34 #include <net/addrconf.h>
35 #include <net/rawv6.h>
37 #include <net/transp_v6.h>
39 #include <asm/uaccess.h>
41 #define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
42 in old IPv6 RFC. Well, it was reasonable value.
44 #define FL_MAX_LINGER 60 /* Maximal linger timeout */
48 #define FL_MAX_PER_SOCK 32
49 #define FL_MAX_SIZE 4096
50 #define FL_HASH_MASK 255
51 #define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
53 static atomic_t fl_size = ATOMIC_INIT(0);
54 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
56 static void ip6_fl_gc(unsigned long dummy);
57 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
59 /* FL hash table lock: it protects only of GC */
61 static DEFINE_SPINLOCK(ip6_fl_lock);
65 static DEFINE_SPINLOCK(ip6_sk_fl_lock);
67 #define for_each_fl_rcu(hash, fl) \
68 for (fl = rcu_dereference_bh(fl_ht[(hash)]); \
70 fl = rcu_dereference_bh(fl->next))
71 #define for_each_fl_continue_rcu(fl) \
72 for (fl = rcu_dereference_bh(fl->next); \
74 fl = rcu_dereference_bh(fl->next))
76 #define for_each_sk_fl_rcu(np, sfl) \
77 for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \
79 sfl = rcu_dereference_bh(sfl->next))
81 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
83 struct ip6_flowlabel *fl;
85 for_each_fl_rcu(FL_HASH(label), fl) {
86 if (fl->label == label && net_eq(fl->fl_net, net))
92 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
94 struct ip6_flowlabel *fl;
97 fl = __fl_lookup(net, label);
98 if (fl && !atomic_inc_not_zero(&fl->users))
100 rcu_read_unlock_bh();
105 static void fl_free(struct ip6_flowlabel *fl)
108 if (fl->share == IPV6_FL_S_PROCESS)
109 put_pid(fl->owner.pid);
110 release_net(fl->fl_net);
116 static void fl_release(struct ip6_flowlabel *fl)
118 spin_lock_bh(&ip6_fl_lock);
120 fl->lastuse = jiffies;
121 if (atomic_dec_and_test(&fl->users)) {
122 unsigned long ttd = fl->lastuse + fl->linger;
123 if (time_after(ttd, fl->expires))
126 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
127 struct ipv6_txoptions *opt = fl->opt;
131 if (!timer_pending(&ip6_fl_gc_timer) ||
132 time_after(ip6_fl_gc_timer.expires, ttd))
133 mod_timer(&ip6_fl_gc_timer, ttd);
135 spin_unlock_bh(&ip6_fl_lock);
138 static void ip6_fl_gc(unsigned long dummy)
141 unsigned long now = jiffies;
142 unsigned long sched = 0;
144 spin_lock(&ip6_fl_lock);
146 for (i=0; i<=FL_HASH_MASK; i++) {
147 struct ip6_flowlabel *fl;
148 struct ip6_flowlabel __rcu **flp;
151 while ((fl = rcu_dereference_protected(*flp,
152 lockdep_is_held(&ip6_fl_lock))) != NULL) {
153 if (atomic_read(&fl->users) == 0) {
154 unsigned long ttd = fl->lastuse + fl->linger;
155 if (time_after(ttd, fl->expires))
158 if (time_after_eq(now, ttd)) {
161 atomic_dec(&fl_size);
164 if (!sched || time_before(ttd, sched))
170 if (!sched && atomic_read(&fl_size))
171 sched = now + FL_MAX_LINGER;
173 mod_timer(&ip6_fl_gc_timer, sched);
175 spin_unlock(&ip6_fl_lock);
178 static void __net_exit ip6_fl_purge(struct net *net)
182 spin_lock(&ip6_fl_lock);
183 for (i = 0; i <= FL_HASH_MASK; i++) {
184 struct ip6_flowlabel *fl;
185 struct ip6_flowlabel __rcu **flp;
188 while ((fl = rcu_dereference_protected(*flp,
189 lockdep_is_held(&ip6_fl_lock))) != NULL) {
190 if (net_eq(fl->fl_net, net) &&
191 atomic_read(&fl->users) == 0) {
194 atomic_dec(&fl_size);
200 spin_unlock(&ip6_fl_lock);
203 static struct ip6_flowlabel *fl_intern(struct net *net,
204 struct ip6_flowlabel *fl, __be32 label)
206 struct ip6_flowlabel *lfl;
208 fl->label = label & IPV6_FLOWLABEL_MASK;
210 spin_lock_bh(&ip6_fl_lock);
213 fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
215 lfl = __fl_lookup(net, fl->label);
222 * we dropper the ip6_fl_lock, so this entry could reappear
223 * and we need to recheck with it.
225 * OTOH no need to search the active socket first, like it is
226 * done in ipv6_flowlabel_opt - sock is locked, so new entry
227 * with the same label can only appear on another sock
229 lfl = __fl_lookup(net, fl->label);
231 atomic_inc(&lfl->users);
232 spin_unlock_bh(&ip6_fl_lock);
237 fl->lastuse = jiffies;
238 fl->next = fl_ht[FL_HASH(fl->label)];
239 rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
240 atomic_inc(&fl_size);
241 spin_unlock_bh(&ip6_fl_lock);
247 /* Socket flowlabel lists */
249 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
251 struct ipv6_fl_socklist *sfl;
252 struct ipv6_pinfo *np = inet6_sk(sk);
254 label &= IPV6_FLOWLABEL_MASK;
257 for_each_sk_fl_rcu(np, sfl) {
258 struct ip6_flowlabel *fl = sfl->fl;
259 if (fl->label == label) {
260 fl->lastuse = jiffies;
261 atomic_inc(&fl->users);
262 rcu_read_unlock_bh();
266 rcu_read_unlock_bh();
270 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
272 void fl6_free_socklist(struct sock *sk)
274 struct ipv6_pinfo *np = inet6_sk(sk);
275 struct ipv6_fl_socklist *sfl;
277 if (!rcu_access_pointer(np->ipv6_fl_list))
280 spin_lock_bh(&ip6_sk_fl_lock);
281 while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
282 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
283 np->ipv6_fl_list = sfl->next;
284 spin_unlock_bh(&ip6_sk_fl_lock);
289 spin_lock_bh(&ip6_sk_fl_lock);
291 spin_unlock_bh(&ip6_sk_fl_lock);
294 /* Service routines */
298 It is the only difficult place. flowlabel enforces equal headers
299 before and including routing header, however user may supply options
303 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
304 struct ip6_flowlabel * fl,
305 struct ipv6_txoptions * fopt)
307 struct ipv6_txoptions * fl_opt = fl->opt;
309 if (fopt == NULL || fopt->opt_flen == 0)
312 if (fl_opt != NULL) {
313 opt_space->hopopt = fl_opt->hopopt;
314 opt_space->dst0opt = fl_opt->dst0opt;
315 opt_space->srcrt = fl_opt->srcrt;
316 opt_space->opt_nflen = fl_opt->opt_nflen;
318 if (fopt->opt_nflen == 0)
320 opt_space->hopopt = NULL;
321 opt_space->dst0opt = NULL;
322 opt_space->srcrt = NULL;
323 opt_space->opt_nflen = 0;
325 opt_space->dst1opt = fopt->dst1opt;
326 opt_space->opt_flen = fopt->opt_flen;
329 EXPORT_SYMBOL_GPL(fl6_merge_options);
331 static unsigned long check_linger(unsigned long ttl)
333 if (ttl < FL_MIN_LINGER)
334 return FL_MIN_LINGER*HZ;
335 if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
340 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
342 linger = check_linger(linger);
345 expires = check_linger(expires);
348 fl->lastuse = jiffies;
349 if (time_before(fl->linger, linger))
351 if (time_before(expires, fl->linger))
352 expires = fl->linger;
353 if (time_before(fl->expires, fl->lastuse + expires))
354 fl->expires = fl->lastuse + expires;
358 static struct ip6_flowlabel *
359 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
360 char __user *optval, int optlen, int *err_p)
362 struct ip6_flowlabel *fl = NULL;
367 olen = optlen - CMSG_ALIGN(sizeof(*freq));
369 if (olen > 64 * 1024)
373 fl = kzalloc(sizeof(*fl), GFP_KERNEL);
379 struct flowi6 flowi6;
383 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
387 memset(fl->opt, 0, sizeof(*fl->opt));
388 fl->opt->tot_len = sizeof(*fl->opt) + olen;
390 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
393 msg.msg_controllen = olen;
394 msg.msg_control = (void*)(fl->opt+1);
395 memset(&flowi6, 0, sizeof(flowi6));
397 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
398 &junk, &junk, &junk);
402 if (fl->opt->opt_flen)
404 if (fl->opt->opt_nflen == 0) {
410 fl->fl_net = hold_net(net);
411 fl->expires = jiffies;
412 err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
415 fl->share = freq->flr_share;
416 addr_type = ipv6_addr_type(&freq->flr_dst);
417 if ((addr_type & IPV6_ADDR_MAPPED) ||
418 addr_type == IPV6_ADDR_ANY) {
422 fl->dst = freq->flr_dst;
423 atomic_set(&fl->users, 1);
428 case IPV6_FL_S_PROCESS:
429 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
432 fl->owner.uid = current_euid();
446 static int mem_check(struct sock *sk)
448 struct ipv6_pinfo *np = inet6_sk(sk);
449 struct ipv6_fl_socklist *sfl;
450 int room = FL_MAX_SIZE - atomic_read(&fl_size);
453 if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
456 for_each_sk_fl_rcu(np, sfl)
460 ((count >= FL_MAX_PER_SOCK ||
461 (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
462 !capable(CAP_NET_ADMIN)))
468 static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
472 if (h1 == NULL || h2 == NULL)
474 if (h1->hdrlen != h2->hdrlen)
476 return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
479 static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
483 if (o1 == NULL || o2 == NULL)
485 if (o1->opt_nflen != o2->opt_nflen)
487 if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
489 if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
491 if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
496 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
497 struct ip6_flowlabel *fl)
499 spin_lock_bh(&ip6_sk_fl_lock);
501 sfl->next = np->ipv6_fl_list;
502 rcu_assign_pointer(np->ipv6_fl_list, sfl);
503 spin_unlock_bh(&ip6_sk_fl_lock);
506 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
508 int uninitialized_var(err);
509 struct net *net = sock_net(sk);
510 struct ipv6_pinfo *np = inet6_sk(sk);
511 struct in6_flowlabel_req freq;
512 struct ipv6_fl_socklist *sfl1=NULL;
513 struct ipv6_fl_socklist *sfl;
514 struct ipv6_fl_socklist __rcu **sflp;
515 struct ip6_flowlabel *fl, *fl1 = NULL;
518 if (optlen < sizeof(freq))
521 if (copy_from_user(&freq, optval, sizeof(freq)))
524 switch (freq.flr_action) {
526 spin_lock_bh(&ip6_sk_fl_lock);
527 for (sflp = &np->ipv6_fl_list;
528 (sfl = rcu_dereference(*sflp))!=NULL;
530 if (sfl->fl->label == freq.flr_label) {
531 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
532 np->flow_label &= ~IPV6_FLOWLABEL_MASK;
533 *sflp = rcu_dereference(sfl->next);
534 spin_unlock_bh(&ip6_sk_fl_lock);
540 spin_unlock_bh(&ip6_sk_fl_lock);
543 case IPV6_FL_A_RENEW:
545 for_each_sk_fl_rcu(np, sfl) {
546 if (sfl->fl->label == freq.flr_label) {
547 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
548 rcu_read_unlock_bh();
552 rcu_read_unlock_bh();
554 if (freq.flr_share == IPV6_FL_S_NONE &&
555 ns_capable(net->user_ns, CAP_NET_ADMIN)) {
556 fl = fl_lookup(net, freq.flr_label);
558 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
566 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
569 fl = fl_create(net, sk, &freq, optval, optlen, &err);
572 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
574 if (freq.flr_label) {
577 for_each_sk_fl_rcu(np, sfl) {
578 if (sfl->fl->label == freq.flr_label) {
579 if (freq.flr_flags&IPV6_FL_F_EXCL) {
580 rcu_read_unlock_bh();
584 atomic_inc(&fl1->users);
588 rcu_read_unlock_bh();
591 fl1 = fl_lookup(net, freq.flr_label);
595 if (freq.flr_flags&IPV6_FL_F_EXCL)
598 if (fl1->share == IPV6_FL_S_EXCL ||
599 fl1->share != fl->share ||
600 ((fl1->share == IPV6_FL_S_PROCESS) &&
601 (fl1->owner.pid == fl->owner.pid)) ||
602 ((fl1->share == IPV6_FL_S_USER) &&
603 uid_eq(fl1->owner.uid, fl->owner.uid)))
607 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
608 ipv6_opt_cmp(fl1->opt, fl->opt))
614 if (fl->linger > fl1->linger)
615 fl1->linger = fl->linger;
616 if ((long)(fl->expires - fl1->expires) > 0)
617 fl1->expires = fl->expires;
618 fl_link(np, sfl1, fl1);
628 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
632 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
635 fl1 = fl_intern(net, fl, freq.flr_label);
639 if (!freq.flr_label) {
640 if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
641 &fl->label, sizeof(fl->label))) {
642 /* Intentionally ignore fault. */
646 fl_link(np, sfl1, fl);
659 #ifdef CONFIG_PROC_FS
661 struct ip6fl_iter_state {
662 struct seq_net_private p;
663 struct pid_namespace *pid_ns;
667 #define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
669 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
671 struct ip6_flowlabel *fl = NULL;
672 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
673 struct net *net = seq_file_net(seq);
675 for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
676 for_each_fl_rcu(state->bucket, fl) {
677 if (net_eq(fl->fl_net, net))
686 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
688 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
689 struct net *net = seq_file_net(seq);
691 for_each_fl_continue_rcu(fl) {
692 if (net_eq(fl->fl_net, net))
697 if (++state->bucket <= FL_HASH_MASK) {
698 for_each_fl_rcu(state->bucket, fl) {
699 if (net_eq(fl->fl_net, net))
710 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
712 struct ip6_flowlabel *fl = ip6fl_get_first(seq);
714 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
716 return pos ? NULL : fl;
719 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
723 return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
726 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
728 struct ip6_flowlabel *fl;
730 if (v == SEQ_START_TOKEN)
731 fl = ip6fl_get_first(seq);
733 fl = ip6fl_get_next(seq, v);
738 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
741 rcu_read_unlock_bh();
744 static int ip6fl_seq_show(struct seq_file *seq, void *v)
746 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
747 if (v == SEQ_START_TOKEN)
748 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
749 "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
751 struct ip6_flowlabel *fl = v;
753 "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
754 (unsigned int)ntohl(fl->label),
756 ((fl->share == IPV6_FL_S_PROCESS) ?
757 pid_nr_ns(fl->owner.pid, state->pid_ns) :
758 ((fl->share == IPV6_FL_S_USER) ?
759 from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
761 atomic_read(&fl->users),
763 (long)(fl->expires - jiffies)/HZ,
765 fl->opt ? fl->opt->opt_nflen : 0);
770 static const struct seq_operations ip6fl_seq_ops = {
771 .start = ip6fl_seq_start,
772 .next = ip6fl_seq_next,
773 .stop = ip6fl_seq_stop,
774 .show = ip6fl_seq_show,
777 static int ip6fl_seq_open(struct inode *inode, struct file *file)
779 struct seq_file *seq;
780 struct ip6fl_iter_state *state;
783 err = seq_open_net(inode, file, &ip6fl_seq_ops,
784 sizeof(struct ip6fl_iter_state));
787 seq = file->private_data;
788 state = ip6fl_seq_private(seq);
790 state->pid_ns = get_pid_ns(task_active_pid_ns(current));
796 static int ip6fl_seq_release(struct inode *inode, struct file *file)
798 struct seq_file *seq = file->private_data;
799 struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
800 put_pid_ns(state->pid_ns);
801 return seq_release_net(inode, file);
804 static const struct file_operations ip6fl_seq_fops = {
805 .owner = THIS_MODULE,
806 .open = ip6fl_seq_open,
809 .release = ip6fl_seq_release,
812 static int __net_init ip6_flowlabel_proc_init(struct net *net)
814 if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
820 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
822 remove_proc_entry("ip6_flowlabel", net->proc_net);
825 static inline int ip6_flowlabel_proc_init(struct net *net)
829 static inline void ip6_flowlabel_proc_fini(struct net *net)
834 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
837 ip6_flowlabel_proc_fini(net);
840 static struct pernet_operations ip6_flowlabel_net_ops = {
841 .init = ip6_flowlabel_proc_init,
842 .exit = ip6_flowlabel_net_exit,
845 int ip6_flowlabel_init(void)
847 return register_pernet_subsys(&ip6_flowlabel_net_ops);
850 void ip6_flowlabel_cleanup(void)
852 del_timer(&ip6_fl_gc_timer);
853 unregister_pernet_subsys(&ip6_flowlabel_net_ops);