![Eric Dumazet](/assets/img/avatar_default.png)
syzbot was able to catch a use-after-free read in pid_nr_ns() [1]
ip6fl_seq_show() seems to use RCU protection, dereferencing fl->owner.pid
but fl_free() releases fl->owner.pid before rcu grace period is started.
[1]
BUG: KASAN: use-after-free in pid_nr_ns+0x128/0x140 kernel/pid.c:407
Read of size 4 at addr ffff888094012a04 by task syz-executor.0/18087
CPU: 0 PID: 18087 Comm: syz-executor.0 Not tainted 5.1.0-rc6+ #89
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
__asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
pid_nr_ns+0x128/0x140 kernel/pid.c:407
ip6fl_seq_show+0x2f8/0x4f0 net/ipv6/ip6_flowlabel.c:794
seq_read+0xad3/0x1130 fs/seq_file.c:268
proc_reg_read+0x1fe/0x2c0 fs/proc/inode.c:227
do_loop_readv_writev fs/read_write.c:701 [inline]
do_loop_readv_writev fs/read_write.c:688 [inline]
do_iter_read+0x4a9/0x660 fs/read_write.c:922
vfs_readv+0xf0/0x160 fs/read_write.c:984
kernel_readv fs/splice.c:358 [inline]
default_file_splice_read+0x475/0x890 fs/splice.c:413
do_splice_to+0x12a/0x190 fs/splice.c:876
splice_direct_to_actor+0x2d2/0x970 fs/splice.c:953
do_splice_direct+0x1da/0x2a0 fs/splice.c:1062
do_sendfile+0x597/0xd00 fs/read_write.c:1443
__do_sys_sendfile64 fs/read_write.c:1498 [inline]
__se_sys_sendfile64 fs/read_write.c:1490 [inline]
__x64_sys_sendfile64+0x15a/0x220 fs/read_write.c:1490
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458da9
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f300d24bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458da9
RDX: 00000000200000c0 RSI: 0000000000000008 RDI: 0000000000000007
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000005a R11: 0000000000000246 R12: 00007f300d24c6d4
R13: 00000000004c5fa3 R14: 00000000004da748 R15: 00000000ffffffff
Allocated by task 17543:
save_stack+0x45/0xd0 mm/kasan/common.c:75
set_track mm/kasan/common.c:87 [inline]
__kasan_kmalloc mm/kasan/common.c:497 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
slab_post_alloc_hook mm/slab.h:437 [inline]
slab_alloc mm/slab.c:3393 [inline]
kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3555
alloc_pid+0x55/0x8f0 kernel/pid.c:168
copy_process.part.0+0x3b08/0x7980 kernel/fork.c:1932
copy_process kernel/fork.c:1709 [inline]
_do_fork+0x257/0xfd0 kernel/fork.c:2226
__do_sys_clone kernel/fork.c:2333 [inline]
__se_sys_clone kernel/fork.c:2327 [inline]
__x64_sys_clone+0xbf/0x150 kernel/fork.c:2327
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 7789:
save_stack+0x45/0xd0 mm/kasan/common.c:75
set_track mm/kasan/common.c:87 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
__cache_free mm/slab.c:3499 [inline]
kmem_cache_free+0x86/0x260 mm/slab.c:3765
put_pid.part.0+0x111/0x150 kernel/pid.c:111
put_pid+0x20/0x30 kernel/pid.c:105
fl_free+0xbe/0xe0 net/ipv6/ip6_flowlabel.c:102
ip6_fl_gc+0x295/0x3e0 net/ipv6/ip6_flowlabel.c:152
call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
expire_timers kernel/time/timer.c:1362 [inline]
__run_timers kernel/time/timer.c:1681 [inline]
__run_timers kernel/time/timer.c:1649 [inline]
run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
__do_softirq+0x266/0x95a kernel/softirq.c:293
The buggy address belongs to the object at ffff888094012a00
which belongs to the cache pid_2 of size 88
The buggy address is located 4 bytes inside of
88-byte region [ffff888094012a00, ffff888094012a58)
The buggy address belongs to the page:
page:ffffea0002500480 count:1 mapcount:0 mapping:ffff88809a483080 index:0xffff888094012980
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea00018a3508 ffffea0002524a88 ffff88809a483080
raw: ffff888094012980 ffff888094012000 000000010000001b 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888094012900: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
ffff888094012980: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
>ffff888094012a00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
^
ffff888094012a80: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
ffff888094012b00: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
Fixes: 4f82f45730
("net ip6 flowlabel: Make owner a union of struct pid * and kuid_t")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
863 lines
19 KiB
C
863 lines
19 KiB
C
/*
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* ip6_flowlabel.c IPv6 flowlabel manager.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*/
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#include <linux/capability.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/in6.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <linux/pid_namespace.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#include <net/ipv6.h>
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#include <net/rawv6.h>
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#include <net/transp_v6.h>
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#include <linux/uaccess.h>
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#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
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in old IPv6 RFC. Well, it was reasonable value.
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*/
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#define FL_MAX_LINGER 150 /* Maximal linger timeout */
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/* FL hash table */
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#define FL_MAX_PER_SOCK 32
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#define FL_MAX_SIZE 4096
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#define FL_HASH_MASK 255
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#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
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static atomic_t fl_size = ATOMIC_INIT(0);
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static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
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static void ip6_fl_gc(struct timer_list *unused);
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static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc);
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/* FL hash table lock: it protects only of GC */
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static DEFINE_SPINLOCK(ip6_fl_lock);
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/* Big socket sock */
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static DEFINE_SPINLOCK(ip6_sk_fl_lock);
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#define for_each_fl_rcu(hash, fl) \
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for (fl = rcu_dereference_bh(fl_ht[(hash)]); \
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fl != NULL; \
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fl = rcu_dereference_bh(fl->next))
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#define for_each_fl_continue_rcu(fl) \
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for (fl = rcu_dereference_bh(fl->next); \
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fl != NULL; \
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fl = rcu_dereference_bh(fl->next))
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#define for_each_sk_fl_rcu(np, sfl) \
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for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \
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sfl != NULL; \
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sfl = rcu_dereference_bh(sfl->next))
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static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
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{
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struct ip6_flowlabel *fl;
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for_each_fl_rcu(FL_HASH(label), fl) {
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if (fl->label == label && net_eq(fl->fl_net, net))
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return fl;
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}
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return NULL;
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}
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static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
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{
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struct ip6_flowlabel *fl;
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rcu_read_lock_bh();
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fl = __fl_lookup(net, label);
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if (fl && !atomic_inc_not_zero(&fl->users))
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fl = NULL;
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rcu_read_unlock_bh();
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return fl;
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}
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static void fl_free_rcu(struct rcu_head *head)
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{
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struct ip6_flowlabel *fl = container_of(head, struct ip6_flowlabel, rcu);
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if (fl->share == IPV6_FL_S_PROCESS)
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put_pid(fl->owner.pid);
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kfree(fl->opt);
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kfree(fl);
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}
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static void fl_free(struct ip6_flowlabel *fl)
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{
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if (fl)
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call_rcu(&fl->rcu, fl_free_rcu);
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}
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static void fl_release(struct ip6_flowlabel *fl)
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{
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spin_lock_bh(&ip6_fl_lock);
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fl->lastuse = jiffies;
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if (atomic_dec_and_test(&fl->users)) {
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unsigned long ttd = fl->lastuse + fl->linger;
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if (time_after(ttd, fl->expires))
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fl->expires = ttd;
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ttd = fl->expires;
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if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
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struct ipv6_txoptions *opt = fl->opt;
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fl->opt = NULL;
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kfree(opt);
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}
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if (!timer_pending(&ip6_fl_gc_timer) ||
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time_after(ip6_fl_gc_timer.expires, ttd))
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mod_timer(&ip6_fl_gc_timer, ttd);
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}
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spin_unlock_bh(&ip6_fl_lock);
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}
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static void ip6_fl_gc(struct timer_list *unused)
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{
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int i;
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unsigned long now = jiffies;
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unsigned long sched = 0;
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spin_lock(&ip6_fl_lock);
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for (i = 0; i <= FL_HASH_MASK; i++) {
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struct ip6_flowlabel *fl;
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struct ip6_flowlabel __rcu **flp;
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flp = &fl_ht[i];
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while ((fl = rcu_dereference_protected(*flp,
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lockdep_is_held(&ip6_fl_lock))) != NULL) {
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if (atomic_read(&fl->users) == 0) {
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unsigned long ttd = fl->lastuse + fl->linger;
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if (time_after(ttd, fl->expires))
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fl->expires = ttd;
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ttd = fl->expires;
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if (time_after_eq(now, ttd)) {
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*flp = fl->next;
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fl_free(fl);
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atomic_dec(&fl_size);
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continue;
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}
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if (!sched || time_before(ttd, sched))
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sched = ttd;
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}
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flp = &fl->next;
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}
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}
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if (!sched && atomic_read(&fl_size))
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sched = now + FL_MAX_LINGER;
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if (sched) {
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mod_timer(&ip6_fl_gc_timer, sched);
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}
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spin_unlock(&ip6_fl_lock);
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}
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static void __net_exit ip6_fl_purge(struct net *net)
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{
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int i;
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spin_lock_bh(&ip6_fl_lock);
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for (i = 0; i <= FL_HASH_MASK; i++) {
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struct ip6_flowlabel *fl;
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struct ip6_flowlabel __rcu **flp;
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flp = &fl_ht[i];
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while ((fl = rcu_dereference_protected(*flp,
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lockdep_is_held(&ip6_fl_lock))) != NULL) {
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if (net_eq(fl->fl_net, net) &&
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atomic_read(&fl->users) == 0) {
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*flp = fl->next;
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fl_free(fl);
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atomic_dec(&fl_size);
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continue;
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}
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flp = &fl->next;
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}
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}
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spin_unlock_bh(&ip6_fl_lock);
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}
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static struct ip6_flowlabel *fl_intern(struct net *net,
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struct ip6_flowlabel *fl, __be32 label)
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{
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struct ip6_flowlabel *lfl;
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fl->label = label & IPV6_FLOWLABEL_MASK;
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spin_lock_bh(&ip6_fl_lock);
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if (label == 0) {
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for (;;) {
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fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
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if (fl->label) {
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lfl = __fl_lookup(net, fl->label);
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if (!lfl)
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break;
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}
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}
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} else {
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/*
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* we dropper the ip6_fl_lock, so this entry could reappear
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* and we need to recheck with it.
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*
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* OTOH no need to search the active socket first, like it is
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* done in ipv6_flowlabel_opt - sock is locked, so new entry
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* with the same label can only appear on another sock
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*/
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lfl = __fl_lookup(net, fl->label);
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if (lfl) {
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atomic_inc(&lfl->users);
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spin_unlock_bh(&ip6_fl_lock);
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return lfl;
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}
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}
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fl->lastuse = jiffies;
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fl->next = fl_ht[FL_HASH(fl->label)];
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rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
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atomic_inc(&fl_size);
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spin_unlock_bh(&ip6_fl_lock);
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return NULL;
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}
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/* Socket flowlabel lists */
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struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label)
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{
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struct ipv6_fl_socklist *sfl;
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struct ipv6_pinfo *np = inet6_sk(sk);
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label &= IPV6_FLOWLABEL_MASK;
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rcu_read_lock_bh();
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for_each_sk_fl_rcu(np, sfl) {
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struct ip6_flowlabel *fl = sfl->fl;
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if (fl->label == label) {
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fl->lastuse = jiffies;
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atomic_inc(&fl->users);
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rcu_read_unlock_bh();
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return fl;
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}
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}
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rcu_read_unlock_bh();
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return NULL;
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}
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EXPORT_SYMBOL_GPL(fl6_sock_lookup);
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void fl6_free_socklist(struct sock *sk)
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{
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struct ipv6_pinfo *np = inet6_sk(sk);
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struct ipv6_fl_socklist *sfl;
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if (!rcu_access_pointer(np->ipv6_fl_list))
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return;
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spin_lock_bh(&ip6_sk_fl_lock);
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while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
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lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
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np->ipv6_fl_list = sfl->next;
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spin_unlock_bh(&ip6_sk_fl_lock);
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fl_release(sfl->fl);
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kfree_rcu(sfl, rcu);
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spin_lock_bh(&ip6_sk_fl_lock);
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}
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spin_unlock_bh(&ip6_sk_fl_lock);
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}
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/* Service routines */
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/*
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It is the only difficult place. flowlabel enforces equal headers
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before and including routing header, however user may supply options
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following rthdr.
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*/
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struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
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struct ip6_flowlabel *fl,
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struct ipv6_txoptions *fopt)
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{
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struct ipv6_txoptions *fl_opt = fl->opt;
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if (!fopt || fopt->opt_flen == 0)
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return fl_opt;
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if (fl_opt) {
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opt_space->hopopt = fl_opt->hopopt;
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opt_space->dst0opt = fl_opt->dst0opt;
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opt_space->srcrt = fl_opt->srcrt;
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opt_space->opt_nflen = fl_opt->opt_nflen;
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} else {
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if (fopt->opt_nflen == 0)
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return fopt;
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opt_space->hopopt = NULL;
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opt_space->dst0opt = NULL;
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opt_space->srcrt = NULL;
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opt_space->opt_nflen = 0;
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}
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opt_space->dst1opt = fopt->dst1opt;
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opt_space->opt_flen = fopt->opt_flen;
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opt_space->tot_len = fopt->tot_len;
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return opt_space;
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}
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EXPORT_SYMBOL_GPL(fl6_merge_options);
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static unsigned long check_linger(unsigned long ttl)
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{
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if (ttl < FL_MIN_LINGER)
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return FL_MIN_LINGER*HZ;
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if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
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return 0;
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return ttl*HZ;
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}
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static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
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{
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linger = check_linger(linger);
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if (!linger)
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return -EPERM;
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expires = check_linger(expires);
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if (!expires)
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return -EPERM;
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spin_lock_bh(&ip6_fl_lock);
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fl->lastuse = jiffies;
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if (time_before(fl->linger, linger))
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fl->linger = linger;
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if (time_before(expires, fl->linger))
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expires = fl->linger;
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if (time_before(fl->expires, fl->lastuse + expires))
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fl->expires = fl->lastuse + expires;
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spin_unlock_bh(&ip6_fl_lock);
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return 0;
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}
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static struct ip6_flowlabel *
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fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
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char __user *optval, int optlen, int *err_p)
|
|
{
|
|
struct ip6_flowlabel *fl = NULL;
|
|
int olen;
|
|
int addr_type;
|
|
int err;
|
|
|
|
olen = optlen - CMSG_ALIGN(sizeof(*freq));
|
|
err = -EINVAL;
|
|
if (olen > 64 * 1024)
|
|
goto done;
|
|
|
|
err = -ENOMEM;
|
|
fl = kzalloc(sizeof(*fl), GFP_KERNEL);
|
|
if (!fl)
|
|
goto done;
|
|
|
|
if (olen > 0) {
|
|
struct msghdr msg;
|
|
struct flowi6 flowi6;
|
|
struct ipcm6_cookie ipc6;
|
|
|
|
err = -ENOMEM;
|
|
fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
|
|
if (!fl->opt)
|
|
goto done;
|
|
|
|
memset(fl->opt, 0, sizeof(*fl->opt));
|
|
fl->opt->tot_len = sizeof(*fl->opt) + olen;
|
|
err = -EFAULT;
|
|
if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
|
|
goto done;
|
|
|
|
msg.msg_controllen = olen;
|
|
msg.msg_control = (void *)(fl->opt+1);
|
|
memset(&flowi6, 0, sizeof(flowi6));
|
|
|
|
ipc6.opt = fl->opt;
|
|
err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6);
|
|
if (err)
|
|
goto done;
|
|
err = -EINVAL;
|
|
if (fl->opt->opt_flen)
|
|
goto done;
|
|
if (fl->opt->opt_nflen == 0) {
|
|
kfree(fl->opt);
|
|
fl->opt = NULL;
|
|
}
|
|
}
|
|
|
|
fl->fl_net = net;
|
|
fl->expires = jiffies;
|
|
err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
|
|
if (err)
|
|
goto done;
|
|
fl->share = freq->flr_share;
|
|
addr_type = ipv6_addr_type(&freq->flr_dst);
|
|
if ((addr_type & IPV6_ADDR_MAPPED) ||
|
|
addr_type == IPV6_ADDR_ANY) {
|
|
err = -EINVAL;
|
|
goto done;
|
|
}
|
|
fl->dst = freq->flr_dst;
|
|
atomic_set(&fl->users, 1);
|
|
switch (fl->share) {
|
|
case IPV6_FL_S_EXCL:
|
|
case IPV6_FL_S_ANY:
|
|
break;
|
|
case IPV6_FL_S_PROCESS:
|
|
fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
|
|
break;
|
|
case IPV6_FL_S_USER:
|
|
fl->owner.uid = current_euid();
|
|
break;
|
|
default:
|
|
err = -EINVAL;
|
|
goto done;
|
|
}
|
|
return fl;
|
|
|
|
done:
|
|
fl_free(fl);
|
|
*err_p = err;
|
|
return NULL;
|
|
}
|
|
|
|
static int mem_check(struct sock *sk)
|
|
{
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct ipv6_fl_socklist *sfl;
|
|
int room = FL_MAX_SIZE - atomic_read(&fl_size);
|
|
int count = 0;
|
|
|
|
if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
|
|
return 0;
|
|
|
|
rcu_read_lock_bh();
|
|
for_each_sk_fl_rcu(np, sfl)
|
|
count++;
|
|
rcu_read_unlock_bh();
|
|
|
|
if (room <= 0 ||
|
|
((count >= FL_MAX_PER_SOCK ||
|
|
(count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
|
|
!capable(CAP_NET_ADMIN)))
|
|
return -ENOBUFS;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
|
|
struct ip6_flowlabel *fl)
|
|
{
|
|
spin_lock_bh(&ip6_sk_fl_lock);
|
|
sfl->fl = fl;
|
|
sfl->next = np->ipv6_fl_list;
|
|
rcu_assign_pointer(np->ipv6_fl_list, sfl);
|
|
spin_unlock_bh(&ip6_sk_fl_lock);
|
|
}
|
|
|
|
int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
|
|
int flags)
|
|
{
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct ipv6_fl_socklist *sfl;
|
|
|
|
if (flags & IPV6_FL_F_REMOTE) {
|
|
freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
|
|
return 0;
|
|
}
|
|
|
|
if (np->repflow) {
|
|
freq->flr_label = np->flow_label;
|
|
return 0;
|
|
}
|
|
|
|
rcu_read_lock_bh();
|
|
|
|
for_each_sk_fl_rcu(np, sfl) {
|
|
if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
|
|
spin_lock_bh(&ip6_fl_lock);
|
|
freq->flr_label = sfl->fl->label;
|
|
freq->flr_dst = sfl->fl->dst;
|
|
freq->flr_share = sfl->fl->share;
|
|
freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
|
|
freq->flr_linger = sfl->fl->linger / HZ;
|
|
|
|
spin_unlock_bh(&ip6_fl_lock);
|
|
rcu_read_unlock_bh();
|
|
return 0;
|
|
}
|
|
}
|
|
rcu_read_unlock_bh();
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
|
|
{
|
|
int uninitialized_var(err);
|
|
struct net *net = sock_net(sk);
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
struct in6_flowlabel_req freq;
|
|
struct ipv6_fl_socklist *sfl1 = NULL;
|
|
struct ipv6_fl_socklist *sfl;
|
|
struct ipv6_fl_socklist __rcu **sflp;
|
|
struct ip6_flowlabel *fl, *fl1 = NULL;
|
|
|
|
|
|
if (optlen < sizeof(freq))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&freq, optval, sizeof(freq)))
|
|
return -EFAULT;
|
|
|
|
switch (freq.flr_action) {
|
|
case IPV6_FL_A_PUT:
|
|
if (freq.flr_flags & IPV6_FL_F_REFLECT) {
|
|
if (sk->sk_protocol != IPPROTO_TCP)
|
|
return -ENOPROTOOPT;
|
|
if (!np->repflow)
|
|
return -ESRCH;
|
|
np->flow_label = 0;
|
|
np->repflow = 0;
|
|
return 0;
|
|
}
|
|
spin_lock_bh(&ip6_sk_fl_lock);
|
|
for (sflp = &np->ipv6_fl_list;
|
|
(sfl = rcu_dereference_protected(*sflp,
|
|
lockdep_is_held(&ip6_sk_fl_lock))) != NULL;
|
|
sflp = &sfl->next) {
|
|
if (sfl->fl->label == freq.flr_label) {
|
|
if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
|
|
np->flow_label &= ~IPV6_FLOWLABEL_MASK;
|
|
*sflp = sfl->next;
|
|
spin_unlock_bh(&ip6_sk_fl_lock);
|
|
fl_release(sfl->fl);
|
|
kfree_rcu(sfl, rcu);
|
|
return 0;
|
|
}
|
|
}
|
|
spin_unlock_bh(&ip6_sk_fl_lock);
|
|
return -ESRCH;
|
|
|
|
case IPV6_FL_A_RENEW:
|
|
rcu_read_lock_bh();
|
|
for_each_sk_fl_rcu(np, sfl) {
|
|
if (sfl->fl->label == freq.flr_label) {
|
|
err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
|
|
rcu_read_unlock_bh();
|
|
return err;
|
|
}
|
|
}
|
|
rcu_read_unlock_bh();
|
|
|
|
if (freq.flr_share == IPV6_FL_S_NONE &&
|
|
ns_capable(net->user_ns, CAP_NET_ADMIN)) {
|
|
fl = fl_lookup(net, freq.flr_label);
|
|
if (fl) {
|
|
err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
|
|
fl_release(fl);
|
|
return err;
|
|
}
|
|
}
|
|
return -ESRCH;
|
|
|
|
case IPV6_FL_A_GET:
|
|
if (freq.flr_flags & IPV6_FL_F_REFLECT) {
|
|
struct net *net = sock_net(sk);
|
|
if (net->ipv6.sysctl.flowlabel_consistency) {
|
|
net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
|
|
return -EPERM;
|
|
}
|
|
|
|
if (sk->sk_protocol != IPPROTO_TCP)
|
|
return -ENOPROTOOPT;
|
|
|
|
np->repflow = 1;
|
|
return 0;
|
|
}
|
|
|
|
if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
|
|
return -EINVAL;
|
|
|
|
if (net->ipv6.sysctl.flowlabel_state_ranges &&
|
|
(freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
|
|
return -ERANGE;
|
|
|
|
fl = fl_create(net, sk, &freq, optval, optlen, &err);
|
|
if (!fl)
|
|
return err;
|
|
sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
|
|
|
|
if (freq.flr_label) {
|
|
err = -EEXIST;
|
|
rcu_read_lock_bh();
|
|
for_each_sk_fl_rcu(np, sfl) {
|
|
if (sfl->fl->label == freq.flr_label) {
|
|
if (freq.flr_flags&IPV6_FL_F_EXCL) {
|
|
rcu_read_unlock_bh();
|
|
goto done;
|
|
}
|
|
fl1 = sfl->fl;
|
|
atomic_inc(&fl1->users);
|
|
break;
|
|
}
|
|
}
|
|
rcu_read_unlock_bh();
|
|
|
|
if (!fl1)
|
|
fl1 = fl_lookup(net, freq.flr_label);
|
|
if (fl1) {
|
|
recheck:
|
|
err = -EEXIST;
|
|
if (freq.flr_flags&IPV6_FL_F_EXCL)
|
|
goto release;
|
|
err = -EPERM;
|
|
if (fl1->share == IPV6_FL_S_EXCL ||
|
|
fl1->share != fl->share ||
|
|
((fl1->share == IPV6_FL_S_PROCESS) &&
|
|
(fl1->owner.pid != fl->owner.pid)) ||
|
|
((fl1->share == IPV6_FL_S_USER) &&
|
|
!uid_eq(fl1->owner.uid, fl->owner.uid)))
|
|
goto release;
|
|
|
|
err = -ENOMEM;
|
|
if (!sfl1)
|
|
goto release;
|
|
if (fl->linger > fl1->linger)
|
|
fl1->linger = fl->linger;
|
|
if ((long)(fl->expires - fl1->expires) > 0)
|
|
fl1->expires = fl->expires;
|
|
fl_link(np, sfl1, fl1);
|
|
fl_free(fl);
|
|
return 0;
|
|
|
|
release:
|
|
fl_release(fl1);
|
|
goto done;
|
|
}
|
|
}
|
|
err = -ENOENT;
|
|
if (!(freq.flr_flags&IPV6_FL_F_CREATE))
|
|
goto done;
|
|
|
|
err = -ENOMEM;
|
|
if (!sfl1)
|
|
goto done;
|
|
|
|
err = mem_check(sk);
|
|
if (err != 0)
|
|
goto done;
|
|
|
|
fl1 = fl_intern(net, fl, freq.flr_label);
|
|
if (fl1)
|
|
goto recheck;
|
|
|
|
if (!freq.flr_label) {
|
|
if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
|
|
&fl->label, sizeof(fl->label))) {
|
|
/* Intentionally ignore fault. */
|
|
}
|
|
}
|
|
|
|
fl_link(np, sfl1, fl);
|
|
return 0;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
done:
|
|
fl_free(fl);
|
|
kfree(sfl1);
|
|
return err;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
struct ip6fl_iter_state {
|
|
struct seq_net_private p;
|
|
struct pid_namespace *pid_ns;
|
|
int bucket;
|
|
};
|
|
|
|
#define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
|
|
|
|
static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
|
|
{
|
|
struct ip6_flowlabel *fl = NULL;
|
|
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
|
|
struct net *net = seq_file_net(seq);
|
|
|
|
for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
|
|
for_each_fl_rcu(state->bucket, fl) {
|
|
if (net_eq(fl->fl_net, net))
|
|
goto out;
|
|
}
|
|
}
|
|
fl = NULL;
|
|
out:
|
|
return fl;
|
|
}
|
|
|
|
static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
|
|
{
|
|
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
|
|
struct net *net = seq_file_net(seq);
|
|
|
|
for_each_fl_continue_rcu(fl) {
|
|
if (net_eq(fl->fl_net, net))
|
|
goto out;
|
|
}
|
|
|
|
try_again:
|
|
if (++state->bucket <= FL_HASH_MASK) {
|
|
for_each_fl_rcu(state->bucket, fl) {
|
|
if (net_eq(fl->fl_net, net))
|
|
goto out;
|
|
}
|
|
goto try_again;
|
|
}
|
|
fl = NULL;
|
|
|
|
out:
|
|
return fl;
|
|
}
|
|
|
|
static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
|
|
{
|
|
struct ip6_flowlabel *fl = ip6fl_get_first(seq);
|
|
if (fl)
|
|
while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
|
|
--pos;
|
|
return pos ? NULL : fl;
|
|
}
|
|
|
|
static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
|
|
__acquires(RCU)
|
|
{
|
|
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
|
|
|
|
state->pid_ns = proc_pid_ns(file_inode(seq->file));
|
|
|
|
rcu_read_lock_bh();
|
|
return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
|
|
}
|
|
|
|
static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct ip6_flowlabel *fl;
|
|
|
|
if (v == SEQ_START_TOKEN)
|
|
fl = ip6fl_get_first(seq);
|
|
else
|
|
fl = ip6fl_get_next(seq, v);
|
|
++*pos;
|
|
return fl;
|
|
}
|
|
|
|
static void ip6fl_seq_stop(struct seq_file *seq, void *v)
|
|
__releases(RCU)
|
|
{
|
|
rcu_read_unlock_bh();
|
|
}
|
|
|
|
static int ip6fl_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
|
|
if (v == SEQ_START_TOKEN) {
|
|
seq_puts(seq, "Label S Owner Users Linger Expires Dst Opt\n");
|
|
} else {
|
|
struct ip6_flowlabel *fl = v;
|
|
seq_printf(seq,
|
|
"%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
|
|
(unsigned int)ntohl(fl->label),
|
|
fl->share,
|
|
((fl->share == IPV6_FL_S_PROCESS) ?
|
|
pid_nr_ns(fl->owner.pid, state->pid_ns) :
|
|
((fl->share == IPV6_FL_S_USER) ?
|
|
from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
|
|
0)),
|
|
atomic_read(&fl->users),
|
|
fl->linger/HZ,
|
|
(long)(fl->expires - jiffies)/HZ,
|
|
&fl->dst,
|
|
fl->opt ? fl->opt->opt_nflen : 0);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations ip6fl_seq_ops = {
|
|
.start = ip6fl_seq_start,
|
|
.next = ip6fl_seq_next,
|
|
.stop = ip6fl_seq_stop,
|
|
.show = ip6fl_seq_show,
|
|
};
|
|
|
|
static int __net_init ip6_flowlabel_proc_init(struct net *net)
|
|
{
|
|
if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
|
|
&ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
|
|
{
|
|
remove_proc_entry("ip6_flowlabel", net->proc_net);
|
|
}
|
|
#else
|
|
static inline int ip6_flowlabel_proc_init(struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void ip6_flowlabel_proc_fini(struct net *net)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static void __net_exit ip6_flowlabel_net_exit(struct net *net)
|
|
{
|
|
ip6_fl_purge(net);
|
|
ip6_flowlabel_proc_fini(net);
|
|
}
|
|
|
|
static struct pernet_operations ip6_flowlabel_net_ops = {
|
|
.init = ip6_flowlabel_proc_init,
|
|
.exit = ip6_flowlabel_net_exit,
|
|
};
|
|
|
|
int ip6_flowlabel_init(void)
|
|
{
|
|
return register_pernet_subsys(&ip6_flowlabel_net_ops);
|
|
}
|
|
|
|
void ip6_flowlabel_cleanup(void)
|
|
{
|
|
del_timer(&ip6_fl_gc_timer);
|
|
unregister_pernet_subsys(&ip6_flowlabel_net_ops);
|
|
}
|