linux/net/ipv6/ip6_flowlabel.c
Eric Dumazet d44e3fa5d7 ipv6: fix static key imbalance in fl_create()
fl_create() should call static_branch_deferred_inc() only in
case of success.

Also we should not call fl_free() in error path, as this could
cause a static key imbalance.

jump label: negative count!
WARNING: CPU: 0 PID: 15907 at kernel/jump_label.c:221 static_key_slow_try_dec kernel/jump_label.c:221 [inline]
WARNING: CPU: 0 PID: 15907 at kernel/jump_label.c:221 static_key_slow_try_dec+0x1ab/0x1d0 kernel/jump_label.c:206
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 15907 Comm: syz-executor.2 Not tainted 5.2.0-rc6+ #62
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
 panic+0x2cb/0x744 kernel/panic.c:219
 __warn.cold+0x20/0x4d kernel/panic.c:576
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:static_key_slow_try_dec kernel/jump_label.c:221 [inline]
RIP: 0010:static_key_slow_try_dec+0x1ab/0x1d0 kernel/jump_label.c:206
Code: c0 e8 e9 3e e5 ff 83 fb 01 0f 85 32 ff ff ff e8 5b 3d e5 ff 45 31 ff eb a0 e8 51 3d e5 ff 48 c7 c7 40 99 92 87 e8 13 75 b7 ff <0f> 0b eb 8b 4c 89 e7 e8 a9 c0 1e 00 e9 de fe ff ff e8 bf 6d b7 ff
RSP: 0018:ffff88805f9c7450 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000000000
RDX: 000000000000e3e1 RSI: ffffffff815adb06 RDI: ffffed100bf38e7c
RBP: ffff88805f9c74e0 R08: ffff88806acf0700 R09: ffffed1015d060a9
R10: ffffed1015d060a8 R11: ffff8880ae830547 R12: ffffffff89832ce0
R13: ffff88805f9c74b8 R14: 1ffff1100bf38e8b R15: 00000000ffffff01
 __static_key_slow_dec_deferred+0x65/0x110 kernel/jump_label.c:272
 fl_free+0xa9/0xe0 net/ipv6/ip6_flowlabel.c:121
 fl_create+0x6af/0x9f0 net/ipv6/ip6_flowlabel.c:457
 ipv6_flowlabel_opt+0x80e/0x2730 net/ipv6/ip6_flowlabel.c:624
 do_ipv6_setsockopt.isra.0+0x2119/0x4100 net/ipv6/ipv6_sockglue.c:825
 ipv6_setsockopt+0xf6/0x170 net/ipv6/ipv6_sockglue.c:944
 tcp_setsockopt net/ipv4/tcp.c:3131 [inline]
 tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3125
 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3130
 __sys_setsockopt+0x253/0x4b0 net/socket.c:2080
 __do_sys_setsockopt net/socket.c:2096 [inline]
 __se_sys_setsockopt net/socket.c:2093 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2093
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4597c9
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2670556c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004597c9
RDX: 0000000000000020 RSI: 0000000000000029 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 000000000000fdf7 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00007f26705576d4
R13: 00000000004cec00 R14: 00000000004dd520 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 59c820b231 ("ipv6: elide flowlabel check if no exclusive leases exist")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-11 14:43:25 -07:00

882 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ip6_flowlabel.c IPv6 flowlabel manager.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*/
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/pid_namespace.h>
#include <linux/jump_label_ratelimit.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/rawv6.h>
#include <net/transp_v6.h>
#include <linux/uaccess.h>
#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
in old IPv6 RFC. Well, it was reasonable value.
*/
#define FL_MAX_LINGER 150 /* Maximal linger timeout */
/* FL hash table */
#define FL_MAX_PER_SOCK 32
#define FL_MAX_SIZE 4096
#define FL_HASH_MASK 255
#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
static atomic_t fl_size = ATOMIC_INIT(0);
static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
static void ip6_fl_gc(struct timer_list *unused);
static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc);
/* FL hash table lock: it protects only of GC */
static DEFINE_SPINLOCK(ip6_fl_lock);
/* Big socket sock */
static DEFINE_SPINLOCK(ip6_sk_fl_lock);
DEFINE_STATIC_KEY_DEFERRED_FALSE(ipv6_flowlabel_exclusive, HZ);
EXPORT_SYMBOL(ipv6_flowlabel_exclusive);
#define for_each_fl_rcu(hash, fl) \
for (fl = rcu_dereference_bh(fl_ht[(hash)]); \
fl != NULL; \
fl = rcu_dereference_bh(fl->next))
#define for_each_fl_continue_rcu(fl) \
for (fl = rcu_dereference_bh(fl->next); \
fl != NULL; \
fl = rcu_dereference_bh(fl->next))
#define for_each_sk_fl_rcu(np, sfl) \
for (sfl = rcu_dereference_bh(np->ipv6_fl_list); \
sfl != NULL; \
sfl = rcu_dereference_bh(sfl->next))
static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
{
struct ip6_flowlabel *fl;
for_each_fl_rcu(FL_HASH(label), fl) {
if (fl->label == label && net_eq(fl->fl_net, net))
return fl;
}
return NULL;
}
static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
{
struct ip6_flowlabel *fl;
rcu_read_lock_bh();
fl = __fl_lookup(net, label);
if (fl && !atomic_inc_not_zero(&fl->users))
fl = NULL;
rcu_read_unlock_bh();
return fl;
}
static bool fl_shared_exclusive(struct ip6_flowlabel *fl)
{
return fl->share == IPV6_FL_S_EXCL ||
fl->share == IPV6_FL_S_PROCESS ||
fl->share == IPV6_FL_S_USER;
}
static void fl_free_rcu(struct rcu_head *head)
{
struct ip6_flowlabel *fl = container_of(head, struct ip6_flowlabel, rcu);
if (fl->share == IPV6_FL_S_PROCESS)
put_pid(fl->owner.pid);
kfree(fl->opt);
kfree(fl);
}
static void fl_free(struct ip6_flowlabel *fl)
{
if (!fl)
return;
if (fl_shared_exclusive(fl) || fl->opt)
static_branch_slow_dec_deferred(&ipv6_flowlabel_exclusive);
call_rcu(&fl->rcu, fl_free_rcu);
}
static void fl_release(struct ip6_flowlabel *fl)
{
spin_lock_bh(&ip6_fl_lock);
fl->lastuse = jiffies;
if (atomic_dec_and_test(&fl->users)) {
unsigned long ttd = fl->lastuse + fl->linger;
if (time_after(ttd, fl->expires))
fl->expires = ttd;
ttd = fl->expires;
if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
struct ipv6_txoptions *opt = fl->opt;
fl->opt = NULL;
kfree(opt);
}
if (!timer_pending(&ip6_fl_gc_timer) ||
time_after(ip6_fl_gc_timer.expires, ttd))
mod_timer(&ip6_fl_gc_timer, ttd);
}
spin_unlock_bh(&ip6_fl_lock);
}
static void ip6_fl_gc(struct timer_list *unused)
{
int i;
unsigned long now = jiffies;
unsigned long sched = 0;
spin_lock(&ip6_fl_lock);
for (i = 0; i <= FL_HASH_MASK; i++) {
struct ip6_flowlabel *fl;
struct ip6_flowlabel __rcu **flp;
flp = &fl_ht[i];
while ((fl = rcu_dereference_protected(*flp,
lockdep_is_held(&ip6_fl_lock))) != NULL) {
if (atomic_read(&fl->users) == 0) {
unsigned long ttd = fl->lastuse + fl->linger;
if (time_after(ttd, fl->expires))
fl->expires = ttd;
ttd = fl->expires;
if (time_after_eq(now, ttd)) {
*flp = fl->next;
fl_free(fl);
atomic_dec(&fl_size);
continue;
}
if (!sched || time_before(ttd, sched))
sched = ttd;
}
flp = &fl->next;
}
}
if (!sched && atomic_read(&fl_size))
sched = now + FL_MAX_LINGER;
if (sched) {
mod_timer(&ip6_fl_gc_timer, sched);
}
spin_unlock(&ip6_fl_lock);
}
static void __net_exit ip6_fl_purge(struct net *net)
{
int i;
spin_lock_bh(&ip6_fl_lock);
for (i = 0; i <= FL_HASH_MASK; i++) {
struct ip6_flowlabel *fl;
struct ip6_flowlabel __rcu **flp;
flp = &fl_ht[i];
while ((fl = rcu_dereference_protected(*flp,
lockdep_is_held(&ip6_fl_lock))) != NULL) {
if (net_eq(fl->fl_net, net) &&
atomic_read(&fl->users) == 0) {
*flp = fl->next;
fl_free(fl);
atomic_dec(&fl_size);
continue;
}
flp = &fl->next;
}
}
spin_unlock_bh(&ip6_fl_lock);
}
static struct ip6_flowlabel *fl_intern(struct net *net,
struct ip6_flowlabel *fl, __be32 label)
{
struct ip6_flowlabel *lfl;
fl->label = label & IPV6_FLOWLABEL_MASK;
spin_lock_bh(&ip6_fl_lock);
if (label == 0) {
for (;;) {
fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
if (fl->label) {
lfl = __fl_lookup(net, fl->label);
if (!lfl)
break;
}
}
} else {
/*
* we dropper the ip6_fl_lock, so this entry could reappear
* and we need to recheck with it.
*
* OTOH no need to search the active socket first, like it is
* done in ipv6_flowlabel_opt - sock is locked, so new entry
* with the same label can only appear on another sock
*/
lfl = __fl_lookup(net, fl->label);
if (lfl) {
atomic_inc(&lfl->users);
spin_unlock_bh(&ip6_fl_lock);
return lfl;
}
}
fl->lastuse = jiffies;
fl->next = fl_ht[FL_HASH(fl->label)];
rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
atomic_inc(&fl_size);
spin_unlock_bh(&ip6_fl_lock);
return NULL;
}
/* Socket flowlabel lists */
struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
{
struct ipv6_fl_socklist *sfl;
struct ipv6_pinfo *np = inet6_sk(sk);
label &= IPV6_FLOWLABEL_MASK;
rcu_read_lock_bh();
for_each_sk_fl_rcu(np, sfl) {
struct ip6_flowlabel *fl = sfl->fl;
if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
fl->lastuse = jiffies;
rcu_read_unlock_bh();
return fl;
}
}
rcu_read_unlock_bh();
return NULL;
}
EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
void fl6_free_socklist(struct sock *sk)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6_fl_socklist *sfl;
if (!rcu_access_pointer(np->ipv6_fl_list))
return;
spin_lock_bh(&ip6_sk_fl_lock);
while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
np->ipv6_fl_list = sfl->next;
spin_unlock_bh(&ip6_sk_fl_lock);
fl_release(sfl->fl);
kfree_rcu(sfl, rcu);
spin_lock_bh(&ip6_sk_fl_lock);
}
spin_unlock_bh(&ip6_sk_fl_lock);
}
/* Service routines */
/*
It is the only difficult place. flowlabel enforces equal headers
before and including routing header, however user may supply options
following rthdr.
*/
struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
struct ip6_flowlabel *fl,
struct ipv6_txoptions *fopt)
{
struct ipv6_txoptions *fl_opt = fl->opt;
if (!fopt || fopt->opt_flen == 0)
return fl_opt;
if (fl_opt) {
opt_space->hopopt = fl_opt->hopopt;
opt_space->dst0opt = fl_opt->dst0opt;
opt_space->srcrt = fl_opt->srcrt;
opt_space->opt_nflen = fl_opt->opt_nflen;
} else {
if (fopt->opt_nflen == 0)
return fopt;
opt_space->hopopt = NULL;
opt_space->dst0opt = NULL;
opt_space->srcrt = NULL;
opt_space->opt_nflen = 0;
}
opt_space->dst1opt = fopt->dst1opt;
opt_space->opt_flen = fopt->opt_flen;
opt_space->tot_len = fopt->tot_len;
return opt_space;
}
EXPORT_SYMBOL_GPL(fl6_merge_options);
static unsigned long check_linger(unsigned long ttl)
{
if (ttl < FL_MIN_LINGER)
return FL_MIN_LINGER*HZ;
if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
return 0;
return ttl*HZ;
}
static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
{
linger = check_linger(linger);
if (!linger)
return -EPERM;
expires = check_linger(expires);
if (!expires)
return -EPERM;
spin_lock_bh(&ip6_fl_lock);
fl->lastuse = jiffies;
if (time_before(fl->linger, linger))
fl->linger = linger;
if (time_before(expires, fl->linger))
expires = fl->linger;
if (time_before(fl->expires, fl->lastuse + expires))
fl->expires = fl->lastuse + expires;
spin_unlock_bh(&ip6_fl_lock);
return 0;
}
static struct ip6_flowlabel *
fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
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;
}
if (fl_shared_exclusive(fl) || fl->opt)
static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
return fl;
done:
if (fl) {
kfree(fl->opt);
kfree(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;
if (!atomic_inc_not_zero(&fl1->users))
fl1 = NULL;
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)
{
static_key_deferred_flush(&ipv6_flowlabel_exclusive);
del_timer(&ip6_fl_gc_timer);
unregister_pernet_subsys(&ip6_flowlabel_net_ops);
}