[PATCH net-next v3 1/3] ipv6: enable IPV6_FLOWLABEL_MGR for getsockopt

[PATCH net-next v3 1/3] ipv6: enable IPV6_FLOWLABEL_MGR for getsockopt

[Florent Fourcot]

It is already possible to set/put/renew a label
with IPV6_FLOWLABEL_MGR and setsockopt. This patch
add the possibility to get information about this
label (current value, time before expiration, etc).

It helps application to take decision for a renew
or a release of the label.

v2:
 * Add spin_lock to prevent race condition
 * return -ENOENT if no result found
 * check if flr_action is GET

v3:
 * move the spin_lock to protect only the
   relevant code

Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
---
 include/net/ipv6.h       |  1 +
 net/ipv6/ip6_flowlabel.c | 26 ++++++++++++++++++++++++++
 net/ipv6/ipv6_sockglue.c | 28 ++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index dd96638..2a5f668 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -250,6 +250,7 @@ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 					 struct ipv6_txoptions *fopt);
 void fl6_free_socklist(struct sock *sk);
 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
+int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq);
 int ip6_flowlabel_init(void);
 void ip6_flowlabel_cleanup(void);
 
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 819578e..4a06ed0 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -475,6 +475,32 @@ static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 	spin_unlock_bh(&ip6_sk_fl_lock);
 }
 
+int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq)
+{
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct ipv6_fl_socklist *sfl;
+
+	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);
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 4919a8e..1c6ce31 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1212,6 +1212,34 @@ static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		val = np->sndflow;
 		break;
 
+	case IPV6_FLOWLABEL_MGR:
+	{
+		struct in6_flowlabel_req freq;
+
+		if (len < sizeof(freq))
+			return -EINVAL;
+
+		if (copy_from_user(&freq, optval, sizeof(freq)))
+			return -EFAULT;
+
+		if (freq.flr_action != IPV6_FL_A_GET)
+			return -EINVAL;
+
+		len = sizeof(freq);
+		memset(&freq, 0, sizeof(freq));
+
+		val = ipv6_flowlabel_opt_get(sk, &freq);
+		if (val < 0)
+			return val;
+
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, &freq, len))
+			return -EFAULT;
+
+		return 0;
+	}
+
 	case IPV6_ADDR_PREFERENCES:
 		val = 0;
 
-- 
1.8.4.rc3

[PATCH net-next 2/3] ipv6: increase maximum lifetime of flow labels

[Florent Fourcot]

If the last RFC 6437 does not give any constraints
for lifetime of flow labels, the previous RFC 3697
spoke of a minimum of 120 seconds between
reattribution of a flow label.

The maximum linger is currently set to 60 seconds
and does not allow this configuration without
CAP_NET_ADMIN right.

This patch increase the maximum linger to 150
seconds, allowing more flexibility to standard
users.

Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
---
 net/ipv6/ip6_flowlabel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 4a06ed0..5f10b0d 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -41,7 +41,7 @@
 #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	60	/* Maximal linger timeout */
+#define FL_MAX_LINGER	150	/* Maximal linger timeout */
 
 /* FL hash table */
 
-- 
1.8.4.rc3

[PATCH net-next v2 3/3] ipv6: protect flow label renew against GC

[Florent Fourcot]

Take ip6_fl_lock before to read and update
a label.

v2: protect only the relevant code

Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
---
 net/ipv6/ip6_flowlabel.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 5f10b0d..98fdcc6 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -345,6 +345,8 @@ static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned lo
 	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;
@@ -352,6 +354,8 @@ static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned lo
 		expires = fl->linger;
 	if (time_before(fl->expires, fl->lastuse + expires))
 		fl->expires = fl->lastuse + expires;
+	spin_unlock_bh(&ip6_fl_lock);
+
 	return 0;
 }
 
-- 
1.8.4.rc3

Re: [PATCH net-next v3 1/3] ipv6: enable IPV6_FLOWLABEL_MGR for getsockopt

[Florent Fourcot]

This series replaces the previous one, sent the 5th November.

Regards,

-- 
Florent

Re: [PATCH net-next v3 1/3] ipv6: enable IPV6_FLOWLABEL_MGR for getsockopt

[Hannes Frederic Sowa]

On Thu, Nov 07, 2013 at 05:53:12PM +0100, Florent Fourcot wrote:
> It is already possible to set/put/renew a label
> with IPV6_FLOWLABEL_MGR and setsockopt. This patch
> add the possibility to get information about this
> label (current value, time before expiration, etc).
> 
> It helps application to take decision for a renew
> or a release of the label.
> 
> v2:
>  * Add spin_lock to prevent race condition
>  * return -ENOENT if no result found
>  * check if flr_action is GET
> 
> v3:
>  * move the spin_lock to protect only the
>    relevant code
> 
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

There still are some locking anomalies in ip6_flowlabel. But none
has something to do with your patches. E.g. mem_check runs without
rcu_read_lock.

Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Thanks,

  Hannes

Re: [PATCH net-next v2 3/3] ipv6: protect flow label renew against GC

[Hannes Frederic Sowa]

On Thu, Nov 07, 2013 at 05:53:14PM +0100, Florent Fourcot wrote:
> Take ip6_fl_lock before to read and update
> a label.
> 
> v2: protect only the relevant code
> 
> Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Thanks for fixing this,

  Hannes

Re: [PATCH net-next 2/3] ipv6: increase maximum lifetime of flow labels

[Hannes Frederic Sowa]

On Thu, Nov 07, 2013 at 05:53:13PM +0100, Florent Fourcot wrote:
> If the last RFC 6437 does not give any constraints
> for lifetime of flow labels, the previous RFC 3697
> spoke of a minimum of 120 seconds between
> reattribution of a flow label.
> 
> The maximum linger is currently set to 60 seconds
> and does not allow this configuration without
> CAP_NET_ADMIN right.
> 
> This patch increase the maximum linger to 150
> seconds, allowing more flexibility to standard
> users.

Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Re: [PATCH net-next v3 1/3] ipv6: enable IPV6_FLOWLABEL_MGR for getsockopt

[David Miller]

From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Date: Fri, 8 Nov 2013 13:27:49 +0100

> On Thu, Nov 07, 2013 at 05:53:12PM +0100, Florent Fourcot wrote:
>> It is already possible to set/put/renew a label
>> with IPV6_FLOWLABEL_MGR and setsockopt. This patch
>> add the possibility to get information about this
>> label (current value, time before expiration, etc).
>> 
>> It helps application to take decision for a renew
>> or a release of the label.
>> 
>> v2:
>>  * Add spin_lock to prevent race condition
>>  * return -ENOENT if no result found
>>  * check if flr_action is GET
>> 
>> v3:
>>  * move the spin_lock to protect only the
>>    relevant code
>> 
>> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
> 
> There still are some locking anomalies in ip6_flowlabel. But none
> has something to do with your patches. E.g. mem_check runs without
> rcu_read_lock.
> 
> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

Applied, thanks.

Re: [PATCH net-next 2/3] ipv6: increase maximum lifetime of flow labels

[David Miller]

From: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Date: Thu,  7 Nov 2013 17:53:13 +0100

> If the last RFC 6437 does not give any constraints
> for lifetime of flow labels, the previous RFC 3697
> spoke of a minimum of 120 seconds between
> reattribution of a flow label.
> 
> The maximum linger is currently set to 60 seconds
> and does not allow this configuration without
> CAP_NET_ADMIN right.
> 
> This patch increase the maximum linger to 150
> seconds, allowing more flexibility to standard
> users.
> 
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

Applied.

Re: [PATCH net-next v2 3/3] ipv6: protect flow label renew against GC

[David Miller]

From: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Date: Thu,  7 Nov 2013 17:53:14 +0100

> Take ip6_fl_lock before to read and update
> a label.
> 
> v2: protect only the relevant code
> 
> Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>

Applied.