Re: [PATCH net-next 0/8] netlink: align attributes when needed (patchset #3)

[David Miller]

From: Lars Ellenberg 
Date: Tue, 26 Apr 2016 13:54:27 +0200

> On Tue, Apr 26, 2016 at 10:06:10AM +0200, Nicolas Dichtel wrote:
>> 
>> This is the continuation (series #3) of the work done to align netlink
>> attributes when these attributes contain some 64-bit fields.
>> 
>> It's the last patchset from what I've seen.
>> 
>> The last user of nla_put_u64() is block/drbd. This module does not use
>> standard netlink API (see all the stuff in include/linux/genl_magic_struct.h
>> and include/linux/genl_magic_func.h). I didn't modify it because it's seems
>> hard to do it whithout testing and fully understanding the context
> 
> Something like this should just work.

Unfortunately we had problems using unspec, that's why an explicit new
padding attribute is added for each netlink attribute set.

Re: [PATCH net-next 0/8] netlink: align attributes when needed (patchset #3)

[David Miller]

From: Nicolas Dichtel 
Date: Tue, 26 Apr 2016 10:06:10 +0200

> The last user of nla_put_u64() is block/drbd. This module does not use
> standard netlink API (see all the stuff in include/linux/genl_magic_struct.h
> and include/linux/genl_magic_func.h).

Yet another example where doing things in a special unique way creates
headaches and pain for everyone... sigh.

> I didn't modify it because it's seems hard to do it whithout testing
> and fully understanding the context (for example, why
> include/linux/drbd_genl.h is not part of uapi?).  Any thoughts?

I think you'll need to work with the drbd maintainer(s) to resolve
this and test the result.

Series applied, thanks.

Re: [Drbd-dev] [PATCH net-next 0/8] netlink: align attributes when needed (patchset #3)

[Lars Ellenberg]

On Tue, Apr 26, 2016 at 01:54:27PM +0200, Lars Ellenberg wrote:
> On Tue, Apr 26, 2016 at 10:06:10AM +0200, Nicolas Dichtel wrote:
> > 
> > This is the continuation (series #3) of the work done to align netlink
> > attributes when these attributes contain some 64-bit fields.
> > 
> > It's the last patchset from what I've seen.
> > 
> > The last user of nla_put_u64() is block/drbd. This module does not use
> > standard netlink API (see all the stuff in include/linux/genl_magic_struct.h
> > and include/linux/genl_magic_func.h). I didn't modify it because it's seems
> > hard to do it whithout testing and fully understanding the context
> 
> Something like this should just work.

> + * @attrtype: attribute type
> + * @value: numeric value
> + */
> +static inline int nla_put_u64_64bit_unspec(struct sk_buff *skb, int attrtype,
> + u64 value)
> +{
> + return nla_put_64bit(skb, attrtype, sizeof(u64), , NLA_UNSPEC);

Ok, I confused attribute and policy type there for a sec.
Anyways, 0 works just fine,
all our nested attribute enums are != 0,
because nla_parse skips type 0.

Lars

Re: [PATCH net-next 0/8] netlink: align attributes when needed (patchset #3)

[Lars Ellenberg]

On Tue, Apr 26, 2016 at 10:06:10AM +0200, Nicolas Dichtel wrote:
> 
> This is the continuation (series #3) of the work done to align netlink
> attributes when these attributes contain some 64-bit fields.
> 
> It's the last patchset from what I've seen.
> 
> The last user of nla_put_u64() is block/drbd. This module does not use
> standard netlink API (see all the stuff in include/linux/genl_magic_struct.h
> and include/linux/genl_magic_func.h). I didn't modify it because it's seems
> hard to do it whithout testing and fully understanding the context

Something like this should just work.

diff --git a/include/linux/genl_magic_struct.h 
b/include/linux/genl_magic_struct.h
index eecd19b..5715dac 100644
--- a/include/linux/genl_magic_struct.h
+++ b/include/linux/genl_magic_struct.h
@@ -80,7 +80,7 @@ extern void CONCAT_(GENL_MAGIC_FAMILY, 
_genl_unregister)(void);
nla_get_u32, nla_put_u32, true)
 #define __u64_field(attr_nr, attr_flag, name)  \
__field(attr_nr, attr_flag, name, NLA_U64, __u64, \
-   nla_get_u64, nla_put_u64, false)
+   nla_get_u64, nla_put_u64_64bit_unspec, false)
 #define __str_field(attr_nr, attr_flag, name, maxlen) \
__array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
nla_strlcpy, nla_put, false)
diff --git a/include/net/netlink.h b/include/net/netlink.h
index e589cb3..38ba770 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -871,6 +871,18 @@ static inline int nla_put_u64_64bit(struct sk_buff *skb, 
int attrtype,
 }
 
 /**
+ * nla_put_u64_64bit_unspec - nla_put_u64_64bit() with padattr = 0
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @value: numeric value
+ */
+static inline int nla_put_u64_64bit_unspec(struct sk_buff *skb, int attrtype,
+   u64 value)
+{
+   return nla_put_64bit(skb, attrtype, sizeof(u64), , NLA_UNSPEC);
+}
+
+/**
  * nla_put_be64 - Add a __be64 netlink attribute to a socket buffer and align 
it
  * @skb: socket buffer to add attribute to
  * @attrtype: attribute type

> (for
> example, why include/linux/drbd_genl.h is not part of uapi?).
> Any thoughts?

probably should be.

Thanks,

Lars

[PATCH net-next 0/8] netlink: align attributes when needed (patchset #3)

[Nicolas Dichtel]

This is the continuation (series #3) of the work done to align netlink
attributes when these attributes contain some 64-bit fields.

It's the last patchset from what I've seen.

The last user of nla_put_u64() is block/drbd. This module does not use
standard netlink API (see all the stuff in include/linux/genl_magic_struct.h
and include/linux/genl_magic_func.h). I didn't modify it because it's seems
hard to do it whithout testing and fully understanding the context (for
example, why include/linux/drbd_genl.h is not part of uapi?).
Any thoughts?

 Documentation/networking/gen_stats.txt  |   6 +-
 drivers/net/macsec.c| 121 +++-
 drivers/net/wireless/mac80211_hwsim.c   |   2 +-
 drivers/net/wireless/mac80211_hwsim.h   |   1 +
 fs/quota/netlink.c  |  12 ++--
 include/net/gen_stats.h |   6 +-
 include/uapi/linux/gen_stats.h  |   1 +
 include/uapi/linux/if_link.h|   1 +
 include/uapi/linux/if_macsec.h  |   6 ++
 include/uapi/linux/inet_diag.h  |   4 +-
 include/uapi/linux/openvswitch.h|   2 +
 include/uapi/linux/pkt_cls.h|   2 +
 include/uapi/linux/quota.h  |   1 +
 include/uapi/linux/rtnetlink.h  |   1 +
 include/uapi/linux/tc_act/tc_bpf.h  |   1 +
 include/uapi/linux/tc_act/tc_connmark.h |   1 +
 include/uapi/linux/tc_act/tc_csum.h |   1 +
 include/uapi/linux/tc_act/tc_defact.h   |   1 +
 include/uapi/linux/tc_act/tc_gact.h |   1 +
 include/uapi/linux/tc_act/tc_ife.h  |   1 +
 include/uapi/linux/tc_act/tc_ipt.h  |   1 +
 include/uapi/linux/tc_act/tc_mirred.h   |   1 +
 include/uapi/linux/tc_act/tc_nat.h  |   1 +
 include/uapi/linux/tc_act/tc_pedit.h|   1 +
 include/uapi/linux/tc_act/tc_skbedit.h  |   1 +
 include/uapi/linux/tc_act/tc_vlan.h |   1 +
 net/core/gen_stats.c|  35 +
 net/core/neighbour.c|   3 +-
 net/core/rtnetlink.c|   4 +-
 net/core/sock_diag.c|   2 +-
 net/ipv4/inet_diag.c|   9 ++-
 net/openvswitch/datapath.c  |  27 +++
 net/sched/act_api.c |   7 +-
 net/sched/act_bpf.c |   3 +-
 net/sched/act_connmark.c|   3 +-
 net/sched/act_csum.c|   2 +-
 net/sched/act_gact.c|   2 +-
 net/sched/act_ife.c |   2 +-
 net/sched/act_ipt.c |   2 +-
 net/sched/act_mirred.c  |   2 +-
 net/sched/act_nat.c |   2 +-
 net/sched/act_pedit.c   |   2 +-
 net/sched/act_simple.c  |   2 +-
 net/sched/act_skbedit.c |   2 +-
 net/sched/act_vlan.c|   2 +-
 net/sched/cls_u32.c |   7 +-
 net/sched/sch_api.c |   6 +-
 net/sctp/sctp_diag.c|   5 +-
 48 files changed, 211 insertions(+), 98 deletions(-)

Comments are welcomed,
Regards,
Nicolas