[PATCH net-next 0/4] Rightsize IFLA_AF_SPEC size calculation

[PATCH net-next 0/4] Rightsize IFLA_AF_SPEC size calculation

[Ronen Arad]

if_nlmsg_size() overestimates the minimum allocation size of netlink dump
request (when called from rtnl_calcit()) or the size of the message (when called
from rtnl_getlink()). This is because ext_filter_mask is not supported by
rtnl_link_get_af_size() and rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many VLANs
configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size calculation by
propagating ext_filter_mask to rtnl_link_get_af_size() and adding optional
filtering aware get_af_size_filtered op in struct rtnl_af_ops. Bridge module,
which already used filtering aware sizing for notification, is enhanced to do
the same for netlink dump requests.

Ronen Arad (4):
  rtnetlink: Add get_link_af_size_filtered to rtnl_af_ops
  bridge: br_af_ops add br_get_link_af_size_filtered
  rtnetlink: Prefer filtering-aware af sizing
  bridge: Remove br_get_link_af_size

 include/net/rtnetlink.h |  2 ++
 net/bridge/br_netlink.c | 23 ++---------------------
 net/core/rtnetlink.c    | 12 +++++++++---
 3 files changed, 13 insertions(+), 24 deletions(-)

--
2.1.0

[PATCH net-next 1/4] rtnetlink: Add get_link_af_size_filtered to rtnl_af_ops

[Ronen Arad]

get_link_af_size_filtered() - a filtering-mask aware alternative
function is added to struct rtnl_af_ops in order to allow for
"rightsizing" the IFLA_AF_SPEC calculation in if_nlmsg_size().
This significantly reduces the message size when at least one netdev has
large number of VLANs.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
---
 include/net/rtnetlink.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index aff6ceb..96df9bb 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -130,6 +130,8 @@ struct rtnl_af_ops {
 						    const struct nlattr *attr);
 	int			(*set_link_af)(struct net_device *dev,
 					       const struct nlattr *attr);
+	size_t			(*get_link_af_size_filtered)(const struct net_device *dev,
+							     u32 ext_filter_mask);
 };
 
 void __rtnl_af_unregister(struct rtnl_af_ops *ops);
-- 
2.1.0

[PATCH net-next 2/4] bridge: br_af_ops add br_get_link_af_size_filtered

[Ronen Arad]

Provide get_af_size_filtered (set to br_get_link_af_size_filtered)
in br_af_ops for proper filtering mask aware sizing of AF_BRIDGE
attributes. This is an optimization of netlink message size when
-c[compressvlans] option is entered for iproute2's bridge command.
Optimization will get into effect with rtnetlink change in the next
patch of this set.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
---
 net/bridge/br_netlink.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8..d900881 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1235,8 +1235,9 @@ static size_t br_get_link_af_size(const struct net_device *dev)
 }
 
 static struct rtnl_af_ops br_af_ops __read_mostly = {
-	.family			= AF_BRIDGE,
-	.get_link_af_size	= br_get_link_af_size,
+	.family				= AF_BRIDGE,
+	.get_link_af_size		= br_get_link_af_size,
+	.get_link_af_size_filtered	= br_get_link_af_size_filtered,
 };
 
 struct rtnl_link_ops br_link_ops __read_mostly = {
-- 
2.1.0

[PATCH net-next 3/4] rtnetlink: Prefer filtering-aware af sizing

[Ronen Arad]

Add ext_filter_mask arg to rtnl_link_get_af_size().
rtnl_link_get_af_size() will prefer filtering-aware af sizing when
provided by an address family. It falls back to get_link_af_size for
other families.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
---
 net/core/rtnetlink.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2477595..dd7cda7 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
 }
 EXPORT_SYMBOL_GPL(rtnl_af_unregister);
 
-static size_t rtnl_link_get_af_size(const struct net_device *dev)
+static size_t rtnl_link_get_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct rtnl_af_ops *af_ops;
 	size_t size;
@@ -506,7 +507,12 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
 	size = nla_total_size(sizeof(struct nlattr));
 
 	list_for_each_entry(af_ops, &rtnl_af_ops, list) {
-		if (af_ops->get_link_af_size) {
+		/* Prefer filtering-aware af sizing when available */
+		if (af_ops->get_link_af_size_filtered) {
+			/* AF_* + nested data */
+			size += nla_total_size(sizeof(struct nlattr)) +
+				af_ops->get_link_af_size_filtered(dev, ext_filter_mask);
+		} else if (af_ops->get_link_af_size) {
 			/* AF_* + nested data */
 			size += nla_total_size(sizeof(struct nlattr)) +
 				af_ops->get_link_af_size(dev);
@@ -900,7 +906,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
 	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
 	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
-	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
+	       + rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
 	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
-- 
2.1.0

[PATCH net-next 4/4] bridge: Remove br_get_link_af_size

[Ronen Arad]

Unset get_link_af_size in br_af_ops. br_get_link_af_size() becomes
unused and thus removed.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
---
 net/bridge/br_netlink.c | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index d900881..204222d 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,9 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	return 0;
 }
 
-static size_t br_get_link_af_size(const struct net_device *dev)
-{
-	struct net_bridge_port *p;
-	struct net_bridge *br;
-	int num_vlans = 0;
-
-	if (br_port_exists(dev)) {
-		p = br_port_get_rtnl(dev);
-		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
-						  RTEXT_FILTER_BRVLAN);
-	} else if (dev->priv_flags & IFF_EBRIDGE) {
-		br = netdev_priv(dev);
-		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
-						  RTEXT_FILTER_BRVLAN);
-	}
-
-	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
-}
 
 static struct rtnl_af_ops br_af_ops __read_mostly = {
 	.family				= AF_BRIDGE,
-	.get_link_af_size		= br_get_link_af_size,
 	.get_link_af_size_filtered	= br_get_link_af_size_filtered,
 };
 
-- 
2.1.0

Re: [PATCH net-next 1/4] rtnetlink: Add get_link_af_size_filtered to rtnl_af_ops

[Jiri Benc]

On Tue, 13 Oct 2015 22:58:31 -0700, Ronen Arad wrote:
> --- a/include/net/rtnetlink.h
> +++ b/include/net/rtnetlink.h
> @@ -130,6 +130,8 @@ struct rtnl_af_ops {
>  						    const struct nlattr *attr);
>  	int			(*set_link_af)(struct net_device *dev,
>  					       const struct nlattr *attr);
> +	size_t			(*get_link_af_size_filtered)(const struct net_device *dev,
> +							     u32 ext_filter_mask);
>  };

There's not much point in having two callbacks doing essentially the
same. Why you just don't add the new parameter to the existing
get_link_af_size? Looking at what the patch 3 does, the current
implementations of the callback can just ignore the new parameter and
bridge can remove the current br_get_link_af and rename
br_get_link_af_size_filtered to br_get_link_af.

 Jiri

-- 
Jiri Benc

RE: [PATCH net-next 1/4] rtnetlink: Add get_link_af_size_filtered to rtnl_af_ops

[Arad, Ronen]

>-----Original Message-----
>From: Jiri Benc [mailto:jbenc@redhat.com]
>Sent: Wednesday, October 14, 2015 2:55 AM
>To: Arad, Ronen
>Cc: netdev@vger.kernel.org
>Subject: Re: [PATCH net-next 1/4] rtnetlink: Add get_link_af_size_filtered to
>rtnl_af_ops
>
>On Tue, 13 Oct 2015 22:58:31 -0700, Ronen Arad wrote:
>> --- a/include/net/rtnetlink.h
>> +++ b/include/net/rtnetlink.h
>> @@ -130,6 +130,8 @@ struct rtnl_af_ops {
>>  						    const struct nlattr *attr);
>>  	int			(*set_link_af)(struct net_device *dev,
>>  					       const struct nlattr *attr);
>> +	size_t			(*get_link_af_size_filtered)(const struct
>net_device *dev,
>> +							     u32 ext_filter_mask);
>>  };
>
>There's not much point in having two callbacks doing essentially the
>same. Why you just don't add the new parameter to the existing
>get_link_af_size? Looking at what the patch 3 does, the current
>implementations of the callback can just ignore the new parameter and
>bridge can remove the current br_get_link_af and rename
>br_get_link_af_size_filtered to br_get_link_af.
[@Ronen] I agree with you about br_netlink. There was no need for both
so I removed br_get_link_af. Changing get_link_af_size signature, however,
will require change in other unrelated locations. I wanted to avoid that. The affected location are:
net/ipv4/devinet.c:2374:	.get_link_af_size = inet_get_link_af_size,
net/ipv6/addrconf.c:5868:	.get_link_af_size = inet6_get_link_af_size,

If there is a consensus that adding ext_filter_mask argument to
get_link_af is preferred, I'll submit a v2.

>
> Jiri
>
>--
>Jiri Benc

[PATCH net-next v2] netlink: Rightsize IFLA_AF_SPEC size calculation

[Ronen Arad]

This is a v2 of a 4-parts patch with same subject.
Giving up on backward compatibility allows for much simplified single patch.

if_nlmsg_size() overestimates the minimum allocation size of netlink
dump request (when called from rtnl_calcit()) or the size of the
message (when called from rtnl_getlink()). This is because
ext_filter_mask is not supported by rtnl_link_get_af_size() and
rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many
VLANs configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size
calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
and adding this a argument to get_link_af_size op in rtnl_af_ops.

Bridge module already used filtering aware sizing for notifications.
br_get_link_af_size_filtered() is consistent with the modified
get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
br_get_link_af_size() becomes unused and thus removed.
---
 include/net/rtnetlink.h |  3 ++-
 net/bridge/br_netlink.c | 21 +--------------------
 net/core/rtnetlink.c    |  8 ++++----
 net/ipv4/devinet.c      |  4 ++--
 net/ipv6/addrconf.c     |  3 ++-
 5 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index aff6ceb..2f87c1b 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -124,7 +124,8 @@ struct rtnl_af_ops {
 	int			(*fill_link_af)(struct sk_buff *skb,
 						const struct net_device *dev,
 						u32 ext_filter_mask);
-	size_t			(*get_link_af_size)(const struct net_device *dev);
+	size_t			(*get_link_af_size)(const struct net_device *dev,
+						    u32 ext_filter_mask);

 	int			(*validate_link_af)(const struct net_device *dev,
 						    const struct nlattr *attr);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8..40197ff 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	return 0;
 }

-static size_t br_get_link_af_size(const struct net_device *dev)
-{
-	struct net_bridge_port *p;
-	struct net_bridge *br;
-	int num_vlans = 0;
-
-	if (br_port_exists(dev)) {
-		p = br_port_get_rtnl(dev);
-		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
-						  RTEXT_FILTER_BRVLAN);
-	} else if (dev->priv_flags & IFF_EBRIDGE) {
-		br = netdev_priv(dev);
-		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
-						  RTEXT_FILTER_BRVLAN);
-	}
-
-	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
-}

 static struct rtnl_af_ops br_af_ops __read_mostly = {
 	.family			= AF_BRIDGE,
-	.get_link_af_size	= br_get_link_af_size,
+	.get_link_af_size	= br_get_link_af_size_filtered,
 };

 struct rtnl_link_ops br_link_ops __read_mostly = {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2477595..581aec4 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
 }
 EXPORT_SYMBOL_GPL(rtnl_af_unregister);

-static size_t rtnl_link_get_af_size(const struct net_device *dev)
+static size_t rtnl_link_get_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct rtnl_af_ops *af_ops;
 	size_t size;
@@ -509,7 +510,7 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
 		if (af_ops->get_link_af_size) {
 			/* AF_* + nested data */
 			size += nla_total_size(sizeof(struct nlattr)) +
-				af_ops->get_link_af_size(dev);
+				af_ops->get_link_af_size(dev, ext_filter_mask);
 		}
 	}

@@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
 	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
 	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
-	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
+		+ rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
 	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
@@ -3443,4 +3444,3 @@ void __init rtnetlink_init(void)
 	rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
 }
-
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7350084..cebd9d3 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1644,7 +1644,8 @@ errout:
 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
 }

-static size_t inet_get_link_af_size(const struct net_device *dev)
+static size_t inet_get_link_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);

@@ -2398,4 +2399,3 @@ void __init devinet_init(void)
 	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
 		      inet_netconf_dump_devconf, NULL);
 }
-
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f0326aa..0645fd1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4786,7 +4786,8 @@ nla_put_failure:
 	return -EMSGSIZE;
 }

-static size_t inet6_get_link_af_size(const struct net_device *dev)
+static size_t inet6_get_link_af_size(const struct net_device *dev,
+				     u32 ext_filter_mask)
 {
 	if (!__in6_dev_get(dev))
 		return 0;
--
2.1.0

RE: [PATCH net-next 0/4] Rightsize IFLA_AF_SPEC size calculation

[Arad, Ronen]

>-----Original Message-----
>From: David Miller [mailto:davem@davemloft.net]
>Sent: Wednesday, October 14, 2015 6:44 PM
>To: Arad, Ronen
>Cc: netdev@vger.kernel.org
>Subject: Re: [PATCH net-next 0/4] Rightsize IFLA_AF_SPEC size calculation
>
>From: Ronen Arad <ronen.arad@intel.com>
>Date: Tue, 13 Oct 2015 22:58:30 -0700
>
>> if_nlmsg_size() overestimates the minimum allocation size of netlink dump
>> request (when called from rtnl_calcit()) or the size of the message (when
>called
>> from rtnl_getlink()). This is because ext_filter_mask is not supported by
>> rtnl_link_get_af_size() and rtnl_link_get_size().
>>
>> The over-estimation is significant when at least one netdev has many VLANs
>> configured (8 bytes for each configured VLAN).
>>
>> This patch-set "rightsizes" the protocol specific attribute size calculation
>by
>> propagating ext_filter_mask to rtnl_link_get_af_size() and adding optional
>> filtering aware get_af_size_filtered op in struct rtnl_af_ops. Bridge
>module,
>> which already used filtering aware sizing for notification, is enhanced to
>do
>> the same for netlink dump requests.
>
>There are only three implementations of get_link_af_size, so please just
>simply
>change it's signature by adding the ext_filter_mask parameter instead of
>creating
>a completely new operation.
[@Ronen] I've already submitted a V2 that does that in a simplified
single part patch.

Re: [PATCH net-next 0/4] Rightsize IFLA_AF_SPEC size calculation

[David Miller]

From: Ronen Arad <ronen.arad@intel.com>
Date: Tue, 13 Oct 2015 22:58:30 -0700

> if_nlmsg_size() overestimates the minimum allocation size of netlink dump
> request (when called from rtnl_calcit()) or the size of the message (when called
> from rtnl_getlink()). This is because ext_filter_mask is not supported by
> rtnl_link_get_af_size() and rtnl_link_get_size().
> 
> The over-estimation is significant when at least one netdev has many VLANs
> configured (8 bytes for each configured VLAN).
> 
> This patch-set "rightsizes" the protocol specific attribute size calculation by
> propagating ext_filter_mask to rtnl_link_get_af_size() and adding optional
> filtering aware get_af_size_filtered op in struct rtnl_af_ops. Bridge module,
> which already used filtering aware sizing for notification, is enhanced to do
> the same for netlink dump requests.

There are only three implementations of get_link_af_size, so please just simply
change it's signature by adding the ext_filter_mask parameter instead of creating
a completely new operation.

Re: [PATCH net-next v2] netlink: Rightsize IFLA_AF_SPEC size calculation

[David Miller]

From: Ronen Arad <ronen.arad@intel.com>
Date: Wed, 14 Oct 2015 08:51:28 -0700

> @@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
>  	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
>  	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
>  	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
> -	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
> +		+ rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
>  	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */

Please don't change the indentation on this line, keep it matching
the indentation of all of the surrounding lines of this expression.

Thanks.

[PATCH net-next v3] netlink: Rightsize IFLA_AF_SPEC size calculation

[Ronen Arad]

if_nlmsg_size() overestimates the minimum allocation size of netlink
dump request (when called from rtnl_calcit()) or the size of the
message (when called from rtnl_getlink()). This is because
ext_filter_mask is not supported by rtnl_link_get_af_size() and
rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many
VLANs configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size
calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
and adding this a argument to get_link_af_size op in rtnl_af_ops.

Bridge module already used filtering aware sizing for notifications.
br_get_link_af_size_filtered() is consistent with the modified
get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
br_get_link_af_size() becomes unused and thus removed.
---
 include/net/rtnetlink.h |  3 ++-
 net/bridge/br_netlink.c | 21 +--------------------
 net/core/rtnetlink.c    |  8 ++++----
 net/ipv4/devinet.c      |  4 ++--
 net/ipv6/addrconf.c     |  3 ++-
 5 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index aff6ceb..2f87c1b 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -124,7 +124,8 @@ struct rtnl_af_ops {
 	int			(*fill_link_af)(struct sk_buff *skb,
 						const struct net_device *dev,
 						u32 ext_filter_mask);
-	size_t			(*get_link_af_size)(const struct net_device *dev);
+	size_t			(*get_link_af_size)(const struct net_device *dev,
+						    u32 ext_filter_mask);
 
 	int			(*validate_link_af)(const struct net_device *dev,
 						    const struct nlattr *attr);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8..40197ff 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	return 0;
 }
 
-static size_t br_get_link_af_size(const struct net_device *dev)
-{
-	struct net_bridge_port *p;
-	struct net_bridge *br;
-	int num_vlans = 0;
-
-	if (br_port_exists(dev)) {
-		p = br_port_get_rtnl(dev);
-		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
-						  RTEXT_FILTER_BRVLAN);
-	} else if (dev->priv_flags & IFF_EBRIDGE) {
-		br = netdev_priv(dev);
-		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
-						  RTEXT_FILTER_BRVLAN);
-	}
-
-	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
-}
 
 static struct rtnl_af_ops br_af_ops __read_mostly = {
 	.family			= AF_BRIDGE,
-	.get_link_af_size	= br_get_link_af_size,
+	.get_link_af_size	= br_get_link_af_size_filtered,
 };
 
 struct rtnl_link_ops br_link_ops __read_mostly = {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2477595..7c78b5a 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
 }
 EXPORT_SYMBOL_GPL(rtnl_af_unregister);
 
-static size_t rtnl_link_get_af_size(const struct net_device *dev)
+static size_t rtnl_link_get_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct rtnl_af_ops *af_ops;
 	size_t size;
@@ -509,7 +510,7 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
 		if (af_ops->get_link_af_size) {
 			/* AF_* + nested data */
 			size += nla_total_size(sizeof(struct nlattr)) +
-				af_ops->get_link_af_size(dev);
+				af_ops->get_link_af_size(dev, ext_filter_mask);
 		}
 	}
 
@@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
 	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
 	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
-	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
+	       + rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
 	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
@@ -3443,4 +3444,3 @@ void __init rtnetlink_init(void)
 	rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
 }
-
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7350084..cebd9d3 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1644,7 +1644,8 @@ errout:
 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
 }
 
-static size_t inet_get_link_af_size(const struct net_device *dev)
+static size_t inet_get_link_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
 
@@ -2398,4 +2399,3 @@ void __init devinet_init(void)
 	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
 		      inet_netconf_dump_devconf, NULL);
 }
-
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f0326aa..0645fd1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4786,7 +4786,8 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
-static size_t inet6_get_link_af_size(const struct net_device *dev)
+static size_t inet6_get_link_af_size(const struct net_device *dev,
+				     u32 ext_filter_mask)
 {
 	if (!__in6_dev_get(dev))
 		return 0;
-- 
2.1.0

RE: [PATCH net-next v2] netlink: Rightsize IFLA_AF_SPEC size calculation

[Arad, Ronen]

>-----Original Message-----
>From: David Miller [mailto:davem@davemloft.net]
>Sent: Wednesday, October 14, 2015 7:24 PM
>To: Arad, Ronen
>Cc: netdev@vger.kernel.org
>Subject: Re: [PATCH net-next v2] netlink: Rightsize IFLA_AF_SPEC size
>calculation
>
>From: Ronen Arad <ronen.arad@intel.com>
>Date: Wed, 14 Oct 2015 08:51:28 -0700
>
>> @@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct
>net_device *dev,
>>  	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
>>  	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS +
>IFLA_PORT_SELF */
>>  	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
>> -	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
>> +		+ rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
>>  	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
>
>Please don't change the indentation on this line, keep it matching
>the indentation of all of the surrounding lines of this expression.
[@Ronen] Sure. V3 submitted. My editor didn't like the indentation of the
surrounding lines which are one less than two TAB spaces but consistency
is important. 
>
>Thanks.

Re: [PATCH net-next v3] netlink: Rightsize IFLA_AF_SPEC size calculation

[David Miller]

From: Ronen Arad <ronen.arad@intel.com>
Date: Wed, 14 Oct 2015 22:50:04 -0700

> if_nlmsg_size() overestimates the minimum allocation size of netlink
> dump request (when called from rtnl_calcit()) or the size of the
> message (when called from rtnl_getlink()). This is because
> ext_filter_mask is not supported by rtnl_link_get_af_size() and
> rtnl_link_get_size().
> 
> The over-estimation is significant when at least one netdev has many
> VLANs configured (8 bytes for each configured VLAN).
> 
> This patch-set "rightsizes" the protocol specific attribute size
> calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
> and adding this a argument to get_link_af_size op in rtnl_af_ops.
> 
> Bridge module already used filtering aware sizing for notifications.
> br_get_link_af_size_filtered() is consistent with the modified
> get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
> br_get_link_af_size() becomes unused and thus removed.

This is missing a proper Signoff

[PATCH net-next v3] netlink: Rightsize IFLA_AF_SPEC size calculation

[Ronen Arad]

if_nlmsg_size() overestimates the minimum allocation size of netlink
dump request (when called from rtnl_calcit()) or the size of the
message (when called from rtnl_getlink()). This is because
ext_filter_mask is not supported by rtnl_link_get_af_size() and
rtnl_link_get_size().

The over-estimation is significant when at least one netdev has many
VLANs configured (8 bytes for each configured VLAN).

This patch-set "rightsizes" the protocol specific attribute size
calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
and adding this a argument to get_link_af_size op in rtnl_af_ops.

Bridge module already used filtering aware sizing for notifications.
br_get_link_af_size_filtered() is consistent with the modified
get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
br_get_link_af_size() becomes unused and thus removed.

Signed-off-by: Ronen Arad <ronen.arad@intel.com>
---
 include/net/rtnetlink.h |  3 ++-
 net/bridge/br_netlink.c | 21 +--------------------
 net/core/rtnetlink.c    |  8 ++++----
 net/ipv4/devinet.c      |  4 ++--
 net/ipv6/addrconf.c     |  3 ++-
 5 files changed, 11 insertions(+), 28 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index aff6ceb..2f87c1b 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -124,7 +124,8 @@ struct rtnl_af_ops {
 	int			(*fill_link_af)(struct sk_buff *skb,
 						const struct net_device *dev,
 						u32 ext_filter_mask);
-	size_t			(*get_link_af_size)(const struct net_device *dev);
+	size_t			(*get_link_af_size)(const struct net_device *dev,
+						    u32 ext_filter_mask);
 
 	int			(*validate_link_af)(const struct net_device *dev,
 						    const struct nlattr *attr);
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 94b4de8..40197ff 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -1214,29 +1214,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
 	return 0;
 }
 
-static size_t br_get_link_af_size(const struct net_device *dev)
-{
-	struct net_bridge_port *p;
-	struct net_bridge *br;
-	int num_vlans = 0;
-
-	if (br_port_exists(dev)) {
-		p = br_port_get_rtnl(dev);
-		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
-						  RTEXT_FILTER_BRVLAN);
-	} else if (dev->priv_flags & IFF_EBRIDGE) {
-		br = netdev_priv(dev);
-		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
-						  RTEXT_FILTER_BRVLAN);
-	}
-
-	/* Each VLAN is returned in bridge_vlan_info along with flags */
-	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
-}
 
 static struct rtnl_af_ops br_af_ops __read_mostly = {
 	.family			= AF_BRIDGE,
-	.get_link_af_size	= br_get_link_af_size,
+	.get_link_af_size	= br_get_link_af_size_filtered,
 };
 
 struct rtnl_link_ops br_link_ops __read_mostly = {
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2477595..7c78b5a 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
 }
 EXPORT_SYMBOL_GPL(rtnl_af_unregister);
 
-static size_t rtnl_link_get_af_size(const struct net_device *dev)
+static size_t rtnl_link_get_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct rtnl_af_ops *af_ops;
 	size_t size;
@@ -509,7 +510,7 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
 		if (af_ops->get_link_af_size) {
 			/* AF_* + nested data */
 			size += nla_total_size(sizeof(struct nlattr)) +
-				af_ops->get_link_af_size(dev);
+				af_ops->get_link_af_size(dev, ext_filter_mask);
 		}
 	}
 
@@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
 	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
 	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
-	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
+	       + rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
 	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
 	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
@@ -3443,4 +3444,3 @@ void __init rtnetlink_init(void)
 	rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
 	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
 }
-
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7350084..cebd9d3 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1644,7 +1644,8 @@ errout:
 		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
 }
 
-static size_t inet_get_link_af_size(const struct net_device *dev)
+static size_t inet_get_link_af_size(const struct net_device *dev,
+				    u32 ext_filter_mask)
 {
 	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
 
@@ -2398,4 +2399,3 @@ void __init devinet_init(void)
 	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
 		      inet_netconf_dump_devconf, NULL);
 }
-
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f0326aa..0645fd1 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4786,7 +4786,8 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
-static size_t inet6_get_link_af_size(const struct net_device *dev)
+static size_t inet6_get_link_af_size(const struct net_device *dev,
+				     u32 ext_filter_mask)
 {
 	if (!__in6_dev_get(dev))
 		return 0;
-- 
2.1.0

Re: [PATCH net-next v3] netlink: Rightsize IFLA_AF_SPEC size calculation

[Samudrala, Sridhar]

On 10/19/2015 9:23 AM, Ronen Arad wrote:
> if_nlmsg_size() overestimates the minimum allocation size of netlink
> dump request (when called from rtnl_calcit()) or the size of the
> message (when called from rtnl_getlink()). This is because
> ext_filter_mask is not supported by rtnl_link_get_af_size() and
> rtnl_link_get_size().
>
> The over-estimation is significant when at least one netdev has many
> VLANs configured (8 bytes for each configured VLAN).
>
> This patch-set "rightsizes" the protocol specific attribute size
> calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
> and adding this a argument to get_link_af_size op in rtnl_af_ops.
>
> Bridge module already used filtering aware sizing for notifications.
> br_get_link_af_size_filtered() is consistent with the modified
> get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
> br_get_link_af_size() becomes unused and thus removed.
>
> Signed-off-by: Ronen Arad <ronen.arad@intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>

> ---
>   include/net/rtnetlink.h |  3 ++-
>   net/bridge/br_netlink.c | 21 +--------------------
>   net/core/rtnetlink.c    |  8 ++++----
>   net/ipv4/devinet.c      |  4 ++--
>   net/ipv6/addrconf.c     |  3 ++-
>   5 files changed, 11 insertions(+), 28 deletions(-)
>
> diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
> index aff6ceb..2f87c1b 100644
> --- a/include/net/rtnetlink.h
> +++ b/include/net/rtnetlink.h
> @@ -124,7 +124,8 @@ struct rtnl_af_ops {
>   	int			(*fill_link_af)(struct sk_buff *skb,
>   						const struct net_device *dev,
>   						u32 ext_filter_mask);
> -	size_t			(*get_link_af_size)(const struct net_device *dev);
> +	size_t			(*get_link_af_size)(const struct net_device *dev,
> +						    u32 ext_filter_mask);
>   
>   	int			(*validate_link_af)(const struct net_device *dev,
>   						    const struct nlattr *attr);
> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> index 94b4de8..40197ff 100644
> --- a/net/bridge/br_netlink.c
> +++ b/net/bridge/br_netlink.c
> @@ -1214,29 +1214,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev)
>   	return 0;
>   }
>   
> -static size_t br_get_link_af_size(const struct net_device *dev)
> -{
> -	struct net_bridge_port *p;
> -	struct net_bridge *br;
> -	int num_vlans = 0;
> -
> -	if (br_port_exists(dev)) {
> -		p = br_port_get_rtnl(dev);
> -		num_vlans = br_get_num_vlan_infos(nbp_vlan_group(p),
> -						  RTEXT_FILTER_BRVLAN);
> -	} else if (dev->priv_flags & IFF_EBRIDGE) {
> -		br = netdev_priv(dev);
> -		num_vlans = br_get_num_vlan_infos(br_vlan_group(br),
> -						  RTEXT_FILTER_BRVLAN);
> -	}
> -
> -	/* Each VLAN is returned in bridge_vlan_info along with flags */
> -	return num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
> -}
>   
>   static struct rtnl_af_ops br_af_ops __read_mostly = {
>   	.family			= AF_BRIDGE,
> -	.get_link_af_size	= br_get_link_af_size,
> +	.get_link_af_size	= br_get_link_af_size_filtered,
>   };
>   
>   struct rtnl_link_ops br_link_ops __read_mostly = {
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index 2477595..7c78b5a 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -497,7 +497,8 @@ void rtnl_af_unregister(struct rtnl_af_ops *ops)
>   }
>   EXPORT_SYMBOL_GPL(rtnl_af_unregister);
>   
> -static size_t rtnl_link_get_af_size(const struct net_device *dev)
> +static size_t rtnl_link_get_af_size(const struct net_device *dev,
> +				    u32 ext_filter_mask)
>   {
>   	struct rtnl_af_ops *af_ops;
>   	size_t size;
> @@ -509,7 +510,7 @@ static size_t rtnl_link_get_af_size(const struct net_device *dev)
>   		if (af_ops->get_link_af_size) {
>   			/* AF_* + nested data */
>   			size += nla_total_size(sizeof(struct nlattr)) +
> -				af_ops->get_link_af_size(dev);
> +				af_ops->get_link_af_size(dev, ext_filter_mask);
>   		}
>   	}
>   
> @@ -900,7 +901,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
>   	       + rtnl_vfinfo_size(dev, ext_filter_mask) /* IFLA_VFINFO_LIST */
>   	       + rtnl_port_size(dev, ext_filter_mask) /* IFLA_VF_PORTS + IFLA_PORT_SELF */
>   	       + rtnl_link_get_size(dev) /* IFLA_LINKINFO */
> -	       + rtnl_link_get_af_size(dev) /* IFLA_AF_SPEC */
> +	       + rtnl_link_get_af_size(dev, ext_filter_mask) /* IFLA_AF_SPEC */
>   	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_PORT_ID */
>   	       + nla_total_size(MAX_PHYS_ITEM_ID_LEN) /* IFLA_PHYS_SWITCH_ID */
>   	       + nla_total_size(1); /* IFLA_PROTO_DOWN */
> @@ -3443,4 +3444,3 @@ void __init rtnetlink_init(void)
>   	rtnl_register(PF_BRIDGE, RTM_DELLINK, rtnl_bridge_dellink, NULL, NULL);
>   	rtnl_register(PF_BRIDGE, RTM_SETLINK, rtnl_bridge_setlink, NULL, NULL);
>   }
> -
> diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
> index 7350084..cebd9d3 100644
> --- a/net/ipv4/devinet.c
> +++ b/net/ipv4/devinet.c
> @@ -1644,7 +1644,8 @@ errout:
>   		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
>   }
>   
> -static size_t inet_get_link_af_size(const struct net_device *dev)
> +static size_t inet_get_link_af_size(const struct net_device *dev,
> +				    u32 ext_filter_mask)
>   {
>   	struct in_device *in_dev = rcu_dereference_rtnl(dev->ip_ptr);
>   
> @@ -2398,4 +2399,3 @@ void __init devinet_init(void)
>   	rtnl_register(PF_INET, RTM_GETNETCONF, inet_netconf_get_devconf,
>   		      inet_netconf_dump_devconf, NULL);
>   }
> -
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index f0326aa..0645fd1 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -4786,7 +4786,8 @@ nla_put_failure:
>   	return -EMSGSIZE;
>   }
>   
> -static size_t inet6_get_link_af_size(const struct net_device *dev)
> +static size_t inet6_get_link_af_size(const struct net_device *dev,
> +				     u32 ext_filter_mask)
>   {
>   	if (!__in6_dev_get(dev))
>   		return 0;

Re: [PATCH net-next v3] netlink: Rightsize IFLA_AF_SPEC size calculation

[David Miller]

From: Ronen Arad <ronen.arad@intel.com>
Date: Mon, 19 Oct 2015 09:23:28 -0700

> if_nlmsg_size() overestimates the minimum allocation size of netlink
> dump request (when called from rtnl_calcit()) or the size of the
> message (when called from rtnl_getlink()). This is because
> ext_filter_mask is not supported by rtnl_link_get_af_size() and
> rtnl_link_get_size().
> 
> The over-estimation is significant when at least one netdev has many
> VLANs configured (8 bytes for each configured VLAN).
> 
> This patch-set "rightsizes" the protocol specific attribute size
> calculation by propagating ext_filter_mask to rtnl_link_get_af_size()
> and adding this a argument to get_link_af_size op in rtnl_af_ops.
> 
> Bridge module already used filtering aware sizing for notifications.
> br_get_link_af_size_filtered() is consistent with the modified
> get_link_af_size op so it replaces br_get_link_af_size() in br_af_ops.
> br_get_link_af_size() becomes unused and thus removed.
> 
> Signed-off-by: Ronen Arad <ronen.arad@intel.com>

Applied, thanks.