[PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[ehakim]

From: Emeel Hakim <ehakim@nvidia.com>

Add support for changing Macsec offload selection through the
netlink layer by implementing the relevant changes in
macsec_changelink.

Since the handling in macsec_changelink is similar to macsec_upd_offload,
update macsec_upd_offload to use a common helper function to avoid
duplication.

Example for setting offload for a macsec device:
    ip link set macsec0 type macsec offload mac

Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
---
V3 -> V4: - Dont pass whole attributes data to macsec_update_offload, just pass relevant attribute.
		  - Fix code style.
		  - Remove macsec_changelink_upd_offload
V2 -> V3: - Split the original patch into 3 patches, the macsec_rtnl_policy related change (separate patch)
                       to be sent to "net" branch as a fix.
                 - Change the original patch title to make it clear that it's only adding IFLA_MACSEC_OFFLOAD
                   to changelink
V1 -> V2: Add common helper to avoid duplicating code

 drivers/net/macsec.c | 100 +++++++++++++++++++++++--------------------
 1 file changed, 53 insertions(+), 47 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index d73b9d535b7a..abfe4a612a2d 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2583,38 +2583,16 @@ static bool macsec_is_configured(struct macsec_dev *macsec)
 	return false;
 }
 
-static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
+static int macsec_update_offload(struct net_device *dev, enum macsec_offload offload)
 {
-	struct nlattr *tb_offload[MACSEC_OFFLOAD_ATTR_MAX + 1];
-	enum macsec_offload offload, prev_offload;
-	int (*func)(struct macsec_context *ctx);
-	struct nlattr **attrs = info->attrs;
-	struct net_device *dev;
+	enum macsec_offload prev_offload;
 	const struct macsec_ops *ops;
 	struct macsec_context ctx;
 	struct macsec_dev *macsec;
-	int ret;
-
-	if (!attrs[MACSEC_ATTR_IFINDEX])
-		return -EINVAL;
-
-	if (!attrs[MACSEC_ATTR_OFFLOAD])
-		return -EINVAL;
-
-	if (nla_parse_nested_deprecated(tb_offload, MACSEC_OFFLOAD_ATTR_MAX,
-					attrs[MACSEC_ATTR_OFFLOAD],
-					macsec_genl_offload_policy, NULL))
-		return -EINVAL;
+	int ret = 0;
 
-	dev = get_dev_from_nl(genl_info_net(info), attrs);
-	if (IS_ERR(dev))
-		return PTR_ERR(dev);
 	macsec = macsec_priv(dev);
 
-	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
-		return -EINVAL;
-
-	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
 	if (macsec->offload == offload)
 		return 0;
 
@@ -2627,43 +2605,65 @@ static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
 	if (netif_running(dev))
 		return -EBUSY;
 
-	rtnl_lock();
-
-	prev_offload = macsec->offload;
-	macsec->offload = offload;
-
 	/* Check if the device already has rules configured: we do not support
 	 * rules migration.
 	 */
-	if (macsec_is_configured(macsec)) {
-		ret = -EBUSY;
-		goto rollback;
-	}
+	if (macsec_is_configured(macsec))
+		return -EBUSY;
+
+	prev_offload = macsec->offload;
 
 	ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
 			       macsec, &ctx);
-	if (!ops) {
+	if (!ops)
 		ret = -EOPNOTSUPP;
-		goto rollback;
-	}
 
-	if (prev_offload == MACSEC_OFFLOAD_OFF)
-		func = ops->mdo_add_secy;
-	else
-		func = ops->mdo_del_secy;
+	macsec->offload = offload;
 
 	ctx.secy = &macsec->secy;
-	ret = macsec_offload(func, &ctx);
+	ret = offload == MACSEC_OFFLOAD_OFF ? macsec_offload(ops->mdo_del_secy, &ctx)
+					    : macsec_offload(ops->mdo_add_secy, &ctx);
+
 	if (ret)
-		goto rollback;
+		macsec->offload = prev_offload;
 
-	rtnl_unlock();
-	return 0;
+	return ret;
+}
+
+static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *tb_offload[MACSEC_OFFLOAD_ATTR_MAX + 1];
+	struct nlattr **attrs = info->attrs;
+	enum macsec_offload offload;
+	struct net_device *dev;
+	int ret;
+
+	if (!attrs[MACSEC_ATTR_IFINDEX])
+		return -EINVAL;
+
+	if (!attrs[MACSEC_ATTR_OFFLOAD])
+		return -EINVAL;
+
+	if (nla_parse_nested_deprecated(tb_offload, MACSEC_OFFLOAD_ATTR_MAX,
+					attrs[MACSEC_ATTR_OFFLOAD],
+					macsec_genl_offload_policy, NULL))
+		return -EINVAL;
+
+	dev = get_dev_from_nl(genl_info_net(info), attrs);
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
 
-rollback:
-	macsec->offload = prev_offload;
+	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
+		return -EINVAL;
+
+	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
+
+	rtnl_lock();
+
+	ret = macsec_update_offload(dev, offload);
 
 	rtnl_unlock();
+
 	return ret;
 }
 
@@ -3831,6 +3831,12 @@ static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (ret)
 		goto cleanup;
 
+	if (data[IFLA_MACSEC_OFFLOAD]) {
+		ret = macsec_update_offload(dev, nla_get_u8(data[IFLA_MACSEC_OFFLOAD]));
+		if (ret)
+			goto cleanup;
+	}
+
 	/* If h/w offloading is available, propagate to the device */
 	if (macsec_is_offloaded(macsec)) {
 		const struct macsec_ops *ops;
-- 
2.21.3

[PATCH net-next v2 2/2] macsec: dump IFLA_MACSEC_OFFLOAD attribute as part of macsec dump

[ehakim]

From: Emeel Hakim <ehakim@nvidia.com>

Support dumping offload netlink attribute in macsec's device
attributes dump.
Change macsec_get_size to consider the offload attribute in
the calculations of the required room for dumping the device
netlink attributes.

Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
---
V1 -> V2: Update commit message

 drivers/net/macsec.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index abfe4a612a2d..85208a64f259 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -4237,16 +4237,22 @@ static size_t macsec_get_size(const struct net_device *dev)
 		nla_total_size(1) + /* IFLA_MACSEC_SCB */
 		nla_total_size(1) + /* IFLA_MACSEC_REPLAY_PROTECT */
 		nla_total_size(1) + /* IFLA_MACSEC_VALIDATION */
+		nla_total_size(1) + /* IFLA_MACSEC_OFFLOAD */
 		0;
 }
 
 static int macsec_fill_info(struct sk_buff *skb,
 			    const struct net_device *dev)
 {
-	struct macsec_secy *secy = &macsec_priv(dev)->secy;
-	struct macsec_tx_sc *tx_sc = &secy->tx_sc;
+	struct macsec_tx_sc *tx_sc;
+	struct macsec_dev *macsec;
+	struct macsec_secy *secy;
 	u64 csid;
 
+	macsec = macsec_priv(dev);
+	secy = &macsec->secy;
+	tx_sc = &secy->tx_sc;
+
 	switch (secy->key_len) {
 	case MACSEC_GCM_AES_128_SAK_LEN:
 		csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_128 : MACSEC_DEFAULT_CIPHER_ID;
@@ -4271,6 +4277,7 @@ static int macsec_fill_info(struct sk_buff *skb,
 	    nla_put_u8(skb, IFLA_MACSEC_SCB, tx_sc->scb) ||
 	    nla_put_u8(skb, IFLA_MACSEC_REPLAY_PROTECT, secy->replay_protect) ||
 	    nla_put_u8(skb, IFLA_MACSEC_VALIDATION, secy->validate_frames) ||
+	    nla_put_u8(skb, IFLA_MACSEC_OFFLOAD, macsec->offload) ||
 	    0)
 		goto nla_put_failure;
 
-- 
2.21.3

Re: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Jiri Pirko]

Thu, Dec 08, 2022 at 12:55:16PM CET, ehakim@nvidia.com wrote:
>From: Emeel Hakim <ehakim@nvidia.com>
>
>Add support for changing Macsec offload selection through the
>netlink layer by implementing the relevant changes in
>macsec_changelink.
>
>Since the handling in macsec_changelink is similar to macsec_upd_offload,
>update macsec_upd_offload to use a common helper function to avoid
>duplication.
>
>Example for setting offload for a macsec device:
>    ip link set macsec0 type macsec offload mac
>
>Reviewed-by: Raed Salem <raeds@nvidia.com>
>Signed-off-by: Emeel Hakim <ehakim@nvidia.com>

Looks fine to me.
Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH net-next v2 2/2] macsec: dump IFLA_MACSEC_OFFLOAD attribute as part of macsec dump

[Jiri Pirko]

Thu, Dec 08, 2022 at 12:55:17PM CET, ehakim@nvidia.com wrote:
>From: Emeel Hakim <ehakim@nvidia.com>
>
>Support dumping offload netlink attribute in macsec's device
>attributes dump.
>Change macsec_get_size to consider the offload attribute in
>the calculations of the required room for dumping the device
>netlink attributes.
>
>Reviewed-by: Raed Salem <raeds@nvidia.com>
>Signed-off-by: Emeel Hakim <ehakim@nvidia.com>

Reviewed-by: Jiri Pirko <jiri@nvidia.com>

Re: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Sabrina Dubroca]

2022-12-08, 13:55:16 +0200, ehakim@nvidia.com wrote:
> From: Emeel Hakim <ehakim@nvidia.com>
> 
> Add support for changing Macsec offload selection through the
> netlink layer by implementing the relevant changes in
> macsec_changelink.
> 
> Since the handling in macsec_changelink is similar to macsec_upd_offload,
> update macsec_upd_offload to use a common helper function to avoid
> duplication.
> 
> Example for setting offload for a macsec device:
>     ip link set macsec0 type macsec offload mac
> 
> Reviewed-by: Raed Salem <raeds@nvidia.com>
> Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
> ---
> V3 -> V4: - Dont pass whole attributes data to macsec_update_offload, just pass relevant attribute.
> 		  - Fix code style.
> 		  - Remove macsec_changelink_upd_offload
> V2 -> V3: - Split the original patch into 3 patches, the macsec_rtnl_policy related change (separate patch)
>                        to be sent to "net" branch as a fix.
>                  - Change the original patch title to make it clear that it's only adding IFLA_MACSEC_OFFLOAD
>                    to changelink
> V1 -> V2: Add common helper to avoid duplicating code
> 
>  drivers/net/macsec.c | 100 +++++++++++++++++++++++--------------------
>  1 file changed, 53 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
> index d73b9d535b7a..abfe4a612a2d 100644
> --- a/drivers/net/macsec.c
> +++ b/drivers/net/macsec.c
> @@ -2583,38 +2583,16 @@ static bool macsec_is_configured(struct macsec_dev *macsec)
>  	return false;
>  }
>  
> -static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
> +static int macsec_update_offload(struct net_device *dev, enum macsec_offload offload)
>  {
> -	struct nlattr *tb_offload[MACSEC_OFFLOAD_ATTR_MAX + 1];
> -	enum macsec_offload offload, prev_offload;
> -	int (*func)(struct macsec_context *ctx);
> -	struct nlattr **attrs = info->attrs;
> -	struct net_device *dev;
> +	enum macsec_offload prev_offload;
>  	const struct macsec_ops *ops;
>  	struct macsec_context ctx;
>  	struct macsec_dev *macsec;
> -	int ret;
> -
> -	if (!attrs[MACSEC_ATTR_IFINDEX])
> -		return -EINVAL;
> -
> -	if (!attrs[MACSEC_ATTR_OFFLOAD])
> -		return -EINVAL;
> -
> -	if (nla_parse_nested_deprecated(tb_offload, MACSEC_OFFLOAD_ATTR_MAX,
> -					attrs[MACSEC_ATTR_OFFLOAD],
> -					macsec_genl_offload_policy, NULL))
> -		return -EINVAL;
> +	int ret = 0;
>  
> -	dev = get_dev_from_nl(genl_info_net(info), attrs);
> -	if (IS_ERR(dev))
> -		return PTR_ERR(dev);
>  	macsec = macsec_priv(dev);
>  
> -	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> -		return -EINVAL;
> -
> -	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
>  	if (macsec->offload == offload)
>  		return 0;
>  
> @@ -2627,43 +2605,65 @@ static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
>  	if (netif_running(dev))
>  		return -EBUSY;
>  
> -	rtnl_lock();
> -
> -	prev_offload = macsec->offload;
> -	macsec->offload = offload;
> -
>  	/* Check if the device already has rules configured: we do not support
>  	 * rules migration.
>  	 */
> -	if (macsec_is_configured(macsec)) {
> -		ret = -EBUSY;
> -		goto rollback;
> -	}
> +	if (macsec_is_configured(macsec))
> +		return -EBUSY;
> +
> +	prev_offload = macsec->offload;
>  
>  	ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
>  			       macsec, &ctx);
> -	if (!ops) {
> +	if (!ops)
>  		ret = -EOPNOTSUPP;

		return -EOPNOTSUPP;

It's probably not a problem because macsec_check_offload should catch
that, but it looks wrong.

> -		goto rollback;
> -	}
>  
> -	if (prev_offload == MACSEC_OFFLOAD_OFF)
> -		func = ops->mdo_add_secy;
> -	else
> -		func = ops->mdo_del_secy;
> +	macsec->offload = offload;
>  
>  	ctx.secy = &macsec->secy;
> -	ret = macsec_offload(func, &ctx);
> +	ret = offload == MACSEC_OFFLOAD_OFF ? macsec_offload(ops->mdo_del_secy, &ctx)
> +					    : macsec_offload(ops->mdo_add_secy, &ctx);
> +

nit: unnecessary blank line (sorry, I should have spotted that earlier)

>  	if (ret)
> -		goto rollback;
> +		macsec->offload = prev_offload;
>  
> -	rtnl_unlock();
> -	return 0;
> +	return ret;
> +}
> +
> +static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
> +{
> +	struct nlattr *tb_offload[MACSEC_OFFLOAD_ATTR_MAX + 1];
> +	struct nlattr **attrs = info->attrs;
> +	enum macsec_offload offload;
> +	struct net_device *dev;
> +	int ret;
> +
> +	if (!attrs[MACSEC_ATTR_IFINDEX])
> +		return -EINVAL;
> +
> +	if (!attrs[MACSEC_ATTR_OFFLOAD])
> +		return -EINVAL;
> +
> +	if (nla_parse_nested_deprecated(tb_offload, MACSEC_OFFLOAD_ATTR_MAX,
> +					attrs[MACSEC_ATTR_OFFLOAD],
> +					macsec_genl_offload_policy, NULL))
> +		return -EINVAL;
> +
> +	dev = get_dev_from_nl(genl_info_net(info), attrs);
> +	if (IS_ERR(dev))
> +		return PTR_ERR(dev);
>  
> -rollback:
> -	macsec->offload = prev_offload;
> +	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> +		return -EINVAL;
> +
> +	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
> +
> +	rtnl_lock();
> +
> +	ret = macsec_update_offload(dev, offload);
>  
>  	rtnl_unlock();
> +
>  	return ret;
>  }
>  
> @@ -3831,6 +3831,12 @@ static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
>  	if (ret)
>  		goto cleanup;
>  
> +	if (data[IFLA_MACSEC_OFFLOAD]) {
> +		ret = macsec_update_offload(dev, nla_get_u8(data[IFLA_MACSEC_OFFLOAD]));
> +		if (ret)
> +			goto cleanup;
> +	}
> +
>  	/* If h/w offloading is available, propagate to the device */
>  	if (macsec_is_offloaded(macsec)) {
>  		const struct macsec_ops *ops;

-- 
Sabrina

Re: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Jakub Kicinski]

On Thu, 8 Dec 2022 13:55:16 +0200 ehakim@nvidia.com wrote:
> +	dev = get_dev_from_nl(genl_info_net(info), attrs);

What prevents this dev from disappearing before...

> +	if (IS_ERR(dev))
> +		return PTR_ERR(dev);
> +	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> +		return -EINVAL;
> +
> +	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
> +
> +	rtnl_lock();

... we finally take the lock?

I think you're just moving this code, but still.

> +	ret = macsec_update_offload(dev, offload);
>  
>  	rtnl_unlock();

Re: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Jakub Kicinski]

On Thu, 8 Dec 2022 18:32:44 -0800 Jakub Kicinski wrote:
> I think you're just moving this code, but still.

And by "by still" I mean - it's still a bug, so it needs to be fixed
first.

RE: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Emeel Hakim]

> -----Original Message-----
> From: Jakub Kicinski <kuba@kernel.org>
> Sent: Friday, 9 December 2022 4:33
> To: Emeel Hakim <ehakim@nvidia.com>
> Cc: linux-kernel@vger.kernel.org; Raed Salem <raeds@nvidia.com>;
> davem@davemloft.net; edumazet@google.com; pabeni@redhat.com;
> netdev@vger.kernel.org; sd@queasysnail.net; atenart@kernel.org; jiri@resnulli.us
> Subject: Re: [PATCH net-next v4 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
> 
> External email: Use caution opening links or attachments
> 
> 
> On Thu, 8 Dec 2022 18:32:44 -0800 Jakub Kicinski wrote:
> > I think you're just moving this code, but still.
> 
> And by "by still" I mean - it's still a bug, so it needs to be fixed first.

The code added by those patches does not use the rtnl_lock, the lock is just getting moved as part of sharing similar code,
but the new code is still not using it, I don’t think those  patches need to wait until a fix of an existing locking issue as long
as the new code is not inserting any bugs.

RE: [PATCH net-next v4 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Emeel Hakim]

> -----Original Message-----
> From: Emeel Hakim
> Sent: Friday, 9 December 2022 12:19
> To: Jakub Kicinski <kuba@kernel.org>
> Cc: linux-kernel@vger.kernel.org; Raed Salem <raeds@nvidia.com>;
> davem@davemloft.net; edumazet@google.com; pabeni@redhat.com;
> netdev@vger.kernel.org; sd@queasysnail.net; atenart@kernel.org; jiri@resnulli.us
> Subject: RE: [PATCH net-next v4 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
> 
> 
> 
> > -----Original Message-----
> > From: Jakub Kicinski <kuba@kernel.org>
> > Sent: Friday, 9 December 2022 4:33
> > To: Emeel Hakim <ehakim@nvidia.com>
> > Cc: linux-kernel@vger.kernel.org; Raed Salem <raeds@nvidia.com>;
> > davem@davemloft.net; edumazet@google.com; pabeni@redhat.com;
> > netdev@vger.kernel.org; sd@queasysnail.net; atenart@kernel.org;
> > jiri@resnulli.us
> > Subject: Re: [PATCH net-next v4 1/2] macsec: add support for
> > IFLA_MACSEC_OFFLOAD in macsec_changelink
> >
> > External email: Use caution opening links or attachments
> >
> >
> > On Thu, 8 Dec 2022 18:32:44 -0800 Jakub Kicinski wrote:
> > > I think you're just moving this code, but still.
> >
> > And by "by still" I mean - it's still a bug, so it needs to be fixed first.
> 
> The code added by those patches does not use the rtnl_lock, the lock is just getting
> moved as part of sharing similar code, but the new code is still not using it, I don’t
> think those  patches need to wait until a fix of an existing locking issue as long as
> the new code is not inserting any bugs.

I will send a fix patch shortly as requested.