[PATCH net-next v6 0/2] Add support to offload macsec using netlink update

[PATCH net-next v6 0/2] Add support to offload macsec using netlink update

[ehakim]

From: Emeel Hakim <ehakim@nvidia.com>

This series adds support for offloading macsec as part of the netlink
update routine , command example:
ip link set link eth2 macsec0 type macsec offload mac

The above is done using the IFLA_MACSEC_OFFLOAD attribute hence
the second patch of dumping this attribute as part of the macsec
dump.

Emeel Hakim (2):
  macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink
  macsec: dump IFLA_MACSEC_OFFLOAD attribute as part of macsec dump

 drivers/net/macsec.c | 127 ++++++++++++++++++++++---------------------
 1 file changed, 66 insertions(+), 61 deletions(-)

-- 
2.21.3

[PATCH net-next v6 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>
---
v5 -> v6: - Locking issue got fixed in a separate patch so rebase
V4 -> V5: - Fail immediately if macsec ops does not exist
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 | 116 +++++++++++++++++++++----------------------
 1 file changed, 57 insertions(+), 59 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index bf8ac7a3ded7..1974c59977aa 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2583,95 +2583,87 @@ 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 = 0;
 
-	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;
-
-	rtnl_lock();
-
-	dev = get_dev_from_nl(genl_info_net(info), attrs);
-	if (IS_ERR(dev)) {
-		ret = PTR_ERR(dev);
-		goto out;
-	}
 	macsec = macsec_priv(dev);
 
-	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
 	if (macsec->offload == offload)
-		goto out;
+		return 0;
 
 	/* Check if the offloading mode is supported by the underlying layers */
 	if (offload != MACSEC_OFFLOAD_OFF &&
 	    !macsec_check_offload(offload, macsec)) {
-		ret = -EOPNOTSUPP;
-		goto out;
+		return -EOPNOTSUPP;
 	}
 
 	/* Check if the net device is busy. */
-	if (netif_running(dev)) {
-		ret = -EBUSY;
-		goto out;
-	}
-
-	prev_offload = macsec->offload;
-	macsec->offload = offload;
+	if (netif_running(dev))
+		return -EBUSY;
 
 	/* 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) {
-		ret = -EOPNOTSUPP;
-		goto rollback;
-	}
+	if (!ops)
+		return -EOPNOTSUPP;
 
-	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);
+
+	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);
 
-rollback:
-	macsec->offload = prev_offload;
-out:
 	rtnl_unlock();
+
 	return ret;
 }
 
@@ -3840,6 +3832,12 @@ 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 v6 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 1974c59977aa..0cff5083e661 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -4238,16 +4238,22 @@ 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;
@@ -4272,6 +4278,7 @@ 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 v6 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Sabrina Dubroca]

2023-01-06, 15:35:50 +0200, ehakim@nvidia.com wrote:
[...]
> +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);
> +
> +	if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> +		return -EINVAL;
> +
> +	offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
> +
> +	rtnl_lock();

Why are you putting rtnl_lock() back down here? You just moved it
above get_dev_from_nl with commit f3b4a00f0f62 ("net: macsec: fix net
device access prior to holding a lock"), now you're pretty much
reverting that fix.

> +
> +	ret = macsec_update_offload(dev, offload);
>  
> -rollback:
> -	macsec->offload = prev_offload;
> -out:
>  	rtnl_unlock();
> +
>  	return ret;
>  }
>  

-- 
Sabrina

RE: [PATCH net-next v6 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

[Emeel Hakim]

> -----Original Message-----
> From: Sabrina Dubroca <sd@queasysnail.net>
> Sent: Sunday, 8 January 2023 1:05
> To: Emeel Hakim <ehakim@nvidia.com>
> Cc: netdev@vger.kernel.org; Raed Salem <raeds@nvidia.com>;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; atenart@kernel.org
> Subject: Re: [PATCH net-next v6 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
> 
> External email: Use caution opening links or attachments
> 
> 
> 2023-01-06, 15:35:50 +0200, ehakim@nvidia.com wrote:
> [...]
> > +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);
> > +
> > +     if (!tb_offload[MACSEC_OFFLOAD_ATTR_TYPE])
> > +             return -EINVAL;
> > +
> > +     offload = nla_get_u8(tb_offload[MACSEC_OFFLOAD_ATTR_TYPE]);
> > +
> > +     rtnl_lock();
> 
> Why are you putting rtnl_lock() back down here? You just moved it above
> get_dev_from_nl with commit f3b4a00f0f62 ("net: macsec: fix net device access
> prior to holding a lock"), now you're pretty much reverting that fix.

Ack will fix.

> > +
> > +     ret = macsec_update_offload(dev, offload);
> >
> > -rollback:
> > -     macsec->offload = prev_offload;
> > -out:
> >       rtnl_unlock();
> > +
> >       return ret;
> >  }
> >
> 
> --
> Sabrina