2022-12-07 10:36:29

by Emeel Hakim

[permalink] [raw]
Subject: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

From: Emeel Hakim <[email protected]>

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

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 <[email protected]>
Signed-off-by: Emeel Hakim <[email protected]>
---
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 | 102 +++++++++++++++++++++++++++----------------
1 file changed, 64 insertions(+), 38 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index d73b9d535b7a..1850a1ee4380 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2583,16 +2583,45 @@ static bool macsec_is_configured(struct macsec_dev *macsec)
return false;
}

+static int macsec_update_offload(struct macsec_dev *macsec, enum macsec_offload offload)
+{
+ enum macsec_offload prev_offload;
+ const struct macsec_ops *ops;
+ struct macsec_context ctx;
+ int ret = 0;
+
+ prev_offload = macsec->offload;
+
+ /* Check if the device already has rules configured: we do not support
+ * rules migration.
+ */
+ if (macsec_is_configured(macsec))
+ return -EBUSY;
+
+ ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
+ macsec, &ctx);
+ if (!ops)
+ return -EOPNOTSUPP;
+
+ macsec->offload = offload;
+
+ ctx.secy = &macsec->secy;
+ ret = (offload == MACSEC_OFFLOAD_OFF) ? macsec_offload(ops->mdo_del_secy, &ctx) :
+ macsec_offload(ops->mdo_add_secy, &ctx);
+
+ if (ret)
+ macsec->offload = prev_offload;
+
+ return ret;
+}
+
static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
{
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;
- const struct macsec_ops *ops;
- struct macsec_context ctx;
+ enum macsec_offload offload;
struct macsec_dev *macsec;
+ struct net_device *dev;
int ret;

if (!attrs[MACSEC_ATTR_IFINDEX])
@@ -2629,39 +2658,7 @@ static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)

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;
- }
-
- ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
- macsec, &ctx);
- if (!ops) {
- ret = -EOPNOTSUPP;
- goto rollback;
- }
-
- if (prev_offload == MACSEC_OFFLOAD_OFF)
- func = ops->mdo_add_secy;
- else
- func = ops->mdo_del_secy;
-
- ctx.secy = &macsec->secy;
- ret = macsec_offload(func, &ctx);
- if (ret)
- goto rollback;
-
- rtnl_unlock();
- return 0;
-
-rollback:
- macsec->offload = prev_offload;
+ ret = macsec_update_offload(macsec, offload);

rtnl_unlock();
return ret;
@@ -3803,6 +3800,29 @@ static int macsec_changelink_common(struct net_device *dev,
return 0;
}

+static int macsec_changelink_upd_offload(struct net_device *dev, struct nlattr *data[])
+{
+ enum macsec_offload offload;
+ struct macsec_dev *macsec;
+
+ macsec = macsec_priv(dev);
+ offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
+
+ if (macsec->offload == offload)
+ return 0;
+
+ /* Check if the offloading mode is supported by the underlying layers */
+ if (offload != MACSEC_OFFLOAD_OFF &&
+ !macsec_check_offload(offload, macsec))
+ return -EOPNOTSUPP;
+
+ /* Check if the net device is busy. */
+ if (netif_running(dev))
+ return -EBUSY;
+
+ return macsec_update_offload(macsec, offload);
+}
+
static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack)
@@ -3831,6 +3851,12 @@ static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
if (ret)
goto cleanup;

+ if (data[IFLA_MACSEC_OFFLOAD]) {
+ ret = macsec_changelink_upd_offload(dev, data);
+ 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


2022-12-07 10:39:07

by Emeel Hakim

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

From: Emeel Hakim <[email protected]>

consider IFLA_MACSEC_OFFLOAD in macsec's device dump,
this mandates a change at macsec_get_size to consider the
additional attribute.

Reviewed-by: Raed Salem <[email protected]>
Signed-off-by: Emeel Hakim <[email protected]>
---
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 1850a1ee4380..0b8613576383 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -4257,16 +4257,22 @@ 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;
@@ -4291,6 +4297,7 @@ 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

2022-12-07 16:02:43

by Emeel Hakim

[permalink] [raw]
Subject: RE: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink



> -----Original Message-----
> From: Sabrina Dubroca <[email protected]>
> Sent: Wednesday, 7 December 2022 17:46
> To: Emeel Hakim <[email protected]>
> Cc: [email protected]; Raed Salem <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; [email protected]
> Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
>
> External email: Use caution opening links or attachments
>
>
> 2022-12-07, 12:10:16 +0200, [email protected] wrote:
> > From: Emeel Hakim <[email protected]>
> >
> > Add support for changing Macsec offload selection through the netlink
> > layer by implementing the relevant changes in macsec_change link.
>
> nit: macsec_changelink

Ack

> [...]
> > +static int macsec_update_offload(struct macsec_dev *macsec, enum
> > +macsec_offload offload) {
> > + enum macsec_offload prev_offload;
> > + const struct macsec_ops *ops;
> > + struct macsec_context ctx;
> > + int ret = 0;
> > +
> > + prev_offload = macsec->offload;
> > +
> > + /* Check if the device already has rules configured: we do not support
> > + * rules migration.
> > + */
> > + if (macsec_is_configured(macsec))
> > + return -EBUSY;
> > +
> > + ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload :
> offload,
> > + macsec, &ctx);
> > + if (!ops)
> > + return -EOPNOTSUPP;
> > +
> > + macsec->offload = offload;
> > +
> > + ctx.secy = &macsec->secy;
> > + ret = (offload == MACSEC_OFFLOAD_OFF) ? macsec_offload(ops-
> >mdo_del_secy, &ctx) :
> > + macsec_offload(ops->mdo_add_secy, &ctx);
>
> I think aligning the two macsec_offload(...) calls would make this a bit easier to
> read:
>
> ret = offload == MACSEC_OFFLOAD_OFF ? macsec_offload(ops-
> >mdo_del_secy, &ctx)
> : macsec_offload(ops->mdo_add_secy, &ctx);
>
> (and remove the unnecessary ())

Ack

> > +
> > + if (ret)
> > + macsec->offload = prev_offload;
> > +
> > + return ret;
> > +}
> > +
>
> [...]
> > +static int macsec_changelink_upd_offload(struct net_device *dev,
> > +struct nlattr *data[]) {
> > + enum macsec_offload offload;
> > + struct macsec_dev *macsec;
> > +
> > + macsec = macsec_priv(dev);
> > + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
>
> All those checks are also present in macsec_upd_offload, why not move them into
> macsec_update_offload as well? (and then you don't really need
> macsec_changelink_upd_offload anymore)
>

Right, I thought about it , but I realized that those checks are done before holding the lock in macsec_upd_offload
and if I move them to macsec_update_offload I will hold the lock for a longer time , I want to minimize the time
of holding the lock.

> > + if (macsec->offload == offload)
> > + return 0;
> > +
> > + /* Check if the offloading mode is supported by the underlying layers */
> > + if (offload != MACSEC_OFFLOAD_OFF &&
> > + !macsec_check_offload(offload, macsec))
> > + return -EOPNOTSUPP;
> > +
> > + /* Check if the net device is busy. */
> > + if (netif_running(dev))
> > + return -EBUSY;
> > +
> > + return macsec_update_offload(macsec, offload); }
> > +
>
> --
> Sabrina

2022-12-07 16:09:22

by Jiri Pirko

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

Wed, Dec 07, 2022 at 11:10:17AM CET, [email protected] wrote:
>From: Emeel Hakim <[email protected]>
>
>consider IFLA_MACSEC_OFFLOAD in macsec's device dump,

Sentense starts with capital letter.


>this mandates a change at macsec_get_size to consider the
>additional attribute.

I'm unable to understand what you mean by this description. What should
the codebase consider and why?

Code looks fine.

>
>Reviewed-by: Raed Salem <[email protected]>
>Signed-off-by: Emeel Hakim <[email protected]>
>---
> 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 1850a1ee4380..0b8613576383 100644
>--- a/drivers/net/macsec.c
>+++ b/drivers/net/macsec.c
>@@ -4257,16 +4257,22 @@ 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;
>@@ -4291,6 +4297,7 @@ 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
>

2022-12-07 16:20:39

by Sabrina Dubroca

[permalink] [raw]
Subject: Re: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

2022-12-07, 12:10:16 +0200, [email protected] wrote:
> From: Emeel Hakim <[email protected]>
>
> Add support for changing Macsec offload selection through the
> netlink layer by implementing the relevant changes in
> macsec_change link.

nit: macsec_changelink

[...]
> +static int macsec_update_offload(struct macsec_dev *macsec, enum macsec_offload offload)
> +{
> + enum macsec_offload prev_offload;
> + const struct macsec_ops *ops;
> + struct macsec_context ctx;
> + int ret = 0;
> +
> + prev_offload = macsec->offload;
> +
> + /* Check if the device already has rules configured: we do not support
> + * rules migration.
> + */
> + if (macsec_is_configured(macsec))
> + return -EBUSY;
> +
> + ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
> + macsec, &ctx);
> + if (!ops)
> + return -EOPNOTSUPP;
> +
> + macsec->offload = offload;
> +
> + ctx.secy = &macsec->secy;
> + ret = (offload == MACSEC_OFFLOAD_OFF) ? macsec_offload(ops->mdo_del_secy, &ctx) :
> + macsec_offload(ops->mdo_add_secy, &ctx);

I think aligning the two macsec_offload(...) calls would make this a
bit easier to read:

ret = offload == MACSEC_OFFLOAD_OFF ? macsec_offload(ops->mdo_del_secy, &ctx)
: macsec_offload(ops->mdo_add_secy, &ctx);

(and remove the unnecessary ())

> +
> + if (ret)
> + macsec->offload = prev_offload;
> +
> + return ret;
> +}
> +

[...]
> +static int macsec_changelink_upd_offload(struct net_device *dev, struct nlattr *data[])
> +{
> + enum macsec_offload offload;
> + struct macsec_dev *macsec;
> +
> + macsec = macsec_priv(dev);
> + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);

All those checks are also present in macsec_upd_offload, why not move
them into macsec_update_offload as well? (and then you don't really
need macsec_changelink_upd_offload anymore)

> + if (macsec->offload == offload)
> + return 0;
> +
> + /* Check if the offloading mode is supported by the underlying layers */
> + if (offload != MACSEC_OFFLOAD_OFF &&
> + !macsec_check_offload(offload, macsec))
> + return -EOPNOTSUPP;
> +
> + /* Check if the net device is busy. */
> + if (netif_running(dev))
> + return -EBUSY;
> +
> + return macsec_update_offload(macsec, offload);
> +}
> +

--
Sabrina

2022-12-07 16:23:18

by Jiri Pirko

[permalink] [raw]
Subject: Re: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

Wed, Dec 07, 2022 at 11:10:16AM CET, [email protected] wrote:
>From: Emeel Hakim <[email protected]>
>
>Add support for changing Macsec offload selection through the
>netlink layer by implementing the relevant changes in
>macsec_change link.
>
>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 <[email protected]>
>Signed-off-by: Emeel Hakim <[email protected]>
>---
>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 | 102 +++++++++++++++++++++++++++----------------
> 1 file changed, 64 insertions(+), 38 deletions(-)
>
>diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
>index d73b9d535b7a..1850a1ee4380 100644
>--- a/drivers/net/macsec.c
>+++ b/drivers/net/macsec.c
>@@ -2583,16 +2583,45 @@ static bool macsec_is_configured(struct macsec_dev *macsec)
> return false;
> }
>
>+static int macsec_update_offload(struct macsec_dev *macsec, enum macsec_offload offload)
>+{
>+ enum macsec_offload prev_offload;
>+ const struct macsec_ops *ops;
>+ struct macsec_context ctx;
>+ int ret = 0;
>+
>+ prev_offload = macsec->offload;
>+
>+ /* Check if the device already has rules configured: we do not support
>+ * rules migration.
>+ */
>+ if (macsec_is_configured(macsec))
>+ return -EBUSY;
>+
>+ ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
>+ macsec, &ctx);
>+ if (!ops)
>+ return -EOPNOTSUPP;
>+
>+ macsec->offload = offload;
>+
>+ ctx.secy = &macsec->secy;
>+ ret = (offload == MACSEC_OFFLOAD_OFF) ? macsec_offload(ops->mdo_del_secy, &ctx) :
>+ macsec_offload(ops->mdo_add_secy, &ctx);
>+
>+ if (ret)
>+ macsec->offload = prev_offload;
>+
>+ return ret;
>+}
>+
> static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
> {
> 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;
>- const struct macsec_ops *ops;
>- struct macsec_context ctx;
>+ enum macsec_offload offload;
> struct macsec_dev *macsec;
>+ struct net_device *dev;
> int ret;
>
> if (!attrs[MACSEC_ATTR_IFINDEX])
>@@ -2629,39 +2658,7 @@ static int macsec_upd_offload(struct sk_buff *skb, struct genl_info *info)
>
> 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;
>- }
>-
>- ops = __macsec_get_ops(offload == MACSEC_OFFLOAD_OFF ? prev_offload : offload,
>- macsec, &ctx);
>- if (!ops) {
>- ret = -EOPNOTSUPP;
>- goto rollback;
>- }
>-
>- if (prev_offload == MACSEC_OFFLOAD_OFF)
>- func = ops->mdo_add_secy;
>- else
>- func = ops->mdo_del_secy;
>-
>- ctx.secy = &macsec->secy;
>- ret = macsec_offload(func, &ctx);
>- if (ret)
>- goto rollback;
>-
>- rtnl_unlock();
>- return 0;
>-
>-rollback:
>- macsec->offload = prev_offload;
>+ ret = macsec_update_offload(macsec, offload);
>
> rtnl_unlock();
> return ret;
>@@ -3803,6 +3800,29 @@ static int macsec_changelink_common(struct net_device *dev,
> return 0;
> }
>
>+static int macsec_changelink_upd_offload(struct net_device *dev, struct nlattr *data[])

Only data[IFLA_MACSEC_OFFLOAD] is used there. Pass just this attr.


>+{
>+ enum macsec_offload offload;
>+ struct macsec_dev *macsec;
>+
>+ macsec = macsec_priv(dev);
>+ offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
>+
>+ if (macsec->offload == offload)
>+ return 0;
>+
>+ /* Check if the offloading mode is supported by the underlying layers */
>+ if (offload != MACSEC_OFFLOAD_OFF &&
>+ !macsec_check_offload(offload, macsec))
>+ return -EOPNOTSUPP;
>+
>+ /* Check if the net device is busy. */
>+ if (netif_running(dev))
>+ return -EBUSY;
>+
>+ return macsec_update_offload(macsec, offload);
>+}
>+
> static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
> struct nlattr *data[],
> struct netlink_ext_ack *extack)
>@@ -3831,6 +3851,12 @@ static int macsec_changelink(struct net_device *dev, struct nlattr *tb[],
> if (ret)
> goto cleanup;
>
>+ if (data[IFLA_MACSEC_OFFLOAD]) {
>+ ret = macsec_changelink_upd_offload(dev, data);
>+ 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
>

2022-12-07 22:24:42

by Sabrina Dubroca

[permalink] [raw]
Subject: Re: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

2022-12-07, 15:52:15 +0000, Emeel Hakim wrote:
>
>
> > -----Original Message-----
> > From: Sabrina Dubroca <[email protected]>
> > Sent: Wednesday, 7 December 2022 17:46
> > To: Emeel Hakim <[email protected]>
> > Cc: [email protected]; Raed Salem <[email protected]>;
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]; [email protected]
> > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > IFLA_MACSEC_OFFLOAD in macsec_changelink
> >
> > External email: Use caution opening links or attachments
> >
> >
> > 2022-12-07, 12:10:16 +0200, [email protected] wrote:
> > [...]
> > > +static int macsec_changelink_upd_offload(struct net_device *dev,
> > > +struct nlattr *data[]) {
> > > + enum macsec_offload offload;
> > > + struct macsec_dev *macsec;
> > > +
> > > + macsec = macsec_priv(dev);
> > > + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
> >
> > All those checks are also present in macsec_upd_offload, why not move them into
> > macsec_update_offload as well? (and then you don't really need
> > macsec_changelink_upd_offload anymore)
> >
>
> Right, I thought about it , but I realized that those checks are done before holding the lock in macsec_upd_offload
> and if I move them to macsec_update_offload I will hold the lock for a longer time , I want to minimize the time
> of holding the lock.

Those couple of tests are probably lost in the noise compared to what
mdo_add_secy ends up doing. It also looks like a race condition
between the "macsec->offload == offload" test in macsec_upd_offload
(outside rtnl_lock) and updating macsec->offload via macsec_changelink
is possible. (Currently we can only change it with macsec_upd_offload
(called under genl_lock) so there's no issue until we add this patch)


> > > + if (macsec->offload == offload)
> > > + return 0;
> > > +
> > > + /* Check if the offloading mode is supported by the underlying layers */
> > > + if (offload != MACSEC_OFFLOAD_OFF &&
> > > + !macsec_check_offload(offload, macsec))
> > > + return -EOPNOTSUPP;
> > > +
> > > + /* Check if the net device is busy. */
> > > + if (netif_running(dev))
> > > + return -EBUSY;
> > > +
> > > + return macsec_update_offload(macsec, offload); }
> > > +
> >
> > --
> > Sabrina
>

--
Sabrina

2022-12-08 07:29:29

by Emeel Hakim

[permalink] [raw]
Subject: RE: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink



> -----Original Message-----
> From: Sabrina Dubroca <[email protected]>
> Sent: Thursday, 8 December 2022 0:04
> To: Emeel Hakim <[email protected]>
> Cc: [email protected]; Raed Salem <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; [email protected]
> Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
>
> External email: Use caution opening links or attachments
>
>
> 2022-12-07, 15:52:15 +0000, Emeel Hakim wrote:
> >
> >
> > > -----Original Message-----
> > > From: Sabrina Dubroca <[email protected]>
> > > Sent: Wednesday, 7 December 2022 17:46
> > > To: Emeel Hakim <[email protected]>
> > > Cc: [email protected]; Raed Salem <[email protected]>;
> > > [email protected]; [email protected]; [email protected];
> > > [email protected]; [email protected]; [email protected];
> > > [email protected]
> > > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > > IFLA_MACSEC_OFFLOAD in macsec_changelink
> > >
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > 2022-12-07, 12:10:16 +0200, [email protected] wrote:
> > > [...]
> > > > +static int macsec_changelink_upd_offload(struct net_device *dev,
> > > > +struct nlattr *data[]) {
> > > > + enum macsec_offload offload;
> > > > + struct macsec_dev *macsec;
> > > > +
> > > > + macsec = macsec_priv(dev);
> > > > + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
> > >
> > > All those checks are also present in macsec_upd_offload, why not
> > > move them into macsec_update_offload as well? (and then you don't
> > > really need macsec_changelink_upd_offload anymore)
> > >
> >
> > Right, I thought about it , but I realized that those checks are done
> > before holding the lock in macsec_upd_offload and if I move them to
> > macsec_update_offload I will hold the lock for a longer time , I want to minimize
> the time of holding the lock.
>
> Those couple of tests are probably lost in the noise compared to what
> mdo_add_secy ends up doing. It also looks like a race condition between the
> "macsec->offload == offload" test in macsec_upd_offload (outside rtnl_lock) and
> updating macsec->offload via macsec_changelink is possible. (Currently we can
> only change it with macsec_upd_offload (called under genl_lock) so there's no issue
> until we add this patch)

Ack,
so getting rid of macsec_changelink_upd_offload and moving the locking inside macsec_update_offload
should handle this issue

>
> > > > + if (macsec->offload == offload)
> > > > + return 0;
> > > > +
> > > > + /* Check if the offloading mode is supported by the underlying layers */
> > > > + if (offload != MACSEC_OFFLOAD_OFF &&
> > > > + !macsec_check_offload(offload, macsec))
> > > > + return -EOPNOTSUPP;
> > > > +
> > > > + /* Check if the net device is busy. */
> > > > + if (netif_running(dev))
> > > > + return -EBUSY;
> > > > +
> > > > + return macsec_update_offload(macsec, offload); }
> > > > +
> > >
> > > --
> > > Sabrina
> >
>
> --
> Sabrina

2022-12-08 11:01:50

by Sabrina Dubroca

[permalink] [raw]
Subject: Re: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink

2022-12-08, 06:53:18 +0000, Emeel Hakim wrote:
>
>
> > -----Original Message-----
> > From: Sabrina Dubroca <[email protected]>
> > Sent: Thursday, 8 December 2022 0:04
> > To: Emeel Hakim <[email protected]>
> > Cc: [email protected]; Raed Salem <[email protected]>;
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected]; [email protected]
> > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > IFLA_MACSEC_OFFLOAD in macsec_changelink
> >
> > External email: Use caution opening links or attachments
> >
> >
> > 2022-12-07, 15:52:15 +0000, Emeel Hakim wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Sabrina Dubroca <[email protected]>
> > > > Sent: Wednesday, 7 December 2022 17:46
> > > > To: Emeel Hakim <[email protected]>
> > > > Cc: [email protected]; Raed Salem <[email protected]>;
> > > > [email protected]; [email protected]; [email protected];
> > > > [email protected]; [email protected]; [email protected];
> > > > [email protected]
> > > > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > > > IFLA_MACSEC_OFFLOAD in macsec_changelink
> > > >
> > > > External email: Use caution opening links or attachments
> > > >
> > > >
> > > > 2022-12-07, 12:10:16 +0200, [email protected] wrote:
> > > > [...]
> > > > > +static int macsec_changelink_upd_offload(struct net_device *dev,
> > > > > +struct nlattr *data[]) {
> > > > > + enum macsec_offload offload;
> > > > > + struct macsec_dev *macsec;
> > > > > +
> > > > > + macsec = macsec_priv(dev);
> > > > > + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
> > > >
> > > > All those checks are also present in macsec_upd_offload, why not
> > > > move them into macsec_update_offload as well? (and then you don't
> > > > really need macsec_changelink_upd_offload anymore)
> > > >
> > >
> > > Right, I thought about it , but I realized that those checks are done
> > > before holding the lock in macsec_upd_offload and if I move them to
> > > macsec_update_offload I will hold the lock for a longer time , I want to minimize
> > the time of holding the lock.
> >
> > Those couple of tests are probably lost in the noise compared to what
> > mdo_add_secy ends up doing. It also looks like a race condition between the
> > "macsec->offload == offload" test in macsec_upd_offload (outside rtnl_lock) and
> > updating macsec->offload via macsec_changelink is possible. (Currently we can
> > only change it with macsec_upd_offload (called under genl_lock) so there's no issue
> > until we add this patch)
>
> Ack,
> so getting rid of macsec_changelink_upd_offload and moving the locking inside macsec_update_offload
> should handle this issue

You mean moving rtnl_lock()/unlock inside macsec_update_offload?
changelink is already under rtnl_lock. Just move the checks that you
currently have in macsec_changelink_upd_offload into
macsec_update_offload, and remove them from macsec_upd_offload.

> >
> > > > > + if (macsec->offload == offload)
> > > > > + return 0;
> > > > > +
> > > > > + /* Check if the offloading mode is supported by the underlying layers */
> > > > > + if (offload != MACSEC_OFFLOAD_OFF &&
> > > > > + !macsec_check_offload(offload, macsec))
> > > > > + return -EOPNOTSUPP;
> > > > > +
> > > > > + /* Check if the net device is busy. */
> > > > > + if (netif_running(dev))
> > > > > + return -EBUSY;
> > > > > +
> > > > > + return macsec_update_offload(macsec, offload); }
> > > > > +
> > > >
> > > > --
> > > > Sabrina
> > >
> >
> > --
> > Sabrina
>

--
Sabrina

2022-12-08 11:21:32

by Emeel Hakim

[permalink] [raw]
Subject: RE: [PATCH net-next v3 1/2] macsec: add support for IFLA_MACSEC_OFFLOAD in macsec_changelink



> -----Original Message-----
> From: Sabrina Dubroca <[email protected]>
> Sent: Thursday, 8 December 2022 12:38
> To: Emeel Hakim <[email protected]>
> Cc: [email protected]; Raed Salem <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; [email protected]
> Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> IFLA_MACSEC_OFFLOAD in macsec_changelink
>
> External email: Use caution opening links or attachments
>
>
> 2022-12-08, 06:53:18 +0000, Emeel Hakim wrote:
> >
> >
> > > -----Original Message-----
> > > From: Sabrina Dubroca <[email protected]>
> > > Sent: Thursday, 8 December 2022 0:04
> > > To: Emeel Hakim <[email protected]>
> > > Cc: [email protected]; Raed Salem <[email protected]>;
> > > [email protected]; [email protected]; [email protected];
> > > [email protected]; [email protected]; [email protected];
> > > [email protected]
> > > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > > IFLA_MACSEC_OFFLOAD in macsec_changelink
> > >
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > 2022-12-07, 15:52:15 +0000, Emeel Hakim wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Sabrina Dubroca <[email protected]>
> > > > > Sent: Wednesday, 7 December 2022 17:46
> > > > > To: Emeel Hakim <[email protected]>
> > > > > Cc: [email protected]; Raed Salem <[email protected]>;
> > > > > [email protected]; [email protected]; [email protected];
> > > > > [email protected]; [email protected]; [email protected];
> > > > > [email protected]
> > > > > Subject: Re: [PATCH net-next v3 1/2] macsec: add support for
> > > > > IFLA_MACSEC_OFFLOAD in macsec_changelink
> > > > >
> > > > > External email: Use caution opening links or attachments
> > > > >
> > > > >
> > > > > 2022-12-07, 12:10:16 +0200, [email protected] wrote:
> > > > > [...]
> > > > > > +static int macsec_changelink_upd_offload(struct net_device
> > > > > > +*dev, struct nlattr *data[]) {
> > > > > > + enum macsec_offload offload;
> > > > > > + struct macsec_dev *macsec;
> > > > > > +
> > > > > > + macsec = macsec_priv(dev);
> > > > > > + offload = nla_get_u8(data[IFLA_MACSEC_OFFLOAD]);
> > > > >
> > > > > All those checks are also present in macsec_upd_offload, why not
> > > > > move them into macsec_update_offload as well? (and then you
> > > > > don't really need macsec_changelink_upd_offload anymore)
> > > > >
> > > >
> > > > Right, I thought about it , but I realized that those checks are
> > > > done before holding the lock in macsec_upd_offload and if I move
> > > > them to macsec_update_offload I will hold the lock for a longer
> > > > time , I want to minimize
> > > the time of holding the lock.
> > >
> > > Those couple of tests are probably lost in the noise compared to
> > > what mdo_add_secy ends up doing. It also looks like a race condition
> > > between the "macsec->offload == offload" test in macsec_upd_offload
> > > (outside rtnl_lock) and updating macsec->offload via
> > > macsec_changelink is possible. (Currently we can only change it with
> > > macsec_upd_offload (called under genl_lock) so there's no issue
> > > until we add this patch)
> >
> > Ack,
> > so getting rid of macsec_changelink_upd_offload and moving the locking
> > inside macsec_update_offload should handle this issue
>
> You mean moving rtnl_lock()/unlock inside macsec_update_offload?
> changelink is already under rtnl_lock. Just move the checks that you currently have
> in macsec_changelink_upd_offload into macsec_update_offload, and remove them
> from macsec_upd_offload.

Ack will send new version

> > >
> > > > > > + if (macsec->offload == offload)
> > > > > > + return 0;
> > > > > > +
> > > > > > + /* Check if the offloading mode is supported by the underlying layers
> */
> > > > > > + if (offload != MACSEC_OFFLOAD_OFF &&
> > > > > > + !macsec_check_offload(offload, macsec))
> > > > > > + return -EOPNOTSUPP;
> > > > > > +
> > > > > > + /* Check if the net device is busy. */
> > > > > > + if (netif_running(dev))
> > > > > > + return -EBUSY;
> > > > > > +
> > > > > > + return macsec_update_offload(macsec, offload); }
> > > > > > +
> > > > >
> > > > > --
> > > > > Sabrina
> > > >
> > >
> > > --
> > > Sabrina
> >
>
> --
> Sabrina