[PATCH] mac802154_hwsim: define perm_extended_addr initialization

[PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Ramon Fontes]

This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.

Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
---
 drivers/net/ieee802154/mac802154_hwsim.c | 18 +++++++++++++++++-
 drivers/net/ieee802154/mac802154_hwsim.h |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
index 1cab20b5a..400cdac1f 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.c
+++ b/drivers/net/ieee802154/mac802154_hwsim.c
@@ -41,6 +41,17 @@ enum hwsim_multicast_groups {
 	HWSIM_MCGRP_CONFIG,
 };
 
+__le64 addr_to_le64(u8 *addr) {
+    return cpu_to_le64(((u64)addr[0] << 56) |
+                        ((u64)addr[1] << 48) |
+                        ((u64)addr[2] << 40) |
+                        ((u64)addr[3] << 32) |
+                        ((u64)addr[4] << 24) |
+                        ((u64)addr[5] << 16) |
+                        ((u64)addr[6] << 8)  |
+                        ((u64)addr[7]));
+}
+
 static const struct genl_multicast_group hwsim_mcgrps[] = {
 	[HWSIM_MCGRP_CONFIG] = { .name = "config", },
 };
@@ -896,6 +907,7 @@ static int hwsim_subscribe_all_others(struct hwsim_phy *phy)
 static int hwsim_add_one(struct genl_info *info, struct device *dev,
 			 bool init)
 {
+	u8 addr[8];
 	struct ieee802154_hw *hw;
 	struct hwsim_phy *phy;
 	struct hwsim_pib *pib;
@@ -942,7 +954,11 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
 	/* 950 MHz GFSK 802.15.4d-2009 */
 	hw->phy->supported.channels[6] |= 0x3ffc00;
 
-	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
+	memset(addr, 0, sizeof(addr));
+	/* give a specific prefix to the address */
+	addr[0] = 0x02;
+	addr[7] = idx;
+	hw->phy->perm_extended_addr = addr_to_le64(addr);
 
 	/* hwsim phy channel 13 as default */
 	hw->phy->current_channel = 13;
diff --git a/drivers/net/ieee802154/mac802154_hwsim.h b/drivers/net/ieee802154/mac802154_hwsim.h
index 6c6e30e38..536d95eb1 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.h
+++ b/drivers/net/ieee802154/mac802154_hwsim.h
@@ -1,6 +1,8 @@
 #ifndef __MAC802154_HWSIM_H
 #define __MAC802154_HWSIM_H
 
+__le64 addr_to_le64(u8 *addr);
+
 /* mac802154 hwsim netlink commands
  *
  * @MAC802154_HWSIM_CMD_UNSPEC: unspecified command to catch error
-- 
2.43.0

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Miquel Raynal]

Hello Ramon,

On 25/03/2025 at 13:53:12 -03, Ramon Fontes <ramonreisfontes@gmail.com> wrote:

> This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.

You are now enforcing an (almost) static value, is that the intended
behaviour? If yes I would like a better explanation of why this is
relevant and how you picked eg. 0x02 as prefix to justify the change.

In general I am not opposed, even though I kind of liked the idea of
generating random addresses, especially since hwsim is not the only one
to do that and having a simulator that behaves like regular device
drivers actually makes sense IMO.

Also, please wrap the commit log.

> Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>

Thanks,
Miquèl

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Ramon Fontes]

Hello Miquèl,

This PR aims to replicate functionality similar to what is implemented
in mac80211_hwsim
(https://github.com/torvalds/linux/blob/master/drivers/net/wireless/virtual/mac80211_hwsim.c#L5223).
This approach is useful for testing wireless medium emulation tools
like wmediumd (https://github.com/bcopeland/wmediumd/blob/master/tests/)
and I plan to submit more PRs soon.

I've started developing a wmediumd-like framework for mac802154_hwsim,
which you can find here:
https://github.com/ramonfontes/wmediumd_802154. However, it's still in
its early stages.

Indeed, I'm responsible for Mininet-WiFi
(https://github.com/intrig-unicamp/mininet-wifi) which supports IEEE
802.15.4 emulation via mac802154_hwsim. Having a wireless medium
emulation for mac802154_hwsim would be highly beneficial, as it
enables controlled testing and facilitates prototyping.

> Also, please wrap the commit log.
Apologies for any confusion. Could you clarify if there are any
specific changes I need to make in the PR?


Em qua., 26 de mar. de 2025 às 07:12, Miquel Raynal
<miquel.raynal@bootlin.com> escreveu:
>
> Hello Ramon,
>
> On 25/03/2025 at 13:53:12 -03, Ramon Fontes <ramonreisfontes@gmail.com> wrote:
>
> > This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.
>
> You are now enforcing an (almost) static value, is that the intended
> behaviour? If yes I would like a better explanation of why this is
> relevant and how you picked eg. 0x02 as prefix to justify the change.
>
> In general I am not opposed, even though I kind of liked the idea of
> generating random addresses, especially since hwsim is not the only one
> to do that and having a simulator that behaves like regular device
> drivers actually makes sense IMO.
>
> Also, please wrap the commit log.
>
> > Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
>
> Thanks,
> Miquèl

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Miquel Raynal]

Hello Ramon,

On 26/03/2025 at 07:34:14 -03, Ramon Fontes <ramonreisfontes@gmail.com> wrote:

> Hello Miquèl,
>
> This PR aims to replicate functionality similar to what is implemented
> in mac80211_hwsim
> (https://github.com/torvalds/linux/blob/master/drivers/net/wireless/virtual/mac80211_hwsim.c#L5223).
> This approach is useful for testing wireless medium emulation tools
> like wmediumd (https://github.com/bcopeland/wmediumd/blob/master/tests/)
> and I plan to submit more PRs soon.
>
> I've started developing a wmediumd-like framework for mac802154_hwsim,
> which you can find here:
> https://github.com/ramonfontes/wmediumd_802154. However, it's still in
> its early stages.
>
> Indeed, I'm responsible for Mininet-WiFi
> (https://github.com/intrig-unicamp/mininet-wifi) which supports IEEE
> 802.15.4 emulation via mac802154_hwsim. Having a wireless medium
> emulation for mac802154_hwsim would be highly beneficial, as it
> enables controlled testing and facilitates prototyping.

Okay, I must say I do not know this project, but it looks interesting.
If the others are fine with this change, I'm fine too.

>> Also, please wrap the commit log.
> Apologies for any confusion. Could you clarify if there are any
> specific changes I need to make in the PR?

Yes, just change:

This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.

Into:

This establishes an initialization method for perm_extended_addr,
aligning it with the approach used in mac80211_hwsim.

Thanks,
Miquèl

[PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Ramon Fontes]

This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.

Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
---
 drivers/net/ieee802154/mac802154_hwsim.c | 18 +++++++++++++++++-
 drivers/net/ieee802154/mac802154_hwsim.h |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
index 1cab20b5a..400cdac1f 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.c
+++ b/drivers/net/ieee802154/mac802154_hwsim.c
@@ -41,6 +41,17 @@ enum hwsim_multicast_groups {
 	HWSIM_MCGRP_CONFIG,
 };
 
+__le64 addr_to_le64(u8 *addr) {
+    return cpu_to_le64(((u64)addr[0] << 56) |
+                        ((u64)addr[1] << 48) |
+                        ((u64)addr[2] << 40) |
+                        ((u64)addr[3] << 32) |
+                        ((u64)addr[4] << 24) |
+                        ((u64)addr[5] << 16) |
+                        ((u64)addr[6] << 8)  |
+                        ((u64)addr[7]));
+}
+
 static const struct genl_multicast_group hwsim_mcgrps[] = {
 	[HWSIM_MCGRP_CONFIG] = { .name = "config", },
 };
@@ -896,6 +907,7 @@ static int hwsim_subscribe_all_others(struct hwsim_phy *phy)
 static int hwsim_add_one(struct genl_info *info, struct device *dev,
 			 bool init)
 {
+	u8 addr[8];
 	struct ieee802154_hw *hw;
 	struct hwsim_phy *phy;
 	struct hwsim_pib *pib;
@@ -942,7 +954,11 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
 	/* 950 MHz GFSK 802.15.4d-2009 */
 	hw->phy->supported.channels[6] |= 0x3ffc00;
 
-	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
+	memset(addr, 0, sizeof(addr));
+	/* give a specific prefix to the address */
+	addr[0] = 0x02;
+	addr[7] = idx;
+	hw->phy->perm_extended_addr = addr_to_le64(addr);
 
 	/* hwsim phy channel 13 as default */
 	hw->phy->current_channel = 13;
diff --git a/drivers/net/ieee802154/mac802154_hwsim.h b/drivers/net/ieee802154/mac802154_hwsim.h
index 6c6e30e38..536d95eb1 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.h
+++ b/drivers/net/ieee802154/mac802154_hwsim.h
@@ -1,6 +1,8 @@
 #ifndef __MAC802154_HWSIM_H
 #define __MAC802154_HWSIM_H
 
+__le64 addr_to_le64(u8 *addr);
+
 /* mac802154 hwsim netlink commands
  *
  * @MAC802154_HWSIM_CMD_UNSPEC: unspecified command to catch error
-- 
2.43.0

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Alexander Aring]

Hi,

On Wed, Mar 26, 2025 at 2:09 PM Ramon Fontes <ramonreisfontes@gmail.com> wrote:
>
> This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.
>

that is based on the phy index value instead of a random generated one?

> Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
> ---
>  drivers/net/ieee802154/mac802154_hwsim.c | 18 +++++++++++++++++-
>  drivers/net/ieee802154/mac802154_hwsim.h |  2 ++
>  2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
> index 1cab20b5a..400cdac1f 100644
> --- a/drivers/net/ieee802154/mac802154_hwsim.c
> +++ b/drivers/net/ieee802154/mac802154_hwsim.c
> @@ -41,6 +41,17 @@ enum hwsim_multicast_groups {
>         HWSIM_MCGRP_CONFIG,
>  };
>
> +__le64 addr_to_le64(u8 *addr) {
> +    return cpu_to_le64(((u64)addr[0] << 56) |
> +                        ((u64)addr[1] << 48) |
> +                        ((u64)addr[2] << 40) |
> +                        ((u64)addr[3] << 32) |
> +                        ((u64)addr[4] << 24) |
> +                        ((u64)addr[5] << 16) |
> +                        ((u64)addr[6] << 8)  |
> +                        ((u64)addr[7]));
> +}
> +
>  static const struct genl_multicast_group hwsim_mcgrps[] = {
>         [HWSIM_MCGRP_CONFIG] = { .name = "config", },
>  };
> @@ -896,6 +907,7 @@ static int hwsim_subscribe_all_others(struct hwsim_phy *phy)
>  static int hwsim_add_one(struct genl_info *info, struct device *dev,
>                          bool init)
>  {
> +       u8 addr[8];

why not using directly __le64?

>         struct ieee802154_hw *hw;
>         struct hwsim_phy *phy;
>         struct hwsim_pib *pib;
> @@ -942,7 +954,11 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
>         /* 950 MHz GFSK 802.15.4d-2009 */
>         hw->phy->supported.channels[6] |= 0x3ffc00;
>
> -       ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
> +       memset(addr, 0, sizeof(addr));
> +       /* give a specific prefix to the address */
> +       addr[0] = 0x02;
> +       addr[7] = idx;
> +       hw->phy->perm_extended_addr = addr_to_le64(addr);
>
>         /* hwsim phy channel 13 as default */
>         hw->phy->current_channel = 13;
> diff --git a/drivers/net/ieee802154/mac802154_hwsim.h b/drivers/net/ieee802154/mac802154_hwsim.h
> index 6c6e30e38..536d95eb1 100644
> --- a/drivers/net/ieee802154/mac802154_hwsim.h
> +++ b/drivers/net/ieee802154/mac802154_hwsim.h
> @@ -1,6 +1,8 @@
>  #ifndef __MAC802154_HWSIM_H
>  #define __MAC802154_HWSIM_H
>
> +__le64 addr_to_le64(u8 *addr);
> +

This is a uapi header for netlink which is not yet delivered through
kernel-headers installation.

Why do we need this prototype declaration here?

Thanks.

- Alex

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Ramon Fontes]

On Wed, Mar 26, 2025 at 7:49 PM, Alexander Aring <aahringo@redhat.com> wrote:
>
> Hi,
>
> On Wed, Mar 26, 2025 at 2:09 PM Ramon Fontes <ramonreisfontes@gmail.com> wrote:
> >
> > This establishes an initialization method for perm_extended_addr, aligning it with the approach used in mac80211_hwsim.
> >
>
> that is based on the phy index value instead of a random generated one?

Yes, that's based on the phy index value.

>
> > Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
> > ---
> >  drivers/net/ieee802154/mac802154_hwsim.c | 18 +++++++++++++++++-
> >  drivers/net/ieee802154/mac802154_hwsim.h |  2 ++
> >  2 files changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
> > index 1cab20b5a..400cdac1f 100644
> > --- a/drivers/net/ieee802154/mac802154_hwsim.c
> > +++ b/drivers/net/ieee802154/mac802154_hwsim.c
> > @@ -41,6 +41,17 @@ enum hwsim_multicast_groups {
> >         HWSIM_MCGRP_CONFIG,
> >  };
> >
> > +__le64 addr_to_le64(u8 *addr) {
> > +    return cpu_to_le64(((u64)addr[0] << 56) |
> > +                        ((u64)addr[1] << 48) |
> > +                        ((u64)addr[2] << 40) |
> > +                        ((u64)addr[3] << 32) |
> > +                        ((u64)addr[4] << 24) |
> > +                        ((u64)addr[5] << 16) |
> > +                        ((u64)addr[6] << 8)  |
> > +                        ((u64)addr[7]));
> > +}
> > +
> >  static const struct genl_multicast_group hwsim_mcgrps[] = {
> >         [HWSIM_MCGRP_CONFIG] = { .name = "config", },
> >  };
> > @@ -896,6 +907,7 @@ static int hwsim_subscribe_all_others(struct hwsim_phy *phy)
> >  static int hwsim_add_one(struct genl_info *info, struct device *dev,
> >                          bool init)
> >  {
> > +       u8 addr[8];
>
> why not using directly

Yes, we don't need it.

>
> >         struct ieee802154_hw *hw;
> >         struct hwsim_phy *phy;
> >         struct hwsim_pib *pib;
> > @@ -942,7 +954,11 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
> >         /* 950 MHz GFSK 802.15.4d-2009 */
> >         hw->phy->supported.channels[6] |= 0x3ffc00;
> >
> > -       ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
> > +       memset(addr, 0, sizeof(addr));
> > +       /* give a specific prefix to the address */
> > +       addr[0] = 0x02;
> > +       addr[7] = idx;
> > +       hw->phy->perm_extended_addr = addr_to_le64(addr);

I think we can replace everything with only one line of code:

hw->phy->perm_extended_addr = cpu_to_le64(((u64)0x02 << 56) | ((u64)idx));

This does the trick! What do you think?

> >
> >         /* hwsim phy channel 13 as default */
> >         hw->phy->current_channel = 13;
> > diff --git a/drivers/net/ieee802154/mac802154_hwsim.h b/drivers/net/ieee802154/mac802154_hwsim.h
> > index 6c6e30e38..536d95eb1 100644
> > --- a/drivers/net/ieee802154/mac802154_hwsim.h
> > +++ b/drivers/net/ieee802154/mac802154_hwsim.h
> > @@ -1,6 +1,8 @@
> >  #ifndef __MAC802154_HWSIM_H
> >  #define __MAC802154_HWSIM_H
> >
> > +__le64 addr_to_le64(u8 *addr);
> > +
>
> This is a uapi header for netlink which is not yet delivered through
> kernel-headers installation.
>
> Why do we need this prototype declaration here?

We don't need it.

>
> Thanks.
>
> - Alex
>

[PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Ramon Fontes]

This establishes an initialization method for perm_extended_addr,
aligning it with the approach used in mac80211_hwsim.

Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>
---
 drivers/net/ieee802154/mac802154_hwsim.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
index 1cab20b5a..2f7520454 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.c
+++ b/drivers/net/ieee802154/mac802154_hwsim.c
@@ -942,7 +942,7 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
 	/* 950 MHz GFSK 802.15.4d-2009 */
 	hw->phy->supported.channels[6] |= 0x3ffc00;
 
-	ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);
+	hw->phy->perm_extended_addr = cpu_to_le64(((u64)0x02 << 56) | ((u64)idx));
 
 	/* hwsim phy channel 13 as default */
 	hw->phy->current_channel = 13;
-- 
2.43.0

Re: [PATCH] mac802154_hwsim: define perm_extended_addr initialization

[Miquel Raynal]

On 29/03/2025 at 11:20:10 -03, Ramon Fontes <ramonreisfontes@gmail.com> wrote:

> This establishes an initialization method for perm_extended_addr,
> aligning it with the approach used in mac80211_hwsim.
>
> Signed-off-by: Ramon Fontes <ramonreisfontes@gmail.com>

Yeah, that's simpler, thanks Alex.

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>