Add a helper to add an offset to a ethernet address. This comes in handy
if you have a base ethernet address for multiple interfaces.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Jakub Kicinski <kuba@kernel.org>
---
changes since v1:
 - none

 include/linux/etherdevice.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index a541f0c4f146..f144cadbe99d 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -507,6 +507,20 @@ static inline void eth_addr_inc(u8 *addr)
 	u64_to_ether_addr(u, addr);
 }
 
+/**
+ * eth_addr_add() - Add (or subtract) and offset to/from the given MAC address.
+ *
+ * @offset: Offset to add.
+ * @addr: Pointer to a six-byte array containing Ethernet address to increment.
+ */
+static inline void eth_addr_add(u8 *addr, long offset)
+{
+	u64 u = ether_addr_to_u64(addr);
+
+	u += offset;
+	u64_to_ether_addr(u, addr);
+}
+
 /**
  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
  * @dev: Pointer to a device structure
-- 
2.30.2

On 9/1/22 15:18, Michael Walle wrote:
> Add a helper to add an offset to a ethernet address. This comes in handy
> if you have a base ethernet address for multiple interfaces.
> 
> Signed-off-by: Michael Walle <michael@walle.cc>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Acked-by: Jakub Kicinski <kuba@kernel.org>
> ---
> changes since v1:
>  - none
> 
>  include/linux/etherdevice.h | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
> index a541f0c4f146..f144cadbe99d 100644
> --- a/include/linux/etherdevice.h
> +++ b/include/linux/etherdevice.h
> @@ -507,6 +507,20 @@ static inline void eth_addr_inc(u8 *addr)
>  	u64_to_ether_addr(u, addr);
>  }
>  
> +/**
> + * eth_addr_add() - Add (or subtract) and offset to/from the given MAC address.

                                         an offset
?

> + *
> + * @offset: Offset to add.
> + * @addr: Pointer to a six-byte array containing Ethernet address to increment.
> + */
> +static inline void eth_addr_add(u8 *addr, long offset)
> +{
> +	u64 u = ether_addr_to_u64(addr);
> +
> +	u += offset;
> +	u64_to_ether_addr(u, addr);
> +}
> +
>  /**
>   * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
>   * @dev: Pointer to a device structure

-- 
~Randy

Am 2022-09-02 01:22, schrieb Randy Dunlap:

>> +/**
>> + * eth_addr_add() - Add (or subtract) and offset to/from the given 
>> MAC address.
> 
>                                          an offset
> ?

yes thanks, I'll change that in the next version.

-michael