Re: [dpdk-dev] [PATCH v2] net/null:Different mac address support

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon,  5 Mar 2018 19:35:14 -0800
Mallesh Koujalagi <malleshx.koujalagi@intel.com> wrote:

> After attaching two Null device to ovs, seeing "00.00.00.00.00.00" mac
> address for both null devices. Fix this issue, by setting different mac
> address.
> 
> Signed-off-by: Mallesh Koujalagi <malleshx.koujalagi@intel.com>
> ---
>  drivers/net/null/rte_eth_null.c | 26 +++++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/null/rte_eth_null.c b/drivers/net/null/rte_eth_null.c
> index 9385ffd..599b513 100644
> --- a/drivers/net/null/rte_eth_null.c
> +++ b/drivers/net/null/rte_eth_null.c
> @@ -85,8 +85,17 @@ struct pmd_internals {
>  	uint8_t rss_key[40];                /**< 40-byte hash key. */
>  };
>  
> +static struct ether_addr base_eth_addr = {
> +	.addr_bytes = {
> +		0x4E /* N */,
> +		0x55 /* U */,
> +		0x4C /* L */,
> +		0x4C /* L */,
> +		0x00,
> +		0x00
> +	}
> +};

Cute, but since first octets of Ethernet are the vendor id (OUI)
it might be confusing. At least 'N' is 4E which does not have
the group address (multicast) set; and it does have the local
admin address bit set.

You really should be using a random locally assigned value.

 
> -static struct ether_addr eth_addr = { .addr_bytes = {0} };
>  static struct rte_eth_link pmd_link = {
>  	.link_speed = ETH_SPEED_NUM_10G,
>  	.link_duplex = ETH_LINK_FULL_DUPLEX,
> @@ -492,6 +501,7 @@ eth_dev_null_create(struct rte_vdev_device *dev,
>  	struct rte_eth_dev_data *data = NULL;
>  	struct pmd_internals *internals = NULL;
>  	struct rte_eth_dev *eth_dev = NULL;
> +	struct ether_addr *eth_addr = NULL;
>  
>  	static const uint8_t default_rss_key[40] = {
>  		0x6D, 0x5A, 0x56, 0xDA, 0x25, 0x5B, 0x0E, 0xC2, 0x41, 0x67, 0x25, 0x3D,
> @@ -514,12 +524,21 @@ eth_dev_null_create(struct rte_vdev_device *dev,
>  	if (!data)
>  		return -ENOMEM;
>  
> +	eth_addr = rte_zmalloc_socket(rte_vdev_device_name(dev),
> +			sizeof(*eth_addr), 0, dev->device.numa_node);
> +	if (eth_addr == NULL) {
> +		rte_free(data);
> +		return -ENOMEM;
> +	}
> +
>  	eth_dev = rte_eth_vdev_allocate(dev, sizeof(*internals));
>  	if (!eth_dev) {
> +		rte_free(eth_addr);
>  		rte_free(data);
>  		return -ENOMEM;
>  	}
> -
> +	*eth_addr = base_eth_addr;
> +	eth_addr->addr_bytes[5] = eth_dev->data->port_id;
>  	/* now put it all together
>  	 * - store queue data in internals,
>  	 * - store numa_node info in ethdev data
> @@ -543,7 +562,7 @@ eth_dev_null_create(struct rte_vdev_device *dev,
>  	data->nb_rx_queues = (uint16_t)nb_rx_queues;
>  	data->nb_tx_queues = (uint16_t)nb_tx_queues;
>  	data->dev_link = pmd_link;
> -	data->mac_addrs = &eth_addr;
> +	data->mac_addrs = eth_addr;
>  
>  	eth_dev->data = data;
>  	eth_dev->dev_ops = &ops;
> @@ -662,6 +681,7 @@ rte_pmd_null_remove(struct rte_vdev_device *dev)
>  	if (eth_dev == NULL)
>  		return -1;
>  
> +	rte_free(eth_dev->data->mac_addrs);
>  	rte_free(eth_dev->data->dev_private);
>  	rte_free(eth_dev->data);
>