[PATCH V9] ethdev: fix one address occupies two entries in MAC addrs

[Huisong Li <lihuisong@huawei.com>]

The dev->data->mac_addrs[0] will be changed to a new MAC address when
applications modify the default MAC address by .mac_addr_set(). However,
if the new default one has been added as a non-default MAC address by
.mac_addr_add(), the .mac_addr_set() didn't check this address.
As a result, this MAC address occupies two entries in the list. Like:
add(MAC1)
add(MAC2)
add(MAC3)
add(MAC4)
set_default(MAC3)
default=MAC3, the rest of the list=MAC1, MAC2, MAC3, MAC4
Note: MAC3 occupies two entries.

But .mac_addr_set() cannot remove it implicitly in case of MAC address
shrinking in the list.
So this patch adds a check on whether the new default address was already
in the list and if so requires the user to remove it first.

In addition, this patch documents the position of the default MAC address
and address unique in the list.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
---
v9: request user to remove the address instead of doing it implicitly in
    .mac_addr_set() API.
v8: fix some comments.
v7: add announcement in the release notes and document this behavior.
v6: fix commit log and some code comments.
v5:
 - merge the second patch into the first patch.
 - add error log when rollback failed.
v4:
  - fix broken in the patchwork
v3:
  - first explicitly remove the non-default MAC, then set default one.
  - document default and non-default MAC address
v2:
  - fixed commit log.

---
 doc/guides/rel_notes/release_23_07.rst |  5 +++++
 lib/ethdev/ethdev_driver.h             |  6 +++++-
 lib/ethdev/rte_ethdev.c                | 10 ++++++++++
 lib/ethdev/rte_ethdev.h                |  3 +++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/doc/guides/rel_notes/release_23_07.rst b/doc/guides/rel_notes/release_23_07.rst
index 4ffef85d74..7c624d8315 100644
--- a/doc/guides/rel_notes/release_23_07.rst
+++ b/doc/guides/rel_notes/release_23_07.rst
@@ -96,6 +96,11 @@ API Changes
    Also, make sure to start the actual text at the margin.
    =======================================================
 
+   * ethdev: ensured all entries in MAC address list are uniques.
+     When setting a default MAC address with the function
+     ``rte_eth_dev_default_mac_addr_set``,
+     the default one needs to be removed by user if it was already in
+     the list.
 
 ABI Changes
 -----------
diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index 2c9d615fb5..367c0c4878 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -117,7 +117,11 @@ struct rte_eth_dev_data {
 
 	uint64_t rx_mbuf_alloc_failed; /**< Rx ring mbuf allocation failures */
 
-	/** Device Ethernet link address. @see rte_eth_dev_release_port() */
+	/**
+	 * Device Ethernet link addresses.
+	 * All entries are unique.
+	 * The first entry (index zero) is the default address.
+	 */
 	struct rte_ether_addr *mac_addrs;
 	/** Bitmap associating MAC addresses to pools */
 	uint64_t mac_pool_sel[RTE_ETH_NUM_RECEIVE_MAC_ADDR];
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 4d03255683..d46e74504e 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -4898,6 +4898,7 @@ int
 rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct rte_ether_addr *addr)
 {
 	struct rte_eth_dev *dev;
+	int index;
 	int ret;
 
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
@@ -4916,6 +4917,15 @@ rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct rte_ether_addr *addr)
 	if (*dev->dev_ops->mac_addr_set == NULL)
 		return -ENOTSUP;
 
+	/* Keep address unique in dev->data->mac_addrs[]. */
+	index = eth_dev_get_mac_addr_index(port_id, addr);
+	if (index > 0) {
+		RTE_ETHDEV_LOG(ERR,
+			"New default address for port %u was already in the address list. Please remove it first.\n",
+			port_id);
+		return -EEXIST;
+	}
+
 	ret = (*dev->dev_ops->mac_addr_set)(dev, addr);
 	if (ret < 0)
 		return ret;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 99fe9e238b..09b2ff9e5e 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -4381,6 +4381,9 @@ int rte_eth_dev_mac_addr_remove(uint16_t port_id,
 
 /**
  * Set the default MAC address.
+ * It replaces the address at index 0 of the MAC address list.
+ * If the address was already in the MAC address list,
+ * please remove it first.
  *
  * @param port_id
  *   The port identifier of the Ethernet device.
-- 
2.33.0