From 73ceb049af1b391cdbb4b3bbedc2e8ef8fe399f2 Mon Sep 17 00:00:00 2001
From: liqinhui <liqinhui@xiaomi.com>
Date: Mon, 4 Dec 2023 14:21:45 +0800
Subject: [PATCH] virtio-net: Support for setting MAC addresses of the
 virtio-net interfaces.

Refers to https://docs.oasis-open.org/virtio/virtio/v1.2/cs01/virtio-v1.2-cs01.html#x1-2230004
A driver SHOULD negotiate VIRTIO_NET_F_MAC if the device offers it.
If the driver negotiates the VIRTIO_NET_F_MAC feature, the driver MUST
set the physical address of the NIC to mac. Otherwise, it SHOULD use a
locally-administered MAC address.

Signed-off-by: liqinhui <liqinhui@xiaomi.com>
---
 drivers/virtio/virtio-net.c | 60 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 59 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio-net.c b/drivers/virtio/virtio-net.c
index 5384d6798c..c1908e7dc7 100644
--- a/drivers/virtio/virtio-net.c
+++ b/drivers/virtio/virtio-net.c
@@ -39,6 +39,8 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+#define VIRTIO_NET_F_MAC      5
+
 /* Virtio net header size and packet buffer size */
 
 #define VIRTIO_NET_HDRSIZE    (sizeof(struct virtio_net_hdr_s))
@@ -74,6 +76,24 @@ begin_packed_struct struct virtio_net_hdr_s
   uint16_t csum_offset;
 } end_packed_struct;
 
+/* The definition of the struct virtio_net_config refers to the link
+ * https://docs.oasis-open.org/virtio/virtio/v1.2/cs01/
+ * virtio-v1.2-cs01.html#x1-2230004.
+ */
+
+begin_packed_struct struct virtio_net_config_s
+{
+  uint8_t  mac[IFHWADDRLEN];                 /* VIRTIO_NET_F_MAC */
+  uint16_t status;                           /* VIRTIO_NET_F_STATUS */
+  uint16_t max_virtqueue_pairs;              /* VIRTIO_NET_F_MQ */
+  uint16_t mtu;                              /* VIRTIO_NET_F_MTU */
+  uint32_t speed;                            /* VIRTIO_NET_F_SPEED_DUPLEX */
+  uint8_t  duplex;
+  uint8_t  rss_max_key_size;                 /* VIRTIO_NET_F_RSS */
+  uint16_t rss_max_indirection_table_length;
+  uint32_t supported_hash_types;
+} end_packed_struct;
+
 struct virtio_net_priv_s
 {
   /* This holds the information visible to the NuttX network */
@@ -487,7 +507,7 @@ static int virtio_net_init(FAR struct virtio_net_priv_s *priv,
   /* Initialize the virtio device */
 
   virtio_set_status(vdev, VIRTIO_CONFIG_STATUS_DRIVER);
-  virtio_set_features(vdev, 0);
+  virtio_negotiate_features(vdev, 1 << VIRTIO_NET_F_MAC);
   virtio_set_status(vdev, VIRTIO_CONFIG_FEATURES_OK);
 
   vqnames[VIRTIO_NET_RX]   = "virtio_net_rx";
@@ -520,6 +540,42 @@ static int virtio_net_init(FAR struct virtio_net_priv_s *priv,
   return OK;
 }
 
+static void virtio_net_set_macaddr(FAR struct virtio_net_priv_s *priv)
+{
+  FAR struct net_driver_s *dev = &priv->lower.netdev;
+  FAR struct virtio_device *vdev = priv->vdev;
+  FAR uint8_t *mac = dev->d_mac.ether.ether_addr_octet;
+
+  if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
+    {
+      virtio_read_config(vdev, offsetof(struct virtio_net_config_s, mac),
+                         mac, IFHWADDRLEN);
+    }
+  else
+    {
+      /* Assign a random locally-created MAC address.
+       *
+       * TODO:  The generated MAC address should be checked to see if it
+       *        conflicts with something else on the network.
+       */
+
+      srand(time(NULL) +
+#ifdef CONFIG_NETDEV_IFINDEX
+            dev->d_ifindex
+#else
+            dev % 256
+#endif
+          );
+
+      mac[0] = 0x42;
+      mac[1] = rand() % 256;
+      mac[2] = rand() % 256;
+      mac[3] = rand() % 256;
+      mac[4] = rand() % 256;
+      mac[5] = rand() % 256;
+    }
+}
+
 /****************************************************************************
  * Name: virtio_net_probe
  ****************************************************************************/
@@ -560,6 +616,8 @@ static int virtio_net_probe(FAR struct virtio_device *vdev)
       goto err_with_virtqueues;
     }
 
+  virtio_net_set_macaddr(priv);
+
   return ret;
 
 err_with_virtqueues: