net/devlink: Support setting hardware address of port function

PCI PF and VF devlink port can manage the function represented by a
devlink port.

Allow users to set port function's hardware address.

Example of a PCI VF port which supports a port function:
$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
  function:
    hw_addr 00:00:00:00:00:00

$ devlink port function set pci/0000:06:00.0/2 hw_addr 00:11:22:33:44:55

$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
  function:
    hw_addr 00:11:22:33:44:55
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/devlink.h

@@ -1119,6 +1119,16 @@ struct devlink_ops {
 	int (*port_function_hw_addr_get)(struct devlink *devlink, struct devlink_port *port,
 					 u8 *hw_addr, int *hw_addr_len,
 					 struct netlink_ext_ack *extack);
+	/**
+	 * @port_function_hw_addr_set: Port function's hardware address set function.
+	 *
+	 * Should be used by device drivers to set the hardware address of a function managed
+	 * by the devlink port. Driver should return -EOPNOTSUPP if it doesn't support port
+	 * function handling for a particular port.
+	 */
+	int (*port_function_hw_addr_set)(struct devlink *devlink, struct devlink_port *port,
+					 const u8 *hw_addr, int hw_addr_len,
+					 struct netlink_ext_ack *extack);
 };
 
 static inline void *devlink_priv(struct devlink *devlink)

net/core/devlink.c

@@ -85,6 +85,10 @@ EXPORT_SYMBOL(devlink_dpipe_header_ipv6);
 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwmsg);
 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwerr);
 
+static const struct nla_policy devlink_function_nl_policy[DEVLINK_PORT_FUNCTION_ATTR_MAX + 1] = {
+	[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY },
+};
+
 static LIST_HEAD(devlink_list);
 
 /* devlink_mutex
@@ -827,6 +831,67 @@ static int devlink_port_type_set(struct devlink *devlink,
 	return -EOPNOTSUPP;
 }
 
+static int
+devlink_port_function_hw_addr_set(struct devlink *devlink, struct devlink_port *port,
+				  const struct nlattr *attr, struct netlink_ext_ack *extack)
+{
+	const struct devlink_ops *ops;
+	const u8 *hw_addr;
+	int hw_addr_len;
+	int err;
+
+	hw_addr = nla_data(attr);
+	hw_addr_len = nla_len(attr);
+	if (hw_addr_len > MAX_ADDR_LEN) {
+		NL_SET_ERR_MSG_MOD(extack, "Port function hardware address too long");
+		return -EINVAL;
+	}
+	if (port->type == DEVLINK_PORT_TYPE_ETH) {
+		if (hw_addr_len != ETH_ALEN) {
+			NL_SET_ERR_MSG_MOD(extack, "Address must be 6 bytes for Ethernet device");
+			return -EINVAL;
+		}
+		if (!is_unicast_ether_addr(hw_addr)) {
+			NL_SET_ERR_MSG_MOD(extack, "Non-unicast hardware address unsupported");
+			return -EINVAL;
+		}
+	}
+
+	ops = devlink->ops;
+	if (!ops->port_function_hw_addr_set) {
+		NL_SET_ERR_MSG_MOD(extack, "Port doesn't support function attributes");
+		return -EOPNOTSUPP;
+	}
+
+	err = ops->port_function_hw_addr_set(devlink, port, hw_addr, hw_addr_len, extack);
+	if (err)
+		return err;
+
+	devlink_port_notify(port, DEVLINK_CMD_PORT_NEW);
+	return 0;
+}
+
+static int
+devlink_port_function_set(struct devlink *devlink, struct devlink_port *port,
+			  const struct nlattr *attr, struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[DEVLINK_PORT_FUNCTION_ATTR_MAX + 1];
+	int err;
+
+	err = nla_parse_nested(tb, DEVLINK_PORT_FUNCTION_ATTR_MAX, attr,
+			       devlink_function_nl_policy, extack);
+	if (err < 0) {
+		NL_SET_ERR_MSG_MOD(extack, "Fail to parse port function attributes");
+		return err;
+	}
+
+	attr = tb[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR];
+	if (attr)
+		err = devlink_port_function_hw_addr_set(devlink, port, attr, extack);
+
+	return err;
+}
+
 static int devlink_nl_cmd_port_set_doit(struct sk_buff *skb,
 					struct genl_info *info)
 {
@@ -842,6 +907,16 @@ static int devlink_nl_cmd_port_set_doit(struct sk_buff *skb,
 		if (err)
 			return err;
 	}
+
+	if (info->attrs[DEVLINK_ATTR_PORT_FUNCTION]) {
+		struct nlattr *attr = info->attrs[DEVLINK_ATTR_PORT_FUNCTION];
+		struct netlink_ext_ack *extack = info->extack;
+
+		err = devlink_port_function_set(devlink, devlink_port, attr, extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
@@ -6758,6 +6833,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_TRAP_POLICER_ID] = { .type = NLA_U32 },
 	[DEVLINK_ATTR_TRAP_POLICER_RATE] = { .type = NLA_U64 },
 	[DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
+	[DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {