QCMAP:Netlink Query to Kernel Success

QCMAP (Query Class Map) is not a standard Netlink command, but it seems you are asking about the process of allocating and creating a successful Netlink message, particularly for kernel queries. Here's an overview:

To create a Netlink message in a kernel context (GFP_KERNEL), one typically follows these steps[^1]:

1. Allocate a `struct sk_buff` structure for the Netlink message using `nlsmsg_new()`:

   struct sk_buff *skb;
   skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);

`NLMSG_GOODSIZE` is a constant indicating a good size for a Netlink message payload, and `GFP_KERNEL` ensures that the memory allocation happens within the kernel space.

2. If the allocation fails (i.e., `skb == NULL`), the code would usually handle the error by jumping to a "failure" section or taking appropriate action.

A QCMAP success scenario would involve sending the Netlink message with the query data, receiving a response from the kernel, and then parsing the response accordingly. However, without further details on how QCMAP works, this part remains beyond the scope of the provided information.