/**
* @note "ACK messages also use the message type NLMSG_ERROR and payload format
* but the error code is set to 0."
* (http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_ack)
*/
static int respond_error(struct nlmsghdr *nl_hdr_in, int error)
{
struct nlmsgerr hdr_out;
__u8 *payload = NULL;
char *error_msg;
unsigned int error_msg_len;
hdr_out.error = abs(error);
hdr_out.msg = *nl_hdr_in;
hdr_out.msg.nlmsg_len = 0;
if (error_pool_get_message(&error_msg, &error_msg_len)) {
pr_err("could not get error message from pool.\n");
goto respond_error_on_failure;
}
hdr_out.msg.nlmsg_len = sizeof(hdr_out) + error_msg_len + 1;
payload = kmalloc(hdr_out.msg.nlmsg_len, GFP_KERNEL);
if (!payload) {
pr_err("could not allocate memory for error payload!\n");
kfree(error_msg);
goto respond_error_on_failure;
}
memcpy(payload, (__u8*)&hdr_out, sizeof(hdr_out));
memcpy(payload + sizeof(hdr_out), (__u8*)error_msg, error_msg_len + 1);
error = respond_single_msg(nl_hdr_in, NLMSG_ERROR, payload,
hdr_out.msg.nlmsg_len);
kfree(error_msg);
kfree(payload);
return error;
respond_error_on_failure:
return respond_single_msg(nl_hdr_in, NLMSG_ERROR, &hdr_out,
sizeof(hdr_out));
}
/**
* @note "ACK messages also use the message type NLMSG_ERROR and payload format but the error code
* is set to 0." (http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_ack).
*/
static int respond_error(struct nlmsghdr *nl_hdr_in, int error)
{
struct nlmsgerr payload = { abs(error), *nl_hdr_in };
return respond_single_msg(nl_hdr_in, NLMSG_ERROR, &payload, sizeof(payload));
}
static int respond_setcfg(struct nlmsghdr *nl_hdr_in, void *payload, int payload_len)
{
return respond_single_msg(nl_hdr_in, MSG_SETCFG, payload, payload_len);
}
