net/ncsi: Extend NC-SI Netlink interface to allow user space to send NC-SI command

The new command (NCSI_CMD_SEND_CMD) is added to allow user space application
to send NC-SI command to the network card.
Also, add a new attribute (NCSI_ATTR_DATA) for transferring request and response.

The work flow is as below.

Request:
User space application
	-> Netlink interface (msg)
	-> new Netlink handler - ncsi_send_cmd_nl()
	-> ncsi_xmit_cmd()

Response:
Response received - ncsi_rcv_rsp()
	-> internal response handler - ncsi_rsp_handler_xxx()
	-> ncsi_rsp_handler_netlink()
	-> ncsi_send_netlink_rsp ()
	-> Netlink interface (msg)
	-> user space application

Command timeout - ncsi_request_timeout()
	-> ncsi_send_netlink_timeout ()
	-> Netlink interface (msg with zero data length)
	-> user space application

Error:
Error detected
	-> ncsi_send_netlink_err ()
	-> Netlink interface (err msg)
	-> user space application

Signed-off-by: Justin Lee <justin.lee1@dell.com>
Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 091284760d21..6aa0614d2d28 100644
--- a/net/ncsi/ncsi-manage.c
+++ b/net/ncsi/ncsi-manage.c
@@ -19,6 +19,7 @@
 #include <net/addrconf.h>
 #include <net/ipv6.h>
 #include <net/if_inet6.h>
+#include <net/genetlink.h>
 
 #include "internal.h"
 #include "ncsi-pkt.h"
@@ -406,6 +407,9 @@ static void ncsi_request_timeout(struct timer_list *t)
 {
 	struct ncsi_request *nr = from_timer(nr, t, timer);
 	struct ncsi_dev_priv *ndp = nr->ndp;
+	struct ncsi_cmd_pkt *cmd;
+	struct ncsi_package *np;
+	struct ncsi_channel *nc;
 	unsigned long flags;
 
 	/* If the request already had associated response,
@@ -419,6 +423,18 @@ static void ncsi_request_timeout(struct timer_list *t)
 	}
 	spin_unlock_irqrestore(&ndp->lock, flags);
 
+	if (nr->flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
+		if (nr->cmd) {
+			/* Find the package */
+			cmd = (struct ncsi_cmd_pkt *)
+			      skb_network_header(nr->cmd);
+			ncsi_find_package_and_channel(ndp,
+						      cmd->cmd.common.channel,
+						      &np, &nc);
+			ncsi_send_netlink_timeout(nr, np, nc);
+		}
+	}
+
 	/* Release the request */
 	ncsi_free_request(nr);
 }