[net,v2] net/ncsi: Extend NC-SI Netlink interface to allow user space to send NC-SI command

Message ID 58fff61ffd8d4038b59f32b696e76bbc@AUSX13MPS306.AMER.DELL.COM
State Not Applicable, archived
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  • [net,v2] net/ncsi: Extend NC-SI Netlink interface to allow user space to send NC-SI command
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Commit Message

Justin.Lee1@Dell.com Sept. 28, 2018, 6:15 p.m.
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>

---
 include/uapi/linux/ncsi.h |   3 +
 net/ncsi/internal.h       |  12 ++-
 net/ncsi/ncsi-cmd.c       |  47 ++++++++++-
 net/ncsi/ncsi-manage.c    |  22 +++++
 net/ncsi/ncsi-netlink.c   | 205 ++++++++++++++++++++++++++++++++++++++++++++++
 net/ncsi/ncsi-netlink.h   |  12 +++
 net/ncsi/ncsi-rsp.c       |  71 ++++++++++++++--
 7 files changed, 363 insertions(+), 9 deletions(-)

Comments

Samuel Mendoza-Jonas Oct. 2, 2018, 5:11 a.m. | #1
On Fri, 2018-09-28 at 18:15 +0000, Justin.Lee1@Dell.com wrote:
> 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>

Hi Justin,

This is looking pretty good, combined with Vijay's base patch the two
approaches should fit together nicely (
http://patchwork.ozlabs.org/patch/976510/).

A good merge order would probably be the above patch first, then this
patch and Vijay's further OEM patches based on top of that to reduce
conflicts.

Cheers,
Sam

> 
> ---
>  include/uapi/linux/ncsi.h |   3 +
>  net/ncsi/internal.h       |  12 ++-
>  net/ncsi/ncsi-cmd.c       |  47 ++++++++++-
>  net/ncsi/ncsi-manage.c    |  22 +++++
>  net/ncsi/ncsi-netlink.c   | 205 ++++++++++++++++++++++++++++++++++++++++++++++
>  net/ncsi/ncsi-netlink.h   |  12 +++
>  net/ncsi/ncsi-rsp.c       |  71 ++++++++++++++--
>  7 files changed, 363 insertions(+), 9 deletions(-)
> 
> diff --git a/include/uapi/linux/ncsi.h b/include/uapi/linux/ncsi.h
> index 4c292ec..4992bfc 100644
> --- a/include/uapi/linux/ncsi.h
> +++ b/include/uapi/linux/ncsi.h
> @@ -30,6 +30,7 @@ enum ncsi_nl_commands {
>  	NCSI_CMD_PKG_INFO,
>  	NCSI_CMD_SET_INTERFACE,
>  	NCSI_CMD_CLEAR_INTERFACE,
> +	NCSI_CMD_SEND_CMD,
>  
>  	__NCSI_CMD_AFTER_LAST,
>  	NCSI_CMD_MAX = __NCSI_CMD_AFTER_LAST - 1
> @@ -43,6 +44,7 @@ enum ncsi_nl_commands {
>   * @NCSI_ATTR_PACKAGE_LIST: nested array of NCSI_PKG_ATTR attributes
>   * @NCSI_ATTR_PACKAGE_ID: package ID
>   * @NCSI_ATTR_CHANNEL_ID: channel ID
> + * @NCSI_ATTR_DATA: command payload
>   * @NCSI_ATTR_MAX: highest attribute number
>   */
>  enum ncsi_nl_attrs {
> @@ -51,6 +53,7 @@ enum ncsi_nl_attrs {
>  	NCSI_ATTR_PACKAGE_LIST,
>  	NCSI_ATTR_PACKAGE_ID,
>  	NCSI_ATTR_CHANNEL_ID,
> +	NCSI_ATTR_DATA,
>  
>  	__NCSI_ATTR_AFTER_LAST,
>  	NCSI_ATTR_MAX = __NCSI_ATTR_AFTER_LAST - 1
> diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
> index 8055e39..1a3ef9e 100644
> --- a/net/ncsi/internal.h
> +++ b/net/ncsi/internal.h
> @@ -171,6 +171,8 @@ struct ncsi_package;
>  #define NCSI_RESERVED_CHANNEL	0x1f
>  #define NCSI_CHANNEL_INDEX(c)	((c) & ((1 << NCSI_PACKAGE_SHIFT) - 1))
>  #define NCSI_TO_CHANNEL(p, c)	(((p) << NCSI_PACKAGE_SHIFT) | (c))
> +#define NCSI_MAX_PACKAGE	8
> +#define NCSI_MAX_CHANNEL	32
>  
>  struct ncsi_channel {
>  	unsigned char               id;
> @@ -215,12 +217,17 @@ struct ncsi_request {
>  	unsigned char        id;      /* Request ID - 0 to 255           */
>  	bool                 used;    /* Request that has been assigned  */
>  	unsigned int         flags;   /* NCSI request property           */
> -#define NCSI_REQ_FLAG_EVENT_DRIVEN	1
> +#define NCSI_REQ_FLAG_EVENT_DRIVEN		1
> +#define NCSI_REQ_FLAG_NETLINK_DRIVEN	2
>  	struct ncsi_dev_priv *ndp;    /* Associated NCSI device          */
>  	struct sk_buff       *cmd;    /* Associated NCSI command packet  */
>  	struct sk_buff       *rsp;    /* Associated NCSI response packet */
>  	struct timer_list    timer;   /* Timer on waiting for response   */
>  	bool                 enabled; /* Time has been enabled or not    */
> +
> +	u32                  snd_seq;     /* netlink sending sequence number */
> +	u32                  snd_portid;  /* netlink portid of sender        */
> +	struct nlmsghdr      nlhdr;       /* netlink message header          */
>  };
>  
>  enum {
> @@ -305,6 +312,9 @@ struct ncsi_cmd_arg {
>  		unsigned short words[8];
>  		unsigned int   dwords[4];
>  	};
> +
> +	unsigned char        *data;       /* Netlink data                  */
> +	struct genl_info     *info;       /* Netlink information           */
>  };
>  
>  extern struct list_head ncsi_dev_list;
> diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
> index 7567ca63..43b544c 100644
> --- a/net/ncsi/ncsi-cmd.c
> +++ b/net/ncsi/ncsi-cmd.c
> @@ -17,6 +17,7 @@
>  #include <net/ncsi.h>
>  #include <net/net_namespace.h>
>  #include <net/sock.h>
> +#include <net/genetlink.h>
>  
>  #include "internal.h"
>  #include "ncsi-pkt.h"
> @@ -211,6 +212,39 @@ static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
>  	return 0;
>  }
>  
> +static int ncsi_cmd_handler_oem(struct sk_buff *skb,
> +				struct ncsi_cmd_arg *nca)
> +{
> +	struct ncsi_cmd_pkt *cmd;
> +	unsigned char *dest, *source;
> +	unsigned short len;
> +
> +	/* struct ncsi_cmd_pkt = minimum length
> +	 *                       - frame checksum
> +	 *                       - Ethernet header
> +	 *                     = 64 - 4 - 14 = 46
> +	 * minimum payload = 46 - ncsi header - ncsi checksum
> +	 *                 = 46 - 16 - 4 = 26
> +	 */
> +	len = nca->payload;
> +
> +	/* minimum payload length is 26 bytes to meet minimum packet
> +	 * length 64
> +	 */
> +	if (len < 26)
> +		cmd = skb_put_zero(skb, sizeof(*cmd));
> +	else
> +		cmd = skb_put_zero(skb, len + sizeof(struct ncsi_pkt_hdr) + 4);
> +
> +	dest = (unsigned char *)cmd + sizeof(struct ncsi_pkt_hdr);
> +	source = (unsigned char *)nca->data + sizeof(struct ncsi_pkt_hdr);
> +	memcpy(dest, source, len);
> +
> +	ncsi_cmd_build_header(&cmd->cmd.common, nca);
> +
> +	return 0;
> +}
> +
>  static struct ncsi_cmd_handler {
>  	unsigned char type;
>  	int           payload;
> @@ -244,7 +278,7 @@ static struct ncsi_cmd_handler {
>  	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
>  	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
>  	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
> -	{ NCSI_PKT_CMD_OEM,    0, NULL                     },
> +	{ NCSI_PKT_CMD_OEM,    -1, ncsi_cmd_handler_oem     },
>  	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
>  	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
>  };
> @@ -317,11 +351,20 @@ int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
>  	}
>  
>  	/* Get packet payload length and allocate the request */
> -	nca->payload = nch->payload;
> +	if (nch->payload >= 0)
> +		nca->payload = nch->payload;
> +
>  	nr = ncsi_alloc_command(nca);
>  	if (!nr)
>  		return -ENOMEM;
>  
> +	/* track netlink information */
> +	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
> +		nr->snd_seq = nca->info->snd_seq;
> +		nr->snd_portid = nca->info->snd_portid;
> +		nr->nlhdr = *nca->info->nlhdr;
> +	}
> +
>  	/* Prepare the packet */
>  	nca->id = nr->id;
>  	ret = nch->handler(nr->cmd, nca);
> diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
> index 0912847..29f33a1 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"
> @@ -406,8 +407,13 @@ 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_package *np;
> +	struct ncsi_channel *nc;
> +	struct ncsi_cmd_pkt *cmd;
>  	unsigned long flags;
>  
> +	netdev_dbg(ndp->ndev.dev, "NCSI: %s\n", __func__);
> +
>  	/* If the request already had associated response,
>  	 * let the response handler to release it.
>  	 */
> @@ -415,10 +421,26 @@ static void ncsi_request_timeout(struct timer_list *t)
>  	nr->enabled = false;
>  	if (nr->rsp || !nr->cmd) {
>  		spin_unlock_irqrestore(&ndp->lock, flags);
> +
> +		netdev_dbg(ndp->ndev.dev,
> +			   "NCSI: %s - early return\n", __func__);
> +
>  		return;
>  	}
>  	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);
>  }
> diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c
> index 45f33d6..ce57675 100644
> --- a/net/ncsi/ncsi-netlink.c
> +++ b/net/ncsi/ncsi-netlink.c
> @@ -20,6 +20,7 @@
>  #include <uapi/linux/ncsi.h>
>  
>  #include "internal.h"
> +#include "ncsi-pkt.h"
>  #include "ncsi-netlink.h"
>  
>  static struct genl_family ncsi_genl_family;
> @@ -29,6 +30,7 @@ static const struct nla_policy ncsi_genl_policy[NCSI_ATTR_MAX + 1] = {
>  	[NCSI_ATTR_PACKAGE_LIST] =	{ .type = NLA_NESTED },
>  	[NCSI_ATTR_PACKAGE_ID] =	{ .type = NLA_U32 },
>  	[NCSI_ATTR_CHANNEL_ID] =	{ .type = NLA_U32 },
> +	[NCSI_ATTR_DATA] =		{ .type = NLA_BINARY, .len = 2048 },
>  };
>  
>  static struct ncsi_dev_priv *ndp_from_ifindex(struct net *net, u32 ifindex)
> @@ -366,6 +368,203 @@ static int ncsi_clear_interface_nl(struct sk_buff *msg, struct genl_info *info)
>  	return 0;
>  }
>  
> +static int ncsi_send_cmd_nl(struct sk_buff *msg, struct genl_info *info)
> +{
> +	struct ncsi_dev_priv *ndp;
> +
> +	struct ncsi_cmd_arg nca;
> +	struct ncsi_pkt_hdr *hdr;
> +
> +	u32 package_id, channel_id;
> +	unsigned char *data;
> +	void *head;
> +	int len, ret;
> +
> +	if (!info || !info->attrs) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (!info->attrs[NCSI_ATTR_IFINDEX]) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (!info->attrs[NCSI_ATTR_PACKAGE_ID]) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	if (!info->attrs[NCSI_ATTR_CHANNEL_ID]) {
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +
> +	ndp = ndp_from_ifindex(get_net(sock_net(msg->sk)),
> +			       nla_get_u32(info->attrs[NCSI_ATTR_IFINDEX]));
> +	if (!ndp) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	package_id = nla_get_u32(info->attrs[NCSI_ATTR_PACKAGE_ID]);
> +	channel_id = nla_get_u32(info->attrs[NCSI_ATTR_CHANNEL_ID]);
> +
> +	if (package_id >= NCSI_MAX_PACKAGE || channel_id >= NCSI_MAX_CHANNEL) {
> +		ret = -ERANGE;
> +		goto out_netlink;
> +	}
> +
> +	len = nla_len(info->attrs[NCSI_ATTR_DATA]);
> +	if (len < sizeof(struct ncsi_pkt_hdr)) {
> +		netdev_info(ndp->ndev.dev, "NCSI: no OEM command to send %u\n",
> +			    package_id);
> +		ret = -EINVAL;
> +		goto out_netlink;
> +	} else {
> +		head = nla_data(info->attrs[NCSI_ATTR_DATA]);
> +		data = (unsigned char *)head;
> +	}
> +
> +	hdr = (struct ncsi_pkt_hdr *)data;
> +
> +	nca.ndp = ndp;
> +	nca.package = (unsigned char)package_id;
> +	nca.channel = (unsigned char)channel_id;
> +	nca.type = hdr->type;
> +	nca.req_flags = NCSI_REQ_FLAG_NETLINK_DRIVEN;
> +	nca.info = info;
> +	nca.payload = ntohs(hdr->length);
> +	nca.data = data;
> +
> +	ret = ncsi_xmit_cmd(&nca);
> +out_netlink:
> +	if (ret != 0) {
> +		netdev_err(ndp->ndev.dev,
> +			   "Error %d sending OEM command\n", ret);
> +		ncsi_send_netlink_err(ndp->ndev.dev,
> +				      info->snd_seq,
> +				      info->snd_portid,
> +				      info->nlhdr,
> +				      ret);
> +	}
> +out:
> +	return ret;
> +}
> +
> +int ncsi_send_netlink_rsp(struct ncsi_request *nr,
> +			  struct ncsi_package *np,
> +			  struct ncsi_channel *nc)
> +{
> +	struct sk_buff *skb;
> +	struct net *net;
> +	void *hdr;
> +	int rc;
> +
> +	netdev_dbg(nr->ndp->ndev.dev, "NCSI: %s\n", __func__);
> +
> +	net = dev_net(nr->rsp->dev);
> +
> +	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
> +	if (!skb)
> +		return -ENOMEM;
> +
> +	hdr = genlmsg_put(skb, nr->snd_portid, nr->snd_seq,
> +			  &ncsi_genl_family, 0, NCSI_CMD_SEND_CMD);
> +	if (!hdr) {
> +		kfree_skb(skb);
> +		return -EMSGSIZE;
> +	}
> +
> +	nla_put_u32(skb, NCSI_ATTR_IFINDEX, nr->rsp->dev->ifindex);
> +	if (np)
> +		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID, np->id);
> +	if (nc)
> +		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, nc->id);
> +	else
> +		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, NCSI_RESERVED_CHANNEL);
> +
> +	rc = nla_put(skb, NCSI_ATTR_DATA, nr->rsp->len, (void *)nr->rsp->data);
> +	if (rc)
> +		goto err;
> +
> +	genlmsg_end(skb, hdr);
> +	return genlmsg_unicast(net, skb, nr->snd_portid);
> +
> +err:
> +	kfree_skb(skb);
> +	return rc;
> +}
> +
> +int ncsi_send_netlink_timeout(struct ncsi_request *nr,
> +			      struct ncsi_package *np,
> +			      struct ncsi_channel *nc)
> +{
> +	struct sk_buff *skb;
> +	struct net *net;
> +	void *hdr;
> +
> +	netdev_dbg(nr->ndp->ndev.dev, "NCSI: %s\n", __func__);
> +
> +	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
> +	if (!skb)
> +		return -ENOMEM;
> +
> +	hdr = genlmsg_put(skb, nr->snd_portid, nr->snd_seq,
> +			  &ncsi_genl_family, 0, NCSI_CMD_SEND_CMD);
> +	if (!hdr) {
> +		kfree_skb(skb);
> +		return -EMSGSIZE;
> +	}
> +
> +	net = dev_net(nr->cmd->dev);
> +
> +	nla_put_u32(skb, NCSI_ATTR_IFINDEX, nr->cmd->dev->ifindex);
> +
> +	if (np)
> +		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID, np->id);
> +	else
> +		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID,
> +			    NCSI_PACKAGE_INDEX((((struct ncsi_pkt_hdr *)
> +						 nr->cmd->data)->channel)));
> +
> +	if (nc)
> +		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, nc->id);
> +	else
> +		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, NCSI_RESERVED_CHANNEL);
> +
> +	genlmsg_end(skb, hdr);
> +	return genlmsg_unicast(net, skb, nr->snd_portid);
> +}
> +
> +int ncsi_send_netlink_err(struct net_device *dev,
> +			  u32 snd_seq,
> +			  u32 snd_portid,
> +			  struct nlmsghdr *nlhdr,
> +			  int err)
> +{
> +	struct sk_buff *skb;
> +	struct nlmsghdr *nlh;
> +	struct nlmsgerr *nle;
> +	struct net *net;
> +
> +	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
> +	if (!skb)
> +		return -ENOMEM;
> +
> +	net = dev_net(dev);
> +
> +	nlh = nlmsg_put(skb, snd_portid, snd_seq,
> +			NLMSG_ERROR, sizeof(*nle), 0);
> +	nle = (struct nlmsgerr *)nlmsg_data(nlh);
> +	nle->error = err;
> +	memcpy(&nle->msg, nlhdr, sizeof(*nlh));
> +
> +	nlmsg_end(skb, nlh);
> +
> +	return nlmsg_unicast(net->genl_sock, skb, snd_portid);
> +}
> +
>  static const struct genl_ops ncsi_ops[] = {
>  	{
>  		.cmd = NCSI_CMD_PKG_INFO,
> @@ -386,6 +585,12 @@ static const struct genl_ops ncsi_ops[] = {
>  		.doit = ncsi_clear_interface_nl,
>  		.flags = GENL_ADMIN_PERM,
>  	},
> +	{
> +		.cmd = NCSI_CMD_SEND_CMD,
> +		.policy = ncsi_genl_policy,
> +		.doit = ncsi_send_cmd_nl,
> +		.flags = GENL_ADMIN_PERM,
> +	},
>  };
>  
>  static struct genl_family ncsi_genl_family __ro_after_init = {
> diff --git a/net/ncsi/ncsi-netlink.h b/net/ncsi/ncsi-netlink.h
> index 91a5c25..c4a4688 100644
> --- a/net/ncsi/ncsi-netlink.h
> +++ b/net/ncsi/ncsi-netlink.h
> @@ -14,6 +14,18 @@
>  
>  #include "internal.h"
>  
> +int ncsi_send_netlink_rsp(struct ncsi_request *nr,
> +			  struct ncsi_package *np,
> +			  struct ncsi_channel *nc);
> +int ncsi_send_netlink_timeout(struct ncsi_request *nr,
> +			      struct ncsi_package *np,
> +			      struct ncsi_channel *nc);
> +int ncsi_send_netlink_err(struct net_device *dev,
> +			  u32 snd_seq,
> +			  u32 snd_portid,
> +			  struct nlmsghdr *nlhdr,
> +			  int err);
> +
>  int ncsi_init_netlink(struct net_device *dev);
>  int ncsi_unregister_netlink(struct net_device *dev);
>  
> diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
> index 930c1d3..010970f 100644
> --- a/net/ncsi/ncsi-rsp.c
> +++ b/net/ncsi/ncsi-rsp.c
> @@ -16,9 +16,11 @@
>  #include <net/ncsi.h>
>  #include <net/net_namespace.h>
>  #include <net/sock.h>
> +#include <net/genetlink.h>
>  
>  #include "internal.h"
>  #include "ncsi-pkt.h"
> +#include "ncsi-netlink.h"
>  
>  static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
>  				 unsigned short payload)
> @@ -32,15 +34,22 @@ static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
>  	 * before calling this function.
>  	 */
>  	h = (struct ncsi_rsp_pkt_hdr *)skb_network_header(nr->rsp);
> -	if (h->common.revision != NCSI_PKT_REVISION)
> +
> +	if (h->common.revision != NCSI_PKT_REVISION) {
> +		netdev_dbg(nr->ndp->ndev.dev, "NCSI: unsupported header revision\n");
>  		return -EINVAL;
> -	if (ntohs(h->common.length) != payload)
> +	}
> +	if (ntohs(h->common.length) != payload) {
> +		netdev_dbg(nr->ndp->ndev.dev, "NCSI: payload length mismatched\n");
>  		return -EINVAL;
> +	}
>  
>  	/* Check on code and reason */
>  	if (ntohs(h->code) != NCSI_PKT_RSP_C_COMPLETED ||
> -	    ntohs(h->reason) != NCSI_PKT_RSP_R_NO_ERROR)
> -		return -EINVAL;
> +	    ntohs(h->reason) != NCSI_PKT_RSP_R_NO_ERROR) {
> +		netdev_dbg(nr->ndp->ndev.dev, "NCSI: non zero response/reason code\n");
> +		return -EPERM;
> +	}
>  
>  	/* Validate checksum, which might be zeroes if the
>  	 * sender doesn't support checksum according to NCSI
> @@ -52,8 +61,11 @@ static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
>  
>  	checksum = ncsi_calculate_checksum((unsigned char *)h,
>  					   sizeof(*h) + payload - 4);
> -	if (*pchecksum != htonl(checksum))
> +
> +	if (*pchecksum != htonl(checksum)) {
> +		netdev_dbg(nr->ndp->ndev.dev, "NCSI: checksum mismatched\n");
>  		return -EINVAL;
> +	}
>  
>  	return 0;
>  }
> @@ -900,6 +912,31 @@ static int ncsi_rsp_handler_gpuuid(struct ncsi_request *nr)
>  	return 0;
>  }
>  
> +static int ncsi_rsp_handler_oem(struct ncsi_request *nr)
> +{
> +	return 0;
> +}
> +
> +static int ncsi_rsp_handler_netlink(struct ncsi_request *nr)
> +{
> +	struct ncsi_rsp_pkt *rsp;
> +	struct ncsi_dev_priv *ndp = nr->ndp;
> +	struct ncsi_package *np;
> +	struct ncsi_channel *nc;
> +	int ret;
> +
> +	/* Find the package */
> +	rsp = (struct ncsi_rsp_pkt *)skb_network_header(nr->rsp);
> +	ncsi_find_package_and_channel(ndp, rsp->rsp.common.channel,
> +				      &np, &nc);
> +	if (!np)
> +		return -ENODEV;
> +
> +	ret = ncsi_send_netlink_rsp(nr, np, nc);
> +
> +	return ret;
> +}
> +
>  static struct ncsi_rsp_handler {
>  	unsigned char	type;
>  	int             payload;
> @@ -932,7 +969,7 @@ static struct ncsi_rsp_handler {
>  	{ NCSI_PKT_RSP_GNS,   172, ncsi_rsp_handler_gns     },
>  	{ NCSI_PKT_RSP_GNPTS, 172, ncsi_rsp_handler_gnpts   },
>  	{ NCSI_PKT_RSP_GPS,     8, ncsi_rsp_handler_gps     },
> -	{ NCSI_PKT_RSP_OEM,     0, NULL                     },
> +	{ NCSI_PKT_RSP_OEM,    -1, ncsi_rsp_handler_oem     },
>  	{ NCSI_PKT_RSP_PLDM,    0, NULL                     },
>  	{ NCSI_PKT_RSP_GPUUID, 20, ncsi_rsp_handler_gpuuid  }
>  };
> @@ -1002,6 +1039,17 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
>  		netdev_warn(ndp->ndev.dev,
>  			    "NCSI: 'bad' packet ignored for type 0x%x\n",
>  			    hdr->type);
> +
> +		if (nr->flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
> +			if (ret == -EPERM)
> +				goto out_netlink;
> +			else
> +				ncsi_send_netlink_err(ndp->ndev.dev,
> +						      nr->snd_seq,
> +						      nr->snd_portid,
> +						      &nr->nlhdr,
> +						      ret);
> +		}
>  		goto out;
>  	}
>  
> @@ -1011,6 +1059,17 @@ int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
>  		netdev_err(ndp->ndev.dev,
>  			   "NCSI: Handler for packet type 0x%x returned %d\n",
>  			   hdr->type, ret);
> +
> +out_netlink:
> +	if (nr->flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
> +		ret = ncsi_rsp_handler_netlink(nr);
> +		if (ret) {
> +			netdev_err(ndp->ndev.dev,
> +				   "NCSI: Netlink handler for packet type 0x%x returned %d\n",
> +				   hdr->type, ret);
> +		}
> +	}
> +
>  out:
>  	ncsi_free_request(nr);
>  	return ret;
Justin.Lee1@Dell.com Oct. 2, 2018, 5:36 p.m. | #2
Hi Sam,

Sure, I will generate v3 after Vijay's patch is approved.

Thanks,
Justin


> On Fri, 2018-09-28 at 18:15 +0000, Justin.Lee1@Dell.com wrote:
> > 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>
> 
> Hi Justin,
> 
> This is looking pretty good, combined with Vijay's base patch the two
> approaches should fit together nicely (
> http://patchwork.ozlabs.org/patch/976510/).
> 
> A good merge order would probably be the above patch first, then this
> patch and Vijay's further OEM patches based on top of that to reduce
> conflicts.
> 
> Cheers,
> Sam

Patch

diff --git a/include/uapi/linux/ncsi.h b/include/uapi/linux/ncsi.h
index 4c292ec..4992bfc 100644
--- a/include/uapi/linux/ncsi.h
+++ b/include/uapi/linux/ncsi.h
@@ -30,6 +30,7 @@  enum ncsi_nl_commands {
 	NCSI_CMD_PKG_INFO,
 	NCSI_CMD_SET_INTERFACE,
 	NCSI_CMD_CLEAR_INTERFACE,
+	NCSI_CMD_SEND_CMD,
 
 	__NCSI_CMD_AFTER_LAST,
 	NCSI_CMD_MAX = __NCSI_CMD_AFTER_LAST - 1
@@ -43,6 +44,7 @@  enum ncsi_nl_commands {
  * @NCSI_ATTR_PACKAGE_LIST: nested array of NCSI_PKG_ATTR attributes
  * @NCSI_ATTR_PACKAGE_ID: package ID
  * @NCSI_ATTR_CHANNEL_ID: channel ID
+ * @NCSI_ATTR_DATA: command payload
  * @NCSI_ATTR_MAX: highest attribute number
  */
 enum ncsi_nl_attrs {
@@ -51,6 +53,7 @@  enum ncsi_nl_attrs {
 	NCSI_ATTR_PACKAGE_LIST,
 	NCSI_ATTR_PACKAGE_ID,
 	NCSI_ATTR_CHANNEL_ID,
+	NCSI_ATTR_DATA,
 
 	__NCSI_ATTR_AFTER_LAST,
 	NCSI_ATTR_MAX = __NCSI_ATTR_AFTER_LAST - 1
diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
index 8055e39..1a3ef9e 100644
--- a/net/ncsi/internal.h
+++ b/net/ncsi/internal.h
@@ -171,6 +171,8 @@  struct ncsi_package;
 #define NCSI_RESERVED_CHANNEL	0x1f
 #define NCSI_CHANNEL_INDEX(c)	((c) & ((1 << NCSI_PACKAGE_SHIFT) - 1))
 #define NCSI_TO_CHANNEL(p, c)	(((p) << NCSI_PACKAGE_SHIFT) | (c))
+#define NCSI_MAX_PACKAGE	8
+#define NCSI_MAX_CHANNEL	32
 
 struct ncsi_channel {
 	unsigned char               id;
@@ -215,12 +217,17 @@  struct ncsi_request {
 	unsigned char        id;      /* Request ID - 0 to 255           */
 	bool                 used;    /* Request that has been assigned  */
 	unsigned int         flags;   /* NCSI request property           */
-#define NCSI_REQ_FLAG_EVENT_DRIVEN	1
+#define NCSI_REQ_FLAG_EVENT_DRIVEN		1
+#define NCSI_REQ_FLAG_NETLINK_DRIVEN	2
 	struct ncsi_dev_priv *ndp;    /* Associated NCSI device          */
 	struct sk_buff       *cmd;    /* Associated NCSI command packet  */
 	struct sk_buff       *rsp;    /* Associated NCSI response packet */
 	struct timer_list    timer;   /* Timer on waiting for response   */
 	bool                 enabled; /* Time has been enabled or not    */
+
+	u32                  snd_seq;     /* netlink sending sequence number */
+	u32                  snd_portid;  /* netlink portid of sender        */
+	struct nlmsghdr      nlhdr;       /* netlink message header          */
 };
 
 enum {
@@ -305,6 +312,9 @@  struct ncsi_cmd_arg {
 		unsigned short words[8];
 		unsigned int   dwords[4];
 	};
+
+	unsigned char        *data;       /* Netlink data                  */
+	struct genl_info     *info;       /* Netlink information           */
 };
 
 extern struct list_head ncsi_dev_list;
diff --git a/net/ncsi/ncsi-cmd.c b/net/ncsi/ncsi-cmd.c
index 7567ca63..43b544c 100644
--- a/net/ncsi/ncsi-cmd.c
+++ b/net/ncsi/ncsi-cmd.c
@@ -17,6 +17,7 @@ 
 #include <net/ncsi.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
+#include <net/genetlink.h>
 
 #include "internal.h"
 #include "ncsi-pkt.h"
@@ -211,6 +212,39 @@  static int ncsi_cmd_handler_snfc(struct sk_buff *skb,
 	return 0;
 }
 
+static int ncsi_cmd_handler_oem(struct sk_buff *skb,
+				struct ncsi_cmd_arg *nca)
+{
+	struct ncsi_cmd_pkt *cmd;
+	unsigned char *dest, *source;
+	unsigned short len;
+
+	/* struct ncsi_cmd_pkt = minimum length
+	 *                       - frame checksum
+	 *                       - Ethernet header
+	 *                     = 64 - 4 - 14 = 46
+	 * minimum payload = 46 - ncsi header - ncsi checksum
+	 *                 = 46 - 16 - 4 = 26
+	 */
+	len = nca->payload;
+
+	/* minimum payload length is 26 bytes to meet minimum packet
+	 * length 64
+	 */
+	if (len < 26)
+		cmd = skb_put_zero(skb, sizeof(*cmd));
+	else
+		cmd = skb_put_zero(skb, len + sizeof(struct ncsi_pkt_hdr) + 4);
+
+	dest = (unsigned char *)cmd + sizeof(struct ncsi_pkt_hdr);
+	source = (unsigned char *)nca->data + sizeof(struct ncsi_pkt_hdr);
+	memcpy(dest, source, len);
+
+	ncsi_cmd_build_header(&cmd->cmd.common, nca);
+
+	return 0;
+}
+
 static struct ncsi_cmd_handler {
 	unsigned char type;
 	int           payload;
@@ -244,7 +278,7 @@  static struct ncsi_cmd_handler {
 	{ NCSI_PKT_CMD_GNS,    0, ncsi_cmd_handler_default },
 	{ NCSI_PKT_CMD_GNPTS,  0, ncsi_cmd_handler_default },
 	{ NCSI_PKT_CMD_GPS,    0, ncsi_cmd_handler_default },
-	{ NCSI_PKT_CMD_OEM,    0, NULL                     },
+	{ NCSI_PKT_CMD_OEM,    -1, ncsi_cmd_handler_oem     },
 	{ NCSI_PKT_CMD_PLDM,   0, NULL                     },
 	{ NCSI_PKT_CMD_GPUUID, 0, ncsi_cmd_handler_default }
 };
@@ -317,11 +351,20 @@  int ncsi_xmit_cmd(struct ncsi_cmd_arg *nca)
 	}
 
 	/* Get packet payload length and allocate the request */
-	nca->payload = nch->payload;
+	if (nch->payload >= 0)
+		nca->payload = nch->payload;
+
 	nr = ncsi_alloc_command(nca);
 	if (!nr)
 		return -ENOMEM;
 
+	/* track netlink information */
+	if (nca->req_flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
+		nr->snd_seq = nca->info->snd_seq;
+		nr->snd_portid = nca->info->snd_portid;
+		nr->nlhdr = *nca->info->nlhdr;
+	}
+
 	/* Prepare the packet */
 	nca->id = nr->id;
 	ret = nch->handler(nr->cmd, nca);
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
index 0912847..29f33a1 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"
@@ -406,8 +407,13 @@  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_package *np;
+	struct ncsi_channel *nc;
+	struct ncsi_cmd_pkt *cmd;
 	unsigned long flags;
 
+	netdev_dbg(ndp->ndev.dev, "NCSI: %s\n", __func__);
+
 	/* If the request already had associated response,
 	 * let the response handler to release it.
 	 */
@@ -415,10 +421,26 @@  static void ncsi_request_timeout(struct timer_list *t)
 	nr->enabled = false;
 	if (nr->rsp || !nr->cmd) {
 		spin_unlock_irqrestore(&ndp->lock, flags);
+
+		netdev_dbg(ndp->ndev.dev,
+			   "NCSI: %s - early return\n", __func__);
+
 		return;
 	}
 	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);
 }
diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c
index 45f33d6..ce57675 100644
--- a/net/ncsi/ncsi-netlink.c
+++ b/net/ncsi/ncsi-netlink.c
@@ -20,6 +20,7 @@ 
 #include <uapi/linux/ncsi.h>
 
 #include "internal.h"
+#include "ncsi-pkt.h"
 #include "ncsi-netlink.h"
 
 static struct genl_family ncsi_genl_family;
@@ -29,6 +30,7 @@  static const struct nla_policy ncsi_genl_policy[NCSI_ATTR_MAX + 1] = {
 	[NCSI_ATTR_PACKAGE_LIST] =	{ .type = NLA_NESTED },
 	[NCSI_ATTR_PACKAGE_ID] =	{ .type = NLA_U32 },
 	[NCSI_ATTR_CHANNEL_ID] =	{ .type = NLA_U32 },
+	[NCSI_ATTR_DATA] =		{ .type = NLA_BINARY, .len = 2048 },
 };
 
 static struct ncsi_dev_priv *ndp_from_ifindex(struct net *net, u32 ifindex)
@@ -366,6 +368,203 @@  static int ncsi_clear_interface_nl(struct sk_buff *msg, struct genl_info *info)
 	return 0;
 }
 
+static int ncsi_send_cmd_nl(struct sk_buff *msg, struct genl_info *info)
+{
+	struct ncsi_dev_priv *ndp;
+
+	struct ncsi_cmd_arg nca;
+	struct ncsi_pkt_hdr *hdr;
+
+	u32 package_id, channel_id;
+	unsigned char *data;
+	void *head;
+	int len, ret;
+
+	if (!info || !info->attrs) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!info->attrs[NCSI_ATTR_IFINDEX]) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!info->attrs[NCSI_ATTR_PACKAGE_ID]) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!info->attrs[NCSI_ATTR_CHANNEL_ID]) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ndp = ndp_from_ifindex(get_net(sock_net(msg->sk)),
+			       nla_get_u32(info->attrs[NCSI_ATTR_IFINDEX]));
+	if (!ndp) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	package_id = nla_get_u32(info->attrs[NCSI_ATTR_PACKAGE_ID]);
+	channel_id = nla_get_u32(info->attrs[NCSI_ATTR_CHANNEL_ID]);
+
+	if (package_id >= NCSI_MAX_PACKAGE || channel_id >= NCSI_MAX_CHANNEL) {
+		ret = -ERANGE;
+		goto out_netlink;
+	}
+
+	len = nla_len(info->attrs[NCSI_ATTR_DATA]);
+	if (len < sizeof(struct ncsi_pkt_hdr)) {
+		netdev_info(ndp->ndev.dev, "NCSI: no OEM command to send %u\n",
+			    package_id);
+		ret = -EINVAL;
+		goto out_netlink;
+	} else {
+		head = nla_data(info->attrs[NCSI_ATTR_DATA]);
+		data = (unsigned char *)head;
+	}
+
+	hdr = (struct ncsi_pkt_hdr *)data;
+
+	nca.ndp = ndp;
+	nca.package = (unsigned char)package_id;
+	nca.channel = (unsigned char)channel_id;
+	nca.type = hdr->type;
+	nca.req_flags = NCSI_REQ_FLAG_NETLINK_DRIVEN;
+	nca.info = info;
+	nca.payload = ntohs(hdr->length);
+	nca.data = data;
+
+	ret = ncsi_xmit_cmd(&nca);
+out_netlink:
+	if (ret != 0) {
+		netdev_err(ndp->ndev.dev,
+			   "Error %d sending OEM command\n", ret);
+		ncsi_send_netlink_err(ndp->ndev.dev,
+				      info->snd_seq,
+				      info->snd_portid,
+				      info->nlhdr,
+				      ret);
+	}
+out:
+	return ret;
+}
+
+int ncsi_send_netlink_rsp(struct ncsi_request *nr,
+			  struct ncsi_package *np,
+			  struct ncsi_channel *nc)
+{
+	struct sk_buff *skb;
+	struct net *net;
+	void *hdr;
+	int rc;
+
+	netdev_dbg(nr->ndp->ndev.dev, "NCSI: %s\n", __func__);
+
+	net = dev_net(nr->rsp->dev);
+
+	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(skb, nr->snd_portid, nr->snd_seq,
+			  &ncsi_genl_family, 0, NCSI_CMD_SEND_CMD);
+	if (!hdr) {
+		kfree_skb(skb);
+		return -EMSGSIZE;
+	}
+
+	nla_put_u32(skb, NCSI_ATTR_IFINDEX, nr->rsp->dev->ifindex);
+	if (np)
+		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID, np->id);
+	if (nc)
+		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, nc->id);
+	else
+		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, NCSI_RESERVED_CHANNEL);
+
+	rc = nla_put(skb, NCSI_ATTR_DATA, nr->rsp->len, (void *)nr->rsp->data);
+	if (rc)
+		goto err;
+
+	genlmsg_end(skb, hdr);
+	return genlmsg_unicast(net, skb, nr->snd_portid);
+
+err:
+	kfree_skb(skb);
+	return rc;
+}
+
+int ncsi_send_netlink_timeout(struct ncsi_request *nr,
+			      struct ncsi_package *np,
+			      struct ncsi_channel *nc)
+{
+	struct sk_buff *skb;
+	struct net *net;
+	void *hdr;
+
+	netdev_dbg(nr->ndp->ndev.dev, "NCSI: %s\n", __func__);
+
+	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(skb, nr->snd_portid, nr->snd_seq,
+			  &ncsi_genl_family, 0, NCSI_CMD_SEND_CMD);
+	if (!hdr) {
+		kfree_skb(skb);
+		return -EMSGSIZE;
+	}
+
+	net = dev_net(nr->cmd->dev);
+
+	nla_put_u32(skb, NCSI_ATTR_IFINDEX, nr->cmd->dev->ifindex);
+
+	if (np)
+		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID, np->id);
+	else
+		nla_put_u32(skb, NCSI_ATTR_PACKAGE_ID,
+			    NCSI_PACKAGE_INDEX((((struct ncsi_pkt_hdr *)
+						 nr->cmd->data)->channel)));
+
+	if (nc)
+		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, nc->id);
+	else
+		nla_put_u32(skb, NCSI_ATTR_CHANNEL_ID, NCSI_RESERVED_CHANNEL);
+
+	genlmsg_end(skb, hdr);
+	return genlmsg_unicast(net, skb, nr->snd_portid);
+}
+
+int ncsi_send_netlink_err(struct net_device *dev,
+			  u32 snd_seq,
+			  u32 snd_portid,
+			  struct nlmsghdr *nlhdr,
+			  int err)
+{
+	struct sk_buff *skb;
+	struct nlmsghdr *nlh;
+	struct nlmsgerr *nle;
+	struct net *net;
+
+	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	net = dev_net(dev);
+
+	nlh = nlmsg_put(skb, snd_portid, snd_seq,
+			NLMSG_ERROR, sizeof(*nle), 0);
+	nle = (struct nlmsgerr *)nlmsg_data(nlh);
+	nle->error = err;
+	memcpy(&nle->msg, nlhdr, sizeof(*nlh));
+
+	nlmsg_end(skb, nlh);
+
+	return nlmsg_unicast(net->genl_sock, skb, snd_portid);
+}
+
 static const struct genl_ops ncsi_ops[] = {
 	{
 		.cmd = NCSI_CMD_PKG_INFO,
@@ -386,6 +585,12 @@  static const struct genl_ops ncsi_ops[] = {
 		.doit = ncsi_clear_interface_nl,
 		.flags = GENL_ADMIN_PERM,
 	},
+	{
+		.cmd = NCSI_CMD_SEND_CMD,
+		.policy = ncsi_genl_policy,
+		.doit = ncsi_send_cmd_nl,
+		.flags = GENL_ADMIN_PERM,
+	},
 };
 
 static struct genl_family ncsi_genl_family __ro_after_init = {
diff --git a/net/ncsi/ncsi-netlink.h b/net/ncsi/ncsi-netlink.h
index 91a5c25..c4a4688 100644
--- a/net/ncsi/ncsi-netlink.h
+++ b/net/ncsi/ncsi-netlink.h
@@ -14,6 +14,18 @@ 
 
 #include "internal.h"
 
+int ncsi_send_netlink_rsp(struct ncsi_request *nr,
+			  struct ncsi_package *np,
+			  struct ncsi_channel *nc);
+int ncsi_send_netlink_timeout(struct ncsi_request *nr,
+			      struct ncsi_package *np,
+			      struct ncsi_channel *nc);
+int ncsi_send_netlink_err(struct net_device *dev,
+			  u32 snd_seq,
+			  u32 snd_portid,
+			  struct nlmsghdr *nlhdr,
+			  int err);
+
 int ncsi_init_netlink(struct net_device *dev);
 int ncsi_unregister_netlink(struct net_device *dev);
 
diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index 930c1d3..010970f 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -16,9 +16,11 @@ 
 #include <net/ncsi.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
+#include <net/genetlink.h>
 
 #include "internal.h"
 #include "ncsi-pkt.h"
+#include "ncsi-netlink.h"
 
 static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
 				 unsigned short payload)
@@ -32,15 +34,22 @@  static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
 	 * before calling this function.
 	 */
 	h = (struct ncsi_rsp_pkt_hdr *)skb_network_header(nr->rsp);
-	if (h->common.revision != NCSI_PKT_REVISION)
+
+	if (h->common.revision != NCSI_PKT_REVISION) {
+		netdev_dbg(nr->ndp->ndev.dev, "NCSI: unsupported header revision\n");
 		return -EINVAL;
-	if (ntohs(h->common.length) != payload)
+	}
+	if (ntohs(h->common.length) != payload) {
+		netdev_dbg(nr->ndp->ndev.dev, "NCSI: payload length mismatched\n");
 		return -EINVAL;
+	}
 
 	/* Check on code and reason */
 	if (ntohs(h->code) != NCSI_PKT_RSP_C_COMPLETED ||
-	    ntohs(h->reason) != NCSI_PKT_RSP_R_NO_ERROR)
-		return -EINVAL;
+	    ntohs(h->reason) != NCSI_PKT_RSP_R_NO_ERROR) {
+		netdev_dbg(nr->ndp->ndev.dev, "NCSI: non zero response/reason code\n");
+		return -EPERM;
+	}
 
 	/* Validate checksum, which might be zeroes if the
 	 * sender doesn't support checksum according to NCSI
@@ -52,8 +61,11 @@  static int ncsi_validate_rsp_pkt(struct ncsi_request *nr,
 
 	checksum = ncsi_calculate_checksum((unsigned char *)h,
 					   sizeof(*h) + payload - 4);
-	if (*pchecksum != htonl(checksum))
+
+	if (*pchecksum != htonl(checksum)) {
+		netdev_dbg(nr->ndp->ndev.dev, "NCSI: checksum mismatched\n");
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -900,6 +912,31 @@  static int ncsi_rsp_handler_gpuuid(struct ncsi_request *nr)
 	return 0;
 }
 
+static int ncsi_rsp_handler_oem(struct ncsi_request *nr)
+{
+	return 0;
+}
+
+static int ncsi_rsp_handler_netlink(struct ncsi_request *nr)
+{
+	struct ncsi_rsp_pkt *rsp;
+	struct ncsi_dev_priv *ndp = nr->ndp;
+	struct ncsi_package *np;
+	struct ncsi_channel *nc;
+	int ret;
+
+	/* Find the package */
+	rsp = (struct ncsi_rsp_pkt *)skb_network_header(nr->rsp);
+	ncsi_find_package_and_channel(ndp, rsp->rsp.common.channel,
+				      &np, &nc);
+	if (!np)
+		return -ENODEV;
+
+	ret = ncsi_send_netlink_rsp(nr, np, nc);
+
+	return ret;
+}
+
 static struct ncsi_rsp_handler {
 	unsigned char	type;
 	int             payload;
@@ -932,7 +969,7 @@  static struct ncsi_rsp_handler {
 	{ NCSI_PKT_RSP_GNS,   172, ncsi_rsp_handler_gns     },
 	{ NCSI_PKT_RSP_GNPTS, 172, ncsi_rsp_handler_gnpts   },
 	{ NCSI_PKT_RSP_GPS,     8, ncsi_rsp_handler_gps     },
-	{ NCSI_PKT_RSP_OEM,     0, NULL                     },
+	{ NCSI_PKT_RSP_OEM,    -1, ncsi_rsp_handler_oem     },
 	{ NCSI_PKT_RSP_PLDM,    0, NULL                     },
 	{ NCSI_PKT_RSP_GPUUID, 20, ncsi_rsp_handler_gpuuid  }
 };
@@ -1002,6 +1039,17 @@  int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 		netdev_warn(ndp->ndev.dev,
 			    "NCSI: 'bad' packet ignored for type 0x%x\n",
 			    hdr->type);
+
+		if (nr->flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
+			if (ret == -EPERM)
+				goto out_netlink;
+			else
+				ncsi_send_netlink_err(ndp->ndev.dev,
+						      nr->snd_seq,
+						      nr->snd_portid,
+						      &nr->nlhdr,
+						      ret);
+		}
 		goto out;
 	}
 
@@ -1011,6 +1059,17 @@  int ncsi_rcv_rsp(struct sk_buff *skb, struct net_device *dev,
 		netdev_err(ndp->ndev.dev,
 			   "NCSI: Handler for packet type 0x%x returned %d\n",
 			   hdr->type, ret);
+
+out_netlink:
+	if (nr->flags == NCSI_REQ_FLAG_NETLINK_DRIVEN) {
+		ret = ncsi_rsp_handler_netlink(nr);
+		if (ret) {
+			netdev_err(ndp->ndev.dev,
+				   "NCSI: Netlink handler for packet type 0x%x returned %d\n",
+				   hdr->type, ret);
+		}
+	}
+
 out:
 	ncsi_free_request(nr);
 	return ret;