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>

6 files changed, 309 insertions, 5 deletions

diff --git a/net/ncsi/internal.h b/net/ncsi/internal.h
index 3d0a33b874f5..13c9b5eeb3b7 100644
--- a/net/ncsi/internal.h
+++ b/net/ncsi/internal.h
@@ -175,6 +175,8 @@ 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;
@@ -220,11 +222,15 @@ struct ncsi_request {
         bool                 used;    /* Request that has been assigned  */
         unsigned int         flags;   /* NCSI request property           */
 #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 {
@@ -310,6 +316,7 @@ struct ncsi_cmd_arg {
                 unsigned int   dwords[4];
         };
         unsigned char        *data;       /* NCSI OEM 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 82b7d9201db8..356af474e43c 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"
@@ -346,6 +347,13 @@ int ncsi_xmit_cmd(struct ncsi_cmd_arg *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 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);
 }
diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c
index 32cb7751d216..33314381b4f5 100644
--- a/net/ncsi/ncsi-netlink.c
+++ b/net/ncsi/ncsi-netlink.c
@@ -19,6 +19,7 @@
 #include <uapi/linux/ncsi.h>
 
 #include "internal.h"
+#include "ncsi-pkt.h"
 #include "ncsi-netlink.h"
 
 static struct genl_family ncsi_genl_family;
@@ -28,6 +29,7 @@ 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)
@@ -365,6 +367,202 @@ 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_pkt_hdr *hdr;
+        struct ncsi_cmd_arg nca;
+        unsigned char *data;
+        u32 package_id;
+        u32 channel_id;
+        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;
+        }
+
+        if (!info->attrs[NCSI_ATTR_DATA]) {
+                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 command to send %u\n",
+                            package_id);
+                ret = -EINVAL;
+                goto out_netlink;
+        } else {
+                data = (unsigned char *)nla_data(info->attrs[NCSI_ATTR_DATA]);
+        }
+
+        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 + sizeof(*hdr);
+
+        ret = ncsi_xmit_cmd(&nca);
+out_netlink:
+        if (ret != 0) {
+                netdev_err(ndp->ndev.dev,
+                           "NCSI: Error %d sending 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;
+
+        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;
+
+        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 nlmsghdr *nlh;
+        struct nlmsgerr *nle;
+        struct sk_buff *skb;
+        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,
@@ -385,6 +583,12 @@ 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 91a5c256f8c4..c4a46887a932 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 d66b34749027..85fa59afae34 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 +34,25 @@ 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 +64,11 @@ 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;
 }
@@ -941,6 +956,26 @@ static int ncsi_rsp_handler_gpuuid(struct ncsi_request *nr)
         return 0;
 }
 
+static int ncsi_rsp_handler_netlink(struct ncsi_request *nr)
+{
+        struct ncsi_dev_priv *ndp = nr->ndp;
+        struct ncsi_rsp_pkt *rsp;
+        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;
@@ -1043,6 +1078,17 @@ 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;
         }
 
@@ -1052,6 +1098,17 @@ 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;