NFC: Forward NFC_EVT_TRANSACTION to user space

NFC_EVT_TRANSACTION is sent through netlink in order for a
specific application running on a secure element to notify
userspace of an event. Typically the secure element application
counterpart on the host could interpret that event and act
upon it.

Forwarded information contains:
- SE host generating the event
- Application IDentifier doing the operation
- Applications parameters

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 70 insertions, 0 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 7f1b6351755c..cff3f1614ad4 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -932,6 +932,27 @@ int nfc_remove_se(struct nfc_dev *dev, u32 se_idx)
 }
 EXPORT_SYMBOL(nfc_remove_se);
 
+int nfc_se_transaction(struct nfc_dev *dev, u8 se_idx,
+                       struct nfc_evt_transaction *evt_transaction)
+{
+        int rc;
+
+        pr_debug("transaction: %x\n", se_idx);
+
+        device_lock(&dev->dev);
+
+        if (!evt_transaction) {
+                rc = -EPROTO;
+                goto out;
+        }
+
+        rc = nfc_genl_se_transaction(dev, se_idx, evt_transaction);
+out:
+        device_unlock(&dev->dev);
+        return rc;
+}
+EXPORT_SYMBOL(nfc_se_transaction);
+
 static void nfc_release(struct device *d)
 {
         struct nfc_dev *dev = to_nfc_dev(d);
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index be387e6219a0..14a2d11581da 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -497,6 +497,53 @@ free_msg:
         return -EMSGSIZE;
 }
 
+int nfc_genl_se_transaction(struct nfc_dev *dev, u8 se_idx,
+                            struct nfc_evt_transaction *evt_transaction)
+{
+        struct nfc_se *se;
+        struct sk_buff *msg;
+        void *hdr;
+
+        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+        if (!msg)
+                return -ENOMEM;
+
+        hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
+                          NFC_EVENT_SE_TRANSACTION);
+        if (!hdr)
+                goto free_msg;
+
+        se = nfc_find_se(dev, se_idx);
+        if (!se)
+                goto free_msg;
+
+        if (nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx) ||
+            nla_put_u32(msg, NFC_ATTR_SE_INDEX, se_idx) ||
+            nla_put_u8(msg, NFC_ATTR_SE_TYPE, se->type) ||
+            nla_put(msg, NFC_ATTR_SE_AID, evt_transaction->aid_len,
+                    evt_transaction->aid) ||
+            nla_put(msg, NFC_ATTR_SE_PARAMS, evt_transaction->params_len,
+                    evt_transaction->params))
+                goto nla_put_failure;
+
+        /* evt_transaction is no more used */
+        devm_kfree(&dev->dev, evt_transaction);
+
+        genlmsg_end(msg, hdr);
+
+        genlmsg_multicast(&nfc_genl_family, msg, 0, 0, GFP_KERNEL);
+
+        return 0;
+
+nla_put_failure:
+        genlmsg_cancel(msg, hdr);
+free_msg:
+        /* evt_transaction is no more used */
+        devm_kfree(&dev->dev, evt_transaction);
+        nlmsg_free(msg);
+        return -EMSGSIZE;
+}
+
 static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,
                                 u32 portid, u32 seq,
                                 struct netlink_callback *cb,
diff --git a/net/nfc/nfc.h b/net/nfc/nfc.h
index 88d60064890e..a8ce80b47720 100644
--- a/net/nfc/nfc.h
+++ b/net/nfc/nfc.h
@@ -100,6 +100,8 @@ int nfc_genl_llc_send_sdres(struct nfc_dev *dev, struct hlist_head *sdres_list);
 
 int nfc_genl_se_added(struct nfc_dev *dev, u32 se_idx, u16 type);
 int nfc_genl_se_removed(struct nfc_dev *dev, u32 se_idx);
+int nfc_genl_se_transaction(struct nfc_dev *dev, u8 se_idx,
+                            struct nfc_evt_transaction *evt_transaction);
 
 struct nfc_dev *nfc_get_device(unsigned int idx);