NFC: netlink: Add new netlink command NFC_CMD_ACTIVATE_TARGET

Some tag might get deactivated after some read or write tentative.
This may happen for example with Mifare Ultralight C tag when trying
to read the last 4 blocks (starting block 0x2c) configured as write
only.
NFC_CMD_ACTIVATE_TARGET will try to reselect the tag in order to
detect if it got remove from the field or if it is still present.

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

1 files changed, 30 insertions, 0 deletions

diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 43cb1c17e267..95818314aea6 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -810,6 +810,31 @@ out:
         return rc;
 }
 
+static int nfc_genl_activate_target(struct sk_buff *skb, struct genl_info *info)
+{
+        struct nfc_dev *dev;
+        u32 device_idx, target_idx, protocol;
+        int rc;
+
+        if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+                return -EINVAL;
+
+        device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
+
+        dev = nfc_get_device(device_idx);
+        if (!dev)
+                return -ENODEV;
+
+        target_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);
+        protocol = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);
+
+        nfc_deactivate_target(dev, target_idx);
+        rc = nfc_activate_target(dev, target_idx, protocol);
+
+        nfc_put_device(dev);
+        return 0;
+}
+
 static int nfc_genl_dep_link_up(struct sk_buff *skb, struct genl_info *info)
 {
         struct nfc_dev *dev;
@@ -1455,6 +1480,11 @@ static const struct genl_ops nfc_genl_ops[] = {
                 .doit = nfc_genl_se_io,
                 .policy = nfc_genl_policy,
         },
+        {
+                .cmd = NFC_CMD_ACTIVATE_TARGET,
+                .doit = nfc_genl_activate_target,
+                .policy = nfc_genl_policy,
+        },
 };