NFC: The core part should generate the target index

The target index can be used by userspace to uniquely identify a target
and thus should be kept unique, per NFC adapter. Moreover, some protocols
do not provide a logical index when discovering new targets, so we have to
generate one for them.
For NCI or pn533 to fetch their logical index, we added a logical_idx field
to the target structure.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 18 insertions, 6 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index deb4721ce8a1..d92400087b61 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -428,10 +428,15 @@ EXPORT_SYMBOL(nfc_alloc_recv_skb);
 int nfc_targets_found(struct nfc_dev *dev,
                       struct nfc_target *targets, int n_targets)
 {
+        int i;
+
         pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
 
         dev->polling = false;
 
+        for (i = 0; i < n_targets; i++)
+                targets[i].idx = dev->target_idx++;
+
         spin_lock_bh(&dev->targets_lock);
 
         dev->targets_generation++;
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 9ec065bb9ee1..8737c2089fdd 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -477,7 +477,7 @@ static int nci_activate_target(struct nfc_dev *nfc_dev, __u32 target_idx,
         }
 
         if (atomic_read(&ndev->state) == NCI_W4_HOST_SELECT) {
-                param.rf_discovery_id = target->idx;
+                param.rf_discovery_id = target->logical_idx;
 
                 if (protocol == NFC_PROTO_JEWEL)
                         param.rf_protocol = NCI_RF_PROTOCOL_T1T;
diff --git a/net/nfc/nci/ntf.c b/net/nfc/nci/ntf.c
index 2e3dee42196d..99e1632e6aac 100644
--- a/net/nfc/nci/ntf.c
+++ b/net/nfc/nci/ntf.c
@@ -227,7 +227,7 @@ static void nci_add_new_target(struct nci_dev *ndev,
 
         for (i = 0; i < ndev->n_targets; i++) {
                 target = &ndev->targets[i];
-                if (target->idx == ntf->rf_discovery_id) {
+                if (target->logical_idx == ntf->rf_discovery_id) {
                         /* This target already exists, add the new protocol */
                         nci_add_new_protocol(ndev, target, ntf->rf_protocol,
                                              ntf->rf_tech_and_mode,
@@ -248,10 +248,10 @@ static void nci_add_new_target(struct nci_dev *ndev,
                                   ntf->rf_tech_and_mode,
                                   &ntf->rf_tech_specific_params);
         if (!rc) {
-                target->idx = ntf->rf_discovery_id;
+                target->logical_idx = ntf->rf_discovery_id;
                 ndev->n_targets++;
 
-                pr_debug("target_idx %d, n_targets %d\n", target->idx,
+                pr_debug("logical idx %d, n_targets %d\n", target->logical_idx,
                          ndev->n_targets);
         }
 }
@@ -372,10 +372,11 @@ static void nci_target_auto_activated(struct nci_dev *ndev,
         if (rc)
                 return;
 
-        target->idx = ntf->rf_discovery_id;
+        target->logical_idx = ntf->rf_discovery_id;
         ndev->n_targets++;
 
-        pr_debug("target_idx %d, n_targets %d\n", target->idx, ndev->n_targets);
+        pr_debug("logical idx %d, n_targets %d\n",
+                 target->logical_idx, ndev->n_targets);
 
         nfc_targets_found(ndev->nfc_dev, ndev->targets, ndev->n_targets);
 }
diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c
index 5a839ceb2e82..b2825aa85f64 100644
--- a/net/nfc/rawsock.c
+++ b/net/nfc/rawsock.c
@@ -92,6 +92,12 @@ static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
                 goto error;
         }
 
+        if (addr->target_idx > dev->target_idx - 1 ||
+            addr->target_idx < dev->target_idx - dev->n_targets) {
+                rc = -EINVAL;
+                goto error;
+        }
+
         rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
         if (rc)
                 goto put_dev;