NFC: Add SNL frame building routine

SNL (Service Name Lookup) frames are used to respond to SNL requests.
This is needed for SDP implementation.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 47 insertions, 0 deletions

diff --git a/net/nfc/llcp/commands.c b/net/nfc/llcp/commands.c
index 5e33cba43936..6db280ddc4c8 100644
--- a/net/nfc/llcp/commands.c
+++ b/net/nfc/llcp/commands.c
@@ -420,6 +420,52 @@ error_tlv:
         return err;
 }
 
+int nfc_llcp_send_snl(struct nfc_llcp_local *local, u8 tid, u8 sap)
+{
+        struct sk_buff *skb;
+        struct nfc_dev *dev;
+        u8 *sdres_tlv = NULL, sdres_tlv_length, sdres[2];
+        u16 size = 0;
+
+        pr_debug("Sending SNL tid 0x%x sap 0x%x\n", tid, sap);
+
+        if (local == NULL)
+                return -ENODEV;
+
+        dev = local->dev;
+        if (dev == NULL)
+                return -ENODEV;
+
+        sdres[0] = tid;
+        sdres[1] = sap;
+        sdres_tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, sdres, 0,
+                                       &sdres_tlv_length);
+        if (sdres_tlv == NULL)
+                return -ENOMEM;
+
+        size += LLCP_HEADER_SIZE;
+        size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
+        size += sdres_tlv_length;
+
+        skb = alloc_skb(size, GFP_KERNEL);
+        if (skb == NULL) {
+                kfree(sdres_tlv);
+                return -ENOMEM;
+        }
+
+        skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
+
+        skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
+
+        memcpy(skb_put(skb, sdres_tlv_length), sdres_tlv, sdres_tlv_length);
+
+        skb_queue_tail(&local->tx_queue, skb);
+
+        kfree(sdres_tlv);
+
+        return 0;
+}
+
 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 {
         struct sk_buff *skb;
diff --git a/net/nfc/llcp/llcp.h b/net/nfc/llcp/llcp.h
index fdb2d24e60bd..1c0a66fab570 100644
--- a/net/nfc/llcp/llcp.h
+++ b/net/nfc/llcp/llcp.h
@@ -209,6 +209,7 @@ int nfc_llcp_disconnect(struct nfc_llcp_sock *sock);
 int nfc_llcp_send_symm(struct nfc_dev *dev);
 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock);
 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock);
+int nfc_llcp_send_snl(struct nfc_llcp_local *local, u8 tid, u8 sap);
 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason);
 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock);
 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,