NFC: llcp: Service Name Lookup SDRES aggregation

This modifies the way SDRES PDUs are sent back. If multiple SDREQs are
received within a single SNL PDU, all SDRES replies are sent packed in
one SNL PDU too.
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

net/nfc/llcp/commands.c

@@ -117,6 +117,39 @@ u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
 	return tlv;
 }
 
+struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
+{
+	struct nfc_llcp_sdp_tlv *sdres;
+	u8 value[2];
+
+	sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
+	if (sdres == NULL)
+		return NULL;
+
+	value[0] = tid;
+	value[1] = sap;
+
+	sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
+					&sdres->tlv_len);
+	if (sdres->tlv == NULL) {
+		kfree(sdres);
+		return NULL;
+	}
+
+	sdres->tid = tid;
+	sdres->sap = sap;
+
+	INIT_HLIST_NODE(&sdres->node);
+
+	return sdres;
+}
+
+void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
+{
+	kfree(sdp->tlv);
+	kfree(sdp);
+}
+
 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 			  u8 *tlv_array, u16 tlv_array_len)
 {
@@ -425,48 +458,55 @@ int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 	return err;
 }
 
-int nfc_llcp_send_snl(struct nfc_llcp_local *local, u8 tid, u8 sap)
+static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
+					     size_t tlv_length)
 {
 	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;
+		return ERR_PTR(-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;
+		return ERR_PTR(-ENODEV);
 
 	size += LLCP_HEADER_SIZE;
 	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
-	size += sdres_tlv_length;
+	size += tlv_length;
 
 	skb = alloc_skb(size, GFP_KERNEL);
-	if (skb == NULL) {
-		kfree(sdres_tlv);
-		return -ENOMEM;
-	}
+	if (skb == NULL)
+		return ERR_PTR(-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);
+	return skb;
+}
 
-	skb_queue_tail(&local->tx_queue, skb);
+int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
+			    struct hlist_head *tlv_list, size_t tlvs_len)
+{
+	struct nfc_llcp_sdp_tlv *sdp;
+	struct hlist_node *n;
+	struct sk_buff *skb;
+
+	skb = nfc_llcp_allocate_snl(local, tlvs_len);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
+		memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
 
-	kfree(sdres_tlv);
+		hlist_del(&sdp->node);
+
+		nfc_llcp_free_sdp_tlv(sdp);
+	}
+
+	skb_queue_tail(&local->tx_queue, skb);
 
 	return 0;
 }

net/nfc/llcp/llcp.c

@@ -1144,6 +1144,9 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 	u16 tlv_len, offset;
 	char *service_name;
 	size_t service_name_len;
+	struct nfc_llcp_sdp_tlv *sdp;
+	HLIST_HEAD(llc_sdres_list);
+	size_t sdres_tlvs_len;
 
 	dsap = nfc_llcp_dsap(skb);
 	ssap = nfc_llcp_ssap(skb);
@@ -1158,6 +1161,7 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 	tlv = &skb->data[LLCP_HEADER_SIZE];
 	tlv_len = skb->len - LLCP_HEADER_SIZE;
 	offset = 0;
+	sdres_tlvs_len = 0;
 
 	while (offset < tlv_len) {
 		type = tlv[0];
@@ -1175,14 +1179,14 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 			    !strncmp(service_name, "urn:nfc:sn:sdp",
 				     service_name_len)) {
 				sap = 1;
-				goto send_snl;
+				goto add_snl;
 			}
 
 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
 							  service_name_len);
 			if (!llcp_sock) {
 				sap = 0;
-				goto send_snl;
+				goto add_snl;
 			}
 
 			/*
@@ -1199,7 +1203,7 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 
 				if (sap == LLCP_SAP_MAX) {
 					sap = 0;
-					goto send_snl;
+					goto add_snl;
 				}
 
 				client_count =
@@ -1216,8 +1220,13 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 
 			pr_debug("%p %d\n", llcp_sock, sap);
 
-send_snl:
-			nfc_llcp_send_snl(local, tid, sap);
+add_snl:
+			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
+			if (sdp == NULL)
+				goto exit;
+
+			sdres_tlvs_len += sdp->tlv_len;
+			hlist_add_head(&sdp->node, &llc_sdres_list);
 			break;
 
 		default:
@@ -1228,6 +1237,10 @@ static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
 		offset += length + 2;
 		tlv += length + 2;
 	}
+
+exit:
+	if (!hlist_empty(&llc_sdres_list))
+		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
 }
 
 static void nfc_llcp_rx_work(struct work_struct *work)

net/nfc/llcp/llcp.h

@@ -46,6 +46,17 @@ struct llcp_sock_list {
 	rwlock_t          lock;
 };
 
+struct nfc_llcp_sdp_tlv {
+	u8 *tlv;
+	u8 tlv_len;
+
+	char *uri;
+	u8 tid;
+	u8 sap;
+
+	struct hlist_node node;
+};
+
 struct nfc_llcp_local {
 	struct list_head list;
 	struct nfc_dev *dev;
@@ -218,12 +229,15 @@ int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 /* Commands API */
 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err);
 u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length);
+struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap);
+void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp);
 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err);
 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_snl_sdres(struct nfc_llcp_local *local,
+			    struct hlist_head *tlv_list, size_t tlvs_len);
 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,