1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/bluetooth/h4_recv.h b/drivers/bluetooth/h4_recv.h
new file mode 100644
index 000000000..4f2c89742
--- /dev/null
+++ b/drivers/bluetooth/h4_recv.h
@@ -0,0 +1,146 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *
+ *  Generic Bluetooth HCI UART driver
+ *
+ *  Copyright (C) 2015-2018  Intel Corporation
+ */
+
+#include <asm/unaligned.h>
+
+struct h4_recv_pkt {
+	u8  type;	/* Packet type */
+	u8  hlen;	/* Header length */
+	u8  loff;	/* Data length offset in header */
+	u8  lsize;	/* Data length field size */
+	u16 maxlen;	/* Max overall packet length */
+	int (*recv)(struct hci_dev *hdev, struct sk_buff *skb);
+};
+
+#define H4_RECV_ACL \
+	.type = HCI_ACLDATA_PKT, \
+	.hlen = HCI_ACL_HDR_SIZE, \
+	.loff = 2, \
+	.lsize = 2, \
+	.maxlen = HCI_MAX_FRAME_SIZE \
+
+#define H4_RECV_SCO \
+	.type = HCI_SCODATA_PKT, \
+	.hlen = HCI_SCO_HDR_SIZE, \
+	.loff = 2, \
+	.lsize = 1, \
+	.maxlen = HCI_MAX_SCO_SIZE
+
+#define H4_RECV_EVENT \
+	.type = HCI_EVENT_PKT, \
+	.hlen = HCI_EVENT_HDR_SIZE, \
+	.loff = 1, \
+	.lsize = 1, \
+	.maxlen = HCI_MAX_EVENT_SIZE
+
+static inline struct sk_buff *h4_recv_buf(struct hci_dev *hdev,
+					  struct sk_buff *skb,
+					  const unsigned char *buffer,
+					  int count,
+					  const struct h4_recv_pkt *pkts,
+					  int pkts_count)
+{
+	/* Check for error from previous call */
+	if (IS_ERR(skb))
+		skb = NULL;
+
+	while (count) {
+		int i, len;
+
+		if (!skb) {
+			for (i = 0; i < pkts_count; i++) {
+				if (buffer[0] != (&pkts[i])->type)
+					continue;
+
+				skb = bt_skb_alloc((&pkts[i])->maxlen,
+						   GFP_ATOMIC);
+				if (!skb)
+					return ERR_PTR(-ENOMEM);
+
+				hci_skb_pkt_type(skb) = (&pkts[i])->type;
+				hci_skb_expect(skb) = (&pkts[i])->hlen;
+				break;
+			}
+
+			/* Check for invalid packet type */
+			if (!skb)
+				return ERR_PTR(-EILSEQ);
+
+			count -= 1;
+			buffer += 1;
+		}
+
+		len = min_t(uint, hci_skb_expect(skb) - skb->len, count);
+		skb_put_data(skb, buffer, len);
+
+		count -= len;
+		buffer += len;
+
+		/* Check for partial packet */
+		if (skb->len < hci_skb_expect(skb))
+			continue;
+
+		for (i = 0; i < pkts_count; i++) {
+			if (hci_skb_pkt_type(skb) == (&pkts[i])->type)
+				break;
+		}
+
+		if (i >= pkts_count) {
+			kfree_skb(skb);
+			return ERR_PTR(-EILSEQ);
+		}
+
+		if (skb->len == (&pkts[i])->hlen) {
+			u16 dlen;
+
+			switch ((&pkts[i])->lsize) {
+			case 0:
+				/* No variable data length */
+				dlen = 0;
+				break;
+			case 1:
+				/* Single octet variable length */
+				dlen = skb->data[(&pkts[i])->loff];
+				hci_skb_expect(skb) += dlen;
+
+				if (skb_tailroom(skb) < dlen) {
+					kfree_skb(skb);
+					return ERR_PTR(-EMSGSIZE);
+				}
+				break;
+			case 2:
+				/* Double octet variable length */
+				dlen = get_unaligned_le16(skb->data +
+							  (&pkts[i])->loff);
+				hci_skb_expect(skb) += dlen;
+
+				if (skb_tailroom(skb) < dlen) {
+					kfree_skb(skb);
+					return ERR_PTR(-EMSGSIZE);
+				}
+				break;
+			default:
+				/* Unsupported variable length */
+				kfree_skb(skb);
+				return ERR_PTR(-EILSEQ);
+			}
+
+			if (!dlen) {
+				/* No more data, complete frame */
+				(&pkts[i])->recv(hdev, skb);
+				skb = NULL;
+			}
+		} else {
+			/* Complete frame */
+			(&pkts[i])->recv(hdev, skb);
+			skb = NULL;
+		}
+	}
+
+	return skb;
+}