154 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			154 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0-or-later */
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| /*
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|  *
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|  *  Generic Bluetooth HCI UART driver
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|  *
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|  *  Copyright (C) 2015-2018  Intel Corporation
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|  */
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| 
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| #include <asm/unaligned.h>
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| 
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| struct h4_recv_pkt {
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| 	u8  type;	/* Packet type */
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| 	u8  hlen;	/* Header length */
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| 	u8  loff;	/* Data length offset in header */
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| 	u8  lsize;	/* Data length field size */
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| 	u16 maxlen;	/* Max overall packet length */
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| 	int (*recv)(struct hci_dev *hdev, struct sk_buff *skb);
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| };
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| 
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| #define H4_RECV_ACL \
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| 	.type = HCI_ACLDATA_PKT, \
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| 	.hlen = HCI_ACL_HDR_SIZE, \
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| 	.loff = 2, \
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| 	.lsize = 2, \
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| 	.maxlen = HCI_MAX_FRAME_SIZE \
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| 
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| #define H4_RECV_SCO \
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| 	.type = HCI_SCODATA_PKT, \
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| 	.hlen = HCI_SCO_HDR_SIZE, \
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| 	.loff = 2, \
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| 	.lsize = 1, \
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| 	.maxlen = HCI_MAX_SCO_SIZE
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| 
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| #define H4_RECV_EVENT \
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| 	.type = HCI_EVENT_PKT, \
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| 	.hlen = HCI_EVENT_HDR_SIZE, \
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| 	.loff = 1, \
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| 	.lsize = 1, \
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| 	.maxlen = HCI_MAX_EVENT_SIZE
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| 
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| #define H4_RECV_ISO \
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| 	.type = HCI_ISODATA_PKT, \
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| 	.hlen = HCI_ISO_HDR_SIZE, \
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| 	.loff = 2, \
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| 	.lsize = 2, \
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| 	.maxlen = HCI_MAX_FRAME_SIZE
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| 
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| static inline struct sk_buff *h4_recv_buf(struct hci_dev *hdev,
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| 					  struct sk_buff *skb,
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| 					  const unsigned char *buffer,
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| 					  int count,
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| 					  const struct h4_recv_pkt *pkts,
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| 					  int pkts_count)
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| {
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| 	/* Check for error from previous call */
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| 	if (IS_ERR(skb))
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| 		skb = NULL;
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| 
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| 	while (count) {
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| 		int i, len;
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| 
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| 		if (!skb) {
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| 			for (i = 0; i < pkts_count; i++) {
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| 				if (buffer[0] != (&pkts[i])->type)
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| 					continue;
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| 
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| 				skb = bt_skb_alloc((&pkts[i])->maxlen,
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| 						   GFP_ATOMIC);
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| 				if (!skb)
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| 					return ERR_PTR(-ENOMEM);
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| 
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| 				hci_skb_pkt_type(skb) = (&pkts[i])->type;
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| 				hci_skb_expect(skb) = (&pkts[i])->hlen;
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| 				break;
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| 			}
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| 
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| 			/* Check for invalid packet type */
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| 			if (!skb)
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| 				return ERR_PTR(-EILSEQ);
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| 
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| 			count -= 1;
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| 			buffer += 1;
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| 		}
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| 
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| 		len = min_t(uint, hci_skb_expect(skb) - skb->len, count);
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| 		skb_put_data(skb, buffer, len);
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| 
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| 		count -= len;
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| 		buffer += len;
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| 
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| 		/* Check for partial packet */
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| 		if (skb->len < hci_skb_expect(skb))
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| 			continue;
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| 
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| 		for (i = 0; i < pkts_count; i++) {
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| 			if (hci_skb_pkt_type(skb) == (&pkts[i])->type)
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| 				break;
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| 		}
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| 
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| 		if (i >= pkts_count) {
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| 			kfree_skb(skb);
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| 			return ERR_PTR(-EILSEQ);
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| 		}
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| 
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| 		if (skb->len == (&pkts[i])->hlen) {
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| 			u16 dlen;
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| 
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| 			switch ((&pkts[i])->lsize) {
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| 			case 0:
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| 				/* No variable data length */
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| 				dlen = 0;
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| 				break;
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| 			case 1:
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| 				/* Single octet variable length */
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| 				dlen = skb->data[(&pkts[i])->loff];
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| 				hci_skb_expect(skb) += dlen;
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| 
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| 				if (skb_tailroom(skb) < dlen) {
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| 					kfree_skb(skb);
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| 					return ERR_PTR(-EMSGSIZE);
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| 				}
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| 				break;
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| 			case 2:
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| 				/* Double octet variable length */
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| 				dlen = get_unaligned_le16(skb->data +
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| 							  (&pkts[i])->loff);
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| 				hci_skb_expect(skb) += dlen;
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| 
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| 				if (skb_tailroom(skb) < dlen) {
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| 					kfree_skb(skb);
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| 					return ERR_PTR(-EMSGSIZE);
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| 				}
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| 				break;
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| 			default:
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| 				/* Unsupported variable length */
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| 				kfree_skb(skb);
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| 				return ERR_PTR(-EILSEQ);
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| 			}
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| 
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| 			if (!dlen) {
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| 				/* No more data, complete frame */
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| 				(&pkts[i])->recv(hdev, skb);
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| 				skb = NULL;
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| 			}
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| 		} else {
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| 			/* Complete frame */
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| 			(&pkts[i])->recv(hdev, skb);
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| 			skb = NULL;
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| 		}
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| 	}
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| 
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| 	return skb;
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| }
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