/* 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;
}
