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Bluetooth: hci_sock: Replace use of memcpy_from_msg with bt_skb_sendmsg
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This makes use of bt_skb_sendmsg instead of allocating a different
buffer to be used with memcpy_from_msg which cause one extra copy.

Tested-by: Tedd Ho-Jeong An <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>
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@Vudentz @holtmann
Vudentz authored and holtmann committed Oct 1, 2021
1 parent 4d51fb0 commit 64ba2eb
Showing 1 changed file with 37 additions and 63 deletions.
100 changes: 37 additions & 63 deletions net/bluetooth/hci_sock.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1510,7 +1510,8 @@ static int hci_sock_recvmsg(struct socket *sock, struct msghdr *msg,
return err ? : copied;
}

static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk, void *buf, size_t msglen)
static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk,
struct sk_buff *skb)
{
u8 *cp;
struct mgmt_hdr *hdr;
Expand All @@ -1520,31 +1521,31 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk, void *buf,
bool var_len, no_hdev;
int err;

BT_DBG("got %zu bytes", msglen);
BT_DBG("got %d bytes", skb->len);

if (msglen < sizeof(*hdr))
if (skb->len < sizeof(*hdr))
return -EINVAL;

hdr = buf;
hdr = (void *)skb->data;
opcode = __le16_to_cpu(hdr->opcode);
index = __le16_to_cpu(hdr->index);
len = __le16_to_cpu(hdr->len);

if (len != msglen - sizeof(*hdr)) {
if (len != skb->len - sizeof(*hdr)) {
err = -EINVAL;
goto done;
}

if (chan->channel == HCI_CHANNEL_CONTROL) {
struct sk_buff *skb;
struct sk_buff *cmd;

/* Send event to monitor */
skb = create_monitor_ctrl_command(sk, index, opcode, len,
buf + sizeof(*hdr));
if (skb) {
hci_send_to_channel(HCI_CHANNEL_MONITOR, skb,
cmd = create_monitor_ctrl_command(sk, index, opcode, len,
skb->data + sizeof(*hdr));
if (cmd) {
hci_send_to_channel(HCI_CHANNEL_MONITOR, cmd,
HCI_SOCK_TRUSTED, NULL);
kfree_skb(skb);
kfree_skb(cmd);
}
}

Expand Down Expand Up @@ -1609,13 +1610,13 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk, void *buf,
if (hdev && chan->hdev_init)
chan->hdev_init(sk, hdev);

cp = buf + sizeof(*hdr);
cp = skb->data + sizeof(*hdr);

err = handler->func(sk, hdev, cp, len);
if (err < 0)
goto done;

err = msglen;
err = skb->len;

done:
if (hdev)
Expand All @@ -1624,10 +1625,10 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk, void *buf,
return err;
}

static int hci_logging_frame(struct sock *sk, void *buf, int len, unsigned int flags)
static int hci_logging_frame(struct sock *sk, struct sk_buff *skb,
unsigned int flags)
{
struct hci_mon_hdr *hdr;
struct sk_buff *skb;
struct hci_dev *hdev;
u16 index;
int err;
Expand All @@ -1636,21 +1637,13 @@ static int hci_logging_frame(struct sock *sk, void *buf, int len, unsigned int f
* the priority byte, the ident length byte and at least one string
* terminator NUL byte. Anything shorter are invalid packets.
*/
if (len < sizeof(*hdr) + 3)
if (skb->len < sizeof(*hdr) + 3)
return -EINVAL;

skb = bt_skb_send_alloc(sk, len, flags & MSG_DONTWAIT, &err);
if (!skb)
return err;

memcpy(skb_put(skb, len), buf, len);

hdr = (void *)skb->data;

if (__le16_to_cpu(hdr->len) != len - sizeof(*hdr)) {
err = -EINVAL;
goto drop;
}
if (__le16_to_cpu(hdr->len) != skb->len - sizeof(*hdr))
return -EINVAL;

if (__le16_to_cpu(hdr->opcode) == 0x0000) {
__u8 priority = skb->data[sizeof(*hdr)];
Expand All @@ -1669,39 +1662,32 @@ static int hci_logging_frame(struct sock *sk, void *buf, int len, unsigned int f
* The message follows the ident string (if present) and
* must be NUL terminated. Otherwise it is not a valid packet.
*/
if (priority > 7 || skb->data[len - 1] != 0x00 ||
ident_len > len - sizeof(*hdr) - 3 ||
skb->data[sizeof(*hdr) + ident_len + 1] != 0x00) {
err = -EINVAL;
goto drop;
}
if (priority > 7 || skb->data[skb->len - 1] != 0x00 ||
ident_len > skb->len - sizeof(*hdr) - 3 ||
skb->data[sizeof(*hdr) + ident_len + 1] != 0x00)
return -EINVAL;
} else {
err = -EINVAL;
goto drop;
return -EINVAL;
}

index = __le16_to_cpu(hdr->index);

if (index != MGMT_INDEX_NONE) {
hdev = hci_dev_get(index);
if (!hdev) {
err = -ENODEV;
goto drop;
}
if (!hdev)
return -ENODEV;
} else {
hdev = NULL;
}

hdr->opcode = cpu_to_le16(HCI_MON_USER_LOGGING);

hci_send_to_channel(HCI_CHANNEL_MONITOR, skb, HCI_SOCK_TRUSTED, NULL);
err = len;
err = skb->len;

if (hdev)
hci_dev_put(hdev);

drop:
kfree_skb(skb);
return err;
}

Expand All @@ -1713,7 +1699,6 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg,
struct hci_dev *hdev;
struct sk_buff *skb;
int err;
void *buf;
const unsigned int flags = msg->msg_flags;

BT_DBG("sock %p sk %p", sock, sk);
Expand All @@ -1727,13 +1712,9 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg,
if (len < 4 || len > hci_pi(sk)->mtu)
return -EINVAL;

buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (memcpy_from_msg(buf, msg, len)) {
kfree(buf);
return -EFAULT;
}
skb = bt_skb_sendmsg(sk, msg, len, len, 0, 0);
if (IS_ERR(skb))
return PTR_ERR(skb);

lock_sock(sk);

Expand All @@ -1743,39 +1724,33 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg,
break;
case HCI_CHANNEL_MONITOR:
err = -EOPNOTSUPP;
goto done;
goto drop;
case HCI_CHANNEL_LOGGING:
err = hci_logging_frame(sk, buf, len, flags);
goto done;
err = hci_logging_frame(sk, skb, flags);
goto drop;
default:
mutex_lock(&mgmt_chan_list_lock);
chan = __hci_mgmt_chan_find(hci_pi(sk)->channel);
if (chan)
err = hci_mgmt_cmd(chan, sk, buf, len);
err = hci_mgmt_cmd(chan, sk, skb);
else
err = -EINVAL;

mutex_unlock(&mgmt_chan_list_lock);
goto done;
goto drop;
}

hdev = hci_hdev_from_sock(sk);
if (IS_ERR(hdev)) {
err = PTR_ERR(hdev);
goto done;
goto drop;
}

if (!test_bit(HCI_UP, &hdev->flags)) {
err = -ENETDOWN;
goto done;
goto drop;
}

skb = bt_skb_send_alloc(sk, len, flags & MSG_DONTWAIT, &err);
if (!skb)
goto done;

memcpy(skb_put(skb, len), buf, len);

hci_skb_pkt_type(skb) = skb->data[0];
skb_pull(skb, 1);

Expand Down Expand Up @@ -1846,7 +1821,6 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg,

done:
release_sock(sk);
kfree(buf);
return err;

drop:
Expand Down

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